The Moss Flora of Britain and Ireland

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The Moss Flora of Britain and Ireland This book describes and illustrates in detail the 763 species of mosses currently known to occur in the British Isles and incorporates the most up-to-date information available on classification and nomenclature, together with recent synonyms. The species descriptions provide information on frequency, ecology, geographical relationships and distribution, including information on protected species and those species at risk. For many species there are footnotes to aid identification. In addition to the species descriptions there are descriptions of families and genera and also introductory information on conservation, collection, preservation and examination of material, together with advice on using the keys. An artificial key to genera provides the only workable comprehensive key published in the English language. As a further aid to the user a list of English names for all British mosses is included, plus a comprehensive glossary and bibliography. This second edition incorporates the very considerable advances in knowledge of mosses made in the last quarter of the twentieth century. In this time eight species new to science have been described in Britain, 25 species not previously known in the British Isles have been discovered and taxonomic revisions have led to the addition of a further 51 species. Fourteen species have been removed, bringing the total number of species described to 763. Additionally, modern taxonomic methods have led to an increase in the number of genera from 175 to 214. This thoroughly updated and comprehensive Flora represents a unique resource for all those interested in this fascinating group of organisms TONY SMITH received undergraduate and postgraduate degrees from Lincoln College,

Oxford, before embarking on a research and teaching career at the University Colleges of Swansea and Bangor. He became Reader in Botany at the University of Wales, Bangor in 1981, retiring from this post in 1999. His book publications include Bryophyte Ecology, The Liverworts of Britain and Ireland and Atlas of the Bryophytes of Britain and Ireland (with M. O. Hill and C. D. Preston). He was editor of Journal of Bryology for 14 years and Secretary of the British Bryological Society’s distribution maps scheme for 30 years. He is currently an Honorary member of the British Bryological Society.

The Moss Flora of Britain and Ireland SECOND EDITION A. J. E. SMITH With illustrations by Ruth Smith Additional illustrations by A. J. E. Smith

CAMBRIDGE UNIVERSITY PRESS

Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521546720 © A. J. E. Smith 1978, 2004 This publication is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2004 eBook (EBL) ISBN-13 978-0-511-33703-1 ISBN-10 0-511-33703-5 eBook (EBL) paperback ISBN-13 978-0-521-54672-0 paperback ISBN-10 0-521-54672-9

Cambridge University Press has no responsibility for the persistence or accuracy of urls for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate.

Dedicated to the memory of my beloved wife Ruth

Contents

Preface to the first edition Acknowledgements Preface to the second edition Second edition acknowledgements

page ix x xi xii

Introduction

1 1 2 2 3 4 4 4 5 5 7 7

Nomenclature Taxonomic categories Frequency and distribution Illustrations Literature cited Conservation Collection and preservation of material Examination of material Cutting sections Measurements Using the keys

Abbreviations

9

Conspectus of classification

10

Artificial key to the genera of British and Irish mosses

15

Division Bryophyta Class 1 Sphagnopsida Class 2 Andreaeopsida Class 3 Polytrichopsida Class 4 Bryopsida Diphysciideae Dicranideae Funariideae Bryideae

41 43 103 118 143 143 144 494 513

vii

viii

Contents

Geographical relationships of British and Irish mosses

936

Red List of Mosses

938

British and Irish vice-counties

941

English names for British and Irish mosses

945

Glossary Bibliography Index

965 983 986

Preface to the first edition

It is now more than fifty years ago that the third edition of The Student’s Handbook of British Mosses by H. N. Dixon & H. G. Jameson was published in 1924. Since that time the very considerable taxonomic and nomenclatural changes have been such that it is difficult for the non-expert to equate the 1924 taxa with those of today. Taxonomic revisions have resulted in the splitting of genera (and Dixon had an extraordinarily broad concept of the genus in The Handbook) and the recognition of numerous additional species especially in the Bryum capillare, B. erythrocarpum and Plagiothecium denticulatum/nemoreum complexes. As a consequence of the marked increase in interest in field bryology since the end of the Second World War numerous new species have been added to the British and Irish lists. Dixon recognised 115 genera and 625 species (in present day terms) compared with the 175 genera and 692 species described here. There is also an increasing awareness of the extent of morphological variation and the existence of taxonomically difficult groups requiring further study. It was felt that a new moss flora was long overdue, hence the production of this book. It must be stressed that this is not a revision of Dixon & Jameson but is a completely new moss flora embodying recent ideas and views, some doubtless controversial, on the taxonomy of mosses. Although I have sought opinions and guidance from many sources, except for the three genera contributed by other authors (Sphagnum, Campylopus and Pottia) the views expressed here are entirely my own. Bangor, August 1976

ix

Acknowledgements

I am greatly indebted to Mr A. C. Crundwell for the assistance afforded me during the preparation of this flora. He has been unstinting in his help over nomenclature, in taxonomic discussion and the loan of specimens. I have made free use of his manuscripts on certain genera of the Dicranaceae, Mnium and accounts of species not previously described from Britain. Without his assistance the preparation of the book would have been a much more onerous task. I have received much comment and helpful criticism from Dr E. V. Watson, Professor P. W. Richards allowed me free access to his herbarium; to both these bryologists I am most grateful. I wish also to tender my thanks to the following individuals for the loan of specimens or the provision of information: Mrs J. Appleyard, Mr M. F. V. Corley, Mr L. Derrick, Dr U. K. Duncan, Dr J. G. Duckett, Mr Alan Eddy, Mr M. O. Hill, Mrs J. A. Paton, Mr A. R. Perry, Dr F. Rose, Mr E. C. Wallace and Dr H. L. K. Whitehouse. The Directors or Curators of the following institutions have also been most helpful in lending material: British Museum (Natural History); Royal Botanic Garden, Edinburgh; National Museum of Wales, Cardiff; National Botanic Gardens, Dublin; the Manchester Museum, University of Manchester; Department of Botany, University of Oxford; Botanical Museum, University of Helsinki; Museum of Natural History, Stockholm; and the New York Botanical Gardens. I am indebted to Professor J. L. Harper of the School of Plant Biology, University College of North Wales for providing facilities and for his forbearance during the progress of this work. Finally I would like to thank my wife for all the time and trouble spent in preparing illustrations and my mother who typed much of the manuscript, often from almost illegible handwriting.

x

Preface to the second edition

Since the publication of the first edition in 1978, in which 693 species were described, there have been considerable advances in our knowledge of British and Irish mosses and in the taxonomy of critical groups such as Andreaea and the Hypnum cupressiforme, Racomitrium heterostichum, R. canescens and Schistidium apocarpum complexes. Since 1978, eight species new to science have been described in Britain, 25 species not previously known in the British Isles have been discovered and taxonomic revisions have led to the addition of a further 51 species. Fourteen species have been reduced to varieties of or to synonymy with other species or removed from the British list. This has resulted in an increase of 70 in the number of species making a total of 763. Additionally, critical studies of generic limits, as in the Amblystegiaceae and Pottiaceae, and DNA studies have led to a considerable increase in the number of genera – from 175 to 214 in the British Isles. There have also been major changes in the overall classification of mosses. Clearly, the first edition of this book was in dire need of updating. Apart from additions and taxonomic changes, the original descriptions of species have been revised and in some instances augmented and footnotes added or increased where thought necessary. The key to genera and keys to species have been revised in the light of experience since they were first published. Llandudno, Conwy, March 2003

xi

Second edition acknowledgements

To those whose help was acknowledged in the first edition I would like to add the following: Mrs Kathryn Childerhouse, National Museums and Galleries of Wales, ´ Munoz, ˜ ´ for the loan of specimens, Dr Jesus Real Jard´ın Botanico, Madrid, for assistance with Grimmia and Dr Rosa Ma Ros for providing photographs of Pottia spores. I am also most grateful to Mr T. L. Blockeel, Mr A. C. Crundwell, Dr S. R. Edwards, Dr M. O. Hill, Dr D. T. Holyoak, Mr G. P. Rothero, Mr C. C. Townsend and Dr H. L. K. Whitehouse for the provision of material and/or information. I would also like to thank the many correspondents who over the years have made suggestions and pointed out improvements that could be made to the first edition of this book. I am indebted to Dr S. R. Edwards for providing the cover photographs and Figure 1 and information on section cutting. I would particularly like to thank Mr Roy Perry for his unstinting help and for undertaking the arduous task of proof-reading the original typescript. And finally, also much appreciated, was the care taken by Alison Litherland of Cambridge University Press in copyediting the manuscript.

xii

Introduction

For information on all aspects of bryology see A. J. Shaw & B. Goffinet (eds.), Bryophyte Biology, Cambridge University Press, 2000.

Nomenclature I have followed the nomenclature of Corley et al. (1981) deviating from this where there have been subsequent taxonomic or nomenclatural changes. Only recent synonyms are given except for names used by Dixon & Jameson (1924). Author abbreviations are those recommended by Brummitt & Powell (1992) although where three or more authors are involved I have used only the first name followed by et al. (e.g. Gaertn. et al. rather than Gaertn., B. Mey. & Scherb.). Authorities for species are those given on the Missouri Botanic Garden website W3 MOST (http://mobot.mobot.org/W3T/Search/most.html). For place of publication abbreviations I have followed Crosby (1999).

Bryologia Europaea citations Bryologia Europaea was published in 65 fascicles between 1837 and 1855 but not in any systematic order. On the title pages the names P. Bruch, W. P. Schimper ¨ ¨ and W. T. Gumbel appear. However, the general consensus now is that Gumbel was the illustrator and did not describe any mosses and I have therefore not used his name for any Bryologia Europaea citations. The citation of Bruch & Schimper or Schimper alone is also problematic. Bruch died in 1847 and the last part of Bryologia Europaea did not appear until 1855. I have followed Stafleu & Cowan (1976) who give the date and authorship of each genus in Bryologia Europaea. The frequently used citation BSG should be avoided.

Use of ex and in ‘Ex’ is used to connect the names of two or more persons, for example Schimp. ex ¨ Hal., the second of whom (C. Muller, ¨ Mull. Halle) validly published a name proposed by but not validly published by the first person (Schimper). When citing authorities, for example on a moss packet, both names or groups of names should be used. 1

2

Introduction

‘In’ is used to connect the names of two persons (e.g. Hook. in Grev.) the second of whom (Greville) was the editor or author of a work in which the first person (Hooker) was responsible for validly publishing or making available a name. When citing the authority for a moss name it is not necessary to cite the ‘in’ name. The ‘in’ author is only used when the publication is cited.

English names of mosses I have not given English names of mosses in the text as they are more difficult to remember and often more cumbersome than Latin names. However, there is the absurd requirement in the Wildlife and Countryside Act, 1981, for common names to be used. I have therefore provided a list of preferred English names (pp. 945–964) from Edwards (1999).

Taxonomic categories In the first edition of this book I adopted a somewhat broader concept of the genus than some other authors of the time but it is now clear that as a result of genetical and other studies this was incorrect, hence the increase in the number of genera from 175 to 214. More equivocal is the status of a number of taxa now recognised as species but treated in the past as varieties or subspecies. However, I have followed, albeit sometimes somewhat reluctantly, current practices in the treatment of such taxa.

Frequency and distribution The publication of volumes 2 and 3 of the Atlas of the Bryophytes of Britain and Ireland (Hill et al. 1992, 1994) has provided a much better picture of the frequency and distribution of mosses than was available at the time the first edition of this Flora was written and it has proved possible to give more accurate information on a regional basis. I have used six estimates of frequency : very rare, rare, occasional, frequent, common and very common. To which of these categories a particular species belongs is to some extent a matter of personal opinion but it was felt that this system was more satisfactory than using a multiplicity of phrases such as ‘not infrequent’, ‘not uncommon’ etc. that have been used elsewhere. There are two sets of frequency figures given at the end of the British and Irish distribution information. The first is the number of vice-county records in Britain and Ireland. There are 112 British and 40 Irish vice-counties and one for the Channel islands. As an example, 17, H3, C means the plant has been recorded from 17 British, 3 Irish vice-counties and the Channel Islands. The second set of figures is the number of 10 km squares of the British Ordnance Survey National Grid and Irish Ordnance Survey/Suirbheireacht Ordonais National Grid from which species have been recorded. The Universal Transverse

Illustrations

3

Mercator (UTM) grid is used for the Channel Islands. There are about 2640 British 10 km squares, about 1000 Irish and 15 Channel Islands’. Records from 1950 onwards and those pre-1950, indicated by *, are distinguished. Thus, GB873 + 98*, IR86 + 7*, C6 + 2* indicates 73 recent and 98 pre-1950 records from Great Britain, 86 recent and 7 pre-1950 Irish records and 6 recent and 1 pre-1950 Channel Islands’ records. These figures have been taken from Hill et al. (1992, 1994). The figures for Great Britain and the Channel Islands are a reasonable indication of frequency and whether or not species have decreased. The Irish records are incomplete because of inadequate recent recording in Ireland and many old records are the only ones available and should not be taken as an indication of change in frequency. Altitudinal ranges have also been taken from Hill et al. (1992, 1994). Hill & Preston (1998) carried out an analysis of the geographical relationships of the bryophytes of the British Isles and they recognized 43 floristic elements. The element to which each species belongs is given in italics in the distribution data in this Flora. For further information on this see pp. 936–937. Information on world distribution comes from Duell (1984, 1985, 1992), supplemented with data from other sources where appropriate. Most distributional information predates recently changed political boundaries; hence the use of Czechoslovakia and Yugoslavia. The term Macaronesia technically covers the extreme S. W. corner of the Iberian Peninsula, Madeira, the Azores, Canary Islands, Salvage Islands, Cape Verde islands and the coastal strip of N. W. Africa. The sense in which I use the term includes what is referred to in German as LauriMakaronesien, i.e. the Azores, Madeira and the Canary Islands.

Illustrations With the exception of a small number of species (Buxbaumia viridis, Cinclidotus riparius, Cynodontium gracilescens, Grimmia crinita, G. elatior, Lescuraea saxicola, Meesia triquetra, Mnium medium, Neckera pennata, Orthotrichum gymnostomum, O. shawii, Paraleucobryum longifolium, Schistidium flaccidum, Syntrichia norvegica, Tetrodontium repandum, Trematodon ambiguus, Weissia controversa var. wimmeriana) all figures have been prepared from British and Irish specimens, although some have been augmented by material from other sources, as far as possible from continental Europe. Illustrations from the first edition, except for those of Tortula species 12–16, Protobryum bryoides, Pottia and Microbryum rectum, which were drawn by Miss Gillian A. Meadows of the Royal Botanic Garden, Edinburgh, were prepared by Mrs Ruth Smith using a Leitz Laborlux microscope with either a Leitz camera lucida or a Leitz drawing apparatus. Additional drawings for this edition were made by the author using the same equipment. Figure 1 was drawn by Dr S. R. Edwards and the photographs in Fig. 115 were provided by Dr Rosa Ma Ros of the Universidad de Murcia. For reasons of economy only the minimum of illustrations has been used and habit drawings have for the most part been omitted, being of little use.

4

Introduction

They need be of such a size that they take up an amount of space far in excess of their value.

Literature cited Where a reference is not listed in the Bibliography it is given in full in the text, e.g. A. C. Crundwell, Trans. Brit. Bryol. Soc. 4, 67–74, 1965. Where a work is listed in the Bibliography, only name(s) of author(s) and date of publication are cited in the text, e.g. Dixon & Jameson (1924).

Conservation A number of bryophytes have decreased markedly over the past 100 years and many species are now endangered or at risk. The reasons for this are varied – urbanisation, industrialisation, changing agricultural practices, atmospheric and aquatic pollution and over-collection (see A. J. E. Smith, Mosses, liverworts and hornworts in D. L. Hawkesworth, ed., The Changing Wildlife of Great Britain and Ireland, 2000, for the situation since 1973). Care should therefore be taken when collecting bryophytes. If material is sparse only the minimum amount necessary for determination should be collected. This applies particularly to cushion or tuft forming species, some of which, such as Grimmia species, are very slow growing. DO NOT REMOVE A WHOLE SPECIMEN IF IT IS THE ONLY ONE GROWING AT A PARTICULAR SITE. A photograph is a very satisfactory alternative as it preserves the original habit and colour of the plant concerned and can also illustrate features of the habitat. For useful information on the photography of bryophytes see S. R. Edwards, J. Bryol. 16, 443–84, 1991. The Joint Nature Conservation Council has produced a Red List of British Mosses (Church et al., 2001), giving extinct, critically endangered, endangered and vulnerable species. This list is given on pp. 936–938 and I have indicated in the list those species that it is a criminal offence under the Wildlife and Countryside Act, 1981 to collect. However, this 1981 list of mosses is unsatisfactory as it seems to be a random selection of rare species made without reference to competent field bryologists. Also, some of the species listed cannot be identified without collecting a specimen, hence the strictures on care in collecting. Recently, a database of threatened bryophytes was set up (see N. G. Hodgetts, Bull. Br. Bryol. Soc. 80, 52–9, 2003).

Collection and preservation of material An adequate specimen for determination should be collected, bearing in mind the above comments on conservation, which will show part or whole of the growth form of the moss. A search should be made for perichaetia and perigonia and sporophytes as these may be useful or essential for identification. For mosses

Cutting sections

5

growing in temporary or unstable habitats it is useful to collect 5 mm or so of the substrate beneath the plant so that rhizoidal gemmae if present are collected. If specimens cannot be examined immediately they should be air dried as plants left in wet paper packets, polythene bags or dishes of water often grow etiolated shoots and may become mouldy. Specimens are best put in appropriately labelled newspaper or paper packets (not envelopes which undo if wet). They should not be pressed as pressed mosses often do not recover their original shape when remoistened. Once dried, mosses can be kept indefinitely. Specimens even a hundred or more years old will assume their original form when moistened, although they may have lost their original coloration. Bryophytes are best kept in flat paper packets on which collection data and any other relevant information (name, habitat, altitude, locality, grid reference, collector, collection number, date) can be written. Packets may conveniently be made from A4 sheets of non-acid paper. The bottom one-third of the sheet is folded upwards, the two sides folded inwards thus forming a pocket to contain the specimen. The top third is then folded over and information can be written on the upper side.

Examination of material Specimens or portions of specimens should be moistened before dissection as dry mosses are often brittle. Where difficulty is experienced with remoistening dried plants, as with members of the Fissidentaceae, Mniaceae and Polytrichaceae, the process can be expedited by adding a little household detergent to the water used. Dissection of specimens is best carried out using a dissecting microscope as most mosses are too small to do this satisfactorily with the naked eye. For study of leaf shape, cells, etc. leaves should be removed from stems, care being taken that complete leaves are detached as basal and alar cells are often important in identification. It should be remembered that auricles if present, as in Plagiomnium and Plagiothecium, may remain attached to the stem, so it is useful to mount a piece of stem, from which leaves have been stripped, on a slide to check this.

Cutting sections The following method, modified from an account by Dr S. R. Edwards (pers. commun.), allows good transverse sections of about 10 μm thickness to be taken from any required part of a moss leaf or stem. If possible, a dissecting microscope should be used. For leaf sections selected, moist leaves should be arranged parallel to each other on a glass slide, with the parts to be sectioned aligned as arrowed in Fig. 1(a). A second slide is laid over the leaves, so that its long edge is also aligned with the parts to be sectioned (Fig. 1(b)). Firm pressure is applied to the upper slide by the

6

Introduction

Fig. 1 Diagram illustrating technique for section cutting. (a) arrangement of leaves on lower slide; (b) cutting sections; (c) angle of tilt, θ, of razor blade. P1 and P2 are fulcrums.

finger of one hand (Fig. 1(b)), and half a double-edged razor blade is drawn with the other hand across the leaves, using the upper slide as a guide (Fig. 1(b)). Only a corner of the blade is used, with an angle of elevation of the blade of about 15◦ –20◦ . This should give a perfectly clean cut. Sections are made by adjusting the angle of tilt of the razor blade for each successive cut. The first cut is made with the blade at an angle of about 15◦ –20◦ from the vertical. This angle is progressively reduced with each successive cut. This is shown diagrammatically in Fig. 1(c), where θ is the angle of tilt and P1 is the fulcrum. Depending upon the change in the angle of tilt with successive cuts, so the thickness of sections can be controlled. After the tilt of the blade has passed 0◦ (vertical), the fulcrum moves down to P2 (Fig. 1(c)), resulting in a finer control over the thickness of the last few sections. Pressure on the blade has to be judged by experience, but it should be no more than is necessary to cut the leaves. One blade corner may provide many series of sections and only with very

Using the keys

7

old and fragile material should a fresh corner be used for each operation. With a little practice excellent sections can be cut. For small leaves and sections of stems or branches, as in Sphagnum, the same technique is used. But stems or branches are laid side by side.

Measurements Height of plants is height of the gametophyte and excludes any sporophytes that may be present. Leaf length is from middle of insertion to apex unless otherwise stated (in some mosses with hyaline leaf apices). Cell dimensions are from middle lamella (or where it would be if visible) to middle lamella. Capsule length is from mouth to junction between neck and seta.

Using the keys It is important that with each dichotomy of a key both parts are read carefully and particular note taken where ‘usually’ and ‘or if’ occur. Once a plant has been named it is essential that the specimen is carefully compared with the specific description and illustration before any firm conclusion is reached as to its identity.

Key to genera It must be stressed that the generic key is merely a guide to the allocation of specimens to genera and is far from infallible. Unfortunately, many characters that are useful in classification, such as peristome structure, sex and DNA sequences, may not be available in material collected or may only be useable with highly sophisticated technical equipment. Also, differences in appearance that enable an expert to determine a moss in the field with a hand lens cannot be described in quantitative or qualitative terms and it is necessary to rely on characteristics such as excurrence of costae or degree of papillosity that are open to misinterpretation or ambiguity. Whilst every effort has been made to avoid the use of vague or relative characters, because of the poor distinctions between some genera, such as some members of the Brachytheciaceae or Pottiaceae, precise definition is impossible. Where generic distinctions are based on the sporophyte, as in the Funariaceae, it may not be possible to identify sterile material. Where a species may exhibit both alternatives of a dichotomy, e.g. excurrence/non-excurrence of the costa or margins plane/recurved, allowance has been made as far as possible in the keys. However, allowing for every eventuality would make the key inordinately long and when in doubt it may be necessary to try both alternatives of a dichotomy. In acrocarpous mosses leaf characters are based upon leaves from the upper part of the stem or comal leaves but care should be taken that perichaetial or perigonial

8

Introduction

leaves are not used as these may differ in shape and areolation from stem leaves. In pleurocarpous mosses stem and branch leaves may be very different in form, especially in the Brachytheciaceae, and leaf characters refer to stem leaves unless otherwise stated. Where there is an overlap in dimensions such as cell size, only with very few exceptions are specimens encountered with the dimensions exactly in the overlap range. Thus if cells in one taxon are given as 8–16 μm and in a second as 14– 24 μm the majority of cells in the first will be less than 14 μm long and those in the second mostly more than 16 μm long.

Keys to species The same remarks apply to the keys to species, although in most instances the characters are more clear cut and misinterpretation less likely. However, difficulty may be experienced with genera such as Bryum, Didymodon and some Brachytheciaceae. It must be remembered that this is a regional flora and that some of the key dichotomies will not necessarily work elsewhere. Thus in the generic key in dichotomy 86, Coscinodon is separated from Grimmia and Schistidium by having plicate leaves, but in Continental Europe Coscinodon humilis Milde lacks leaf plicae and Grimmia caespiticia (Brid.) Jur. has strongly plicate leaves.

Abbreviations

auct. C c. cm GB H IR KOH m m n q.v. s.s. ssp. var. x μm ± ∗ ∗

Auctor(es), author(s) Channel Islands (referring to the vice-county or the number of 10 km grid squares in the Channel Islands) circa, approximately centimetre Great Britain (referring to the number of 10 km grid squares in Great Britain) Hibernia, Ireland (referring to number of vice-counties in Ireland) Ireland (referring to the number of 10 km grid squares in Ireland) Potassium hydroxide (2% solution) metre m-chromosomes, micro-chromosomes the functional haploid chromosome number quod vide, which see sensu stricto, in the strict sense subspecies variety basic haploid chromosome number micron, 1 × 10−6 m, 1 /1000 mm; colloquially ‘mu’ more or less following a chromosome number, means based on British or Irish material following number of grid squares, meaning pre-1950 records

9

Conspectus of classification

Traditionally, the division Bryophyta has included three classes, Hepaticopsida or Marchantiopsida (liverworts), Anthocerotopsida (hornworts) and Musci (mosses). Recent evidence, however, suggests that at an early stage in the evolution of terrestrial plants the liverworts diverged from other land plants, then hornworts diverged and finally mosses (see Willis & McElwain, 2002). Thus, the original concept of the division Bryophyta as consisting of three classes cannot be maintained and it is here considered to consist only of the mosses. Until the beginning of the 1980s the classification of mosses was based upon the morphology and anatomy of the gametophyte and sporophyte and it was sometimes a matter of dispute as to which of the two should be used for a particular group. Over the past 20 years or so new techniques have been developed, especially DNA sequencing, which provide information on the genetic relationships of taxa. This has confirmed some older classifications but others have been shown to be incorrect. The classification of mosses is now in a state of flux as a result of the development of these new techniques, Rather than using a traditional classification, such as that used by Corley et al. (1981), which is clearly very out of date, I have followed the tentative classification of D. H. Vitt (in Shaw & Goffnet, 2000). However, it is likely that further studies will lead to refinements, and even major changes, to this classification.

Division Bryophyta (Musci) Class 1. Sphagnopsida Order 1. Sphagnales Family 1. Sphagnaceae 1. Sphagnum

Class 2. Andreaeopsida Order 2. Andreaeales Family 2. Andreaeaceae 2. Andreaea

Class 3. Polytrichopsida Order 3. Polytrichales Family 3. Polytrichaceae

3. 4. 5. 6. 7. Order 4. Family 4. 8. 9. Family 5. 10.

10

Pogonatum Polytrichastrum Polytrichum Oligotrichum Atrichum Tetraphidales Tetraphidaceae Tetraphis Tetrodontium Oedipodiaceae Oedipodium

Conspectus of classification Order 5. Buxbaumiales Family 6. Buxbaumiaceae 11. Buxbaumia

Class 4. Bryopsida Subclass 1. Order 6. Family 7. 12. Subclass 2. Order 7. Family 8. 13. Order 8. Family 9. 14. 15. 16. 17. 18. 19. 20. 21. Family 10. 22. Family 11. 23. 24. 25. 26. 27. 28. Family 12. 29. 30. 31. 32. 33. 34. 35. 36. Family 13. 37. Family 14.

Diphysciideae Diphysciales Diphysciaceae Diphyscium Dicranideae Archidiales Archidiaceae Archidium Dicranales Ditrichaceae Pleuridium Pseudephemerum Trichodon Ditrichum Saelania Distichium Ceratodon Cheilothela Bruchiaceae Trematodon Rhabdoweisiaceae Rhabdoweisia Oreoweisia Cynodontium Oncophorus Dichodontium Dicranoweisia Dicranaceae Aongstroemia Dicranella Arctoa Kiaeria Dicranum Dicranodontium Campylopus Paraleucobryum Leucobryaceae Leucobryum Fissidentaceae

38. 39. Family 15. 40. Order 9. Family 16. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. Family 17. 73. Family 18. 74. 75.

Fissidens Octodiceras Schistostegaceae Schistostega Pottiales Pottiaceae Eucladium Weissia Tortella Trichostomum Pottiopsis Pleurochaete Paraleptodontium Dialytrichia Pseudocrossidium Bryoerythrophyllum Leptodontium Hymenostylium Anoectangium Gyroweisia Gymnostomum Molendoa Barbula Didymodon Scopelophila Stegonia Pterygoneurum Aloina Leptobarbula Tortula Protobryum Phascum Pottia Microbryum Hennediella Acaulon Leptophascum Syntrichia Cinclidotaceae Cinclidotus Ephemeraceae Micromitrium Ephemerum

11

12 Order 10. Family 19. 76. 77. 78. 79. Family 20. 80. 81. 82. Order 11. Family 21. 83. 84. 85. Subclass 3. Order 12. Family 22. 86. Order 13. Family 23. 87. Order 14. Family 24. 88. Family 25. 89. 90. 91. 92. Subclass 4. Order 15. Family 26. 93. 94. 95. 96. Family 27. 97. 98. 99. 100.

Conspectus of classification Grimmiales Grimmiaceae Coscinodon Schistidium Grimmia Racomitrium Ptychomitriaceae Ptychomitrium Glyphomitrium Campylostelium Seligeriales Seligeriaceae Blindia Seligeria Brachydontium Funariideae Timmiales Timmiaceae Timmia Encalyptales Encalyptaceae Encalypta Funariales Disceliaceae Discelium Funariaceae Funaria Entosthodon Physcomitrium Aphanorrhegma Bryideae Splachnales Splachnaceae Tayloria Tetraplodon Aplodon Splachnum Meesiaceae Paludella Meesia Amblyodon Leptobryum

Family 28. 101. Order 16. Family 29. 102. Family 30. 103. 104. 105. 106. Family 31. 107. 108. 109. 110. 111. 112. 113. 114. Family 32. 115. Family 33. 116. 117. 118. 119. 120. Order 17. Family 34. 121. Family 35. 122. 123. 124. Order 18. Family 36. 125. Order 19. Family 37. 126. Family 38. 127.

Catoscopiaceae Catoscopium Bryales Orthodontaceae Orthodontium Bryaceae Plagiobryum Anomobryum Bryum Rhodobryum Mniaceae Mielichhoferia Epipterygium Pohlia Mnium Cinclidium Rhizomnium Plagiomnium Pseudobryum Aulacomniaceae Aulacomnium Bartramiaceae Plagiopus Bartramia Conostomum Philonotis Breutelia Orthotrichales Amphidiaceae Amphidium Orthotrichaceae Zygodon Orthotrichum Ulota Hedwigiales Hedwigiaceae Hedwigia Rhizogoniales Rhizogoniaceae Leptotheca Calomniaceae Calomnion

Conspectus of classification Order 20. Family 39. 128. 129. Family 40. 130. Family 41. 131. 132. Order 21. Family 42. 133. Family 43. 134. Family 44. 135. 136. Family 45. 137. 138. 139. Family 46. 140. Family 47. 141. Family 48. 142. 143. Family 49. 144. Family 50. 145. 146. 147. Family 51. 148. Family 52. 149. 150. 151. 152. 153.

Hookeriales Hookeriaceae Hookeria Achrophyllum Pilotrichaceae Cyclodictyon Daltoniaceae Calyptrochaeta Daltonia Hypnales Fontinalaceae Fontinalis Climaciaceae Climacium Cryphaeaceae Cryphaea Dendrocryphaea Leucodontaceae Leucodon Antitrichia Pterogonium Myuriaceae Myurium Leptodontaceae Leptodon Neckeraceae Neckera Homalia Thamnobryaceae Thamnobryum Pterigynandraceae Pterigynandrum Habrodon Heterocladium Myriniaceae Myrinia Leskeaceae Leskea Pseudoleskeella Pseudoleskea Lescuraea Ptychodium

Family 53. 154. Family 54. 155. 156. Family 55. 157. 158. Family 56. 159. 160. 161. 162. Family 57. 163. 164. 165. 166. 167. 168. 169. 170. 171. 172. 173. 174. 175. 176. Family 58. 177. 178. 179. 180. 181. 182. 183. 184. 185. 186. 187. 188. 189.

Anomodontaceae Anomodon Thuidiaceae Abietinella Thuidium Helodiaceae Helodium Palustriella Amblystegiaceae Cratoneuron Amblystegium Hygroamblystegium Leptodictyum Campyliaceae Conardia Campylium Campyliadelphus Drepanocladus Warnstorfia Straminergon Calliergon Scorpidium Hamatocaulis Tomentypnum Pseudocalliergon Sanionia Hygrohypnum Pictus Brachytheciaceae Isothecium Scorpiurium Homalothecium Brachythecium Pseudoscleropodium Scleropodium Cirriphyllum Platyhypnidium Rhynchostegium Eurhynchium Kindbergia Oxyrrhynchium Rhynchostegiella

13

14 Family 59. 190. Family 60. 191. 192. 193. 194. 195. 196. 197. 198. Family 61. 199. Family 62. 200.

Conspectus of classification Entodontaceae Entodon Plagiotheciaceae Myurella Platydictya Orthothecium Plagiothecium Isopterygiopsis Pseudotaxiphyllum Herzogiella Taxiphyllum Sematophyllaceae Sematophyllum Hypnaceae Campylophyllum

201. 202. 203. 204. 205. 206. 207. 208. Family 63. 209. 210. 211. 212. 213. 214.

Calliergonella Pylaisia Platygyrium Homomallium Hypnum Ptilium Ctenidium Hyocomium Hylocomiaceae Rhytidium Pleurozium Rhytidiadelphus Loeskeobryum Hylocomiastrum Hylocomium

Artificial key to the genera of British and Irish mosses For information on use of this key see pages 7–8 1 Plants acrocarpous Plants pleurocarpous

2 192

Note. Acrocarpous mosses are those in which the main axis of the gametophyte is sympodial and is usually ± erect. The plants usually form turfs or cushions or may occur as scattered or gregarious individuals. Leaf cells are isodiametric to narrowly rectangular, narrowly hexagonal or rarely linear; the costa may be excurrent. Gametangia and sporophytes are produced at the apices of stems or main branches with further vegetative growth continued by lateral branch(es) or innovation(s). Pleurocarpous mosses have monopodial main stems. These are usually prostrate to ascending, producing secondary stems or branches and the plants often form mats or wefts or occur as scattered ± prostrate shoots. Stem leaves may be of different size and shape from branch leaves, leaf cells are often ± linear and the costae are very rarely excurrent. Gametangia are produced on dwarf bud-like lateral branches on the main stems and branches and because of this sporophytes may appear to grow directly from these. In a few instances (e.g. Cryphaea, Fontinalis) pleurocarpous mosses are cladocarpous with gametangia borne on short lateral branches. 2 Branch leaves ecostate, with network of green cells surrounding large hyaline cells with annular thickenings, branches in fascicles 1. Sphagnum (p. 44) Leaves costate or rarely ecostate, green cells not forming network, large hyaline cells lacking, branches not in fascicles 3 3 Plants saxicolous, deep red to brown or blackish, fragile when dry, leaf cell walls strongly incrassate, reddish to brownish, capsules dehiscing by 4(−8) longitudinal slits 2. Andreaea (p. 103) Habitat various, plants not as above, capsules dehiscing by a lid or cleistocarpous 4 4 Gametophytes minute, leaf and perichaetial leaf margins ciliate, setae coarsely papillose, capsules inclined, oblique, somewhat flattened on upper side 11. Buxbaumia (p. 141) Plants not as above 5 15

16

Artificial key to the genera

5 Leaf cells 2–3-stratose, obscure, costa poorly defined, perichaetial bracts with ciliate margins, capsules immersed, oblique 12. Diphyscium (p. 143) Plants not as above 6 6 Basal cells of leaves linear, transverse walls thin, longitudinal walls thick, sinuose-nodulose, cells above with sinuose walls, peristome teeth divided into filiform segments 79. Racomitrium (p. 457) Leaf areolation not as above, peristome teeth if present divided or not 7 7 Leaves lingulate to spathulate, rarely oblong-lanceolate, basal cells large, hyaline, narrower at the margins, cells above strongly papillose, very obscure, calyptrae completely covering erect cylindrical capsules, axillary uniseriate branched propagules to 2 mm long sometimes present 87. Encalypta (p. 497) Plants not as above 8 8 Plants occurring on dung or decaying animal remains 28 Substrate various but not dung or decaying animal remains, capsules without conspicuous hypophysis (except in Trematodon) 9 9 Capsules cleistocarpous 30 Capsules dehiscent or absent 10 10 Leaves distichous or complanate 41 Leaves spirally arranged 11 11 Plants with axillary bulbils or with gemma-cups or gemma-bearing pseudopodia at shoot tips 46 Plants without bulbils, gemma-cups or pseudopodia 12 12 Leaves ecostate 49 Leaves costate 13 13 Capsules ± globose or subglobose when moist, plants not ephemeral or if so then setae cygneous 187 Capsule shape various but not globose or subglobose or if so then plants ephemeral and setae straight, or capsules absent 14 14 Leaves with filaments or lamellae on adaxial side of costa at least in upper part of leaf 51 Leaves lacking lamellae or filaments on adaxial side 15 15 Leaves squarrose or squarrose-recurved when moist 55 Leaves appressed or imbricate to reflexed but not squarrose when moist 16 16 Leaf margins with border of narrow cells or with several-stratose marginal band 61 Leaves unbordered, without thickened marginal band 17 17 Plants minute, to 2(−3) mm high or if more then leaves markedly trifarious, saxicolous, forming lax or rarely dense patches, sporophytes usually present (except in Leptobarbula) 73 Plants very small to large, leaves not trifarious, habitat and habit various, sporophytes present or not 18


17

18 Plants terricolous, ephemeral or short-lived, scattered or gregarious, sporophytes usually present 76 Plants persisting, habit and habitat various, sporophytes present or not 19 19 Costa excurrent in hyaline hair-point or leaf apices hyaline when moist, whitish when dry 83 Costa if excurrent not forming hyaline hair-point, leaf apices not hyaline 20 20 Leaf apices obtuse or rounded 88 Leaves subacute to longly acuminate 21 21 Mid-leaf cells ± isodiametric 22 Mid-leaf cells longer than wide 25 22 Basal cells of leaves hyaline, ascending up margins, transition from basal to upper cells usually abrupt, V-shaped 43. Tortella (p. 278) Basal cells if hyaline not ascending up margins, transition from basal to upper cells not abrupt or V-shaped 23 23 Costa excurrent 108 Costa ending in or below apex 24 24 Margins recurved for at least part of leaf length on one or both sides 123 Leaf margins ± plane or incurved 142 155 25 Costa 1/4 or more width of leaf near base Costa narrower 26 26 Alar cells differentiated from other basal cells, often coloured, forming distinct group 161 Alar cells not differentiated 27 27 Leaf cells smooth 164 Leaf cells mamillose or papillose 187 28 Leaves tapering to long acumen, hypophysis of ± similar width to body of capsule 94. Tetraplodon (p. 516) Leaves obtuse to shortly acuminate, hypophysis as wide as or wider than body of capsule 29 29 Hypophysis of similar colour to body of capsule, antheridia borne on slender branches, marginal row of leaf cells larger than other cells 95. Aplodon (p. 517) Hypophysis purplish, wider than body of capsule or not, antheridia terminal on main stems, marginal row of leaf cells not enlarged 96. Splachnum (p. 518) 30 Plants minute, arising from persistent protonemata, capsules ± globose, ovoid or obovoid 31 Plants minute to small, protonemata not persisting, capsule shape various 32

18


31 Capsules without apiculus, ring of differentiated cells delimiting lid which separates under pressure, leaves ecostate 74. Micromitrium (p. 391) Capsules with apiculus, no lid delimited, leaves ecostate or costate 75. Ephemerum (p. 391) 32 Plants persisting, leaves on sterile stems distant, spores c. 16 per capsule, 130–260 μm 13. Archidium (p. 144) Plants ephemeral or short-lived, leaves crowded, spores numerous, 16–40(−50) μm 33 33 Upper leaves and perichaetial bracts linear-lanceolate or longly acuminate 34 Leaves wider, not longly acuminate 36 34 Leaves crisped or curled when dry, cells isodiametric, papillose 42. Weissia (p. 264) Leaves erect-flexuose when dry, cells in upper part of leaf longer than wide, smooth 35 35 Perichaetial bracts longer than upper stem leaves, costa ending in apex or excurrent, cells c. 8 μm wide 14. Pleuridium (p. 147) Perichaetial bracts and upper stem leaves of ± similar length, costa ending below apex, cells 10–15 μm wide 15. Pseudephemerum (p. 148) 36 Upper leaf and perichaetial bract margins bluntly dentate from about half way up leaf, costa ending well below apex 92. Aphanorrhegma (p. 513) Margins entire, papillose or denticulate, or if dentate then only towards apex, costa extending ± to apex or excurrent 37 37 Leaves spathulate, cells 14–30 μm wide, rhizoidal gemmae abundant, sporophytes very rare 71. Leptophascum (p. 378) Leaves ovate to lanceolate, cells 9–24 μm wide, rhizoidal gemmae sparse or absent, sporophytes common 38 38 Perichaetial bract margins toothed towards apex, capsules ± spherical, with or without minute apiculus 70. Acaulon (p. 376) Perichaetial bract margins entire or papillose, capsules spherical, ovoid or ellipsoid, with apiculus or beak 39 39 Capsules exserted above perichaetial bracts, with at least one row of differentiated cells below beak, leaf cells 16–24 μm wide 65. Protobryum (p. 361) Capsules immersed or laterally exserted or if vertically exserted then leaf cells 9–15 μm wide, cells below beak not differentiated 40 40 Plants pale green, upper leaves and perichaetial bracts imbricate or convolute, concealing capsules when viewed from above laminal KOH reaction yellow 66. Phascum (p. 362) Plants green to brown or reddish green, upper leaves and perichaetial bracts erect or erect-patent, not concealing capsules when viewed from above, laminal KOH reaction red 68. Microbryum (p. 369)


19

41 Leaves ecostate 40. Schistostega (p. 261) Leaves costate 42 42 Lower part of leaf with conduplicate portion (sheathing lamina) 43 Lower part of leaves without conduplicate portion 44 43 Conduplicate portion of leaves about 1/2 total leaf length, capsules longly exserted, habitat various 38. Fissidens (p. 241) 1 Conduplicate portion of leaves about /3 total leaf length, capsules barely emergent, aquatic plant 39. Octodiceras (p. 260) 44 Leaf margins bordered 113. Plagiomnium (p. 628) Leaf margins unbordered 45 45 Leaves abruptly narrowed to long fine acumen, terricolous or saxicolous plants 19. Distichium (p. 160) Leaves obtuse or obtuse and apiculate, epiphytic on tree fern trunks, very rare 127. Calomnion (p. 696) 46 Plants with gemma-cups or gemma-bearing pseudopodia at stem tips 47 Plants with axillary bulbils 48 47 Plants with gemma-cups containing discoid gemmae, capsules with 4 peristome teeth 8. Tetraphis (p. 137) Plants with pseudopodia bearing clavate gemmae, capsules with 16 exostome teeth 115. Aulacomnium (p. 636) 48 Leaves on sterile stems ovate to broadly ovate, rarely lanceolate, margins entire or obscurely denticulate towards apex, cells ± rhomboid-hexagonal 105. Bryum (p. 532) Leaves lanceolate to ovate-lanceolate, margins denticulate above, cells narrowly rhomboidal 109. Pohlia (p. 593) 49 Plants medium-sized, leaf cells strongly papillose, capsules immersed or emergent 125. Hedwigia (p. 691) Plants minute, leaf cells smooth, capsules exserted 50 50 Plants not bud-like, leaf cell walls incrassate, capsules ± ellipsoid, peristome teeth 4 9. Tetrodontium (p. 139) Plants bud-like, leaf cell walls thin, capsules ± globose, peristome teeth 16 88. Discelium (p. 504) 51 Leaves with branched green filaments on adaxial side of costa 62. Aloina (p. 339) Leaves with longitudinal lamellae on adaxial side of costa at least above 52 52 Leaves pellucid, margins unbordered, entire, capsules gymnostomous 61. Pterygoneurum (p. 336) Leaves opaque or if pellucid then margins with border of elongate cells, dentate, capsules with short peristome teeth joined to epiphragm 53

20


53 Leaves not differentiated into hyaline sheathing base and opaque blade, margins with border of narrow elongate cells 7. Atrichum (p. 133) Leaves differentiated into hyaline sheathing base and opaque blade, margins unbordered 54 54 Leaves with c. 12 sinuose lamellae on adaxial side of costa 6. Oligotrichum (p. 131) Lamellae on adaxial side of costa numerous, ± straight 3. Pogonatum, 4. Polytrichastrum, 5. Polytrichum (p. 119) 55 Leaf apices obtuse 27. Dichodontium (p. 178) Leaf apices acute to longly acuminate 56 56 Mid-leaf cells ± isodiametric, papillose or mamillose 57 Mid-leaf cells longer than wide, smooth 59 57 Leaf margins denticulate below, crenulate and irregularly toothed above, band of hyaline cells ascending up basal margins 46. Pleurochaete (p. 291) Leaf margins entire below, hyaline cells not ascending up basal margins 58 58 Leaf margins papillose-crenulate above, plants not occurring in fens 58. Didymodon (p. 315) Leaf margins dentate above, very rare fen plant 97. Paludella (p. 521) 59 Plants 3–5 cm high, leaves trifarious, narrowly triangular 98. Meesia (p. 521) Plants rarely more than 1 cm high, leaves not trifarious, abruptly narrowed above basal part to long acumen 60 60 Leaf acumens denticulate all round, cells in sheathing base rhomboidal, capsules ± erect 16. Trichodon (p. 149) Leaf acumens only denticulate at margins, cells in sheathing base rectangular to linear, capsules inclined or erect 30. Dicranella (p. 184) 61 Leaf margins 3–5-stratose, forming distinct band ± circular in section, cells hardly differing in shape from other lamina cells 62 Marginal cells elongate, differing in shape from other lamina cells, forming distinct border 63 62 Leaf margins recurved, cells strongly papillose, capsules exserted 48. Dialytrichia (p. 292) Leaf margins plane, cells smooth or faintly papillose, capsules usually immersed 73. Cinclidotus (p. 388) 63 Leaf cells ± isodiametric 64 Leaf cells longer than wide 68 64 Leaf cells smooth, pellucid 65 Leaf cells papillose, opaque 66 65 Leaf margins spinosely dentate, teeth double, costae often toothed on abaxial side 110. Mnium (p. 615)


66

67

68

69 70

71

72

21

Leaf margins ± entire to dentate, teeth if present single, not spinose, costae not toothed abaxially 113. Plagiomnium (p. 628) Plants 3–10 cm high, leaf margins serrulate below, coarsely serrate above 47. Paraleptodontium (p. 292) Plants to 2.5 cm high, leaf margins entire or dentate towards apex 67 Leaf margins ± entire towards apex, rhizoidal gemmae lacking, peristomes spirally twisted 64. Tortula (p. 344) Leaf margins denticulate towards apex, rhizoidal gemmae present, capsules gymnostomous 69. Hennediella (p. 372) Plants to 0.5 cm high, capsules erect, peristome rudimentary or absent, leaf cells lax, thin walled 90. Entosthodon (p. 506) Plants to 12(−15) cm high, capsules inclined to pendulous, peristome well developed, cells firm, walls at least slightly thickened 69 Leaf apices rounded, margins entire 70 Leaves acute to obtuse, margins entire or toothed 71 Costa reaching apex and confluent with border, mid-leaf cells 15–35 μm wide 111. Cinclidium (p. 622) Costa ending well below apex, mid-leaf cells 35–50 μm wide 112. Rhizomnium (p. 623) Leaf margins toothed, sometimes spinosely so or if entire then sterile shoots procumbent to arcuate 113. Plagiomnium (p. 628) Leaf margins entire or denticulate, sterile shoots erect 72 Leaf bases not very narrow, costa ± reaching apex or excurrent, bulbils lacking 105. Bryum (p. 532) Leaf bases very narrow, costa ending well below apex, spherical or ovoid bulbils, to 300 μm diameter, usually present at stem bases and developing in situ into leafy shoots 108. Epipterygium (p. 592)

73 Leaf margins and cells papillose 74 Leaf margins and cells not papillose 75 74 Perichaetial and perigonial bracts hardly differing in shape from vegetative leaves, sporophytes common, gymnostomous, protonemal gemmae present 54. Gyroweisia (p. 306) Bracts longer than vegetative leaves, bases sheathing, sporophytes very rare, peristomes spirally coiled, protonemal gemmae lacking 63. Leptobarbula (p. 343) 75 Mid-leaf cells isodiametric, setae cygneous when moist, upper leaves and perichaetial bracts linear 82. Campylostelium (p. 476) Cells longer than wide, setae straight or arcuate when moist, upper leaves and perichaetial bracts usually narrowed from ovate or lanceolate basal part to subulate acumen 173 76 Leaf cells lax, thin-walled Leaf cells firm, thin-walled to incrassate

166 77

22


77 Plants bud-like with strongly concave imbricate leaves, costa ending below apex, peristome perfect, very rare montane plant 60. Stegonia (p. 335) Plants not bud-like, costa ending below apex to excurrent, peristome absent, imperfect or perfect, usually lowland plants 78 78 Capsules globose, mid-leaf cells rectangular to narrowly rectangular 119. Philonotis (p. 646) Capsule shape various but not globose, cells isodiametric 79 79 Leaf, margins often toothed above, setae 5–9 mm long, lid remaining attached to columella after dehiscence 69. Hennediella (p. 372) Leaf margins entire or papillose-crenulate, setae 2–5 mm long, lid falling at dehiscence 80 80 Leaves linear-lanceolate 42. Weissia (p. 264) Leaves wider 81 81 Leaf cells 7–11 μm wide, perichaetial bracts wider than upper stem leaves, sheathing, peristome well developed, spores 15–19 μm 45. Pottiopsis (p. 290) Leaf cells (9−)10–24 μm wide, perichaetial bracts of similar width to stem leaves, not sheathing, spores 20–25(−44) μm 82 82 Leaf cells 13–24 μm wide, capsule lids rostrate or longly rostrate, annulus present or not, laminal KOH reaction yellow 64. Tortula (p. 344) Leaf cells (9−)10–12(−18) μm wide, capsule lids conical or mamillate, annulus absent, laminal KOH reaction red 67. Pottia (p. 365) 83 Mid-leaf cells longer than wide 105. Bryum (p. 532) Mid-leaf cells ± isodiametric 84 84 Leaf apices hyaline when moist, whitish when dry, costa vanishing in apex 85 Costa excurrent in hyaline or very rarely reddish hair-point 90 85 Mid-leaf cells papillose, 10–16 μm wide, walls not sinuose, capsules immersed, ribbed, peristome double, exostome teeth pale 123. Orthotrichum (p. 664) Mid-leaf cells 6–12 μm wide, usually smooth, walls often sinuose, capsules immersed or exserted, peristome single, teeth reddish to brownish 86 86 Leaf margins plane, lamina with thickened plicae on either side of costa in upper half of leaf, capsules emergent, peristome teeth strongly cribrose 76. Coscinodon (p. 397) Leaf margins plane, incurved or recurved, plicae lacking, capsules immersed, emergent or exserted, peristome teeth entire to strongly cribrose 87 87 Leaf margins usually recurved, perichaetial bracts usually larger than and often differing in shape from stem leaves, capsules immersed 77. Schistidium (p. 399) Leaf margins plane, incurved or recurved, perichaetial bracts larger than stem leaves but not differing markedly in shape, capsules exserted, very rarely immersed 78. Grimmia (p. 427)


23

88 Leaves widest above middle 89 Leaves widest below middle 91 89 Leaves ovate-spathulate to orbicular with narrow ciliate bases, cells 50–100 μm wide, capsules gymnostomous 10. Oedipodium (p. 140) Leaves not as above, cells narrower, capsules with peristomes 90 90 Plants usually 0.2–1.0 cm high, leaves not constricted at or below middle, hair-points if present smooth, gemmae lacking, laminal KOH reaction yellow 64. Tortula (p. 344) Plants (0.2−)0.5–10.0 cm high, hyaline points if present denticulate or if smooth then leaves contracted at or below middle, gemmae sometimes present on adaxial side of leaves or stem tips or rhizoids, laminal KOH reaction red 72. Syntrichia (p. 380) 91 Leaf cells longer than wide 92 Leaf cells ± isodiametric 94 92 Leaves imbricate when moist, cells rectangular 29. Aongstroemia (p. 184) Leaves not imbricate, cells narrowly hexagonal with ± pointed ends 93 93 Stems not tomentose below, leaf cells not in radiating rows 105. Bryum (p. 532) Stems with dark brown tomentum below, leaf cells in radiating rows 114. Pseudobryum (p. 635) 94 Leaf cells ± smooth, pellucid, lumens quadrate to rounded 95 Leaf cells mamillose or papillose, pellucid or opaque, or if smooth then lumens stellate 100 95 Leaves toothed near apex, costa excurrent, very rare tree fern epiphyte 126. Leptotheca (p. 694) Plants not as above 96 96 Leaf margins denticulate to dentate above 97 Leaf margins entire or bluntly toothed above 98 97 Leaf cells 8–20 μm wide, capsules without hypophysis 23. Rhabdoweisia (p. 167) Leaf cells 20–40 μm wide capsules with hypophysis 93. Tayloria (p. 514) 98 Leaves ovate-lanceolate to broadly ovate, capsules exserted 58. Didymodon (p. 315) Leaves lingulate or narrowly lingulate to narrowly lanceolate or if ovate then capsules immersed 99 99 Leaves lingulate-lanceolate to lanceolate or ovate, capsules immersed, plants occurring within flood zone of streams and rivers 77. Schistidium (p. 399) Leaves lingulate or narrowly lanceolate, capsules exserted, plants of dry rocks 78. Grimmia (p. 427) 100 Stems with dense reddish brown tomentum or if tomentum absent then cell lumens stellate 115. Aulacomnium (p. 636) Stems not matted with tomentum, cell lumens not stellate 101

24


101 Leaf margins denticulate to dentate 102 Leaf margins entire or papillose-crenulate 103 102 Mid-leaf cells 8–10 μm wide, marginal row of cells not differentiated from other cells 27. Dichodontium (p. 178) Mid-leaf cells 10–16(−20) μm wide, marginal rows of cells pellucid 51. Leptodontium (p. 300) 103 Leaves linear-lanceolate, margins papillose-crenulate, notched and sometimes irregularly toothed above 58. Didymodon (p. 315) Leaves not as above 104 104 Leaves incurved, strongly curved or crisped when dry 105 Leaves ± erect and/or appressed, twisted or not when dry 106 105 Leaf margins plane, apices cucullate 44. Trichostomum (p. 285) Leaf margins recurved almost to apex or narrowly recurved below, apices plane 57. Barbula (p. 312) 106 Capsules immersed or emergent, leaf margins recurved or incurved, entire or toothed above, gemmae frequently present on leaves 123. Orthotrichum (p. 664) Capsules exserted, leaf margins plane, papillose-crenulate, gemmae if present axillary 107 107 Leaf apices obtuse to subacute, basal cells rectangular, axillary gemmae lacking 55. Gymnostomum (p. 307) Leaf apices rounded, cells ± quadrate except at extreme base, ovoid to fusiform axillary gemmae frequently present 56. Molendoa (p. 310)

108 Uppermost leaves with terminal clusters of gemmae, cells papillose 109 Uppermost leaves without terminal clusters of gemmae, cells smooth or papillose 110 109 Leaves flexuose when dry, margins coarsely toothed above 51. Leptodontium (p. 300) Leaves tightly curled when dry, margins entire 124. Ulota (p. 681) 110 Leaves tapering from below middle, margins recurved ± from base to apex 111 Leaf margins plane or recurved below or if recurved to near apex then leaves broadly pointed 112 111 Leaf margins recurved, not papillose, often bluntly toothed near apex, cells smooth, pellucid, capsules inclined to horizontal, strumose 20. Ceratodon (p. 163) Leaf margins revolute, papillose, cells papillose, opaque, capsules erect, symmetrical 49. Pseudocrossidium (p. 294) 112 Leaf margins recurved below 113 Leaf margins plane 119 113 Leaf margins toothed ± from base to apex 117. Bartramia (p. 640)


114

115 116

117 118

119

120

121

122

25

Leaf margins entire, or papillose-crenulate, or denticulate or dentate above 114 Leaves lingulate or spathulate, widest above middle and shortly pointed, or costa widened above, capsules exserted 64. Tortula (p. 344) Leaf shape various but not as above, widest below middle, costa not widened above or if so then capsules immersed 115 Leaves shortly pointed 57. Barbula (p. 312) Leaves tapering from below middle 116 Capsules immersed, leaf cell walls ± sinuose, plants of coastal rocks 77. Schistidium (p. 399) Capsules exserted, cell walls not sinuose, habitat various but not coastal rocks 117 Leaves crisped when dry, cells smooth 26. Oncophorus (p. 176) Leaves ± straight or imbricate when dry, cells smooth or papillose 118 Leaves spirally arranged, erect-patent to patent when moist, margins entire, peristomes spirally coiled 58. Didymodon (p. 315) Leaves quinquefarious, imbricate when moist, margins serrulate above, peristomes straight 118. Conostomum (p. 645) Plants yellowish green, leaves narrowly triangular to ovate, cells bistratose above, very strongly papillose, very obscure 21. Cheilothela (p. 165) Plants not as above 120 Leaves linear-lanceolate from expanded denticulate basal part, margins plane above 41. Eucladium (p. 262) Leaf shape various, margins entire near base or if denticulate then basal part not expanded 121 Basal cells of leaves incrassate, not hyaline, axillary gemmae present although sometimes sparse 122. Zygodon (p. 659) Basal cells thin-walled and hyaline at least towards margins, gemmae absent 122 Plants to 1 cm high, autoicous, sporophytes common, peristome teeth rudimentary, fugacious 42. Weissia (p. 264) Plants 0.5–10.0 cm high, dioicous, sporophytes rare, peristome well developed 44. Trichostomum (p. 285)

123 Stems matted with brown or reddish brown tomentum, plants yellowish green to green above 124 Stems not matted with tomentum or if stems tomentose then plants reddish tinged throughout 125 124 Leaf margins papillose-crenulate, cells opaque, sporophytes on short lateral branches 53. Anoectangium (p. 304) Leaf margins entire or denticulate above, cells pellucid, sporophytes terminal 115. Aulacomnium (p. 636)

26


125 Leaf margins entire, denticulate or dentate above but not papillose or papillose-crenulate 126 Leaf margins crenulate or papillose-crenulate above, dentate or not 140 126 Leaves ± erect, flexuose or not when dry 127 Leaves incurved, curled or crisped when dry 131 127 Cells smooth or papillose, lumens ± quadrate, capsules exserted or if immersed then smooth and leaf cell walls usually sinuose, peristomes single 128 Cells papillose, walls not sinuose, lumens ± rounded, capsules immersed, emergent or exserted, usually striate, peristomes double 134 128 Leaf margins recurved ± from base to apex, capsules strumose 20. Ceratodon (p. 163) Leaf margins recurved below or at middle, capsules not strumose 129 129 Costa 2-winged on abaxial side above, basal cells linear with sinuose walls 78. Grimmia (p. 427) Costa not 2-winged, basal cells shorter, walls not sinuose 130 130 Capsules exserted, cells papillose or smooth, walls not sinuose 58. Didymodon (p. 315) Capsules immersed, cells usually smooth, walls ± sinuose 77. Schistidium (p. 399) 131 Leaf margins entire, bases not sheathing 132 Leaf margins denticulate or dentate at least above or if entire then bases sheathing 136 132 Cell lumens ± quadrate, capsules exserted, peristomes single 133 Cell lumens ± rounded, capsules immersed, emergent or exserted, usually striate, peristomes double 134 133 Mid-leaf cells 10–14 μm wide 28. Dicranoweisia (p, 181) Mid-leaf cells 6–10 μm wide 58. Didymodon (p. 315) 134 Leaf margins narrowly recurved below, gemmae lacking, capsules exserted, calyptrae glabrous 121. Amphidium (p. 657) Leaf margins strongly recurved, gemmae sometimes present on leaves, capsules immersed, emergent or exserted, calyptrae glabrous or hairy 135 135 Capsules immersed or emergent, calyptrae glabrous to sparsely hairy, basal part of leaves not widened, concave or plicate, basal cells near margins not differentiated 123. Orthotrichum (p. 664) Capsules exserted, calyptrae hairy (sparsely so in Ulota calvescens), basal part of leaves widened, concave, sometimes plicate, basal marginal cells wider than other cells, hyaline 124. Ulota (p. 681) 136 Leaf cells usually opaque, mamillose 137 Leaf cells pellucid, smooth or mamillose 138 137 Leaves strongly crisped when dry, margins remotely denticulate above, cells partially bistratose 24. Oreoweisia (p. 170)


138

139

140

141

27

Leaves incurved when dry, margins denticulate to dentate, cells unistratose 27. Dichodontium (p. 178) Leaf bases plicate, longitudinal walls of basal cells more strongly thickened than transverse walls 80. Ptychomitrium (p. 474) Leaf bases not plicate, walls of basal cells of ± uniform thickness 139 Leaf bases not sheathing, upper cells smooth or mamillose at least on abaxial side, capsules striate 25. Cynodontium (p. 171) Leaf bases ± sheathing, cells smooth, capsules smooth 26. Oncophorus (p. 176) Plants rusty red below, or reddish tinged, leaves usually at least bluntly dentate towards apex, or plants reddish brown throughout 50. Bryoerythrophyllum (p. 297) Plants not rusty red below, not reddish tinged or reddish brown throughout, margins not toothed above 141 Leaves oblong-lanceolate or lingulate, tapering in upper part only 57. Barbula (p. 312) Leaves broadly ovate to linear-lanceolate, tapering from middle or below 58. Didymodon (p. 315)

142 Leaf cells smooth, pellucid 143 Leaf cells mamillose or papillose, pellucid or opaque 148 143 At least upper leaves lingulate, widest at or above middle 59. Scopelophila (p. 334) Leaf shape various, widest below middle 144 144 Plants 1–10 cm high, leaf margins irregularly dentate with single or double teeth, mid-leaf cells 20–24 μm wide 110. Mnium (p. 615) Plants 0.5–3.0 cm high, leaf margins entire to dentate above, teeth single, 145 145 Leaves ± erect, flexuose when dry, lanceolate to ovate-spathulate 122. Zygodon (p. 659) Leaves crisped when dry, lingulate to ligulate or linear-lanceolate 146 146 Leaves ligulate to lingulate, acute to obtuse, margins entire to dentate 23. Rhabdoweisia (p. 167) Leaves linear-lanceolate or with linear acuminate upper part, margins entire 147 147 Mid-leaf cells mostly 6–8 μm wide, alar cells forming auricles, spores 12–20 μm 28. Dicranoweisia (p. 181) Cells 10–12 μm wide, auricles lacking, spores 40–50 μm 81. Glyphomitrium (p. 476) 148 Leaves with expanded or sheathing basal part and lanceolate or narrowly lanceolate limb 149 Leaves not differentiated into basal part and limb 150

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149 Plants small, to 1 cm high, leaf limb narrowly linear-lanceolate, margins crenulate 58. Didymodon (p. 315) Plants medium-sized to large, 2–9 cm high, leaf limb obscurely to coarsely dentate above 86. Timmia (p. 494) 150 Stems matted below with reddish brown tomentum, sporophytes on short lateral branches 53. Anoectangium (p. 304) Stems not matted with tomentum, sporophytes terminal 151 151 Plants pale or glaucous green, often coated with calcareous matter, leaf margins denticulate near base 41. Eucladium (p. 262) Plants yellowish green to dark green, not coated with calcareous matter, leaf margins usually entire below 152 152 Leaves 2–7 mm long 44. Trichostomum (p. 285) Leaves 1.0–2.5 mm long 153 153 Leaves oblong-lanceolate to lingulate, peristomes spirally twisted 57. Barbula (p. 312) Leaves linear-lanceolate to ovate, peristomes rudimentary or absent 154 154 Leaves linear to linear-lanceolate or ligulate, tapering from c. 1 /4 from base, gemmae lacking 55. Gymnostomum (p. 307) Leaves narrowly lanceolate to ovate, tapering from 1 /3 –1 /2 from base, stem gemmae present although sometimes sparse 122. Zygodon (p. 659)

155 Plants whitish when dry, costa of leaf limb in section consisting of large hyaline cells and small green cells, lamina consisting of a few rows of hyaline cells extending up margins 156 Plants not as above 157 156 Plants forming silky tufts, leaves longly tapering, alar cells inflated, very rare plant 36. Paraleucobryum (p. 237) Plants frequently forming rough textured ± hemispherical cushions, leaves shortly pointed, alar cells not differentiated, common plants 37. Leucobryum (p. 239) 157 Leaf apices rounded 98. Meesia (p. 521) Leaves with long fine acumens 158 158 Setae straight when moist, capsules pendulous, smooth, leaf cells ± linear-rhomboidal throughout 100. Leptobryum (p. 524) Setae straight or arcuate when moist, capsules inclined, striate or furrowed, cell shape various but not linear rhomboidal throughout 159 159 Capsules common, smooth when moist, strumose or not, setae straight when moist, alar cells not differentiated, plants usually 1–3 cm high 30. Dicranella (p. 184) Capsules rare (except in Campylopus introflexus), usually striate when moist, setae usually cygneous before capsule maturity, alar cells inflated and hyaline or brownish or not, plants 0.5–13.0(−25.0) cm high 160


29

160 Costa denticulate on abaxial side above, longly excurrent in non-hyaline rough point, in section with band of stereids on adaxial side 34. Dicranodontium (p. 213) Costa smooth on abaxial side above, ending below apex to excurrent in smooth or hyaline point, in section with few or no stereids on adaxial side 35. Campylopus (p. 216) 161 Cells in upper part of leaf linear, costa excurrent in subulate point 83. Blindia (p. 477) Cells in upper part or leaf quadrate to rectangular, costa if excurrent not forming subulate point 162 162 Leaves abruptly narrowed above basal part to long acumen, costa longly excurrent, capsules wide-mouthed when dry and empty 31. Arctoa (p. 194) Leaves gradually tapering, costa ending below apex to excurrent but not longly so, capsules not wide-mouthed when dry and empty 163 163 Autoicous, capsules usually strumose, costa excurrent, in section without stereids or with a few on abaxial side only, montane plants 32. Kiaeria (p. 196) Dioicous, capsules not strumose, costa ending below apex to excurrent, in section with stereids or if stereids lacking then plants lowland 33. Dicranum (p. 200) 164 Leaf cells lax, thin-walled 165 Leaf cells firm, thin-walled to incrassate, firm 168 165 Leaf margins entire or denticulate above, capsules asymmetrical, inclined, spores c. 40 μm 99. Amblyodon (p. 523) leaf margins usually bluntly toothed above, capsules erect and symmetrical or if not then spores 16–28(−30) μm 166 166 Setae arcuate when moist, flexuose and twisted when dry, capsules asymmetrical, striate at maturity, sulcate when dry, mouth oblique, exostome teeth united at tips to small central disc 89. Funaria (p. 506) Plants not as above 167 167 Capsules symmetrical or gibbous and asymmetrical, lids convex, peristome present or not, calyptrae cucullate, oblique 90. Entosthodon (p. 506) Capsules symmetrical, lids apiculate or rostellate, capsules gymnostomous, calyptrae mitriform, symmetrical 91. Physcomitrium (p 510) 168 Leaf apices acuminate or subulate, consisting largely or entirely of costa 169 Leaves acute or subacute or if acuminate then acumen not consisting largely or entirely of costa 176 169 Leaf margins serrate above 116. Plagiopus (p. 639) Leaf margins entire or denticulate above 170

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170 Neck of capsule as long as body of capsule (not seen since 1883) 22. Trematodon (p. 166) Neck shorter than body of capsule or capsules absent 171 171 Leaves linear-lanceolate to linear, costa ending in or below apex, mid-leaf cells linear 102. Orthodontium (p. 526) Leaves wider, or narrowed from broad basal part to long acumen, costa ending in apex to excurrent or if ending below apex then mid-leaf cells rectangular 172 172 Plants minute, usually 1–3 mm high or if more then costa excurrent in stout subula or leaves trifarious 173 Plants usually larger, costa if excurrent not forming subula, leaves not trifarious 174 173 Setae straight or arcuate when moist, capsules smooth, leaves trifarious or not 84. Seligeria (p. 479) Setae straight, capsules striate at maturity, deeply furrowed when dry leaves not trifarious 85. Brachydontium (p. 493) 174 Leaves abruptly narrowed to long acumen, cells above basal part rectangular or narrowly rectangular 17. Ditrichum (p. 149) Leaves tapering to acumen or if abruptly narrowed then cells above basal part linear 175 175 Cells in basal part of leaf narrowly rectangular, leaves not abruptly narrowed above basal part, plants not reddish 17. Ditrichum (p. 149) Cells in basal part of leaf rectangular or if narrower then leaves abruptly narrowed above basal part or plants red tinged 30. Dicranella (p. 184) 176 Mid-leaf cells 7–10(−12) μm wide, cell ends rounded to flat 177 Mid-leaf cells 12–24 μm wide or if narrower then cells linear and/or cell ends pointed 183 177 Plants dark green, vegetative shoots slender with small distant lanceolate leaves, fertile shoots with larger crowded leaves, mid-leaf cells 8–10 μm wide, capsules immersed, cleistocarpous 13. Archidium (p. 144) Plants not as above 178 178 Plants glaucous blue-green, leaf margins bluntly dentate above, stems entwined with fungal hyphae 18. Saelania (p. 158) Plant colour various but not glaucous blue-green, leaf margins entire, denticulate or dentate above, fungal hyphae lacking 179 179 Plants with very crowded slender shoots forming dense tufts, sporophytes borne on lateral branches, plants of montane copper-containing rocks 107. Mielichhoferia (p. 591) Plants not as above, sporophytes terminal on main stems, habitat various 180 180 Leaves 1.0–2.4 mm long, linear-lanceolate to lanceolate 52. Hymenostylium (p. 302) Leaves to 1.4 mm long, ovate to lanceolate 181


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181 Leaf margins toothed 119. Philonotis (p. 646) Leaf margins entire or obscurely toothed above 182 182 Plants scattered, in patches or small tufts, to 1.5 cm high, leaves acute, margins plane or narrowly recurved below 17. Ditrichum (p. 149) Plants forming tufts or often hemispherical cushions, to 4(−7) cm high, leaves acuminate, margins recurved below 101. Catoscopium (p. 526) 183 Shoots julaceous with concave imbricate leaves when moist 184 Shoots not julaceous when moist 185 184 Leaves broadly ovate, cells narrowly hexagonal, thin-walled, 14–24 μm wide in mid-leaf, capsule mouth oblique 103. Plagiobryum (p. 528) Leaves lanceolate to ovate, cells linear-vermicular, thick-walled, 9–16 μm wide in mid-leaf capsule mouths transverse 104. Anomobryum (p. 530) 185 Robust plants arising from rhizomatous stems, upper leaves spathulate, margins dentate above 106. Rhodobryum (p. 589) Plants small to medium-sized, rhizomatous stems absent, upper leaves narrowly lanceolate to ovate, margins entire to denticulate above 186 186 Leaf margins entire or denticulate near apex, cells narrowly hexagonal or if ± linear then plants bright green or bright red 105. Bryum (p. 532) Leaf margins denticulate above, cells elongate hexagonal to linear or if rhomboidal then plants whitish green or glaucous green 109. Pohlia (p. 593) 187 Plants robust, shoots procumbent or ascending, leaves longitudinally plicate 120. Breutelia (p. 656) Plants very small to robust, shoots erect, leaves not longitudinally plicate or if so only near base 188 188 Plants forming dense tufts or cushions 189 Plants scattered, gregarious or forming lax tufts or cushions 190 189 leaves lanceolate, mid-leaf cells 8–10 m wide, smooth, capsules c. 1 mm diameter, ± black at maturity, smooth and glossy when dry 101. Catoscopium (p. 526) Leaves narrowly lanceolate, cells 8–13 m wide, mamillose, capsules larger, brown, furrowed when dry 118. Conostomum (p. 645) 190 Leaves ovate-lanceolate to ovate 119. Philonotis (p. 646) Leaves linear-lanceolate to narrowly lanceolate 191 191 Leaf cells ± smooth 116. Plagiopus (p. 639) Leaf cells mamillose 117. Bartramia (p. 640) 192 Plants robust or very robust, leaves scarious when dry or squarrose, or stems ascending, arcuate to procumbent with short spreading branches and falcate-secund leaves 211. Rhytidiadelphus (p. 925) Plants not as above, leaves not scarious or squarrose 193

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193 Leaf cells to twice as long as wide at least towards margins at widest part of leaf 199 Leaf cells more than twice as long as wide 194 194 Leaves complanate and/or margins with border of narrow elongate cells 215 Leaves not complanate, margins unbordered 195 195 Leaf apices obtuse to rounded, apiculate or not, or leaves abruptly narrowed to long apiculus from ovate to wider than long basal part 222 Leaf apices subacute to filiform 196 196 Leaves falcate-secund to circinate-secund at least at stem and branch tips 244 Leaves ± straight 197 197 Costa extending less than half way up leaf or lacking 257 Costa extending half way or more up leaf 198 198 Leaves plicate 276 Leaves not or hardly plicate 283 199 Costa extending at least half way up leaf 200 Costa extending less than half way up leaf or absent 211 200 Stems with abundant paraphyllia, regularly 1–3-pinnately branched 201 Paraphyllia few or absent, stems irregularly or pinnately branched but not 2–3-pinnate 202 201 Stems pinnately branched 155. Abietinella (p. 746) Stems 2–3-pinnately branched 156. Thuidium (p. 749) 202 Leaf margins denticulate or dentate for most of length 203 Leaf margins entire, crenulate or denticulate above 205 203 Plants slender, leaves to 1.2 mm long 147. Heterocladium (p. 731) Plants medium-sized to robust, leaves longer except on ultimate branches 204 204 Secondary stems often dendroid, branch leaves not plicate, margins dentate ± from base to apex 144. Thamnobryum (p. 724) Secondary stems not dendroid, leaves longitudinally plicate, margins with spinose often recurved teeth towards apex 138. Antitrichia (p. 714) 205 Stems and branches inrolled when dry, leaf apices rounded 141. Leptodon (p. 717) Stems and branches not inrolled when dry, leaves obtuse to acuminate 206 206 Plants robust, very rarely slender, primary stems stolonifolrm, secondary stems erect, (1−)2–8 cm long, leaf bases decurrent 154. Anomodon (p. 743) Plants not as above, leaf bases not decurrent 207 207 Plants cladocarpous, medium-sized to robust, stems usually with numerous short branches, capsules immersed 208


208

209 210

211 212

213 214

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Plants pleurocarpous, extremely slender to slender, branches not crowded, capsules exserted 209 Primary stems with numerous branches, branch leaves gradually tapering to acute to acuminate apex, margins narrowly recurved below 135. Cryphaea (p. 709) Primary stems sparsely branched, branch leaves shortly pointed, obtuse, margins plane 136. Dendrocryphaea (p. 711) Leaf cells smooth or faintly papillose 150. Pseudoleskeella (p. 737) Leaf cells papillose at least on abaxial side 210 Leaves not plicate, acute to obtuse, sporophytes common, epiphytic plants 149. Leskea (p. 735) Leaves slightly plicate, apices acuminate to filiform, sporophytes unknown in Britain, saxicolous plants 151. Pseudoleskea (p. 740) Plants medium-sized to large, leaves 0.8–2.5 mm long 212 Plants very slender to slender, leaves 0.3–1.2 mm long 213 Leaves longitudinally plicate, margins entire, costa absent 137. Leucodon (p. 712) Leaves not plicate, margins denticulate above, costa double, extending to 139. Pterogonium (p. 715) c. 1/4 way up leaf Leaf margins denticulate, cells papillose 147. Heterocladium (p. 731) Leaf margins entire of finely crenulate, cells smooth 214 Leaves acuminate, mid-leaf cells c. 10 μm wide 146. Habrodon (p. 730) Leaves acute, mid-leaf cells 12–16 μm wide 148. Myrinia (p. 734)

215 Leaf margins with border of narrow elongate cells 216 Leaf margins unbordered 218 216 Costa very short, mid-leaf cells 25–40 μm wide 131. Calyptrochaeta (p. 701) 217 Costa extending c. 3/4 way up leaf, mid-leaf cells 6–30 μm wide 217 Shoots to 8 cm long, leaves complanate 130. Cyclodictyon (p. 700) Shoots to 1.5 cm long, leaves spirally arranged 132. Daltonia (p. 702) 218 Mid-leaf cells 40–100 μm wide 219 Mid-leaf cells 4–22 μm wide 220 219 Leaves not dimorphic, mid-leaf cells 60–100 μm wide, frequent plant 128. Hookeria (p. 698) Leaves dimorphic, mid-leaf cells 40–60 μm wide, very rare plant 129. Achrophyllum (p. 700) 220 Costa single, extending 1/2–3/4 way up leaf, mid-leaf cells 3–4 times as long as wide 143. Homalia (p. 722) Costa very short or if not then double, cells 4–20 times as long as wide 221 221 Stems pinnately branched, branches spreading 142. Neckera (p. 719) Stems irregularly branched, branches not spreading 267

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222 Leaves abruptly narrowed to long apiculus from ovate to wider than long basal part 223 Leaf apices obtuse to rounded, apiculus if present short 228 223 Costa single, extending half way or more up leaf 224 Costa short or absent 226 224 Stems usually regularly pinnately branched, leaves imbricate when moist, plicate 183. Cirriphyllum (p. 837) Stems irregularly branched, leaves erect-patent to spreading when moist, not plicate 225 225 Acumen forming half or more total leaf length 165. Campyliadelphus (p. 775) Acumen forming 20–25% total leaf length 175. Hygrohypnum (p. 800) 226 Leaves strongly concave, imbricate when moist 140. Myurium (p. 717) Leaves weakly concave, patent to spreading or squarrose when moist 227 227 Plants slender to robust, leaves 1.2–3.6 mm long, margins entire or obscurely denticulate at widest part 164. Campylium (p. 773) Plants slender, leaves mostly 0.4–1.0 mm long, margins denticulate below or above 200. Campylophyllum (p. 889) 228 Costa extending half way or more up leaf 229 Costa extending less than half way up leaf or absent 237 229 Stems ± regularly pinnately branched, branches complanate, leaves plicate, auricles lacking 181. Pseudoscleropodium (p. 833) Branching irregular or if pinnate then branches not complanate and leaves not plicate, auricles present or not 230 230 Leaves straight, acute to obtuse 231 Leaf apices rounded or if obtuse then leaves falcate-secund 233 231 Usually robust plants of rocks subject to immersion in running water, leaves concave, margins denticulate or dentate ± from base to apex 184. Platyhypnidium (p. 840) Plants terrestrial, small to medium-sized, leaf margins entire or denticulate above 232 232 Stem leaves larger and wider than branch leaves, alar cells not forming auricles, setae papillose, lids rostrate 182. Scleropodium (p. 835) Stem and branch leaves ± similar, alar cells forming poorly defined auricles, setae smooth, lids with subulate beaks 185. Rhynchostegium (p. 843) 233 Stem leaves broadly ovate to orbicular or if narrower then falcate-secund 234 Stem leaves oblong-lanceolate or ovate-lanceolate to ovate or ovate-triangular, straight 235 234 Leaves patent to spreading when moist or falcate-secund 175. Hygrohypnum (p. 800) Leaves imbricate when moist, straight 173. Pseudocalliergon (p. 794) 235 Plants deep purplish red 167. Warnstorfia (p. 781)


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Plants yellowish green to green or brownish 236 236 Branches sparse or numerous, leaves patent to spreading when moist and when dry 169. Calliergon (p. 786) Branches absent or sparse, leaves imbricate when moist and when dry 168. Straminergon (p. 786) 237 Plants very slender, leaves 0.3–0.6 mm long, high altitude plants 191. Myurella (p. 862) Plants medium-sized to large, leaves longer, altitudinal range various 238 238 Stems pinnately branched 239 Stems irregularly branched 241 239 Stems yellowish to pale brown, leaves with poorly defined auricles 190. Entodon (p. 861) Stems reddish brown or deep red, auricles well defined 240 240 Stems reddish brown, branches not down-turned, alar cells inflated, hyaline 201. Calliergonella (p. 891) Stems deep red, branches often down-turned, alar cells rectangular, not inflated or hyaline 210. Pleurozium (p. 924) 241 Alar cells inflated, forming longly and narrowly decurrent auricles, terrestrial plants 194. Plagiothecium (p. 867) Alar cells not longly and narrowly decurrent, plants of wet or aquatic habitats 242 242 Leaves falcate-secund, often rugose, alar cells inflated, hyaline, forming small fugacious auricles 170. Scorpidium (p. 789) Leaves ± straight or if falcate-secund then not rugose, auricles if present persisting 243 243 Plants 0.5–8.0 cm long, leaves broadly ovate to ovate-orbicular or if narrower then falcate-secund 175. Hygrohypnum (p. 800) Plants to 25 cm long, leaves ovate-lanceolate, straight 173. Pseudocalliergon (p. 794) 244 Costa extending half way or more up leaf, alar cells not opaque 245 Costa absent or extending less than half way up leaf or if longer then alar cells opaque with granular contents 253 245 Leaves tapering to longly acuminate apices 246 Leaves more shortly pointed, acute to acuminate 251 246 Leaves at least weakly longitudinally plicate when moist 247 Leaves not longitudinally plicate when moist 248 247 Leaves tapering from c. 3 /4 way from base, weakly plicate, margins entire, auricles absent 171. Hamatocaulis (p. 792) Leaves tapering almost from base, strongly plicate, margins finely denticulate, auricles present 174. Sanionia (p. 797) 248 Leaf margins denticulate above 167. Warnstorfia (p. 781) Leaf margins entire or at most slightly sinuose 249

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249 Leaves with distinct auricles 166. Drepanocladus (p. 778) Auricles lacking or 2–3 alar cells inflated, hyaline, very fragile and fugacious 250 250 Plants often reddish or purplish tinged, leaves strongly falcate to circinate, outer layer of stem cells enlarged (parts of cells of the cortex remain attached to leaf bases when leaves are removed) 170. Scorpidium (p. 789) Plants green to yellowish-brown or brown, leaves falcate, cells of outer layer of stem cortex not enlarged 173. Pseudocalliergon (p. 794) 251 Leaves rugose when dry, bases not cordate, auricles not extending to costa, paraphyllia lacking 209. Rhytidium (p. 923) Leaves not rugose when dry, stem leaf bases cordate-auriculate or cordate-triangular, auricles large, extending ± to costa, paraphyllia abundant or not 252 252 Stem and branch leaves usually falcate-secund, longitudinally plicate, mid-leaf cells (6−)9–15 times as long as wide 158. Palustriella (p. 754) Stem leaves usually ± straight with secund acumens, branch leaves subfalcate to falcate-secund, leaves not plicate, cells 2–4(−6) times as long as wide 159. Cratoneuron (p. 759) 253 Leaves longitudinally plicate and/or bases cordate 254 Leaves not plicate, bases not cordate 255 254 Stems closely complanately branched, branches short, paraphyllia abundant, leaves strongly plicate 206. Ptilium (p. 916) Branching various, paraphyllia lacking, leaves not or weakly plicate 207. Ctenidium (p. 917) 255 Leaves shortly pointed, plants of fast-flowing water 175. Hygrohypnum (p. 800) Leaves tapering to apex, terrestrial plants 256 256 Leaves falcate-secund, alar cells forming distinct auricles 201. Calliergonella (p. 891) Alar cells not inflated or if so then leaves circinate-secund 205. Hypnum (p. 898)

257 Plants cladocarpous, aquatic, very robust, forming straggling tufts to 80(−150) cm long, leaves keeled or strongly concave, capsules immersed 133. Fontinalis (p. 703) Plants pleurocarpous, terrestrial, not as above, capsules exserted 258 258 Stems red or reddish brown, with abundant paraphyllia 259 Stems yellowish to green or brown or whole plant red, paraphyllia sparse or absent 261


37

259 Stem leaves strongly plicate, branch leaves with single costa extending 1 /2 –3 /4 way up leaf, ending in tooth on abaxial side 213. Hylocomiastrum (p. 931) Stem leaves not or weakly plicate, costa of branch leaves thin, from almost absent to extending to half way up leaf, not ending in a tooth 260 260 Stems irregularly pinnately branched, paraphyllia 20–130 μm long 212. Loeskeobryum (p. 929) Stems regularly bipinnate, paraphyllia 200–1000 μm long 214. Hylocomium (p. 934) 261 A few alar cells inflated, hyaline, forming small non-decurrent auricles 199. Sematophyllum (p. 886) Alar cells not inflated or if so then forming longly decurrent auricles 262 262 Alar cells undifferentiated and green or colourless, or longly decurrent or forming longly decurrent auricles 263 Alar cells ± quadrate or rectangular, forming ± distinct non-decurrent group, usually 1.0–1.5 times as long as wide, or forming non-decurrent auricles 271 263 Plants exceedingly slender to slender, not reddish, leaves to c. 0.25–0.75 mm long, cells 2–6 times as long as wide 264 Plants small to robust or if slender then reddish, leaves (0.75−)1.0–5.0 mm long, cells longer 266 264 Leaves ovate to broadly ovate, acute to obtuse, cells papillose on abaxial side above 145. Pterigynandrum (p. 728) Leaves lanceolate, acuminate, cells smooth 265 265 Stem and perichaetial leaf margins entire or obscurely denticulate, capsules ± horizontal, plants autoicous 160. Amblystegium (p. 762) Margins of at least well developed leaves denticulate, perichaetial leaf margins spinosely denticulate, capsules inclined, plants dioicous 192. Platydictya (p. 863) 266 Plants forming silky red or red-tinged patches, auricles absent 193. Orthothecium (p. 865) Plants yellowish-green to green or brownish-green, not silky, auricles present or not 267 267 Leaf margins denticulate ± from base to apex 197. Herzogiella (p. 882) Leaf margins entire or denticulate only towards apex 268 268 Alar cells hyaline, longly decurrent, sometimes forming longly decurrent auricles (decurrent alar cells remain attached to stems when leaves are removed and are best viewed in situ) 194. Plagiothecium (p. 867) Alar cells green, not decurrent, but forming auricles 269 269 Leaves acute, mid-leaf cells 6–10 μm wide, 8–10 times as long as wide, calcicole 198. Taxiphyllum (p. 885) Leaf apices ± filiform, mid-leaf cells 4–7 μm wide, 10–23 times as long as wide, calcifuge to weakly calcicole 270

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270 Leaves rarely complanate, margins entire, fusiform axillary gemmae sometimes present 195. Isopterygiopsis (p. 880) Leaves strongly complanate, margins often denticulate near apex, flagelliform axillary branches often present and sometimes abundant 196. Pseudotaxiphyllum (p. 881) 271 Stem leaves abruptly narrowed to short point, alar cells forming orange-brown excavate group, very rare plant 176. Pictus (p. 809) Alar cells not forming excavate group or if so then leaves tapering to apex, usually common plants 272 272 Stem leaves plicate, cordate-triangular, rapidly narrowed to acute to filiform apex, setae papillose 208. Hyocomium (p. 922) Stem leaves not plicate, ovate to narrowly lanceolate, More gradually tapering to acute or acuminate apex, setae smooth 273 273 Some basal cells between alar cells and costa with flat ends, plants autoicous, fertile branches numerous, crowded, lids conical 202. Pylaisia (p. 894) Basal cells with pointed ends, plants usually dioicous, fertile branches not crowded, lids conical or rostrate 274 274 Leaf margins recurved, axillary deciduous branchlets often present at stem and branch tips 203. Platygyrium (p. 895) Leaf margins not or hardly recurved, deciduous branchlets absent 275 275 Plants autoicous, slender, stem leaves narrowly lanceolate to lanceolate, capsules strongly inclined to horizontal, curved, lid conical, very rare plant 204. Homomallium (p. 896) Plants dioicous, slender or robust, stem leaves ovate lanceolate to broadly ovate, capsules erect and straight or inclined and curved, lid rostrate, common plants 205. Hypnum (p. 898) 276 Secondary stems erect, dendroid, with terminal cluster of branches 134. Climacium (p. 709) Stems not dendroid, branches not in terminal clusters 277 277 Stems tomentose with abundant paraphyllia or rhizoids 278 Paraphyllia and/or rhizoids if present not forming tomentum 279 278 Stems irregularly branched, leaf cells smooth 172. Tomentypnum (p. 793) Stems pinnately branched, leaf cells papillose 157. Helodium (p. 754) 279 Stems with numerous paraphyllia, leaf apices acuminate, cells smooth or papillose, very rare montane plants 280 Paraphyllia lacking, leaf apices longly acuminate or filiform, cells smooth, widespread plants 281 280 Leaves gradually tapering from widest part to acuminate apex, cells papillose 152. Lescuraea (p. 741) Leaves ± abruptly narrowed to long or short acuminate apex, cells smooth 153. Ptychodium (p. 741)


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281 Leaves tapering from near base to long acumen, cells linear-vermicular throughout except at basal angles 179. Homalothecium (p. 816) 1 Leaves tapering from about /4 from base, basal cells shorter and wider than cells above 282 282 Stem and branch leaves of ± similar shape, margins entire or denticulate above, lids conical 180. Brachythecium (p. 818) Stem and branch leaves differing in shape, margins denticulate ± from base to apex, lids with subulate beaks 186. Eurhynchium (p. 847)

283 Basal and alar cells isodiametric or shortly rectangular, alar cells strongly incrassate opaque 284 Basal and alar cells longer, pellucid, alar cells differentiated or not 285 284 Secondary stem erect and dendroid, or procumbent and not closely branched, costa usually extending 1/2–3/4 way up leaf, sometimes forked above 177. Isothecium (p. 810) Stems prostrate, closely branched, branches curved, costa stout, extending almost to apex, not forked 178. Scorpiurium (p. 815) 285 Alar cells opaque with granular contents 175. Hygrohypnum (p. 800) Alar cells lacking granular contents, pellucid 286 286 Stem leaves tapering to apex, mid-leaf cells short, mostly 2–6 times as long as wide 287 Mid-leaf cells of stem leaves longer or if not then leaves shortly pointed 290 287 Costae stout, more than 40 μm wide near leaf base, extending to blunt apex 161. Hygroamblystegium (p. 768) Costae thinner, not reaching leaf apex, leaves acute to acuminate 288 288 Basal marginal cells transversely rectangular, capsules erect 150. Pseudoleskeella (p. 737) Basal marginal cells longer than wide, capsules usually inclined to horizontal 289 289 Leaves (0.25−)0.6–2.2 mm long, ± entire at widest part of leaf, gemmae lacking, autoicous, sporophytes occasional to common 160. Amblystegium (p. 762) Leaves 0.3–0.7 mm long, denticulate at widest part of leaf, gemmae often present at leaf tips, dioicous, sporophytes unknown in Europe 163. Conardia (p. 772) 290 Leaves widely spreading, often subcomplanate162. Leptodictyum (p. 770) Leaves not spreading or subcomplanate 291 291 Leaves weakly to strongly asymmetrical, alar cells longly decurrent down stem 194. Plagiothecium (p. 867) Leaves symmetrical, alar cells not longly decurrent 292

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292 Plants usually medium-sized to robust, leaves longly tapering, often subsecund or subfalcate at stem and branch tips, plants of wet to aquatic habitats 293 Plants very slender to robust, if leaves longly tapering then plants very slender to small, habitat various 294 293 Leaf margins entire 166. Drepanocladus (p. 778) Margins denticulate above 167. Warnstorfia (p. 781) 294 Stem leaves cordate-triangular to lanceolate-triangular, tapering to acuminate or filiform apex, branch leaves differing in shape 295 Stem and branch leaves of ± similar shape 296 295 Stems irregularly branched, sporophytes rare, lids conical, rare high altitude plants 180. Brachythecium (p. 818) Stems interruptedly 1–2-pinnately branched, sporophytes frequent, lids with subulate beaks 187. Kindbergia (p. 851) 296 Plants slender or very slender, lids with subulate beaks 189. Rhynchostegiella (p. 857) Plants usually medium-sized to robust or if slender then lids conical 297 297 Stems with numerous branches, branches short, crowded or not, curved, leaves strongly concave, acute to obtuse or abruptly narrowed to acuminate apex, setae papillose 298 Branches not crowded, ± long, leaves plane to concave, apices obtuse to filiform, setae smooth or papillose 299 298 Leaves acute to obtuse, mid-leaf cells mostly 6–15 times as long as wide, lids rostrate 182. Scleropodium (p. 835) Leaves abruptly narrowed to acuminate apex, mid-leaf cells 5–6 times as long as wide, lids with subulate beaks 183. Cirriphyllum (p. 837) 299 Lids conical or rostrate, setae papillose at least above, leaves acuminate, margins usually entire or denticulate above 180. Brachythecium (p. 818) Lids with subulate beaks, setae smooth or papillose, leaves acute or occasionally acuminate, margins denticulate to dentate ± from base to apex 300 300 Leaves not or slightly concave, costa of branch leaves ending in small tooth on abaxial side, setae papillose 188. Oxyrrhynchium (p. 853) Leaves concave or very concave, costa of branch leaves not ending in tooth on abaxial side, setae smooth 301 301 Usually robust plants of rocks subject to submergence in running water, leaves 1.5–2.5 mm long 184. Platyhypnidium (p. 840) Plants small to medium-sized, terrestrial, leaves 1.0–1.5 mm long 185. Rhynchostegium (p. 843)

Division Bryophyta (Musci)

Alternation of generations heteromorphic; the sexual generation, the leafy gametophyte dominant (‘the moss plant’), the asexual generation, the sporophyte dependent on the gametophyte for survival. Gametophyte stems without xylem or phloem but sometimes with tubular conducting cells; multicellular rhizoids often present; leaves typically unistratose but sometimes thicker; costa present or not; cells isodiametric to linear. Female gametangia, archegonia, flask-shaped and containing a single female gamete; male gametangia, antheridia, producing numerous biflagellate male gametes. Fusion of gametes resulting in the development of an embryo in the venter of the archegonium. Sporophyte consisting of foot embedded in gametophyte tissue, seta, frequently with tubular conducting cells and capsule; capsules usually with stomata and photosynthetic tissue, usually dehiscing by lid, occasionally cleistocarpous, rarely by longitudinal slits; later development of capsule controlled by the calyptra derived from neck of archegonium; spores produced by meiosis in spore sac of the capsule. About 12 000 species (almost certainly an overestimate). A highly successful group of plants occurring in almost every available natural habitat except the sea.

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Class 1 Sphagnopsida M. O. HILL Protonemata thalloid, with secondary filaments consisting of ± unbranched rows of cells with oblique dividing walls. Leafy shoots lacking rhizoids, consisting of erect main axis from which sprout fascicles of branches (in a few species there is only one much reduced branch per fascicle). Leaves ecostate, with two main types of cell. Elongate cells, dead at maturity, constitute a border. The main part of the lamina (except sometimes in perichaetial leaves) is composed of a mesh of two types of cell, chlorocysts, which are narrow and green, and hyalocysts, which are hyaline, inflated and dead at maturity of the leaf. Antheridia lateral, in leaf axils. Antherozoids biflagellate, with elongate body coiled in 2 turns of a sinistrorse spiral. Archegonia in groups of 1–5 at apex of a short specialised branch or the main stem. Setae absent, capsules joined directly to foot and exserted from perichaetium by elongation of pseudopodium composed of gametophytic tissue just below the archegonium. Capsules globose, urn-shaped when dry and empty, with a convex lid, lacking a peristome; exothecial cells brown at maturity, with scattered non-functional stomata; spore sac amphithecial in origin, overarching columella; calyptra a thin hyaline membrane, irregularly ruptured at maturity by growth of capsule. Spores arising in tetrads, each with a conspicuous triradiate scar on inner face. There are two orders, Sphagnales and Ambuchananiales. The latter contains a monotypic genus, Ambuchanania, known only from Tasmania. The ordinal status of the Ambuchananiales is still uncertain. Its basic architecture is similar to that of Sphagnum but the antheridia and archegonia are borne on the main stem and its antheridia are similar in shape to those of the Bryopsida.

1 Sphagnales Leaves unistratose. Antheridia globose, borne singly in axils of branch leaves. Archegonia in groups of 1–5 at apex of short lateral branch.

1 Sphagnaceae With the characters of the order.

43

44

1 Sphagnaceae

1 SPHAGNUM L., SP. PL., 1753 Autoicous or dioicous. Stems, which are conducting, differentiated into a cortex of 1–4 layers of often hyaline parenchymatous cells surrounding a central cylinder; cylinder with thin-walled parenchymatous cells at centre, merging gradually outwards into thick-walled, smaller and often pigmented prosenchymatous cells inside cortex. Branches arising in fascicles of (1−)2–8, differentiated in most species into divergent branches which stand out from stem and bear the main photosynthetic leaves, and pendent branches appressed to stem and may assist in water conduction. Branch cellular anatomy similar to that of stems, or cells of branch cortex dimorphic, consisting of large, often protuberant retort cells, each with a pore at distal end and smaller non-protuberant cells usually without pores (branch cortex is unistratose). The stems do not fork, an enlarged fascicle branch developing into a new stem. Branch and stem leaves spirally arranged with a 2/5 phyllotaxy; fascicles of branches arise in a position adjacent to every fourth leaf in stem leaf spiral, and hence themselves arise in a reverse 2/5 ‘phyllotaxy’. Hyalocysts normally solitary, each bordered by a mesh of chlorocysts; but in the stem leaves of several species, hyalocysts form pairs or larger groups without intervening chlorocysts. In the text that follows, these groups are referred to as ‘septate hyalocysts’, as if they were a single cell with divisions. Hyalocyst cell walls may be ornamented. These ornamentations are fibrils (annular thickenings) and pores (circular, semicircular or elliptical perforations or membrane thinnings within which the cell wall is wholly or partially resorbed). Pores and, in some species, spiral fibrils often found in the stem and branch cortex. Antheridia solitary on leaf axils; ± unspecialised branches, globose, with a narrow stalk of 2–4 rows of cells. After fertilisation the perichaetial leaves grow rapidly, but the pseudopodium elongates only at maturity. Spore discharge is by an ‘airgun’ mechanism, the ripe capsule shrinking in dry weather to build up an internal pressure, reputedly 4–6 atmospheres, blowing off lid and ejecting the spores several centimetres into the air. The mechanism frequently does not work, and then the lid merely falls off, or the capsule disintegrates. Sphagnum species occur as variously coloured tussocks and ‘lawns’ in bogs, marshes, pools, wet woodland, moors and damp grassland, rarely if ever in localities with a pH exceeding 6.0. Sphagnum may be divided into about 11 sections of which 6 are represented in Britain and Ireland. About 250 species distributed through much of the world in humid climates but rare in tropical Africa. Derivation: from the Ancient Greek name of a plant of now unknown identity.

Notes on the examination of Sphagna Most species can be determined by examination of the stem leaves and branch leaves. Transverse sections of the stem are often useful, particularly in Section Subsecunda. Leaf sections are sometimes necessary, but the exposure of the chlorocysts on the abaxial and adaxial surface can often be assessed by focussing up and down on 2 leaves, one placed with the abaxial (convex) surface facing upwards, the other with the adaxial (concave) surface facing upwards. Details of pore structure are

1 Sphagnum

45

not easy to see without stain unless the pores are surrounded by a fibril ring. Dissection is often necessary to observe pores in the stem cortex, as the cylinder is opaque. Although most species can normally be determined without stain, staining simplifies identification. An aqueous solution of crystal violet or gentian violet is suitable. Scrapings from the lead of an indelible pencil dissolved in water make an effective stain. Branch leaf dimensions refer to the large leaves of the divergent branches. Pore measurements are taken longitudinally (relative to leaf shape). In the branch leaves, pore dimensions refer to those from the central part of the leaf unless otherwise stated. Pores are often absent in stem leaves except near the apex. In the stem leaves, therefore, pore dimensions refer to the part of the leaf about 2/3 –3/4 of the distance from leaf base, or higher in the leaf if necessary.

Keys to sections of Sphagnum Key 1 uses reliable structural characters but may be found difficult by beginners. Key 2 is more artificial, but is based on characters that may be found easier to use. Key 2 should be reliable with well grown plants, but may occasionally give the wrong answer when applied to abnormal growth forms. When in doubt use Key 1.

Key 1 1 Cortical cells of stems and branches with spiral fibrils (always easy to see in pendent branches) Section Sphagnum (p. 46) Cortical cells without fibrils 2 2 Chlorocysts of branch leaves triangular or trapezoid in section, broadly exposed on adaxial surface, less exposed on abaxial surface Section Acutifolia (p. 59) Chlorocysts not, or slightly exposed on adaxial surface, or if with a moderate adaxial exposure then with a greater abaxial exposure 3 3 Branch leaves denticulate at margin owing to resorption of cells in border; cells of branch cortex not dimorphic, all with a pore at distal end Section Rigida (p. 75) Branch leaves with intact border; cells of branch cortex dimorphic, consisting of large retort cells with a pore at distal end, and smaller cells which usually lack pores 4 4 Pores in middle of branch leaves large, numerous and conspicuous, 12–40 μm long Section Squarrosa (p. 55) Pores small, less than 12 μm, or if larger then not more than one per cell 5 5 Chlorocysts of branch leaves triangular or trapezoid in section, broadly exposed on abaxial surface; adaxial surface of stem leaves with extensive resorption near apex, or else with pores mostly greater than 15 μm long(use stain); stem cortex 2–3 layers, sometimes so indistinctly differentiated from central cylinder as to appear absent Section Cuspidata (p. 86)

46

1 Sphagnaceae Chlorocysts of branch leaves ± barrel-shaped in section, with a narrow exposure on abaxial surface; adaxial surface of stem leaves intact or with pores mostly less than 12 μm wide; stem cortex very distinct, 1–3 layers (often only 1) Section Subsecunda (p. 78)

Key 2 1 Branch leaves wide, cucullate, rarely less than 1 mm wide; stem cortex Section Sphagnum (p. 46) occupying 1/3 –1/2 diameter of stem Branch leaves narrow, or if wider than 1 mm then stem cortex less than 1/4 diameter of stem 2 2 Leaves without reddish pigments 3 Leaves with rose-pink, crimson or red pigments 8 3 Stem leaves with patches of narrow cells at basal angles, these being roughly the same width as cells of border, so that border, if present, appears to merge with them 4 Border distinct to base, not appearing to merge with patches of narrow cells 5 4 Branch leaves with large pores, 8–30 μm, normally 3 or more per cell; stem leaves erect and appressed to stem (except in compact forms) Section Acutifolia (p. 59) Branch leaves with pores 9 μm or less (sometimes absent), or if pores larger then not more than 1 per cell; stem leaves spreading or hanging Section Cuspidata (p. 87) 5 Stem leaves large, lingulate, 1.2–2.0 mm long, lacking fibrils Section Squarrosa (p. 55) Stem leaves various, if large and lingulate then with conspicuous fibrils 6 6 Stem leaves spreading or hanging 7 Stem leaves erect and appressed to stem 8 7 Branch leaves denticulate because of resorption of outer part of walls in border; pores medium-sized or large, 5–25 μm Section Rigida (p. 75) Branch leaves entire, with an intact border; pores small, 2–6 μm, or sometimes absent Section Subsecunda (p. 78) 8 Pores small, less than 6 μm; stem cortex with a single layer of hyaline cells Section Subsecunda (p. 78) Pores 8–30 μm; stem cortex 2–4 layers Section Acutifolia (p. 59) Section 1 Sphagnum Plants medium-sized or robust. Stems usually 0.6–1.2 mm diameter; cortex 3–4 layers, hyaline, (60−)100–300 μm wide, occupying about half diameter of stem; cortical cell walls with sinistrally spiralling fibrils (sometimes absent in surface layer but always present in inner cells); outer surface with 1–8 pores per cell; diameter of cortical cells measured at right-angles to radius 25–90(−120) μm, numerous cells always exceeding 50 μm; cylinder strongly differentiated from cortex. Branches in fascicles of 3–7, (1−)2(−3) divergent, 1–4 pendent; branch cortex

Section Sphagnum

47

with 0–1 pores per cell, the cells not dimorphic, their walls with sinistrally spiralling fibrils (not always obvious in divergent branches, easily seen in pendent branches). Stem leaves erect or hanging, usually 1.1–2.0 × 0.7–1.4 mm, ± rectangular; border 2–5 cells wide, rather ill-defined, denticulate along sides of leaf, becoming irregular and almost unrecognisable near apex; cells of border 8–14 μm wide, those at margin extensively resorbed on outer surface and usually represented only by a resorption furrow, or sometimes ± intact near base; hyalocysts septate or not; abaxial surface almost completely resorbed and lacking through much of leaf; adaxial surface intact, with or without fibrils in upper leaf. Branch leaves cucullate, elliptic or broadly ovate, usually 1.1–2.8 × 0.9–1.9 mm; margin denticulate, the border 1 cell wide, completely resorbed on outer surface and represented only by a resorption furrow (margin appears denticulate owing to projection of transverse cell walls which persist after destruction of border); chlorocysts in section varying from completely enclosed on both surfaces to broadly exposed on adaxial surface with a slight exposure on abaxial surface; hyalocysts in cucullate region near leaf apex wider than long, their abaxial surface with a large membrane gap in distal half of cell, so that leaf apex appears scabrous because of projecting cell walls; abaxial pores in mid-leaf 8–25 μm, (0−)3–6(−16) per cell, in mid-leaf normally occurring in triplets, one at each corner of three adjacent hyalocysts, towards margin of leaf (and rarely in centre) more numerous and not confined to cell angles; adaxial pores few or absent in mid-leaf, more numerous towards margins, positioned along commissures. Antheridia on divergent branches. Perichaetial leaves oblong, rounded and tattered at apex; border 2–3 cells wide, ± intact in lower half of leaf, strongly resorbed above and absent at apex; hyalocysts fibrillose and porose near apex, not resorbed on either surface below, above ± lacunose on abaxial surface.

Key to Sphagnum Section Sphagnum 1 Inside walls of hyalocysts of branch leaves ornamented with papillae or lamellae where they abut on chlorocysts, so that in surface view of leaf the chlorocysts appear to be papillose or lamellate; cells near centre of stem leaves mostly septate; plants green, yellowish, ochre or brown with no red tinge 2 Surface of chlorocysts of branch leaves appearing smooth; cells near centre of stem leaves not or hardly septate; plants green, yellowish, pinkish-orange or red 4 2 Surface of chlorocysts appearing papillose; chlorocysts in cross-section barrel-shaped with bulging sides and thick cell walls on adaxial surface 3. S. papillosum Surface of chlorocysts with transverse lamellae (comb-fibrils), which project into hyalocysts like the teeth of a comb; chlorocysts in cross-section triangular, with straight sides, lacking thickened adaxial cell walls 3 3 Branches in fascicles of 3; stem leaves with comb-fibrils in upper part; usually in compact brownish hummocks 1. S. austinii

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1 Sphagnaceae

Branches in fascicles of 4; stem leaves lacking comb-fibrils; usually lax green or yellowish plants in loose tufts 2. S. affine 4 Chlorocysts of branch leaves completely enclosed on both surfaces of leaf; plants dull crimson, rarely completely green 5. S. magellanicum Chlorocysts of branch leaves reaching surface on both sides of leaf, often fully exposed on adaxial face; colour various, sometimes pinkish-orange or brick-red, but not dull crimson 3. S. palustre 1 S. austinii Sull. ex Aust., Musci Appalach., 1870 (Fig. 2) S. imbricatum Hornsch. ex Russow ssp. austinii (Sull. ex Aust.) Flatberg Dioicous. Shoots to 15 cm long, usually in compact, reddish brown, mottled hummocks, rarely in lax brownish tussocks. Stems (0.3−)0.5–0.9 mm diameter; cortex 3–4 layers; pores on outer surface 1–4 per cell; cylinder dark brown. Branches 3 per fascicle, 2 divergent, 1 pendent, the divergent branches often somewhat curved; fibrils of cortex 2–3 times more numerous on inner surface adjacent to cylinder than they are on outer surface (in other European members of Section Sphagnum except S. affine they are equally numerous on both surfaces). Stem leaves 1.1– 1.8 × 0.8–1.0 mm, lingulate or rectangular; cells near middle of leaf 50–100% septate; cells near leaf apex with short comb-fibrils (see below). Branch leaves 1.3–2.2 × 0.9–1.5 mm, concave, ovate, mostly less than 0.7 times as wide as long, cucullate; thickness of lamina in mid-leaf 25–42 μm in middle of hyalocysts, 12– 16 μm where these abut on chlorocysts; internal walls of hyalocysts where these abut on chlorocysts with conspicuous comb-fibrils, i.e. lamellae that mostly run perpendicular to the chlorocysts, projecting to give a comb-like appearance to the chlorocysts in surface view of leaf; chlorocysts in section equilaterally triangular, straight-sided, reaching surface on both sides of leaf, broadly exposed on adaxial face; abaxial pores in mid leaf 11–18 μm, (0−)3–8 per cell, adaxial pores usually absent in mid-leaf, occasionally to 5 per cell. Antheridial leaves densely imbricate. Capsules very rare, summer. Ombrotrophic bogs on deep peat. 0–500 m. Devon to Shetland, confined to the north and west; widespread in Ireland; local and seldom abundant. Sub-fossil S. austinii is a major component of the peat of raised bogs in many parts of the British Isles. 35, H20. GB64 + 12∗ , IR42 + 6∗ . Hyperoceanic Temperate. An oceanic species, found near coasts of N. W. Europe, and N. E. and N. W. North America; another subspecies occurs in arctic Asia and arctic N. America. Sphagnum austinii and S. affine are components of the S. imbricatum complex, which was monographed by K. I. Flatberg, K. Norske Vidensk. Selsk. Skr. 3, 1–80, 1984. The combfibrils in the branch leaves are sometimes ± obsolete except near the margins at the base. The characteristic ornamentation of the inner surface of the branch cortex is, however, constant. In the field, the mottled colour and often slightly curved branches are useful characters. Lax forms can be distinguished by having uniformly 3 branches per fascicle.

Section Sphagnum

49

Fig. 2 1–5, Sphagnum austinii: 1, divergent branch leaves; 2, stem leaf; 3, 4, cells at middle of divergent branch leaf, adaxial and abaxial side; 5, divergent branch leaf section. 6–11, S. affine: 6, moist fascicle (×4); 7, divergent branch leaves; 8, stem leaf; 9, 10, cells at middle of divergent branch leaf, adaxial and abaxial side; 11, divergent branch leaf section. Leaves ×27, cells ×280.

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1 Sphagnaceae

2 S. affine Renauld & Cardot, Rev. Bryol., 1885 (Fig. 2) S. imbricatum Hornsch. ex Russow ssp. affine (Renauld & Cardot) Flatberg Dioicous. Shoots to 15 cm long, green or yellowish, forming lax tussocks or ‘lawns’. General anatomy similar to that of S. austinii, differing as follows. Inner surface of stem cortex with densely-packed fibrils resembling those of the inner surface of branch cortex (S. austinii has such fibrils in the branches but not the stems). Branches in fascicles of 4, 2 divergent, 2 pendent, the divergent branches not curved. Stem leaves lacking comb-fibrils, hyalocysts in upper part of leaf more septate than in S. austinii, often divided into groups of 3–4. Branch leaves 1.1– 2.0 × 0.9–1.6 mm, broadly ovate, mostly more than 0.7 times as wide as long. Antheridial leaves densely imbricate, ochre. Spores 24–28 μm. Capsules rare, summer. Ditches, marshes, basic seepages and in-filling lakes. 0–400 m. Occasional to frequent in high-rainfall parts of western Britain from N. Wales northwards; very rare in eastern Scotland and S. W. Ireland, an old record from Armagh. 21, H3. GB44 + 9∗ , IR2 + 1∗ . Suboceanic Boreal-montane. W. and C. Europe north to Iceland, Azores, eastern North America, Central America, Cuba. In the field it resembles S. papillosum, but can with experience usually be recognised by the combination of smaller size, stronger colour and more tapering branches. For further information see M. O. Hill, J. Bryol. 15, 109–15, 1988.

3 S. papillosum Lindb., Acta Soc. Sci. Fenn., 1872 (Fig. 3) Dioicous. Shoots to 20 cm long, green, yellowish or ochre, forming hummocks or loose tussocks. Stems 0.7–1.0 mm diameter; cortex 3–4 layers; pores on outer surface 1–5(−6) per cell; cylinder green or brown. Branches (3−)4 per fascicle, (1−)2 divergent, (1−)2 pendent. Stem leaves 1.1–1.8 × 0.8–1.4 mm, obovate, lingulate or ± rectangular; cells near middle of leaf 50–100% septate, or rarely not septate. Branch leaves 1.5–2.5 × 1.3–1.9 mm, concave, broadly ovate, apices cucullate, wide and rounded; lamina in mid-leaf 27–48 μm thick in middle of hyalocysts, (16−)20–32 μm thick where these abut on chlorocysts; internal walls of hyalocysts where these abut on chlorocysts papillose; chlorocysts in section reaching surface on both sides of leaf, either barrel-shaped and moderately exposed on adaxial face or lens-shaped with a negligible exposure on adaxial face; abaxial pores in midleaf 13–22 μm, 3–10 per cell; adaxial pores absent in mid-leaf. Antheridial leaves densely imbricate, ochre. Spores 27–30 μm. Capsules occasional, summer. n = 19, 38 + 4 m∗ . On moors and bogs, mainly in strongly acid localities, but sometimes in acidic fens. 0–1050 m. Abundant in the north and west, local in the southeast. 99, H40. GB908 + 64∗ , IR241 + 14∗ . European Boreo-temperate. Suboceanic, discontinuously circumboreal, extending south to India and the Carolinas. Generally easy to recognise, with a characteristic ochre colour and stubby branches. Partially shaded forms strongly resemble S. palustre, and cannot always be distinguished from it in the field. Well grown plants of S. palustre differ from S. papillosum in having 3–4 pendent branches per fascicle; but the compact forms that are most likely to be confused with

Section Sphagnum

51

Fig. 3 1–5, Sphagnum papillosum: 1, divergent branch leaves; 2, stem leaf; 3, 4, cells at middle of divergent branch leaf, abaxial and adaxial side; 5, divergent branch leaf section. 6–8, S. palustre var. centrale: 6, 7, cells at middle of divergent branch leaf, adaxial and abaxial side; 8, divergent branch leaf section. Leaves ×27, cells ×280.

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1 Sphagnaceae

S. papillosum have only (1−)2 pendent branches, so the difference is not much use in practice. Compact forms of both species superficially resemble S. compactum, but differ in the much larger stem leaves and more cucullate branch leaves. For differences from S. affine see notes under that species. Weakly papillose forms are rare but can be confusing; in these the papillae are ± obsolete except near the margins in the lower part of the leaf.

4 S. palustre L., Sp. Pl., 1753 Dioicous. Shoots to 25 cm long, variously green, pinkish orange or slightly yellowish, forming whitish or green tussocks or untidy ‘lawns’. Stems 0.6–1.2 mm diameter; cortex 3–4 layers; pores on outer surface 1–8(−10) per cell; cylinder green or brown. Branches (3−)4–6(−7) per fascicle, 2(−3) divergent, (1−)2–4 pendent. Stem leaves 1.2–2.0 × 0.9–1.4 mm, obovate, lingulate or ± rectangular; cells not septate, or rarely a few septate near middle of leaf. Branch leaves 1.7– 2.8 × 1.1–1.8 mm, concave, ovate or broadly ovate, the apex cucullate, normally wide and rounded, but in shade forms narrower, ± acute and somewhat squarrose (though the extreme tip is always cucullate); lamina in mid-leaf 30–50 μm thick in middle of hyalocysts, 19–30 μm thick where these abut on chlorocysts; internal walls of hyalocysts lacking papillae or lamellae; chlorocysts reaching surface on both sides of leaf, in section variously triangular or barrel-shaped and exposed on adaxial face or lens-shaped with negligible adaxial exposure; abaxial pores in mid-leaf variable, 8–25 μm, 3–16 per cell; adaxial pores in mid-leaf absent or very few. Antheridial leaves densely imbricate, bright pinkish-orange in autumn and winter, changing to yellowish in summer. Spores 26–32 μm. Capsules occasional, summer. Chlorocysts in section triangular, with straight sides Chlorocysts in section barrel- or lens-shaped, with bulging sides Var. palustre S. cymbifolium Hedw.

var. palustre var. centrale (Fig. 4)

Chlorocysts of branch leaves in section narrowly triangular, with straight sides and cell walls unthickened on adaxial leaf surface. n = 38, 38 + 4 m∗ . Mesotrophic marshes, streamsides and wet woodland. 0–1000 m. Abundant in the north and west, frequent in the south-east. 111, H35, C. GB1180 + 83∗ , IR189 + 4∗ , C1. Circumpolar Boreo-temperate. Suboceanic, discontinuously circumpolar, mainly in the southern boreal and northern broad-leaved forest zones, extending south to the Himalayas, Azores, Algeria, Mexico. Var. centrale (C. E. O. Jensen) A. Eddy in Daniels & Eddy, Handb. Eur. Sphagna, 1985 (Fig. 3) S. centrale C. E. O. Jensen, S. subbicolor auct. non Hampe Chlorocysts of branch leaves in section barrel- or lens-shaped, with bulging sides and cell walls thickened on adaxial surface. n = c. 38. Scattered localities in

Section Sphagnum

53

Fig. 4 Sphagnum palustre var. palustre: 1, moist fascicle with dehisced capsules (×1.5); 2, divergent branch leaves); 3, stem leaf; 4, 5, cells at middle of divergent branch leaf, abaxial and adaxial side; 6, margin of divergent branch leaf near apex showing resorption of cells; 7, marginal cells at widest part of stem leaf; 8, divergent branch leaf section; 9, stem cortex, surface view; 10, divergent branch cortex, surface view; 11, stem section. Leaves ×27, leaf cells ×280, cortex cells ×110.

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England, Wales and the Isle of Man, distribution very poorly known, Caernarfon, old records from W. Lancashire, N. E. Yorkshire, I. of Man. 4. Circumpolar, mainly in the boreal zone, with a subcontinental distribution in Europe. In the field Sphagnum palustre can be confused with S. denticulatum, S. compactum and S. squarrosum; but the members of Section Sphagnum are distinct not only in the cucullate apex of the branch leaves, but also in the wide hyaline cortex, occupying 1/3 –1/2 the diameter of the stem (pull stem in half to see this). The field distinction between S. papillosum and S. palustre can be difficult, though with experience most plants can be named correctly. The branches of S. palustre are more tapering, its colour is more commonly green, and the branches at the centre of the capitulum are commonly pinkishorange, not ochre as in S. papillosum. For differences from S. magellanicum see under that species. Var. centrale, as it occurs in Britain, appears to be little more than an uncommon morph with no correlated characters. One of the Isle of Man specimens has capsules. Intermediates, with chlorocysts of both types in a single leaf, are sometimes found. Var. centrale is the common form in more northern and continental areas. The majority of authors both in Europe and North America treat it as a species.

5 S. magellanicum Brid., Muscol. Recent. II, 1798 S. medium Limpr.

(Fig. 5)

Dioicous. Shoots to 20 cm long, dull crimson or occasionally green, forming tussocks or loose carpets. Stems 0.7–1.1 mm diameter, cortex 3–4 layers; pores on outer surface (0−)1(−3) per cell; cylinder blackish-red. Branches 3–5 per fascicle, 2 divergent, 1–3 pendent. Stem leaves 1.4–1.8 × 0.7–1.2 mm, ± rectangular; cells near middle of leaf not septate, or rarely a few septate. Branch leaves 1.7– 2.7 × 1.5–2.0 mm, concave, broadly ovate, the apex wide and rounded, cucullate; thickness of lamina in mid-leaf 30–45 μm in middle of hyalocysts, 27–40 μm at cell junctions; internal walls of hyalocysts without papillae or lamellae; chlorocysts in section lens-shaped, completely enclosed by the hyalocysts and not reaching either face of leaf; abaxial pores in mid-leaf 11–19 μm, (0−)3–6 per cell; adaxial pores in mid-leaf absent or very few. Antheridial leaves densely imbricate, crimson. Spores 26–30 μm. Capsules rare, summer. n = 18 + 3−4 m, 19. On deep-peat bogs and valley bogs, usually mixed with S. papillosum but much less common. 0–1030 m. Throughout the British Isles, but rare in south-east England. 68, H33. GB375 + 35∗ , IR120 + 10∗ . Circumpolar Boreal-montane. Circumpolar, mainly boreal, also C. and S. America to Tierra del Fuego, and scattered elsewhere in the Southern Hemisphere and tropics. The branches are stubby, so that the habit resembles S. papillosum. The dull crimson colour, once known, is unmistakable, but can easily be confused by the inexperienced with the pinkish orange (occasionally brick-red) developed by S. palustre in autumn. S. magellanicum changes colour in weak alkali, turning a mud brown; the colour of S. palustre is hardly altered.

Section Squarrosa

55

Fig. 5 Sphagnum magellanicum: 1, divergent branch leaves; 2, stem leaf; 3, 4, cells at middle of divergent branch leaf, abaxial and adaxial side; 5, divergent branch leaf section. Leaves ×27, cells ×280.

Section 2 Squarrosa (Russow) Schimp., Syn. Musc. Eur. 2, 1876 Plants slender to robust. Stems usually 0.5–1.2 mm diameter; cortex 2–4 layers, hyaline, 30–70 μm wide, cell walls without fibrils; outer surface mostly without pores, or with scattered patches of cells having a single indistinct pore at upper end; diameter of cortical cells measured at right-angles to radius, 15–55 μm; cylinder strongly differentiated from cortex. Branches in fascicles of 4–6(−7), 2–3 (−4) divergent, 2–3(−4) pendent; branch cortex with 0–1 pores per cell, the cells dimorphic (dimorphism often weak in divergent branches), cell walls without spiral fibrils; retort cells flat or with an indistinct neck, in groups of 1–4(−6). Stem leaves hanging, spreading or erect, usually 1.2–2.0 × 0.8–1.3 mm, lingulate; border 2–6 cells wide, ceasing below rounded region of apex where marginal cells are resorbed and fimbriate; patches of narrow cells at basal angles absent; hyalocysts hardly septate except near basal angles, lacking fibrils, or rarely with weak

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fibrils near basal angles; abaxial surface almost completely resorbed, lacking or (less often) very thin; adaxial surface ± intact. Branch leaves ovate or broadly ovate, not cucullate, usually 1.0–3.1 × 0.5–1.8 mm, with an intact border of 1–3 narrow cells; chlorocysts ± trapezoid in section, more exposed on abaxial than adaxial surface; hyalocysts near apex longer than broad, their abaxial surface often with a pore at distal angle but not lacunose; abaxial pores in mid-leaf 12–40 μm, (0−)1–12(−16) per cell, not normally in triplets at cell angles, sometimes centrally placed and coalescing into large membrane gaps; adaxial pores mostly along commissures, 0–11(−15) per cell in mid-leaf, more numerous towards margins, near apex commonly in triplets, one at each corner of 3 adjacent hyalocysts. Antheridia on divergent branches. Perichaetial leaves oblong or cuneate; border 1–2 cells wide, intact in lower half of leaf, ± resorbed in upper half and absent at apex. Hyalocysts lacking fibrils and pores; abaxial surface extensively resorbed, thin or lacking throughout leaf; adaxial surface ± intact.

Key to Sphagnum Section Squarrosa 1 Robust green or slightly brownish plants; stems 0.7–1.2 mm diameter; branch leaves usually squarrose, 1.7–3.1 × 1.0–1.8 mm 6. S. squarrosum Plants slender or medium-sized, greenish yellow or brown, rarely completely green; stems 0.5–0.7 mm diameter; branch leaves ± appressed, rarely squarrose, 1.0–2.3 × 0.5–1.2 mm 7. S. teres 6 S. squarrosum Crome, Samml. Deutschl. Laubm., 1803 (Fig. 6) Autoicous. Shoots to 20 cm long, green or somewhat brownish, with mediumsized terminal buds, forming untidy ‘lawns’. Stems 0.7–1.2 mm diameter; cortex 2–4 layers; outer surface without pores, or with pores in a few scattered patches of cells; cylinder green or brown. Branches 4–6(−7) per fascicle, 2–3(−4) divergent, 2–3(−4) pendent; retort cells in groups of 1–6, often weakly differentiated from other cells on divergent branches. Stem leaves erect, spreading or hanging, 1.7–2.0 × 0.8–1.3 mm, lingulate; border 2–6 cells wide, ceasing below rounded region of apex, patches of narrow cells at basal angles absent or rarely to about 8 cells wide; hyalocysts near basal angles often septate, above not, or hardly septate; abaxial surface lacking or very thin; adaxial surface intact, without fibrils or pores. Branch leaves 1.7–3.1 × 1.0–1.8 mm, ovate or broadly ovate, apices normally bent back sharply in mid-leaf so that leaf is strongly squarrose; border 1–3 cells wide; chlorocysts in section ± trapezoid with bulging sides, the greater exposure being on the abaxial surface; interior walls of hyalocysts where they abut on chlorocysts obscurely papillose; abaxial pores in mid-leaf variable, 13–50 μm, (0−)1– 12(−16) per cell, perforate or imperforate, centrally placed or along commissures; adaxial pores in mid-leaf imperforate, 12–25 μm, 0–11(−15) per cell. Antheridial leaves not markedly squarrose, green or slightly yellowish. Perichaetial leaves with the characters of the Section, cuneate, with truncate or retuse apex. Spores 27–30 μm. Capsules common, summer. n = 19 + 2 m, 19 + 4 m, 38 + 4 m∗ .

Section Squarrosa

57

Fig. 6 1–6, Sphagnum squarrosum: 1, moist fascicle; 2, divergent branch leaves; 3, stem leaf; 4, 5, cells at middle of divergent branch leaf, adaxial and abaxial side; 6, divergent branch leaf section. 7–12, S. teres: 7, moist fascicle; 8, divergent branch leaves; 9, stem leaves; 10, 11, cells at middle of divergent branch leaf, abaxial and adaxial side; 12, divergent branch leaf section. Fascicles ×1.5, leaves ×27, cells ×280.

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Among rushes and other large higher plants, sometimes abundant in swampy woodland or on swampy ground by lakes, or in smaller quantity in upland flushes, confined to markedly eutrophic situations. Mainly lowland but occasional in the mountains and ascending to 1030 m in W. Inverness. Frequent to common throughout the British Isles. 103, H34. GB610 + 78∗ , IR54 + 14∗ . Circumpolar Wideboreal. Circumpolar, arctic, boreal and cool temperate. With its robust habit, green colour and strongly squarrose branch leaves S. squarrosum is usually easy to recognise in the field. It can resemble shade forms of S. palustre but differs in the relatively narrow stem cortex (occupying 1/4 of the diameter of the stem, as opposed to nearly half in S. palustre). S. compactum occasionally has squarrose branch leaves but differs in its small stem leaves. For distinction from S. teres see under that species.

7 S. teres (Schimp.) Ångstr. in Hartm., Skand. Fl., 1861 S. squarrosum var. teres Schimp.

(Fig. 6)

Dioicous. Shoots to 20 cm long, green, yellowish or brown, with large terminal buds, forming ‘lawns’ and loose tufts. Stems 0.5–0.7 mm diameter; cortex 2–4 layers; outer surface with indistinct pores in scattered patches of cells; cylinder brown. Branches 4–5(−7) per fascicle, usually 3 divergent, 2 pendent; retort cells in groups of 1–2(−5). Stem leaves erect, spreading or hanging, 1.2–2.0 × 0.8– 1.1 mm, lingulate; border 2–5 cells wide, ceasing below rounded region of apex; patches of narrow cells at basal angles absent; hyalocysts near basal angles often septate, above not or hardly septate; abaxial surface lacking or very thin; adaxial surface intact, without fibrils or pores. Branch leaves 1.0–2.3 × 0.5–1.2 mm, ovate, not or only slightly squarrose, or in shade forms sometimes strongly squarrose; border 1–3 cells wide; chlorocysts in section trapezoid with the greater exposure on the abaxial surface; interior walls of hyalocysts where they abut on chlorocysts sometimes finely papillose; abaxial pores in mid-leaf 12–40 μm, 3–8 per cell, often centrally placed and coalescing into ± extensive membrane gaps; adaxial pores in mid-leaf imperforate, 12–25 μm, 1–7 per cell, or sometimes absent (though numerous near margins). Antheridial leaves greenish. Perichaetial leaves with the characters of the Section, oblong with a retuse apex. Spores 24–26 μm. Capsules rare, summer. n = 19 + 4 m, 19 + 5 m. Among rushes and small sedges, indicative of base-rich flushing. 0–1050 m. Throughout the British Isles; rare in the lowlands, frequent to common in the uplands. 66, H7. GB251 + 51∗ , IR8 + 3∗ . Circumpolar Boreo-arctic Montane. Circumpolar, mainly arctic and boreal, extending south in mountains to Italy and California. Can normally be recognised in the field by its rather rigid branches, with leaves slightly bent backwards in mid-leaf, the yellowish or brown colour, and large terminal buds. It can have a strong superficial resemblance to S. girgensohnii, but differs when well illuminated in its dark brown stems and in normally having 3+2 branches per fascicle. Robust greenish forms can be exceedingly hard to separate from S. squarrosum. The best policy is to make a careful search in the field to find typical S. teres or S. squarrosum in the immediate vicinity.

Section Acutifolia

59

There is no reliable microscopic distinction, and differences given by various authors break down when applied to the apparently intermediate forms. It should be appreciated, however, that these forms are unusual, and that S. teres normally looks so different from S. squarrosum that their close relationship is not apparent without microscopic examination.

Section 3 Acutifolia Wilson, Bryol. Brit., 1855 Plants slender to medium-sized, with red or brown pigments. Stems usually 0.3– 0.9 mm diameter; cortex 2–4 layers, hyaline, 40–200 μm wide, cell walls without fibrils; outer surface without pores or with 1(−2) pores per cell, diameter of cortical cells measured at right-angles to radius, 20–85 μm; cylinder strongly differentiated from cortex. Branches in fascicles of 3–5(−6), 2–3 divergent, (0−)1–2(−3) pendent; branch cortex with clearly dimorphic cells, cell walls without spiral fibrils; retort cells with a moderate to strong neck, in groups of 1(−2), except in S. molle. Stem leaves erect, or in compact forms spreading, usually 0.8–1.7 × 0.5–1.2 mm (larger in the nearly isophyllous S. molle), spathulate, triangular or lingulate; border 2–9 cells wide, entire or denticulate (± lacking in S. fimbriatum); patches of narrow cells at basal angles occupying (0−)20–80% of leaf base; hyalocysts in upper leaf (0−)20–100% septate, with or without fibrils, extensively resorbed on adaxial surface, abaxial surface in most species ± intact. Branch leaves ovate or narrowly ovate, not cucullate, usually 0.8–2.7 × 0.4–1.8 mm; border 1–3(−4) cells wide, intact (except S. molle); chlorocysts triangular in section, broadly exposed on adaxial surface; hyalocysts near apex longer than broad, not lacunose; abaxial pores in mid-leaf 8–30(−55) μm, 1–16 per cell, towards leaf apex often in triplets, one at each corner of 3 adjacent hyalocysts; adaxial pores in mid-leaf often absent, when present centrally placed, 10–20 μm, to 5 per cell, more numerous towards margins. Antheridia on divergent branches. Perichaetial leaves ovate or oblong; border intact to apex; hyalocysts intact on both surfaces, lacking fibrils and pores (except sometimes S. molle).

Key to Sphagnum Section Acutifolia 1 Branch leaves denticulate at margin in upper half owing to resorption of cell walls in border; stem leaves strongly fibrillose, 1.5–2.8 mm long 17. S. molle Branch leaves with intact border; stem leaves to 1.4 mm long, or if longer then lacking fibrils 2 2 Stem leaves triangular or triangular-lingulate, margin plane or inrolled at apex 3 Stem leaves lingulate or spathulate, margin ± plane at apex 6 3 Fascicles mainly with 4–5 branches, some or most with 3 divergent branches; stem cylinder predominantly green with at most a few red flecks, invariably green in plants whose leaves are green; stem cortex with scattered pores (use stain); leaves on divergent branches normally 5-ranked 11. S. quinquefarium

60

4

5

6

7

8

9

10

1 Sphagnaceae Fascicles mainly with 3–4 branches, rarely with more than 2 divergent branches; stem cylinder usually with red or brown pigment, even in plants whose leaves are green; stem cortex without pores, or if with pores then branch leaves not 5-ranked 4 Stem leaves without fibrils or fibrils weak, apices acute with inrolled leaf margins; branch leaves (0.9−)1.2–2.7 mm long 5 Stem leaves with conspicuous fibrils, or if not then apices ± plane; branch leaves (0.6−)0.9–1.4 mm long 10 Fascicles with 3(−4) branches, none or very few having more than 1 pendent branch; stem leaves mostly less than 0.6 times as wide as long, cells in upper part 80–100% septate, many divided more than once; stem cortex lacking pores 15. S. subnitens Fascicles with 3–4 branches, many with 2 pendent branches; stem leaves mostly more than 0.6 times as wide as long, cells less septate, few divided more than once; stem cortex with scattered pores 16. S. skyense Brown plants with dark brown stems 14. S. fuscum Plants green or red, with pale or reddish stems, or if plants slightly brownish, then stems pale 7 Green or slightly brownish plants with no trace of red pigment; stem leaves lacking fibrils, often extensively fimbriate near apex, equally resorbed on both surfaces so that when stained extensive gaps are visible both near apex and at base 8 Red pigment often present; stem leaves with or without fibrils, not or only slightly fimbriate near apex, with extensive resorption only on adaxial surface and hence not showing gaps when stained 9 Stem leaves spathulate, widest above base, border lacking or if present ceasing at or below middle of leaf 8. S. fimbriatum Stem leaves lingulate, widest at base, border continued to near apex 9. S. girgensohnii Stem leaves lingulate with broad rounded apices; many cells in middle part of branch leaves having more than 8 abaxial pores; surface of stem cortex with scattered pores (use stain) 10. S. russowii Stem leaves various, sometimes lingulate with broad rounded apices; cells in middle part of branch leaves with 3–7 abaxial pores, rarely a few cells with up to 9 pores; stem cortex without pores 10 Pores on abaxial side of branch leaves near apex small, 2–6(−8) μm, each bordered by a thick ring and appearing round in surface view of cell; stem leaves without fibrils or fibrils weak 12. S. warnstorfii Pores larger, (5−)8–13 μm, not normally with thick rings, mostly flattened against margins of cells and appearing semicircular in surface view; fibrils of stem leaves usually conspicuous, occasionally weak or absent 13. S. capillifolium

Section Acutifolia

61

8 S. fimbriatum Wilson in J. D. Hook. & Wilson, Fl. Antarct., 1846 (Fig. 7) Autoicous. Shoots to 20 cm long, green, with large terminal buds, forming extensive ‘lawns’ or discrete tussocks. Stems 0.4–0.9 mm diameter; cortex 2–3 layers, pores present in 40–100% of cells on outer surface, 1(−2) per cell, round; cylinder green. Branches 3–4(−5) per fascicle, 2(−3) divergent, 1–2 pendent. Stem leaves 0.8–1.3 × 0.8–1.2 mm, spathulate, erect and appressed to stem; margin plane, fimbriate round most of upper leaf; border absent, or else 2–4 cells wide, ceasing below mid-leaf; patches of narrow cells at basal angles not pigmented, occupying 30–60% of leaf base; hyalocysts lacking fibrils and pores, extensively resorbed on both surfaces; upper cells 20–90% septate, grossly distorted in consequence of leaf margin having grown more than middle. Branch leaves 0.8–2.0 × 0.4–1.2 mm, ovate, not 5-ranked; border 1–3 cells wide; chlorocysts in section narrowly trapezoid, reaching both surfaces, with the greater exposure on the adaxial face; abaxial pores 10–20 μm, 5–13 per cell, near leaf base larger, often coalescing into extensive membrane gaps; adaxial pores 11–16 μm, 2–5 per cell, or sometimes absent in mid-leaf though always present near apex. Antheridial leaves green or yellowish-brown. Perichaetial leaves ± rectangular; border intact to apex; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 25–28 μm. Capsules common, summer.

Fig. 7 Sphagnum fimbriatum: 1, stem leaf (hatching indicates extent of narrow cells); 2, divergent branch leaves; 3, stem leaf cells 2/3 from base, abaxial side; 4, 5, cells at middle of divergent branch leaf, adaxial and abaxial side; 6, divergent branch leaf section. Leaves ×27, cells ×280.

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1 Sphagnaceae

n = 19, 19 + 4 m, 38 + 4 m∗ . Among Betula and Molinia in damp woodland, or on moors, banks, streamsides and degenerating bogs. 0–350 m. Frequent to common throughout the British Isles. 103, H24. GB664 + 52∗ , IR36 + 8∗ . Circumpolar Wideboreale. Arctic and cool temperate regions of the world in both hemispheres. Readily identified in the field by pulling off the top of the capitulum. The spathulate stem leaves appear as a conspicuous ‘ruff’ at the top of the decapitated stems. The large terminal buds are also a useful field character.

9 S. girgensohnii Russow, Arch. Naturk. Liv- Ehst- Kurlands, Ser. 2, 1865 (Fig. 8) Dioicous. Shoots to 20 cm long, green or faintly brownish, with medium-sized terminal buds, forming loose tussocks or ‘lawns’. Stems 0.5–0.8 mm diameter; cortex 2–3(−4) layers, pores present in 60–100% of cells on outer surface, 1(−2) per cell, round or transversely elliptical; cylinder green or pale brown. Branches 3–4(−5) per fascicle, 2(−3) divergent, 1–2 pendent. Stem leaves 0.8–1.3 × 0.6–0.9 mm, lingulate, erect and appressed to stem; apices plane, truncate and fimbriate or sometimes entire and rounded; border 2–5 cells wide, intact to near apex; patches

Fig. 8 Sphagnum girgensohnii: 1, stem leaves (hatching indicates extent of narrow cells); 2, divergent branch leaves; 3, stem cortex, surface view; 4, stem leaf cells 2/3 from base, abaxial side; 5, 6, cells at middle of divergent branch leaf, adaxial and abaxial side; 7, divergent branch leaf section. Leaves ×27, cells ×280.

Section Acutifolia

63

of narrow cells at basal angles usually with brown pigment, occupying 40–70% of leaf base; hyalocysts lacking fibrils and pores, equally and extensively resorbed on both surfaces; upper cells not, or hardly septate, some usually distorted by margin of leaf having grown more than middle. Branch leaves 1.1–1.6 × 0.5– 0.8 mm, ovate, not 5-ranked; margins strongly inrolled above so that the apex forms a snout which is slightly but distinctly bent backwards; border 1–2 cells wide; chlorocysts in section narrowly trapezoid, reaching both surfaces with the greater exposure on adaxial face; abaxial pores 8–16 μm, 4–15 per cell; adaxial pores 10– 15 μm, 3–5 per cell, or sometimes absent in mid-leaf though always present near apex. Antheridial leaves yellowish-brown. Perichaetial leaves oblong; border intact; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 22–25 μm. Capsules rare, summer. n = 19 + 4 m. On ditch sides, damp grassy banks and in mesotrophic marshes. 0–1000 m. Frequent to common in Wales, N. England and Scotland; rare in Ireland and southern England. 85, H9. GB373 + 31∗ , IR8 + 6∗ . Circumpolar Boreo-arctic Montane. Circumpolar, mainly boreal. Distinguished from S. fimbriatum in the field by the stem leaves widest at the base and fimbriate only at the apex, and by the often conspicuous brown pigmentation at their basal angles. The branches are stiffer and more rigid, and the snout-like apex of the branch leaves is usually more pronounced. S. girgensohnii can also resemble both S. teres and S. russowii (q.v. for differences), but the stem leaves are normally more torn than in either of those species.

10 S. russowii Warnst., Hedwigia, 1886 ¨ S. girgensohnii var. robustum (Russow) Dixon, S. robustum Roll

(Fig. 9)

Dioicous. Shoots to 20 cm long, variously crimson, variegated crimson and green, or green flecked with pink, rarely without any trace of red pigment, lacking enlarged terminal buds, forming loose tussocks. Stems 0.5–0.8 mm diameter; cortex 2–4 layers, pores present in 5–50(−100)% of cells on outer surface, 1 per cell, round, transversely elliptical or semicircular; cylinder green or red. Branches 3–4 per fascicle, 2 divergent, 1–2 pendent. Stem leaves erect and appressed to stem, 1.1–1.4 × 0.6–0.9 mm, lingulate; apex plane, usually rounded and ± entire, occasionally truncate and fimbriate because of resorption; border 3–5 cells wide, intact; patches of narrow cells at basal angles usually with red pigment, occupying 40–70% of leaf base; hyalocysts in upper leaf 0–50% septate, usually with obscure fibrils; abaxial surface ± intact, mostly with small longitudinal folds (membrane pleats); adaxial surface extensively resorbed and lacking; abaxial pores absent, or sometimes 1 per cell, 10–15 μm. Branch leaves 1.1–1.8 × 0.5–0.9 mm, ovate, varying from strongly 5-ranked to not at all 5-ranked, apices variable, sometimes appressed to branch, in others snout-like and slightly recurved when dry; border 1–3 cells wide; chlorocysts in section ± triangular, reaching both surfaces, broadly exposed on adaxial face; abaxial pores 9–18 μm, 7–13 per cell; adaxial pores often absent in mid-leaf, when present to 4 per cell, 8–16 μm (there are usually some

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Fig. 9 Sphagnum russowii: 1, stem leaves (hatching indicates extent of narrow cells); 2, divergent branch leaves; 3, stem cortex, surface view; 4, stem leaf cells 2/3 from base, abaxial side; 5, cells at middle of divergent branch leaf, abaxial side; 6, divergent branch leaf section. Leaves ×27, cells ×280.

adaxial pores near leaf apex). Antheridial leaves bright crimson, conspicuous. Perichaetial leaves oblong, obtuse; border intact to apex; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 24–27 μm. Capsules rare, summer. n = 38 + 8 m, 42. In marshes and on wet rocky ground, sometimes also on well drained banks with S. quinquefarium. 0–1200 m. Frequent to common from Wales northwards, especially at higher altitudes; rare in Ireland and southern England. 52, H13. GB217 + 24∗ , IR13 + 6∗ . Circumpolar Boreo-arctic Montane. Circumpolar, mainly boreal. Often hard to distinguish from S. capillifolium in the field, though normally more robust and with relatively broader branch leaves. Microscopically, S. russowii is distinguished by pores in the stem cortex, membrane pleats in the stem leaves and more numerous pores in the branch leaves. Green forms are occasionally hard to separate from S. girgensohnii. Usually they are distinct in the weakly fibrillose stem leaves. When stained, the different pattern of abaxial and adaxial resorption provides a definite structural difference.

Section Acutifolia

65

An allied species, S. rubiginosum Flatberg, is frequent in central Norway and might well occur in Scotland. It is autoicous and reddish, with stem leaves resembling those of S. girgensohnii; most fascicles have 3 divergent branches.

11 S. quinquefarium (Lindb. ex Braithw.) Warnst., Hedwigia, 1886 S. acutifolium var. quinquefarium Lindb. ex Braithw.

(Fig. 10)

Autoicous. Shoots to 20 cm long, green or pink, forming loose tussocks. Stems 0.4– 0.8 mm diameter; cortex 2–3 layers; pores present on outer surface, 1 per cell in 10–30% of cells, semicircular or occasionally round; cylinder green, or in plants whose leaves are pink, sometimes with a few red flecks. Branches (3−)4–5(−6) per fascicle, 2–3 divergent, 1–2(3) pendent. Stem leaves erect and appressed to stem, 0.9–1.4 × 0.6–0.9 mm, triangular or triangular-lingulate; apex rounded or acute, plane or somewhat inrolled; border 3–7 cells wide, entire; patches of narrow

Fig. 10 Sphagnum quinquefarium: 1, moist fascicle (×3); 2, stem leaves (hatching indicates extent of narrow cells); 3, divergent branch leaves; 4, stem leaf cells 2/3 from base, abaxial side; 5, cells at middle of divergent branch leaf, abaxial side; 6, divergent branch leaf section. Leaves ×27, cells ×280.

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cells at basal angles occupying 20–70% of leaf base; hyalocysts in upper leaf 30– 100% septate, weakly fibrillose or with fibrils absent; abaxial surface intact; adaxial surface extensively resorbed and lacking; abaxial pores normally absent, occasionally to 2 per cell, 15–25 μm. Branch leaves 0.8–1.6 × 0.4–0.6 mm, ovate or narrowly ovate, often strongly 5-ranked; chlorocysts in section triangular, broadly exposed on adaxial face; abaxial pores 11–22 μm, 4–7 per cell; adaxial pores absent. Antheridial leaves conspicuous, crimson or bright pink. Perichaetial leaves ovate; border intact; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 22–25 μm. Capsules occasional, summer or autumn. n = 19 + 2 m. On well drained sheltered banks and in steeply sloping acid woodland, avoiding waterlogged ground. 0–550 m. Frequent to common in the north and west, absent from central Ireland and from the Midlands and south-east of England. 58, H19. GB314 + 23∗ , IR38 + 8∗ . Suboceanic Boreal-montane. C. and W. Europe, chiefly in mountains and southern parts of the boreal zone, Transcaucasia, Japan, eastern and western N. America. Can be confused with S. capillifolium and S. subnitens. For differences see key. In the field, green forms can be confused with S. recurvum agg. (species 30–32). The erect stem leaves are a good macroscopic character separating it from members of Section Cuspidata. All fruiting plants examined were autoicous, but non-fruiting material is often apparently male.

12 S. warnstorfii Russow, Sitzungsber. Dorpater Naturf.-Ges., 1887 S. acutifolium var. gracile Russow, S. warnstorfianum Du Rietz

(Fig. 11)

Dioicous. Shoots to 15 cm long, variously crimson, rose-pink or green flecked with pink, forming loose carpets. Stems 0.4–0.5 mm diameter; cortex 2–3 layers, lacking pores on outer surface; cylinder red or green. Branches 3–4 per fascicle, 2 divergent, 1–2 pendent. Stem leaves erect and appressed to stem, 0.9– 1.3 × 0.5–0.8 mm, lingulate or triangular-lingulate; apices plane and rounded; border 3–7 cells wide, entire; patches of narrow cells at basal angles occupying 50–70% of leaf base; hyalocysts in upper leaf 30–100% septate, without fibrils or sometimes weakly fibrillose; abaxial surface intact; adaxial surface extensively resorbed and lacking; pores absent. Branch leaves 0.6–1.4 × 0.3–0.7 mm, ovate or narrowly ovate, usually strongly 5-ranked; border 1–4 cells wide; chlorocysts in section triangular, reaching both surfaces, broadly exposed on adaxial face; abaxial pores in mid-leaf 8–16 μm, 3–6 per cell, near leaf apex 2–6(−8) μm, (1−)2–6 per cell, thick-ringed, round, sometimes dimorphic with the pore at distal angle of cell then 6–8 μm when the lateral ones are 2–5 μm; adaxial pores absent in mid-leaf, above variably present or absent, 2–5 μm, to 4 per cell. Antheridial leaves conspicuous, crimson or bright pink. Perichaetial leaves as in S. capillifolium. Capsules unknown in Britain or Ireland. n = 19 + m. In base-rich flushes, frequent in upland areas with sufficiently base-rich water. 0–950 m but mainly above 400 m, descending to sea level in the west. N. Wales, N. England and

Section Acutifolia

67

Fig. 11 1–5, Sphagnum fuscum: 1, stem leaves (hatching indicates extent of narrow cells); 2, divergent branch leaves; 3, stem leaf cells 2/3 from base, abaxial side; 4, cells at middle of divergent branch leaf, abaxial side; 5, divergent branch leaf section. 6–12, S. warnstorfii: 6, stem leaves (hatching indicates extent of narrow cells); 7, divergent branch leaves; 8, divergent branch leaf cells near apex, abaxial side; 9, divergent branch leaf section; 10, stem leaf cells 2/3 from base, adaxial side; 11, cells at middle of divergent branch leaf, abaxial side. Leaves ×27, cells ×280.

Scotland; rare in Ireland. 31, H3. GB148 + 19∗ , IR2 + 2 m∗ . Circumpolar Boreo-arctic Montane. Circumpolar, arctic and boreal. Closely resembling S. capillifolium, both anatomically and in the field. It often grows with S. contortum and S. teres, and may be easier to recognise because of these associates than by its appearance. The branch leaves of S. warnstorfii are usually more markedly 5-ranked with narrower apices than those of S. capillifolium, but these characters are not constant and, occasionally intermediate plants can be found.

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13 S. capillifolium (Ehrh.) Hedw., Fund. Musc., 1782 Autoicous or dioicous. Shoots to 15 cm long, variously crimson, rose pink or green flecked with pink, forming hummocks, tussocks or loose carpets. Stems 0.4–0.6 mm diameter; cortex 2–4 layers, lacking pores on outer surface; cylinder red or green. Branches 3–4(−5) per fascicle, 2(−3) divergent, 1–2 pendent. Stem leaves erect and appressed to stem, or in compact forms sometimes spreading, 0.9– 1.4 × 0.5–0.9 mm, widest at base, lingulate or triangular-lingulate, rarely triangular; apices varying from plane and rounded to acute and somewhat inrolled; border 3–8 cells wide, entire; patches of narrow cells at basal angles occupying 20–70% of leaf base; hyalocysts in upper leaf 30–100% septate, a few often divided more than once, weakly or strongly fibrillose; abaxial surface intact; adaxial surface extensively resorbed and lacking; pores absent or sometimes a few ill-defined abaxial pores present. Branch leaves 0.8–1.4 × 0.4–0.6 mm, ovate or narrowly ovate, 5-ranked or not; chlorocysts in section triangular, broadly exposed on adaxial face; abaxial pores in mid-leaf 8–25 μm, 4–7(−9) per cell, near leaf apex 5–13 (−16) μm, 3–8 per cell, not normally thick-ringed, mostly flattened against commissures except at upper cell angles; adaxial pores absent or very few. Antheridial leaves bright crimson, conspicuous. Perichaetial leaves ovate; border intact; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 24–27 μm. Plants forming often dense tussocks; individual shoots with capitula rounded in outline; stem leaves usually more than 1.2 mm long ssp. capillifolium Habit variable, either in tussocks or forming loose carpets; individual shoots with flat-topped capitula; stem leaves usually less than 1.2 mm long ssp. rubellum Ssp. capillifolium (Fig. 12) S. acutifolium Ehrh. ex Schrad., S. capillaceum (Weiss) Schrank, S. nemoreum auct. non Scop. Autoicous or possibly also dioicous. Forming tussocks and hummocks. Capitula rounded in outline. Pendent branches appressed to stem and ± concealing it. Stem leaves lingulate or triangular-lingulate, 1.1–1.4 mm long, fibrillose in upper half, patches of narrow cells taking up 20–40% of width of leaf. Branch leaves imbricate, not or only slightly 5-ranked. Capsules frequent, summer. n = 19 + 2 m∗ , 19 + 4 m. On moors and blanket bogs. Widespread in upland Britain, generally much less common than ssp. rubellum; its distribution in Britain and Ireland is poorly known, Denbigh, Derby, Mid-West Yorkshire, S. Northumberland, Cumberland. 5. Circumpolar Boreo-temperate. Circumboreal. Ssp. rubellum (Wilson) M. O. Hill in Blockeel & Long, Check-List Cens. Cat. Brit. Irish Bryoph., 1998 (Fig. 12) S. rubellum Wilson, S. capillifolium var. tenellum (Schimp.) Crum Dioicous. Forming tussocks, hummocks or loose carpets. Capitula flattish at top. Pendent branches appressed to stem or not. Stem leaves lingulate, rounded at apex, 0.9–1.2 mm long, weakly fibrillose above, patches of narrow cells taking up

Section Acutifolia

69

Fig. 12 1, Sphagnum capillifolium ssp. capillifolium: 1, capitulum (×3). 2–11, S. capillifolium ssp. rubellum: 2, capitulum (×3); 3, moist fascicle (×3); 4 stem leaves (hatching indicates extent of narrow cells); 5, divergent branch leaves; 6, 7, stem leaf cells 2 /3 from base from different plants, adaxial side; 8, divergent branch leaf cells near apex, adaxial side; 9, cells at middle of divergent branch leaf, abaxial side; 10, stem section; 11, divergent branch leaf section. Leaves ×27, cells ×280.

35–70% of width of leaf. Branch leaves variously imbricate or loosely packed, often markedly 5-ranked. Capsules rare, summer. n = 19, 19 + 2 m∗ , 19 + 4 m. In bogs, marshes, moors and open woodland, avoiding localities that are either very wet or heavily shaded. 0–1040 m. Abundant in the north and west, frequent on bogs in the south and east. 104, H38. GB1018 + 74∗ , IR253 + 15∗ . Circumpolar Boreo-temperate. Circumboreal. Some authors recognise at least four microspecies within S. capillifolium in Britain and Ireland, but the pattern of variation is complex and cannot be summarised tidily in this

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way. The two subspecies are known to intergrade, but are distinguished by numerous correlated characters including their enzyme complements. The habit of ssp. capillifolium, with rounded capitula, in tussocks that are often dense, is the most reliable mark of distinction from ssp. rubellum. Ssp. capillifolium is on average more robust but there is wide overlap in size. Features of the stem leaves can be misleading, because plants that are undoubtedly ssp. rubellum sometimes produce relatively long, fibrillose stem leaves. Ssp. capillifolium is reported to be sometimes dioicous in other parts of its range. British plants with capsules are apparently all autoicous, but many non-fruiting plants could possibly be dioicous.

14 S. fuscum (Schimp.) H. Klinggr., Phys.-ök. Ges. Königsb., 1872 S. acutifolium var. fuscum Schimp.

(Fig. 11)

Dioicous. Shoots to 15 cm long, brown, forming hummocks or occasionally carpets. Stems 0.3–0.5 mm diameter; cortex 3–4 layers, lacking pores on outer surface; cylinder dark brown. Branches 3–4 per fascicle, 2 divergent, 1–2 pendent. Stem leaves erect and appressed to stem, 0.8–1.3 × 0.4–0.7 mm, lingulate or lingulatespathulate, either widest at base or somewhat narrowed in mid-leaf and widest near apex; apices plane and rounded; border 5–9 cells wide, entire; patches of narrow cells at basal angles occupying 40–80% of leaf base; hyalocysts in upper leaf (40−)80–100% septate, sometimes divided more than once, lacking fibrils; abaxial surface intact; adaxial surface extensively resorbed and lacking; pores absent. Branch leaves 0.9–1.3 × 0.3–0.5 mm, ovate or narrowly ovate, not 5-ranked; border 1–2 cells wide; chlorocysts in section triangular, reaching both surfaces, broadly exposed on adaxial face; abaxial pores 12–30 μm, 3–7 per cell; adaxial pores 10– 20 μm, 0(−1) per cell. Antheridial leaves brown, somewhat darker than other leaves. Perichaetial leaves ovate; border intact; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 24–27 μm. Capsules rare, summer. n = 19 + 2 m. In most of Britain and Ireland a rather rare plant of raised bogs; more frequent in N. E. England and E. Scotland, occurring in flushes and on blanket bogs. 0–1000 m but mainly above 400 m. 36, H18. GB184 + 12∗ , IR48 + 7∗ . Circumpolar Boreo-arctic Montane. Circumpolar, mainly in the boreal zone and tundra. Easily recognised in the field, resembling S. capillifolium in habit, but brown. It is sometimes confused with brown forms of S. subnitens, but is at once distinct in the shape of the stem leaves. In most of the characters given above it comes close to S. capillifolium, especially ssp. rubellum, but S. fuscum has markedly bigger pores near the base of the branch leaves (15– 40 μm, as opposed to 8–20(−25) μm), and there is a greater contrast between the size of the cells in the leaf base and those at the apex than in S. capillifolium. In S. fuscum the abaxial pores near the leaf apex are sometimes small, resembling those of S. warnstorfii.

15 S. subnitens Russow & Warnst. in Warnst., Abh. Bot. Ver. Prov. Brandenburg 1888 ¨ S. acutifolium var. subnitens (Russow & Warnst.) Dixon, S. plumulosum Roll Autoicous. Shoots to 20 cm long, variously green, brown, red or pink, with a metallic sheen when dry, forming loose or compact tussocks or greenish ‘lawns’.

Section Acutifolia

71

Stems 0.4–0.7 mm diameter; cortex (2−)3–4 layers lacking pores on outer surface, cylinder usually coppery-brown, sometimes red or green. Branches in fascicles of 3(−4), 2 divergent 1(−2) pendent. Stem leaves erect and appressed to stem, or in compact forms sometimes spreading, 1.1–1.7 × 0.6–1.0 mm, triangular; apex acute, often somewhat cuspidate because of inrolled margins; border 3–7 cells wide, entire; patches of narrow cells at basal angles occupying 20–60% of leaf base; hyalocysts in upper leaf (50−)80–100% septate, often divided more than once, without fibrils or rarely weakly fibrillose; abaxial surface intact; adaxial surface extensively resorbed and lacking; pores absent. Branch leaves (0.9−)1.2– 2.7 × 0.5–1.3 mm, ovate or narrowly ovate, not 5-ranked, or in small plants rarely with weak 5-ranking; chlorocysts in section triangular, broadly exposed on adaxial face; abaxial pores commonly ± invisible without folding leaf because of bulging hyalocysts, 16–30 μm, 4–10 per cell; adaxial pores absent. Antheridial leaves not markedly different in pigmentation from others. Perichaetial leaves ovate; border intact; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 26– 30 μm. Capsules common, summer. Suboceanic Boreo-temperate. Colour various, plants developing red pigment when well illuminated; stem leaves acute with inrolled margins var. subnitens Plants brownish, lacking red pigment; stem leaves subacute to acute, with weakly inrolled margins var. ferrugineum Var. subnitens (Fig. 13) Colour various, plants developing red pigment when well illuminated; stem leaves acute with inrolled margins. This is the common form in Britain and Ireland. On moors, heaths, rocky banks and in woods, avoiding flat acid bogs. 0–800 m. Abundant in the north and west, common in woods and on heaths in the Midlands and south. 108, H39, C. GB1031 + 73∗ , IR254 + 18∗ . Circumpolar, extending south to the Azores; New Zealand (probably introduced). Var. ferrugineum (Flatberg) M. O. Hill in Blockeel & Long, Check-List Cens. Cat. Brit. Irish Bryoph., 1998 ¨ S. subnitens ssp. ferrugineum Flatberg, S. subfulvum auct. hib. non Sjors Colour brownish, plants lacking red pigment; stem leaves subacute to acute, with weakly inrolled margins. Very rare, Stirling, W. Galway, Roscommon, W. Mayo, Antrim. 1, H4. GB1, 1R4. Norway, west Greenland, northern Canada and Alaska, in the boreal zone and low Arctic. The name subnitens refers to the pronounced lustre that the species often has when dry. This can be a useful diagnostic character in the herbarium. Green forms of ditches and damp woods can resemble S. inundatum or S. fallax. S. inundatum has rounded stem leaves, and in S. fallax the stem leaves are hanging. For differences from S. quinquefarium see key. S. capillifolium is normally smaller, with a pronounced concentration of red pigment in the central part of the capitulum. In S. subnitens the centre of the capitulum is seldom redder

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Fig. 13 Sphagnum subnitens var. subnitens: 1, stem leaves (hatching indicates extent of narrow cells); 2, divergent branch leaves; 3, stem leaf cells 2/3 from base, abaxial side; 4, cells at middle of divergent branch leaf, abaxial side; 5, divergent branch leaf section. Leaves ×27, cells ×280. than the surrounding branches, and is often paler. Moreover, S. subnitens often contains some brown pigment, making the red rather dingy. Var. ferrugineum appears to be little more than a brownish morph of typical Sphagnum subnitens. The shape of the stem leaves is not decisive; leaves of similar shape can be found in undoubted var. subnitens. When an Irish specimen of var. ferrugineum was first found, it ¨ This view was challenged by K. I. Flatberg (Lindbergia, was thought to be S. subfulvum Sjors. 11, 38–54, 1985) who demonstrated a complex pattern of variation in the S. subnitens–S. subfulvum group, with the characters that supposedly define S. subfulvum not being as well correlated as had been supposed.

16 S. skyense Flatberg, J. Bryol., 1988 (Fig. 14) Sexuality unknown. Robust, in habit resembling a large form of S. subnitens. Stems pale red, cortex 3–4 cells wide, some cells on outer surface with one ± circular pore. Branches in fascicles of 3–4, 2 divergent. Stem leaves broadly triangular or triangular-lingulate, 1.4–1.8 × 1.0–1.5 mm, acute to subacute, margins ± plane or somewhat inrolled above; patches of narrow cells at basal angles occupying 20– 60% of leaf base; hyalocysts in upper part of leaf either not septate or divided into two, rarely a few divided into 3 or 4. Branch leaves ovate, not or scarcely 5-ranked, 1.5–1.8 × 0.5–0.7 mm. Wet heath. Lowland. Skye. 1. GB1. Endemic (Hyperoceanic Temperate).

Section Acutifolia

73

Fig. 14 Sphagnum skyense: 1, moist fascicle (×4); 2, stem leaves; 3, divergent branch leaves; 4, divergent branch leaf margin near apex, abaxial side; 5, 6, cells at middle of divergent branch leaf, adaxial and abaxial side; 7, divergent branch leaf section. Leaves ×27, cells ×280. A little known plant, found in 1987 in a single locality and not re-found in spite of searching. The best field character to distinguish it from S. subnitens is that many of the fascicles have 2 pendent branches whilst in S. subnitens almost all the fascicles have 1 pendent branch. Microscopically the areolation of both stem and branch leaves is laxer than is usual in S. subnitens. K. I. Flatberg (J. Bryol. 15, 101–7, 1988) suggested that S. skyense might be a hybrid between S. quinquefarium and S. subnitens. He also pointed out the similarity to S. junghuhnianum Dozy & Molk., a mainly Asian species which occurs rarely in the Pacific Northwest of North America. Daniels & Eddy (1990) state that S. skyense and S. junghuhnianum are probably conspecific.

17 S. molle Sull., Musci Allegh., 1845 (Fig. 15) Autoicous. Shoots to 10 cm long, whitish or pink, forming low tussocks. Stems 0.2– 0.5 mm diameter; cortex (1−)2–3 layers, with pores in 10–50% of cells on outer surface; cylinder green or pale brown. Branches 2–3(−4) per fascicle, mostly squeezed together in the tufts and pointing upwards, sometimes 1(−2) pendent; retort cells in groups of (1−)2–5 (mostly solitary in other Section Acutifolia). Stem leaves spreading or erect, 1.5–2.8 × 0.4–1.5 mm, rhomboid, oblong

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Fig. 15 Sphagnum molle: 1, stem leaves; 2, divergent branch leaves; 3, stem leaf cells 2/3 from base, abaxial side; 4, cells at middle of divergent branch leaf, abaxial side; 5, divergent branch leaf margin near apex, abaxial side; 6, divergent branch leaf section. Leaves ×27, cells ×280.

or lingulate; apices acute, plane or with ± inrolled margins; border (1−)2–3 cells wide, denticulate above because of resorption of cell walls along margins; patches of narrow cells at basal angles absent; hyalocysts fibrillose in a zone 40–100% of leaf, 0–40% septate in mid-leaf; abaxial pores ringed, 13–22 μm, 0–8 per cell; adaxial pores large, 15–30 μm, unringed, 0–3 per cell, or sometimes replaced by larger membrane gaps. Branch leaves 1.4–2.3 × 0.5–1.2 mm, ovate, not 5-ranked; border 1–2 cells wide, denticulate at least in upper half because of resorption of outer surface of cells along margin (border is intact in branch leaves in European Section Acutifolia); chlorocysts in section triangular, broadly exposed on adaxial surface, not, or hardly, exposed on abaxial surface; hyalocysts strongly protuberant on abaxial surface; abaxial pores ± invisible without folding leaf because of highly protuberant hyalocysts, 14–22 μm, 6–12 per cell; adaxial pores absent. Antheridial leaves greenish, not different in pigmentation from others. Perichaetial leaves ovate, acuminate; border 3–4 cells wide; hyalocysts lacking fibrils and pores, or a few cells with fibrils and abaxial pores. Spores 28– 32 μm. Capsules common, summer. n = 19, 19 + 2 m, 19 + 4 m. On damp ground

Section Rigida

75

by streams and on heaths. 0–350 m. Throughout the British Isles but rare in most districts except western Scotland. 59, H17. GB129 + 20∗ , IR33 + 2∗ . Suboceanic Temperate. Western Europe eastwards to the Baltic and C. Europe; eastern N. America. In habit resembling S. compactum, but immediately distinct in the large stem leaves, pale stem and traces of pink colouring. Lax forms may resemble S. subnitens, but the large stem leaves and lack of well defined pendent branches will usually separate S. molle. In S. molle the tufts are usually interwoven with ± unbranched julaceous stems, whose cortex has well marked retort cells. This is one aspect of a general lack of differentiation between stems and branches which is manifested also in the leaves.

Section 4 Rigida (Lindb.) Schlieph. ex Limpr., Laubm. Deutschl., 1885 Plants medium-sized. Stems usually 0.4–0.8 mm diameter; cortex 2–3 layers, hyaline, 30–100 μm wide, cell walls without spiral fibrils, those on outer surface each with one ± semicircular pore at upper end; diameter of cortical cells measured at right-angles to radius, 20–70 μm; cylinder strongly differentiated from cortex. Branches in fascicles of 2–7, the 1–3 divergent branches very sharply differentiated from the 1–5 pendent branches; cells of branch cortex each with an apical pore, not dimorphic, lacking spiral fibrils. Stem leaves hanging, usually 0.3–0.7 × 0.4– 0.7 mm, triangular or trapezoid, with a border of 3–8 narrow cells; border intact below, above varying from ± entire to extensively resorbed and tattered; patches of narrow cells at basal angles absent; hyalocysts not, or a few, septate; abaxial surface with or without fibrils; adaxial surface almost completely resorbed, and either lacking or very thin with large pores. Branch leaves varying from oblong and ± cucullate to ovate-acuminate with a squarrose acumen, usually 1.7– 3.0 × 0.8–1.8 mm; apex rounded or broadly truncate; border 1(−3) cells wide, usually completely resorbed and represented only by a resorption furrow (margin appears denticulate owing to projection of transverse cell walls which persist after resorption of border); chlorocysts lens-shaped or elliptical in section, either enclosed by hyalocysts or slightly exposed on abaxial surface; hyalocysts near leaf apex longer than wide (a few at extreme apex ± as wide as long), their abaxial surface sometimes with a pore at distal angle but not lacunose; abaxial pores in mid-leaf 5–25 μm, 0–4(−8) per cell, positioned at cell angles or more generally along commissures (a few large pores are sometimes centrally placed, but these are never the majority); adaxial pores absent in mid-leaf, near apex present or absent, either in triplets at corners of 3 adjacent hyalocysts, or distributed more generally along commissures (in mid-leaf the annular fibrils of adaxial pores may be present but without any marked membrane thinning within them). Antheridia on pendent branches. Perichaetial leaves resembling branch leaves, ovate, acute; border intact, 2–6 cells wide, distinct to apex; hyalocysts not extensively resorbed on either surface, fibrillose and porose in at least the upper half of leaf, often throughout; pores various, commonly present on both surfaces, positioned at cell angles or distributed more generally along commissures.

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Key to Sphagnum Section Rigida Stems greenish or pale brown; branch leaves squarrose, chlorocysts just reaching abaxial surface; abaxial pores in upper half of leaf 1(−6) per cell, 10–25 μm, mostly positioned at distal angles of hyalocysts 18. S. strictum Stems dark brown or black, rarely pale; branch leaves usually ± appressed, occasionally squarrose, chlorocysts completely enclosed on both surfaces; abaxial pores in upper half of leaf few to numerous, (1−)3–10(−12) per cell, 5–12(−16) μm, distributed along commissures and not concentrated on distal angles of hyalocysts 19. S. compactum 18 S. strictum Sull., Musci Allegh., 1845 (Fig. 16) Autoicous. Shoots to 15 cm long, green or brownish, forming small tussocks. Stems 0.5–0.8 mm diameter; cortex 2–3 layers; pores on outer surface one per cell; cylinder green or pale brown. Branches 3–6 per fascicle, 2–3 divergent, 1–3 pendent. Stems leaves hanging, 0.5–0.7 × 0.5–0.6 mm, triangular, apices rounded and ± cucullate; border 4–8 cells wide, near apex denticulate but not fimbriate; patches of narrow cells at basal angles absent; hyalocysts not, or a few, septate, lacking fibrils; abaxial surface intact; adaxial surface ± completely resorbed and lacking. Branch leaves 1.7–2.7 × 0.8–1.5 mm, ovate, with squarrose acumens whose extreme apex is abruptly truncate; border 1 cell wide, denticulate because of resorption; chlorocysts just reaching abaxial surface of leaf, enclosed on adaxial surface, in section lens-shaped, measuring (15−)17–27 μm along long axis; interior walls of hyalocysts where they abut on chlorocysts obscurely papillose; abaxial pores in mid-leaf often absent, when present 10–25 μm, mostly one per cell at distal angle, sometimes more numerous, especially near leaf apex; adaxial pores normally absent in mid-leaf, near apex occurring in triplets, one at the corner of each of 3 adjacent hyalocysts. Antheridial leaves whitish, not contrasting with leaves on sterile pendent branches. Perichaetial leaves ovate, acute, fibrillose; border 3–5 cells wide; abaxial pores large, mostly 1 per cell at distal angle, or sometimes absent; adaxial pores also large, near leaf apex forming well defined triplets one at each corner of 3 adjacent hyalocysts. Spores 28–30 μm. Capsules frequent, summer. n = 19 + 2 m. On blanket bog and wet moorland, especially among Molinia. 0–550 m. N. Wales, Lake District, N. and W. Scotland, N. and W. Ireland; rare except in the hyperoceanic districts of Scotland and Ireland. 20, H9. GB126 + 9∗ , IR22 Hyperoceanic Temperate. Europe from western and southern Scandinavia south to Switzerland; eastern N. America; another subspecies is widespread in the tropics and southern Africa. With its squarrose branch leaves it has some resemblance to S. squarrosum, but differs in its small stem leaves. In the field it can be distinguished from squarrose-leaved forms of S. compactum by its pale stems and usually laxer habit. The difference in pore structure from S. compactum appears constant in British and Irish plants but does not hold in N. America.

Section Rigida

Fig. 16 1–6, Sphagnum strictum: 1, moist fascicle (×3); 2, divergent branch leaves; 3, stem leaves; 4, cells at middle of divergent branch leaf, abaxial side; 5 divergent branch leaf section; 6, stem section. 7–12, S. compactum: 7, moist fascicle (×3); 8, divergent branch leaves; 9, stem leaves; 10, cells at middle of divergent branch leaf, abaxial side; 11 divergent branch leaf section; 12, stem section. Leaves ×27, cells ×280.

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19 S. compactum Lam. & DC., Fl. Franç., 1805 S. rigidum (Nees & Hornsch.) Schimp.

(Fig. 16)

Autoicous. Shoots to 10 cm long, variously whitish green, yellowish or bright ochre, forming low, often dense tussocks. Stems 0.4–0.7 mm diameter; cortex 2–3 layers; pores on outer surface 1 per cell; cylinder dark brown or black, rarely pale. Branches 2–7 per fascicle, 1–2 divergent, 1–5 pendent. Stem leaves hanging, 0.3–0.7 × 0.4–0.7 mm, triangular or trapezoid, apices rounded, truncate or retuse; border 3–8 cells wide, intact in lower part of leaf, near apex variable, usually strongly resorbed and tattered; patches of narrow cells at basal angles absent; hyalocysts not, or slightly septate, with or without fibrils; abaxial surface intact; adaxial surface ± completely resorbed and lacking. Branch leaves 1.8–3.0 × 0.9– 1.8 mm, varying from oblong and ± cucullate to ovate with squarrose acumens, extreme apex rounded or truncate; border 1(−3) cells wide, denticulate because of resorption of outer surface of cells along margins; chlorocysts completely enclosed by hyalocysts, in section elliptical, measuring 11–16 μm along long axis; interior walls of hyalocysts smooth; abaxial pores in mid-leaf very variable, perforate or imperforate, 5–12(−16) μm, 0–4(−8) per cell, distributed along commissures, near leaf apex more numerous, to 12 per cell; adaxial pores absent in mid-leaf. (Numerous annular fibrils are often present along commissures on both surfaces, but the membrane within them is mostly not thinned.) Antheridial leaves white, not contrasting with those on sterile pendent branches. Perichaetial leaves ovate, acute; border 2–6 cells wide; hyalocysts fibrillose, with abundant, mostly imperforate small ringed commissural pores on both surfaces, or those on adaxial surface sometimes larger and less abundant. Spores 30–35 μm. Capsules frequent, summer. n = 19 + 2 m. On wet heaths, blanket bogs and among rocks, favouring moist but not wet ground, especially where there has been some disturbance such as burning. 0–1050 m. Frequent to common throughout the British Isles except in the Irish and English midlands. 93, H34. GB575 + 70∗ , IR102 + 12∗ . Circumpolar Boreo-temperate. Circumpolar in the boreal zone and low Arctic, and in mountains south to Macaronesia, Turkey and southern USA, Colombia, Hawaii. Usually easy to recognise in the field, the shoots being so densely crowded that the upper branches point upwards and the individual capitula are hard to discern. The habit may resemble Leucobryum glaucum. S. compactum can resemble compact forms of S. molle, S. palustre, S. papillosum or S. squarrosum, but differs in its minute hanging stem leaves. For field differences from S. strictum see under that species.

Section 5 Subsecunda (Lindb.) Schlieph. ex Schimp., Syn. Musc. Eur. (Ed. 2), 1876 Plants slender to robust. Stems usually 0.4–0.8 mm diameter; cortex 1–3 layers, hyaline, 15–60 μm wide, cell walls without fibrils, those on outer surface without pores or with a single indistinct pore at upper end; diameter of cortical cells measured at right angles to radius 15–50(−60) μm; cylinder strongly differentiated from cortex. Branches often curved, in fascicles of 1–6(−7), 1–3 divergent,

Section Subsecunda

79

0–4 pendent; branch cortex with clearly dimorphic cells, cell walls without spiral fibrils; retort cells with a moderate neck, in groups of (1−)2(−4). Stem leaves erect, spreading or hanging, usually 0.4–2.0 × 0.4–1.1 mm; border 3–6 cells wide, near apex entire or denticulate; patches of narrow cells at basal angles absent; hyalocysts septate or not, strongly or weakly fibrillose, not extensively resorbed on either surface, or rarely with extensive adaxial resorption; abaxial pores ringed, 2–8 μm, absent or to 40 per cell; adaxial pores ringed or not, 3–15 μm, absent or to 20 per cell. Branch leaves ovate or elliptical, sometimes concave and cucullate, usually 0.7–2.5 × 0.4–1.5 mm, with an intact border of 2–4 narrow cells; chlorocysts lens-shaped or barrel-shaped in cross-section, ± equally exposed on both surfaces, or slightly more exposed on abaxial surface; hyalocysts near apex longer than wide, their abaxial surface without a large pore at distal angle; abaxial pores in mid-leaf (1−)2–6 μm, (0−)12–40(−50) per cell, strongly ringed, positioned along commissures, usually with 2 corresponding to each fibril, one on each commissure; adaxial pores normally absent, when present similar to abaxial pores though often confined to cell angles. Antheridia on divergent branches. Perichaetial leaves triangular or oblong; border 2–3 cells wide, distinct almost to apex; hyalocysts fibrillose near leaf apex, not extensively resorbed on either surface; abaxial pores numerous, resembling those of branch leaves; adaxial pores few, similar.

Key to Sphagnum Section Subsecunda 1 Stem leaves triangular or lingulate, 0.4–1.3(−1.5) mm long, fibrillose for 40% or less of length of leaf, adaxial pores equally or more developed than abaxial pores (abaxial pores may be absent); pendent branches strongly or weakly differentiated from divergent branches; colour green or yellowish, not coppery-red 2 Stem leaves lingulate, oblong or elliptical, (1.0−)1.3–2.3 mm, fibrillose in upper 40% or more, abaxial pores numerous, adaxial pores usually much fewer, occasionally equally numerous; pendent branches weakly or not at all differentiated from divergent branches; colour green, yellowish or coppery-red 4 2 Stem cortex consisting of 2–3 layers of enlarged cells; cylinder green or pale brown; adaxial pores of stem leaves 3–6 μm, lying along commissures 23. S. contortum Stem cortex 1 layer; cylinder green, pale brown, or in well illuminated plants usually dark brown; adaxial pores of stem leaves 5–15 μm, some usually centrally placed 3 3 Slender plants (size similar to S. capillifolium); stem leaves 0.4–0.9 × 0.4–0.6 mm; upper cells fibrillose in a zone 0–25% of length of leaf; branch leaves 0.7–1.5 × 0.4–0.8 mm 20. S. subsecundum Medium-sized plants; stem leaves 0.9–1.3(−1.5) × 0.6–0.9 mm; upper cells fibrillose in a zone 20–40% of leaf length; branch leaves (1.0−)1.3–2.2 × 0.6–1.5 mm 21. S. inundatum

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4 Stem cortex uniformly 1 cell thick; stem leaves lingulate or oblong, often ± plane, 40–100% fibrillose; branches tumid or not, arising in fascicles of 3–5 22. S. denticulatum Stem cortex irregularly 1–2(−3) cells thick; stem leaves elliptical, markedly concave, 80–100% fibrillose; branches tumid, fascicles of 1–3(−4) 24. S. platyphyllum 20 S. subsecundum Nees in Sturm, Deutschl. Fl., Abt. II, Cryptog., 1819 (Fig. 17) Dioicous. Shoots to 15 cm long, normally yellow or ochre but green in shade and submerged forms, growing in loose carpets or as scattered plants. Stems 0.4– 0.7 mm diameter; cortex one layer, cells of outer surface with indistinct pores at upper end or pores absent; cylinder dark brown, or in shade forms green. Branches 4–6(−7) per fascicle, 2–3 divergent, 2–4 pendent; divergent branches clearly differentiated from pendent branches, often markedly curved. Stem leaves hanging, or a few sometimes spreading, 0.4–0.9 × 0.4–0.6 mm, triangular or triangularlingulate, apices plane or cucullate, rounded; border 3–6 cells wide, ± strongly fringed round apex; patches of narrow cells at basal angles absent; hyalocysts not septate; upper cells fibrillose in a zone 0–25% of length of leaf; abaxial pores absent; adaxial pores 5–14 μm, 0–10 per cell, unringed, centrally placed or lying along commissures. Branch leaves 0.7–1.5 × 0.4–0.8 mm, ovate, secund and pointing towards centre of curve of branch; border 2–3 cells wide; chlorocysts in section lens-shaped, reaching both surfaces or just enclosed on adaxial surface; abaxial pores 2–5 μm, (0−)20–40 per cell ringed, lying along commissures, adaxial pores absent or rarely 4–6 μm, to 6 per cell. Antheridial leaves bright yellow. Perichaetial leaves narrowly ovate, fibrillose and porose near apex. Spores 27–29 μm. Capsules rare. n = 19 + 2 m. In base-rich flushes and fens, favouring slightly more acid conditions than S. contortum. 0–740 m. Throughout Britain, frequent in some upland districts but mostly rather rare, rare in Ireland. 23, H5. GB50 + 7∗ , IR4. Circumpolar, mainly in the boreal zone. Usually easy to recognise in the field, with bright yellow or ochre colour, dark brown stems, curved branches, and slender habit resembling S. capillifolium. Depauperate S. inundatum can be mistaken for it, and sometimes produces stem leaves that are similar. Branch leaf size will usually distinguish these forms. Moreover, S. subsecundum is quite stable in its small size, but depauperate S. inundatum almost always betrays its true identity by producing some normal-sized stems and branch leaves in parts of the plant.

21 S. inundatum Russow, Arch. Nat. Dorpat II, 1894 (Fig. 17) S.auriculatum var. inundatum (Russow) M. O. Hill, S. bavaricum Warnst., S. subsecundum var. bavaricum (Warnst.) Åberg, S. subsecundum var. inundatum (Russow) C. E. O. Jensen Dioicous. Shoots to 20 cm long, green or yellow, forming ‘lawns’ or loose tufts. Stems 0.4–0.8 mm diameter; cortex 1 layer, cells of outer surface without

Section Subsecunda

81

Fig. 17 1–8, Sphagnum subsecundum: 1, moist fascicle (×3); 2, divergent branch leaves; 3, stem leaves (hatching indicates distribution of fibrils); 4, cells at middle of divergent branch leaf, abaxial side; 5, stem leaf cells 3/5 from base, adaxial side; 6, stem leaf margin near apex; 7 divergent branch leaf section; 8, stem section. 9–13, S. inundatum: 9, divergent branch leaves; 10 stem leaf (hatching indicates distribution of fibrils); 11, cells at middle of divergent branch leaf, abaxial side; 12, stem leaf cells 3/5 from base, adaxial side; 13, stem leaf margin near apex, abaxial side. Leaves ×27, cells ×280.

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pores; cylinder dark brown or black, or in shade forms green. Branches 4–6(−7) per fascicle, differentiated into 2–3 divergent, 2–4 pendent; divergent branches curved or not. Stem leaves spreading or hanging, 0.9–1.3(−1.5) × 0.6–0.9 mm, lingulate or triangular-lingulate, apex rounded; border 3–5 cells wide, ± fringed or toothed near apex; patches of narrow cells near basal angles absent; hyalocysts 0–50% septate, fibrillose in a zone 20–40% of length of leaf; abaxial pores near apex variously absent to numerous, 3–8(−11) μm; adaxial pores well developed, unringed, 5–12(−15) μm, centrally placed or positioned along commissures, some usually relatively large (8–12 μm). Branch leaves (1.0−)1.3– 2.2 × 0.6–1.5 mm, patent or imbricate; border 2–3 cells wide; chlorocysts in section barrel-shaped or lens-shaped, exposed on both surfaces or slightly enclosed on adaxial surface; abaxial pores 2–6 μm, (0−)20–40(−50) per cell, ringed, lying along commissures; adaxial pores absent or rarely 2–6 μm, to 6 per cell. Antheridial leaves yellow. Perichaetial leaves ovate or triangular, acute, fibrillose and porose above. Spores 31–34 μm. Capsules occasional, summer. n = 38 + 4 m∗ , c. 42. In marshes, heathy depressions, and wet woodland. 0–850 m. Frequent to common throughout the British Isles. 98, H30. European Boreotemperate. Cool-temperate zone of N. W. Europe, eastern N. America and eastern Asia. When growing in well illuminated conditions the dark stem is a useful field character separating it from unrelated species. The name inundatum is misleading: swollen submerged plants of S. subsecundum agg. are almost always S. denticulatum. S. inundatum is intermediate in most respects between S. subsecundum and S. denticulatum; notes on how to distinguish it are given under these species. There has been a debate as to whether S. inundatum ought to be treated as a subspecies of S. subsecundum or of S. denticulatum. Most European authors now treat it as a separate species, thereby avoiding the problem.

22 S. denticulatum Brid., Bryol. Univ., 1826 (Fig. 18) S. auriculatum Schimp., S. contortum auct. non Schultz, S. lescurii Sull., S. rufescens (Nees & Hornsch.) Limpr., S. subsecundum auct. angl. p.p. Dioicous. Shoots to 20 cm long, green, yellow or coppery red, forming loose carpets or tussocks. Stems 0.4–0.8 mm diameter; cortex 1 layer, cells of outer surface without pores; cylinder dark brown or black, or in shade and submergence forms green. Branches 3–4(−5) per fascicle, either not differentiated, or weakly differentiated into 2–3 divergent, 1–2(−3) pendent; divergent branches curved or not (when there are 5 branches in a fascicle one or two are often small and poorly developed). Stem leaves erect, spreading or hanging, (1.1−)1.3– 2.0(−2.7) × 0.6–1.0(−1.5) mm, lingulate or oblong, apex rounded; border 3–5 cells wide, ± fringed or toothed near apex; patches of narrow cells near basal angles absent; hyalocysts 0–100% septate, fibrillose in a zone 40–100% of length of leaf; abaxial pores near apex numerous, 3–8 μm, to 30 per cell; adaxial pores 0–20 per cell, 3–8(−12) μm, when present mostly lying along

Section Subsecunda

83

Fig. 18 Sphagnum denticulatum: 1, moist fascicle (×3); 2, divergent branch leaves; 3, stem leaf (hatching indicates distribution of fibrils); 4, cells at middle of divergent branch leaf, abaxial side; 5, stem leaf cells 3/5 from base, adaxial side; 6, stem leaf margin near apex, abaxial side; 7, divergent branch leaf section; 8, stem section. Leaves ×27, cells ×280.

commissures. Branch leaves 1.3–2.5(−3.5) × 0.8–1.5(−2.0) mm, imbricate or occasionally patent; border 2–3 cells wide; chlorocysts in section barrel-shaped or lens-shaped, exposed on both surfaces or slightly enclosed on adaxial surface; abaxial pores 3–6 μm, (0−)20–40(−50) per cell, ringed, lying along commissures; adaxial pores absent or rarely 3–5 μm, to 5 per cell. Antheridial leaves yellow (but not observed in reddish plants). Perichaetial leaves ovate or triangular, acute, fibrillose and porose above. Spores 30–33 μm. Capsules occasional, summer. n = 38 + 4∗ . In woods, moorland runnels and pools, tolerant of very acid water, sometimes completely submerged. 0–1100 m. Throughout the British Isles; very common in the north and west; frequent to common in the south and

84

1 Sphagnaceae

east. 106, H38. GB1093+80∗ , IR214+24∗ , C3. European Boreo-temperate. N. W. Europe, N. Africa, eastern Asia, western and eastern N. America, south to northern S. America. Variable both in habit and colour, with a strong phenotypic response to the position of the water-table. Coppery forms of flushed base-poor upland banks normally have curled branches resembling cattle horns, and can be recognised at a glance. Turgid plants submerged in pools have a superficial resemblance to S. palustre but differ in the narrow stems without a wide cortex layer. Green or yellowish forms of woods and marshes can closely resemble S. inundatum and may require microscopic examination. Even then, some plants may appear intermediate. Whether these are genetically intermediate is not known.

23 S. contortum Schultz, Prodr. Fl. Starg. Suppl., 1819 (Fig. 19) S. laricinum (Wilson) Spruce Dioicous. Shoots to 15 cm long, green, yellow or brownish, in loose carpets or occurring as scattered stems. Stems 0.4–0.7 mm diameter; cortex 2–3 layers, cells of outer surface mostly with a rather faint pore at upper end; cylinder green or pale brown. Branches 4–5(−7) per fascicle, 2–3 divergent, (1−)2–4 pendent; divergent branches clearly differentiated from pendent branches, often markedly curved. Stem leaves spreading or hanging, 0.7–1.3 × 0.5–1.0 mm, triangular or triangularlingulate, apex rounded or retuse; border 3–5 cells wide, partially resorbed and denticulate or fringed round apex; patches of narrow cells at basal angles absent; hyalocysts not septate; upper cells fibrillose in a zone 10–35% of length of leaf; abaxial pores near leaf apex 2–4 μm, 0–4(−6) per cell; adaxial pores 3–6 μm, 3–12 per cell, lying along commissures. Branch leaves 1.0–1.9 × 0.5–0.9 mm, ovate or narrowly ovate, often distinctly secund and pointing towards centre of curve of branch; border 2–4 cells wide; chlorocysts in section lens-shaped, reaching abaxial surface, just enclosed on adaxial surface; abaxial pores in mid-leaf very small, 1–3 μm, sometimes to 30 per cell, often ± indistinct or obsolete; adaxial pores absent. Antheridial leaves ochre with a slight pink tinge. Perichaetial leaves ovate, fibrillose and porose above. Spores 24–27 μm. Capsules unknown in Britain. Confined to base-rich habitats, mainly upland flushes, less often lowland fens. 0–800 m. Throughout the British Isles, frequent in the north and west, rare in the south and east. 57, H23. GB186 + 32∗ , IR20 + 9∗ . Boreal-montane. Circumpolar, mainly in the boreal zone. In the field the curved branches and normally ochre colour will suggest this species, S. subsecundum or S. inundatum. Well illuminated S. contortum can be distinguished by its pale stems, but greenish shade forms are hard to recognise in the field. The base-rich habitat is characteristic: S. contortum is usually associated with such indicators as Carex pulicaris, Scorpidium revolvens, S. scorpioides and Sphagnum teres.

Section Subsecunda

85

Fig. 19 1–6, Sphagnum contortum: 1, moist fascicle (×3); 2, divergent branch leaves; 3, stem leaves (hatching indicates distribution of fibrils); 4, cells at middle of divergent branch leaf, abaxial side; 5, divergent branch leaf section; 6, stem section. 7–11, S. platyphyllum: 7, divergent branch leaves; 8, stem leaf (hatching indicates distribution of fibrils); 9, cells at middle of divergent branch leaf, abaxial side; 10, divergent branch leaf section; 11, stem section. Leaves ×280, cells ×280.

86

1 Sphagnaceae

24 S. platyphyllum (Lindb. ex Braithw.) Sull. ex Warnst., Flora, 1884 (Fig. 19) S. contortum var. platyphyllum (Lindb. ex Braithw.) Åberg, S. laricinum var. platyphyllum Lindb. ex Braithw. Dioicous. Shoots to 15 cm long, green or yellowish with distinct terminal buds, forming untidy carpets. Stems 0.3–0.7 mm diameter; cortex irregularly 1–2(−3) layers, cells of outer surface mostly with a pore at upper end; cylinder green or brown. Branches 1–3(−4) per fascicle, to 13 mm long, not differentiated into pendent and divergent. Stem leaves erect or spreading, 1.2–2.3 × 0.8–2.0 mm, concave, elliptical, resembling branch leaves; border 2–4(−6) cells wide; patches of narrow cells at basal angles absent; hyalocysts not septate, fibrillose in a zone 80–100% of leaf; abaxial pores 2–5 μm, to 25 per cell, or ill-defined and ± obsolete; adaxial pores absent, or 2–4 μm, 0–6 per cell, ringed and confined to cell angles. Branch leaves 0.9–2.1 × 0.7–2.0 mm, concave, elliptical; border 1–3 cells wide; chlorocysts in section barrel-shaped or lens-shaped, exposed on both surfaces, or just enclosed on adaxial surface; abaxial pores in mid-leaf 2–5 μm, to 40 per cell, or ill-defined and ± obsolete; adaxial pores absent. Perichaetial leaves broadly elliptical-oblong, blunt, fibrillose and porose above. Spores 32–35 μm. Capsules unknown in Britain or Ireland. n = 19. In ± base-rich seasonally wet peaty runnels and swamps, often with Scorpidium revolvens. 0–450 m. Rare, but probably overlooked, Brecon, Pembroke, Cardigan, N. Wales to W. Sutherland and Lewis, S. Kerry, W. Galway, W. Mayo, Fermanagh. 21, H4. GB20 + 12∗ , IR3 + 1∗ . Circumpolar Boreal-montane. Circumpolar, boreal and north temperate, with a somewhat continental distribution on the mainland of Europe. Resembling semi-submerged forms of S. denticulatum, but with relatively broader and more concave stem leaves, more pronounced terminal buds and branches often in fascicles of 1–2. The stem cylinder is usually pale, but may be blackened by swampy habitat. More than one section may be necessary to demonstrate the 2-layered stem cortex: often on a single stem there are parts where the cortex is 2-layered and others where it is 1-layered.

Section 6 Cuspidata (Lindb.) Schlieph. ex Schimp., Syn. Musc. Eur. (ed. 2), 1876 Plants slender to moderately robust. Stems usually 0.3–1.0 mm diameter; cortex 2–3(−4) layers, 25–80 μm wide, hyaline or not, cell walls without fibrils, outer surface without pores; diameter of cortical cells measured at right-angles to radius, 15–40(−60) μm; cylinder in some species strongly differentiated from cortex, in others weakly so. Branches in fascicles of (2−)3–5(−6), in some species not differentiated into pendent and divergent branches, in those that have differentiation 2(−3) divergent, 1–3 pendent; branch cortex with clearly dimorphic cells (except S. lindbergii and submerged forms), cell walls without spiral fibrils; retort cells various, with almost no neck or a moderate or large one, in groups of 1–2. Stem leaves hanging or spreading, usually 0.8–1.6 × 0.5–1.3 mm; border 4–10 cells wide, near

Section Cuspidata

87

apex entire or resorbed; patches of narrow cells at basal angles large, occupying 50–100% of leaf base, hyalocysts not, or hardly septate, variously fibrillose or not; abaxial1 surface ± intact (except S. lindbergii); adaxial surface extensively resorbed near leaf apex, or more rarely with large pores. Branch leaves ovate or lanceolate, concave or straight, in several species altering markedly when dry, becoming erect-patent or squarrose (a character confined to this Section among European Sphagna), usually 0.8–3.5 × 0.4–0.9(−1.2) mm; border intact, 2–6 cells wide; chlorocysts triangular or trapezoid in section, broadly exposed on abaxial surface, with a lesser or absent exposure on adaxial surface; hyalocysts near apex longer than wide (sometimes ± isodiametric in S. tenellum), their abaxial surface near leaf apex sometimes with a large pore at distal angle (usually not); abaxial pores in mid-leaf 0–1(−3) per cell, 2–9 μm (larger in S. tenellum), confined to ends of cell (especially distal end), or occasionally a few at other angles (in some species there are more numerous abaxial pores, but these are then 2–8 μm, unringed, not appressed to commissures); adaxial pores (2−)4–9(−18) μm, 0–10(−12) per cell, faint, unringed, often visible only with intense staining, appressed to commissures (except in S. obtusum). Antheridia on divergent branches. Perichaetial leaves with border intact to apex (except S. lindbergii), hyalocysts fibrillose or not, often resorbed on adaxial surface.

Key to Sphagnum Section Cuspidata 1 Stem leaves with fibrils near apex 2 Stem leaves without fibrils near apex 6 2 Small greenish plants with branches 4–8(−10) mm; branch leaves concave, ovate or broadly ovate, to 1.5 mm long; hyalocysts near apex of branch leaves 20–40 μm wide, 1–4 times as long as wide 25. S. tenellum Habit and colour various, branches often exceeding 10 mm; branch leaves concave or not, ovate or lanceolate, often exceeding 1.5 mm long; hyalocysts near apex of branch leaves less than 20 μm wide, 3–9 times as long as wide 3 3 Colour orange, yellow or golden-brown 4 Colour green or dingy 8 4 Stems darker than leaves, brown or dark brown (occasionally this pigmentation is manifested only in patches); relatively robust plants with branches in dry state 1–3 mm diameter 29. S. pulchrum Stems pale, plants slender or medium-sized, the branches in dry specimens rarely exceeding 1.3 mm diameter 5 5 Stem cortex strongly differentiated; stem leaves ± spreading; branches in fascicles of 3(−4) 28. S. balticum 1

Because the leaves of mature stems hang down in Section Cuspidata the abaxial side is pressed against the stem so that what is technically the abaxial side may be interpreted as the adaxial side. However, in the capitulum the stem leaves are erect.

88

6

7

8

9

10

11

12

1 Sphagnaceae Stem cortex weakly differentiated; stem leaves hanging; branches in fascicles of 4–5 8 Stems dark brown; plants usually brownish; stem leaves widest near the fringed retuse apex 35. S. lindbergii Stems pale; plants of various colours; stem leaves widest near base 7 Terminal buds large, conspicuous; stem leaves conspicuously cleft at apex 34. S. riparium Terminal buds small, ± hidden among capitulum branches; stem leaves entire or somewhat fringed at apex, not cleft 8 Pendent branches weakly or not at all differentiated, not appressed to stems, their leaves resembling those of divergent branches; plants often ± submerged; when growing in drier places the leaves at ends of branches rolled into a sharp cusp; stem leaves usually with fibrils; stem cortex ± clearly differentiated 9 Pendent branches with leaves whitish when moist, clearly differentiated from divergent branches, appressed to stems and ± concealing it; plants rarely submerged; leaves at branch apex not rolled into a cusp; stem leaves usually without fibrils; stem cortex usually very indistinct, occasionally well differentiated 10 Colour dingy olive; hyalocysts of branch leaves with abundant (usually c. 10 per cell) unringed abaxial pores (use stain) 27. S. majus Colour green, rarely dingy olive, hyalocysts of branch leaves with 0–1(−3) ringed abaxial pores per cell, unringed abaxial pores absent 26. S. cuspidatum Stem leaves acute, with margins inrolled at apex to form an apiculus 30. S. fallax Stem leaves obtuse, apices plane or slightly cucullate 11 Pendent branches longer than spreading branches; stem leaves equilaterally triangular, entire at apex; divergent-branch leaves recurved when dry; plants greenish or brightly coloured 31. S. angustifolium Pendent branches shorter than or equal to spreading branches; stem leaves triangular-lingulate, longer than wide, fringed at apex; branch leaves erect-patent but not recurved when dry; plants greenish 12 Adaxial pores of leaves of divergent branches very indistinct even with heavy staining, 2–5 μm 33. S. obtusum Adaxial pores of leaves of divergent branches 5–20 μm, clearly visible with heavy staining, at least near apex of leaf 32. S. flexuosum

25 S. tenellum (Brid.) Bory, Voy. Iˆles Afrique III, 1804 S. molluscum Bruch

(Fig. 20)

Dioicous. Shoots to 10 cm long, green or faintly brownish, forming loose tussocks or growing as scattered plants. Stems 0.3–0.5 mm diameter; cortex

Section Cuspidata

89

Fig. 20 1–7, Sphagnum tenellum: 1, moist fascicle (×3); 2, divergent branch leaves; 3 stem leaves; 4, cells at middle of divergent branch leaf, abaxial side; 5, divergent branch leaf section; 6, divergent branch cortex, surface view showing retort cells; 7, stem section. 8–13, S. cuspidatum: 8, moist fascicle (×3); 9, divergent branch leaves; 10 stem leaves; 11, cells at middle of divergent branch leaf, abaxial side; 12, divergent branch leaf section; 13, stem section. Leaves ×27, cells ×280.

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1 Sphagnaceae

(1−)2–3 layers, clearly differentiated from cylinder, lacking pores on outer surface; cylinder green. Branches 4–8(−10) mm long, (2−)3(−4) per fascicle, of which usually 2 divergent, 1 pendent, the pendent branch small, not appressed to stems, weakly differentiated from divergent branches; retort cells in pairs, with strongly protuberant necks. Stem leaves large for size of plants, 0.9–1.4 × 0.5– 0.7 mm, lingulate, entire, spreading, apices rounded, often ± cucullate; border 5–10 cells wide, at basal angles merging with patches of narrow cells which take up 50–100% of leaf base; hyalocysts fibrillose in upper 40–100% of leaf; abaxial surface intact, or with a few large pores at distal angles of hyalocysts; adaxial surface near apex usually with a single large pore 13–30 μm at distal angle of each cell, occasionally more extensively resorbed. Branch leaves 0.8–1.5 × 0.4– 0.7 mm, ovate, concave, little modified when dry, apex acute or obtuse; border 2–3(−5) cells wide; chlorocysts in section triangular or trapezoid, broadly exposed on abaxial surface, reaching adaxial surface and usually somewhat exposed on it; hyalocysts near leaf apex 1–4 times as long as wide; abaxial pores in midleaf 4–12(−25) μm, 0–1(−2) per cell, when present usually confined to distal angle of cell; adaxial pores faint, unringed, 4–18 μm, 0–2 per cell, confined to ends of cell. Antheridial leaves faintly yellowish. Perichaetial leaves ovate, acute, composed either of uniform vermicular cells, or if cells dimorphic then hyalocysts fibrillose above, intact on abaxial surface, on adaxial surface with large pores one per cell at distal angle. Spores 35–40 μm. Capsules frequent, summer. n = 19, 19 + 2 m∗ . Among other sphagna, particularly S. capillifolium and S. papillosum, on wet heaths and bogs; in high-rainfall areas on sheltered rocky banks. 0–1090 m. Common in the north and west, local in S. E. England. 92, H39. GB586 + 76∗ , IR186 + 15∗ . Suboceanic Boreo-temperate. Circumpolar, suboceanic; S. America. Usually easy to recognise in the field. Good field characters are the short branches, ovate concave branch leaves, weak differentiation between pendent and divergent branches, and the relatively large spreading stem leaves. Microscopically, the necks of the retort cells are more protuberant than in any other European Sphagnum. S. tenellum is a somewhat aberrant member of Section Cuspidata, sometimes placed on its own in Section Mollusca Schlieph. ex Casares-Gil.

26 S. cuspidatum Ehrh. ex Hoffm., Deutschl. Fl., 1796 S. viride Flatberg

(Fig. 20)

Dioicous. Shoots to 15 cm long in terrestrial plants, often much longer in aquatic forms, green or slightly brownish, forming flaccid wefts. Stems 0.4–0.8 mm diameter; cortex 2–3 layers, ± clearly differentiated from cylinder, lacking pores on outer surface; cylinder green. Branches 3–5(−6) per fascicle, straight or sometimes strongly curved, not or hardly differentiated into pendent and divergent. Stem leaves 0.9–1.3 × 0.6–1.0 mm, rounded-triangular, entire, variously hanging or spreading; border 4–9 cells wide, merging at basal angles with patches of

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narrow cells which take up 60–100% of leaf base; hyalocysts fibrillose in upper (0−)20–40% of leaf; abaxial surface intact; adaxial surface near leaf apex either with 3–5 large (8–25 μm) pores per cell, or ± extensively lacking. Branch leaves 1.5–3.5 × 0.3–0.7 mm, lanceolate or ovate, sometimes little modified when dry, or strongly recurved except at the cuspidate branch tips; border 3–6 cells wide; chlorocysts in section triangular or trapezoid, broadly exposed on abaxial surface, reaching adaxial surface and often moderately exposed on it; abaxial pores in mid-leaf 2–6 μm, 0–1(−3) per cell, ringed, usually at distal angle of cell, less often at proximal end or other angles; adaxial pores faint, unringed, 4–8 μm, 4–10 per cell, confined to cell angles or distributed along commissures. Antheridial leaves brown, contrasting with green ordinary leaves. Perichaetial leaves oblong, obtuse, fibrillose above; abaxial surface intact; adaxial surface with pores or more extensive resorption near leaf apex. Spores 32–37 μm. n = 19 + 2 m∗ , 19 + 4 m. Capsules occasional, summer. On wet peaty ground, usually in pools and runnels on acid bogs and moorland; also among Cyperaceae by oligotrophic lakes and pools, or free-floating as an aquatic. 0–1030 m. Throughout the British isles; common in the north and west, local in S. E. England. 105, H40. GB805 + 61∗ , IR216 + 24∗ . European Boreo-temperate. Circumpolar, mainly in the boreal zone. In the field the best marks of distinction from S. recurvum agg. (species 30–32) are the narrowly lanceolate leaves, the absence of well defined pendent branches, and, in terrestrial forms, the tightly rolled leaves of the cuspidate branch apices. Submerged forms are sometimes highly modified, with a flaccid habit that has been likened to a drowned kitten; such forms may have ± denticulate leaf margins. For the distinction from S. majus see under that species. Sphagnum viride is a segregate of S. cuspidatum described by Flatberg (K. Norske Vidensk. Selsk. Skr. 1, 1–64, 1988). The distinction is entirely morphometric and comparative, with S. viride being greener, with arcuate rather than falcate branches in terrestrial forms. In S. cuspidatum the branch leaves are less than 0.28 times as wide as long, with hyalocysts more than 8 times as long as wide. In S. viride the branch leaves are more than 0.28 times as wide as long, with hyalocysts less than 8 times as long as wide. The defining characters are neither clear cut nor well correlated. S. viride cannot be maintained as a taxon distinct from S. cuspidatum.

27 S. majus (Russow) C. E. O. Jensen, Bot. For. Festskr., 1890 S. cuspidatum var. majus Russow, S. dusenii Warnst.

(Fig. 21)

Dioicous. Shoots to 25 cm long, dull brownish green, forming loose wefts. Stems 0.6–0.8 mm diameter; cortex 2–3 layers, ± clearly differentiated from cylinder, lacking pores on outer surface; cylinder green. Branches 4–5 per fascicle, not or hardly differentiated into pendent and divergent. Stem leaves 0.9–1.4 × 0.8– 1.0 mm, rounded-triangular, entire, variously hanging or spreading; border 4–8 cells wide, merging at basal angles with patches of narrow cells which take up 60– 100% of leaf base; hyalocysts fibrillose in upper 20–40% of leaf; abaxial surface

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Fig. 21 1–5, Sphagnum majus: 1, divergent branch leaves; 2, stem leaves; 3, cells at middle of divergent branch leaf, abaxial side; 4, divergent branch leaf section; 5, stem section. 6–10, S. balticum: 6, divergent branch leaves; 7, stem leaves; 8, cells at middle of divergent branch leaf, abaxial side; 9, divergent branch leaf section; 10, stem section. Leaves ×27, cells ×280.

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93

intact; adaxial surface near leaf apex extensively resorbed, often ± completely lacking. Branch leaves 1.7–3.0 × 0.6–0.8 mm, ovate or lanceolate, little modified when dry; border 3–5 cells wide; chlorocysts in section triangular or trapezoid, broadly exposed on abaxial surface, reaching adaxial surface and often moderately exposed on it; abaxial pores in mid-leaf 5–8 μm, (2−)8–18 per cell, unringed, many of them in middle of cell surface, not appressed to commissures; adaxial pores faint, unringed, 5–7 μm, 0–6 per cell, confined to cell angles. Antheridial leaves rusty-brown, contrasting with ordinary leaves. Perichaetial leaves oblong, obtuse, fibrillose near apex; abaxial surface intact; adaxial surface of hyalocysts resorbed near leaf apex. Spores 27–38 μm. n = 38. Capsules very rare. Semi-submerged in bog hollows and beside pools. Very rare but doubtless overlooked, S. Northumberland, E. Inverness, W. Sutherland and formerly Angus. 4. GB3 + 1∗ . Circumpolar Boreal-montane. Circumpolar in the boreal zone; distribution in Europe mainly continental. In the field resembling S. cuspidatum, to which it is closely allied. The main distinguishing feature is the dingy brownish-green colour. S. cuspidatum is predominantly green except for the antheridial leaves. Microscopically the numerous abaxial pores are an easy mark of distinction, but because they lack rings they are hard to see without stain.

28 S. balticum (Russow) Russow ex C. E. O. Jensen, Bot. For. Festskr., 1890 (Fig. 21) S. recurvum ssp. balticum Russow Dioicous. Shoots to 15 cm long, greenish orange or yellowish, forming loose carpets. Stems 0.3–0.7 mm diameter; cortex 2–3 layers, clearly differentiated from cylinder, lacking pores on outer surface; cylinder yellowish, pale. Branches 3(−4) per fascicle, of which 2 divergent, 1(−2) pendent; pendent branch sometimes weakly differentiated from divergent, more often whitish, appressed to stems. Stem leaves 0.9–1.2 × 0.5–0.8 mm, lingulate, entire, ± spreading, the margins at apex inrolled so that until flattened under a cover-slip the leaf appears triangular; border 4–7(−9) cells wide, merging at basal angles with patches of narrow cells which take up to 60–80% of leaf base; hyalocysts fibrillose in upper 20– 50% of leaf; abaxial surface intact; adaxial surface near leaf apex resorbed and usually ± completely lacking. Branch leaves 0.9–1.7(−2.4) × 0.4–0.7 mm, ovate, little modified when dry; border 2–3 cells wide; chlorocysts in section ± triangular, broadly exposed on abaxial surface, reaching adaxial surface and sometimes slightly exposed on it; abaxial pores in mid-leaf 5–9 μm, 0–1 per cell, when present usually confined to distal angle of cell (but in a Northumberland population plants occur with up to 9 unringed abaxial pores resembling those of S. majus); adaxial pores faint, unringed, 5–8 μm, 5–12 per cell, distributed along commissures. Antheridial leaves brown, contrasting with ordinary leaves. Perichaetial leaves oblong, weakly fibrillose above, hyalocysts ± extensively resorbed on adaxial

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surface near leaf apex. Spores 26–28 μm. Capsules not known in Britain. n = 19 + 2 m. Ditches and depressions in ombrotrophic bogs. 0–660 m. Very rare, Cardigan, S. W. Yorkshire, S. Northumberland, Dumfries, S. Aberdeen, E. Inverness, old records from Cheshire, W. Lancashire. 8. GB6 + 2∗ . Circumpolar Boreoarctic Montane. Circumpolar, slightly continental. Superficially like a strongly coloured, slender form of S. fallax. Useful field characters are the ± spreading stem leaves and the smaller number of branches per fascicle. Most British plants have the branches regularly in fascicles of 3, but plants from one site had branches mainly in fascicles of 4.

29 S. pulchrum (Lindb. ex Braithw.) Warnst., Bot. Centralb., 1900 (Fig. 22) Dioicous. Shoots to 15 cm long, orange-brown, orange or yellow-green, forming loose carpets and ‘lawns’. Stems 0.5–0.8 mm diameter; cortex 2–3 layers, ± clearly differentiated from cylinder but not hyaline, lacking pores on outer surface; cylinder brown, darker than leaves, or sometimes partly green. Branches regularly 4 per fascicle, 2 divergent, 2 pendent; pendent branches short, not exceeding 13 mm long; divergent branches also rather short, to c. 17 mm long, in dried specimens generally 1.5–2.0 mm wide (including leaves) and appearing rather stubby. Stem leaves 0.9–1.2 × 0.7–0.9 mm, triangular, hanging or spreading, the margins inrolled at apex to form a pronounced cusp; border 5–9 cells wide, merging at basal angles with patches of narrow cells which take up 60–80% of leaf base; hyalocysts fibrillose in upper 20–50% of leaf; abaxial surface intact; adaxial surface near leaf apex resorbed and lacking. Branch leaves 1.2–1.8 × 0.5–0.9 mm, ovate, appressed in 5 distinct rows when wet, much modified and flexuose at margin when dry, erect-patent (but not recurved) so that branch appears stubby; border 2–4 cells wide; chlorocysts in section triangular, broadly exposed on abaxial surface, completely enclosed on adaxial surface; abaxial pores in mid-leaf 3–8 μm, 0–1(−2) per cell, when present usually confined to distal angle of cell; adaxial pores faint, unringed, 4–8 μm, 3–9 per cell, confined to cell angles or distributed along commissures. Antheridial leaves bright orange-brown, contrasting markedly with other leaves. Perichaetial leaves ovate-oblong, intact on both surfaces, lacking fibrils or pores. Spores 27–30 μm. n = 19. Capsules unknown in Britain or Ireland. In wetter parts of raised bogs in western Britain and Ireland; also on valley bogs in S. E. Dorset. 0–280 m. Rare but locally abundant. 14, H6. GB26 + 3∗ , IR15. Suboceanic Boreo-temperate. Atlantic and sub-Atlantic regions of Europe and eastern N. America, Japan. A distinctive species, the bright colour rapidly attracting attention. In the field, the 5-ranked branch leaves distinguish it from S. denticulatum; the dark stems distinguish it from S. balticum and S. fallax; the triangular stem leaves distinguish it from S. lindbergii. Microscopically it is close to S. fallax but can be distinguished by the combination of fibrillose stem leaves and branch leaves less than 2.5 times as long as wide (more than 2.7 times as long as wide in S. fallax).

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Fig. 22 1–6, Sphagnum pulchrum: 1, moist fascicle (×3); 2, divergent branch leaves; 3, stem leaves; 4, cells from middle of divergent branch leaf, abaxial side; 5, divergent branch leaf section; 6, stem section. 7–9, S. obtusum: 7, divergent branch leaves; 8, stem leaves; 9, cells from middle of divergent branch leaf, abaxial side. Leaves ×27, cells ×280.

30–32 S. recurvum agg. S. intermedium auct. non Hoffm. Dioicous. Shoots to 20 cm long, green or orange, in loose tussocks or low carpets. Stems 0.4–0.9 mm diameter; cortex 2–3 layers, weakly to moderately differentiated from cylinder, lacking pores on outer surface; cylinder green or pale orange, rarely pinkish. Branches 4–5(−6) per fascicle, straight or hanging, clearly differentiated into 2(−3) divergent and 2–3(−4) pendent; pendent branches appressed to stem and ± whitish. Stem leaves 0.6–1.2 × 0.6–1.0 mm, triangular or

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triangular-lingulate, mostly hanging and appressed to stem; apices acute or rounded; border 4–8 cells wide, merging at basal angles with patches of narrow cells which take up 60–80% of base; hyalocysts without fibrils or occasionally with fibrils in upper 20–40% of leaf; abaxial surface intact; adaxial surface near leaf apex resorbed and lacking. Branch leaves 1.2–2.1 × 0.3–0.8 mm, ovate or narrowly ovate, 5-ranked or not, appressed when wet and either erectpatent or recurved when dry; border 2–4 cells wide; chlorocysts in section triangular or trapezoid, broadly exposed on abaxial surface, reaching adaxial surface or not, not or moderately exposed on it; abaxial pores in mid-leaf 4–9 μm, 0–1(−2) per cell, ringed, when present usually confined to distal angle of cell; adaxial pores faint, unringed, 5–9 μm, 3–7 per cell, ± confined to cell angles, often larger, ringed and perforate near leaf apex. Antheridial leaves yellowish or orange, contrasting markedly with ordinary leaves. Perichaetial leaves ovate or oblong, ± obtuse with a small apiculus, intact on both surfaces, lacking fibrils and pores. The Sphagnum recurvum group comprises three species in Britain and Ireland, or five species if the taxonomy of Flatberg (Lindbergia 19, 96–110, 1992) is followed. S. recurvum P. Beauv. is a robust American taxon absent from Europe, with fringed rounded stem leaves and the branch leaves strongly recurved (i.e. squarrose) when dry. The aggregate can generally be recognised by the pale stem and widely spaced, ± triangular, hanging stem leaves. Members of the S. recurvum group are most likely to be confused with S. cuspidatum but can almost always be distinguished by their clearly differentiated pendent branches, which are whitish and appressed to the stems. Rarely, when growing semi-submerged, the pendent branches may lose their distinctness and the stem leaves may develop pronounced fibrils. The stem section and shape of the branch leaves will usually distinguish such plants.

30 S. fallax (H. Klinggr.) H. Klinggr., Vers. Topogr. Fl. Westpreuss., 1880 (Fig. 23) S. recurvum var. mucronatum (Russow) Warnst., S. recurvum var. brevifolium ¨ (Lindb. ex Braithw.) Warnst. p.p., S. brevifolium (Lindb. ex Braithw.) Roll emend. Flatberg, S. isoviitae Flatberg Shoots green, yellow or orange, often forming extensive ‘lawns’. Stems pale or slightly reddish; cortex slightly to moderately well differentiated. Branch bases with or without red pigment. Pendent branches ± equal in length to divergent branches, sometimes shorter or longer. Stem leaves 0.8–1.1 × 0.6– 1.0 mm, triangular or triangular-lingulate, acute, with margins inrolled above to form a distinct cusp, rarely ± rounded at apex but even then with a weak cusp; apices not fringed. Chlorocysts of divergent-branch leaves triangular in section, reaching adaxial surface or enclosed. Abaxial pores of pendentbranch leaves 5–10(−14) μm, very rarely exceeding 12 μm. Spores 27–30 μm. n = 19 + 2 m∗ . Capsules occasional, August. Occurring in a wide range of permanently moist or wet acid habitats, in wet fields, bogs, by streams, in ditches, woods, swamps, on wet moorland and flushed banks. It occurs in pools and runnels

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97

Fig. 23 1–4, Sphagnum fallax: 1, moist fascicle (×3) 2, stem leaf; 3, divergent branch leaf; 4, divergent branch leaf cells, abaxial side. 5–8, S. angustifolium: 5, moist fascicle (×3) 6, stem leaf; 7, divergent branch leaf; 8, divergent branch leaf cells, abaxial side. Leaves ×50, cells ×280.

in bogs. 0–1000 m. 110, H35. GB1053 + 65∗ , IR145 + 9∗ . European Boreo-temperate. Circumboreal. S. fallax is a variable species with a complex pattern of intraspecific variation. Flatberg (J. Bryol. 17, 1–13, 1992) distinguished three taxa within S. fallax as understood here, namely S. fallax, S. isoviitae and S. brevifolium. The distinctions between these segregates present great difficulties because the defining characters are not clear-cut and often occurr in ˚ ‘wrong’ combinations. A subsequent genetic study by Flatberg’s group (S. M. Sastad et al., System. Bot. 24, 95–107, 1999) confirmed the distinctness of S. fallax from S. angustifolium and S. flexuosum but suggested that the segregates of S. fallax form a single interbreeding population. Accordingly, Flatberg’s segregates are not recognised here, even at the subspecific rank (S. fallax ssp. isoviitae (Flatberg) M. O. Hill) used in Blockeel & Long (1998). The form originally described as S. isoviitae has reddish branch bases and branch leaves that are strongly 5-ranked, erect-patent but not recurved in the dry state, with chlorocysts distinctly enclosed

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on the adaxial surface. It can be confused with S. pulchrum (q.v. for differences). The more usual forms of S. fallax have branch bases scarcely pigmented, branch leaves weakly or not 5-ranked, distinctly recurved in the dry state, with chlorocysts reaching the adaxial surface.

31 S. angustifolium (C. E. O. Jensen ex Russow) C. E. O. Jensen, Bih. Kongl. Svenska Vetensk-Akad. Handl., 1896 (Fig. 23) S. recurvum var. tenue H. Klinggr., S. parvifolium (Warnst.) Warnst. Slightly more slender than S. fallax and S. flexuosum. Shoots green, yellowish or orange, forming loose carpets and lax tufts. Stems green or occasionally redflecked; cortex indistinctly differentiated. Branch bases often reddish when well illuminated. Pendent branches longer than divergent branches. Stem leaves 0.6– 0.8 × 0.6–0.8 mm, triangular, as wide as long, rounded with apices slightly cucullate, not or scarcely fringed. Divergent-branch leaves 5-ranked or not, recurved when dry; chlorocysts triangular in section, reaching adaxial surface. Abaxial pores of pendent-branch leaves 7–20(−30) μm, at least some exceeding 12 μm. Capsules not reliably reported in Britain or Ireland. Soligenous marshes, flushed moorland banks and woods, often mixed with S. fallax but not occurring in the more acid habitats of the latter. 0–500 m. Throughout Britain and Ireland, scarce in the south; frequent to common in upland areas but poorly recorded. 41, H8. GB38 + 8∗ , IR9. Circumpolar Boreal-montane. Circumboreal, widespread in continental interiors. When growing in woodland, S. angustifolium has markedly convex capitula, giving the plants a characteristic ‘pom-pom’ appearance. The relatively short, triangular, stem leaves with rounded apices can be readily observed in the field. Dried specimens can be distinguished from S. flexuosum by their recurved branch leaves.

32 S. flexuosum Dozy & Molk., Prodr. Fl. Bat. 2, 1851 S. recurvum var. amblyphyllum (Russow) Warnst.

(Fig. 24)

Shoots green, forming loose tufts and low carpets. Stems pale, cortex very indistinctly differentiated. Branch bases lacking red or brown pigment. Pendent branches shorter than or equal to divergent branches. Stem leaves 0.8–1.2 × 0.6– 0.9 mm, triangular-lingulate or lingulate, longer than wide; apices rounded, plane or slightly cucullate, ± extensively fringed because of resorption. Leaves of divergent branches when dry erect-patent with wavy margins, not or scarcely recurved; chlorocysts triangular or trapezoid in section, reaching adaxial surface and often exposed on it. Abaxial pores of pendent-branch leaves 5–20(−30) μm, sometimes with many exceeding 12 μm. Marshes, boggy moorland and damp woods, generally in more basic habitats than S. fallax though often mixed with it. 0–500 m. Probably throughout Britain and Ireland, but scarcer than S. fallax except in parts of southern England, very rare in Ireland, W. Galway and formerly W. Cork. 53,

Section Cuspidata

99

Fig. 24 Sphagnum flexuosum: 1, moist fascicle (×3); 2, divergent branch leaves; 3, stem leaf; 4, cells at middle of divergent branch leaf, abaxial side; 5, divergent branch leaf section; 6, stem section. Leaves ×50, cells ×280.

H2. GB47 + 12∗ , IR1 + 1∗ . European Boreo-temperate. Circumboreal but scarce or absent in continental interiors. This is the greenest species in the S. recurvum aggregate, never with reddish pigments or orange leaves, developing at most a faint yellowish tinge. The rounded, fringed stem leaves, longer than wide, can be observed in the field by pulling off the capitulum.

33 S. obtusum Warnst., Bot. Zeitung (Berlin), 1877 (Fig. 22) Similar to S. flexuosum, differing in pore structure and slightly more robust habit. Stem leaves rounded-triangular, obtuse, ± fringed at apex because of resorption. Leaves of divergent branches with very small unringed abaxial pores, 2–5 μm, 0–14 per cell in one or two rows along middle of cell surface, not appressed against commissures; adaxial pores also very small, unringed, 2–5 μm, 0–8 per cell, appressed against commissures or not, often very indistinct. Abaxial pores of pendent branch leaves 3–5(−8) μm. Lowland. Formerly in W. and S. Lancashire but thought to be extinct through drainage. 2. GB2∗ . Circumpolar Boreo-arctic Montane. Circumpolar; a boreal species with a somewhat eastern distribution in Europe. The characteristic unringed abaxial pores are usually easiest to see near the margin in the lower parts of the leaves but can be present in middle of leaves. Intense staining is

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1 Sphagnaceae

required: the leaf should be almost black. When a leaf of S. flexuosum is stained in this way the relatively large adaxial pores are easily visible, at least near leaf apex.

¨ 34 S. riparium Ångstr., Ofvers Föhr. Kongl. Svenska Vetensk.-Akad., 1864 (Fig. 25) S. intermedium var. riparium (Ångstr.) Lindb. Dioicous. Shoots to 25 cm long, green or faintly brownish, with large terminal buds, forming loose green carpets. Stems 0.5–1.0 mm diameter; cortex 2–3 layers, weakly differentiated from cylinder, lacking pores on outer surface; cylinder green. Branches in fascicles of 4–5, 2(−3) divergent, 2–3 pendent. Stem leaves mostly hanging, 1.3–1.6 × 0.9–1.3 mm, triangular or triangular-lingulate, conspicuously cleft at apex; border 3–8 cells wide, merging at basal angles with patches of narrow cells which take up 60–80% of leaf base; hyalocysts lacking fibrils; adaxial surface of hyalocysts extensively resorbed and lacking in upper half of leaf, both surfaces being resorbed near apical cleft. Branch leaves 1.3–3.0 × 0.5–0.9 mm, ovate, somewhat recurved when dry; border 2–4(−6) cells wide; chlorocysts in section triangular or trapezoid, broadly exposed on abaxial surface, reaching adaxial surface and often moderately exposed on it; near apex of leaf there are no hyalocysts, undifferentiated chlorocysts combining to form a snout 100–500 μm long; abaxial pores dimorphic, in upper and mid-leaf 4–6 μm, 0–1 per cell, confined to distal angles of cells, in middle and lower leaf near margin often consisting of membrane gaps 14–28 μm, also confined to distal angles, these being repeated on adaxial surface to give a colander-like appearance; in the pendent branch leaves, the colanderlike membrane gaps occur throughout upper part of leaves, giving them a striking appearance when stained; adaxial pores (except for large perforated pores opposite abaxial membrane gaps) 3–15 μm, faint, unringed, 0–14 per cell, distributed along commissures. Antheridial leaves brownish. Perichaetial leaves oblong, entire; apices rounded with small apiculus; hyalocysts intact on both surfaces, lacking fibrils and pores. Spores 25–27 μm. Capsules very rare, summer. n = 19 + 4 m. In marshes and by streams, often among rushes on moderately nutrient-rich ground. 0–750 m. Rare, northern England to Shetland, markedly eastern and showing a preference for higher altitudes; casual in Berkshire during the 1960s. 17. GB15 + 8∗ . Circumpolar Boreal-montane. Circumpolar, common in the Arctic, more scattered further south. In the field the stem leaves are unmistakable, but this plant is not conspicuous and can be overlooked as a robust S. girgensohnii or S. fallax.

¨ 35 S. lindbergii Schimp. ex Lindb., Ofvers Föhr. Kongl. Svenska Vetensk.-Akad., 1857 (Fig. 25) Autoicous. Shoots to 20 cm long, often fulvous brown but sometimes greenish in spring after snow-melt, with large terminal buds, forming low carpets. Stems 0.5–0.9 mm diameter, dark brown or almost black; cortex 3–4 layers, strongly differentiated from cylinder, lacking pores on outer surface; cylinder dark brown.

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Fig. 25 1–7, Sphagnum riparium: 1, divergent branch leaves; 2, stem leaf; 3, cells at middle of divergent branch leaf, abaxial side; 4, cells at middle of pendent branch leaf, abaxial side; 5, cells near apex of divergent branch leaf, adaxial side; 6, divergent branch leaf section; 7, stem section. 8–13, S. lindbergii: 8, divergent branch leaf; 9, stem leaves; 10, cells at middle of divergent branch leaf, abaxial side; 11, divergent branch leaf section; 12, stem cortex, surface view; 13, stem section. Leaves ×27, cells ×280.

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Branches in fascicles of 4–5(−6), not clearly differentiated into pendent and divergent, or occasionally well differentiated; cells of branch cortex not clearly differentiated into retort and non-retort cells, almost all cells having a pore at distal end. Stem leaves hanging, 1.3–1.6 × 0.9–1.5 mm, cuneate or rectangular, with retuse, conspicuously tattered apices; border 3–7 cells wide, continued up sides of leaf but not extending across apex, at basal angles merging with patches of narrow cells which take up 80–100% of leaf base; hyalocysts lacking fibrils, extensively and equally resorbed, both surfaces being largely absent in upper leaf. Branch leaves 1.3–2.5 × 0.5–0.8 mm, narrowly ovate, not recurved when dry; border 3–5 cells wide; chlorocysts in section triangular or somewhat barrel-shaped, with a wide abaxial exposure, not exposed on adaxial surface; abaxial pores 3–8 μm, 0–1(−2) per cell, when present normally confined to distal angle of cells; adaxial pores 3–8 μm, faint, unringed, (0−)4–10 per cell, in cell angles or distributed along commissures. Antheridial leaves slightly darker than others, not conspicuous. Perichaetial leaves oblong, either obtuse and entire or retuse and ± fringed at apex, lacking fibrils, extensively resorbed on both surfaces near apex. Spores 29– 32 μm. Capsules very rare, summer. n = 10, 19 + 2 m. In montane flushes. Rarely below 600 m and ascending to 1000 m. Rare, Highlands of Scotland from Mid Perth and Angus to W. Sutherland and Shetland. 10. GB16 + 1∗ . Circumpolar, common in the northern boreal zone and Arctic, scattered further south. When the colour is bright orange-brown S. lindbergii is conspicuous. The dark brown stems and usually cuneate, fringed stem leaves make it unmistakable on close examination.

Class 2 Andreaeopsida

Protonemata thalloid. Plants acrocarpous. Seta absent, capsule joined directly to foot and exserted from perichaetium by elongation of pseudopodium (stalk of archegonium); capsule dehiscing by 4(−8) longitudinal slits; spore sac endothecial in origin, overtopping columella, no air cavities between spore sac and capsule wall; calyptrae small. One family.

2 Andreaeales 2 Andreaeaceae One or possibly two genera.

2 ANDREAEA HEDW., SP. MUSC. FROND., 1801 Reddish brown to purple or blackish small to medium-sized tuft- or cushionforming plants. Stems fragile, lacking central strand. Leaves straight to falcate, ovate to narrowly lanceolate or panduriform, abruptly narrowed above basal part to long or short limb or not, apex acuminate to rounded; margins entire or denticulate; costate or ecostate; basal cells short to elongate, walls often sinuose and/or pitted, cells above rounded or quadrate, incrassate, smooth or papillose. Plants usually of acidic rocks in cool temperate, oceanic and sub-polar regions. A worldwide genus of about 50 species. Derivation: named after J. G. R. Andreae (1724–1793), an apothecary of Hanover. The following descriptions are modified from those by B. M. Murray in her monograph of the genus in the British Isles (J. Bryol. 15, 17–82, 1988).

1 Leaves ecostate 2 Leaves costate 6 2 Basal margins of leaves denticulate 1. A. alpina Basal margins of leaves entire or weakly crenulate 3 3 Basal marginal cells of leaves rectangular, other basal cells strongly sinuose and strongly pitted, spores mostly 13–19 μm, very rare high altitude plant 5. A. sinuosa 103

2 Andreaeaceae

104

4

5

6

7

8

9

10

Basal marginal cells oblate to shortly rectangular, other basal cells not or hardly sinuose, pitted or not, spores mostly 20–26 μm (12–21 μm in A. mutabilis) 4 Spores 12–21 μm, leaf bases hardly sheathing, often with patch of yellow cells at base, basal cells hardly pitted, perigonia numerous, crimson 4. A. mutabilis Spores mostly 20–26 μm, leaf bases sheathing, lacking patch of yellow cells at base, basal cells usually pitted 5 Leaves usually subfalcate to falcate-secund, papillae usually prominent at least abaxially on upper leaves, frequent plant 2. A. rupestris Leaves usually straight, papillae usually low or absent, very rarely prominent, very rare high altitude plant 3. A. alpestris Leaf margins papillose-crenulate to serrate throughout, cells papillose 10. A. nivalis Leaf margins entire or very rarely dentate above, cells smooth 7 Spores (10−)11–19(−23) μm, basal cells mostly rectangular, longer than cells above, walls little pitted, rarely slightly sinuose, dioicous 9. A. blyttii Spores more than 20 μm, basal cells mostly quadrate, rounded or oblate, ± similar to cells above (sometimes rectangular near costa or margins), walls often strongly pitted and sinuose, autoicous 8 Leaves gradually tapering to apex, perichaetial bract cells smooth, very rare high altitude plant 7. A. frigida Leaves ± abruptly narrowed to limb, perichaetial bract cells usually papillose 9 Spores mostly 26–36 μm, costa more than 1/3 width of leaf base, poorly defined above, doubtfully British plant A. crassinervia (p. 113) Spores mostly 36–90 μm, costa less than 1/3 width of leaf base, well defined above or not 10 Spores mostly 50–90 μm, leaf cells distinct in upper part of limb, inner perichaetial bracts with low rounded papillae 8. A. megistospora Spores mostly 36–52 μm, leaf cells indistinct in upper part of limb or if distinct then inner perichaetial bracts without or with only low sparse papillae 6. A. rothii

Subgenus 1 Andreaea Perichaetial bracts differentiated from stem leaves, convolute. Section 1 Andreaea Leaves ecostate. 1 A. alpina Hedw., Sp. Musc. Frond., 1801 (Fig. 26) Autoicous. Reddish brown to purplish black tufts or patches, 1–6(−8) cm high. Leaves imbricate when dry, patent to spreading when moist, larger and less

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Fig. 26 1–4, Andreaea alpina: 1, moist shoot tip with sporophyte (×25); 2, leaves (×40); 3, cells at widest part of leaf; 4, basal marginal cells. 5–8, A. alpetris: 5, leaves (×80); 6, basal cells; 7, basal marginal cells; 8, upper cells. Cells ×420.

crowded on capsule-bearing stems, ovate-spathulate to panduriform, widest at or above middle, narrowed to short to long acute to obtuse apex; margins plane to incurved, denticulate from near base to middle of leaf constriction, entire above; costa lacking; basal cells rectangular to narrowly rectangular, walls strongly incrassate, pitted, sinuose, transition from basal to upper cells ± abrupt, upper cells rounded to oval, smooth, 8–10 μm wide. Perichaetial bracts differentiated from stem leaves, convolute. Spores 26–38 μm but frequently aborted. Capsules occasional to common, summer. On moist to continuously dripping rocks in streams, on ledges, cliffs, moist and periodically irrigated outcrops and boulders, in montane areas in acidic to mildly basic situations. 60–1300 m. Rare in S. Wales, frequent or common in N. W. Wales, Lake district and the Scottish Highlands, extending north to Shetland, rare in eastern Ireland, frequent in the far west. 39, H12. GB176 + 34∗ , IR22 + 10. Austria, Faeroes, France, Norway, Greenland, western

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S. America from Colombia southwards, Tasmania, New Zealand, cold temperate and sub-antarctic Southern Hemisphere islands. Easily identified by its large size and panduriform ecostate leaves with margins denticulate below.

2 A. rupestris Hedw., Sp. Musc. Frond., 1801 A. petrophila Ehrh. Autoicous. Green-bronze to red-brown or black often coalescing tufts, 0.5–3.0 cm high. Leaves imbricate when dry, patent or often secund or falcate-secund when moist; straight to falcate, ovate to oblong-lanceolate, little constricted above base to panduriform, widest above or below constriction, upper part short to long, obtuse to acute; margins plane or ± incurved; costa lacking; cells incrassate, basal rectangular to narrowly rectangular, walls pitted, not sinuose, basal marginal cells oblate to rectangular, transition to upper cells ± abrupt, cells above quadrate to shortly rectangular, walls usually strongly pitted, characteristically with prominent colourless papillae on abaxial side but sometimes without, c. 8–10 μm wide. Perichaetial bracts larger than stem leaves, convolute, cells usually strongly papillose. Turgid green spores usually 26–32(−48) μm but frequently aborted. Capsules common, summer. n = 9 + m, 10, 11. Leaves lanceolate or occasionally panduriform, gradually narrowed to short or long obtuse to acute apex, frequent or common plant var. rupestris Leaves abruptly narrowed from ovate or panduriform basal part to long acute apex, very rare plant var. papillosa Var. rupestris (Fig. 27) Cushions, rarely more than 3 cm high. Leaves tapering to short or long apex; papillae when present longer than wide but rarely twice as long as wide. On dry to periodically moist neutral to acidic rocks, cliffs, walls, also in snow-beds, very rarely on lithosols. 0–1330 m. W. Cornwall (old record), Devon, frequent or common in western and northern Britain from Wales north to Shetland, occasional in N. E. Ireland, rare elsewhere. 62, H20. GB454 + 77∗ , IR40 + 13∗ . Widespread in the Northern Hemisphere, C. and S. America, southern Africa, Tasmania, New Zealand, Antarctica. Var. papillosa (Lindb.) Podp., Consp. Musc. Eur., 1954 A. obovata var. papillosa (Lindb.) Nyholm

(Fig. 27)

Plants small (in Britain). Leaves from ovate basal part abruptly narrowed to often very long narrow acute upper part; cells with prominent colourless papillae often more than twice as long as wide, rarely low and inconspicuous. On acidic rocks in mountains. Very rare, Merioneth, Caernarfon, Cumberland (old record).

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Fig. 27 1–5, Andreaea rupestris var. rupestris: 1, leaves; 2, basal marginal cells; 3, basal cells; 4, upper cells; 5, section of upper part of leaf. 6, A. rupestris var. papillosa: leaves. Leaves ×80, cells ×420.

3. GB2 + 1∗ . Austria, Finland, Norway, Poland, Svalbard, Sweden, N. Russia, arctic Asia, N. America. A. rupestris var. rupestris is polymorphic but can usually be distinguished from other ecostate species by its falcate leaves with pitted non-sinuose basal cells and papillose upper cells.

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Closely related to A. alpestris from which stunted forms may be difficult or impossible to separate. Var. papillosa is distinguished from var. rupestris by the leaves abruptly narrowed to a long upper part. Most long-tipped material from Britain has gradually tapering leaves and is referable to var. rupestris. Typically, var. papillosa is a robust plant and British material identified as var. papillosa, at the southern edge of its distribution, is depauperate.

3 A. alpestris (Thed.) Schimp. in Bruch et al., Bryol. Eur., 1855 (Fig. 26) A. petrophila var. alpestris Thed., A. rupestris var. alpestris (Thed.) Sharp Reportedly autoicous. Small brown, brown-black to black, occasionally reddish cushions or mats, to 1 cm high (in Britain). Leaves imbricate, very rarely falcate distally, stiff or soft when dry, widely spreading from middle when moist, lanceolate, usually widest near to and little constricted above base, rarely panduriform, apex straight or occasionally turned to one side, short, incurved, obtuse, rarely acute; margins plane or slightly incurved, entire; costa absent; basal cells shortly rectangular, weakly pitted, not sinuose, basal marginal cells oblate to rectangular, transition to upper cells very gradual, upper cells ± quadrate, walls non-pitted, brownish papillae present but low, inconspicuous and irregular on abaxial side, also on adaxial side where cells bistratose, cells (7−)8–10(−11) μm wide. Perichaetial bracts larger than stem leaves, convolute, cells with low papillae. Spores (21−) 22–26(−32) μm, frequently aborted. Capsules occasional, summer. On periodically moist rock or wet lithosols. 700–1335 m. Very rare, Angus, S. Aberdeen, Banff, Inverness, E. Ross. 6. GB6 + 4∗ . Montane and northern Europe from 40◦ N in Spain north to Fennoscandia, Asia, N. America, Greenland. A. alpestris is recognisable from the thread-like shoots, which are usually a soft brown-black or occasionally glossy black colour, the leaves are usually straight and obtuse. Microscopically, it is characterised by mostly non-pitted cells with inconspicuous papillae. Most British material identified as A. alpestris is A. rupestris var. rupestris or A. mutabilis. Whether the plant should be treated as a distinct species or as a variety of A. rupestris is debatable.

4 A. mutabilis Hook. f. & Wilson, Lond. J. Bot., 1844 A. obovata var. sparsifolia auct. angl. non (F. Zetterst.) Nyholm

(Fig. 28)

Autoicous. Usually small purple-red to black flattened spreading cushions, sometimes glaucous or green-black, rarely more than 1 cm high. Leaves often distant, erect-spreading, not clasping, sometimes secund when dry, spreading when moist, lanceolate, widest near base, gradually tapering to acute to obtuse apex; margins often incurved, entire; costa lacking; cells papillose from near base to apex, basal elongate, thick-walled, walls hardly pitted, not sinuose, an irregularly shaped yellowish patch of cells often present at leaf base, basal marginal cells isodiametric to oblate, transition to upper cells gradual, upper cells rounded or oval, thick-walled, ± pitted, papillose, 9–12 μm wide. Perigonia numerous, crimson. Perichaetial bracts larger than stem leaves, convolute. Spores 12–21(very rarely

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Fig. 28 1–4, Andreaea mutabilis: 1, leaves; 2, basal marginal cells; 3, basal cells; 4, upper cells. 5–8, A. sinuosa: 5, leaves; 6, leaf apex; 7, basal cells and axillary hairs. Leaves ×80, cells ×420. 5–7 modified from B. M. Murray, J. Bryol. 15, 17–82, 1988.

to 32) μm. Capsules common, summer. On dry to wet exposed acidic rocks, rarely on soil over rock. (60–)600–1300 m. Rare to occasional in N. Wales, northern England and the Scottish Highlands, extending north to Ross. 24. GB20 + 14∗ . Faeroes, Finland, France, Spain, British Columbia, widespread in the Southern Hemisphere. A. mutabilis is often recognisable by the small flattened cushions with numerous tiny crimson perigonia. It has leaves that are not or only very slightly sheathing, basal cells little pitted and esinuose, basal marginal cells that are isodiametric. There is often a marked central yellow patch at the base of leaves. It also has small spores. The leaves tend to be more distant in A. mutabilis than in other ecostate species so that the non-clasping leaf bases and insertions are often clearly visible. In the field A. mutabilis is likely to be mistaken for A. rupestris or A. alpestris but it tends to occur in very small flattened spreading cushions

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and to be purple-red (rarely glaucous from dense papillae). The report of A. obovata var. sparsifolia (F. Zetterst.) Nyholm from Britain is based on a misidentification. The collection is A. mutabilis.

5 A. sinuosa B. M. Murray, Bryologist, 1987 (Fig. 28) Apparently dioicous but possibly autoicous. Very small tufts or occasional stems in A. blyttii, green-brown, red-brown, purple-black or black, rarely more than 1 cm high. Leaves sometimes appearing tristichous when dry, slightly spreading when moist, narrowly lanceolate to linear-lanceolate, widest just above slightly sheathing base, apex acute or occasionally rounded; margins incurved, entire; costa lacking; basal cells rectangular to oblong, longitudinal walls incrassate, conspicuously pitted and strongly sinuose, basal marginal cells narrowly rectangular, transition to upper cells gradual, upper cells 10–12 μm wide, irregularly rounded, oval or oblate, with large low brown to colourless papillae that are more numerous centrally than marginally or apically. Perichaetial bracts larger than stem leaves, convolute. Capsules emergent to shortly exserted, base 1/2 or more length of capsule; spores (11−)13–19(−21) μm. Capsules common, summer. On acidic rock in extreme snow-beds or deep gullies with late snow-lie. 950–1100. Very rare, S. Aberdeen, Banff, E. Inverness, Ross. 5. GB5. Aleutian Islands, British Columbia. A. sinuosa can be distinguished from other ecostate Andreaea species by its strongly sinuose basal cell walls. It also has smaller spores than other species in the British Isles. In the field it can be confused with forms of A. rupestris var. rupestris with acuminate leaves that also occur at high altitudes. A. sinuosa, however, has less sheathing leaves with more strongly incurved margins.

¨ Section 2 Nerviae Cardot, Wiss. Erb. Schwed. Sudpolar-Exp., 1908 Leaves costate. 6 A. rothii F. Weber & D. Mohr, Bot. Taschenb., 1807 Autoicous, rarely synoicous. Brown to black cushions, sometimes coalescing and forming extensive mats, 0.5–2.5 cm high. Leaves erect to secund when dry, erectspreading to secund when moist, usually sharply contracted from ovate basal part to acute limb 2–5 times as long as basal part; margins entire or crenulate, rarely distantly toothed; costa percurrent to excurrent, filling upper limb, well defined, with occasional abaxial papillae, bulging abaxially, weaker towards base, about 1/ –1/ width of leaf base; basal cells of similar shape to upper cells, walls not pit6 3 ted, longer towards costa, marginal basal cells ± isodiametric, cells above mostly rounded to oblate, distinct or not, smooth or bulging, 8–12 μm wide. Perichaetial bracts larger than stem leaves, convolute. Spores (30−)36–52(−60–80) μm, occasionally aborted. Capsules common, spring, summer. Leaves usually weakly falcate, rarely brittle, cells usually distinct to near apex, costa usually percurrent or if excurrent filling up to 1/4 of apex, inner perichaetial bracts smooth or with very low sparse papillae ssp. rothii

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Leaves usually strongly falcate, brittle, costa usually filling 1/4 –1/2 upper part of leaf, cells rarely distinct to near apex, inner perichaetial bracts with dense high papillae above ssp. falcata Ssp. rothii (Fig. 29) Leaves erect to secund, rarely distinctly falcate when moist, rarely brittle; limb 2–3 times as long as basal part of leaf, cells distinct in limb; margins of limb entire or crenulate; costa usually percurrent, when excurrent filling only upper 1/4 of limb; cells usually distinct to near apex. Innermost perichaetial bracts usually with trace of costa, papillae lacking or very low and sparse. n = 10. On periodically moist acidic ± exposed rocks. 0–750 m. Rare in western and northern Britain and Ireland. 25, H11. GB26, IR15. Europe north to Fennoscandia, Iceland, Caucasus, Mongolia, N. America. Ssp. falcata (Schimp.) Lindb., Musci. Scand., 1879 (Fig. 29) A. crassinervia auct. non Bruch, A. crassinervia var. huntii (Lindb.) Braithw. Leaves usually strongly falcate when moist, brittle, limb 3–5 times as long as basal part, cells indistinct or sometimes distinct in limb; limb margins entire, crenulate or rarely distantly dentate; costa usually excurrent, occasionally percurrent, filling upper 1/4 –1/2 of limb; cells rarely distinct to near apex. Innermost perichaetial bracts usually ecostate; usually with dense sharp oblique papillae above, sometimes lacking in some plants in a population. n = 11∗ . On periodically moist acidic ± exposed rocks. 0–1344 m. Frequent to common in western and northern Britain, extending from Cornwall north to Shetland, frequent or common in W. Ireland, rare elsewhere. 66, H20. GB169, H36. Europe from Sardinia and Spain north to Sweden, Oregon. Ssp. rothii differs from ssp. falcata in its only slightly falcate and non-brittle leaves, in the lamina usually distinct almost to the apex, the costa only occasionally excurrent and the cells of the inner perichaetial leaves usually smooth. However, in the British Isles specimens of ssp. rothii frequently have somewhat falcate leaves, an excurrent costa and cells with scattered low papillae. It is possible that this intermediate form is the result of hybridisation between ssp. rothii and ssp. falcata. Typical material of ssp. falcata may be recognised by the black strongly falcate brittle leaves with long excurrent costa filling the upper limb and by the strongly papillose inner perichaetial bracts (although not necessarily in every perichaetium) – the papillae may be seen with a dissecting microscope. Ssp. falcata differs from A. crassinervia in its larger spores and its narrower abaxially bulging costa. Ssp. falcata is much commoner than ssp. rothii, constituting almost 90% of British and Irish gatherings named A. rothii and all gatherings named A. crassinervia. Ssp. rothii differs from A. frigida in the more abruptly formed limb, larger spores and its tendency to occur at lower elevations in drier sites. It has smaller spores than and lacks the dense perichaetial bract papillae of A. megistospora.

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Fig. 29 1–7, Andreaea rothii ssp. rothii: 1, 2, moist and dry shoot tips with sporophytes; 3, leaves; 4, basal marginal cells; 5, basal cells; 6, upper cells; 7, upper cells of inner perichaetial bract. 8–9, Andreaea rothii ssp. falcata: 8, leaves; 9, upper cells of inner perichaetial bract. Leaves ×65, cells ×420.

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A. crassinervia Bruch, Abh. Math-Phys. Cl. Königl. Bayer. Akad. Wiss., 1832

Autoicous. Brown to black tufts, 0.5–2.5 cm high. Leaves erect to falcate-secund when dry, erect-spreading to secund when moist, ± abruptly tapering from an ovate basal part to acute limb 2–4 times as long as basal part; margins plane, entire; costa excurrent, filling almost entire limb, strong, poorly defined, often papillose abaxially, weaker towards base, usually 1/3 –1/2 width of leaf base; basal cells similar to upper, cells near costa with walls often sinuose, cells above indistinct and usually present only in lower 1/3 of limb, rounded, oval or oblate, smooth to bulging, 9–12 μm wide. Perichaetial bracts differentiated from stem leaves, sheathing, inner bracts ecostate, with or without scattered low rounded papillae, papillae rarely dense or sharp. Spores (20−)26–36(–50) μm. Usually montane. One specimen doubtfully collected at Dubh Loch, S. Aberdeen (possibly 1870). Europe, North America. A. crassinervia is easily recognized by the very wide poorly defined costa that fills almost the entire limb. It is distinguished from other species in which the costa fills a large part of the limb by its spores, which are larger than those of A. blyttii and smaller than those of A. rothii ssp. falcata. With one exception all British material previously identified as A. crassinervia was misidentified A. rothii ssp. falcata. There is one specimen labelled Dunloch in NY but careful search at the locality (Dubh Loch) failed to find A. crassinervia. Because of the poor labelling of the packet and the nature of its contents the specimen must be regarded as of doubtful provenance and the species excluded from the British list.

7 A. frigida Huebener, Hepaticol. Germ., 1834 A. rothii ssp. frigida (Huebener) Schultze-Motel

(Fig. 30)

Autoicous. Coarse red-maroon cushions, to over 4 cm high. Leaves erect, straight or often secund when moist, little changed when dry, ± lanceolate or gradually narrowed from ovate basal part to acute limb 1.5–2.0 times as long as basal part; margins entire; costa percurrent or rarely excurrent, filling upper 1/4 of limb, ± well defined, smooth, weaker towards leaf base, about 1/4 –1/3 width of leaf base; basal cells of similar shape to cells above, not pitted, cells near costa rectangular, usually with sinuose walls, upper cells distinct, rounded, oval or oblate, ± thin-walled, smooth to bulging, 8–12 μm wide. Perichaetial bracts differentiated from stem leaves, convolute, inner bracts partly costate, rarely ecostate, cells smooth. Spores (20−)25–35(−40) μm. Capsules common, summer. On acidic boulders or rock subject to periodic inundation in mountain streams and by lochs. (50−)660–1200 m. Very rare, N. W. Yorkshire (old record), Cumberland, S. Aberdeen, Banff. 4. GB4 + 1∗ . Europe from Romania and Portugal Norway, Iceland. Recognisable by the combination of gradually narrowed, lanceolate leaves with the cells distinct to the apex and spores (20−)25–35(−40) μm. Distinguished from A. rothii and A. megistospora by its large size and occurrence in wet montane habitats. A. frigida is regarded as vulnerable in the Red List of British Mosses.

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Fig. 30 1–3, Andreaea megistospora: 1, leaves; 2, basal cells; 3, upper cells. 4–7, A. frigida: 4, leaves; 5, basal marginal cells; 6, basal cells; 7, upper cells. Leaves ×90, cells ×420.

8 A. megistospora B. M. Murray, Bryologist, 1987 (Fig. 30) Autoicous. Brown to black small, rarely medium-sized plants, usually less than 1 cm high, rarely to 1.5 cm. Leaves appressed when dry, erect-spreading or secund when moist, often abruptly contracted from an ovate or oblong basal part to acute

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limb 2–3 times as long as basal part; margins plane, entire; costa strong, percurrent to excurrent, filling upper 1/4 of limb, well defined, with occasional abaxial papillae, biconvex or bulging abaxially, rarely weaker towards base, c. 1/6 –1/4 width of leaf base; basal cells similar to or slightly longer than upper, walls often sinuose, not pitted, cells distinct in limb, mostly rounded to oblate, thin-walled, smooth or bulging, 8–12 μm wide. Perichaetial bracts differentiated from stem leaves, convolute, inner bracts ecostate, usually with low rounded papillae, papillae rarely sharp and oblique. Spores very large (40−)50–90(−110) μm. Capsules common, spring, summer. On dry to moist, usually exposed acidic rock. 0–700(−1100) m. Rare, Pembroke, Merioneth, scattered localities in western Scotland from Kircudbright north to the Outer Hebrides, W. Cork, Sligo, old records from Durham, Westmorland, Mid Cork, Leitrim. 19, H4. GB16 + 11∗ , IR2 + 2∗ . N. W. Portugal, Norwegian coast north to 63◦ N, N. W. North America. A. megistospora is distinguished from all other Andreaea species by its very large spores. It is also recognisable by its relatively small size and leaves with the cells distinct to the apex. It is distinguished from A. rothii ssp. rothii and A. frigida, the other taxa in the British Isles with similar leaves, by its papillose perichaetial bracts. European material of A. megistospora belongs to ssp. megistospora; a second subspecies, ssp. papillosa B. M. Murray, occurs in N. W. North America.

9 A. blyttii Schimp. in Bruch et al., Bryol. Eur., 1855 (Fig. 31) Dioicous. Brown to black tufts or patches, often brown below and black above, 0.5– 2.5 cm high. Leaves erect to secund, brittle when dry, erect-spreading to secund or spreading when moist, ± abruptly narrowed from narrow oblong or ovate basal part to limb 3–4 times as long as basal part, limb narrow, often only two cells wide apically, uneven in outline, fragile; margins plane, entire; costa present, ± filling limb, weaker or occasionally absent basally, poorly defined, with occasional abaxial papillae, not bulging abaxially, c. 1/6 –1/3 width of leaf base; basal cells rectangular to shortly rectangular, in longitudinal rows, walls incrassate, hardly pitted, very rarely inconspicuously finely sinuose, basal marginal cells mostly shortly rectangular, upper cells indistinct in limb, rounded or quadrate, ± smooth to bulging, rarely with low papillae, (9−)10–12 μm wide. Perichaetial bracts differentiated from stem leaves, convolute, inner bracts ecostate, cells smooth or with low scattered papillae. Spores (11−)13–19(−23) μm. Capsules occasional, summer. On acidic rock slabs or boulders in scree by late snow-patches, usually on more or less perpendicular drier surfaces, snow-covered rocks or in melt-water early in summer, dry and exposed later on. c. 900–1200 m. Very rare, S. Aberdeen, Banff, Inverness, Ross. 6. GB8. Finland, France, Iceland, Norway, Poland, Spain, Svalbard, Sweden, N. Russia, N. America, Greenland. A. blyttii differs from other costate Andreaea species in its very narrow limb, the lamina often only two cells wide on either side of the costa above, basal cells mostly rectangular, costa often weak to absent in the base of the leaf, the spores small and it is dioicous.

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Fig. 31 1–2, Andreaea nivalis: 1, leaves (×40); 2, cells at widest part of leaf. 3–5, A. blyttii: 3, leaves (×80); 4, basal cells; 5, upper cells. Cells ×420. J. W. Heslop-Harrison & R. B. Cooke (J. Bot. Lond, 80, 35–38, 1942) reported A. blyttii and A. obovata Thed. (as A. hartmanii Thed.) as new to the British Isles but the records were not substantiated.

Subgenus 2. Chasmocalyx (Lindb. ex Braithw.) Limpr., Laubm. Deutschl., 1885 Stem epidermal cells very small. Leaf margins often incurved or recurved; leaf bases auriculate. Perichaetial bracts differentiated from stem leaves, sheathing or not. Pseudopodium formed from gametophyte stem as well as achegonial stalk. 10 A. nivalis Hook., Trans. Linn. Soc. Lond., 1811 (Fig. 31) Dioicous. Brownish green to red-brown tufts, patches or large mats, (1−)4– 6(−10) cm high. Leaves imbricate when dry, patent to spreading or falcate-secund when moist, narrowly lanceolate to ovate-lanceolate, gradually tapering from oblong basal part to acute apex, base somewhat decurrent or auriculate; margins irregularly denticulate or papillose-crenulate, sometimes partially recurved

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on one or both sides; costa reddish, subpercurrent or filling leaf apex, strongly papillose on abaxial side; basal cell walls not sinuose or pitted, cells in upper part of leaf distinct, coarsely papillose on both sides, quadrate to rounded, 8–11 μm wide. Perichaetial bracts similar to but a little larger than stem leaves, not convolute. Spores 24–33(−40) μm, occasional spores aborted. Capsules occasional, early summer. n = 10. On wet rocks at edges of streams and flushes that are usually fed by snow-beds, on seeping outcrops and ledges that are flat to gently sloping. (720−)880–1300 m. Rare but locally abundant in the Scottish Highlands. 10. GB15 + 4∗ . Montane Europe from Austria and Italy north to Fennoscandia, Caucasus, Siberia, Japan, North America, Greenland.

Class 3 Polytrichopsida

Acrocarpous. Plants frequently large, stems simple or branched, tough, with internal anatomical differentiation. Leaves often with broad costa bearing adaxial longitudinal lamellae. Setae long; capsules dehiscent; peristome nematodontous. The peristome teeth of members of the Polytrichales are not homologous with those of members of the Bryopsida or Tetraphidales which in turn are not homologous with those of the Bryopsidia.

3 Polytrichales Plants large, usually rhizomatous. Stems with central strand with differentiated conducting tissue. Leaves usually differentiated into sheathing base with narrow costa, and blade composed largely of expanded costa bearing longitudinal lamellae on adaxial side, lamina usually narrow, 1–2-stratose; margins toothed or entire, sometimes bordered. Capsules erect to horizontal, spherical to cylindrical, terete or 2–6-angled, hypophysis present or not; annulus absent; peristome nematodontous, with 32 or 64 teeth; columella expanded at top into membranous epiphragm joined to tips of peristome teeth; calyptrae cucullate, glabrous or hairy. A probably ancient group of one family and about 23 genera.

3 Polytrichaceae For a conspectus of the genera of the Polytrichaceae see G. L. Smith, Mem. New York Bot. Gard. 21(3), 1–82, 1971. Vegetative propagules unknown but many species readily regenerating from fragments of leaves and stems.

3 POGONATUM P. BEAUV., MAG. ENCYCL., 1804 Dioicous. Shoots arising from decumbent rhizome-like stems or from persistent protonemata. Leaves with broad sheathing basal part abruptly narrowed into lingulate to narrowly lanceolate blade consisting mainly of costa bearing numerous straight lamellae on adaxial side. Capsules erect, terete, without hypophysis or stomata, exothecial cells mamillose, not pitted; peristome teeth 32; calyptrae densely hairy, covering capsule. A cosmopolitan genus of 32 species.

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¨ For a homograph of Pogonatum see J. Hyvonen, Acta Bot. Fennica 138, 1–87, 1989. Derivation: bearded, referring to the hairy calyptrae.

Key to species of Pogonatum, Polytrichastrum and Polytrichum 1 Leaf margins entire, inflexed over blade 2 Leaf margins toothed, not inflexed over blade 5 2 Leaf apices cucullate, costae ending in apex or shortly excurrent, capsules obscurely angled 4. Polytrichastrum sexangulare (p. 125) Leaf apices not cucullate, costa excurrent in arista, capsules sharply angled 3 3 Costae excurrent in hyaline arista, smooth on abaxial side above, crenulae of lamellae directed towards leaf apex 2. Polytrichum piliferum (p. 129) Costa excurrent in brownish arista, toothed on abaxial side above, lamellae crenulae ± erect 4 4 Plants mostly 1–7 cm high, tomentum if present brownish, spores 8–10(–12) μm 3. Polytrichum juniperinum (p. 130) Plants mostly 6–20 cm high, stems with dense off-white tomentum below, spores (12–)14–18 μm 4. Polytrichum strictum (p. 130) 5 Plants to 2 cm high, unbranched, shoots arising from dark green persistent protonemata, capsules terete 6 Plants (1–)2–40 cm high, shoots sometimes branched, arising from prostrate rhizome-like stems, capsules terete or angled 7 6 Capsules ± spherical, exothecial cells finely papillose, leaf blades shortly oblong, bluntly pointed 1. Pogonatum nanum (p. 119) Capsules usually shortly cylindrical, exothecial cells coarsely mamillose, leaf blades lingulate to oblong-lanceolate, acute to obtuse 2. Pogonatum aloides (p. 120) 7 Apical cells of lamellae papillose, capsules terete 8 Apical cells of lamellae smooth, capsules angled 9 8 Leaves glaucous green, acute, lamellae 5–6 cells high with apical cells rounded or elliptical in section 3. Pogonatum urnigerum (p. 122) Leaves dull green, acuminate, lamellae 6–8(–9) cells high with apical cells strawberry-shaped in section 1. Polytrichastrum alpinum (p. 123) 9 Capsules obscurely angled, leaf lamina on each side of costa in mid-blade 6 or more cells wide, cells 14–25 μm wide 2. Polytrichastrum longisetum (p. 123) Capsules sharply 4–6-angled, lamina in mid-blade 1–5 cells wide, cells 10–16 μm wide 10 10 Apical cells of lamellae rounded in section, capsules rectangular, 4–6-angled 3. Polytrichastrum formosum (p. 125) Apical cells of lamellae grooved or flat-topped in section, capsules cubic to shortly rectangular, 4-angled 1. Polytrichum commune (p. 128)

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1 P. nanum (Schreb. ex Hedw.) P. Beauv., Prodr. Aethéogam., 1805 Polytrichum nanum Schreb. ex Hedw.

(Fig. 32)

Dark green patches or scattered plants, to 5(–10) mm high, arising from dark green persistent protonemal mat. Leaves crowded, erect when dry, erect-patent when moist, blade ± shortly oblong, bluntly pointed; margins bluntly toothed from about the middle of the blade, teeth mostly consisting of only 1 cell; lamellae 4–6(–10) cells high, apical cells smooth, rounded in section, not enlarged; costa percurrent. Setae deep red, flexuose, 0.5–3.0 cm long; capsules erect or inclined, spherical to ovoid, urceolate or turbinate when dry and empty; exothecial cells finely papillose; peristome teeth 320–400 μm long; lid rostellate; columella cylindrical; spores 24–27 μm. Capsules common, winter. n = 7. On acidic soil on banks, heaths and roadsides. 0–550 m. Occasional but not seen recently in many vicecounties throughout Britain and Ireland. 97, H19, C. GB210 + 139∗ , IR 10 + 12∗ , C3. European Temperate. Europe, Faeroes, Iceland, Macaronesia, N. Africa. P. nanum cannot be distinguished from small forms of P. aloides when capsules are lacking. Possibly overlooked as there has been confusion with P. aloides (q.v.). P. nanum seems to have decreased considerably in central and eastern England.

2 P. aloides (Hedw.) P. Beauv., Prodr. Aethéogam., 1805 Polytrichum aloides Hedw.

(Fig. 32)

Dark green scattered shoots or lax patches, to about 2 cm high, arising from persistent protonemal mat. Leaves crowded, erect when dry, erect-patent to spreading when moist, blade lingulate to oblong-lanceolate, obtuse to acute; margins plane or erect, toothed from base of blade to apex, teeth of 2 to several cells but in small forms unicellular and only from about mid-blade; lamellae 40–60, 5–6 cells high, apical cells smooth, in section rounded, not enlarged; costa ending in apex to slightly excurrent. Setae deep red, 1–4 cm long; capsules erect or slightly inclined, shortly cylindrical to ovoid or obovoid, frequently slightly asymmetrical or urceolate when dry and empty, exothecial cells conically mamillose; peristome teeth 150–200 μm long; columella 4-winged; spores 8–13 μm. Capsules common, autumn, winter. n = 7∗ , 14. On sheltered disturbed acid, peaty or mineral soil by roads, on banks, sides of ditches, in woods, often on vertical or sloping substrates. 0–400(–600) m. Frequent or common except in basic habitats. 110, H37, C. GB1230 + 117∗ , IR196 + 10∗ , C9. European Boreo-temperate. Throughout most of Europe, Faeroes, Caucasus, Turkey, Macaronesia, New Zealand (introduced). Depauperate forms of P. aloides cannot be distinguished from P. nanum when sterile but normal plants have more acutely pointed leaves with marginal teeth, composed of 2 to several cells, from base to apex of the blade. The capsules of P. aloides also differ in shape except in stunted forms which may be distinguished from P. nanum by the coarsely mamillose exothecial cells (easily seen at the edge of a flattened capsule), shorter peristome teeth and larger spores. Both species differ from P. urnigerum and Polytrichastrum and Polytrichum species

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Fig. 32 1–6, Pogonatum nanum: 1, shoot; 2, leaves; 3, leaf margin towards apex; 4, part of lamella in side view; 5, section of lamella; 6, capsule (×10). 7–12, P. aloides: 7, shoot; 8, leaves; 9, leaf margin towards apex; 10, part of lamella in side view; 11, section of lamella; 12, capsule (×10). 13–18, P. urnigerum: 13, shoot; 14, leaf; 15, part of lamella in side view; 16, section of lamella; 17, capsule with calyptra (×7.5); 18, capsule (×7.5). Plants ×1, leaves ×7.5, cells ×450.

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in the shoots arising from persistent protonemata instead of from prostrate rhizome-like stems. ¨ J. Hyvonen (loc. cit.) in his monograph treats P. aloides var. minimum (Crome) Molendo, as a synonym of the type.

3 P. urnigerum (Hedw.) P. Beauv., Prodr. Aethéogam., 1805 Polytrichum urnigerum Hedw.

(Fig. 32)

Glaucous green patches or scattered plants, to 7(–10) cm high. Shoots arising from prostrate rhizome-like stems; protonemata not persisting. Leaves erect when dry, patent to spreading when moist, blade lanceolate to narrowly lanceolate, acute; margins with coarse spinose teeth; lamellae 30–50, mostly 5–6 cells high, apical cells papillose, incrassate, in section enlarged, rounded or elliptical; costa excurrent. Setae 1–3(–5) cm; capsules shortly cylindrical, ± erect to inclined; exothecial cells coarsely mamillose; spores 10–14 μm. Capsules common, autumn, winter. n = 7∗ , 14. On acidic, well drained, disturbed, often sandy or gravelly soil on banks, amongst rocks, in turf, on wall tops, roadsides. 0–1330 m. Rare to occasional in lowland England, frequent to common elsewhere. 105, H34, C. GB880 + 82∗ , IR143 + 4∗ , C1. Circumpolar Boreo-arctic Montane. Throughout Europe north to Svalbard, Faeroes, Iceland, Caucasus, Asia, New Guinea, Macaronesia, N. America, Greenland, Caribbean. Although usually distinct from Polytrichastrum alpinum in its glaucous green colour, taller forms on damp ground may lack the glaucous tint but differ in the relatively shorter broader leaf blades, the shorter lamellae with apical cells rounded or elliptical in section and the ± erect capsules with coarsely mamillose exothecial cells. Vegetative propagation by caducous leaves may sometimes occur. Although not reported in the literature the apical cells of the lamellae are very rarely completely smooth.

4 POLYTRICHASTRUM G. L. Sm., MEM. NEW YORK BOT. GARD., 1971 Dioicous. Protonemata ephemeral. Shoots arising from prostrate rhizome-like stems. Leaves with broad sheathing basal part abruptly narrowed into erect-patent to spreading lanceolate to linear-lanceolate blade composed mainly of costa with very narrow lamina on either side; costa with numerous ± straight lamellae on the adaxial side. Capsules inclined to horizontal, terete or obscurely or sharply 4–6-angled, hypophysis weakly or well differentiated, stomata present; exothecial cells smooth, not pitted; peristome teeth 64 (c. 45 in P. alpinum as a result of fusion), without appendages or wings on the inner face (leiodont); epiphragm fleshy, dorsal margins entire or with tooth-like projections adhering to the inner surface of the peristome teeth, ventral margins entire, annulus-like structure present on the under surface; calyptrae densely hairy, covering capsules. About 13 species world-wide. Derivation: incomplete similarity to Polytrichum.

For key to species of Polytrichastrum see under Pogonatum (p. 118).

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Section 1 Polytrichastrum Leaf margins toothed, not inflexed; apical cells of lamellae papillose, not pyriform in section. Capsules terete, hypophysis obscure, exothecial cells smooth, not pitted; peristome teeth variable in number because of fusion. 1 P. alpinum (Hedw.) G. L. Sm., Mem. New York Bot. Gard., 1971 ¨ Pogonatum alpinum (Hedw.) Rohl., Polytrichum alpinum Hedw.

(Fig. 33)

Lax dull green tufts, tall turfs or patches, to c. 10 cm high. Leaves erect-inflexed when dry, erect-patent to recurved when moist, blade linear-lanceolate, acuminate; margins toothed; lamellae 30–40, 5–9 cells high, apical cells incrassate, papillose, enlarged and strawberry-shaped in section; costa excurrent. Setae flexuose, yellowish above, reddish below, 0.5–3.0 cm long; capsules suberect to inclined, asymmetrical, subglobose to subcylindrical, terete, rugose but not angled when dry, exothecial cells smooth, not pitted, stomata present at base of poorly defined hypophysis; lid with long curved beak; peristome teeth c. 45, irregular, short; spores 18–20 μm. Capsules common, autumn. n = 7∗ , 14. On stony banks, amongst rocks, on cliff ledges and moorland peat, in montane areas. 0–915 m. Absent from lowland England, occasional to common elsewhere, occasional in N. W. Ireland, very rare elsewhere. 68, H22. GB341 + 53∗ , IR39 + 8∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N., C. and E. Asia, Kerguelen Is., N. America, Greenland, Mexico, southern S. America, Antarctica. A very variable species both in size of the gametophyte and shape of the capsules. The plant named var. septentrionale (Sw.) Lindb., about 2 cm tall with very short setae and ± globose capsules, appears to be an extreme form not worthy of taxonomic recognition (see A. Schreibl, Carinthia (Klagenfurt) 181/101, 461–506, 1991). P. alpinum differs from other Polytrichastrum and from Polytrichum species in the terete capsules and the papillose marginal cells of the leaf lamellae. For the differences from Pogonatum urnigerum see under that plant.

Section 2 Sexangularia (Bruch & Schimp.) G. L. Sm., Mem. New York Bot. Gard., 1971 Leaf margins toothed, if inflexed not greatly broadened; apical cells of lamellae smooth, not pyriform in section. Capsules sharply or obscurely angled, hypophysis poorly or well defined, exothecial cells smooth, not pitted; peristome teeth 64. 2 P. longisetum (Sw. ex Brid.) G. L. Sm., Mem. New York Bot. Gard., 1971 (Fig. 33) Polytrichum aurantiacum Brid., Polytrichum gracile Metnz., Polytrichum longisetum Sw. ex Brid. Dark green tufts or turfs, 1.5–10.0 cm high. Leaves ± erect, flexuose when dry, spreading, recurved when moist, blade narrowly lanceolate, acuminate; margins erect, toothed, lamellae usually 25–35, 5–7 cells high, apical cells smooth, incrassate, in section hardly enlarged; costa excurrent in denticulate brown arista;

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Fig. 33 1–7, Polytrichastrum alpinum: 1, shoot; 2, leaf; 3, part of lamella in side view; 4, section of lamella; 5. capsule. 6–7, Plant referred to as P. alpinum var. septentrionale: 6, plant 7, capsule. 8–14, P. longisetum: 8, shoot; 9, leaf; 10, part of lamella in side view; 11, section of lamella; 12, marginal cells of leaf blade; 13, 14, moist and dry capsules. Shoots ×1, leaves ×7, capsules ×5, cells ×450.

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125

lamina at middle of blade 6 or more cells wide, cells 16–20(–25) μm wide. Setae flexuose, reddish brown below, yellowish above, 1.5–6.0 cm long; capsules erect at maturity, inclined with age, obloid, obscurely 5–6-angled; hypophysis well defined; lid with long beak; spores 20–26 μm. Capsules common, summer. n = 7∗ , 14. On well drained acidic soil on heaths and moorland and in woods. 0–1030 m. Generally distributed, occasional. 92, H31. GB261 + 78∗ , IR26 + 20∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. Asia, Korea, Japan, New Guinea, N. America, Greenland, Chile, New Zealand. This plant has been confused in the past with P. formosum as one of the key characters given in Dixon & Jameson (1924), the length of the cells in the sheathing leaf base, is unreliable. Fertile material differs from other Polytrichastrum and from Polytrichum species except Polytrichastrum sexangulare in the obscurely angled capsules. When sterile it differs in the wider laminae with larger cells and the costa with fewer lamellae.

3 P. formosum (Hedw.) G. L. Sm., Mem. New York Bot. Gard., 1971 Polytrichum formosum Hedw.

(Fig. 34)

Dark green tufts or turfs, to 10(–20) cm high. Leaves erect-flexuose when dry, spreading to recurved when moist, sheathing base not glossy, blade narrowly lanceolate, acuminate; margins plane or erect, toothed; lamellae to 70, 5–7 cells high, apical cells smooth, incrassate, in section rounded, not or scarcely enlarged; costa excurrent in denticulate arista; lamina in mid-blade 2–5 cells wide, cells 10–14(–16) μm wide. Setae flexuose, yellowish above, reddish below, 2.5–6.0 cm long; capsules erect or inclined, rectangular, sharply (4–)6-angled, hypophysis distinct; lid longly rostrate; spores 12–16 μm. Capsules frequent, summer. n = 7∗ , 14. On usually acidic soils on heaths, moorland, in woods, on rocks, cliff ledges, crevices in scree and old walls. 0–500 m. Frequent to common and sometimes locally abundant in suitable habitats. 112, H39, C. GB1527 + 75∗ , IR236 + 3∗ , C6. Circumpolar Boreo-temperate. Europe, Faeroes, Iceland, Caucasus, Turkey, Asia, New Guinea, Macaronesia, Algeria, southern Africa, N. America, Greenland, New Zealand. Typical forms of Polytrichum commune are larger than P. formosum with more distant leaves with shiny bases. However, forms of Polytrichum commune from drier habitats such as rock ledges and woodland may be much smaller and resemble plants of P. formosum but have shorter, consistently 4-angled capsules. In the absence of capsules, sections of the lamellae are necessary for identification.

¨ 4 P. sexangulare (Florke ex Brid.) G. L. Sm., Mem. New York Bot. Gard., 1971 (Fig. 35) ¨ Polytrichum norvegicum auct. non Hedw., Polytrichum sexangulare Florke ex Brid. Dark green patches, shoots erect or decumbent, 1–10 cm long. Leaves rigid, imbricate, incurved at the tips when dry, patent when moist, narrowly to broadly

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Fig. 34 1–7, Polytrichum commune var. commune: 1, shoot; 2, leaf (×5) and 3, perichaetial leaf (×5); 4, section of lamella; 5, part of lamella in side view; 6, 7, dry and moist capsules. 8–9, P. commune var. perigoniale: 8, perichaetial leaf (×7); 9, section of lamella. 10, P. commune var. humile: perichaetial leaf (×7). 11–17, Polytrichastrum formosum: 11, shoot; 12, leaf (×5); 13, section of lamella; 14, marginal cells of leaf blade; 15, part of lamella in side view; 16, 17, moist and dry capsules. Shoots ×1, capsules ×5, cells ×450.

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127

Fig. 35 1–4, Polytrichum juniperinum: 1, shoot; 2, leaf; 3, section of lamella; 4, part of lamella in side view. 5–8, Polytrichum piliferum: 5, shoot; 6, leaf; 7, section of lamella; 8, part of lamella in side view. 9–12, Polytrichastrum sexangulare: 9, shoot; 10, leaf; 11, section of lamella; 12, part of lamella in side view. 13–16, Polytrichum strictum: 13, shoot; 14, leaf; 15, section of lamella; 16, part of lamella in side view. Shoots ×1, leaves ×7, cells ×450.

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ligulate, apex broad to acute, cucullate; margins entire, erect below, incurved above; lamellae 30–35, 5–7 cells high, apical cells smooth, incrassate, in section rounded to conical, not or scarcely enlarged; costa ending in apex to shortly excurrent. Setae 2–3 cm long, stout; capsules erect or inclined, obloid, bluntly 6-angled, hypophysis hardly distinct; lid with long beak; spores 18–20 μm. Capsules occasional, summer. n = 14. On soil, often in areas of late snow-lie in the Scottish Highlands. 900–1325 m. Very rare, Perth, Aberdeen, Banff, Inverness, Ross. 9. GB21 + 1∗ . European Arctic-montane. Europe, from Pyrenees, Alps and Greece north to Svalbard, Faeroes, Iceland, Caucasus, Siberia, Japan, N. America, Greenland.

5 POLYTRICHUM HEDW., SP. MUSC. FROND., 1801 Gametophytes indistinguishable from those of Polytrichastrum. Capsules erect to horizontal, sharply 4–6-angled, hypophysis distinct, stomata present; exothecial cells bulging or mamillose, walls pitted; peristome teeth 64, each with vertical partitions and spur-like appendages on the inner face (pterygodont); epiphragm membranous with sac-like lobes on ventral margin alternating with peristome teeth; calyptrae densely hairy, covering capsules. A cosmopolitan genus of some 100 mainly calcifuge species. Derivation: many hairs, referring to the calyptrae.

For a key to Polytrichum species see under Pogonatum (p. 118). Section 1 Polytrichum Leaf margins toothed, not inflexed; apical cells of lamellae smooth, not pyriform in section. 1 P. commune Hedw., Sp. Musc. Frond. Frond., 1801 Plants 2–40 cm. Leaves flexuose when dry, spreading to squarrose when moist, leaf sheath glossy, blade narrowly lanceolate, acuminate; margins toothed; lamellae to c. 70, 5–9 cells high, apical cells smooth, in section enlarged, grooved or flat-topped; costa excurrent in denticulate point; lamina at mid-blade 1–3 cells wide, cells 10– 16 μm wide. Perichaetial leaves with long sheathing base gradually or abruptly narrowed into acuminate apex. Setae flexuose, reddish, 5–9 cm long; capsules erect at maturity, becoming inclined with age, cubic to shortly rectangular, sharply 4-angled, slightly trapezoid in section, hypophysis very distinct; spores 8–12 μm. Capsules frequent, summer. 1 Plants (2–)5–40 cm high, apical cells of lamellae in section 16–20 μm wide, grooved, inner perichaetial leaves toothed above var. commune Plants to 6 cm high, apical cells of lamellae 10–14 μm wide, in section flat-topped or hardly grooved, inner perichaetial leaves entire or only slightly toothed above 2

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2 Inner perichaetial leaves gradually tapering to long acuminate apex var. perigoniale Inner perichaetial leaves abruptly narrowed from sheathing base to short acuminate apex var. humile Var. commune (Fig. 34) Dark green tufts or turfs, sometimes of considerable size, (2–)5–40 cm high. Leaf margins sharply toothed; apical cells of lamellae in section 16–20 μm wide, grooved but towards base of blade less deeply grooved or flat-topped. Inner perichaetial leaves longly tapering, denticulate towards apex. Capsules cubic to shortly rectangular. n = 7∗ , 14. In bogs, by streams, on wet heaths, Racomitrium heath and in woodland. 0–1050 m. Frequent to common and sometimes abundant in suitable habitats. 112, H37, C. GB1416 + 112∗ , IR227 + 7∗ , C1 + 1∗ . Circumpolar Wideboreal. Europe, Faeroes, Iceland, Caucasus, N. and E. Asia, Macaronesia, Africa, N. America, Greenland, Peru, Brazil, Australasia, Chatham Is. Var. perigoniale (Michx.) Hampe, Linnaea, 1819 P. perigoniale Michx.

(Fig. 34)

Plants to c. 6 cm high. Leaves less sharply toothed than in var. commune; apical cells of lamellae less deeply grooved or flat-topped, 10–14 μm wide in section. Perichaetial leaves tapering to entire or slightly toothed acuminate apex. Capsules cubic. On soil and rock ledges in drier habitats than var. commune. Rare, scattered localities from S. Devon and Hampshire north to Ross and Orkney. 25. Europe, Madeira, N. Africa, N. America, Australia. Var. humile Sw., Adnat. Bot., 1829 P. commune var. minus De Not.

(Fig. 34)

Similar to var. perigoniale but perichaetial leaves abruptly narrowed from sheathing base into short acuminate apex. Similar habitats to var. perigoniale. Rare; and not seen recently, extending from W. Cornwall and E. Sussex north to Angus and E. Inverness, Down. 20, H1. Central Europe, Morocco, Macaronesia. P. commune may occur in open woodland on extremely acid soil where it may be mistaken for Polytrichastrum formosum (q.v.). A. Schriebl (Carinthia/Klagenfurt 181/101, 461– 506, 1991) suggests on the basis of cultivation experiments that var. perigoniale should be raised to specific status but he does not present any convincing evidence in support of this. He makes no mention of var. humile. P. swartzii Hartm. has been reported from Britain but the determinations are incorrect (see A. C. Crundwell, Trans. Br. Bryol. Soc. 3, 174–9, 1957).

Section 2 Juniperifolia Brid., Musc. Rec., Suppl., 1806 Leaf margins entire, greatly broadened and inflexed above; apical cells of lamellae smooth, in section pyriform.

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2 P. piliferum Hedw., Sp. Musc. Frond., 1801 (Fig. 35) Green to brownish green patches, (0.5–)1.0–6.0 cm high. Leaves crowded towards stem apex, 2–3 mm long, appressed, straight when dry, patent when moist, blade narrowly lanceolate, acute to acuminate, smooth on abaxial side; margins entire, inflexed and overlapping in upper half or more of blade; lamellae 30–35(–40), 4–8 cells high, crenulate with crenulae directed towards leaf apex, apical cells smooth, cruciform in section at least in middle of blade; costa excurrent in hyaline point up to 1 mm long. Perigonia intense red. Setae 1.5–3.0 cm long, red; capsules inclined, obloid, sharply 4(–6)-angled, hypophysis well defined; lid rostrate; spores 12–15 μm. Capsules common, summer. n = 7∗ , 14, 21. On exposed well drained sandy or gravelly soil or thin peat on heaths, roadsides, boulders, walls, in scree and open woodland, calcifuge. 0–1170 m. Frequent to common throughout the British Isles. 112, H34, C. GB1296 + 101∗ , IR151 + 1∗ , C7 + 3∗ . Circumpolar Wideboreal. More or less cosmopolitan. Usually readily separated from P. juniperinum by the hyaline hair-points of the leaves but forms with hair-points poorly developed or lacking may be determined from lamella characters. For information about the two species see S. R. Edwards, Bull. Br. Bryol. Soc. 65, 49–50, 1995.

3 P. juniperinum Hedw., Sp. Musc. Frond., 1801 (Fig. 35) Grey-green to dark green patches, 1–7(–10) cm high. Stems without or with sparse brown tomentum below. Leaves ± uniformly arranged up stem, 3–5 mm long, appressed, straight or with apiculus slightly flexuose when dry, patent when moist; blade narrowly lanceolate to linear-lanceolate, acute to acuminate, occasionally obtuse, toothed on abaxial side above; margins entire, inflexed but overlapping only towards apex; lamellae (30–)35–50(–70), 5–8 cells high, crenulate, crenulae not directed towards blade apex, apical cells sometimes minutely papillose, ± pyriform in section; costa excurrent in short brown point. Perigonia yellow-olive to orange-red. Perichaetial leaves sometimes with white hair-points. Setae 3–5 cm long, red; capsules erect or suberect, rectangular, sharply 4(–6)-angled, 2.25–4.00 mm long excluding lid, 1.5–2.4 times as long as wide, hypophysis well defined; spores 8–10(–12) μm. Capsules common, summer. n = 7∗ , 14. On exposed well drained soil on roadsides, wall tops, boulders, heaths, moorland, waste ground, open woodland, calcifuge. 0–300(–800) m. Common and sometimes locally abundant. 112, H38, C. GB1596 + 101∗ , IR238 + 10∗ , C8 + 2∗ . Circumpolar Wide-boreal. Temperate and cooler parts of the world. 4 P. strictum Brid., J. Bot. (Schrader), 1801 ¨ P. alpestre Hoppe, P. juniperinum ssp. strictum (Brid.) Nyl. & Sal.

(Fig. 35)

Dense matted dark green tufts, (3–)6–20 cm high. Stems slender, densely tomentose below with off-white tomentum. Leaves imbricate when dry, patent when

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131

moist, blade narrowly lanceolate, acuminate, toothed on abaxial side above; margins entire, inflexed but overlapping only towards apex; lamellae 25–40, 5–6 cells high, crenulate to serrulate, apical cells incrassate, smooth, ± pyriform in section; costa excurrent in brownish arista. Setae slender, 3–4 cm long, red; capsules shortly rectangular, sharply 4-angled, 1.75–3.50 mm long excluding lid, 1.3–2.0 times as long as wide, hypophysis well defined; spores (12–)14–18 μm. Capsules occasional, summer. n = 7∗ . In bogs and on blanket peat, calcifuge. 0–1080 m. Common in suitable habitats in western and northern Britain, very rare and decreasing elsewhere. 80, H28. GB409 + 47∗ , IR70 + 5∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N., C. and E. Asia, N. Africa, N. America, Greenland, Patagonia, Antarctica. The taxonomic status of this plant is open to question and various authorities treat it as a synonym, variety or subspecies of P. juniperinum. Occasional plants are encountered that are intermediate in form and cannot be named but the capsule is usually shorter and the spores larger than in P. juniperinum and additionally the dirty white tomentum of P. strictum distinguishes it from Polytrichastrum and other large Polytrichum species.

6 OLIGOTRICHUM LAM. & DC., FL. FRANÇ., 1805 Dioicous. Leaves broadly lanceolate to lingulate, gradually tapering from broad base, concave; margins not bordered; costa broad with tall sinuose longitudinal lamellae on adaxial side and a few longitudinal lamellae on abaxial side; lamina 1–2-stratose. Capsules ovoid to subcylindrical, lacking hypophysis, stomata present at base; peristome teeth 32; calyptrae sparsely hairy. A ± world-wide genus of about 25 species. Derivation: few hairs, referring to the sparsely hairy calyptrae.

1 O. hercynicum (Hedw.) Lam. & DC., Fl. Franç., 1805 (Fig. 36) Yellowish green to dark green or reddish brown scattered plants or lax patches, 0.5–4.0(–9.0) cm high. Stems rigid. Leaves incurved to crisped when dry, erectpatent, ± incurved when moist, narrowly triangular to lanceolate from broad base, apex cucullate, obtuse to acute; margins plane and obscurely toothed below, erect and bluntly toothed above; costa with c. 12 lamellae on adaxial side in upper 2 /3 of leaf, lamellae sinuose, to 12 cells high; margins notched and crenulate; on abaxial side of costa 2–4 widely spaced lamellae, 1–3 cells high; costa stout, ending in apex. Setae yellow, 1.5–3.5 cm long; capsules erect or slightly inclined, shortly cylindrical; lid rostrate; spores 12–15 μm. Capsules occasional, late summer. n = 7. On loose or gravelly acidic soil in western and northern Britain. 0–1330 μm. Frequent to common in submontane and montane areas, rare at low altitudes. 69, H18. GB438 + 37∗ , IR51 + 4∗ . Circumpolar Boreo-arctic Montane. Europe, Faeroes, Iceland, Turkey, Siberia, Japan, N. America, Greenland.

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Fig. 36 1–5, Oligotrichum hercynicum: 1, plant; 2, leaves (×15); 3, leaf section; 4, part of lamella in side view; 5, capsule (×7.5). 6–11, Atrichum undulatum var. undulatum: 6, plant; 7, leaf (×7.5); 8, part of leaf in side view (×15); 9, section of upper part of costa; 10, mid-leaf cells; 11, capsule (×5). 12–14, plant referred to as A. undulatum ‘var. minus’: 12, plant; 13, 14, capsules from different specimens (×5). Plants ×1, sections ×180, cells ×450.

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7 ATRICHUM P. BEAUV., MAG. ENCYCL., 1805 Autoicous or dioicous. Leaves narrowly lingulate to ovate, crisped when dry, sometimes undulate when moist, lamina often toothed on abaxial side above; margins with 1–3-stratose border of elongate narrow cells, toothed, teeth single or double; costa toothed on abaxial side above, with 2–9 lamellae 1–9 cells high on adaxial side in upper half of leaf. Capsules ovoid to cylindrical, straight to arcuate, erect or inclined; lid longly rostrate; peristome with 32 teeth; calyptrae glabrous. About 15 mainly temperate species. Derivation: hairless, with reference to the glabrous calyptrae. For a monograph of the genus see E. Nyholm, Lindbergia 1, 1–33, 1971. For an account of rhizoidal gemmae in Atrichum see T. Arts, Lindbergia 13, 72–74, 1987.

1 Leaves with 4–7 lamellae, cells in mid-leaf 12–18(–20) μm wide, spores 12–14 μm 4. A. angustatum Leaves with 1–6 lamellae, mid-leaf cells 30–50 μm wide, spores 16–20 μm 2 2 Leaves strongly undulate when moist, lingulate-lanceolate to narrowly lanceolate, not or scarcely narrowed towards base 3. A. undulatum Leaves not or only slightly undulate when moist, ± ovate to lanceolate, narrowed towards base 3 3 Leaves with 1–2(–4) obscure lamellae 1–3 cells high, mid-leaf cells 24–50 μm wide 1. A. crispum Leaves with 2–4(–5) lamellae (5–)6–9 cells high, mid-leaf cells 20–30(–40) μm wide 2. A. tenellum 1 A. crispum (Hampe) Sull. & Lesq., Musci Bor.-Amer., 1856 Catharinea crispa Hampe

(Fig. 37)

Dioicous. Pale green to green tufts or patches, (0.5–)1.0–7.0 cm high. Leaves crisped when dry, soft, patent, not or scarcely undulate when moist, ovate or oblong to oblong-lanceolate, sometimes obovate or oblanceolate, acute, narrowed at base, lamina without teeth on abaxial side; margins toothed almost from base, teeth single or occasionally double; lamellae 1–3(–4) in upper half of leaf, 1–3 cells high, often obscure; costa ending below apex; cells irregularly quadrate to ± hexagonal, obscurely papillose, 24–50 μm wide in midleaf, smaller towards margins, longer towards base. Gemmae usually present on rhizoid wicks, whitish to light brown, ± spherical, (50–)130–300 μm in diameter. Only male plants known in the British Isles. n = 7. On acidic sandy or gravelly soil or peat by ditches, streams, rivers and lakes, particularly in moorland habitats. 0–450 m. Frequent and sometimes locally abundant in Wales and parts of N. W. England, rare or occasional in S. W. England, Surrey, I. of Man, Wicklow, Leitrim. 27, H2. GB120 + 21∗ , IR3. Introduced (Suboceanic

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Fig. 37 1–3, Atrichum crispum: 1, leaves; 2, mid-leaf cells; 3, section of upper part of leaf. 4–7, A. tenellum: 4, leaves; 5, mid-leaf cells; 6, section of upper part of leaf; 7, capsule. 8–11, A. angustatum: 8, leaves; 9, mid-leaf cells; 10, section of upper part of leaf; 11, capsule. Leaves ×10, sections ×250, cells ×450, capsules ×7.5.

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Boreal-montane). Spain, eastern N. America (records from Belgium and Luxembourg are erroneous). Differs from other species of Atrichum in leaf shape, the very low lamellae and the absence of teeth on the abaxial side of the leaf. Because of the obscure lamellae the plant may be mistaken for a species of the Mniaceae but it differs in the frequent presence of gemmae and the albeit obscure lamellae. The earliest British record of this plant is from Rochdale, Lancashire, by John Nowell in 1848. It is clearly an introduction from N. America as until recently it was unknown elsewhere in Europe and only male plants occur. It is likely that the plants in the British Isles are a single clone, having spread by fragments and/or gemmae.

¨ 2 A. tenellum (Rohl.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1844. (Fig. 37) ¨ Catharinea tenella Rohl. Dioicous. Dull green lax tufts or patches, to c. 1.5 cm high. Leaves crisped when dry, soft, erect-patent, not or scarcely undulate when moist, ovate or lanceolate, narrowed towards insertion, obtuse in lower leaves, acute to acuminate in upper, lamina with a few scattered teeth on abaxial side above; margins with single or double spinose teeth from about the middle; lamellae 2–4(–5), (3–)6–9 cells high; costa ending in apex; cells ± quadrate to irregularly hexagonal, 20–30(–40) μm wide in mid-leaf, smaller towards margins, longer towards base. Gemmae usually present on rhizoid wicks, pale brown to brown, ± spherical to irregular in shape, 130–400 μm diameter. Setae yellowish to reddish; capsules inclined, shortly cylindrical, straight or curved; spores 20–25 μm. Capsules rare, late summer to winter. n = 7, 14. On disturbed acidic soil in open habitats in woodland and by tracks. Lowland. Rare in S. E. England, very rare elsewhere, extending from W. Cornwall north to Ross, S. Kerry, W. Cork, W. Galway, W. Donegal. 23, H4. GB30 + 6∗ , IR1. Circumpolar Boreo-temperate. Italy and Yugoslavia north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Siberia, Japan, N. America. The gemmae described above have not been seen in British material but according to T. Arts they are always present if sufficient substrate is collected. It may be confused with small forms of A. undulatum but differs in the relatively wider, scarcely undulate leaves with only a few scattered teeth on the abaxial side, the fewer taller lamellae and the presence of rhizoidal gemmae.

3 A. undulatum (Hedw.) P. Beauv., Prodr. Aethéogam., 1805 Catharinea undulata (Hedw.) F. Weber & D. Mohr Yellowish green to green lax tufts or patches, sometimes extensive, or scattered plants, to 7 cm high. Leaves crisped when dry, soft, patent and strongly undulate when moist, narrowly lingulate to narrowly lanceolate, acuminate, not narrowed towards insertion, lamina with rows of teeth on abaxial side above; margins spinosely dentate with single or double teeth from near base; lamellae 3–6,

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3–7 cells high; costa ending in apex; cells irregularly hexagonal, incrassate, 20– 40 μm wide in mid-leaf, smaller towards margins, longer and more thin-walled towards base. Capsules inclined, cylindrical, arcuate; spores 16–20(–28) μm. Capsules common, winter. Circumpolar Boreo-temperate. Setae reddish, capsules curved, plants usually autoicous, very common var. undulatum Setae yellowish, capsules straight or slightly curved, plants paroicous, very rare var. gracilisetum Var. undulatum (Fig. 36) Usually autoicous, rarely apparently dioicous. Setae red, 1.5–3.0 cm long, frequently 2 or more per perichaetium; capsules curved. n = 7∗ , 14∗ , 21∗ . On disturbed soil in woods, on banks, heaths, damp grassland, by ditches and rivers. 0–600 m. Common and sometimes locally abundant. 112, H39, C. GB1880 + 76∗ , IR272 + 7∗ , C3 + 1∗ . Circumpolar Boreo-temperate. Throughout Europe, Faeroes, Iceland, Caucasus, Asia, Macaronesia, Algeria, Morocco, Canada, Mexico, C. America. Var. gracilisetum Besch., Ann. Sci. Nat. Bot., 1883 A. undulatum var. haussknechtii (Jur. & Milde) Frye Paroicous. Antheridia terminal, archegonia outside perigonial leaves; stems continuing growth for 2 or more years so that persistent setae appear lateral. Setae yellow, to 2 cm long, often several per perichaetium; capsules straight or slightly curved. n = 7, 14, 21. Similar habitats to the type but very rare and not seen for more than 70 years. Surrey, Warwick, Shropshire, S. Lancashire. 4. Throughout Europe north to Svalbard, Asia, western N. America. The various chromosome races of A. undulatum form an autopolyploid series within which some cytological differentiation has taken place although the plants are morphologically indistinguishable. The plant known as ‘var. minus’ auct. non (Hedw.) Paris has a gametophyte similar to that of var. undulatum but rarely more than 2 cm high. The setae are c. 1 cm long, the capsules shortly cylindrical and often stunted or malformed, and the spores variable in size, 20–40 μm, with many aborted. It is usually present in small quantities often with var. undulatum and is generally distributed, being recorded from 48 vice-counties. It is in all probability a hybrid between different cytotypes or genotypes and cannot be recognised as a variety. Chromosome counts of n = 7, 14 and 21 have been reported for var. minus Fritsch, 1991, but whether these are from the same plant that occurs in Britain is unknown.

4 A. angustatum (Brid.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1844 (Fig. 37) Catharinea angustata (Brid.) Brid. Dioicous. Dull green, sometimes red-tinged, lax tufts or patches, to 3 cm high. Leaves crisped when dry, stiff, patent, smooth to strongly undulate when moist,

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137

narrowly lingulate to lingulate-lanceolate, obtuse to acuminate, not narrowed towards insertion, lamina with scattered teeth on abaxial side above; margins dentate, sometimes spinosely so, from below middle; lamellae 3–4(–7), 5–9 cells high; costa ending in apex; cells ± hexagonal, 12–18(–20) μm wide in mid-leaf, smaller towards margins. Setae yellowish to purple; capsules narrowly cylindrical, erect and straight to inclined and curved; spores 12–14 μm. Capsules rare, winter. n = 7. On acidic soil in woods, especially on damp rides. Lowland. Locally frequent in Kent and Sussex, very rare elsewhere, Dorset, Surrey, N. Essex, E. Gloucester, Worcester, Carmarthen, W. Perth, Tyrone, Down. 10, H2. GB18 + 16∗ , IR2. European Temperate. Europe, Iceland, Caucasus, Turkey, Tenerife, Azores, N. America. Distinguished in the field from A. undulatum with which it sometimes grows by the narrower leaves and the sometimes slight reddish tinge. The plant referred to as var. rhystophyllum ¨ Hal.) P. W. Richards & E. C. Wallace has more strongly undulate and sharply toothed (Mull. leaves but intergrades with normal plants to such an extent that it is not worthy of taxonomic recognition. This species is considered endangered in the Red List of British mosses.

4 Tetraphidales Small acrocarpous plants. Leaves not differentiated into sheathing base and blade; costa narrow or absent, without adaxial lamellae. Peristome double, single or absent. Three families.

4 Tetraphidaceae Plants small. Leaves ovate or lanceolate; costa when present without lamellae on adaxial surface; cells rounded-hexagonal, smooth, unistratose. Capsules erect, symmetrical, smooth; annulus absent; peristome teeth 4, basal membrane lacking. Protonemata producing frondiform entire or forked outgrowths (protonemal leaves). Two genera. 8 TETRAPHIS HEDW., SP. MUSC. FROND., 1801 Autoicous. Stems with central strand. Stem leaves numerous, costa distinct. Capsules without stomata; calyptrae plicate. Protonemal leaves not persisting. Two north temperate species. Derivation: Referring to the four peristome teeth.

1 T. pellucida Hedw., Sp. Musc. Frond., 1801 (Fig. 38) Patches or tufts, bright green above, brownish below, to 15(–35) mm high. Leaves loosely appressed when dry, patent when moist, lower orbicular to ovate, upper ovate to lanceolate, acute; margins plane, entire; costa ending below apex; cells irregularly hexagonal, incrassate, 10–20 μm wide in mid-leaf. Uppermost leaves of sterile stems frequently crowded, orbicular, forming gemma-cups

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Fig. 38 1–5, Tetraphis pellucida: 1, leaves (×22.5); 2, shoot with gemma cup (×8); 3, mid-leaf cells (×450); 4, gemma (×80); 5, capsule (×22.5). 6–9, Tetrodontium brownianum: 6, plant (×20); 7, leaves (×22.5); 8, mid-leaf cells (×450); 9, protonemal leaves (×15). 10–12, T. repandum: 10, leaf (×22.5); 11, propaguliferous shoot (×60); 12, protonemal leaves (×30). 13–16, Oedipodium griffithianum: 13, leaf (×15); 14, marginal cells from middle of leaf (×300); 15, capsule (×15); 16, axillary gemma (×115).

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139

containing discoid gemmae c. 40 μm diameter. Perichaetial leaves narrowly lanceolate, acuminate. Setae straight, 4–15 mm long; capsules cylindrical; lid conical; peristome teeth 4; spores 10–12 μm. Capsules rare in lowland Britain, occasional elsewhere; throughout the year. n = 6, 7, 8∗ . On rotting wood, peat and sandstone rocks, calcifuge. 0–380 m. Frequent or common except in eastern England and N. Scotland, occasional in Ireland. 107, H33. GB1030 + 71∗ , IR61 + 5∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Caucasus, Turkey, Siberia, China, Japan, Korea, N. America. ¨ 9 TETRODONTIUM SCHWAGR., SP. MUSC. FROND. SUPPL. 2, 1824 Autoicous. Plants minute, bud-like; stems without central strand. Stem leaves few; costa weak or absent. Stomata present at base of capsule; calyptrae smooth. Protonemal leaves persistent. Three species. Derivation: referring to the four peristome teeth.

Protonemal leaves to 2.5 mm long, plants without flagelliform branches 1. T. brownianum Protonemal leaves to 0.5 mm long, flagelliform branches often present 2. T. repandum ¨ 1 T. brownianum (Dicks.) Schwagr., Sp. Musc. Frond. Suppl. 2, 1824 Tetraphis browniana (Dicks.) Grev.

(Fig. 38)

Plants gregarious, minute, to 2 mm high. Protonemal leaves to 2.5 mm long, linear to narrowly lingulate or narrowly spathulate, sometimes forked; margins entire; cells 2–3-stratose. Stem and perichaetial leaves imbricate, ovate to lanceolate, acuminate; costa lacking in lower leaves, weak in upper leaves; cells irregularly rectangular, very incrassate. Setae to 4 mm long; capsules ellipsoid; peristome teeth 4; spores 14–16 μm. Capsules common, summer. n = 8∗ . In crevices, on vertical surfaces and under overhangs of often slightly basic siliceous rock in shaded sites by streams and rivers. 0–700 m. Frequent in northern England and W. Scotland, rare or very rare elsewhere, Devon, Sussex, W. Gloucester, Stafford, Derby, Wales, rare in Ireland. 54, H9. GB161 + 20∗ , IR10 + 4∗ . Suboceanic Temperate. Pyrenees and Yugoslavia north to S. W. Norway, Caucasus, Turkey, Japan, N. America, Chile, New Zealand. ¨ 2 T. repandum (Funck) Schwagr., Sp. Musc. Frond. Suppl. 2, 1824 Tetraphis browniana var. repanda (Funck) Hampe

(Fig. 38)

Plants minute, gregarious. Protonemal leaves to 0.5 mm long, entire to coarsely and irregularly toothed; cells unistratose. Stem and perichaetial leaves imbricate, perichaetial leaves without costa or costa very poorly developed. Tristichous flagelliform shoots often present at base of stems. Capsules unknown in England.

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On the underside of moist gritstone or sandstone rock. Very rare, E. Sussex, N. E. Yorkshire. 2. GB2. Suboceanic Boreal-montane. From C. Europe north to Svalbard and Jan Mayen, Caucasus, China, Japan, western N. America, Newfoundland. For the occurrence of this plant in Britain see J. Appleyard, Trans. Br. Bryol. Soc. 3, 64–65, 1966. There is an unconfirmed nineteenth-century record from Cheshire. This species is regarded as critically endangered on the Red List of British mosses.

5 Oedipodiaceae A monotypic family with the characters of the only species. ¨ 10 OEDIPODIUM SCHWAGR., SP. MUSC. FROND. SUPPL. 2, 1823 Derivation: meaning swollen foot from the swollen hypophysis.

¨ 1 O. griffithianum (Dicks.) Schwagr., Sp. Musc. Frond. Suppl 2, 1823 (Fig. 38) Autoicous or synoicous. Acrocarpous. Lax pale green tufts or scattered plants, to 1 cm high. Leaves shrivelled when dry, soft, succulent, erect-patent to spreading when moist, obovate-spathulate to ± orbicular, with long narrow ciliate base, apices rounded; margins plane, entire; costa ending below apex; cells hexagonal, ± collenchymatous, smooth, 50–100 μm wide in mid-leaf. Discoid or oval stalked multicellular gemmae, to 300 μm long, often present in leaf axils. Setae succulent; capsules erect, shortly ellipsoid, brown, with long brownish hypophysis with numerous stomata, tapering into seta; peristome lacking; columella expanded above but not exserted after dehiscence; spores 24–30 μm. Capsules occasional, summer. On peaty soil in shaded rock crevices and boulder scree in montane areas. To 1200 m. Rare to occasional in Wales, the Lake District and the Scottish mountains, extending north to W. Ross, old records from S. Kerry and W. Donegal. 30, H2. GB48 + 30∗ , IR2∗ . Oceanic Boreal-montane. Norway, Sweden, Finland, Siberia, Japan, Canada, Alaska, Greenland, Falkland Is. Traditionally placed in the Funariales, DNA studies suggest that Oedipodium is most closely related to Tetraphis.

5 Buxbaumiales Dioicous. Acrocarpous. Protonemata persistent. Female plants with very short simple stems. Leaves very small, green in lower part, hyaline above with brown marginal cilia forming protective tomentum over base of seta; costa lacking. Perichaetial leaves similar to stem leaves, surrounding a single archegonium. Setae elongate, warty; capsules oblique, inclined, ovoid, asymmetrical, somewhat flattened on upper surface, tapering to small mouth; lid conical; outer peristome of 1–4 concentric rings of short teeth, inner conical, plicate. Male plants consisting

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of a single leaf surrounding a single antheridium. One family and one genus with about 10 species.

6 Buxbaumiaceae 11 BUXBAUMIA HEDW., SP. MUSC. FROND., 1801 Derivation: named after a German botanist Johann Buxbaum (1693–1730).

Capsules glossy, cuticle not peeling from flattened upper surface 1. B. aphylla Capsules dull, upper surface scarcely flattened, cuticle splitting longitudinally and peeling from surface of capsule 2. B viridis 1 B. aphylla Hedw., Sp. Musc. Frond., 1801 (Fig. 39) Plants minute, solitary or scattered, usually but not always ephemeral, arising from brownish protonemal mat. Perichaetial leaves minute, ovate, ciliate, cilia

Fig. 39 1–6, Diphyscium foliosum: 1, leaves (×10); 2, leaf cells (×450); 3 and 4, outer and inner perichaetial leaves (×7.5); 5, capsule (×7.5); 6, shoot with sporophyte (×4). 7–8, Buxbaumia viridis: 7, sporophyte (×4); 8, part of seta (×25). 9–10, B. aphylla: 9, sporophyte (×4); 10, part of seta (×25).

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becoming filamentous with age and forming protonemal-like mass at base of setae. Male plants on side of female shoots. Setae erect, very coarsely papillose, (3–)5–10(–20) mm long; capsules glossy brown, with short neck, inclined to horizontal, ± obliquely ovoid, upper surface flattened with ± angular edges; exothecial cells sparsely and coarsely papillose; stomata immersed; cuticle peeling back from mouth but not from the upper side of ripe capsules; outer peristome teeth in a single row, filiform; spores (8–)10–13 μm. Capsules spring to autumn. n = 8. On humus-rich acidic sandy soil or occasionally on rotting wood, in shaded habitats, especially conifer woods, or on colliery spoil where colonies may persist for several years. Lowland. Very rare but widely distributed throughout Britain, S. Kerry (not seen recently). 33, H1. GB25 + 21∗ , IR1∗ . Circumpolar Boreal-montane. Europe, Caucasus, N. Asia, Japan, N. America, Australasia. The capsules of this pioneering species are disproportionately large relative to the size of the gametophyte and it is likely that in the later stages of development the sporophyte is nutritionally self-supporting. Despite the enormous spore output, c. 5 000 000 per capsule, the plant is usually only rarely encountered.

2 B. viridis (Moug. ex DC) Brid. ex Moug. & Nestl., Stirpes Cryptog. Vogeso-Rhenan, 1823 B. indusiata Brid.

(Fig. 39)

Gametophyte similar to that of B. aphylla. Setae coarsely papillose; capsules pale brown, not glossy, obliquely ellipsoid, scarcely angled or flattened on back; cuticle splitting longitudinally and peeling from upper side of capsule at maturity; stomata superficial; outer peristome of 4 concentric rows of teeth; spores c. 10 μm. Capsules summer. n = 8. Decaying wood in deciduous or more especially coniferous woodland. Lowland. Very rare and endangered; seen recently in E. Perth and E. Inverness with old records from Angus, S. Aberdeen and E. Ross. 5. GB2 + 3∗ . European Boreal-montane. Northern Europe, Corsica, Turkey, Caucasus, China, N. America. This species is considered endangered in the Red List of British Mosses and is a protected plant under the Wildlife and Countryside Act. It is also listed as vulnerable in the Red Data Book of European Bryophytes.

Class 4 Bryopsida

Acrocarpous or pleurocarpous. Plants minute to large; stems simple to much branched, with or without central strand. Leaves spirally arranged, rarely distichous; costa single or double, well developed or not, or lacking; cells usually unistratose except sometimes at margins or towards apex, isodiametric to linear, thin-walled to strongly incrassate, smooth, papillose or mamillose. Early divisions of zygote resulting in radially symmetrical embryo. Setae short or long; capsules erect to pendulous, globose to cylindrical, dehiscing by lid or more rarely cleistocarpous; mouth with peristome of one (haplolepideous mosses) or two (diplolepideous mosses) concentric rings of articulated teeth, each ring of 16 simple or variously divided teeth, teeth variously ornamented, sometimes reduced or absent; spore sac cylindrical, surrounding but not overtopping columella; spores usually small, to 40 μm, numerous, mostly 5000–50 000 000 per capsule, usually wind-dispersed. The nature of the peristome has been regarded as highly important in the classification of mosses. For accounts of the structure and ontogeny of peristome teeth see S. R. Edwards in Clarke & Duckett (1979) and S. R. Edwards in Schuster (1983).

Subclass 1 Diphysciideae Dioicous or autoicous. Acrocarpous. Protonemata persistent. Stems short, simple. Leaves lingulate or lingulate-spathulate; costa present; cells unistratose at base, 2(−3)-stratose above, rounded-quadrate, mamillose or smooth. Perichaetial leaves larger than stem leaves; margins ciliate above; costa longly excurrent. Setae very short; capsules oblique, ovoid, gibbous, terete, tapering to small mouth; lid conical; outer peristome of 16 very short teeth, inner conical with 16 plicae. One family, genera.

6 Diphysciales 7 Diphysciaceae 12 DIPHYSCIUM D. MOHR, OBSERV. BOT., 1803 About 29 mainly Northern Hemisphere genus. Derivation: referring to the double tissue of the exothecium and sporangium.

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1 D. foliosum (Hedw.) D. Mohr, Observ. Bot., 1803 (Fig. 39) Dioicous. Green to brownish patches or scattered plants, shoots very short, to c. 5 mm high. Leaves crisped when dry, spreading, soft when moist, fragile, narrowly lingulate from a sometimes slightly sheathing base, obtuse to acute; margins plane, finely crenulate; costa poorly defined, ending below apex; cells incrassate, rounded-hexagonal, mamillose, 2–3-stratose, obscure, 10–12 μm wide, basal cells thinner-walled, smooth, basal marginal band hyaline, rectangular. Perichaetial leaves ± lanceolate, acute to obtuse; margins ciliate above; costa excurrent in long smooth or slightly denticulate setaceous point. Setae very short; capsules immersed or slightly exserted, oblique, ovoid, gibbous; peristome white, becoming brown with age; spores 8–13 μm. Capsules frequent, spring to autumn. n = 9∗ . On sheltered acidic peaty or mineral soil on banks, in rock crevices and by tracks and streams. 0–1205 m. Frequent in western and northern Britain, very rare elsewhere, Kent, E. Sussex, Oxford, Stafford, rare in most of Ireland. 67, H21. GB410 + 36∗ , IR36 + 6∗ . European Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Japan, Madeira, Azores, N. America, Mexico, Guatemala, Jamaica. When fertile readily recognised by the oblique ± immersed capsules, but sterile plants may be mistaken for Tortella species which, however, occur in base-rich usually exposed habitats and differ in leaf shape and unistratose cells.

Subclass 2 Dicranideae Plants acrocarpous or rarely cladocarpous. Peristome haplolepideous with exostome lacking, outer peristomial layer of 32 cells, primary peristomial layer of 16 cells and inner peristomial layer of 24 cells, late state division of the inner peristomial layer asymmetric.

7 Archidiales Acrocarpous. Plants small; stems with central strand. Stem leaves small, lanceolate. Perichaetial leaves larger with sheathing base. Early cell divisions of zygote resulting in a bilateral embryo. Setae lacking; capsules cleistocarpous, wall unistratose, columella and inner spore sac lacking; spores 4–176, thick-walled, 50–310 μm. One genus. It has been reported in the literature that the spores are derived from the outermost layer of the endothecium, but this is incorrect and they are derived from the amphithecium as in other mosses. For a monograph of Archidium see J. A. Snider, J. Hattori Bot. Lab. 39, 105–201, 1975.

8 Archidiaceae 13 ARCHIDIUM BRID., BRYOL. UNIV., 1826 About 30 species distributed ± throughout the world. Derivation: meaning primitive.

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145

1 A. alternifolium (Dicks. ex Hedw.) Mitt., Ann. Mag. Nat. Hist., 1851 (Fig. 40) Paroicous. Dense dull dark green, perennial tufts or patches, to 2 cm high. Plants consisting of simple or branched stems, often innovating from below perichaetium, or of long sterile and short fertile stems arising from old prostrate stems. Leaves distant on sterile stems, crowded on fertile stems, erect-patent when moist, lanceolate to lanceolate-subulate, acute to acuminate; margins plane, denticulate; costa ending ± in apex; cells incrassate, basal rectangular, cells above rhomboidal to narrowly hexagonal, 8–10 μm wide in mid-leaf. Perichaetial leaves much larger with broad sheathing base. Capsules immersed, cleistocarpous, globose, wall pellucid; spores angular, 127–262 μm. Capsules frequent, spring. n = 13, 26. On muddy to sandy open or disturbed soil in fields, old quarries, on moorland, woodland rides, by rivers and streams. 0–500 m. Very rare in eastern England, common in the west, occasional elsewhere, rare in Ireland. 99, H20, C. GB378 + 75∗ , IR31 + 6∗ , C2. European Southern-temperate. Europe north to southern Fennoscandia, Faeroes, Iceland, Turkey, Siberia, Macaronesia, N. Africa, N. America, Mexico. Large hyaline to pale brown moniliform gemmae, to 3(−4) mm long, have been reported from mainly southern European gatherings (T. Arts, Lindbergia 16, 59–61, 1990) but have not yet been detected in British plants.

8 Dicranales Acrocarpous. Plants very small to large. Apical cell of stem with 2 or 3 cutting faces. Leaves spirally arranged or distichous; cells quadrate to linear, usually smooth, sometimes porose, alar cells sometimes enlarged or otherwise differentiated. Setae usually long; capsules ovoid to cylindrical, frequently curved; peristome single, teeth usually bifid, with fine vertical striae between the transverse articulations, rarely capsules cleistocarpous. Thirteen families.

9 Ditrichaceae Plants usually small, stems with central strand. Upper leaves longer than lower usually straight, usually lanceolate, and acuminate or longly acuminate; costa percurrent or excurrent, narrow, in section with guide cells and two stereid bands; basal cells elongate, alar cells undifferentiated, cells above isodiametric to elongate, usually. Perichaetial leaves usually longer than stem leaves, often with sheathing bases. Setae very short or long, straight; capsules dehiscent or cleistocarpous, erect, usually cylindrical, straight or slightly curved, smooth or longitudinally striate, strumose or not, annulus usually of large cells, separating; peristome teeth 16, perforated or bifid nearly to base into terete segments, smooth below, smooth or papillose; calyptrae usually cucullate. Twenty-five genera. Differences between the Ditrichaceae and Dicranaceae are not clear cut although the differentiated alar cells of some genera of the latter are not found in the former. The Ditrichaceae differs from the Dicranaceae in the peristome teeth divided to the base into terete filiform papillose segments rather than flat teeth vertical pitted-striate below.

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Fig. 40 1–4, Archidium alternifolium: 1, plant (×15); 2, 3, stem and perichaetial leaves (×50); 4, leaf cells. 5–7, Pseudephemerum nitidum: 5, plant (×10); 6, perichaetial leaf (×20); 7, cells near leaf base. 8–10, Pleuridium acuminatum: 8, perichaetial leaf (×20); 9, leaf apex; 10, basal cells. 11–15, Pleuridium subulatum: 11, plant (×10); 12, 13, stem and perichaetial leaves (×20); 14, basal cells; 15, leaf apex. Cells ×450.

14 Pleuridium

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14 PLEURIDIUM RABENH., DEUTSCHL. KRYPT. FLORA., 1848 Small plants with usually unbranched stems. Perichaetial leaves much larger than stem leaves, with sheathing base tapering to acuminate apex. Setae very short; capsules immersed, erect, cleistocarpous, stomata only at base; calyptrae cucullate. A mainly Northern Hemisphere genus of about 30 species, a few of which occur in S. America and Australia. Derivation: meaning on one side, apparently referring to capsules being lateral.

Plants paroicous, antheridia in persistent dwarf axillary buds, cells at shoulder of perichaetial leaves unistratose 1. P. subulatum Plants paroicous, antheridia naked in outer perichaetial leaf axils, cells at shoulder of perichaetial leaves bistratose 2. P. acuminatum 1 P. subulatum (Hedw.) Rabenh., Deutschl. Krypt. Flora., 1848 P. alternifolium Dixon

(Fig. 40)

Autoicous. Green to yellowish green tufts or patches, to c. 1 cm high. Stem leaves from ovate basal part tapering to acuminate apex, upper longer, merging into perichaetial leaves; upper and perichaetial leaves from ovate basal part usually abruptly narrowed to long denticulate setaceous acumen; basal cells rectangular, cells at shoulder of perichaetial leaves unistratose, upper cells rectangular to narrowly rectangular, c. 8 μm wide. Antheridia in persistent dwarf axillary branches. Capsules common, spring, summer. n = 13. In similar to or sometimes less acidic habitats than P. acuminatum. 0–380 m. Occasional in England (except the east), Wales and S. E. Scotland, rare elsewhere, extending north to Orkney, very rare in Ireland. 90, H10, C. GB246 + 87∗ , IR4 + 9∗ , C2. Circumpolar Temperate. Europe, Iceland, Turkey, Caucasus, Palestine, Macaronesia, N. Africa, N. America, New Zealand, Oceania. ¨ 2 P. acuminatum Lindb., Ofvers Förh. Kongl. Svenska Vetensk Akad., 1863 (Figs. 40, 41) P. subulatum F. Weber & D. Mohr Paroicous. Green or yellowish green tufts or patches, to c. 1 cm high. Lower leaves spreading, lanceolate or ovate, acuminate, upper longer, ± erect or slightly secund, merging into perichaetial leaves; upper and perichaetial leaves from ovate-lanceolate basal part usually gradually tapering to long acuminate apex; margins entire or slightly denticulate; costa broad, obscure below, excurrent in upper leaves; basal cells rectangular, cells at shoulder of perichaetial leaves irregularly bistratose, cells above becoming ± linear, c. 8 μm wide. Pale to dark brown, spherical to elongate rhizoidal gemmae with slightly bulging cells, with a hyaline outer layer, to 120 μm diameter or 400 μm long, sometimes present. Antheridia naked in axils of perichaetial leaves. Capsules immersed and ± concealed by perichaetial leaves, cleistocarpous, ovoid with blunt apiculus; spores 22–30 μm.

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Capsules common, spring, summer. n = 13∗ , 26. In slightly shaded or exposed habitats on soil in fields, waste places, heaths, moorland, open places in woodland, calcifuge. 0–450 m. Common and sometimes locally abundant in England (except in the east), Wales and S. E. Scotland, rare elsewhere and in Ireland. 105, H21, C. GB659 + 104∗ , IR20 + 13∗ , C6. European Temperate. Europe, Caucasus, Turkey, Cyprus, Macaronesia, Algeria, China, N. America. Plants of P. acuminatum with capsules are usually devoid of antheridia but the dwarf antheridial branches of P. subulatum persist. Also, rhizoidal gemmae have only been found in P. acuminatum. It has been shown that the shape of the perichaetial leaves is an unreliable character for separating the two species but that the cells at the shoulder of the perichaetial leaves of P. subulatum are unistratose whilst those of P. acuminatum are irregularly bistratose (see K. L. Yip., Bryologist 105, 259–61, 2002). Some authorities treat P. acuminatum and P. subulatum as synonymous, as in some mixed populations intermediates occur. However, it is possible that these intermediates are of ` de Lecq and Les hybrid origin. A curious form of P. acuminatum occurs on Jersey (at Greve Landes, St. Ouen’s) in which the perichaetial leaves are about 1/2 –2/3 the length of those in typical plants. The taxonomic status of this form is uncertain as it is not known whether intermediates between it and typical plants occur.

15 PSEUDEPHEMERUM (LINDB.) I. HAGEN, NORSK VID. SELSK. SKRIFT., 1910 A monotypic genus with the characters of the species (see T. Matzui & Z. Iwarsuki, J. Hattori Bot. Lab. 68, 317–66). Derivation: referring to the resemblance to the genus Ephemerum. Placed in the Dicranaceae by many authorities but the genus seems close to Pleuridium on the basis of chromosomal similarity and this is supported by the reported occurrence of hybrids between species of the two genera. Further, DNA studies (M. Stech, Inaugural ¨ ¨ dissertation zur Erlangung der Doctorwurde Freien UniversitatBerlin) indicate a close relationship to Trichodon cylindricus.

1 P. nitidum (Hedw.) Loeske, Stud. Morph. Syst. Laubm., 1910 Pleuridium axillare (Sm.) Lindb.

(Fig. 40)

Synoicous. Patches or scattered very small plants, to 5 mm high, pale green, becoming orange-brown with age. Stems with central strand. Leaves increasing in size up stems, upper and perichaetial leaves of similar length, patent when moist, lanceolate, longly acuminate; margins entire below, denticulate above; costa ending below apex, in section with stereid band; cells lax, thin-walled, rectangular to narrowly rectangular throughout, 10–15 μm wide. Setae very short; capsules immersed but conspicuous, cleistocarpous, ovoid with conical beak, thin-walled, orange-brown when ripe; spores 20–32 μm. Capsules common throughout the year but especially late summer and autumn. In deep shade to exposed sites on damp soil on banks, cultivated ground, woodland rides. Lowland. Frequent or

17 Ditrichum

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common in most of England and Wales, rare or occasional elsewhere, occasional in Ireland. 105, H26, C. GB640 + 76∗ , IR68 + 3, C4. European Temperate. Europe, Sri Lanka, Assam, Nepal, Japan, Macaronesia, Algeria, Morocco, Congo Kenya, Rwanda, Zaire, Madagascar, British Columbia, Oregon, Mexico, Brazil, Tasmania, New Zealand. Distinguished from Pleuridium species by the upper leaves being of similar length to the perichaetial leaves and, because of the shorter perichaetial leaves, the more conspicuous capsules. Gemmae are produced by P. nitidum, but only rarely. When present they are numerous, bright yellow to pale orange-brown, mulberry-shaped, 60–160 × 45–110 μm (see T. Arts & S. Risse, Lindbergia 17, 55–8, 1992).

16 TRICHODON SCHIMP., COROLL. BRYOL. EUR., 1855 A monotypic genus with the characters of the species. Derivation: meaning hair-like tooth, referring to the divisions of the peristome teeth. For the reasons for recognising this genus see R. S. Seppelt, Bryobrotheria 5, 1189–94, 1999.

1 T. cylindricus (Hedw.) Schimp., Coroll. Bryol. Eur., 1855 Ditrichum cylindricum (Hedw.) Grout, D. tenuifolium Lindb.

(Fig. 41)

Dioicous. Dull, yellowish green tufts, patches or scattered plants, to 5 mm high. Stems usually simple. Upper leaves squarrose-flexuose, from oblong sheathing basal part abruptly narrowed to long acumen composed almost entirely of costa, denticulate all round and not just at margins; margins plane; cells in sheathing base rhomboidal, 2–3 marginal rows narrowly rectangular, upper cells rectangular. Brownish, ovoid, 1–3-celled rhizoidal gemmae, c. 130 μm long, usually present. Setae reddish below, yellow above; capsules erect, cylindrical, straight or slightly curved; lid longly rostrate; spores 12–16 μm. Capsules very rare, summer. n = 12, 13. On disturbed soil in fields, on roadsides, banks, open places in woodland. 0–700 m. Common in lowland areas, rare elsewhere. 111, H23, C. GB748 + 51∗ , IR56 + 3∗ , C2. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, N. Asia, Japan, Tenerife, N. America. The squarrose longly acuminate leaves will readily distinguish T. cylindricus from most other arable mosses except Dicranella schreberiana (q.v.). Pleuridium species are autoicous or paroicous and the capsules are very common and immersed; Dicranella staphylina has much shorter non-squarrose leaves and gemmae 3–4 cells long and 1–3 cells wide.

17 DITRICHUM HAMPE, FLORA, 1876 Usually dioicous. Leaves from lanceolate basal part gradually tapering to long or short frequently channelled acumen; costa often broad, ending below apex to excurrent; cells in lower part of leaf linear to ± rectangular, in upper part quadrate or rectangular, smooth. Setae long; capsules ± erect, narrowly ellipsoid or

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Fig. 41 1–3, Trichodon cylindricus: 1, leaves (×20); 2, basal cells; 3, leaf apex. 4–7, Ditrichum zonatum var. zonatum: 4, leaves (×50); 5, basal cells; 6, mid-leaf cells; 7, leaf apex. 8, D. zonatum var. scabrifolium: leaf apex (×220). 9–12, Rhizoidal gemmae (×220): 9. Trichodon cylindricus; 10, Ditrichum heteromallum; 11, D. subulatum; 12, Pleuridium acuminatum. Cells ×450.

17 Ditrichum

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cylindrical, straight or slightly curved, smooth; peristome teeth 16, divided to base into papillose filiform segments. A cosmopolitan genus of c. 90 species. Derivation: meaning two hairs, referring to the divided peristome teeth. The sporophytes of some species of Ditrichum and Dicranella are very similar. Ditrichum differs from Dicranella in the peristome teeth divided to the base into filiform papillose not vertical pitted-striate below. In Dicranella the teeth are divided to about the middle into flat segments and are papillose above and pitted-striate below. For an account of rhizoidal and protonemal gemmae in European Ditrichum species see T. Arts, J. Bryol. 18, 43–61, 1994.

1 Plants 1–11 cm high, leaves ± abruptly narrowed from broad basal part to long acumen composed largely of costa 2 Leaves gradually tapering to long or short apex or if abruptly narrowed above basal part then plants not more than 1 cm high 3 2 Leaves mostly 1.0–3.5 mm long, basal part constituting 1/3 –1/2 total leaf length, marginal cells at middle of basal part thick-walled, not hyaline 8. D. flexicaule 1 1 Leaves mostly 3–8 mm long, basal part constituting /4 – /3 total leaf length, marginal cells at middle of basal part thin-walled and hyaline 9. D. gracile 3 Paroicous, leaves abruptly narrowed above basal part into long acumen 7 D. subulatum Dioicous, leaves ± gradually tapering from widest part to long or short apex 4 4 Leaves tapering to long acumen consisting largely or entirely of costa 5 Leaves shortly pointed, costa not constituting all or much of upper part of leaf 7 5 Leaf margins recurved at least at middle part of leaf, denticulate above 1. D. pusillum Leaf margins plane or narrowly recurved, entire or with a few denticulations near apex only 6 6 Cells in lower part of leaf narrowly rectangular to linear, mostly 40–80 μm long, sporophytes common 5. D. heteromallum Cells in lower part of leaf rectangular, mostly 10–24 μm long, sporophytes unknown 6. D. zonatum 7 Leaves erect-patent to patent when moist, cells in lower part of leaf 7–12 × 15–25 μm 2. D. cornubicum Leaves appressed when moist, cells in widest part of leaf 5–9 × 15–46 μm 8 8 Upper leaves 3–4 times as long as wide, margins recurved on one or both sides 3. D. lineare Upper leaves 2–3 times as long as wide, margins plane 4. D. plumbicola 1 D. pusillum (Hedw.) Hampe, Flora, 1867 D. tortile (Schrad.) Brockm.

(Fig. 42)

Dioicous. Dull green tufts, to 10 mm high; stems usually simple. Leaves erectpatent, slightly secund, lower ovate-lanceolate, acute, upper larger, lanceolate,

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Fig. 42 1–4, Ditrichum subulatum: 1, leaf; 2, leaf apex; 3, basal cells; 4, capsule. 5–9, D. heteromallum: 5, leaf; 6, basal cells; 7, marginal cells at middle of leaf; 8, leaf apex; 9, capsule. 10–13, D. pusillum: 10, leaves; 11, basal cells; 12, capsule; 13, rhizoidal gemmae (×175). Leaves ×30, cells ×450, capsules ×20.

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narrowing to channelled acumen; margins denticulate, recurved at least at middle of leaf; costa stout, percurrent or excurrent; cells in lower part of leaf narrowly rectangular, 10–12 μm wide, narrower and shorter towards margins, cells above quadrate to rectangular. Yellow or yellowish brown, pyriform rhizoidal gemmae, 100–150 × 75–100 μm, abundant on sterile plants, occasional on fertile plants. Setae red; capsules erect, ovoid to cylindrical; spores 12–15 μm. Capsules frequent, winter. n = 13∗ . On sandy soil and in quarries, rarely but probably overlooked in non-calcareous arable fields. 0–900 m. Rare, widely distributed from S. England to N. W. Scotland, very rare in Ireland and not seen recently. 24, H6. GB24 + 10∗ , IR4∗ . Circumpolar Boreo-temperate. Europe, Iceland, Caucasus, Siberia, Amur, India, Madeira, Tenerife, Algeria, N. America. Plants in arable fields lack capsules and may be very depauperate, resembling juvenile Ceratodon purpureus but are readily recognised by the rhizoidal gemmae (see H. L. K. Whitehouse, J. Bryol. 9, 7–11, 1976).

2 D. cornubicum Paton, J. Bryol., 1976. (Fig. 43) Dioicous. Dull green patches or scattered plants, Very small, 1–5 mm high. Lower leaves distant, upper more crowded, appressed, uppermost on well grown stems slightly secund when dry, erect-patent to patent when moist, 0.4–0.9 mm long, c. 3 times as long as wide, widest c. 1/4 from base, concave, lanceolate, tapering to obtuse to sub-acute apex; margins plane with a few obscure denticulations above; costa broad, ending just below apex; cells in lower part of leaf irregularly rectangular, 1–2 marginal rows narrower, cells above rectangular, narrowly rectangular by costa, 7–10(−12) × 15–25 μm at widest part of leaf. Brownish multicellular rhizoidal gemmae, spherical to ovoid or irregular in shape, 80–160 μm long, present. Only male plants known. On peaty soil on copper-mine waste. A very rare and endangered species known from only two localities in Cornwall. 2. GB2. Endemic (Oceanic Temperate). For a description of this plant see J. A. Paton, J. Bryol. 9, 171–5, 1976. D. plumbicola is considered endangered in the Red List of British Mosses and is a protected plant under the Wildlife and Countryside Act. It is listed as critically endangered on the European Red List.

3 D. lineare (Sw.) Lindb., Acta Soc. Sci. Fenn., 1871 D. vaginans (Sull.) Hampe

(Fig. 43)

Dioicous. Dense green or yellowish green tufts, patches or scattered plans, 5–15 mm high. Shoots slender, stems innovating from below. Leaves rigid, loosely appressed, scarcely altered when dry, lower leaves small, ovate to ovate-lanceolate, shortly pointed, upper larger, 0.6–1.4 mm long, 3–4 times as long as wide, widest c. 1/4 from base, lanceolate, channelled above, tapering to bluntly pointed to acuminate apex; margins frequently narrowly recurved on one or both sides, entire or obscurely denticulate towards apex; costa broad, percurrent to shortly

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Fig. 43 1–6, Ditrichum lineare: 1, leaf (×45); 2, basal cells; 3, mid-leaf cells; 4, leaf apex; 5, section at middle of leaf; 6, stem section. 7–13, D. plumbicola: 7, leaves (×45); 8, basal cells; 9, mid-leaf cells; 10, leaf apex; 11, section at middle of leaf; 12, stem section; 13, rhizoidal gemma (×220). 14–20, D. cornubicum: 14, leaves (×65); 15, basal cells; 16, mid-leaf cells; 17, leaf apex; 18, section at middle of leaf; 19, stem section; 20, rhizoidal gemma (×160). Sections and apices ×300, cells ×420.

17 Ditrichum

155

excurrent; cells thick-walled, in lower part of leaf narrowly rectangular, sometimes becoming narrower towards margins, cells above rectangular to narrowly rectangular, 5–8 × 15–46 μm at widest part of leaf. Setae yellowish; capsules ellipsoid; spores c. 12 μm. Only female plants known in the British Isles. n = 13, 13 + m. On disturbed acidic soil on montane ridges and in areas of late snow-lie, on banks in woodland, by streams and lanes. 100–1040 m. Rare, Mid and N. Wales, Westmorland, Kirkcudbright, Scottish Highlands, Lewis, Sligo and Antrim but not seen recently. 18, H2. GB39 + 1∗ , IR2∗ . European Boreal-montane. C. and N. Europe, Spain, Iceland, Japan, eastern N. America. Rhizoidal gemmae similar to those of Ditrichum heteromallum have been reported from Belgian and Japanese plants but have not been detected in British or Irish plants. D. cornubicum, D. lineare and D. plumbicola are somewhat similar in appearance and easily confused. D. plumbicola has more shortly pointed leaves with plane margins, the stem is less triangular in section and the costa is thinner and less prominent at the back; the plant occurs on lead-containing soils, a habitat from which D. lineare is not known. The leaves of D. cornubicum are intermediate in shape between those of the other two species but they differ in being erect-patent to patent when moist and with shorter wider cells in the widest part of the leaf. D. lineare and D. plumbicola are superficially similar in appearance to Aongstroemia longipes but differ in leaf shape and areolation.

4 D. plumbicola Crundw., J. Bryol., 1976 (Fig. 43) Dense pale yellowish green ± glossy patches. Shoots very slender, 5–15 mm high. Leaves closely appressed, scarcely altered when dry, of ± similar size except at base of stems, 0.4–0.7 mm long, 2–3 times as long as wide, widest 1/3 –1/2 from base, concave, ovate to ovate-lanceolate, channelled above, shortly tapering to blunt apex; margins plane or in young leaves incurved above, entire or with a few obscure denticulations towards apex; costa broad, percurrent; cells thick-walled, in lower part of leaf narrowly rectangular, narrower or not towards margins, cells above rectangular to quadrate, 5–9 × 15–42 μm at widest part of leaf. Dark reddish brown rhizoidal gemmae consisting of 5–8 cells spirally twisted into a subspherical helix, 150–200 μm diameter, sometimes sparsely present. Gametangia and sporophytes unknown. On lead-mine spoil. 0–460 m. Very rare, W. Cornwall, N. Somerset, Mid and N. Wales, 9. Northumberland, I. of Man, Mid Perth. 8. GB12. Oceanic Temperate. Germany. For an account of this plant see A. C. Crundwell, J. Bryol. 9, 167–9, 1976. This plant is listed as vulnerable in the Red Data Book of European Bryophytes.

5 D. heteromallum (Hedw.) E. Britton, N. Am. Fl., 1913 D. homomallum (Hedw.) Hampe

(Figs. 41, 42)

Dioicous. Slightly silky yellowish green lax tufts or patches, seldom more than 1 cm high. Leaves erect-patent to subsecund, from ovate to lanceolate basal part tapering to channelled acumen; margins plane, entire; costa ill-defined below,

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occupying most of upper part of leaf and excurrent in slightly denticulate point; cells in lower part of leaf narrowly rectangular to linear, 6–10 × (24−)40–80 μm, cells above linear by costa, rectangular at margins. Dark reddish brown rhizoidal gemmae consisting of a uniseriate row of 3–9 thick-walled cells spirally twisted into a subspherical helix c. 90–300 μm diameter, occasionally and sometimes sparsely present. Setae purple; capsules erect, narrowly ellipsoid, ± straight; spores 12–18 μm. Capsules common, spring. n = 13∗ , 13 + m. On soil on banks by streams, paths, in woods and on moorland, calcifuge. 0–820 m. Very rare in lowland England except the extreme south, common elsewhere, frequent in W. Ireland and occasional in other parts. 95, H29. GB587 + 83∗ , IR90 + 4∗ . European Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, N., W. and E. Asia, N. Africa, western N. America, Tierra del Fuego. Small forms of Dicranella heteromalla without sporophytes may be confused with this plant but differ in the relatively wider costa, which is c. 1/3 width of leaf base and is also biconvex in section, whereas in Ditrichum heteromallum it is flat on the adaxial side.

6 D. zonatum (Brid.) Kindb., Bot. Not., 1882 D. homomallum var. zonatum (Brid.) Lindb. Dioicous. Small dark tufts or large dense cushions, glossy green above, reddish below. Shoots 0.3–5.0 cm high, often with annual growth zones when forming dense tufts; stems fragile. Leaves erect to erect-patent, tapering from ovate or ovate-lanceolate basal part to short channelled acumen; margins plane below, erect or sometimes slightly incurved above, entire; costa stout, extending to apex or percurrent; cells in lower part of leaf rectangular to narrowly rectangular, (5−)6–8 × 10–24(−32) μm, shorter towards margins and costa, in upper part of leaf shortly rectangular or quadrate, bistratose. A few dark reddish brown rhizoidal gemmae, similar to those of D. heteromallum, very occasionally present. Capsules unknown in the British Isles. European Arctic-montane. Cells and abaxial side of costa in upper part of leaves smooth Cells and abaxial side of costa in upper part of leaves papillose

var. zonatum var. scabrifolium

Var. zonatum (Fig. 41) Cells and abaxial side of costa in upper part of leaf smooth. Small cushions on rocks and dense tufts in rock crevices, in areas of late snow-lie and in scree, calcifuge. (400−)800–1335 m. Rare, Mid and N. Wales, N. England, Scottish Highlands, Antrim (not seen recently). 26, H1. GB76 + 6∗ , IR2 + 1∗ . Pyrenees and Alps north to Fennoscandia, Alaska. Var. scabrifolium Dixon, J. Bot. Lond., 1902 (Fig. 41) Cells and abaxial side of costa in upper part of leaf scabrous with large conical papillae. Damp rock crevices, especially where slightly basic. Usually at high altitudes.

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Rare, mid and N. Wales, Westmorland, Kirkcudbright, Scottish Highlands, W. Galway, W. Donegal. 19, H2. Canada. Well grown plants are easily recognised by the dense tufts, green above and reddish-brown below but the plant also occurs, looking very different, as small cushions on exposed rocks. These, and also large plants, may be recognised by the brittle stems, which make removal of the leaves difficult, and the ± quadrate mid-leaf cells. D. zonatum is distinct from D. heteromallum in habit and lamina cells extending ± to the leaf apex. In its typical form var. scabrifolium is very distinctive, although the papillae may be lost in old specimens; as there are some ecological differences between the type and var. zonatum the variety seems to be a sound taxon.

7 D. subulatum Hampe, Flora, 1867 (Figs. 41, 42) Paroicous. Silky yellowish green tufts or patches to 8 mm high. Leaves distant below, crowded above, lower small, narrowly lanceolate, upper larger, from ovate or oblong base abruptly narrowed into long channelled acumen composed largely of costa, uppermost and perichaetial leaves falcate-secund; margins plane below, erect or inflexed and entire or slightly denticulate above; costa longly excurrent in upper leaves; basal cells in lower leaves quadrate to quadrate-rectangular, in upper leaves variable in shape, rectangular or rhomboidal to narrowly rectangular, 8–14 μm wide, narrower towards margins and apex. Dark reddish brown rhizoidal gemmae, similar to those of D. heteromallum, often present. Setae yellowish red; capsules erect, ovate-ellipsoid; spores 14–18 μm. Capsules common, winter, spring. n = 14∗ . On shaley soil in rock crevices and on rocky or earthy roadside banks. Lowland. Very rare, seen recently only in Cornwall, old records from S. Devon, E. Kent. 4. GB8 + 3∗ . Mediterranean-Atlantic. Mediterranean region, W. France, Macaronesia, N. America. ¨ 8 D. flexicaule (Schwagr.) Hampe, Flora, 1867 D. flexicaule auct. var. densum (Bruch & Schimp.) Braithw.

(Fig. 44)

Dioicous. Bright to dark green, dense or very dense, rarely lax tufts or patches, 1–5(−6) cm high. Stems fragile, densely tomentose below. Leaves erect, rarely flexuose or secund when moist, apices not twisted together when dry, 1.0–3.5 mm long, from sheathing basal part, constituting 1/3 –1/2 total leaf length, abruptly tapering to entire channelled acumen; costa broad, indistinct below, longly excurrent; cells in basal part variable in shape, near costa shortly rectangular to rectangular, cells above ± uniformly quadrate to shortly rectangular, incrassate, marginal cells about half way up basal part thick-walled, ± quadrate to oval, rarely rectangular, not hyaline, cells in acumen rectangular. Deciduous flagelliform shoots often present. Perichaetial leaves from sheathing base narrowed to long acumen. Capsules not known in the British Isles. On basic soil, in grassland, sand-dunes, quarries, on walls and cliff ledges. 0–1200 m. Widely distributed but apparently rare, from Cornwall east to E. Sussex and north to Sutherland, a few localities in

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Ireland. 37, H5, C. GB7 + 42∗ , IR5. Circumpolar Wide-temperate. Spain, Austria and Romania north to Svalbard, Caucasus, Siberia, northern N. America, Greenland. This is the plant referred to by Dixon & Jameson (1924) as D. flexicaule var. densum Bruch & Schimp. There are numerous collections of this plant made during the nineteenth and the first few years of the twentieth century, especially from Derbyshire, but it has been ignored since. It is probably considerably more common than the number of records suggests and the large number of old gatherings is a reflection of the lack of interest in the plant over the last 100 years or so. For a detailed comparison of D. flexicaule and D. gracile see A. A. Frisvoll, Bryologist 88, 31–40, 1985 and A. J. E. Smith, Bull. Br. Bryol. Soc. 61, 45–54, 1993. For differences from D. gracile see under that species.

9 D. gracile (Mitt.) Kuntze, Rev. Gén. Pl., 1891 (Fig. 44) ¨ Hal.) Paris, D. flexicaule auct. non (Schwagr.) ¨ D. crispatissimum (Mull. Hampe Dioicous. Yellowish green to green, often glossy and silky, lax to moderately dense tufts or patches, (2−)4–11 cm high. Stems fragile, usually only sparsely tomentose below. Leaves erect to secund when moist, flexuose, with apices sometimes twisted together when dry, 3–6 mm long, from sheathing basal part constituting 1/ –1/ total leaf length gradually tapering to long channelled entire to finely den4 3 ticulate acumen; costa broad, indistinct below, longly excurrent; sheathing part with basal cells near costa rectangular to very narrowly rectangular, cells above uniformly rectangular to elongate or more usually variable in size with mixed rounded to elongate often curved cells, rarely cells ± quadrate, marginal cells about half way up basal part very thin-walled, hyaline, narrowly rectangular to linear, rarely shorter, cells in acumen rectangular. Flagelliform shoots lacking. Innermost perichaetial leaves with sheathing base abruptly narrowed into acumen. Capsules ellipsoid, slightly curved; very rare, found at two localities in Scotland and not seen since 1902. n = 13. On soil in grassland, sand-dunes, quarries and on cliff ledges, calcicole. 0–1180 m. Common in basic areas, rare elsewhere. 91, H29, C. GB561 + 88∗ , IR88 + 9∗ , C2 + 2∗ . Circumpolar Boreo-temperate. Europe, Faeroes, Iceland, Siberia, China, New Guinea, N. America, Greenland, Guatemala, New Zealand. This is the plant referred to in both old and recent floras as D. flexicaule. D. flexicaule s.s. and D. gracile are very close and occasional plants are encountered that are difficult to determine. However, D. gracile usually differs in its larger size, hardly tomentose stems, lack of flagelliform shoots, the leaves flexuose when dry, the relatively shorter sheathing basal part more gradually tapering into the acumen and the areolation of the sheathing base.

18 SAELANIA LINDB., UTKAST EUR. BLADMOSS, 1878 A monotypic genus with the characters of the species. Derivation: named after a Finnish botanist Anders T. Saelan (1834–1921)

18 Saelania

159

Fig. 44 1–3, Ditrichum flexicaule: 1, leaves; 2, and 3, marginal and inner cells from middle part of leaf base; a and b, each from different gatherings. 4–7, D. gracile: 4, leaves; 5, perichaetial leaf; 6 and 7, marginal and inner cells from middle part of leaf base; c and d each from different gatherings. Leaves ×15, cells ×420.

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1 S. glaucescens (Hedw.) Broth. in Bomansson & Broth., Herb. Musc. Fenn. (ed. 2) Musci, 1894 (Fig. 46) S. caesia (Villars ex P. Beauv.) Lindb. Autoicous. Glaucous, bluish green tufts, to 3.5 cm high. Leaves appressed, upper flexuose when dry, erect-patent when moist, lower tapering ± from base to apex, upper longer, gradually tapering from narrowly lanceolate basal part to narrow acuminate apex; margins plane, bluntly toothed above; costa ending in or below apex in lower leaves, percurrent or excurrent in upper; basal cells in lower leaves rectangular, becoming ± quadrate above, in upper leaves basal cells rectangular or narrowly rectangular, becoming rectangular to quadrate-rectangular in mid-leaf, longer above, c. 10 μm wide in mid-leaf. Setae to 1 cm long; capsules erect, narrowly ellipsoid; smooth when moist, rugose when dry and empty; peristome teeth divided into papillose filiform segments; spores 14–16 μm. Capsules occasional, late summer. n = 13, 13 + m. On usually damp shaded soil over basic montane rock. C. 600 m. Very rare but locally frequent, Angus and E. Inverness. 2. GB2. Circumpolar Boreo-arctic Montane. Pyrenees, Alps and Carpathians north to Svalbard, Iceland, Turkey, Caucasus, N. Asia, Himalayas, N. America, Greenland, southern Africa, New Zealand, Hawaii. The glaucous appearance of this species is due to a covering of fungal hyphae. This species is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside Act. It is also listed as vulnerable in the Red Data Book of European Bryophytes.

19 DISTICHIUM BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1846 Leaves distichous, acuminate from broad whitish sheathing basal part; cells of acumen quadrate to rectangular, papillose. Capsules ovoid to cylindrical; peristome teeth strongly perforated or irregularly divided. A cosmopolitan genus of c. 8 species. Derivation: referring to the leaves arranged in two ranks.

Plants glossy, bright green above, reddish brown below or dull green, capsules erect or slightly inclined, spores 17–22 μm, paroicous 1. D. capillaceum Plants dull green, capsules inclined, spores 30–40 μm, autoicous 2. D. inclinatum 1 D. capillaceum (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 45) Swartzia montana Lindb. Paroicous. Silky loose or compact tufts, bright green above reddish brown below, or more rarely dull green, to 10(−15) cm high. Stems radiculose. Leaves strongly

19 Distichium

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Fig. 45 1–3, Distichium capillaceum: 1, plant; 2, leaf; 3, cells at shoulder of sheathing base. 4–6, D. inclinatum: 4, plant; 5, leaf; 6, cells at shoulder of sheathing base. 7–9, Trematodon ambiguus: 7, leaf; 8, cells near shoulder of leaf base; 9, capsule (×15). Shoots ×5, leaves ×15, cells ×450.

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distichous, erect to spreading, flexuose when dry, reflexed, often sharply so when moist, basal part sheathing, whitish, abruptly narrowed into sharply reflexed setaceous denticulate acumen composed mainly of excurrent costa; basal cells of sheathing part narrowly rectangular, cells above rectangular, cells in acumen shortly rectangular. Antheridia naked in axils of upper leaves. Setae to 15 mm long; capsules ovoid to cylindrical, erect or slightly inclined; peristome teeth c. 40 μm wide at base, irregularly split into filiform segments; spores 17–22 μm. Capsules frequent, summer. n = 14∗ , 28. On soil, boulders and on rock ledges, in damp basic sites or where there is basic seepage, in montane habitats, also occasionally in basic lowland grassland by streams and rivers and in dune-slacks. 0–1205 m. W. Cornwall, frequent or common in the mountains in S. and N Wales, N. England and the Scottish Highlands and in N. W. Ireland, very rare elsewhere in Ireland. 49, H13. GB230 + 30∗ , IR20 + 9∗ . Circumpolar Boreo-arctic Montane. More or less cosmopolitan. When well grown the dense bright green silky tufts, reddish brown below, and sharply reflexed leaves readily distinguish this plant from D. inclinatum, but small dull green plants with less sharply reflexed leaves which may occur on sand-dunes or in other lowland habitats cannot be distinguished from D. inclinatum in the absence of capsules; such plants from N. Somerset and Surrey have been named D. capillaceum but their identity is uncertain.

2 D. inclinatum (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 45) Swartzia inclinata (Hedw.) P. Beauv. Autoicous. Dull or dark green tufts or patches. Plants to 5 cm high. Leaves distichous, flexuose when dry, somewhat reflexed when moist, abruptly narrowed from sheathing basal part into ± reflexed denticulate acumen composed mainly of excurrent costa; basal cells of sheathing part narrowly rectangular, cells above rectangular, cells of acumen shortly rectangular. Antheridia in dwarf axillary branches. Setae to 10 mm long. Capsules ovoid, inclined; peristome teeth 40– 50 μm wide at base, irregularly perforated but not split; spores 30–40 μm. Capsules frequent, summer. n = 13, 14. In calcareous sand-dunes and grassland, in quarries and on rock ledges. 0–950 m. Occasional but sometimes locally abundant, scattered localities from W. Cornwall, N. Somerset and S. Wales north to Shetland, rare in N. W. Ireland. 39, H10. GB62 + 13∗ , IR9 + 3∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Turkey, N. and C. Asia, Japan, N. America. This and small forms of D. capillaceum may be confused with Ditrichum gracile or D. flexicaule but differ in the distichous leaves with acumen reflexed and more abruptly narrowed from the base.

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20 CERATODON BRID., BRYOL. UNIV., 1826 Dioicous. Leaves ovate to narrowly lanceolate; margins recurved; costa percurrent or excurrent; cells uniform throughout, ± quadrate, or longer towards base, smooth, unistratose. Inner perichaetial leaves with long sheathing base. Setae purplish red or yellow; capsules inclined, straight or curved, strumose, sulcate when dry; annulus of large cells; peristome teeth bifid into papillose filiform segments; calyptrae cucullate. Cosmopolitan, four species. Derivation: derived from the Greek for horn and tooth referring to the resemblance of a peristome tooth to an animal horn. For a monograph Of Ceratodon see J. S. Burley & N. M. Pritchard, Harvard Papers in Botany 2, 17–76, 1990.

Capsules inclined, strumose, peristome segments with pale margins, leaves often somewhat recurved when moist, margins often toothed near apex, calcifuge 1. C. purpureus Capsules ± erect, not or hardly strumose, peristome segments without pale margins, leaves straight, margins entire, calcicole 2. C. conicus 1 C. purpureus (Hedw.) Brid., Bryol. Univ., 1826 (Fig. 46) Tufts or patches ranging in colour from yellowish green to vinous or brownish red, to 3.5 cm high. Lower leaves closely appressed, ± straight, upper slightly twisted, flexuose when dry, erect-patent and often recurved when moist, ovate-lanceolate to linear-lanceolate, acute to acuminate, very rarely obtuse, channelled; margins ± recurved from base to apex, often bluntly toothed near apex; costa stout, percurrent or excurrent, in section c. 1.5 times as wide as thick; cells rectangular at base, becoming quadrate to irregularly hexagonal above, incrassate or not, smooth, pellucid, 9–12 μm wide in mid-leaf. Perichaetial leaves longer with expanded bases. Setae deep purplish red; capsules reddish brown, obloid, inclined to horizontal, curved, strumose, sulcate when dry; lid conical; peristome segments with pale margins from base to about middle, with 11–13(−16) articulations; spores 10–14 μm. Capsules common, spring, early summer. n = 13∗ . A primary coloniser on soil, rocks, walls, in a great variety of habitats, sometimes epiphytic, calcifuge. 0–1210 m. The most commonly found acrocarpous moss in the British Isles, pollution tolerant and occurring in urban and industrial areas. 112, H40, C. GB2120 + 192∗ , IR272 + 9∗ , C8 + 1∗ . Circumpolar Wide-boreal. Europe north to Svalbard, Caucasus, S. W, Asia, Himalayas, N. E. China, Japan, Korea, Macaronesia, N. America, Greenland. A highly polymorphic primary colonising species that may be found on almost any basepoor substrate. Usually easily recognised by the deep purple-red setae, the channelled

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Fig. 46 1–3, Saelania glaucescens: 1, leaves; 2, mid-leaf cells; 3, capsule (×10). 4–9, Ceratodon purpureus: 4, leaves; 5, basal cells; 6, mid-leaf cells; 7, costa section 1 /3 from leaf base; 8, capsule (×15); 9, peristome tooth. 10–13, C. conicus: 10, leaf; 11, costa section 1 /3 from leaf base; 12, capsule (×15); 13, peristome tooth. 14–16, Cheilothela chloropus; 14, leaf; 15, costa section 1 /3 from leaf base; 16, mid-leaf cells. Leaves ×21, sections ×300; cells ×420.

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leaves with stout costa, margins recurved almost to the apex and the smooth pellucid cells. There have been several literature reports of rhizoidal gemmae in C. purpureus but these are almost certainly erroneous (see H. L. K. Whitehouse, J. Bryol. 9, 177–84, 1976). Axillary green to pale brown filamentous, usually uniseriate propagules, 150–190 μm long, borne on older parts of the stem, have been reported from riparian habitats in N. America but I have been unable to find them on British material from similar situations. All British and Irish material belongs to ssp. purpureus, the other two subspecies occurring outside the British Isles.

2 C. conicus (Hampe) Lindb., Musci Scand., 1889 (Fig. 46) C. purpureus ssp. conicus (Hampe) Dixon, C. purpureus var. conicus (Hampe) Husn. Yellowish green tufts or patches, to 1 cm high. Leaves erect-patent, straight when moist, hardly altered when dry, forming comal tufts, ovate to ovate-lanceolate, acute; margins recurved ± from base to apex, entire; costa excurrent, sometimes longly so, in section relatively thin, about 3 times as wide as thick; basal cells rectangular, becoming quadrate above, incrassate, smooth, pellucid, 5–12 μm wide in mid-leaf. Setae orange-red; capsules ± erect, ellipsoid, not or hardly strumose, smooth or slightly sulcate when dry; lid conical; peristome segments without or with only very narrow pale margins in lower half, with 7–9(−12) articulations; spores 11–13 μm. Capsules occasional, spring. On thin dry soil, particularly over oolitic limestone, on tops of and in crevices of walls, on paths and in quarries, calcicole. Lowland. Rare and decreasing; seen recently only in Oxford, Berkshire and Warwick with old confirmed records from Northampton, E. Gloucester and S. Lincoln. 6. GB7 + 13∗ . Submediterranean-Subatlantic. Germany, Norway, Sweden, Alps, S. W. Asia, La Palma, Tenerife, N. Africa. C. conicus is readily distinguished from C. purpureus when capsules are present, but sterile plants may present problems and not all can be named. However, C. conicus is a calcicole, is usually yellowish green, has straight leaves, which are similar moist or dry, in a comal tuft and the costa relatively less thick than in C. purpureus. This species is considered endangered in the Red List of British mosses and this is because of the destruction of habitats, especially walls, where it occurs.

21 CHEILOTHELA (LINDB.) BROTH., NAT. PFLANZENFAM., 1901 Dioicous. Leaves increasing in size up stem, rigid when moist, ovate-lanceolate to triangular; costa well defined, excurrent; cells smooth at base of leaf, mamillose and bistratose above. Capsules similar to those of Ceratodon but not strumose. A mainly Southern Hemisphere genus of about 6 species. Derivation: meaning thick nipple, referring to the capsule beak.

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1 C. chloropus (Brid.) Broth., Nat. Pflanzenfam., 1901 Ceratodon chloropus (Brid.) Brid.

(Fig. 46)

Dull yellowish green sometimes extensive patches, to 1 cm high. Underground horizontal axes often present. Leaves appressed, straight when dry, erect-patent, rigid when moist, ± narrowly triangular to ovate, acuminate; margins plane, finely crenulate below, papillose-crenulate above; costa broad, excurrent in stout point; basal cells shortly rectangular, smooth, hyaline, cells above smaller, quadrate, mamillose, bistratose, very obscure, 6–8 μm wide in mid-leaf. Setae pale yellow; capsules ellipsoid, not strumose. Capsules not known in England. On thin soil overlying basic rock. Lowland. Very rare, S. Devon, N. Somerset. 2. GB4. Mediterranean-Atlantic. South-west and Mediterranean Europe, Turkey, Cyprus, Algeria, Macaronesia, southern Africa. C. chloropus is very unusual in that the vertical axes produce underground horizontal branches which ramify through the top 1 cm of soil forming an intricate network (see R. Porley, J. Bryol. 17, 164–6, 1992).

10 Bruchiaceae Leaves spirally arranged; alar cells not differentiated, cells above rectangular. Capsules dehiscent (Trematodon) or cleistocarpous (Bruchia), neck half or more total length of capsule with numerous stomata; peristome teeth bifid or perforated; annulus absent. Five genera.

22 TREMATODON MICHX., FL. BOR.-AMER., 1893 Autoicous. Leaves ± abruptly narrowed from sheathing base into acumen; costa excurrent. Capsules dehiscent, subclavate, slightly curved; peristome teeth ± entire to deeply bifid. A ± cosmopolitan genus of nearly 100 species. Derivation: meaning perforated tooth, referring to the peristome.

1 T. ambiguus (Hedw.) Hornsch., Flora, 1819 (Fig. 45) Green or brownish tufts, to 1 cm high. Leaves erect-patent when moist, from oblong or oblong-lanceolate sheathing basal part rapidly narrowed to long blunt acumen composed mainly of costa, acumen about 1/2 length of lamina in leaves from middle part of stem, shorter in upper and perichaetial leaves; margins plane, entire; costa stout, excurrent, obscurely toothed on abaxial side towards apex; basal cells of sheathing portion narrowly rectangular, narrower towards margins, shorter above, rectangular at shoulder, cells in acumen narrowly rectangular. Setae yellow, 1–3 cm long; capsules erect, slightly curved, neck about same length as capsule body, slightly strumose; spores 30–36 μm. Capsules common, summer. n = 13 + 2m. On moist peaty soil in montane areas. 350 m. Probably extinct, Mid

23 Rhabdoweisia

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Perth, 1883, not seen since. 1. GB1∗ . European Boreal-montane. N. and C. Europe, Iceland, Himalayas, Kamchatka, Japan, N. America. Although widely scattered in northern Europe this species has only been found once in the British Isles, although when capsules are present it is hardly likely to be overlooked.

11 Rhabdoweisiaceae Usually autoicous. Stems with or without central strand. Leaves spirally arranged, linear-lanceolate to ovate; alar cells differentiated or not, cells above quadrate, smooth or mamillose. Capsules erect, ovoid to ellipsoid, symmetrical or not, often longitudinally furrowed or sulcate when dry and empty; stomata present; annulus cells small; peristome teeth entire, perforated or deeply cleft, smooth or with oblique striations alternating in direction with each articulation; calyptrae cucullate. Eleven genera.

23 RHABDOWEISIA BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1846 Autoicous. Stems without central strand. Leaves crisped when dry, spreading when moist, narrowly linear-lanceolate to lingulate, acute to obtuse; margins plane or recurved below, toothed above; costa ending below apex; basal cells rectangular, alar cells not differentiated, cells above ± quadrate, slightly mamillose or not. Setae short; capsules erect, ovoid, striate; lid with oblique beak; peristome teeth entire, smooth or with oblique striations alternating in direction with each articulation. A small genus of 5 species occurring in Europe, E. and C. Asia, W. and C. Africa, Macaronesia and the Americas. Derivation: meaning fluted column, referring to the striate capsules.

1 Cells in upper part of leaf 12–20 μm wide, margins irregularly dentate 3. R. crenulata Cells in upper part of leaf 8–12(−14) μm wide, margins entire or denticulate above 2 2 Lamina 3–4(−5) cells wide on either side of costa 220 μm from apex, peristome teeth very narrow, fugacious 1. R. fugax Lamina 5–7 cells wide on either side of costa 220 μm from apex, peristome teeth lanceolate, not fugacious 2. R. crispata 1 R. fugax (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 47) Bright green or yellowish green tufts, 0.5–1.0 cm high. Leaves crisped when dry, flexuose-spreading when moist, ligulate or linear-lanceolate, gradually tapering to acuminate apex, lamina 6–9 cells wide on each side of costa at middle of leaf, 3–4(−5) cells wide 220 μm from apex; margins plane, entire or denticulate near

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Fig. 47 1–4, Rhabdoweisia fugax: 1, leaves; 2, cells at leaf apex; 3, capsule; 4, peristome tooth. 5–8. R. crispata: 5, leaves; 6, cells at leaf apex; 7, capsule; 8, peristome tooth. 9–11, R. crenulata: 9, leaves; 10, cells at leaf apex; 11, capsule. Leaves ×25, cells ×420, capsules ×15, teeth ×175.

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apex; costa ending below apex; basal cells rectangular, rounded-quadrate or wider than long above, 8–12 μm wide in upper part of leaf. Setae yellowish; capsules ovoid, longitudinally striate, contracted or not below mouth when dry; lid with oblique beak; peristome teeth very narrow from a broad base, fugacious; spores 14– 20(−22) μm. Capsules common, ± throughout year. n = 13. In shaded non-basic rock crevices in ravines, woods and on cliffs. 0–800 m. Frequent in N. W. Wales, occasional in other montane parts of Britain, rare in Ireland. 45, H11. GB125 + 22∗ , IR5 + 9∗ . European Boreal-montane. Europe, Faeroes, Caucasus, Macaronesia, S. Africa, Mexico, S. America. 2 R. crispata (Dicks. ex With.) Lindb., Acta Soc. Sci. Fenn., 1871 R. denticulata (Brid.) Bruch & Schimp.

(Fig. 47)

Bright yellowish green tufts, 0.5–1.5 cm high. Leaves crisped when dry, flexuosespreading when moist, narrowly lingulate to ligulate, abruptly to gradually tapering to acute to obtuse apex, lamina 6–12 cells wide on each side of costa in middle of leaf, 5–7 cells wide 220 μm from apex; margins plane or narrowly recurved below, denticulate towards apex; costa ending below apex; basal cells rectangular, cells above quadrate-hexagonal, 10–12(−14) μm wide in upper part of leaf. Setae yellowish; capsules ovoid, longitudinally striate when dry; lid with oblique beak; peristome teeth gradually tapering from base to apex; spores 18–20 μm. Capsules common, ± throughout year. n = 13, 13 + m∗ , 14. Shaded rock crevices, amongst rocks in ravines, rarely on peat, usually in acidic habitats but occasionally where basic. 0–950 m. Frequent or common in western Britain, rare to occasional in Ireland. 53, H18 GB172 + 24∗ , IR20 + 7∗ . Suboceanic Boreal-montane. Europe, Faeroes, Amur, China, Korea, Japan, Java, N. Africa, N. and S. America, Greenland, Hawaii. R. crispata is intermediate between the other two British species. R. crenulata differs in its usually larger size, and its wider more shortly pointed and more coarsely toothed leaves, although sometimes the only reliable character is cell size and leaf width near the apex. R. fugax has the leaves narrower near the apex and very narrow fugacious peristome teeth.

3 R. crenulata (Mitt.) H. Jameson, Rev. Bryol., 1890 (Fig. 47) Bright yellowish green or green tufts, cushions or patches, 1–3 cm high. Leaves crisped when dry, erect-patent to spreading or recurved when moist, narrowly lingulate, acute to obtuse, lamina 9–14 cells wide on either side of costa in middle of leaf, 6–10 cells wide 220 μm from apex; margins plane or narrowly recurved below, strongly irregularly dentate above; costa ending below apex; basal cells rectangular, cells above ± quadrate-hexagonal, sometimes wider than long, 12–20 μm wide in upper part of leaf. Setae yellowish; capsules ovoid or ovate-ellipsoid, longitudinally striate; lid with oblique beak; peristome teeth gradually tapering from base to apex; spores 18–24 μm. Capsules common, spring,

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summer. n = 13 + m∗ . In rock crevices and on damp rocks in sheltered nonbasic montane habitats, often by waterfalls. 0–800 m. Occasional to frequent in N. W. Wales, N. W. England and W. Scotland north to W. Sutherland, very rare in S. and Mid Wales, Cheshire, Durham, N. Northumberland, occasional in W. Ireland. 35, H15. GB89+15∗ , IR19+2∗ . Oceanic Boreal-montane. Belgium, Czechoslovakia, France, Germany, Norway, Spain, Switzerland, Sikkim, China, Taiwan, N. America, Greenland, Columbia, Hawaii.

24 OREOWEISIA DE NOT., ATTI REALE UNIV. GENOVA, 1869 Autoicous. Stems with central strand. Leaves incurved and crisped when dry, erect-patent to spreading when moist, linear-lanceolate; cells quadrate, mamillose. Capsules ± erect, ovoid, smooth when moist and when dry; annulus cells small, persisting. Derivation: meaning mountain Weissia.

1 O. bruntonii (Sm.) Milde, Bryol. Siles., 1860 Cynodontium bruntonii (Sm.) Bruch & Schimp.

(Fig. 49)

Dense dark green cushions or tufts, 1–3 cm high. Leaves strongly curled inwards when dry, erect-spreading with tips often recurved when moist, narrowly lanceolate, gradually tapering to acute apex; margins recurved to about half way up leaf, remotely crenulate-denticulate above; costa ending in or below apex, slightly rough on abaxial side above; basal cells rectangular, cells above quadrate, mamillose on both sides, partially bistratose, opaque, 7–14 μm wide in mid-leaf. Yellowish brown rhizoidal gemmae 50–90 μm long, consisting of unbranched or branched row of cells, sometimes present. Perigonial leaves subacute. Setae yellowish; capsules pale brown, erect, ovoid, smooth, ± symmetrical, slightly contracted at mouth, when dry sometimes slightly plicate; annulus persisting; lid entire at base; peristome teeth irregular, to 160 μm long, variously divided; spores 15–19 μm. Capsules frequent, late spring, early summer. n = 13∗ , 14∗ , 15∗ . In clefts and crevices of sheltered non-basic rocks and walls, in montane areas. 0–480 m. Occasional in western England, frequent in Mid and N. Wales, occasional in eastern Scotland, very rare elsewhere and in Ireland, Jersey. 64, H11, C. GB188 + 40∗ , IR8 + 6∗ , C1. European Temperate. Europe north to Svalbard, Iceland, Turkey, Azores, Canary Islands. Differs from Cynodontium species in capsule characters. When sterile it may be distinguished from C. polycarpon and C. strumiferum by the more densely tufted habit, the leaves strongly curled inwards when dry and the lower leaves smaller than the upper; the leaf cells are bistratose and opaque. It is more likely to be confused with Dicranoweisia cirrata, which, however, grows on exposed rather than sheltered rocks and walls as well as on trees. The presence of rhizoidal gemmae in O. bruntonii may also be a useful character.

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25 CYNODONTIUM BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1856 Autoicous. Lax or dense tufts. Leaves crisped when dry, erect-patent to spreading when moist, narrowly lanceolate, channelled; margins recurved to about half way, ± toothed above, often bistratose; costa ending at or just below apex or (in non-British species) excurrent; basal cells rectangular, shorter at margins, alar cells not or scarcely differentiated, cells above quadrate, thick-walled, slightly collenchymatous, smooth to conically mamillose. Setae long; capsules ± erect or inclined, straight or curved, usually striate, sometimes strumose; lid with long oblique beak; peristome teeth divided to half way or below, sometimes irregular and short, longitudinally striate below, papillose above. About 12 species occurring mainly in Europe. Derivation: meaning dog tooth, referring to the appearance of a peristome tooth of Cynodontium (Oreoweisia) bruntonii. This genus has been misunderstood in Britain. For an account of Cynodontium (including Oreoweisia bruntonii) see A. C. Crundwell, Trans Br. Bryol. Soc. 3, 706–12, 1960. The present account of the genus is based upon an unpublished manuscript by A. C. Crundwell.

1 Cells 11–22 μm wide in mid-leaf, smooth 2. C. jenneri Cells 9–14 μm wide in mid-leaf, smooth or mamillose 2 2 Leaf margins unistratose throughout 4. C. fallax Leaf margins bistratose above 3 3 Capsules inclined, curved, strumose 1. C. strumiferum Capsules ± straight, not or hardly strumose 4 4 Leaf cells distinctly mamillose especially on adaxial side, perigonial leaves ± acute, annulus separating, lid crenulate at base 3. C. polycarpon Leaves smooth or slightly mamillose with mamillae mainly on abaxial side, perigonial leaves obtuse, annulus persisting, lid entire at base 5. C. tenellum ¨ 1 C. strumiferum (Hedw.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1869 (Fig. 48) C. polycarpon var. strumiferum (Hedw.) Schimp. Dense green tufts, 1–4 cm high. Leaves somewhat crisped when dry, spreading, subsecund when moist, narrowly lanceolate, gradually tapering to acute apex; margins strongly recurved to middle of leaf or above, irregularly crenulatedenticulate above; costa ending in or below apex; basal cells rectangular, cells above quadrate, bistratose at margins, unistratose elsewhere, strongly mamillose on both sides, pellucid, 9–12 μm wide in mid-leaf. Perigonial leaves subacute. Setae yellowish; capsules oblong-ellipsoid, inclined, curved, striate, conspicuously strumose; lid crenulate at base; annulus of 3 rows large cells, separating; peristome teeth all of similar length, 300–400 μm long, divided to half way or below; spores

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Fig. 48 1–6, Cynodontium strumiferum: 1, dry shoot; 2, leaf (×20); 3, marginal cells at middle of leaf; 4, leaf margin section; 5, capsule; 6, peristome tooth. 7–12, C. polycarpon: 7, dry shoot; 8, leaf (×15); 9, marginal cells at middle of leaf; 10, leaf margin section; 11, capsule; 12, peristome tooth. 13–17, C. fallax: 13, leaf (×15); 14, marginal cells at middle of leaf; 15, leaf margin section; 16, capsule; 17, peristome tooth. 18–22, C. gracilescens: 18, leaf (×15); 19, marginal cells at middle of leaf; 20, leaf margin section; 21, capsule; 22, peristome tooth. Cells ×450, capsules ×10, teeth ×100.

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18–24 μm. Capsules common, early summer. n = 14, 15. On sheltered acidic rocks and in scree. (30−)350–600 m. Very rare, E. Perth, Angus, Aberdeen, E. Inverness, Skye, E. Ross. 7. GB8 + 5∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Iceland, Caucasus, Siberia, N. America, Greenland. Plants without sporophytes cannot be distinguished from C. polycarpon but both species produce sporophytes freely and differ markedly in capsule form although in central Europe the distinction is less clear cut and some authorities treat C. strumiferum as a variety of C. polycarpon. C. strumiferum is the only British species with peristome teeth of equal length.

2 C. jenneri (Schimp.) Stirt., Ann. Scot. Nat. Hist., 1906 (Fig. 49) Dense or lax bright green tufts, 1–4 cm high. Leaves crisped when dry, erectspreading when moist, narrowly lanceolate, gradually tapering to acute apex; margins narrowly recurved to about half way up leaf, rarely plane, coarsely dentate to almost entire above; costa ending in or below apex, usually slightly toothed on abaxial side above; basal cells rectangular, cells above quadrate, unistratose throughout, smooth on both surfaces, pellucid, 11–22 μm wide in midleaf. Perigonial leaves ± acute. Setae yellowish; capsules erect, symmetrical, ellipsoid with long neck, striate, not or only slightly strumose; lid crenulate at base; annulus of 2 rows of large cells, separating; peristome teeth shorter on one side of capsule than on the other, 300–400 μm long; spores 18–24 μm. Capsules common, summer. n = 14. On sheltered acidic rocks or rock ledges, occasionally on soil in woodland. 0–730 m. Occasional in N. Wales, N. W. England and Scotland (mainly in the east and centre), extending north to Caithness and Orkney. 23. GB37 + 11∗ . Suboceanic Boreal-montane. Westphalia, Scandinavia, Newfoundland, Pacific N. America. May be recognised when sterile by the leaves with unistratose margins and the cells larger than in other Cynodontium species.

3 C. polycarpon (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 (Fig. 48) Dense or lax green tufts, 2–4 cm high. Leaves crisped when dry, erect-spreading when moist, narrowly lanceolate, gradually tapering to acute apex; margins recurved to above half way up leaf, crenulate-denticulate above; costa ending in or below apex, slightly mamillose on abaxial side above; basal cells rectangular, cells above quadrate, bistratose at margins, unistratose elsewhere, mamillose, especially on adaxial side, pellucid, 8–14 μm wide in mid-leaf. Perigonial leaves acute. Setae yellowish; capsules ± erect, ellipsoid, neck short, not or scarcely strumose; lid crenulate at base; annulus of 3 rows of cells, separating; peristome teeth shorter on one side of capsule than on the other, 300–400 μm long, bifid to below middle; spores 20–25 μm. Capsules common, early summer. n = 14. Sheltered rocks in montane habitats. Ascending to 880 m. Very rare, Merioneth, N. Northumberland, Cumberland, Angus, S. Aberdeen, E. Inverness (old record). 6. GB5 + 2∗ . European Boreal-montane. Europe north to Svalbard, Iceland, Turkey, Caucasus, C. Asia, Japan, Canada (Northern Territories), Greenland.

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Fig. 49 1–6, Cynodontium jenneri: 1, dry shoot; 2, leaf; 3, marginal cells at middle of leaf; 4, leaf margin section; 5, capsule; 6. peristome tooth. 7–12, C. tenellum: 7, dry shoot; 8, leaf; 9, marginal cells at middle of leaf; 10, leaf margin section; 11, capsule; 12, peristome tooth. 13–19. Oreoweisia bruntonii: 13, dry shoot; 14, leaf; 15, marginal cells at middle of leaf; 16, leaf margin section; 17, capsule; 18, peristome teeth; 19, rhizoidal gemmae (×300). Shoots ×5, leaves ×15, capsules ×10, cells ×450, teeth ×150.

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4 C. fallax Limpr., Laubm. Deutschl., 1886 (Fig. 48) Dense or lax green tufts, 2–6 cm high. Leaves crisped when dry, erect-spreading when moist, narrowly lanceolate to linear-lanceolate, gradually tapering to acute apex; margins recurved to about half way, crenulate-denticulate above; costa ending in or below apex, strongly mamillose on abaxial side above; basal cells rectangular, cells above quadrate, bistratose at margins, unistratose elsewhere, with numerous pointed mamillae on adaxial side, smooth or mamillose on abaxial side, pellucid, cells 9–14 μm wide in mid-leaf. Perigonial leaves acuminate. Setae yellowish; capsules ± erect, almost symmetrical, ellipsoid, neck short, striate, not strumose; lid entire at base; annulus a single row of small persistent cells; peristome teeth shorter on one side of capsule than on the other, 250–350(−450) μm long, bifid to below half way and usually with slits and perforations below; spores 18– 23 μm. Capsules common, summer. On sheltered acidic rocks. The single British record is based upon a gathering from Glen Phee, Angus, made in 1868. 1. GB1∗ . Eurasian Boreal-montane. C. and E. Europe north to Svalbard, N. Asia east to the Altai. In N. Europe the leaf cells of C. fallax are mamillose on the adaxial side only but in central Europe the cells may also be mamillose on the abaxial side. A record of C. gracilescens (D. Weber & F. Mohr) Schimp. (Fig. 48, 18–22), based upon a single unlocalised gathering from Wales by Evans in 1821 is questionable and the species should be deleted from the British list.

5 C. tenellum (Bruch & Schimp.) Limpr., Krypt.-Fl. Schlesien, 1877 (Fig. 49) Dense green tufts, 1–3 cm high. Leaves crisped when dry, erect-spreading when moist, narrowly lanceolate, gradually tapering to acute apex; margins recurved to more than half way up leaf, irregularly crenulate-denticulate or rarely entire above; costa ending in or below apex, smooth or slightly roughened on abaxial side above; basal cells rectangular, cells above quadrate, bistratose at margins, elsewhere unistratose, smooth on adaxial side, smooth or slightly mamillose on abaxial side, pellucid, cells 7–12 μm wide in mid-leaf. Perigonial leaves obtuse. Setae yellowish; capsules ± erect and symmetrical, ellipsoid with short neck, striate, not strumose; lid entire at base, annulus of 2 rows of small cells, persisting; peristome teeth shorter on one side of capsule than on the other, 220–280 μm long, divided nearly to base; spores 16–20 μm. On sheltered acidic rocks and scree. 150–600 m. Rare, Berwick, Perth, Angus, Kincardine, S. Aberdeen, Moray, E. Inverness. 8. GB14+4∗ . Circumpolar Boreo-arctic Montane. C. and N. Europe north to Svalbard, Caucasus, N. America. Confused in the past with C. polycarpon from which it differs in the obtuse perigonial leaves, the upper cells smooth on the abaxial side, the persistent annulus and the peristome teeth divided nearly to the base.

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26 ONCOPHORUS (BRID.) BRID., BRYOL. UNIV., 1826 Autoicous. Leaves crisped when dry, spreading when moist, from ± sheathing basal part narrowed to lanceolate, acuminate limb; costa reaching apex or excurrent; basal cells rectangular, alar cells enlarged or not; cells above roundedquadrate to rectangular, ± smooth. Setae straight; capsules inclined, curved, gibbous, strumose, not striate when moist but often sulcate when dry; peristome teeth divided almost to base. A small genus of c. 13 species occurring in temperate and arctic regions, Sri Lanka and southern S. America. Derivation: the name refers to the goitre-like swelling at the capsule base.

Leaf margins recurved at least on one side, alar cells enlarged, sometimes forming auricles, capsules mostly 2–3 times as long as wide 1. O virens Leaf margins plane, alar cells not enlarged, capsules 1.5–1.7 times as long as wide 2. O. wahlenbergii 1 O. virens (Hedw.) Brid., Bryol. Univ., 1826 Cynodontium virens(Hedw.) Schimp.

(Fig. 50)

Dense tufts or patches, yellowish green above, brownish below, 2–9 cm high. Leaves flexuose to crisped when dry, spreading when moist, upper leaves longer than lower, ± reflexed, tapering from ovate or oblong sheathing basal part to narrowly lanceolate acuminate limb; margins recurved below at least on one side, entire or toothed above; costa percurrent or shortly excurrent; basal cells rectangular or narrowly rectangular, alar cells shorter, wider, 2–3-stratose, sometimes forming weak auricles, cells above rounded-quadrate, smooth, bistratose at margins, 8–12 μm wide in mid-leaf. Setae reddish; capsules inclined, ellipsoid, curved, strumose, smooth, 1.5–2.0 mm long, (1.5−)2.0–3.0 times as long as wide; lid with oblique beak; peristome teeth bifid; spores 20–28 μm. Capsules frequent, summer. n = 14. On damp ground, on wet rocks by streams and in flushes, in basic habitats. 640–970 m. Rare, Westmorland, Cumberland, Perth, Angus, S. Aberdeen, Inverness, Skye, Sutherland. 10, GB21 + 2∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Turkey, Caucasus, Himalayas, N. Asia, Morocco, California, Greenland. Differs from Cynodontium species in occurring in habitat and in the smooth strumose capsules. O. wahlenbergii differs in the shorter capsules and more narrowly pointed leaves which lack auricles.

2 O. wahlenbergii Brid., Bryol. Univ., 1826 Cynodontium wahlenbergii (Brid.) Hartm.

(Fig. 50)

Green or yellowish green tufts or patches, to 3 cm high. Leaves crisped when dry, patent when moist, upper leaves scarcely longer than lower, gradually or abruptly tapering from short sheathing basal part to lanceolate or linear-lanceolate

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Fig. 50 1–4, Oncophorus virens: 1, leaves; 2, alar cells (×320); 3, mid-leaf cells (×450); 4, capsule. 5–8, O. wahlenbergii: 5, leaves; 6, alar cells (×320); 7, mid-leaf cells (×450); 8, capsule. Leaves ×20, capsules ×10.

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acuminate limb; margins plane, denticulate towards apex; costa ending below apex to excurrent; basal cells rectangular, alar cells shorter but not enlarged, unistratose, cells above irregularly quadrate, incrassate, smooth, bistratose at margins above, 8–12 μm wide in mid-leaf. Setae reddish; capsules inclined, ovoid, curved, smooth, strumose, 1.2–1.7 mm long, 1.5–1.7 times as long as wide; lid with oblique beak; spores 20–28 μm. Capsules frequent, summer. n = 14. Damp rocky hillsides and by streams and springs. 700–1000 m. Rare, Mid Perth, S. Aberdeen, W. Inverness, Argyll, Skye, E. Ross, old records from E. Perth, Dunbarton, and W. Ross. 10. GB12 + 6∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Caucasus, Himalayas, E. Asia, Arizona, Greenland.

27 DICHODONTIUM SCHIMP., COROLL. BRYOL. EUR., 1856 Plants forming tufts or patches; stems with central strand. Leaves narrowly lanceolate to ovate, acute to obtuse; margins usually dentate; cells in upper part of leaf mamillose and often opaque, rounded-quadrate. Capsules ovoid to cylindrical, straight or curved, smooth; annulus lacking; peristome teeth divided and papillose above, pitted -striate below; calyptrae cucullate. Six species occurring in Europe, Asia, America, New Zealand. Dervation: Referring to the peristome teeth split in two.

1 Leaves squarrose when moist, cells smooth, pellucid 3. D. palustre Leaves spreading to reflexed when moist, cells coarsely mamillose, usually opaque 2 2 Capsules curved, 1–2 times as long as wide, leaves 2.4–3.9 times as long as wide 1. D. pellucidum Capsules straight or nearly so, ± erect, 2–4 times as long as wide, leaves 4.0–5.5 times as long as wide 2. D. flavescens

1 D. pellucidum (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 (Fig. 51) Lax, dull or light green tufts or patches, to 7 cm high. Leaves incurved when dry, spreading to sharply reflexed when moist, 2.4–3.9 times as long as wide, lanceolate to ovate from broad basal part, widest c. 1 /5 from base, acute to obtuse; margins recurved below, serrulate to coarsely dentate, sometimes undulate above; costa stout, 60–100 μm wide near base, strongly toothed on abaxial side above, teeth 12–14 μm wide; cells incrassate, sometimes opaque above, lower narrowly rectangular, becoming smaller and moderately to coarsely mamillose above, mamillae concealing lumens, ± quadrate from mid-leaf in ovate-leaved forms, towards apex in narrow-leaved forms, 8–10 μm wide in mid-leaf, marginal cells above similar to other cells. Brown globular ellipsoid or clavate, several-celled gemmae, 60–100 μm long, on filamentous branches arising below leaf insertions, occasionally produced. Setae straight, thick, yellow; capsules inclined, ovoid to

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Fig. 51 1–5, Dichodontium pellucidum: 1, leaves (×15); 2, basal cells; 3, mid-leaf cells; 4, capsule; 5, gemmae (×300). 6–8, D. flavescens: 6, leaf (×15); 7, mid-leaf cells; 8, capsules. 9–10, Aongstroemia longipes: 9, leaves (×25); 10, mid-leaf cells. Cells ×420, capsules ×15.

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ellipsoid, curved, smooth, 1.5–3.0 times as long as wide excluding lid; lid rostrate, less than half length of capsule; spores 10–12 μm. Capsules occasional, autumn to spring. n = 14∗ , 14 + m. On gravelly soil, sand and rocks by streams and rivers, on damp soil and on dune-slacks, often but not necessarily where there is some base, rarely in limestone grassland. Very rare in most of lowland England although frequent in the south-east, common elsewhere, frequent in the west of Ireland, rare to occasional elsewhere. 99, H33. GB1017 + 91∗ , IR57 + 4∗ . Circumpolar Boreoarctic Montane. Europe north to Svalbard, Faeroes, Iceland, Turkey, Siberia, China, Japan, Madeira, Algeria, Colorado. An extremely variable species. Distinguished from D. flavescens when sporophytes are present by the shorter inclined or curved capsules. When sterile it may be distinguished by the relatively wider leaves, more strongly papillose cells and the upper marginal cells of similar size to other cells. D. flavescens is regarded by some authorities as a variety of or synonymous with D. pellucidum. Thus, Nyholm (1987) says that plants with straight and curved capsules occur in the same tuft. However, examination of herbarium specimens showed capsule differences to be consistent. This is born out by recent observation by J. Werner, J. Bryol. 24, 215–21, 2002. Both Werner’s observations and mine were made on herbarium material rather than random field gatherings and the dangers of using only such material when coming to taxonomic conclusions must be borne in mind. Plants with small sharply reflexed ovate leaves have been named var. fagimontanum (Brid.) Schimp., but because of the large number of intermediates the variety is not recognised here. Stunted forms of D. pellucidum may be mistaken for Leptodontium flexifolium but that species differs in the shorter basal cells, rounded-hexagonal upper cells and the row of pale marginal cells near the leaf base. Gemmae are only occasionally produced but when present may be so abundant as to render the plants dusty in appearance. For a description of the gemmae see M. E. Newton, J. Bryol. 15, 806–8, 1989.

2 D. flavescens (Dicks. ex With.) Lindb., Bot. Not., 1879 D. pellucidum var. flavescens (Dicks. ex With.) Kindb.

(Fig. 51)

Yellowish to dark green tufts or patches, to 7 cm high. Leaves lanceolate from wide erect basal part, widest near base, acute to obtuse, 4.0–5.5 times as long as wide; margins irregularly toothed to coarsely toothed; costa stout, ending below apex, 55–110 μm wide near base, teeth on abaxial side 10–12 μm wide; cells incrassate, lower narrowly rectangular, becoming ± quadrate towards the apex, mamillose, mamillae not covering lumen, 8–10 μm wide in mid-leaf, upper marginal cells larger than other cells. Gemmae similar to those of D. pellucidum very rarely produced. Capsules ± erect, narrowly ellipsoid to cylindrical, straight, smooth, 12– 4 times as long as wide excluding lid; lid more than half length of capsule; spores 20–24 μm. Capsules autumn to spring. n = 7∗ , 14. In similar habitats to D. pellucidum. Mainly at low altitudes. Rare in western and northern Britain, Dublin,

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Wicklow, Antrim, Londonderry (but many records require confirmation). 27, H4. GB10 + 30∗ , IR1 + 3. Belgium, France, Italy, Luxembourg, Spain, Caucasus, British Columbia. 3 D. palustre (Dicks.) M. Stech, Nova Hedwigia, 1999 (Fig. 52) Anisothecium palustre (Dicks.) I. Hagen, Dicranella palustris (Dicks.) Crundw. & E. F. Warb., Dicranella squarrosa (Schrad.) Schimp. Dioicous. Yellowish green to bright green tufts or patches, 1–10(−15) cm high. Leaves squarrose when moist, basal part oblong, sheathing, decurrent, gradually tapering to squarrose oblong-lanceolate limb, apex obtuse; margins plane, crenulate or rarely entire above; costa thin, ending well below apex, cells in sheathing basal part narrowly rectangular or narrowly rhomboidal, hyaline, in limb gradually becoming smaller, irregular in shape and more incrassate, smooth, rectangular, 8–12 μm wide in mid-leaf. Spherical reddish brown or brown rhizoidal gemmae, 200–250 μm diameter, often present. Setae purple; capsules ovoid, inclined, gibbous, smooth; lid with oblique beak; spores 16–22 μm. Capsules rare, autumn to spring. n =15∗ . In marshes, flushes, springs, at edges of small streams. 0–1100 m. Almost absent from lowland England, common elsewhere. 93, H32. GB714 + 57∗ , IR104 + 9∗ . European Boreal-montane. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Japan, N. America, Greenland. Although usually placed in Dicranella, DNA studies show that this species is closely related to D. pellucidum (see M. Stech, Nova Hedwigia 69, 237–40, 1999). Stunted forms may be confused with D. pellucidum, which, however, differs in toothed leaves and strongly mamillose obscure cells.

28 DICRANOWEISIA LINDB. IN MILDE, BRYOL. SILES., 1869 Autoicous. Plants forming dense tufts or cushions; stems with central strand. Leaves crisped when dry, patent to spreading when moist, from ovate or lanceolate basal part abruptly narrowed or gradually tapering to apex; margins plane or recurved; costa ending below apex; alar cells enlarged or not, cells above quadrate or rectangular, mamillose or smooth. Setae straight; capsules erect, symmetrical, smooth; peristome teeth deeply inserted; entire or bifid at tips. Twenty-four species occurring in temperate, arctic, antarctic and tropical montane regions. Derivation: a combination of Dicranum and Weissia.

Leaves with recurved unistratose margins, auricles absent, mid-leaf cells 12–14 μm wide, capsules narrowly ellipsoid to subcylindrical 1. D. cirrata Leaf margins plane, bistratose above, at least some leaves with distinct brownish auricles, mid-leaf cells 6–8(−10) μm wide, capsules ovate-ellipsoid 2. D. crispula

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Fig. 52 1–3, Dichodontium palustre: 1, leaves (×12.5); 2, mid-leaf cells; 3, capsule (×15). 4–7, Dicranoweisia crispula: 4, leaf (×25); 5, basal cells; 6, mid-leaf cells; 7, capsule. 8–12, D. cirrata: 8, leaf; 9, basal cells; 10, mid-leaf cells; 11, capsule; 12, gemmae (×280). Cells ×420, capsules ×15.

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1 D. cirrata (Hedw.) Lindb. in Milde, Bryol. Siles., 1869 (Fig. 52) Yellowish green to green tufts or cushions, 0.5–3.0 cm high. Leaves strongly crisped and incurved when dry, erect-patent to spreading when moist, lower lanceolate, upper narrowly lanceolate, gradually tapering to acute apex; margins entire, recurved at middle of leaf; costa ending below apex; basal cells rectangular, (9−)12–18 μm wide, alar cells shorter and wider but not forming auricles, cells above quadrate or rounded-quadrate, smooth, pellucid, unistratose at margins, 10–14 μm wide in mid-leaf. Ellipsoid to cylindrical gemmae, to 150 μm long, often present and sometimes abundant on adaxial side of leaves near leaf base. Setae yellow; capsules narrowly ellipsoid to subcylindrical; lid obliquely rostrate; spores 12–20 μm. Capsules common, autumn to spring. n = 11, 11 + m, 13∗ , 14. On bark, thatch, rocks and walls, tolerant of some degree of pollution and occurring in urban and industrial areas, calcifuge. 0–625 m. Common at low altitudes, rare in northern Scotland and Ireland. 109, H19, C. GB1473 + 96∗ , IR30 + 16∗ , C1 + 2∗ . European Temperate. Europe, Faeroes, Turkey, Cyprus, Caucasus, Himalayas, Mongolia, Macaronesia, N. Africa, N. America, Tasmania, Hawaii. Only likely to be confused with Oreoweisia bruntonii (q.v.) and Dicranum montanum (q.v.). One of the few mosses that seems to be increasing, possibly because acidification of substrates reduces competition from other more pollution susceptible species.

2 D. crispula (Hedw.) Milde, Bryol. Siles., 1869 (Fig. 52) Yellowish green to green or sometimes blackish tufts or cushions, 1–3 cm high. Leaves crisped, incurved when dry, flexuose-spreading, sometimes secund when moist, from ovate or lanceolate basal part abruptly narrowed or gradually tapering to linear acuminate limb; margins plane, entire; costa shortly excurrent; basal cells linear, 6–8 μm, alar cells enlarged or inflated and forming auricles, becoming brownish with age in most leaves, cells above irregularly quadrate, smooth, pellucid, bistratose at margins, 6–8(−10) μm wide in mid-leaf. Setae yellow; capsules ovate-ellipsoid; spores 12–20 μm. Capsules common, spring, summer. n = 11, 14. On exposed siliceous, rarely basic rocks, on stony soil. (60−)300–1335 m. Cornwall, Devon, Caernarfon, Yorkshire, Lake District, frequent in the central Scottish Highlands, rare elsewhere in Scotland. 24. GB45 + 11∗ . Circumpolar Boreoarctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Turkey, Caucasus, Himalayas, Siberia, Japan, Morocco, N. America, Greenland, Peru.

12 Dicranaceae Plants small to large. Stems with central strand, often tomentose. Leaves usually of ± uniform size up stems, straight to falcate, narrowly to broadly lanceolate, usually acuminate; costa ending below apex to excurrent, in section with stereids; cells often porose, basal elongate, alar cells often differentiated, cells above quadrate to elongate, smooth or mamillose. Setae usually long, straight to cygneous; capsules

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ovoid to cylindrical, straight or curved, sometimes strumose, very rarely cleistocarpous; peristome teeth 16, well developed, deeply bifid, papillose above, pittedstriolate below; calyptrae cucullate. About 50 genera. Subfamily 1 ANISOTHECIOIDEAE Plants usually small. Leaves lanceolate, acuminate; without differentiated alar cells, cells smooth. Capsules erect or inclined, straight or curved, sometimes strumose, smooth or striate; peristome teeth divided to about midway, papillose above.

29 AONGSTROEMIA BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1846 Dioicous. Plants small. Leaves imbricate, ovate with wide base, obtuse to acute; costa thin; cells lax, thin-walled. Perigonia and perichaetia bud-like with leaves larger, more acute and with stronger costa than stem leaves. Capsules erect, ovoid; lid obliquely rostrate; peristome teeth entire or irregularly cleft to midway. A mainly tropical genus with about 17 species. ¨ (1813–1879). Derivation: named after the Swedish botanist J. Ångstrom

1 A. longipes (Sommerf.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 51) Dense, bright green tufts, patches or scattered shoots, 10(−15) mm high; stems innovating from below inflorescences. Leaves imbricate when wet and when dry, difficult to detach from fragile stems, concave, ovate-oblong, obtuse; margins plane, entire; costa ending below apex; cells rectangular, thick-walled, decreasing in size from costa to margins, shorter and smaller towards apex, in mid-leaf 10–15 μm wide. Perigonia and perichaetia swollen, bud-like, bracts larger than stem leaves, tapering to blunt or acute apex, costa stouter, ending in apex. Vegetative propagation by fragile stems. Setae red; capsules erect, ± ovoid; spores 15–20 μm. Capsules rare, summer. On damp sandy soil in open habitats below dams, in quarries, on gravel by rivers, where slightly basic. Ascending to 400 m. Very rare, Mid and E. Perth, Moray, Inverness, Argyll, Dunbarton, Islay, W. Ross. 8. GB10. Circumpolar Boreal-montane. Northern and central Europe north to Svalbard, Iceland, Siberia, N. America, Greenland. Somewhat resembling Pohlia filum in general appearance but differing in the obtuse leaves, areolation and lack of axillary bulbils. For the occurrence of this plant in Scotland see A. C. Crundwell, Trans. Br. Bryol. Soc. 4, 67–74, 1965.

¨ 30 DICRANELLA (MULL. HAL.) SCHIMP., COROLL. BRYOL. EUR., 1856 Usually dioicous. Leaves narrow, differentiated into sheathing base and acuminate limb or gradually tapering from insertion, ± secund or squarrose; margins usually plane, entire or denticulate above; costa ending apex to excurrent; cells

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rectangular, smooth, alar cells not differentiated. Setae straight; capsules inclined, symmetrical or gibbous, sometimes strumose; annulus present or not; peristome teeth reddish, 16, bifid or divided to about middle into flat segments, papillose above, point-striate below; calyptrae cucullate. About 100 mainly terrestrial species, cosmopolitan. Derivation: meaning diminutive Dicranum. Many authorities recognise two genera, Dicranella and Anisothecium Mitt., but the latter is not recognised here as it separates closely related species.

1 Costa occupying 1/3 or more width of leaf base, setae yellow at maturity (becoming brown with age) 2 Costa occupying up to 1/5 width of leaf base, setae red to purple (but becoming brown with age) 3 2 Capsules strumose, leaf margins entire or finely denticulate towards apex, basal cells 70–115 μm long 8. D. cerviculata Capsules not strumose, leaf margins denticulate above, basal cells 30–50 μm long 9. D. heteromalla 3 Leaves squarrose or reflexed from erect sheathing base 4 Leaves ± erect-spreading to secund 6 4 Capsules suberect, symmetrical, cells in mid-leaf 4–6 μm wide 3. D. crispa Capsules inclined, gibbous, mid-leaf cells 6–14 μm wide 5 5 Leaf margins usually denticulate above, mid-leaf cells 8–14 μm wide, capsules smooth 1. D. schreberiana Leaf margins usually entire, mid-leaf cells c. 6 μm wide 2. D. grevilleana 6 Leaves abruptly narrowed or gradually tapering from erect sheathing basal part, capsules striate 7. D. subulata Leaves gradually tapering ± from insertion, basal part not sheathing, capsules smooth 7 7 Plants usually reddish tinged, leaf margins plane, capsules ± erect 6. D. rufescens Plants greenish, leaf margins narrowly recurved below, capsules erect or inclined 8 8 Upper leaves linear-lanceolate, mid-leaf cells 4–9 μm wide, perichaetial leaves similar in shape to stem leaves, capsules inclined, common 4. D. varia Upper leaves lanceolate, mid-leaf cells 10–14 μm wide, perichaetial leaves from sheathing basal part abruptly narrowed to long acumen, capsules erect, unknown in the British Isles 5. D. staphylina

Section 1 Dicranella (Mull.) ¨ Nyholm, Ill. Fl. Nord. Mosses, 1987 Stem and perichaetial leaves ± similar in shape but perichaetial leaves larger. Rhizoidal gemmae often present. Setae red; exothecial cells parenchymatous, stomata present; lid narrowly conical or ± obliquely rostrate

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1 D. schreberiana (Hedw.) Hilfarty ex H. A. Crum & L. E. Anderson, Mosses E. N. Amer., 1981 (Fig. 53) Anisothecium schreberianum (Hedw.) Dixon, D. schreberi (Hedw.) Schimp. Dioicous. Yellowish green patches or scattered plants, 3–10(−30) mm high. Leaves loosely crisped when dry, squarrose-flexuose when moist, from oblong sheathing basal part abruptly narrowed to lanceolate, acuminate limb; margins plane, denticulate at least towards apex, rarely entire; in taller forms leaves shorter, wider, less sharply reflexed, margins more strongly toothed; costa thin, ending in or below apex; cells in basal part rectangular to narrowly rectangular, in limb shorter, narrower, ± irregular in shape, 8–14 μm wide in mid-leaf. Brown to reddish brown ± spherical gemmae, 90–140 μm. Setae purple; capsules inclined, ovoid, gibbous, not strumose, smooth; exothecial cells with longitudinal walls more heavily thickened than transverse walls; lid with conical to acuminate beak; spores 12–16 μm. Capsules frequent, autumn to winter. n = 7, 14, 14 + m. On damp heavy often calcareous soil in fields, gardens, on woodland rides, ditch banks, moorland. Lowland. Common in lowland areas, rare elsewhere. 105, H36 C. GB688 + 85∗ , IR59 + 8∗ , C1 + 1∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Iceland, Caucasus, Siberia, Korea, Azores, N. America, Australasia. May occur with Ditrichum cylindricum but that plant has the costa longly excurrent and denticulate all the way round, not just on the margins.

2 D. grevilleana (Brid.) Schimp., Coroll. Bryol. Eur., 1856 Anisothecium grevilleanum (Brid.) H. Arnell & C. E. O. Jensen

(Fig. 53)

Dioicous or autoicous. Yellowish green tufts, 3–8 mm high. Leaves loosely crisped when dry, squarrose-flexuose when moist, from oblong sheathing basal part abruptly narrowed to channelled acumen; margins entire or obscurely denticulate near apex; costa thin, percurrent; basal cells narrowly rectangular, cells above ± rectangular, c. 6 μm wide in mid-leaf. Spherical brown or reddish brown rhizoidal gemmae, 90–140 μm diameter, sometimes present. Setae purple; capsules inclined, ovoid, slightly curved, very slightly strumose, faintly striate when dry; exothecial cells with uniformly thickened walls; lid with long beak; spores 12–22 μm. Capsules frequent, late summer, early autumn. n = 15. On disturbed damp basic soil on rock ledges, banks and in old quarries. Rarely below 380 m. Very rare, Mid and E. Perth, Argyll, E. Ross, W. Sutherland, Wicklow (not seen recently), Sligo, Antrim. 5, H3. GB7 + 1∗ , IR3 + 1∗ . Circumpolar Boreal-montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, China, N. America. Differs from D. schreberiana in its montane habitat, smaller leaf cells and the cells of the exothecium with uniformly thickened walls.

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Fig. 53 1–3. Dicranella schreberiana: 1, leaves (×40); 2, mid-leaf cells; 3, capsule. 4–6, D. grevilleana: 4, leaves (×40); 5, mid-leaf cells; 6, capsule. 7–9, D. subulata: 7, leaves (×25); 8, mid-leaf cells; 9, 10, capsules. Cells ×420, capsules ×15.

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3 D. crispa (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 Anisothecium vaginale (Dicks. ex With.) Loeske

(Fig. 54)

Dioicous or autoicous. Yellowish green to green tufts, 5–10 mm high. Leaves loosely crisped when dry, squarrose-flexuose when moist, basal part oblong, sheathing, abruptly narrowed to long channelled linear acuminate limb; margins plane, entire below, erect or inflexed above, entire or denticulate towards apex; costa thin, ending in apex to excurrent, occupying most of acumen; cells in basal part linear to rectangular or rhomboidal, above very narrow, linear, 4–6 μm wide. Setae reddish brown; capsules erect, ellipsoid or obovoid, ± symmetrical, striate when dry; lid with long oblique beak; spores 16–20(−26) μm. Capsules common, autumn to winter. n = 14, 15. In open habitats on disturbed soil on banks by ditches, streams, rivers and roadsides, vertical sandstone rocks and dune-slacks. 0–550 m. Widely distributed but rare in Britain, very rare in Ireland. 44, H10. GB28 + 40∗ , UR4 + 7∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Siberia, N. America, Greenland.

4 D. varia (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 Anisothecium varium (Hedw.) Mitt.

(Fig. 54)

Dioicous. Lax or dense bright or yellowish green tufts, patches or scattered plants, 2–10(−30) mm high. Leaves rigid, straight to slightly secund when dry, erectpatent, sometimes slightly secund when moist, basal part not sheathing, upper leaves linear-lanceolate, gradually tapering from insertion to acuminate apex, lower leaves shorter and wider; margins usually narrowly recurved, entire or slightly denticulate near apex; costa ending in apex to slightly excurrent, c. 55– 85(−100) μm wide near base, in section with scattered stereids on adaxial side and with 2 rows of guide cells; basal cells rectangular, incrassate, smaller near margins, cells above narrowly rectangular to linear, unistratose throughout, 4–9 μm wide in mid-leaf. Perichaetial leaves similar in shape to stem leaves, subsecund, margins denticulate. Irregular pale brown rhizoidal gemmae, 100–140(−250) × 60– 95 μm, often present. Setae purplish brown; capsules inclined, ovoid, gibbous, smooth when dry; exothecial cells with straight longitudinal walls more heavily thickened than transverse walls; lid conical or shortly beaked; spores 24–28 μm. Capsules common, autumn to spring. n = 7, 14∗ , 15. In open habitats, on damp, usually basic soil on roadsides, ditch banks, in fields, quarries, on heavy-metal mine waste. 0–490 m. Occasional in Scotland, frequent or common elsewhere. 111, H40, C. GB1128 + 89∗ , IR193 + 5∗ , C2 + 1∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Turkey, Cyprus, Siberia, Kashmir, Yunnan, Macaronesia, N. Africa, N. America south to Guatemala, Cuba, Jamaica, Hawaii. A curious form, referred to as var. callistoma (With.) Schimp., occurs occasionally. The setae are very short, the capsules erect, symmetrical, very small but with normal size lids; the

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Fig. 54 1–3, Dicranella crispa: 1, leaves (×25); 2, mid-leaf cells; 3, capsule. 4–5, Plant intermediate between D. varia and D. howei: 4, leaves (×40); 5, exothecial cells. 6–11, D. varia: 6, leaves (×40); 7, mid-leaf cells; 8, rhizoidal gemmae (×175); 9, normal capsule; 10, capsule, possibly of apogamous origin, from plant referred as var. callistoma; 11, exothecial cells. Cells ×420, capsules ×15.

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spores are shrunken. The plant possibly has apogamous or hybrid sporophytes but cannot be considered a variety in the true sense of the word. D. rufescens differs in its usually reddish tinge, the leaves with plane denticulate margins and larger cells, and the erect capsules with uniformly thickened exothecial cell walls. A closely related species, D. howei Renauld & Cardot occurs in southern Europe (see A. C. Crundwell & E. Nyholm, Lindbergia 4, 34–8, 1977). This differs from D. varia in the usually plane leaf margins, the costa 85–100 μm wide near the base and occupying about 1/3 the width of the leaf base, and in section with only a single row of guide cells. The longitudinal walls of the exothecial cells are slightly sinuose and hardly thicker than the transverse walls. This plant has not been detected in the British Isles, but plants with sporophytes intermediate between those of the two species, possibly of hybrid origin, have been found in Caernarfon and it is very possible that D. howei occurs in Britain.

5 D. staphylina H. Whitehouse, Trans. Brit. Bryol. Soc., 1969 Anisothecium staphylinum (H. Whitehouse) Sipman et al.

(Fig. 55)

Dioicous. Dense bright green tufts or scattered plants, to 1 cm high. Leaves erect when dry, erect-patent to spreading, rarely secund when moist, lanceolate, tapering to acute apex; margins plane or recurved below, with a few obscure teeth towards apex; costa thin, ending below apex; cells ± rectangular, 10–14 μm wide in mid-leaf. Perichaetial leaves with sheathing basal part, abruptly narrowed to long flexuose or squarrose limb, not secund. Brownish rhizoidal gemmae, irregular in shape but often ± isodiametric, 50–100 × 50–80 μm always present. Setae bright yellow to orange (probably red at maturity); capsules erect; lid rostrate with slightly oblique beak; spores 15–18(−20) μm. Capsules unknown in the British Isles. On disturbed soil in fields, gardens, bare patches in grassland, gravel pits, by paths and roads, on banks and woodland rides. Lowland. Common in England and Wales, rare to occasional in Scotland, rare in Ireland. 108, H23, C. GB231, IR24 + 1∗ , C4. European Temperate. Europe north to Finland, Faeroes, Tenerife, Canada. Somewhat similar to D. varia and D. rufescens and more closely related to the former, which differs in the narrower more secund leaves, stronger costa, narrower cells and perichaetial leaves similar to stem leaves. D. rufescens is usually reddish, has longer narrower secund leaves with plane more obviously toothed margins, perichaetial leaves similar to stem leaves and most particularly the reddish coloration of the older parts of the plants. In D. staphylina the gemmae are constantly present but they are usually only present in senescing plants of D. rufescens and D. varia. For an account of this plant see H. L. K. Whitehouse, Trans. Br. Bryol. Soc. 5, 757–65, 1969. The description of the sporophyte was taken from T. Arts, Lindbergia 11, 55–9, 1985.

6 D. rufescens (With.) Schimp., Coroll. Bryol. Eur., 1856 Anisothecium rufescens (With.) Lindb.

(Fig. 55)

Dioicous. Yellowish green, usually strongly red-tinged tufts, patches or scattered plants, 3–8(−10) mm high. Leaves erect or flexuose-secund when dry, secund

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Fig. 55 1–4, Dicranella rufescens: 1, leaves (×40); 2, mid-leaf cells; 3, capsule; 4, rhizoidal gemmae (×250). 5–7, D. staphylina: 5, leaves (×63); 6, mid-leaf cells; 7, rhizoidal gemmae (×250). 8–11, D. cerviculata: 8, leaves (×25); 9, cells near leaf base; 10, cells from upper part of leaf; 11, capsule. Cells ×420, capsules ×15.

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when moist, narrowly lanceolate, base not sheathing, gradually tapering from near base to acuminate apex; margins plane, denticulate at least above; costa thin, ending in apex to excurrent; basal cells irregularly narrowly rectangular, cells above smaller, 8–14 μm wide in mid-leaf. Perichaetial leaves similar to upper stem leaves, flexuose-secund. Red moniliform rhizoidal gemmae, composed of 2(−4) cells, each cell 70–100 μm diameter, sometimes present, especially in senescing plants. Setae deep red; capsules erect, ellipsoid, symmetrical, smooth; exothecial cells with uniformly thickened walls; lid with oblique beak; spores 12–16 μm. Capsules occasional to frequent, autumn to spring. n = 10, 11∗ , 14. On usually fine damp acidic soil by streams, pools, beds of dried-out reservoirs, paths and occasionally woodland rides. 0–450 m. Frequent in southern England but very rare elsewhere in lowland England, frequent or common in other parts except N. E. Scotland, occasional in Ireland. 102, H28, C. GB532 + 66∗ , IR51 + 12∗ , C1 + 1∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Iceland, Turkey, Caucasus, Japan, Madeira, N. America. Readily recognised by its small size, reddish colour, regularly secund leaves and erect capsules.

Section 2 Pseudodicranella (Mull. ¨ Hal.) Nyholm, Ill. Fl. Nord. Mosses, 1987 Stem leaves tapering from ± ovate-lanceolate basal part. Perichaetial leaves with broad sheathing basal part ± abruptly narrowed into acuminate point. Setae red or yellow; exothecial cells prosenchymatous, stomata present or not; lid with subulate, often oblique beak. 7 D. subulata (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 D. curvata (Hedw.) Schimp., D. secunda Lindb.

(Fig. 53)

Dioicous. Yellowish green to dark green tufts, 5–20 mm high. Leaves erect to curved or secund when dry, erect-patent or more usually secund when moist, basal part sheathing, oblong, gradually tapering or abruptly narrowed to long channelled acumen; margins plane below, erect or incurved above, towards apex entire or denticulate; costa thin, excurrent; cells in basal part narrowly rectangular, above linear, 4–6 μm wide in mid-leaf. Perichaetial leaves sheathing or not. Dark brown rhizoidal gemmae, 110–170 × 95–150 μm, often present. Setae reddish purple to brownish purple; capsules ovoid, erect and symmetrical to inclined and gibbous, striate or sulcate when dry; lid with long acuminate beak; spores 16–20 μm. Capsules common, autumn, winter. n = 13∗ , 14, 14 + m. On disturbed sandy or stony ground in turf, on banks by roads and streams, on damp sandstone and in sandstone quarries. 0–1050 m. Very rare in lowland Britain, occasional elsewhere, rare in Ireland. 64, H11. GB120 + 45∗ , IR4 + 6∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Turkey, Caucasus, Siberia, China, California, Greenland.

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8 D. cerviculata (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 (Fig. 55) Dioicous. Yellowish green to green patches, 5–20 mm high. Leaves flexuose when dry, erect-patent to secund when moist, basal part half-sheathing, ovate to oblong, gradually or rapidly tapering to long channelled acumen, lower leaves smaller, more gradually tapering; margins plane below, erect or reflexed above, entire or finely denticulate towards apex; costa stout, 1/3 –1/2 width of leaf base, excurrent in entire or denticulate point in upper leaves, ending below apex in lower; cells in basal part narrowly rectangular, 70–115 μm long, 6–10 times as long as wide, cells above smaller, narrowly rectangular, bistratose, 4–5 × 20–40 μm in mid-leaf. Perichaetial leaves from sheathing basal part abruptly narrowed to long acumen. Setae yellowish, becoming brown with age; capsules inclined, ovoid, curved, strumose, sulcate when dry; lid with curved acuminate beak; spores 16–22 μm. Capsules common, summer to winter. n = 13∗ , 14, 15. On damp, acidic, sandy or gravelly soil, ditch banks, partially shaded peat especially in peat cuttings. Lowland. Generally distributed, occasional to frequent but rare in N. Scotland and Ireland. 84, H32. GB178 + 102∗ , IR15 + 3∗ . Circumpolar Boreal-montane. Europe, Faeroes, Iceland, Siberia, Japan, N. America, Greenland. May occur mixed with D. heteromalla but differs in the shorter curved strumose capsules, the leaves only finely denticulate towards the apex and with longer cells.

9 D. heteromalla (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 (Fig. 56) Dioicous. Dull green or yellowish green tufts or patches, 1–3(−6) cm high. Leaves falcate-secund, rarely erect-patent when moist, scarcely altered when dry, from ovate or lanceolate basal part gradually tapering to long channelled acumen;

Fig. 56 1–4, Dicranella heteromalla: 1, leaves (×25); 2, basal cells (×420); 3, cells from upper part of leaf (×420); 4, capsule (×15).

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margins plane, denticulate above especially towards apex; costa strong, percurrent or excurrent, occupying c. 1/3 width of leaf base, occupying greater part of acumen; cells in basal part rhomboidal to narrowly rectangular, 30–50 μm long, 2–6 times as long as wide, smaller and narrower towards margins, cells above smaller, rectangular to narrowly rectangular and extending in narrow band towards apex, 4–6 × 10–14 μm wide in mid-leaf. Perichaetial leaves abruptly narrowed from sheathing basal part to long acumen. Setae yellowish, becoming brown with age; capsules inclined or horizontal, ellipsoid, gibbous, not strumose, sulcate when dry; lid with long curved acuminate beak; spores 12–17 μm. Capsules common, winter, spring. n = 7, 11, 11 + m, 13∗ , 14. 13 + 2–3m, 14. On banks in hedgerows, ditches, woods, among rocks, on tree boles and stumps, peaty banks on heaths and moorland, calcifuge but occurring in calcareous areas on leached soil and tree boles. 0–1100 m. Common and sometimes abundant or locally dominant. 112, H38, C. GB1940 + 79, IR255 + 7∗ , C3. Circumpolar Boreo-temperate. Europe north to northern Scandinavia, Faeroes, Iceland, Caucasus, Turkey, Lebanon and Himalayas northwards, Malaysia, Macaronesia, Kenya, N. America, Bolivia. Easily recognised by the silky falcate-secund leaves and yellow setae. Plants on sandstone may have narrower erect-spreading or subsecund leaves and have been referred to as var. sericea (Schimp.) Schimp. but such plants are merely an extreme form of a continuous series.

Subfamily 2 DICRANOIDEAE Plants usually large. Leaves straight or falcate, narrowly lanceolate, acuminate; basal cells often porose, alar cells usually differentiated from other basal cells, often coloured, upper cells smooth or papillose. Capsules ovoid to cylindrical, straight or curved, rarely strumose, smooth or striate; peristome teeth divided to about half way, pitted-striolate below, papillose above. 31 ARCTOA BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1846 Autoicous. Leaves from ovate or lanceolate basal part abruptly or gradually narrowed to long channelled acumen; costa longly excurrent; in section with or without stereids; basal cells elongate, walls not porose, a few alar cells differentiated, brownish, cells above shorter. Perigonia bud-like, immediately below perichaetia. Setae short, thick; capsules erect, slightly asymmetrical, furrowed when dry. Three north temperate and arctic species. Derivation: from the northern distribution of the genus.

1 A. fulvella (Dicks.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 Dicranum fulvellum (Dicks.) Sm. (Fig. 57) Dense yellowish green to green tufts, brownish or blackish below, 0.5–3.0 cm high. Leaves slightly crisped or secund when dry, erect-flexuose to falcate-secund

31 Arctoa

195

Fig. 57 1–5, Arctoa fulvella: 1, leaves (×20); 2, alar cells (×320); 3, cells c. 1 /3 way up leaf (×320); 4, 5, mature and dry empty capsules (×15). 6–11, costa sections, all except 11 c. 1 /4 from base. 6, Arctoa fulvella; 7, Kiaeria falcata; 8, K. starkei; 9, K. blyttii; 10, K. glacialis; 11, K. glacialis, c. 3 /4 from base. Costa sections ×320.

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when moist, from ovate or lanceolate basal part narrowed to long faintly denticulate acumen composed almost entirely of longly excurrent costa; basal cells elongate, not porose, alar cells quadrate, brownish, distinct, cells above narrowly rectangular, in upper part irregularly quadrate at margins, narrowly rectangular by costa, 4–8 μm wide in mid-leaf. Setae short, 2–4 mm long, thick, yellowish; capsules erect, ovoid, slightly asymmetrical, contracted below mouth and widemouthed with spreading peristome teeth when dry and empty; lid with oblique beak; spores c. 20 μm. Capsules common, summer. n = 14. On basic or acidic rocks, in crevices on mountain tops and cliffs, often in areas of late snow-lie. 450–1340 m. Rare to occasional in N. Wales, Lake District and Scottish Highlands, S. Kerry, W. Donegal. 23, H2. GB45 + 28∗ , IR2. European Arctic-montane. Europe north to Svalbard, Faeroes, Iceland, Japan, N. America. When fertile it is readily recognised by the erect wide-mouthed capsules with spreading peristome teeth. When sterile it may be distinguished from Kiaeria species by the leaves more abruptly contracted above the basal part and with longly excurrent costa. Blindia acuta is a plant of damper habitats and has inflated orange alar cells.

32 KIAERIA I. HAGEN, KONGEL NORSKE VIDENSK. SELSK. SKR. (TRONDHEIM)., 1915 Autoicous. Leaves lanceolate, longly tapering to acuminate apex; costa in section usually without stereids; alar cells brownish, distinct or not; basal cells porose or not. Perigonia bud-like, immediately beneath or far from perichaetia. Capsules ovoid to subcylindrical, inclined, strumose. An arctic–alpine genus of 5 species. Derivation: named after the Norwegian bryologist F. C. Kiaer (1835–1893).

1 Alar cells grading into other basal cells, leaf acumen with low papillae 2 Alar cells ± differentiated from other basal cells, forming distinct group, leaf acumen not papillose 3 2 Plants usually yellowish green or green, leaves scarcely altered when dry, exothecial cells thick-walled, annulus persisting 1. K. falcata Plants dull or dark green, leaves crisped when dry, exothecial cells thin-walled, annulus fugacious 2. K. blyttii 3 Leaves falcate, basal cells not or only slightly porose, cells above not porose 3. K. starkei Leaves erect-spreading to secund, basal and sometimes cells above porose 4. K. glacialis 1 K. falcata (Hedw.) I. Hagen, Kongel Norske Vidensk. Selsk. Skr. (Trondheim), 1915 (Figs. 57, 58) Dicranum falcatum Hedw. Dense yellowish to green tufts or patches, 1–2(−5) cm high. Leaves falcate-secund, hardly altered when dry, from lanceolate base tapering to papillose channelled

32 Kiaeria

197

Fig. 58 1–4, Kiaeria falcata: 1, leaves; 2, mid-leaf cells; 3, capsule (×15); 4, exothecial cells (×320). 5–8, K. blyttii: 5, leaves; 6, mid-leaf cells; 7, capsule (15); 8, exothecial cells (×320). 9–12, K. starkei: 9, leaf; 10, mid-leaf cells; 11, capsule (×15); 12, exothecial cells (×320). 13–16, K. glacialis: 13, leaves; 14, basal cells; 15, mid-leaf cells; 16, capsule (×10). Leaves ×15, leaf cells ×420.

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acumen; margins entire or slightly denticulate above; costa excurrent, in section without stereids; cells not porose, basal rectangular to narrowly rectangular, alar cells quadrate, brownish, grading with other basal cells and not forming distinct group, upper cells quadrate to shortly rectangular or rhomboidal, in upper part of leaf with low papillae. Perigonia immediately below perichaetia. Setae to 10 mm long; capsules inclined, ovoid, curved, strumose, sometimes furrowed but not striate when dry and empty; exothecial cells mostly less than twice as long as wide, strongly incrassate; annulus of 2–4 rows of small persisting cells; spores 14– 15 μm. Capsules common, summer. n = 7, 14. On or among sheltered boulders or on stones or coarse detritus, especially in areas of late snow-lie. 950–1340 m. Frequent on the higher Scottish mountains, very rare elsewhere, Caernarfon, Lake District, Dumfries. 24. GB44 + 6∗ . European Arctic-montane. Montane and northern Europe north to Svalbard, Jan Mayen, N. America. When lacking capsules, K. falcata may be distinguished from K. blyttii by its colour and the leaves being hardly altered when dry. It differs from K. starkei in its smaller size, indistinct alar cells and papillose leaf acumen; it also forms more compact tufts and the leaves are more regularly falcate.

2 K blyttii (Bruch & Schimp.) Broth., Laubm. Fennoskand., 1923 Dicranum blyttii Bruch & Schimp.

(Figs. 57, 58)

Dull to dark green or blackish green tufts or patches, 1–3(−5) cm high. Leaves somewhat crisped when dry, patent-flexuose, hardly secund when moist, 2–4 mm long, from lanceolate basal part tapering to papillose channelled acumen; margins entire; costa excurrent, in section without stereids; basal cells quadrate to quadrate-rectangular, rarely porose, alar cells quadrate, brownish, grading into other basal cells and not forming a distinct group, upper cells quadrate-rectangular to quadrate, in upper part of leaf papillose with protruding cell walls. Perigonia distant from perichaetia or on separate branches. Setae to 15 mm long; capsules inclined, ovate-ellipsoid, curved, strumose, not striate when dry and empty; exothecial cells mostly more than twice as long as wide, thin-walled; annulus a single row of fugacious cells; spores 16–19 μm. Capsules frequent, summer. n = 7, 8, 13 + m, 14. Among boulders and on rocks in block scree and on detritus on mountain ridges. 100–1340 m. Rare in N. W. Wales, Lake District, N. W. Yorkshire, N. Northumberland, S. W. Scotland, frequent in the Scottish Highlands, W. Mayo, W. Donegal, Londonderry. 24, H3. GB94 + 8∗ , IR3. European Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Himalayas, N. Asia, Azores, N. America. K. blyttii differs from the other three British species of Kiaeria in having the perigonia distant from the perichaetia or on separate branches, in its dark green colour and the leaves somewhat crisped when dry. The other species are typically although mot exclusively late snow-patch species, a habitat in which K. blyttii is not found. K. falcata and K. starkei usually have strongly falcate leaves, which is not a feature of K. blyttii.

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3 K. starkei (F. Weber & D. Mohr) I. Hagen, Kongel Norske Vidensk. Selsk. Skr. (Trondheim)., 1915 (Figs. 57, 58) Dicranum starkei F. Weber & D. Mohr Yellowish green to green tufts or patches, 2–6(−10) cm high. Leaves flexuose when dry, erect to falcate-secund when moist, 2.0–4.5 mm long, from lanceolate basal part tapering to channelled acumen; margins entire or denticulate towards apex; costa excurrent, in section without stereids; basal cells quadrate to quadraterectangular, sometimes slightly porose, alar cells brown, often forming a distinct group, upper cells quadrate to rectangular, neither papillose nor porose, Perigonia immediately below perichaetia. Setae to 16 mm long; capsules ellipsoid to subcylindrical, curved, ± strumose, striate when dry and empty; exothecial cells mostly twice as long as wide, thin-walled; annulus of one row of large fugacious cells; spores 14–16 μm. Capsules frequent, summer. n = 7, 13 + m, 14. On stony ground, among rocks and boulders and on slabs, especially in areas of late snow-lie. 560–1340 m. Frequent on the higher Scottish mountains, very rare elsewhere, N. W. Yorkshire, Westmorland. 18. GB48 + 4∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Turkey, N. Asia, N. America, Greenland. Easily confused with K. falcata as sometimes the alar cells do not form a distinct group. The thin-walled exothecial cells and fugacious annulus are distinctive. The plants are usually larger than those of K. falcata and the leaf acumen is not papillose.

4 K. glacialis (Berggr.) I. Hagen, Kongel Norske Vidensk. Selsk. Skr. (Trondheim)., 1915 (Figs. 57, 58) Dicranum glaciale Berggr. Lax tufts, yellowish green to green above, brown below, to 12 cm high. Leaves flexuose, erect to secund when dry, erect-patent to secund when moist, 5–7 mm long, from ovate or ovate-lanceolate basal part tapering to entire or obscurely denticulate channelled acumen; costa ending ± in apex, without lamellae or teeth on abaxial side above, in section with a few stereids on abaxial side; cells porose at least in lower part of leaf and often throughout, basal cells narrowly rectangular, alar cells brownish, forming distinct group, upper cells rectangular to narrowly rectangular, not papillose, 6–13 μm wide in mid-leaf. Setae to 15 mm long; capsules inclined, subcylindrical, curved, strumose, furrowed when dry and empty; exothecial cells more than twice as long as wide, incrassate; spores c. 16 μm. Capsules frequent, autumn. On stony or rocky ground or among boulders in areas of late snow-lie and on high-altitude ridges. 900–1330 m. Rare, Perth, Angus, S. Aberdeen, Banff, Inverness, Argyll, Ross. 11. GB18 + 6∗ . Circumpolar Arcticmontane. Czechoslovakia and Fennoscandia north to Svalbard, N. Asia, N. America, Greenland. More likely to be mistaken for a Dicranum species, especially D. scoparium, than for another Kiaeria species. Montane forms of D. scoparium may have entire leaves lacking lamellae and

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teeth on the abaxial side of the costa. However, it has wider mid-leaf cells, two rows of stereids in costa section, dwarf males and non-strumose capsules with a persisting annulus.

33 DICRANUM HEDW., SP. MUSC. FROND., 1801 Dioicous. Female plants usually robust, male plants minute or of similar size to female plants. Leaves erect to falcate-secund, from ovate or lanceolate basal part gradually tapering to acuminate apex; margins usually plane, frequently dentate or denticulate above; costa ending below apex to excurrent, in section usually with one or two stereid bands; cells incrassate, porose or not, basal linear or narrowly rectangular, becoming narrowly rectangular to quadrate above, mamillose or not. Setae straight; capsules erect or inclined, straight or curved, not strumose, often ± striate; peristome teeth reddish, divided to about half way into 2–3 unequal segments, pitted-striolate below, papillose above; lid rostrate; calyptrae cucullate. About 150 mainly north temperate and arctic–alpine species but also occurring on tropical mountains; replaced in the Southern Hemisphere by Dicranoloma (Renauld) Renauld. Derivation: from the Greek for a two-pronged fork, referring to the peristome teeth. D. montanum, D. flagellare, D. tauricum and sometimes D. scottianum are placed by some authorities in the genus Orthodicranum (Bruch & Schimp) Loeske but the characters separating this from Dicranum are poorly defined and the genus is not recognised here.

1 Leaf cells porose throughout 2 Only basal cells with porose walls or cells non-porose throughout 6 2 Leaf margins recurved below, spinosely toothed above 1. D. polysetum Leaf margins plane below, usually dentate but not spinosely so above 3 3 Leaves falcate-secund, 9–15 mm long, setae yellowish green 5. D. majus Leaves erect to secund, to 10 mm long, setae reddish at least below 4 4 Upper part of leaves deeply channelled or ± tubular, margins entire or weakly toothed above 3. D. leioneuron Leaves not deeply channelled or tubular above, margins usually toothed above 5 5 Leaves transversely undulate above, costa 40–70 μm wide at widest part of leaf, with 2–4 low lamellae and not or scarcely toothed on abaxial side above 2. D. bonjeanii Leaves plane or undulate above, costa 75–120 μm wide at widest part of leaf, with 4 toothed lamellae on abaxial side above 4. D. scoparium 6 Leaves rugose or undulate when moist 7 Leaves not rugose or undulate 8 7 Leaves incurved and crisped when dry, cells mamillose on abaxial side towards apex 6. D. spurium Leaves ± erect when dry, cells not mamillose 7. D. bergeri 8 Leaves flexuose, curved or crisped when dry 9 Leaves straight, appressed when dry 13

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9 Costa percurrent or excurrent, supra-alar cells longer than alar cells 10 Costa ending below apex, alar cells and supra-alar cells of similar length 12 10 Capsules erect, leaves erect-flexuose when dry, basal cells 2–4 times as long as wide, margins usually entire 11. D. scottianum Capsules inclined, leaves crisped when dry, basal cells 3–8 times as long as wide, margins entire to dentate 11 11 Leaf margins usually denticulate, costa papillose or toothed and cells smooth to coarsely mamillose on abaxial side above, cells towards apex ± quadrate 8. D. fuscescens Leaf margins entire or weakly denticulate, costa usually smooth and cells smooth on abaxial side above, cells towards apex variable in shape 9. D. flexicaule 12 Cells in upper part of leaf mamillose, margins and abaxial side of costa in upper part of leaf dentate, flagelliform branches absent 13. D. montanum Cells smooth, costa smooth, margins denticulate only near apex, flagelliform shoots usually present 14. D. flagellare 13 Leaves not fragile, usually intact, stems densely tomentose, montane 10. D. elongatum Leaves fragile, usually with missing tips, stems not tomentose, lowland 12. D. tauricum

Subgenus 1 Dicranum Costa ending below apex, occupying up to c. 1/8 width of leaf base, with stereids in section; alar cells unistratose, delimited from other basal cells and not extending to costa, cell walls porose throughout or only basal cells porose or all cells nonporose. Capsules inclined, curved. Section 1 Dicranum Male plants usually minute. Costa with distinct or indistinct lamellae on adaxial side above; cells elongate, smooth, walls porose throughout. Capsules inclined, curved, annulus lacking; peristome teeth striolate in lower part, papillose above. 1 D. polysetum Sw., Monthly Rev., 1801 (Fig. 60) D. undulatum F. Weber & D. Mohr, D. rugosum (Dicks.) Hoffm. ex Brid. Yellowish green tufts or patches, to 15 cm high. Stems tomentose. Leaves spreading, occasionally subsecund, strongly transversely undulate; margins recurved below, plane and coarsely spinosely toothed above; costa ending below apex, with 2 strongly toothed lamellae on abaxial side above; alar cells brownish, distinct, other cells ± uniformly narrowly elliptical with porose walls throughout leaf. Setae 1–5 per perichaetium; capsules inclined, strongly curved; unknown in Britain. n = 12, 12 + m, 12 + 3m, 14. In conifer and birch woods, on heaths and raised bogs. Lowland. Widely distributed but rare, extending from S. Hampshire north to

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Elgin. 33. GB34 + 17∗ . Circumpolar Boreal-montane. Europe north to Fennoscandia, Caucasus, Turkey, Siberia, Japan, N. America. The leaves scarcely altered when dry, strongly undulate and margins recurved below and coarsely spinosely toothed above will readily distinguish D. polysetum from other Dicranum species. D. spurium has the leaves incurved and crisped when dry and in D. bergeri the leaves are acute to obtuse rather than acuminate and the margins are entire to denticulate.

2 D. bonjeanii De Not. in Lisa, Elenco Muschi, 1837 (Fig. 59) Usually bright green tufts or turfs, to 13 cm high, rarely more. Stems tomentose. Leaves erect-patent to subsecund, transversely undulate above, scarcely altered when dry, 4–9 mm long, lanceolate, tapering to acute to obtuse apex; margins plane below, erect, dentate above; costa ending below apex, narrow, 40–70 μm wide at widest part of leaf, with 2(−4) low, scarcely toothed lamellae on abaxial side above, in section with one row of large empty cells; cell walls porose throughout leaf, basal cells linear to narrowly rectangular, alar cells brownish, distinct, cells above linear-rectangular to elliptical-rectangular, smooth. Flagelliform propaguliferous shoots occasionally present. Sporophytes 1–2 per perichaetium; setae reddish below, yellowish above; capsules inclined, cylindrical, curved; spores 18–20 μm. Capsules very rare, autumn. On wet or marshy ground, wet moorland, in fens, damp woods, and well drained basic grassland, rarely on acidic soils or among Sphagnum. 0–430 m. Widespread, rare to occasional in central England, southern and northern Scotland and Ireland, frequent to common elsewhere. 108, H27, C. GB615 + 138∗ , IR52 + 11∗ , C1 + 1∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Turkey, Azores, N. and C. Africa, N. America, Greenland. A variable species some forms of which may be difficult to separate from paludal plants of D. scoparium which may have strongly undulate leaves. The latter has a wider costa, which has toothed lamellae on the abaxial side above, and the upper leaf cells are shortly rectangular to irregularly quadrate. D. bonjeanii is usually found in more eutrophic habitats than the next two species.

3 D. leioneuron Kindb., Bull. Torrey Bot. Club, 1889 (Fig. 59) Yellowish green tufts, to 8 cm or more high; stems sparsely tomentose. Leaves erect-flexuose when moist, not undulate, to 5 mm long, erect, narrowly lanceolate, gradually tapering to deeply channelled or ± tubular acumen; margins entire or weakly denticulate above; costa ending below apex, with two poorly developed toothless lamellae on abaxial side above; cells incrassate, walls porose throughout leaf, basal cells linear or narrowly rectangular, alar cells brown, distinct, cells above gradually becoming shorter narrowly rectangular. Flagelliform branches with small ovate to lanceolate concave appressed leaves sometimes present. Capsules unknown in Britain. On Sphagnum tussocks on raised and blanket bogs

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Fig. 59 1–3, Dicranum bonjeanii: 1, leaf; 2, basal cells; 3, mid-leaf cells. 4–6, D. leioneuron: 4, leaf; 5, basal cells; 6, mid-leaf cells. 7–13, costa sections, 7, 9, 11, 12 c. 1 /4 from apex, 8, 10, 13 c. 3 /4 from base. 7, 8, D. bonjeanii; 9, D. leioneuron; 10, 11, D. scoparium; 12, 13, D. majus. Leaves ×10, cells and sections ×320.

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and in drier habitats under heather and in thin turf over boulders. 0–800 m. Very rare, Brecon, Cardigan, Montgomery, S. Northumberland, Cumberland, Mid Perth, Angus. 7. GB9 Circumpolar Boreal-montane. Norway, Sweden, Finland, Spain, W. Russia, Mongolia, Siberia, N. America. Most likely to be confused with and overlooked as D. scoparium as it occurs in a wider range of habitat types than was originally thought (see M. F. V. Corley, J. Bryol. 16, 485–6, 1991). It differs from that species and D. bonjeanii in the leaf margins being entire or only weakly denticulate and the upper part of the leaf being deeply channelled or almost tubular. D. bonjeanii has strongly undulate leaves. The flagelliform branches of D. leioneuron are a useful character when present but they may also occur on D. bonjeanii growing amongst Sphagnum. For the occurrence of this plant in Britain see T. Ahti et al., Bryologist 68, 197–201, 1965. This species is treated as vulnerable in the Red List of British Mosses.

4 D. scoparium Hedw., Sp. Musc. Frond., 1801 (Figs. 59, 60) Lax or dense, yellowish green to dark green tufts or patches, to c. 10 cm high; stems tomentose. Leaves crowded, erect to secund, flexuose when moist, hardly altered when dry, sometimes undulate above, 5–10 mm long, gradually tapering from ovate-lanceolate or lanceolate basal part to channelled acumen; margins plane, entire to serrate above; costa ending below apex, 75–120 μm wide at widest part of leaf, with 4 toothed lamellae on abaxial side above, in section with 1 row of large cells; cells incrassate, walls porose throughout leaf, basal cells narrowly rectangular, alar cells brown, distinct, cells becoming shorter above, 12–16 μm wide in mid-leaf, upper cells rectangular to irregularly quadrate, at margins rhomboidal, cells in lower half of leaf ± quadrate in section. Sporophytes usually 1 per perichaetium; setae yellowish above, reddish below; capsules suberect, cylindrical, curved, smooth, 3–4 mm long excluding longly rostrate lid; spores 12–22 μm. Capsules frequent in wetter parts of the British Isles and in humid habitats, rare elsewhere, summer to winter. n = 11, 12∗ , 12 + m∗ , 13, 13 + m, 14, 14 + 3m. In a wide range of exposed to sheltered habitats including acidic or leached soil in woodland, grassland, bogs, marshes, on heaths, moorland, sand-dunes, rocks, bark, walls, calcifuge. 0–1220 m. Frequent or common and sometimes locally abundant. 112, H40, C. GB1998+91∗ , IR164 + 7∗ , C2 + 1∗ . Circumpolar Wide-boreal. Europe north to Svalbard, Faeroes, Iceland, Turkey, Caucasus, N. Asia, Mongolia, Japan, Macaronesia, N. Africa, N. and C. America, Andes, Greenland, New Zealand. A very variable plant for which a number of varieties have been described but because of phenotypic plasticity these cannot be satisfactorily discriminated (see D. Briggs, New Phytol. 64, 366–86, 1965). Luxuriant plants with secund leaves may resemble D. majus but differ in the leaves having toothed lamellae on the abaxial side of the costa and, in section, with laminal cells ± quadrate and the costa with only one row of large cells. Small plants with entire leaves lacking toothed lamellae may be confused with the alpine species Kiaeria glacialeis (q.v.). In D. fuscescens, D. flexicaule and D. scottianum the leaf cells are narrower and non-porose at least above the basal part, and in the first two species the leaves are crisped when dry. For the differences from D. bonjeanii see under that species.

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Fig. 60 1–4, Dicranum scoparium: 1, leaves of (a) woodland plant, (b) marsh plant, (c) exposed dry ground plant; 2, basal cells; 3, mid-leaf cells; 4, capsule. 5–7, D. polysetum: 5, leaf; 6, basal cells; 7, upper cells. 8–11, D. majus: 8, leaf; 9, basal cells; 10, mid-leaf cells; 11, capsule. Leaves ×10. cells ×320, capsules ×7.5.

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5 D. majus Turner, Muscol. Hibern. Spic., 1804 (Figs. 59, 60) Lax light green to dark green tufts or patches, to 15 cm high; stems tomentose. Leaves not crowded, uniformly falcate-secund, flexuose when moist, hardly altered when dry, not undulate, 9–15 mm long, from lanceolate basal part narrowing to long channelled acumen; margins plane, serrate above; costa ending below apex, 90–120 μm wide at widest part of leaf, without lamellae but toothed on abaxial side above, in section with two rows of large cells; cells incrassate with porose walls throughout leaf, basal cells narrowly rectangular, alar cells brownish, distinct, cells above narrowly rectangular or rectangular, rhomboidal at margins, cells in lower half of leaf rectangular in section. Sporophytes 1–5 per perichaetium; setae yellowish green; capsules inclined to horizontal, shortly cylindrical, curved, to 3 mm long excluding longly rostrate lid; spores 14–26 μm. Capsules occasional to frequent in wetter parts of the British Isles and in humid habitats, rare elsewhere. n = 11, 12∗ , 12 + m∗ , 13. On rocks, soil and bark in woods, among boulders, on heaths and moorland, rock ledges and sheltered banks, calcifuge. 0–1080 m. Rare in lowland Britain except in the south, frequent or common and sometimes locally abundant elsewhere. 101, H33, C. GB1055 + 103∗ , IR115 + 19∗ , C4 + 1∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Turkey, Caucasus, N. and C. Asia, China, Korea, Japan, N. America, Greenland. Section 2 Spuria Bruch & Schimp. in Bruch et al., Bryol. Eur., 1847 Male plants minute. Leaves transversely undulate; margins serrate; costa ending below apex or excurrent, abaxial side smooth or mamillose; cell walls in lower part of leaf porose, in upper part isodiametric, not porose. Peristome teeth rough. 6 D. spurium Hedw., Sp. Musc. Frond., 1801 (Fig. 61) Tumid green or yellowish green cushions, to 10 cm high; stems tomentose. Leaves incurved, crisped, rugose when dry, erect on new growth, otherwise spreading, rugose when moist, 5–7 mm long, from ovate or ovate-lanceolate basal part narrowed to acuminate often twisted apex; margins entire to serrate; costa ending below apex, mamillose but not toothed on abaxial side above; basal cells ± linear with porose walls, alar cells brownish, distinct, cells above rhomboidal, not porose, coarsely mamillose on abaxial side. Capsules suberect, curved; spores 14–24 μm. Capsules very rare, summer. n = 12. On wet and dry heaths and on banks in sparse Pinus sylvestris woodland. Lowland. Occasional in Hampshire, Sussex, Surrey and eastern central Scotland, very rare elsewhere and decreasing. 30. GB43 + 36∗ . European Boreal-montane. N., W. and C. Europe, Siberia, Sikkim, eastern N. America. This species is treated as vulnerable in the Red List of British Mosses.

7 D. bergeri Blandow in Sturm, Deutschl, Fl., 1805 D. affine Funck, D. undulatum Schrad. ex Brid.

(Fig. 61)

Large dull to yellowish green tomentose tufts, to 15 cm high. Leaves erect-patent, transversely undulate and rugose when moist, hardly altered when dry, 4–7 mm

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Fig. 61 1–3, Dicranum spurium: 1, leaf (×10); 2, basal cells; 3, mid-leaf cells. 4–6, D. bergeri: 4, leaf (×10): 5, basal cells; 6, mid-leaf cells. 7–9, D. elongatum: 7, leaves (×20); 8, basal cells; 9, mid-leaf cells. 10–14, D. fuscescens: 10, leaves (×10); 11, basal cells; 12, mid-leaf cells; 13, cells near leaf apex; 14, capsule (×7.5). 15–17, D. flexicaule: 15, leaves (×10); 16, basal cells; 17, cells near leaf apex. Cells ×320.

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long, from lingulate to ovate-lanceolate basal part tapering to acute to obtuse apex; margins plane, denticulate or occasionally entire above; costa not mamillose and not or only slightly toothed on abaxial side above; basal cells linear with porose walls, alar cells brownish, distinct, cells above quadrate-rectangular to elliptical or rhomboidal, neither porose nor mamillose. Capsules suberect, narrowly ellipsoid, curved; spores 20–24 μm. Capsules rare, summer. n = 11, 12, 13. Mainly on raised bogs, rare and decreasing. 0–350 m. Scattered localities from Cardigan and Shropshire north to Caithness, Offaly. 15, H1. GB16 + 11∗ , IR3. Circumpolar Boreo-arctic Montane. N., W. and C. Europe, Iceland, Caucasus, C. Asia, Japan, N. America. This species is treated as vulnerable in the Red List of British Mosses.

Section 3 Fuscescentiformia Kindb., Eur. N. Amer. Bryin., 1897 Male and female plants of similar size. Leaves falcate to falcate-secund, deeply channelled above with inflexed margins; costa ending below apex to excurrent, occupying up to 1/4 width of leaf at widest part of leaf; cells near base sometimes porose. Capsules inclined and curved or erect and straight; annulus of 1–3 rows large cells; peristome teeth striate below, papillose above. 8 D. fuscescens Turner, Muscol. Hibern. Spic., 1804 (Fig. 61) Dull green or yellowish green tufts or patches, to 12 cm high. Stems tomentose. Leaves ± crisped when dry, suberect to strongly falcate-secund, rarely ± erect and straight when moist, 4–8 mm long, from ovate-lanceolate or lanceolate basal part tapering to denticulate or occasionally entire long channelled acumen; costa ending below apex to excurrent, 100–200 μm wide at widest part of leaf, usually denticulate on abaxial side above; basal cells narrowly rectangular, 3–8 times as long as wide, walls porose or not, alar cells brownish, distinct, cells above not porose, in mid-leaf 8–12(−16) μm wide, cells in upper part of leaf of ± uniform shape, quadrate or shortly rectangular, smooth to strongly mamillose on abaxial side. Setae yellowish, becoming reddish with age; capsules inclined, subcylindrical, curved, striate; spores 18–24 μm. Capsules occasional, autumn. n = 8, 9∗ , 10∗ , 10 + m∗ , 12, 24. On soil, rocks, rock faces and bark in deciduous and coniferous woodland and ravines, on boulders, cliff faces and on Racomitrium heath. 0–1205 m. Very rare in lowland England, frequent or common elsewhere, occasional in Ireland. 83, H22. GB499 + 55∗ , IR45 + 6∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Turkey, N. and C. Asia, Japan, N. America, Greenland. A very variable species which may be confused with D. flexicaule (q.v.) or D. scottianum. D. fuscescens is easily distinguished from the latter by its inclined capsules and, when sterile, by the leaves usually crisped when dry. However, forms of D. fuscescens with ± straight leaves may present problems. Such plants can be recognised by one or more of the following characters: leaf margins denticulate above, upper cells mamillose on abaxial side, costa

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toothed and/or papillose on abaxial side above, basal cells 3–8 times as long as wide; none of these characters is present in D. scottianum but one or more of them, except length of basal cells, may be absent in plants of D. fuscescens.

9 D. flexicaule Brid., Bryol. Univ., 1826 (Fig. 61) D. congestum auct. non Brid., D. fuscescens var. congestum auct. non (Brid.) Kindb. Lax or dense dull green or yellowish green tufts, patches or turfs, to 10 cm high. Leaves flexuose to crisped when dry, subsecund to strongly falcate-secund when moist, lanceolate, tapering to long channelled entire or weakly denticulate acumen; costa ending in apex to excurrent, smooth or sparsely toothed on abaxial side above; basal cells narrowly rectangular, 3–8 times as long as wide, walls porose or not, alar cells brownish, distinct, cells above not porose, in mid-leaf 8–12(−16) μm wide, cells towards apex of variable shape, rectangular, rhomboidal and quadrate mixed together, not mamillose on abaxial side. Capsules inclined, subcylindrical, curved; unknown in the British Isles. On rocks, cliff ledges and soil, usually at high altitudes but descending to near sea level in W. Sutherland. 10–1340 m. Rare, N. W. Yorkshire, N. Northumberland and Mid Perth north to Caithness, Outer Hebrides. 11. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, N. and E. Asia, N. America. Probably under-recorded, being mistaken for high-altitude D. fuscescens, which is indistinguishable in the field. D. flexicaule is a poorly defined species as some of the characters distinguishing it from D. fuscescens – ± entire acumen, non-mamillose upper cells, costa not toothed on abaxial side – may occur individually in the latter species. Experimental studies into the status of D. flexicaule are required.

Section 4 Elongata I. Hagen, Kongel Norske Vidensk. Selsk. Skr. (Trondheim), 1914 Leaves acute to obtuse, margins incurved above; upper cells quadrate to shortly rectangular, not porose or elongate and porose. Capsules curved or ± straight; annulus cells large; peristome teeth papillose and striate or smooth above or throughout. ¨ 10 D. elongatum Schleich. ex Schwagr., Sp. Musc. Frond. Suppl. 1, 1811 (Fig. 61) Densely matted, yellowish green tufts, to 6(−12) cm high; stems tomentose. Leaves ± straight, appressed when dry, erect-patent, sometimes secund when moist, lanceolate or narrowly lanceolate, tapering to short entire or denticulate acumen; costa wide, ending in or below apex; basal cells narrowly rectangular or rectangular, porose, alar cells brownish, distinct, cells above rhomboidal, not porose, 6–10(−12) μm wide in mid-leaf. Capsules suberect, ovoid, curved; not known in Britain. n = 13. On peaty soil or peat overlying rocks. To 1150 m. Very rare and seen recently only in S. Aberdeen, old records from N. Northumberland, Angus, Inverness, W. Ross, Caithness, Shetland. 8. GB1 + 5∗ . Circumpolar

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Arctic-montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, C. Asia, Japan, Colorado, Greenland. This is a critically endangered species in the Red List of British Mosses.

Section 5 Crassinervia Roth, Eur. Laubm., 1904 Costa broad, excurrent; cells in upper part of leaf rounded-quadrate, partially bistratose, in section with projections between cells. Capsules straight or slightly curved; annulus cells large; peristome teeth slightly striate or weakly papillose. Leaf tips fragile, caduceus. 11 D. scottianum Turner, Muscol. Hibern. Spic., 1904 Orthodicranium scottianum (Turner) Roth

(Fig. 62)

Dull green tufts or cushions, to 7.5 cm high. Leaves usually erect-flexuose when dry, erect-patent, sometimes slightly secund when moist, lanceolate to narrowly lanceolate, tapering to entire or rarely weakly denticulate channelled acumen; costa excurrent, smooth on abaxial side above, 17–30% width of lamina at widest part; basal cells rectangular, 2–4 times as long as wide, walls very rarely porose, alar cells brownish, distinct, cells above ± uniformly quadrate, not porose or mamillose, 8–11 μm wide in mid-leaf. Capsules erect, cylindrical, straight or slightly curved; spores 25–30 μm. Capsules occasional to frequent, summer. n = 8∗ , 12∗ . On usually ± vertical, exposed or sheltered rock faces, rarely on bark. 0–430 m. Occasional to frequent in the Weald, S. W. and N. England, W. Wales, W. Scotland, W. Ireland, very rare elsewhere, Jersey. 46, H21, C. GB176 + 38∗ , IR55 + 24∗ , C1 + 1∗ . Western Europe from Portugal north to Svalbard, Switzerland, Macaronesia, N. America.

Subgenus 2. Orthodicranum Bruch & Schimp. in Bruch et al., Bryol. Eur., 1851 Leaves longly acuminate from lanceolate basal part, costa ending below apex or excurrent, occupying 1/5 –1/3 width of leaf base, with or without stereids in section; alar cells unistratose, extending nearly to costa, basal cells elongate, walls ± porose, cells above quadrate to shortly rectangular, not porose. Capsules erect. 12 D. tauricum Sapjegin, Bot. Jahrb. Syst., 1911 D. strictum (Dicks.) Sm., Orthodicranum strictum (Dicks.) Broth.

(Fig. 62)

Light green tufts or patches, to 4 cm high. Leaves straight, appressed when dry, erect-patent when moist, lanceolate, tapering to narrow channelled acumen composed mainly of costa which is frequently broken off; margins entire or finely denticulate; costa longly excurrent, smooth or very finely denticulate on abaxial side above, without stereids in section; alar cells hyaline or brownish, extending almost to costa, ± unistratose, cells near base rectangular, walls not or slightly porose, cells above rectangular to quadrate, smooth, not porose, 9–12 μm wide in

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Fig. 62 1–4, Dicranum scottianum: 1, leaf (×10); 2, basal cells; 3, mid-leaf cells; 4, capsule. 5–8, D. montanum: 5, leaf (×20); 6, leaf apex (×125); 7, basal cells; 8, mid-leaf cells. 9–12, D. flagellare: 9, leaf (×20); 10, basal cells; 11, mid-leaf cells; 12, capsule. 13–15, D. tauricum: 13, leaves (×20); 14, basal cells; 15, mid-leaf cells. Cells ×320, capsules ×7.5.

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mid-leaf. Capsules erect, cylindrical, straight; spores 14–18 μm. Capsules very rare. n = 12∗ , 12 + 2m, 14. In woodland on logs, tree stumps, bark, rarely on rock. Lowland. Occasional to frequent and increasing in lowland England, rare elsewhere, from N. Somerset east to Kent and north to Elgin. 66. GB213 + 11∗ . European Temperate. Europe north to Fennoscandia, Iceland, Turkey, Algeria, Kerguelen Is., N. America. D. tauricum is tolerant of some degree of atmospheric pollution and has increased markedly since 1930. Broken-off leaf tips probably act as a means of vegetative propagation.

13 D. montanum Hedw., Sp. Musc. Frond., 1801 Orthodicranum montanum (Hedw.) Loeske

(Fig. 62)

Small, green or dark green tufts or cushions, to 3 cm high. Leaves strongly curled when dry, spreading, flexuose, sometimes subsecund when moist, lanceolate, tapering to long denticulate acumen; costa ending below apex, toothed on abaxial side above, in section with stereids; cell walls not porose, alar cells hyaline or brownish, ± extending to costa, cells near base rectangular, cells above shortly rectangular to quadrate, mamillose on abaxial side, 12–16 μm wide in mid-leaf. Small propaguliferous shoots sometimes produced at stem tips; deciduous leaves also common. Capsules erect, cylindrical, straight; not known in Britain. n = 7, 12, 13, 14. On trunks, branches and exposed roots, rarely on sandstone, in woods and on banks. Lowland. Frequent and increasing in S. E. England, rare elsewhere, extending north to Elgin. 63. GB165 + 18∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Turkey, Siberia, Kashmir, Himalayas, China, Azores, N. America, Peru. When dry very similar in appearance to Dicranoweisia cirrata but differing in the denticulate leaf margins and differentiated alar cells extending to the costa.

14 D. flagellare Hedw., Sp. Musc. Frond., 1801 Orthodicranum flagellare (Hedw.) Loeske

(Fig. 62)

Green or yellowish green tufts or patches, to 5 cm high. Leaves crisped when dry, erect-patent to subsecund when moist, tapering to ± tubular entire or weakly denticulate acumen; costa ending below apex, slightly toothed on abaxial side above, in section with stereids; alar cells brownish, unistratose, extending ± to costa, cells near base rectangular, walls not porose, cells above rhomboidal to irregularly quadrate, not mamillose or porose, c. 12 μm wide in mid-leaf. Small, erect, propaguliferous flagelliform branches usually present. Capsules erect, subcylindrical, straight. Capsules very rare, summer. n = 12. On decaying logs and tree stumps in woodland. 0–370 m. Occasional in S. E. England, very rare elsewhere, extending from Glamorgan and N. Lincolnshire north to Mid Perth. 20. GB31 + 12∗ . Circumpolar Boreo-temperate. Europe north to northern Fennoscandia, Caucasus, Asia, Madeira, N. America, Guatemala, Mexico. Readily distinguished from all other species of Dicranum by the flagelliform propagules.

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Subfamily 3 CAMPYLOPODIOIDEAE Leaves lanceolate, longly tapering; costa usually occupying more than half width of leaf near base, usually with dorsal and ventral stereid bands with a median row of guide cells; alar cells differentiated, forming auricles or not, cells above ovate to elongate. Setae usually strongly cygneous so that capsules are frequently buried in the perichaetial leaves; peristome teeth opening when moist. 34 DICRANODONTIUM BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1847 Dioicous. Leaves gradually or abruptly narrowed to long, channelled, entire or denticulate acumen composed mainly of costa; costa in section with one row of guide cells and an adaxial and abaxial band of stereids; alar cells ± inflated, sometimes extending to costa, hyaline or brownish, often not persisting; basal cells near costa rectangular, becoming narrower towards margins, cells above becoming narrower, porose or not. Setae straight or cygneous; peristome teeth vertically striate below, papillose or not above; calyptrae entire or fringed. A mainly Northern Hemisphere genus of 7 species. Derivation: meaning two-pronged tooth, referring to the peristome teeth. For a monograph of the genus see J.-P. Frahm, Acta Bot. Fenn. 34, 179–204, 1997.

1 Leaf margins toothed almost to base 2. D. asperulum Margins toothed in upper half of leaf only 2 2 Costa in lower part of leaf clearly defined, cells beside costa above auricles hyaline 1. D. uncinatum Costa not clearly defined, cells beside costa above auricles not hyaline 2. D. denudatum ¨ 1 D. uncinatum (Harv.) A. Jaeger, Ber. Thatigk. St. Gallischen Naturwiss. Ges., 1880 (Figs. 63, 64) Dicranum uncinatum (Dicks.) Sm. Silky tufts, golden yellow above, brownish below, to 12 cm high. Leaves falcatesecund, less commonly erect or secund when moist, hardly altered when dry, from ovate or oblong sheathing basal part with entire margins rapidly narrowed to long setaceous acumen with margins denticulate from c. half way up leaf; costa longly excurrent, well defined below, to c. 1/4 width of leaf base, excurrent, finely denticulate on abaxial side above; alar cells inflated, hyaline to brownish, not persisting, cells by costa above alar cells broadly rectangular, hyaline, other basal cells quadrate-rectangular, walls not porose, at margins ± linear, forming border extending to shoulder of basal part, cells above narrowly rectangular to linear, with single marginal row shorter. Setae arcuate or straight; capsules erect; calyptrae fringed. Capsules unknown in the British Isles. On acidic humus on montane slopes, cliff ledges and rock faces, in moist shaded situations. 0–750 m. Frequent

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Fig. 63 1–3, Dicranodontium uncinatum: 1, leaf (×10); 2, leaf apex; 3, basal cells. 4–6, D. asperulum: 4 leaf (×10); 5, leaf apex; 6, basal cells. 7–10, D. denudatum: 7, leaf (×10); 8, leaf apex; 9, basal cells; 10, capsule (×7). 11–13, Campylopus subporodictyon: 11, leaves (×7.5); 12, alar cells; 13, cells c. 1/4 from leaf base. Apices ×130, cells ×320.

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Fig. 64 Costa sections about 1 /4 from leaf base. 1. Campylopus subporodictyon; 2, Dicranodontium asperulum; 3, D. uncinatum; 4, D. denudatum. All ×420.

in N. W. Scotland, rare elsewhere, Lake District, Kirkcudbright, eastern Scottish Highlands, W. Galway, W. Mayo, old records from N. Kerry and Wicklow. 18, H4. GB50 + 11∗ , IR8 + 2∗ . Suboceanic Boreal-montane. Western and central Europe, Yugoslavia, Himalayas, Sri Lanka, Java, Philippines, Taiwan, Japan, Morocco. Whilst easily identified microscopically, this and D. asperulum may be difficult to separate in the field. D. uncinatum usually has falcate-secund leaves, whereas D. asperulum usually has the leaves ± straight to secund.

2 D. asperulum (Mitt.) Broth., Nat. Pflanzenfam., 1901 Dicranum asperulum Mitt.

(Figs. 63, 64)

Silky yellowish green tufts, to 7.5 cm high. Leaves flexuose when dry, erect-patent to secund, occasionally falcate-secund when moist, often deciduous, from ovate sheathing basal part abruptly narrowed to long spinosely denticulate setaceous subula; margins denticulate from shoulders of and sometimes almost from base of sheathing part; costa longly excurrent, well defined below, 1/4 –1/3 width of leaf near base, spinosely denticulate on abaxial side above; alar cells inflated, hyaline to brownish, cells beside costa above alar cells enlarged, other basal cells quadrate to quadrate-rectangular, walls not porose, linear at margins, cells above narrowly rectangular to linear, single marginal row shorter. Setae straight; capsules erect; calyptrae entire. Capsules not known in the British Isles. On acidic humus among rocks, on steep mountain slopes and rock ledges in damp sheltered situations. 330–850 m. Rare, Caernarfon, Roxburgh, Stirling and Perth north to Sutherland, Leitrim, Cavan, Fermanagh. 19, H3. GB27 + 3∗ , IR4 + 1∗ . Suboceanic Boreal-montane. Central and northern Europe, Carpathians, Sikkim, Taiwan, Japan, N. America.

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3 D. denudatum (Brid.) E. Britton in R. D. Williams, N. Amer. Fl., 1913 (Figs. 63, 64) Dicranodontium longirostre (F. Weber & D. Mohr) Bruch & Schimp. Silky yellowish green or green patches or lax or rarely dense tufts, to 5(−10) cm high; stems with reddish brown tomentum. Leaves soft, rarely rigid, often deciduous, erect to secund, flexuose when dry, spreading to secund when moist, from ovate-lanceolate sheathing basal part gradually tapering to smooth or slightly denticulate acumen; margins recurved, ± entire; costa longly excurrent, poorly defined in lower part of leaf, 1/3 –1/2 width of leaf base, smooth on abaxial side above; alar cells inflated, forming hyaline or brownish auricles, cells beside costa above alar cells narrowly rectangular, not hyaline, other basal cells rectangular, not porose, narrower at margins, cells above rectangular to rhomboidal. Setae straight or cygneous; capsules cylindrical, straight, smooth; calyptrae entire. Capsules very rare. n = 11, 11–12. On damp shaded rocks, decaying wood and peaty soil in woods and occasionally in open habitats. 0–950 m. Frequent or common in montane areas, very rare elsewhere, E. Cornwall, S. Devon, S. Hampshire, Sussex, Stafford, Cheshire, Waterford, Wexford, Wicklow, Dublin, frequent in western Ireland. 57, H17. GB239 + 27∗ , IR37 + 6∗ . European Boreal-montane. Europe north to Finland and Sweden, Iceland, Caucasus, Siberia, Himalayas, China, Taiwan, Korea, Japan, N. America, Mexico, Colombia, Hawaii. D. denudatum may be distinguished from other Dicranodontium species by its habitat and deciduous leaves. Var. alpinum (Schimp) I. Hagen is regarded as no more than a habitat variant.

35 CAMPYLOPUS BRID., MUSCOL. RECENT. SUPPL., 1819 M. F. V. Corley

Dioicous or sterile. Moderate-sized to very robust plants; stems with central strand. Leaves long with wide basal part, tapering to channelled or tubular acuminate upper part; margins ± incurved throughout. Costa wide, 1/3 or more leaf width near base, reaching apex or excurrent, sometimes forming a hyaline hair-point; in section with median layer of large transversely oval cells, an adaxial layer of clear cells of very variable size and an abaxial layer of small cells of which alternate cells usually project downwards to form low ribs which are rarely produced to form lamellae several cells high; between median and abaxial band is another layer of clear cells or an intermediate band of groups of stereid cells. Alar cells often differentiated to form auricles; basal cells rectangular, wider beside costa than at margins, gradually or abruptly passing into upper cells which are of very variable shape and size, vermicular or more often consisting of longitudinal rows of mainly trapezoid and shortly rectangular cells mixed with a few quadrate and triangular cells. Vegetative propagation frequently occurs by one or more of the following deciduous structures: whole leaf tips, shoot tips or specialised diminutive leaves.

35 Campylopus

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Perichaetial leaves have wider basal portion and narrower costa. Male plants as large as female, rarely reduced and gemmiform. Setae yellow to light brown, cygneous with capsules buried in the leaves before maturation but erect and flexuose when the capsules are ripe (except in C. subulatus where it is erect throughout); capsules inclined, ellipsoid, straight or slightly curved with mouth slightly oblique, striate; calyptrae cucullate, fringed at base but fringe often deciduous; lid conicalrostrate; annulus of 2–3 rows of cells, separating; peristome teeth 16, divided to a little over half way, orange-brown below with transverse bars and minute vertical striations, becoming hyaline and papillose above; spores finely verrucose. Derivation: meaning bent foot, referring to the arcuate setae. A very large genus of c. 750 species, primarily occurring in the tropics; in temperate regions most numerous in areas of high rainfall. The British Isles are richer in species, all of which are calcifuge, than any other part of Europe. Hybrid sporophytes (C. flexuosus × C. fragilis) have been found once; the spores were abortive.

Notes on the identification of Campylopus species In the following key and descriptions measurements are made as follows: costa width is measured just above the auricles or in an equivalent position if auricles are absent; costa sections are taken c. 1/4 way up leaf unless otherwise stated; the proportion of the thickness of the costa (in the middle) in section occupied by the adaxial cells is given as a percentage of the total costa thickness. Costa section characters are of great importance for the identification of Campylopus species. The key that follows uses other characters first but costa section characters are also given. Wherever there is any doubt sections should be made. 1 Costa c. 3/4 width of leaf near base, cells porose ± throughout leaf, basal cell deep brown, alar cells longer and narrower, costa in section with stereids forming broad band on adaxial side of costa, rare plant 13. C. subporodictyon Plants lacking above combination of characters 2 2 Tall, usually blackish plants with long hair-points on some leaves (often broken off others), cells usually vermicular, lower cells pigmented 9. C. atrovirens Plants lacking above combination of characters 3 3 Basal cells above auricles hyaline, sharply delimited from green cells along an oblique line from costa to margins (as in Tortella species), leaves often with hair-points 4 Basal cells pigmented or if hyaline not delimited as above, hair-points absent 6 4 Lower green cells ± vermicular, costa section with stereids on both sides (although few on adaxial side) 12. C. brevipilus

218

5

6 7

8

9

10

11

12

12 Dicranaceae Lower green cells not vermicular, costa section with stereids confined to abaxial side 5 Fertile plants usually with nodose shoots (sterile plants usually not nodose), abaxial side of costa smooth or with ribs one cell high, widespread plant 11. C. introflexus Nodose shoots never present, abaxial side of costa in upper part of leaf with lamellae 2–4 cells high (best seen in section from upper part of leaf), plant of western coasts 10. C. pilifer Auricles absent or very rarely weakly developed 7 Auricles conspicuous 10 Lower cells narrow, to 14 μm wide, plants often with deciduous shoot tips, costa section without stereids 8 Lower cells wider, to 20 μm or more wide, plants often with deciduous leaves, costa section with abaxial stereids 9 Slender non-tomentose loosely growing plants, leaves less than 4 mm long 1. C. subulatus Small to robust, densely tufted plants, either with tomentose stems or with leaves more than 4 mm long 2. C. schimperi Leaves widest at 1/8 –1/4 from base, tapering towards base, plants robust 4. C. fragilis Leaves widest at or almost at base, shoots slender 5. C. pyriformis Costa 2/3 or more of leaf width at base, costa section without stereids 3. C. gracilis 2 11 Costa less than /3 leaf width near base, costa in section with stereids Leaves gradually tapering to stout acumen, costa section without adaxial stereids and with adaxial cells smaller and more numerous than median cells 6. C. flexuosus Leaves distinctly contracted above basal part into slender acumen, costa section not as above 12 Stems without tomentum, costa section with adaxial cells occupying up to half costa thickness, leaves toothed above 7. C. setifolius Stems tomentose, costa section with adaxial cells occupying more than half costa thickness, leaves almost entire 8. C. shawii

Subgenus Pseudocampylopus Limpr., Laubm. Deutschl., 1886 Costa in section without stereids. 1 C. subulatus Schimp. in Rabenh., Bryoth. Eur., 1861 (Figs. 65, 68) Slender golden yellow or yellowish green loose turfs, low patches or scattered plants, 0.4–3.0(−5.0) cm high; tomentum lacking or rarely present at base in taller plants. Leaves 2–4 mm long, erect, straight when moist, more appressed when dry, parallel-sided at base for (1/10)1/5 –1/3 of length, tapering above at first strongly then

35 Campylopus

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Fig. 65 Campylopus: transverse sections of costa c. 1 /4 from leaf base. 1, C. subulatus: 2, C. schimperi: 3, C. gracilis: 4, C. fragilis: 5, C. setifolius: 6, C. pyriformis var. pyriformis, from typical plant; 7, C. pyriformis, from slender plant; 8, C. flexuosus, from typical plant; 9, C. flexuosus, from xeromorphic form; 10, C. shawii. All ×420.

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12 Dicranaceae

gradually to apex, acumen rather short; margins entire below, faintly denticulate near apex which ends in 1–2 larger teeth; lamina cells in 2–9 rows at mid-leaf. Costa shortly excurrent, 1/2 –2/3 leaf width, in section with adaxial cells larger than median, occupying 32–47% of costa thickness, stereid cells absent, abaxial side of costa rough with low ribs. Basal cells thin-walled, hyaline, linear to rectangular, with hyaline cells continuing up margins in a tapering band; alar cells slightly wider and more incrassate than basal cells but usually little differentiated, rarely forming ± distinct hyaline auricles; upper cells subquadrate, shortly rectangular and trapeziform, 4–9 μm wide. Vegetative propagation by deciduous shoot tips. Setae erect, straight when moist and when dry, 1 cm long; capsules erect, ellipsoid, symmetrical or slightly asymmetrical; very rare, found only once in Britain. In sheltered sandy or gravelly places on roadsides, banks, by streams, rarely on damp rocks. 0–850 m. Occasional in western Britain from Cornwall north to W. Ross and Orkney, very rare in S. E. England and eastern Scotland, very rare in Ireland, Jersey. 34, H8, C. GB67 + 16∗ , IR3 + 6∗ , C1. Suboceanic Temperate. From Spain east to Yugoslavia and north to Scandinavia, Faeroes, Iceland, Turkey, Bhutan, Yunnan, California, C. America. 2 C. schimperi Milde, Bot. Zeit., 1864 C. subulatus var. schimperi (Milde) Husn.

(Figs. 65, 66)

Densely matted green to yellowish green tufts, 2.5–8.0 cm high; matted with reddish tomentum in lower part or rarely almost without tomentum. Leaves 2.5– 7.5 mm long, erect, often lightly secund when moist, becoming more appressed when dry, basal part parallel-sided for up to 1/3 of leaf length then tapering gradually to apex, apex entire or minutely denticulate, ending in 1–3 teeth; upper part of leaf sometimes finely papillose on abaxial side; lamina cells in 1–3(–8) rows at mid-leaf. Costa shortly excurrent, 1/2 –2/3 width of leaf base; in section with adaxial cells much larger than median, occupying 46–55% of costa thickness; stereids absent; adaxial side of costa with low ribs which are sometimes obsolete. Basal cells hyaline or slightly chlorophyllous, thin-walled, linear or rectangular, often not clearly delimited from upper cells; alar cells fragile, slightly wider than basal cells, hyaline or brownish, sometimes forming distinct hyaline auricles, upper cells shortly rectangular or trapeziform, 3–10 μm wide. Vegetative propagation by fragile leaf tips and occasionally deciduous leaves or shoot tips. Capsules not known in the British Isles. In areas of late snow-lie, in corries and gullies, on mountain ridges and banks below cliffs. (60−)400–850 m. Very rare but occasionally locally abundant, from Stirling and Arran north to Shetland, Kerry, Wicklow, W. Donegal. 18, H4. GB24 + 19∗ , IR3 + 6∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, China, Himalayas, Japan, Alaska, Greenland. This species varies considerably in size, plants from lower altitudes in W. Scotland and Ireland being taller and longer leaved, while those from C. and E. Scotland and high

35 Campylopus

221

Fig. 66 1–4, Campylopus fragilis: 1, leaf (×15); 2, alar cells; 3, cells from shoulder of leaf base; 4, capsule (×10). 5–7, C. gracilis: 5, leaf (×20); 6, alar cells; 7, cells 1 /4 from leaf base. 8–10, C. schimperi: 8, leaf (×25); 9, alar cells; 10, cells 1 /4 from leaf base. Cells ×320.

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altitudes in the west are more stunted with short leaves and more abundant tomentum. C. schimperi is very close on the one hand to C. subulatus and on the other to C. gracilis. Some authors have relegated it to varietal status under C. subulatus but it differs markedly in size, leaf length, distinctness of basal areolation, habit and habitat from that species and is not very likely to be confused with it, so it seems best to keep them apart. Confusion is more likely with C. gracilis, but this has the costa wider and excurrent for about half the leaf length besides having auricles constantly present and generally lacking tomentum. The leaf base of C. schimperi is longer and more sharply contracted into the acumen than in C. gracilis.

¨ 3 C. gracilis (Mitt.) A. Jaeger, Ber. Thatigk. St. Gallischen Naturwiss. Ges., 1872. (Figs. 65, 66) C. schwarzii Schimp. Gametangia unknown. Robust dense glossy yellow-green or golden tufts or turfs, 1–8 cm high; tomentum absent or very scanty. Leaves 2.5–8.0 mm long, erectpatent, straight or slightly secund, rarely strongly falcate when moist, becoming more erect and appressed when dry, tapering gradually from just above auricles to entire or faintly toothed apex, ending in 1–3 teeth; lamina cells in 0–2 rows in mid-leaf. Costa longly excurrent, excurrent part comprising about half total leaf length, very wide, 3 /5 –4 /5 leaf width; in section with adaxial cells large, occupying 40–53% of costa thickness; stereids absent; abaxial side of costa with low ribs. Basal cells hyaline or slightly chlorophyllous, thin-walled, linear or rectangular, not clearly differentiated from upper cells; alar cells forming conspicuous hyaline or mauve-red auricles, upper cells thick-walled, rectangular or trapeziform, 3–12 μm wide, linear at margins. Vegetative propagation by fragile leaf tips and shoot tips. Capsules unknown. In shallow bogs and flushes, on soil amongst rocks on steep slopes and on flushed rocks, slabs and dripping rocks. 0–900 m. Sometimes frequent on upland moorland and on mountains, occasional to frequent in N. W. Wales, the Lake District and W. Scotland north to W. Sutherland and the Outer Hebrides, Angus, occasional in Ireland especially in the west. 24, H13. GB99 + 16∗ , IR28 + 5∗ . Suboceanic Boreal-montane. Montane Europe north to Norway, Faeroes, Iceland, Himalayas, Taiwan, Japan, Korea, Kamchatka, British Columbia. Var. huntii (Stirt.) Dixon is a highly aberrant plant, possibly belonging to this species.

Subgenus Campylopus Costa in section with stereids on abaxial side only. 4 C. fragilis (Brid.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1847 (Figs. 65, 66) Lax green turfs or dense tufts, 0.5–8.0 cm high, with abundant red-brown tomentum in large plants. Leaves 3–6 mm long, erect-patent, straight, rather rigid when

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moist, more erect and appressed, slightly flexuose when dry, often strongly imbricate at apex of shoots, base obcuneate, widest at 1/3 –3/4 from base, then rapidly contracted to a tapering acumen, finely toothed in upper part with a few coarser teeth at apex; lamina cells in 1–6 rows at mid-leaf. Costa 1/3 –2/3 leaf width, ending in apex; in section with adaxial cells larger than median, occupying 35–66% of costa thickness, about equal in number to median cells; back of costa with low ribs. Basal cells rectangular, hyaline, in dried material tending to remain full of air bubbles after moistening, alar cells not differentiated, upper cells irregular, mainly trapeziform and rectangular, 3–19 μm wide. Abundant minute deciduous leaves often present at shoot tips; normal leaves and occasionally leaf tips may also break off. Capsules straight or slightly curved; peristome teeth 300–470 μm long; spores 9–20 μm. Capsules occasional, spring. More base-tolerant than other species of the genus, most commonly on peat on moorland and peaty soil on rocks and in rock crevices in woodland and near the sea, on rotting tree boles and logs, in limestone grassland and on sand-dunes. 0–760 m. Frequent in the south-west, west and north-west of Britain but rare or absent from much of lowland England and eastern Scotland, frequent in western Ireland. 86, H26. GB564 + 71∗ , IR106 + 10∗ , C2. Suboceanic Temperate. Europe north to Scandinavia, Faeroes, Turkey, Himalayas, Japan, Canary Islands, British Columbia, Arkansas, C. and S. America. Often confused with C. pyriformis, which has similar areolation and also lacks auricles but differing markedly in leaf shape and habit. C. fragilis has the leaves widest at some distance from the base, tapering gradually towards the base and rapidly above the widest point to the acumen. The wide leaf bases are conspicuous and usually whitish in moist plants. The shoots are thick and pencil-like (if of any length) with the leaves very closely placed on them and spreading widely when moist. The thickness of the shoots causes them to be rather few in number on a given area of ground. C. pyriformis has the leaves widest at or very shortly above the base, soon contracted to the shorter acumen; the leaves may or may not be contracted at the extreme base; the short basal lamina sometimes appears whitish as in C. fragilis but is never so conspicuous; the shoots are slender with the leaves less densely placed and more erect, allowing the shoots to grow closer together. The whitish leaf bases and habit should distinguish C. fragilis from all other non-piliferous Campylopus species.

5 C. pyriformis (Schultz) Brid., Bryol. Univ., 1826 C. fragilis var. pyriformis (Schultz) Agst. Low bright or yellowish green mats, 0.2–2.5 cm high; tomentum reddish, present only on large forms. Leaves 2.5–7.5 mm long (perichaetial leaves to 9.5 mm) long, erect-patent when moist, ± straight, the lower more appressed, the upper somewhat flexuose when dry, basal part ovate to ovate-lanceolate, abruptly contracted to long slender acumen, widest at or very near the insertion; margins toothed in upper half of leaf or only towards apex; lamina cells in 1–3(–4) rows at middle of leaf. Costa reaching apex or shortly excurrent, 1/3 –3/5 leaf width; in section with adaxial cells as large as or larger than median, occupying 32–54% of costa

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12 Dicranaceae

thickness, the two rows of cells about equal in number; stereids present on abaxial side of median cells in well grown plants but these cells are often thin-walled; abaxial side of costa with low ribs. Basal cells rectangular, hyaline, sometimes remaining air-filled when moistened; alar cells variable, usually undifferentiated, hyaline or pale red, rarely forming distinct auricles; upper cells irregular, mostly trapeziform or rectangular, 3–23 μm wide. Vegetative propagation by means of deciduous leaves or less frequently by diminutive leaf tips or shoot tips. Male plants similar to female or sometimes gemmiform. Capsules straight or sometimes asymmetrical, mouth slightly oblique; peristome teeth 260–400 μm long; spores 8–17 μm. Capsules occasional in well developed plants, spring. n = 10∗ , 12. The commonest species of Campylopus in the south and east of England. Leaf apices 20–42 μm wide 200 μm from tip, costa usually more than 2/3 of leaf width, in section with adaxial cells 14–19 μm high var. pyriformis Leaf apices very slender, 11–32 μm wide 200 μm from the tip, costa usually less var. azoricus than 2/3 leaf width, in section with adaxial cells 9–14 μm high Var. pyriformis (Figs. 65, 67) Pale or yellowish green, rarely dark green turfs, usually more than 1.5 cm high; tomentum sparse or absent. Leaf tips (16−)20–42 μm wide c. 200 μm from apex, toothed in upper part with teeth rather close together. Costa 2/3 –3/4 leaf width; in section with adaxial cells 14–19 μm high. Alar cells colourless, undifferentiated. Vegetative propagation by deciduous leaves, sometimes of reduced size, rarely by shoot tips or fragile leaf tips. On light, acid soils especially in open woodland and on peat on heaths and moorland, also on rotting tree stumps and logs. 0–800 m. Common in suitable habitats throughout the British Isles. 112, H39, C. GB1121 + 91∗ , IR175 + 10∗ , C8. Suboceanic Temperate. Europe north to Scandinavia, Madeira, Azores, north-east N. America, S. America, Australia, New Zealand. Var. azoricus (Mitt.) M. F. V. Corley, J. Bryol., 1976 (Fig. 67) C. azoricus Mitt. Loose yellowish green tufts, 0.5–3.5 cm high; tomentum sparse to abundant. Leaves long and slender, leaf tips narrow in all leaves but markedly so in perichaetial leaves, toothing very variable, sometimes from mid-leaf but most often only in upper quarter of leaf, teeth rather distant, rarely entire. Costa more excurrent, 1/3 –2/3 of leaf width; in section with adaxial cells 9–14 μm high. Alar cells rarely differentiated from other cells of leaf base, frequently pale red or brown. Vegetative propagation by fragile leaf tips, occasionally also by deciduous leaves but these never of reduced size. In bogs, on decaying tussocks of Molinia and Cyperaceae on damp peat, peaty soil and wet rotten logs. 0–580 m. Rare but widely distributed from E. Cornwall to Kent and north to W. Sutherland and

35 Campylopus

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Fig. 67 Campylopus pyriformis. 1–7, var. pyriformis: 1, shoot with sporophyte (×10); 2, leaf; 3, leaf apex; 4, alar cells; 5, cells at leaf base shoulder; 6, capsule (×10); 7, peristome tooth (×250). 8–10, var. pyriformis, juvenile form: 8, leaf; 9, leaf apex; 10, alar cells. 11–13, var. azoricus: 11, leaf; 12, leaf apex; 13, alar cells. Leaves ×15, apices ×115, cells ×320.

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Caithness, Longford, old records from Wicklow, W. Mayo and W. Donegal. 43, H4. GB40 + 18∗ , IR1 + 2∗ . Suboceanic Temperate. France, Germany, Denmark, Azores. C. pyriformis is a distinct species rarely confused in its typical form with related species. The numerous deciduous leaves scattered on the tops of the plants are characteristic but not always present. Some shoots of some plants superficially resemble Dicranodontium denudatum but the stems are not bare of leaves below as in the latter. Dicranella heteromalla has all the leaf cells rectangular and strongly chlorophyllous and the leaves are usually secund. In some plants of C. pyriformis there are no stereid cells in the costa section, the relevant cells being thin-walled; such plants could be mistaken for C. subulatus but this has the leaf cells smaller and narrower, the upper part of the leaf almost entire and the whole plant of a golden yellow colour and often taller than C. pyriformis. For the differences from C. fragilis and C. flexuosus see notes under those species. Most of the confusion that has arisen in the past between these two species and C. pyriformis has been due to var. azoricus not having been recognised as a distinct taxon. This variety does not resemble C. fragilis any more than does the type, except that the leaf bases are more conspicuous and whitish, especially in the perichaetial leaves. Confusion with C. flexuosus is due to the existence of forms of this variety with coloured alar cells and the absence of deciduous leaves. Otherwise, the variety differs from C. flexuosus in the same ways as does the type. Var. azoricus intergrades with var. pyriformis and not all plants can be assigned with certainty to one variety or other. The ´ M. F. V. Corley has been shown to be plant referred to as C. pyriformis var. fallaciosus (Ther.) a juvenile form of var. pyriformis. Rhizoidal gemmae have been reported from this species in Belgian and non-European material (see T. Arts & J.-P. Frahm, Bryologist 93, 290–4, 1990). On the basis of its world distribution, which is similar to that of C. introflexus i.e. western European and Southern Hemisphere, it has been suggested that C. pyriformis may have been introduced into Europe in historical times (see M. F. V. Corley & J.-P. Frahm, J. Bryol. 12, 187–90, 1982).

6 C. flexuosus (Hedw.) Brid., Muscol. Recent. Suppl., 1819 C. paradoxus Wilson

(Figs. 65, 68)

Forming dark green tufts, sometimes with shoots very uneven in length, plants 0.5–9.0 cm high; tomentum present but very variable in abundance, reddish, occasionally zoned in different colours. Leaves 2–7 mm long, erect-patent, straight or falcate-secund when moist, more appressed below, flexuose above when dry, parallel-sided or slightly tapering in basal 1/8 –1/4 , then gradually tapering to apex; lamina cells in (3−)4–19 rows at mid-leaf. Costa reaching apex but not excurrent, 1/ –3 / leaf width; in section with adaxial cells more numerous than median cells 5 2 (1.3:1 to 1.9:1) and smaller than them (16–36% of costa thickness); leaves of large plants occasionally have a few of the adaxial cells divided transversely giving the impression of stereid cells on adaxial side of costa; abaxial side of costa with or without low ribs. Basal cells rectangular, usually thick-walled; alar cells differentiated to form hyaline or reddish brown auricles, upper cells irregular, mainly

35 Campylopus

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Fig. 68 1–4, Campylopus flexuosus: 1, leaf (×15); 2, alar cells; 3, cells 1 /3 from leaf base; 4, capsule (×10). 5–7, C. subulatus: 5, leaf (×25); 6, alar cells; 7, cells 1 /4 from leaf base. 8–10, C. setifolius: 8, leaf (×15); 9, alar cells; 10, cells 1 /3 way up leaf. Cells ×320.

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trapeziform and shortly rectangular, 3–19 μm wide. Vegetative propagation by deciduous leaves or shoot tips, rarely by leaf tips. Capsules curved and asymmetrical with mouth ± oblique; peristome teeth 290–560 μm long; spores 10–17(−24) μm. Capsules occasional, spring. n = 10∗ , 11∗ , 12∗ . In exposed or sheltered situations on bare peat on heaths and moorland, humus in woodland, on rotten wood, less frequently on rocks on moorland and shaded vertical rock faces. 0–800 m. 111, H37, C. GB1279 + 105∗ , IR240 + 12∗ , C1 + 2∗ . Suboceanic Temperate. Europe north to Scandinavia, Faeroes, Iceland, Asia, Macaronesia, Africa, N., C. and S. America, Australia, New Zealand. Differs from all other British species of the subgenus Campylopus in the costa section, in which the adaxial cells are smaller and more numerous than the other cells of the median layer. Confusion can only arise with abnormal plants. Some robust forms have stereid-like cells on the adaxial side of the costa, which might lead to their being taken for a muticous form of C. brevipilus which, however, has quite different areolation. Stunted forms of C. flexuosus have poorly developed auricles and the adaxial cells of the costa section about as large as the median cells. Such plants might be mistaken for C. pyriformis but differ markedly in leaf shape, having gradually tapering leaves with many rows of cells at mid-leaf, whereas C. pyriformis has rapidly contracted leaves with slender acumens and only 1–3(−4) rows of lamina cells at mid-leaf.

7 C. setifolius Wilson, Bryol. Brit., 1855 (Figs. 65, 68) Deep loose dark green or olive-green tufts, often tinged dark brown, (1−)3– 13(−25) cm high; tomentum absent or a few pale rhizoids present. Leaves 3.0– 8.5 mm long, when moist straight, never falcate, erect-patent, often very laxly placed on stem, more flexuose when dry; parallel-sided or slightly narrowed towards base, gradually tapering to long acumen from 1 /12 –1/8 from base, upper quarter of base (rarely less) with numerous spinose teeth, apex crowned with 1–4 large teeth; lamina cells in 2–9 rows at mid-leaf. Costa not excurrent, 2/5 –3/5 width of leaf; in section with adaxial cells about equal in number and of similar size to median cells, occupying 30–52% of costa thickness; costa smooth or with low toothed ribs near apex. Basal cells rectangular, usually thick-walled with few to many cells with porose walls, rarely hyaline, becoming thick-walled above; alar cells forming large orange-red auricles, upper cells thick-walled, irregular, mostly trapeziform or rectangular, occasionally shortly vermicular, 4–23 μm wide. Vegetative propagation by broken-off leaf tips or whole leaves, very rarely by shoot tips. Male plants much rarer than female. Capsules unknown. In very humid situations, on wet rock ledges and in block scree under tall heather on steep slopes, in spray zones of waterfalls and elsewhere where water drips from above, and in shallow bogs. 0–800 m. Rare but very locally frequent, N. W. Wales, the Lake District, Kirkcudbright and the far west of Scotland from Arran north to W. Sutherland and the Outer Hebrides, the far west of Ireland. 13, H12. GB62 + 6∗ , IR42 + 6∗ . Hyperoceanic Temperate. N. Spain.

35 Campylopus 8 C. shawii Wilson in Hunt, Mem. Lit. Soc. Manchester, 1868 ¨ C. setifolius var. shawii (Wilson) Monk.

229 (Figs. 65, 69)

Extensive yellowish green turfs, 3–11 cm high; tomentum reddish brown, abundant, conspicuous, rarely absent. Leaves 5.0–11.5 mm long, widely spreading to almost erect, straight or falcate when moist, becoming slightly appressed and flexuose when dry; parallel-sided at base for 1/8 –1/5 of leaf length or slightly narrowed towards base, gradually tapering above to long slender acumen, finely toothed at extreme apex only, rarely entire or toothed in the upper 1/8 of leaf, ending in 1–2(−3) small teeth; lamina cells in 1–4(−6) rows at mid-leaf. Costa not or scarcely excurrent, 2 /5 –2/3 of leaf width; in section with adaxial cells equal in number to median cells but not much larger, occupying 48–70% of costa thickness; abaxial side of costa smooth or slightly roughened with very low ribs. Basal cells rectangular, thick- or thin-walled, if thin-walled then these cells giving way to thick-walled cells further up leaf, lowest thick-walled cells with or without porose walls; alar cells forming conspicuous hyaline or reddish brown auricles, upper cells rather thin-walled, walls sometimes porose, mostly trapeziform or rectangular, 3–22 μm wide. Vegetative propagation by fragile leaf tips or occasionally whole leaves. In wet turf, flush bogs and flushes, in peat cuttings and wet rock ledges, in high rainfall districts. 0–440 m. Very local but abundant in some areas, W. Inverness, Mull, Skye, W. Ross, W. Sutherland and the Outer Hebrides, Kerry, W. Cork, W. Mayo. 6, H4. GB51 + 12∗ , IR8 + 3∗ . Hyperoceanic Southern-temperate. Azores, S. America. A striking plant more resembling one of the larger Dicranum species than a Campylopus but yellower in colour than is usual in the former genus and with wider costa. C. gracilis is somewhat similar but its leaves are shorter and have wider costa. The costa section of C. shawii with its very large adaxial cells will distinguish it at once from all other species with auriculate leaves.

9 C. atrovirens De Not., Syll. Musc., 1838 Plants 1–13(−20) cm; scarcely tomentose. Leaves 3.5–9.0 mm long, the terminal pieces of stem sometimes becoming detached and when this occurs these leaves may be very long, to 18 mm. Leaves erect-patent to erect, straight or rarely falcate when moist, more appressed, slightly flexuose or straight when dry, basal part lanceolate, tapering above to long entire acumen; lamina cells in 5–16 rows at mid-leaf. Costa excurrent in a spinose-dentate hair-point of very variable length, often lacking in some leaves and rarely in all leaves; costa 2 /5 –3 /5 leaf width; in section with adaxial cells slightly larger than median cells and about equal to them in number, 24–40% of costa thickness, abaxial side of costa with ribs one cell high. Basal cells shortly rectangular or quadrate, very incrassate, ± porose, rarely thinwalled; alar cells forming distinct hyaline or red-brown auricles, upper cells from very shortly above the base becoming trapeziform, linear or vermicular, rarely without some vermicular cells, incrassate throughout, walls usually porose in lower part of leaf only, 4–19 μm wide. Vegetative propagation by deciduous shoot

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Fig. 69 1–3, Campylopus shawii: 1, leaf; 2, alar cells; 3, cells near shoulder of leaf base. 4–6, C. atrovirens var. atrovirens: 4, leaf; 5, alar cells; 6, cells 1 /3 from leaf base. 7, C. atrovirens var. gracilis: leaf. 8, C. atrovirens var. falcatus: leaf. Leaves ×15, cells ×320.

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tips, and leaf tips which often break off at the base of the hair-point, occasionally whole leaves are deciduous. Capsules unknown in the British Isles. 1 Leaves strongly falcate, not flexuose when dry var. falcatus Leaves straight or if slightly falcate then flexuose when dry 2 2 Slender yellowish green plants with narrow leaves, basal cells thin-walled, upper cells not vermicular var. gracilis Plants without above combination of characters var. atrovirens

Var. atrovirens (Figs. 69, 71) Tall tufts or deep turfs, brownish black or greenish at shoot tips, yellowish brown or blackish within, whole plants commonly having a deep brown appearance. Leaves straight, erect or if falcate then becoming flexuose when dry. Basal cells walls very incrassate, porose, upper cells mostly vermicular or linear, rarely rectangular or trapeziform. n = 11∗ . In bogs and on wet rocks on moors and mountains. 0–940 m. Frequent in western Britain from Cornwall north to Shetland, common in the west of Ireland, occasional on mountains elsewhere. 60, H30. GB512 + 43∗ , IR121 + 13∗ . Hyperoceanic Temperate. Montane Europe north to Scandinavia, N. Caucasus, Pacific coast of N. America, N. Carolina. Var. falcatus Braithw., Brit. Moss Fl., 1882 (Fig. 69) Similar to var. atrovirens but leaves strongly falcate-secund with different shoots facing in different directions, unaltered when dry. Sporophytes unknown. In bogs and on wet rocks. Rare in areas of high rainfall near the west coast, Westmorland north to Sutherland and the Outer Hebrides, Shetland, S. Kerry, W. Cork, W. Galway, Sligo, W. Donegal, Antrim. 9, H6. GB17 + 7∗ , IR3 + 2∗ . Hyperoceanic Temperate. Norway. Var. gracilis Dixon, J. Bot., 1902 (Fig. 69) Plants more slender than the type, yellowish green, brown below, never blackish. Leaves sometimes slightly flexuose when dry, very slender, narrower than in the type. Basal cells thin-walled, walls scarcely porose, upper cells rectangular or trapeziform, not vermicular. In rocky or stony places. Very rare from Merioneth north to Angus and Skye but seen recently only in Dumfries, Angus, W. Inverness and the Outer Hebrides with an old record from W. Cork. 11, H1. Hyperoceanic Temperate. Endemic. C. setifolius and C. brevipilus are similarly coloured. The first has the leaf margins strongly toothed, whilst they are entire in C. atrovirens, teeth being confined to the hair-point. C. brevipilus has the basal cells thin-walled and hyaline, these cells ascending higher at the margins than next to the costa, but the costa section is the surest way to distinguish them.

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10 C. pilifer Brid., Muscol. Recent. Suppl., 1819 (Figs. 70, 71) C. polytrichoides De Not., C. introflexus var. polytrichoides (De Not.) Giacom. Loose green tufts or patches, brown or blackish below with individual stems densely leaved and rather thick as in C. fragilis, 0.5–5.0(−9.0) cm high; tomentum reddish, variable in abundance, Leaves 3.0–5.5 mm long, straight, erect-patent when moist, more tightly appressed when dry, with straight hair-points; parallelsided at base for 1/4 –1/3 of leaf length with a short evenly tapering entire acumen; lamina cells in 5–16 rows at mid-leaf. Costa excurrent in a short straight spinosetoothed hyaline hair-point; costa 1/2 –3/4 leaf width; in section with adaxial cells large, occupying 30–50% of costa thickness, approximately equal to median cells in number; numerous stereid cells in each group with rather thinner walls than is usual for such cells; abaxial rib cells large in lower part of leaf, smaller and thicker-walled in upper part and forming lamellae 2–3(−4) cells high. Basal cells rectangular, thin-walled, hyaline or chlorophyllous, extending higher at margins than at costa, usually sharply demarcated from upper cells along a straight oblique line (as in Tortella spp.); alar cells thin-walled, hyaline or pale reddish, forming auricles of very variable size; upper cells thicker-walled, rectangular or trapeziform, rather short, 4–15 μm wide. Vegetative propagation by deciduous leaves and shoot tips. Setae c. 4 mm long; capsules small, 0.76–0.87 mm long; spores c. 17 μm. Capsules very rare, found only once, in Ireland. On acid rocks or stony ground, usually near the sea, in warm, exposed situations. Lowland. Very rare on southwest and west coasts, Cornwall, S. Devon, Merioneth, Caernarfon, Jura, Skye, Lewis, Kerry, W. Cork, W. Galway, W. Mayo, Jersey, Guernsey. 8, H5, C. GB19 + 1∗ , IR17 + 1∗ , C9. Oceanic Southern-temperate. Coastal Europe north to Belgium and east to Italy, Turkey, Macaronesia, Africa, India to Java, southern N. America, C. America, Venezuela, Galapagos Islands. Similar in appearance to some forms of C. brevipilus but differs in habitat, in the costa section with no adaxial stereids and in the areolation which is of short trapeziform cells. Muticous forms are known from the Channel Islands and the Azores. Some plants are blackish below and might be mistaken for C. atrovirens, but that plant differs in the areolation, having the basal cells incrassate and the upper cells generally vermicular; it is also normally taller with longer leaves.

11 C. introflexus (Hedw.) Brid., Muscol. Recent. Suppl., 1819 (Figs. 70, 71) Olive-green or rarely green patches or loose tufts, often hoary when dry, 0.5– 5.0 cm high; fertile plants with swollen perichaetial or perigonial nodes and slender internodes; tomentum reddish brown, often rather scanty. Leaves 2.5–6.5 mm long, straight, erect-patent when moist, more tightly appressed when dry with hair-points strongly reflexed, particularly on nodal leaves, but sometimes straight if very short, leaves widest 1/8 –1/3 from base or parallel-sided for a similar length with upper part of leaf tapering, acuminate, entire; lamina cells in 3–13 rows at mid-leaf. Costa excurrent in strongly toothed hyaline hair-point, 1/4 –1/2 length of

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Fig. 70 1–4, Campylopus pilifer: 1, dry shoot tip (×5); 2, leaf; 3, alar cells; 4, cells c. 1 /3 from leaf base. 5–8, C. introflexus: 5, dry shoot tip (×7); 6, leaf; 7, cells c. 1 /3 from leaf base; 8, capsule (×15). Leaves ×20, cells ×320.

lamina but sometimes very short or lacking in some leaves, especially in the internodes, costa very variable in width, 1/3 –3/4 leaf width; in section with adaxial cells occupying 23–50% of costa thickness, approximately equal to the median cells in number or slightly more numerous; stereid cells few in each group and

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with large lumens; upper part of costa with ribs one cell high. Basal cells rectangular, becoming short and trapeziform above, thin-walled, hyaline, rarely slightly chlorophyllous, extending higher at margins than by costa, demarcated from upper cells along a curved or irregular line; alar cells thin-walled, hyaline to dark red-brown, forming auricles of variable size or auricles absent when the leaf base may be decurrent; upper cells very irregular, shortly rectangular, trapeziform or triangular, strongly incrassate, 8–15 μm wide. Vegetative propagation by deciduous leaves. Setae 7–12 mm long, shoots sometimes apparently polysetous (one seta from each of several perichaetia at one node); capsules ovoid-cylindrical, 1.0–1.4 mm long, deeply furrowed and shrunken when dry; peristome teeth 280– 420 μm long; spores 10–14 μm long. Capsules rare in drier areas, frequent and sometimes locally abundant in wetter parts of the British Isles, spring. n = 12∗ . Most commonly on bare peat and sandy or gritty soil in bogs, peat cuttings, by forestry tracks, on burnt moorland, rotten wood or tree boles, rarely on rocks and tiles. 0–400 m. Frequent except in the Midlands and parts of eastern Britain, common and often very abundant in Ireland. 110, H39, C. GB979 + 1∗ , IR223 + 2∗ , C2. Introduced (Suboceanic Temperate). Europe from Spain to southern Scandinavia and east to Czechoslovakia, Poland and Switzerland, Faeroes, New Guinea S. Africa, Southern N. America, C. and S. America, Galapagos Islands, New Zealand, Kerguelen Island, Falkland Islands. Introduced, first found in Sussex in 1941 and in Co. Dublin in 1942, since when it has spread very rapidly. Hardly likely to be confused with any other species except C. pilifer, from which it differs in the stems commonly having slender internodes and swollen nodes whereas in C. pilifer the stems are of uniform thickness. Some hair-points are usually strongly reflexed when dry, often to an angle of 90◦ or more; in C. pilifer they are straight or slightly reflexed. The two species also differ in colour and in habitat but the most useful distinction is in the costa section, taken in the upper part of the leaf, where C. pilifer has lamellae 2–3 cells high, whereas C. introflexus has low ribs one cell high. The setae and capsules are much larger in C. introflexus and capsules are so rare in C. pilifer that fruiting plants are almost certain to be C. introflexus. A form of C. introflexus occurs on acid gravelly soil such as tracks through heathland and forestry plantations with leaves lacking hair-points or with short straight hair-points and as the plants are sterile the stems are not nodose. Although they have the leaf morphology and areolation of C. introflexus they may be mistaken for C. flexuosus, especially as they may have deciduous shoot tips, or for C. pilifer. For the occurrence of this plant in the British Isles see P. W. Richards, Trans. Br. Bryol. Soc. 4, 404–17, 1963, and P. W. Richards & A. J. E. Smith, J. Bryol, 8, 293–8, 1975.

Subgenus Palinocraspis Limpr., Laubm. Deutschl., 1886 Costa section with stereids on adaxial and abaxial sides. 12 C. brevipilus Bruch & Schimp. in Bruch et al, Bryol. Eur., 1847 (Fig. 71) Yellowish green, olive or blackish brown, close turfs or loose patches, 0.5– 5.0 cm high; tomentum fairly plentiful but inconspicuous, pale brown. Leaves

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Fig. 71 1–3, Campylopus brevipilus: 1, leaf (×20); 2, alar cells (×330); 3, cells 1/2 from leaf base (×320). 4–11, leaf costa sections: 4, C. atrovirens var. atrovirens, 1 /4 from leaf base; 5, C. brevipilus, 1 /4 from leaf base. 6–8, C. pilifer: 6, near leaf tip; 7, 1/2 from leaf base; 8, near leaf base. 9–11, C. introflexus: 9, near leaf tip; 10, 1/2 from leaf base; 11, near leaf base. Sections ×420.

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2.5–6.0 mm long, straight, erect, rarely falcate when moist, more tightly appressed when dry but with the leaf tips free and straight or slightly reflexed hair-points, basal part of leaves oblong, elliptical or lanceolate, gradually tapering to entire acuminate apex, widest at 1/3 –1/2 from base, very variable in width relative to length; margins often narrowly recurved at about mid-leaf, especially in perichaetial leaves; lamina cells in 6–25 rows at mid-leaf. Costa excurrent, sometimes entire, but usually ± toothed, often forming a hyaline hair-point of variable length but never very long; 1/4 –1/2 leaf width, down to 1 /7 of leaf width in some perichaetial leaves; in section occasionally biconvex, adaxial layer of cells smaller than median, with a band of stereid cells between adaxial and median cells, often reduced to a few cells only; abaxial layer with more numerous stereids, arranged in groups, alternating with abaxial cells; abaxial side of costa smooth or slightly rough. Basal cells thin-walled, hyaline, rectangular, extending further up margins than near costa; alar cells forming small rather fragile auricles, hyaline or brownish, often not clearly differentiated from basal cells; upper cells from shortly above base becoming trapeziform, linear or shortly vermicular, 4–12 μm wide, walls usually strongly incrassate and often porose. Vegetative propagation by fragile shoot tips and occasionally whole leaves. Perichaetial leaves from wider base more suddenly contracted with hair-points longer than in vegetative leaves. Peristome teeth 350– 440 μm long; spores 11–13 μm. Capsules very rare. On heaths and moors, raised, valley and blanket bogs, acid fixed sand-dunes. Lowland. Always local, very common in some areas but unaccountably absent or very rare in other apparently suitable districts, occasional in the far south of England, west Wales, and the west of Scotland, extending north to Shetland, rare or very rare elsewhere, occasional to frequent in W. Ireland. 63, H24, C. GB219 + 64∗ , IR55 + 3∗ , C2. Oceanic Temperate. Europe east to Italy and Switzerland, north to Norway, Azores, Algeria. Perhaps the most variable species of the genus, showing great diversity in almost every character, particularly leaf width relative to length, presence or absence of hair-points, length of hair-points, and cell length and hence cell shape. The hair-points may vary not only from plant to plant but also up the stem; whole plants may lack hair-points altogether; such muticous forms are much more frequent than equivalent plants in other species and in some districts may form whole populations. The areolation in the best developed forms closely resembles that of C. atrovirens with its incrassate porose vermicular cells, but the basal cells of C. brevipilus are thin-walled and hyaline. The narrow costa, areolation and especially the costa section should distinguish C. brevipilus at all times.

13 C. subporodictyon (Broth.) B. H. Allen & R. Ireland, Linbergia, 2002 (Figs. 63, 64) Dicranodontium subporodictyon Broth., Dicranum subporodictyon (Broth.) Gao et al. Glossy yellowish green tufts, reddish below, c. 5 cm high. Leaves appressed, straight or with slightly flexuose points when dry, erect-patent when moist, with scattered

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dark brown rhizoids on abaxial side near base, from lanceolate basal part tapering to long channelled setaceous acumen consisting mainly of costa; margins inflexed, denticulate near apex; costa c. 3/4 width of leaf near base, ending in apex, not denticulate on abaxial side, also present on abaxial side; basal cells rectangular, incrassate, deep brown, walls porose, alar cells longer, narrower, not inflated, cells above elongate-rhomboidal, sinuose, porose, becoming narrower in upper part of leaf, marginal cells below very narrow, mid-leaf cells 10–12 μm wide. Sporophytes unknown. On flushed acidic rocks and slabs. 36–180 m. Very rare but sometimes locally abundant. W. Inverness, Skye, W. Ross. 2. GB5. Hyperoceanic Temperate. Sikkim, Yunnan, N. W. Canada. Very distinct in the broad costa, reddish brown basal cells and the scattered rhizoids near the leaf bases. The plant is possibly a Cretaceous relict. Originally placed in Dicranodontium and later transferred to Dicranum, it does not fit comfortably in either genus and has recently been transferred to Campylopus (see B. H. Allen & R. Ireland, Lindbergia 27, 77–8, 2003). For an account of D. subporodictyon in Scotland see E. C. Wallace & M. F. V. Corley, J. Bryol. 8, 85–9, 1974.

36 PARALEUCOBRYUM (LIMPR.) LOESKE, HEDWIGIA, 1908 Dioicous. Leaves lanceolate, acuminate; costa very wide, in section with 2–5 rows of hyaline cells with a middle layer of green cells, stereids lacking; alar cells inflated, hyaline or brownish. Capsules erect, cylindrical. A mainly Northern Hemisphere genus of 7 species. Derivation: meaning resembling Leucobryum.

1 P. longifolium (Ehrh. ex Hedw.) Loeske, Hedwigia, 1908 Dicranum longifolium Hedw.

(Fig. 72)

Silky tufts, pale green when moist, whitish when dry, to 4(−6) cm high. Leaves flexuose when dry, secund or falcate-secund when moist, from lanceolate basal part gradually tapering to channelled or ± tubular acumen composed entirely of costa; margins denticulate above, spinosely so near apex; costa 1/3 –1/2 width of leaf base, denticulate on abaxial side above, spinosely so near apex, longitudinally ridged on abaxial side above, in section with 3 rows of hyaline cells and a layer of chlorophyllous cells; basal cells rectangular, narrower towards margins, alar cells inflated, hyaline or brownish, lamina consisting of only 2–3 rows of shortly rectangular cells extending a short distance up leaf. Capsules erect, cylindrical, straight or curved; unknown in Scotland. n = 12, 14. On acidic or basic boulders in scree or by small lakes. 730–1000 m. Very rare, seen recently in Mid Perth, Banff and E. Inverness, old records from Dumfries, Angus and S. Aberdeen. 6. GB3 + 4∗ . Circumpolar Boreal-montane. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Turkey, Caucasus, Siberia, Madeira, N. America, Greenland. This species is treated as vulnerable in the Red List of British Mosses.

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Fig. 72 1–2, Paraleucobryum longifolium: 1, leaf; 2, leaf section (×320). 3–5, Leucobryum glaucum: 3, leaf; 4, section of basal part of leaf (×175); 5, capsule. 6–8, L. juniperoideum: 6, leaves; 7, section of basal part of leaf (×175); 8, capsule. Leaves ×20, capsules ×10.

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13 Leucobryaceae Male plants minute, female plants large, whitish. Leaves consisting largely of costa, composed of 2 or more layers of large hyaline cells with large circular pores on inner walls and a central layer of chlorophyllous cells. Capsules erect or inclined, straight or curved, without stomata; peristome dicranoid. Four genera.

37 LEUCOBRYUM HAMPE, LINNAEA, 1839 Plants robust, forming compact cushions. Leaves composed mainly of costa, with a few rows of narrow hyaline cells towards the base representing the lamina; costa in section of 2 to several rows of hyaline cells with large irregular pores in the inner walls, with a central layer of small chlorophyllous cells. Sporophytes relatively small. A mainly tropical, taxonomically difficult genus of c. 180 species. Derivation: meaning white moss.

Basal part of leaves usually longer than narrowly triangular upper part, capsules markedly strumose, curved 1. L. glaucum Basal part of leaves shorter than ± parallel-sided upper part, capsules slightly strumose, slightly curved 2. L. juniperoideum 1 L. glaucum (Hedw.) Ångstr. in Fries., Summa Veg. Scand., 1846 (Fig. 72) Male plants minute, epiphytic on female plants. Female plants pale glaucous green when moist, whitish when dry, forming dense ± hemispherical cushions to 20(−50) cm high. Leaves imbricate when dry, erect-patent or sometimes subsecund in large plants when moist, mostly 6–9 mm long, composed mainly of costa, basal part ovate to lanceolate, 1.2–2.1 mm wide, usually longer than the narrowly triangular ± tubular upper part; margins entire; costa in section in middle of basal part 4–6 cells thick, adaxial cells 24–48 × 44–120 (−140) μm; basal cells, lamina of a few rows of elongate hyaline cells extending from base to near apex. Setae straight, 10–18 mm long; capsules curved, asymmetrical, markedly strumose, striate, sulcate when dry, 1.5–2.1 mm long; spores 16–20 μm. Capsules rare, autumn, winter. n = 11∗ , 14. On well or poorly drained soil and on rocks in woodland, on heaths, moorland, in bogs, calcifuge. 0–1030 m. Very rare in central and eastern England, frequent or common and sometimes locally abundant elsewhere. 107, H38, C. GB924 + 102∗ , IR174 + 14∗ , C1 + 4∗ . European Temperate. Europe north to northern Scandinavia, Turkey, Caucasus, Hong Kong, Japan, Macaronesia, eastern N. America, Colombia. In favourable situations colonies of L. glaucum grow to considerable size, as much as 2 m in diameter and 55 cm high, possibly by the coalescence of neighbouring plants. It has been estimated that such colonies may be about 70 years old (see J. W. Bates, J. Bryol. 15, 785–91,

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1989). Although sporophytes are rare, propagation by leaf and shoot fragments is very likely in both species in the British Isles. L. glaucum forms cushions of a more compact and neater appearance than those of L. juniperoideum, which often have the leaves slightly crisped when dry, and when the two are growing together the differences are obvious, as also when capsules are present. When sterile, L. glaucum may be identified by the leaves with the basal portion being longer than the upper part, which is narrowly triangular; in L. juniperoideum the basal part is shorter and abruptly narrowed into the upper part, which at least below has almost parallel sides.

¨ Hal., Linnaea, 1845 2 L. juniperoideum (Brid.) Mull. (Fig. 72) Male plants minute, epiphytic on female. Female plants forming ± hemispherical cushions, pale glaucous green when moist, whitish when dry, to 15 cm or more high. Leaves often slightly crisped when dry, often subsecund or secund when moist, mostly 5–7 mm long, basal portion ovate-lanceolate, 1.0–1.6 mm wide, usually shorter than the ± parallel-sided upper part; margins entire; costa in middle of basal part 2 cells thick, adaxial cells (15−)22–35(−44) × 33–110 μm, lamina of a few rows of elongate hyaline cells extending from base to near apex. Setae 8–12(−15) mm long; capsules slightly curved and inclined, weakly strumose, 1.0–1.6 mm long; spores 18–20 μm. Capsules rare, winter, spring. On well drained acidic soil, on rocks and tree boles in deciduous and rarely coniferous woodland, rarely on heaths, calcifuge. 0–400 m. Occasional in southern England and in Wales, very rare elsewhere in western Britain, extending north to Inverness, Kerry, W. Cork, Waterford, Carlow, W. Galway. 44, H6. GB76 + 3∗ , IR4. European Temperate. Western and central Europe, Turkey, Caucasus, China, Taiwan, Japan, ´ Macaronesia, N. America, Mauritius, Reunion, Madagascar. This is the plant referred to as L. albidum (Brid. ex P. Beauv.) Lindb. and L. minus (Hampe) Sull. by Dixon & Jameson (1924) and Braithwaite (1887), respectively. For the occurrence of L. juniperoideum in Britain and a detailed account of the two British species see A. C. Crundwell, J. Bryol. 7, 1–5, 1972.

14 Fissidentaceae Apical cell of stems bilateral. Leaves alternate, distichous in one plane. Each leaf consists of 3 parts: a conduplicate part, the sheathing lamina (or vaginant lamina), the apical lamina (or superior lamina) extending beyond the sheathing lamina and the dorsal lamina (or inferior lamina) forming the whole of the dorsal part of the lamina. Costa single; cells in upper half of leaf usually ± hexagonal, unistratose or bistratose in patches, 1–3-stratose border of narrow elongate cells present or not. Perichaetial leaves similar to stem leaves but sometimes longer and narrower. Sporophytes terminal or on short lateral branches; setae long or short; capsules erect or inclined, symmetrical or not; peristome dicranoid, of 16 deeply bifid teeth,

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rarely rudimentary; calyptrae mitriform or cucullate, entire at base. A taxonomically difficult but very natural family containing 5 genera and c. 1100 species most of which belong to Fissidens. It is thought that the sheathing lamina is derived from the true leaf lamina and that the apical and dorsal laminae are lamellar outgrowths. On the basis of peristome structure this family has affinities with the Dicranaceae but has greater specialisation of the gametophyte. It is because of this greater specialisation that I place the Fissidentaceae after other families of the Dicranales rather than before, as is done by most other authors.

38 FISSIDENS HEDW., SP. MUSC. FROND., 1801 Stems with central strand. Sheathing laminae c. 1/2 total length of leaf. Setae long; capsules longly exserted, with stomata. About 800 species, world-wide. For information on species 1–6 (the Fissidens viridulus complex) see M. F. V. Corley, J. Bryol. 11, 191–208, 1980 and on species 1–11 see M. A. Bruggeman-Nannenga, Proc. K. Ned. Akad. Wet. Ser. C 85, 59–104, 1982 and 88, 183–207, 1985. The latter author points out some useful distinguishing characters such as gametangia length and peristome tooth width. I have followed M. A. Bruggeman-Nannenga’s infrageneric treatment of the genus (Proc. K. Ned. Akad. Wet. Ser. C 81, 387–402, 1978). Derivation: meaning split tooth, referring to the peristome teeth.

1 Leaves with border of narrow elongate cells at least on sheathing laminae of perichaetial leaves; margins entire or obscurely denticulate above 2 Stem and perichaetial leaves unbordered; margins crenulate-serrulate or dentate above 15 2 Leaves gradually tapering to apex from below middle, cells c. twice as long as wide 15. F. curvatus Leaves ± abruptly narrowed to apex, cells ± isodiametric 3 3 Border present only on sheathing laminae of perichaetial leaves, minute aquatic plants 1.5–2.5 mm long 1. F. exiguus Border usually present on all laminae at least of perichaetial leaves, aquatic or terrestrial plants, if aquatic then 7–25 mm long 4 4 Capsules inclined or horizontal, leaf cells 6–10 μm wide, not protuberant 6. F. incurvus Capsules erect or inclined or if cernuous or horizontal then cells 4–8 μm wide and protuberant 5 5 Border confluent with costa at apex of stem leaves 6 Border not confluent with costa at apex of stem leaves 10 6 Antheridia in gemmiform axillary shoots, fertile plants 5–25 mm long 7 Antheridia on dwarf branches at base of female shoots, rarely in minute axillary buds, or plants dioicous or synoicous, fertile plants mostly 1.5–6.0 mm long 11

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7 Older parts of stems matted with deep red or occasionally brown rhizoids 8. F. curnovii Rhizoids ± sparse, brown or reddish brown 8 8 Leaf borders thin, 1(−3)-stratose, usually colourless, spores 10–14 μm, terricolous plants 7. F. bryoides Border 3 or more stratose, colourless or yellowish, spores 14–20 μm, plants aquatic or of habitats subject to submergence 9 9 Perichaetial leaves ± similar to upper stem leaves, leaf border yellowish, cells 8–10 μm wide, capsules ± erect 9. F. rivularis Perichaetial leaves markedly narrower than upper stem leaves, leaf border colourless, cells mostly 10–14 μm wide, capsules inclined 10. F. monguillonii 10 Sterile and fertile plants 5–20 mm long, spores 18–28 μm, aquatic plants 11 Fertile plants to 6(−7) mm long, sterile plants sometimes longer, spores 6–20 μm, plants terrestrial or aquatic 12 11 Leaf cells mostly 10–18 μm wide, archegonia 420–600 μm long, peristome teeth 51–86 μm wide at base 11. F. crassipes Leaf cells mostly 6–10 μm wide, archegonia 300–460(−560) μm long, peristome teeth mostly 43–66 μm wide 12. F. rufulus 12 Leaf cells 4–8 μm wide, usually protuberant in upper part of leaves 3. F. limbatus Cells mostly 8–15 μm wide, not or hardly protuberant in upper part of leaves 13 13 Perichaetial bracts 7–9 times as long as wide, costa percurrent to excurrent 5. F. gracilifolius Perichaetial bracts 4–6 times as long as wide, costa ending in or below apex 14 14 Perichaetial bracts ± similar to stem leaves but larger, sides of leaves at leaf apices usually concave (see Fig. 73, 12), plants terricolous 2. F. viridulus Perichaetial bracts longer and narrower than stem leaves, sides of leaves at apex often flat or convex (see Fig. 73, 6), plants saxicolous 4. F. pusillus 15 Plants to 5 mm long, costa ending below apex or percurrent 16 Plants larger, 1–10(−30) cm long, costa ending below apex to excurrent 17 16 Stems with 2–4 pairs of leaves, costa straight, cells 8–12 μm wide 13. F. exilis Stems with up to 18 pairs of leaves, costa with distinct bend half way up leaf, cells 12–20 μm wide 14. F. celticus 17 Leaves irregularly dentate towards apex, 3–4 rows marginal cells forming pale band especially in older leaves 18 Margins crenulate or regularly serrate above, marginal cells not differentiated 20 18 Leaf cells not mamillose, sporophytes borne on dwarf lateral or basal branches, setae red, common plants 19

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Leaf cells conically mamillose (best seen in side view of folded leaf), sporophytes terminal, setae yellowish, very rare plant 20. F. serrulatus 19 Cells in upper part of leaves 6–12 μm wide, partially bistratose, spores 10–16 μm 18. F. dubius Cells 12–20 μm wide, unistratose, spores 18–24 μm 19. F. adianthoides 20 Costa excurrent, cells 6–10 μm wide, shoots to 5 cm long, setae red 17. F. taxifolius Costa ending in or below apex, cells 8–22 μm wide, shoots 2–10 cm long, setae purple or yellow 21 21 Shoots to 10 cm long, leaves lingulate, cells 12–22 μm wide, setae purple 16. F. osmundoides Shoots to 20(−30) cm long, leaves narrowly lingulate or narrowly lanceolate, cells 8–14 μm wide 21. F. polyphyllus Section 1 Fissidens Plants small to large. At least sheathing lamina of leaves with border of elongate cells with pointed ends and margins entire or obscurely toothed above or all laminae unbordered and margins entire, crenulate or serrate at least above; cells smooth or rarely mamillose. Setae terminal; capsules usually with stomata. 1 F. exiguus Sull., Musc. Allegh., 1846 (Fig. 74) Dioicous. Scattered plants or small patches. Fertile plants 1.5–2.5 mm long with 2–4 pairs of leaves. Stem leaves ovate to lanceolate, acute; margins entire, unbordered; costa ending below apex; cells 8–12 μm wide in middle of apical lamina. Perichaetial leaves longer and narrower than stem leaves, to 5 times as long as wide, bordered only on sheathing lamina; costa ending below apex. Sporophytes terminal; setae red; capsules erect or slightly inclined; spores 10– 16 μm. Capsules common, spring. On shaded wet or submerged acidic rocks in streams and rivers. 0–205 m. Rare in S. E. England, very rare elsewhere, S. Devon, S. Somerset, Warwick, Brecon, Cumberland, N. Tipperary. 8, H1. GB12, IR1. European Temperate. Rare in Europe with definite records from Denmark, France and Germany, Azores, N. America. A reasonably good species, although almost impossible to separate from small forms of F. viridulus with poorly developed leaf border except by habitat, F. viridulus never occurs on wet or submerged stones or rock. Aquatic forms of F. pusillus are much larger with a well developed border on the stem leaves.

2 F. viridulus (Sw.) Wahlenb., Fl. Lapp., 1812 (Fig. 73) F. bryoides ssp. viridulus (Sw.) Kindb., F. viridulus var. bambergeri (Schimp.) Waldh. Dioicous, autoicous or synoicous. Dark green patches; fertile plants 2.5–6.0 mm long with 2–5(−8) pairs of leaves, sterile stems sometimes longer with more leaves. Stem leaves lingulate to narrowly lanceolate, 3–5 times as long as wide, often

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Fig. 73 1–5, Fissidens pusillus: 1, plant from limestone boulder in stream; 2, plant from shaded calcareous rock; 3, stem leaf (a, sheathing lamina; b, apical lamina; c, dorsal lamina); 4, perichaetial bract; 5, leaf tip; 6, leaf apices (×150). 7–8, F. gracilifolius: 7, plant; 8, perichaetial bract. 9–10, F. limbatus: 9, plant; 10, leaf tip. 11–12, F. viridulus: 11, plant; 12, leaf apices. (×150) Plants ×10, leaves ×40, cells ×420.

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acuminate or cuspidate with margins concave at apex (see Fig. 73, 12), but some leaves sometimes acute; margins entire or obscurely denticulate towards apex; border colourless, unistratose, always present on sheathing lamina and usually also present on apical and dorsal laminae, sometimes extending almost to leaf apex but not fusing with costa, not reaching base of dorsal lamina; costa ending below apex; cells irregular in shape and size, (6–)8–15 μm wide in middle of apical lamina, not protuberant. Perichaetial bracts of similar shape to but larger than stem leaves; costa ending below apex to excurrent. When autoicous, antheridia borne on short basal branches or rarely in minute axillary buds. Sporophyte terminal; setae red; capsules erect or slightly inclined, ellipsoid; spores 8–15 μm. Capsules common, winter, spring. n = 5, 10. On basic to slightly acidic soil on banks, stream sides, in woodland, amongst rocks and on thin soil overlying rock. 0–700 m. Common in England, Wales and S. Scotland but becoming rare further north, extending to W. Ross, occasional in Ireland. 75, H16. GB873 + 98∗ , IR86 + 7∗ , C7. Circumpolar Widetemperate. Europe to about 68◦ N, Asia, Macaronesia, Africa, N. and C. America, Australia. Confused in the past with F. pusillus and F. limbatus. F. pusillus differs in its perichaetial leaves longer and narrower than the stem leaves, the stem leaves with apex acute to obtuse, and always occurring on rock and sometimes being aquatic. Recent authorities stress the difference in apex shape of the leaves between the two species but I have seen numerous gatherings of F. pusillus with apices similar to those of F. viridulus. F. limbatus differs in the smaller, frequently protuberant cells and the perichaetial leaves longer and narrower than the stem leaves. F. bryoides differs in the bud-like axillary male branches which are almost invariably present. The plant referred to as F. viridulus var. bambergeri intergrades with F. viridulus and cannot be separated from it.

3 F. limbatus Sull., Expl. Railroad Mississippi Pacific, Descr. Moss. Liverw., 1856 (Fig. 73) F. herzogii Ruthe ex Herzog, F. minutulus Sull. non auct. angl. Synoicous, autoicous or dioicous. Small patches; plants 2–7 mm long with up to 15 pairs of leaves. Leaves lingulate to narrowly lanceolate, acute, acuminate or cuspidate; border colourless, unistratose, in upper leaves ending below apex to reaching apex and fusing with costa, border of dorsal lamina rarely reaching leaf base; costa ending in or below apex; cells irregular in shape and size, (3–)4– 8(–10) μm wide in middle of apical lamina, often protuberant. Perichaetial leaves longer and narrower than stem leaves, border ending below apex to reaching apex and fusing with costa; costa ending in or below apex. When autoicous antheridia borne on short basal branches or rarely in small axillary buds. Sporophytes terminal; setae red; capsules erect and symmetrical, ellipsoid; spores 8–18 μm. Capsules common, autumn to spring. n = 5. On basic to slightly acid soil in woods and on ditch and stream banks and on limestone or sandstone in sheltered but not wet sites. Lowland. Rare but widely distributed from Cornwall east to Sussex and north

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to Argyll and the Hebrides, rare in Ireland, Jersey. 38, H6, C. GB45 + 13∗ , IR6, C1. Mediterranean-Atlantic. S., W. and C. Europe, Turkey, Israel, Iran, Azores, Canary Islands. Plants of the F. viridulus complex occurring on soil or acidic rock with perichaetial leaves longer and narrower than the stem leaves are usually F. limbatus. There has been much confusion about the identity of F. minutulus Sull., which was thought for a time to be synonymous with F. pusillus. It has been shown that the name F. minutulus is an earlier name for F. limbatus; because of the confusion that would be caused by replacing the name F. limbatus with F. minutulus the name F. minutulus has been rejected in favour of the later name, F. limbatus.

4 F. pusillus (Wilson) Milde, Br. Siles., 1869 F. minutulus auct. non Sull., F. viridulus var. lylei Wilson

(Fig. 73)

Dioicous or autoicous. Plants dark green, gregarious or forming patches; fertile plants 1.5–6.0 mm long with up to 10 pairs of leaves. Leaves lingulate to narrowly elliptical, usually acute to obtuse with margins at apex straight or convex (see Fig. 73, 6); border colourless, yellow or reddish, 1–3-stratose, usually ending below apex, border of dorsal lamina not reaching leaf base, a single row of chlorophyllous cells present outside border towards base of sheathing laminae; costa ending below apex; cells irregular in shape and size, 6–15 μm wide in middle of apical lamina, not protuberant. Perichaetial bracts longer and narrower than stem leaves, 4–6 times as long as wide, acute to obtuse, border ending below to ± reaching apex but not confluent with costa; costa ending below apex. When autoicous, antheridia borne on short basal branches. Archegonia (250−)290–350(−440) μm long. Sporophytes terminal; setae red; capsules erect and symmetrical; peristome teeth (24−)30–47(−53) μm wide at base; spores 10–19 μm. Capsules common, late summer to spring. n = 10, 12. On dry or wet chalk, limestone or sandstone, sometimes completely submerged in fast-flowing streams or rivers. Frequent or common in basic areas, rare elsewhere. 81, H23. Europe north to southern Sweden, Turkey, Japan, Azores, Madeira. Some authors treat aquatic plants as F. pusillus and plants on terrestrial rocks as F. gracilifolius. However, in F. pusillus there is a complete intergradation from large aquatic forms, approaching F. crassipes in size, to smaller plants on both aquatic and terrestrial rocks. Furthermore, whilst F. gracilifolius in its typical form is very distinctive and occurs on dry rocks, a habitat also sometimes occupied by F. pusillus, it intergrades considerably with F. pusillus and can only be regarded as a very poorly defined species. Large aquatic forms of F. pusillus may be difficult or impossible to distinguish from small plants of F. crassipes unless fertile, although the cells of the dorsal lamina tend to be shorter. If capsules or archegonia are present then width of peristome teeth, spore size and archegonium length are distinctive.

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5 F. gracilifolius Brugg.-Nann. & Nyholm in Nyholm, Ill. Fl. Nord. Mosses, 1987 (Fig. 73) F. pusillus var. tenuifolius Boulay, F. viridulus var. tenuifolius (Boulay) A. J. E. Sm. Autoicous. Plants dark green, gregarious. Fertile plants mostly 1.5–2.5(−3.5) mm long with 2–4 or rarely more pairs of leaves. Leaves narrowly lanceolate, acute. Perichaetial leaves linear-lanceolate, 7–9 times as long as wide, acuminate, border reaching apex and confluent with costa; costa usually excurrent. Capsules similar to those of F. pusillus but sometimes two per perichaetium; spores 9–14 μm. On dry chalk, especially small pieces, limestone and calcareous sandstone in woodland and sheltered habitats. Lowland. Frequent in calcareous habitats in southern and central England, rare elsewhere, extending north to Perth and Kintyre, rare in Ireland. 53, H9. GB166 + 30∗ , IR6 + 4∗ . Widespread but rare in Europe, extending from the Mediterranean to S. Scandinavia, Turkey, Japan, Azores, Madeira. A poorly defined species which might be better treated as a variety of F. pusillus.

¨ 6 F. incurvus Starke ex Rohl., Deutschl. Fl (ed. 2) Kryptog. Gew., 1813 ¨ F. bryoides ssp. incurvus (Starke ex Rohl.) Bertsch

(Fig. 74)

Autoicous or dioicous. Dark green patches or scattered plants. Fertile shoots decumbent, 2–5(−10) mm long with 3–12 pairs of leaves. Leaves oblonglanceolate to lanceolate, cuspidate; margins entire; all laminae bordered, border pale, unistratose, usually confluent with percurrent costa, not reaching base of dorsal lamina; cells irregular in shape and size, 6–10 μm wide in middle of apical lamina. Perichaetial leaves narrower, more acute. When autoicous, antheridia borne on small branches at base of female shoots. Sporophytes terminal; setae red; capsules inclined to horizontal, asymmetrical, often curved; spores 12–16 μm. Capsules common, winter, spring. n = 4. On soil on arable and waste ground, banks, in open or sheltered situations. Lowland. Common in calcareous areas of lowland England, occasional in other parts of England and Wales, very rare in N. England and Scotland, extending north to Arran and Angus, rare in Ireland. 78, H14, C. GB382 + 90∗ , IR6 + 8∗ , C1 + 1∗ . Submediterranean-Subatlantic. Europe from the Mediterranean north to S. Scandinavia, Caucasus, Syria, N. Asia, Macaronesia, Africa, N, America, Australia. F. incurvus differs from F. bryoides in the inclined to horizontal, frequently curved capsules and the antheridia on short basal branches. The capsules tend to become horizontal when empty, but plants with the gametophyte of F. incurvus and erect capsules similar to those of F. viridulus confuse the distinctions between the two species. However, it is likely that such plants are erect-capsuled forms of F. incurvus rather than intermediates.

7 F. bryoides Hedw., Sp. Musc. Frond., 1801 (Fig. 74) Autoicous. Dark green patches. Fertile plants procumbent to ± erect, 3–20 mm long with 3–10 pairs of leaves, sterile shoots sometimes longer. Rhizoids few,

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Fig. 74 1–2, Fissidens incurvus: 1, plant; 2, stem leaf (×40). 3–6, F. exiguus: 3, plant; 4, perichaetial bract (×40); 5, margin of sheathing lamina of perichaetial bract; 6, leaf apex. 7–9, F. bryoides: 7, plant; 8, stem leaf (×40); 9, stem leaf apex. 10–11, F. curnovii: 10, leaf with axillary male branch (×20); 11, stem leaf apex. Plants ×10, cells ×320.

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brownish. Leaves oblong to lanceolate, 3–5 times as long as wide, cuspidate; border colourless, usually unistratose but sometimes 2(−3)-stratose, usually confluent with percurrent to excurrent costa, reaching stem at base of dorsal lamina; cells ± regularly hexagonal, 8–12(−14) m wide in middle of apical lamina. Perichaetial leaves longer and more acute than stem leaves, border confluent with percurrent or excurrent costa. Antheridia in gemmiform axillary shoots, rarely naked in leaf axils. Sporophytes terminal; setae red; capsules erect, ellipsoid; spores 10–14 μm. Capsules common, winter, spring. n = 5, 10, 12. On neutral to acid soil or more rarely on wood or stones in open places, arable fields, gardens, woods, on banks. 0–580 m. Capsules common, winter, spring. Occasional in N. E. Scotland, common or very common elsewhere, frequent in Ireland. 112, H36, C. GB1513 + 83∗ , IR150 + 6∗ , C7. Circumpolar Temperate. Europe, extending north to Svalbard, Azores, Madeira, N. Africa, Camaroon, Madagascar, N. America, southern S. America, New Zealand, Prince Edward Is. F. bryoides is usually readily distinguished from other small terrestrial Fissidens species by the leaves with the border confluent with the costa and the ± regularly hexagonal cells and the dwarf axillary male branches. F. curnovii differs in the larger spores and the stems usually with a dense tomentum of deep red or occasionally brownish rhizoids. F. monguillonii differs in habitat and has very narrow perichaetial leaves.

8 F. curnovii Mitt., J. Linn. Bot. Soc., 1885 F. bryoides var. caespitans Schimp.

(Fig. 74)

Autoicous. Dark green patches or scattered plants. Plants (4−)6–20 mm long with (3–4)-numerous pairs of leaves. Stems matted below with tomentum of deep red or occasionally brown rhizoids. Leaves oblong to lanceolate, cuspidate; border 2–3-stratose, colourless, confluent with percurrent to excurrent costa, reaching stem at bass of dorsal lamina; cells 8–12(−14) μm wide in middle of apical lamina. Perichaetial leaves longer than stem leaves. Antheridia in dwarf axillary shoots. Sporophytes terminal; setae red; capsules usually inclined but occasionally erect, ellipsoid; spores 16–20 μm. Capsules common, late spring, summer. On moist acidic soil, flushed rocks and in moist rock crevices by streams and rivers ± at normal water level, and on coastal cliffs. Lowland. Occasional to frequent in S. W. England, W. Wales, Lake District, I. of Man, extreme west of Scotland, very rare elsewhere, Lancashire, Mid-West Yorkshire, N. Northumberland, Sutherland, occasional in W. Ireland. 36, H12, C. GB166 + 18∗ , IR23 + 28∗ , C1∗ . Oceanic Southerntemperate. Belgium, Czechoslovakia, France, Italy, Portugal, Spain, Switzerland, Sicily, Macaronesia, N. Africa. F. curnovii is treated by continental European authors as a variety of F. bryoides, but although occasional intermediates do occur, it is sufficiently distinct to be treated as a species and is certainly a much stronger taxon than F. gracilifolius. F. curnovii is usually characterised by the dense tomentum of deep red rhizoids but occasional populations occur with brown rhizoids. If such plants are small and sterile they cannot be distinguished from F. bryoides on

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morphological grounds, but the habitat gives an indication of its identity. For a discussion of rhizoid colour see D. T. Holyoak & H. L. K. Whitehouse, J. Bryol. 20, 103–8, 1998.

9 F. rivularis (Spruce) Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 75) Autoicous. Dark green, sometimes silt-encrusted patches or scattered plants; plants 7–20 mm long. Rhizoids brownish. Leaves numerous, lingulate to lingulatelanceolate, acute to obtuse and mucronate; border very stout, yellowish, confluent with excurrent costa at apex and forming stout mucro, reaching stem at base of dorsal lamina; cells 8–10 μm wide in middle of apical lamina. Perichaetial leaves hardly differing from stem leaves. Antheridia in gemmiform axillary branches. Sporophytes terminal; setae red; capsules erect or slightly inclined, ellipsoid; spores 17–20 μm. Capsules occasional, winter. Shaded moist or submerged neutral or acidic rocks, rarely on limestone, in streams, rivers and by lakes. Lowland. Occasional in Cornwall, Devon, S. Somerset, S. Wales, very rare elsewhere in widely scattered localities from N. Somerset east to E. Sussex and north to Kirkcudbright and Kintyre, N. Kerry, Jersey. 18, H1, C. GB28 + 2∗ , IR1, C1∗ . MediterraneanAtlantic. From Portugal east to Azerbaijan and north to S. Sweden, La Palma, Tenerife, Azores, Algeria. Readily distinguished from all other aquatic Fissidens species by the very stout yellowish border confluent with the excurrent costa and forming a stout mucro. In some localities this species appears tolerant of some degree of aquatic pollution.

´ Bull. Soc. Agric. Sarthe, 1899 10 F. monguillonii Ther., ´ Podp. F. rivularis var. monguillonii (Ther.)

(Fig. 75)

Autoicous or dioicous. Dull green, often silt-encrusted patches or scattered plants. Plants 4–25 mm long with up to 20 pairs of leaves. Rhizoids few, brownish. Stem leaves oblong to lingulate-lanceolate, obtuse and often mucronate; margins obscurely denticulate above; border well developed, ± colourless, 2–3-stratose, ± confluent with percurrent costa, reaching stem at base of dorsal lamina; cells (8−)9–14 μm wide in middle of apical lamina. Perichaetial leaves very narrow, linear-lanceolate, 6–12(−15) times as long as wide, markedly differing from preceding stem leaves. Antheridia in gemmiform axillary shoots, on short lateral branches or on separate plants. Sporophytes terminal or on short ventral branches; setae red; capsules ellipsoid, inclined; spores 14–18 μm. Capsules occasional, winter. On silt-covered rocks, rock ledges and tree roots on damp soil by lakes, on muddy banks at or below flood level of slow-flowing rivers and on bases of Phragmites stems in fens. Lowland. Very rare, E. Cornwall, Devon, S. Somerset, Carmarthen, Pembroke, Caernarfon, Anglesey, Leitrim, Cavan, Fermanagh. 8, H3. GB11, IR3. Oceanic Southern-temperate. Belgium, France, Spain, Azores. Distinguished from species 5–8 by the larger leaf cells and markedly differentiated perichaetial leaves. The border confluent with the costa will distinguish this plant from F. crassipes, and F. rufulus and the latter and F. pusillus have smaller cells; furthermore, these

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Fig. 75 1–4, Fissidens monguillonii: 1, plant (×10): 2, stem leaf; 3, perichaetial bract; 4, stem leaf apex. 5–7, F. rivularis: 5, plant (×5); 6, stem leaf; 7, stem leaf apex. 8–10, F. crassipes: 8, plant (×5); 9, stem leaf; 10, stem leaf apex. 11–12, F. rufulus: 11, stem leaf; 12, stem leaf apex. Leaves ×20, apices ×320.

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three species occur in fast-flowing water. For the occurrence of this plant in Britain see A. H. Norkett, Trans. Br. Bryol. Soc. 2, 11–14, 1952.

11 F. crassipes Wilson ex Bruch & Schimp. in Bruch et al., Bryol. Eur., 1849 (Fig. 75) F. mildeanus Schimp. ex Milde Dioicous. Dark green patches or scattered ± decumbent plants, 7–20 mm long, with numerous pairs of leaves. Rhizoids few, brownish. Leaves lanceolate to narrowly lanceolate, acute; margins obscurely denticulate above; border 2–4-stratose, colourless to reddish, ending below apex, border of dorsal lamina ending before leaf base; costa ending in apex; cells thin-walled to incrassate, (6−)10–14(−18) μm wide in middle of apical lamina. Perichaetial bracts ± similar to stem leaves. Archegonia 420–600 μm long. Sporophytes terminal; setae red; capsules ellipsoid, erect or inclined; peristome teeth 51–86 μm wide at base; spores 18–28 μm. At or below normal water level on usually but not necessarily basic rocks in sometimes somewhat polluted streams and rivers and on canal sides. Lowland. Occasional to frequent throughout England, E. Wales and S. Scotland, extending north to Kintyre and Skye, occasional throughout Ireland. 72, H21. GB284 + 76∗ , IR26 + 2∗ . European Southern-temperate. Europe north to southern Finland and Sweden, Turkey, Asia, Canary Islands, Azores, N. and C. Africa, Australia. Some of the characters used to distinguish F. crassipes and F. rufulus – presence or absence of intralaminal border at base of the sheathing laminae, and the reddish border in F. rufulus – are unreliable. The most useful distinguishing characters are leaf cell size, archegonium length and peristome tooth width. In F. crassipes the border of the dorsal lamina does not reach the stem and the leaf apex is narrower. Small plants of F. crassipes are very similar to large aquatic plants of F. pusillus (q.v.).

12 F. rufulus Bruch & Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 75) Dioicous. Dark green patches, plants ± decumbent, to 20 mm long with numerous leaves. Rhizoids few, brownish. Leaves oblong-lanceolate to lingulate-lanceolate, apex broad, ± obtuse; border strong, often orange or red, not reaching apex, border of dorsal lamina extending to leaf base; costa ending in apex; cells 8–10(−12) μm wide in middle of apical lamina. Perichaetial leaves ± similar to stem leaves. Archegonia 300–400(−560) μm long. Sporophytes terminal; setae red; capsules ellipsoid, erect or inclined; peristome teeth (37−)43–66(−71) μm wide at base; spores 18–22 μm. Capsules occasional, winter. On rocks ranging from acidic to limestone at or below normal water level in unpolluted fast-flowing streams and rivers. 0–300 m. Occasional in S. W. Wales, N. England and southern Scotland, very rare elsewhere, Worcester, E. Perth, Angus, rare in Ireland. 20, H6. GB47 + 10, IR7 + 3∗ . European Temperate. Rare in W., C. and S. Europe. 13 F. exilis Hedw., Sp. Musc. Frond., 1801 (Fig. 76) Autoicous or dioicous. Plants ephemeral, in pale green thin patches or scattered, decumbent, 1.5–3.0 mm long with 2–4 pairs of leaves. Leaves lingulate to narrowly

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Fig. 76 1–3, Fissidens exilis: 1, plant (×10); 2, leaf (×40); 3, leaf apex. 4–6, F. celticus: 4, plant (×10); 5, leaf (×40); 6, leaf apex. 7–9, F. curvatus: 7, plant (×10); 8, leaf (×40); 9, leaf apex. 10–12, F. osmundoides: 10, plant (×5); 11, leaf (×30); 12, leaf apex. Apices ×320.

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lanceolate, acute; margins unbordered, crenulate or crenulate-serrulate; costa ending in apex; cells 8–12(−14) μm wide in middle of apical lamina. Perichaetial leaves ± similar to stem leaves. Male branches gemmiform at base of female stems or antheridia on separate plants. Sporophytes terminal; setae red; capsules erect, ellipsoid to subcylindrical; spores 10–12 μm. Capsules common, autumn to spring. n = 12. On loam or clay soil in woodland, on sheltered banks and stream sides and in damper parts of fields and grassland. Lowland. Occasional to frequent in southern Britain, rare or very rare in the north, extending to Caithness, rare in Ireland. 83, H10, C. GB284 + 18∗ , IR4 + 8∗ , C2∗ . European Temperate. Europe, extending to about 62◦ N, Turkey, Kashmir, N. Asia, Japan, La Gomera, Algeria, eastern N. America. 14 F. celticus Paton, Trans. Brit. Bryol. Soc., 1965 (Fig. 76) Dioicous. Dull green patches or scattered plants. Plants ± erect, 2.5–4.6 mm long with up to 14(−18) pairs of leaves. Deep red rhizoids at base of stems. Leaves lingulate to lanceolate, acute; margins unbordered, crenulate with projecting cell walls; costa with distinct bend at about half way up leaf, percurrent; cells ± hexagonal, marginal row 8–12 μm wide, in middle of apical lamina 12–20 μm wide. Perichaetial leaves similar to but larger than stem leaves. Antheridia and sporophytes unknown. On shaded soil banks in woods and by streams. Lowland. Occasional to frequent in S. E. and S. W. England, W. Wales and W. Scotland from Kintyre to Skye, very rare elsewhere, Lake District, Kirkcudbright, Wigtown, rare in Ireland. 41, H12. GB189, IR13. (European Temperate). Endemic. Easily recognised in the field by the ± erect plants with numerous leaves, resembling miniature palm fronds. For details of this plant see J. A. Paton, Trans. Br. Bryol. Soc. 4, 780–4, 1965.

Section 2 Pycnothallia Mull. ¨ Hal., Gen. Musc. Frond., 1900 A heterogeneous group of species with bordered leaves and papillose cells. 15 F. curvatus Hornsch., Linnaea, 1841 F. algarvicus Solms

(Fig. 76)

Dioicous. Small patches or scattered decumbent plants, 1.5–3.0 mm long, fertile stems with 3–5 pairs of leaves, sterile stems with more. Leaves linear-lanceolate, gradually tapering from below middle to acuminate apex; all laminae bordered, border stout, wide, confluent with costa at apex; cells in upper part of leaf irregular, narrowly hexagonal, about twice as long as wide, papillose, 4–8 μm wide in apical lamina, cells in sheathing lamina larger. Male plants minute, bud-like. Sporophytes terminal; setae red; capsules erect, ovoid; spores c. 14 μm. Capsules occasional, winter, spring. On clayey soil on shaded banks. Lowland. Very rare, sporadic in appearance, Cornwall, S. Devon, E. Gloucester, Radnor, Pembroke,

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Merioneth, Caernarfon, S. Kerry. 8, H1. GB13 + 3∗ , IR2. Mediterranean-Atlantic. S. and W. Europe, Turkey, Macaronesia, N. Africa. Distinguished from other small terricolous Fissidens species with bordered leaves by the longly tapering leaves with elongate papillose cells but possibly overlooked because of its small size and sporadic occurrence in small quantity.

Section 3 Serridium Mull. ¨ Hal., Gen. Musc. Frond., 1900 Plants medium-sized to robust. Leaf laminae unbordered; margins crenulate or serrate; cells smooth. 16 F. osmundoides Hedw., Sp. Musc. Frond., 1801 (Fig. 76) Dioicous. Dense bright to dark green erect tufts, to 10 cm high. Leaves numerous, lingulate-lanceolate to oblong-lingulate, acute to subobtuse and apiculate; margins regularly crenulate, unbordered; costa ending below or in apex; cells incrassate, variable in size, 12–22 μm wide in middle of apical lamina. Light to dark brown or blackish irregularly-shaped rhizoidal gemmae, to 1500 μm long, sometimes present. Sporophytes terminal; setae purple; capsules erect or inclined, ellipsoid; spores 18–24 μm. Capsules occasional, winter. n = 12, 16. On moist rock ledges and crevices on cliffs and in ravines, often where slightly basic, by mountain streams and flushes. 0–920 m. S. Hampshire, frequent or common in western and northern Britain, and in montane parts of Ireland. 67, H31. GB503 + 35∗ , IR77 + 13∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Siberia, C. Asia, Japan, Malaya, Azores, N. America, Greenland, southern S. America. Distinguished from other species with unbordered leaves by the terminal sporophytes with purple setae, the relatively shorter and wider leaves and the usually wider cells. F. taxifolius has a percurrent or excurrent costa and in the other species the margins are variously toothed. For an account of rhizoidal gemmae in F. osmundoides, F. polyphyllus and F. serrulatus see T. Arts, Lindbergia 14, 151–4, 1988.

17 F. taxifolius Hedw., Sp. Musc. Frond., 1801 Autoicous. Light green to reddish brown patches, sometimes extensive. Shoots procumbent to erect, to 2(−3) cm long, branching from base, old stems rhizome-like, tomentose. Leaves numerous, lingulate-lanceolate or rarely linearlanceolate; margins unbordered, crenulate or serrulate, sometimes finely so; costa strong, percurrent or excurrent; cells 6–10 μm wide in middle of apical lamina, marginal row smaller, often more pellucid. Sporophytes axillary near base of main branches; setae red; capsules usually horizontal, ellipsoid; spores 12–18 μm. Capsules occasional to frequent, winter to spring. Leaves lanceolate-lingulate, acute or obtuse and apiculate, margins crenulate or serrulate var. taxifolius Leaves lanceolate to linear-lanceolate, acuminate; margins finely crenulate or finely serrulate var. pallidicaulis

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14 Fissidentaceae

Var. taxifolius (Fig. 77) Shoots mostly 1–2 cm long. Leaves lanceolate-lingulate, ± shortly tapering to acute or obtuse and apiculate apex; margins crenulate or serrulate; cells 6–10 μm in middle of apical lamina. Dark brown to blackish rhizoidal gemmae, irregular in shape, 300–700 μm diameter, sometimes present. n = 9, 10, 12∗ , 12 + m∗ , 16. On basic to acidic, especially clayey soils, on rocks, in rock crevices, in woods, arable fields, gardens, on banks, by ditches and streams. 0–460 m. Very common except in N. E. Scotland. 112, H40, C. GB1744 + 69∗ , IR257 + 5∗ , C3 + 1∗ . European Southerntemperate. Europe to about 64◦ N, Faeroes, Turkey, Caucasus, Asia, Macaronesia, Tunisia, the Americas, New Zealand. Var. pallidicaulis (Mitt.) Corb. in Pitard & Negri, Mém. Soc. Bot. France, 1907 (Fig. 77) ¨ F. pallidicaulis Mitt. F. taxifolius ssp. pallidicaulis (Mitt.) Monk. Shoots 2–3 cm long. Leaves mostly lanceolate to linear-lanceolate, tapering from end of sheathing lamina to acuminate apex; margins finely crenulate or finely serrulate; cells 7–9 μm wide in middle of apical lamina. Capsules unknown in the British Isles. On damp soil on rocky stream banks. Rare but widely dispersed from S. Devon and S. Hampshire north to Shetland, rare in Ireland. 22, H5. Oceanic Southern-temperate. S. and W. Europe north to France, Macaronesia, C. America. For an account of var. pallidicaulis in the British Isles see E. C. Wallace, J. Bryol. 9, 161–2, 1972. In its extreme form such as is found on Madeira, it is very distinctive with shoots up to 6 cm long and the leaves to 10 times as long as wide. The British and Irish plants are much less distinctive and only merit varietal status. The narrower and more closely set leaves of var. pallidicaulis may lead to confusion with F. polyphyllus but the smaller cells and excurrent costa are distinctive. Rhizoidal gemmae have only been found on sterile plants of var. taxifolius and the relationship between these and fertile plants requires investigation.

18 F. dubius P. Beauv., Prodr. Aethéogam., 1805 F. cristatus Wilson ex Mitt., F. decipiens De Not.

(Fig. 77)

Autoicous or dioicous. Dense dull green or brownish green tufts, to 6 cm high. Plants erect, older parts of stems often with eroded leaves, tomentose below, branches to 2(−3) cm long with numerous leaves. Leaves ovate-lanceolate to lanceolate, acute to obtuse and apiculate; margins crenate-serrate to irregularly toothed towards apex, unbordered; costa ending below apex or rarely excurrent; cells incrassate, opaque, bistratose in patches in upper part of leaf, mostly 8– 12 μm wide in middle of apical lamina, 3–4 marginal rows more incrassate and pellucid, forming pale marginal band. Sporophytes borne on dwarf branches arising from middle or base of stems; setae pale red; capsules ± horizontal, ellipsoid; spores 10–16 μm. Capsules occasional, winter, spring. n = 12∗ , 12 + m, 13 + 2m, 16. On shaded soil and rocks by streams, on cliffs and on soil in calcareous grassland, sand-dunes, occasionally on wood and in bogs. 0–760 m. Common in wetter parts of the British Isles but limited to calcareous sites elsewhere. 108, H39,

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Fig. 77 1–4, Fissidens taxifolius var. taxifolius: 1, plant (×5): 2, leaves (×25); 3, apical lamina cells; 4, leaf apex. 5–6, F. taxifolius var. pallidicaulis: 5, leaf (×25); 6, apical lamina cells. 7–10, F. adianthoides: 7, plant (×4); 8, leaf (×15); 9, leaf apex; 10, section of apical lamina. 11–13, F. dubius: 11, leaf (×15); 12, leaf apex; 13, section of apical lamina. Cells ×320.

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C. GB971 + 59∗ , IR183 + 5∗ , C2 + 1∗ . European Temperate. Europe to about 68◦ N, Faeroes, Iceland, Turkey, Caucasus, Manchuria, Japan, India, Java, Macaronesia, N. America, Mexico, Haiti. Close to F. adianthoides but usually distinguishable by the smaller leaf cells and more conspicuous marginal band of pale cells. Forms of F. adianthoides from dry ground may have smaller cells and may be difficult to separate, but have the leaf cells unistratose throughout. It seems possible that F. adianthoides is an autopolyploid derivative of F. dubius. According to T. Arts (Lindbergia 12, 119–20, 1986), reddish-brown to black or occasionally paler, spherical to irregularly-shaped rhizoidal gemmae, 80–500(−1000) × 100–600(−1600) μm, are often present in F. dubius.

19 F. adianthoides Hedw., Sp. Musc. Frond., 1801 (Fig. 77) Autoicous or dioicous. In dense yellowish green to dark green tufts, to 10(−25) cm high. Plants decumbent to erect, branches to 5(−7) cm long with numerous leaves. Leaves broadly lingulate to lingulate-lanceolate, acute to obtuse and apiculate; margins crenulate below, sharply and irregularly toothed above, unbordered; costa ending in or below apex; cells opaque, incrassate, unistratose throughout, 12– 20 μm wide in middle of apical lamina, 3–4 marginal rows more incrassate, pellucid, forming pale marginal band. Sporophytes borne on dwarf branches arising from middle of stems; setae reddish; capsules, erect or inclined, ellipsoid, straight or curved; spores 18–24 μm. Capsules frequent, autumn to spring. n = 24∗ . In damp or wet situations on ledges and in crevices on cliffs, in flushes, fens, ditches, dune-slacks, also in chalk and limestone grassland, rarely on wood, a calcicole when in drier habitats. 0–950 m. Common in wetter parts of the British Isles but frequent only on chalk and limestone in lowland England. 112, H38, C. GB1106 + 130∗ , IR215 + 8∗ , C1 + 1∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Japan, Hong Kong, Azores. Madeira, N. America, Tierra del Fuego. Recognisable on sight in montane and moist habitats, having relatively wider shoots with longer pale-bordered toothed leaves than F. osmundoides, which has terminal sporophytes. Small forms may be confused with F. dubius (q.v.).

20 F. serrulatus Brid., Sp. Musc. Frond., 1806 (Fig. 78) Dioicous. Loose green tufts or patches, plants to 7.5 cm long, stems procumbent to erect, simple or branched. Leaves numerous, oblong-lanceolate to lingulate, acuminate to obtuse or obtuse and apiculate; margins crenulate below, irregularly toothed above, unbordered; costa ending in or below apex; cells incrassate, conically mamillose, partially bistratose, 10–16 μm wide in middle of apical lamina, 3–4 marginal rows more incrassate, pellucid, forming pale marginal band. Spherical or irregular, reddish brown to blackish rhizoidal gemmae, to 800 μm diameter, often present. Sporophytes terminal; setae yellowish; capsules inclined, ovoid. Only male plants known in the British Isles. On alluvial sand and gravel and on rocks below flood level of deeply shaded streams in ravines. Lowland.

38 Fissidens

259

Fig. 78 1–3, Fissidens serrulatus: 1, leaf (×5); 2, section of apical lamina (×320); 3, leaf apex (×320). 4–5, F. polyphyllus: 4, leaf (×5); 5, leaf apex (×320). 6–8, Octodiceras fontanum: 6, plant (×5); 7, leaf (×14); 8, leaf apex (×320). 9–12, Schistostega pennata:, 9, 10, sterile and fertile shoots (×10); 11, leaf (×20); 12, calls from upper part of leaf (×320).

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Very rare, W. Cornwall, S. Devon, Merioneth, S. Kerry, W. Mayo. 3, H2. GB4, IR2. Mediterranean-Atlantic. Corsica, France, Greece, Italy, Portugal, Spain, Yugoslavia, Macaronesia, Tunisia, Algeria. Similar to F. adianthoides but with smaller conically mamillose cells. F. polyphyllus has narrower leaves with smooth cells and no pale marginal band. The mamillae are most easily seen in side view on a folded leaf. This species is treated as vulnerable in the Red List of British Mosses.

21 F. polyphyllus Wilson ex Bruch & Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 78) Dioicous or autoicous. Dark green tufts to extensive patches. Plants procumbent, to 20(−30) cm long. Leaves numerous, narrowly lingulate to narrowly lanceolate, acuminate, acute to obtuse and apiculate; margins finely and obscurely denticulate towards apex, unbordered and without a pale marginal band; costa ending in apex; cells pellucid, smooth, 8–14 μm wide in middle of apical lamina, single marginal row smaller. Irregularly shaped, reddish brown rhizoidal gemmae, to 800 μm long, sometimes present. Sporophytes borne on dwarf lateral branches on upper parts of stems; capsules inclined, ovoid; unknown in the British Isles. Damp shaded rocks and hard-packed soil by streams and waterfalls and on dripping rocks. Lowland. Rare, Cornwall, S. Devon, N. W. Wales, Argyll, Kintyre, Jura, Kerry, W. and Mid Cork, Waterford, Wicklow, Sligo. 9, H7. GB30 + 2∗ , IR5 + 5∗ . Hyperoceanic Southerntemperate. Western Europe north to S. W. Norway, Italy, Tenerife, Madeira, Azores.

39 OCTODICERAS BRID., MUSCOL. RECENT. SUPPL., 1806 Stems without central strand. Sheathing laminae 1/4 –1/3 total leaf length. Capsules ± immersed in perichaetial leaves, without stomata. About 15 species distributed through Europe, Asia and America. Derivation: meaning 8 double horns based on the erroneous assumption that there were 8 divided peristome teeth

¨ 1 O. fontanum (Bach. Pyl.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 78) O. julianum Brid., Fissidens fontanus (Bach. Pyl.) Steud. Autoicous. Submerged dull green patches. Plants to 3 cm long. Leaves distant, spreading, linear to linear-lanceolate, gradually tapering from near base to blunt apex; margins entire, unbordered; costa ending below apex; cells thin-walled to incrassate, c. 10 μm wide in middle of apical lamina, larger towards margins and base. Antheridia and archegonia terminal on short lateral branches. Capsules ± immersed, ellipsoid; unknown in the British Isles. On submerged wood, stones, concrete and man-made structures, on fresh-water sponges, from near the surface to 80 cm deep in sluggishly flowing, fresh or slightly polluted water in rivers

40 Schistostega

261

and canals. Lowland. Rare but sometimes locally abundant, from E. Cornwall, S. Wiltshire and N. Essex north to S. Lancashire and M. W. Yorkshire, Pembroke, W. Galway, Leitrim. 26, H2. GB19 + 19∗ , IR2. European Temperate. Europe from Portugal, Spain and Italy north to S. Sweden, Madeira, Africa, N. America, Mexico, Chile, Australia, New Zealand.

15 Schistostegaceae With the characters of the single species.

40 SCHISTOSTEGA D. MOHR, OBSER. BOT., 1803 Derivation: meaning split lid from the erroneous assumption that the capsule lid split.

1 S. pennata (Hedw.) F. Weber & D. Mohr, Ind. Mus. Pl. Crypt., 1803 S. osmundacea D. Mohr

(Fig. 78)

Pseudodioicous. Glaucous green patches, reddish brown below. Shoots variable in length, to 1.5 cm long. Stems flexuose, naked below, arising from persistent thalloid protonemata with light reflecting properties. Leaves on sterile stems in two ranks, ovate-lanceolate to lanceolate, confluent at base, acute to acuminate; margins plane, entire; costa lacking; cells thin-walled, rhomboidal, 16–30 μm wide in mid-leaf. Fertile stems similar to sterile stems or with leaves in rosette at apex. Obclavate protonemal gemmae, 80–200 × 15–20 μm and composed of 3–4 cells, usually present. Setae thin, to 4 cm long; capsules ovoid, gymnostomous; lid convex; spores 8–12 μm. Capsules occasional, spring, summer. n = 11∗ , 14. On deeply shaded, usually friable soil on lane banks, entrances to caves, old rabbit burrows and mine shafts, crevices between granite rocks. Lowland. Frequent in Cornwall and rare to occasional from Devon east to Surrey and north to W. Inverness, Jersey. 42, C. GB105 + 29∗ , C1. Suboceanic Boreo-temperate. Europe north to Fennoscandia, Amur, Japan, N. America. Because of the light refractive properties of the convex cells of the persistent protonemata this moss appears luminescent when growing in dark places such as the mouths of caves or rabbit holes.

9 Pottiales Acrocarpous. Leaves linear to spathulate, acuminate to rounded; costa in section with one or two stereid bands. Setae usually long; capsules cleistocarpous or dehiscent; peristome absent, rudimentary or well developed; teeth entire, perforated or bifid to base into filiform often spirally coiled segments. Six families.

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16 Pottiaceae

16 Pottiaceae Usually small plants, often with xeromorphic features. Leaves linear to spathulate or ovate, acuminate to rounded; margins entire to dentate, usually unbordered; costa usually strong, in section with one or two stereid bands; basal cells rectangular, ± hyaline, cells above hexagonal or quadrate, often papillose, sometimes obscure. Setae very short to long, usually straight; capsules erect or inclined, globose to cylindrical, straight or curved, cleistocarpous or dehiscent; peristome absent, rudimentary, imperfect or perfect, teeth straight or spirally coiled, entire, perforated or variously cleft or divided into filiform segments. About 80 genera. A diverse family, many species of which show strongly xeromorphic features, recently monographed by Zander (1993). The monograph is based upon detailed anatomical and morphological studies resulting in a radical reclassification of many genera and species. I have largely followed Zander in the division of the Pottiaceae into subfamilies and tribes. However, his classification is based upon cladistics and this appears to have misplaced some genera, as is indicated by recent DNA studies (see V. Spagnuolo et al., Pl. Syst. Evol. 216, 69–79, 1999), which show that Weissia should be in the Trichostomoideae and not in the Pottioideae, where Zander (1993) places it. That species of Weissia hybridise with Tortella supports this. In discussing subfamilies and tribes Zander talks in terms of clades and ancestral nodes rather than providing descriptions of the taxa concerned. For this reason some of his descriptions are extremely short and inadequate.

Subfamily 1 TRICHOSTOMOIDEAE Stems with sclerodermis poorly differentiated, hyalodermis usually present. Leaves lanceolate, basal part expanded or not; margins plane or narrowly recurved below, plane or incurved above; costa 4–6 cells wide, not grooved on adaxial side; basal cells often hyaline, sometimes extending up margins, cells above with crowded papillae. Perichaetial leaves not sheathing. Clavate axillary gemmae lacking.

41 EUCLADIUM BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1846 A monotypic genus with the characters of the species. Laminal KOH reaction yellow. Derivation: meaning repeatedly branched stems.

1 E. verticillatum (Brid.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 79) Weissia verticillata Brid. Dioicous. Dense tufts, pale or glaucous green above, often encrusted with calcareous matter below mostly 0.5–3.0 cm high. Stems lacking central strand; rhizoids light brown. Leaves erect to erect-patent, flexuose when dry, patent to spreading

41 Eucladium

263

Fig. 79 1–4, Eucladium verticillatum: 1, leaves (×25); 2, mid-leaf cells; 3, marginal cells near leaf base; 4, capsule (×10). 5–8, Weissia controversa var. controversa: 5, stem and perichaetial leaves (×40); 6, adaxial side of costa at middle of leaf; 7, capsule (×20); 8, capsule mouth (×40). 9, W. controversa var. densifolia: leaf (×40). 10–11, W. controversa var. wimmeriana: 10, leaf (×40); 11, mid-leaf cells. Cells ×420.

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when moist, linear or linear-lanceolate from ± expanded basal part, acute; margins plane, toothed near base, finely papillose-crenulate above; costa ending below apex to shortly excurrent, adaxial cells quadrate to elongate; basal cells narrowly rectangular, hyaline, cells above rectangular to quadrate, incrassate, papillose, pellucid, c. 10 μm wide in mid-leaf. Setae straight, long, reddish. Capsules erect, ovoid to ellipsoid; lid longly rostrate, oblique; peristome teeth oblique, nodulose, irregularly cleft or perforated; spores 12–14 μm. Capsules rare, spring. n = 13∗ . On damp or wet shaded base-rich rocks, especially limestone, on cliffs, in ravines, by streams, waterfalls, in flushes, sometimes forming tufa, also on drier rock in woodland. Lowland. Occasional to common throughout the British Isles. 107, H38, C. GB476 + 75∗ , IR63 + 13∗ , C1∗ . European Southern-temperate. Europe north to Scandinavia, Caucasus, Turkey, Cyprus, Asia, Macaronesia, Africa, N. and C. America. Plants growing in deeply shaded habitats produce protonemal gemmae, 40–50 × 25–30 μm, but these are lacking in colonies occurring where light is brighter (see H. L. K. Whitehouse, J. Bryol., 11, 133–8, 1980).

42 WEISSIA HEDW., SP. MUSC. FROND., 1801 Usually autoicous. Small plants, frequently with much-branched stems. Leaves curled or crisped when dry, erect-patent to spreading when moist, increasing in size up stems, narrowly lanceolate to linear-lanceolate, acute to acuminate; margins plane, incurved or involute above, entire or papillose-crenulate, sometimes minutely toothed near base of perichaetial leaves; costa stout, ending below apex to excurrent, 4–8(−10) cells wide on adaxial side, cells quadrate or elongate, in section with two stereid bands; basal cells ± rectangular, hyaline, cells above rounded-quadrate, strongly papillose, opaque or pellucid. Perichaetial leaves similar to or larger than stem leaves. Setae straight, long or short; capsules dehiscent or cleistocarpous; lid or beak usually longly rostrate, oblique; peristome teeth short, rudimentary or absent, teeth when present usually 16, variously cleft or perforated; epiphragm present or not; calyptrae cucullate. Laminal KOH reaction yellow. A world-wide genus of c. 125 species. Derivation: named after the German botanist F. W. Weis (or Weiss), 1744–1826. Weissia as recognised here is divided by some authors into two or three genera: Weissia (species 1–4), Hymenostomum R. M. Brit. (species 5–8) and Astomum Hampe (species 9–13). The difference between the first two is presence or absent of peristome and epiphragm but in the presence of intermediates these taxa hardly merit generic status. Astomum is based on the operculum absent or poorly defined and the capsules indehiscent. W. levieri has dehiscent capsules and in W. longifolia var. angustifolia the capsules dehisce under pressure. On this evidence Astomum cannot be maintained as a separate genus. Different species of Weissia and Tortella sometimes occur in mixed populations and the following hybrids have been recorded: W. controversa × W. longifolia,

42 Weissia

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W. longifolia × W. controversa, W. controversa var. crispata × W. longifolia, W. longifolia × W. controversa var. crispata, W. controversa × W. brachycarpa, Tortella flavovirens × W. longifolia (female parent cited first).

1 Setae longer than capsules 2 Setae shorter than or as long as capsules 9 2 Capsules with at least a rudimentary peristome, epiphragm lacking 3 Capsules without peristome, epiphragm present or capsules cleistocarpous 5 3 Margins of upper and perichaetial leaves plane or only narrowly incurved, spores 22–28 μm 3. W. rutilans Margins of upper and perichaetial leaves involute, spores 16–20 μm 4 4 Adaxial cells of costa papillose, quadrate at least in patches in upper half of leaf 1. W. controversa Adaxial cells of costa smooth, elongate in upper half of leaf 2. W. perssonii 5 Setae 1.5–7.0 mm long, operculum not persisting at maturity of capsules 6 Setae 0.7–1.7 mm long, capsules cleistocarpous 8 6 Costa 60–120 μm wide near leaf base, spores 14–20 μm 4. W. condensa Costa to 55 μm wide near leaf base, spores 20–34 μm 7 7 Plants forming dense tufts or patches, lacking distant-leaved innovations, leaves patent when moist, exothecial cell walls thick 5. W. brachycarpa Plants forming lax patches, distant-leaved innovations arising from below perichaetia, leaves spreading to recurved when moist, exothecial cells very thin-walled 6. W. squarrosa 8 Plants to 5 mm high, perichaetial leaves 1.9–2.2 mm long, similar to upper stem leaves, spores normal 7. W. rostellata Plants to 15 mm high, perichaetial leaves 3–4 mm long, distinctly longer than stem leaves, spores often aborted W. × mittenii (p. 273) 9 Fertile stems usually with clustered short branches, sporophytes often two or more per perichaetium 9. W. sterilis Fertile stems hardly branched, rarely more than one sporophyte per perichaetium 10 10 Capsules dehiscent in nature, spores finely papillose 10. W. levieri Capsules indehiscent in nature, spores finely or coarsely papillose 11 11 Fertile plants c. 15 mm high, leaves crisped when dry, transition from spreading stem leaves to erect perichaetial leaves abrupt spores finely papillose 8. W. multicapsularis Fertile plants c. 10 mm high, leaves strongly curled when dry, transition from stem to perichaetial leaves not abrupt, spores coarsely papillose 11. W. longifolia Section 1 Weissia Setae longer than capsules; capsules exserted, ovoid to narrowly ellipsoid, dehiscent; peristome present; epiphragm lacking.

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1 W. controversa Hedw., Sp. Musc. Frond., 1801 Yellowish green to dark green tufts or patches, 5–40 mm high. Leaves crisped when dry, patent to spreading when moist, from oblong-lanceolate basal part abruptly narrowed into linear-lanceolate limb, apex acute and often mucronate; margins plane, entire below, strongly involute above; costa stout, excurrent, adaxial cells in upper half of leaf quadrate at least in patches; basal cells rectangular, hyaline, cells above quadrate-hexagonal, papillose, obscure. Setae yellowish, (1.5−)2.0– 6.0 mm long; capsules erect or slightly inclined, ovoid to narrowly ellipsoid, symmetrical or slightly asymmetrical, narrowed at mouth, smooth or slightly furrowed when dry and empty; lid longly rostrate; peristome teeth poorly developed or rudimentary, to 100 μm long; spores 16–20 μm. Capsules common, winter, spring. 1 Costa reddish, (60−)70–100 μm wide near base var. crispata Costa greenish, 30–50(−65) μm wide near base 2 2 Plants synoicous, widespread 3 Plants paroicous, very rare montane plant var. wimmeriana 3 Plants mostly 3–10 mm high, upper leaves larger and more crowded than lower, setae usually 2–6 mm long var. controversa Plants 15–40 mm high, leaves of ± uniform length and distribution along stems, setae c. 1.5 mm long var. densifolia

Var. controversa (Fig. 79) Autoicous. Dull green or yellowish green tufts or patches, sometimes extensive, 3–10 mm high. Lower leaves short, distant, upper longer, more crowded; costa 30– 60(−65) μm wide near base. Setae (1.5−)3.0–6.0 mm long, n = 11, 13∗ , 13 + m, 14. On light soil in turf, on banks, walls, roadsides, cliffs, sand-dunes and among rocks, in usually but not always exposed habitats. 0–550 m. Frequent or common except in eastern England and N. W. Scotland, frequent in Ireland. 112, H39, C. GB982 + 121∗ , IR172 + 4∗ , C8 + 1∗ . Circumpolar Wide-temperate. More or less cosmopolitan. Var. crispata (Nees & Hornsch.) Nyholm, Ill. Moss Fl. Fennoscandia. 2. Musci, fasc. 6, (Fig. 79) W. controversa var. fallax (Sehlm.) R. H. Zander, W. crispata (Nees & Hornsch.) ¨ Hal., W. fallax Sehlm. Mull. Autoicous. Lax yellowish green tufts. Costa reddish, stout, (60−)70–100 μm wide near leaf base. n = 12∗ . On banks, in chalk and limestone grassland, on cliffs, calcicole. Lowland. Rare but widely distributed from Cornwall east to Surrey and north to Berwick and Roxburgh. 18. GB14 + 6∗ . Circumpolar Wide-temperate. From Mediterranean Europe north to Scandinavia, Faeroes, Caucasus, Turkey, Asia. Macaronesia, N. Africa, N. America.

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Var. densifolia (Bruch & Schimp.) Wilson, Bryol. Brit., 1855 (Fig. 79) Autoicous. Very dense dark green tufts or patches, sometimes extensive, 15– 40 mm high. Leaves of uniform size and distribution along stems. Setae c. 1.5 mm long. n = 13∗ . On soil, especially associated with heavy-metal mine workings. Lowland. Rare in western Britain from Cornwall north to Cumberland and I. of Man, Berwick, W. Lothian, Mid Perth, S. Kerry, N. Tipperary, Fermanagh. 22, H3. GB42 + 13∗ , IR2 + 1∗ . European Temperate. Rare in Europe, N. Africa. Var. wimmeriana (Sendtn.) Blockeel & A. J. E. Sm., J. Bryol., 1998 W. wimmeriana (Sendtn.) Bruch & Schimp.

(Fig. 79)

Paroicous. Antheridia 2–3 together with paraphyses in the axils of leaves below the perichaetium. On soil among rocks. 500 m. Very rare, E. Inverness. 1. GB1. European Boreal-montane. Montane Europe north to Scandinavia, Iceland, Caucasus, Turkey, Kashmir. W. controversa is more widespread than W. brachycarpa, which is more strongly calcicole. The two can only be distinguished when mature capsules are present, the presence of poorly developed peristome teeth and absence of an epiphragm being characteristic of the former. Although var. wimmeriana is usually treated as a species, the only consistent difference between it and var. controversa is that the former is paroicous and on these grounds it cannot be considered as more than a variety. For an account of the occurrence of var. wimmeriana in Scotland see E. F. Warburg, Trans. Brit. Bryol. Soc. 3, 171–3, 1957.

2 W. perssonii Kindb., Bot. Not., 1898 W. controversa ssp. perssonii (Kindb.) Podp.

(Fig. 80)

Dull green or yellowish green patches, to 10 mm high. Leaves strongly crisped when dry, patent to spreading when moist, from oblong-lanceolate basal part abruptly narrowed to linear-lanceolate upper part, acute; margins plane, entire below, involute above; costa (45−)50–70 μm wide near base, adaxial cells in upper half of leaf elongate, not papillose; basal cells hyaline, cells above quadratehexagonal, incrassate, papillose, obscure. 9–10 μm wide in mid-leaf. Setae 2–5 mm long; capsules ovoid or ellipsoid, strongly contracted at mouth, smooth when dry and empty; epiphragm lacking; peristome teeth rudimentary, 20–50 μm long; spores 16–20 μm. n = 13∗ . By the coast on soil on cliffs and cliff tops and in rock crevices on calcareous or non-calcareous substrates. Lowland. Occasional along the west coast from Cornwall to Shetland, Monmouth, very rare in W. and N. Ireland. 25, H6, C. GB60 + 2∗ , IR7 + 1∗ , C2. Oceanic Temperate. Brittany, Norway, N. Spain, Sweden, Faeroes. Distinct from W. controversa in the wider costa with elongate adaxial cells and from this and all other species of Weissia by the non-papillose adaxial cells. Some gatherings identified as W. controversa var. crispata are this plant. For information on W. perssonii see A. C. Crundwell, Trans. Brit. Bryol. Soc. 6,221–4, 1971.

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Fig. 80 1–4, Weissia rutilans: 1, stem and perichaetial leaves; 2, mid-leaf cells; 3, capsule (×20); 4; capsule mouth. 5–8, W. condensa: 5, stem and perichaetial leaves; 6, mid-leaf cells; 7, capsule (×20); 8, capsule mouth. 9–12, W. perssonii: 9, stem and perichaetial leaves; 10, adaxial side of costa at middle of leaf; 11, capsule (×20); 12, capsule mouth. Leaves ×40, cells ×420, capsule mouths ×40.

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¨ 3 W. rutilans (Hedw.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad, 1863 (Fig. 80) W. mucronata Bruch & Schimp. Dull green or yellowish green patches, 3–10 mm high. Leaves incurved and crisped when dry, patent from erect basal part when moist, lower leaves oblonglanceolate, upper and perichaetial leaves oblong-lanceolate to narrowly lanceolate, acute; margins plane or slightly incurved above; costa stout, excurrent in mucro, adaxial cells ± quadrate in upper half of leaf; basal cells rectangular, hyaline, cells above ± quadrate, papillose, obscure, 8–10 μm wide in mid-leaf. Setae yellowish green, 8–10 mm long; capsules ovate-ellipsoid to ellipsoid, straight or slightly curved, smooth or striate when dry and empty, epiphragm lacking; peristome teeth rudimentary, to 80 μm long; spores 22–28 μm. Capsules common, autumn to spring. n = 13. On non-calcareous soil and on clay in turf, on woodland rides and banks, also on upland calcareous soil among rocks and in flushes. 0–450 m. Rare or occasional from Cornwall east to Kent and north to Orkney, W. Donegal, Down, Antrim, Londonderry. 72, H4, C. GB102 + 39∗ , IR1 + 3∗ , C1. European Temperate. Italy, Yugoslavia, C. and W. Europe, north to Scandinavia, Faeroes, Iceland, N. and E. Asia, N. and C. Africa, Canada, Australia. Distinguished in the field from the preceding and next two species in the relatively wider leaves with the margins only narrowly incurved above. According to Duell (1992), hardly distinct from W. squarrosa. However, the two are markedly distinct in capsule characters and W. squarrosa produces innovations from below the perichaetium.

Section 2 Hymenostomum (R. Brit.) Mull. ¨ Hal., Syn., 1849 Capsules emergent or exserted; peristome absent, epiphragm present; lid falling at maturity. ¨ 4 W. condensa (Voit) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 80) ¨ ¨ ¨ Hymenostomum tortile (Schwagr.) Bruch & Schimp., W. tortilis (Schwagr.) Mull. Hal. Loose, readily disintegrating patches, green above, brownish below, mostly 5–15 mm high. Upper leaves crisped when dry, patent when moist, narrowly lanceolate, acute to obtuse and mucronate; margins plane below, involute above; costa stout, 80–100 μm wide near base, ending in apex or excurrent in mucro, adaxial cells ± quadrate in upper half of leaf; basal cells rectangular, hyaline, cells above ± quadrate, papillose, obscure, 8–9 μm wide in mid-leaf. Setae 2–4 mm long; capsules ellipsoid, symmetrical or slightly asymmetrical, mouth partially closed by fugacious epiphragm; peristome absent; spores 14–24 μm. Capsules frequent, spring. n = 13. On dry calcareous soil in turf, on stony banks, limestone terrain and among boulders. Lowland. Very rare, S. Devon, N. Somerset, Dorset, I. of Wight, S. Hampshire, Sussex, Kent, Surrey, E. Gloucester, Berwick. 12. GB13 + 5∗ .

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Submediterranean-Subatlantic. S., W. and C. Europe, Caucasus, Turkey, Cyprus, S. W. Asia, Canary Islands, N. Africa, Canada, Texas. This species is treated as vulnerable in the Red List of British Mosses.

¨ Ungarn, 1882 5 W. brachycarpa (Nees & Hornsch.) Jur., Laubm. Ost. ¨ Hal., Hymenostomum microstomum (Hedw.) R. Br., W. microstoma (Hedw.) Mull. W. ludwigii Crum Dark green tufts or patches, sometimes extensive, 7–10 mm high. Leaves strongly crisped when dry, patent when moist, narrowly lanceolate or from oblonglanceolate basal part narrowed to linear-lanceolate upper part, acute; margins plane below, involute above or plane throughout; costa excurrent, 35–50 μm wide near base, adaxial cells quadrate or elongate in upper half of leaf; basal cells rectangular, hyaline, cells above ± quadrate, papillose, obscure, 10–12 μm wide in mid-leaf. Setae yellowish, 1.5–7.0 mm long; capsules ovoid to ellipsoid, symmetrical, brown at maturity, contracted at mouth, epiphragm present but rupturing at maturity to release spores; exothecial cells not fragile; peristome lacking; spores 20–34 μm. Capsules common, winter, spring. Circumpolar Southern-temperate. Leaves narrowly lanceolate, basal part not wider than upper part margins plane var. brachycarpa Leaves linear-lanceolate from oblong-lanceolate basal part, margins involute above var. obliqua Var. brachycarpa ¨ Hal. W. microstoma var. brachycarpa (Nees & Hornsch.) Mull.

(Fig. 81)

Leaves narrowly lanceolate, not narrowed above basal part, margins plane throughout. Capsules ovoid to ellipsoid; spores 24–34 μm. On damp acidic soil in arable fields, on banks and woodland rides. Lowland. Rare in England, very rare in Scotland, extending north to Caithness, Fermanagh. 29, H1. GB44 + 6∗ , IR1. Europe, western N. America. Var. obliqua (Nees & Hornsch.) M. O. Hill, J. Bryol., 1981 ¨ Hal. var. microstoma W. microstoma (Hedw.) Mull.

(Fig. 81)

Leaves narrowly lanceolate from oblong-lanceolate basal part; margins plane below, involute above. Capsules ovate-ellipsoid or ellipsoid; spores 20–28 μm. n = 13∗ , 26. On banks and bare soil in turf in chalk and limestone grassland, occasionally on soil among rocks in lowland habitats and in ravines in montane habitats, calcicole. 0–420 m. Common in chalk and limestone areas in S. England, rare to occasional elsewhere, extending north to Shetland, rare in Ireland. 97,

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Fig. 81 1–5, Weissia brachycarpa var. obliqua: 1, stem and perichaetial leaves (×40); 2, mid-leaf cells (×420); 3, capsule; 4, capsule mouth (×40); 5, exothecial cells (×280). 6, W. brachycarpa var. brachycarpa: leaf (×40). 7–9, W. squarrosa: 7, leaf (×40); 8, capsule; 9, exothecial cells (×280). 10–13, W. rostellata: 10, plant (×10); 11, stem and perichaetial leaves (×20); 12, marginal cells at middle of leaf (×20); 13, capsule. 14–17, W. ×mittenii: 14, plant (×10); 15, stem and perichaetial leaves (×20); 16, mid-leaf cells (×420); 17, capsule. Capsules ×20.

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H17, C. GB346 + 84∗ , IR21 + 9∗ , C1 + 1∗ . Europe north to southern Scandinavia, Caucasus, Turkey, Cyprus, Asia, Azores, Algeria, Tunisia, N. America. Var. brachycarpa grows in moister habitats than var. obliqua and is not a calcicole, but the status of var. obliqua as a variety is questionable and it is not recognised by recent continental European authors.

¨ Hal., Syn. Musc. Frond., 1849 6 W. squarrosa (Nees & Hornsch.) Mull. Hymenostomum squarrosum Nees & Hornsch.

(Fig. 81)

Lax dull green patches, to c. 10 mm high, becoming decumbent at maturity of capsules and producing distant-leafed innovations from below perichaetia. Leaves somewhat crisped when dry, spreading to recurved when moist; margins of lower leaves plane, of upper leaves narrowly incurved above; costa excurrent, cells on adaxial side elongate in upper half of leaf; basal cells rectangular, hyaline, cells above ± quadrate, papillose, obscure, 10–12 μm wide in mid-leaf. Setae yellowish; capsules ellipsoid, dark greenish brown at maturity, epiphragm present, exothecial cells thin-walled, capsule walls rupturing at maturity to release spores; lids falling at maturity but epiphragm not rupturing; peristome absent; spores 22–28 μm. Capsules frequent, spring. Damp acid ground in fields, by ditches and ponds. Lowland. Rare and seen recently only in southern England but formerly extending north to Westmorland and Fife. 23. GB10 + 39∗ . Suboceanic Temperate. Rare in Europe, extending from Yugoslavia north to Scandinavia, Israel. Distinguished from W. brachycarpa by the frequently decumbent shoots with distant-leaved innovations and the thin-walled exothecial cells of the capsules rupturing to release the spores. The decrease in frequency of W. squarrosa may be due to changed agricultural practices. This species is considered endangered in the Red List of British mosses.

Section 3 Astomum (Hampe) Nyholm, Ill. Flora Nordic Mosses I, 1989 Capsules as long as or longer than setae, globose to ovoid, immersed or shortly exserted, usually cleistocarpous. For an account of the species of subgenus Astomum see A. C. Crundwell & E. Nyholm, J. Bryol. 7, 7–19, 1972.

¨ 7 W. rostellata (Brid.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1864 (Fig. 81) Astomum rostellatum (Brid.) Bruch & Schimp., Hymenostomum rostellatum (Brid.) Schimp. Ephemeral plants forming lax patches, c. 5 mm high. Leaves increasing in size up stems. Perichaetial leaves similar to upper stem leaves, crisped when dry, erectpatent when moist, 1.9–3.2 mm long, linear-lanceolate, acuminate; margins plane or occasionally narrowly incurved above, entire or in innermost perichaetial leaves

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minutely denticulate near base; costa excurrent to 75–150 μm, c. 50 μm wide near base, adaxial cells smooth, elongate; basal cells rectangular, hyaline, 30–70 μm long, cells above quadrate, pellucid, c. 10 μm wide in mid-leaf. Setae yellowishgreen, 0.7–1.5 mm long; capsules ovoid with oblique beak, cleistocarpous; spores (18−)22–27 μm. Capsules common, autumn. On moist gravel and mud by reservoirs, ditches and rivers, in hollows in grassland and on woodland rides. Lowland. Rare but widely distributed from N. Devon and E. Kent north to S. Northumberland and Midlothian, Anglesey, Leitrim, E. Mayo, Antrim, Cavan. 22, H4. GB31 + 9∗ , IR3 + 2∗ . European Temperate. Rare in Europe, extending north to S. Scandinavia, probably endemic to Europe. W. × mittenii (Bruch & Schimp.) Mitt. emend. A. J. E. Sm., J. Bryol. in press (Fig. 81) Astomum mittenii Bruch & Schimp., W. mittenii (Bruch & Schimp.) Mitt. Plants to 15 mm high. Lower leaves crisped when dry, spreading when moist, of ± uniform size up stems, only a few transitional to larger perichaetial leaves. Perichaetial leaves erect, 3–4 mm long, narrowly lanceolate; margins plane or occasionally very narrowly incurved above, entire; costa excurrent 50–140 μm, adaxial cells smooth, elongate; basal cells rectangular, hyaline, to 50 μm long cells above ± quadrate, pellucid, c. 10 μm wide in mid-leaf. Setae 1.0–1.7 mm long; capsules ± ovoid with long or short acute or blunt beak, but often malformed, cleistocarpous; spores very variable in size, (13−)18–20(−40) μm, often aborted. Capsules spring. On bare soil on clay banks, woodland rides and in arable fields. Lowland. Very rare, recorded from 5 localities in Sussex and Surrey but not seen since 1920. 3. GB5∗ . Endemic First found by William Mitten at two sites in Sussex in 1846 growing with W. multicapsularis, and was last found by W. E. Nicholson in 1920. The sporophyte resembles that of W. rostellata and the gametophyte that of W. multicapsularis, except that the adaxial cells of the costa are elongate. In view of the variable size of the spores and the capsules sometimes being malformed this plant is almost certainly of hybrid origin. It is possible that the gametophytes are derived from spores from the F1 hybrid between W. rostellata (from which the elongate adaxial cells of the costa may be derived) and W. multicapsularis (from which the habit of the plant is possibly derived). This would mean that the sporophytes of W. × mittenii are F2 hybrids. However, the situation is not clear as F1 hybrid capsules have never been found in mixed populations of the putative parents and W. × mittenii has only been found with W. multicapsularis.

8 W. multicapsularis (Sm.) Mitt., Ann. Mag. Nat. Hist., 1851 Astomum multicapsularis (Sm.) Bruch & Schimp.

(Fig. 82)

Plants ephemeral, forming lax dull green patches, to 15 mm high. Stems mostly unbranched. Leaves somewhat crisped when dry, stem leaves spreading when moist, of ± uniform size up stems except for a few transitional to the longer ± erect perichaetial leaves. Perichaetial leaves, 3.5–4.5 mm long, narrowly lanceolate;

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Fig. 82 1–5, Weissia multicapsularis: 1, plant; 2, stem and perichaetial leaves; 3, cells near base of perichaetial leaf; 4, marginal cells at middle of leaf; 5, capsule. 6–10, W. sterilis: 6, plant; 7, stem and perichaetial leaves; 8, marginal cells at middle of leaf; 9, cells near base of perichaetial leaf; 10, capsule. 11–15, W. levieri: 11, plant; 12, stem and perichaetial leaves; 13, marginal cells at middle of leaf; 14, cells near base of perichaetial leaf; 15, capsule. Plants ×10, leaves and capsules ×20, cells ×420.

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margins plane or occasionally very narrowly incurved above, ± entire; costa excurrent to 50–80 μm, c. 60 μm wide near base, adaxial cells in upper half of leaf papillose, quadrate; basal cells rectangular, hyaline, 40–120 μm long, cells above irregularly quadrate, papillose, pellucid, 9–10 μm wide in mid-leaf. Sporophytes rarely more than one per perichaetium; setae 0.5–0.8 mm long; capsules ovoid with ± conical beak, cleistocarpous, 0.70–0.85 mm long; spores 16–21 μm, finely papillose. Capsules occasional, spring. On damp acidic clay soil in turf, fields and on woodland rides. Lowland. Rare, Cornwall, S. Devon, Sussex, W. Kent, Oxford, Monmouth, Cheshire. 9. GB13 + 8∗ . Oceanic Temperate. France. Differs from other cleistocarpous Weissia species in the abrupt transition from short spreading stem leaves to long erect perichaetial leaves. It seems a curious misnaming that this plant, which usually only produces one sporophyte per perichaetium, should be called W. multicapsularis whilst W. sterilis usually produces more than one sporophyte per perichaetium. This species is considered endangered in the Red List of British mosses and is also listed as endangered in the Red Data Book of European Bryophytes.

9 W. sterilis W. E. Nicholson, J. Bot. Lond., 1903 ¨ Astomum crispum var. sterilis (W. E. Nicholson) Monk.

(Fig. 82)

Small groups or lax patches of plants, to 15 mm high. Stems often with clustered branches, each bearing two or more sporophytes per perichaetium. Leaves strongly crisped when dry, patent to spreading when moist, gradually increasing in size up stems with upper stem leave similar in length to perichaetial leaves. Perichaetial leaves 3.0–3.7 mm long, narrowly lanceolate; margins erect or narrowly incurved above, inner perichaetial leaves with a few small teeth near base; costa excurrent to 80–90 μm, 30–40 μm wide near base, adaxial cells smooth, quadrate; basal cells rectangular, hyaline, 30–70 μm long, cells above ± quadrate, papillose, pellucid, c. 10 μm wide in mid-leaf. Frequently 2 or more sporophytes per perichaetium; setae c. 4 mm long; capsules globose or ovoid with rostrate beak, cleistocarpous, c. 0.7 mm long; spores finely papillose, 18–20 μm. Capsules common, winter. On calcareous soil in south-facing chalk and limestone grassland. Lowland. Rare to occasional in southern England from S. Devon east to Kent, and north to Worcester and Cambridge, Montgomery. 19. GB26 + 13∗ . Oceanic Temperate. N. W. France. Distinct from the other cleistocarpous Weissia species in the clustered short branches at the tops of stems often with 2 or more capsules per perichaetium. It differs from W. longifolia in being taller with shorter perichaetial leaves with usually plane margins and from W. multicapsularis in the stem leaves grading in length to the perichaetial leaves.

10 W. levieri (Limpr.) Kindb., Eur. N. Amer. Bryin., 1897 Astomum levieri Limpr.

(Fig. 82)

Ephemeral plants forming compact dull green tufts, to 10 mm high; stems rarely branched. Leaves gradually increasing in size up stems, uppermost leaves not markedly distinct from perichaetial leaves. Perichaetial leaves strongly curled

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when dry, erect to erect-patent when moist, 3.0–4.5 mm long, 0.6–0.8 mm wide, narrowly lanceolate, acuminate; margins plane or occasionally slightly incurved above, often slightly denticulate near base of inner perichaetial leaves; costa excurrent to 130 μm, 50–80 μm wide near base, adaxial cells papillose, quadrate in upper part; basal cells rectangular, thin-walled, hyaline, 40–90 μm long, cells above quadrate, papillose, pellucid, c. 9 μm wide in mid-leaf. Usually only one sporophyte per perichaetium; setae 0.3–0.6 mm long; capsules ovoid, dehiscent, c. 0.7 × 0.9 mm long; beak 50–200 μm long; spores finely papillose, 18–22(−24) μm. Capsules common, late winter, early spring. In limestone grassland on soil and among rocks. Lowland. Very rare, W. Somerset, Glamorgan. 2. GB3. Mediterranean-Atlantic. Europe from Spain and Portugal east to Yugoslavia and north to France, Ukraine, Crimea, Algeria. Very similar in appearance to W. longifolia but readily distinguished by the capsules dehiscing in nature. For the occurrence of this plant in Britain see E. F. Warburg, Trans. Brit. Bryol. Soc. 3, 713–14, 1960. This species is considered endangered in the Red List of British mosses.

11 W. longifolia Mitt., Ann. Mag. Nat. Hist., 1851 Ephemeral plants in dull green, loose or compact patches, to 10 mm high. Leaves strongly curled when dry, erect-patent when moist. Perichaetial leaves 2.5– 6.0 mm long, narrowly lanceolate to linear-lanceolate; margins plane or incurved above; costa excurrent 30–100 μm, to 50(−80) μm wide near base, adaxial cells smooth and elongate or papillose and quadrate; basal cells irregularly rhomboidal, hyaline, cells above ± quadrate, papillose, opaque, 9–10 μm wide in mid-leaf. Setae 0.30–0.85 mm long; capsules ovoid, beaked, indehiscent in nature, 0.5– 1.2 mm long; spores coarsely papillose, 17–23 μm. Capsules common, winter, spring. Perichaetial leaves 3–6 mm long; margins plane or narrowly incurved above, capsules indehiscent, exothecial cells pale var. longifolia Perichaetial leaves 2.5–3.7 mm long; margins involute above, capsules dehiscing under pressure, exothecial cells yellowish var. angustifolia Var. longifolia (Fig. 83) W. crispa (Hedw.) Mitt., W. crispa var. aciculata (Hedw.) Dixon, Astomum crispum (Hedw.) Hampe Perichaetial leaves longer than stem leaves, conspicuous, 3–6 mm long, up to 0.9 mm wide, from broad ± colourless basal part linear-lanceolate, acuminate; margins plane or narrowly incurved above; margins of inner perichaetial leaves often denticulate near base; costa excurrent to 30 μm, adaxial cells quadrate or elongate; basal cells thin-walled, hyaline. Setae 0.3–0.6 mm long; capsules ovoid, indehiscent, 0.7–1.0 mm long, beak 80–140(−210) μm long; exothecial cells pale; calyptrae 0.5–0.7 mm long. n = 13, 13 + m. On non-calcareous loam and sandy soil in turf, on paths and in gardens. Lowland. Occasional to frequent in chalk

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Fig. 83 1–5, Weissia longifolia var. longifolia: 1, plant (×10); 2, stem and perichaetial leaves (×20); 3, cells near base of perichaetial leaf; 4, mid-leaf cells; 5, capsule (×29). 6–7, W. longifolia var. angustifolia: 6, perichaetial leaf (×20); 7, cells near base of perichaetial leaf. 8–11, Tortella inflexa: 8, plant (×10); 9, leaves (×40); 10, basal cells; 11, mid-leaf cells. Cells ×420.

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grassland north of London, very rare elsewhere, extending from Cornwall east to Kent and north to Durham and Berwick. 36. GB66 + 13∗ European Temperate. Europe north to Fennoscandia, Caucasus, Turkey, Asia, Canary Islands, N. Africa. Var. angustifolia (Baumgartner) Crundw. & Nyholm, J. Bryol., 1972 W. crispa auct. angl.

(Fig. 83)

Leaves increasing in size up stems so that perichaetial leaves are not noticeably larger than upper stem leaves. Perichaetial leaves 2.5–3.7 mm long, to 0.8 mm wide, expanded basal part of leaf yellowish; margins strongly incurved above, usually entire towards base in inner perichaetial leaves; costa excurrent to 50–100 μm, adaxial cells papillose, quadrate; basal cells incrassate, mostly yellowish. Setae 0.75–0.84 mm long; capsules indehiscent in nature but lid coming off under pressure on a slide; exothecial cells deep yellow; beak 200–350 μm long; calyptrae 0.75–1.20 mm long. On calcareous soil in chalk and limestone grassland, banks, paths and among limestone rocks. Occasional to frequent in chalk and limestone areas of southern and eastern England, rare elsewhere, extending north to S. Northumberland, rare in Ireland. 47, H7. GB119 + 53∗ , IR2 + 7∗ . European Temperate. Belgium, France, Portugal, Yugoslavia. The two varieties are distinct ecologically and in the incurvature of the perichaetial leaf margins, but intergrade to a considerable extent in Continental Europe. They differ from other cleistocarpous species of Weissia with short setae in their relatively small size, usually being less than 10 mm high.

43 TORTELLA LIMPR., LAUBM. DEUTSCHL., 1888 Dioicous. Stems usually without central strand, weak sclerodermis and hyalodermis present. Leaves crisped and curled when dry, erect to recurved when moist, usually fragile, lanceolate to linear-lanceolate, acute to obtuse and mucronate; margins plane or incurved above; costa ending in apex or excurrent, in section with two stereid bands, adaxial side 2–6(−10) cells wide, cells quadrate to elongate; basal cells hyaline and often ascending up margins, transition to chlorophyllous cells usually abrupt, upper cells hexagonal, papillose, opaque or pellucid. Perichaetial leaves ± similar to stem leaves. Capsules erect, ellipsoid or cylindrical, straight or slightly curved, peristome teeth filiform, usually spirally coiled; calyptrae cucullate. A ± world-wide genus of about 50 mainly calcicole species. Derivation: diminutive of twisted, referring to the twisted peristomes.

1 Leaves straight or curved but not twisted or crisped when dry, cells in upper part of leaf 6–8 μm wide, 2–3-stratose forming with costa long trigonous very fragile setaceous acumen 3. T. fragilis Leaves usually crisped, strongly twisted, curled or incurved when dry, cells unistratose throughout, apex various but never setaceous 2

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2 Leaves tightly incurved and imbricate with costae conspicuous and glossy when dry, upper part nearly always lost 4. T. nitida Leaves not tightly incurved nor costae conspicuously glossy when dry, most leaves usually intact 3 3 Lamina cells continuous over adaxial side of costa at least in middle part of leaves 4 Lamina cells not continuous over adaxial side of costa 6 4 Leaves strongly curled and crisped when dry, flexuose and undulate when moist, longly tapering to acuminate apex 1. T. tortuosa Leaves not as above 5 5 Costa excurrent, transition from basal to upper chlorophyllous cells abrupt, plants on soil or sand 8. T. flavovirens Costa ending in or below apex, transition from basal to chlorophyllous cells not abrupt, plants saxicolous 5. T. inflexa 6 Leaves gradually tapering to acuminate apex 2. T. densa Leaves shortly or abruptly tapered to acute or subobtuse apex 7 7 Leaves patent to spreading when moist, upper cells strongly papillose, opaque, 8–10 μm wide 6. T. inclinata Leaves reflexed from ± erect base when moist, upper cells obscurely papillose, ± pellucid, 8–12 μm wide 7. T. limosella 1 T. tortuosa (Hedw.) Limpr., Laubm. Deutschl., 1888 Trichostomum tortuosum (Hedw.) Dixon

(Fig. 84)

Yellowish to green, sometimes large cushions, tufts or patches, 1–8 cm high. Leaves strongly curled and contorted when dry, spreading, flexuose when moist, linear, gradually tapering from hyaline basal part to long acuminate apex, rarely narrowly lanceolate and more abruptly tapering, lamina sometimes torn or broken; margins plane, undulate, papillose-crenulate, denticulate or not near apex; costa excurrent, adaxial cells in middle part of leaf quadrate-hexagonal; basal cells narrowly rectangular to linear, hyaline, extending up margins, transition to chlorophyllous cells abrupt, cells above quadrate-hexagonal, papillose, unistratose throughout, 8–10 μm wide in upper part of leaf. Setae yellowish red; capsules cylindrical, straight to curved; peristome teeth long, filiform, spirally curved; spores 20–26 μm. Capsules rare, summer. n = 13. On rocks, in rock crevices, soil in turf, in flushes, where the substrate has at least some trace of base. 0–1200 m. Rare in lowland England, frequent or common elsewhere, common in western Ireland, occasional elsewhere. 100, H37, C. GB798 + 75∗ , IR27 + 8∗ , C1. Circumpolar Boreo-temperate. Europe north to Svalbard, Turkey, Cyprus, Caucasus, N. and E. Asia, Madeira, Canary Islands, Algeria, Morocco, N. America, Greenland, Peru, Tierra del Fuego. The linear, longly tapering leaves, curled and contorted when dry, usually readily distinguish T. tortuosa from other species. Short-leaved forms may be confused with T. densa, T. inclinata or T. flavovirens. The two latter have the leaves less contorted when dry and in the

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Fig. 84 1–4, Tortella tortuosa: 1, leaves; 2, leaf base (×40); 3, adaxial side of costa at middle of leaf; 4, capsule (×15). 5–7, T. nitida: 5, 6, young and old leaves; 7, mid-leaf cells. 8–11, Tortella fragilis: 8, very young leaf; 9, older broken leaf; 10, leaf base (×30); 11, mid-leaf cells. Leaves ×15, cells ×420.

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former they are scarcely undulate when moist. In T. densa and T. inclinata the cells on the adaxial side of the costa are elongate. In the short-leaved forms of T. tortuosa, which occur particularly in Ireland and have also been mistaken for T. fragilis, the cells of the lamina are only partially continuous over the adaxial side of the costa. Such plants may be worthy of varietal recognition. T. fragilis differs in the 2–3-stratose and fragile upper part of the leaf.

2 T. densa (Lorentz & Molendo) Crundw. & Nyholm, Trans. Brit. Bryol. Soc., 1962 (Fig. 85) T. tortuosa fo curta Albertson Dull green patches or tufts, to 4 cm high; stems not tomentose. Lower leaves straight or slightly curved, upper ± erect and curled when dry, erect-patent, hardly flexuose when moist, narrowly lanceolate to linear-lanceolate, gradually tapering to acuminate apex; margins papillose-crenulate, hardly undulate; costa ending in apex or shortly excurrent, adaxial cells elongate; basal cells narrowly rectangular to linear, hyaline, ascending up margins, transition to chlorophyllous cells abrupt, cells above hexagonal, papillose, opaque, cells in upper part of leaf 7–10 μm wide. Sporophytes unknown. n = 14. On exposed shallow soil, in limestone crevices and grassy flushes, strongly calcicole. 0–580 m. Occasional in the Pennines, very rare elsewhere, from E. Gloucester and Caernarfon north to Skye and W. Sutherland, Clare, Mayo, Sligo, Fermanagh. 12, H5. GB16 + 3∗ , IR4. Suboceanic Temperate. Central and western Europe north to Norway, Turkey, Caucasus. 3 T. fragilis (Hook. & Wilson) Limpr., Laubm. Deutschl., 1888 ¨ Hal. Trichostomum fragile (Hook. & Wilson) Mull.

(Fig. 84)

Yellowish green to green patches, 0.5–2.5 cm high. Leaves rigid, lower ± straight, upper curved when dry, erect-patent, not or scarcely flexuose or undulate when moist, narrowly linear-lanceolate, tapering from hyaline basal part to long setaceous apex, usually broken off except in young leaves; margins plane or inflexed above, papillose-crenulate; costa glossy on abaxial side when dry, extending to apex and forming with 2–3-stratose upper lamina cells a long fragile setaceous apex, cells on adaxial side hexagonal; basal cells linear, hyaline, extending up margins, transition to chlorophyllous cells abrupt, cells above ± hexagonal, papillose, opaque, 6–10 μm wide, in upper part of leaf 2–3-stratose and hardly distinguishable from costa, 6–10 μm wide. Sporophytes unknown in the British Isles. On basic montane rock ledges and in calcareous dune-slacks. 0–1060 m. Very rare, Fife, Mid Perth, Angus, Banff, Sutherland, Caithness, Fermanagh. 7, H1. GB7 + 2∗ , IR1. Circumpolar Boreo-arctic Montane. The Netherlands and montane and northern Europe north to Svalbard, Faeroes, Iceland, Turkey, Caucasus, Asia, Tenerife, Sahara, South Africa, N. America, Tierra del Fuego, Antarctica, New Zealand, Hawaii. The fragile leaf apices appear to provide a means of vegetative propagation. When dry the rigid and curved rather than strongly crisped or incurved leaves will distinguish this plant

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Fig. 85 1–4, Tortella flavovirens: 1, leaves (×25): 2, capsule (×10); 3, adaxial side of costa at middle of leaf: 4, 5, mid-leaf cells. 6–7, T. inclinata: 6, leaf (×25); 7, adaxial side of costa at middle of leaf. 8–9, T. densa: 8, leaf (×25); 9, adaxial side of costa at middle of leaf. 10–12, T. limosella: 10, leaves (×40); 11, mid-leaf cells; 12, adaxial side of costa at middle of leaf. Cells ×420.

43 Tortella

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from T. tortuosa, some forms of which may have fragile leaf apices and with which it has been confused. The setaceous leaf apices if present are also distinctive.

4 T. nitida (Lindb.) Broth., Nat. Pflanzenfam., 1902 Trichostomum nitidum (Lindb.) Schimp.

(Fig. 84)

Light green to yellowish green tufts, 0.5–1.0 cm high. Leaves tightly incurved when dry, erect-patent to spreading, slightly undulate when moist, very fragile, upper part of leaf usually missing, linear-lanceolate, acute to acuminate; margins plane, papillose-crenulate; costa excurrent in short mucro, whitish and shining on abaxial side when dry, adaxial cells quadrate; basal cells rectangular, ascending up margins, transition to chlorophyllous cells not very abrupt, cells above quadrate to hexagonal, papillose, opaque, 6–10 μm wide in upper part of leaf. Sporophytes unknown in the British Isles. On exposed basic rocks and wall tops, especially limestone. Lowland. Occasional in S. W. England and Wales, very rare elsewhere, W. Sussex, Hereford, north to Derby, Stirling and Rum, occasional in W. Ireland, Jersey. 40, H15, C. GB124 + 40∗ , IR36 + 5∗ , C1. Mediterranean-Atlantic. Europe north to the British Isles, Turkey, Cyprus, Macaronesia, N. Africa. Recognisable when dry by the neat rounded tufts and the tightly incurved fragile leaves with conspicuous glossy costae. Has been confused with T. tortuosa and T. flavovirens but differs from these in the characters just mentioned and in the leaves having the transition from the hyaline basal cells to chlorophyllous cells not as abrupt.

5 T. inflexa (Bruch) Broth., Nat. Pflanzenfam., 1902 (Fig. 83) Small bright green patches, 2–6 mm high. Leaves strongly curled when dry, erect to spreading when moist, linear-lanceolate to linear, apex ± acute, often subcucullate; margins often inflexed at least above, papillose-crenulate; costa ending below apex, adaxial cells quadrate-hexagonal at middle of leaf; basal cells narrowly rectangular, hyaline, ascending up margins, transition to chlorophyllous cells gradual, cells above quadrate-hexagonal, papillose, opaque, cells in upper part of leaf 8–10 μm wide. Setae 5 mm long; capsules narrowly ellipsoid, only seen once in England. On chalk or oolitic limestone stones in grassland, on banks and in woodland. Lowland. Rare to occasional from Dorset east to Kent and north to Hereford and Bedford, S. E. Yorkshire. 21. GB68. Mediterranean-Atlantic. France, Portugal, Sardinia, Minorca, Malta, Crete, Israel, N. Africa. Although not recognised in Britain until 1957 this species is probably native but is apparently spreading in southern England. As fertile material with immature capsules has only been found once in England it probably spreads by vegetative means, pairs of deciduous leaves falling away from the stem apex. For an account of this plant in Britain see E. C. Wallace, J. Bryol. 7, 153–6, 1972.

6 T. inclinata (R. Hedw.) Limpr., Laubm. Deutschl., 1888 Trichostomum inclinatum (R. Hedw.) Dixon

(Fig. 85)

Yellowish green patches, c. 1 cm high; stems without central strand, tomentose below. Leaves curled inwards, not or scarcely crisped when dry, patent to spreading,

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slightly undulate when moist, linear-lanceolate, shortly or abruptly tapering to slightly cucullate acute or subobtuse apex; margins plane, papillose-crenulate; costa excurrent, adaxial cells elongate; basal cells narrowly rectangular to linear, hyaline, extending up margins, transition to chlorophyllous cells abrupt, cells above rounded-hexagonal, papillose, opaque, 8–10 μm wide in upper part of leaf. Small terminal propaguliferous shoots sometimes present. Capsules ellipsoid, straight or slightly curved; peristome teeth filiform, spirally coiled, fugacious; spores 10–16 μm. n = 7. Capsules very rare, summer. On shallow soil on limestone, chalk banks and calcareous sand-dunes. 0–500 m. Rare, widely distributed from Surrey, N. Norfolk and E. Gloucester north to Caithness, W. Mayo, Down. 26, H2. GB26 + 7∗ , IR3. Circumpolar Temperate. Europe north to Fennoscandia, Turkey, Caucasus, N. Asia, Azores, Algeria, southern Africa, N. America, Australia. 7 T. limosella (Stirt.) P. W. Richards & E. C. Wallace, Trans. Brit. Bryol. Soc., 1950 (Fig. 85) T. flavovirens ssp. limosella (Stirt.) Podp., Trichostomum limosellum (Stirt.) Dixon Dense patches, 4–8 mm high. Upper leaves longer than lower, loosely curled, hardly crisped when dry, reflexed from erect basal part when moist, lanceolatelingulate, acute to subobtuse and apiculate; margins plane, crenulate-serrulate with scattered irregular poorly defined teeth; costa excurrent, adaxial cells at middle of leaf elongate; basal cells hyaline, ascending up margins, sharply differentiated from chlorophyllous cells, cells above thick-walled, quadrate-hexagonal, weakly papillose, hardly opaque, 8–12 μm wide in upper part of leaf. Gametangia and sporophytes unknown. Seashore west of Arisaig, W. Inverness, 1906, not seen since. 1. GB1∗ . Endemic (Oceanic Boreo-temperate). Dixon & Jameson (1924) suggest this plant is closely related to T. flavovirens but the elongate adaxial cells of the costa indicate that its relationship is with T. inclinata, but it differs from that species in the reflexed leaves and larger obscurely papillose cells. The precise status of T. limosella is obscure, but having examined the type specimen there are no grounds for regarding it as a subspecies or variety of any other Tortella species. Listed as extinct in both the Red List of British mosses and the Red Data Book of European Bryophytes.

8 T. flavovirens (Bruch) Broth., Nat. Pflanzenfam., 1902 (Fig. 85) T. flavovirens var. glareicola (A. Chr.) Crundw, & Nyholm, Trichostomum flavovirens Bruch Yellowish green to brownish green tufts or patches, to 1.5 cm high; stems often with central strand, not tomentose below. Leaves crisped when dry, lower small, erect-patent, upper larger, spreading when moist, narrowly lanceolate to linear-lanceolate, shortly or abruptly tapering to acute or subobtuse, mucronate, frequently cucullate apex; margins plane below, usually erect or incurved above, papillose-crenulate; costa excurrent, adaxial cells in middle part of leaf hexagonal;

44 Trichostomum

285

basal cells narrowly rectangular to linear, hyaline, ascending up margins, transition to chlorophyllous cells abrupt, upper cells hexagonal, papillose, hardly opaque, 8–14 μm wide in mid-leaf. Setae purplish-red; capsules narrowly ellipsoid; peristome teeth filiform, straight, fugacious; spores 12–14 μm. Capsules very rare. In calcareous dune-slacks, on sandy soil, on banks and in rock crevices, almost exclusively in maritime situations, sometimes within the spray zone. Lowland. Rare along the east and north coasts, frequent or common along the south and west coasts. 61, H17, C. GB221 + 26∗ , IR26 + 3∗ . Submediterranean-Subatlantic. Mediterranean and Atlantic coasts of Europe, Turkey, Cyprus, China, Japan, Macaronesia, N. Africa, western N. America. Var. glareicola, a plant with leaf cells 10–14 μm wide, distinguished from the type with cells 8–10 μm wide, has been recognised in Britain. However, in Cornwall the two varieties intergrade completely (Dr D. T. Holyoak, pers. commun.) so I have not maintained the variety. T. flavovirens occurs in a variety of coastal habitats but never inland, whereas T. inclinata, which also occurs inland, is only found on calcareous sand-dunes when near the coast. The two species cannot be separated in the field but the shape of the cells on the adaxial side of the costa will readily separate the two microscopically.

¨ 44 TRICHOSTOMUM BRUCH IN F. MULL., FLORA, 1829 Usually dioicous. Plants forming tufts or patches. Stems with or without central strand. Leaves linear-lanceolate to lanceolate or lingulate, acute or obtuse; margins plane or recurved, papillose-crenulate; costa ending below apex or excurrent, adaxial cells quadrate, in section with two stereid bands; basal cells ± rectangular, hyaline or yellowish, cells above ± hexagonal, papillose, opaque. Setae long; capsules erect, ellipsoid or cylindrical; lid rostrate; peristome teeth short, straight or spirally coiled, divided, perforated or entire; calyptrae cucullate. Laminal KOH reaction yellowish orange to orange. A ± world-wide genus of 130 species. Derivation: meaning hair + mouth, referring to the peristome teeth. The genus Trichostomum even as recognised by Zander (1993) is a heterogeneous collection of species. The situation is improved somewhat if the two species, T. recurvifolium and T. caespitosum, placed in Trichostomum by Zander (1993) are moved to Paraleptodontium and Pottiopsis respectively.

1 Leaf apices usually cucullate 2. T. crispulum Leaf apices plane 2 2 Costa excurrent in stout mucro 1. T. brachydontium Costa ending below apex or if slightly excurrent then not forming a mucro 3 3 Basal part of leaf hardly expanded; margins often sinuose or toothed above, mid-leaf cells ± quadrate 3. T. tenuirostre Leaf bases expanded; margins not sinuose or toothed, mid-leaf cells often shortly rectangular 4. T. hibernicum

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Fig. 86 1–4: Trichostomum brachydontium: 1, leaves; 2, leaf apex (×100); 3, mid-leaf cells; 4, capsule. 5–8, T. crispulum: 5, leaves; 6, leaf apex (×100); 7, mid-leaf cells; 8, capsule. Leaves ×25, cells ×420, capsules ×15.

¨ 1 T. brachydontium Bruch in F. Mull., Flora, 1829 T. mutabile Bruch

(Fig. 86)

Yellowish green to dark green patches or tufts, sometimes reddish below, (0.5−)1.0–4.0 cm high. Leaves crisped and incurved when dry, patent to recurved

44 Trichostomum

287

when moist, lingulate to narrowly lingulate-lanceolate or linear-lanceolate, obtuse to acute, rarely acuminate; margins plane or narrowly recurved, finely crenulate above, sometimes denticulate near base; costa strong, usually excurrent in stout mucro, rarely in a cuspidate point; basal cells irregularly rectangular to narrowly rectangular, hyaline or yellowish, cells above irregularly hexagonal, papillose, opaque, 6–8 μm wide in mid-leaf. Setae yellow; capsules ellipsoid to narrowly ellipsoid; peristome teeth short, very fragile; spores 14–18 μm. Capsules rare, spring. In basic or acidic habitats by the coast, in basic habitats elsewhere, on soil in turf, on banks, cliffs, sand-dunes, in rock and wall crevices, in shaded or exposed situations. 0–700 m. Rare in lowland England and eastern Scotland, frequent or common elsewhere, common in western Ireland. 96, H27, C. GB777 + 65∗ , IR115 + 13∗ , C10 + 1∗ . Submediterranean-Subatlantic. Europe north to Scandinavia, Faeroes, Iceland, Turkey, Cyprus, Caucasus, Siberia, China, Japan, Bali, Macaronesia, Africa, C. and S. America, Juan Fernandez, New Zealand. A very variable species for which two varieties have been recorded from the British Isles, var. littorale (Mitt.) C. E. O. Jensen and var. cophocarpum (Schimp.) P. Cout., but both intergrade with the type to such an extent that they cannot be maintained. Whilst T. brachydontium tends to have a western distribution in the British isles it is sometimes the only moss species found in very dry sites in soil and rock crevices in the Mediterranean region and Macaronesia.

¨ 2 T. crispulum Bruch in F. Mull., Flora, 1829 (Fig. 86) Dense yellowish green to dark green tufts or patches, sometimes blackish below, 0.5–4.0(−8.0) cm high. Leaves crisped when dry, erect-patent to patent or slightly recurved when moist, lingulate to lanceolate or narrowly lanceolate, tapering to acute to obtuse, apiculate, usually cucullate apex; margins in upper part usually erect or incurved, finely crenulate above; costa ending below apex to excurrent; hyaline basal cells variable in extent up leaf, narrowly rectangular and incrassate towards costa, shorter, wider and thinner-walled towards margins, cells above quadrate-hexagonal, papillose, opaque, 6–8(−10) μm wide in mid-leaf. Setae reddish; capsules narrowly cylindrical; spores 16–18 μm. Capsules rare or occasional, spring. n = 12, 13. In shady or exposed basic habitats, on soil, rocks, rocky banks, cliff ledges, mortar of old walls, sand-dunes and in chalk grassland. 0–1175 m. Generally distributed, frequent or common in basic areas, rare elsewhere, extending north to Shetland. 101, H39, C. GB601 + 53∗ , IR121 + 10∗ , C1 + 2∗ . Circumpolar Southern-temperate. Europe north to Svalbard, Turkey, Cyprus, Caucasus, Asia Minor, Siberia, E. Asia, New Guinea, Macaronesia, N. and C. Africa, Newfoundland, New Mexico. An exceedingly variable species usually easily recognised by the cucullate leaf apices. Four varieties of T. crispulum have been recognised in the British isles: var. brevifolium (Schimp.) ¨ Hal.) Bruch & Schimp., var. elatum Schimp., var. nigroviride (Braithw.) Dixon and var. Mull. viridulum (Bruch) Dixon. These varieties are based on habit, colour, leaf shape and size, form of leaf apex and cell size – all of which may be environmentally influenced. They are of

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doubtful status and not recognised here as equally distinctive but undescribed plants occur and some of the distinctive varietal characters may be found in otherwise typical plants. It seems likely that the plants are subject to environment and genetic variation not amenable to taxonomic treatment. Forms with plane apices may be separated from T. tenuirostre by the margins not undulate or sinuose. T. brachydontium usually has wider leaves with more longly excurrent costa.

¨ 3 T. tenuirostre (Hook. & Taylor) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1884 ¨ Hal. Oxystegus tenuirostis (Hook. & Taylor) A. J. E. Sm., T. cylindricum (Brid.) Mull. Lax tufts or patches, to 7 cm high. Leaves distant or crowded, often varying in size along stems, loosely incurved or curled when dry, erect-patent to spreading, sometimes secund, often undulate when moist, 3–7 mm long, from ± erect but not expanded basal part linear-lanceolate, apex acute to subobtuse; margins plane, finely crenulate, often sinuose, notched or obscurely toothed above or with 2–3 teeth near apex; costa ending below apex to slightly excurrent; cells in basal part inflated, thin-walled, hyaline, irregularly rectangular, cells above quadrate, papillose or not, opaque, 7–10 μm wide in mid-leaf, 1–2 marginal rows sometimes more incrassate and distinct. Setae yellowish, flexuose; capsules cylindrical; peristome teeth short, straight, porose; spores 16–18 μm. Capsules very rare, late spring, early summer. Leaves not crowded, spreading, mid-leaf cells 8–10 μm wide Leaves crowded, erect-patent, mid-leaf cells 7–8 μm wide

var. tenuirostre var. holtii

Var. tenuirostre (Fig. 87) Plants yellowish green above, darker or blackish below. Leaves not crowded, spreading, linear-lanceolate; cells papillose, 8–10 μm wide in mid-leaf. On usually acidic rocks and in rock crevices by streams, springs, waterfalls, upland pools and lakes, rarely on tree trunks, in woodland at low altitudes, in sheltered or exposed habitats at higher altitudes. 0–610 m. Frequent or common in the west from Cornwall to W. Sutherland, rare elsewhere, rare to occasional in Ireland. 66, H21. GB408 + 34∗ , IR71 + 7∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Turkey, Caucasus, Algeria, Morocco. Var. holtii (Braithw.) Dixon, Stud. Handb. Br. Mosses, 1896 (Fig. 87) Plants greenish. Leaves crowded, ± erect-patent, linear-lanceolate; cells somewhat papillose to almost smooth, 7–8 μm wide in mid-leaf. On damp shaded rocks. Rare, western Britain from N. W. Wales, Derby and Westmorland north to Argyll and Skye, old records from Kerry. 13, H2. Germany, Norway. The status of var. holtii is open to question as the characters attributed to it may occur independently in the type. T. tenuirostre has sometimes been confused with T. hibernicum but the latter is distinct in the leaves not or scarcely undulate, sharply reflexed from an expanded base, the margins not notched or toothed and the cells often shortly rectangular.

44 Trichostomum

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Fig. 87 1–4, Trichostomum tenuirostre var. tenuirostre: 1, leaf (×15); 2, leaf base (×70); 3, leaf apex (×70); 4, mid-leaf cells (×420). 5, T. tenuirostre var. holtii: mid-leaf cells (×420). 6–9, T. hibernicum: 6, leaves (×15); 7, leaf base (×70); 8, leaf apex (×100); 9, mid-leaf cells (×420). 10–14, Pottiopsis caespitosa: 10, plant (×10); 11, perichaetial bract (×40); 12, stem leaf (×40); 13, cells from upper part of leaf (×430); 14, capsule mouth (×450).

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R. H. Zander (Lindbergia 4, 285–8, 1978) describes as var. gemmiparum (Schimp.) R. H. Zander a form of this species with gemmae borne on rhizoids arising from the adaxial surface of the leaves. The gemmae are red-brown to brown, clavate, simple or branched, multicellular and 150–250(−800) × 70–90(−140) μm. The plant, which is rare, is reported from montane habitats in E. France, Switzerland and elsewhere in the Northern Hemisphere and could possibly occur in the British isles.

4 T. hibernicum (Mitt.) Dixon, Stud. Handb. Br. Mosses, 1896 Oxystegus hibernicus (Mitt.) Hilp.

(Fig. 87)

Yellowish green tufts or scattered plants, 1–10 cm high. Leaves not crowded, crisped and incurved when dry, spreading, flexuose, usually not undulate when moist, from expanded basal part narrowly linear-lanceolate, tapering to acute apex; margins plane, finely crenulate, not notched or toothed; costa ending in apex or slightly excurrent; cells in basal part inflated, irregularly rectangular, hyaline, cells above shortly rectangular to irregularly quadrate, papillose, 8–10 μm wide in mid-leaf. Capsules cylindrical, very rare. Among rocks and in crevices by streams and waterfalls, on damp sheltered cliff ledges. 0–800 m. Rare in western Scotland from Arran north to Ross, Skye the Outer Hebrides and W. Sutherland, Kerry, E. Cork, W. Galway, W. Mayo, W. Donegal. 16, H6. GB34 + 6∗ , IR14 + 6∗ . Hyperoceanic Temperate. Doubtfully recorded from Czechoslovakia and Turkey. Distinctive in the expanded leaf bases, the margins not sinuose or toothed, and the midleaf cells often shortly rectangular.

45 POTTIOPSIS BLOCKEEL & A. J. E. SM., J. BRYOL., 1998 A monotypic genus with the characters of the species. Derivation: meaning with the appearance of a Pottia.

1 P. caespitosa (Bruch ex Brid.) Blockeel & A. J. E. Sm., J. Bryol., 1998 (Fig. 87) ¨ Hal., Trichostomum caespitosum (Bruch ex Pottia caespitosa (Bruch ex Brid.) Mull. Brid.) Jur. Autoicous. Gregarious or scattered ephemeral plants. Stems with central strand. Leaves broadly lanceolate, 2–3 times as long as wide, acute; margins plane, entire; costa excurrent 25–75 μm, adaxially 2 cells wide, cells quadrate, in section with well developed abaxial stereid band, poorly developed adaxial band; cells irregularly rounded-quadrate, verrucose, 7–11 μm wide in upper part of leaf. Perichaetial leaves distinctly broader than stem leaves, sheathing, concave. Setae yellow, 1.7–3.0 mm long; capsules ovoid, 0.9–1.0 × 0.55–0.70 mm with one row of thick-walled cells at the constricted mouth; lid rostrate; annulus present; peristome teeth 25–110 μm long, imperfect, usually cleft; calyptrae smooth, cucullate;

46 Pleurochaete

291

spores minutely papillose, 15–19 μm. Capsules common, December to April. Laminal KOH reaction yellow to orange. On patches of soil in chalk grassland, on sand-dunes and limestone banks. Lowland. Rare in southern England, extending north to Hereford and Cambridge. 17. GB19 + 10∗ . European Temperate. C. and S. Europe. The above description is an augmentation of that of Pottia caespitosa prepared by Dr D. F. Chamberlain in the first edition of this book, but for reasons given below this species is now placed in its own genus. It differs from Pottia and species of Tortula section Pottia in the larger sheathing perichaetial leaves, smaller spores and incrassate leaf cells. It differs from both in the perichaetial leaves being larger than the stem leaves. It differs from Trichostomum in its ephemeral habit, in being autoicous and in producing abundant capsules.

¨ ¨ 46 PLEUROCHAETE LINDB., OFVERS FORH. KONGL. SVENSKA VETENSK-AKAD., 1864 Dioicous. Stems with small central strand. Leaves crisped when dry, squarrose from erect sheathing basal portion when moist, acute; margins toothed above; costa percurrent or excurrent; basal cells rectangular, coloured except for marginal band of hyaline cells, cells above hexagonal, papillose. Perichaetia on very short lateral branches. Setae lateral, long; capsules erect, cylindrical, curved; peristome with basal membrane, 32 filiform papillose slightly twisted teeth; calyptrae cucullate. Laminal KOH colour reaction deep yellow to orange. A small genus of 4 species distributed through Europe, Asia, N. and C. Africa, America. Derivation: meaning side hair, from the lateral position of the setae.

¨ 1 P. squarrosa (Brid.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1864 (Fig. 88) Lax yellowish green tufts, 1–7 cm high. Upper leaves crisped when dry, squarrose from ± erect sheathing base when moist, lanceolate to linear-lanceolate, acuminate; margins plane, denticulate below, crenulate and irregularly toothed above; costa percurrent or very shortly excurrent; smooth on abaxial side; basal cells rectangular or narrowly rectangular, incrassate, coloured, 3–4 marginal rows hyaline, with thinner walls, ascending up margins and forming hyaline band in lower part of leaf, upper cells ± quadrate, papillose, opaque, 8–10 μm wide in mid-leaf. Capsules unknown in the British Isles. On dry ground on sand-dunes, in chalk and limestone grassland and on cliff tops, especially near the sea. 0–300 m. Occasional but sometimes locally abundant in coastal areas, from Cornwall north to Westmorland and east to E. Kent, rare inland, Clare, Wicklow, Dublin, Meath. 34, H4, C. GB73 + 33∗ , IR4 + 2∗ , C7 + 2∗ . Submediterranean-Subatlantic. S. and W. Europe north to Gotland, Turkey, Cyprus, Caucasus, Iran, Himalayas, China, Macaronesia, N. Africa, Kenya, Arizona, C. America.

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47 PARALEPTODONTIUM D. G. LONG, J. BRYOL., 1982 A monotypic genus with the characters of the species. Derivation: meaning close to Leptodontium.

1 P. recurvifolium (Taylor) D. G. Long, J. Bryol., 1982 (Fig. 88) Bryoerythrophyllum recurvifolium (Taylor) R. H. Zander, Leptodontium recurvifolium (Taylor) Lindb., Trichostomum recurvifolium (Taylor) R. H. Zander Lax green or yellowish green tufts, 3–10 cm high; stems without central strand. Leaves strongly crisped when dry, patent to squarrose from erect base, ± undulate when moist, fragile, ovate to lanceolate, apex acute to obtuse and apiculate; margins plane, coarsely serrate above, serrulate below; costa ending in apex to shortly excurrent, with large papillae and isodiametric cells on adaxial side; basal cells rectangular to shortly rectangular, cells above quadrate to hexagonal, papillose, opaque, thin-walled to incrassate, 12–16 μm wide in mid-leaf, 1–2 marginal rows elongate, more incrassate, smooth, pellucid, forming narrow border. Only female plants known. On damp base-rich cliffs, rock ledges, banks and rock crevices, often near waterfalls. 100–720 m. Rare in Merioneth, Caernarfon, Westmorland, Cumberland, occasional in the western Scottish Highlands from Stirling to Sutherland, Outer Hebrides, Kerry, W. Cork. W. Galway, W. Mayo, W. Donegal. 17, H6. GB37 + 7∗ , IR11 + 3∗ . Oceanic Boreal-montane. Nepal, British Columbia, Alaska. Variously placed in Leptodontium, Bryoerythrophyllum or Trichostomum. D. G. Long (J. Bryol. 12, 179–84, 1982) presents excellent grounds for placing this species in a genus of its own.

Subfamily 2 MERCEYOIDEAE Stem sclerodermis usually differentiated from central cylinder. Leaves lanceolate, frequently with differentiated basal part; costa mostly with two stereid bands, adaxial side often grooved, mostly 2(−4) cells wide. Clavate gemmae sometimes present.

Tribe 1 Bryoerythrophylleae Plants often large. Leaf margins recurved or revolute, sometimes denticulate or dentate above, costa 2(−4) cells wide on adaxial side, in section with two stereid bands, abaxial band often reniform.

48 DIALYTRICHIA (SCHIMP.) LIMPR., LAUBM. DEUTSCHL., 1888 A monotypic genus with the characters of the species. Derivation: meaning separate hairs, referring to the peristome teeth.

48 Dialytrichia

293

Fig. 88 1–4, Dialytrichia mucronata: 1, leaves (×15); 2, mid-leaf cells; 3, section through margin at middle of leaf; 4, sporophyte (×7). 5–7, Pleurochaete squarrosa: 5, leaves (×17.5); 6, marginal cells at middle of leaf; 7, marginal cells towards leaf base. 8–9, Paraleptodontium recurvifolium: 8, leaves (×30); 9, marginal cells in upper part of leaf. Cells ×420.

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1 D. mucronata (Brid.) Broth., Nat. Pflanzenfam., 1902 Cinclidotus mucronatus (Brid.) Molendo, C. brebissonii (Brid.) Husnot

(Fig. 88)

Dioicous. Dull green or dark green tufts, often embedded in alluvial detritus, 0.5–3.0(−5.0) cm high. Stems sparsely branched, central strand strong, sclerodermis weak, hyalodermis lacking. Axillary hairs 6–15 cells long, basal 1–4 yellowish. Leaves flexuose or curled when dry, erect-patent to spreading when moist, oblong-lanceolate to lingulate, obtuse and mucronate; margins recurved, thickened, papillose-crenulate above; costa stout, excurrent in mucro, adaxially 2–4 cells wide, cells elongate, in section with two stereid bands; basal cells narrowly rectangular, cells above irregularly quadrate-hexagonal, papillose with bifid papillae, opaque, 8–12 μm wide in mid-leaf, marginal band of cells 2–4-stratose forming a thick border. Perichaetial leaves sheathing. Setae 8–10 mm long; capsules erect, ellipsoid to cylindrical; lid longly rostrate; peristome teeth 32, filiform, papillose, weakly spirally coiled; calyptrae cucullate; spores finely papillose, 14–16 μm. Capsules occasional, spring. Laminal KOH reaction yellow or yellowish orange. On tree roots and boles or less commonly on rocks and walls above and below flood zone of streams and rivers, but also occasionally away from water. Lowland. Occasional to frequent in southern England except the south-west, very rare elsewhere in England and Wales, extending north to Durham and formerly Roxburgh. 47. GB152 + 42∗ . Mediterranean-Atlantic. Mediterranean and western Europe, extending north to Austria, Germany and the Netherlands, Asia, Algeria, Tunisia. Distinguished from all other members of the family by the thickened margins of the leaves. In this respect it resembles species of Cinclidotus but differs in leaves with recurved margins and papillose leaf cells. Cinclidotus fontinaloides has immersed capsules.

49 PSEUDOCROSSIDIUM R. S. Williams, BULL. TORREY BOT. CL., 1915 Dioicous. Plants forming cushions or turfs. Stems with central strand, sclerodermis usually differentiated, hyalodermis weak or absent. Axillary hairs of 3–8 usually hyaline cells. Leaves appressed, often spirally curved when dry, erect-patent to patent when moist, ovate to ligulate or lanceolate; margins revolute; costa excurrent, adaxial side 2–5 cells wide, cells quadrate, papillose, sometimes with photosynthetic filaments, in section adaxial stereid band small or absent, abaxial band strong; basal cells rectangular, cells above quadrate or hexagonal, usually densely papillose. Perichaetial leaves usually much larger than stem leaves. Capsules ellipsoid to cylindrical, straight or curved; peristome of 32 filiform spirally coiled segments; calyptrae cucullate. Laminal KOH reaction yellow to orange. A mainly montane genus of 16 species distributed through Europe, Middle East, Africa, N. and S. America, Australasia. Derivation: meaning resembling Crossidium (tassel-like, referring to the filaments on the costa).

49 Pseudocrossidium

295

Leaves acuminate, incurved and spirally twisted when dry, mid-leaf cells 10–14 μm wide 1. P. hornschuchianum Leaves obtuse and apiculate, tightly incurved when dry, cells 8–10 μm wide 2. P. revolutum 1 P. hornschuchianum (Schultz) R. H. Zander, Phytologia, 1979 Barbula hornschuchiana Schultz

(Fig. 89)

Green patches or scattered plants, 3–15 mm high. Leaves incurved, spirally twisted when dry, erect-patent when moist, giving shoots a stellate appearance when viewed from above, lanceolate, tapering from near base to acuminate apex; margins revolute ± from base to apex and often reaching costa in upper part of leaf; costa stout, excurrent in acuminate point, adaxial cells ± quadrate; basal cells rectangular, cells above quadrate-hexagonal, incrassate, papillose; pellucid, 10–14(−16) μm wide in mid-leaf. Perichaetial leaves larger than stem leaves, tapering to filiform apex. Setae orange-red; capsules narrowly ellipsoid; lid longly obliquely rostrate; peristome teeth long, filiform, spirally coiled; spores 8–10 μm. Capsules rare, winter, spring. n = 12, 13, 14. On calcareous soil on paths, in chalk and limestone grassland, old quarries, on sandy and gravelly ground, sand-dunes, in open situations. 0–330 m. Frequent or common on basic terrain in England and Wales, occasional in Scotland and Ireland. 109, H26, C. GB660 + 77∗ , IR40 + 9∗ , C3. Eurosiberian Southern-temperate. Europe north to southern Scandinavia, Asia Minor, Macaronesia, N. Africa, probably introduced in Massachusetts, British Columbia and Australia. Differs from P. revolutum in the leaves tapering ± from base to acuminate apex, twisted and less tightly incurved when dry and with larger cells. May be recognised in the field by the stellate appearance of moist shoots when viewed from above.

2 P. revolutum (Brid.) R. H. Zander, Phytologia, 1979 Barbula revoluta Brid.

(Fig. 89)

Dense dark green tufts or cushions, 3–15 mm high. Leaves tightly incurved when dry, giving plants a neat appearance, erect-patent when moist, narrowly lingulate to narrowly lanceolate, obtuse and apiculate; margins revolute ± from base to apex and reaching costa in upper part of leaf; costa stout and often widened above, usually excurrent in a mucro, adaxial cells ± quadrate; cells incrassate, basal rectangular, cells above quadrate with rounded lumens, papillose, opaque, 8–10 μm wide in mid-leaf. Setae flexuose, orange-red; capsules narrowly ellipsoid; lid longly obliquely rostrate; peristome teeth filiform, spirally coiled, fragile; spores 10–14 μm. Capsules rare to occasional, spring. In crevices in limestone and base-rich rocks, in old quarries, on walls and old buildings. 0– 500 m. Common in base-rich areas, elsewhere mainly in man-made habitats, in

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16 Pottiaceae

Fig. 89 1–5, Pseudocrossidium hornschuchianum: 1, leaves (×40); 2, leaf apex (×100); 3, basal cells; 4, mid-leaf cells; 5, capsule (×15). 6–10, P. revolutum: 6, leaves (×40); 7, leaf apex (×100); 8, basal cells; 9, mid-leaf cells; 10, capsule (×15). 11–13, Bryoerythrophyllum caledonicum: 11, leaves (×40); 12; basal cells; 13, marginal cells towards leaf apex. Cells ×420.

50 Bryoerythrophyllum

297

exposed situations. 107, H37, C. GB590 + 106∗ , IR125 + 4∗ , C3. SubmediterraneanSubatlantic. Europe north to southern Scandinavia, Iran, Madeira, Canary Islands, N. Africa. Brown rhizoidal gemmae of irregular size and shape, 300–600 × 100–400 μm, have been reported from Belgium (T. Arts, Lindbergia 14, 59–62, 1988) but have not been detected in British material. There is also a report of leaf gemmae.

50 BRYOERYTHROPHYLLUM P. C. CHEN, HEDWIGIA, 1941 Usually dioicous. Plants usually green above, reddish or brown below; stems with central strand. Axillary hairs with 0–3 brownish cells at base. Leaves ovate to lanceolate; margins recurved below, papillose-crenulate, toothed or not above, often with a border of 3–4 rows of thick-walled cells; costa ending below apex to excurrent, adaxial cells quadrate, papillose, abaxial cells elongate, papillose; basal cells rectangular, hyaline, cells above quadrate to shortly rectangular, incrassate, strongly papillose, opaque. Perichaetial leaves sheathing, larger than stem leaves. Capsules ellipsoid to cylindrical; peristome lacking to well developed, with 16 entire or deeply bifid straight to spirally coiled teeth. Laminal KOH reaction orange-red to red. Twenty-seven species world-wide. Derivation: meaning red-leaved moss.

1 Leaves toothed in upper 1/3 –1/2, (1−)2–3(−4) rows marginal cells in upper half of leaf incrassate, smooth, forming distinct border 3. B. caledonicum Leaves entire or with a few teeth near apex, unbordered 2 2 Plants green above, reddish brown below, leaves strongly curled when dry, linear-lanceolate, often toothed near apex 1. B. recurvirostrum Plants reddish brown throughout, leaves ± erect when dry, ovate-lanceolate, entire 2. B. ferruginascens 1 B. recurvirostrum (Hedw.) P. C. Chen, Hedwigia, 1941 Barbula recurvirostra (Hedw.) Dixon, B. rubella (Huebener) Mitt.

(Fig. 90)

Paroicous or synoicous. Tufts or patches, green above, rusty red or reddish brown below, to 5 cm high; stems not tomentose. Leaves flexuose to curved when dry, patent to spreading when moist, lanceolate to narrowly lanceolate, tapering from expanded basal part to acute apex; margins strongly recurved, papillose-crenulate, often irregularly and bluntly toothed towards apex; costa strong, ending below apex to percurrent, adaxial cells shortly rectangular, abaxial cells papillose in upper half of leaf; basal cells narrowly rectangular, hyaline, cells above quadrate to quadrate-hexagonal, papillose, opaque, c. 10 μm wide in mid-leaf. Setae deep red; capsules ellipsoid to cylindrical; lid narrowly conical, oblique; peristome teeth filiform, straight, short, c. 250 μm long; spores 14–20 μm Capsules frequent to

298

16 Pottiaceae

Fig. 90 Bryoerythrophyllum recurvirostrum: 1, leaves (×25); 2, leaf apex; 3, basal cells; 4, mid-leaf cells; 5, capsule (×15). 6–10, B. ferruginascens: 6, leaves (×40); 7, basal cells; 8, mid-leaf cells; 9, leaf apex; 10, rhizoidal gemma (×175). Cells ×420, apices ×100.

50 Bryoerythrophyllum

299

common, autumn to spring. n = 12 + m∗ , 13∗ , 13 + m. In sheltered, basic situations on thin soil, rocks, in crevices, on stream banks, old buildings, walls, in quarries, on tree boles in flood zone of streams and rivers. 0–1180 m. Very common. 112, H36, C. GB1306 + 109∗ , IR176 + 4∗ , C3. Circumpolar Boreo-temperate. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Turkey, Cyprus, Caucasus, Asia, N., C. and southern Africa, N. and C. America, Greenland, Tasmania, Hawaii. A variable species usually readily recognised by the reddish-brown older parts, the leaf margins toothed near the apex and the narrow hyaline basal cells. B. ferruginascens differs in the reddish brown colour of the whole plant, the slender tomentose stems and the presence of rhizoidal gemmae. Reddish brown rhizoidal gemmae, 25–30 μm diameter, have been reported by K. Saito (J. Hattori Bot. Lab. 60, 373–537, 1975) from Japanese specimens of B. recurvirostrum, but they have not been found in European plants.

2 B. ferruginascens (Stirt.) Giacom., Atti Ist. Bot. Univ. Pavia (ser. 5), 1957 (Fig. 90) Barbula ferruginascens Stirt., Barbula rubella var. ruberrima Fergusson, Barbula ¨ botelligera Monk. Sex unknown. Bright reddish brown tufts, patches or scattered plants, to 5 cm high; stems slender, tomentose. Leaves erect, slightly incurved when dry, patent to spreading from ± erect basal part when moist, lanceolate, tapering to ± acute apex; margins strongly recurved below, papillose-crenulate above, not toothed; costa stout, ending in apex, adaxial cells shortly rectangular, papillose, abaxial side papillose in upper part of leaf; cells incrassate, basal narrowly rectangular, hyaline, cells above irregularly quadrate, strongly papillose, opaque, 8–10(−12) μm wide in mid-leaf. Elongate reddish brown rhizoidal gemmae, 200–400 × 115–140 μm, usually present. Gametangia and sporophytes unknown. On base-rich soil and rock on cliffs and in ravines, in rock crevices on stream banks and sides of tracks. 0–1075 m. S. Devon, Hereford, Radnor, occasional to frequent in montane habitats in Wales, N. England and the Scottish Highlands, occasional in Ireland. 51, H13. GB153 + 9∗ , IR20 + 4∗ . Eurosiberian Boreal-montane. Montane and northern Europe, Faeroes, Iceland, Siberia, Japan(?), New Guinea, N. America, Greenland, Mexico. 3 B. caledonicum D. G. Long, J. Bryol., 1982 (Fig. 89) Sex unknown. Reddish-tinged lax tufts or patches, 1–3(−4) cm high. Leaves erect, appressed with curled tips when dry, erect-patent when moist, ovate-oblong, acute to rounded and weakly mucronate, shallowly keeled or not above; margins usually narrowly recurved below, weakly to coarsely toothed in upper 1/3 –1/2; costa reddish, ending below apex to shortly excurrent, adaxial cells ± quadrate, papillose, abaxial cells densely papillose in upper part of leaf; basal cells narrowly rectangular, hyaline, decreasing in width from costa to margins, cells above rounded-quadrate, densely papillose, opaque, 7–12 μm wide in mid-leaf, (1−)2–3(−4) rows marginal

300

16 Pottiaceae

cells smooth, incrassate, forming distinct border in upper half of leaf. Propagules, gametangia and sporophytes unknown. n = 13∗ . On permanently moist soil on sloping calcareous rock on ledges and by streams. 380–1060 m. Rare but locally frequent to abundant, Mid Perth, W. Inverness, Argyll, Rum, Skye. 4. GB12. Endemic (Oceanic Boreal-montane). Of similar colour to B. ferruginascens but differing in the broader, serrate, bordered leaves. This plant was referred to as a curious form of Leptodontium flexifolium in Dixon & Jameson (1924) but has recently been described as a new species. For a detailed account see D. G. Long, J. Bryol. 12, 141–57, 1982. R. H. Zander (Bryologist 89, 16–19, 1989) considers that this plant might be synonymous with B. andersoniana R. H. Zander & Sharp.

Tribe 2 Leptodontieae Stems lacking central strand.

¨ ¨ ¨ 51 LEPTODONTIUM (MULL. HAL.) HAMPE IN LINDB., OFVERS FORH. KONGL. SVENSKA VETENSK-AKAD., 1864 Dioicous. Plants forming tufts or short turfs; stems without central strand. Leaves flexuose or crisped when dry, patent to squarrose when moist, oblong-lanceolate, acute to obtuse; margins plane or recurved below, coarsely toothed above; costa ending below apex to excurrent, adaxial cells elongate; basal cells rectangular, cells above hexagonal, papillose or mamillose. Setae erect, flexuose; capsules ellipsoid to cylindrical; lid conical or rostrate; peristome without basal membrane, teeth 32, filiform, straight, smooth or finely papillose; annulus present; calyptrae cucullate. Laminal KOH reaction usually yellow. A world-wide genus of c. 40 species. Derivation: meaning slender tooth, referring to the peristome teeth. For an account of the two species described here see R. A. Rogeon & R. Schumacker, Bull. Soc. Bot. Centre Oest, NS 15, 81–102, 1984.

Leaf apices rounded to obtuse and apiculate, costa ending below apex in upper leaves, not gemmiferous 1. L. flexifolium Leaf apices acute, costa excurrent with clusters of gemmae at apex in upper leaves 2. L. gemmascens ¨ 1 L. flexifolium (Dicks.) Hampe in Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1864 (Fig. 91) Dull green to yellowish green or brownish green patches, 2–15 mm high. Leaves erect, flexuose when dry, soft, patent to spreading or recurved from erect base when moist, oblong-lanceolate to broadly lingulate or lingulate-spathulate, apex rounded or obtuse and apiculate; margins plane or recurved below, coarsely

51 Leptodontium

301

Fig. 91 1–3, Leptodontium flexifolium: 1, leaves (×30); 2, marginal cells from upper part of leaf; 3, capsule (×15). 4–6, L. gemmascens: 4, leaves (×30); 5, marginal cells from upper part of leaf; 6, gemmae (×250). 7–10, Hymenostylium recurvirostrum: 7, leaves (×40); 8, basal cells; 9, cells near leaf apex; 10, capsule (×20). 11–13, H. insigne: 11, leaves (×40); 12, basal cells; 13, cells near leaf apex. Cells ×420.

302

16 Pottiaceae

toothed above; costa stout, ending below apex, smooth on abaxial side; basal cells shortly rectangular to rectangular, cells above hexagonal, thin-walled to strongly incrassate, mamillose, opaque, 10–16(−20) μm wide in mid-leaf, a single marginal row pellucid. Deciduous bulbiform branches sometimes present; very rarely flaskshaped stem gemmae, composed of up to 15–16 cells, present. Setae flexuose, yellow; capsules narrowly ellipsoid to shortly cylindrical, straight or slightly curved; lid longly rostrate; peristome teeth straight, filiform; spores 12–14 μm. Capsules occasional, spring. On peaty soil, often on sites of fires, on heaths, moorland, woodland rides and soil on boulders. 0–750 m. Rare in lowland England and N. Scotland, occasional to frequent elsewhere, rare in Ireland. 84, H15. GB257 + 51∗ , IR14 + 4∗ . Oceanic Temperate. Belgium, Denmark, France, Germany, the Netherlands, Norway, Portugal, Spain, Nepal, Sikkim, Mongolia, China, Taiwan, Japan, Sumatra, Java, Lombok, New Guinea, Cameroon, Zaire, Kenya, N., C. and S. America. For an account of the gemmae of L. flexifolium see M. E. Newton & D. Boyce, J. Bryol. 14, 737–40, 1987.

2 L. gemmascens (Mitt.) Braithw., Brit. Moss Fl., 1887 (Fig. 91) Dull green tufts or patches, 2–10 mm high. Leaves erect, flexuose when dry, soft, spreading when moist, oblong-lanceolate to lanceolate, ± tapering to acute apex; margins plane or narrowly recurved below, coarsely toothed above; costa stout, excurrent with cluster of gemmae on excurrent portion in upper leaves; basal cells shortly rectangular, cells above hexagonal, thin-walled, papillose, opaque, 10–18 μm wide in mid-leaf, a single marginal row pellucid. Gemmae obovoid to shortly fusiform, 80–100 μm long, abundant on apices of upper leaves and in leaf axils. Gametangia and sporophytes unknown. On old thatch, bases of grass and Juncus tussocks on heaths, rarely on trees, ephemeral. Lowland. Rare and decreasing, scattered localities from S. Devon east to W. Kent and north to E. Gloucester, Hereford and Suffolk. 18. GB9 + 22∗ . Oceanic Temperate. Denmark, France, subantarctic Marion Is. This species is treated as vulnerable in the Red List of British Mosses.

52 HYMENOSTYLIUM BRID., BRYOL. UNIV., 1827 Dioicous. Plants forming tufts or cushions; stems often with reddish tomentum. Axillary hairs c. 8 cells long, 1–2 basal cells usually brownish. Leaves incurved or twisted when dry, spreading when moist, lingulate to linear-lanceolate; margins plane or recurved, entire; costa ending just below apex to excurrent, usually 3–4 cells wide on adaxial side, cells elongate; basal cells rectangular, cells above variable in shape, quadrate to rectangular, walls often porose, papillose, pellucid. Perichaetial leaves larger than stem leaves. Capsules ovoid, gymnostomous;

52 Hymenostylium

303

calyptrae cucullate. Laminal KOH reaction yellow. A world-wide genus of c. 18 mainly calcicole saxicolous species. Derivation: from the Greek words for membrane and pillar but it is not clear to what part of the moss this refers.

Leaves mostly 1.0–1.6 mm long, base not or only slightly expanded, costa 30–60 μm wide near base, longitudinal walls of basal cells non-porose 1. H. recurvirostrum Leaves mostly 1.6–2.4 mm long, base expanded, ± sheathing, costa (35−)60–100 μm wide near base, longitudinal walls of basal cells porose, 2. H. insigne 1 H. recurvirostrum (Hedw.) Dixon, Rev. Bryol. Lichénol., 1934 (Fig. 91) ¨ Hal. Gymnostomum recurvirostrum Hedw., Weissia curvirostris (Erhr.) Mull. Dense green or dull green tufts or cushions, (0.5−)1.0–10.0 cm high. Leaves erect, appressed or flexuose or occasionally slightly twisted when dry, erect-patent to patent when moist, mostly 1.0–1.6 mm long, lanceolate to linear-lanceolate, basal part not or only slightly expanded, apex acute to acuminate; margins recurved on one or both sides, entire or papillose-crenulate; costa ending below apex, 30– 60 μm wide near base; cells incrassate, basal rectangular to narrowly rectangular, often with oblique transverse walls thinner than non-porose longitudinal walls, cells above ± shortly rectangular, smooth to strongly papillose, towards apex rectangular to ± quadrate, pellucid, 8–12 μm wide. Capsules erect, ovoid, gymnostomous; lid longly obliquely rostrate, attached to columella and sometimes persisting; columella lengthening at maturity; peristome lacking; spores 18–20 μm. Capsules occasional, autumn. n =12 + m, 13∗ . On damp, basic rock faces, boulders, in crevices, on limestone pavement, old walls and heavy metal mine-waste. 0–1070 m. Cornwall, N. Somerset, rare in Wales, occasional to frequent from Derby north to Shetland, rare in Ireland. 55, H16. GB194 + 22∗ , IR16 + 5∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Iceland, Turkey, Madeira, Asia, Algeria, N. America, Greenland, Mexico, Peru. Var. cataractacum (Schimp.) Podp. appears to be a dustbin taxon in which aberrant forms of H. recurvirostrum are placed and cannot be maintained.

2 H. insigne (Dixon) Podp., Consp. Musc. Eur., 1954 (Fig. 91) Gymnostomum insigne (Dixon) A. J. E. Sm., G. recurvirostrum var. insigne (Dixon) P. W. Richards & E. C. Wallace, Weissia curvirostris var. insigne (Dixon) H. Schmidt Dark green to brownish green tufts or patches, 4–12 cm high. Leaves loosely incurved when dry, patent to spreading when moist, mostly 1.6–2.4 mm long, basal part erect, ± sheathing, limb gradually tapering to acuminate apex; margins recurved below, not papillose; costa ending in or below apex, (35−)60–100 μm

304

16 Pottiaceae

wide near base; cells incrassate, basal rectangular to narrowly rectangular, transverse walls ± oblique, thinner than often porose longitudinal walls, cells above irregularly rhomboidal to ± quadrate, smooth, pellucid, 8–12 μm wide towards apex. Capsules ellipsoid, very rare. Calcareous montane rock ledges and humid lowland ravines. 0–680 m. Rare, western Scotland from Mid Perth north to W. Sutherland, Sligo, Leitrim. 8, H2. GB14 + 5∗ , IR4. Oceanic Boreal-montane. Spain, British Columbia, Peru. Although treated by some recent authors (e.g. Zander, 1993) as a variety of the previous species, this plant is distinct, differing from H. recurvirostrum in the leaves loosely incurved when dry, more widely spreading when moist, with expanded sheathing basal part, the often porose basal cell walls and the non-papillose upper cells.

Tribe 3 Barbuleae Stems with central strand or if absent then costa in section with only one stereid band.

¨ 53 ANOECTANGIUM SCHWAGR., SP. MUSC. FROND. SUPPL. 1, 1811 Dioicous. Plants tufted, stems tomentose, central strand present. Axillary hairs 3–10 cells long, all hyaline or basal 1–2 brownish. Leaves appressed when dry, erect-patent when moist, lingulate to lanceolate, channelled above; margins plane or narrowly recurved below, papillose-crenulate above; costa ending in or below apex, on adaxial side 2–3 cells wide, cells elongate, in section with one stereid band; basal cells rectangular, cells above rounded-quadrate, papillose, opaque. Perichaetia and perigonia on short lateral branches. Setae long; capsules ovoid to ellipsoid; gymnostomous; calyptrae cucullate. Laminal KOH reaction yellow to yellowish orange. A world-wide genus of about 40 species. Derivation: meaning open vessel, from the wide-mouthed capsules of some species.

1 A. aestivum (Hedw.) Mitt., J. Linn. Soc. Bot., 1869 ¨ A. compactum Schwagr.

(Fig. 92)

Dense soft tufts or cushions, bright green above, light brown below, 2–10 cm high; stems slender, often with well defined annual growth zones, tomentose below with reddish brown rhizoids. Leaves spirally curled when dry, patent when moist, keeled, ovate to lanceolate, acute; margins usually, plane papillose-crenulate; costa usually ending in or below apex, adaxial cells elongate; cells incrassate, basal rectangular, cells above rounded-hexagonal, papillose, opaque, 8–10 μm wide in mid-leaf, apical cell clearly defined, pellucid. Setae lateral, 7–10 mm long; capsules emerging 1–2 mm above leaves, ellipsoid, gymnostomous; lid with oblique subulate beak; spores 12–16 μm. Capsules rare, spring, summer. n = 13. On usually basic moist or sheltered rocks and in crevices on cliffs, in ravines, by waterfalls. 0–1180 m. Rare in S. Wales, frequent or common in N. Wales, N. W. England and

53 Anoectangium

305

Fig. 92 1–4, Anoectangium aestivum: 1, leaves; 2, mid-leaf cells; 3, leaf apex; 4, capsule. 5–11, Gyroweisia tenuis: 5, plant (×10); 6, 7, lower and upper leaves: 8, basal cells; 9, apical cells; 10, protonemal gemmae (×45); 11, capsule mouth (×40). 12–17, G. reflexa: 12, plant (×10); 13, 14, lower and upper leaves; 15, basal cells; 16, apical cells; 17, capsule mouth (×40). Leaves ×40, cells ×420.

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16 Pottiaceae

the Scottish Highlands, north to Caithness, very rare elsewhere, Stafford, Derby, rare to occasional in W. Ireland. 49, H17. GB278 + 15∗ , IR30 + 10∗ . European Boreal-montane. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Himalayas, Japan, Philippines, Canary Islands, Madeira, N. Africa, Cameroon, N., C. and S. America, Greenland. 54 GYROWEISIA SCHIMP., SYN. MUSC. EUR. (ED. 2), 1876 Dioicous. Plants very small, gregarious. Stems mostly simple, with or without central strand. Leaves appressed, incurved when dry, erect-patent to recurved when moist, linear-lanceolate to lingulate, apex usually obtuse or rounded; margins plane, papillose-crenulate; costa ending below apex, 2–4 cells wide on adaxial side, cells elongate, in section with adaxial stereid band weak or absent; basal cells rectangular, hyaline, cells above rounded-quadrate, incrassate, papillose or smooth. Setae straight; capsules erect, ovoid or ellipsoid; lid conical; peristome rudimentary or absent; annulus of 2–3 rows large cells; calyptrae cucullate. Six species distributed through Europe, Middle East, China, N. Africa, N. America. Derivation: from the well developed annulus circling the capsule mouth and the resemblance to Weissia.

Peristome absent, upper and perichaetial leaves patent to reflexed 1. G. tenuis Rudimentary peristome present, upper and perichaetial leaves strongly recurved to squarrose 2. G. reflexa 1 G. tenuis (Schrad. ex Hedw.) Schimp., Syn. Musc. Eur. (2nd edn.), 1876 (Fig. 92) ¨ Hal. Weissia tenuis (Schrad. ex Hedw.) Mull. Plants gregarious, 1.0–2.5 mm high, forming light green patches. Leaves erect to spreading, flexuose when dry, patent or spreading when moist, lower lingulate, apex rounded, upper longer, lingulate-lanceolate, apex rounded or obtuse; margins plane, papillose; costa ending below apex, 20–30 μm wide near base; basal cells narrowly rectangular, in lower leaves to 50 μm long, in upper to 90 μm long, cells above quadrate-rectangular, papillose, ± pellucid, towards apex irregularly quadrate, c. 8 μm wide. Perichaetial leaves patent to reflexed from sheathing base. Pale ovoid or irregular protonemal gemmae, 50–70 μm long, sometimes present. Setae yellowish, 3–5 mm long; capsules narrowly ellipsoid to subcylindrical, gymnostomous; lid obliquely rostrate; spores 8–10 μm. Capsules common in the north and west, rare in the south and east, summer, autumn. n = 13. On damp shaded often vertical chalk, limestone, sandstone, mortar, old brickwork, particularly by streams and pools, shade tolerant. 0–400 m. Occasional to frequent in England and S. E. Scotland, rare in Wales and much of Scotland, extending north to Shetland, occasional in Ireland. 98, H24. GB345 + 52∗ , IR25 + 11∗ . European

55 Gymnostomum

307

Temperate. Europe north to Scandinavia, Turkey, Syria, Iran, China, Tunisia, N. America. 2 G. reflexa (Brid.) Schimp., Syn. Musc. Eur. (ed. 2), 1876 Weissia reflexa Brid.

(Fig. 92)

Plants 1.5–2.0 mm high. Lower leaves erect-patent, upper and perichaetial leaves much larger, crowded, strongly recurved to squarrose when moist, lingulate, sometimes with expanded basal part, apex rounded to acuminate; margins plane, entire; costa ending below apex; basal cells rectangular, 2–4 times as long as wide, cells above shortly rectangular, incrassate, papillose, towards apex ± quadrate, 6–8 μm wide. Protonemal gemmae similar to those of G. tenuis often present. Perichaetial leaves with sheathing bases, acuminate. Setae flexuose, yellowish; capsules ovoid to ellipsoid, lid conical, oblique; 16 irregular rudimentary peristome teeth present, soon falling; spores 10–14 μm. Capsules common, winter. Found in a sandstone quarry in Nuneaton, Stafford in 1933 and last seen in 1938. The site is now a housing estate. 1. GB1∗ . Mediterranean region, Turkey, Madeira, N. Africa, N. America. Some forms of G. tenuis approach this plant but the upper leaves are less crowded and not strongly recurved or squarrose. For the occurrence of this plant in Britain see Rep. Brit. Bryol. Soc. 3(2), 118, 1933 under Weissia tenuis.

55 GYMNOSTOMUM NEES & HORNSCH. IN NEES ET AL., BRYOL. GERM., 1823 Dioicous. Plants forming lax or dense tufts. Leaves appressed, ± incurved when dry, erect-patent to spreading when moist, linear-lanceolate to lanceolate, acute to obtuse; margins plane or recurved, entire or papillose-crenulate; costa ending below apex, on adaxial side 2–4(−6) cells wide, cells usually quadrate or rectangular, in section with adaxial stereid band weak or lacking; basal cells rectangular, cells above quadrate to quadrate-hexagonal, papillose, opaque. Setae long, straight; capsules ovoid or ellipsoid, smooth; lid longly rostrate, oblique; annulus of one row of small persistent cells; peristome absent; calyptrae cucullate. Laminal KOH reaction yellow to yellowish orange. A ± world-wide genus of c. 25 species. Derivation: meaning naked mouth, referring to the absence of peristome teeth.

1 Costa 60–110 μm wide near leaf base, cells in upper part of leaf (8−)10–14 μm wide 3. G. aeruginosum Costa 30–45 μm wide near base, upper cells 5–10 μm wide 2 2 Leaves lingulate to ligulate, 3–7 times as long as wide, axillary gemmae lacking 1. G. calcareum Leaves ovate to ovate-lanceolate, 2–4 times as long as wide, axillary gemmae often present 2. G. viridulum

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1 G. calcareum Nees & Hornsch. in Nees et al., Bryol. Germ., 1823 ¨ Hal. Weissia calcarea (Nees & Hornsch.) Mull.

(Fig. 93)

Dense bright green turfs or cushions, 5–20 mm high. Leaves appressed, slightly twisted when dry, spreading to recurved when moist, lanceolate to ligulate, 0.5–1.0 × 0.1–0.2 mm, 5–7 times as long as wide, obtuse to subacute; margins plane, papillose-crenulate, costa reaching nearly to apex, 30–40 μm wide near base, in section circular near base, with very well developed abaxial stereid band, poorly developed adaxial band; basal cells near costa rectangular, smooth, lumens with rounded corners, c. 10 × 30 μm, cells above unistratose, strongly papillose, opaque, quadrate, incrassate, lumens rounded, 5–10 μm wide in upper part of leaf. Perichaetial leaves wider than stem leaves. Setae pale yellow; capsules ellipsoid to cylindrical, gymnostomous; lid obliquely rostrate; spores 8–12 μm. Capsules rare, spring, summer. n = 13. On damp sheltered calcareous rocks, rarely on mortar on walls. 0–550 m. Occasional in the Pennines and western Scottish Highlands, very rare elsewhere, in widely scattered localities from E. Cornwall and W. Sussex north to W. Sutherland, rare in Ireland. 28, H12. GB75 + 7∗ , IR17 + 3∗ . Eurosiberian Southern-temperate. Europe, extending north to Sweden and Finland, Turkey, Cyprus, Caucasus, Middle East, Himalayas, Tibet, China, Azores, Canary Islands, N. and southern Africa, N. America, S. Africa, Australasia. R. H. Zander (Bryologist 80, 233–69, 1977) treats G. calcareum as a synonym of G. aeruginosum, but the two differ in size, colour, leaf shape, cell size and the form of the costa. For a discussion of this see M. E. Newton, J. Bryol. 12, 343–9, 1983.

2 G. viridulum Brid., Bryol. Univ., 1826 ´ ´ ´ G. luisieri (Sergio) Sergio & Crundw., Gyroweisia luisieri Sergio

(Fig. 93)

Dense bright green turfs, 1.5–5.0 mm high. Leaves appressed when dry, spreading or recurved when moist, 0.3–0.7 × 0.15–0.30 mm, 2–4 times as long as wide, ovate to ovate-lanceolate, obtuse or occasionally subacute; margins plane, papillose-crenulate; costa 30–35 μm wide near base, ± reaching apex, in section circular towards base, with abaxial stereid band only; basal cells near costa c. 20 × 40 μm, smooth, cells above unistratose, rounded-quadrate, papillose, opaque, 5–10 μm wide in upper part of leaf. Ovoid multicellular axillary gemmae, 40–90 × 20–30 μm, frequently present; protonemal gemmae also sometimes present. Perichaetial leaves wider than stem leaves. Setae pale yellow; capsules ellipsoid. gymnostomous; lid obliquely rostrate; spores 10– 12 μm. Capsules very rare. In sheltered or exposed situations in limestone crevices, on limestone soil, limestone wall tops and crumbling mortar. Lowland. Rare, from S. Devon and S. Hampshire north to Caernarfon, S. W. and N. W. Yorkshire, Alderney. 16, H10, C. GB27 + 2∗ , IR11 + 1∗ , C1. Mediterranean-Atlantic. Mediterranean region, extending north to Czechoslovakia, Switzerland, Belgium,

55 Gymnostomum

Fig. 93 1–5, Gymnostomum calcareum: 1, plant (×25); 2, leaves (×75); 3, basal cells; 4, cells near leaf apex; 5, capsule (×20). 6–10. G. viridulum: 6, plant (×50); 7, leaves (×125); 8, basal cells; 9, leaf apex; 10, axillary gemma (×420). Cells ×420.

309

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W. France, Germany, Turkey, Caucasus, Middle East, N. W. India, W. Asia, N. and E. Africa. Only recently recognised as occurring in the British Isles, having in the past been confused with G. calcareum. It differs from that species in leaf shape, width of basal cells and frequent presence of gemmae. Small forms of G. aeruginosum may be distinguished from G. viridulum by the leaves distinctly crisped when dry, the wider costa with adaxial stereids in section and the larger upper cells. Leptobarbula berica differs from G. calcareum and G. viridulum in the more longly tapering leaves, and Gyroweisia tenuis may be distinguished by the larger basal cells and the presence of bottle-shaped protonemal gemmae. For a detailed account of G. calcareum and G. viridulum see H. L. K. Whitehouse & A. C. Crundwell, J. Bryol. 16, 561–79, 1991.

3 G. aeruginosum Sm., Fl. Brit., 1804 ¨ ¨ Hal. Weissia rupestris (Schwagr.) Mull.

(Fig. 94)

Tufts or cushions, dull green above, reddish brown below, 0.5–8.0 cm high. Leaves twisted when dry, erect-patent to patent when moist, variable in shape, linear, ligulate, linear-lanceolate or ovate-lanceolate, basal part sometimes expanded, apex acute to subobtuse; margins plane, sometimes obscurely toothed below, erect or incurved and papillose-crenulate above; costa ending below apex, stout, 60– 100 μm wide near base, in section 1.5–2.0 times as wide as thick, 3 cells thick towards apex, with adaxial and abaxial stereid bands; cells incrassate, basal rectangular or narrowly rectangular, cells above unistratose or bistratose, irregularly quadrate, papillose or strongly papillose, opaque, near apex (8−)10–14 μm wide. Perichaetial leaves larger than stem leaves, base sheathing. Setae 4–8 mm long; capsules ellipsoid; lid obliquely rostrate, gymnostomous; spores 8–14 μm. Capsules occasional, late summer, autumn. n = 13∗ . On damp or wet usually basic rocks, in flushes, moist crevices on cliffs, in ravines, on coastal cliffs, old walls. 0–1175 m. Absent from lowland England, rare in S. W. England, occasional to frequent elsewhere, occasional in Ireland. 75, H25. GB465 + 38∗ , IR54 + 11∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Turkey, Caucasus, China, Japan, New Guinea, Madeira, Canary Islands, N. and C. America, Peru. 56 MOLENDOA LINDB., UTKAST. EUR. BLADMOSS, 1878 Dioicous. Plants forming turfs. Stems with central strand. Leaves appressed, twisted, incurved when dry, spreading or spreading-recurved when moist, ovate to ligulate or linear-lanceolate, acute to rounded; margins plane or recurved below, entire or sinuose, sometimes denticulate at shoulders of basal part; costa ending below apex to excurrent, 2–7 cells wide on adaxial side, cells quadrate to elongate, in section with or without stereid bands; basal cells rectangular, cells above quadrate or rectangular, often bistratose at margins, papillose, papillae simple or multifid. Perichaetia on short lateral branches; perichaetial leaves sheathing. Capsules cylindrical; lid longly rostrate; peristome lacking; calyptrae

56 Molendoa

311

Fig. 94 1–6, Molendoa warburgii: 1, plant (×10); 2, leaves (×65); 3, mid-leaf cells; 4, leaf apex; 5, capsule (×25); 6, gemmae (×280). 7–10, Gymnostomum aeruginosum: 7, leaves (×40); 8, basal cells; 9, leaf apex; 10, capsule (×20). Cells ×420.

cucullate. Fifteen species distributed through all continents except Australasia and Antarctica. Derivation: named after the German bryologist Ludwig Molendo (1833–1902).

1 M. warburgii (Crundw. & M. O. Hill) R. H. Zander, Bull. Buffalo Soc. Nat. Sci., 1993 (Fig. 94) Anoectangium warburgii Crundw. & M. O. Hill Small to extensive yellowish green patches or scattered plants, to 1 cm high; stems often innovating from below; rhizoids deep reddish brown. Lower leaves minute, upper larger, appressed when dry, erect-patent to patent when moist, ovate to

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lanceolate, to 0.6 mm long, apices rounded; margins plane, papillose-crenulate; costa broad, ending below apex, lamina cells extending over costa in upper part of leaf; extreme basal cells shortly rectangular, cells elsewhere ± quadrate, gradually becoming smaller towards apex, obscure with papillae, cells in mid-leaf c. 8 μm wide. Green to brownish ± ovoid to fusiform several-celled gemmae, 80–110 μm long with thin cell walls, frequently present in axils of lower leaves. Setae lateral; capsules narrowly ovoid, gymnostomous; lid longly rostrate. Capsules rare, spring or early summer. On moist usually vertical rock by streams and waterfalls and in seepage areas on rock. 0–1070 m. Occasional in N. Wales, occasional to frequent in the western and central Scottish Highlands from Arran and Stirling north to Sutherland, W. Mayo. 23, H1. GB112 + 1∗ , IR1. Oceanic Boreal-montane. Endemic. Confused in the past with Gymnostomum calcareum which, however, occurs in drier and more exposed habitats, forms dense bright green tufts and has less strongly papillose leaves with more extensive and markedly longer basal cells. Anoectangium aestivum is larger but depauperate plants may be distinguished by the single translucent well defined apical cell of the leaves. For an account of this plant see A. C. Crundwell & M. O. Hill, J. Bryol., 9, 435–40, 1977.

57 BARBULA HEDW., SP. MUSC. FROND., 1801 Dioicous. Plants forming small tufts, cushions or short turfs. Stems with central strand. Axillary hairs 2–10 cells long, usually completely hyaline. Leaves often contorted or twisted when dry, spreading when moist, spathulate, lingulate, lanceolate or elongate-triangular, acute or obtuse; margins usually recurved, papillosecrenulate; costa percurrent or shortly excurrent, adaxial and abaxial cells usually elongate, in section with two stereid bands; basal cells rectangular, cells above ± quadrate, papillose, opaque. Perichaetial leaves differing from stem leaves or not. Capsules ovoid to cylindrical; peristome of 32 spirally coiled filiform segments. Laminal KOH reaction usually yellowish or yellowish orange. A cosmopolitan genus of c. 200 species. Derivation: from the Latin for beard, referring to the peristomes.

1 Setae yellowish, leaf margins narrowly recurved on one or both sides below, costa ending below apex, rarely shortly excurrent Setae dark red or purplish, leaf margins recurved almost to apex, costa excurrent 3. B. unguiculata 2 Plants mostly 2–5 mm high, yellowish green or bright green, leaf margins not undulate, cells strongly papillose, opaque 2. B. convoluta Plants mostly 5–10 mm high, dark green, leaf margins undulate, cells papillose, pellucid 3. B. sardoa 1 B. convoluta Hedw., Sp. Musc. Frond., 1801 (Fig. 95) Bright green or yellowish green tufts or patches, sometimes extensive, usually 2–25 mm high; stems tomentose below; central strand lacking Leaves strongly curled when dry, erect-patent to spreading or recurved when moist,

57 Barbula

313

Fig. 95 1–7, Barbula convoluta: 1, plant (×5); 2, leaves (×30); 3, leaf apex (×70); 4, basal cells; 5, mid-leaf cells; 6, capsule (×15); 7, rhizoidal gemmae (×175). 8–12, B. unguiculata: 8, leaves (×30); 9, leaf apex (×70); 10, basal cells; 11, mid-leaf cells; 12, capsule (×10). 13, B. sardoa: leaf (×30). Cells ×420.

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oblong-lanceolate, 0.6–0.9 mm long obtuse to acute; margins narrowly recurved on one or both sides below, papillose-crenulate; costa strong, green to brownish, ending in or below apex or shortly excurrent in apiculus, adaxial cells elongate; cells ± incrassate, basal irregularly rectangular, chlorophyllose narrower towards margins, cells above quadrate or quadrate-hexagonal, strongly papillose, opaque, 8–10(−12) μm wide in mid-leaf. Brown spherical rhizoidal gemmae, 110–140 μm long, often present. Perichaetial leaves convolute, inner ecostate. Setae pale yellow; capsules ellipsoid to subcylindrical, straight or slightly curved, c. 1.5 mm long excluding longly rostrate lid; peristome of long filiform spirally coiled segments; spores 8–10 μm. Capsules occasional, spring, summer. n = 11, 13, 14∗ . In open sites on disturbed soil, waste ground, paths, tarmac, arable fields, in gardens, soil-filled crevices in walls and old buildings. 0–490 m. Very common at low altitudes. 112, H40, C. GB1763 + 82∗ , IR290 + 6∗ , C8 + 1∗ . Circumpolar Wide-temperate. Widespread in the Northern Hemisphere, C. and S. Africa, New Zealand (probably introduced in Southern Hemisphere localities). 2 B. sardoa (Schimp.) J.-P. Frahm, J. Bryol., 2004 B. convoluta var. commutata (Jur.) Husn. Plants forming dense tufts 5–10 (–25) mm high; stems with central strand. Leaves strongly curled when dry, spreading to recurved when moist, 0.8–1.5 mm long, lingulate, acute to obtuse; margins of at least upper leaves undulate; basal cells rectangular, hyaline, cells above quadrate to quadrate-hexagonal, papillose, pellucid, 8–10 (–12) μm wide in mid-leaf. Gemmae not known. Setae pale yellow; capsules cylindrical, c. 2 mm long excluding lid. On base-rich soil, walls and in rock crevices. Occasional in N. Britain, frequent elsewhere. 77, H31, C. South and Central Europe. The status of this plant was regarded as debatable but it has been shown by J.-P. Frahm & J. Ahmed (J. Bryol., 26, 29–35, 2004) that it is a good species.

3 B. unguiculata Hedw., Sp. Musc. Frond., 1801 (Fig. 95) Plants forming patches, bright green above, reddish brown below, mostly 5–25 mm high; stems orange-red, not tomentose. Leaves twisted or incurved when dry, erect-patent, patent or recurved when moist, lingulate to narrowly lingulate or lingulate-lanceolate, apex obtuse or rounded, apiculate, occasionally acute or acuminate; margins recurved almost to apex, papillose-crenulate; costa stout, green to brownish, excurrent in thick point, adaxial cells quadrate; basal cells rectangular or narrowly rectangular, shorter towards margins, above ± quadrate, incrassate, papillose, opaque, 10–14 μm wide in mid-leaf. Perichaetial leaves larger than stem leaves with slightly sheathing bases. Setae dark red to purplish; capsules narrowly ellipsoid, straight; lid longly rostrate; peristome deeply bifid into filiform spirally coiled segments; spores 10–14 μm. Capsules frequent, summer to spring. n = 11∗ , 11 + m, 12 + m∗ , 13∗ , 13 + m∗ , 13 + 2m∗ , 14, 14 + 2m, 16∗ , 24∗ . On disturbed soil in open or slightly sheltered, especially man-made habitats, on paths, in fields, gardens, waste places, stony ground, crevices of walls and old

58 Didymodon

315

buildings. 0–530 m. Very common in lowland areas. 112, H38, C. GB1695 + 77∗ , IR248 + 19∗ , C3 + 1∗ . Circumpolar Wide-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Turkey, Cyprus, Asia, Macaronesia, C. and S. Africa, N. America, Mexico, southern S. America, Australia, New Zealand (probably introduced in Southern Hemisphere localities). A very variable species. A form with narrower leaves with more acute tapering apices is referred to as var. cuspidata (Schultz) Brid., but with the range of forms that exist it is not possible to delimit this plant satisfactorily and it is not recognised here. B. unguiculata may be confused with B. convoluta, but the latter differs in the tomentose stems, leaf shape, leaf margins plane or only narrowly recurved below, the costa rarely excurrent and yellow setae.

58 DIDYMODON HEDW., SP. MUSC. FROND., 1801 Usually dioicous. Plants forming tufts, cushions or patches. Stems with central strand. Axillary hairs c. 5 cells long, basal 1–2 cells brownish. Leaves appressed, curved or crisped when dry, erect-patent to squarrose when moist, lanceolate to narrowly lanceolate, acute to obtuse or rounded; margins plane, recurved or revolute; costa below apex to excurrent, usually smooth on abaxial side in upper half of leaf, adaxially 2–4(−8) cells wide, cells quadrate or elongate, stereid bands present or adaxial band weak or absent; basal cells quadrate to rectangular, upper cells quadrate or rounded-hexagonal, incrassate or not, smooth, papillose or mamillose. Capsules ellipsoid to cylindrical; peristome teeth 16, perforated to deeply bifid, long or short, straight or spirally coiled. A temperate and montane genus of about 120 species. Derivation: Alluding to the bifid peristome teeth. For an account of Central European species of Didymodon, which includes descriptions or mention of all British and Irish species, see J. Kuˇcera, Meylania 19, 1–49, 2000.

1 Adaxial cells of costa in at least upper half of leaf ± isodiametric, rarely rectangular 2 Adaxial cells of costa elongate 14 2 At least upper leaves with costa excurrent in acute or acuminate point 3 Costa ending in or below apex or if excurrent then in a stout point 6 3 Leaves broadly ovate, costa stout, 70–100 μm wide near base, numerous axillary gemmae present 11. D. cordatus Leaves linear-lanceolate to ovate, costa narrower, gemmae lacking 4 4 Leaves linear-lanceolate 9. D. insulanus Leaves ovate to lanceolate 5 5 Plants not very slender, in patches or scattered, leaf cells smooth, ± rounded, annulus not separating 1. D. acutus Plants very slender, in dense rufts, leaf cells often papillose, particularly on the abaxial side, quadrate to rounded-quadrate, annulus of one row of large separating cells 2. D. icmadophilus 6 Leaf margins bistratose at least above, axillary gemmae often present 7 Leaf margins unistratose throughout, gemmae rarely present 9

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16 Pottiaceae

7 Leaf cells distinctly papillose, 6–8 μm wide in mid-leaf, gemmae if present in British and Irish material very rare 5. D. nicholsonii Leaf cells slightly papillose, 8–10 μm wide in mid-leaf, axillary gemmae almost always present although sometimes sparsely so 8 8 Leaves lanceolate, tapering to stout blunt apex, cells not mamillose, widespread plant 3. D. rigidulus Leaves ovate to lanceolate, cells mamillosely bulging, very rare montane plant 4. D. mamillosus 9 Leaf apices often missing, margins undulate, sinuose and sometimes notched or irregularly toothed 12. D. sinuosus Leaf apices present, margins entire or papillose-crenulate, not undulate, notched or toothed 10 10 Leaves imbricate when dry, ovate-lanceolate to broadly ovate, apices acute to rounded 10. D. luridus Leaves erect-flexuose, crisped or incurved when dry, linear-lanceolate or ligulate-lanceolate to ovate, acuminate to acute 11 11 Leaves erect-flexuose when dry, lanceolate to ovate 8. D. vinealis Leaves usually crisped, curled or incurved when dry, linear-lanceolate or ligulate-lanceolate 12 12 Basal part of leaves expanded, with very narrow marginal cells 7. D. australasiae var. umbrosus Leaf bases not expanded, basal marginal cells not differentiated 13 13 Plants 2–3 mm high, leaves incurved when dry, ligulate-lanceolate, chains of axillary gemmae sometimes present 6. D. glaucus Plants 5–50 mm high, leaves crisped when dry, linear-lanceolate, gemmae lacking 9. D. insulanus 14 Leaves lingulate from ovate or lanceolate basal part, apices rounded to obtuse or shortly acute 13. D. tophaceus Leaves ovate or ovate-lanceolate, tapering to acute or acuminate apex 15 15 Leaves patent to recurved, plants to 2.5(−3.0) cm high 16 Leaves squarrose or if recurved then plants 3–9 cm high 18 16 Plants to c. 6 mm high, leaf margins entire, sausage-shaped rhizoidal gemmae present 16. D. tomaculosus Plants to 30 mm high, leaf margins entire or papillose-crenulate, rhizoidal gemmae lacking 17 17 Leaves usually recurved when moist, upper mostly 1.2–2.4 mm long, acuminate, peristome teeth spirally coiled 15. D. fallax Leaves patent or spreading when moist, upper mostly 1.8–4.0 mm long, apex acute to obtuse, peristome teeth straight 14. D. spadiceus 18 Plants to 2.5 cm high, leaves 0.8–1.8 mm long, basal cells not incrassate 17. D. ferrugineus Plants 3–9 cm high, leaves 2–4 mm long, basal cells incrassate 18. D. maximus

58 Didymodon

317

Section Didymodon Leaves erect to spreading when moist, concave; margins plane or recurved below; costa percurrent to excurrent, adaxial cells in upper half quadrate, in section adaxial stereid band usually lacking; lamina cells quadrate, smooth or papillose, papillae simple or bifid. Peristome teeth short, hardly twisted. 1 D. acutus (Brid.) K. Saito, J. Hattori Bot. Lab., 1975 (Fig. 96) ¨ Barbula acuta (Brid.) Brid., B. gracilis (Schleich.) Schwagr., D. rigidulus var. gracilis (Schleich.) R. H. Zander Green to brownish patches or scattered plants, 3–20 mm high. Leaves appressed, flexuose when dry, erect-patent when moist, concave, ovate to lanceolate, gradually tapering to acute apex; margins narrowly recurved below, entire; costa strong, occupying most of upper part of leaf, in upper leaves shortly to longly excurrent, adaxial cells rounded-quadrate; basal cells rectangular, cells above rounded to rounded-quadrate, incrassate, smooth, pellucid, 8–10(−15) μm wide in mid-leaf. Capsules ellipsoid or narrowly ellipsoid; annulus not separating; lid obliquely rostrate; peristome teeth filiform, spirally coiled; spores 9–12 μm. Capsules rare, late winter, spring. n = 13. Usually in small quantity in sparse turf or on bare soil in exposed situations in chalk and limestone grassland and on sand-dunes, very rarely on base-rich montane ledges. 0–600 m. Occasional but widely distributed from W. Cornwall east to W. Kent and north to Westmorland, very rare in Scotland, Angus, N. Aberdeen, Banff, rare in Ireland, formerly Jersey and Guernsey. 37, H8, C. GB57 + 17∗ , IR4 + 3∗ , C4∗ . Circumpolar Southern-temperate. Europe north to Svalbard, Caucasus, Cyprus, Turkey, Macaronesia, N. and C. America. Small axillary gemmae have been reported in D. acutus, but it is possible that such plants are misidentified D. rigidulus. It has also been suggested that some gatherings named D. acutus belong to D. icmadophilus; the situation requires further investigation.

¨ Hal.) K. Saito, J. Hattori Bot. Lab., 1975 2 D. icmadophilus (Schimp. ex Mull. (Fig. 96) ¨ Hal., D. acutus var. icmadophilus (Schimp. Barbula icmadophila Schimp. ex Mull. ¨ Hal.) R. H. Zander, D. rigidulus var. icmadophilus (Schimp. ex Mull. ¨ ex Mull. Hal.) R. H. Zander Plants very slender, forming dense blue-green tufts or patches. Leaves appressed, slightly flexuose when dry. Patent when moist, concave, lanceolate, tapering to long acuminate apex consisting mainly of costa; margins narrowly recurved below, entire; costa strong, excurrent, often longly so; basal cells shortly rectangular, cells above quadrate to rounded-quadrate, often papillose, especially on the adaxial side. Capsules narrowly ellipsoid; annulus of a single row of separating cells. Capsules unknown in the British Isles. On basic ledges on cliffs and in gullies, on crumbling rock and in short turf. 60–600 m. Very rare, Cumberland, Mid and E. Perth, Banff, Skye, W. Sutherland, Sligo (old record). 6, H1.

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Fig. 96 1–5, Didymodon acutus: 1, leaves; 2, leaf apex; 3, basal cells; 4, mid-leaf cells; 5, adaxial cells of costa at middle of leaf. 6–9, D. icmadophilus: 6, leaf; 7, leaf apex; 8, basal cells; 9, mid-leaf cells. 10–16, D. rigidulus: 10, leaves; 11, leaf apex; 12, basal cells; 13, mid-leaf cells; 14, section of margin at middle of leaf (×250); 15, gemmae (×420); 16, capsule (×15). 17, leaf of plant resembling D. subandreaeoides. Leaves ×40, apices ×70, cells ×420.

58 Didymodon

319

GB9, IR1∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Caucasus, Siberia, Kamchatka, Kashmir, N. America. Although in the past in the British Isles D. icmadophilus has been separated from D. acutus by its slender habit and longly excurrent costa, apparently the only reliable characters are cell shape and papillosity and the nature of the annulus. The latter charter is of little use as D. acutus very rarely produces sporophytes in the British Isles and only five gatherings of D. icmadophilus with sporophytes have ever been seen from elsewhere.

3 D. rigidulus Hedw., Sp. Musc. Frond., 1801 Barbula rigidula (Hedw.) Mitt.

(Fig. 96)

Dense dark green to yellowish green cushions, mostly 3–10 mm high. Leaves appressed, flexuose, sometimes slightly twisted when dry, patent when moist, lanceolate to narrowly lanceolate, gradually tapering to stout, blunt apex; margins recurved or plane below, entire; costa ending below apex to shortly excurrent, adaxial cells ± hexagonal; cells in lower part of leaf rectangular, above quadrate-hexagonal, incrassate, sometimes strongly so, slightly papillose, pellucid, bistratose at margins above, 8–10 μm wide in mid-leaf. Globose, several-celled gemmae, 25–80 μm diameter, present in axils of upper leaves. Setae orange-red; capsules ellipsoid to cylindrical; lid longly rostrate, oblique; peristome teeth short, 320–480 μm long, filiform, ± straight; spores 10–12 μm. Capsules occasional, autumn to spring. n = 13∗ . On basic rocks, walls, old buildings, concrete, in situations where there is usually some shelter. 0–750 m. Common except in E. Anglia and N. E. England, rare to common in Scotland, occasional in Ireland. 112, H37, C. GB1078 + 116∗ , IR123 + 22∗ , C1. Circumpolar Boreo-temperate. Europe north to Fennoscandia, Turkey, Cyprus, Caucasus, Asia, Canary Islands, Africa, N. and C. America, Antarctica. The axillary gemmae always seem to be present though sometimes sparsely so. These and the bluntly pointed leaves will distinguish this plant from other Didymodon species. A plant from Snowdon (Fig. 96, 17), originally identified as Grimmia andreaeoides Limpr. was later thought by E. F. Warburg & E. W. Jones (Trans. Brit. Bryol. Soc. 1, 367–8, 1950) to be a montane form of D. rigidulus – they did not suggest that the two taxa were synonymous. The correct name of G. andreaeoides is Didymodon subandreaeoides (Kindb.) R. H. Zander and ¨ is a good species (J. Kuˇcera & H. Kockinger, J. Bryol. 22, 49–54, 2000). The two authors considered that the Snowdon specimen that they examined was too depauperate to allocate it to either D. rigidulus or D. subandreaeoides. The leaf morphology, areolation and presence of filiform shoots in the Snowdon material that I have seen are identical with those of D. subandreaeoides. However, the plants have abundant gemmae like those of D. rigidulus, unknown in D. subandreaeoides, so its identity is open to question.

4 D. mamillosus (Crundw.) M. O. Hill, J. Bryol., 1981 Barbula mamillosa Crundw.

(Fig. 97)

Dioicous. Dense compact green and brown tufts, 4–8 mm high, stems frequently branched. Leaves appressed, scarcely altered and not at all crisped when dry, erectspreading when moist, 0.5–1.2 mm long, ovate to lanceolate, channelled, tapering

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Fig. 97 1–5, Didymodon nicholsonii: 1, leaf; 2, leaf apex (×70); 3, basal cells; 4, mid-leaf cells; 5, section of margin at middle of leaf. 6–10, D. glaucus: 6, leaf; 7, leaf apex (×100); 8, basal cells; 9, mid-leaf cells; 10, gemmae (×420). 11–16, D. mamillosus: 11a, b, dry and moist shoots (×10); 12, leaves; 13, basal cells; 14, mid-leaf cells; 15, adaxial cells of costa at middle of leaf; 16, gemmae (×250). Leaves ×40, cells ×420.

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to acute, not or only slightly acuminate apex; margins narrowly recurved above; costa ending shortly below apex or percurrent, lamina cells continuous over adaxial surface except in lower part of leaf; basal cells quadrate to shortly rectangular, cells above quadrate or oblate, 8–10 μm wide, incrassate with round or oval lumens, mamillosely protuberant, obscurely papillose, marginal cells bistratose above. Brown spherical or ovoid gemmae, 30–45 m diameter, abundant in axils of upper !eaves. Only male plants known. on calcareous crags. 600 m. W. and Mid Perth. 2. GB2. Germany, Iceland, Portugal. Close to and possibly synonymous with D. rigidula, but differing in its smaller size, the leaves relatively wider with less regularly recurved margins, straighter and more closely appressed when dry, and in the mamillose cells. For an account of the species see A. C. Crundwell, J. Bryol. 9, 163–6, 1976.

5 D. nicholsonii Culm., Rev. Bryol., 1907 (Fig. 97) Barbula nicholsonii Culm., D. luridus var. nicholsonii (Culm.) Loeske, D. vinealis var. nicholsonii (Culm.) R. H. Zander Dark green tufts or patches, often coated with alluvial detritus, mostly 5–20 mm high. Leaves flexuose or appressed and straight when dry, patent, soft when moist, ovate to ovate-lanceolate, tapering to acute to obtuse, sometimes ± cucullate apex; margins recurved below, entire; costa ending below apex, adaxial cells quadratehexagonal; basal cells shortly rectangular, cells above quadrate-hexagonal, slightly incrassate, papillose, pellucid, bistratose at margins above, 6–8 μm wide in midleaf. Setae orange-red; capsules cylindrical; lid rostrate; peristome imperfect, teeth c. 800 μm long, filiform, straight when dry; spores 8–15 μm. Capsules very rare, spring. n = 13∗ . On rocks, exposed roots, walls and concrete below flood level of streams and rivers, occasionally on gravel, tarmac or concrete paths. Lowland. Rare but sometimes locally frequent, from Cornwall east to W. Sussex and Surrey, north to Roxburgh, Berwick and Arran, N. Kerry, E. Cork, Wexford, Offaly, Leitrim, Fermanagh. 46, H6. GB378 + 15∗ , IR5 + 1∗ . Suboceanic Temperate. Belgium, France, Germany, the Netherlands, Portugal, Spain, Turkey, California. Distinct from D. rigidulus in the wider leaves and smaller cells. The taxonomic position and status of D. nicholsonii has been a matter of some doubt as is evidenced by the synonymy. Its treatment as a variety of other Didymodon species is probably a reflection of the lack of familiarity with the plant by the authors concerned as on morphological grounds it is distinct. S.E.M. studies of leaf surfaces (A. J. E. Smith, unpublished) indicate that it is not related either to D. rigidulus or to D. vinealis. Sporophytes have only been seen once (M. F. V. Corley et al., J. Bryol. 14, 653–57, 1987). With regard to gemmae in D. nicholsonii, Dixon & Jameson (1924) say ‘Axillary gemmae occur, but apparently not so constantly as in B. rigidula’. I have not seen gemmae in British material and T. L. Blockeel (in M. O. Hill et al., 1992) suggests the reports are open to question. However, I have seen axillary gemmae similar to those of D. rigidulus in Belgian and German material of D nicholsonii. This suggests that reports of gemmae in British material are likely to be correct. T. Arts (Bull. Soc. R. Belg.

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120, 3–6), in addition to describing axillary gemmae, also reports the presence of rhizoidal gemmae in D. nicholsonii. A plant closely related to but distinct from D. nicholsonii was found on a concrete ride in Harewood Forest, near Andover, N. Hampshire, in 1985 and 1993. The plant is diploid (the only known example of diploidy in Didymodon) and should probably be treated as distinct species. However, until it is found elsewhere this is not advisable on the grounds of the considerable variability found within some Didymodon species. A description of the Harewood forest plant is as follows: Sex unknown. Dull green tufts, 7–10 mm high. Leaves erect, appressed, straight when dry, erect-patent when moist, lanceolate, tapering from near base to obtuse apex; margins usually recurved from near base to c. 3 /4 way up leaf, papillose-crenulate above; costa stout, ending below apex, adaxial cells quadrate; cells incrassate, strongly papillose except near base, at extreme base rectangular, cells above irregular in shape, shortly rectangular, irregularly quadrate to wider than long, in longitudinal rows, becoming ± quadrate-hexagonal and irregularly arranged in upper part of leaf, very opaque, bistratose at margins, 8–10 μm wide in mid-leaf. Vegetative propagules, gametangia and sporophytes unknown. n = 26∗ (Fig. 98).

6 D. glaucus Ryan, Rev. Bryol., 1901 (Fig. 97) ¨ Barbula glauca (Ryan) H. Moller, D. rigidulus var. glaucus (Ryan) Wijk & Margad. Plants very small, in bright green patches, 1–3 mm high. Leaves incurved when dry, patent to recurved from erect basal part when moist, ligulate-lanceolate, tapering to long acute to acuminate apex; margins plane or variously recurved, sometimes obscurely denticulate near base, ± crenulate above; costa ending below apex, adaxial cells quadrate; basal cells rectangular, hyaline, cells above hexagonal, thin-walled, papillose, pellucid, unistratose at margins, 6–10 μm wide in mid-leaf. Chains of brown, spherical, 1–3-celled axillary gemmae, 13–25 μm diameter, often produced. Only female plants known in Britain. Capsules unknown. In crevices of chalk and limestone and on chalk soil. Lowland. Very rare and endangered, S. Wiltshire, W. Sussex (1915), N. W. Yorkshire (1914). 3. GB1 + 2∗ . European Temperate. Austria, Czechoslovakia, Germany, Greece, Hungary, Italy, Luxembourg, Norway, Romania, Sweden, Switzerland, Turkey. There has been confusion between D. glaucus and D. australasiae var. umbrosus but the latter differs in the expanded leaf bases with narrow marginal cells and the plane crenulate margins. This species is regarded as critically endangered in the Red List of British Mosses and is a protected species under the Wildlife and Countryside Act.

¨ Hal.) 7 D. australasiae (Hook. & Grev.) R. H. Zander var. umbrosus (Mull. R. H. Zander (Fig. 98) ¨ Hal.) R. H. Zander, Trichostomopsis umbrosus (Mull. ¨ Hal.) D. umbrosus (Mull. H. Rob. Pale green patches, often encrusted with calcareous matter, 2–10 mm high. Leaves spreading, flexuose or somewhat curled when dry, spreading from erect basal part when moist, lower small, upper longer, from expanded basal part narrowly

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Fig. 98 1–9, Didymodon nicholsonii (diploid form): 1, 2, moist and dry shoots (×10); 3, leaves (×30); 4, axillary hair (×250); 5, section of leaf margin; 6, adaxial cells of costa; 7, basal cells; 8, mid-leaf cells; 9, leaf apex. 10–13, D. australasiae var. umbrosus: 10, leaves (×40); 11, leaf apex (×100); 12, basal cells; 13, mid-leaf cells; 14, rhizoidal gemmae (from A. C. Crundwell & H. L. K. Whitehouse, J. Bryol. 10, 5–8. Cells ×420.

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linear-lanceolate, acute or occasionally obtuse; margins plane, crenulate; costa thin, percurrent, adaxial cells rectangular; basal cells rectangular, hyaline, very narrow near margins, cells above hexagonal, often wider than long, thin-walled, mamillose, opaque, bistratose at margins from near base to bistratose apex, 8–12 μm wide in mid-leaf. Brown irregularly shaped rhizoidal gemmae, 25–200 μm wide, abundant. Only female plants known in the British Isles. On damp mortar at the base of walls, in chalk and limestone quarries, on banks by springs, in shady situations. Lowland. Occasional in England from W. Cornwall and N. Somerset east to Sussex and north to W. Yorkshire, Glamorgan, Dublin. 35, H1. GB43, IR1. Oceanic-temperate. Czech Republic, Germany, Portugal, Spain, Canary Islands, Morocco, Tunisia, California, Mexico, Uruguay, Argentina. Originally thought to be an introduction but probably native. Likely to have been overlooked in the past because of its small size, and its recent apparent spread could be due to increasing familiarity with the species and the habitat in which it grows. That it has been found in natural habitats also supports the suggestion that it is native. For an account of this plant in Britain see A. C. Crundwell & H. L. K. Whitehouse, J. Bryol. 10, 5–8, 1978.

Section Vineales (Steere) R. H. Zander, Bryologist, 1978 Leaves spreading when moist, keeled or concave; margins weakly recurved to revolute; costa percurrent to shortly excurrent, adaxial cells quadrate in upper half of leaf, in section with adaxial stereid band lacking; cells unistratose above or occasionally bistratose at margins, smooth or papillose. Peristome absent to well developed and spirally coiled. 8 D. vinealis (Brid.) R. H. Zander, Phytologia, 1978 Barbula vinealis Brid.

(Fig. 99)

Dense olive green tufts, mostly 5–20 mm high. Leaves erect, flexuose, slightly twisted when dry, erect-patent, not flexuose when moist, upper 1–3 mm long, lanceolate to narrowly lanceolate, tapering to acute apex; margins narrowly recurved to above middle; costa ending in or below apex, adaxial cells quadratehexagonal; basal cells quadrate to shortly rectangular, cells above irregularly quadrate, relatively thin-walled, papillose, opaque, unistratose at margins, 6–10 μm wide in mid-leaf, apex ending in a single smooth pellucid cell. Setae red below, orange above; capsules narrowly ellipsoid to ellipsoid; lid oblique, longly rostrate; peristome teeth filiform, spirally coiled, c. 500–600 μm long; spores c. 10 μm. Capsules rare, spring to autumn. n = 14. In dry open situations on basic rocks, walls, old buildings, concrete, hard calcareous soil, sand-dunes. Frequent or common in the southern part of Britain, rare in the north, extending to Shetland, rare in Ireland. 83, H20, C. GB539 + 88∗ , IR12 + 8∗ , C2. European Southern-temperate. Europe north to Scandinavia, Iceland, Turkey, Cyprus, Caucasus, Nepal, China, Macaronesia, N. Africa, N. America, Mexico, Jamaica. Recognised in the field by the dense olive green cushions and the leaves erect, rigid and twisted with almost bristly points when dry.

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The record of D. reedii H. Rob. from Britain, reported by J. Appleyard (J. Bryol. 14, 319– 321, 1985) is based upon a form of D. vinealis (see T. L. Blockeel & A. J. E. Smith, J. Bryol. 20, 65–68, 1998).

9 D. insulanus (De Not.) M. O. Hill, J. Bryol., 1981 (Fig. 99) Barbula cylindrica (Taylor) Schimp., B. vinealis ssp. cylindrica (Taylor) Podp., D. vinealis var. flaccidus (Bruch & Schimp.) R. H. Zander Lax olive green to brownish green tufts or patches, mostly 5–50 mm high. Upper and sometimes lower leaves crisped when dry, patent, flexuose and sometimes undulate when moist, upper leaves 2–5(−7) mm long, linear-lanceolate, very longly tapering to acute or acuminate apex; margins recurved to about the middle; costa ending below apex to excurrent, adaxial cells quadrate-hexagonal; basal cells quadrate to shortly rectangular, cells above irregularly quadrate-hexagonal, papillose, opaque, unistratose at margins, 6–10 μm wide in mid-leaf, apex ending in a single smooth hyaline cell. Setae red below, orange above; capsules cylindrical; lid longly rostrate, oblique; peristome teeth filiform, spirally coiled, 500– 600 μm long; spores c. 10 μm. Capsules very rare, spring, summer. On usually base-rich damp rocks, cliff ledges, sheltered walls and wall bases, tree boles and roots by streams and rivers, on soil. 0–430 m. Occasional in N. Scotland, frequent or common elsewhere, frequent in Ireland. 112, H37, C. GB1368 + 85∗ , IR186 + 6∗ , C3. Eurasian Southern-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Turkey, Cyprus, Caucasus, Tibet, China, Macaronesia, N. Africa, N. and C. America. D. insulanus differs from D. vinealis in the laxer tufts and the longer more tapering leaves which are crisped when dry. There is also apparently a difference in capsule shape, but as capsules are only rarely produced it is uncertain how constant this is. Occasional intermediates between the two species occur and there is some difference of opinion as to whether D. insulanus should be treated as a species or as a variety of D. vinealis. Dark brown rhizoidal gemmae, 87–135 × 65–92 μm, have been reported from D. insulanus by L. T. Ellis & A. C. Smith (J. Bryol. 12, 509–10, 1993), but they appear to be extremely rare.

10 D. luridus Hornsch. ex Spreng., Syst. Veg., 1827 (Fig. 99) Barbula lurida (Hornsch. ex Spreng.) Lindb., B. trifaria (Hedw.) Mitt., D. ¨ trifarius (Hedw.) Rohl., D. vinealis var. luridus (Hornsch. ex Spreng.) R. H. Zander Dark green to brownish tufts or patches, 5–30 mm high. Leaves imbricate, not shrunken when dry, patent when moist, concave, ovate-lanceolate to broadly ovate, apex rounded to acute, base slightly decurrent; margins recurved below, entire; costa stout, 40–60(−80) μm wide near base, ending in or below apex, adaxial cells ± hexagonal; cells at extreme base shortly rectangular, elsewhere ± hexagonal, incrassate, smooth, pellucid, unistratose at margins, 6–10 μm wide in mid-leaf. Setae purplish; capsules ellipsoid to subcylindrical; lid obliquely rostrate;

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Fig. 99 1–7, Didymodon vinealis: 1, dry shoot (×10); 2, leaves (×25); 3, leaf apex (×70); 4, adaxial side of costa at middle of leaf: 5, basal cells; 6, mid-leaf cells; 7, capsule (×15). 8–9, D. insulanus: 8, dry shoot (×10); 9, leaf (×25). 10–15, D. luridus: 10, leaves (×40); 11, leaf apex (×70); 12, adaxial side of costa at middle of leaf; 13, basal cells; 14, mid-leaf cells; 15, capsule (×15). Cells ×420.

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peristome teeth short, c. 100 μm long, straight; spores 12–16 μm. On calcareous rocks, stones, wall bases, old buildings, thin soil, rarely on tree roots by rivers, usually but not necessarily in moist situations. Lowland. Common in the southern half of England, occasional elsewhere in England, Wales and S. Scotland, very rare in N. Scotland, Banff, Arran, Shetland, rare in Ireland. 81, H20, C. GB523 + 84∗ , IR8 + 14∗ , C1 + 4∗ . Submediterranean-Subatlantic. Europe north to S. Scandinavia, Turkey, Cyprus, Caucasus, W. Asia, Macaronesia, N. Africa, western N. America. Recognised by the broad leaves, appressed but otherwise hardly altered when dry. Sometimes confused with D. tophaceus but differing in the leaves imbricate when dry, leaf shape, the ± hexagonal adaxial cells of the costa and the smooth lamina cells. D. cordatus has a wider costa and axillary gemmae.

11 D. cordatus Jur., Bot. Zeit., 1866 Barbula cordata (Jur.) Braithw.

(Fig. 100)

Dark green or brownish green tufts or patches, c. 10 mm high. Leaves slightly incurved and narrowed when dry, patent when moist, concave, broadly ovate, tapering to acute apex (in British plants); margins strongly recurved, entire; costa very stout, 70–100 μm wide near base, excurrent, adaxial cells ± hexagonal; basal cells rectangular, cells above quadrate-hexagonal, slightly incrassate, smooth, pellucid, unistratose at margins, 6–8 μm wide in mid-leaf. Numerous spherical several-celled gemmae, c. 30 μm diameter, in axils of upper leaves. Only female plants known in Britain. On soil on a sea-cliff and a rock outcrop. Lowland. Very rare and endangered, N. Devon. 1. GB1. European Southern-temperate. Europe north to Belgium and Germany, east to the Crimea, Caucasus, Turkey. This species is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside Act.

12 D. sinuosus (Mitt.) Delogne, Bull. Soc. Roy. Bot. Belgique, 1873 (Fig. 100) Barbula sinuosa (Mitt.) Gravet, Oxystegus sinuosus (Mitt.) Hilp., Trichostomum ¨ Hal. sinuosum (Mitt.) Mull. Green tufts or patches, to 20 mm high. Leaves curled when dry, patent, flexuose when moist, fragile, from slightly expanded basal part linear-lanceolate, tapering to narrowly lingulate to subulate fragile obtuse apical part; margins plane or narrowly recurved below, undulate, crenulate, sinuose and often notched and/or irregularly toothed above; costa ending below apex, adaxial cells quadrate; basal cells rectangular, cells above ± quadrate-hexagonal, incrassate, papillose, opaque, unistratose at margins, 6–8 μm wide in mid-leaf. Only female plants known in the British Isles; capsules unknown. On damp shaded usually basic rocks by streams and rivers and in sheltered habitats on walls and old buildings, among tree roots in woodland. Lowland. Common in the southern half of England, frequent in N. W. Wales, Lancashire, western Yorkshire, very rare in Scotland, extending

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Fig. 100 1–6, Didymodon cordatus: 1, leaf (×40); 2, leaf apex; 3, basal cells; 4, mid-leaf cells; 5, gemmae (×250). 6–9, D. sinuosus: 6, leaves (×25); 7, leaf apex; 8, basal cells; 9, mid-leaf cells. 10–15, D. tophaceus: 10, leaves (×30); 11, adaxial side of costa at middle of leaf; 12, basal cells; 13, mid-leaf cells from broad-leaved plant; 14, mid-leaf cells from narrow-leaved plant; 15, capsule (×15). Apices ×70, cells ×420.

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north to Shetland, occasional in Ireland. 76, H27, C. GB477 + 58∗ , IR33 + 8∗ , C1. Submediterranean-Subatlantic. Europe north to Sweden, Turkey, Caucasus, Alaska. The caducous leaf tips probably act as vegetative propagules. The plant from Roscommon, resembling Oxystegus obtusifolius Hilp., mentioned in the first edition of this book, has been shown to be a form of D. sinuosus (see M. O. Hill & H. L. K. Whitehouse, J. Bryol. 14, 594–5, 1987).

Section Fallaces (De Not.) R. H. Zander, Bryologist, 1977 Leaves spreading to strongly recurved when moist; margins plane to recurved; costa ending below apex to shortly excurrent, adaxial cells shortly rectangular to elongate, in section adaxial stereid band usually present; lamina cells papillose or not. Peristome rudimentary or well developed and spirally coiled. 13 D. tophaceus (Brid.) Lisa, Elenco Muschi Torino, 1837 Barbula tophacea (Brid.) Mitt.

(Fig. 100)

Olive green to brownish tufts or patches, 5–50 mm high. Leaves erect, flexuose to slightly incurved, shrunken or not when dry, ± patent when moist, concave or not, from broadly ovate to lanceolate basal part ± lingulate and hardly tapering, apex rounded to obtuse or shortly acute; margins narrowly recurved, entire; costa ending below apex, adaxial cells elongate; cells usually incrassate, basal rectangular, cells above irregular, hexagonal to rhomboidal in narrow-leaved forms to ± regularly quadrate in broad-leaved forms, slightly papillose, pellucid, unistratose at margins, 10–12 μm wide in mid-leaf. Brown uniseriate 2–6-celled gemmae, 25–74 μm long, occasionally produced in leaf axils and on rhizoids. Setae deep red; capsules ellipsoid; lid obliquely rostrate, long or short; peristome short, c. 250 μm long; spores 12–16 μm. On sheltered, base-rich and especially damp or wet rocks, stones, walls in woods, on cliffs, coastal undercliffs, stream banks, flushes, on tracks and soil, often lime-encrusted and forming tufa in calcareous habitats. 0–440 m. Occasional in Scotland and Ireland, frequent or common and sometimes locally abundant elsewhere. 111, H29, C. GB850 + 115∗ , IR74 + 4∗ , C3. European Southern-temperate. Europe north to Svalbard, Faeroes, Iceland, Turkey, Cyprus, Caucasus, Asia, Canary Islands, Africa, N. America, Mexico, Bolivia. A very variable species for which a number of varieties of no value have been described. Usually easily recognised when growing in moist base-rich habitats by the olive-green to brownish colour and the leaves hardly tapering to usually obtuse or rounded apices.

14 D. spadiceus (Mitt.) Limpr., Laubm. Deutschl., 1888 Barbula spadicea (Mitt.) Braithw.

(Fig. 101)

Greenish brown tufts, mostly 10–30 mm high. Leaves erect, flexuose, ± twisted when dry, erect-patent when moist, (1.6−)1.8– 4.0 mm long, from ovate to lanceolate basal part tapering to acute to obtuse apex; margins recurved below, papillosecrenulate above; costa stout, ending below apex, adaxial cells elongate; extreme

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Fig. 101 1–5, Didymodon spadiceus: 1, leaves (×25); 2, leaf apex (×70); 3, basal cells; 4, mid-leaf cells; 5, capsule (×15). 6–8, D. maximus: 6, leaf (×17.5); 7, basal cells; 8, mid-leaf cells. 9–12, D. tomaculosus: 9, leaves (×75); 10, basal cells; 11, mid-leaf cells; 12, rhizoidal gemmae (×500). Cells ×420.

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basal cells rectangular to narrowly rectangular, above irregularly hexagonal, incrassate, papillose, pellucid, unistratose at margins, 8–10(−12) μm wide in midleaf. Setae deep red below, paler above; capsules ellipsoid to cylindrical, straight or slightly curved; lid oblique, longly rostrate; peristome teeth short, c. 500 μm long, filiform, ± straight; spores 10–16 μm. Capsules occasional, autumn. On baserich rocks and on tree boles by fast-flowing streams and rivers, often embedded in alluvial detritus, in seepage areas in ravines. 0–550 m. Rare to occasional in W. and N. Britain, very rare elsewhere, E. Sussex, W. Kent, rare in Ireland. 58, H21. GB138 + 67∗ , LR13 + 14∗ . European Temperate. Europe north to Scandinavia, Cyprus, Caucasus, N. Asia, N. America, Greenland. Close to D. fallax but usually a larger plant, lacking a reddish tinge, with longer leaves which are erect-patent rather than spreading or recurved when moist and less well developed peristome with straight teeth.

15 D. fallax (Hedw.) R. H. Zander, Phytologia, 1979 Barbula fallax Hedw.

(Fig. 102)

Dull green to brownish green, often tinged with red, loose tufts or patches or scattered plants, to 15(−30) mm high. Leaves distant, erect, flexuose, twisted when dry, erect-patent to spreading or frequently recurved when moist, 1.2–2.4 mm long, from broad base lanceolate to narrowly lanceolate, tapering to acute apex, keeled above, often with a plica on either side of the costa towards base; margins recurved at least below, entire to papillose-crenulate above; costa stout, reddish brown, ending below apex to percurrent, adaxial cells elongate; basal cells rectangular, cells above irregularly hexagonal with rounded lumens, weakly to strongly papillose, pellucid, unistratose at margins, 8–12 μm wide in mid-leaf. Setae reddish brown; capsules ellipsoid to narrowly ellipsoid, straight or slightly curved; peristome teeth 1.0–1.5 mm long, filiform, spirally coiled; spores 12–16 μm. Capsules occasional, winter, spring. n = 13. In open base-rich sites on soil or clay, in fields, by ditches and streams, on sand-dunes. 0–490 m. Occasional in N. W. Scotland, frequent or common elsewhere, frequent in Ireland. 111, H39, C. GB1323 + 98∗ , IR211 + 5∗ , C2. Circumpolar Southern-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Turkey, Cyprus, Caucasus, Asia, La Palma, Madeira, N. Africa, N. America, Greenland. A variable species usually recognisable in the field by its reddish-tinged shoots and spreading to recurved leaves. Papillosity of the leaves varies greatly, ranging from faint to very strong; similarly with the margins which range from entire to papillose-crenulate.

16 D. tomaculosus (Blockeel) M. F. V. Corley, J. Bryol., ’981 Barbula tomaculosa Blockeel

(Fig. 101)

Small, dark green patches or scattered plants, c. 6 mm high. Leaves erect to curved when dry, erect-patent, patent or occasionally squarrose when moist, ovate or ovate-lanceolate, acuminate; margins recurved, entire; costa percurrent to shortly

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Fig. 102 1–6. Didymodon fallax: 1, leaves (×40); 2, leaf apex (×100); 3, basal cells; 4, mid-leaf cells; 5, adaxial cells of costa at middle of leaf; 6, capsule and lid (×15). 7–10, D. ferrugineus: 7, shoot (×15); 8, leaf (×40); 9, basal cells; 10, mid-leaf cells. Cells ×420.

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excurrent, adaxial cells elongate; basal cells quadrate to rectangular, cells above longer than wide to wider than long, somewhat mamillose, pellucid, unistratose at margins, 8–14 μm wide in mid-leaf. Brownish sausage-shaped rhizoidal gemmae consisting of a single row of cells, 40–140 μm long, usually abundant. Only female plants known. On moist disturbed ground in open situations on usually heavy clay soil. Lowland. Very rare, Derby, S. W. and M. W. Yorkshire, Offaly, Kildare. 3, H2. GB6, IR2. Endemic (Suboceanic Temperate). Likely to be overlooked because of its small size and the frequently scattered plants. Readily distinguished microscopically by the sausage-shaped rhizoidal gemmae. For an account of this plant see T. L. Blockeel, J. Bryol. 11, 585–9, 1981.

17 D. ferrugineus (Schimp. & Besch.) M. O. Hill, J. Bryol., 1981 Barbula recurvifolia Schimp., B. reflexa (Brid.) Brid.

(Fig. 102)

Lax reddish brown tufts or patches, to 25 mm high. Leaves erect, flexuose when dry, squarrose when moist, keeled above, ovate-lanceolate, tapering to acute apex; margins recurved below, papillose-crenulate; costa ending below apex, adaxial cells elongate; basal cells shortly rectangular, cells above hexagonal, incrassate, papillose with tall papillae, pellucid, unistratose at margins, lumens rounded, 6–10 μm wide in mid-leaf. Capsules ellipsoid; peristome teeth ± straight, c. 600 μm long. Capsules unknown in the British Isles. In open or slightly shaded base-rich situations on rock, in scree, on thin soil, sand-dunes and in chalk-pits. 0–785 m. Rare to occasional but sometimes locally abundant, from Cornwall east to Kent and north to Orkney, occasional in Ireland. 65, H23. GB124 + 29∗ , IR45 + 8∗ . European Boreo-temperate. N. and C. Europe, Turkey, Caucasus, Siberia, Himalayas, China, N. America. Sometimes difficult to separate from forms of D. fallax with strongly recurved leaves, but distinguishable on the basis of a combination of characters: reddish-brown coloration, strongly squarrose more shortly pointed leaves and cells with tall papillae.

18 D. maximus (Syed & Crundw.) M. O. Hill, J. Bryol., 1981 Barbula maxima Syed & Crundw., B. reflexa var. robusta Braithw.

(Fig. 101)

Tall yellowish brown to brown tufts, 2–8 cm high. Leaves strongly flexuose when dry, strongly recurved when moist, 2–4 mm long, lanceolate from broad basal part, gradually tapering to acute apex; margins recurved, papillose-crenulate; costa ending in apex, adaxial cells elongate; cells incrassate, basal narrowly rectangular, cells above irregularly hexagonal with ± angular lumens, papillose, pellucid; margins unistratose, 10–12 μm wide in mid-leaf. Gametangia and sporophytes unknown. On damp ledges or soil on limestone cliffs. 300 m. Very rare but locally common. Sligo, Leitrim. H2. IR5. Hyperoceanic Temperate. Canada (?). Specifically distinct from D. ferrugineus in its larger size, and narrower and more longly tapering leaves with angular cell lumens (see H. Syed & A. C. Crundwell, J. Bryol., 7, 527– 9, 1973).

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There are two specimens of a somewhat similar looking species, D. asperifolius (Mitt.) H. A. Crum et al. (Barbula asperifolia Mitt., B. rufa (Lor.) Jur.), collected by J. Stirton apparently from Ben Lawers in 1867. There is some doubt as to the authenticity of the locality (see A. C. Crundwell, Trans. Brit. Bryol. Soc. 3, 174–9, 1957).

59 SCOPELOPHILA (MITT.) LINDB., ACTA SOC. SCI. FENN., 1872 Dioicous. Plants forming turfs. Stems without central strand. Axillary hairs 3–5 cells long, basal cell usually brownish. Leaves incurved to spreading, contorted when dry, spreading when moist, lingulate to ligulate or lanceolate, acute to obtuse; margins plane or recurved below, entire, crenulate or denticulate above; costa ending below apex to percurrent, 2–4 cells wide on adaxial side, cells quadrate to rectangular, in section with one stereid band; basal cells rectangular, cells above rounded-quadrate or hexagonal, smooth. Perichaetial leaves similar to stem leaves. Capsules ellipsoid to shortly cylindrical, gymnostomous; lid rostrate; calyptrae cucullate. Three species of substrates containing heavy-metals, distributed through Europe, Asia, C. Africa, N. and S. America, Hawaii. Derivation: referring to the rocky or stony habitat.

1 S. cataractae (Mitt.) Broth., Nat. Pflanzenfam., 1902 (Fig. 103) Dense tufts or patches, sometimes extensive, dull olive-green to glossy green above, reddish brown below, to 5 cm high. Leaves curved when dry, erect-patent to patent when moist, lower narrowly lanceolate, upper ± lingulate, widest at or above middle, abruptly tapering to acute apex, strongly channelled above; margins plane or recurved below, entire; costa percurrent or slightly excurrent, adaxial cells rectangular; basal cells rectangular, decreasing in size from costa to margins, cells above irregularly quadrate to hexagonal or wider than long, incrassate, smooth, 6–10(−12) μm wide in mid-leaf. Protonemal gemmae, 50–100 μm long, 1–6 cells long, sometimes present. Only male plants known in Europe. n = 13∗ . Heavymetal mine heaps and waste, Lowland. Very rare, Cornwall, S. Devon, Glamorgan, Cardigan, Caernarfon, I. of Man. 7. GB7. Circumpolar Southern-temperate. Belgium, France, Germany, Italy, the Netherlands, Spain, tropical Asia, Korea, Japan, N. Carolina, Arizona, C. America. Rhizoidal gemmae have been reported from material from Belgium, France and the Netherlands. The gemmae are pale brown, very irregular in shape and size, 50–400 × 20–150 μm (see T. Arts, Lindbergia 14, 59–62, 1988). For accounts of S. cataractae in England and Wales see M. F. V. Corley & A. R. Perry, J. Bryol. 13, 323–8, 1985, A. C. Crundwell, J. Bryol. 14, 387, 1986 and F. Rumsey & M. E. Newton, J. Bryol. 15, 519–24, 1989. Known from an old metal mine in S. Devon, zinc waste in Glamorgan and lead-spoil in Cornwall, Cardigan, Caernarfon and the Isle of Man. Some authorities consider this species to be introduced in Europe, having been brought in with ore. However, as it also occurs on spoil from mines to which ore would not have been introduced this seems unlikely.

60 Stegonia

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Fig. 103 Scopelophila cataractae: 1, leaves (×60); 2, basal cells (×280); 3, mid-leaf cells (×420).

Subfamily 3 Pottioideae Stems with sclerodermis poorly differentiated from central strand. Leaves usually lingulate to spathulate, more rarely narrowly lanceolate to elliptical, basal part often expanded and hyaline; costa usually with only one stereid band; cells in upper part usually bulging on adaxial side, and weakly convex on abaxial side. Clavate axillary gemmae rare. In British genera laminal KOH reaction either yellow or red. Tribe 1 Hyophileae Leaf cells bulging on adaxial side, ± flat on abaxial side or if cells not bulging on adaxial side then only one stereid band present in costa section.

60 STEGONIA VENTURI., REV. BRYOL., 1883 Autoicous. Stems with central strand; sclerodermis and hyalodermis lacking. Axillary hairs 3–6 cells long. Leaves imbricate, broadly ovate or elliptical, strongly concave; costa percurrent to excurrent in hyaline point, 3–4 cells wide on adaxial side, cells shortly rectangular, in section with abaxial stereid band; basal cells rectangular, cells above smooth, hexagonal, in upper 1 /4 –1 /3 of leaf usually hyaline,

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thick-walled. Capsules cleistocarpous and immersed or dehiscent and exserted, peristome absent, imperfect or well developed; calyptrae cucullate. Laminal KOH reaction red. Three Northern Hemisphere species. Derivation: from the Greek, meaning to cover closely, a reference to the strongly concave leaves. The genus as defined above by Zander (1993) is unnatural, containing one species with immersed cleistocarpous capsules and two with exserted dehiscent capsules.

¨ 1 S. latifolia (Schwagr.) Venturi ex Broth., Laubm. Fennoskand., 1923 (Fig. 104) ¨ ¨ Hal. Pottia latifolia (Schwagr.) Mull. Small pale green patches or clusters of bud-like short-lived plants, c. 2 mm high. Leaves imbricate when moist, hardly altered when dry, very strongly concave, obovate to broadly obovate-spathulate, apices obtuse or rounded; margins plane, faintly denticulate above; costa weak, ending below apex; cells in lower part of leaf narrowly rectangular, hyaline, becoming smaller, rectangular to irregularly rhomboidal above, smooth, 8–16 μm wide in widest part of leaf, smaller and more incrassate towards margins and apex and sometimes colourless. Capsules narrowly ellipsoid, erect or nearly so; peristome well developed; spores 40–50 μm. Capsules common, summer, autumn. n = 26. On calcareous soil on rock ledges, amongst rocks and in crevices. C. 550 m. Very rare, E. Perth, S. Aberdeen, Banff, old records from Mid Perth and Angus. 5. GB6 + 3∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Turkey, Asia, N. America, New Zealand (introduced), Antarctica. The very concave leaves with costa ending below the apex will distinguish this species from other British members of the Pottiaceae. Tortula leucostoma, with which it sometimes occurs, has acuminate leaves with strongly recurved margins.

¨ 61 PTERYGONEURUM JUR., LAUBM.-FL. OSTERR.-UNG., 1882 Autoicous. Stems with central strand, sclerodermis and hyalodermis absent. Axillary hairs c. 7 cells long. Leaves concave, ovate or obovate, obtuse or rounded; margins plane or narrowly recurved; costa excurrent in frequently hyaline hairpoint, expanded above with 2–4 chlorophyllous lamellae, c. 12 cells high, on adaxial surface, in section with abaxial stereid band; basal cells rectangular, cells above quadrate or wider than long, smooth or with small papillae. Perichaetial leaves not sheathing. Setae long or short, straight; capsules ± erect, symmetrical, ovoid to cylindrical; lid rostrate; peristome imperfect and spirally curved or absent. Twelve species distributed through Europe, N. and W. Asia, N. and southern Africa, N. America, southern S. America, Australia. Derivation: referring to the ‘wings’ on the adaxial side of the costa. ´ et al., Nova Hedwigia 61, For observations on the genus Pterygoneurum see J. S. Carrion 481–96, 1995.

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337

Fig. 104 1–4, Pterygoneurum ovatum: 1, leaves; 2, mid-leaf cells; 3, capsule; 4, cells of lid. 5–8, P. lamellatum: 5, leaves; 6, mid-leaf cells; 7, capsule; 8, cells of lid. 9–12, Stegonia latifolia: 9, leaves; 10, mid-leaf cells; 11, cells from near leaf apex; 12, old capsule. Leaves ×25, cells ×420, capsules ×15.

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Setae 2–3 mm long, capsules ovoid or ovate-ellipsoid, cells of lid in straight rows, spores papillose, 26–40 μm 1. P. ovatum Setae 3–6 mm long, capsules ellipsoid, cells of lid in spiral rows, spores smooth, 10–30 μm 2. P. lamellatum 1 P. ovatum (Hedw.) Dixon, Rev. Bryol. Lichénol., 1934 Tortula pusilla Mitt.

(Fig. 104)

Small greenish or sometimes hoary patches, 1–2 mm high. Leaves imbricate when dry, ± imbricate or erect-patent when moist, very concave, ovate, obovate to obovate-spathulate, obtuse; margins ± plane, entire; costa excurrent in short to long (to 1 mm), often hyaline, slightly denticulate hair-point, stout, enlarged in upper part of leaf with 2–4 green lamellae on adaxial side; cells in lower part of leaf rectangular, hyaline, cells above quadrate-hexagonal, incrassate, slightly papillose, 10–18 μm wide in widest part of leaf, smaller towards margins and apex. Setae 2–3 mm long; capsules ovoid or ovate-ellipsoid, erect, straight, dark purplish brown, sulcate when dry and empty; lid obliquely rostrate with cells in straight rows; peristome lacking; spores papillose, 26–40 μm. Capsules common, autumn, winter. n = 26. On basic soil on banks, among rocks, in quarries, on cliffs and formerly on mud-capped walls. Lowland. Rare to occasional in calcareous areas of England, very rare in Wales and Scotland, extending north to E. Ross, old records from Mid Cork, and Down. 56, H2. GB52 + 88∗ , IR3∗ . Circumpolar Southerntemperate. Europe north to Scandinavia, Caucasus, Turkey, W. Asia, Algeria, Morocco, N. America, Tierra del Fuego, Australia. This and particularly the next species were once frequent on newly mud-capped calcareous walls, a habitat that is now almost completely lost.

¨ 2 P. lamellatum (Lindb.) Jur., Laubm.-Fl. Osterr.-Ung., 1882. Tortula lamellata Lindb.

(Fig. 104)

Plants 1–2 mm high. Leaves very similar to those of P. ovatum but hair-points not exceeding 400 μm long. Setae 3–6 mm long; capsules ellipsoid, erect, straight or slightly curved, brown; lid obliquely rostrate with cells in spiral rows; peristome poorly developed and falling with lid; spores very finely papillose, 10–30 μm. Capsules common, autumn, winter. n = 52. On calcareous soil and mud-capped limestone walls and in chalk pits. Lowland. Now probably extinct, recorded from scattered localities from S. Devon east to W. Kent and north to Yorkshire, Stirling, Dublin, Down, but seen recently only in W. Norfolk and Cambridge. 17, H2. GB2 + 26∗ , IR3∗ . Circumpolar Southern-temperate. Central and western Europe, Greece, Sicily, C. Asia, N. and C. America, Greenland. Very much decreased because of the destruction of the species’ main habitat, mudcapped walls. Only distinguished with certainty from P. ovatum by the cells of the capsule

62 Aloina

339

lid in spiral rows, although P. ovatum sometimes has longer leaf hair-points and larger spores.

62 ALOINA KINDB., BIH. KONGL. SVENSKA VETENSKT.-AKAD. HANDL., 1882 Dioicous or autoicous. Stems short, with or without central strand. Leaves rigid, thick, usually incurved when dry, erect to spreading when moist, from hyaline sheathing base, ovate to lingulate, concave, apex obtuse to rounded, cucullate; margins entire; costa broad, usually ending in or below apex, with chlorophyllous branched granulose filaments on adaxial surface in upper part, in section with abaxial stereid band; cells in sheathing base rectangular, hyaline, cells above quadrate or transversely oblong or elliptical. Setae straight; capsules erect or inclined, ellipsoid to cylindrical, straight or curved; annulus persistent or not; peristome with short basal membrane and 32 filiform spirally coiled teeth. Laminal KOH reaction yellow. A small world-wide genus of about 8 species. Derivation: alluding to the fleshy nature of the leaves. For a monograph of Aloina in the Mediterranean and neighbouring areas see M. T. Gallego et al., Nova Hedwigia 69, 173–94, 1999.

1 Marginal cells near leaf base elongate, hyaline, thin- walled, forming distinct border, annulus separating 2 Marginal cells near leaf base quadrate or rectangular, if hyaline then thick-walled, annulus persisting 3 2 Leaves mostly 2.0–3.5 times as long as wide, spores 18–22 μm 1. A. brevirostris Leaves mostly 4–6 times as long as wide, spores 10–16 μm 2. A. rigida 3 Basal membrane of peristome not projecting above mouth of capsule, spores 18–25 μm 3. A. aloides Basal membrane projecting above mouth of capsule, spores 12–16 μm 4. A. ambigua 1 A. brevirostris (Hook. & Grev.) Kindb., Bih. Kongl. Svenska Vetenskt.-Akad. Handl., 1883 (Fig. 105) Tortula brevirostris Hook. & Grev. Synoicous or sometimes male only. Greenish or brownish patches, 1–2 mm high. Leaves incurved when dry, erect to spreading when moist, very concave, lower leaves ± orbicular, upper broadly lingulate, 2.0–3.5 times as long as wide, hyaline basal part as long as or longer than blade, apex rounded or obtuse, cucullate; costa poorly defined, ending in apex, in section with 1–3 rows of guide cells and 1(−2) stereid bands; marginal cells near base elongate, thin-walled,

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Fig. 105 1–3, Aloina brevirostris: 1, leaves; 2, leaf section; 3, capsule. 4–6, A. rigida: 4, leaves; 5, capsule; 6, capsule mouth. 7–9, A. ambigua: 7, leaves; 8, capsule; 9, capsule mouth. 10–13, A. aloides: 10, leaves; 11, leaf section; 12, capsule; 13, capsule mouth. Leaves ×25, sections ×165, capsules ×10, capsule mouths ×70.

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341

hyaline. Capsules erect, narrowly ellipsoid, straight, 1.8–2.0 mm long; lid obliquely rostrate, 1 /3 (−1/2) length of body of capsule; annulus of large separating fugacious cells; basal membrane of peristome of 3–5 rows of cells, projecting above mouth of capsule; spores hardly papillose, 18–22 μm. Capsules common, autumn to spring. n = 24, 28∗ . On highly calcareous chalk or magnesian limestone soil in chalk pits, cuttings, on hillsides. Lowland. Very rare in chalk areas of S. England and chalk and magnesian limestone in N. E. England, Cheshire, Midlothian. 17. GB17 + 4∗ . Circumpolar Boreo-arctic Montane. Rare in Europe from Spain and Greece north to Svalbard, Turkey, Siberia, Tenerife, Algeria, Tunisia, N. America, Greenland. A. brevirostris differs from A. rigida in the hyaline basal part of the leaf as long as or longer than the blade, the synoicous inflorescence and larger spores.

2 A. rigida (Hedw.) Limpr., Laubm. Deutschl., 1888 Tortula rigida (Hedw.) Schrad. ex Turner

(Fig. 105)

Dioicous. Small dull green or brownish patches or scattered plants, c. 2 mm high. Leaves incurved when dry, spreading when moist, mostly 4–6 times as long as wide, lingulate to lingulate-spathulate or lingulate-lanceolate, hyaline basal part shorter than blade, apex rounded and apiculate, rarely obtuse and mucronate, cucullate; costa well defined, ending in apex or excurrent in mucro, in section with 1–3 rows of guide cells and 3–6(−8) rows of stereids; marginal cells of basal part elongate, thin-walled, hyaline. Capsules erect, narrowly ellipsoid, straight, c. 2–3 mm long; lid obliquely rostrate, c. 1/2 length of body of capsule; annulus of large separating fugacious cells; basal membrane of peristome of 3–5 rows of cells, projecting above mouth of capsule; spores ± smooth, 14–16 μm. Capsules common, autumn to spring. n = 24, 26, 28. On bare calcareous soil on banks and cliffs, in quarries, especially in chalk and limestone areas. 0–500 m. Rare and much decreased, from S. Wiltshire east to W. Kent and north to E. Ross, Dublin, Kildare, old records from Down, Antrim. 43, H4. GB33 + 50∗ , IR1 + 5∗ . European Boreal-montane. Greece, N. Italy and Pyrenees north to S. Scandinavia, Faeroes, Caucasus, Turkey, Cyprus, Turkestan, former USSR, N., E. and southern Africa, N. America, Ecuador, Bolivia, Peru, Australia (introduced?). ¨ Hal.) Broth., as A. rigida var. mucronulata (Bruch & Schimp.) Lindb., A. obliquifolia (Mull. was reported from the British Isles by M. C. Delgadillo (Bryologist 78, 245–306, 1975) from Gloucestershire, 1837, coll. Atark and Glasnevin, near Dublin, coll. D. Moore. These specimens are in BM together with a third, also named by Delgadillo, from Newhaven, 1855, coll. Hemmings. A. obliquifolia differs from A. rigida in the leaves having an excurrent costa and the basal membrane of the endostome not projecting above the mouth of the capsule. The specimen from Glasnevin was redetermined A. rigida by M. T. Galego, and all three specimens have tall basal membranes so it would appear that A. obliquifolia does not occur in the British Isles.

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3 A. aloides (D. J. Koch ex Schultz) Kindb., Bih. Kongl. Svenska Vetenskt.-Akad. Handl., 1883 (Fig. 105) Tortula aloides (D. J. Koch ex Schultz) De Not. Dioicous. Dark green to reddish brown patches or scattered plants, 2–5 mm high. Leaves rigid, incurved and glossy when dry, erect-patent when moist, narrowly lingulate or lanceolate, apex obtuse and apiculate to acute or acuminate, apiculus or acumen not reflexed, sometimes hyaline; margins inflexed above; costa ending in apex or shortly excurrent; marginal cells near leaf base quadrate to rectangular, not hyaline. Capsules erect or more usually inclined, narrowly ellipsoid to cylindrical, straight to strongly carved, 1.6–2.4(−2.8) mm long; lid obliquely rostrate; basal membrane of peristome of 1–2 rows of cells, not projecting above mouth of capsule; spores smooth, 18–22(−25) μm. Capsules common, autumn to spring. n = 26∗ . On exposed basic soil on banks, rock ledges, cliffs, sand-dunes, in quarries. 0–450 m. Frequent in the southern half of England and in Wales, rare further north, extending to E. Ross, occasional in Ireland. 86, H26, C. GB312 + 83∗ , IR49 + 8∗ , C3. SubmediterraneanSubatlantic. Europe north to Sweden, Turkey, Cyprus, Caucasus, N. Africa, Newfoundland. The rosettes of dark green succulent-looking, glossy leaves make this and the next species easily recognisable. I have followed Corley et al. (1981) in treating A. ambigua as a separate species as it is usually distinct from A. aloides in the British Isles, but the two do intergrade elsewhere and are treated by some authorities as varieties of a single species. A. aloides has less spreading and frequently more acute leaves than A. ambigua and the capsules are often markedly inclined, but the only constantly reliable characters for separating the two are length of basal membrane and spore size.

4 A. ambigua (Bruch & Schimp.) Limpr., Laubm. Deutschl., 1888 (Fig. 105) A. aloides var. ambigua (Bruch & Schimp.) F. J. Craig., Tortula ambigua (Bruch & Schimp.) Ångstr. Dioicous. Dark green to reddish brown patches or scattered plants, 2–5 mm high. Leaves rigid, curved and glossy when dry, erect-patent to spreading when moist, lingulate-lanceolate, apex cucullate, obtuse, sometimes with reflexed apiculus; margins inflexed; costa ending in apex or shortly excurrent; marginal cells near leaf base quadrate to rectangular, not hyaline. Capsules erect or slightly inclined, cylindrical, straight or slightly curved, (2.0−)2.2–3.2 mm long; lid obliquely rostrate; basal membrane of peristome of 3–5 rows of cells, projecting above capsule mouth; spores ± smooth, (12−)14–16 μm. Capsules common, winter, spring. n = 23 + m, 24, 25 + 2m. On exposed basic soil on banks, rock ledges, cliffs, in quarries. Lowland. Rare to occasional in England and Wales and extending north to N. Northumberland and Westmorland, very rare in Ireland and seen recently

63 Leptobarbula

343

only from E. Cork, Waterford and Clare. 50, H7, C. GB50 + 56∗ , IR3 + 5∗ , C1. European Southern-temperate. Europe north to Sweden, Caucasus, Turkey, Cyprus, Lebanon, Iran, Siberia, Azores, Canary Islands, Tunisia, N. America, Mexico, Australia (introduced?). Tribe 2 Pottieae Lamina cells often convex on both faces. Setae commonly twisted anticlockwise when dry.

63 LEPTOBARBULA SCHIMP., REV. BRYOL., 1876 A monotypic genus with the characters of the species. Derivation: meaning slender Barbula.

1 L. berica (De Not.) Schimp., Rev. Bryol., 1876 (Fig. 106) Dioicous. Plants bright green, scattered or forming dense tufts, to 2 mm high. Stems with central strand, sclerodermis absent or weakly developed, hyalodermis absent. Axillary hairs 6–7 cells long, basal 2 brown. Leaves erect-patent from erect basal part when moist, hardly altered when dry, increasing in size up stems and more crowded near top, very narrowly lanceolate, obtuse; margins plane, papillose-crenulate; costa ending below apex, 2–4 cells wide on adaxial side, cells quadrate, in section with 2 stereid bands but abaxial band weak or absent; cells in lower part of leaf rectangular, incrassate, 4–8 × 12–25 μm, cells above quadrate, very incrassate, densely papillose, opaque, 3–6 μm wide. Perigonial and perichaetial bracts longer than stem leaves with inflated sheathing bases narrowed into patent or spreading ± linear limb, obtuse in outer, acute in innermost perichaetial leaves. Setae long; capsules erect, cylindrical; lid rostrate; peristome with 32 filamentous spirally coiled teeth; calyptrae cucullate; spores c. 8 μm. Capsules very rare. On limestone rocks and stones in woodland, shaded brickwork, stonework and mortar. Lowland. Rare in southern and eastern England from Cornwall east to E. Kent and north to Yorkshire, W. Galway. 27, H1. GB46, IR1. Mediterranean-Atlantic. Mediterranean region and north to Belgium, Germany and the Netherlands, Turkey, Madeira, Azores, N. Africa. Differs from Gymnostomum calcareum in the smaller size of the plants, the leaves being very narrowly lanceolate and gradually tapering instead of lingulate. Unlike L. berica, Gymnostomum calcareum does not have strongly differentiated perigonial and perichaetial leaves. Gyroweisia tenuis has wider leaves, usually abundant gymnostomous capsules and protonemal gemmae. It is uncertain if this species is spreading or whether because of its small size it has been overlooked in the past. For an account of its discovery and a detailed description see J. Appleyard, M. O. Hill & H. L. K. Whitehouse, J. Bryol. 13, 461–70, 1985.

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Fig. 106 Leptobarbula berica: 1, 2, sterile and female shoots (×35); 3, leaves (×60); 4, basal cells (×420); 5, mid-leaf cells (×420); 6, perichaetial leaf (×60).

64 TORTULA HEDW., SP. MUSC. FROND., 1801 Monoicous or dioicous. Plants forming cushions or tufts; stems with central strand. Leaves erect-patent to spreading when moist, usually obovate or spathulate, apex acute to rounded; margins usually recurved below and entire above; costa shortly to longly excurrent, 3–4(−5) cells wide on adaxial side, cells ± quadrate, smooth or papillose, in section adaxial stereid band circular to semicircular; basal cells rectangular, hyaline, thin-walled and often lax, cells above rounded-quadrate to hexagonal, usually thin-walled, papillose, marginal 1–4 rows often smaller, less papillose. Vegetative propagules lacking. Perichaetial leaves similar to or larger than stem leaves. Setae very short to long; capsules usually erect, spherical to cylindrical, dehiscent; peristome teeth 16, perfect, variously divided and often spirally coiled, or irregular, rudimentary or absent;

64 Tortula

345

calyptrae cucullate. Laminal KOH reaction usually yellow. About 165 species world-wide. Derivation: a diminutive meaning twisted, referring to the peristomes. Tortula differs from Syntrichia in the costa in section having a circular or semicircular rather than lunate stereid band and the adaxial costa cells are quadrate rather than elongate. The laminal KOH reaction is yellow in Tortula, red in Syntrichia. Hennediella differs in the leaf margins dentate above and in the red KOH reaction. The descriptions of species 12–16 are based upon those in the first edition of this book by Dr D. F. Chamberlain, when they were included in the genus Pottia.

1 Capsules ± spherical, ovoid, ellipsoid or turbinate, lid mamillate, conical or rostrate, peristome teeth if present straight 2 Capsules cylindrical or rarely narrowly ellipsoid, ± erect, lid very longly rostrate, peristome long, spirally twisted, or capsules absent 8 2 Capsules cernuous or horizontal, leaf margins with border of narrow cells 10. T. cernua Capsules ± erect, leaf margins unbordered 3 3 Peristome teeth well developed 4 Peristome teeth rudimentary or absent 5 4 Leaf margins strongly recurved ± from base to apex, costa thickened in upper part of leaves 11. T. atrovirens Margins recurved below, costa not thickened in upper part 12. T. lanceola 5 Leaf margins plane, cells smooth, capsules turbinate, widest at mouth 16. T. truncata Leaf margins recurved, cells usually papillose, capsules obloid to ellipsoid, widest below mouth 6 6 Cells in upper part of leaf 13–17 μm wide, papillose, spores 19–26 μm 13. T. wilsonii Cells 17–24 μm wide, faintly papillose, spores 25–34 μm 7 7 Leaves spathulate-oblong, apex rounded, costa excurrent 100–1100 μm 14. T. viridifolia Leaves oblong-lanceolate, apex acute, costa excurrent 100–300(−500) μm 15. T. modica 8 Costa excurrent in hyaline hair-point, rarely excurrent in yellowish point, cells 8–16 μm wide at widest part of leaf 9 Costa ending in or below apex or excurrent in yellowish or greenish point, rarely excurrent in hyaline point, leaf cells 16–24 μm wide 10 9 Leaf margins revolute ± from base to apex, peristome teeth free almost to base, plants forming rounded cushions, tufts or patches 8. T. muralis Margins plane or only recurved at middle of leaf, peristome teeth united for 1/ –1/ their length, plants scattered or forming patches 7. T. canescens 3 2 10 Leaves with distinct border of elongate incrassate cells at least below 11

346

11

12 13 14 15

16 Pottiaceae Leaves without border of elongate incrassate cells although marginal band of otherwise differentiated cells sometimes present 12 Leaves mostly 3.5–7.0 mm long, costa ending in apex or excurrent in mucro, 1. T. subulata lower 3/4 of peristome tubular Leaves less than 2 mm long, costa excurrent in yellowish point to 3/4 length of lamina, peristome teeth free almost to base 5. T. marginata Leaf margins revolute ± from base to apex 9. T. leucostoma Leaf margins plane or partly recurved 13 Cells 16–24 μm wide at widest part of leaf 14 Cells 10–16 (−18) μm wide 15 Leaves acute, cells smooth 2. T. cuneifolia Leaf apices rounded, cells papillose 6. T. vahliana Costa ending below apex, margins plane 3. T. freibergii Costa ending in apex or excurrent at least in some leaves, margins plane or recurved 4. T. solmsii

Section 1 Tortula Leaf apices usually rounded; costa usually excurrent in long hyaline point, 3–6 cells wide on adaxial side, cells densely papillose, in section with guide cells; lamina cells relatively small, mostly 10–13 μm wide, densely papillose. Capsules usually with peristomes. 1 T. subulata Hedw., Sp. Musc. Frond., 1801 Autoicous. Dull green patches or scattered plants, rarely more than 10 mm high. Leaves incurved, twisted when dry, spreading when moist, very variable in shape, narrowly lanceolate, narrowly lingulate, spathulate or ovate, obtuse to acute or acuminate; margins recurved below, bordered at least below, entire or opaquely toothed above; costa stout, percurrent or excurrent in mucro; cells in lower part of leaf rectangular, hyaline, at margins narrower with marginal band of narrow incrassate cells extending up margins half way or more up leaf and sometimes forming conspicuous yellow border, cells in upper part of leaf irregularly hexagonal or ± quadrate, papillose, opaque, variable in size, 12–28 μm wide at widest part of leaf. Setae reddish; capsules cylindrical, slightly curved; peristome tubular for c. 3/4 of its length, spirally coiled; spores 10–28 μm. Capsules common, spring, summer. 1 Leaves acute or acuminate, border poorly developed and rarely reaching half way up leaf, cells weakly papillose, 16–28 μm wide at widest part of leaf var. graeffii Apices rounded to acuminate, border extending half way or more up leaf, cells strongly papillose, (10−)12–20(−22) μm wide 2 2 Leaves narrowly lanceolate, acuminate, border strongly developed, extending almost to acuminate apex var. angustata Leaves narrowly lingulate to spathulate or ovate-lanceolate, apices rounded to 3 acuminate, border extending 1/2–3/4 way up leaf

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347

3 Leaves usually narrowly lingulate to ovate-lanceolate, obtuse to acuminate, var. subulata border extending 1/2–3/4 way up leaf Leaves spathulate, apices rounded or obtuse and apiculate, border poorly var. subinermis developed, usually ending c. 1/2 way up leaf Var. subulata (Fig. 107) Leaves narrowly lingulate to ovate-lanceolate, obtuse to acuminate; margins bordered to 1/2–3/4 way up leaf, entire or opaquely toothed above; cells 12–20(−22) μm wide at widest part of leaf. Spores 10–20 μm. n = 12, 13, 14∗ , 18, 24, 26∗ , 48, 48 + m, 60. On light neutral to basic soil in open to sheltered sites on roadsides, banks, rock ledges, in woods and on tree roots and boles. 0–500 m. Frequent or common throughout most of Britain, rare to occasional in Ireland. 110, H25. GB627 + 141∗ , IR25 + 13∗ . Eurosiberian Southern-temperate. Europe north to Fennoscandia, Faeroes, Caucasus, Turkey, Kashmir, China, Canary Islands, Madeira, Algeria, eastern N. America. Var. angustata (Schimp.) Limpr., Laubm. Deutschl., 1888 T. angustata Limpr.

(Fig. 107)

Leaves narrowly lanceolate, tapering to acuminate apex; margins strongly bordered almost to apex, irregularly and opaquely toothed above; cells strongly papillose, mostly 12–20 μm wide at widest part of leaf. Spores 10–12 μm. On light, usually acidic soil in shady places. Lowland. Rare, from Devon and S. Hampshire north to the Lothians, N. Aberdeen, Orkney, Shetland, recorded from 28 vicecounties but seen recently from only 10, Down (old record). 28, H1. Europe north to Scandinavia, Turkey, Kashmir, China, Canary Islands, Algeria, Morocco, Tunisia, N. America. Var. subinermis (Bruch & Schimp.) Wilson, Bryol. Brit., 1855 (Fig. 107) Leaves spathulate, apex obtuse or rounded and apiculate, border poorly developed, ending at about half way up leaf; cells strongly papillose, 12–16 μm wide at widest part of leaf. Spores c. 16 μm. n = 24. On soil, tree boles and roots by streams and rivers. Lowland. Rare, scattered localities from N. Somerset and W. Sussex north to Stirling and N. Aberdeen, Down. 34, H1. Europe north to Scandinavia, Turkey, Kashmir, China, Canary Islands, Algeria, N. America. Var. graeffii Warnst., Krypt.-Fl. Brandenburg, Laubm., 1904 (Fig. 107) Leaves acute to acuminate, border poorly developed, ending about half way up leaf; cells opaquely papillose, 16–24 μm wide. Spores 14–20 μm. n = 26∗ . On light calcareous soil. Lowland. Rare to occasional, from N. Somerset, Dorset and I. of Wight north to Shetland, Westmeath, Cavan. 19, H2. Austria, Denmark, France, Germany, Norway, Poland, Sweden, Switzerland, Turkey. The usually present, relatively large, slightly curved capsules arising from rosettes of leaves make this plant readily recognisable. T. subulata is extremely variable in leaf characters, spore size and chromosome number. The status of var. angustata and var. subinermis is open

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Fig. 107 1–3, Tortula subulata var. subulata: 1, leaves; 2, marginal cells at widest part of leaf; 3, capsule (×7). 4–5, T. subulata var. subinermis: 4, leaf, 5, marginal cells at widest part of leaf. 6–7, T. subulata var. graeffii: 6, leaf; 7, marginal cells at widest part of leaf. 8–9, T. subulata var. angustata: 8, leaf; 9, marginal cells at widest part of leaf. 10–12, T. cuneifolia: 10, leaves; 11, cells at widest part of leaf; 12, capsule (×10). Leaves ×10, cells ×280.

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to question as they may be difficult to separate from the type and further investigation is required. Var. graeffii retains its characters in cultivation and appears to have a genetic basis (see A. C. Crundwell, Trans. Br. Bryol. Soc. 2, 292, 1956).

2 T. cuneifolia (Dicks.) Turner, Muscol. Hibern. Spic., 1804 (Fig. 107) Green patches or scattered plants, c. 5 mm high. Leaves shrunken, appressed when dry, lower erect-patent, upper thin, soft, crowded, patent to erect-patent when moist, broadly spathulate, rarely more than twice as long as wide, concave, abruptly narrowed to acute apex; margins plane, entire; costa percurrent to excurrent in smooth yellowish or sometimes hyaline point to 1/3 length of lamina; cells in lower part of leaf rectangular, above irregularly quadrate-hexagonal to shortly rhomboidal, thin-walled, smooth, pellucid, 16–24 μm wide at widest part of leaf, marginal cells thicker-walled but of similar shape to inner cells. Setae red; capsules cylindrical to narrowly ellipsoid; peristome teeth free nearly to base, spirally coiled; spores 14–18 μm. Capsules common, spring. n = 20∗ . On soil and in rock crevices on banks, in old quarries and fallow fields, especially near the coast. Lowland. Rare in southern Britain and much decreased, extending north to Anglesey and E. Suffolk, recorded from 21 vice-counties but seen recently only in 9, rare in Ireland and not seen recently. 21, H8, C. GB9 + 30∗ , IR10∗ , C2. MediterraneanAtlantic. S. and W. Europe, Turkey, Cyprus, Syria, Palestine, C. Asia, Macaronesia, Algeria, Morocco, Tunisia. T. cuniefolia has decreased markedly and is no longer known from inland habitats and has vanished from many coastal sites. This and the next two species are extremely variable in leaf shape and may be confused. T. freibergii differs in the usually narrower, bordered leaves with the costa usually ending below the apex and smaller cells. In T. solmsii at least some of the marginal cells of the leaves are usually of different shape from the inner cells which are smaller and densely papillose. This species is treated as vulnerable in the Red List of British Mosses.

3 T. freibergii Dixon & Loeske, Ann. Bryol., 1934 (Fig. 108) Autoicous or apparently dioicous. Yellowish green to dark green patches, to 2 mm high. Leaves slightly twisted, incurved when dry, erect-patent to spreading when moist, slightly concave, lingulate-lanceolate to spathulate, 1.75–4.00 times as long as wide, apex rounded to obtuse, rarely subacute, frequently with short apiculus; margins plane, entire or crenulate; costa ending below apex, rarely percurrent, adaxial cells rectangular; cells in lower part of leaf narrowly rectangular, above quadrate to rectangular, thin-walled, papillose, pellucid, 10–14(−18) μm wide at widest part of leaf, smaller towards apex, smooth or rarely sparsely papillose, pellucid, up to 12 marginal rows with thicker walls, some rectangular to elongate, forming sometimes distinct border. Setae pale yellow; capsules narrowly ellipsoid to cylindrical, ± symmetrical; peristome teeth free almost to base, spirally coiled; spores 8–12 μm. Capsules common, spring. n = 26∗ . On moderately exposed base-poor sandstone rocks and walls. Lowland. Very rare, E. Sussex,

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Fig. 108 1–3, Tortula vahliana: 1, leaves (×25); 2, marginal cells from widest part of leaf; 3, capsule. 4–5, T. solmsii: 4, leaves (×50); 5, marginal cells at widest part of leaf. 6–8, T. freibergii: 6, leaves (×20); 7, marginal cells at widest part of leaf; 8, capsule. Cells ×280, capsules ×15.

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Cheshire, S. Lancashire, N. E. Yorkshire. 4. GB6. Suboceanic Southern-temperate France, Portugal, Spain and Giglio Is. (Italy). For differences from T. cuneifolia and T. solmsii see under those species. For the occurrence of this plant in England see A. C. Crundwell & E. Nyholm, J. Bryol. 7, 161–4, 1972, and for an augmented account see T. L. Blockeel & F. J. Rumsey, J. Bryol. 16, 179–85, 1990. This plant is listed as vulnerable in the Red Data Book of European Bryophytes.

4 T. solmsii (Schimp.) Limpr., Laubm. Deutschl., 1888 (Fig. 108) Dioicous. Dense low tufts or scattered plants, 1.0–2.5 mm high. Leaves erect, slightly twisted when dry, erect-patent when moist, lingulate, spathulate or ovate, apex rounded to obtuse or acute or obtuse and mucronate; margins plane or narrowly recurved at middle of leaf, papillose-crenulate; costa ending below apex to excurrent to 400 μm in yellowish to greenish hair-point; basal cells thin-walled, hyaline, lax, narrowly rectangular, shorter and narrower towards margins, upper cells variable in shape, quadrate to rectangular or hexagonal, densely papillose, opaque, 12–16 (−18) μm wide in mid-leaf, 2–5 (−8) marginal rows rectangular and/or quadrate, ± smooth, less well or hardly differentiated in shade forms, usually unistratose. Setae yellowish when young, brown with age; capsules erect, shortly cylindrical; lid straight or slightly oblique; peristome teeth c. 600 μm long, spirally coiled; spores 10–15 μm. Capsules occasional, spring. On neutral to slightly basic rock or in crevices in granite walls. Lowland. Very rare, Scilly Isles, W. Cornwall, S. Devon. 2. GB4. Mediterranean-Atlantic. Mediterranean and Atlantic Europe, extending north to England, Turkey, Macaronesia, Algeria, Morocco. A variable species, shade forms differing markedly from plants in exposed habitats. Shade forms have lingulate-obovate, obtuse to acute leaves with costa ending well below the apex to percurrent, the cells less densely papillose and marginal rows poorly or hardly differentiated from inner cells. In open-ground forms the leaves are lingulate or spathulate with rounded to obtuse apices, costas ending below apex to excurrent in hair-point, cells strongly papillose with marginal cells differentiated and forming a distinct border. Confused in Britain with T. vahliana, which differs in the more spreading leaves, the margins papillose-crenulate, the narrowly cylindrical capsules and in being synoicous. T. freibergii has more spreading leaves with the costa ending well below the apex, the broader border 4–6(−12) cells wide and the other cells less strongly papillose, the capsules cylindrical and in being autoicous. The above description is based, largely upon that in a paper by D. G. Long & M. O. Hill (J. Bryol. 12, 159–69, 1982), where a detailed account of the species may be found.

5 T. marginata (Bruch & Schimp.) Spruce, London J. Bot., 1845 (Fig. 109) Dioicous. Yellowish green patches, 2–3 mm high. Leaves twisted when dry, erectpatent when moist, narrowly lanceolate or lingulate to lingulate-spathulate, occasionally spathulate, apex obtuse or acute; margins plane, bordered, sinuose with projecting cell walls; costa yellowish, excurrent in yellowish point to half length of lamina; cells in lower part of leaf narrowly rectangular, cells above shortly rectangular to irregularly quadrate-hexagonal, not incrassate, papillose, opaque,

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Fig. 109 1–4, Tortula muralis var. muralis: 1, leaf; 2, cells from widest part of leaf; 3, capsule; 4, peristome. 5, T. muralis var. aestiva: leaf. 6–9, T. canescens: 6, leaf; 7, cells from widest part of leaf; 8, capsule; 9, peristome. 10–12, T. marginata: 10, leaves; 11, marginal cells; 12, capsule. Leaves ×25, cells ×420, capsules ×15, peristomes ×62.5.

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8–14 μm wide at widest part of leaf, 2–4 marginal rows elongate, incrassate, forming distinct border extending almost from base to apex. Setae orange-red; capsules shortly cylindrical, symmetrical; peristome teeth free almost to base; spores c. 8 μm. Capsules common, spring. n = 24. On damp usually shaded basic rocks and walls in both natural and man-made habitats. Locally common in lowland England north to Cheshire and Durham, very rare elsewhere, Berwick, Argyll, Dunbarton, a few localities in Ireland, Guernsey. 56, H10, C. GB245 + 35∗ , IR7 + 4∗ , C1∗ . Mediterranean-Atlantic. S. and W. Europe extending north to Germany, Turkey, Cyprus, W. Asia, India, Macaronesia, N. Africa. Differing from T. muralis in the plants forming patches in damp shaded habitats and in the bordered leaves with the costa excurrent in a yellowish point.

6 T. vahliana (Schultz) Mont. in Gay, Hist. Phys. Cuba Bot. Pl. Cell, 1850 (Fig. 108) Autoicous. Bright green patches or scattered plants, to 5 mm high. Leaves erect, twisted when dry, thin, soft, spreading when moist, narrowly lingulate to spathulate, apices rounded; margins plane or recurved at middle of leaf, papillosecrenulate; costa excurrent in smooth greenish point to c. 220 μm long; cells in lower part of leaf rectangular, above hexagonal, thin-walled, papillose, pellucid, 16–20 μm wide, 1–2 marginal rows ± quadrate, less papillose. Setae red; capsules cylindrical, slightly curved; peristome teeth free almost to base, spirally coiled; spores 12–16 μm. Capsules occasional, spring. On shaded moist chalky clay soil on roadsides and in old chalk pits. Lowland. Very rare, Devon, S. Somerset, E. Kent, N. Essex, E. Suffolk, Cambridge, old records from W. Kent, Gloucester, Hereford and Dublin. 11, H1. GB9 + 9∗ , IR3∗ . Mediterranean-Atlantic. Mediterranean and Atlantic Europe, extending north to the British Isles, Turkey, Cyprus, Canary Islands, N. Africa, Chile. Over-recorded in the past because of confusion with forms of T. muralis occurring on soil. In T. muralis the leaf margins are recurved almost from base to apex, the leaf cells are smaller and the hair-points are usually hyaline.

7 T. canescens Mont., Arch. Bot. (Paris), 1833 (Fig. 109) Autoicous. Dense patches or scattered plants, 1–5 mm high. Leaves erect, flexuose, scarcely twisted when dry, erect-patent to patent when moist, from broad base broadly ovate to lanceolate or spathulate, not or scarcely constricted at or below middle, obtuse; margins plane or recurved at middle of leaf; costa strong, excurrent in smooth hyaline hair-point to 1/2–2 /3 length of lamina; cells in lower part of leaf rectangular, hyaline, cells above hexagonal, papillose, not incrassate, opaque, 12–16 μm wide at widest part of leaf. Setae reddish; capsules cylindrical; peristome tubular for 1/3–1/2 its length, spirally coiled; spores 14–16 μm. Capsules common, late winter, spring. n = 26∗ . On acidic soil in turf and on and among rocks, on shady banks and in wall crevices, in open situations. Lowland. Rare, Cornwall, N. Devon, Montgomery, Merioneth, Kintyre, old records from S. Devon, E. Sussex,

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Radnor, Pembroke, Jersey. 10, C. GB17 + 5∗ , C1∗ . Mediterranean-Atlantic. Europe north to Germany, Caucasus, Turkey, C. Asia, Madeira, Canary Islands, N. Africa. Resembling T. muralis, which rarely grows on soil, differing in the leaf margins plane or only recurved at the middle of the leaf, the peristome tubular for 1/3–1/2 its length and larger spores.

8 T. muralis Hedw., Sp. Musc. Frond., 1801 Autoicous. Small cushions, tufts or patches, green when moist, usually hoary and blackish when dry, rarely exceeding 10 mm high. Leaves twisted or curved when dry, erect-patent to squarrose-spreading when moist, lingulate or lingulatespathulate, apex obtuse or rounded, sometimes emarginate; margins strongly recurved almost from base to apex; costa stout, often reddish, usually excurrent in smooth hyaline hair-point to as long as lamina, rarely excurrent in short yellowish green point; cells in basal part of leaf rectangular, smaller towards margins, above quadrate-hexagonal, incrassate, papillose, opaque, 8–16(−20) μm wide at widest part of leaf, 1–2 marginal rows less papillose, more incrassate. Setae purple; capsules erect, cylindrical or narrowly ellipsoid, straight; peristome teeth free almost to base, bifid into filiform spirally coiled papillose segments; spores 7–12(−14) μm. Capsules common, spring, summer. Plants forming hoary cushions, tufts or patches, leaves with costa excurrent in hyaline hair-point var. muralis Plants forming non-hoary patches, costa excurrent in yellowish green point var. aestiva Var. muralis (Fig. 109) Plants forming cushions, tufts or patches, hoary when dry. Leaves lingulate or lingulate-lanceolate; costa excurrent in ± smooth hyaline hair-point. n = 13 + m, 18, 24, 26∗ , 26 + m∗ , 27∗ , c. 40, 48∗ , 50∗ , 52∗ , 55∗ , 60, 66. On usually exposed mortared or basic walls, roof tiles, concrete and basic rocks, rarely on acidic substrates, bark or hard-packed soil. 0–950 m. Very common in urban areas and able to withstand atmospheric pollution, occasional in natural habitats. 112, H40, C. GB1925 + 93∗ , IR334 + 20∗ , C3. Circumpolar Southern-temperate. Cosmopolitan. Var. aestiva Hedw., Sp. Musc. Frond., 1801 (Fig. 109) Plants in patches, bright green when moist, not hoary when dry. Leaves narrowly lingulate-spathulate; costa excurrent in short yellowish green point. n = 13, 26, 48. Occasional from S. Devon east to W. Kent and north to Wigtown and Berwick. 34. Europe north to Sweden, Caucasus, Turkey, E. Asia, Azores, Madeira, N. Africa, N. and southern S. America. Var. aestiva is possibly only a habitat modification and its status requires investigation. Large forms of T. muralis with large sporophytes are diploid and are conspicuously different from normal-sized plants and have been referred to as var. rupestris Chev. However, these intergrade completely with smaller plants, some of which are also diploid, and there is

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no correlation between chromosome number and morphology and the variety cannot be maintained (see M. E. Newton, Trans. Br. Bryol. Soc. 5, 523–35, 1968).

9 T. leucostoma (R. W. Br.) Hook. & Grev., Edinburgh J. Sci., 1824 (Fig. 110) Desmatodon leucostaoma (R. W. Br.) Berggr., D. suberectus (Hook.) Limpr., Tortula suberecta Hook. Autoicous. Tufted or gregarious ephemeral plants, 2–3 mm high. Leaves erect when dry, erect-patent when moist, broadly to narrowly triangular, ovatelanceolate or lanceolate, acute; margins revolute almost to apex, papillosecrenulate above; costa stout, excurrent in long or short yellowish hair-point; basal cells rectangular, hyaline, becoming smaller, quadrate, papillose, opaque above, 8–12 μm wide in mid-leaf, smaller and very obscure towards apex, cells towards margins less papillose, pellucid, forming pale band. Capsules erect or inclined, cylindrical, straight or slightly curved; lid rostrate; peristome with tall basal membrane, teeth spirally coiled; spores coarsely papillose, 20–26 μm. Capsules common, summer. On soil amongst calcareous rocks and on ledges. 550 m. Very rare, E. Perth, S. Aberdeen. 2. GB2. Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, N. and E. Asia, N. America, Greenland. A very rare species often associated with the similarly rare plant Stegonia latifolia; it is treated as vulnerable in the Red List of British Mosses.

10 T. cernua (Huebener) Lindb., Musci Scand., 1887 Desmatodon cernuus (Huebener) Bruch & Schimp.

(Fig. 110)

Autoicous. Bright green patches, 2–7 mm high. Leaves erect, twisted when dry, erect-patent to patent when moist, lanceolate, oblanceolate or spathulate, acuminate; margins bordered, recurved to middle of leaf or higher, denticulate above; costa stout, excurrent in cuspidate point; cells in basal part of leaf rectangular, hyaline, narrower at margins, cells above variable in shape and size, ± irregularly hexagonal, smooth or papillose, pellucid 10–20 μm wide at widest part of leaf, 1–3 marginal rows longer and narrower, forming distinct border, bistratose below. Setae red, flexuose; capsules cernuous or horizontal, ovoid, curved; lid obliquely rostrate; peristome teeth ± straight; spores coarsely papillose, 36–40 μm. Capsules common, autumn. n = 25, 26∗ . On highly calcareous soil on lime waste and quarry spoil, by paths and in quarries. Lowland. Very rare and sporadic in occurrence. Derby, Cheshire, S. W. Yorkshire, old records from Nottingham and Mid-West Yorkshire. 5. GB5 + 5∗ . Circumpolar Boreal-montane. Europe, extending north to Svalbard, Siberia, Mongolia, C. Asia, Tibet, N. America, Greenland. This species is considered endangered in the Red List of British Mosses and is a protected plant under the Wildlife and Countryside Act.

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Fig. 110 1–4, Tortula atrovirens: 1, leaves (×25); 2, marginal cells; 3, mid-leaf cells; 4, capsule. 5–8, T. leucostoma: 5, leaf (×35); 6, marginal cells; 7, mid-leaf cells; 8, old capsule. 9–12, T. cernua: 9, leaves (×25); 10, marginal cells; 11, mid-leaf cells; 12, capsule. Cells ×420, capsules ×15.

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¨ 11 T. atrovirens (Sm.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad. 1864 (Fig. 110) Desmatodon convolutus (Brid.) Grout Autoicous. Dark green tufts or patches, c. 2 mm high. Leaves spirally twisted when dry, erect-patent or patent when moist, concave, oblanceolate or obovate, broadly acute to obtuse and apiculate; margins usually strongly recurved, entire; costa stout, thickened in upper half of leaf, excurrent in mucro; basal cells ± rectangular, hyaline, cells above regularly quadrate-hexagonal, finely papillose, 10–12 μm wide at widest part of leaf. Capsules erect or slightly inclined, ovoid or ellipsoid; lid conical; peristome with short basal membrane, teeth straight; spores finely papillose, 24–26 μm. Capsules common, winter, spring. n = 26∗ . In open coastal situations on sandy soil or soil in rock crevices and on walls, often close to high tide level, very rare inland. Lowland. Occasional along the coast from Cornwall east to E. Kent and north to I. of Man, N. Northumberland, Dumfries, Banff and E. Ross, Hereford, Warwick, Derby, very rare on Irish coasts. 30, H10, C. GB54 + 33∗ , IR1 + 9∗ , C6. Circumpolar Southern-temperate. More or less cosmopolitan. Section 2 Pottia (Ehrh. ex Rchb.) Kindb., Bih. Kongl. Svenska Vetensk.-Ak. Handl., 1883 Leaves usually acute; costa usually shortly excurrent in yellowish brown point, 2–3 cells wide on adaxial side, these cells often bulging or forming low lamellae, smooth or with 1–2 papillae per cell; lamina cells usually large, 15–24 μm wide, smooth or weakly papillose. Peristome often rudimentary or short. The descriptions of species 12–16 were written by Dr D. F. Chamberlain as part of his account of the genus Pottia for the first edition of this book.

Species 12–16 by D. F. Chamberlain 12 T. lanceola R. H. Zander, Bull. Buffalo Soc. Nat. Sci., 1993 ¨ Hal. Pottia lanceolata (Hedw.) Mull.

(Fig. 112)

Autoicous. Plants in bright green tufts or patches, ephemeral, to 5 mm high. Leaves ovate-lanceolate, 2.5–3.0 times as long as wide, acute; margins recurved nearly to apex, ± entire; costa excurrent 150–300 μm; upper cells quadrate, thinwalled, papillose, 13.0–17.0(−19.5) μm wide. Setae 2.8–5.5 mm long; capsules ellipsoid, 1.00–1.75 × 0.6–0.9 mm, with 2–4(−7) rows of thick-walled cells below constricted mouth; lid longly rostrate; annulus present; peristome teeth well developed, straight, 250–450 μm long, imperfectly divided above; spores densely and finely papillose, (19.0−)21.5–30.0 μm; calyptrae smooth. Capsules common, winter, early spring. n = 23, 24∗ , 26, 26 + m. On open or disturbed usually calcareous soil in thin turf, quarries, on sea-cliffs, wall tops. 0–550 m. Frequent in the south, becoming rarer in the north, extending to Caithness, rare in Ireland.

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75, H6. GB174 + 105∗ , IR31 + 4∗ . Circumpolar Southern-temperate. Europe north to S. Scandinavia, W. Asia, Japan, Madeira, Canary Islands, N. Africa, N. America. Pale brown to brown rhizoidal gemmae, variable in size and shape, isodiametric and from 80 to 300 μm or ellipsoid or pyriform and 50 × 300 to 100 × 400 μm have been reported from Belgian and German material (see T. Arts, Lindbergia 13, 130–2, 1987).

13 T. wilsonii (Hook.) R. H. Zander, Bull. Buffalo. Soc. Nat. Sci., 1993 Pottia asperula Mitt., P. wilsonii (Hedw.) Schimp.

(Fig. 111)

Paroicous. Bright or pale green tufts, c. 5 mm high. Leaves obovate-lanceolate, 2.5–4.0 times as long as wide, apex acute to rounded; margins recurved; costa excurrent 150–650 μm; upper cells quadrate, strongly papillose, pellucid, walls moderately thick, 15–17 μm wide. Setae 2.0–3.3 mm long; capsules obovoid, 0.8–1.7 × 0.7–1.0 mm, widest well below constricted mouth, with 3–5 rows differentiated cells below mouth; lid rostrate; annulus present; peristome absent or rudimentary and up to 75 μm long; spores granulate-papillose, 19.0–26.5 μm; calyptrae smooth to scabrid. Capsules common, spring. On soil on rocky cliffs, Cornish ‘hedges’, wall tops, sandy banks, hedge banks and on wall tops. Lowland. Occasional along the coast from Cornwall to E. Norfolk and S. Lancashire but lost from all inland and many coastal localities (recorded from 21 British vice-counties but seen recently only in five), Jersey, old records from Guernsey, E. Cork, Dublin and Wicklow. 21, H3, C. GB20 + 34∗ , IR6∗ , C1 + 3∗ . Mediterranean and western Europe, extending north to the British Isles, British Columbia. T. wilsonii has decreased markedly since its discovery by W. Wilson in Cheshire in 1828. It is no longer known in any inland localities and has vanished from many coastal sites. At least some plants of the type specimen of P. asperula Mitt. fall within the range of P. wilsonii. This species is considered endangered in the Red List of British mosses.

14 T. viridifolia (Mitt.) Blockeel & A. J. E. Sm., J. Bryol., 1998 (Fig. 111) Pottia crinita Wilson ex Bruch & Schimp., P. viridifolia Mitt., P. wilsonii var. crinita (Wilson ex Bruch & Schimp.) Warnst. Autoicous. Dense light or pale green tufts, to 5 mm high. Leaves spathulate-oblong, (2.5−)3.0–4.0 times as long as wide, apices obtuse or rounded; margins recurved; costa excurrent 100–1100 μm; upper cells quadrate, papillose, thin-walled, 17– 24 μm wide. Setae 2–4 mm long; capsules obloid, 0.8–1.7 × 0.6–1.0 mm, widest at or slightly constricted towards mouth, with 2–4 rows thin-walled differentiated cells below mouth; lid rostrate; annulus present; peristome absent; spores granulate-papillose, 25–35 μm; calyptrae ± roughened, occasionally scabrous. Capsules common, spring. n = 48∗ . On soil on banks, cliffs, stream banks, ant hills and by paths. Lowland. Frequent along the coast from Cornwall east to Sussex and north to Kintyre, very rare along east coast north to Shetland, Radnor, rare along Irish coast. 39, H12, C. GB95 + 24∗ , IR4 + 8∗ , C8. Mediterranean-Atlantic. S. and

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Fig. 111 1–4, Tortula viridifolia: 1, plant (×10); 2, cells at mouth of capsule (×450); 3, upper leaf (×20); 4, cells from upper part of leaf (×430). 5–8, T. wilsonii: 5, cells at mouth of capsule (×450); 6, plant (×10); 7, upper leaf (×20); 8, cells from upper part of leaf (×430).

W. Europe north to Faeroes, Turkey, Israel, S. W. Asia, Gran Canaria, Tenerife, Algeria, Morocco. Plants with shortly excurrent costae have been described as var. viridifolia (Mitt.) Kindb. of Pottia crinita (i.e. T. viridifolia) but as there is no other reliable difference, nor any clear cut discontinuity in the degree of excurrence of the costa, the variety is not recognised here.

15 T. modica R. H. Zander, Bull. Buffalo Soc. Nat. Sci. 1993 (Fig. 112) ¨ Pottia intermedia (Turner) Furnr., P. littoralis Mitt., P. truncata var. major (F. Weber & D. Mohr) Bruch & Schimp. Autoicous. Patches or scattered plants, to 15 mm high. Leaves oblong-lanceolate, 3–4 times as long as wide, acute; margins plane or recurved, entire or crenulate above; costa excurrent to 100–300(−500) μm; upper cells quadrate, smooth or slightly papillose, 17–22 μm. Setae 4.0–6.2 mm; capsules obloid, 0.8–1.6 × 0.6– 1.0 mm, with 3–5 rows thick-walled differentiated cells below slightly constricted

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Fig. 112 1–4, Tortula truncata: 1, plant; 2, cells from mouth of capsule (×450); 3, leaf (×40); 4, cells from upper part of leaf. 5–8, T. modica: 5, cells at mouth of capsule (×450); 6, plant; 7, leaf (×20); 8, cells from upper part of leaf. 9–12, T. lanceola: 9, plant; 10, peristome teeth; 11, leaf (×20); 12, cells from widest part of leaf. Plants ×10, leaf cells ×430.

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mouth; lid rostrate; annulus present; peristome absent or rudimentary, reduced to a basal membrane 35 μm high; spores papillose, 17–34 μm; calyptrae smooth or slightly scabrous. Capsules common, mainly winter and spring. n = 52. On disturbed, calcareous or acidic soil, in arable fields, quarries, gardens, coastal turf and on banks. Lowland. Widespread but local, extending north to Ross, rare in Ireland. 86, H16, C. GB218 + 101∗ , IR7 + 13∗ , C5. Circumpolar Temperate. Europe north to S. Scandinavia, Iceland, Turkey, China, Japan, N. and C. America, Australia. Rhizoidal gemmae, indistinguishable from those of T. lanceola, have been reported from Belgian material (T. Arts, Lindbergia 13, 130–2, 1987). Intermediates between T. lanceola and T. truncata are often found with one or both of these species, and are possibly hybrid derivatives of them. May be distinguished from T. lanceola by capsule shape and the absent or rudimentary peristome and from T. truncata by the presence of an annulus and several rows of thick-walled cells below the capsule mouth. The plant referred to as var. littoralis (Mitt.) Corb. by Dixon & Jameson (1924), which in its extreme state is a well marked form with thick-walled smooth leaf cells and relatively narrow capsules, may be of different origin from the typical form. On present evidence it is not sufficiently distinct from the type to be maintained as a variety.

16 T. truncata (Hedw.) Mitt. in Godman, Nat. Hist. Azores, 1870 (Fig. 112) ¨ Pottia truncata (Hedw.) Bruch & Schimp., P. truncatula (With.) Buse Autoicous. Ephemeral plants forming dull green tufts or patches, to 10 mm high. Leaves oblong-lanceolate, 3–4 times as long as wide, acute; margins plane, slightly denticulate above; costa excurrent 50–300 μm; upper cells quadrate, 17–24 μm wide, thin-walled, smooth. Setae 2.0–3.5 mm long; capsules turbinate, 0.9–1.2 × 0.65–1.00 mm, widest at mouth, with 1–2 rows thin-walled differentiated cells below mouth; lid rostrate; annulus and peristome lacking; spores 24–36 μm; calyptrae smooth. Capsules throughout year but more commonly in spring. n = 20∗ , 25, 26, 52∗ . On disturbed non-calcareous soil in fields, gardens, quarries, on roadsides, woodland rides. Lowland. Common in the south, becoming less frequent in the north. 110, H35, C. GB1164 + 76∗ , IR136 + 7∗ , C8 + 1∗ . Circumpolar Temperate. Europe north to Fennoscandia, Turkey, Asia, Macaronesia, Algeria, Morocco, N. and C. America, New Zealand. Rhizoidal gemmae indistinguishable from those of T. lanceola have been reported from Belgium (T. Arts, Lindbergia 13, 130–2, 1987). Occasional gigas forms, about twice the size of normal plants with larger spores, may be encountered either as solitary plants in normal populations or as a pure population.

65 PROTOBRYUM (LIMPR.) J. GUERRA & M. J. CANO, J. BRYOL., 2000 D. F. Chamberlain

A monotypic genus with the characters of the species.

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Derivation: meaning first Bryum. For the reasons for placing the species in its own genus see J. Guerra & M. J. Cano, J. Bryol. 22, 91–7, 2000.

1 P. bryoides (Dicks.) J. Guerra & M. J. Cano, J. Bryol., 2000 Pottia bryoides (Dicks.) Mitt., Tortula protobryoides R. H. Zander

(Fig. 113)

Autoicous. Ephemeral gregarious dull green or brownish plants, 2–5 mm high. Upper leaves much larger than lower, lanceolate, 2.5–4.0 times as long as wide, acuminate, upper leaves much longer than lower; margins recurved, entire; costa excurrent 250–750 μm long; upper cells quadrate, smooth or slightly papillose, 16– 24 μm wide. Setae 2.0–5.5 mm; capsules ellipsoid, 1.0–1.8 × 0.7–0.9 mm, cleistocarpous but with at least one row of differentiated cells at base of beak; peristome rudimentary; spores minutely papillose, 25–32 μm; calyptrae smooth. Capsules common, winter, spring. On exposed basic soil in grassland, quarries, gravel pits, on banks, roadsides, tracks, paths, and cliffs by the sea. Lowland. Occasional in lowland England, rare in Wales, very rare in Scotland, extending north to Caithness, old records from Dublin, Antrim. 57, H2. GB98 + 53∗ , IR2∗ . European Temperate. Europe, W. Asia, western N. America. Rhizoidal gemmae, indistinguishable from those of T. lanceola, have been reported from Belgium (T. Arts, Lindbergia 13, 130–2, 1987).

66 PHASCUM HEDW., SP. MUSC. FROND., 1801 Two species with the characters of the species below. Derivation: from the Ancient Greek name for a plant of now unknown identity.

1 P. cuspidatum Hedw., Sp. Musc. Frond., 1801 Tortula acaulon (With.) R. H. Zander, T. atherodes R. H. Zander, P. cuspidatum var. curvisetum Nees & Hornsch. Autoicous or paroicous. Ephemeral plants forming pale green tufts, (1−)2– 5(−9) mm high. Leaves slightly twisted, appressed-flexuose when dry, lower patent, upper imbricate to convolute when moist, lower leaves ovate, upper and perichaetial leaves larger, ovate to ovate-lanceolate, acute; margins recurved, entire; costa excurrent; cells very variable, lower lax, above irregularly rectangular to hexagonal, usually thin-walled, smooth to strongly papillose, 9–21 × 11–31 μm in upper part of leaf. Setae short, 0.1–0.5 mm long, straight or curved; capsules immersed or slightly emergent, erect or inclined. Cleistocarpous, subglobose, shortly apiculate; spores 25–40(−44) μm. Capsules common throughout year. 1 Plants 4.5–9.0 mm high, stems branching from above var. schreberianum Plants rarely more than 4 mm high, stems branching from base

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Fig. 113 1–5, Phascum cuspidatum var. cuspidatum: 1, plant; 2, leaves; 3, adaxial cells of costa from upper part of leaf (×420); 4, costa section from upper part of leaf (×420); 5, capsules (×10). 6, P. cuspidatum var. piliferum: leaf. 7–8, P. cuspidatum var. papillosum: 7, adaxial side of costa from upper part of leaf (×420); 8, section of costa from upper part of leaf (×420). 9, P. cuspidatum var. schreberianum: plant. 10–13, Protobryum bryoides: 10, plant: 11, leaf; 12, leaf apex; 13, cells (×340). Plants ×10, leaves ×20.

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2 Costa excurrent in slightly flexuose hyaline point 0.6–1.4 mm long 2 var. piliferum Costa excurrent in yellowish cuspidate point to 0.6 mm long 3 3 Adaxial cells of upper part of costa rectangular, cells in upper part of lamina 10–21 × 21–31 μm, smooth or weakly papillose, spores with truncate or rounded papillae var. cuspidatum Adaxial cells of costa quadrate or shortly rectangular, cells in upper part of lamina 9–15 × 11–20 μm, papillose, spores spinosely papillose var. papillosum Var. cuspidatum (Fig. 113) Plants (1.0−)2.0–4.5 mm high. Stems branched or forked at base. Leaves crowded; costa excurrent in yellowish cuspidate point (0.1−)0.2–0.6 mm long, adaxial cells in upper part of leaf rectangular, in section not or only slightly inflated; upper cells of lamina 10–21 × 21–31 μm, smooth or with 2(−3) papillae per cell. Setae straight or rarely arcuate; capsules immersed or rarely laterally emergent; spores with rounded or truncate papillae. n = 21, 26∗ , 42, 52. Disturbed soil in fields, gardens, grassland, on waste ground, banks, woodland rides. Lowland. Very common in England, much of Wales and E. Scotland, rare elsewhere, extending north to Orkney, occasional in Ireland. 99, H34, C. GB938 + 70∗ , IR47 + 9∗ , C8. Circumpolar Southern-temperate. Europe to 64◦ N, Turkey, Asia, Madeira, Canary Islands Algeria, Morocco, N. America, Ecuador. Var. papillosum (Lindb.) Roth, Eur. Laubm., 1904 (Fig. 113) Phascum cuspidatum ssp. papillosum (Lindb.) Guerra & Ros, Tortula acaulon var. papillosa (Lindb.) R. H. Zander Plants as in var. cuspidatum. Adaxial cells of costa in upper part of leaf quadrate or shortly rectangular, strongly papillose, inflated and sometimes forming a pad on adaxial side of costa; cells in upper part of leaf papillose, 9–15 × 11–30 μm. Spores spinosely papillose. Lowland. Very rare, W. Cornwall, Stafford, Hereford, Nottingham, old records from Merioneth and Antrim. 5, H1. Belgium, Denmark, France, Germany, Italy, the Netherlands, Portugal, Spain, Sweden. Var. piliferum (Hedw.) Hook. & Taylor, Muscol. Brit., 1818 Tortula acaulon var. pilifera (Hedw.) R. H. Zander

(Fig. 113)

Similar to var. cuspidatum but costa excurrent in slightly flexuose hyaline point, 0.6–1.4 mm long. Capsules immersed. n = 27. On open disturbed usually basic soil in turf, on cliffs, banks, edges of paths, stony ground, in dune-slacks. Lowland. Rare, mainly in coastal localities from Cornwall east to Kent and north to Caithness, Guernsey. 31, C. GB35 + 14∗ , C1. Europe north to southern Scandinavia, Caucasus, Turkey, Iran, N. Africa, N. America.

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Var. schreberianum (Dicks.) Brid., Muscol. Recent., 1802 (Fig. 113) P. cuspidatum var. maximum auct., Tortula acaulon var. schreberiana (Dicks.) R. H. Zander Plants 4.5–9.0 mm high. Stems simple below, branched above. Leaves as in var. acaulon, lower distant, upper erect to erect-patent. Capsules immersed. On disturbed soil in fields, on banks, waste ground. Lowland. Rare, scattered localities from S. Devon, N. Somerset and Surrey north to Durham. 16. Rare in Europe, N. Africa, N. America, Antarctica. A very variable species but much of the variation is continuous and many of the infraspecific taxa described in the past are based on arbitrary and unsatisfactory characters. In the British Isles the varieties described above appear sufficiently distinct to merit recognition although experimental studies are required to determine their status. The characters given in Dixon & Jameson (1924) for the varieties of P. cuspidatum are unsatisfactory; the only reliable character of var. piliferum is the longly excurrent costa. The plant referred to as var. curvisetum Nees & Hornsch. is not worth maintaining as the main distinguishing feature, the curved seta, is not infrequently encountered in all the forms of P. cuspidatum. Var. papillosum was raised to subspecific status by Guerra et al. (Crypt. Bryol. Lichén. 12, 379–423, 1991) and was recorded by them from Angus, although this record has not been confirmed. The above description and key characters of var. papillosum have been taken from that paper. However, the differences between var. papillosum and var. cuspidatum are not clear cut and do not correlate and I consider that the taxon only merits varietal status. For the occurrence of var. papillosum in Britain see T. L. Blockeel, Bull. Br. Bryol. Soc. 65, 59–60, 1995.

¨ 67 POTTIA (RCHB.) FURNR., FLORA, 1823 Paroicous or occasionally synoicous. Small scattered or gregarious plants. Stems very short, with or without central strand; sclerodermis and hyalodermis absent. Axillary hairs 3–6 cells long. Leaves appressed when dry, spreading when moist, lanceolate to ovate, acute; margins recurved; costa usually excurrent, 3–4(−6) cells wide on adaxial side, cells ± quadrate, in section with abaxial stereid band; basal cells rectangular, cells above quadrate, papillose, papillae usually simple, marginal cells often less papillose and more incrassate. Perichaetial leaves similar in shape to but larger than stem leaves. Setae short, straight; capsules exserted, shortly cylindrical to ellipsoid or turbinate, dehiscent; lid conical, peristome teeth rudimentary to well developed. Laminal KOH colour reaction red. Probably only two European species. Derivation: named after the German botanist J. F. Pott (1738–1805). The descriptions of the two species are modified from those by D. F. Chamberlain in the first edition of this book, in the light of information in the two papers referred to in the footnote to P. starkeana.

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Fig. 114 1–5, Pottia starkeana: 1, upper leaf (×40); 2, cells from upper part of leaf (×430); 3, capsule (×20); 4, capsule mouth (×450); 5, spore (×800). 6–11, P. davalliana: 6, plants (×10); 7, upper leaves (×40); 8, cells from upper part of leaves of different plants (×450); 9, capsule (×20); 10, capsule mouths from different plants (×450); 11, spores from different plants (×800).

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Zander (1993) includes these two species of Pottia in Microbryum but J. Guerra & M. J. Cano (J. Bryol. 22, 91–7, 2000) provide sound reasons for separating the two genera and I have followed them.

1 Spores with warty protuberances or ridges or vermiform ornamentations (Fig. 115, 1–6) 1. P. starkeana Spores with dense papilla-like or spiny processes or a mixture of protuberances and warts or ± smooth 2 2 Spores with dense papilla-like or spinose processes (Fig. 115, 7–18) 2. P davalliana Spores with a mixture of protuberances and processes or ± smooth (Fig. 115, 19–22) Probable hybrids ¨ Hal., Syn. Musc. Eur. Musc. Frond., 1849 1 P. starkeana (Hedw.) Mull. (Figs. 114, 115) Microbryum starkeanum (Hedw.) R. H. Zander, P. starkeana var. brachyodus ¨ Hal. (Bruch & Schimp.) Mull. Autoicous. Very small gregarious ephemeral plants, 1–2 mm high. Leaves ovatelanceolate, 2.0–4.5 times as long as wide, acute; margins recurved; costa percurrent or excurrent to c. 175 μm; upper cells quadrate, thick-walled, papillose, (9−)10–12(−18) μm wide. Setae 1–4 mm long; capsules ellipsoid, usually widest at about middle with (1−)2–4 rows thickened cells below constricted mouth; peristome absent to well developed; lid conical to mamillate; annulus absent; spores 19–42 μm, with rounded protuberances, low ridges or vermiform ornamentations; calyptrae scabrous or occasionally smooth. Capsules common, winter, spring, rarely early summer. n = 26. On disturbed shallow soil on cliffs, walls, banks, by roads and tracks, woodland rides, in grassland, fields, on basic substrates. Lowland. Occasional in coastal areas, rare inland, in southern England and Wales, rare elsewhere and extending north to Angus and Kintyre, very rare in Ireland and seen recently only in Dublin. 35, H6, C. GB59 + 30∗ , IR1 + 5∗ , C3 + 2∗ . Submediterranean-Subatlantic. Europe north to S. Sweden, Turkey, Cyprus, Madeira, Canary Islands, N. Africa, N. America, Australia and New Zealand (introduced?). The taxonomy of the Pottia starkeana aggregate, including this and P. davalliana has proved very problematical for many years. Dixon & Jameson (1924) recognised four species and one variety and D. F. Chamberlain, in the first edition of this book, two species, three ´ & M. J. Cano (Pl. Syst. Evol. subspecies and one variety. R. M. Ros, J. Guerra, J. S. Carion 199, 153–65, 1996), after a detailed study of the various taxa concerned, concluded that spore morphology is the only character of taxonomic value and that the various taxa previously recognised constitute just two species. These can only be separated on the basis of spore morphology and even between these intermediates occur (Fig. 115) which may be of hybrid origin. These intermediate spores may be smooth or with weak protuberances or

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Fig. 115 Light micrographs of spores. 1–6, spores of Pottia starkeana; 7–11, spores from plants of P. davalliana with well developed peristomes; 12–18, spores from plants of P. davalliana with rudimentary or no peristomes; 19–22, spores of an intermediate type. Scale = 10 μm. I am indebted to Dr Rosa M. Ros, University of Murcia, Spain for these micrographs.

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ornamentations or sparse spines. The key to these two species is modified from that of the ´ R. M. Ros & J. Guerra, authors quoted above. Three is also an earlier paper (J. S. Carion, Nova Hedwigia 56, 89–112, 1993) discussing the correlation, or rather lack of correlation, between spore morphology and development of the peristome. Whether the two species should be maintained as separate taxa is very much open to question.

2 P. davalliana (Sm.) C. E. O. Jensen, Danmarks Mosser, 1923 (Figs. 114, 115) Microbryum davallianum (Sm.) R. H. Zander, P. commutata Limpr., P. minutula ¨ ¨ (Schwagr.) Furnr., P. starkeana ssp. commutata (Limpr.) D. F. Chamb., ¨ P. starkeana ssp. conica (Schwagr.) D. F. Chamb., P. starkeana ssp. minutula ¨ (Schwagr.) D. F. Chamb. Autoicous. Very small gregarious ephemeral plants. Leaves ovate-lanceolate, 2.0–4.5 times as long as wide; margins recurved; costa excurrent 10–200 (−280) μm; upper cells (9−)13–16(−21) μm wide, moderately papillose. Setae 1.0–2.5 mm long; capsules narrowly cylindrical to turbinate, widest at or slightly constricted at mouth, with 1–3 rows thin- or thick-walled cells below mouth; lid conical or mamillate; peristome teeth absent or rudimentary and up to 40 μm long; spores (22−)31–40(−42) μm, with papilla-like or spinose processes to c. 4 μm long. Capsules common, winter to summer. n = 26, 27 + m∗ , 28, 30. On disturbed shallow soil on cliffs, in fields, quarries, grassland, on woodland rides, by paths and among rocks, on basic substrates. Common in S. E. England, occasional elsewhere in England and Wales, very rare in the north, extending to Orkney, rare to occasional in Ireland. 73, H13, C. GB354 + 146∗ , IR21 + 16∗ , C1 + 1∗ . Submediterranean-Subatlantic. Europe north to Fennoscandia, Turkey, Cyprus, Canary Islands, N. Africa, N. America, Australasia.

68 MICROBRYUM SCHIMP., SYN. MUSC. EUR., 1860 Paroicous or occasionally synoicous. Small scattered or gregarious plants. Stems very short, with or without central strand; sclerodermis and hyalodermis absent. Axillary hairs 3–6 cells long. Leaves appressed when dry, spreading when moist, lanceolate to ovate, acute; margins recurved; costa usually excurrent, 3–4(−6) cells wide on adaxial side, cells ± quadrate, in section with abaxial stereid band; basal cells rectangular, cells above quadrate, papillose, papillae usually simple, marginal cells often less papillose and more incrassate. Perichaetial leaves similar in shape to but larger than stem leaves. Setae very short; capsules immersed or exserted, ovoid, cleistocarpous. Laminal KOH colour reaction red. Five European species, occurring especially in drier regions. Derivation: meaning small Bryum.

1 Setae 70–100 μm long, capsules immersed Setae 0.5–1.5 mm long, capsules exserted

3. M. floerkeanum 2

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2 Setae straight, capsules erect, exserted above perichaetial leaves 1. M. rectum Setae cygneous, capsules laterally exserted, horizontal or pendulous 2. M. curvicolle 1 M. rectum (With.) R. H. Zander, Bull. Buffalo Soc. Nat. Sci., 1993 Pottia recta (With.) Mitt.

(Fig. 116)

D. F. Chamberlain

Paroicous. Very small ephemeral gregarious plants. Leaves lanceolate, 2–3 times as long as wide, acute; margins recurved, entire; costa excurrent 50–130 μm; upper cells quadrate, 9–12(−15) μm wide, strongly papillose. Setae 0.6–1.0 mm long; capsules. spherical, cleistocarpous or with semideciduous apiculate lid, with 1–2 rows thickened cells at base of lid; peristome absent; spores with long spines, 23–30 μm; calyptrae rough. n = 26∗ . Capsules common, winter, spring. On soil in turf, on cliffs, banks, by tracks, in quarries, on basic substrates. Lowland. Occasional to frequent in the southern half of England, rare to occasional in Wales and northern England, rare in Scotland, extending north to Orkney, rare in Ireland. 60, H13, C. GB205 + 43∗ , IR8 + 5∗ , C1∗ . Mediterranean-Atlantic. C. and S. Europe, Caucasus, Turkey, Algeria, Morocco. Rhizoidal gemmae, indistinguishable from those of Tortula lanceola, have been reported from France (T. Arts, Lindbergia 13, 130–2, 1987).

2 M. curvicolle (Hedw.) R. H. Zander, Bull Buffalo Soc. Nat. Sci., 1993 (Fig. 116) Phascum curvicolle Hedw. Paroicous or synoicous. Ephemeral greenish to brownish gregarious or scattered plants, 1.5–3.0 mm high. Lower leaves patent, upper and perichaetial leaves erect-patent when moist, lower oblong-lanceolate, upper larger, narrowly lanceolate, acuminate; margins recurved, entire or sometimes papillosecrenulate above; costa weak below, strong above, excurrent in cuspidate point, 100–300 μm long; basal cells rectangular, cells in mid-leaf quadrate-rectangular to quadrate-hexagonal, thin-walled, strongly papillose, opaque, 12–16 μm wide, towards apex irregularly quadrate-hexagonal to rounded-hexagonal. Setae cygneous, 0.5–1.5 mm long; capsules laterally exserted, cleistocarpous, horizontal to pendulous, ovoid with stout blunt oblique apiculus; spores 24–28 μm; calyptrae cucullate. Capsules common, autumn to spring. On bare soil in chalk and limestone grassland, quarries, occasionally in stubble fields. Lowland. Frequent on the chalk in southern England, rare elsewhere and very rare in Scotland, extending north to E. Ross, W. Galway (old record), Dublin. 50, H2. GB104 + 28∗ , IR2∗ . Submediterranean-Subatlantic. S., W. and C. Europe, north to southern Scandinavia, Turkey, Algeria, Tunisia.

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Fig. 116 1–2, Microbryum curvicolle: 1, plant (×25); 2, leaves (×40). 3–5, M. floerkeanum: 3, plant (×25); 4, leaf (×65); 5, capsule (×65). 6–9, M. rectum: 6, plant (×20); 7, leaf (×40); 8, leaf apex (×80); 9, cells from upper part of leaf. (×340). 10–14, Hennediella heimii: 10, plant (×10); 11, leaf (×20); 12, leaf apex (×40); 13, cells from upper part of leaf (×340); 14, capsule (×20).

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3 M. floerkeanum (F. Weber & D. Mohr) Schimp., Syn. Musc. Eur., 1860 (Fig. 116) Phascum floerkeanum F. Weber & D. Mohr Paroicous. Ephemeral reddish green gregarious or scattered plants, 0.6–1.2 mm high. Lower leaves spreading, upper and perichaetial leaves erect-patent, concave, ovate, acuminate; margins plane or narrowly recurved, entire; costa reddish brown, weak below, strong above, excurrent in cuspidate point; basal cells lax, rectangular-hexagonal, cells above quadrate, hexagonal to rhomboidal, finely papillose on abaxial side, 12–16 μm wide in mid-leaf, towards apex smaller, ± hexagonal. Setae straight, very short, 70–100 μm long; capsules immersed but not concealed by perichaetial leaves, cleistocarpous, subglobose with blunt apiculus, symmetrical; spores 15–25 μm; calyptrae subcucullate. Capsules common, August to October. On bare soil in arable fields, more rarely in grassland or quarries, on chalk, rarely on limestone terrain. Lowland. Frequent on the chalk in England, very rare elsewhere, extending north to Yorkshire and Durham. 32. GB62 + 21∗ . European Temperate. Europe north to southern Fennoscandia, Turkey, Algeria, N. America. 69 HENNEDIELLA PARIS, INDEX BRYOL., 1896 Dioicous or monoicous. Plants forming cushions or turfs. Stems with central strand, sclerodermis and hyalodermis absent. Leaves somewhat incurved when dry, spreading or recurved when moist, narrowly lanceolate to ovate, lingulate or spathulate, acute; margins usually plane, often dentate above; costa percurrent or shortly excurrent, adaxial cells in 4–5 rows, quadrate or shortly rectangular, in section with single stereid band; basal cells rectangular, cells above quadrate or hexagonal, papillose, marginal cells longer, narrower, less papillose or smooth, forming border. Perichaetial leaves larger than stem leaves. Setae short to long; capsules ovoid to cylindrical; peristome absent, rudimentary or of 32 filiform teeth; calyptrae cucullate. Laminal KOH reaction red. A ± world-wide genus of c. 20 species. Derivation: named after the Scottish algologist Roger Hennedy (1809–1877).

1 Leaf cells slightly papillose, pellucid, marginal cells not differentiated, rhizoidal gemmae lacking 3. H. heimii Leaf cells strongly papillose, opaque, marginal cells elongate, pellucid, rhizoidal gemmae usually present 2 2 Leaves obtuse and apiculate, apiculus 25–75 μm long, mid-leaf cells 12–18 × 15–2 μm, cells towards apex usually 10–15(−24) μm wide 1. H. stanfordensis Leaves acute with apiculus 100–150 μm long, mid-leaf cells 15–20 × 25–35 μm, cells towards apex 10–25 μm wide 2. H. macrophylla

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1 H. stanfordensis (Steere) Blockeel, J. Bryol., 1990 (Fig. 117) Hyophila stanfordensis (Steere) A. J. E. Sm. & H. Whitehouse, Tortula stanfordensis Steere Dioicous. Yellowish green or green patches or scattered plants, 2–7 mm high. Leaves somewhat incurved when dry, spreading when moist and forming a flat rosette, to 2.5 mm long, lingulate to spathulate, in small plants ovate, obtuse and apiculate, apiculus 25–75 μm long; margins plane, bordered nearly to apex, irregularly toothed near apex; costa excurrent in small apiculus, adaxial cells quadrate; basal cells rectangular, hyaline, 15–20 × 65–95 μm, cells above rectangular, becoming quadrate, strongly papillose, opaque, in mid-leaf 12–18 × 15–25 μm, near apex 10–15(−24) μm wide, 2–4 marginal rows elongate, pellucid, forming distinct border. Pale brown irregularly ovoid rhizoidal gemmae, 30–60 × 50–100 μm, with protuberant cells, always present. Only 5 immature sporophytes have ever been seen. n = 13∗ . On sheltered footpaths, stream and river banks and soil on magnesian limestone ledges, very rarely in arable fields. Lowland. Rare or locally occasional, W. Cornwall, E. Sussex, E. Kent, E. Suffolk, Cambridge, banks of Rivers Severn, Teme, Wye and Dee, N. E. England, Peebles, E. and Mid Lothian, Dublin. 25, H1. GB63, IR1. European Southern-temperate. France, Greece, California, Australia. For differences from H. macrophylla see footnote to that species. Most populations of H. stanfordensis are female only. The species has only once been found with capsules (immature) in the British Isles (the only known sporophytes), and the gametophytes bearing them, although typical of H. stanfordensis, were apparently autoicous. H. stanfordensis has been found to be relatively widely distributed in Britain since its discovery in Cornwall in 1958 and is known also from France, Greece, California and Australia. It almost certainly occurs elsewhere but is likely to have been overlooked because of its small size and occurrence in what are regarded as bryologically unpromising habitats. As the species is so widespread in Britain and frequently occurs in habitats where it is unlikely to have been introduced, it is very probable that it is native, contrary to the commonly held view that it is an introduction from N. America or Australia. For an account of H. stanfordensis and its discovery in Cornwall see H. L. K. Whitehouse, Trans. Br. Bryol. Soc. 4, 84–94, 1961.

2 H. macrophylla (R. M. Br.) Paris, Index Bryol., 1896 Tortula brevis H. Whitehouse & M. E. Newton

(Fig. 117)

Autoicous or occasionally synoicous. Bright green patches or tufts, 2–25 mm high. Leaves incurved when dry, patent when moist, to 2.8(−4.0) mm long, spathulate, acute and apiculate, apiculus 100–150 μm long; margins bordered, toothed towards apex; costa percurrent, adaxial cells quadrate; basal cells rectangular, thinwalled, hyaline, 20–35 × 80–100 μm, cells above rectangular, strongly papillose, opaque, in upper part of leaf quadrate, cells in mid-leaf 15–20 × 25–35 μm, cells in upper part of leaf 10–25 μm wide, marginal cells elongate, pellucid, forming

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Fig. 117 1–4, Hennediella stanfordensis: 1, leaves; 2, marginal cells at widest part of leaf; 3, leaf apex; 4, rhizoidal gemmae (×190). 5–8, H. macrophylla: 5, leaves; 6, marginal cells at widest part of leaf; 7, leaf apex; 8, capsules (×10). Leaves ×22.5, cells ×280.

69 Hennediella

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distinct border. Brown multicellular, irregularly shaped rhizoidal gemmae present; gemmae consisting of uniseriate row of thick-walled cells occasionally present on adaxial surface of leaves. Setae very stout, c. 2 mm long; capsules slightly inclined, narrowly ellipsoid; peristome lacking; lid rostrate; spores 20–22 μm. Capsules frequent, May, June. n = 26∗ , 52∗ . Suboceanic Temperate. Rare to occasional in two areas: in S. E. England and in Northumberland and S. E. Scotland, I. of Wight. 17. GB30. Tierra del Fuego, New Zealand. In their original description H. L. K. Whitehouse & M. E. Newton (J. Bryol. 15, 83–99, 1988) say that H. stanfordensis differs from H. macrophylla in its relatively narrower, obtuse, more shortly apiculate leaves with smaller cells. However, H. macrophylla is a variable plant and forms occur with relatively narrower leaves and/or smaller leaf cells. Also, occasional plants of H. stanfordensis have cells 12–20(−24) μm wide in the upper part of the leaf and it is evident that the species are not as distinct as was originally thought. Whether H. stanfordensis and H. macrophylla can be maintained as separate species remains to be seen (see T. L. Blockeel, J. Bryol. 16, 187–92 for a discussion of this). Although H. macrophylla is known elsewhere only from the Southern Hemisphere there is no reason to consider that it is an introduced species in Great Britain. It occurs in natural habitats and is very possible that the two groups of populations in Britain arose as a consequence of polyploidy on two occasions in H. stanfordensis. That the haploid has not been seen in New Zealand or Tierra del Fuego, where H. macrophylla is found, does not mean that it does not occur there.

3 H. heimii (Hedw.) R. H. Zander, Bull. Buffalo Soc. Nat. Sci., 1993 ¨ Desmatodon heimii (Hedw.) Mitt., Pottia heimii (Hedw.) Furnr.

(Fig. 116)

D. F. Chamberlain

Autoicous, rarely synoicous. Plants ephemeral. Leaves narrowly oblonglanceolate, 3–5 times as long as wide, acute; margins plane, toothed or entire towards apex; costa percurrent to excurrent to 100 μm; upper cells quadrate, thickwalled, faintly papillose, pellucid, 13.0–21.5 μm wide. Setae 5–9 mm long; capsules obloid, 1.00–1.95 × 0.7–1.0 mm, with 2–4 rows thickened cells below slightly constricted mouth; lid rostrate, remaining attached to columella, and persisting for some time after dehiscence; annulus and peristome absent; spores minutely to coarsely papillose, 29–34 μm; calyptrae smooth. Capsules common, all year but mainly spring to early summer. n = 26∗ . Earth-covered rocks, bare patches of soil and in upper reaches of salt-marshes. Lowland. Frequent in coastal areas, very rare inland. 74, 18, C. GB210 + 67∗ , IR11 + 9∗ , C4 + 2∗ . Mediterranean-Atlantic. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, N. and C. America, Caribbean. H. heimii may usually be easily distinguished from species of Tortula section Pottia, and from Pottia and Microbryum species by the persistent lid and toothed leaves.

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16 Pottiaceae

¨ 70 ACAULON MULL. HAL., BOT. ZEIT., 1847 Dioicous or autoicous. Plants small, bud-like. Stems very short, without central strand, sclerodermis or hyalodermis. Leaves ± imbricate, convolute or not, concave, sometimes strongly keeled; margins plane or recurved, entire or toothed; costa ending below apex to excurrent, adaxially 3–4 cells wide, cells elongate, in section with abaxial stereid band, sometimes with 2 lamellae on adaxial side; basal cells rectangular, cells above various in shape, rectangular to rhomboidal or quadrate, smaller towards margins and apex, smooth or papillose. Setae very short, straight or curved; capsules immersed, globose, with or without small apiculus, cleistocarpous; calyptrae small, conical. Laminal KOH reaction red. A small genus of about 15 species occurring in Europe, W. Asia, N. Africa, America, Australasia, Hawaii. Derivation: meaning without a stem.

Upper leaves convolute, plants rounded when viewed from above, setae straight, capsules erect 1. A. muticum Upper leaves barely overlapping, plants ± triangular when viewed from above, setae curved, capsules inclined 2. A. triquetrum ¨ Hal., Bot. Zeit., 1847 1 A. muticum (Schrad. ex Hedw.) Mull. A. minus (Hook. & Taylor) A. Jaeger Autoicous or dioicous. Minute ephemeral pale green gregarious or scattered plants, to 2 mm high. Lower leaves patent, upper erect, convolute, partially or completely concealing capsules when viewed from above, concave, ovate, acute or obtuse with reflexed apiculus; margins plane, toothed towards apex; costa ending below apex to excurrent in apiculus; basal cells irregularly rectangular, cells in mid-leaf narrowly rhomboidal to hexagonal, 14–30 μm wide, mostly 1–3 times as long as wide, narrower towards margins, shorter near apex. Setae c. 120 μm long, straight; capsules immersed, erect, globose, cleistocarpous, with small blunt apiculus; spores spherical or ovoid, granulose or spinulose. Capsules common, autumn to spring. Spores finely granulose Spores spinulose

var. muticum var. meditaerraneum

Var. muticum (Fig. 118) Spores granulose, 30–50 μm. n = 26. On usually neutral well drained bare soil in stubble fields, gravel pits, on banks and roadsides. Lowland. Occasional throughout much of England, rare in Wales, very rare in Scotland, extending north to E. Ross, very rare in Ireland and not seen recently. 72, H7, C. GB102 + 94∗ , IR7∗ , C2. European Temperate. Europe north to Fennoscandia, W. and C. Asia, Siberia, Azores, Gran Canaria, Tenerife, Algeria, Morocco, N. America, Australia.

70 Acaulon

377

Fig. 118 1–5, Acaulon muticum var. muticum: 1, plant (×20); 2, leaves (×40); 3, cells near leaf apex from different plants; 4, mid-leaf cells from different plants; 5, capsule. 6–8, A. triquetrum: 6, leaves (×65); 7, mid-leaf cells; 8, capsule. Cells ×420, capsules ×65.

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16 Pottiaceae

´ Var. mediterraneum (Limpr.) Sergio, Bol. Soc. Brot., 1972 Spores c. 30 μm, spinulose, spinules 2–3 μm high. Capsules common, winter. On and by paths and tracks, bare soil in turf, fields and on cliff tops. Occasional in Cornwall, very rare elsewhere, Cornwall, S. Devon, S. Somerset. 4. GB8 + 1∗ . Crete, France, Greece, Italy, Portugal, Sardinia, Spain, Sweden, Turkey, Australia. Var. mediterraneum is variously treated as a species or a variety of or synonymous with A. muticum. The only known difference between the type and var. mediterraneum is spore ornamentation, although the latter has a more southerly distribution. For a discussion of the taxonomic status of var. mediterraneum see D. T. Holyoak, Bull. Br. Bryol. Soc. in press. It has been shown that there is no discontinuity in variation in morphological and spore characters between A. muticum and A. minus, and the latter cannot be maintained as a distinct taxon (see M. O. Hill, J. Bryol. 12, 11–14, 1982).

¨ Hal., Bot. Zeit., 1847 2 A. triquetrum (Spruce) Mull. (Fig. 118) Minute ephemeral green to yellowish brown gregarious or scattered plants, to 1.5 mm high. Upper leaves imbricate but scarcely overlapping, usually the three uppermost strongly keeled so that plant appears ± triangular when viewed from above. Leaves ovate, obtuse to acute; margins narrowly recurved above with a few sharp teeth near apex; costa excurrent in reflexed apiculus; basal cells shortly rectangular, cells in mid-leaf quadrate-rectangular to trapezoid, 12–20 μm wide, shorter towards apex. Setae arcuate, thin, fragile; capsules inclined, globose, cleistocarpous, with small blunt apiculus; spores finely papillose, c. 30 μm. Capsules common, winter. On bare chalky ground on coastal cliffs and banks. Lowland. Very rare, S. Devon (old record), Dorset, I. of Wight, E. Sussex. 4. GB4 + 6∗ . Submediterranean-Subatlantic. Europe from the Mediterranean north to Belgium and Germany, Turkey, Fuerteventura, Tenerife, Algeria, Morocco, Australia. This species is considered endangered in the Red List of British mosses and is a protected plant under the Wildlife and Countryside Act.

¨ 71 LEPTOPHASCUM (MULL. HAL.) J. GUERRA & M. J. CANO, J. BRYOL., 2000 A monotypic genus with the characters of the species. Derivation: meaning slender Phascum.

¨ Hal.) J. Guerra & M. J. Cano, J. Bryol., 2000 1 L. leptophyllum (Mull. (Fig. 119) ¨ Hal.) R. H. Zander, Phascum leptophyllum Mull. ¨ Hal., Chenia leptophylla (Mull. Tortula rhizophylla (Sakurai) Z. Iwats. & M. Saito, T. vectensis E. F. Warb. & Crundw. Ephemeral green or brownish green gregarious or scattered plants, to 3 mm high. Leaves incurved, contorted when dry, patent to widely spreading with reflexed tips

71 Leptophascum

379

Fig. 119 1–3, Leptophascum leptophyllum: 1, leaves; 2, cells from widest part of leaf; 3, rhizoidal gemmae (×250). 4–5, Syntrichia norvegica: 4, leaf; 5, cells from widest part of leaf. 6–11, S. ruralis var. ruralis: 6, leaf; 7, leaf apex (×70); 8, costa section (×175); 9, basal cells; 10, cells from widest part of leaf; 11, capsule (×10). 12, S. ruralis var. ruraliformis: leaf. Leaves ×25, cells ×280.

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16 Pottiaceae

when moist, spathulate, rapidly narrowed to acute to acuminate apex; margins plane, subcrenulate above; costa excurrent in short reflexed apiculus; cells collenchymatous but not incrassate, basal shortly rectangular, cells above irregularly hexagonal with brownish walls smooth, pellucid, very variable in size, 14–30 μm wide at widest part of leaf, smaller towards apex. Irregular ± elongate brownish rhizoidal gemmae, 70–190 × 30–125 μm, abundant. Setae very short, 0.1–0.2 mm long, straight; capsules immersed, ± subspherical, cleistocarpous, with longly rostrate oblique beak; spores 15–20 μm. Capsules unknown in Britain. On basic to acidic soil in stubble fields, on gravelly soil and cliff paths. Lowland. Very rare, Scilly Isles, W. Cornwall, I. of Wight. 2. GB3. Oceanic Southern-temperate. Germany, Italy, Spain, India, China, Japan, New Guinea, Azores, Canary Islands., east and southern Africa, N. and S. America, Easter Is., Hawaii. It seems unlikely that this plant is an introduction as it occurs in widely scattered localities ± throughout the world. Its small size and frequent lack of sporophytes mean that it is likely to be passed over for sterile Tortula sect. Pottia, Pottia or Mictobryum species. It differs in the morphology of the abundant rhizoidal gemmae and, in Britain, absence of capsules. In cultivation the plants from the Isle of Wight proved to be female. For the occurrence of this plant in Britain see E. F. Warburg & A. C. Crundwell, Trans. Br. Bryol. Soc. 4, 763–6, 1965, and for a more detailed account, from which the above description of sporophytes was taken, see T. Arts & P. Sollman, Lindbergia 17, 20–7, 1991. For the reasons for placing L. leptophyllum in its own genus see J. Guerra & M. J. Cano, J. Bryol. 22, 91–97, 2000.

72 SYNTRICHIA BRID., J. BOT. (SCHRADER), 1801 Dioicous, autoicous or synoicous. Plants often large, forming cushions or turfs. Stems with or without central strand. Leaves ± appressed when dry, spreading to squarrose when moist, narrowly lingulate to broadly spathulate; margins plane or recurved, usually entire; costa stout, ending below apex to longly excurrent in hyaline usually denticulate point, 2–4 cells wide adaxially, cells rounded-quadrate, papillose, abaxial cells elongate, papillose to dentate, in section with crescent-shaped abaxial stereid band; basal cells sharply differentiated from cells above, narrowly rectangular, thin-walled, hyaline, cells above rounded-quadrate, papillose. Vegetative propagules sometimes present. Perichaetial leaves ± similar to stem leaves. Setae long; capsules cylindrical, often slightly curved; peristome teeth filiform, papillose, spirally coiled; lid longly rostrate; calyptrae cucullate, smooth. Laminal KOH reaction red. About 90 species world-wide. Derivation: meaning joined hair, referring to the fusion of the peristome teeth below.

1 Costa excurrent in usually hyaline hair-point 2 Costa ending in or below apex 8 2 Leaf margins incurved or involute above, 2–several-celled gemmae on adaxial side of costa 7. S. papillosa

72 Syntrichia

381

Leaf margins plane to recurved from base to apex, gemmae lacking 3 3 Hair-points reddish except sometimes at tip 2. S. norvegica Hair-points hyaline except sometimes at base 4 4 Leaves not contracted at or below middle, margins recurved ± from base to apex 1. S. ruralis Leaves contracted at or below middle, margins plane to recurved to 3 /4 way up leaf 5 5 Hair-points smooth or sparsely and opaquely denticulate, gemmae resembling minute leaves sometimes present 6. S. laevipila Hair-points denticulate or spinulose, gemmae lacking 6 6 Plants 0.2–2.0(−3.0) cm high, basal cells in lower part of leaves rectangular, 20–40 μm long 5. S. virescens Plants 1–4 cm high, basal cells narrowly rectangular, 50−80 μm long 7 7 Dioicous, leaf cells 8–10(−12) μm wide at widest part of leaf 3. S. intermedia Synoicous, cells (10−)12–20(−22) μm wide 4. S. princeps 8 Leaf apices rounded, emarginate or not, small ± spherical gemmae usually present on adaxial side of leaves, rhizoidal gemmae lacking, plants often silt-encrusted 8. S. latifolia Leaf apices obtuse, apiculate or not, leaf gemmae lacking, rhizoidal gemmae present, plants not silt-encrusted, very rare 9. S. amplexa 1 S. ruralis (Hedw.) F. Weber & D. Mohr, Index Musc. Pl. Crypt., 1803 Dioicous. Loose cushions or turfs, brownish when dry, golden green above, reddish below when moist, 1–8 cm high. Stems without central strand. Leaves appressed, ± twisted when dry, squarrose when moist, lingulate, not or hardly constricted at or below middle, apex rounded and sometimes emarginated to obtuse or tapering into hair-point; margins strongly recurved ± from base to apex, papillose-crenulate; costa stout, brownish, excurrent in denticulate to spinulose hyaline hair-point to as long as lamina; cells in lower part of leaf rectangular, hyaline, shorter and narrower towards margins, above hexagonal, strongly papillose, opaque, 12–16 μm wide at widest part of leaf. Capsules cylindrical, slightly curved, peristome spirally coiled, tubular in lower 2 /3 –3 /4 ; spores 10–12 μm. Capsules rare, spring, early summer. n = 12, 26. Leaf apices obtuse or rounded, not tapering into hyaline point var. ruralis Leaf apices acute, tapering into hyaline point var. ruraliformis Var. ruralis (Fig. 119) S. calcicola J. J. Amann, S. calcicolens (W. A. Kramer) Duell, Tortula calcicolens W. A. Kramer, T. ruralis (Hedw.) P. Gaertn. et al. Leaves lingulate, apices rounded or obtuse, sometimes emarginated. Exposed sunny walls, roof tiles, concrete, stony ground, rock outcrops, sand-dunes,

382

16 Pottiaceae

calcicole. 0–350 m. Frequent or common in England, Wales and eastern Scotland, occasional elsewhere and in Ireland. 100, H35, C. GB738 + 116∗ , IR54 + 13∗ , C5 + 1∗ . Circumpolar Wide-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Asia, Africa, Macaronesia, N. America, Greenland, Patagonia, Australia, Oceania. Var. ruraliformis (Besch.) Husn. Ex T. Durand, Bull. Soc. Bot. Belg., 1890 (Fig. 119) S. ruraliformis (Besch.) Cardot, Tortula ruraliformis (Besch.) Ingham, T. ruralis ssp. ruraliformis (Besch.) Dixon, T. ruralis var. arenicola Braithw. Dioicous. Lax cushions or turfs, sometimes almost buried in sand. Leaves oblonglanceolate, apices acute, tapering into hair-point. n = 13∗ . Exposed sunny situations on walls, rock outcrops, stony and sandy ground and especially sand-dunes, calcicole. Lowland. Common along coasts throughout the British Isles, occasional inland in S. England and S. Wales. 88, H19. C. GB305 + 44∗ , IR142 + 5∗ , C7. European Southern-temperate. Europe north to Scandinavia, Iceland, Caucasus, Turkey, Cyprus, Asia, Macaronesia, Algeria, western N. America. S. ruralis may be confused with S. intermedia but differs in the leaves squarrose when moist, not or hardly contracted at or below the middle and the margins recurved to near the apex. The two varieties usually differ in leaf shape and ecology, var. ruraliformis occurring most commonly on sand-dunes and rare inland whereas var. ruralis is rare on sand-dunes and common in inland habitats. However, intermediates occur and I have followed M. T. Gallego et al. (Bot. J. Linn. Soc. 138, 209–24, 2000) in their treatment of the taxa. Duell (1992) suggests that for similar reasons S. intermedia should be treated as a subspecies of S. ruralis. There is in addition another taxon, S. calcicola Amann, described as differing from S. ruralis in having erect-patent lingulate leaves with margins recurved to c. 3 /4 way up, shorter hyaline bases and cells with less dense and horseshoe-shaped papillae. Some British specimens agree with this but so many intermediates exist that S. calcicola cannot be maintained as a distinct taxon in the British Isles.

2 S. norvegica F. Weber, Arch. Syst. Naturgesch., 1804 (Fig. 119) Tortula norvegica (F. Weber) Wahlenb. ex Lindb., T. ruralis var. alpina Wahlenb. Dioicous. Lax cushions, reddish brown when dry, yellowish green above, reddish brown below when moist, 1–10 cm high. Leaves appressed, ± twisted when dry, squarrose when moist, oblong-spathulate, not or hardly constricted at or below middle, apex obtuse; margins recurved 2 /3 –3 /4 way up leaf; hair-point denticulate, reddish throughout or hyaline only at apex; cells in basal part rectangular, hyaline, cells above hexagonal, strongly papillose, opaque, 12–16(−20) μm wide at widest part of leaf. Capsules shortly cylindrical; spores 10–14 μm. Capsules unknown in Britain. n = 12 + m. In rock crevices and among boulders, strongly calcicolous. C. 1000 m. Very rare, Mid Perth, Angus, W. Inverness. 3. GB2 + 3∗ . Circumpolar

72 Syntrichia

383

Arctic-montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Turkey, Cyprus, Asia, Madeira, N. Africa, N. America, Greenland, Mexico. This species is treated as vulnerable in the Red List of British Mosses.

3 S. intermedia Brid., Bryol. Univ., 1826 Tortula crinita (De Not.) De Not., T. intermedia (Brid.) De Not.

(Fig. 120)

Dioicous. Lax cushions, greyish brown and hoary when dry, greenish when moist, 1–4 cm high. Stems usually without a central strand. Leaves appressed, incurved or twisted when dry, erect-patent to spreading, rarely subsquarrose when moist, broadly spathulate, contracted at or below the middle, apex rounded, sometimes emarginate; margins recurved 1 /2 –2 /3 way up leaf, papillose-crenulate; costa strong, reddish, excurrent in denticulate hyaline point to 3 /4 –1 length of lamina; cells in lower part of leaf narrowly rectangular, hyaline, mostly 50–80 μm long, shorter and narrower towards margins, cells above hexagonal, papillose, opaque, 8–10(−12) μm wide at widest part of leaf. Capsules shortly cylindrical, slightly curved or not, 2–3 mm long; lower 2 /3 of peristome tubular; spores 14–16 μm. Capsules occasional, spring, summer. n = 12, 12 + m∗ , 13∗ . In usually exposed situations on limestone, concrete, walls, roof tiles, rarely on stony ground, trees and acidic rocks. 0–625 m. Frequent or common in the southern half of Britain, occasional elsewhere and extending north to Shetland, occasional in Ireland. 101, H31, C. GB736 + 89∗ , IR44 + 12∗ , C6 + 1∗ . Submediterranean-Subatlantic. Europe north to southern Scandinavia, Caucasus, Turkey, Cyprus, N. Asia, Macaronesia, N. Africa, N. and C. America. 4 S. princeps (De Not.) Mitt., J. Linn. Soc. Bot., 1859 Tortula princeps De Not.

(Fig. 120)

Synoicous. Dense spreading tufts or patches, green above, reddish below, 1–4 cm high. Stems with a central strand. Leaves in interrupted tufts on stems, flexuose, twisted when dry, patent or recurved when moist, oblong-spathulate, constricted at or below middle, apex rounded, sometimes emarginate; margins recurved to 1 /2 –3 /4 way up leaf; costa stout, reddish brown, excurrent in denticulate hyaline hair-point; cells in lower part of leaf narrowly rectangular, hyaline, shorter and narrower towards margins, cells above hexagonal, papillose, opaque, (10−)12– 20(−22) μm wide at widest part of leaf. Capsules cylindrical, slightly curved, 3.5– 4.5 mm long; spores 12–14 μm. Capsules frequent, autumn. n = 12, 24, 26, 24 + m, 26, 36 + 2m. In open situations on rock outcrops, and in crevices, cliff ledges, walls, rarely in open woodland, calcicole. 100–500 m. Rare and decreasing, widely scattered from Shropshire and Derby north to W. Sutherland, Sligo, old records from Antrim and Londonderry. 22, H3. GB15 + 18∗ , IR6∗ . European Temperate. Europe north to Scandinavia, Caucasus, Turkey, Cyprus, N. Asia, China, Canary Islands, Madeira, Algeria, N. America, Australia, New Zealand, Oceania.

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16 Pottiaceae

Fig. 120 1–5, Syntrichia intermedia: 1, leaves (×25); 2, costa section; 3, basal cells; 4, cells from widest part of leaf; 5, capsule. 6–8, S. princeps: 6, leaf (×17.5) 7, cells at widest part of leaf; 8, capsule. 9–12, S. virescens: 9, leaves (×25); 10, costa section; 11, basal cells; 12, cells at widest part of leaf. Sections ×175, cells ×280, capsules ×10.

72 Syntrichia 5 S. virescens (De Not.) Ochyra, Fragm. Florist. Geobot., 1992 T. pulvinata (Jur.) Limpr., T. virescens (De Not.) De Not.

385 (Fig. 120)

Dioicous. Dense dull green tufts or patches, 0.5–3.0 cm high. Stems in section with small central strand. Leaves twisted, incurved when dry, slightly recurved when moist, oblong-spathulate, constricted at or below middle, subacute to obtuse or rounded and almost always some emarginate; margins plane or recurved only in lower part of leaf; costa reddish brown, excurrent in denticulate hyaline hair-point 1 /4 –1 /3 length of lamina, in section with 1–2(−3) rows of abaxial stereids; basal cells rectangular, hyaline, 20–40 μm long, cells above quadrate-hexagonal, papillose, 12–16 μm wide at widest part of leaf. Capsules narrowly cylindrical, 2–3 mm long; spores 8–12 μm. Capsules very rare. On tree trunks in open situations, stones, walls, concrete, asphalt paths. Lowland. Occasional in eastern England, very rare elsewhere, from S. Wiltshire and W. Sussex north to E. Ross. 32. GB52 + 2∗ . European Temperate. Europe from Spain, Sardinia and Sicily north to C. Scandinavia, Caucasus, Turkey, Kashmir, Canary Islands, N. America. Related to S. laevipila, S. intermedia and S. ruralis but differing in its smaller size and thinner band of stereids in the costa section, this rendering the costa less prominent in side view. It differs from S. laevipila in the denticulate hair-points. For the occurrence of this species in Britain see E. F. Warburg & A. C. Crundwell, Trans. Br. Bryol. Soc. 3, 568–70, 1965.

6 S. laevipila Brid., Muscol. Recent. Suppl, 1819 (Fig. 121) ¨ Tortula laevipila (Brid.) Schwagr., T. laevipila var. laevipiliformis (De Not.) Limpr., Autoicous or dioicous. Light green or yellowish green tufts or patches, 1.0– 1.5(−3.0) cm high. Stems in section with central strand. Leaves twisted, incurved when dry, spreading to recurved when moist, broadly spathulate, constricted at or below middle, apex rounded; margins plane or recurved near middle of leaf, papillose-crenulate; costa stout, excurrent in hyaline smooth to obscurely and sparsely denticulate hair-point, 1 /4 –1 length of lamina, in section with several rows of stereid cells; cells in lower part of leaf hyaline, rectangular, narrower towards margins, cells above quadrate-hexagonal, papillose, opaque, 10–14 μm wide at widest part of leaf, 0–4 marginal rows more incrassate and pellucid, less papillose. Gemmae, in the form of minute leaves with costa, sometimes present at stem tips. Capsules cylindrical, slightly curved, 2–3 mm long; peristome tubular in lower half; spores 14–20 μm. Capsules occasional to frequent, summer, autumn. n = 12, 15, 26∗ . On trunks and branches of trees and shrubs in open situations, very rarely on rocks and walls. Lowland. Frequent or common in Wales and the southern half of England, S. E. Scotland, rare to occasional elsewhere, extending north to Caithness, occasional in Ireland. 103, H34, C. GB704 + 125∗ , IR47 + 15∗ , C7. Submediterranean-Subatlantic. Europe north to S. Sweden, Turkey, Cyprus, N. and

386

16 Pottiaceae

Fig. 121 1–6, Syntrichia laevipila: 1, leaves; 2, costa section (×125); 3, cells from widest part of leaf; 4, capsule (×10): 5, marginal cells from widest part of leaf; 6, gemmae (×45). 7–9, S. latifolia: 7, leaf; 8, cells from widest part of leaf; 9, gemmae (×175). 10–12, S. papillosa: 10, leaves; 11, cells from widest part of leaf; 12, gemmae (×175). 13–15, S. amplexa: 13, leaves; 14, marginal cells at widest part of leaf; 15, gemmae (×300). Leaves ×25, cells ×280.

72 Syntrichia

387

E. Asia, Azores, Canary Islands, Algeria, Morocco, Kenya, N. America, southern S. America, Australia, New Zealand, Antarctica. In the first edition of this flora two varieties of this species were described, var. laevipila (autoicous, often with capsules and lacking gemmae) and var. laevipiliformis (De Not.) J. Amann (dioicous, without capsules but with gemmae). Investigation of a quantity of gatherings has shown that some with capsules also have gemmae and that some sterile gatherings lack gemmae. The sex of such gatherings is uncertain. It is clear that in the light of this the two varieties cannot be maintained as separate taxa. There is a species reported from continental Europe, S. pagorum (Hedw.) J. J. Amann, and which could occur in the British Isles. It differs from S. laevipila in capsule characters and in the gemmae lacking a costa.

¨ 7 S. papillosa (Wilson) Jur., Laubmfl. Osterr.-Ung., 1882 Tortula papillosa Wilson

(Fig. 121)

Dioicous. Small dark green patches or tufts, 2–10 mm high. Leaves incurved when dry, spreading or recurved when moist, broadly ovate-spathulate, constricted below middle, apex rounded; margins inflexed above, papillose-crenulate; costa broad, strongly papillose on abaxial side above, excurrent in smooth hyaline hairpoint 1 /3 –1 /2 length of lamina; cells in lower part of leaf rectangular, hyaline, cells above quadrate-hexagonal, papillose, pellucid, 16–24 μm wide at widest part of leaf. Irregularly spherical or ovoid 2-several celled gemmae, 30–100 μm long, present on adaxial side of upper part of costa in younger leaves. Capsules known only from Australasia. n = 6 + m, 12, 24. On bark, particularly of mature trees, very rarely on rocks or walls. Lowland. Rare to occasional and decreasing in England, Wales and E. Scotland, extending north to Ross, rare in Ireland. 90, H17, C. GB165 + 202∗ , IR14 + 14∗ , C3. European Temperate. Europe north to Scandinavia, Canary Islands, Africa, N. America, Ecuador, Andes, Tierra del Fuego, Falkland Islands, Australia, Tasmania. New Zealand. 8 S. latifolia (Bruch ex Hartm.) Huebener, Muscol. Germ., 1883 Tortula latifolia Bruch ex Hartm., T. mutica Lindb.

(Fig. 121)

Dioicous. Dull or brownish green often silt-encrusted patches, to 3 cm high. Leaves ± appressed or incurved when dry, lower erect-patent, upper crowded, soft, spreading when moist, broadly spathulate, apex rounded, sometimes emarginate; margins plane or narrowly recurved below, papillose-crenulate, often eroded; costa strong, brownish, ending below apex to percurrent; cells in lower part of leaf rectangular, cells above hexagonal, papillose, pellucid, 12–16 μm wide at widest part of leaf. Small ± spherical gemmae, 24–36 μm diameter, present on adaxial surface of leaves. Capsules cylindrical, slightly curved; lower 1 /3 of peristome tubular; spores 10–12 μm. Capsules very rare, spring. n = 12. On tree boles, exposed roots, rocks and walls in flood zone of streams and rivers, rarely away from water. Lowland. Frequent or common in Wales and the southern half of

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17 Cinclidotaceae

England, becoming rarer northwards and extending to Banff, rare in Ireland. 85, H14. GB406 + 60∗ , IR8 + 11∗ . European Temperate. W. and C. Europe, extending north to S. Sweden, Turkey, Caucasus, eastern N. America. 9 S. amplexa (Lesq.) R. H. Zander, Bull. Buffalo Soc. Nat. Sci., 1993 Tortula amplexa (Lesq.) Steere

(Fig. 121)

Dioicous. Dense green tufts, reddish brown below, to 6 mm high. Leaves ± twisted when dry, spreading when moist, slightly concave, lingulate-spathulate, obtuse, apiculate or not; margins recurved below, plane, entire above; costa ending just below apex; basal cells rectangular, narrower towards margins, cells above irregularly quadrate, papillose, (13−)15–25(−28) μm wide at widest part of leaf, c. 4 marginal rows smaller, more incrassate, less papillose, forming yellowish border. Abundant, pale brown, 1–3-celled rhizoidal gemmae, 20–75 × 20–35 μm, present. Only female plants known in Britain. On disturbed clay. Lowland. Very rare, known from only a few sites in Leicester. 1. GB1. Introduced (Suboceanic Temperate). California, Washington, British Columbia. Originally discovered on modelling clay in a pottery class in Tunbridge Wells, Kent, the source of which was traced to clay pits in Leicestershire where the plant was found growing. It seems very likely that S. amplexa is an introduction from N. America. For an account of its discovery see A. G. Side & H. L. K. Whitehorse, J. Bryol. 8. 15–18, 1974, and for further information about distribution see R. Porley & N. G. Hodgetts, Bull. Br. Bryol. Soc. 65, 61–3, 1995.

17 Cinclidotaceae With the characters of the single genus. ´ 73 CINCLIDOTUS P. BEAUV., PRODR. AETHEOGAM., 1805 European species usually cladocarpous, dioicous. Robust, often aquatic plants with lateral or terminal gametangia; stems without central strand. Leaves erect or curled when dry, patent to spreading when moist, lanceolate to broadly lingulate, apex acute to rounded; margins plane or recurved, strongly thickened; costa ending below apex to excurrent, in section with two stereid bands; basal cells rectangular, cells above hexagonal, smooth or slightly papillose, marginal severalstratose. Setae short or long; capsules immersed or exserted, ellipsoid to cylindrical, ribbed when dry; peristome teeth 16, bifid into filiform smooth or papillose segments, straight or spirally coiled; calyptrae cucullate. About 10 species occurring in Europe, N. Africa, Macaronesia and N. America. Derivation: from the Greek word meaning latticed referring to the latticed peristome.

Capsules immersed, leaves often asymmetrical, acute to obtuse, margins in section with inner cells smaller and thicker-walled than outer 1. C. fontinaloides

73 Cinclidotus

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Fig. 122 1–4, Cinclidotus fontinaloides: 1, shoot tip with sporophyte (×10); 2, leaves; 3, mid-leaf cells; 4, section of margin at middle of leaf. 5–8, C. riparius: 5, leaf; 6, mid-leaf cells; 7, section of margin at middle of leaf; 8, sporophyte (×7). Leaves ×15, cells ×420.

Capsules exserted, leaves symmetrical, apex obtuse or rounded, marginal cells ± uniform in section 2. C. riparius

1 C. fontinaloides (Hedw.) P. Beauv., Prodr. Aethéogam., 1805 (Fig. 122) Lax olive-green to blackish green floating or ± decumbent tufts, 2–12 cm long, stems fastigiately branched. Leaves flexuose or contorted when dry, patent and often secund when moist, oblong-lanceolate to narrowly lanceolate, frequently asymmetrical, keeled above, acute to obtuse; margins strongly thickened, plane, entire or obscurely and irregularly toothed at extreme apex, older leaves frequently eroded; costa stout, ending in apex; cells at extreme base shortly rectangular, elsewhere irregularly hexagonal, faintly papillose, 8–14 μm wide in mid-leaf; margins in section ± circular, with inner cells smaller and more incrassate than

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outer. Perichaetia usually on short lateral branches but occasionally terminal on main stems and branches. Setae very short, c. 0.5 mm long; capsules immersed, ellipsoid; lid longly rostrate, oblique, red at maturity; peristome teeth divided into purplish filiform papillose segments; spores coarsely papillose, 18–20 μm. Capsules frequent, spring, summer. n = 13∗ . On basic rocks, especially limestone and on wood by fast-flowing streams and rivers; in lowland areas usually by weirs, locks and embankment walls; abundant in Irish turloughs; usually in situations subject to periodic inundation. 0–300 m. Rare or occasional in lowland areas, frequent in upland regions. 102, H34. GB398 + 66∗ , IR128 + 6∗ . European Southerntemperate. Europe north to Scandinavia, Caucasus, Asia, China, Tibet, Madeira, Canary Islands, Tunisia, E. Africa. A very variable species some forms of which resemble C. riparius (q.v.). In habit the plant may resemble Schistidium rivulare, but it has longer and narrower leaves with strongly thickened margins, and different areolation and capsule characters. Orthotrichum rivulare differs in the rounded leaf apices, recurved margins and capsules with a double peristome with broad outer teeth.

2 C. riparius (Host ex Brid.) Arnott, Mem. Soc. Linn. Paris, 1827 (Fig. 122) Compact to lax blackish green tufts, to 5 cm high. Leaves erect, loosely appressed and sometimes slightly twisted when dry, erect-patent, often with reflexed apex when moist, ovate-elliptical to narrowly lingulate, plane above, obtuse or rounded and usually mucronate; margins strongly thickened, plane; costa percurrent or excurrent in short mucro; basal cells shortly rectangular, cells above quadrate to hexagonal, smooth or faintly papillose, often partially bistratose near margins, 8–16(−20) μm wide in mid-leaf; margins in section usually oval with all cells of ± similar size. Perichaetia terminal on short lateral branches, main stems and branches. Setae 3–6 mm long; capsules exserted, ellipsoid, straight or slightly curved; peristome teeth yellowish, smooth, spirally coiled; spores c. 20 μm. Male plants and sporophytes unknown in the British Isles. n = 13. On rocks and stonework in the flood-zone of rivers. Lowland. Very rare but locally frequent, Hereford, Worcester, Shropshire, Clare (1884). 3, H1. European Southern-temperate. Europe north to Germany and Poland, Turkey, N. Africa. The presence of this species in the British Isles has been a matter of dispute for about a century but its occurrence has recently been confirmed (see T. L. Blockeel, J. Bryol. 20, 109–19, 1998). When capsules are present C. fontinaloides and C. riparius are readily distinguished but sterile plants can only be identified with certainty by leaf margin sections. However, there is often some difference in leaf shape, with those of C. riparius tending to be elliptical or narrowly lingulate and relatively wider than the ovate-lanceolate and often asymmetrical leaves of C. fontinaloides, and the leaf apices are often obtuse or rounded and mucronate. C. riparius is usually a more compact and darker plant and the leaves are scarcely twisted when dry.

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18 Ephemeraceae Plants minute, annual or ephemeral, arising from persistent protonemata. Leaves forming a rosette, ovate-lanceolate to narrowly lanceolate; margins plane, dentate or entire; costa present or not; cells large, lax, ± narrowly hexagonal. Capsules immersed, ± globose, cleistocarpous or dehiscent and gymnostomous, thinwalled; spores large, (20−)40–80 μm. Three genera.

74 MICROMITRIUM AUSTIN, MUSCI APPALLACH., 1870 Autoicous. Plants minute. Leaves lanceolate; costa lacking; cells lax. Setae lacking; capsules globose, capsule wall only one cell thick, stomata absent; ring of differentiated cells delimiting rudimentary lid; calyptrae minute, persisting. About 10 mainly American species but with a few in Europe, Asia, Australia and Oceania. Derivation: referring to the minute calyptrae.

1 M. tenerum (Bruch & Schimp.) Crosby, Bryologist, 1968 Nanomitrium tenerum (Bruch & Schimp.) Lindb.

(Fig. 123)

Minute ephemeral plants arising from a usually persistent protonema. Lower leaves spreading, upper erect-patent, ovate-lanceolate to lanceolate, acuminate; margins subentire to opaquely denticulate; costa absent; cells lax, rhomboidhexagonal, 20–25 μm wide in mid-leaf. Capsules ± globose, cleistocarpous but dehiscing along a ring of differentiated cells under pressure; spores papillose, 20–30 μm. Capsules common, autumn. On mud of dried-out ponds and around reservoirs. Lowland. Very rare and sporadic, endangered because of loss of habitats. W. Sussex, Anglesey, old records from E. Sussex and W. Kent, Surrey. 5. GB3 + 7∗ . Suboceanic Temperate. Belgium, Czechoslovakia, France, Germany, N. Spain, S. Sweden, E. Asia, N. America. This is a critically endangered species in the Red List of British mosses.

75 EPHEMERUM HAMPE, FLORA, 1837 Autoicous or dioicous. Minute ephemeral plants arising from usually persistent protonemata. Leaves ± lanceolate; costa present or not; cells lax, pellucid. Setae very short; capsules immersed, cleistocarpous, ± globose or ovoid, apiculate, wall of two layers of cells, lacking ring of differentiated cells, stomata present; calyptrae not persisting. A cosmopolitan genus of about 27 species. Derivation: meaning short-lived.

1 Leaves costate Leaves ecostate

2 5

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18 Ephemeraceae

Fig. 123 1–3, Micromitrium tenerum: 1, plant (×30); 2, leaf (×85); 3, marginal cells. 4–6, Ephemerum recurvifolium: 4, plant (×20); 5, leaves (×40); 6, marginal cells. 7–9, E. sessile: 7, plant (×20); 8, leaf (×40); 9, marginal cells. 10–12, E. stellatum: 10, plant with young capsule (×20); 11, leaf (×40); 12, leaf cells. 13–15, E. cohaerens: 13, leaf (×40); 14, marginal cells; 15, capsule (×30). Cells, all from upper part of leaf, ×280.

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2 Costa poorly defined, upper cells spinulose papillose 4. E. spinulosum Costa well defined, cells smooth 3 3 Upper leaves lanceolate, costa ending in apex, mid-leaf cells 60–80 μm long 3. E. cohaerens Upper leaves narrowly lanceolate to linear-lanceolate, costa excurrent, mid-leaf cells 10–50 μm long 4 4 Upper leaves recurved, capsules with oblique apiculus, stomata near base of capsule only, spores ± smooth 1. E. recurvifolium Leaves erect-patent, capsules with straight apiculus, stomata scattered over whole of capsule, spores coarsely papillose 2. E. sessile 5 Leaf margins entire or denticulate, mid-leaf cells 50–90 μm long, spores ± smooth 5. E. stellatum Leaf margins spinosely dentate, mid-leaf cells 100–160 μm long, spores finely or coarsely papillose 6 6 Marginal teeth of leaves straight, spores coarsely papillose, without hyaline membrane 6. E. serratum Marginal teeth of leaves often recurved, spores finely papillose, usually surrounded by hyaline membrane 7. E. minutissimum 1 E. recurvifolium (Dicks.) Boulay, Musci de l’Est, 1872 Ephemerella recurvifolia (Dicks.) Schimp.

(Fig. 123)

Pseudodioicous. Minute ephemeral scattered plants on persistent protonemata. Leaves erect-patent, upper and perichaetial leaves recurved, narrowly lanceolate, acuminate; margins denticulate, sometimes with 1–2 coarse teeth near apex; costa well defined, excurrent; mid-leaf cells 8–14(−20) × 10–40 μm. Capsules ± globose with oblique apiculus, stomata at base of capsule only; spores ± smooth, 40–55 μm; calyptrae cucullate. Capsules common, autumn, winter. On basic clay and damp soil on woodland rides, in beech woods, fields and grassland. Lowland. Occasional from S. Devon east to Kent and north to Caernarfon, Cheshire, Durham, 33. GB48 + 13∗ . European Southern-temperate. Europe north to Sweden and Finland, Israel, Turkey, N. Africa. ¨ Hal., Syn. Musc., 1848 2 E. sessile (Bruch) Mull. Ephemerella sessilis (Bruch) Nyholm

(Fig. 123)

Pseudodioicous. Minute ephemeral scattered plants or small patches on persistent protonemata. Upper and perichaetial leaves erect-patent, narrowly lanceolate, denticulate; costa weak below, strong above, excurrent; cells in mid-leaf 10–12 × 35–50 μm. Capsules ± globose with short straight apiculus, stomata scattered over whole surface of capsule; spores coarsely papillose, 60–80 μm long; calyptrae mitriform. Capsules common, autumn, winter. On acidic or neutral soil on woodland rides, edges of reservoirs. Lowland. Rare or very rare, from Cornwall east to W. Kent and north to Yorkshire and S. Northumberland, Wexford,

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W. Galway, Donegal, Antrim. 19, H4. GB16 + 9∗ , IR4. European Southern-temperate. Europe north to S. Sweden and Finland, Israel, Turkey, Morocco. 3 E. cohaerens (Hedw.) Hampe, Flora, 1837 (Fig. 123) Pseudodioicous. Minute ephemeral scattered plants or small patches on persistent protonemata. Leaves patent or recurved, upper and perichaetial leaves lanceolate, acuminate; margins dentate; costa strong above, ending below apex in upper leaves; cells in mid-leaf 10–20 × 50–80 μm. Capsules globose, apiculus short, straight, stomata scattered over whole surface; spores coarsely papillose, 60–70 μm long; calyptrae campanulate, lobed or torn at base. Capsules common, autumn. n = 27. On non-calcareous soil on moist banks and at edges of reservoirs. Lowland. Very rare, W. Sussex, Hertford, Leicester, S. E. Galway (old record), Leitrim. 3, H2. GB3, IR1 + 1∗ . European Temperate. Rare in Europe, extending north to Germany and Poland, Turkey, China, western N. America. This is a critically endangered species in the Red List of British mosses.

4 E. spinulosum Bruch & Schimp. ex Schimp., Syn. Musc. Eur., 1860 (Fig. 124) Pseudodioicous. Minute ephemeral scattered plants, to 2.2 mm high, arising from extensive persistent protonemata. Lower leaves few, patent lanceolate, and perichaetial leaves erect or slightly incurved, linear-lanceolate to linear, acuminate; margins plane, sharply toothed ± from base to apex, teeth spreading or recurved; costa wide, ill-defined, extending to apex, papillose on abaxial side above; mid-leaf cells 11–20 × 40–70 μm, upper cells prorate with spinose papillae. Setae absent; capsules ovoid with oblique blunt apiculus; stomata limited to lower part of capsule; spores 50–70 × 70–110 μm; calyptrae cucullate, ± covering capsules. Capsules common, probably late summer to autumn. On silty mud of a reservoir. Very rare, Antrim. H1. IR1. China, Taiwan, Japan, eastern N. America. Distinguished from other costate species of Ephemerum by the poorly defined costa and all other species occurring in the British Isles by the cells in the upper part of the leaf prorate with spinose papillae. For the occurrence of this plant in Ireland see D. T. Holyoak, J. Bryol. 23, 139–41, 2001. It is possible that it is of casual occurrence having been brought by birds from eastern N. America.

5 E. stellatum H. Philib., Rev. Bryol., 1879 (Fig. 123) Pseudodioicous. Minute ephemeral scattered plants on persistent protonemata. Lower leaves crowded, spreading in stellate fashion, narrowly lanceolate, upper and perichaetial leaves erect-patent, ± straight, ligulate-lanceolate, acute to acuminate; margins entire to slightly denticulate; costa absent; cells thin-walled, in mid-leaf 10–16 × 50–90 μm, incrassate, basal cells larger and shorter, thin-walled. Capsules obovoid with conical apiculus: spores smooth, 40–50 μm; calyptrae large, campanulate, lobed at base covering more than half the capsule. On compressed soil on woodland rides and cliff paths. Lowland. Very rare, Hampshire, W. Sussex,

75 Ephemerum

395

Fig. 124 1–4, Ephemerum serratum var. serratum: 1, leaf (×40); 2, marginal cells from upper part of leaf (×280): 3, capsule (×20); 4, spore (×420). 5, E. serratum var. praecox: leaf (×40). 6–9, E. minutissimum: 6, plant (×30); 7, leaf (×40); 8, marginal cells from upper part of leaf (×280); 9, spore (×420). 10–13, E. spinulosum: 10, plant (×40); 11, leaf (×75); 12, marginal cells from middle of leaf (×420); 13, cells from upper part of leaf, abaxial side (×420).

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S. Kerry, old records from E. Sussex and W. Kent. 5, H1. GB2 + 2∗ , IR2. European Temperate. Extremely rare, France, Germany, Portugal, Turkey, N. Africa. This species is considered endangered in the Red List of British mosses and is listed as vulnerable in the Red Data Book of European Bryophytes.

6 E. serratum (Hedw.) Hampe, Flora, 1837 Pseudodioicous. Minute ephemeral scattered or gregarious plants, 1.4–2.2 mm high, on persistent protonemata. Upper and perichaetial leaves erect-patent, lanceolate, apex often twisted; margins spinosely toothed above, teeth straight; costa lacking or very rarely faintly present in upper part of leaf; mid-leaf cells (10−)16–30 × 100–160 μm. Capsules spherical, with conical apiculus, stomata at base of capsule only; spores coarsely papillose, mostly 65–90 μm long; calyptrae small, campanulate, torn at base. Capsules common, autumn to spring. Leaves without costa, cells 16–24 μm wide in upper part of leaf Leaves with faint costa in upper part, cells 10–16 μm wide

var. serratum var. praecox

Var. serratum (Fig. 124) Costa lacking; cells in upper part of leaves 16–24 μm wide. On damp noncalcareous soil in fields, grassland, on roadsides and margins of lakes and reservoirs. 0–350 m. Occasional in lowland England, rare in Scotland, extending north to Shetland, rare in Ireland. 52, H9. European Temperate. Europe north to Fennoscandia, China, Morocco, N. America. Var. praecox A. W. H. Walther & Molendo, Laubm. Oberfrank., 1868 E. intermedium Braithw.

(Fig. 124)

Faint costa present in upper part of leaves; cells in upper part of leaf 10–16 μm wide. Very rare and not seen recently, several localities in W. Sussex. 1. Bavaria. Whether var. praecox is worth maintaining as a variety is very questionable.

7 E. minutissimum Lindb., Not. Sllsk. Fauna Fl. Fenn. Föhr., 1874 (Fig. 124) E. serratum var. angustifolium auct. non Bruch & Schimp., E. serratum var. minutissimum (Lindb.) Grout Pseudodioicous. Minute ephemeral scattered or gregarious plants, 1.0–1.8 mm high, on persistent protonemata. Upper and perichaetial leaves narrowly lanceolate; margins spinosely toothed above, teeth often recurved; costa lacking; cells in mid-leaf c. 20 μm wide. Capsules spherical, with conical apiculus; stomata at base of capsule only; spores finely papillose, 50–65 μm long, often surrounded by hyaline membrane; calyptrae small, campanulate, torn at base. On damp noncalcareous soil in fields, grassland and on woodland rides. Lowland. Frequent

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in lowland Britain becoming rarer northwards, extending north to Shetland. 85, H17. European Temperate. Europe, extending north to southern Scandinavia, Israel, N. America. The treatment of E. minutissimum varies from synonymy with E. serratum to specific status. On the basis of examination of European material, S. Risse (Bryological Times 90, 6, 1995 and 92, 7, 1997) considers the two taxa to be specifically distinct and I have followed him. The nature of the spores is the only reliable character and it is necessary that mature capsules are examined. E. minutissimum is the more frequent of the two, especially in arable fields, but it does not occur beside lakes or reservoirs.

10 Grimmiales Acrocarpous or cladocarpous. Tufted or cushion- or mat-forming plants. Leaves ovate to linear, often with hyaline apices; upper cells small, quadrate, rounded or rectangular, incrassate, sinuose or esinuose, 1–3-stratose, papillose or not, lower cells longer, less incrassate, walls sometimes strongly sinuose or sinuose-nodulose, sometimes hyaline. Setae short or long, straight or variously curved; capsules spherical to cylindrical, smooth or striate; peristome usually present, single, teeth papillose, entire or variously perforated or cleft; calyptrae cucullate or mitriform. Nearly all the species are saxicolous. Four families.

19 Grimmiaceae Acrocarpous or cladocarpous. Leaves erect and appressed to tightly incurved, rarely crisped when dry, often with hyaline apices; margins usually entire; costa ending below apex to excurrent, if apex hyaline then costa ending below or in hyaline part; basal cells quadrate to ± linear, thin-walled to strongly incrassate, esinuose, sinuose or sinuose-nodulose, alar cells usually undifferentiated, upper cells quadrate to rectangular, 1–3-stratose, smooth or papillose. Capsules immersed, emergent or exserted. Eight genera. The differences between the first three genera or the Grimmiaceae are very trivial and some authorities (e.g. Crum & Anderson, 1981) recognise only a single genus, Grimmia. S. P. Churchill (in V. A. Funk & D. R. Brooks, eds., Advances in Cladistics, pp. 127–44, 1981), on the basis of a cladistic analysis, places Campylostelium, Ptychomitrium and Racomitrium in the subfamily Ptychomitrioideae of the Grimmiaceae. I find this treatment unacceptable on morphological and anatomical grounds as the first two genera differ from members of the Grimmiaceae as usually defined and are much better placed in a separate family.

76 COSCINODON SPRENG., ANLEIT. KENTN. GEW., 1804 Acrocarpous. Leaves lanceolate, plicate or not above; margins plane; hyaline points usually present; basal cells rectangular, hyaline, cells above shorter. Setae straight; capsules erect, emergent; peristome teeth cribrose; columella not falling with lid;

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19 Grimmiaceae

Fig. 125 Coscinodon cribrosus: 1, leaves (×15); 2, mid-leaf cells (×420); 3, basal marginal cells (×420); 4, leaf sections (×210); 5, peristome tooth (×115); 6, capsule (×22.5); 7, calyptra (×22.5).

calyptrae campanulate, plicate, enveloping capsule. A small genus of 7 species occurring in the Northern Hemisphere, S. America and New Zealand. Derivation: from sieve and tooth, referring to the cribrose peristome teeth.

1 C. cribrosus (Hedw.) Spruce, Ann. Mag. Nat. Hist., 1849 Grimmia cribrosa Hedw.

(Fig. 125)

Dioicous. Dense blackish or greyish, often dust-filled cushions, tufts or patches, hoary when dry, to 1 cm high. Leaves appressed when dry, erect-patent when moist, ovate to lanceolate, apex broad, upper leaves longitudinally plicate near costa above; margins plane, entire; hyaline points of upper leaves 1 /4 –1(−2) length of lamina, flattened at base and sometimes decurrent down margins, terete above, smooth or occasionally slightly denticulate; basal cells rectangular, thin-walled, ± hyaline, towards margins shorter with thickened transverse walls, cells above quadrate, not sinuose, often partially bistratose, 8–10 μm wide in mid-leaf, cells of plicae with more heavily thickened walls. Perichaetial leaves larger and wider than vegetative. Setae short, straight; capsules emergent, erect, obloid; peristome teeth strongly cribrose, fragile; spores 10–12(−14) μm, calyptrae plicate, campanulate, partially covering capsules. Capsules occasional, spring.

77 Schistidium

399

Crevices and cracks of very acidic, especially slatey rocks, more rarely on rock faces. 0–500 m. Occasional in N. Wales and N. W. England, very rare elsewhere, E. Cornwall, S. Devon, Carmarthen, Cardigan, N. E. and Mid-West Yorkshire, Dumfries, Kirkcudbright, Midlothian, Mid Perth. 18. GB26 + 11∗ . Circumpolar Boreo-temperate. Rare in Europe from Sicily and Sardinia north to c. 69◦ N, Cyprus, Turkey, Caucasus, Siberia, Himalayas, Japan, Tenerife, N. Africa, N. America, Greenland, Patagonia. C. cribrosus may be mistaken for a Schistidium or Grimmia species, especially when sterile. It differs from both in the leaves plicate above, the campanulate plicate calyptrae and the strongly cribrose peristome teeth. It also differs from Schistidium species (except S. trichodon) in the columella not falling with the lid.

77 SCHISTIDIUM BRID., MUSCOL. RECENT SUPPL., 1819 Autoicous or rarely dioicous. Acrocarpous plants forming cushions, tufts or rough mats. Leaves narrowly lanceolate to ovate; margins plane or recurved; with or without hyaline points; costa ending below apex to excurrent; basal cells quadrate to rectangular, incrassate, not hyaline, cells towards margins shorter, sometimes hyaline, cells above quadrate to shortly rectangular, incrassate, sinuose or not, papillose or not, 1–2-stratose, 1–3(−4)-stratose at margins. Perichaetial leaves much longer than and often differing in shape from vegetative leaves, sheathing and hyaline at base, usually overtopping and sometimes concealing capsules. Setae short, straight; capsules immersed, erect, annulus absent; columella attached to and falling with lid (except in S. trichodon); peristome teeth entire, cleft or variously perforated; calyptrae small, cucullate or mitriform, not plicate. About 120– 150 species world-wide with c. 50 in Europe, occurring particularly on nutrientrich rocks in arctic to temperate regions but occurring in warmer parts at higher altitudes. Derivation: from the Greek word for split, presumably referring to the split calyptra. B. Bremer published a taxonomic revision of Schistidium (Lindbergia 6, 1–6, 89–117, 1980, 7, 73–90, 1981), but her treatment of the S. apocarpum agg. is very unsatisfactory and does not reflect the true situation. The Schistidium apocarpum complex in Scandinavia has recently been revised by H. H. Blom (1996) and he describes 31 Scandinavian species. He gives a briefer account of the genus in Nyholm (1998). Blom reports 11 species, one subspecies and a variety from the British Isles compared with the five species and two varieties previously recognised. I have followed Blom’s (in Nyholm 1998) subdivision of the genus.

Notes on the identification of Schistidium species Care should be taken that vegetative and perichaetial leaves are not confused as the two usually differ markedly in shape and areolation. Leaf descriptions are of upper leaves; lower leaves may have shorter hyaline points or be epilose and, in the case of species with papillose cells, the papillae may have been lost. Papillae are best seen on leaves at the shoot apex. Several leaves should be examined

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especially for the detection of marginal teeth. The relative degree of thickening of the longitudinal and transverse walls of the basal marginal cells of the leaves is a very useful character, especially when taken in conjunction with the shape of the exothecial cells in the lower half of the capsule. The perichaetial leaves extend beyond the capsules to a varying degree depending upon species; when described as not concealing capsules in side view this means that at least part of a capsule is visible. Capsule shape is of moist capsules that have not been placed under a cover-slip – doing so will flatten capsules and considerably alter their shape. Capsule shape and dimensions exclude the capsule lid. Careful comparison should be made with descriptions as it is possible that species may be found additional to those reported from the British Isles. It should also be borne in mind that mixed populations occur, which may cause confusion. Records in Blockeel & Long (1998) for S. apocarpum and S. confertum cannot be accepted as many gatherings named as these belong to other species of the complex. There are inadequate records of S. papillosum, S. frigidum, S. crassipilum and S. elegantulum which give no more than an indication of frequency and distribution. There is no reason to doubt records of S. trichodon, S. strictum, S. robustum and S. atrofuscum as the great majority of specimens I have seen have been correctly determined. 1 Leaves without hyaline points, capsules ± hemispherical or turbinate after dehiscence, spores 16–28 μm 2 Hyaline points usually but not always present and sometimes very short, capsules hemispherical to shortly cylindrical after dehiscence, spores usually 8–15 μm 5 2 Leaves rigid when moist, costa percurrent to excurrent, spores 20–28 μm, plants of acidic rocks near the sea 1. S. maritimum Leaves soft when moist, costa ending in or below apex, spores 16–20 μm, plants on rocks in or by fresh water 3 3 Capsules obloid after dehiscence, turbinate when dry and empty, leaves oblong-ligulate to linear-lanceolate, margins usually plane 4. S. agassizii Capsules ± hemispherical after dehiscence, leaves lanceolate to broadly ovate, margins recurved 4 4 Leaves lanceolate to ovate-lanceolate, often asymmetrical and secund, costa 65–145 μm wide near base, perichaetial leaves overtopping capsules, exothecial cells incrassate 2. S. rivulare Leaves ovate-lanceolate to ovate, symmetrical, straight, costa 48–90 (−105) μm wide near base, perichaetial leaves not or scarcely overtopping capsules, exothecial cells thin-walled 3. S. platyphyllum 5 Mid-leaf cells 8–12 μm wide 6 Mid-leaf cells mostly 5–8 μm wide 17 6 Leaf margins toothed (sometimes bluntly and obscurely so), papillose-denticulate or papillose towards apex 7 Leaf margins entire towards apex 11

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7 Basal marginal cells of leaves sometimes hyaline, transverse walls more strongly thickened than longitudinal walls, exothecial cells in middle and lower half of capsule mostly shortly rectangular, spores mostly c. 10 μm 16. S. crassipilum Basal marginal cells not hyaline, walls of ± uniform thickness, exothecial cells in middle and lower half of capsules mostly ± isodiametric or wider than long, spores 10–15(−19) μm 8 8 Plants dull green to brownish or black, at least some leaf margins bluntly toothed towards apex, cells smooth 9 Plants usually reddish or rust coloured, margins papillose or papillose-denticulate towards apex, cells sparsely to densely papillose in upper part of leaf 10 9 Plants dull green to brownish, columella falling with lid, peristome teeth patent to spreading when dry 5. S. apocarpum Plants blackish, columella persisting, peristome teeth incurved with overlapping tips when dry 6. S. trichodon 10 Leaf cells strongly papillose on abaxial side, papillae on abaxial side of costa tall (to 10 μm high) in upper part of leaf, capsules 1.5–2.0 times as long as wide 7. S. papillosum Leaf cells sparsely papillose on abaxial side, papillae on abaxial side of costa low (to 5 μm high) in upper part of leaf, capsules 1.1–1.4 times as long as wide 9. S. strictum 11 Basal marginal cells of leaves with walls of ± uniform thickness 12 Basal marginal cells of leaves with transverse walls more strongly thickened than longitudinal walls 14 12 Plants often somewhat hoary when dry, hyaline points coarse, 0.4–1.6 mm long, mid-leaf cells shortly rectangular, walls strongly sinuose, exothecial cells mostly shortly rectangular 11. S. robustum Plants rarely hoary, hyaline points slender, mostly 0–0.5 mm long, mid-leaf cells ± quadrate, esinuose to sinuose, exothecial cells ± isodiametric to wider than long 13 13 Perichaetial leaves broad, ligulate-lanceolate to ovate or elliptical, ± concealing capsules in side view, hyaline points mostly 0–0.5 mm long, as wide at base as green lamina apex 5. S. apocarpum Perichaetial leaves long and narrow, ligulate-lanceolate, hyaline points 0–150 μm long, narrower at base than green lamina apex 10. S. dupretii 14 Plants black, forming readily disintegrating tufts, leaves brown, opaque above 15. S. atrofuscum Plants not as above 15 15 Basal marginal cells hyaline with very strongly thickened transverse walls, forming a border, mid-leaf cells 6–10 μm wide, exothecial cells variable in shape in middle and lower half of capsules 14. S. frigidum Basal marginal cells forming a border or not, mid-leaf cells 8–10(−12) μm wide, exothecial cells shortly rectangular 16

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16 Plants rarely hoary when dry, leaves ovate to lanceolate, acute, hyaline points flattened below, usually decurrent down margins 16. S. crassipilum Plants often somewhat hoary when dry, leaves lanceolate or narrowly lanceolate, acuminate, hyaline points not flattened below, not decurrent down margins 17. S. elegantulum 17 Upper cells of leaves papillose, margins and abaxial side of costa papillose above, basal marginal cells not hyaline, with walls of ± uniform thickness 8. S. pruinosum Leaf margins entire, cells and costa smooth, basal marginal cells hyaline, transverse walls more strongly thickened than longitudinal walls 18 18 Perichaetial leaves plicate, capsules apparently gymnostomous, with conspicuously red mouths 13. S. flaccidum Perichaetial leaves not plicate, capsules with peristomes, mouths dull deep red 19 19 Basal cells of leaves 20–40 μm long, basal marginal cells quadrate or shortly rectangular, nor forming a border, cells above not or hardly sinuose, exothecial cells in middle and lower half of capsules shortly rectangular 12. S. confertum Basal cells 40–75 μm long, basal marginal cells hyaline, rectangular, forming a border, cells above usually sinuose, exothecial cells in middle and lower half of capsules irregular in shape 14. S. frigidum

Apocarpum group Leaf margins plane or recurved, sometimes papillose or toothed above; hyaline points when present thin, flexuose; costa sometimes papillose on abaxial side above; marginal basal cells chlorophyllous, walls ± uniformly thickened, cells in upper part of leaf ± isodiametric, mostly unistratose except at margins, smooth or papillose. Exothecial cells shortly rectangular, ± isodiametric or wider than long; peristome teeth strongly curved when dry. Rivulare subgroup Leaves with very short or no hyaline point; cells ± quadrate, slightly sinuose. Capsules subglobose or ovate-obloid when mature, hemispherical or turbinate when dry and empty; exothecial cells thin- or thick-walled; peristome teeth long, curved; spores 16–28 μm. KOH laminal reaction orange or red. Five species in N. W. Europe. Although Blom (in Nyholm, 1998) treats the Rivulare subgroup as a group distinct from the Apocarpum group, more recently he has combined the two groups (pers. commun.).

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1 S. maritimum (Turner) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 126) Grimmia maritima Turner Dark green to dark brown tufts or cushions, to c. 2 cm high. Leaves rigid, erect, appressed, curved when dry, erect-patent when moist, ovate to lanceolate, tapering to blunt apex; margins recurved below on one or both sides; hyaline points lacking; costa strong, sometimes thickened above, percurrent to excurrent in stout point; basal cells rectangular, pellucid, shorter towards margins, cells above quadrate, incrassate, slightly sinuose, slightly papillose, opaque, bistratose at margins and towards apex, 8–10 μm wide in mid-leaf. Perichaetial leaves larger than vegetative leaves, from ± narrowly rectangular basal part narrowed to bluntly pointed acumen; costa excurrent. Capsules immersed, ovate-obloid at maturity, turbinate when dry and empty; exothecial cells mostly rectangular but irregularly arranged, walls somewhat thickened; peristome teeth red, reflexed when dry, perforated; spores 20–26(−28) μm. Capsules common, winter. n = 13∗ . Crevices and ledges of acidic coastal rocks and cliffs within the sea-spray zone, very rare on basic rocks. Lowland. Frequent or common and sometimes locally abundant on rocky shores along the west coast of Britain from Cornwall and Devon north to Shetland, rarer along the east coast, from N. E. Yorkshire northwards, common along the west coast of Ireland, rare elsewhere. 51, H21, C. GB288 + 84∗ , IR56 + 19∗ , C6. Oceanic Boreo-temperate. Atlantic and Baltic coasts of Europe north to Svalbard, Faeroes, Iceland, Jan Mayen, Japan, N. American coasts, Greenland, southern S. America. Usually only found in the spray zone and not more than 400 m from the sea except on some of the western Scottish Islands or as a relic in silted or reclaimed estuaries. Spore dispersal seems very inefficient as capsules produced in the previous year may still remain about 3 /4 full of spores. British and Irish material belongs to ssp. maritimum; ssp. piliferum (I. Hagen) Bremer, in which the leaves have a spinulose hyaline point, occurs in Scandinavia, N. America and Greenland.

2 S. rivulare (Brid.) Podp., Beih. Bot. Centralbl., 1911 (Fig. 127) G. alpicola var. rivularis (Brid.) Wahlenb., S. alpicola var. rivulare (Brid.) Limpr. Dark green cushions or prostrate or floating tufts, 2.5–10.0 cm long; stems much branched, often denuded below. Leaves ± secund, often asymmetrical, sharply keeled, lanceolate to ovate-lanceolate, (1.5−)2.0–3.2(−3.4) times as long as wide, acute to obtuse; margins recurved, usually more on one side than the other, entire or bluntly toothed near apex; hyaline points lacking; costa ending in or below apex, often curved, 65–145 μm wide near base; basal cells rectangular, basal marginal cells rectangular, walls of uniform thickness, cells above thinwalled to incrassate, quadrate, not or slightly sinuose, bistratose at margins and towards apex, 8–10 μm wide in mid-leaf. Perichaetial leaves longly overtopping

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Fig. 126 1–7, Schistidium maritimum: 1, shoot with sporophyte; 2, leaves; 3, mid-leaf cells (×420); 4, perichaetial leaf; 5, dry empty capsule; 6, exothecial cells (×210). 7, peristome tooth. 8–14, S. agassizii: 8, shoot with sporophyte; 9, leaves; 10, mid-leaf cells (×420); 11, perichaetial leaf; 12, dry empty capsule; 13, exothecial cells (×210). 14, peristome tooth. Shoots ×12, leaves and capsules ×20, teeth ×60.

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Fig. 127 1–7, Schistidium platyphyllum: 1, shoot with sporophyte; 2, leaves; 3, mid-leaf cells (×420); 4, perichaetial leaf; 5, dry empty capsule; 6, exothecial cells (×210); 7, peristome tooth. 8–14, S. rivulare: 8, shoot with sporophyte; 9, leaves; 10, mid-leaf cells (×420); 11, perichaetial leaf; 12, dry empty capsule; 13, exothecial cells (×210); 14, peristome tooth. Shoots ×12, leaves and capsules ×20, teeth ×60.

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capsules. Surface cells of setae incrassate, walls to 4.5 μm thick; capsules subglobose before dehiscence, hemispherical when empty; exothecial cells ± isodiametric, incrassate; peristome teeth bright red, recurved when dry, with few to many perforations; spores 16–20 μm. Capsules common, autumn to spring. n = 13∗ . On rocks, tree boles and roots by base-rich or base-poor rivers and lakes; when by rivers with fluctuating water levels usually occupying middle part of flood-zone. 0–760 m. Absent from most of lowland England, frequent or common elsewhere. 73, H17. GB386 + 69∗ , IR319. Europe north to Svalbard, Faeroes, Iceland, N. and E. Asia, N. America, Greenland, southern S. America, Australasia, Antarctica. The descriptions of this and the next species have been modified in the light of observations by A. Orange (Bull. Br. Bryol. Soc. 65, 51–8, 1995). The main characters separating the two species are leaf shape and costa form; perichaetial leaf length is also a useful character. Forms of S. apocarpum in riparian habitats may have very short or no hyaline points to the leaves but the plants are usually yellowish-brown, the leaf cells are usually sinuose and the capsules ovate-obloid. S. agassizii differs in capsule and leaf shape and leaf cells unistratose throughout. There are no intermediates between this and the next taxon (A. Orange, loc. cit.), and there seems good reason for treating them as distinct species.

3 S. platyphyllum (Mitt.) H. Perss. in H. Perss. & Gjaever., Kongel. Norske Vidensk. Selsk. Forh., 1961 (Fig. 127) ¨ Grimmia apocarpa var. alpicola auct. non (Hedw.) Rohl., S. alpicola auct. non (Hedw.) Limpr., S. latifolium (J. E. Zetterst.) Weim., S. rivulare ssp. latifolium (J. E. Zetterst.) B. Bremer Dark green tufts or cushions, 0.5–4.0 cm high; stems sparsely branched. Leaves not or slightly secund, symmetrical, widely keeled, broadly ovate to ovate-lanceolate, 1.5–2.7(−2.8) times as long as wide, acute to subobtuse; margins recurved, usually equally on both sides, entire or bluntly toothed above; hyaline points lacking; costa ending in or below apex, straight, 48–90(−105) μm wide near base; basal cells rectangular, basal marginal cells rectangular, walls of ± uniform thickness, cells above quadrate, thin-walled to slightly incrassate, not or hardly sinuose, bistratose at margins and towards apex, 8–10 μm wide in mid-leaf. Perichaetial leaves of ± similar size to upper vegetative leaves, lingulate to broadly lingulate, shortly pointed, not or scarcely overtopping capsules but when doing so concealing capsules in side view. Capsules subglobose, hemispherical when empty, exothecial cells thin-walled; peristome teeth bright red, recurved when dry, with numerous perforations; spores 16–20 μm. Capsules common, spring. On rocks beside rivers with base-rich water, especially in limestone areas. Occasional in S. Wales and N. England, very rare elsewhere, Dumfries, Berwick, W. Lothian, Mid and E. Perth, Skye, Shetland, rare in Ireland. 32, H7. GB24 + 14∗ , IR5 + 2∗ . Circumpolar

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Boreo-temperate. Europe north to Svalbard, Siberia, Kashmir, Japan, Azores, N. and C. Africa, N. and C. America, Greenland, Peru. H. H. Blom (in Nyholm, 1998) reports hyaline points in S. platyphyllum 0–0.3 mm long, but I have not seen hyaline points in British plants. British and Irish material belongs to ssp. platyphyllum; ssp. abrupticostatum (Bryhn) Blom. occurs in arctic regions.

4 S. agassizii Sull. & Lesq. in Sull., Musci Bor.-Amer., 1856 Grimmia agassizii (Sull. & Lesq.) A. Jaeger

(Fig. 126)

Small brownish cushions to lax tufts, 1.5–5.0 cm high. Leaves oblong-ligulate to linear-lanceolate, subacute, obtuse or rounded; margins plane or rarely narrowly recurved below, entire or crenulate above; hyaline points lacking; costa ending below apex; basal cells rectangular, shorter towards margins, cells above quadrate, ± sinuose, unistratose throughout, 8–10 μm wide in mid-leaf. Perichaetial leaves overtopping but not concealing capsules in side view. Capsules obloid, turbinate when empty; exothecial cells incrassate, mostly wider than long; peristome teeth red, strongly recurved when dry, narrowly perforated; spores 16–20 μm. Capsules occasional, spring. On basic rocks subject to flooding by fastflowing streams and rivers, on boulders in hollows subject to seasonal flooding. 300–1100 m. Rare, in scattered localities in N. W. Wales and N. England north to E. Ross and Sutherland. 13. GB8 + 5∗ . European Boreal-montane. Europe north to Svalbard, Iceland, N. America, Greenland. Showing considerable variation in leaf shape, with plants growing submerged in fastflowing water tending to have narrower more acute leaves than plants less subject to submergence. Misidentified in the past as S. rivulare, this species is less rare in Britain than originally thought. For accounts of S. agassizii in Britain see H. H. Birks & H. J. B. Birks, Trans. Br. Bryol. Soc. 5, 215–17, 1967, N. T. H. Holmes, J. Bryol. 9, 275–8, 1976 and A. Orange, Bull. Br. Bryol. Soc. 65, 51–8, 1995. The correct name of this plant is currently uncertain as the type specimen is what has for a long time been known as S. alpicola (i.e. S. platyphyllum). Clearly, confusion would arise if the name of S. agassizii were to be changed to S. alpicola, but the matter has not yet been decided upon.

Species 5–17, Schistidium apocarpum complex In his monograph of the Schistidium apocarpum complex, Blom (1996) recognised 31 species and an additional two species appear on his account in Nyholm (1998) of which 13 are reported from the British Isles. Undoubtedly, further species will be added to these in due course. For an excellent account of and key to all the N. W. European species see H. H. Blom in Nyholm (1998). The following descriptions are based upon British specimens supplemented from Blom (in Nyholm, 1998) where material has not been adequate.

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Apocarpum subgroup Leaf margins often bluntly toothed above; hyaline points thin; costa often papillose on abaxial side above; cells smooth. Capsules cup-shaped to shortly cylindrical, not narrowed at mouth when dry and empty; peristome teeth often semi-perforated in middle and lower part. KOH laminal reaction orange or red. Six species in N. W. Europe. 5 S. apocarpum (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 128) Grimmia apocarpa Hedw. Dull green to brownish tufts, patches or rough mats, shoots procumbent to suberect, 0.5–5.0(−8.0) cm long. Epidermal cells of stems strongly incrassate with small lumens. Leaves appressed, sometimes subsecund when dry, erect-patent, sometimes subsecund when moist, straight to subfalcate, ovate to narrowly lanceolate, sharply keeled above; margins recurved ± from base to apex, entire or sparsely bluntly toothed towards apex; hyaline points usually present, (0−)0.05– 0.50(−1.20) mm long, thin, flexuose, entire to spinulose-denticulate, decurrent down margins or not; costa smooth or with sparse low papillae on abaxial side above; basal cells rectangular, thin-walled to incrassate, chlorophyllous, basal marginal cells shortly rectangular to wider than long, not larger than cells above, walls of ± uniform thickness, cells above rounded-quadrate to shortly rectangular, incrassate, usually sinuose, smooth, ± unistratose, in mid-leaf mostly 8–10 μm wide, margins 2–3(−4)-stratose. Perichaetial leaves larger than vegetative leaves, lingulate-lanceolate to ovate, concealing capsules in side view. Capsules orange to orange-red, obloid, 1.2–1.6(−2.0) times as long as wide; exothecial cells thinwalled, ± isodiametric to wider than long in middle and lower half of capsule; peristome teeth red, patent to spreading, curved and twisted, with upturned tips when dry, (350−)400–700 μm long, longly tapering, perforated or not, coarsely papillose above; spores 11–15(−19) μm. Capsules common, winter, spring. On exposed basic rocks, walls, mortar, concrete, in a wide range of habitats, very rarely on trees. 0–1210 m (summit of Ben Lawers). Occasional to frequent in lowland England, frequent or common elsewhere. Eurasian Boreo-temperate. Europe north to western Norway, Faeroes, Caucasus, Altai, Siberia, Madeira, Newfoundland. Forms of this plant with costae papillose on the abaxial side above may be mistaken for S. papillosum, S. pruinosum or S. strictum, but these species have leaf margins papillose or papillose-denticulate above and the costae more densely papillose; the first two have strongly papillose lamina cells and the last has shorter capsules. Most likely to be confused with S. crassipilum or S. elegantulum (q.v.).

6 S. trichodon (Brid.) Poelt, Svensk. Bot. Tidskr, 1953 Grimmia trichodon Brid.

(Fig. 128)

Plants forming black tufts or straggling, sometimes extensive patches, shoots greenish only at the tips, leafless below, to 8 cm long. Leaves straight to subsecund

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Fig. 128 1–7, Schistidium apocarpum: 1, shoot with sporophyte; 2, leaves; 3, leaf apex in side view (×60); 4, basal marginal cells (×420); 5, mid-leaf cells (×420); 6, perichaetial leaf; 7, dry empty capsule; 8, exothecial cells (×210); 9, peristome tooth. 10–18: S. trichodon: 10, shoot with sporophyte; 11, leaves; 12, leaf apex in side view (×60); 13, basal marginal cells (×420); 14, mid-leaf cells (×420); 15, perichaetial leaf; 16, dry empty capsule; 17, exothecial cells (×210); 18, peristome tooth. Shoots ×12, leaves and capsules ×20, teeth ×60.

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when dry, erect-patent, sometimes subsecund when moist, ovate-lanceolate, tapering to acuminate apex from widest part; margins narrowly recurved, irregularly bluntly toothed towards apex at least in some leaves; hyaline points 0–80 μm long, spinulose, decurrent down margins; costa often papillose on abaxial side above; basal cells rectangular, chlorophyllous, basal marginal cells quadrate to wider than long, walls ± uniformly thickened, cells above shortly rectangular to rounded-quadrate, incrassate, sinuose, smooth, ± unistratose, in mid-leaf 8–10 μm wide, at margins bistratose but with unistratose patches in middle and upper part of leaf. Perichaetial leaves larger than vegetative leaves, ovatelanceolate, ± concealing capsules in side view; hyaline points 0–100 μm long. Capsules obloid, 1.4–2.1 times as long as wide; exothecial cells ± isodiametric to shortly rectangular in middle and lower half of capsule, thin-walled; peristome teeth red, incurved with tips overlapping when dry, (450−)500–650(−750) μm long, longly tapering, narrowly perforated or not, finely papillose throughout; columella persisting; spores 10–14 μm. Capsules common, winter, spring. Exposed calcareous rocks. 10–1100 m. Caernarfon, occasional in the Pennines and the central Scottish Highlands, very rare further north, extending to W. Sutherland. 15. GB18 + 1∗ . Circumpolar Boreal-montane. Europe from the Alps and Carpathians north to northern Norway, Iceland, Georgia, Armenia, N. W. India, China, Japan, N. America. Whilst the tips of the peristome teeth overlapping when dry is a feature unique to S. trichodon in the genus, the teeth are in a suitable state for only a short time during the year. In the absence of suitable capsules it differs from S. apocarpum in its black colour, the very short or absent hyaline points of the leaves, which are acuminate rather than acute as in S. apocarpum. This plant was first reported from Britain by A. C. Crundwell, Trans. Br. Bryol. Soc. 3, 558–62, 1959. British material belongs to var. trichodon; var. nutans Blom, in which the plants are smaller and brownish with arcuate, secund stems and relatively longer capsules, is known from Scandinavia and could occur in Britain.

Strictum subgroup Plants often reddish. Leaf margins papillose or papillose-denticulate above; hyaline points thin; costa papillose on abaxial side above; cells in upper part of leaf papillose. Exothecial cells ± isodiametric or wider than long. KOH laminal reaction orange or red. Seven species. 7 S. papillosum Culm. in Amann, Fl. Mouss. Suisse, 1918 (Fig. 129) Lax or dense tufts or patches, reddish above, olivaceous below. Shoots to 10 cm long. Epidermal cells of stems strongly incrassate with small lumens. Leaves appressed to subsecund when dry, erect-patent, subsecund when moist, straight to subfalcate, lanceolate to ovate, gradually tapering from widest part to acute to acuminate apex; margins recurved in middle and lower part or ± from base to apex, papillose-denticulate above; hyaline points 0–0.50(−1.25) mm long but often short, thin, flexuose, slightly to strongly spinulose-denticulate at least below,

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Fig. 129 1–9, Schistidium papillosum: 1, shoot with sporophyte; 2, leaves; 3, leaf apex in side view (×60); 4, basal marginal cells (×420); 5, mid-leaf cells (×420); 6, perichaetial leaf; 7, dry empty capsule; 8, peristome tooth; 9, exothecial cells (×210). 10–18: S. pruinosum: 10, shoot with sporophyte; 11, leaves; 12, leaf apex in side view (×60); 13, basal marginal cells (×420); 14, mid-leaf cells (×420); 15, perichaetial leaf; 16, dry empty capsule; 17, exothecial cells (×210); 18, peristome tooth. Shoots ×12, leaves and capsules ×20, teeth ×60.

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shortly to longly decurrent down margins; costa strongly papillose on abaxial side, papillae to 10 μm high; cells incrassate, basal rectangular, not sinuose, chlorophyllous, basal marginal cells quadrate to wider than long, walls of ± uniform thickness, cells above mostly shortly rectangular, sinuose, strongly papillose on abaxial side, sparsely papillose on adaxial side, ± unistratose, 8–10 μm wide in mid-leaf. Perichaetial leaves ± similar in shape to vegetative leaves or linearlanceolate, larger, concealing capsules in side view or not. Capsules dark red to reddish brown, obloid, 1.5–2.0 times as long as wide; exothecial cells quadrate to wider than long in middle and lower half of capsule, thin-walled; peristome teeth reddish, erect-patent, curved and twisted, becoming squarrose with age when dry, (310−)330–500 μm long, tapering to long fine points, entire or with narrow perforations, densely papillose above; spores 10–13 μm. Capsules common, autumn. On basic to acidic sheltered to exposed montane rocks except in the driest habitats. To 1210 m (summit of Ben Lawers). Rare to occasional, Merioneth, Dumfries and the Central Scottish Highlands. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Asia, Madeira, N. America, Greenland. The papillae are best seen on leaves near the stem tips. Much rarer than S. strictum, from which it differs in the leaf cells coarsely papillose and longer capsules.

8 S. pruinosum (Wilson) Roth, Eur. Laubm., 1904 Grimmia conferta var. pruinosa (Wilson) Braithw.

(Fig. 129)

Dense olivaceous or brownish, frequently grit-filled tufts or more rarely patches, often hoary when dry, shoots 1.5–3.0(−4.5) cm long. Leaves appressed when dry, erect-patent when moist, straight, lanceolate to ovate, acute to obtuse, sharply keeled and opaque above; margins recurved on one or both sides, papillose above; hyaline points to 1.6 mm long, terete, straight, entire to spinulose below, decurrent down margins or not; costa papillose above on abaxial side; basal cells rectangular, chlorophyllous, walls moderately thickened, sinuose or not, basal marginal cells quadrate or wider than long, walls of ± uniform thickness, cells above rounded-quadrate, sinuose or not, coarsely papillose on both surfaces, bistratose, opaque in upper part of leaf, 6–8 μm wide in mid-leaf,. Perichaetial leaves ovate-lanceolate, much larger than vegetative leaves, concealing capsules in side view. Capsules red or reddish brown with metallic sheen, obloid, 1.3–2.0 times as long as wide; exothecial cells isodiametric to wider than long in middle and lower half of capsule, thin-walled; peristome teeth red, patent to recurved when dry, straight or curved, 270–390(−450) μm long, narrowly perforated, densely and coarsely papillose above; spores 10–14(−15) μm. Capsules common. On dry or seasonally moist, usually exposed calcareous rocks and cliffs. 400–850 m. Rare, Derby, central Scotland, Clare, Down, Antrim, Londonderry. 11, H4. European Boreal-montane. Northern and montane Europe to 64◦ N, Iceland, Caucasus, Turkey.

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The coarsely papillose cells, 6–8 μm wide in mid-leaf, are diagnostic, distinguishing S. pruinosum from other British and Irish species. Treated by Braithwaite (1887–1905) and Dixon & Jameson (1924) as a variety of S. confertum, despite the opaque strongly papillose leaf cells and longer capsules, and was recognised until the time of the Second World War after which it was treated as a synonym of S. confertum. Thus, a number of records of S. confertum belong to S. pruinosum. Plants of S. pruinosum from dry situations form small hoary cushions, and as the leaves have long hyaline points and are opaque above, they are likely to be mistaken for a Grimmia species with opaque leaf cells, but differ in areolation and the almost always present immersed capsules. Where conditions are moist, the plants form straggling patches and the hyaline points are much shorter. It is such plants that formed the basis of the record of S. boreale Poelt from Scotland (E. F. Warburg, Trans. Br. Bryol. Soc. 4, 757–759, 1965). S. boreale, which is a black plant with papillose leaves, is not known in the British Isles although it could well occur.

˚ 9 S. strictum (Turner) Loeske ex Martensson, Kongl. Svenska Vetensk. Acad. Handl., 1956 (Fig. 130) ¨ ¨ Grimmia apocarpa var. gracilis Rohl., G. stricta Turner, S. gracile (Rohl.) Limpr. Dull red to rust-coloured dense tufts to straggling patches, shoots to 10(−12) cm long. Stems often with dwarf branches; lacking central strand in section. Leaves imbricate when dry, erect-patent when moist, straight or slightly curved, from ovate to lanceolate basal part ± rapidly tapered to acute or acuminate upper part; margins recurved below or sometimes ± to apex, papillose or papillose-denticulate towards apex; hyaline points 0–350(−600) μm long, not or hardly decurrent down margins, sparsely spinulose; costa papillose on abaxial side, papillae to 5 μm high; cells incrassate, esinuose to strongly sinuose, basal rectangular, chlorophyllous, basal marginal cells quadrate to wider than long, walls ± uniformly thickened, cells above rounded-quadrate to shortly rectangular, with scattered low papillae on abaxial side, unistratose with scattered bistratose patches, 8–10 μm wide, in mid-leaf. Perichaetial leaves larger than vegetative leaves, lingulate-lanceolate to ovate, hardly concealing capsules in side view. Capsules deep red, ± spherical to obovoid before dehiscence, 1.1–1.4 times as long as wide; exothecial cells mostly wider than long in middle and lower half of capsule, thin-walled; peristome teeth red, erect-patent when dry, curved and twisted, becoming squarrose with age, 350–500(−570) μm long, entire or with narrow perforations or not, finely papillose, tapering to fine point; spores 12–15(−18) μm. Capsules common, winter. On exposed, dry, basic montane cliff ledges and rocks, rarely in lowland ravines and on sea-cliffs. 0–1210 m. Rare in Wales, N. England and southern Scotland, frequent in parts of the Scottish Highlands, extending north to Orkney, also recorded from S. Devon and Worcester, rare in Ireland. 38, H15. GB103 + 13∗ , IR11 + 8∗ . Suboceanic Wide-boreal. An oceanic species occurring in S. W. Norway, Faeroes, Iceland, Pyrenees, Madeira, western N. America. Most of the specimens I have seen determined as S. strictum are correctly named, very few belonging to S. papillosum or S. apocarpum, so that currently available distribution data are

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Fig. 130 1–9, Schistidium strictum: 1, shoot with sporophyte; 2, leaves; 3, leaf apex in side view (×60); 4, basal marginal cells (×420); 5, mid-leaf cells (×420); 6, perichaetial leaf; 7, dry empty capsule; 8, exothecial cells (×210); 9, peristome tooth. 10–17: S. robustum: 10, shoot with sporophyte; 11, leaves; 12, basal marginal cells (×420); 13, mid-leaf cells (×420); 14, perichaetial leaf; 15, dry empty capsule; 16, exothecial cells (×210); 17, peristome tooth. Shoots ×12, leaves and capsules ×20, teeth ×60.

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likely to be largely accurate. The sparsely papillose leaves and cup-shaped capsules will distinguish S. strictum from S. papillosum and S. pruinosum. The papillae on the leaves are difficult to detect in S. strictum but the usually reddish coloration, the leaf margins papillosedenticulate above and the costae papillose on the abaxial side will identify this plant. Forms of S. apocarpum and S. crassipilum with papillose costae differ in their longer capsules and leaf shape; S. apocarpum does not have papillose-denticulate leaf margins and in S. crassipilum the basal marginal cells of the leaves have the transverse walls strongly thickened. H. H. Blom (in Nyholm, 1998) says that in S. strictum the leaves are spirally arranged when dry, but I find this difficult to detect. He also says it is a lowland species, using this as a key character, but in the British Isles it rarely occurs at low altitudes.

Robustum group Leaf margins recurved, entire; hyaline points coarse or not; basal marginal cells with ± uniformly thickened walls, cells above incrassate, usually longer than wide, smooth. Perichaetial leaves long and narrow. Capsules obloid to shortly cylindrical; exothecial cells shortly rectangular or rectangular with unevenly thickened longitudinal walls; peristome teeth spreading to recurved, ± straight. KOH laminal reaction orange or red. Six species in N. W. Europe. ´ W. A. Weber, Phytologia, 1986 10 S. dupretii (Ther.) (Fig. 131) Small brown or more rarely dull green tufts, to c. 1.5 cm high. Stem epidermal cells slightly thickened, with large lumens. Leaves erect when dry, lower leaves patent, upper erect-patent when moist, narrowly lanceolate to ovate-lanceolate, gradually tapering from widest part to obtuse to acute apex; margins broadly recurved at least on one side, entire; hyaline points very short but rarely absent, 0–150 μm long, narrow, spinulose, base narrower than apex of lamina or grading into lamina apex; costa smooth on abaxial side; cells incrassate, basal rectangular, chlorophyllous, esinuose, basal marginal cells quadrate to wider than long, walls of ± uniform thickness, cells above rounded-quadrate to shortly rectangular, sinuose or not, smooth, unistratose or with bistratose patches, mostly 8–10 μm wide in mid-leaf. Perichaetial leaves narrow, ligulate-lanceolate, longly overtopping but not concealing capsules in side view. Capsules reddish brown, shortly cylindrical, 1.4–2.0 times as long as wide, becoming striate in middle and lower 1 /2 –3 /4 when dry and empty; exothecial cells variable in shape in middle and lower half of capsule, thin-walled; peristome teeth red to reddish brown, not curved or twisted, reflexed when dry, (250−)270–380 μm long, tapering to fine point, not perforated, finely papillose above; spores 8–11 μm. Capsules common. On exposed or partially shaded dry calcareous rocks. Apparently very rare, Midlothian, W. and Mid Perth, Angus. 4. Circumboreal Montane. Montane and northern Europe north to northern Norway, Iceland, Georgia, Kazakstan, India, Japan, N. America. S. dupretii may be recognised by its small size and the long narrow perichaetial leaves longly overtopping but not concealing the capsules, a particularly noticeable feature when the plants are dry. This is also a feature of S. frigidum var. havaasii with which S. dupretii is likely to be confused, but S. frigidum differs in capsule shape, leaves with basal marginal

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Fig. 131 1–8, S. dupretii; 1, shoot with sporophyte; 2, leaves; 3, basal marginal cells (×420); 4, mid-leaf cells (×420); 5, perichaetial leaf; 6, dry empty capsule; 7, exothecial cells (×210); 8, peristome tooth. 9–16, S. confertum: 9, shoot with sporophyte; 10, leaves; 11, basal marginal cells (×420); 12, mid-leaf cells (×420); 13, perichaetial leaf; 14, dry empty capsule; 15, exothecial cells (×210); 16, peristome tooth. Shoots ×12, leaves and capsules ×20, teeth ×60. cells rectangular, hyaline, with strongly thickened transverse walls and mid-leaf cells mostly 6–8 μm wide. The small size may also lead to confusion with S. confertum (q.v.).

11 S. robustum (Nees & Hornsch.) H. H. Blom, Bryophyt. Biblioth., 1996 (Fig. 130) Grimmia apocarpa var. homodictyon (Dixon) Crundw., G. homodictyon Dixon, S. apocarpum var. homodictyon (Dixon) Crundw. & Nyholm Dull green to light brown or rusty red tufts or patches, often hoary when dry; shoots 1–3(−5) μm long. Leaves erect when dry, erect-patent when moist, straight,

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lanceolate to ovate-lanceolate, gradually tapering from widest part to acute apex; margins recurved ± from base to apex, entire; hyaline points coarse, straight, flattened below, terete above, spinulose, (0.2−)0.4–1.6 mm long, decurrent down margins, strongly spinulose; costa prominent, smooth on abaxial side above; cells incrassate, walls whitish, basal rectangular, chlorophyllous, strongly sinuose, basal marginal cells quadrate to wider than long, walls of ± uniform thickness, cells above shortly rectangular, strongly sinuose, smooth, unistratose, occasionally with bistratose streaks, 8–12 μm wide in mid-leaf. Perichaetial leaves ligulatelanceolate, not concealing capsules in side view. Capsules light brown, shortly cylindrical, 1.8–2.3 times as long as wide; exothecial cells mainly shortly rectangular in middle and lower half of capsule, thin-walled; peristome teeth orange-red, not curved or twisted, recurved when dry, 300–400 μm long, longly tapering to thin fragile points, perforated, densely papillose above; spores 8–12 μm. Capsules occasional to frequent, winter, spring. On exposed limestone and basic rocks and cliff ledges. 0–750 m. S. E., Mid-West and N. W. Yorkshire, Westmorland, rare to occasional in Scotland from Mid Perth and Angus north to Skye and W. Sutherland. 15. GB28 + 1∗ . European Boreal-montane. Europe north to northern Norway, Corsica, Caucasus, Canada. S. robustum is readily recognised by the long coarse spinulose hyaline points and thickwalled strongly sinuose leaf cells.

Confertum group Plants small, dull green. Leaf margins plane or recurved at about middle on one or both sides, entire; hyaline points thin, ± flattened; basal marginal cells with transverse walls more strongly thickened than longitudinal walls, cells above smooth, small, 6–9 μm wide. Capsules ± spherical to shortly cylindrical; exothecial cells various; peristome teeth irregular, often strongly perforated. KOH laminal reaction intense yellow. Four species in N. W. Europe. The laminal KOH reaction is a useful additional character for members of this group as in all other groups it is orange-red or red.

12 S. confertum (Funck) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 131) Grimmia conferta Funck, S. canariense Wint., S. apocarpum var. confertum ¨ (Funck) H. Moller Small tight often grit-filled, dark green cushions, to 1.5 cm high. Stem epidermal cells slightly incrassate, with large lumens. Leaves erect, appressed when dry, erectpatent when moist, straight, narrowly lanceolate to ovate, gradually tapering from widest part to acute apex, bluntly keeled below, sharply keeled above; margins recurved to 3 /4 way up leaf on one side, less so or plane on the other, entire; hyaline points flattened, spinulose-denticulate, 0–200 μm long, not decurrent down margins; costa prominent on abaxial side, smooth above; basal cells rectangular, esinuose, sometimes hyaline, 20–40 μm long, basal marginal cells ± hyaline, quadrate

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to shortly rectangular, transverse walls more strongly thickened than longitudinal walls, cells above hexagonal to rounded-quadrate, thin-walled to incrassate, not or hardly sinuose, 1–2-stratose, 5–8 μm wide in mid-leaf. Perichaetial leaves larger than vegetative leaves, ovate, not plicate, concealing capsules in side view or not. Capsules yellowish brown to reddish brown, cup-shaped after dehiscence, 1.1– 1.3 times as long as wide; exothecial cells mostly shortly rectangular, walls ± uniformly slightly thickened; peristome teeth orange-red, not curved or twisted, erect to erect-patent, becoming reflexed with age when dry, 230–320 μm long, strongly perforated, coarsely papillose above; spores 8–10(−11) μm. Capsules common, spring, autumn. On exposed basic rocks. 5–700 m (Clogwyn Du’r Arddu). Rare, W. Norfolk, scattered localities in Wales and northern Britain, Antrim, Londonderry. 14, H2. Circumpolar Boreo-temperate. Europe north to southern Scandinavia, Iceland, Turkey, Cyprus, Georgia, Armenia, India, China, N. America, Greenland. About 50% of specimens identified as S. confertum have been misnamed and current distribution data cannot be accepted. S. pruinosum, S. frigidum var. havaasii and S. dupretii are similar in appearance. S. pruinosum differs in the usually much longer hyaline points, coarsely papillose leaf cells and longer capsules; S. frigidum var. havaasii has longer basal leaf cells, the rectangular hyaline basal marginal cells with very strongly thickened transverse walls are also distinctive, the cells above sinuose and the exothecial cells variable in shape. S. dupretii has basal marginal cells with walls of ± uniform thickness, long narrow perichaetial leaves and exothecial cells variable in shape.

13 S. flaccidum (De Not.) Ochyra, Nova Hedwigia, 1989 S. pulvinatum (Hedw.) Brid.

(Fig. 132)

Dense olive-green cushions, blackish below, sometimes hoary, 0.5–1.8 cm high. Leaves erect when moist, narrowly lanceolate to ovate; margins plane or recurved on one or both sides, entire; hyaline points 150–850 μm long, flattened, not or hardly decurrent down margins, denticulate; costa smooth on abaxial side; basal cells rectangular, ± hyaline, sinuose and sometimes nodulose, 34–67 μm long, basal marginal cells quadrate to shortly rectangular, ± hyaline, transverse walls strongly thickened, cells above rounded-quadrate, thick-walled, not or slightly sinuose, unistratose with bistratose patches, 7–9(−10) μm wide in mid-leaf. Perichaetial leaves large, plicate, ± concealing capsules in side view. Capsules yellowish brown to orange-brown, ± spherical to obovoid, 0.9–1.3 times as long as wide, cup-shaped after dehiscence; exothecial cells irregularly shaped in upper part of capsule, irregularly rectangular below, thin-walled; lid mamillate; peristome teeth rudimentary, 17–25 μm long, not or scarcely extending beyond bright red capsule mouth; spores 8–10 μm. Capsules common. On exposed baserich rock faces. Very rare, Caernarfon, 1. GB1. Circumpolar Boreal. Montane Europe from Spain and Greece north to Norway, Iceland, Cyprus, Turkey, Azerbaijan, India, Tenerife, N. America, Antarctica. Likely to be confused with S. confertum or S. frigidum var. havaasii, but differing in the apparently gymnostomous red-mouthed capsules and plicate perichaetial leaves. The mamillate

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Fig. 132 1–8, Schistidium frigidum var. frigidum: 1, shoot with sporophyte; 2, leaves; 3, basal marginal cells (×420); 4, mid-leaf cells (×420); 5, perichaetial leaf; 6, dry empty capsule; 7, exothecial cells (×210); 8, peristome tooth. 9–16, S. frigidum var. havaasii: 9, shoot with sporophyte; 10, leaves; 11, basal marginal cells (×420); 12, mid-leaf cells (×420); 13, perichaetial leaf; 14, dry empty capsule; 15, exothecial cells (×210); 16, peristome tooth. 17–24, S. flaccidum: 17, shoot with sporophyte; 18, leaves; 19, basal marginal cells (×420); 20, mid-leaf cells (×420); 21, perichaetial leaf; 22, dry empty capsule; 23 and 24, exothecial cells from upper and lower parts of capsules (×210). Shoots ×12, leaves and capsules ×20, teeth ×60.

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lid of S. flaccidum is unique in the genus, all other species having rostrate lids. Even very old capsules of other species usually have at least some basal parts of the peristome teeth still present. The leaves of S. flaccidum differ from those of S. confertum in the longer hyaline points and longer basal cells and from those of S. frigidum in the cells not or hardly sinuose. For the occurrence of this plant in Britain see C. C. Townsend, J. Bryol. 19, 815–17, 1997.

14 S. frigidum H. H. Blom, Bryophyt. Biblioth., 1996 Small dense olive-green cushions or sometimes extensive tufts; shoots to 2 cm long. Leaves appressed when dry, spreading from erect basal part when moist, linear-lanceolate to lanceolate, acute to acuminate; margins recurved on one or both sides, entire; hyaline points 0–800 μm long, not decurrent down margins, flattened, spinulose; costa smooth on abaxial side; basal cells rectangular, hyaline, not sinuose, 40–75 μm long, basal marginal cells hyaline, rectangular, with very strongly thickened transverse walls, often forming a distinct marginal band, cells above shortly rectangular to quadrate, incrassate, sinuose, smooth, unistratose with bistratose patches, 6–10 μm wide in mid-leaf. Perichaetial leaves larger than vegetative leaves, lingulate-lanceolate to lanceolate, not plicate, concealing capsules in side view. Capsules orange-brown to reddish brown, cup-shaped to shortly cylindrical; exothecial cells variable in shape in middle and lower half of capsule, thin-walled; peristome teeth orange-red, spreading to reflexed when dry, not curved or twisted, 190–300 μm long, tapering to broad obtuse or truncate points, perforated or cleft, coarsely papillose above; spores 10–13(−17) μm. Capsules common, spring. Capsules 1.4–2.1 mm long excluding lid, 1.2–1.5 times as long as wide, perichaetial leaves narrowly elliptical to lanceolate, concave, costa percurrent or excurrent, stems hardly branched var. frigidum Capsules 0.5–0.6 mm long, 0.9–1.2 times as long as wide, perichaetial leaves lingulate-lanceolate, strongly concave, costa ending below apex, stems much branched var. havaasii Var. frigidum (Fig. 132) Dense sometimes extensive tufts. Shoots to 5 cm long; stems hardly branched. Leaves lanceolate; hyaline points 0–800 μm long. Subperichaetial leaves similar to leaves below. Perichaetial leaves narrowly elliptical to lanceolate, concave, costa percurrent to excurrent. Capsules obloid to shortly cylindrical, 1.4–2.1 mm long, 1.2–1.5 times as long as wide; peristome teeth 230–300 μm long. On exposed usually basic montane rocks and ledges, but also on walls, old buildings and slate, often where periodically moist. Rare, in scattered localities in western and northern Britain from Montgomery north to Inverness and Argyll, Sutherland. Circumpolar Boreal-montane. Circumpolar Wide-temperate. Montane and N. Europe north to Svalbard, Jan Mayen, N. W. Russia, Tenerife, Faeroes, Iceland, N. America, Greenland.

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Var. havaasii H. H. Blom, Bryophyt. Biblioth., 1996 (Fig. 132) Dense cushions, to c. 1.5 cm high. Stems much branched. Leaves narrowly lanceolate to lanceolate; hyaline points terete, ± smooth, 0–200 μm long. Subperichaetial leaves much larger than leaves below. Perichaetial leaves lingulate-lanceolate, very concave, costa ending well below apex. Capsules ± spherical to obloid, 0.5– 0.6 mm long, 0.9–1.2 times as long as wide; peristome teeth 190–250(−290) μm long. On exposed basic rock, boulders and in scree. 700–1000 m (Ben Lawers). Caernarfon, N. W. Yorkshire, Dumfries, Mid Perth. 4. European Boreal-montane. Norway. In S. frigidum the basal marginal cells are rectangular, usually hyaline and with very strongly thickened transverse walls – these walls may sometimes be so strongly thickened as to appear quadrate – and often form a distinct border at the base of the leaves. This border and the irregularly shaped exothecial cells will distinguish S. frigidum var. frigidum from S. crassipilum and S. elegantulum. For the differences between S. frigidum var. havaasii and S. dupretii and S. confertum see under those species.

Atrofuscum group Leaf margins plane to recurved to 3 /4 (−4 /5 ) way up leaf, entire; hyaline points where present coarse, terete in upper part; basal marginal cells with transverse walls more strongly thickened than longitudinal walls or not, cells above ± isodiametric, smooth. Exothecial cells rectangular or isodiametric and rectangular mixed. KOH laminal reaction orange or red. Six species in N. W. Europe. 15 S. atrofuscum (Schimp.) Limpr., Laubm. Deutschl., 1889 Grimmia atrofusca Schimp.

(Fig. 133)

Dense blackish, readily disintegrating, often grit-filled tufts or cushions, 1–3 cm high. Epidermal cells of stem slightly incrassate, with large lumens. Leaves brown, opaque above, appressed when dry, erect-spreading when moist, lanceolate to broadly lanceolate, subacute to obtuse; margins recurved on one or both sides, entire; hyaline points usually absent but occasionally present and up to 60 μm long; costa percurrent, smooth on abaxial side, in section hemispherical; cells at extreme base shortly rectangular, ± thin-walled, not sinuose, basal marginal cells quadrate to wider than long, subhyaline, transverse walls more strongly thickened than longitudinal walls, cells above moderately thickened, not or slightly sinuose, smooth, partially bistratose, 8–10 μm wide in mid-leaf. Perichaetial leaves larger than vegetative leaves, elliptical, concealing capsules in side view, hyaline points absent. Capsules deeply immersed, yellow to orange or light orange-brown, obloid, 1.3–1.7 times as long as wide; exothecial cells variable in shape in middle and lower half of capsule, thin-walled; peristome teeth orange, not curved or twisted, patent to reflexed when dry, to 320 μm long, obtuse or truncate, or rudimentary, coarsely papillose; spores c. 10 μm. Capsules occasional. On dry, strongly calcareous boulders. 550–650 m. Very rare, E. Perth, S. Aberdeen, Banff,

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Fig. 133 1–7, Schistidium atrofuscum: 1, shoot with sporophyte; 2, leave; 3, basal marginal cells (×420); 4, mid-leaf cells (×420); 5, perichaetial leaf; 6, dry empty capsule; 7, exothecial cells (×210); 8–16, S. crassipilum: 8, shoot with sporophyte; 9, leaves; 10, leaf apex (×40); 11, basal marginal cells (×420); 12, mid-leaf cells (×420); 13, perichaetial leaf; 14, dry empty capsule; 15, exothecial cells (×210); 16, peristome tooth. Shoots ×12, leaves and capsules ×20, teeth ×60.

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E. Inverness. 4. GB4. European Boreal-montane. Southern Norway, southern Sweden, Austria, Croatia, Czechoslovakia, Germany, Greece, Iceland, Macedonia, Montenegro, Spain, Turkey, western N. America. Readily recognised by the dense blackish readily disintegrating cushions, the brown leaves and the deeply immersed capsules. S. atrofuscum produces capsules less frequently than most other species and as these are deeply immersed they may appear to be lacking. They may, however, be detected by the presence of projecting perichaetial leaves. For the occurrence of this species in Scotland see E. F. Warburg, Trans. Br. Bryol. 3, 172–3, 1957.

16 S. crassipilum H. H. Blom, Bryophyt. Biblioth., 1996 (Fig. 133) Dark olive-green tufts, rarely hoary when dry; shoots 1–3 cm long. Leaves appressed when dry, erect to patent when moist, straight or slightly curved, lanceolate to ovate, acute; margins recurved to 2 /3 –3 /4 way up leaf, sometimes papillosedenticulate or bluntly toothed above, teeth consisting of projecting cell ends; hyaline points 0–1 mm long, coarse, stiff, spinulose-denticulate, flattened towards base, usually decurrent down margins; costa smooth or with scattered low papillae on abaxial side above; basal cells rectangular, incrassate, often noticeably wider than cells above, basal marginal cells ± quadrate and chlorophyllous or rectangular and hyaline and forming a border, transverse walls more strongly thickened than longitudinal walls, cells above mostly quadrate to wider than long, moderately thickened to incrassate, smooth, not or slightly sinuose, 8–10(−12) μm wide in mid-leaf. Perichaetial leaves larger than vegetative leaves, ovate to lanceolate, ± concealing capsules in side view. Capsules reddish brown or orangebrown, obloid or shortly cylindrical, 1.5–2.0 times as long as wide; exothecial cells shortly rectangular in middle and lower half of capsule, walls slightly thickened; peristome teeth red, ± erect to spreading when dry, not curved or twisted, 300– 450 μm long, gradually tapering to narrow or broad, obtuse or truncate apices, not curved or twisted, not perforated, coarsely papillose above, papillae in rows; spores (6−)9–11(−12) μm. Capsules common. Exposed or sheltered dry baserich rocks, cliff ledges, limestone pavement, walls, buildings. 0–720 m. Common, especially in lowland areas and likely to be found in all vice-counties. Circumpolar Wide-temperate. Europe north to W. Norway, Faeroes, Iceland, Georgia, Ukraine, Turkey, Cyprus, Armenia, N. America. Distinguished from S. elegantulum by the more shortly tapered leaves with margins recurved to 2 /3 –3 /4 way up leaf and often toothed or papillose-denticulate towards the apex and the hyaline points flattened below and usually decurrent down the margins; the basal cells are noticeably larger than the cells above and the basal marginal cells are sometimes rectangular and hyaline. This latter feature may lead to confusion with S. frigidum var. frigidum, but that species differs in the entire margins, non-papillose costae, non-decurrent hyaline apices, narrower perichaetial leaves and exothecial cells variable in shape. Also likely to be mistaken for S. apocarpum, but that species differs in the basal marginal cells with ± uniformly thickened walls, the shorter capsules, exothecial cells ± isodiametric or wider than long in the lower half of the capsule and smaller spores. Where the leaf

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margins are papillose-denticulate and/or the costae sparsely papillose on the abaxial side above, this may cause confusion with S. strictum or S. papillosum. Both these species differ in colour, basal marginal cells, their papillose leaf cells and exothecial cell shape, and the former differs in its shorter capsules. The most common lowland species of Schistidium in the British Isles. Blom (1996) says that the species is common or very common in artificial habitats and is probably the most common and important species that grows on wall tops throughout much of Europe.

17 S. elegantulum H. H. Blom, Bryophyt. Biblioth., 1996 Dull green mats or tufts, usually somewhat hoary when dry; shoots 1.5–3.0 cm long. Epidermal cells of stems strongly incrassate with small lumens. Leaves imbricate when dry, erect-patent when moist, straight or slightly curved, linearlanceolate to lanceolate, acuminate; margins recurved to 1 /3 –2 /3 way up one side of leaf, plane or more shortly recurved on other side, entire; hyaline points to 1.25 mm long, terete, straight, not flattened below, spinulose, not decurrent down margins; costa smooth on abaxial side above; basal cells rectangular, basal marginal cells quadrate to wider than long, with thickened transverse walls, chlorophyllous, cells above rounded-quadrate to transversely elliptical, incrassate, not or hardly sinuose, smooth, unistratose with bistratose patches, 9–10 μm wide in midleaf. Perichaetial leaves ligulate-lanceolate, concealing capsules in side view or not. Capsules yellow-brown to orange-brown, obloid or shortly cylindrical, 1.6– 2.5 times as long as wide; exothecial cells mostly shortly rectangular in middle and lower half of capsule, walls slightly thickened; peristome teeth orange to red, not curved or twisted, erect-patent to patent when dry, 350–510 μm long, gradually tapering to fine points, with narrow perforations, coarsely papillose above; spores 8–10(−12) μm. Capsules common. Mats or decumbent tufts, hyaline points spinulose-denticulate, costa moderately thick, 45–70 μm wide in middle and lower part of leaf ssp. elegantulum Dense tufts, hyaline points minutely spinulose, costa stout, 75–90 μm wide in middle and lower part of leaf ssp. wilsonii

Ssp. elegantulum (Fig. 134) Mats or decumbent tufts; shoots 1.5–3.0 cm long. Hyaline points 0.3–1.0 mm long, ± pellucid, often yellowish at insertion, terete, spinulose-denticulate; costa 45–70 μm wide and 4–5-stratose towards base; basal cells 12–23 μm long. Hyaline points of perichaetial leaves 0.7–0.9 mm long. Capsules light yellow to light orange-brown; stomata 6–8, peristome teeth orange to orange-red, 350–430 μm long, longly tapering, tips incurved when dry, densely papillose throughout. On sheltered or exposed calcareous rocks, boulders and wall tops. Lowland. Rare, W. Gloucester, Anglesey, Argyll, W. Sutherland, E. Cork. 4, H1. Eurasian

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Fig. 134 1–8, Schistidium elegantulum ssp. elegantulum: 1, shoot with sporophyte; 2, leaves; 3, leaf apex (×40); 4, basal marginal cells (×420); 5, mid-leaf cells (×420); 6, perichaetial leaf; 7, dry empty capsule (×20); 8, exothecial cells (×210). 9–12, S. elegantulum ssp. wilsonii: 9, shoot with sporophyte; 10, leaves; 11, leaf apex (×40); 12, perichaetial leaf. Shoots ×12, leaves ×20.

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Boreo-temperate. Europe from the Pyrenees, Italy and the Crimea north to S. W. Norway, Caucasus, Turkey, Pakistan, Altai, China, Japan, Mexico. Ssp. wilsonii H. H. Blom, Bryophyt, Biblioth., 1996 (Fig. 134) Dense tufts, 1.3–5.0 cm high. Hyaline points 0.55–1.25 mm long, whitish, coarse, terete, spinulose with very small spinulae; costa stout, 75–90 μm wide and 5–7stratose below; basal cells 25–44 μm long. Hyaline points of perichaetial leaves 1.0–1.5 mm long. Capsules orange brown to light reddish brown; stomata 8–16; peristome teeth red, 370–510 μm long, tips not incurved when dry, longly tapering, smooth below, densely papillose above. On limestone boulders, outcrops, cliffs and especially on man-made basic substrates. Lowland. Rare, Hereford, Worcester, Glamorgan, Skye, Clare, W. Galway, E. Mayo. 4, H3. Suboceanic Temperate. Rare in Europe S. W. Norway, Croatia, Faeroes, Italy, Majorca, Portugal, Spain. S. elegantulum is the least common of the Schistidium species formerly included in S. apocarpum. In ssp. wilsonii the costae are conspicuously stout and the spinulae of the hyaline points are very small, barely detectable under the low power of the microscope.

Species of Schistidium likely to occur in the British Isles Species omitted from the following accounts are those with an arctic or eastern distribution, but in view of the presence in the British Isles of species such as S atrofuscum or S. frigidum var. havaasii almost any of the species described by Blom (1996) might occur. The descriptions below are taken from Blom (1996) and Blom (in Nyholm, 1998) and are not based upon original observations. Apocarpum subgroup S. flexipile (Lindb. ex Broth.) Roth: Close to S. apocarpum, but leaves lanceolate; margins strongly recurved, entire; hyaline points not decurrent; basal cells narrowly rectangular, strongly sinuose. Subperichaetial leaves conspicuously different from leaves below. Peristome teeth orange-brown. On exposed montane and lowland rocks. S. lancifolium (Kindb.) H. H. Blom: Upper leaves curved and contorted when dry; margins with irregular teeth above, teeth consisting partly of whole cells; hyaline points short or absent; costa coarsely papillose on abaxial side. Moist rocks in woods and ravines. S. trichodon var. nutans H. H. Blom: see under S. trichodon (p. 408). Strictum subgroup S. boreale Poelt: Similar to S. papillosum and S. pruinosum. Plants usually black. Leaf cells strongly sinuose with dark red walls. Peristome teeth not curved or twisted, 220–320 μm long. Dry calcareous montane rocks. S. confusum H. H. Blom: Similar to S. papillosum and S. pruinosum. Plants dull green to brownish, basal cells wider (9–14 μm vs. 7–11 μm) wide), ± strongly sinuose cells immediately above wider (10–12 μm vs. 6–11 μm wide), mid-leaf cells 8–11 μm wide, cells above weakly papillose. Peristome teeth not curved or twisted. Exposed calcareous montane rocks.

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Robustum group S. subjulaceum H. H. Blom: Upper leaves of fertile shoots appressed and sheathing; hyaline points short, thin, decurrent or not; cells incrassate with orange walls. Capsules 1.4– 2.0 times as long as wide. Base-rich rocks in and beside mountain streams. Confertum group S. venetum H. H. Blom: Cells at widest part of leaf above esinuose, basal cells in oblique lines diverging from costa, basal marginal cells hyaline, forming border, cells above partially bistratose, often opaque. On base-rich soil on mountain cliffs and ledges. Umbrosum group S. pulchrum H. H. Blom: Stem epidermal cells strongly incrassate with small lumens. Hyaline points conspicuously white; margins strongly recurved or revolute above; costa not widened above. Capsules 1.2–1.8 times as long as wide; exothecial cells quadrate, rectangular or transversely rectangular in patches; peristome teeth bright red, entire or with slits, finely papillose. On dry or moist rocks in humid situations on mountains. S. umbrosum (Zetterst.) H. H. Blom: Similar to S. pulchrum but plants intricately branched; costa widened above. Capsules 1.1–1.3 times as long as wide; peristome teeth dull red, strongly perforated, coarsely papillose. In crevices of ± vertical montane cliffs. Atrofuscum group S. singarense (Schiffn.) Laz.: Plants usually jet black. Stem epidermal cells slightly thickened, lumens large. Leaves obtusely keeled above; hyaline points short, coarse, terete, not decurrent, coarsely spinulose; basal marginal cells chlorophyllous or subhyaline, transverse walls sometimes thickened. Capsules 1.6–2.3 times as long as wide; exothecial cells very variable in size and shape; peristome teeth strongly perforated. On basic rocks and walls in lowland areas (likely to occur in southern England).

78 GRIMMIA HEDW., SP. MUSC. FROND., 1801 Autoicous or dioicous. Acrocarpous, usually tufted or cushion-forming plants. Stems with or without central strand. Leaves ovate to linear-lanceolate, usually with hyaline points; margins plane, incurved or recurved; costa in section semiterete, reniform or poorly differentiated from lamina; basal cells quadrate to linear, sinuose or not, sometimes nodulose, frequently hyaline towards margins, cells above usually isodiametric, often incrassate and sinuose, 1–3(−5)-stratose, usually smooth or occasionally bulging, very rarely papillose. Perichaetial leaves usually similar to but larger than vegetative leaves or rarely strongly differentiated, hyaline and filmy. Setae straight or curved; capsules exserted or immersed, smooth or ribbed; annulus present; columella not falling with lid; exothecial cells isodiametric to narrowly rectangular; peristome teeth entire or variously perforated or divided above, segments not filiform; calyptrae mitrate or cucullate, not

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plicate, 2–3 cells thick, covering lid. A cosmopolitan genus of c. 70 almost exclusively saxicolous species. Derivation: Named after a German physician and botanist, J. F. Grimm (1737–1821). A difficult genus because of the rarity of many of the species and because of taxonomic and nomenclatural confusion. For a well illustrated account of central European Grimmia species, which includes most British taxa, see E. Maier & P. Geissler, Herzogia 11, 1–80, ˜ & F. Pando, 1995. A very usable key to the world’s Grimmia species is provided by J Munoz Mon. Syst. Bot., Missouri Bot. Gard., 83, 1–133, 2000. Also very useful is an account of Latin ˜ American species by J. Munoz, Ann. Missouri Bot. Gard. 85, 367–403, 1996. For a monograph of European species see Greven (1995). Many Grimmia species have decreased in the British Isles over the past 150 years, partly because of over-collecting and partly because of atmospheric pollution. There are copious old gatherings of species from localities in which they now no longer occur. Many species are very slow growing and lack any obvious means of propagation and great care should be exercised when collecting material to minimise the possibility of further extinctions.

1 Leaves without hyaline points 2 At least uppermost vegetative leaves and perichaetial leaves with some trace of hyaline points 4 2 Basal part of leaves ovate, pellucid, abruptly narrowed into narrowly lingulate, very opaque upper part, margins erect 6. G. unicolor Leaves tapering from widest part to apex, ± pellucid above, margins recurved on one or both sides 3 3 Costa not winged on abaxial side above, basal cells near costa 1–4 times as long as wide, setae straight 14. G. atrata Costa winged on abaxial side above, basal cells linear, setae arcuate when moist 26. G. ramondii 4 Basal marginal cells of leaves uniformly thin-walled 5 Basal marginal cells of leaves with transverse walls more heavily thickened than longitudinal walls 8 5 Leaves crisped when dry, narrowly lanceolate or ligulate from ovate basal part 19. G. incurva Leaves straight to flexuose when dry, ovate to lanceolate 6 6 Leaves of ± uniform size up stems, hyaline points very short, to 160 μm long in upper leaves, capsules unknown in Britain 12. G. elongata Upper leaves much longer than lower, hyaline points to as long as or longer than lamina in upper leaves, capsules very common 7 7 Setae straight, capsules erect, leaves not homomallous when dry 10. G. donniana Setae curved when moist, capsules ± horizontal, leaves homomallous when dry 11. G. arenaria 8 Plants brownish, leaves spirally crisped when dry 17. G. torquata Plant colour various, leaves straight or flexuose when dry 9 9 Capsules immersed, inclined, gibbous, leaves strongly concave 10

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Capsules exserted or if immersed then erect and symmetrical or capsules lacking, leaves concave or not 11 Capsules gymnostomous, leaves widest below middle, mid-leaf cells 8–10 μm wide 1. G. anodon Capsules peristomate, leaves widest above middle, mid-leaf cells 10–12 μm wide, 2. G. crinita Cells in upper part of leaf conspicuously papillose, opaque 25. G elatior Leaf cells smooth, pellucid or opaque 12 Leaves channelled above, costa poorly defined, not conspicuous on abaxial side of leaf, in section hardly distinct from lamina cells, lamina cells 2−4-stratose, opaque 13 Leaves keeled above, costa well defined, conspicuous on abaxial side of leaf, in section ± semiterete or reniform, not grading into lamina cells, lamina cells 1−2-stratose, pellucid or opaque 15 Leaves acuminate, basal cells near costa 4–8 times as long as wide 5. G. ovalis Leaves obtusely pointed, basal cells near costa 0.5–2.0 times as long as wide 14 Basal marginal cells of leaves to twice as wide as long, capsules exserted 3. G. laevigata Basal marginal cells 1–2 times as long as wide, capsules immersed 4. G. tergestina Leaf margins plane or incurved, cells in upper half of leaf opaque 16 Leaf margins at least partially recurved on one or both sides, cells pellucid or opaque 18 Lamina cells bulging in transverse section, 8–13 μm wide in mid-leaf, capsules fusiform, exothecial cells thick-walled 9. G. alpestris Lamina cells not bulging in section, 5–8 μm wide in mid-leaf, capsules ovoid or ellipsoid, exothecial cells thin-walled 17 Dioicous, setae 2–4 mm long, capsule lids rostrate, acute, peristome teeth 50–90 μm wide at base, basal marginal cells 2.0–4.5 times as long as wide 7. G. montana Autoicous, setae to 2 mm long, lids bluntly mamillate, peristome teeth 40–50 μm wide at base, basal marginal cells 1–2 times as long as wide 8. G. ungeri Leaves abruptly narrowed into hyaline points so that apices are ± obtuse, capsules common 19 Leaves tapering into hyaline points, acuminate, capsules rare (except G. decipiens) 20 Basal cells of leaves 2–4 times as long as wide, capsules ellipsoid, lids usually rostrate, perigonia inconspicuous, immediately beneath perichaetia, outer perigonial bracts much modified, filmy, orange, muticous, ecostate 15. G. pulvinata

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Basal cells 4–8 times as long as wide,1 capsules ± spherical, lids mamillate, perigonia conspicuous, terminal on branches, outer perigonial bracts unmodified, similar to stem leaves, green 16. G. orbicularis Plants dark grey, leaves spirally imbricate when dry giving shoots string-like appearance, flagelliform shoots often present 18. G. funalis Colour various, leaves if imbricate then not spirally so when dry, flagelliform shoots lacking 21 Costa reniform in section, poorly defined above, lamina cells opaque above, setae straight 13. G. longirostris Costa ± semiterete in section, clearly defined above, lamina cells pellucid, setae arcuate when moist 22 Hyaline points to as long as lamina in upper leaves, strongly denticulate, decurrent down margins, basal cells near costa to 10 times as long as wide, upper cells strongly sinuose, capsules common 24. G. decipiens Hyaline points not as above, basal cells near costa 2–6(−8) times as long as wide, upper cells esinuose to sinuose, capsules rare 23 Upper leaves secund when moist, clusters of brown gemmae often present at shoot tips 23. G. hartmanii Upper leaves patent to squarrose when moist, clusters of gemmae lacking 23 Costa section 2 cells wide on adaxial side, at extreme base with two layers of guide cells, plants calcifuge 20. G. trichophylla Costa section 4 cells wide on adaxial side, at extreme base with one layer of guide cells, plants of acidic or strongly basic habitats 25 Leaves patent to spreading when moist, costa section at extreme base with 4 guide cells, plants calcicole 21. G. dissimulata Leaves usually recurved to squarrose when moist, costa section at extreme base with 6 guide cells, plants calcifuge 22. G. lisae

Subgenus 1 Grimmia Leaf cells unistratose or bistratose above. Setae less than 1 mm long, curved; capsules globose, smooth or weakly ribbed, gibbous, gymnostomous or not. 1 G. anodon Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 135) Autoicous. Small dark green cushions, hoary when dry, to 1.5 cm high. Leaves appressed when dry, patent when moist, keeled, oblong-lanceolate to oblongobovate, obtuse; margins recurved at middle of leaf; hyaline points to as long as lamina, smooth to denticulate, often decurrent down margins; costa 2 cells wide on adaxial side in section; basal cells rectangular, hyaline, basal cells next to costa 2–4 times as long as wide, basal marginal cells 1–2 times as long as wide, transverse walls thicker than longitudinal walls, cells above quadrate, bistratose at margins and towards apex, 8–10 μm wide in mid-leaf. Setae c. 0.4 mm long, curved; capsules immersed, inclined, ± globose, gibbous, wide-mouthed when 1

In British Isles material.

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Fig. 135 1–5, Grimmia anodon: 1, leaves; 2, section of costa in lower part of leaf; 3, basal marginal cells; 4, mid-leaf cells; 5, capsule. 6–10, G. crinita: 6, leaves; 7, section of costa in lower part of leaf; 8, basal marginal cells; 9, mid-leaf cells; 10, capsule. Leaves ×30, sections ×280, cells ×420, capsules ×10.

empty; peristome absent; spores 8–10 μm. Capsules common, spring. In crevices of exposed vertical calcareous rock on cliffs and on walls. 150–250 m. Probably extinct, Westmorland (1960s, now extinct), Midlothian (1869). 2. GB1 + 1∗ . Circumpolar Wide-temperate. Europe north to Svalbard, Caucasus, Turkey, Iran, Saudi Arabia, C. and N. Asia, Tenerife, Algeria, Morocco, Egypt, N. America, Greenland, Mexico, Peru, Bolivia, Patagonia. Most likely to be confused with Coscinodon cribrosus or Schistidium flaccidum. The former has erect capsules with peristomes and plicate leaves. S. flaccidum has erect capsules and narrowly lanceolate leaves. Other Schistidium species differ in their erect capsules with peristomes, leaf shape and areolation. G. anodon has also been confused with G. tergestina, which is dioicous and has different leaf areolation. For a discussion of the distribution of G. anodon in Britain see T. L. Blockeel, J. Bryol. 19, 181–4, 1996.

2 G. crinita Brid., Muscol. Recent. Suppl. 1, 1806 (Fig. 135) Grey patches, to c. 1 cm high, resembling mouse fur when dry. Shoots julaceous when moist. Leaves concave, ovate-lanceolate to obovate, abruptly narrowed into hyaline point; margins plane; hyaline points in upper leaves as long as or longer than lamina, flattened at base, terete above, smooth; costa 2 cells wide on adaxial side in section; basal cells hyaline, cells next to costa 1.0–1.5 times as long as wide,

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basal marginal cells 2–3 times as long as wide, transverse and longitudinal walls of similar thickness, cells above shortly rectangular to quadrate, incrassate, sinuose, unistratose throughout, 10–12 μm wide in mid-leaf. Setae c. 1 mm long, curved; capsules ± immersed in points of perichaetial leaves, inclined, ovoid, smooth or weakly ribbed, gibbous; peristome present; spores 10–12 μm. Capsules common. On limestone rocks and mortar. Lowland. Recorded from a dry mortared wall of a canal bridge near Hatton, Warwickshire, between 1872 and 1882, but not seen again in England until a recent discovery in E. Cornwall, Dublin (1950) 2, H1. GB1 + 1∗ , IR1. Submediterranean-Subatlantic. Europe, extending north to Poland and Baltic Russia, Caucasus, Israel, Lebanon, Algeria. Known from Warwickshire from 1872 to 1882 and thought to be an introduction, but found on a concrete wall in Cornwall in 1999. There is also a specimen from Dublin, collected in 1950, so it seems likely that G. crinita is native to the British Isles.

Subgenus 2 Guembelia Schimp., Coroll. Bryol. Eur., 1856 Leaves concave, ± ovate, not keeled; margins plane or incurved above; costa obscure above; cells above 2 or more stratose, opaque. Capsules erect, symmetrical, immersed or exserted; annulus of large reddish separating cells. 3 G. laevigata (Brid.) Brid., Bryol. Univ, 1826 G. campestris Burchell ex Hook., G. leucophaea Grev.

(Fig. 136)

Readily disintegrating tufts or patches, hoary when dry, 0.5–1.5 cm high. Leaves appressed, straight when dry, erect-patent when moist, triangular to lanceolate with broad base, apex obtuse; margins plane or erect; hyaline points in upper leaves to as long as or longer than lamina, flattened, finely denticulate, decurrent down margins; costa broad at base, narrower and poorly defined above, several cells wide on adaxial side in section; cells incrassate, esinuose, bistratose, opaque except near base, basal cells near costa twice as long as wide, basal marginal cells transversely oblong, to twice as wide as long, transverse walls thicker than longitudinal walls, cells above quadrate or wider than long, 6–10 μm wide in mid-leaf. Setae straight; capsules ellipsoid, smooth; spores 10–15 μm. Capsules rare, spring. n = 13. On acidic or slightly basic rocks, cliffs, outcrops by rivers, sarsen stones and roofing slates, especially in coastal areas. 0–350 m. Scattered localities from Cornwall east to Kent and north to Angus and Skye, W. and E. Cork, Antrim, Jersey, Guernsey. 33, H3, C. GB21 + 30∗ , IR1 + 4∗ , C6. Circumpolar Southerntemperate. From Mediterranean region north to S. Fennoscandia, Turkey, Cyprus, Caucasus, temperate and tropical Asia, Macaronesia, N. Africa, N. America, Argentina, Brazil, Chile, Australasia, Hawaii. This species can withstand extremes of drought and is tolerant of some degree of pollution. It is, however, decreasing, except in southern England where it has increased in recent years.

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Fig. 136 1–6, Grimmia laevigata: 1, leaves 2, costa section in lower part of leaf; 3, basal marginal cells; 4, basal cells next to costa; 5, mid-leaf cells; 6, capsule. 7–12, G. tergestina: 7, leaves; 8, costa section in lower part of leaf; 9, basal marginal cells; 10, basal cells next to costa; 11, mid-leaf cells; 12, capsule. Leaves ×20, sections ×280, cells ×420, capsules ×10.

4 G. tergestina Tomm. ex Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 136) Dioicous. Blackish green, readily disintegrating tufts or patches, hoary when dry, to 1 cm high. Leaves erect when dry, erect-patent when moist, concave, ovatelanceolate, obtuse; margins plane below, ± incurved above; hyaline points in upper leaves to as long as or longer than lamina, smooth or slightly denticulate, flattened, decurrent down margins; costa poorly defined, several cells wide on adaxial side in section; cells incrassate, basal cells by costa 2–3 times as long as wide, towards margins hyaline, basal marginal cells, 1–2 times as long as wide, transverse walls much more strongly thickened than longitudinal walls, cells above bistratose, opaque, rounded-quadrate, 6–12 μm wide in mid-leaf. Setae straight; capsules

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immersed, erect, ovoid, smooth; peristome present; spores 8–10 μm. Capsules occasional. On dry exposed basic rocks. Very rare, Argyll, Mull. 2. GB4. Eurasian Southern-temperate. S., C. and W. Europe extending north to the Netherlands and Gotland (Sweden), Asia, Tenerife, N. Africa, N. America, Caribbean, Bolivia, Peru. Macroscopically similar to G. laevigata but differing in the smooth or slightly denticulate hyaline points and the basal marginal cells longer than wide with strongly thickened transverse walls. It has been confused with G. anodon, which has pellucid cells in the upper part of the leaf and the usually present immersed inclined asymmetrical capsules. For an account of G. tergestina in Scotland see H. C. Greven, J. Bryol. 18, 499–502, 1995. This species is considered a recent arrival in N. W, France, Belgium and the Netherlands (although there is no evidence for this) but the Scottish plants appear to be of long standing (see T. L. Blockeel, J. Bryol. 19, 189–91, 1996). This species is treated as vulnerable in the Red List of British Mosses.

5 G. ovalis (Hedw.) Lindb., Acta Soc. Sci. Fenn., 1871 G. commutata Huebener, G. ovata F. Weber & D. Mohr

(Fig. 137)

Dioicous. Dark green to blackish tufts or cushions, sometimes hoary when dry, (0.5−)1.0–4.0 cm high. Leaves loosely appressed, straight when dry, erect-patent when moist, concave, from ovate ± sheathing basal part narrowed to lanceolate or narrowly lanceolate acuminate upper part, channelled above; margins plane; hyaline points to as long as lamina in upper leaves, flattened below, terete above, weakly denticulate; costa poorly defined, wide below, scarcely protruding on abaxial side, obscure above, ending in apex, in section several cells wide adaxially and scarcely distinct from lamina cells; basal cells near costa incrassate and esinuose to strongly incrassate and sinuose, 4–8 times as long as wide, basal marginal cells (1−)2–3 times as long as wide, transverse walls thicker than longitudinal walls, cells above irregularly quadrate, incrassate, 2–4-stratose, opaque, 6–8 μm wide in mid-leaf. Setae straight; capsules ovoid, smooth, narrowed at mouth; exothecial cells irregularly rectangular, thin-walled; lid obliquely rostrate; spores 9–12 μm. Capsules rare, spring. n = 13. On acidic or neutral rocks and roofing tiles. At low altitudes. Very rare and decreasing, E. Sussex, W. Kent, N. Essex and a few scattered localities from W. Gloucester and E. Wales north to Sutherland. 25. GB15 + 28∗ . Circumpolar Boreo-temperate. Europe north to c. 68◦ N, temperate and tropical Asia, Canary Islands, Madeira, N. Africa, N. America, Mexico, Guatemala. Although confused nomenclaturally and taxonomically in the past with G. longirostris, G. ovalis is readily distinguished by the leaves channelled above, the plane margins and the costa section. This species is treated as vulnerable in the Red List of British Mosses.

6 G. unicolor Hook. in Grev., Scott. Crypt. Fl., 1825 (Fig. 137) Dioicous. Dark green tufts, 2–5 cm high; stems ± unbranched. Leaves appressed when dry, patent when moist, from pellucid ovate basal part narrowed to opaque narrowly lingulate obtuse ± cucullate upper part, channelled above, margins plane

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Fig. 137 1–7, Grimmia ovalis: 1, leaves (×20); 2, costa section in lower part of leaf; 3, costa section in upper part of leaf; 4, basal marginal cells; 5. basal cells next to costa; 6, mid-leaf cells; 7, capsule. 8–13, G. unicolor: 8, leaves (×35); 9, costa section in lower part of leaf; 10, basal marginal cells; 11, basal cells next to costa; 12, mid-leaf cells; 13, old capsule. Sections ×280, cells ×429, capsules ×15.

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below, erect above; hyaline points absent; costa strong below, very obscure above, in section several cells wide on adaxial side distinct from lamina cells; basal cells near costa thick-walled, 5–10 times as long as wide, basal marginal cells hyaline, 4–10 times as long as wide, longitudinal walls very thin, transverse walls thicker, cells above irregularly quadrate, very incrassate, sinuose, 2–4-stratose, very opaque, c. 8 μm wide in mid-leaf. Setae straight; capsules ovoid to ovate-ellipsoid, smooth; lid longly rostrate; spores 10–12 μm. Capsules occasional, spring. Wet sloping schist rock. 470 m. Very rare, Angus. 1. GB1 + 1∗ . European Boreal-montane. Montane and northern Europe to about 68◦ N, Caucasus, Siberia, Mongolia, Kashmir, N. America. Unlikely to be mistaken for any other moss, the broad pellucid basal part narrowed into the opaque narrowly lingulate channelled ± cucullate upper part being characteristic. It is reported from C. Europe that if the substrate becomes dry the leaves of this plant may ˜ develop hyaline points, but all such specimens have proved to be stunted G. ovalis (J. Munoz, pers. commun.). This species is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside Act.

Subgenus 3 Orthogrimmia Schimp., Coroll. Bryol. Eur., 1856 Leaves keeled above; margins plane or incurved; costa well defined above; basal marginal cells often with thickened transverse walls, cells above bistratose, opaque. Setae straight (except G. arenaria), smooth; annulus of small cells, persisting or separating individually. Section 1 Montanae I. Hagen, Kongel. Norske Vidensk. Selsk. Skr. (Trondheim), 1909 Basal marginal cells of leaves not hyaline, with thickened longitudinal walls and more strongly thickened transverse walls. Annulus persisting; calyptrae cucullate. 7 G. montana Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 138) Small dense dark green to blackish cushions or patches, sometimes hoary when dry, to 1 cm high. Leaves erect, appressed, flexuose when dry, erect-patent when moist, from ovate to ovate-lanceolate basal part narrowed to lanceolate to linearlanceolate channelled upper part, keeled towards apex; margins plane below, incurved above; hyaline points 1/2 –3/4 (−1) length of lamina in upper leaves, entire or denticulate; costa stout, well defined, prominent abaxially, 2 cells wide in adaxial side in section; basal cells thick-walled, esinuose, near costa and margins 2.0–4.5 times as long as wide, marginal cells with transverse walls thicker than longitudinal walls, cells above irregularly quadrate, incrassate, slightly sinuose, 2–3(−4)-stratose, opaque, in section not bulging, 8–10 μm wide in mid-leaf. Setae straight, 2–4 mm long; capsules ovoid, ± abruptly narrowed into seta, smooth, without stomata at base; exothecial cells irregularly rectangular, thinwalled, peristome teeth of similar colour to capsule, 50–90 μm wide at base, perforated and cleft; lid rostrate, acute; spores c. 12 μm. Capsules rare, spring. n = 13.

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Fig. 138 1–7, Grimmia montana: 1, leaves (×20); 2, section of costa in lower part of leaf; 3, basal marginal cells; 4, basal cells next to costa; 5, mid-leaf cells; 6, capsule; 7, exothecial cells. 8–14, G. ungeri: 8, leaves (×20); 9, section of costa in lower part of leaf; 10, basal marginal cells; 11, basal cells next to costa (×420); 12, mid-leaf cells; 13, capsule; 14, exothecial cells. Sections and exothecial cells ×280, leaf cells ×420, capsules ×15.

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On exposed, acidic to basic rocks. 0–500 m. Rare and decreasing, scattered localities in W. and N. Britain from S. Devon north to S. Aberdeen and Argyll, Jersey. 20, C. GB18 + 14∗ , C2∗ . Circumpolar Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, N. and C. Asia, China, Macaronesia, Morocco, western N. America, Greenland, Mexico. Readily distinguished from G. ungeri when capsules are present but sterile plants differ only in the length of the basal marginal cells and the more longly tapering leaves channelled above as a consequence of the incurved margins. Poorly developed specimens may be impossible to name. Sporophytes are rare in G. montana but common in G. ungeri.

8 G. ungeri Jur. in Unger & Kotschv., Ins. Cypern, 1865 (Fig. 138) G. alpestris auct. Angl. non (F. Weber & D. Mohr) Schleich., G. sessutana auct. Non De Not. Autoicous. Blackish green tufts or patches, to 1 cm high. Leaves ± erect when dry, erect-patent when moist, ovate-lanceolate, keeled above; margins incurved above and sometimes partially recurved below; hyaline points to as long as lamina in upper leaves, denticulate; costa stout, well defined or not, ± prominent abaxially, in section 2 cells wide on adaxial side; basal cells of ± same length from costa to margins, mostly 1–2 times as long as wide, towards margins more hyaline with thickened transverse walls, cells above irregularly quadrate, incrassate, sinuose, bistratose, opaque, c. 8 μm wide in mid-leaf. Setae straight, 1–2 mm long; capsules ovoid, ± abruptly narrowed into seta, smooth, stomata lacking at base; exothecial cells isodiametric and rectangular mixed, thin-walled; lid mamillate, blunt; peristome teeth of similar colour to capsule, 40–50 μm wide at base; spores 8–10 μm. Capsules common, spring, summer. On dry serpentine rocks. 580 m. Very rare, Angus (old record), Aberdeen. 3. GB2 + 1∗ . Sardinia, Cyprus, Tenerife, common in western N. America, Quebec, Mexico. The first Scottish gathering of this plant was named G. ungeri by its collector, Rev. J. Fergusson, in 1870 but Scottish material was later referred to as G. alpestris (F. Weber ¨ Hal. (as G. & D. Mohr) Schleich. In 1992, British material was renamed G. reflexidens Mull. sessitana De Not.) by H. C. Greven (J. Bryol. 18, 499–502, 1995). It has since been shown that ˜ the Scottish specimens belong G. ungeri (see J. Munoz, Ann. Missouri Bot. Gard. 85, 367–403, 1998). G. reflexidens differs from G. ungeri in the basal cells of the leaves 2–6 times as long as wide, the exothecial cells ± rectangular, stomata present, and the peristome teeth orange, contrasting with the brown capsule. This species is treated as vulnerable (as G. sessitana) in the Red List of British Mosses.

9 G. alpestris (F. Weber & D. Mohr) Schleich., Cat. Pl. Helv. 1808 Dioicous. Blackish green tufts or patches. Leaves ± erect when dry, erect-patent when moist, ovate-lanceolate, keeled above; margins plane below, incurved above; hyaline points to as long as lamina in upper leaves, hardly denticulate; costa stout, well defined, ± prominent abaxially, in section 2 cells wide on adaxial

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side; basal cells of ± same length from costa to margins, mostly 1.0–3.5 times as long as wide, towards margins more hyaline with thickened transverse walls, cells above irregularly quadrate, incrassate, sinuose, bistratose in upper 1 /3 , opaque, in section bulging, 8–13 μm wide in mid-leaf. Setae straight, 2–4 mm long; capsules fusiform, smooth; exothecial cells isodiametric, thick-walled; lid comical or mamillate, obtuse; peristome teeth 50–70 μm wide at base, of similar colour to capsule; spores 10–14 μm. On exposed siliceous rocks. 780 m. Very rare, Merioneth. 1. GB1. Montane Europe and Asia, N. America. This is the first confirmed (by E. Maier) occurrence of this species in Britain. It as found by J. Werner–Braun (pers. Commun.) in Merioneth in 2004. For a summary of the differences between G. montana, G. ungeri and G. alpestris see A J. E. Smith, Field Bryology 82, 8–10, 2004. G. alpestris (F. Weber & D. Mohr) Schleich. was recorded from Marros, Carmarthenshire (altitude 150 m), a locality where Coscinodon cribrosus occurs. It was later also reported from Pembrokeshire, but that specimen is Coscinodon cribrosus. It seem highly likely that the specimen from Marros also belongs to that species.

Section 2 Donianae (Loeske) J. Munoz, ˜ Ann. Missouri Bot. Gard., 1998 Basal marginal cells hyaline, cell walls uniformly thin. Annulus separating; calyptrae mitrate. 10 G. donniana Sm., Engl. Bot., 1804 (Fig. 139) Autoicous. Small dark green cushions, tufts or scattered plants, hoary when dry, to 1.5 cm high. Leaves loosely appressed, straight when dry, erect-patent when moist, small below, increasing in size up female stems and intergrading with perichaetial leaves, from ovate or narrowly ovate, ± hyaline basal part narrowed into or tapering into lanceolate or narrowly lanceolate, keeled, acute or acuminate upper part; margins often incurved near base, plane above; hyaline points in lower leaves short, increasing in length up stems, in upper and perichaetial leaves to as long as or longer than lamina, flattened below, terete above, denticulate; costa strong below, well defined above, prominent on abaxial side, 2 cells wide on adaxial side in section; basal cells thin-walled or occasionally somewhat thickened towards costa, near costa and towards margins 4–6(−8) times as long as wide, marginal cells uniformly very thin-walled, cells above quadrate, incrassate, ± sinuose, bistratose, opaque, 10–12 μm wide in mid-leaf. Perichaetial leaves with hyaline points flexuose, not twisted. Setae straight; capsules emergent to exserted, pale brown, ovoid, smooth, with stomata at base; lid conical or shortly rostrate, blunt; spores 10–12 μm. Capsules common, spring to autumn. n = 12 + m, 13∗ . In exposed situations in crevices of hard acidic especially slatey rocks on cliffs, in scree, on mine and quarry waste and walls, often where heavy metals are present, in montane areas. 0–950 m. Rare in S. W. England, frequent or common in N. Wales, N. W. England and Scotland as far north as S. Aberdeen and W. Inverness, rare or occasional further north to Shetland, rare in Ireland. 53, H14. GB198 + 91∗ , IR14 + 9∗ . European Boreo-arctic Montane. Europe north to Svalbard, Iceland, Caucasus, Turkey,

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Fig. 139 1–6, Grimmia donniana: 1, leaves (×20); 2, costa section in lower part of lead; 3, basal marginal cells; 4, basal cells next to costa; 5, mid-leaf cells; 6, capsule. 7–12, G. arenaria: 7, leaves (×25); 8, costa section in lower part of leaf; 9 basal marginal cells; 10, basal cells next to costa; 11, mid-leaf cells; 12, capsule. 13–17, G. elongata: 13, leaves (×20); 14, costa section in lower part of leaf; 15, basal marginal cells; 16, basal cells next to costa; 17, mid-leaf cells. Sections ×380, cells ×420, capsules ×15.

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Himalayas, temperate Asia, Madeira, Tenerife, E. Africa, N. America, Greenland, Mexico, Ecuador, Bolivia, Antarctica. By far the commonest of the Grimmia species with erect capsules. Attention is usually first drawn to this plant because of the numerous pale brown capsules. The only other species likely to be confused with G. doniana are G. arenaria (q.v.), G. alpestris and G. ungeri, all of which are very rare. The very-thin-walled basal marginal cells will separate G. donniana and G. arenaria from other species except G. elongata and G. incurva. The former has very short hyaline points and the latter leaves crisped when dry.

11 G. arenaria Hampe, Linnaea, 1836 (Fig. 139) G. donniana var. arenaria (Hampe) Loeske, G. donniana var. curvula Spruce Autoicous. Small dark green tufts or patches, hoary when dry, with homomallous leaf tips giving plants a brushed appearance, to 1 cm high. Leaves loosely appressed when dry, erect-patent when moist, small below, increasing in size up stems and intergrading with perichaetial leaves, from ovate or narrowly ovate, ± hyaline basal part narrowed into or tapering into lanceolate or narrowly lanceolate, keeled, acute or acuminate upper part; margins often incurved near base, plane above; hyaline points in lower leaves short, increasing in length up stems, in upper and perichaetial leaves to as long as or longer than lamina, flattened below, terete above, denticulate, often homomallous; costa strong, well defined, prominent abaxially, 2 cells wide on adaxial side in section; basal cells thin-walled, near costa and towards margins 4–10 times as long as wide, basal marginal cells uniformly very thin-walled, cells above quadrate, incrassate, sinuose, bistratose, opaque, 10–12 μm wide in mid-leaf. Perichaetial leaves longer than vegetative leaves, with sheathing bases; hyaline points flexuose, twisted. Setae curved, ± burying capsules in hyaline points of perichaetial leaves; capsules ± horizontal, ovoid, smooth; lid mamillate; spores 10–12 μm. Capsules common, spring, autumn. n = 13∗ . Crevices in walls and hard acidic rocks, especially where slatey, in sheltered situations. Lowland. Occasional in Merioneth, very rare elsewhere, Cardigan, Caernarfon, Denbigh (old record), Cumberland. 5. GB6 + 5∗ . Suboceanic Temperate. Rare in Europe from Spain, Italy and Romania north to Norway and Finland. Treated as a variety of G. donniana by recent authors but is a distinct species, there being no intermediates (see Greven, 1995). It differs from all other British Grimmia species in the leaf tips homomallous when dry, giving the plants a brushed appearance, and the capsules ± horizontal amongst the perichaetial leaves. G. hartmanii, which has secund leaves, differs in habitat, habit and short hyaline points. Although the setae are curved, G. arenaria will not be mistaken for a member of subgenus Rhabdogrimmia as they have setae arcuate when moist

Section 3 Elongatae With the characters of G. elongata.

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12 G. elongata Kaulf. in Sturm., Deutschl. Fl. Abt. 2, Crypt., 1815 (Fig. 139) Dioicous. Brownish green readily disintegrating, erect or depressed tufts, shoots to 2 cm long. Leaves of ± uniform length along stems, ± straight to slightly twisted when dry, erect-patent when moist, lanceolate to narrowly lanceolate, keeled above, apex obtuse; margins narrowly recurved on one or both sides below or plane; hyaline points lacking in lower leaves, very short in upper, to 150 μm long, smooth; costa well defined, ending in or below apex, 2 cells wide on adaxial side in section; basal cells thin-walled, near costa 3–6 times as long as wide, basal marginal cells 4–6(−10) times as long as wide, hyaline uniformly thin-walled, cells above irregularly quadrate, incrassate, strongly sinuose, 1–2-stratose, opaque, c. 8 μm wide in mid-leaf. Setae straight; capsules ovoid; spores 12–15 μm. Capsules unknown in Britain. On exposed dry or damp montane rocks. 500–1080 m. Very rare, Caernarfon, Westmorland, Cumberland, S. Aberdeen, old records from N. Northumberland and Angus. 6. GB6 + 4∗ . Circumpolar Arctic-montane. Montane and northern Europe north to c. 67◦ N, Iceland, Caucasus, Turkey, Sikkim, Siberia, China, Taiwan, Japan, N. Africa, N. America, Greenland, Latin America. Recognised by the very short hyaline points and the uniformly thin-walled basal marginal cells.

Subgenus 4 Atratae (Bruch & Schimp.) Leaf margins recurved above; basal cells near costa elongate, becoming shorter towards margins, cells above 1–2-stratose, opaque. Setae straight; capsules erect, smooth; annulus of 3–5 rows large separating cells. 13 G. longirostris Hook., Musci Exot., 1818 (Fig. 140) ¨ G. affinis Hornsch., G. ovalis auct. non (Hedw.) Limpr., G. ovata Schwagr. Autoicous. Small compact tufts or cushions, sometimes hoary when dry, 1.0– 1.5(−2.5) cm high. Leaves ± erect, straight when dry, erect-patent when moist, ovate-lanceolate to lanceolate, tapering from widest part to acuminate apex, channelled above; margins narrowly recurved in middle region of leaf on one or rarely both sides; hyaline points 1/4 –2/3 (−1) length of lamina in upper leaves, smooth to slightly denticulate, not or hardly decurrent; costa strong below, obscure above, hardly prominent on abaxial side, in section reniform, with U-shaped sinus and 4–8 cells wide on adaxial side; basal cells near costa with thick nodulose longitudinal walls, thin transverse walls, 3–6 times as long as wide, marginal cells hyaline, 1–3 times as long as wide, longitudinal walls thin, transverse walls thick, cells above rectangular to quadrate, very sinuose, incrassate, unistratose, ± pellucid, at margins 1–2-stratose, in mid-leaf 8–12 μm wide. Perichaetial leaves similar to upper vegetative leaves but with expanded sheathing basal part. Setae straight; capsules barely emergent above perichaetial leaves to exserted, ovoid to cylindrical, smooth; exothecial cells rectangular, thinwalled; annulus separating; lid mamillate to longly rostrate; spores 10–12 μm.

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Fig. 140 1–7, Grimmia longirostris: 1, leaves (×20); 2, costa section in lower part of leaf; 3, costa section in upper part of leaf; 4, basal marginal cells; 5, basal cells next to costa; 6, mid-leaf cells; 7, capsule. 8–13, G. atrata: 8, leaves (×30); 9, costa section in lower part of leaf; 10, basal marginal cells; 11, basal cells next to costa; 12, mid-leaf cells; 13, capsule. Sections ×280, lamina cells ×429, capsules ×15.

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Capsules frequent, winter. n = 13. On dry exposed acidic or basic rocks, cliffs and scree. 0–550 m Very rare and declining, W. and N. Britain from Devon north to W. Sutherland, S. Kerry, old records from Mid Cork, Down and Antrim. 22, H4. GB19 + 21∗ , IR1 + 4∗ . Circumpolar Boreo-temperate. World-wide except for Antarctica. The costa reniform with U-shaped adaxial sinus in transverse section provides an absolute character separating G. longirostris from all other Grimmia species. The long incrassate basal cells near the costa and the leaves channelled rather than keeled above are also useful ˜ distinguishing characters. For a detailed account of G. longirostris see J. Munoz, Ann. Missouri Bot. Gard. 85, 352–65, 1998. Because of nomenclatural and taxonomic confusion some records of G. longirostris may belong to G. ovalis. Other specimens referred to G. britannica or G. austrofunalis (see under G. trichophylla) belong here.

14 G. atrata Miel. ex Hornsch., Flora, 1819 (Fig. 140) Dioicous. Greenish black tufts, 1–4(−7) cm high. Stems radiculose below. Leaves flexuose to ± crisped when dry, erect to erect-patent when moist, narrowly ligulate, narrowly lanceolate or from narrowly ovate basal part narrowed to ligulate upper part, obtuse, channelled above; margins narrowly recurved on one or both sides below; hyaline points absent; costa strong, prominent on abaxial side, ending in apex, several cells wide on adaxial side in section; cells at extreme base with ± straight walls, above becoming incrassate, strongly nodulose, basal cells near costa incrassate, 1–4 times as long as wide, 2–3 rows of basal marginal cells hyaline, 1–3 times as long as wide, longitudinal walls very thin, transverse walls thicker, cells above quadrate, thin-walled to incrassate and sinuose, smooth, unistratose with bistratose patches, ± pellucid, 8–12 μm wide in mid-leaf. Perichaetial leaves similar to upper vegetative leaves. Setae straight; capsules ovate-ellipsoid, smooth; exothecial cells quadrate to rectangular, thickwalled; lid rostellate; spores c. 14 μm. Capsules occasional, autumn. n = 13∗ . On moist sheltered or exposed acidic heavy-metal-bearing rocks on cliffs, in scree and by lakes. 200–900 m. Rare, N. W. Wales, Lake District, Dumfries, central Scottish Highlands north to W. Sutherland, W. Donegal. 16, H1. GB23 + 6∗ , IR1. Suboceanic Boreal-montane. Very rare in Europe, from Spain, Italy and Romania north to Norway and Sweden, temperate and tropical Asia, Labrador, Bolivia.

Subgenus 5 Rhabdogrimmia Limpr., Laubm. Deutschl., 1889 Leaf margins recurved; cells usually unistratose except at margins, usually pellucid. Setae long, arcuate when moist; capsules cernuous or pendulous, usually striate or ribbed. Section 1 Pulvinatae Bruch & Schimp., in Bruch et al., Bryol. Eur., 1845 Autoicous. Leaves abruptly narrowed at apex; costa in section semiterete, with small group of stereids; basal cells wide, quadrate or rectangular.

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Fig. 141 1–7, Grimmia pulvinata: 1, leaves; 2, costa section in lower part of leaf; 3, basal marginal cells; 4, basal cells next to costa; 5, mid-leaf cells; 6, 7, capsules. 8–13, G. orbicularis: 8, leaf; 9, costa section in lower part of leaf; 10, basal marginal cells; 11, basal cells next to costa; 12, mid-leaf cells; 13, capsule. Leaves ×15, sections ×280, lamina cells ×420, capsules ×15.

15 G. pulvinata (Hedw.) Sm., Engl. Bot., 1807 G. pulvinata var. africana (Hedw.) Hook. f. & Wilson

(Fig. 141)

Autoicous. Dense rounded grey-green cushions, hoary when dry, to 3 cm high. Leaves erect, appressed when dry, erect-patent when moist, upper lanceolate to ovate-lanceolate, keeled above, shortly tapering or abruptly narrowed into hyaline point; margins recurved on one or both sides, bistratose above, hyaline points 1/ –1(−2) length of lamina in upper leaves, smooth to slightly denticulate; costa 2 well defined, in section 2 cells wide adaxially; basal cells mostly shortly rectangular or rectangular, those next to costa with walls thin and straight to incrassate and nodulose, 2–4(−6) times as long as wide, basal marginal cells 1–4 times as long

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as wide, with transverse walls thicker than longitudinal, cells above quadrate to quadrate-rectangular, incrassate, sinuose, unistratose, pellucid, 7–10 μm wide in mid-leaf. Perigonia inconspicuous, immediately below perichaetia, outer perigonial bracts very different from vegetative leaves, filmy, orange, muticous, ecostate. Perichaetial leaves longer than vegetative leaves, bases sheathing. Setae flexuose when dry; arcuate when moist, burying capsules in points of perichaetial leaves; capsules ovate-ellipsoid or occasionally ovoid, ribbed; peristome teeth ± entire; lid rostrate or rostellate, conical when capsules ovoid; spores 8–12 μm; calyptrae mitriform. Capsules very common, spring. n = 13∗ , 26∗ , 26 + m∗ . On dry exposed usually basic rocks, especially characteristic of man-made habitats such as walls, old buildings and concrete, rarely on trees. 0–625 m. Very common except in the Scottish Highlands. 112, H40, C. GB1649 + 84∗ , IR246 + 8∗ , C6 + 1∗ . Circumpolar Southern-temperate. From most parts of the world except the Arctic and Antarctic. The commonest species of Grimmia in the British Isles and only likely to be confused with G. orbicularis. The latter differs in the larger, blacker, readily disintegrating less neat tufts, in the longer basal cells of the leaves (although in some non-British G. pulvinata these cells may be long), in the perigonia and in capsule shape. G. decipiens looks superficially like G. pulvinata, but forms larger laxer tufts and has longly tapering leaves with long narrow basal cells. The plant referred to as var. africana (Hedw.) Hook. f. & Wilson has ovoid capsules with shortly conical lids and may be mistaken for G. orbicularis. However, it is clear from the limited amount of material that I have seen that intermediates occur even in the same gathering and var. africana cannot be maintained.

16 G. orbicularis Bruch in Wilson, Eng. Bot. Suppl. 4, 1844 (Fig. 141) Autoicous. Lax readily disintegrating cushions, greenish black above, blackish below, hoary when dry, to c. 4 cm high. Leaves erect, appressed when dry, erect-patent when moist, upper lanceolate-elliptical to ovate-lanceolate, keeled above, abruptly narrowed to hyaline point; margins recurved on one or both sides at middle of leaf; hyaline points 1/2 –1(−2) length of lamina, smooth or slightly denticulate; costa well defined, in section 2 cells wide adaxially; basal cells narrowly rectangular to elongate, with thick longitudinal walls and thin transverse walls except near margins, cells near costa with incrassate nodulose longitudinal walls, (6−)8–10 times as long as wide, basal marginal cells 4–8 times as long as wide, transverse walls thicker than longitudinal walls, cells above quadrate or quadrate-rectangular, incrassate, sinuose, unistratose or bistratose in patches, pellucid, 10–12 μm wide in mid-leaf. Perigonia conspicuous, terminal on branches, outer perigonial bracts similar to stem leaves. Perichaetial leaves longer than vegetative leaves, with sheathing bases. Setae arcuate when moist, immersing capsules in perichaetial leaf points; capsules subglobose, striate; peristome teeth cribrose and cleft; lid mamillate, obtuse; calyptrae cucullate; spores 10–14 μm. On dry exposed basic rocks and walls, especially limestone, also on

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heavy-metal-bearing rocks. 0–365 m. Rare to occasional and decreasing, but sometimes locally common, from W. Cornwall and Devon east to W. Kent and north to Skye and W. Sutherland, old records from Mid and E. Cork, Dublin. 35, H3. GB41 + 51∗ , IR5∗ . Submediterranean-Subatlantic. Europe from the Mediterranean region north to the Netherlands, Germany and Poland, Caucasus, Turkey, Cyprus, Middle East, Pakistan, U.S.A., Mexico, New Zealand, Kerguelen Is. Section 2 Trichophyllae Bruch & Schimp., in Bruch et al., Bryol. Eur., 1845 Dioicous or autoicous. Leaves tapering to acuminate apex; costa in section semiterete or reniform, sometimes winged, with ± distinct group of stereids in section; basal cells narrow. 17 G. torquata Hornsch. ex Drumm., Musci Scot. Exsicc., 1825 (Fig. 142) Dioicous. Brownish often tumid tufts, 1–5 cm high. Leaves loosely spirally crisped when dry, erect-patent when moist, narrowly oblong-lanceolate, keeled above, acute; margins recurved on one or both sides; hyaline points short, to 250 μm long in upper leaves, very rarely longer, smooth; costa faint below, strong above, ending in or below apex, 2 cells wide on adaxial side in section; basal cells with very incrassate nodulose longitudinal walls and thin transverse walls except at margins, cells next to costa 6–9 times as long as wide, basal marginal cells 4–8 times as long as wide, transverse walls not thicker than longitudinal walls, 1–3 rows of cells at margins thin-walled, hyaline, cells above quadrate-rectangular to quadrate, very incrassate, sinuose, unistratose, pellucid, 8–10 μm wide in midleaf. Brown multicellular gemmae, 40–120 μm diameter, often present on abaxial side of upper leaves. Setae arcuate; capsules ovoid. Capsules unknown in the British Isles. On sheltered or exposed, usually slightly basic, periodically moist rock ledges and scree, rarely on coastal cliffs. 0–1050 m. Occasional in W. and N. Britain from Carmarthen and Brecon north to Sutherland, Kerry, Waterford, S. Tipperary, Wicklow, W. Mayo. 34, H6. GB135 + 33∗ , IR8 + 2∗ . European Boreoarctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Siberia, China, Madeira, La Palma, Tenerife, N. America, Greenland, Hawaii. ¨ 18 G. funalis (Schwagr.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 142) Dioicous. Dense dark grey readily disintegrating tufts, (1−)2–4 cm high. Leaves spirally arranged, appressed, curved when dry, sometimes giving shoots string-like appearance, erect-patent when moist, ovate-lanceolate to narrowly lanceolate, keeled above; margins recurved; hyaline points thin, 1/2 –1 as long as lamina in upper leaves, slightly denticulate; costa faint below, strong above, ending in apex, 2 cells wide on adaxial side in section; basal cells with very incrassate nodulose longitudinal walls and thin transverse walls except near margins, those by costa 3–8(−10) times as long as wide, basal marginal cells (1−)3–6 times as long as wide, transverse walls thicker than longitudinal walls, 1–2 rows at margins elongate,

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Fig. 142 1–8, Grimmia funalis: 1, dry shoot; 2, leaves (×25); 3, costa section in lower part of leaf; 4, basal marginal cells; 5, basal cells next to costa; 6, mid-leaf cells; 7, capsule; 8, filiform shoot. 9–15, G. torquata: 9, dry shoot; 10, leaves (×35); 11, costa section in lower part of leaf; 12, basal marginal cells; 13, basal cells next to costa; 14, mid-leaf cells; 15, gemma (×15). 16–21, G. incurva: 16, leaves (×20); 17, costa section in lower part of leaf; 18, basal marginal cells; 19, basal cells next to costa; 20, mid-leaf cells; 21, capsule. Dry shoots ×10, sections ×280, lamina cells ×420, capsules ×15.

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hyaline, cells above quadrate-rectangular to quadrate, sinuose, unistratose, pellucid, 10 μm wide in mid-leaf. Caducous flagelliform shoots with minute concave leaves with bent costa and recurved apiculus often present. Setae arcuate when moist, concealing capsules in points of perichaetial leaves; capsules ovoid, striate; spores 16–18 μm. Capsules occasional, late summer. On ledges and in crevices of dry or periodically damp basic rocks, rock ledges and scree, rarely on sea-cliffs. (0−)300–1205 m. Occasional in N. W. Wales, N. W. England and the Scottish mountains, rare in W. Ireland, S. Tipperary, Dublin. 35, H11. GB116 + 43∗ , IR10 + 12∗ . European Boreal-montane. Europe north to c. 67◦ N, Faeroes, Iceland, Caucasus, Turkey, Himalayas, Altai, China, Japan, El Hierro, Tenerife, Algeria, Morocco, Lebanon, Labrador, Greenland. The neat dark grey tufts with the appressed curved leaves often giving the shoots a stringlike appearance when dry make this an easy species to recognise. When present the flagelliform shoots with appressed concave leaves are also very distinctive. G. trichophylla is a coarser plant of different aspect when dry.

¨ 19 G. incurva Schwagr., Sp. Musc. Frond. Suppl. 1, 1811. (Fig. 142) Dioicous. Dark green tufts or patches, blackish below, 1.0–2.5 cm high. Leaves crisped or rarely ± straight when dry, spreading from ± erect basal part when moist, narrowly linear-lanceolate to narrowly lanceolate or ligulate from narrowly ovate basal part, keeled above, acute; margins plane or slightly recurved; hyaline points absent in lower leaves, very short in upper, to 120 μm long; costa very strong, ending in or below apex; basal cells thin-walled, hyaline, those adjacent to costa 6–10 times as long as wide, basal marginal cells 6–10 times as long as wide, walls uniformly very thin, cells above quadrate, incrassate, sinuose, ± opaque, bistratose at margins and towards apex, 10–12 μm wide in mid-leaf. Setae arcuate when moist, burying capsules in perichaetial leaf points; capsules ovate-ellipsoid, smooth; spores c. 15 μm. Capsules very rare, spring. On exposed dry acidic rocks. especially on hill or mountain summits but also in boulder scree. 300–950 m. Rare, Shropshire, Caernarfon, N. Northumberland, Lake District, Kirkcudbright, E. Perth, Angus, Kincardine, S. Aberdeen, Banff, Argyll. 13. GB16 + 7∗ . European Boreo-arctic Montane. Montane Europe from Spain, Italy and Yugoslavia north to Svalbard, Iceland, Novaya Zemlya, Caucasus, Urals, Mongolia, China, Japan, Azores, N. America, Greenland, Mexico. A variable species, forms from exposed situations having shorter wider leaves less strongly crisped when dry. Such plants may superficially resemble an Andreaea in the field but differ in presence of short hair-points and in areolation. May also be mistaken for Dicranoweisia crispula, but that species has muticous leaves and different areolation.

20 G. trichophylla Grev., Fl. Edinensis, 1824 (Fig. 143) ¨ Hal., G. britannica A. J. E. Sm., G. stirtonii G. ausrtofunalis auct. non Mull. Schimp., G. trichophylla var. robusta (Fergusson) A. J. E. Sm. Dioicous. Yellowish green to blackish green lax readily disintegrating tufts or patches, hoary when dry; shoots to 3.5 cm long, with plants to 1 cm high. Leaves

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Fig. 143 Grimmia trichophylla: 1, moist leaves; 2, dry leaves; 3, costa section in lower part of leaf (×210); 4, basal marginal cells from different plants; 5, basal cells next to costa from different plants; 6, mid-leaf cells; 7, capsule (×15); 8, gemmae (×420). Leaves ×20, lamina cells ×420.

appressed-flexuose to slightly twisted, folded longitudinally above when dry, erect to spreading, rarely squarrose when moist, lanceolate to narrowly lanceolate, keeled above, tapering to acute apex, narrowed or not at insertion; margins recurved on one or both sides below; hyaline points to 3/4 length of lamina in upper leaves, smooth to denticulate; costa in section semicircular, 2 cells wide on adaxial side, with 2 layers of guide cells at extreme base, abaxial layer 4 cells wide; basal cells near costa 2–6 times as long as wide, thin-walled and straight to thick-walled and nodulose, basal marginal cells 2–4 times as long as wide, transverse walls thicker than longitudinal walls, cells above quadrate, incrassate, usually sinuose, 1–2-stratose, pellucid, bistratose at margins, 8–10 μm wide in mid-leaf. Irregularly shaped gemmae, to c. 60 μm diameter sometimes present on abaxial surface

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of leaves. Setae flexuose when dry, arcuate when moist, burying capsules in tips of perichaetial leaves; capsules ovoid to obloid, ribbed, abruptly narrowed into seta; peristome teeth papillose, split; spores 10–14 μm. Capsules rare, spring. n = 13, 26. On exposed cliffs, rock outcrops, sarsen stones, tombstones, glacial erratics, boulders, roofs, walls, where acidic, calcifuge. 0–990 m. Very rare in lowland England and lowland Ireland, frequent to common elsewhere. 96 H28, C. GB641 + 92∗ , IR63 + 16∗ , C6 + 1∗ . Circumpolar Wide-temperate. Europe to c. 65◦ N, Faeroes, Caucasus, Turkey, Cyprus, Siberia, Macaronesia, Morocco, Algeria, N. and C. America, Andes from Venezuela to Tierra del Fuego, Australasia, Hawaii. G. trichophylla is the commonest Grimmia of acidic rocks and is usually easily recognised by the readily disintegrating tufts or patches, which are hoary when dry. Most frequently confused with members of the Schistidium apocarpum agg. which, however, have relatively shorter wider leaves, different leaf areolation and immersed capsules, and usually occur on basic substrates. A number of varieties have been described from the British Isles. Some of these are based upon leaf areolation, but this is a feature very much influenced by environmental conditions ˜ (J. Munoz, pers. commun.). These include var. stirtonii and var. robusta (G. britannica). On the other hand, var. tenuis (Wahlenb.) Wijk & Margad. and var. subsquarrosa (Wilson) A. J. E. Sm. have been shown to be species in their own right, i.e. G. muehlenbeckii Schimp., which does not occur in the British Isles, and G. lisae De Not. The former differs from G. trichophylla in the costa being ribbed on the abaxial side. For the differences from G. lisae see under that species. I concluded that var. robusta should be treated as a species and named it G. britannica. Later, H. G. Greven (J. Bryol. 19, 927–830, 1997) said that G. britannica was synonymous ¨ Hal. However, all British and Irish with the Southern Hemisphere G. austrofunalis Mull. ˜ specimens named G. britannica/G. austrofunalis examined by J. Munoz (pers. commun.) belong either to G. trichophylla or G. longirostris, and G. austrofunalis (which is very distinct from G. trichophylla) does not occur in the Northern Hemisphere. In G. trichophylla, gemma development leads to degeneration of the cells producing them ˜ and the ultimate destruction of the leaf. For a detailed account of this see J. Munoz, Ann. Missouri Bot. Gard. 86, 118–91, 1999.

Section 3 Hartmaniae 21 G. dissimulata E. Maier, Candollea, 2002 Dioicous. Lax readily disintegrating greenish tufts, hoary when dry, shoots to c. 2 cm long. Leaves loosely appressed to imbricate, ± straight and flat when dry, patent to spreading when moist, lanceolate, tapering to acute apex, channelled above, margins recurved below; hyaline points to 1/2 length of lamina in upper leaves, slightly denticulate; costa in section 4 cells wide on adaxial side, with single layer of 4 guide cells at extreme base; basal cells near costa 4–6 times as long as wide, basal marginal cells 2–4 times as long as wide, transverse walls thicker than longitudinal walls, other basal cells nodulose, cells above quadrate to rounded-quadrate, sinuose, bistratose at margins, 8–10 μm wide in mid-leaf. Setae flexuose when dry, arcuate when moist; capsules ovoid, ribbed; rare, spring.

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On limestone walls, tombstones and rocks, calcicole. Distribution and frequency uncertain but apparently frequent in east Anglia, rare elsewhere, N. Hampshire, Derby, E. Ross. 7. Europe. It is likely that specimens from limestone or similarly basic rocks named G. trichophylla belong to this species. It resembles G. lisae macroscopically when dry with appressed, ± straight and flat leaves and in the costa four cells wide on the adaxial side. It differs in the costa having 4 instead of 6 guide cells at the extreme base and in being markedly calcicolous. There are said to be differences from G. trichophylla in the shape of the basal marginal cells and G. dissimulata has nodulose basal cell walls. However, some forms of G. trichophylla have nodulose basal cells and length of basal marginal cells is very variable so basal areolation is an unreliable character. The nature of costa section is the best character for differentiation. For the occurrence of G. dissimulata in Britian see R. D. Porley, Field Bryology 82, 13–17, 2004.

22 G. lisae De Not., Musc. Ital. Spic., 1837 (Fig. 144) G. retract Stirt., G. subsquarrosa Wilson, G. trichophylla var. subsquarrosa (Wilson) A. J. E. Sm. Dioicous. Greenish black sometimes silt-encrusted lax or tight tufts or patches, to 3.5 cm high. Leaves loosely appressed to imbricate, straight, ± flat above when dry, usually recurved to squarrose when moist, lanceolate or ovate-lanceolate, tapering to acute apex, channelled above; margins recurved below; hyaline points to 3/4 length of lamina in upper leaves, slightly denticulate; costa in section 4 cells wide on adaxial side, with single layer of 6 guide cells at extreme base; basal cells thickened, esinuose or slightly sinuose, near costa 2–6 times as long as wide, basal marginal cells 1–3 times as long as wide, transverse walls thickened, cells above quadrate to wider than long, incrassate or not, esinuose, unistratose with bistratose patches, pellucid, 8–10 μm wide in mid-leaf. Gemmae lacking in British and Irish material. Setae arcuate when moist; capsules ellipsoid, weakly ribbed, unknown in the British Isles. On acidic rocks, often near water, in sheltered situations such as ravines and woods, also in exposed sites, often below flood level by rivers, streams and lakes. 0–600 m. Occasional in western and northern Britain, and a few localities in Ireland. Distribution data require revision. Mediterranean-Atlantic. S. and W. Europe, Cyprus, Macaronesia, western N. America, Mexico. G. lisae differs from G. trichophylla in the leaves usually squarrose when moist and ± straight and flat above (i.e. not longitudinally folded when dry) and the costa 4 cells wide on the adaxial side in section. It differs from G. hartmanii in the squarrose rather than secund leaves, the usually longer hyaline points and the thinner-walled esinuose or slightly sinuose basal cells. The type specimens of G. retracta Stirt. and G. subsquarrosa Wilson belong to G. lisae. Most British and Irish specimens so named that I have examined are G. lisae, although a few are G. trichophylla. A number of gatherings labelled ‘subsquarrosa’ belong to G. trichophylla and the distribution of G. lisae in the British Isles requires revision.

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Fig. 144 1–6, Grimmia lisae: 1, moist leaves; 2, dry leaves; 3, costa section in lower part of leaf; 4, basal marginal cells; 5, basal cells next to costa; 6, mid-leaf cells. 7–12, G. hartmanii: 7, leaves; 8, costa section in lower part of leaf; 9, basal marginal cells; 10, basal cells next to costa; 11, mid-leaf cells; 12, gemmae (×125). Leaves ×15, sections ×280, lamina cells ×420.

23 G. hartmanii Schimp., Syn. Musc. Eur., 1860 (Fig. 144) Dioicous. Yellowish green to green tufts or patches (0.5−)1.0–4.0(−6.0) cm high. Leaves slightly contorted and often with tips secund when dry, patent or recurved and frequently secund when moist, lanceolate, keeled above, tapering to acute apex; margins recurved on one or both sides below; hyaline points 40–320(−500) μm long in upper leaves, rarely longer, denticulate; costa 4 cells wide on adaxial side in section; basal cells incrassate, slightly to strongly sinuose, cells next to costa 2–5 times as long as wide, basal marginal cells 1–2 times

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as long as wide, transverse walls strongly thickened, cells above quadrate, incrassate, usually sinuose, unistratose except at margins, pellucid, 8–10 μm wide in mid-leaf. Clusters of brownish mulberry-shaped gemmae, c. 250 μm diameter, usually present on the tips of progressively deformed leaves at shoot apices. Setae arcuate; capsules ovoid, smooth, unknown in the British Isles. On periodically moist basic or acidic rock, rarely on tree trunks, usually by water, in woods and ravines, on exposed rocks by lakes. 0–915 m. Occasional to frequent and sometimes locally abundant in western and northern Britain, from E. Cornwall, S. Devon, W. Gloucester and Wales north to Sutherland, rare in Ireland. 47, H13. GB161 + 51∗ , IR5 + 12∗ . European Boreal-montane. From Mediterranean Europe to c. 69◦ N, Caucasus, Turkey, Siberia, Japan, N. Africa, N. America. Usually distinguished by the secund leaves and presence of gemmae at the shoot tips. In humid woodland G. hartmanii may form a short turf and gemmae may be absent. Plants with long hyaline points do occur and I have seen gatherings with the hyaline points as long as the lamina, but such plants are exceedingly rare.

24 G. decipiens (Schultz) Lindb. in Hartm., Scand. Fl., 1861 (Fig. 145) Autoicous. Lax readily disintegrating tufts or cushions, blackish below, hoary when dry, 1.0–2.5(−4.0) cm high. Leaves loosely appressed when dry, erectpatent when moist, lanceolate to broadly lanceolate, tapering to acute apex, keeled above, both margins recurved; hyaline points to as long as lamina in upper leaves, decurrent down margins, strongly denticulate; costa ending in apex, 4–6 cells wide on adaxial side in section; basal cells elongate, incrassate, esinuose or slightly sinuose, those next to costa 4–8 times as long as wide, basal marginal cells hyaline, 1–4 times as long as wide, with thickened transverse walls, forming conspicuous marginal band, cells above rectangular to quadrate, incrassate, very sinuose, unistratose except at margins, pellucid, 7–10 μm wide in mid-leaf. Setae arcuate when moist, immersing capsules in tips of perichaetial leaves; capsules ellipsoid, abruptly narrowed into seta, striate; peristome teeth papillose, split; spores 12– 14 μm. Capsules common. n = 13. On often sloping exposed or slightly shaded calcareous or more rarely acidic rocks and walls. Lowland. Rare and decreasing, widely distributed from Cornwall east to Sussex and north to Sutherland and Caithness, very rare in Ireland, Guernsey, Jersey. 48, H8, C. GB23 + 43∗ , IR2 + 9∗ , C1 + 1∗ . Submediterranean-Subatlantic. Mediterranean Europe and the Crimea to c. 67◦ N, Cyprus, Turkey, Armenia, Madeira, Canary Islands, Algeria, Morocco, Canada, Alaska. This species has probably suffered from over-collecting because of the conspicuous nature of the tufts. It is like coarse G. pulvinata, but differs in leaf shape and areolation. From G. trichophylla it differs in habitat, habit, leaf areolation and costa section.

Section 4 Elatiores With the characters of the species.

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Fig. 145 1–6, Grimmia decipiens: 1, leaves (×15); 2, costa section in lower part of leaf; 3, basal marginal cells; 4, basal cells next to costa; 5, mid-leaf cells; 6, capsule. 7–11, G. elatior: 7, leaves (×15); 8, costa section in lower part of leaf; 9, basal marginal cells; 10, basal cells next to costa; 11, mid-leaf cells. 12–17, G. ramondii: 12, leaves (×20); 13, costa section in lower part of leaf; 14, basal marginal cells; 15, basal cells next to costa; 16, mid-leaf cells; 17, old capsule. Sections ×280, lamina cells ×420, capsules ×15.

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25 G. elatior Bruch ex Bals.-Criv. & De Not., Mem. Reale Acad. Sci. Torino, 1838 (Fig. 145) Dioicous. Dark green to brownish readily disintegrating tufts or patches, shoots to 7 cm long. Leaves loosely appressed when dry, erect-patent to spreading when moist, narrowly lanceolate from broad base, keeled above; margins strongly recurved on one side, less so or plane on the other; hyaline points to 1/2 length of lamina in upper leaves, smooth to slightly denticulate; costa ending in apex, 2 cells wide on adaxial side in section; longitudinal walls of basal cells strongly incrassate, nodulose, transverse walls thin except towards margins, cells adjacent to costa (1−)2–3 times as long as wide, basal marginal cells 1–2 times as long as wide, with ± thickened transverse walls, marginal row longer, cells above irregularly quadrate to rounded-hexagonal, incrassate, very sinuose, strongly papillose, 2–3-stratose, opaque, 8–10 μm wide in mid-leaf. Setae arcuate when moist; capsules ellipsoid, striate; spores c. 15 μm. Capsules not known in Scotland. In large masses in Glen Clova, Angus, but not seen since 1871, also recorded from an unknown site in S. Aberdeen. 2. GB1∗ . Circumpolar Boreal-montane. Montane Europe north to Svalbard, Caucasus, Turkey, Urals, Siberia, India, Altai, China, Taiwan, Japan, N. America, Greenland. Hardly likely to be mistaken for any other species of British Grimmia because of its large size and opaque strongly papillose cells. There are large gatherings in various herbaria and the species has probably been lost because of over-collecting.

Subgenus 6 Dryptodon (Brid.) Lindb., Musci Scand., 1879 With the characters of the species. 26 G. ramondii (Lam. & DC.) Margad., Lindbergia, 1972 (Fig. 145) Dryptodon patens (Dicks. ex Hedw.) Brid., G. curvata (Brid.) De Sloover, G. patens (Dicks. ex Hedw.) Bruch & Schimp., Racomitrium patens (Dicks. ex Hedw.) Huebener Dioicous. Lax green or yellowish green to brownish patches, blackish below, stems (1−)2–10 cm long, procumbent to erect, often curved. Leaves loosely appressed when dry, patent, often subsecund when moist, lanceolate, tapering to acute to subobtuse entire or slightly toothed apex, keeled above; hyaline points lacking; margins recurved on one or both sides; hyaline points absent; costa stout, prominently two-winged on abaxial side above, in section 4 or 6 cells wide on adaxial side; basal cells linear, walls strongly incrassate, nodulose, cells next to costa 3–5 times as long as wide, basal marginal cells 1–2 times as long as wide, transverse walls of marginal 1–2 rows thicker than longitudinal walls, cells above irregularly quadrate or quadrate-rectangular, strongly incrassate and sinuose, unistratose except at margins, pellucid, 8–12 μm wide in mid-leaf. Setae yellow, arcuate at maturity, flexuose with age; capsules ellipsoid, ribbed, plicate when dry and empty; spores 12–16 μm. Capsules rare, spring. n = 22. On acidic to slightly basic moist

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sheltered or exposed rocks by water and on intermittently flushed rock outcrops and cliffs. 0–1000 m. Rare to occasional in N. W. Wales, N. W. England and the Scottish Highlands north to Shetland, very rare elsewhere, E. Cornwall, S. Devon, Carmarthen, Derby, rare in Ireland. 37, H14. GB140 + 44∗ , IR12 + 4∗ . European Boreal-montane. Montane Europe north to c. 69◦ N, Iceland, Faeroes, Siberia, Altai, Japan, Madeira, Tenerife, N. America, Greenland. Only likely to be mistaken in the field for Racomitrium aquaticum (q.v.). Variously placed in Grimmia, Dryptodon Brid. and Racomitrium, but all the sporophyte characters are found in at least some of the species of Grimmia subgenus Rhabdogrimmia and the best place for the species seems to be in the genus Grimmia (Greven, 1995).

79 RACOMITRIUM BRID., MUSCOL. RECENT. SUPPL., 1819 RHACOMITRIUM AUCT. NON BRID. Dioicous. Cladocarpous, stems erect to prostrate, often elongate and frequently with numerous short branches. Leaves lingulate to narrowly lanceolate, with or without hyaline apex; margins plane or recurved, usually entire; costa ending in apex; basal cells linear, sinuose-nodulose, alar cells differentiated or not, other cells sinuose, incrassate, quadrate to narrowly rectangular, sometimes bistratose at margins and/or above, smooth or papillose. Antheridia and archegonia on short lateral branches. Setae usually straight; capsules ellipsoid to cylindrical, smooth; peristome teeth perforated or divided nearly to base into 2–3 filiform papillose segments; calyptrae mitriform, not plicate. A cosmopolitan genus of about 80 mainly saxicolous species. Derivation: Meaning fringed cap, referring to the calyptrae. Recent revisions of the R. heterostichum agg., species 5–8 (A. A. Frisvoll, Gunneria 59, 1–289, 1988) and the R. canescens agg., species 11–13 (A. A. Frisvoll, Gunneria 41, 1–191, 1983), have resolved some long-standing problems in the taxonomy of the species concerned and have resulted in an increase by four in the number of species recognised in the British Isles.

1 Leaves with coarsely and irregularly toothed hyaline points 10. R. lanuginosum Hyaline points if present entire or denticulate but never coarsely and irregularly toothed 2 2 Leaf cells smooth or slightly papillose, hyaline points if present entire or denticulate, not papillose 3 Leaf cells strongly papillose, hyaline points if present papillose at least towards base, ± denticulate 12 3 Leaves without hyaline points 4 At least uppermost leaves with hyaline points 8

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4 Leaf apices rounded, often toothed 7. R. aciculare Apices acuminate to obtuse, entire 5 5 Cells in upper part of leaf narrowly rectangular to linear, costa weak, poorly defined above, stems with numerous short branches 9. R. fasciculare Upper cells quadrate to rectangular, costa strong, short branches present or not 6 6 Cells in upper part of leaves bistratose, opaque, costa constituting most of upper part of leaf 1. R. ellipticum Cells in upper part of leaves unistratose except sometimes at margins, pellucid, costa not filling leaf apex 7 7 Leaf apices obtuse; margins narrowly recurved below, plane above, cells weakly papillose 8. R. aquaticum Leaf apices acuminate to obtuse; margins recurved ± to apex, cells smooth 8 8 Cells in upper part of leaf narrowly rectangular, 3–4 times as long as wide, apex of innermost perichaetial leaves somewhat reflexed 6. R. himalayanum Upper cells quadrate to rectangular, not more than twice as long as wide, perichaetial leaf tips not reflexed 9 9 Plants often but not always dark grey to blackish and hoary when dry, costa in section bistratose except near base, 4–8 cells wide on adaxial side in middle part of leaf, hyaline points if present often decurrent down margins, capsules cylindrical 5. R. heterostichum Plants not grey to blackish and hoary when dry, costa 3–4-stratose except towards apex, c. 4 cells wide on adaxial side in middle part of leaf, hyaline points rarely decurrent down margins, capsules ellipsoid or cylindrical 10 10 Leaf apices not attenuate, hyaline points if present flattened towards base, costa in section ± flat on adaxial side in lower par of leaf, capsules cylindrical, leaves usually lying flat when mounted on a slide 4. R. affine Leaf apices attenuate, hyaline points if present not flattened, costa channelled in lower part, capsules ellipsoid, leaves rarely lying flat on a slide 11 11 Marginal 2–4 rows of cells in upper part of leaves bistratose, moderately robust usually reddish brown plants 2. R. macounii Marginal cells unistratose or only one row bistratose, slender to moderately robust dull green to brownish plants 3. R. sudeticum 12 Marginal row of hyaline non-sinuose supra-alar cells (i.e. cells immediately above enlarged alar cells) quadrate 12. R. elongatum Supra-alar cells rectangular 13 13 Leaves strongly keeled above, costa extending to apex, papillae on abaxial side of leaf near costa about 1/3 from base 0.5–1.0 times as tall as wide 11. R. ericoides Leaves weakly keeled above, costa extending 1/2 –3/4 way up leaf, abaxial papillae 1–2 times as tall as wide 13. R. canescens

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Section 1 Laevifolia (Kindb.) Nog., J. Hattori Bot. Lab., 1974 Leaves lanceolate, usually with denticulate hyaline points; alar cells slightly differentiated, row of esinuose hyaline basal marginal cells usually present, cells above not papillose. Setae smooth, twisted anticlockwise when dry. 1 R. ellipticum (Turner) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 146) Dark green to brownish or rarely reddish brown tufts, not hoary when dry, 0.5–2.0 cm high. Shoots erect; stems reddish, branched. Leaves ± straight, closely appressed when dry, spreading when moist, lanceolate from broad base, subobtuse; hyaline points lacking; margins plane or recurved on one or both sides below; costa broad, constituting much of apex; cells smooth, incrassate, basal ± linear, sinuose-nodulose, shorter towards margins, basal marginal cells hyaline, cells above sinuose, in mid-leaf rectangular, 8–10 μm wide, above irregularly quadrate, opaque, bistratose. Setae straight or slightly curved; capsules broadly ovoid; lid longly rostrate; peristome teeth divided into 2–3 filiform segments; spores 18–20 μm. Capsules common, early summer. n = 13∗ . On damp or periodically flushed acidic or mildly basic usually shaded rocks and rock ledges. 0–800 m. Occasional to frequent in N. W. Wales, the Lake District and N. W. Scotland, occasional in N. and W. Ireland. 28, H13. GB141 + 25∗ , IR29 + 13∗ . Oceanic Boreal-montane. Faeroes, Norway, Iceland, Tenerife, Japan (?). More likely to be confused in the field with Ulota hutchinsiae than with other species of Racomitrium except R. macounii (q.v.). The Ulota differs in the leaf cells unistratose, not sinuose, the ribbed ovate-ellipsoid capsules becoming ± cylindrical when dry and empty and in the hairy calyptrae.

2 R. macounii Kindb. ssp. alpinum (E. Lawton) Frisvoll, Gunneria, 1988 (Fig. 147) Reddish green to reddish brown tufts or patches, never hoary when dry. Shoots moderately robust, 3.5–5.5 cm long; stems simple or sparsely branched. Leaves appressed, straight when dry, erect-patent to spreading when moist, upper 2–3 mm long including hyaline point if present, narrowly lanceolate, tapering to attenuate apex; uppermost leaves mostly with at least some trace of hyaline or more usually reddish points, often reflexed when dry, 0–200 μm long, constituting 0.0–5.0(−7.5)% total leaf length, not flattened at base nor decurrent down margins; margins plane to strongly recurved on one side; costa in section channelled on adaxial side, strongly convex on abaxial side, 3–4-stratose near base, 3–4-stratose and c. 4 cells wide on adaxial side at middle of leaf; cells smooth, incrassate, basal elongate, sinuose-nodulose, row of 0–20 basal marginal cells hyaline, esinuose, cells above sinuose, in mid-leaf quadrate-rectangular, 6–8 μm wide, 2–4 marginal rows bistratose in upper part of leaf. Perichaetial leaves hardly differentiated from stem leaves. Setae 2.8–3.6 mm long; capsules ellipsoid to narrowly ellipsoid, 1.00–1.72 mm long; spores 12–14 μm. Capsules very rare, early

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Fig. 146 1–6, Racomitrium ellipticum: 1, leaves (×30); 2, leaf apex; 3, section of upper part of leaf (×28); 4, basal cells; 5, cells from upper part of leaf; 6, capsule. 7–11, R. aquaticum: 7, leaf (×15); 8, leaf apex; 9, basal cells; 10, upper cells; 11, capsule. 12–16, R. aciculare: 12, leaves (×15); 13, leaf apex; 14, basal cells; 15, upper cells; 16, capsule. Apices ×115, cells ×420, capsules ×15.

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Fig. 147 1–6, Racomitrium macounii ssp. alpinum: 1, leaves; 2, leaf sections; 3, basal cells; 4, mid-leaf cells; 5, perichaetial leaf; 6, capsule. 7–12, R. sudeticum: 7, leaves; 8, leaf sections; 9, basal cells; 10; mid-leaf cells; 11, perichaetial leaf; 12, capsule. Leaves ×15, sections (a, near base, b, near middle, c, near apex) all ×200, cells ×420, capsules ×15.

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summer. On ± acidic rocks by streams and on flushed rocks in montane habitats. 40–1160 m. Very rare, Carmarthen, Merioneth, Caernarfon, Westmorland, Mid-Perth, Angus, S. Aberdeen, Banff, Inverness, Argyll, Ross, W. Sutherland, S. Kerry. 14, H1. GB13 + 1∗ , IR1. European Boreal-montane. Widespread but rare in Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Japan, north-west N. America, Greenland. This is the plant referred to as R. heterostichum var. alopecurum by Dixon & Jameson (1924) and is not to be confused with genuine var. alopecurum (i.e. R. affine). It differs from robust forms of R. ellipticum in that the leaves have attenuate apices and the uppermost usually have short reddish points; also in R. ellipticum the cells in the upper part of the leaf are bistratose and opaque. R. macounii differs from other members of the R. heterostichum complex in the usually reddish brown colour of the plants and the leaves with 2–4 marginal rows of cells bistratose in the upper part.

3 R. sudeticum (Funck) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1845 (Fig. 147) R. affine auct. angl. Dull green to brownish, blackish or occasionally reddish brown cushions, tufts or mats, not hoary when dry. Shoots slender to robust, procumbent to erect, to 4–5 cm long, Stems simple or sparsely branched. Leaves loosely appressed, straight or slightly curved when dry, erect-patent to patent, subsecund when moist, 1.6–2.7(−3.0) mm long including hyaline points if present, narrowly lanceolate, tapering to acuminate apex; hyaline points usually short or absent, 0.0–0.2(−0.4) mm long, 0–10(−20)% total leaf length, rigid, denticulate or not, not flattened at base, not decurrent down margins; margins usually broadly recurved on one side, narrowly so on the other; costa in section channelled on adaxial side, strongly convex on abaxial side, 3–4-stratose except near apex, c. 4 cells wide on adaxial side at middle of leaf; cells smooth, incrassate, basal cells narrowly rectangular, sinuose-nodulose, row of 0–10(−15) basal marginal cells hyaline, esinuose, other cells sinuose, in mid-leaf rectangular or shortly rectangular, 8–10 μm wide, upper cells irregularly quadrate-rectangular, unistratose throughout or single marginal row bistratose. Inner perichaetial leaves differing slightly in shape from stem leaves, basal part hyaline; hyaline points slightly longer than in stem leaves. Setae 2.5–4.0 mm long, straight or curved; capsules ellipsoid, 0.8–1.4 mm long excluding rostrate lid; spores 12–16 μm. Capsules frequent, spring to autumn. n = 13 + m∗ , 14. On exposed acidic rocks, cliff ledges, walls, usually at high altitudes, occasionally on soil. 0–1344 m. Frequent or common in montane parts of the British Isles but under-recorded. 50, H15. GB46 + 5∗ , IR11 + 2∗ . Circumpolar Boreo-arctic Montane. Montane and arctic Europe north to Svalbard, Faeroes, Iceland, Turkey, Japan, N. America, Greenland. Likely to be confused with R. affine and non-hoary forms of R. heterostichum. A useful feature is that when mounted on a slide the leaves of R. sudeticum usually lie sideways whereas those

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of the next two species mostly lie flat. The leaves of R. sudeticum are relatively narrower with attenuate apices, the hyaline points where present are rigid and not flattened at the base. In R. affine, the costa in section near the leaf base is flat on the adaxial side whilst that of R. sudeticum is concave. In section, the costa of R. heterostichum, unlike that of R. sudeticum, is usually bistratose throughout except at the extreme base.

4 R. affine (Schleich. ex F. Weber & D. Mohr) Lindb., Acta Soc. Sci. Fenn., 1875 (Fig. 148) R. heterostichum var. alopecurum Huebener, R. heterostichum var. gracilescens Bruch & Schimp. Dull green to blackish or yellowish green tufts or patches, rarely hoary when dry. Shoots slender to medium-sized, to c. 5 cm long. Shoots erect to decumbent; stems sparsely to much branched. Leaves loosely appressed, straight or curved when dry, erect-patent to patent, sometimes subsecund when moist, lanceolate, (1.7−)2.0– 3.2(−3.6) mm long including hyaline points; hyaline points (0.0−)0.1–1.1 mm long, (0−)5–35% total leaf length, flexuose, denticulate, flattened at base, sometimes decurrent down margins; margins recurved on one side, plane or narrowly recurved on the other; costa in section flat on adaxial side near base, convex on abaxial side, 3−4-stratose and 4 cells wide on adaxial side near middle of leaf; cells smooth, incrassate, basal cells narrowly rectangular, sinuose-nodulose, row of 0–7 basal marginal cells hyaline, esinuose, other cells sinuose, in mid-leaf rectangular or shortly rectangular, 8–10 μm wide, upper cells shortly rectangular or irregularly quadrate, marginal row of cells unistratose or partially bistratose. Innermost perichaetial leaves differing markedly from stem leaves, smaller, hyaline, bluntly pointed, without hyaline points. Setae straight, 5–9 mm long; capsules shortly cylindrical, 2.0–2.4 mm long excluding rostrate lid; spores 12–20 μm. Capsules occasional, spring. On moist or dry acidic rocks, walls, roofs, tombstones. Mainly at low altitudes. Very rare in lowland England, occasional to frequent elsewhere, apparently rare in Ireland. 50, H6. GB36 + 21∗ , IR3 + 1∗ , but underrecorded. European Temperate. Europe north to Svalbard, Faeroes, Iceland, Jan Mayen, Turkey, Cyprus, Asia, N. Africa, Macaronesia, N. America. Often similar in appearance to R. sudeticum (q.v.) and in the past sometimes regarded as synonymous with it, but shown by A. A. Frisvoll (loc. cit.) to be distinct. Closely related to R. heterostichum (q.v.) and as intermediates occur it might perhaps be better treated as a variety of that species, i.e. var. alopecurum Huebener.

5 R. heterostichum (Hedw.) Brid., Muscol. Recent. Suppl., 1819 R. obtusum (Brid.) Brid.

(Fig. 148)

Dull green, brownish or blackish tufts or patches, often hoary when dry. Shoots slender to medium-sized, to 5 cm long; stems prostrate to ascending, sparsely to much branched, often with dwarf branches. Leaves loosely appressed, curved or

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Fig. 148 1–6, Racomitrium heterostichum: 1, leaves; 2, leaf sections; 3, basal cells; 4, mid-leaf cells; 5, perichaetial leaf; 6, capsule. 7–12, R. affine: 7, leaves; 8, leaf sections; 9, basal cells; 10, mid-leaf cells; 11, perichaetial leaf; 12, capsule. Leaves ×15, sections (a, near base, b, near middle, c, near apex) all ×200, cells ×420, capsules ×15.

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twisted when dry, erect-patent to patent when moist, mostly 2.0–3.5 mm long including hyaline points, lanceolate or more rarely narrowly lanceolate; hyaline points rarely absent, (0.0−)0.2–1.2(−1.4) mm long, (0−)10–35(−40)% total leaf length, flexuose and sometimes crinkled, flattened at base and often decurrent down margins; margins recurved on one side, sometimes strongly so, plane or less recurved on the other; costa in section somewhat channelled on adaxial side near base, weakly convex on abaxial side, mostly bistratose throughout except near base, 4–8 cells wide on adaxial side near middle of leaf; cells smooth, incrassate, basal narrowly rectangular, sinuose-nodulose, row of 0–8 basal marginal cells hyaline, esinuose, cells above sinuose, in mid-leaf rectangular or shortly rectangular, 8–10 μm wide, upper cells shortly rectangular or irregularly quadrate, marginal row of cells unistratose or partially bistratose. Innermost perichaetial leaves differing markedly from stem leaves, smaller, hyaline below, bluntly pointed, without hyaline points. Setae straight, 4.8–9.0 mm long; capsules ± shortly cylindrical, (1.5−)1.8–2.6 mm long excluding longly rostrate lid; spores 10–18 μm. Capsules occasional, spring. n = 13∗ , 14. On dry exposed or shaded acidic rocks, boulders, cliffs, walls, roofs, tombstones, sarsen stones. 0–400 m. Rare in lowland England, common elsewhere at lower altitudes. 85, H24. CB84 + 54∗ , IR21 + 3∗ . Suboceanic Boreo-temperate. W. Europe to 70◦ N, rare in E. Europe, Iceland, Macaronesia, western N. America. Although A. A. Frisvoll (loc. cit.) treats R. obtusum (Brid.) Brid. as a distinct species, and indeed in its extreme form it is very distinctive, in the British Isles it intergrades to such an extent with R. heterostichum that it cannot be recognised as taxonomically distinct even at the varietal rank. Usually distinct from R. sudeticum in leaf shape, the hyaline points flattened towards the base and decurrent down the margins, but small green shade forms may have narrowly lanceolate leaves with short hyaline points and it is necessary to cut sections of the costa to identify them. R. affine resembles slender forms of R. heterostichum, but may usually be distinguished by the costa in the middle of the leaf 3–4 cells thick and 4 cells wide on the adaxial side in section.

6 R. himalayanum (Mitt.) A. Jaeger, Ber. Thatigk. St. Gallishen Naturwiss. Ges., 1874 (Fig. 149) R. microcarpon auct. angl. non (Hedw.) Brid. Greenish to blackish patches, not hoary when dry. Shoots ± decumbent, to 4 cm long; stems with numerous short branches. Leaves appressed when dry, erectpatent to patent when moist, 1.6–3.1 mm long including hyaline point, lanceolate to narrowly lanceolate; hyaline points (0.0−) 0.2–0.7 mm long, (0−)10–25% total leaf length, flexuose, not denticulate; costa 2–3-stratose near base, bistratose and 5–8 cells wide at middle of leaf; cells smooth, incrassate, basal cells sinuosenodulose, row of 7–13 basal marginal cells hyaline, esinuose, other cells sinuose,

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Fig. 149 Racomitrium himalayanum: 1, leaves (×15); 2, leaf sections: a, near base; b, near middle; c, near apex; 3, basal cells; 4, mid-leaf cells; 5, cells from upper part of leaf; 6, perichaetial leaves (×15); 7, capsule (×15). Sections (×210), cells ×450.

in mid-leaf rectangular, 8–10 μm wide, towards apex narrowly rectangular, 3–4-times as long as wide, marginal row bistratose. Inner perichaetial leaves with reflexed tips, innermost ovate, chlorophyllous above, acuminate, without hyaline points. Setae straight, 2.4–3.6 mm long; capsules narrowly ellipsoid, 1.1–1.5 mm long excluding longly rostrate lid; spores 12–16 μm. Capsules frequent, spring. On dry acidic rocks, recent record at low altitude from Skye, old records at medium to high altitudes from Ben Lawers range, Creag Mohr, Beinn Dorain. 3. GB1 + 3∗ . Oceanic Boreal-montane. Himalayas, Tibet, Yunnan, Shensi. All British specimens identified as R. microcarpon (Hedw.) Brid. have proved to be R. himalayanum or R. sudeticum. R. microcarpon is common in Norway and Sweden and it could well occur in Britain. It may be recognised by the leaves with cells at the base neither sinuose nor nodulose and a basal marginal band of 10–20 hyaline esinuose cells; the tips of the perichaetial leaves are not reflexed. R. sudeticum differs in the structure of the costa and in the inner perichaetial leaves not having reflexed tips. R. himalayanum may also be confused with R. affine and R. heterostichum, but occurs at higher altitudes and has narrowly rectangular upper cells.

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Section 2 Stenotrichum (Chev.) Bedn.-Ochyra, Fragm. Flor. Geobot. Ser. Polon., 1995 Leaves linear-lanceolate to ovate, apices acuminate to rounded; hyaline points lacking; alar cells differentiated or not, row of basal marginal cells esinuose or not, cells above unistratose, with low papillae. Setae smooth. twisted clockwise or anticlockwise when dry. 7 R. aciculare (Hedw.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 146) Dark green to blackish green tufts, to 6 cm high. Shoots erect; stems branched or not. Leaves ± straight, appressed when dry, patent when moist, ovate to ovate-lanceolate, apex rounded; hyaline points lacking; margins recurved below, often dentate above; costa ending below apex; cells obscurely papillose, incrassate, unistratose throughout, basal linear, sinuose-nodulose, alar cells sometimes enlarged, row of basal marginal cells hyaline, esinuose, other cells sinuose, in midleaf quadrate to rectangular, 8–9 μm wide, towards apex irregularly quadrate. Capsules ellipsoid to shortly cylindrical; lid longly rostrate; spores 16–20 μm. Capsules frequent, spring. n = 12, 13∗ , 14. On acidic rocks subject to submergence in and by water or on irrigated rocks. 0–830 m. Frequent or common in western and northern Britain, very rare in lowland England and central Ireland. 89, H32. GB987 + 71∗ , IR191 + 4∗ , C2 + 2∗ . Suboceanic Boreo-temperate. Europe to 71◦ N, Faeroes, Iceland, Turkey, Japan, Macaronesia, north and southern Africa, N. America. 8 R. aquaticum (Brid. ex Schrad.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 146) R. protensum (A. Braun) Huebener Olive-green to greenish brown patches. Shoots decumbent to erect, 2–12 cm long; stems sparsely branched. Leaves straight, appressed when dry, patent or often subsecund when moist, lanceolate to narrowly lanceolate, obtuse; hyaline points lacking; margins plane or recurved below, entire; costa stout, ending below apex, 3–4 stratose at middle of leaf; cells incrassate, unistratose, papillose, basal linear, sinuose-nodulose, row of basal marginal cells hyaline, esinuose, cells above slightly papillose, other cells sinuose, in mid-leaf rectangular, 8–10 μm wide, towards apex irregularly quadrate. Capsules ellipsoid to shortly cylindrical; lid longly rostrate; spores 14–20 μm. Capsules occasional, spring. n = 12∗ . In montane areas on sheltered acidic usually steeply sloping or vertical rocks that are moist or flushed at least in winter, or on soil in areas of late snow-lie. 0–1220 m. Occasional to common in S. W. and N. W. England, Wales, western and central Scotland, occasional in Ireland. 70, H33. GB530 + 59∗ , IR89 + 4∗ . Suboceanic Temperate. Europe north to Svalbard, Faeroes, Turkey, Asia, Azores, Tenerife, southern Africa, Kerguelen Is, N. America, Greenland, Tierra del Fuego, New Zealand. Small stunted forms may be difficult to separate from epilose forms of R. heterostichum agg. (species 5–8) but differ in the weakly papillose leaf cells, the papillae being best seen in

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transverse sections. R. fasciculare differs in its frequently yellowish colour, numerous short branches and elongate leaf cells. Grimmia ramondii is superficially similar but has the costae winged on the abaxial side.

9 R. fasciculare (Hedw.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 150) Dense golden brown to yellowish green or olive green patches. Shoots to 10 cm long; stems prostrate, with numerous short branches. Leaves loosely appressed to spreading or slightly crisped when dry, patent to spreading when moist, linearlanceolate from broad base, acute to obtuse; hyaline points lacking; margins recurved below, entire above; hyaline points absent; costa weak, ill-defined and ceasing well below apex; cells incrassate, unistratose, basal linear, sinuosenodulose, alar cells larger, row of basal marginal cells hyaline, esinuose, cells above finely papillose, in mid-leaf narrowly rectangular, 8–12 μm wide, above narrowly rectangular to linear but sometimes shorter near apex. Capsules shortly cylindrical; lid longly rostrate; spores 13–15 μm. Capsules frequent, late spring. n = 13∗ . On often exposed dry acidic rocks, rock outcrops, walls and roofs. 0–1320 m. Very rare in lowland parts of Britain and Ireland, frequent or common elsewhere. 97, H33. GB862 + 88∗ , IR134 + 2∗ . European Boreo-temperate. Europe north to Svalbard, N. Asia, Azores, N. America, Greenland, southern S. America. Section 3 Racomitrium Leaves linear-lanceolate; irregularly dentate papillose hyaline points present; alar cells differentiated, basal marginal row of cells esinuose. Setae papillose, twisted anticlockwise when dry. 10 R. lanuginosum (Hedw.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 150) Dark green to yellowish brown tufts or patches, hoary when dry. Shoots to 15 cm or more long; stems procumbent with numerous branches. Leaves falcatesecund, particularly at stem tips, appressed when dry, patent when moist, linearlanceolate, gradually narrowed from near base to long hyaline points to as long as lamina, coarsely and irregularly toothed, strongly papillose, decurrent down margins, very rarely lacking; margins recurved; costa strong, extending into hyaline point; cells obscurely papillose, incrassate, unistratose, basal elongate, sinuosenodulose, row of basal marginal cells hyaline, esinuose, cells in mid-leaf narrowly rectangular, c. 10 μm wide, towards apex rectangular. Setae coarsely papillose; capsules ovoid to ovate-ellipsoid; lid longly rostrate; 8–12 μm. Capsules occasional, spring. n = 12, 13∗ , 14. On exposed rocks and soil on heaths, bogs, moorland, especially where nutrient-poor, walls and roofs, strongly calcifuge. 0–1340 m. Rare in lowland Britain and Ireland, common elsewhere and sometimes abundant or dominant at high altitudes and forming Racomitrium heath. 99, H39. GB968 + 61∗ , IR213 + 6∗ . Circumpolar Boreo-arctic Montane. Cosmopolitan. R. lanuginosum has decreased markedly in some upland areas, as in Snowdonia, probably as a consequence of pollution and changed agricultural practices.

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Fig. 150 1–6, Racomitrium fasciculare: 1, leaves (×30); 2, leaf apex (×115); 3, section of upper part of leaf (×210); 4, basal cells; 5, mid-leaf cells; 6, capsule. 7–11, R. lanuginosum: 7, leaves (×15); 8, portion of upper part of leaf (×65); 9, basal cells; 10, upper cells; 11, capsule. Cells ×420, capsules ×15.

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Fig. 151 Racomitrium ericoides: 1, leaves ×15); 2, leaf apex (×60); 3, alar and supra-alar cells (×380); 4, mid-leaf cells (×420); 5, lamina section c. 1 /3 from base; 6, leaf sections near a, base, b, middle, c, apex (×175) 7, capsule (×15).

Section 4 Canescentia Kindb., Eur. N. Am. Bryin, 1897 Leaves ovate to lanceolate; hyaline points present in at least some plants of all species, denticulate, variously papillose; alar cells inflated, basal marginal row of esinuose cells present, cells above coarsely papillose. Setae smooth, twisted anticlockwise when dry. 11 R. ericoides (F. Weber ex Brid.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 151) R. canescens var. ericoides (F. Weber ex Brid.) Hampe Dull or yellowish green tufts or patches, only occasionally hoary when dry; shoots to 6 cm long. Stems decumbent to ± erect with numerous short branches.

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Leaves appressed when dry, erect-patent or slightly recurved when moist, strongly keeled above, 1.8–3.0 mm long including hyaline point, ovate to lanceolate; hyaline points not reflexed when dry, often short or absent, 0–10(−20)% total leaf length, papillose below but not above, denticulate, not decurrent down leaf margins; margins recurved ± from base to apex; costa distinct, extending ± to apex of lamina; basal cells elongate, sinuose-nodulose, alar cells enlarged, row of supra-alar marginal cells rectangular, thin-walled, hyaline, smooth, esinuose, other cells papillose, sinuose, incrassate, in mid-leaf irregularly quadrate to quadrate-rectangular, c. 10 μm wide, quadrate above; papillae on abaxial side of leaf near costa c. 1/3 from base 0.5–1.0 times as long as wide. Capsules narrowly ellipsoid, lid very longly rostrate; spores 9–12 μm. Capsules occasional, winter. n = 12∗ . On dry to damp exposed or sheltered, often but not necessarily acidic, gritty or sandy soil, sand-dunes, rocks, roadsides, in quarries and short turf. 0–1340 m. Occasional in lowland Britain, frequent to common elsewhere, occasional in Ireland. 72, H26. GB109 + 31∗ , IR15 + 11∗ . Suboceanic Wide-boreal. Europe north to Svalbard, Iceland, Azores, Japan, N. America, Greenland. The commonest species of the R. canescens aggregate in the British Isles and sometimes growing mixed with one or other of these. The other two species usually have longer hyaline points which are papillose throughout. R. ericoides is the only species that frequently has; Leaves with very short or no hyaline points. In R. canescens the weakly channelled leaf, the weak costae and the tall papillae are distinctive. R. elongatum differs in the quadrate supra-alar cells.

12 R. elongatum Ehrh. ex Frisvoll, Gunneria, 1983 (Fig. 152) Dull green or green tufts or patches, often hoary when dry. Shoots procumbent to ± erect, to 6 cm long; stems with usually numerous short branches. Leaves appressed when dry, patent to recurved when moist, 2–3 mm long including hyaline point, ovate to lanceolate, strongly keeled above; hyaline points reflexed when dry, 15–45% total leaf length, rarely absent, denticulate, papillose in upper part and strongly so below, decurrent down margins; margins recurved ± from base to apex; costa distinct, extending ± to apex of lamina; cells incrassate, papillose, basal cells elongate, sinuose-nodulose, alar cells enlarged, supra-alar cells hyaline, thick-walled, not sinuose, quadrate, other cells sinuose, incrassate, in mid-leaf irregularly quadrate to quadrate-rectangular, c. 10 μm wide, quadrate above, papillae on abaxial side of leaf near costa about 1/3 from base 0.5–1.0(−1.3) times as long as wide. Capsules narrowly ellipsoid; lid very longly rostrate; spores 9–11 μm. Capsules not known in the British Isles. On exposed gravelly or sandy soil, rocks, roadsides, in quarries, short turf, sometimes on limestone. 0–1175 m. Widespread and occasional to frequent in Great Britain, Wicklow, Antrim. 49, H2. GB67 + 10∗ , IR1 + 1∗ . Suboceanic Boreo-temperate. Europe north to N. Norway, Faeroes, Iceland, Madeira, N. America, Greenland.

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Fig. 152 Racomitrium elongatum: 1, leaves (×15); 2, leaf apex (×60); 3, alar and supra-alar cells (×280); 4, mid-leaf cells (×420); 5, lamina section c. 1 /3 from base; 6, leaf sections near a, base, b, middle, c, apex (×175); 7, capsule (×15).

13 R. canescens (Hedw.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 153) Dull green or green patches or tufts, often hoary when dry; shoots to 8 cm. Stems decumbent to ascending; branches long or short, sparse to frequent. Leaves appressed when dry, patent to squarrose when moist, 2.0–3.6 mm long including hyaline point, ovate to ovate-lanceolate, weakly keeled above; hyaline points not reflexed when dry, (0−)10–45% total leaf length, denticulate, papillose in upper part and strongly so below, not decurrent down margins; margins recurved ± from base to apex; costa weak, extending 1/2 –3/4 way up lamina, often forked above; cells incrassate, coarsely papillose, basal elongate, sinuose-nodulose, alar cells enlarged, row of supra-alar marginal cells hyaline, not sinuose, rectangular or shortly rectangular, other cells sinuose, in mid-leaf irregularly quadrate or quadraterectangular, c. 10 μm wide, upper cells quadrate; papillae on abaxial side of leaf near costa c. 1/3 from base 1–2 times as long as wide. Capsules narrowly ellipsoid;

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Fig. 153 Racomitrium canescens: 1, leaves (×15 ); 2, leaf apex (×60); 3, alar and supra-alar cells (×280); 4, mid-leaf cells (×420); 5, lamina sections c. 1 /3 from base (×420); 6, leaf sections near a, base, b, middle, c, apex (×175); 7, capsule (×15).

lid very longly rostrate; spores 8–10 μm. Capsules very rare, winter. n = 12. On sandy or gravelly soil, sand-dunes and rocks, weakly calcicolous. Mainly lowland but ascending to 1000 m in Mid Perth. Occasional but widely distributed in Britain, extending north to Caithness, Dublin, Meath, Down, Jersey. 30, H3, C. GB25 + 13∗ , IR2 + 1∗ , C1. Circumpolar Boreo-arctic Montane. Spain east to Turkey and north to Fennoscandia and N. Russia, Caucasus, Asia, N. America. The rarest species of the complex in the British Isles. The weakly channelled leaves with poorly developed costa and tall papillae will distinguish R. canescens from most forms of the

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previous two species. Some forms of R. elongatum may have tall papillae but its quadrate supra-alar cells are distinctive. R. canescens is said to have relatively wider leaves than the other two species but this does not seem to be so in British material.

20 Ptychomitriaceae Usually tuft- or cushion-forming mosses. Leaves usually crisped when dry, lanceolate to linear, acuminate; margins plane or incurved, entire to irregularly dentate; costa ending below apex; basal cells rectangular to narrowly rectangular, cells above ± isodiametric. Setae long, straight or arcuate; capsules erect, smooth; annulus falling or not; peristome teeth entire, perforated or cleft or in pairs, smooth or papillose; calyptrae campanulate. Three genera. Most authorities have placed this family next to the Orthotrichaceae (in the Diplolepideae), but it has been shown that the peristomes of the three genera are haplolepideous. The structure of the peristome teeth of Glyphomitrium resembles that of the Seligeriaceae, which, apart from the possible exception of Dicranoweisia, is unique amongst British mosses (see S. R. Edwards in Clarke & Duckett, 1979). DNA studies indicate a relationship between the Grimmiaceae, Ptchomitriaceae and Seligeriaceae. Hence the placement of the three families adopted here.

¨ 80 PTYCHOMITRIUM FURNR., FLORA, 1829 Autoicous. Leaves lanceolate, often crisped when dry, erect-patent to spreading when moist, acuminate; margins recurved below; basal cells long and narrow, cells above quadrate-rectangular or quadrate, unistratose except at margins. Perichaetial leaves similar to stem leaves. Setae straight; capsules ovoid to ellipsoid, smooth; peristome teeth deeply bifid, erect when dry; calyptrae campanulate, plicate. A ± world-wide genus of c. 80 species. Derivation: Meaning fold and cap, referring to the plicate calyptrae.

1 P. polyphyllum (Sw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1839 (Fig. 154) Dense dull green cushions, blackish inside, to 4 cm high. Leaves strongly crisped when dry, patent to spreading, flexuose when moist, narrowly lanceolate, longly acuminate, base plicate; margins recurved below, coarsely dentate above; costa stout, ending in or below apex; basal cells linear, longitudinal walls heavily thickened, cells above becoming quadrate-rectangular to quadrate, ± arranged in rows, walls uniformly thickened, smooth, unistratose except at margins, 8–12 μm wide in mid-leaf. Perichaetial leaves similar to stem leaves. Sometimes 2 or more sporophytes per perichaetium; setae straight, 3–7 mm long; capsules narrowly ellipsoid, smooth; peristome teeth erect, deeply divided into filiform segments; spores 10– 14 μm. Capsules common, late spring, early summer. n = 13∗ . In crevices and

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Fig. 154 1–4, Ptychomitrium polyphyllum: 1, leaf (×30); 2, basal cells; 3, mid-leaf cells; 4, capsule. 5–8, Glyphomitrium daviesii: 5, leaf (×40); 6, basal cells; 7, mid-leaf cells; 8, capsule. 9–13, Campylostelium saxicola: 9, leaf (×40); 10, basal cells; 11, mid-leaf cells; 12, capsule; 13, plant (×10). Cells ×420.

hollows of exposed or slightly shaded acidic or slightly basic rocks and walls. 0–760 m. Rare or very rare in lowland England, and N. E. Scotland, frequent or common elsewhere in the west and north of Britain, common in Ireland except in the Central Lowlands. 82, H35, C. GB593 + 102∗ , IR203 + 7∗ , C1 + 1∗ .

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Oceanic Southern-temperate. From Spain, Corsica and Yugoslavia north to southern Scandinavia, Faeroes, Macaronesia.

81 GLYPHOMITRIUM (DICKS.) BRID., MUSCOL. RECENT. SUPPL., 1819 Autoicous. Leaves crisped when dry, narrowly lanceolate, acuminate; margins plane or slightly recurved below; basal cells elongate, cells above roundedquadrate, incrassate. Perichaetial leaf bases sheathing. Setae straight; capsules ovoid, smooth; peristome teeth united in pairs, reflexed when dry, similar in structure to those of Seligeria; calyptrae campanulate, plicate, enclosing capsules. A mainly Northern Hemisphere genus of 14 species. Derivation: meaning sculptured cap, referring to the furrowed calyptrae.

1 G. daviesii (Dicks.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 154) Autoicous. Dense dark green cushions or patches, to 1 cm high. Leaves crisped when dry, spreading when moist, linear-lanceolate, acuminate, base not plicate; margins plane or slightly recurved below, entire; costa ending in apex; basal cells rectangular, hyaline, walls of ± uniform thickness, cells above rounded-quadrate, in rows, unistratose except at margins, 10–12 μm wide in mid-leaf. Rhizoidal gemmae, green when young, brown with age, consisting of uniseriate cells, simple or branched, 20–30 × 250–500 μm, usually present. Setae straight, 2–3 mm long; capsules ovoid, smooth; peristome teeth entire, united in pairs, lanceolate, reflexed when dry; spores 40–50 μm. Capsules common, summer. On exposed dry or periodically irrigated acidic or basic rocks. 0–490 m. Occasional in the extreme west of Scotland, Cumberland, formerly recorded from E. Cornwall, S. Devon, Merioneth, Caernarfon, Anglesey (type locality), Westmorland, rare in W. Ireland. 18, H9. GB61 + 16∗ , IR12 + 17∗ . Oceanic Southern-temperate. S. W. Norway, Faeroes, Iceland, China, Madeira, Azores.

82 CAMPYLOSTELIUM BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR. 1846 Autoicous. Plants minute, gregarious. Leaves crisped when dry, linear or linearlanceolate; cells bistratose, rectangular near base, rounded-quadrate above. Setae arcuate; capsules narrowly ellipsoid, smooth; peristome teeth bifid; calyptrae mitriform, smooth. Two species. Derivation: Meaning bent handle, referring to the arcuate setae.

1 C. saxicola (F. Weber & D. Mohr) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 154) Plants gregarious, forming patches 1–2 mm high. Leaves flexuose-crisped when dry, erect-patent when moist, lower linear-lanceolate, upper linear, apex acute

83 Blindia

477

to rounded; margins plane, entire; costa ending in apex; basal cells rectangular, thin-walled, hyaline, cells above rounded-quadrate, ± bistratose, c. 8 μm wide in mid-leaf. Setae arcuate when moist, flexuose when dry, 3–5 mm long; capsules narrowly ellipsoid, smooth; peristome teeth irregularly divided. Capsules common, winter. On acidic or slightly basic sandstone or slatey rocks in ravines and gullies, sometimes on heavy metal-containing rocks. 0–680 m. Rare but widely distributed, from S. Devon east to Kent and north to Argyll and Skye, very rare in Ireland. 28, H7. GB25 + 20∗ , IR3 + 5∗ . Suboceanic Temperate. Europe north to Germany and Poland, Japan, N. America. Distinguished from superficially similar minute species except Seligeria recurvata by the arcuate setae. It differs from S. recurvata and other Seligeria species in leaf areolation and the upper part of the leaves not being subulate.

11 Seligeriales Two families. The second, Wardiaceae differs from the Seligeriaceae in the large plants, ecostate leaves, the peristome attached at the mouth of the capsule and the large spores.

21 Seligeriaceae Plants minute and gregarious or larger and tufted, saxicolous. Stems with central strand. Leaves usually subulate from ± ovate or lanceolate basal part; costa ending below apex to longly excurrent and filling most of subula; cells smooth, usually not differentiated at basal angles, unistratose. Setae usually long, straight or arcuate; capsules ovoid, ellipsoid or pyriform, usually smooth; annulus usually lacking; peristome perfect, teeth smooth, entire, imperfect or absent; calyptrae usually cucullate. Four genera. Traditionally placed in the Dicranales next to the Ditrichoideae, but it has been shown by S. R. Edwards (in Clarke & Duckett, 1979) that the peristome teeth of members of the Seligeriaceae are not like those of the Dicranales but similar to those of Glyphomitirium in the Grimmiales. For this reason I have followed Corley et al. (1981) in placing the Seligeriaceae in its own order next to the Grimmiales.

83 BLINDIA BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1846 Plants forming tufts. Leaves lanceolate, subulate; alar cells enlarged, orangebrown. Capsules usually exserted, ovoid or pyriform, smooth, stomata present; peristome teeth entire, smooth or absent. Sixteen species occurring in Eurasia, America and Australia. Derivation: named after J. J. Blind, a German pastor. For a review of the genus see J. K. Bartlett & D. H. Vitt, New Zeal. J. Bot. 24, 203–46, 1986.

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Fig. 155 1–4, Blindia acuta: 1, leaves (×20); 2, basal cells (×280); 3, marginal cells 1 /2 way up leaf (×450); 4, capsule (×15). 5–7, B. caespiticia: 5, leaves (×20); 6, marginal cells 1 /2 way up leaf (×450); 7, capsule (×20).

Plants (0.5−)1.5–10.0 cm high, costa stout, well defined, capsules exserted, peristome present 1. B. acuta Plants 0.5–1.5 mm high, costa thin below, ill-defined above, capsules immersed, gymnostomous 2. B. caespiticia 1 B. acuta (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 155) Dioicous. Dark green or yellowish green tufts or patches, (0.5−)1.5–10.0 cm high. Leaves erect-patent, sometimes secund when moist, hardly altered when dry, lower lanceolate, subulate, upper from ovate or ovate-lanceolate basal part narrowing to entire or faintly denticulate subula composed mainly of costa and up to 3 times length of basal part, acute to obtuse; margins plane; costa excurrent; cells incrassate, basal and alar cells orange-brown, basal cells narrowly elliptical,

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alar cells differentiated, rounded or elliptical, cells above elliptical, incrassate, 6–8 μm wide in mid-leaf, narrower at margins. Perichaetial leaves with broader base more abruptly narrowed into subula than in vegetative leaves. Setae erect, flexuose, 4–5 mm long; capsules ovoid to pyriform, stomata present at base; lid longly obliquely rostrate; spores 18–20 μm. Capsules frequent, summer. n = 13∗ , 14. On damp or wet ± vertical basic rock faces, on rocks by streams and in flushes, rarely on fixed dunes. 0–1000 m. Rare in S. W. England, frequent or common in Wales and from Derby and Yorkshire northwards, frequent in montane parts of Ireland. 66, H23. GB598 + 39∗ , IR81 + 11∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Caucasus, N. Asia, Nepal, ´ Japan, Madeira, Azores, Zaire, Reunion, N. America, Greenland, Guatemala, Tasmania. The degree of excurrence of the costae is very variable. Forms with a long subula have been recognised as var. arenacea Mol. (var. trichodes (Wilson) Braithw.), but the taxon is not recognised here as it is merely the extreme of a range of forms.

¨ Hal., Deutschl. Moose, 1853 2 B. caespiticia (F. Weber & D. Mohr) Mull. (Fig. 155) Stylostegium caespiticium (F. Weber & D. Mohr) Bruch & Schimp. Autoicous. Dull yellowish green tufts, 5–15 mm high. Leaves crowded, erect, slightly secund, hardly altered when dry, from ovate basal part narrowed to fine subula, entire or obscurely denticulate near apex, composed almost entirely of costa, about same length as basal part; costa excurrent, narrow below, broader but obscure above; cells incrassate, basal and alar orange-brown, basal cells narrowly elliptical, alar cells elliptical, cells above elliptical, 6–8 μm wide in mid-leaf, narrower at margins. Setae very short, c. 0.5 mm long; capsules ± immersed, ovoid, columella falling with lid; peristome and annulus lacking; spores 10–12 μm. Capsules common, summer. On vertical basic rock faces on cliffs and on boulders. 900–1175 m. Very rare, Stirling, Mid Perth, W. Inverness. 3. GB2 + 1∗ . European Arctic-montane. Europe north to Scandinavia, C. Africa. Readily distinguished from B. acuta when the ± immersed capsules, produced abundantly in the summer, are present. When sterile it differs in the costa thin below and wider but poorly defined above. This species is considered endangered in the Red List of British mosses.

84 SELIGERIA BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1846 Autoicous. Plants minute or very small, gregarious or forming tufts or cushions; stems usually unbranched. Leaves usually increasing in size up stems, from ovate or lanceolate basal part, narrowed to acute to obtuse often subulate upper

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21 Seligeriaceae

part; margins plane, entire or denticulate; costa ending below apex to longly excurrent, wider above than below; basal cells rectangular or narrowly rectangular, alar cells not or hardly differentiated, cells above quadrate to narrowly rectangular. Setae straight, flexuose or arcuate; capsules erect, ellipsoid to turbinate; stomata few; peristome teeth entire, smooth, sometimes reduced or absent; calyptrae cucullate. About 18 saxicolous usually calcicole Northern Hemisphere species. Derivation: named after a Silesian pastor and bryologist, Ignaz Seliger (1752–1812). For a monograph of North American Seligeria species, which includes many of those occurring in the British Isles, see D. H. Vitt, Lindbergia 3, 241–75, 1976. For an alternative key to species of the British Isles see T. L. Blockeel et al., J. Bryol. 22, 29–33, 2000.

1 Leaves distinctly trifarious, in sterile shoots imbricate when moist 2 Leaves not trifarious, variously spreading when moist 3 2 Spores 24–32 μm, columella not lengthening after dehiscence, leaf apices smooth 10. S. trifaria Spores 18–22 μm, columella lengthening after dehiscence, leaf apices smooth to rough with papillosely projecting cell ends 11. S. patula 3 Setae very stout relative to size of capsules, capsules ± globose, spores 20–30 μm, plants 5–15 mm high or upper leaves strongly secund with very long subulas 4 Setae relatively slender, capsules ovoid to ellipsoid or pyriform, spores 9–18 μm, plants rarely more than 3 mm high, leaves not secund 5 4 Plants 5–15 mm high, upper and perichaetial leaves not secund, with short stout subulas 12. S. oelandica Plants 2–3 mm high, upper and perichaetial leaves strongly secund, with setaceous subulas much longer than sheathing basal part 13. S. carniolica 5 Setae arcuate when moist 6 Setae straight or flexuose when moist 7 6 Costa ending below leaf apex 5. S. campylopoda Costa longly excurrent 6. S. recurvata 7 Margins distinctly denticulate in basal part of leaves, capsules gymnostomous 9. S. donniana Margins entire or sometimes slightly denticulate below, capsules with peristomes 8 8 Leaves on sterile stems much longer than those on fertile stems 4. S. diversifolia Leaves on sterile and fertile stems of similar length (although perichaetial leaves may be long) 9 9 Costa of upper and perichaetial leaves usually ending in or below apices 10 Costa of upper and perichaetial leaves excurrent 11

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10 Setae 2–3 mm long, capsules ovoid, surface cells narrowly rectangular, 4–8 times as long as wide, exothecial cells irregularly arranged 1. S. pusilla Setae 1–2 mm long, surface cells rectangular, 2–4 times as long as wide, capsules obovoid, exothecial cells arranged in rows 3. S. brevifolia 11 Upper and perichaetial leaves bluntly pointed, spores 14–18 μm 8. S. calcarea Upper and perichaetial leaves acutely pointed, spores 9–14 μm 12 12 Perichaetial leaves sometimes reaching bases of capsules, capsules abruptly narrowed into setae, widest at mouth when dry and empty 2. S. acutifolia Perichaetial leaves not reaching bases of capsules, capsules tapering into setae, widest below mouth when dry and empty 7. S. calycina

Subgenus 1 Seligeria Plants minute or very small, green to bright green; stems unbranched. Leaves from ovate or lanceolate basal part linear, ligulate, lanceolate or subulate; costa slender, percurrent to excurrent; leaf cells usually longer than wide. Perichaetial leaves usually larger than vegetative leaves with wider basal part. Setae straight or flexuose when moist, slender; capsules ovoid or obovoid, turbinate when dry and empty; columella immersed, ± persisting; spores 10–14 μm. 1 S. pusilla (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 156) Green or pale green patches, 2–3 mm high. Lower leaves narrowly lanceolate, upper and perichaetial leaves longer, lanceolate or narrowly lanceolate, tapering to blunt or acute but not subulate acumen; margins sometimes slightly denticulate with projecting cell ends below; costa not filling leaf acumen, usually ending below apex; cells ± rectangular below and above. Setae straight when moist, 2–3 mm long, surface cells narrowly rectangular, 4–8 times as long as wide; capsules ovoid, abruptly narrowed into seta, widest at mouth when dry and empty; exothecial cells irregular in shape, not in rows, walls slightly thickened; peristome teeth c. 100 μm long; lid obliquely rostrate; spores 10–12 μm. Capsules common, summer. n = 13. On shaded limestone, basalt and calcareous sandstone, rarely on chalk, on cliffs and in ravines in humid situations. 0–470 m. Occasional to frequent in limestone areas of western England and the Pennines, rare elsewhere, extending north to W. Sutherland, Sligo, Leitrim, Fermanagh, Antrim. 44, H4. GB90 + 23∗ , IR5 + 2∗ . European Boreo-temperate. Scattered through Europe north to S. Scandinavia, Caucasus, Japan, N. America. This and the next two species differ from other British Seligeria species except S. donniana in that the margins of the basal part of the leaves are sometimes slightly denticulate below. S. donniana has basal leaf margins markedly denticulate and it also differs in capsule

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Fig. 156 1–7, Seligeria pusilla: 1, plant; 2–4, lower, upper and perichaetial leaves (×40); 5, basal marginal cells; 6, cells c. 1 /3 from leaf base; 7, dry empty capsule (×15). 8–13, S. brevifolia: 8, plant; 9–11, lower, upper and perichaetial leaves (×55); 12, basal marginal cells; 13, cells c. 1 /3 from leaf base. 14–19, S. acutifolia: 14, plant; 15–17, lower, upper and perichaetial leaves (×40); 18, basal cells; 19, cells c. 1 /3 from leaf base. Plants ×15, cells ×420.

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characters. In S. acutifolia, the perichaetial leaves often reach the bases of the capsules and the upper and perichaetial leaves have excurrent costae. S. brevifolia differs in leaf shape and the somewhat indistinct costae. In both S. acutifolia and S. brevifolia the surface cells of the setae are only c. 2–4 times as long as wide.

2 S. acutifolia Lindb. in Hartm., Handb. Skand. Fl. (ed. 6), 1864 S. acutifolia var. longiseta Lindb.

(Fig. 156)

Green patches, to c. 2 mm high. Lower leaves lanceolate, acuminate, upper and perichaetial leaves longer, lanceolate or narrowly lanceolate, longly tapering to acute but not subulate acumen; margins slightly denticulate below with projecting cell ends; costa ending below apex in lower leaves, excurrent in upper and perichaetial leaves; basal cells rectangular, cells in acumen quadrate to rectangular. Setae straight when moist, 1.0–1.5 mm long, surface cells shortly rectangular or rectangular, 2–4 times as long as wide; capsules ovoid-pyriform, abruptly narrowed into seta, widest at mouth when dry and empty; exothecial cells ± isodiametric, irregularly arranged, thick-walled; lid obliquely rostrate; spores 12– 14 μm. Capsules common, summer. Under overhangs and in crevices of limestone. 0–450 m. With a distribution similar to that of S. pusilla but rarer, very rare in S. W. England, Oxford, S. Wales, Montgomery, Derby, E. Perth, W. Inverness, Skye, occasional in the Pennines, Clare, Sligo, Leitrim, Cavan, Fermanagh, Antrim (old record), Londonderry. 22, H7. GB27 + 18∗ , IR2 + 2∗ . European Temperate. From Spain, Italy and Yugoslavia north to Sweden, Caucasus, Turkey, C. Asia, Japan, Morocco, N. America. British plants have been referred to var. longiseta Lindb. because the setae are longer than the perichaetial leaves, but seta length is a variable character and plants occur in which the perichaetial leaves reach the capsules. Because of this variation the variety cannot be maintained.

¨ 3 S. brevifolia (Lindb.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1890 (Fig. 156) Plants minute, forming dense light green tufts c. 1 mm high. Leaves increasing in size up stems, erect to erect-patent when moist, scarcely altered when dry, lanceolate, ovate-lanceolate or more rarely lingulate, obtuse to subacute or in lower leaves occasionally acute; margins sometimes slightly denticulate below with projecting cell ends; costa often somewhat indistinct, reaching to near apex but not excurrent; cells quadrate to rectangular throughout leaf. Perichaetial leaves of similar length to upper vegetative leaves, from long sheathing base ± abruptly narrowed into apex; costa ending in or below apex. Setae straight when moist, 1.0– 1.5 mm long, surface cells rectangular, 2–4 times as long as wide; capsules obovoid, tapering into seta, turbinate, wide-mouthed when dry and empty; exothecial cells rectangular, in rows; lid shortly rostrate; peristome teeth c. 180 μm long; spores

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11–13 μm. Capsules common, September. On ± vertical sheltered base-rich or acidic rock. 400–700 m. Very rare, Caernarfon, Derby, W. and E. Perth. 4. GB4. Eurosiberian Boreal-montane. Rare in montane and northern Europe north to Fennoscandia, Iceland, Caucasus, Siberia, Japan, N, America. Only likely to be confused with S. pusilla (q.v.) in the British Isles. For the occurrence of S. brevifolia in Britain see M. O. Hill, J. Bryol. 11, 7–10, 1980. This species is treated as vulnerable in the Red List of British Mosses.

Subgenus 2 Cyrtoseligeria Vitt, Lindbergia, 1976 Plants very small, light to dark green; stems usually unbranched. Leaves from broad basal part lanceolate, oblong-lanceolate or subulate; costa percurrent to longly excurrent; lower cells rectangular, upper quadrate. Perichaetial leaves differentiated from vegetative leaves or not. Setae straight or arcuate when moist, slender; capsules ovoid to ellipsoid; columella immersed, not persisting; spores 8–14 μm. ¨ 4 S. diversifolia Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1861 (Fig. 157) Yellowish green patches, to 2 mm high. Leaves imbricate when moist, from narrowly lanceolate or linear-lanceolate basal part very gradually tapering to obtuse apex, on sterile stems to 2.5 mm long, on fertile stems to 1 mm long; margins entire; costa of ± uniform thickness throughout leaf, ending in or below apex; cells in basal part rectangular, quadrate to rectangular above. Perichaetial leaves larger than vegetative leaves, subulate from ovate basal part; costa excurrent. Setae flexuose when moist, 2–4 mm long, surface cells narrowly rectangular, 4–8 times as long as wide; capsules ovoid, abruptly narrowed into seta, widest below mouth when dry and empty; exothecial cells irregular in shape, not arranged in rows, thin-walled; spores 10–14 μm. Capsules common, spring, summer. On sheltered vertical rock faces on cliffs. 140–400 m. Very rare, N. E. Yorkshire, W. Inverness. 2. GB2. Circumpolar Boreal-montane. Montane and northern Europe north to Svalbard, Caucasus, Siberia, N. America. Only likely to be confused with S. pusilla or S. acutifolia but these differ in capsule shape, in the acutely pointed leaves and in the latter species in the shorter surface cells of the setae. For an account of this plant in Britain see A. C. Crundwell, J. Bryol. 7, 261–3, 1973.

5 S. campylopoda Kindb. in Macoun, Cat. Canad. Pl., 1882 (Fig. 157) Bright green to yellowish green patches, 1–2 mm high. Leaves lanceolate or lanceolate-ligulate, obtuse; margins entire or obscurely toothed towards apex; costa narrow, ± percurrent; cells incrassate, basal rectangular, becoming almost rounded above and extending to apex. Perichaetial leaves similar to but longer than vegetative leaves; costa ending below apex. Setae 2–4 mm long, straight when

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Fig. 157 1–5, Seligeria diversifolia: 1, 2, fertile and sterile plants (×15); 3, leaves (×30); 4, basal marginal cells; 5, dry empty capsule (×15). 6–10, S. campylopoda: 6, plant (×20); 7, leaves (×70); 8, perichaetial leaf (×70); 9, basal cells; 10, cells 1 /3 from leaf base. 11–15, S. recurvata: 11, plant (×15); 12, leaves (×40); 13, perichaetial leaf (×40); 14, basal marginal cells; 15, cells 1/2 way from leaf base. Cells ×420.

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21 Seligeriaceae

dry, arcuate when moist; capsules ovoid, abruptly narrowed into seta, slightly narrower and widest below mouth when dry and empty; spores 8–10 μm. Capsules common, summer. On sheltered hard vertical calcareous rocks. Lowland. Very rare, Buckingham, W. Gloucester (old record), Monmouth. 3. GB2 + 2∗ . Rare but widely distributed in Europe from Italy, Bulgaria and the Ukraine to Sweden and Finland, Siberia, Canada. Most likely to be confused with S. recurvata, but differing in the leaf lamina remaining distinct to the apex, the costae ending in or below the apex and the margins sometimes obscurely toothed near the apex. This is the plant referred to as a form of S. recurvata by E. F. Warburg, Trans. Br. Bryol. Soc. 1, 14–15; 1947; it was first reported from Britain by L. Gos & R. Ochrya, Fragm. Flor. Geobot. 39, 383–9, 1994. For a more detailed account see T. L. Blockeel et al., J. Bryol. 22, 29–33, 2000.

6 S. recurvata (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 157) Dull or dark green patches or scattered plants, 1–3 mm high. Leaves from ovate or lanceolate basal part narrowed to long bluntly acute subula; margins entire; costa longly excurrent, cells incrassate, rectangular in basal part, shortly rectangular to quadrate-rhomboidal above, not extending to apex. Perichaetial leaves similar to but longer than vegetative leaves. Setae flexuose when dry, arcuate when moist, to 5 mm long; capsules ovoid, tapering into seta, narrowly ovoid to shortly cylindrical, when dry and empty widest below mouth; spores 8–10 μm. Capsules common, spring. n = 13, 14∗ . On shaded basic or acidic rocks but never chalk, at cliff bases, in rock crevices and on rocks by streams. 0–700 m. Very rare in lowland England, I. of Wight, Hampshire, Sussex, frequent in parts of Wales and northern England, occasional throughout most of Scotland, north to Orkney, rare in Ireland. 64, H11. GB187 + 31∗ , IR11 + 2∗ . European Boreo-temperate. Europe north to northern Scandinavia, Turkey, Asia, N. America.

Subgenus 3 Anodus (Bruch & Schimp.) Boulay, Musc. France, 1884 Plants minute or very small; stems unbranched. Leaves subulate from broad basal part; margins entire or denticulate below subula; costa excurrent; cells in upper part of leaf quadrate to rectangular. Perichaetial leaves slightly differentiated from vegetative leaves. Setae straight when moist, slender; capsules turbinate when dry and empty, columella immersed, caducous; spores 9–18 μm. ¨ 7 S. calycina Mitt. ex Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1864 (Fig. 158) S. paucifolia auct. non (With.) Carruth. Plants forming pale green patches, to 2 cm high. Leaves from ovate or lanceolate basal part tapering to acuminate to acute longly subulate apex; margins

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Fig. 158 1–6, Seligeria calycina: 1, plant; 2–4, lower, upper and perichaetial leaves; 5, basal marginal cells; 6, cells 1 /3 from leaf base. 7–11, S. donniana: 7, plant; 8, leaves; 9, perichaetial leaf; 10, basal marginal cells; 11, dry empty capsule. 12–18, S. calcarea: 12, plant; 13–15, lower, upper and perichaetial leaves; 16, basal marginal cells; 17, cells 1 /3 from leaf base; 18, dry empty capsule. Plants and capsules ×15, leaves ×80, cells ×420.

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21 Seligeriaceae

entire; costa percurrent or excurrent; cells in basal part rectangular to linear, thinwalled, shorter towards margins, cells above rectangular or narrowly rectangular. Perichaetial leaves slightly larger than upper vegetative leaves, ovate-lanceolate, tapering to subulate apex; costa excurrent. Setae straight when moist, to 2 mm long; capsules ovoid to ellipsoid or pyriform, tapering into seta, narrowed at mouth when dry and empty; exothecial cells rectangular, thick-walled; spores 9–12 μm. Capsules common, summer. n = 12∗ . On chalk stones in woodland, in chalk pits and rarely in chalk grassland. 0–250 m. Frequent and sometimes locally common in chalk areas in southern and eastern England, Antrim, Londonderry (old record). 25, H2. GB132 + 13∗ , IR1 + 1∗ . Suboceanic Temperate. Belgium, Crete, France, Italy, Portugal. 8 S. calcarea (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 158) Plants dark green, gregarious or scattered, to 2 mm high. Leaves from lanceolate or ovate-lanceolate basal part tapering to stout blunt subula; margins entire below, entire or finely crenulate above; costa stout, filling subula, excurrent; cells in basal part of leaf rectangular, above ± linear. Perichaetial leaves of similar length to upper vegetative leaves but with wider basal part; costa excurrent in blunt subula. Setae straight when moist, 1–2 mm long; capsules ovoid to pyriform, tapering into seta, widest at mouth when dry and empty; spores 14–18 μm. Capsules common, summer. n = 12 + m. On shaded usually vertical chalk or oolite rock faces, blocks and stones and in chalk pits. 0–220 m. Rare to frequent in suitable habitats in lowland England, extending north to Derby, S. Lincoln and S. E. Yorkshire. Antrim, Londonderry. 32, H2. GB91 + 23∗ , IR4 + 3∗ . European Temperate. Europe north to Sweden and east to the Black Sea, N. America. This species has a very similar distribution to and sometimes occurs with S. calycina, but the latter differs in the leaves having long thin acute subulas and capsules narrowed at the mouth when dry and empty.

¨ Hal., Syn. Musc. Frond., 1848 9 S. donniana (Sm.) Mull. (Fig. 158) Minute yellowish green to green gregarious or scattered plants, to c. 2 mm high. Lower leaves lanceolate, shortly subulate, upper leaves tapering from ovatelanceolate basal part to stout acute or obtuse subula; margins denticulate in basal part; costa becoming stout above, filling subula, excurrent; cells in basal part rectangular or rhomboidal, narrower towards margins, rectangular to linear above. Perichaetial leaves longer than upper leaves, with long stout subula consisting mainly of costa. Setae straight when moist, to 2(−3) mm long; capsules shortly ovoid to pyriform, abruptly or gradually narrowed into seta, hemispherical, widemouthed when dry and empty; lid conical; peristome absent; spores 10–14 μm. Capsules common, summer. n = 12 + m, 13∗ . On shaded limestone cliffs, in rock

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crevices and on limestone stones, occasionally on calcareous sandstone in woodland, very rarely on chalk in woodland. 0–730 m. Rare in Wales and the southern half of England, locally frequent further north and extending to Sutherland, Clare, Leitrim, Cavan, Monaghan, Antrim. GB48, H5. GB97 + 37∗ , IR5 + 2∗ . Eurosiberian Boreal-montane. Montane Europe north to Fennoscandia, Caucasus, Siberia, C. Asia, China, Japan, N. America. Readily known when mature capsules are present by the absence of peristomes. When suitable capsules are lacking it may be recognised by the margins of upper and perichaetial leaves denticulate in the lower part and the stout excurrent costae.

Subgenus 4 Megasporia Vitt, Lindbergia, 1976 Plants small to medium-sized, dark green to black; stems branched or not. Leaves ± trifarious, stoutly subulate from broad basal part; costa excurrent; upper cells quadrate. Perichaetial leaves ± similar to upper vegetative leaves. Setae straight or slightly curved when moist; capsules hemispherical or turbinate when dry and empty, columella persisting; spores 16–32 μm. ¨ 10 S. trifaria (Brid.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 159) S. tristicha (Brid.) Bruch & Schimp. Brownish green to blackish green patches, often encrusted with calcareous matter, 2–7(−10) mm high; stems brittle, sterile stems often with 2 or more annual growth zones. Leaves imbricate, trifarious, from ovate or lanceolate basal part rapidly tapering to smooth acute to obtuse subula; margins entire; costa excurrent and occupying most of subula; cells incrassate, in basal part narrowly rectangular, shorter above. Perichaetial leaves similar to upper vegetative leaves, with long stout subula. Setae stout, straight when moist, to 2 mm long; capsules ovoid, tapering into seta; wide-mouthed when dry and empty; columella persisting, not lengthening after dehiscence; spores 24–32 μm, strongly papillose. On lightly shaded flushed ± vertical limestone rock faces. To 300 m. Apparently very rare. S., C. and W. Europe, extending north to Germany, Caucasus. This and the next species are readily distinguished from other Seligeria species by the trifarious leaves, especially noticeable in dry sterile shoots. Until recently, S. trifaria and S. patula have not been distinguished in the British Isles, but the latter occurs in a key to British and Irish species of Seligeria (see T. L. Blockeel et al., J. Bryol. 22, 29–33, 2000). I have seen only one specimen of S. trifaria in the National Museum of Wales and in the Royal Botanic Garden, Edinburgh all the rest being S. patula. All material found by D. T. Holyoak in N. W. Ireland that could be identified was S. patula. S. trifaria has the leaf apices smooth, the columella not elongating after dehiscence and the strongly papillose spores 24–32 μm. However, some specimens of S. patula, identified on the basis of spore size, have

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Fig. 159 1–3, Seligeria trifaria: 1, sterile plant; 2, stem and perichaetial leaves; 3, stem leaf apex (×280). 4–8, S. patula: 4, fertile plant; 5, 6, stem and perichaetial leaves; 7, basal marginal cells (×420); 8, stem leaf apex (×280). Plants ×15, leaves ×80.

smooth leaf apices and it would seem that sterile material with smooth leaf apices cannot be determined.

11 S. patula (Lindb.) Broth., Nat. Pflanzenfam., 1909 (Fig. 159) Dark green patches, often encrusted with calcareous matter, 2–4 mm high; stems brittle, sterile stems often with 2 or more annual growth zones. Leaves imbricate, trifarious, from ovate or lanceolate basal part rapidly tapering to acute to obtuse subula, subula smooth to rough with projecting cell ends; margins entire; costa excurrent and occupying most of subula; cells incrassate, in basal part narrowly rectangular, shorter above. Perichaetial leaves similar to upper vegetative leaves, with long stout subula. Setae stout, straight when moist, to 2 mm long; capsules ovoid, longly tapering into seta; wide-mouthed when dry and empty; columella persisting, lengthening after dehiscence; spores 16–22 μm,

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smooth to weakly papillose. Capsules occasional. n = 13. On lightly shaded flushed ± vertical limestone rock faces. To 300 m. Occasional in the Pennines, very rare elsewhere, Brecon, Derby, E. Perth, W. Sutherland, Sligo, Leitrim, Fermanagh. 7, H3. GB16 + 5∗ , IR4. European boreal-montane. Sweden, Alps, Carpathians, Caucasus. The distribution and habitat of S. patula are similar to those of S. trifaria, although the former appears to be more frequent.

12 S. oelandica C. E. O. Jensen & Medelius, Bot. Not., 1929 S. lapponica Nyman & Uggla

(Fig. 160)

Lax or dense blackish green tufts or patches, 5–15 mm high, often encrusted with calcareous matter; stems branched. Upper leaves larger than lower, from ovate or lanceolate basal part narrowed to stout obtuse subula; margins plane, entire; costa excurrent; basal cells hyaline at margins, becoming brown towards costa, rectangular. Perichaetial leaves similar to upper vegetative leaves but with longer basal part. Setae stout, straight when moist, c. 2.5 mm long; capsules spherical, widest at mouth, turbinate when dry and empty; peristome teeth truncate; columella persisting with rostrate lid remaining attached for some time after dehiscence, both finally falling; spores 22–30 μm. Capsules common, summer. On flushed vertical limestone rock faces. 300 m. Very rare, Sligo, Leitrim, Fermanagh. H3. IR4. European Boreal-montane. Norway, Sweden, Svalbard, Czechoslovakia, Alaska, Yukon, Greenland. Distinct from other Seligeria species in its larger size, stout setae and capsule shape. For an account of this species in Ireland see A. C. Crundwell & E. F. Warburg, Trans. Br. Bryol. Soc. 4, 426–8, 1962.

13 S. carniolica (Breidl. & Beck) Nyholm., Ill. Moss Fl. Fennoscandia, 1969 (Fig. 160) Trochobryum carniolicum Breidl. & Beck Dark green patches or scattered plants, c. 3 mm high. Leaves strongly secund, lower small, from ovate basal part narrowed to subula to as long as base, upper and perichaetial leaves much larger, abruptly narrowed from ovate basal part to entire subula several times longer than basal part; margins entire; costa very longly excurrent; cells in basal part rhomboidal or rectangular. Setae very stout, straight or curved when moist, to 2.5 mm long; capsules ± spherical, widemouthed and wider than deep when dry and empty; conical lid attached to columella and remaining for some time after dehiscence; peristome teeth truncate; spores 20–27 μm. Capsules common, summer. On damp shaded sandstone or limestone by streams. 250 m. Very rare, S. Northumberland, Roxburgh. 2. GB1 + 1∗ .

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21 Seligeriaceae

Fig. 160 1–5, Brachydontium trichodes: 1, 2, stem and perichaetial leaves (×50); 3, basal cells; 4, cells 1/2 way up leaf; 5, capsule (×25). 6–11, Seligeria oelandica: 6, plant; 7, 8, stem and perichaetial leaves (×55); 9, basal marginal cells; 10, cells at shoulder of leaf base; 11, dry empty capsule (×10). 12–14, S. carniolica: 12, plant; 13, 14, stem and perichaetial leaves (×30). Plants ×10, cells ×420.

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Suboceanic Boreal-montane. Austria, France, Germany, Norway, Romania, Sweden, Switzerland, Yugoslavia. Very distinctive with the very longly subulate homomallous leaves and the ± spherical capsules on very stout setae. First discovered in Britain in a gathering of S. recurvata from Roxburgh, where it has not been seen since. In the second British locality in S. Northumberland, where it has not been seen recently, it occupied in quantity on a steeply sloping rock face. It is regarded as critically endangered in the Red List of British Mosses. For the occurrence of this plant in Britain see E. F. Warburg, Trans. Br. Bryol. Soc, 1, 199–201, 1949. Although the sporophytes of S. carniolica and S. oelandica differ from those of other British Seligeria species, there is a Scandinavian species, S. tristichoides Kindb., which is intermediate and hence its placement in Seligeria.

¨ 85 BRACHYDONTIUM FURNR., FLORA, 1827 Autoicous. Apparently close to Seligeria but differing in the capsules striate when mature, annulus present, peristome teeth papillose and calyptrae mitriform. Two species, the second occurring in S. America. Derivation meaning short tooth, referring to the short peristome teeth.

1 B. trichodes (F. Weber) Milde, Flora, 1827 Brachyodus trichodes (F. Weber) Nees & Hornsch.

(Fig. 160)

Plants minute, dull green, scattered or in patches, 1–2 mm high. Leaves from ovate or lanceolate basal part narrowed to long acute entire subula; margins entire; costa excurrent, filling most of subula; cells in basal part rectangular, above quadrate, opaque. Setae straight when moist, 2–3 mm long; capsules ovoid or obloid, striate at maturity, furrowed when dry and empty; peristome teeth very short, not projecting above annulus, papillose; spores 10–12 μm. Capsules common, autumn. On sandstone in lowland habitats, in montane habitats on basic or acidic vertical rock faces, in ravines, on cliffs, boulders, rocks in flushes, scree, old quarries, especially where the substrate is sandstone. 0–1000 m. Rare in lowland England, Wales and S. Scotland, frequent in northern England and parts of the Scottish Highlands, old records from Dublin, Wicklow, Sligo, Down and Londonderry. 44, H5. GB70 + 31∗ IR5∗ . Suboceanic Temperate. Montane Europe, north to Norway, Caucasus, N. America. Resembling some Seligeria species but differing in the striate capsules which become furrowed when dry and empty. May be distinguished when the capsules are absent by the opaque upper cells of the leaves. DNA studies suggest that Brachydontium is not related to other members of the Seligeriaceae.

494

22 Timmiaceae

Subclass 3 Funariideae Acrocarpous. Stems usually with central strand. Annulus usually well developed.

12 Timmiales With the characters of the single genus.

22 Timmiaceae 86 TIMMIA HEDW., SP. MUSC. FROND., 1801 Autoicous or dioicous. Plants robust. Leaves with erect sheathing basal part and lanceolate or narrowly lanceolate spreading limb; margins plane or incurved and serrate above; costa ending in or below apex, papillose and/or toothed or not on abaxial side above, in section with two stereid bands; cells in basal part linear, narrower at margins, cells in limb quadrate or hexagonal, papillose in abaxial side, mamillose or not. Setae long; capsules inclined to pendulous, ovate-ellipsoid, furrowed when dry, outer exostome teeth papillose, inner with appendiculate free or united cilia; calyptrae cucullate, large. Nine Northern Hemisphere species. Derivation: named after J. C. Timm (1734–1805), a German botanist.

1 Margins of leaf blade and upper part of leaf sheathing base sharply toothed, plants superficially resembling Atrichum 3. T. megapolitana Leaf margins only toothed above 2 2 Leaves caducous, cells at extreme leaf base sharply differentiated from cells above, plants superficially resembling a Dicranum species 2. T. norvegica Leaves not caducous, extreme basal cells not differentiated from cells immediately above, plants superficially resembling a Polytrichum or Polytrichastrum species 1. T. austriaca 1 T. austriaca Hedw., Sp. Musc. Frond., 1801 (Fig. 161) Dioicous. Dark green tufts or patches, 6–9 cm high; stems tomentose below. Leaves of ± similar size along stems, lower appressed, upper curled when dry, patent when moist, from orange-brown sheathing basal part abruptly narrowed into narrowly lanceolate limb, tapering to blunt to acute apex; margins plane or inflexed, entire below, obscurely to coarsely toothed above; costa strong, ending in apex, with a few teeth but not papillose on abaxial side above, with low mamillae on adaxial side, lacking stereids in section; cells in basal part of leaf linear, smooth below, papillose on abaxial side in upper part of sheath, cells at extreme base not differentiated from cells immediately above, in limb irregularly quadrate, mamillose on adaxial side, smooth on abaxial side, 8–15 μm wide in mid-leaf. Capsules horizontal, ovate-ellipsoid; unknown in the British Isles. n = 15 + m, 16. On bare soil or in short turf on calcareous cliff ledges. (160−)500–900 m. Very rare, Mid Perth,

86 Timmia

495

Fig. 161 1–4, Timmia austriaca: 1, leaves (×10); 2, mid-leaf cells (×420); 3, section of basal part of leaf (×280); 4, costa section at middle of leaf blade (×280). 5–8, T. norvegica: 5, leaves (×10); 6, mid-leaf cells (×420); 7, section of basal part of leaf (×280); 8, costa section at middle of leaf blade (×280). 9–11, T. megapolitana: 9, leaves (×15,); 10, mid-leaf cells (×280); 11, section of costa in basal part of leaf (×280).

496

22 Timmiaceae

Angus, Sligo. 2, H1. GB3 + 3∗ , IR1. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Turkey, Siberia, N. America, Greenland. T. austriaca and T. norvegica often grow together and may be distinguished in the field by their general appearance. T. austriaca superficially resembles a Polytrichum species, is dark green in colour and has ± uniformly sized leaves, whilst T. norvegica is lighter in colour, has the upper leaves larger than the lower and more closely resembles a Dicranum species from which it differs, however, in the sheathing leaf bases. For an account of T. austriaca see G. Brassard, Lindbergia 6, 129–36, 1980. This species is considered endangered in the Red List of British Mosses.

¨ 2 T. norvegica T. E. Zetterst., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1862 (Fig. 161) Dioicous. Green tufts, patches or scattered plants, 2–8 cm high; stems tomentose below. Upper leaves larger than lower, lower curved, upper strongly curved when dry, patent when moist, basal part sheathing, hyaline in young leaves, deep red to blackish in older leaves, gradually or abruptly narrowed into narrowly lanceolate acute limb; margins plane, entire below, coarsely toothed above; costa stout, ending in apex, densely mamillose on adaxial side, papillose on abaxial side at least above; basal cells narrowly rectangular to linear, incrassate, sometimes papillose, 1-several rows at extreme base abruptly delimited, thin-walled, hyaline, fragile, cells in limb hexagonal or quadrate-hexagonal, mamillose on adaxial side, smooth on abaxial side, 8–10 μm wide in mid-leaf. Capsules unknown in the British Isles. Among other bryophytes in crevices or in short turf on calcareous cliff ledges. 475–1170 m. Rare, W. and Mid Perth, Inverness, Argyll, Skye, Sligo, Leitrim. 6. H2. GB11, IR3. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Caucasus, Turkey, Siberia, Altai, N. America, Greenland, New Zealand. For an account of T. norvegica see G. Brassard, Lindbergia 5, 39–53, 1979.

3 T. megapolitana Hedw., Sp. Musc. Frond., 1801 (Fig. 161) Autoicous or synoicous. Yellowish green lax to dense tufts, 3–4 cm high. Leaves flexuose to crisped when dry, patent to spreading when moist. upper leaves longer than lower, lingulate-lanceolate from sheathing orange-brown basal part, margins plane, distantly toothed in upper part of base, becoming coarsely toothed and sometimes inflexed above; costa strong, ending in or below apex, in section with abaxial stereid band in middle of sheathing base; cells of sheath rectangular or narrowly rectangular, papillose on abaxial side in upper part of sheath, cells of limb slightly incrassate, rectangular to rounded quadrate, mamillose on abaxial side towards apex, in mid-leaf 8–12 μm wide. Capsules cernuous to horizontal, broadly ellipsoid, occasional. On ± horizontal silt-covered Salix branches and exposed

87 Encalyptra

497

roots in carr. Lowland. Very rare, E. Norfolk. 1. GB1. C. and E. Europe. S. Finland, Siberia, Mongolia, Himalayas, China, Japan, N. America. Distinct from other species of the genus in the British Isles in the lowland habitat and the leaf margins toothed from the upper part of the sheathing base to the apex. May be overlooked as Atrichum undularum but lacking the double marginal teeth and costal lamellae. The status of the plant in Norfolk is unknown but it is possible that it is a recent arrival from the Netherlands, the nearest continental European locality. For the occurrence of this plant in East Anglia see R. D. Porley & R. W. Ellis, J. Bryol. 24, 151–6, 2002.

13 Encalyptrales 23 Encalyptraceae Two genera, the second, Bryobrittonia R. S. Williams, resembling Encalypta. The Encalyptaceae is placed by most modern authors before the Pottiaceae but the diplolepideous structure of the peristome (see S. R. Edwards in Clarke & Duckett, 1979) suggests that this is incorrect. The similarity of gametophytes to those of some Pottiaceae is probably due to convergent evolution. For an account of the Encalyptaceae see D. G. Horton, J. Hattori Bot. Lab., 54, 353–532, 1983. Derivation: meaning to cover with a veil, referring to the large calyptrae.

87 ENCALYPTRA HEDW., SP. MUSC. FROND., 1801 Acrocarpous. Plants forming tufts or patches. Leaves ± erect to twisted when dry, erect-patent to inflexed when moist, lingulate to spathulate or lanceolate, often broadly pointed; margins plane or recurved, papillose-crenulate; costa ending below apex to longly excurrent, in section with 2–8 rows of abaxial stereids; basal cells large, rectangular, hyaline, smooth, marginal cells narrower or not, cells above hexagonal to quadrate, obscure with c-shaped papillae. Vegetative propagules rarely present. Setae long, straight; capsules erect, cylindrical, smooth or ribbed; peristome double or inner and outer fused, or single, rudimentary or lacking; lid longly rostrate; annulus usually undifferentiated; calyptrae mitratecylindrical, covering and extending below base of capsules. A mainly Northern Hemisphere genus with about 20 species commonly of montane or arctic habitats but with some species occurring in Africa, C. and S. America and Antarctica. 1 Leaves lanceolate or narrowly ovate-lanceolate, tapering ± from middle to apex, mid-leaf cells 8–10 μm wide, capsules smooth when moist 2. E. alpina Leaves lingulate or spathulate, abruptly narrowed to apex, mid-leaf cells 10–20 μm wide, capsules smooth or ribbed 2

498

23 Encalyptraceae

2 Capsules spirally ribbed, leaves with costa ending in or below apex, papillose on abaxial side above, brown filiform axillary propagules often present 1. E. streptocarpa Capsules smooth or longitudinally ribbed when moist, costa percurrent to longly excurrent or if ending below apex then smooth on abaxial side above, filiform propagules lacking 3 3 Capsules longitudinally ribbed when moist 4. E. rhaptocarpa Capsules smooth when moist 4 4 Calyptrae ciliate at base, smooth towards apex, spores smooth or ridged 6. E. ciliata Calyptrae entire or erose at base, very rarely ciliate, towards apex papillose, spores papillose 5 5 Costa smooth on abaxial side towards apex, capsules gymnostomous 5. E. vulgaris Costa coarsely papillose on abaxial side above, peristome present 3. E. brevicollis

Section 1 Streptotheca (Kindb.) Broth., Nat. Pflanzenfam., 1902 Filiform axillary gemmae often present. Setae red; capsules longitudinally or spirally ribbed at maturity, furrowed when dry; annulus separating; peristome double, outer and inner usually ± fused; upper part of vaginula cup-shaped; spore ornamentation ± similar at proximal and distal ends; calyptrae lacerate at base. 1 E. streptocarpa Hedw., Sp. Musc. Frond., 1801 (Fig. 162) Dioicous. Dull or yellowish green tufts or patches, to 6 cm high. Leaves incurved or crisped when dry, spreading when moist, lingulate to lingulate-spathulate, 5–7 mm long, apex ± obtuse, sometimes subcucullate; margins plane or narrowly recurved near base, papillose-crenulate; costa stout, reddish, ending in or below apex, strongly papillose on abaxial side; basal cells rectangular, thin-walled, hyaline, basal marginal cells narrower, mid-leaf cells strongly papillose, obscure, 10–14 μm wide. Clusters of brown filiform branched axillary propagules, to 2 mm long, composed of quadrate uniseriate cells, often present. Setae red, c. 8 mm long; capsules spirally ribbed; peristome double, outer teeth long, filiform, orange; upper part of vaginula cup-shaped; spores finely papillose, 10–14 μm, ornamentation ± similar at proximal and distal ends; calyptrae erose at base, papillose towards apex. Capsules very rare, spring. n = 13. On calcareous rocks, walls, mortar, often where shaded or damp, hard-packed soil, sand-dunes, gravel in calcareous woodland. 0–760 m. Generally distributed, frequent or common. 106, H37. GB994 + 108∗ , IR169 + 6∗ . Eurasian Boreo-temperate. Europe, Iceland, Caucasus, Siberia, Turkey, La Palma. Although capsules are very rare, E. streptocarpa may be distinguished from other Encalypta species by its larger size, leaves with costa ending in or below the sometimes subcucullate apex and the frequent presence of axillary propagules.

87 Encalyptra

Fig. 162 1–6, Encalyptra streptocarpa: 1, plant with sporophyte (×2.5); 2, leaves; 3, mid-leaf cells; 4, axillary propagules; 5, calyptra; 6, capsule. 7–10, E. vulgaris: 7, leaves; 8, mid-leaf cells; 9, calyptra; 10, capsule. 11–14, E. rhaptocarpa: 11, leaf; 12, mid-leaf cells; 13, calyptra; 14, capsule. Leaves ×15, cells ×420, calyptrae and capsules ×10.

499

500

23 Encalyptraceae

Section 2 Diplolepis Kindb., Eur. N. Am. Bryin., 1897 Setae red or orange; capsules smooth; annulus mot separating; peristome double or absent; vaginula elongate, cup-shaped at top; spores papillose, similar at proximal and distal ends; calyptrae fringed at base. 2 E. alpina Sm., Engl. Bot., 1805 E. commutata Nees & Hornsch.

(Fig. 163)

Autoicous. Light or dull green tufts, to 6 cm high. Leaves appressed, hardly twisted with apices incurved when dry, erect-spreading when moist, 2.0–3.5 mm long, oblong-lanceolate, gradually tapering to acute apex, very rarely ± obtuse and cucullate; margins plane, papillose-crenulate; costa stout, reddish, percurrent to longly excurrent in hyaline hair-point, coarsely papillose towards apex on abaxial side; basal cells rectangular, thin-walled, hyaline, basal marginal cells narrower, mid-leaf cells densely papillose, very obscure, 8–10 μm wide. Setae dark red to blackish; capsules smooth even when dry; peristome lacking; vaginula elongate, cup-shaped at top; spores papillose, variable in size, 28–40 μm, ornamentation similar at proximal and distal ends; calyptrae irregularly torn at base, smooth towards apex. Capsules common, autumn. n = 13, 14. Dry or moist, often sheltered, base-rich rock crevices and on cliffs. 350–1205 m. Rare, Caernarfon (old record), N. W. Yorkshire, Perth, Angus, Inverness, Argyll, Skye, W. Sutherland, Sligo. 10, H1. GB16 + 2∗ , IR1 + 1∗ . Circumpolar Arctic-montane. Northern and montane Europe, Iceland, Caucasus, Turkey, Mongolia, China, Japan, Morocco, N. America, Greenland. Distinguished from other members of the genus by the gradually narrowed leaves with small cells that are so strongly papillose that they are extremely difficult to see.

3 E. brevicollis (Bruch & Schimp.) Ångstr., Nova Acta Regiae Soc. Sci. Upsal., 1844 (Fig. 163) Autoicous. Plants 0.5–2.0 cm high. Leaves incurved, hardly twisted when dry, erect-spreading to recurved when moist, 2.0–3.5 mm long, lanceolate to lingulate or spathulate, ± abruptly narrowed at apex; margins plane, papillose-crenulate; costa green to brown, percurrent to excurrent in a sometimes hyaline hair-point, coarsely papillose to papillose-denticulate on abaxial side above; basal cells rectangular, thin-walled, hyaline, basal marginal cells narrower, mid-leaf cells strongly papillose, obscure, 16–20 μm wide. Setae dark red; capsules smooth, not or hardly constricted below mouth when dry and empty; peristome double, outer with 16 white teeth; vaginula elongate, cup-shaped at top; spores papillose, 30–36 μm, ornamentation similar at proximal and distal ends; calyptrae fringed but fringe soon lost, becoming erose with age, papillose towards apex. Capsules common. In a steep river valley (outside Britain it is reported from lightly sheltered basic rock outcrops, crevices, cliff ledges). Lowland. Very rare, Angus (1871). 1. GB1∗ .

87 Encalyptra

501

Fig. 163 1–4, Encalyptra alpina: 1, leaf; 2, mid-leaf cells; 3, calyptra; 4, capsule. 5–8, E. ciliata: 5, leaf; 6, mid-leaf cells; 7, calyptra; 8, capsule. 9–12, E. brevicollis: 9, leaves; 10, mid-leaf cells; 11, calyptra; 12, capsule. Leaves ×15, cells ×420, calyptrae and capsules ×10.

502

23 Encalyptraceae

Circumpolar Boreo-arctic Montane. Norway, Sweden, Finland, N. Russia, Svalbard, Urals, Caucasus, N. America, Greenland. The above description is based upon Scandinavian material. Known in the British Isles from a single gathering mixed with E. ciliata from a steep river valley (see D. G. Horton, J. Bryol., 11, 209–12, 1980). The Scottish plant belongs to ssp. brevicollis.

Section 3 Rhabdotheca Mull. ¨ Hal., Syn Musc. Frond., 1849 Setae red; capsules smooth or longitudinally striate; annulus not separating; peristome single or absent; vaginula short with umbrella-like top; spores with proximal surface with radial ridges, minutely granular, distal surface with prominent papillae; calyptrae erose at base. ¨ 4 E. rhaptocarpa Schwagr., Sp. Musc. Frond. Suppl. 1, 1811 ¨ E. rhabdocarpa Schwagr.

(Fig. 162)

Autoicous. Dull green patches, to 2(–5) cm high. Leaves incurved to crisped when dry, erect-patent to spreading when moist, 2.0–2.5 cm long, lanceolate to lingulatespathulate, acute to obtuse and apiculate; margins plane or sometimes recurved near base, inflexed above, papillose-crenulate; costa reddish, excurrent in a sometimes hyaline point, papillose or not on abaxial side above; basal cells rectangular, thin-walled, hyaline, basal marginal cells narrower, mid-leaf cells strongly papillose, obscure, 12–16 μm wide. Setae orange to dark red; capsules longitudinally ribbed at maturity, deeply furrowed when dry and empty; peristome single, short, red; vaginula short with umbrella-like top; spores sparsely papillose, variable in size 34–50 μm, proximal surface with radial ridges, minutely granular, distal surface with prominent papillae; calyptrae entire or erose at base, papillose towards apex. Capsules common, summer, autumn. n = 13, 26. On dry or seasonally moist soil on ledges and in crevices of base-rich montane rocks, on sanddunes. 0–1190 m. Rare, Caernarfon (1880), M. W. and N. W. Yorkshire, Durham, N. Northumberland, Westmorland, C. and N. Scottish Highlands north to Shetland, Sligo, old records from Clare, W. Mayo and Leitrim. 23, H4. GB36 + 9∗ , IR1 + 4∗ . Circumpolar Boreo-arctic Montane. N. and montane Europe, Sardinia, Faeroes, Iceland, Caucasus, Turkey, Tibet, Kashmir, Himalayas, China, N. America, Greenland, Hawaii, Antarctica. 5 E. vulgaris Hedw., Sp. Musc. Frond., 1801 (Fig. 162) Autoicous. Dull or yellowish green tufts or patches, 0.5–2.0 cm high. Leaves incurved, twisted when dry, erect-patent to spreading when moist, mostly 2–4 mm long, lingulate or spathulate, acute to obtuse, apiculate or not; margins plane or reflexed; costa ending below apex to excurrent, rarely longly so or in a hyaline point, reddish below, smooth on abaxial side; basal cells rectangular, thin-walled, hyaline, basal marginal cells narrower, mid-leaf cells strongly papillose, obscure, 14–20 μm wide. Setae reddish, capsules smooth at maturity, sulcate when dry and empty; peristome absent; vaginula short with umbrella-like top; spores coarsely

87 Encalyptra

503

papillose, variable in size, 30–45 μm, proximal surface with radial ridges, minutely granular, distal surface with prominent papillae; calyptrae entire or erose at base, papillose towards apex. Capsules common, spring. n = 13. On dry base-rich rocks, walls, cliffs, soil in calcareous grassland and on shaded chalk. 0–730 m. Frequent or common in basic habitats in England, Wales and E. Scotland, occasional in Ireland. 87, H25. GB252 + 96∗ , IR19 + 13∗ . Circumpolar Temperate. Europe, Caucasus, Turkey, Cyprus, Tibet, Kashmir, Himalayas, China, New Guinea, Madeira, Canary Islands, Africa, N. and C. America, Tasmania, New Zealand. In the British Isles E. vulgaris differs from E. rhaptocarpa in the smooth gymnostomous capsules and the costa smooth on the abaxial side. However, in N. America the two species intergrade to such an extent that the specific status of the plants is open to question. Of the other species with smooth capsules, E. alpina differs in leaf shape and cell size, E. ciliata in the fringed calyptrae and the spores smooth or ridged. E. brevicollis and also E. streptocarpa have the costa papillose on the abaxial side above and the latter has the costa ending in or below the leaf apex and is a larger plant.

Section 4 Encalypta Setae yellow; capsules smooth; annulus not separating; peristome single or absent; vaginula elongate, cup-shaped at top; spores with numerous radial ridges on proximal face, 5–7 ridges on distal face; calyptrae fringed at base. 6 E. ciliata Hedw., Sp. Musc. Frond., 1801 (Fig. 163) Bright or light green tufts or patches, to 5 cm high. Leaves incurved, ± crisped when dry, erect-patent to spreading when moist, (2.5−)3.0–3.5 mm long, lingulate or lingulate-spathulate; margins narrowly recurved at about middle of leaf, papillose-crenulate; costa ending below apex to shortly excurrent, reddish below, ± smooth on abaxial side; basal cells rectangular, thin-walled, hyaline, basal marginal cells narrower, mid-leaf cells strongly papillose, obscure, 10–15 μm wide. Setae yellow to pale red; capsules smooth when ripe, contracted below mouth when dry and empty; peristome if present single, fragile, short, reddish; vaginula elongate, cup-shaped at top; spores smooth or ridged, 30–38 μm, with numerous radial ridges on proximal face, 5–7 ridges on distal face; calyptrae smooth towards apex, fringed at base but fringe lost with age and base becoming erose. Capsules common, late summer, autumn. n = 13∗ . On dry or damp sheltered calcareous montane cliffs and ledges. 200–1100 m. Occasional in Mid and N. Wales, N. England, Scottish Highlands, Offaly, Londonderry, old records from W. Mayo and Antrim. 37, H4. GB881 + 23∗ , IR1 + 2∗ . Circumpolar Boreal-montane. Europe, Faeroes, Iceland, Caucasus, N., C. and E. Asia, New Guinea, Algeria, Ethiopia, C. and S. Africa, Greenland, N. and C. America, Andes, Australia, New Zealand, Hawaii. Easily distinguished from all species except E. brevicollis by the fringed calyptrae. The fringe may be lost from old calyptrae but the plant may be distinguished from E. vulgaris by the calyptrae smooth towards the apex, the smooth or ridged spores and the narrowly recurved

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25 Funariaceae

leaf margins. E. brevicollis differs in the capsules not or hardly contracted below the mouth when dry and empty, the calyptrae papillose above, the leaves with plane margins and the costa coarsely papillose on the abaxial side.

14 Funariales Acrocarpous. Plants terricolous or on decaying plant or animal remains. Leaves ovate-lanceolate, upper usually crowded; costa thin; cells large, lax, rhomboidhexagonal, thin-walled, smooth. Capsules dehiscent or rarely cleistocarpous; exerted or immersed, erect or inclined, symmetrical or asymmetrical, globose to ovoid or pyriform, with distinct neck; peristome double or single, perfect or imperfect, or absent; calyptrae large. Three families.

24 Disceliaceae A monotypic family with the characters of the species. The taxonomic position of the Disceliaceae has been open to debate. However, on the basis of peristome studies it has been shown that the correct position of the family appears to be in the Funariales (see J. Shaw & B. H. Allen, Bryologist 88, 263–7, 1985).

88 DISCELIUM BRID., BRYOL. UNIV., 1826 Derivation: meaning two legs, from the cleft peristome teeth.

1 D. nudum (Dicks.) Brid., Bryol. Univ., 1826 (Fig. 164) Pseudodioicous. Minute bud-like scattered or gregarious male and female plants produced from the same persistent protonemata. Leaves without chlorophyll, concave, ovate to lanceolate, acute, bluntly dentate above; costa lacking or traces present in upper part of leaf; cells lax, rhomboid-hexagonal, pellucid, narrower towards margins. Colourless 1(–3) – celled rhizoidal gemmae with cells ± spherical and 80–150 μm diameter, sometimes present. Setae pale red, thin, to 2.5 cm long; capsules ± horizontal, ± globose; lid mamillate, obtuse; peristome single, teeth divided below, entire above; spores 20–24 μm; calyptrae cucullate. Capsules common, autumn, winter. Clayey banks of ditches and streams, dried-out beds of ponds and reservoirs, clay roadside banks. 0–520 m. Frequent and sometimes locally abundant in the Pennines, very rare elsewhere, extending from E. Cornwall to E. Kent and north to Dunbarton and E. Ross, Cavan. 31, H1. GB85 + 25∗ , IR1. Circumpolar Boreal-montane. Rare in Europe from Spain north to Scandinavia, Siberia, Japan, N. America.

25 Funariaceae Plants mostly annual or biennial. Stems short, with central strand. Protonemata not persisting. Leaves soft, concave, ovate-lanceolate; margins usually dentate above; costa ending in apex to excurrent, in section with central stereid band;

88 Discelium

505

Fig. 164 1–4, Discelium nudum: 1, plant (×5); 2, leaf (×40); 3, leaf cells; 4, capsule (×15);. 5–8, Funaria hygrometrica: 5, leaves (×20); 6, marginal, cells from upper part of leaf; 7, 8, mature and dry empty capsules (×10). 9–13, Entosthodon muhlenbergii: 9, leaf (×20); 10, marginal cells from middle of leaf; 11, leaf apex; 12, capsule (×15); 13, spores (×420). Cells ×280.

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25 Funariaceae

cells large, lax, rhomboid-hexagonal, thin-walled, smooth. Setae long or short; capsules usually dehiscent and emergent, erect or inclined, symmetrical or asymmetrical, usually pyriform with numerous stomata at base; annulus present or not; peristome double, single, imperfect or lacking; calyptrae large, cucullate or mitriform. Fifteen genera. Hybrids between various members of the Funariaceae have been found in continental Europe and the following have been recorded in Great Britain: reciprocal hybrids between Physcomitrium pyriforme and Aphanorrhegma patens, and between Physcomitrium sphaericum and Aphanorrhegma patens (see A. Pettet, Trans. Br. Bryol. Soc. 4, 642–8, 1964). For a generic revision of the Funariaceae see A. J. Fife, J. Hattori Bot. Lab. 58, 149–96, 1985.

89 FUNARIA HEDW., SP. MUSC. FROND., 1801 Derivation: from cord, referring to the seta of Funaria hygrometrica being twisted and resembling a cord when dry.

1 F. hygrometrica Hedw., Sp. Musc. Frond., 1801 (Fig. 164) Autoicous. Plants ephemeral, forming yellowish green or green patches, sometimes very extensive, to 3 cm high. Lower leaves spreading to erect-patent, upper crowded, imbricate when moist, concave, ovate-lanceolate to lanceolatespathulate, shortly pointed; margins plane, entire to bluntly dentate; costa ending in or below apex; cells lax, thin-walled, basal rectangular, upper irregularly rectangular to quadrate-hexagonal, 35–50 μm wide in mid-leaf, 1–3 rows of marginal cells narrower. Setae arcuate when moist, flexuose, twisted when dry and old; capsules narrowly pyriform, gibbous, asymmetrical, mouth oblique, striate at maturity, sulcate when dry and empty, neck long; exothecial cells in alternating vertical bands of thin- and thick-walled cells, walls cuneate in cross-section; annulus of large cells, revoluble; lid convex; peristome double, exostome teeth curved in partial spiral, joined at tips to a central disc; spores finely papillose, 16–22 μm; calyptrae cucullate, oblique. Capsules very common, late winter to autumn. n = 14∗ , 21, 28∗ , 56. On disturbed or cultivated ground and especially on sites of fires, in gardens, flower-pots, on old walls and buildings. Mainly lowland bur ascending to 715 m in Mid Perth. Frequent and sometimes locally abundant. 112, H39, C. GB1198 + 86∗ , IR95 + 8∗ , C10. Circumpolar Wide-temperate. Cosmopolitan. ¨ 90 ENTOSTHODON SCHWAGR., SP. MUSC. FROND. SUPPL. 2, 1823 Autoicous. Leaves usually crowded at tops of stems, ovate-lanceolate or obovatelanceolate, acute to acuminate; margins dentate or entire; costa ending below apex; cells large, lax, towards margins sometimes elongate. Setae straight; capsules erect or inclined, pyriform, symmetrical, smooth at maturity, smooth when dry and empty or neck sulcate, exothecial cells ± uniformly thickened; annulus of

90 Entosthodon

507

small cells, not revoluble; lid concave; peristome double, single, rudimentary or absent, where present tips of exostome teeth free; calyptrae cucullate. Derivation: meaning teeth inside, referring to the insertion of the peristome teeth below the mouth of the capsule.

1 Capsules inclined, asymmetrical with oblique mouths, peristome double 2 Capsules erect, symmetrical, peristome single and imperfect or absent 3 2 Leaf margins dentate above, apical cell of leaves to 450 μm long, spores coarsely papillose 1. E. muhlenbergii Leaf margins ± entire, apical cell of leaves to 280 μm long, spores finely papillose 2. E. pulchellus 3 Leaves distinctly bordered with 1–2 rows narrow incrassate cells, spores 30–38 μm 4. E. obtusus Leaves not obviously bordered, spores 24–30 μm 4 1 2 4 Capsules narrowly pyriform, neck /2 – /3 length of capsule body, rhizoids deep cerise 3. E. attenuatus Capsules obovoid or shortly pyriform, neck 1/4 –1/3 length of capsule body, rhizoids brownish 5. E. fascicularis 1 E. muhlenbergii (Turner) Fife, J. Hattori Bot. Lab., 1985 (Fig. 164) Funaria muhlenbergii Turner, F. calcarea Wahlenb., F. mediterranea Lindb. Yellowish green patches or scattered plants, to 5 mm high. Lower leaves spreading, upper crowded, ± erect when moist, obovate to oblanceolate, abruptly narrowed to long fine apices; margins plane, bluntly dentate above; costa ending in or below apex; cells lax, thin-walled, basal rectangular, upper irregularly rectangular to quadrate-hexagonal, 35–50 μm wide in mid-leaf, apical cell to 450 μm long. Setae straight at maturity, not flexuose when old, 7–11 mm long; capsules inclined, pyriform, gibbous, asymmetrical with oblique mouth, smooth at maturity, neck long, slightly sulcate when dry; lid conical-mamillate, marginal cells of lid more strongly coloured than but not contrasting with other cells of lid; peristome double, outer teeth curved in partial spiral, tips free; spores coarsely papillose, 18–28(−30) μm; calyptrae cucullate, oblique. Capsules common, spring. Basic soil in turf, among rocks and on soil-covered rocks, calcicole. 0–380 m. Rare in western England and Wales, Mid Perth, old records from Mid and E. Cork. 20, H2. GB27 + 3∗ , IR2∗ . Submediterranean-Subatlantic. W. and C. Europe north to Scandinavia, Caucasus, Turkey, Cyprus, S. W. Asia, Macaronesia, N. Africa, western N. America. ´ Orsis, 2000 2 E. pulchellus (H. Philib.) Brugues, Funaria pulchella H. Philib.

(Fig. 165)

Gregarious or scattered yellowish green plants, to 5 mm high. Lower leaves spreading, upper crowded, erect, ovate to obovate, ± tapering to acuminate apex; margins plane, entire or sinuose, rarely obscurely dentate above; costa ending well

508

25 Funariaceae

Fig. 165 1–5, Entosthodon pulchellus: 1, leaf (×20); 2, leaf apex; 3, marginal cells from middle of leaf; 4, capsule (×10); 5, spores (×420). 6–8, E. attenuatus: 6, leaf (×30); 7, marginal cells from upper part of leaf; 8, capsule. 9–11, E. obtusus: 9, leaf (×30); 10, marginal cells from upper part of leaf; 11, capsule. 12–15, E. fascicularis: 12, leaf (×30); 13, marginal cells from upper part of leaf; 14, capsule; 15, calyptra (×10). Cells ×280, capsules ×10.

90 Entosthodon

509

below apex, rarely percurrent; cells lax, thin-walled, basal rectangular, upper irregularly rectangular to quadrate-hexagonal, 35–50 μm wide in mid-leaf, apical cell to 280 μm long. Setae straight at maturity, not flexuose when old, 3–8 mm long; capsules inclined, pyriform, gibbous, asymmetrical with oblique mouth, smooth at maturity, sulcate when dry and empty; lid conical-mamillate, with margin of orange-red or red cells contrasting with other cells of lid; peristome double, outer teeth curved in partial spiral, tips free; spores finely papillose, 20–28 μm; calyptrae cucullate, oblique. Capsules common, spring. On basic soil in grassland and among rocks, calcicole. Lowland, Very rare, scattered localities from E. Cornwall east to W. Sussex and north to Anglesey, W. Lancashire and Banff. 13. GB10 + 6∗ . Submediterranean-Subatlantic. Mediterranean region north to Germany, Austria, Switzerland and Hungary, Caucasus, Turkey, Cyprus, Samarkand, Macaronesia, N. Africa, Arizona. Differing from E. muhlenbergii in the leaves with ± entire margins and shorter apical cell, the marginal cells of the lid contrasting in colour with inner cells and in the finely papillose spores. For an account of this plant in Britain see A. C. Crundwell & E. Nyholm, Lindbergia 2, 22–9, 1974.

3 E. attenuatus (Dicks.) Bryhn, Kongel Norske Vidensk. Selsk. Skr. (Trondheim), 1908 (Fig. 165) Funaria attenuata (Dicks.) Lindb., F. templetonii Sm. Green patches or scattered plants, to 5 mm high. Rhizoids at base of stems deep cerise. Leaves erect-patent to spreading, concave, lanceolate to ovate or obovate, acute to acuminate; margins bluntly dentate; costa ending in or below apex; basal cells rectangular, cells above shorter, 24–40 μm wide in mid-leaf, 1–2 marginal rows narrower but not forming distinct border. Setae straight, 5–15 mm long; capsules erect, narrowly pyriform, ± symmetrical, smooth, neck 1/2 –2/3 length of body of capsule; lid ± convex; peristome a single row of small fugacious teeth; spores slightly angular, smooth, 24–30 μm; calyptrae cucullate, oblique. Capsules common, spring to autumn. n = 28∗ . Damp soil by streams, ditches, in woodland, on moorland, rock ledges, cliffs. 0–700 m. Rare in S. W. and northern England and S. Wales, frequent in N. Wales and the western Scottish Highlands, occasional in W. Ireland, Jersey. 55, H25, C. GB232 + 46∗ , IR70 + 12∗ , C2. MediterraneanAtlantic. S., W. and C. Europe, extending north to Faeroes and Iceland and east to Israel, Cyprus, Turkey, Syria, Tadzekistan, China, Macaronesia, N. Africa, N. America. ¨ 4 E. obtusus (Hedw.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1865 (Fig. 165) Funaria ericetorum (Bals.-Criv. & De Not.) Dixon, F. obtusa (Hedw.) Lindb. Green patches or scattered plants, to 5 mm high. Stems with pale brown rhizoids below. Leaves lanceolate-spathulate to lanceolate, acuminate; margins

510

25 Funariaceae

plane, ± entire to bluntly dentate above; costa ending below apex; basal cells rectangular, upper shortly rectangular to hexagonal, 24–40 μm wide in mid-leaf; 2–3 marginal rows very narrow, incrassate, yellowish, forming distinct border. Setae straight, to 6 mm long; capsules erect, ovoid or shortly pyriform, symmetrical, smooth, neck 1/4 –1/3 length of body of capsule; peristome rudimentary or absent; lid ± convex; spores papillose, 30–38 μm. Capsules common, winter to spring. n = 26∗ , 28∗ . On damp neutral or acidic peaty or gravelly soil on heaths, moorland, by streams and ditches, on rock ledges. 0–780 m. Occasional to frequent from Cornwall east to Kent, Wales, N. England and the western Scottish Highlands, rare elsewhere, occasional in Ireland. 85, H30, C. GB419 + 67∗ , IR94 + 13∗ , C7 + 1∗ . Submediterranean-Subatlantic. Mediterranean and western Europe, extending north to Scandinavia, Faeroes, Iceland, Turkey, Macaronesia, Algeria, Tunisia. ¨ Hal., Syn. Musc. Frond., 1848 5 E. fascicularis (Hedw.) Mull. Funaria fascicularis (Hedw.) Lindb

(Fig. 165)

Ephemeral green patches or scattered plants, to 1 cm high. Rhizoids brownish. Leaves erect-patent, lanceolate-spathulate to oblanceolate-spathulate, acuminate; margins plane, dentate; costa ending in or below apex; cells ± uniformly rectangular, 24–40 μm wide in mid-leaf, 1–2 rows marginal cells narrower but not forming border. Setae straight, 3–10 mm long; capsules erect, pyriform, ± symmetrical, 1/ –1/ length of body of capsule; lid plano-convex, inner surface cells about half 4 3 size of outer cells; peristome rudimentary or absent; calyptrae cucullate, oblique; spores coarsely but not spinosely papillose, 24–28 μm. n = 26∗ , 27. On usually damp acidic soil in fields, on waste ground, banks and paths. Lowland. Occasional in the southern half of England and in Wales, rare further north, extending to S. Aberdeen, rare in Ireland. 70, H13, C. GB144 + 80∗ , IR5 + 16∗ , C3. European Temperate. Europe north to southern Scandinavia, Caucasus, Turkey, Algeria Egypt, Morocco, western N. America. Similar to and likely to be confused with Physcomitrium pyriforme; for differences see under that species

91 PHYSCOMITRIUM (BRID.) BRID., BRYOL. UNIV., 1827 Autoicous. Gametophytes similar to those of Entosthodon. Capsules erect, symmetrical, gymnostomous; lid apiculate or rostellate; calyptrae symmetrical, mitriform. A cosmopolitan genus of c. 100 species. Derivation: meaning bladder cap, referring to the calyptrae.

1 Setae 5–15 mm long, capsules ± pyriform, about twice as long as wide, ± urceolate when empty 1. P. pyriforme Setae 1–5 mm long, capsules ± spherical, about as long as wide, ± hemispherical when empty 2

91 Physcomitrium

511

2 Leaf margins distinctly dentate above, setae 2–5 mm long, spores 30–40 μm 2. P. eurystomum Leaf margins ± entire, setae 1–2 mm long, spores 24–32 μm 3. P. sphaericum 1 P. pyriforme (Hedw.) Hampe, Flora, 1837 (Fig. 166) Ephemeral green patches or scattered plants, to 5 mm high. Leaves erect-patent to spreading, concave, variable in shape, ovate to lanceolate, oblanceolate or spathulate, acute; margins dentate above; costa ending in apex; cells lax, thinwalled, lower narrowly rectangular to rectangular, cells above irregularly rectangular to hexagonal, 20–50 μm wide in mid-leaf, marginal cells narrower. Setae 5–15 mm long; capsules ± narrowly pyriform, narrowed at mouth, with short distinct neck, ± urceolate when dry and empty; lid convex, apiculate to rostellate, surface cells of ± similar size; spores spinosely papillose, 28–36 μm; calyptrae mitriform, symmetrical. Capsules common, late winter to summer. n = 9, 18, 26∗ , 27, 36, 52, 54, 72. On damp soil in fields, waste ground, by streams, ditches and pools and on soil dredged therefrom. Lowland. Frequent in England and Wales, rare to occasional in Scotland and Ireland. 97, H30, C. GB499 + 100∗ , IR23 + 13, C4 + 3∗ . Circumpolar Temperate. Europe north to S. Scandinavia, Caucasus, Turkey, east to Siberia, Macaronesia, N. America, Mexico, Australia (introduced?). The only reliable characters distinguishing P. pyriforme from Entosthodon fascicularis are the symmetrical mitriform calyptrae and the apiculate to rostellate capsule lids. Also, in the former the cells towards the middle of the lid are about the same size as those at the edge, whereas in E. fascicularis the inner cells are about half the size of the outer.

2 P. eurystomum Sendtn., Denkschr. Bayer. Bot. Ges. Regensburg, 1841

(Fig. 166)

Ephemeral green patches or scattered plants, to 3 mm high. Leaves erect-patent to spreading, ovate to ovate-lanceolate, acuminate; margins bluntly dentate above; costa ending in apex; lower cells narrowly rectangular to rectangular, cells above irregularly rectangular to hexagonal, 20–35 μm wide in mid-leaf, 2–3 marginal rows narrower. Setae 2–5 mm long; capsules shortly pyriform to ± spherical with distinct neck, hemispherical when empty; lid mamillate; spores 30–40 μm; calyptrae mitriform, symmetrical. Capsules common, autumn, winter. On exposed basic mud by pools and reservoirs. Lowland. Very rare, Hertford, N. Norfolk. 2. GB4. Eurasian Temperate. W. and C. Europe, Caucasus, Turkey, N. India, Sikkim, Vietnam, Taiwan, China, Japan, New Guinea. For the occurrence of this plant in Britain see B. F. T. Ducker & E. F. Warburg, Trans. Br. Bryol. Soc. 4, 95–7, 1961. This species is considered endangered in the Red List of British mosses.

512

25 Funariaceae

Fig. 166 1–4, Physcomitrium pyriforme: 1, leaves (×15); 2, marginal cells at middle of leaf; 3, capsule (×15); 4, calyptra (×15). 5–7, P. eurystomum: 5, leaf (×20); 6, marginal cells at middle of leaf; 7, capsule (×20). 8–10, P. sphaericum: 8, leaf (×20); 9, marginal cells at middle of leaf; 10, capsule (×15). 11–13, Aphanorrhegma patens: 11, plant (×10); 12, leaf (×15); 13, marginal cells from upper part of leaf. Cells ×280.

92 Aphanorrhegma

513

¨ 3 P. sphaericum (C. E. Ludw.) Furnr. in Hampe, Flora, 1837 (Fig. 166) Ephemeral green patches or scattered plants, to 4 mm high but usually less. Leaves erect-patent to spreading, ovate to ovate-lanceolate, acute to obtuse; margins entire or obscurely crenulate above; costa ending below apex, lower cells rectangular, cells above quadrate to hexagonal, 12–30 μm wide in mid-leaf. Setae 1–2 mm long; capsules ± spherical, hemispherical when empty; lid mamillate; spores 24–32 μm; calyptrae mitriform, symmetrical. Capsules common, autumn, winter. On mud of dried-out ponds, lakes and reservoirs. Lowland. Rare and sporadic in appearance, recorded from scattered localities from E. Sussex and Surrey north to Dunbarton, Antrim. 12. H1. GB14 + 9∗ , IR1. Eurasian Temperate. Rare in Europe, extending north to S. Sweden, Siberia, Amur, C. India, Taiwan, Korea, China, Japan. 92 APHANORRHEGMA SULL. IN J. E. GRAY, MANUAL, 1858 Aphanorhegma auct. Non Sull. Paroicous or synoicous. Plants minute, ephemeral, protonemata not persisting. Setae very short; capsules immersed, cleistocarpous, globose, apiculate. Five species distributed through Europe, Asia, N. America, Australia. Derivation: referring to the ‘unapparent’ nature of the capsules, dehiscing only under pressure and the line of dehiscence not visible in immature capsules.

¨ 1 A. patens (Hedw.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1865 (Fig. 166) Physcomitrella patens (Hedw.) Bruch & Schimp. Ephemeral green patches or scattered plants, to 2.5 mm high. Leaves erect or erect-patent when moist, ovate to lanceolate, shortly acuminate; margins plane, bluntly dentate from about the middle; costa ending in or below apex; cells narrowly rectangular below, shorter above, 15–20 μm wide in mid-leaf, 1–2 marginal rows narrower. Setae very short, c. 100 μm long; capsules immersed, cleistocarpous, globose, with short blunt beak; spores 26–32 μm. By streams, ditches, ponds, lakes, reservoirs, bottoms of dried-out ponds, wet tracks and woodland rides. Lowland. Occasional in England, rare in Wales, very rare in Scotland, extending north to Dunbarton and Kintyre, rare in Ireland. 66, H11. GB168 + 71∗ , IR8 + 4∗ . Eurosiberian Temperate. Europe, except the Mediterranean region, north to southern Scandinavia, Yenesei, N. America.

Subclass 4 Bryideae Peristome double, exostome teeth alternating with processes of endostome, endostome with cilia, late stage division of inner peristome layer asymmetric.

514

26 Splachnaceae

15 Splachnales Leaf cells rhomboidal to elongate, smooth. Capsules with differentiated neck; peristome single or double; cilia rudimentary or absent. Three families.

26 Splachnaceae Leaves soft, lanceolate to ± orbicular; margins plane, entire to dentate; costa thin; cells lax, rectangular, smooth. Setae long; capsules erect, body ovoid or ellipsoid to shortly cylindrical, hypophysis sometimes greatly enlarged; peristome single; columella sometimes extending after dehiscence; spores often sticky and dispersed by flies. Plants frequently growing on dung or decaying animal matter. Seven genera. 93 TAYLORIA HOOK., J. SCI. ART (LONDON), 1816 Autoicous, synoicous or dioicous. Leaves soft, lanceolate-spathulate to lingulate, margins plane, entire or dentate; costa ending in or below apex; cells lax, rectangular to hexagonal. Setae thin, flexuose; capsules with pyriform hypophysis narrower than rest of capsule; constricted at base; peristome teeth single or united in pairs. A ± cosmopolitan genus of c. 65 species. Derivation: named after the Protestant Irish physician and bryologist Thomas Taylor (1775– 1848).

Leaves obovate-spathulate to lanceolate-spathulate, margins dentate Leaves lingulate to ovate-lanceolate, margins ± entire

1. T. tenuis 2. T. lingulata

1 T. tenuis (Dicks. ex With.) Schimp., Syn. Misc. Eur. (2nd edn), 1876 (Fig. 167) T. longicollis (Dicks.) Dixon, T. serrata var. tenuis (Dicks. ex With.) Bruch & Schimp. Autoicous. Lax green tufts, to 2 cm high. Leaves slightly shrunken when dry, erect-patent when moist, obovate-spathulate to lanceolate-spathulate, acute or with acuminate apiculus; margins plane, serrate; costa ending below apex; basal cells rectangular, cells above hexagonal, 20–40 μm wide in mid-leaf. Setae deep red, slender, flexuose, to 2.5 cm long; body of capsule ellipsoid, tapering into long narrow hypophysis; peristome teeth reflexed when dry; spores c. 12 μm. Capsules frequent, summer. On damp decaying plant matter and soil in montane habitats. To 850 m. Very rare and recorded recently only from Mid Perth and Caithness, but old records from Durham, Mid Perth, Angus, S. Aberdeen, E. Inverness, W. Ross and Londonderry. 8, H1. GB2 + 14∗ , IR1∗ . Circumpolar Boreal-montane. France and N. Italy north to Fennoscandia, Siberia, Uganda, Kenya, N. America, Greenland. This species is regarded as critically endangered ion the Red List of British mosses.

93 Tayloria

515

Fig. 167 1–3, Tayloria tenuis: 1, leaf; 2, marginal cells from middle of leaf; 3, capsule. 4–6, T. lingulata: 4, leaf; 5, cells from middle of leaf; 6, capsule. 7–10, Tetraplodon angustatus: 7, leaf; 8, marginal cells at middle of leaf; 9, leaf apex; 10, capsule. 11–14, T. mnioides: 11, leaf; 12, marginal cells from middle of leaf; 13, leaf apex; 14, capsule. Leaves ×10, cells ×280, capsules ×10.

516

26 Splachnaceae

2 T. lingulata (Dicks.) Lindb., Musci Scand., 1879 (Fig. 167) Synoicous. Dense tufts, pale green above, blackish below, or scattered plants among other bryophytes, to 5 cm high. Leaves somewhat flexuose when dry, ± erect when moist, lingulate to ovate-lanceolate, apex obtuse to rounded; margins plane, entire or obscurely dentate above; costa ending below apex; cells ± rectangular, 30–50 μm wide in mid-leaf. Setae bright red, slender, flexuose, to 3 cm long; capsules ovoid, wide-mouthed when empty, tapering into hypophysis; peristome teeth erect when dry; spores 20–30 μm. Capsules frequent, summer. In basic montane flushes. To 850 m. Very rare, Mid Perth, S. Aberdeen, old records from Stirling, E. Perth and Angus. 5. GB3 + 6∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Iceland, Turkey, Siberia, Yunnan, Korea, Japan, N. America, Greenland. This species is considered endangered in the Red List of British mosses.

94 TETRAPLODON BRUCH & SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1844 Autoicous. Leaves lanceolate to obovate, acuminate; margins entire or dentate; cells lax, usually thin-walled. Antheridia terminal on lateral branches. Capsules ± erect, hypophysis of similar colour to and narrower to slightly wider than rest of capsule; peristome teeth at first in fours and then in pairs, reflexed when dry; columella not exserted after dehiscence. A mainly Northern Hemisphere genus of 13 species. Derivation: meaning fourfold teeth, from the initial arrangement of the peristome teeth.

Leaf margins dentate above, setae to 5 mm long Margins ± entire, setae (7–)10–30 mm long

1. T. angustatus 2. T. mnioides

1 T. angustatus (Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1844 (Fig. 167) Light green tufts, to 6 cm high. Leaves appressed, twisted when dry, erect-patent when moist, lanceolate or oblanceolate, gradually tapering to flexuose acumen; margins sharply dentate above; costa ending in apex; cells ± rectangular, 15–25 μm wide in mid-leaf, apical cells 12–26 μm wide. Setae short, to 5 mm long; capsules barely exserted above leaves, hypophysis pyriform, slightly wider than body of capsule; spores c. 10 μm. On decaying bones and less commonly on dung. To 910 m. Rare, Caernarfon, Perth and Angus north to W. Sutherland, Offaly. 13, H1. GB21 + 15∗ , IR1. Circumpolar Boreal-montane. Montane and northern Europe north to Fennoscandia, Siberia, China, Japan, N. America, Greenland. 2 T. mnioides (Sw. ex Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1844 (Fig. 167) Light green tufts, to 6 cm high but usually less. Leaves shrunken when dry, erectpatent when moist, concave, ovate-lanceolate to oblanceolate, gradually narrowed

95 Aplodon

517

to flexuose sometimes long acumen; margins entire or occasionally with a few obscure teeth above; costa ending in apex; cells ± rectangular, 15–25 μm wide. Setae thick, succulent, 7–30 mm long; capsules narrowly ellipsoid, hypophysis similar in colour to and hardly wider than body of capsule, when dry body of capsule shrunken and hypophysis pyriform; spores 10–12 μm. Capsules common, spring, summer. n = 8, 11∗ , 19. On decaying bones, less frequently on dung in bogs, on boggy ground, moorland and in the mountains. 0–950 m. Rare in southern Britain, Devon, Surrey, S. Wales, occasional to frequent from N. Wales north to Orkney, occasional in Ireland. 60, H22. GB171 + 37∗ , IR26 + 7∗ . Circumpolar Boreoarctic Montane. Europe north to Svalbard, east to Sakhalin, Japan, E. Africa, Borneo, New Guinea, N., C. and S. America, Greenland, Tasmania. This and the previous species are distinguished form Aplodon wormskjoldii and Splachnum species by the longly acuminate leaf apices.

95 APLODON (R. BR.) RCHB., CONSP. REGN. VEG., 1828 A monotypic genus with the characters of the species. Intermediate between Splachnum and Tetraplodon. Derivation: meaning single teeth, referring to the peristome teeth finally being equidistant.

1 A. wormskjoldii (Hornem.) Kindb., Eur. N. Am. Bryin., 1897 (Fig. 168) Haplodon wormskjoldii auct., Splachnum wormskjoldii Hornem., Tetraplodon wormskjoldii (Hornem.) Lindb. Autoicous. Plants slender, in lax tufts to 6 cm high. Leaves shrunken when dry, erect-patent when moist, concave, broadly ovate to broadly obovate, lower obtuse, upper with frequently reflexed blunt acumens; margins entire, costa ending below apex; cells ± rectangular throughout, 20–40 μm wide in mid-leaf, marginal row larger than other cells, apical cell 30–50 × 30–80 μm, 1–2(−3) times as long as

Fig. 168 Aplodon wormskjoldii: 1, leaves (×15); 2, marginal cells at middle of leaf; 3, leaf apex; 4, capsule (×10). Cells × 280.

518

26 Splachnaceae

wide. Antheridia terminal on thin lateral branches. Setae thin, flexuose, hyaline, to 20 mm long; capsules ovoid, hypophysis ovoid, scarcely wider than body of capsule at maturity, capsules turbinate and hypophysis much narrower with age; columella not exserted beyond mouth after dehiscence; peristome teeth at first in pairs then separate, reflexed when dry; spores 10–15 μm. On dung in boggy places at higher altitudes. To 580 m. Very rare, Durham, Cumberland, E. Inverness, old records from Westmorland and Mid Perth. 5. GB6 + 2∗ . Circumpolar Arctic-montane. Arctic Europe north to Svalbard, Siberia, northern N. America, Greenland. When fertile may be recognised by the hyaline setae; when sterile by the leaves with frequently reflexed broad blunt acumens with the marginal row of cells wider than other cells and the apical cell 30–50 μm wide, wider than other members of the Splachnaceae. This is a critically endangered species in the Red List of British Mosses.

96 SPLACHNUM HEDW. SP. MUSC. FROND., 1801 Dioicous or autoicous. Leaves soft, ovate-lanceolate to broadly ovate, bluntly acute to acuminate; margins entire or dentate; costa ending in or below apex; cells lax, thin-walled, hexagonal or rhomboidal. Setae thin, flexuose; capsules ovoid to shortly cylindrical, hypophysis of different colour and texture from and usually wider than body of capsule, ovoid to umbrella-shaped; columella exserted beyond mouth of capsule and often inflated at apex after dehiscence; peristome teeth in pairs, reflexed when dry. A largely Northern Hemisphere genus of 10 mainly coprophilous species. Derivation: from an Ancient Greek name for some now unknown plant.

1 Leaves broadly ovate, obtuse or bluntly pointed, margins ± entire 3. S. vasculosum Leaves ovate to obovate or oblanceolate, acuminate, margins entire or dentate 2 2 Leaf margins entire to obscurely dentate, cells near leaf apex 1–2 times as long as wide, hypophysis of similar width to body of capsule 1. S. sphaericum Leaf margins obscurely to strongly dentate, cells near leaf apex 2–3 times as long as wide, hypophysis much wider than body of capsule 2. S. ampullaceum 1 S. sphaericum Hedw., Sp. Musc. Frond., 1801 S. ovatum Dicks. ex Hedw.

(Fig. 169)

Dioicous. Light green tufts, 1–2 cm high. Leaves shrunken when dry, erect-patent when moist, obovate or ovate to lanceolate, with narrow base, abruptly acuminate; margins entire or obscurely toothed; costa ending in or below apex; cells in mid-leaf rhomboid-hexagonal, 20–30 μm wide, cells near apex 1–2 times as long as wide, apical cell c. 25–30 μm wide. Setae thin, flexuose, reddish below,

96 Splachnum

519

Fig. 169 1–4, Splachnum sphaericum: 1, leaf; 2, marginal cells near leaf apex; 3, leaf apex; 4, capsule. 5–8, S. ampullaceum: 5, leaf; 6, marginal cells near leaf apex; 7, leaf apex; 8, capsule. 9–12, S. vasculosum: 9, leaf; 10, cells at middle of leaf; 11, leaf apex; 12, capsule. Leaves ×10, cells ×280, capsules ×10.

520

26 Splachnaceae

yellow above, to 4(–14) cm long; capsules ovoid, hypophysis ovoid, slightly wider to slightly narrower than capsule body, deep purple, rugose when dry; spores 8–12 μm. Capsules common, spring to autumn. n = 9. On dung or occasionally on bones on wet heaths, moorland and in bogs. 0–920 m. Occasional to frequent in western and northern Britain, occasional in western and northern Ireland. 60, H18. GB238 + 48∗ , IR46 + 6∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Siberia, N. America, Greenland. When sterile may be distinguished from Tetraplodon species by the more shortly pointed leaves, from Aplodon wormskjoldii by the narrower apical cell of the leaves, and from S. ampullaceum by the ± entire leaf margins and the shorter cells near the leaf apex.

2 S. ampullaceum Hedw., Sp. Musc. Frond., 1801 (Fig. 169) Autoicous. Light green tufts, to 3 cm high. Leaves shrunken when dry, erect-patent when moist, concave, obovate-lanceolate to oblanceolate, with narrow base, tapering to short to long acumen, base narrow; margins obscurely to spinosely dentate; costa ending in or below apex; cells in mid-leaf ± hexagonal, c. 25 μm wide, cells near apex 2–3 times as long as wide, apical cell 16–20 μm wide. Setae thin, flexuose, weak, deep red; capsules shortly cylindrical, hypophysis pyriform, much wider than capsule body, pale purple, rugose when dry; spores c. 8 μm. Capsules common, summer. n = 9∗ . On dung on wet heaths, moorland and in bogs. Usually lowland, but ascending to 740 m in S. Aberdeen. Rare to occasional, widely distributed in suitable habitats throughout the British Isles but decreasing in England because of habitat destruction. 79, H22. GB151 + 76∗ , IR48 + 11∗ . Circumpolar Boreal-montane. Europe north to Scandinavia, Faeroes, Iceland, Caucasus, N. Africa, N. America. When sterile may be distinguished from Tetraplodon species by the more shortly pointed leaves with relatively shorter cells.

3 S. vasculosum Hedw., Sp. Musc. Frond., 1801 (Fig. 169) Dioicous. Lax pale green to dark green patches, to 7 cm high. Leaves shrunken when dry, erect-patent when moist, broadly ovate with narrow base, lower obtuse, upper obtuse and shortly apiculate; margins ± entire; costa ending in or below apex; basal cells rectangular, cells above ± rhomboidal, c. 40 μm wide, 2–3 marginal rows rectangular, apical cell about as long as wide. Setae thin, pale red, c. 2 cm long; capsules ovoid, hypophysis dark purple, broadly globose, much wider than capsule body, rugose when dry; spores 8–10 μm. Capsules frequent, summer. n = 9. On dung in springs and flushes at high altitudes. 760–870 m. Rare but sometimes locally common from N. W. Yorkshire (old record) and Westmorland north to E. Sutherland. 15. GB19 + 12∗ . Circumpolar Arctic-montane. Germany and Fennoscandia north to Svalbard, Siberia, northern N. America.

98 Meesia

521

27 Meesiaceae Dioicous. autoicous or synoicous. Large tufted plants; stems with central strand, tomentose. Leaves erect-patent or squarrose-recurved, lanceolate; margins entire or toothed; costa thin or stout, ending in or below apex; cells rectangular or hexagonal, smooth or mamillose. Setae long, thin; capsules asymmetrical, ± pyriform or clavate, curved, smooth, with distinct neck; lid conical; peristome double, outer teeth usually short, processes long, cilia rudimentary or absent; calyptrae small. Five genera. The genera show wide divergence in gametophyte characters but are very similar sporophytically.

97 PALUDELLA BRID., MUSCOL. RECENT. SUPPL., 1817 A monotypic genus with the characters of the species. Derivation: diminutive of marsh, i.e. little marsh plant.

1 P. squarrosa (Hedw.) Brid., Muscol. Recent. Suppl., 1817 (Fig. 170) Dioicous. Dense matted light green tufts, to 15 cm high; stems tomentose below. Leaves in 5 ranks, strongly squarrose-recurved when moist, ovate, acute, base decurrent; margins narrowly recurved below, sharply serrate above; costa thin, ending below apex; basal cells narrowly rectangular, becoming ± roundedhexagonal, incrassate and coarsely mamillose above, c. 10 μm wide in mid-leaf. Setae to 10 cm long; capsules ellipsoid, curved; exostome teeth about same length as processes; spores 15–20 μm. Capsules unknown in the British Isles. n = 10, 11. In intermediate to rich fens; widespread after the last Ice Age but known from only three localities in historical times, Cheshire (1832), N. E. Yorkshire (1916) and S. E. Yorkshire (1861); found in 1998 in W. Mayo. 3, H1. GB3∗ , IR1. Circumpolar Boreo-arctic Montane. Alps and Carpathians north to Svalbard, Iceland, Kazakstan, Mongolia, Japan, N. America, Greenland. 98 MEESIA HEDW., SP. MUSC. FROND., 1801 Dioicous, autoicous or synoicous. Leaves narrowly lingulate, lanceolate or ovate; margins entire or toothed; costa very stout, ending below apex; cells narrowly rectangular to shortly rectangular, smooth or slightly mamillose. Setae long; capsules asymmetrical, narrowly pyriform, curved; outer exostome teeth shorter than processes, cilia rudimentary. Twelve species distributed through Europe, N. and C. Asia, C. Africa, the Americas, Australia and New Zealand. Derivation: named after D. Meese, a Dutch gardener (1723–1770).

Leaves erect-patent, ligulate to linear-lanceolate, obtuse Leaves squarrose, narrowly triangular, acute

1. M. uliginosa 2. M. triquetra

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27 Meesiaceae

Fig. 170 1–2, Meesia triquetra: 1, leaf (×15); 2, mid-leaf cells. 3–5, M. uliginosa: 3, leaf (×15); 4, mid-leaf cells; 5, capsule (×15). 6–7, Paludella squarrosa: 6, leaves (×15); 7, mid-leaf cells. 8–10, Catoscopium nigritum: 8, leaf (×20); 9, mid-leaf cells; 10, capsule (×20). 11–13, Amblyodon dealbatus: 11, leaf (×15); 12, mid-leaf cells; 13, capsule (×7.5). Cells ×420.

99 Amblyodon 1 M. uliginosa Hedw., Sp. Musc. Frond., 1801 M. trichodes Spruce

523 (Fig. 170)

Autoicous or synoicous. Dark green tufts, to 5 cm high; stems tomentose below. Leaves appressed, straight when dry, erect-patent when moist, ligulate to linearlanceolate, apex obtuse or rounded; margins recurved below, entire; costa very stout, occupying 1/2 –3/4 with of leaf base, ending below apex; cells narrowly rectangular below, rectangular above, c. 10 μm wide in mid-leaf. Setae thin, 1–4 cm long; capsules asymmetrical, narrowly pyriform, curved; spores 40–50 μm. Capsules common, late spring, summer. n = 13, 14∗ , 14 + m∗ . In dune-slacks, machair, in montane flushes and rock crevices, calcicole. 0–990 m. Rare in coastal habitats, occasional in the mountains of northern England and Scotland, extending north to Sutherland and Caithness. 27. GB56 + 20∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, N. and C. Asia, Himalayas, China, N. America, Greenland, Tierra del Fuego, Antarctica. 2 M. triquetra (A. Richter) Ångstr., Nova Acta Regiae Soc. Sci. Upsal., 1844 (Fig. 170) M. trifaria H. A. Crum et al., M. tristicha Bruch Dioicous. Large lax bright green patches, to 5 cm high. Leaves trifarious, squarrose, from erect sheathing ovate basal part narrowly triangular; margins plane, sharply serrate almost from base; costa strong, to 1/4 width of leaf base; cells pellucid, slightly incrassate, basal rectangular, cells above smaller, ± shortly rectangular, smooth, c. 15 μm wide in mid-leaf. Capsules similar to those of M. uliginosa but larger; unknown in Ireland. n = 10, 20. In a calcareous flush in blanket bog. Lowland. One locality in W. Mayo, now probably extinct. H1. IR1. Circumpolar Boreoarctic Montane. Montane and arctic Europe north to Svalbard, Iceland, Caucasus, N. Africa, N. America, Greenland, S. E. Australia. Most likely to be confused with Dichodontium palustre or D. pellucidum in the field. It differs from the former in the serrate leaf margins, from the latter in the smooth cells and from both in the trifarious leaves. For the occurrence of this species in Ireland see E. F. Warburg, Trans, Br. Bryol. Soc. 3, 378–81, 1958.

99 AMBLYODON P. BEAUV., MAG. ENCYCL., 1804 A monotypic genus with the characters of the species. Derivation: meaning blunt tooth, alluding to the short obtuse exostome teeth. The gametophyte resembles that of the Funariaceae and the sporophyte that of Meesia. On cytological grounds this genus clearly belongs near Meesia.

1 A. dealbatus (Sw. ex Hedw.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1841 (Fig. 170) Autoicous or polyoicous. Lax green tufts, to 2 cm high. Leaves ± erect, shrunken when dry, erect-patent when moist, oblong-lanceolate, acute; margins plane,

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27 Meesiaceae

entire or denticulate above; costa stout, ending below apex; cells thin-walled, lower rectangular, cells above lax, narrowly hexagonal, smooth, c. 20 μm wide in mid-leaf. Setae thin, 1.0–4.5 cm long; capsules asymmetrical, pyriform, curved, smooth, neck distinct, tapering; exostome teeth about 1/2 length of processes, cilia absent; spores c. 40 μm. Capsules common, summer. n = 10, 14∗ , 18, 20∗ . In montane flushes and crevices on cliffs, in dune slacks, calcicole. 0–760 m. Very rare in southern Britain, N. Devon, Suffolk, Worcester, Warwick, Derby, Wales, rare to occasional from the Pennines north to Sutherland, occasional in western Ireland. 43, H17. GB62 + 29∗ , IR11 + 7∗ . European Boreal-montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Iran, Altai, N. America, Greenland, Tierra del Fuego. Like Meesia uliginosa and Catoscopium nigritum this species occurs in both lowland (mainly sand-dune) and montane habitats and it seems likely that, in common with a number of flowering plants such as Armeria maritima and Silene maritima, the lowland populations are relicts of the last Ice Age.

100 LEPTOBRYUM (BRUCH & SCHIMP.) WILSON, BRYOL. BRIT., 1855 Synoicous or dioicous. Annual species with slender stems. Upper leaves setaceous from broad basal part; margins unbordered; cells linear. Capsules pyriform, pendulous, glossy. Two species, the second, L. wilsonii (Mitt.) Broth, occurring in Lesotho, Mexico, S. America and Antarctica. Derivation: meaning slender Bryum.

1 L. pyriforme (Hedw.) Wilson, Bryol. Brit., 1855 (Fig. 171) Usually synoicous. Lax pale green tufts or patches, to 2 cm high. Stems slender, naked below with leaves increasing in size up stems. Leaves erect-flexuose when dry, flexuose, spreading when moist, lower leaves lanceolate, acute to acuminate, upper and perichaetial leaves forming comal tuft, ± abruptly narrowed from broad erect basal part to long setaceous subula composed mainly of costa; margins plane, unbordered, finely denticulate above; costa broad below, occupying c. 1/3 width of leaf base, ending below apex in lower leaves, excurrent in upper; cells thinwalled, ± linear-rhomboidal throughout, c. 5 μm wide, basal larger than upper. Ellipsoid, dark brown gemmae, 125–140 μm long present on rhizoids, occasionally also axillary. Setae thin, flexuose, variable in length, to 4 cm long; capsules inclined or pendulous, pyriform, body of capsule smooth, glossy, neck sulcate with age; exostome teeth yellow; spores 14–16 μm. n = 20∗ , 20 + m, 20 + 2m, 21, 22, 33. Capsules common, spring, summer. Commonly in flower pots but also on disturbed ground in gardens, fields, by paths, roads, streams and ponds, on banks and sites of fires, pollution tolerant. Mainly lowland but ascending to 610 m on Harris. Common in flowerpots, occasional in natural habitats in England and Wales, rare in Scotland and Ireland. 101, H21, C. GB375 + 83∗ , IR13 + 12∗ , C2. Circumpolar Wide-temperate. Cosmopolitan.

100 Leptobryum

525

Fig. 171 1–6, Othrodontium gracile: 1, 2, lower and upper leaves (×25); 3, mid-leaf cells; 4, costa section; 5, capsule; 6, exostome teeth. 7–12, O. lineare: 7, 8, lower and upper leaves (×25); 9, mid-leaf cells; 10, costa section; 11, capsule; 12, exostome teeth. 13–17, Leptobryum pyriforme: 13, 14, lower and upper leaves (×25); 15, basal cells; 16, capsule; 17, rhizoidal gemma (×175). Cells and sections ×420, capsules ×10.

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29 Orthodontiaceae

28 Catoscopiaceae A monotypic family with the characters of the species. 101 CATOSCOPIUM BRID., BRYOL. UNIV., 1826 Derivation: meaning to look down, referring to the cernuous capsules.

1 C. nigritum Brid., Bryol. Univ., 1826 (Fig. 170) Dioicous. Dense bright green to dark green tufts or cushions, blackish below, to 4(−7) cm high; shoots slender, stems mostly unbranched, tomentose below. Leaves ± erect when dry, erect-patent when moist, lanceolate, gradually tapering to acuminate apex; margins recurved below, entire; costa stout, ending in apex; cells incrassate, quadrate-rectangular, narrower near costa and at base, ± smooth, 8–10 μm wide in mid-leaf. Setae yellowish red, very slender, rigid, to 1 cm long; capsules very small, scarcely 1 mm diameter, cernuous, subglobose, glossy, reddish, smooth at maturity, becoming blackish; lid conical; exostome teeth short, endostome rudimentary; spores 40–45 μm; calyptrae cucullate. Capsules frequent, autumn. n = 13∗ , 14. In dune-slacks and montane flushes, calcicole. 0–550 m. Rare, from Anglesey, Lancashire and N. W. Yorkshire north to Shetland, W. Mayo, W. Donegal, Londonderry, old records from E. Donegal and Antrim. 21, H5. GB39 + 17∗ , IR5 + 4∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, N. and C. Asia, Japan, N. America, Greenland. Sporophytes when present make this an easy plant to recognise as they superficially resemble small black pins. The dense, green or dark green tufts or ± hemispherical cushions with slender shoots with very small leaves also render this plant distinctive.

16 Bryales Acrocarpous. Leaves bordered or not, cells isodiametric to linear, sometimes large, smooth or mamillose, rarely papillose. Setae long; capsules inclined to pendulous, dehiscent; peristome double, usually well developed, exostome teeth with median septum on outer face, processes arising from high basal membrane, keeled and perforated, alternating with outer teeth, cilia frequently present. Eight families.

29 Orthodontiaceae With the characters of Orthodontium. Two genera. ¨ 102 ORTHODONTIUM SCHWAGR., SP. MUSC. FROND. SUPPL. 2, 1827 Polyoicous. Leaves flexuose, linear-lanceolate, unbordered; costa narrow; cells ± linear except near base. Setae slender, flexuose; capsules erect or inclined, ovoid to cylindrical with tapering neck; exostome teeth narrow, basal membrane short or absent; annulus absent. A world-wide genus of 14 species. Derivation: meaning upright tooth, referring to the peristome.

102 Orthodontium

527

For an account of European species of Orthodontium see W. D. Margadant & W. Meijer, Trans. Br. Bryol. Soc. 1, 266–74, 1950.

Exostome teeth smooth, costa in section lacking stereid band 1. O. gracile Exostome teeth finely papillose, costa in section with abaxial stereid band 2. O. lineare ¨ ex Bruch & Schimp., Bryol. Eur., 1844 (Fig. 171) 1 O. gracile (Wilson) Schwagr. Paroicous. Dense silky bright green tufts, to 1 cm high. Leaves linear to linearlanceolate; margins unbordered, plane, entire or obscurely denticulate above; costa ending in or below apex, in section without stereid band; basal cells rectangular, cells above linear-rhomboidal, in section incrassate, rounded, hardly bulging, 8–12 μm wide in mid-leaf. Setae thin, flexuose, capsules narrowly clavate; exostome teeth smooth. Capsules common, spring, summer. n = 12. On sheltered sandstone and gritstone rocks. Lowland. Rare and decreasing, widely scattered localities from S. Devon and E. Sussex north to Stirling, Fermanagh; of the 18 vice-county records 11 are old. 17, H1. GB9 + 25∗ , IR1. Oceanic Southern-temperate. Finisterre (France), Madeira, Tanzania, California, subtropics and tropics. O. gracile is a rare species and is out-competed by O. lineare, which has led to its disappearance from many of its localities. This species is treated as vulnerable in the Red List of British Mosses.

¨ 2 O. lineare Schwagr., Sp. Musc. Frond., Suppl. 2, 1827 O. gracile var. heterocarpum W. Watson

(Fig. 171)

Autoicous, heteroicous or synoicous. Silky dull green tufts or patches, sometimes extensive, to 1 cm high. Leaves flexuose when dry, erect, secund or recurved when moist, linear to linear-lanceolate; margins unbordered, plane, obscurely denticulate above; costa ending in or below apex, in section with abaxial stereid band; basal cells rectangular, cells above ± linear-rhomboidal, in section hardly thick-walled, oval, bulging, 8–14 μm wide in mid-leaf. Setae thin, flexuose; capsules narrowly pyriform to narrowly clavate, sometimes gibbous, sulcate or not when dry; exostome teeth and processes finely papillose except at base; spores (10−)16−20 μm. Capsules common, spring, summer. n = 20∗ , 22∗ . On acidic rocks, peat, rotting wood, on tree boles and stumps, particularly on vertical surfaces, pollution tolerant. 0–500 m. Common in England and Wales except the extreme west and extending north to E. Ross, very rare in Ireland. 108, H11, C. GB917 + 2∗ , IR6 + 1∗ , C1. Introduced (European Temperate). Western Europe, extending north to Scandinavia and east to Czechoslovakia and Poland, Madeira, Malawi, S. Africa, southern S. America, Australia, Tasmania, New Zealand. Although O. lineare occurs on a greater variety of substrates than O. gracile the two species are very similar and difficult to separate. For certain identification of O. gracile, the lack of a stereid band in the costa is a very useful character for separating it from O. lineare (see R. D. Porley, J. Bryol. 20, 500–1, 1998). The gametophyte of O. lineare more closely resembles

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that of a member of the Dicranaceae than that of the Bryaceae but the plant is readily distinguished by leaf areolation and capsule shape. O. lineare is almost certainly an introduction. Although first collected in Cheshire in 1910, until its description by W. Watson in 1920, O. lineare was only known from the Southern Hemisphere. It has since spread widely in England and Wales and is still extending its distribution in Scotland and is spreading eastwards in continental Europe.

30 Bryaceae Dioicous, autoicous or synoicous. Usually erect tufted or turf-forming plants. Leaves broadly ovate to lanceolate, often forming comal tuft, frequently bordered with narrow elongate cells; costa well developed, often excurrent; cells thinwalled, frequently rhomboid-hexagonal, smooth, pellucid. Setae long; capsules inclined to pendulous, ovoid to cylindrical, with differentiated neck; peristome usually double, inner often with well developed basal membrane, cilia present or not; calyptrae cucullate. Twelve genera.

Subfamily 1 BRYOIDEAE Leaf margins frequently bordered, usually entire; costa usually excurrent, in section with one row of stereids, without large median cells, with 1–2 rows large cells on adaxial side in upper part of leaf, marginal cells usually elongate, narrow, forming border. ¨ ¨ 103 PLAGIOBRYUM LINDB., OFVERS FORH. KONGL. SVENSKA VETENSK-AKAD., 1863 Dioicous. Plants tufted. Leaves imbricate or not, ovate to lanceolate, margins plane or recurved, areolation lax, often thin-walled. Perichaetial and perigonial leaves longer, narrower, with narrower cells than stem leaves. Setae short, curved or cygneous; capsules gibbous, mouth oblique; neck long; exostome shorter than endostome, cilia rudimentary. Seven species scattered through Europe, N. and E. Asia, Africa, N. America and New Zealand. Derivation: meaning oblique Bryum, alluding to the capsules.

Tufts silvery or whitish above, reddish below, shoots julaceous when moist, leaves broadly ovate, costa ending in or below apex 1. P. zieri Tufts reddish brown throughout, shoots hardly julaceous, leaves lanceolate to ovate-lanceolate, costa excurrent 2. P. demissum ¨ 1 P. zieri (Dicks. ex Hedw.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 172) Shoots julaceous, forming tufts, silvery or whitish above, reddish below, to 2(–4) cm high; stems brittle. Leaves imbricate when moist, hardly altered when

103 Plagiobryum

529

Fig. 172 1–3, Anomobryum julaceum var. julaceum: 1, leaf (×35); 2, mid-leaf cells (×420); 3, capsule (×10). 4, A. julaceum var. concinnatum: leaf (×35). 5–8, Plagiobryum zieri: 5, 6, leaves from sterile and fertile stems (×25); 7, mid-leaf cells (×280); 8, capsule (×7). 9–12, P. demissum: 9, 10, leaves from sterile and fertile stems (×25); 11, mid-leaf cells (×280); 12, capsule (×7).

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30 Bryaceae

dry, concave, broadly ovate, acute to obtuse or rounded and apiculate, margins erect, entire, unbordered; costa reddish, ending in or below apex; cells lax, thinwalled, elongate-hexagonal, 14–24 μm wide in mid-leaf, 2–3 marginal rows narrower but not forming border. Setae curved, 6–10 mm long; capsules ± horizontal, ellipsoid, slightly gibbous, mouth oblique, neck 1–2 times length of body of capsule; spores not adhering in tetrads at maturity, 34–40 μm. Capsules frequent, autumn. n = 10∗ . In damp shaded rock crevices on cliffs and in ravines in montane habitats and on soil in gullies in ravines. (0−)300–1205 m. Occasional to frequent in Wales, the Pennines and the Scottish Highlands, extending north to Orkney, rare in Ireland. 57, H9. GB200 + 19∗ , IR10 + 3∗ . Circumpolar Boreo-arctic Montane. N., W. and C. Europe, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, China, N. Africa, N. America, Greenland. Readily recognised by the silvery or whitish tufts which are reddish below and, when fertile, by the ± horizontal asymmetrical long-necked capsules. The reddish tinged older parts distinguish the plant from Anomobryum julaceum and Bryum argenteum. P. demissum differs in the narrower leaves with excurrent costa, the ± pendulous capsules, the spores adhering in tetrads and the reddish brown coloration of the tufts.

¨ 2 P. demissum (Hook.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 172) Reddish brown tufts, to 0.5 cm high. Shoots hardly julaceous. Leaves ± erect when moist, slightly concave, lanceolate to ovate-lanceolate, acuminate, margins plane or recurved, entire, unbordered; costa reddish, excurrent in upper leaves; cells narrowly hexagonal to rectangular, walls slightly thickened, 18–22 μm wide in mid-leaf, 2–3 marginal rows narrower but not forming border. Setae cygneous; capsules ± pendulous, gibbous, mouth oblique, neck about same length as body of capsule; spores c. 40 μm, adhering in tetrads. Capsules frequent, summer. On damp calcareous rock outcrops and in rock crevices. 760–1150 m. Very rare, Mid Perth, E. Perth (old record), Angus, Argyll. 4. GB5 + 3∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, C. Asia, N. America, Greenland. This species is considered endangered in the Red List of British Mosses.

104 ANOMOBRYUM SCHIMP., SYN. MUSC. EUR., 1860 Shoots julaceous. Leaves concave, ± imbricate, obtuse to acute, margins plane, entire, unbordered; costa ending well below apex to excurrent; basal cells ± rectangular, cells above narrowly hexagonal to vermicular. Setae long; capsules ± horizontal to pendulous, pyriform or narrowly pyriform with neck about

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length of capsule body; cilia appendiculate. A world-wide genus of c. 65 species.

Derivation: meaning diverging from Bryum.

1 A. julaceum (Schrad. ex Gaertn. et al.) Schimp., Syn. Musc. Eur., 1860 A. filiforme (Dicks.) Husn., A. juliforme Solms-Laub., Bryum filiforme Dicks., Pohlia filiformis (Dicks.) A. L. Andrews Dioicous. Pale green or yellowish green tufts, patches or scattered plants, pale brown below, shoots slender, julaceous or not, 1–5(−10 cm long. Leaves imbricate when moist, scarcely altered when dry, concave or slightly concave, ovate to lanceolate, acute to obtuse and apiculate, margins plane, entire or obscurely toothed above; costa weak, ending in or below apex; basal cells rectangular, towards margins and above becoming narrower, linear-vermicular, 9–16 μm wide in mid-leaf. Caducous clavate axillary shoots sometimes present. Capsules inclined or pendulous, pyriform or narrowly pyriform; spore size varying from plant to plant, 10–18 μm. Shoots julaceous, leaves concave with costa extending to 1/2 –3/4 way up leaf var. julaceum Shoots hardly julaceous, leaves slightly concave, costa reaching apex var. concinnatum Var. julaceum (Fig. 172) Tufts or scattered plants. Shoots julaceous. Leaves imbricate when moist, very concave, ovate, obtuse or obtuse and apiculate; costa extending 1/2 –3/4 way up leaf; midleaf cells 10–16 μm wide. Capsules occasional, autumn. n = 10. On damp sandy or gravelly soil and in rock crevices by lakes and streams, near waterfalls, on damp rock faces, in flushes on old mine-waste and in quarries, usually in mildly basic situations. 0–950 m. Cornwall, S. Devon and frequent or common from Wales and N. W. England north to Shetland, frequent or common in W. Ireland. 65, H21. GB397 + 33∗ , IR63 + 10∗ . Circumpolar Boreal-montane. Europe, Faeroes, Iceland, Caucasus, India, China, Manchuria, Cameroon, Ethiopia, Ruwenzori, Congo, N. and C. America, Greenland, sub-antarctic islands. Var. concinnatum (Spruce) Zetterst., Kongl. Svenska Vetensk. Akad. Handl., 1865 (Fig. 172) A. concinnatum (Spruce) Lindb. Shoots very slender, scarcely julaceous. Leaves erect but hardly imbricate when moist, slightly concave, ovate to lanceolate, acute; costa reaching apex or nearly so; cells ± narrowly hexagonal, 9–12 μm in mid-leaf. Sporophytes unknown. n = 10. On dry exposed basic rocks and cliffs, crevices of damp slate and damp montane rock faces. 380–1100 m. Rare in montane habitats from Brecon north to Harris, very rare in Ireland. 32, H8. GB49 + 6∗ , IR8. Circumpolar Boreal-montane. Montane

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30 Bryaceae

and northern Europe north to Norway, Sweden and Finland, Iceland, Caucasus, Turkey, N., C. and E. Asia, Macaronesia, India, Japan, N. America, Greenland. Var. concinnatum is a poorly defined taxon regarded by some authorities as no more than a habitat form.

105 BRYUM HEDW., SP. MUSC. FROND., 1801 Dioicous, autoicous or synoicous. Plants usually densely tufted, stems innovating from below inflorescences. Leaves usually ovate or lanceolate; margins plane to revolute, entire or denticulate, rarely dentate above; costa ending below apex to longly excurrent; cells ± rhomboid-hexagonal, rarely narrower, 1–several marginal rows often narrow, forming obscure to well defined 1–3–stratose border. Axillary bulbils or gemmae and/or rhizoidal gemmae sometimes present. Setae long; capsules horizontal to pendulous, broadly pyriform to subcylindrical; lid conical to mamillate; peristome double, exostome of 16 entire or occasionally perforated teeth with numerous thickened transverse articulations, endostome with thin basal membrane c. 1/3 –1/2 height of peristome, with 16 perforated processes alternating with exostome teeth, 0–4 rudimentary, simple, nodulose or appendiculate cilia between processes; calyptrae small, cucullate, fugacious. A very large taxonomically difficult cosmopolitan genus of c. 1050 mainly terricolous or saxicolous species. Derivation: from the Ancient Greek name bryon (meaning moss) of some now unknown cryptogamic plant. The classification used here follows Nyholm (1993). For a discussion of the taxonomy of Bryum and related genera see J. R. Spence, J. Bryol. 14, 659–76, 1987; however, DNA studies have led to a reappraisal of the relationships of the genera within the Bryaceae, hence the marked changes from the first edition of this book.

Notes on the identification of Bryum species The key below is intended only as a guide to identification. Careful comparison of plants with descriptions should be made before naming. Some species of Bryum are very variable morphologically but the key caters only for ‘typical’ specimens; some species hybridise readily and it has to be accepted that not all gatherings can be named. For determining the sex of plants gametangia may be found within enlarged comal tufts of leaves. With dioicous or autoicous species, if mature inflorescences are present there is no problem. With synoicous species in which sporophytes are already developing it may be difficult; however, antheridia may be sought at the base of developing sporophytes, although in such situations old antheridia may readily be lost. The endostome is best observed by placing a

105 Bryum

533

ripe or dehisced capsule in a small drop of water1 on a slide, cutting the top of the capsule longitudinally and then transversely below the mouth. This will provide two halves of the capsule mouth, which may be flattened out under a cover slip. Care should be taken not to confuse split processes (endostome teeth) with cilia, which are easily visible although fragile in species that possess them. Species with appendiculate or nodulose cilia have small spores, 7–20(–26) μm, whereas those without or with rudimentary or simple cilia have larger spores, (16−)20–45 μm. 1 Leaf apices hyaline, shoots silvery white when dry, julaceous when moist 34. B. argenteum Leaf apices not hyaline, shoots of various colours when dry but not silvery, rarely julaceous when moist 2 2 Leaves spirally twisted around stems and with flexuose hair-points when dry, widest above the middle, brown to deep reddish brown rhizoidal gemmae usually present 14. B. capillare Plants lacking above combination of characters 3 3 Plants glossy, often reddish, to 10 cm high, stems matted below with brown tomentum, costa stout, percurrent to shortly excurrent 51 Plants lacking above combination of characters 4 4 Bulbils or ± spherical gemmae present in axils of upper leaves of sterile shoots 5 Axillary bulbils or gemmae lacking (although filiform axillary propagules may be present) 7 5 Plants with axillary bulbils 6 Plants with ± spherical axillary gemmae 56 6 Leaves ovate-lanceolate to lanceolate, costa 75–100 μm wide near base, mid-leaf cells narrowly rhomboidal 52. B. gemmiparum Leaves ovate to ovate-lanceolate, costa usually not more than 70 μm wide near base, mid-leaf cells narrowly hexagonal 53 7 At least lower leaves with obtuse or rounded apices, apiculate or not or if acute then plants pinkish and leaf bases longly decurrent 8 Leaves acute to acuminate, bases not or hardly decurrent 14 8 Plants robust, to 12 cm high, pinkish, leaf bases longly decurrent 11. B. weigelii Plants robust or not, if pinkish then leaf bases not decurrent 9 9 Leaves with distinct border 10 Leaves unbordered or border ill-defined 11 10 Synoicous, plants bud-like, c. 0.5 cm high, leaves crowded 6. B. lawersianum

1

Adding a little liquid detergent to the water will greatly facilitate the wetting of the material.

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22 23

24

30 Bryaceae Dioicous, plants not bud-like, 1–10 cm high, leaves ± distant 31. B neodamense Leaves not shrunken when dry, bases reddish 51. B. muehlenbeckii Leaves shrunken when dry, bases not reddish 12 Dioicous, leaves distant, obovate to orbicular, filamentous axillary gemmae sometimes present 12. B. cyclophyllum Autoicous, leaves crowded, ovate, gemmae absent 13 Capsules ± as long as wide, leaf margins ± plane, very obscurely bordered, mid-leaf cells mostly 60–80 μm long 1. B. marratii Capsules longer than wide, margins of upper leaves recurved, bordered, mid-leaf cells mostly 40–60 μm long 4. B. calophyllum Leaves unbordered, cells very long and narrow, 8–12 × 60–80(–112) μm in mid-leaf, plants with metallic sheen, often purplish red 53. B. alpinum Leaves bordered or not, mid-leaf cells shorter and wider, plants lacking metallic sheen 15 Leaves broadly ovate, strongly concave, margins plane 16 Leaves narrower, concave or not, margins plane or recurved 17 Leaves erect-patent when moist, mid-leaf cells 20–40(–60) μm wide 10. B. schleicheri var. latifolium Leaves imbricate when moist, mid-leaf cells 12–16 μm wide 33. B. funkii Basal cells of leaves of similar colour to cells above 18 Basal cells of leaves reddish, differing in colour from cells above at least in older leaves 20 Plants dull green, leaves not pink-tinged, margins obscurely bordered, strongly recurved, costa longly excurrent, mid-leaf cells 12–16 μm wide 32. B caespiticium Plants lacking above combination of characters 19 Dioicous, plants usually pink to vinous red, leaf margins recurved, border strong, bistratose 8. B. pallens Plants lacking above combination of characters 34 Leaves usually widest at or above middle 21 Leaves widest below middle 28 Leaf border very stout, 2–3-stratose, confluent with stout shortly excurrent costa 13. B. donianum Border if present not confluent with excurrent costa 22 Plants with filamentous axillary gemmae 23 Filamentous axillary gemmae lacking 24 Axillary gemmae finely papillose, leaf margins plane or slightly recurved, lowland epiphyte 17. B. laevifilum Axillary gemmae coarsely papillose, leaf margins strongly recurved, upland epilith 18. B. subelegans Leaf margins unbordered, dentate above 20. B. canariense Leaves with poorly to well developed border, entire or denticulate above 25

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25 Shoots julaceous when moist, rhizoids coarsely papillose 15. B. elegans Shoots not julaceous when moist, rhizoids finely papillose 26 26 Plants dioicous, leaf cells porose, rhizoidal gemmae lacking 16. B. stirtonii Plants dioicous or synoicous, leaf cells not porose, rhizoidal gemmae often present 27 27 Plants dioicous, leaves strongly spirally twisted round stems when dry, rhizoidal gemmae brown or dark reddish brown 14. B. capillare Plants usually synoicous, leaves not or hardly spirally twisted round stems when dry, rhizoidal gemmae red 19. B. torquescens 28 Leaf margins plane, unbordered 35. B. dixonii Leaf margins recurved at least below and/or bordered 29 29 Leaf margins unbordered, mid-leaf cells 20–24 μm wide, rhizoidal gemmae lacking 51. B. muehlenbeckii Leaf margins bordered or if unbordered then cells 10–16 μm wide and rhizoidal gemmae present 30 30 Rhizoidal gemmae present 31 Rhizoidal gemmae lacking 32 31 Gemmae flattish, lobed 49. B. riparium Gemmae spherical or pyriform, not lobed but cells sometimes protuberant 58 32 Upper leaves scarcely larger or more crowded than lower 33 Upper leaves larger and more crowded than lower, forming comal tufts 34 33 Plants 0.5–1.5 cm high, leaves obscurely bordered, mid-leaf cells 8–16 μm wide 50. B. mildeanum Plants 1–10 cm high, leaves distinctly bordered, mid-leaf cells mostly 12–24 μm wide 49 34 Exostome teeth with obvious vertical and/or oblique lines joining transverse articulations 35 Oblique or vertical lines absent or very obscure 36 35 Cells at leaf base reddish, spores 22–36 μm, mouth of ripe capsules red 21. B. algovicum var. rutheanum Cells at leaf base of similar colour to cells above, spores 28–45 μm, mouth of ripe capsules yellow to orange 3. B warneum 36 Endostome cilia simple, rudimentary or absent, spores (16−) 20–42 μm 37 Cilia appendiculate or nodulose, spores 8–20(−24) μm 44 37 Cells at leaf base not differing in colour from cells above 38 Basal cells reddish 41 38 Plants dioicous, usually pink to vinous red 8. B. pallens Plants autoicous or synoicous, colour various 39 39 Spores 36–42 μm 2. B. mamillatum Spores 20–30 μm 40 40 Plants deep red, leaf border partially bistratose, capsules symmetrical 5. B. arcticum

536

41 42

43

44

45

46 47

48

49

50

51

52

30 Bryaceae Plants greenish, border 2 or more stratose, capsule mouth oblique 7. B. uliginosum Border weak, costa ending below apex or percurrent 22. B. knowltonii Border well developed, costa excurrent 42 Exostome teeth frequently perforated near base, exothecial cells near mouth mostly 30–40 μm wide 24. B. salinum Exostome teeth not perforated near base, exothecial cells near capsule mouth mostly 20–25 μm wide 43 Spores densely papillose, blackish, process perforations narrow 23. B. archangelicum Spores finely papillose, pale, processes with wide gaping perforations 25. B. imbricatum Basal cells of leaves of similar colour to cells above, border well developed, mid-leaf cells 15–30 μm wide 45 Basal cells of leaves reddish at least in older leaves or if not then border poorly developed and mid-leaf cells 12–16 μm wide 46 Capsules not turbinate when dry and empty, leaf margins recurved 8. B. pallens Capsules turbinate when dry and empty, leaf margins plane 9. B. turbinatum Plants dioicous 47 Plants autoicous or synoicous 49 Upper leaves larger and more crowded than lower, forming distinct comal tufts 32. B. caespiticium Upper leaves scarcely more crowded or larger than lower, not forming comal tufts 48 Plants robust, 1–15 cm high, mid-leaf cells mostly 12–25 μm wide, rhizoidal gemmae lacking 51 Plants to 1.5 cm high, mid-leaf cells 10–20 μm wide, rhizoidal gemmae present 56 Leaf border poorly developed, capsule mouth oblique, cilia nodulose, spores 18–24 μm 26. B. intermedium Border well developed, mouth oblique or not, cilia appendiculate, spores 12–20(–22) μm 50 Upper leaves hardly forming comal tufts, costa only slightly excurrent, processes with perforations about as wide as long 51 Upper leaves crowded into comal tufts, costa markedly excurrent or if only shortly excurrent then process perforations 1–2 times as long as wide 52 Plants dioicous, mid-leaf cells mostly 20–24 μm wide spores usually 12–18 μm 29. B. pseudotriquetrum Plants synoicous, mid-leaf cells mostly 12–16 μm wide, spores 15–25 μm 30. B. bimum Spores 14–16 μm, process perforations about as long as wide, plants synoicous 27. B. creberrimum

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Spores 18–20(–22) μm, process perforations 1–2 times as long as wide, plants synoicous or autoicous 28. B. pallescens Bryum dichotomum complex 53 Shoot tips julaceous with imbricate concave leaves, at least some leaves with enlarged or inflated alar cells forming shortly decurrent auricles (which may be left on stem when leaves are removed), bulbils one per axil, brownish below 39. B. dyffrynense Shoot tips not julaceous, alar cells not forming auricles, bulbils if only one per axil greenish 54 54 Bulbils orange or reddish, (5−)20–30 per axil in upper leaves, 100–160 (−200) μm long with distinct leaf primordia 36. B. gemmiferum Bulbils green or yellowish, not more than 5 per axil, 100–480 μm long with or without distinct leaf primordia 55 55 Bulbils yellowish, leaf primordia rudimentary or indistinguishable 37. B. gemmilucens Bulbils green, very rarely yellowish green, leaf primordia 1/4 –1/2 total length of bulbils 38. B. dichotomum Bryum erythrocarpum complex 56 Rhizoidal gemmae mostly less than 100 μm long or in diameter 57 Rhizoidal gemmae more than 120 μm diameter 59 57 Gemmae brown or reddish brown, pyriform, about twice as long as wide, 3–5 cells long, 2 cells wide 44. B. sauteri Gemmae reddish, ± spherical, at least 3 cells wide 58 58 Rhizoids dull mauve to bright violet, cells of gemmae not protuberant 42. B. violaceum Rhizoids pale brown, gemmae with protuberant cells 43. B. klinggraeffii 59 Rhizoids usually deep violet 41. B. ruderale Rhizoids paler, not violet 60 60 Leaves not or scarcely bordered, mid-leaf cells 10–16 μm wide 61 Leaves distinctly bordered, cells 14–20 μm wide 63 61 Costa strong, longly excurrent, basal cells ± quadrate, rhizoids densely papillose, gemmae usually brownish, not contrasting in colour with brownish rhizoids, calcicole plant 40. B. radiculosum Costa less strong, shortly excurrent, basal cells ± quadrate (except sometimes in lower leaves), rhizoids papillose but not densely so, gemmae red or yellowish, contrasting with brownish rhizoids, plants calcicole or not 63 62 Gemmae yellowish, seldom more than 180 μm diameter 45. B. tenuisetum Gemmae red, frequently more than 200 μm diameter 46. B. subapiculatum 63 Gemmae never axillary, translucent in transmitted light, cells (30−) 45–60 μm diameter, not protuberant, calcifuge plant 47. B. bornholmense

538

30 Bryaceae Gemmae often axillary, opaque in transmitted light, cells 30–35(–40) μm diameter, strongly protuberant, plant of slightly acidic to highly basic habitats 48. B. rubenss

Section 1 Amblyophyllum Mull. ¨ Hal., Syn. Musc. Frond., 1848 Leaves bordered or not; cells of uniform colour throughout, basal cells with redpigmented cell sap, cells above usually thin-walled, 15–40 μm wide in mid-leaf, marginal cells usually narrow, elongate, partially bistratose. Cilia absent to long and appendiculate; spores 20–40 μm. 1 B. marratii Wilson, Bryol. Brit., 1855 (Fig. 173) Autoicous. Green patches, 2–5 mm high. Lower leaves distant, upper more crowded, shrunken when dry, spreading when moist, very concave, ovate, obtuse, not reddish at base; margins unbordered in lower leaves, obscurely bordered in upper, plane or narrowly recurved below, entire or obscurely denticulate above; costa yellowish to brown, ending below apex; basal cells rectangular, cells above irregularly rectangular to rhomboid-hexagonal, 16–26 × 60–80(−90) μm in mid-leaf, 2–3 rows in upper leaves narrower forming very ill-defined unistratose border. Setae very slender; capsules pendulous, broadly pyriform, hardly longer than wide, neck short, abruptly narrowed into seta, mouth small, orange; lid mamillate with obtuse beak; exostome and endostome partially fused, outer teeth reddish below, yellow above, processes coarsely papillose, narrowly perforated, cilia rudimentary; spores 26–32 μm. Capsules occasional, summer, autumn. In damp, usually calcareous dune-slacks and on sandy and muddy ground by the sea. Lowland. Rare, west coast from Cardigan north to Kintyre and W. Sutherland and east coast from N. Lincoln to Caithness, S. Kerry, W. Mayo, W. Donegal, old records from Dublin and Londonderry. 16, H5. GB8 + 12∗ , IR3 + 2∗ . European Boreal-montane. Western European coasts from northern France to Norway and the Baltic, Newfoundland, Alberta, N. Dakota. Distinctive in the strongly concave obtuse hardly bordered leaves and only likely to be confused with B. calophyllum (q.v.) with which it sometimes grows. This species is considered endangered in the Red List of British Mosses.

2 B. mamillatum Lindb. in Hartm., Handb. Skand. Fl. (6th edn.), 1864 (Fig. 173) Autoicous. Dark green tufts, to c. 0.5 cm high. Leaves appressed, twisted when dry, erect-patent when moist, ovate to lanceolate, acute to acuminate, not reddish at base; margins bordered, recurved to about 1/2 way up in upper leaves, obscurely denticulate towards apex; costa brownish, ending below apex in lower leaves, excurrent in upper; basal cells rectangular, cells above shortly rectangular or rhomboid-hexagonal, 12–20(–30) μm wide in mid-leaf, 2–3 marginal rows narrow, forming distinct bistratose border. Capsules pyriform, wide-mouthed when dry and empty, mouth reddish brown; lid convex, apiculate; outer and inner

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Fig. 173 1–3, Bryum marratii: 1, leaves (×25); 2, mid-leaf cells: 3, capsule. 4–6, B. mamillatum: 4, leaf (×17.5); 5, mid-leaf cells; 6, capsule. 7–10, B. warneum: 7, leaves (×25); 8, mid-leaf cells; 9, capsule; 10, lower part of exostome tooth (×175). 11–13, B. calophyllum: 11, leaves (×25); 12, mid-leaf cells; 13, capsule. Cells ×280, capsules ×10.

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peristomes partly fused, outer teeth incurved when dry, yellowish, papillose, occasional vertical lines joining lower articulations processes narrowly perforated, cilia rudimentary or absent; spores 36–42 μm. Capsules common, early summer. In dune slacks and on sandy soil by the sea. Lowland. Very rare, N. Lincoln, old records from W. Norfolk and S. Lancashire. 3. GB1 + 4∗ . European Boreal-montane. Baltic coast, Svalbard, Austria (?), Switzerland (?), Greenland. The large spores are characteristic, but large spores mixed with smaller and aborted spores do occur in abnormal capsules of other species. Intermediate between B. marratii and B. warneum, distinct in capsule and leaf shape from the former; for differences from B. warneum see under that species. B. mamillatum cannot be determined without mature capsules. This species is regarded as critically endangered in the Red List of British mosses and is a protected species under the Wildlife and Countryside Act.

¨ 3 B. warneum (Rohl.) Brid., Bryol. Univ., 1826 (Fig. 173) Autoicous. Greenish patches, 0.5–1.0 cm high. Leaves ± spaced on stems, erect, flexuose when dry, lower spreading, upper erect-patent when moist, ovate to ovate-lanceolate, acuminate, not reddish at base; margins bordered, recurved, entire or denticulate towards apex; costa stout, reddish to brown, ending in apex to excurrent in short point; basal cells rectangular, cells above shortly rectangular to rhomboid-hexagonal, 18–30 μm wide in mid-leaf, 2–3 marginal rows narrower, more incrassate, forming distinct partially bistratose border. Capsules pendulous, pyriform, about twice as long as wide, neck gradually tapering into seta, mouth small, yellow to orange; lid conical; inner and outer peristome partially fused, outer teeth with vertical and oblique lines joining transverse articulations, processes narrowly perforated, cilia rudimentary or absent; spores 25–45 μm. Capsules occasional, late summer, autumn. n = 15∗ . In dune slacks and on damp sand near the sea, very rarely inland in gravel pits. Lowland. Rare but sometimes locally frequent, on the west coast from N. Devon north to W. Ross and on the east coast from E. Kent north to Moray. Dublin (old record). 22, H1. GB16 + 20∗ , IR2∗ . European Boreal-montane. European coasts from northern France to Norway, rare in C. and E. Europe, Himalayas, Altai, Quebec. Sometimes occurring with B. marratii and/or B. calophyllimm from which it differs in leaf shape. B. mamillatum has capsules with wider mouths and peristome teeth lacking oblique or vertical lines, although it does have occasional oblique lines joining the transverse articulations but these are not at all obvious. B. algovicum, which often occurs on sand-dunes, has larger capsules and smaller spores and leaves with more longly excurrent costae. This species cannot be determined without mature capsules. This species is treated as vulnerable in the Red List of British Mosses.

4 B. calophyllum R. Br., Suppl. App. Perry’s Voy., 1823 (Fig. 173) Autoicous. Pale green or dull green tufts, to 1.5 cm high. Leaves shrunken and imbricate when dry, erect-patent to spreading when moist, comal leaves larger,

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more crowded, concave, ovate to broadly ovate, obtuse or obtuse and apiculate, not reddish at base; margins in lower leaves unbordered, plane, in upper leaves bordered and narrowly recurved, obscurely denticulate above; costa yellowish or brown, ending in or below apex; basal cells rectangular, cells above rhomboidhexagonal or hexagonal, 16–30 × 40–60(–80) μm in mid-leaf, 0–2 marginal rows narrower, more incrassate, forming poorly to well defined bistratose border. Capsules pendulous, elliptical to narrowly obovoid, mouth yellowish orange; lid bluntly mamillate; exostome teeth with occasional perforations along median line, processes narrowly perforated, cilia rudimentary; spores 26–40 μm. Capsules common, winter. n = 40. In dune slacks, gravel pits and on damp sand near the sea. Lowland. Rare along west coast from N. Devon to Westmorland, W. Ross, east coast from N. E. Yorkshire to Caithness, Cheshire, W. Mayo. 16, H1. GB10 + 11∗ , IR1. Circumpolar Boreo-arctic Montane. European coast from the Netherlands to Svalbard, Iceland, Romania, Siberia, C. Asia, Tibet, N. America, Greenland. Most likely to be confused with B. marratii or B. cyclophyllum. The latter differs in habitat and has broader and less concave leaves. The former differs in capsule shape. Sterile material of B. calophyllum differs from that of B. marratii in the upper leaves wider with narrowly recurved margins with a ± distinct border. Depauperate specimens may be difficult to separate but the leaf cells of B. calophyllum are shorter in relation to their width than in B. marratii. This species is treated as vulnerable in the Red List of British Mosses.

5 B. arcticum (R. Br.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 174) Synoicous. Small deep red tufts or patches, to 0.5 cm high. Upper leaves in comal tufts, appressed, flexuose when dry, erect-patent or patent when moist, very concave, ovate-lanceolate, acuminate, of ± uniform colour throughout; margins bordered, recurved, entire or obscurely denticulate above; costa reddish, shortly excurrent; basal cells rectangular, cells above shortly rectangular, 20–32 μm wide in mid-leaf, 2–3 marginal rows very narrow, forming distinct bistratose border. Capsules cernuous or pendulous, pyriform, slightly asymmetrical, abruptly narrowed into neck, mouth small; exothecial cells thin-walled; lid shortly conical; a few oblique lines joining transverse articulations on inside surface of lower part of exostome teeth, processes with narrow perforations, cilia rudimentary; spores pale, 20–28 μm. Capsules common, summer. n = 20. On basic soil among rocks. 700–1000 m. Very rare, Mid and E. Perth, Angus, S. Aberdeen, Skye. 4. GB5 + 2∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Iceland, Siberia, Altai, Tibet, Korea, N. America, Greenland. B. arcticum can be determined only when mature capsules are present. The lines joining the articulations of the exostome teeth are faint and difficult to detect in British material. The plant is best recognised by its small stature and deep red coloration; it is only likely to

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Fig. 174 1–4, Bryum arcticum: 1, leaf; 2, mid-leaf cells; 3, capsule; 4, lower part of exostome tooth. 5–7, B. uliginosum: 5, leaf; 6, mid-leaf cells; 7, capsule. 8–12, B. pallens: 8, leaves; 9, mid-leaf cells; 10, capsule; 11, lower part of exostome tooth; 12, 13, lower part of endostome from different plants. Leaves ×25, cells ×280, peristomes ×175.

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be mistaken for small forms of B. pallens, which usually differ in their pink colour, dioicous inflorescence and usually larger size. B. purpurascens (R. Br.) Bruch & Schimp. was recorded from crevices of limestone rocks near Litton, Yorkshire, by J. Whitehead in 1879. According to Braithwaite (1884–1895) the gathering ‘quite agrees with Norwegian specimens’. However, the record must be disregarded in the absence of specimens and the low altitude of the habitat, B. purpurascens being an arctic–alpine species.

6 B. lawersianum H. Philib., Rev. Bryol., 1890 B. pallens ssp. lawersianum (H. Philib.) Podp.

(Fig. 176)

Synoicous. Plants bud-like, in dull green patches, lacking any reddish coloration, c. 5 mm high. Leaves imbricate when moist, lower ovate, obtuse, comal much larger, broadly ovate or suborbicular, obtuse, innermost narrower, acute, not reddish at base; margins bordered, recurved below, with 1–2 obscure teeth towards apex; costa stout, orange-red, shortly excurrent; basal cells rectangular, cells above irregularly narrowly hexagonal, 20–35 μm wide in mid-leaf, 2–3 marginal rows very narrow, forming distinct bistratose border. Setae c. 2.5 cm long; capsules ± pendulous, narrowly pyriform with long neck about as long as body of capsule; lid obtusely mamillate; endostome without cilia; spores finely papillose, 26–32 μm. Capsules common, summer. On damp micaceous soil at c. 1070 m. Very rare, Ben Lawers, Mid Perth. 1. GB1∗ . Endemic (Suboceanic Boreal-montane). B. lawersianum is very distinctive in the bud-like plants with very broad leaves. It seems to be a good species and is probably related to B. arcticum and B. pallens. According to Dixon & Jameson (1924) the leaf bases are reddish, but this is incorrect. The original gathering was by W. E. Nicholson, R. S. Salmon and H. N. Dixon from Ben Lawers on 27 July 1899 and the above description is based upon this specimen. The species was again seen in 1912 and 1924. Listed as extinct in both the Red List of British mosses and the Red Data Book of European Bryophytes.

7 B. uliginosum (Brid.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1839 (Fig. 174) B. cernuum (Hedw.) Lindb. Autoicous. Greenish patches, to 3 cm high. Leaves erect, slightly twisted when dry, erect-patent when moist, lower distant, ovate, acute, upper closer, lanceolate to narrowly lanceolate, acuminate, bases slightly decurrent, not reddish; margins strongly bordered, recurved, entire; costa reddish brown, percurrent or slightly excurrent; basal cells shortly rectangular, cells above rectangular to rhomboidhexagonal, (10−)16–30(–40) μm wide in mid-leaf, 2–3 marginal rows narrow, very incrassate, forming strong 2–3-stratose border. Capsules cernuous or occasionally pendulous, narrowly ellipsoid, asymmetrical, mouth oblique, light brown, neck distinct, abruptly or gradually tapering into seta; lid mamillate, processes

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finely papillose, with ± shortly rectangular perforations, cilia short; spores 22– 30 μm. Capsules frequent, autumn. n = 10. On sheltered slightly basic damp soil by streams and in dune-slacks. Lowland. Always rare and now apparently extremely so, recorded from scattered localities from Berkshire, Oxford, Worcester and N. Wales north to Caithness, scattered localities in Ireland but seen recently only in N. W. Yorkshire, Dumfries and Roscommon. 23, H9. GB2 + 47∗ , IR1 + 8∗ . Circumpolar Boreal-montane. Europe north to southern Scandinavia, Faeroes, eastern Siberia, Himalayas, N. America, Greenland. This species has decreased very markedly in the British isles over the past 100 years but the reasons for this are not known. It can only be identified with mature capsules and has been confused with B. imbricatum, B. intermedium and B. pallens. It differs from all these species in the autoicous inflorescence, from the first two in the leaf bases not reddish and from the latter in the very stout border and simple cilia. This is a critically endangered species in the Red List of British Mosses.

8 B. pallens Sw., Monthly Rev., 1801 B. pallens var. fallax Jur.

(Fig. 174)

Dioicous. Pink, vinous red, rarely brownish or green patches, tufts or scattered plants, to 6 cm high. Leaves more crowded above than below, successive comal tufts sometimes present, ± erect, rigid, flexuose or slightly curved when dry, erectpatent to spreading when moist, lanceolate to ovate, acute, bases shortly decurrent, of similar colour to rest of leaf; margins bordered, recurved, entire or denticulate towards apex; costa stout, deep pink to brownish, ending below apex to excurrent in short point; cells lax, basal rectangular, cells above variable, incrassate or not, rectangular to narrowly hexagonal, 15–30 μm wide in mid-leaf, several marginal rows narrow, very incrassate, forming distinct bistratose border ending at or below apex. Green filamentous axillary gemmae occasionally present. Capsules cernuous or pendulous, narrowly pyriform, ± straight or curved, slightly asymmetrical, neck tapering into seta; outer and inner peristomes rarely adherent below, processes with widely gaping perforations, cilia usually well developed, rarely rudimentary or absent; spores 16–26 μm, often variable in size within a capsule. Capsules rare, summer, autumn. n = 10∗ . On damp acidic to basic soil in turf, by roadsides, streams, rivers, on woodland rides, in fields, flushes and old quarries. 0–1180 m. Occasional to frequent in lowland England, common elsewhere, frequent in Ireland. 110, H35. GB1009 + 135∗ , IR154 + 6∗ . Circumpolar Wide-boreal. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Asia south to Iran, Nepal, China, Japan, Tenerife, N. Africa, Rwanda, N. America, Greenland, Ecuador, Peru, Tierra del Fuego. B. pallens is exceedingly variable but the pinkish or reddish concolorous leaves will distinguish it from most other British Bryum species. B. alpinum differs in leaf shape, areolation and lack of border; B. pseudotriquetrum differs in the leaf bases markedly reddish and the unistratose border; B. arcticum has processes with narrow perforations, rudimentary cilia

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Fig. 175 1–4, Bryum turbinatum: 1, leaf (×25); 2, mid-leaf cells; 3, 4, mature and dry empty capsules (×20). 5–6, B. weigelii: 5, leaf (×18); 6, mid-leaf cells. 7–8, B. cyclophyllum: 7, leaf (×18); 8, marginal cells at middle of leaf. 9–10, B. schleicheri var. latifolium: 9, leaf, (×15), 10, mid-leaf cells. Cells ×280. and a synoicous inflorescence. E. Demaret (Bull. Jard. Bot. Nat. Belg. 56, 205–13, 1986) has shown that B. pallens var. fallax Jur. cannot be distinguished from the type.

9 B. turbinatum (Hedw.) Turner, Muscol. Hibern. Spic., 1804 (Fig. 175) Dioicous. Green to pinkish patches, 1–3 cm high. Leaves erect, slightly twisted when dry, erect-patent when moist, ovate to ovate-lanceolate or narrowly triangular, acuminate, bases slightly decurrent, not reddish; margins weakly bordered, plane, obscurely toothed above; costa strong, reddish brown, ending

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below apex or percurrent; basal cells shortly rectangular, cells above rectangular to rhomboid-hexagonal, 16–24(–30) μm wide in mid-leaf, 2–3 marginal rows narrower, more incrassate, forming poorly defined 1–2-stratose border. Capsules pendulous, broadly pyriform, hardly longer than wide, mouth small, when dry markedly contracted below mouth both before and after dehiscence, turbinate when dry and empty; lid mamillate; processes widely perforated, cilia appendiculate; spores 16–20 μm. Capsules frequent, spring, early summer. n = 10, 10 + m. On damp basic soil and in dune-slacks. Lowland. Formerly rare, seen only three times between 1930 and 1947 and now apparently extinct; recorded from W. Sussex, Oxford, Monmouth, Stafford, Merioneth, S. Lancashire, S. Northumberland, E. Inverness, Rum, W. Mayo. 9. H1. GB16∗ , IR1∗ . Eurasian Boreal-montane. Europe north to Fennoscandia, Caucasus, Turkey, C. and E. Asia, Africa, Ecuador, Peru, Chile, Argentina. ¨ ¨ 10 B. schleicheri Schwagr. var. latifolium (Schwagr.) Schimp., Syn. Musc. Eur. (ed. 2), 1876. (Fig. 175) ¨ B. turbinatum var. latifolium (Schwagr.) Bruch & Schimp. Dioicous. Tumid yellowish green sometimes copper-tinged rafts, 5–10 cm high. Leaves crowded, appressed when dry, erect-patent when moist, very concave and frequently cucullate, broadly ovate, acute, sometimes apiculate, base neither reddish nor decurrent; margins bordered, plane or incurved below, denticulate above; costa relatively thin, ending below apex or excurrent in short reflexed apiculus; cells lax, at extreme base ± quadrate, becoming rectangular or rhomboidal then rhomboidal or rhomboid-hexagonal above, gradually increasing in size towards apex, 20–40(–60) μm wide in mid-leaf, several marginal rows narrow, forming distinct 1–2-stratose border. Capsules similar to those of B. turbunatum, unknown in Britain. In montane flushes. 300 m. Very rare, now known only from Stirling but previously recorded from several sites in Mid Perth. 2. GB1 + 5∗ . Circumpolar Boreal-montane. Central Europe. According to A. C. Crundwell (in Hill et al., 1994) known from Central Europe but the distribution elsewhere is uncertain because of confusion with var. schleicheri and B. turbinatum, the taxonomy of these requiring further investigation. Treated by Dixon & Jameson (1924) as a variety of B. turbinatum and said to be linked by intermediates, but the specimens they quote appear on morphological grounds to be unrelated either to B. turbinatum or to B. schleicheri but seem to be forms of or hybrid derivatives of B. pseudotriquetrum. This species is regarded as critically endangered in the Red List of British Mosses and is a protected species under the Wildlife and Countryside Act.

11 B. weigelii Spreng., Mant. Prim. Fl. Hal., 1807 B. duvalii Voit

(Fig. 175)

Dioicous. Pink or greenish pink patches, to 12 cm high. Leaves distant, ± uniformly spaced, shrunken when dry, patent when moist, pinkish throughout, ovate,

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obtuse to acute or acuminate, base longly decurrent; margins bordered, plane or narrowly recurved below, entire or obscurely toothed above; costa deep pink, ending below apex to shortly excurrent; basal cells rectangular, cells above rectangular to rhomboid-hexagonal, 12–24 μm wide in mid-leaf, 2–3 marginal rows narrow, more incrassate, forming distinct border. Capsules pendulous, obovoid; unknown in the British Isles. In springs and flushes, by snow patches, streams and pool-sides. 230–1070 m. Shropshire, Caernarfon, occasional in the Lake District and Scottish Highlands, north to Orkney, Waterford (old record). 31, H1. GB62 + 21∗ , IR1∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Siberia, E. Asia, Japan, Azores, N. America. Only likely to be confused with B. schleicheri var. latifolium, which has very concave, often cucullate leaves, the bases of which are not decurrent.

¨ 12 B. cyclophyllum (Schwagr.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1839 (Fig. 175) B. tortifolium Brid. Dioicous. Forming straggling bright green mats or patches; stems slender, often procumbent, to 8 cm long. Leaves distant, shrunken when dry, patent, soft when moist, concave, obovate or ± orbicular, apex obtuse or rounded, base slightly decurrent, not reddish; margins hardly bordered, plane, entire; costa relatively thin, ending below apex; basal cells rectangular, cells above shortly rectangular or rhomboid-hexagonal, 16–26 μm wide in mid-leaf, 3–4 marginal rows somewhat narrower but not forming distinct border. Filamentous axillary gemmae often present. Capsules pendulous, obovoid; not known in Britain. n = 10. On wet soil and marshy ground by streams and lakes. Lowland. Very rare, Westmorland, Cumberland, Stirling, Argyll, Dunbarton, Kintyre, W. Ross. 7. GB5 + 4∗ . Circumpolar Boreal-montane. Western and central Europe north to Fennoscandia, Siberia, Amur, Korea, Japan, Greenland. This species is considered endangered in the Red List of British Mosses.

Section 2 Capillaria Spruce, Ann. Mag. Nat. Hist., 1840 Leaves often widest above middle, reddish at base, borders distinct, usually bistratose; cells incrassate, mostly 16–30 μm wide in mid-leaf. Exostome teeth with broad hyaline border below, processes broadly perforated, cilia appendiculate; spores 10–20 μm. For an account of species 14–19 see H. Syed, J. Bryol. 7, 265–326, 1973.

13 B. donianum Grev., Trans. Linn. Soc. London, 1827 (Fig. 176) Dioicous. Dark green tufts, to 1(–2) cm high. Upper leaves forming tight comal tuft, shrunken and curved but not spirally twisted round stems when dry, ± erect-patent when moist, obovate, obovate-lanceolate or lanceolate, often widest above middle, acuminate, reddish at base, not decurrent; margins recurved,

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Fig. 176 1–3, Bryum lawersianum: 1, leaves; 2, mid-leaf cells; 3, capsule. 4–6, B. donianum: 4, leaves; 5, mid-leaf cells; 6, capsule. Leaves ×25, cells ×280, capsules ×10.

obscurely toothed above, with stout yellowish border confluent with stout excurrent costa at apex; basal cells rectangular, cells above rhomboid-hexagonal, incrassate, 14–22 μm wide in mid-leaf, 4–5 marginal rows very long and narrow, forming stout 2–3-stratose border. Capsules pendulous, narrowly pyriform, symmetrical or curved; lid mamillate; cilia appendiculate; spores 12–14 μm. Capsules rare, spring, summer. Usually on light soil in turf, on edges of paths, soil in crevices in walls, on hedge banks, often near the coast. Lowland. Occasional to frequent in southern England and south Wales, extending north to S,. Lincoln and Wigtown, rare in Ireland. 35, H9, C. GB95 + 52∗ , IR6 + 7∗ , C5. Mediterranean-Atlantic. S, and W. Europe north to the Netherlands, Turkey, Cyprus, S. E. Asia, Macaronesia, northern and southern Africa. Readily recognised by the leaves, usually widest above the middle, with a stout border confluent with the excurrent costa.

14 B. capillare Hedw., Sp. Musc. Frond., 1801 Dioicous. Dense or lax tufts, cushions or patches, green, sometimes reddish-tinged, rarely deep red or maroon, 1–5 cm high. Rhizoids brown to deep reddish brown, papillose. Leaves shrunken, twisted to strongly spirally twisted round stems and

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with flexuose points when dry, soft, ± patent and sometimes slightly curved in direction of twisting when moist, plane or concave, narrowly oblanceolate to oblong-spathulate, shortly or longly acuminate, widest above middle, reddish at base, not decurrent; margins bordered, narrowly recurved, entire or denticulate towards apex; costa usually excurrent in piliferous or cuspidate point but sometimes ending below apex, usually colourless but sometimes red or brown; cells rarely porose, basal shortly rectangular, cells above rhomboid-hexagonal, thin-walled, 12–25 μm wide in mid-leaf, marginal cells very narrow, unistratose, usually colourless but sometimes red or brown. Axillary gemmae lacking; sparse to abundant red to deep reddish brown smooth spherical rhizoidal gemmae, 66–200(–440) μm diameter, or ovoid or irregular in shape and 65–250 × 105– 350 μm, usually on long rhizoids. Capsules cernuous, cylindrical to pyriform, symmetrical, contracted below mouth when dry; spores 12–15 μm. Leaves obovate-spathulate, shortly acuminate, border of 3–5 rows of elongate cells var. capillare Leaves narrowly lanceolate or narrowly oblanceolate, longly acuminate, border of 5–7 rows of elongate cells var. rufifolium Var. capillare (Fig. 177) Dense or lax green, sometimes reddish-tinged, rarely deep red or maroon tufts, patches or hemispherical cushions. Leaves strongly spirally twisted round stems when dry, obovate-spathulate, shortly acuminate; basal cells rectangular, 16– 30 μm wide, upper cells 16–25 μm wide, 3–5 marginal rows very narrow, not usually coloured. Capsules common, spring, summer. n = 10∗ , 10 + 2m, 20. On rocks, in rock crevices, on walls, old buildings, tree trunks, branches, soil on banks, roadsides, waste ground. 0–600 m. Very common. 112, H40, C. GB2051 + 93∗ , IR325 + 5∗ , C4 + 2∗ . Circumpolar Boreo-temperate. Cosmopolitan. ´ Morav-Silez. Akad. Vˇed. Pˇrı´r., 1950 (Fig. 177) Var. rufifolium (Dixon) Podp., Prace B. rufifolium (Dixon) Demaret & R. Wilczec Green, deep red or green-red variegated tufts. Leaves shrunken or twisted, sometimes loosely or strongly spirally twisted round stems when dry, narrowly lanceolate or narrowly oblanceolate, longly acuminate but lower leaves sometimes like those of the type, border very wide; costa longly excurrent; basal cells ± rectangular, 15–17 μm wide, upper cells 12–22 μm wide, 5–7 marginal rows very narrow, strongly incrassate, forming wide border. Capsules very rare. On dry limestone rocks and in crevices. Lowland. Rare, in widely scattered localities from S. Somerset and Dorset north to Rhum and Sutherland, Clare, Roscommon, Leitrim, Fermanagh. 21, H3. Madeira(?). B. capillare is one of the most common acrocarpous mosses in the British Isles, readily recognised when dry by the leaves spirally twisted round the stems and when moist by their obovate-spathulate shape. In its typical form var. rufifolium is very distinct and is

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Fig. 177 1–8, Bryum capillare var. capillare: 1, dry shoot (×10); 2, leaves; 3, mid-leaf cells; 4, marginal cells; 5, part of rhizoid (×280); 6, capsule (×10); 7, part of endostome (×175); 8, rhizoidal gemma (×175). 9–10, B. capillare var. rufifolium: 9, leaf; 10, marginal cells. Leaves ×25, cells ×280.

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treated by some authorities as a species, but a range of intermediates between it and the type exist and it cannot be regarded as more than a variety.

15 B. elegans Nees in Brid., Bryol. Univ., 1826 B. capillare var. elegans (Nees) Husn.

(Fig. 179)

Deep reddish or green tinged with red tufts, 1–4 cm high; shoots slender, julaceous. Rhizoids brown or reddish brown, very coarsely papillose. Leaves appressed, not shrunken but sometimes loosely twisted in upper part of stems when dry, ± erect, soft when moist, concave, broadly ovate or obovate, subacute or obtuse, bases red, not decurrent; margins narrowly bordered, plane, entire; costa colourless, excurrent in mucronate to piliferous point; basal cells ± rectangular, upper narrowly hexagonal, 13–28 μm wide, walls porose, 1–3 marginal rows elongate, forming unistratose border. Axillary gemmae lacking. Brown spherical gemmae, 90–200 μm diameter, with non-protuberant cells, rarely present on long rhizoids. Capsules cernuous, subcylindrical, symmetrical, hardly contracted below mouth when dry, neck distinct, shrunken when dry; spores 12–15(–26) μm. Capsules very rare. n = 10. On basic rock, in rock crevices, on walls and in thin calcareous turf. 0–910 m. Occasional in the Pennines, very rare elsewhere, from W. Cornwall and E. Sussex north to Argyll and W. Sutherland. Sligo. 21, H1. GB24 + 7∗ , IR1. European Boreal-montane. Montane and northern Europe north to northern Scandinavia, Jan Mayen, Iceland, Caucasus, Turkey. Distinctive in the shoots julaceous when moist and the very coarsely papillose rhizoids. B stirtonii differs in the finely papillose rhizoids and the non-julaceous shoots.

16 B. stirtonii Schimp., Syn. Musc. Eur. (ed. 2), 1876 (Fig. 178) Dioicous. Dense or lax greenish tufts, 0.5–4.0 cm high. Rhizoids brown to reddish brown, finely papillose. Leaves hardly shrunken, incurved or appressed when dry, erect-patent when moist, ovate to broadly ovate, subacute, bases red, decurrent; margins indistinctly bordered, slightly recurved, entire; costa colourless, ending in or below apex or excurrent in leaves around perichaetium; cell walls porose, basal rectangular, cells above narrowly hexagonal, 15–22 μm wide, 1–2 marginal rows narrower, forming indistinct unistratose border. Axillary and rhizoidal gemmae absent. Capsules cernuous, subcylindrical, symmetrical, not contracted below mouth when dry; spores 12–14(–19) μm. Capsules rare. On basic soil, in rock crevices and springs. 500–1170 m. Very rare, N. Northumberland, Perth, Angus, S. Aberdeen. 6. GB4 + 4∗ . Circumpolar Boreal-montane. Montane and northern Europe north to Fennoscandia, Siberia, northern N. America. This species is treated as vulnerable in the Red List of British Mosses.

17 B. laevifilum Syed, J. Bryol., 1973 B. flaccidum auct. non Brid., B. subelegans auct. non Kindb.

(Fig. 178)

Dioicous. Lax soft light green tufts, 0.5–4.0 cm high. Rhizoids light brown to brown, smooth to finely papillose. Leaves not much shrunken, twisted round

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Fig. 178 1–5, Bryum laevifilum: 1, dry shoot; 2, leaves; 3, marginal cells; 4, mid-leaf cells; 5, axillary gemmae (×100). 6–9, B. stirtonii: 6, dry shoot; 7, leaves; 8, marginal cells; 9, mid-leaf cells. Leaves ×40. cells ×280.

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themselves and not or only rarely round stems, sometimes spreading when dry, erect-patent when moist, not concave, ovate-lanceolate or obovate, acute, reddish at decurrent base; margins bordered, plane or slightly recurved, entire or slightly toothed above; costa brownish or reddish, becoming narrower above, ending below apex to excurrent in hair-point; cells usually thin-walled, rarely porose, basal rectangular, upper cells narrowly hexagonal, 12–30 μm wide, 1–3 marginal rows narrower, elongate, forming unistratose border. Filamentous smooth to finely papillose gemmae, green when young, brown with age, 15–35 μm wide, of variable length, branched or not, in leaf axils. Scattered spherical brown gemmae, 65–120 μm diameter, with non-protuberant cells, on long rhizoids present. Capsules cernuous, subcylindrical, symmetrical or slightly asymmetrical, not contracted below mouth when dry, neck not shrunken when dry; spores 9–13 μm. Capsules not known in the British Isles. On tree trunks, branches and rotten wood in woodland, rarely on soil or rocks. Lowland. Frequent or common in England and Wales except for the far west, rare in eastern Scotland, extending north to Moray and E. Inverness, S. Kerry. 78, H1. GB390 + 1∗ , IR1∗ . Circumpolar Temperate. Greece, C. Europe and Spain north to Fennoscandia, Iceland, Caucasus, Turkey, Asia, N. Africa, N. America. Confused with the next species and treated as a synonym of it by some authorities but differing in being a lowland epiphyte rather than an upland epilith, in the plane or slightly recurved leaf margins and in the smooth or finely papillose filamentous axillary gemmae.

18 B. subelegans Kindb., Skand. Bladmossfl., 1903 Dioicous. Glossy pinkish to greenish brown loosely tufted plants, 1–2 cm high. Rhizoids reddish brown to brown, smooth to finely papillose, rarely coarsely papillose. Leaves loosely imbricate to erect-patent, slightly shrunken when dry, slightly more spreading when moist, slightly concave, ovate to ovate-lanceolate, acute, reddish at base, slightly decurrent, margins bordered, strongly recurved from base to near apex, entire or obscurely denticulate above; costa reddish, strong, strong leaf, percurrent to excurrent in mucro; cells thin-walled, often porose, basal rectangular, cells above rhomboid-hexagonal, 15–35 μm wide in mid-leaf, 1–2 marginal rows narrower, elongate, forming unistratose border. Filamentous coarsely papillose axillary gemmae, 15–32 μm wide, c. 180 μm long present. Rhizoidal gemmae lacking. Male plants and sporophytes unknown (British plants female). On calcareous rocks. 360–950 m. Very rare, Derby, E. Perth. 2. GB3. Very rare in Europe, France, Norway, Sweden. For a comparison of this species and B. laevifilum see N. G. Hodgetts, J. Bryol. 23, 177– 80, 2001. B. subelegans occurs in similar habitats to B. elegans and B. stirtonii, neither of which, however, has axillary gemma. B. elegans also differs in the concave ovate leaves and B. stirtonii has the leaves more longly decurrent and the margins only slightly recurved.

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19 B. torquescens Bruch ex De Not., Syllab. Musc., 1838 B. capillare var. torquescens (Bruch ex De Not.) Husn.

(Fig. 179)

Loose or dense green sometimes red-tinged tufts, 1.0–2.5 cm high. Rhizoids bright red to brown, finely papillose. Leaves hardly shrinking, slightly twisted, spreading to closely appressed when dry, patent when moist, concave or not, ovate, obovate or spathulate, subacute and mucronate to cuspidate, bases red, not decurrent; margins bordered, recurved, usually toothed above, sometimes strongly so; costa brown to red, strongly excurrent; cells not porose, basal narrowly rectangular, cells above narrowly hexagonal, 12–18 μm wide, 34 marginal rows narrow, elongate, incrassate, forming distinct unistratose border. Filamentous axillary gemmae lacking. Red globose gemmae, 75–255 μm diameter, with non-protuberant cells, usually abundant on long rhizoids. Capsules cernuous or subpendulous, subcylindrical or cylindrical, slightly contracted below mouth when dry, neck not shrinking when dry; exothecial cells below mouth in ± longitudinal rows; processes abruptly contracted at apex and ending in long projection, cilia appendiculate; spores 10–16 μm. Capsules common, spring n = 20. On basic soil in grassland, by roads, on banks, sand-dunes, rarely on rocks or walls, never on trees. Lowland. Rare to occasional in southern Britain, very rare further north, extending to W. Perth and E. Ross, old records from N. Kerry and E. Donegal. 38, H2. GB291 + 22∗ , IR2∗ . Mediterranean-Atlantic. Europe north to Gotland, Turkey, Cyprus, W. Asia, Pakistan, Nepal, China, Azores, Canary Islands, N. and southern Africa, Kenya, N. America, Mexico, Chile, Australia, New Zealand. When synoicous or autoicous the inflorescence will distinguish B. torquescens from other members of the B. capillare group. When dioicous it may be distinguished by the red rather than reddish brown rhizoidal gemmae. Most likely to be confused with B. capillare, which, however, differs in the leaves spirally twisted round the stems when dry.

20 B. canariense Brid., Sp. Musc. Frond., 1817 (Fig. 179) B. canariense var. provinciale (Philib.) Huebener, B. provinciale H. Philib. Autoicous or occasionally synoicous. Dull green or reddish green tufts or patches, 0.3–5.0 cm high; stems matted with deep red rhizoids below. Lower leaves small, upper crowded in comal tuft, 2 or more successive comal tufts sometimes present, appressed, ± straight when dry, erect or imbricate when moist, ovate to ovateoblong or obovate-oblong, widest at or above middle, acute or subacute, reddish at base; margins unbordered, recurved below, distinctly toothed above; costa stout, reddish, excurrent in cuspidate point; basal cells rectangular, cells above narrowly hexagonal, 16–22 μm wide in mid-leaf, a few marginal rows narrower but not forming border. Red spherical rhizoidal gemmae, 180–300 μm diameter, with non-protuberant cells, usually present. Capsules pendulous, narrowly pyriform, ± symmetrical; lid mamillate; spores 13–16 μm. Capsules occasional, spring, summer. On soil in dry crevices of limestone or chalk. Lowland. Rare, in widely

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Fig. 179 1–5, Bryum elegans: 1, dry shoot (×10); 2, leaves (×40); 3, marginal cells; 4, mid-leaf cells; 5, part of rhizoid (280). 6–10, B. torquescens: 6, dry shoot (×10); 7, leaf (×25); 8, mid-leaf cells; 9, capsule; 10, part of endostome (×175). 11–13, B. canariense: 11, leaf (×25); 12, mid-leaf cells; 13, capsule. Cells ×280, capsules ×10.

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scattered localities on chalk and limestone from S. Devon east to Kent and north to Anglesey and W. Lancashire, Jersey. 18. C. GB20 + 10∗ , C1∗ . MediterraneanAtlantic. Mediterranean coasts, Atlantic coast of France and Belgium, Macaronesia, Zimbabwe, Tanzania, N. America. According to A. C. Crundwell (in Hill et al., 1994) although the dioicous non-British B. provinciale is treated as a synonym of B. canariense it is possible that the two taxa are distinct.

Section 3 Bryum Leaf bases reddish, differing in colour from rest of leaf; cells ± incrassate, 12–20 (–24) μm wide in mid-leaf, border usually wide, unistratose. Processes broadly or narrowly perforated, cilia usually rudimentary, spores mostly 18–36 μm. ´ Morav. – Silez. Akad. Vˇed. Pˇrı´r., Subsection 1 Penduliformia (Kindb.) Podp., Prace 1950 Apical leaves usually larger, forming comal tuft. Gemmae unknown. Processes with narrow to ovate perforations, cilia short; spores (16–)20 μm or more. 21 B. algovicum Sendtn. var. rutheanum (Warnst.) Crundw., Trans. Brit. Bryol. Soc., 1970 (Fig. 181) B. pendulum (Hornsch.) Schimp., B. roellii H. Philib., B. angustirete Kindb. Synoicous. Yellowish green to dark green patches or tufts, to c. 1.5 cm high. Upper leaves crowded, sometimes in two or more successive comal tufts, appressed, flexuose when dry, lower erect-patent, upper ± imbricate when moist, slightly concave, ovate to lanceolate, acuminate, reddish at base; margins bordered, recurved, entire or slightly denticulate above; costa stout, reddish, excurrent in stout cuspidate point; basal cells shortly rectangular, cells above ± rectangular to rhomboid-hexagonal or narrowly hexagonal, 16–28 μm wide in mid-leaf, 3–4 marginal rows narrow, more incrassate, forming distinct unistratose border. Capsules pendulous, ± pyriform, symmetrical, mouth red; lid mamillate; exostome teeth with oblique and vertical lines joining transverse articulations, forming an irregular network pattern, basal membrane adherent to exostome, processes widely perforated, cilia rudimentary or absent; spores (18–)22–36(–40) μm. Capsules common, spring. n = 10, 20, 27∗ , 30∗ . On usually basic sandy soil in open places, on sand-dunes, basic cliff ledges, in rock crevices, quarries. 0–460 m. Occasional and widely scattered throughout the British Isles. 97, H25, C. GB192 + 90∗ , IR15 + 20∗ , C1 + 2∗ . Circumpolar Boreotemperate. Europe north to Svalbard, Asia, Ethiopia, Tanzania, N. America, Greenland, S. America, Australasia, Falkland Islands, S. Georgia, Kerguelen Islands. A somewhat variable species that can only be determined when mature capsules are present. The peristome teeth are of characteristic appearance and will readily separate

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the plant from other British and Irish Bryum species except B. warneum. That species differs in the concolorous leaves, the small-mouthed capsules, the narrow perforations of the processes and the usually larger spores; the capsules are also later maturing. Var. algovicum, which is autoicous or rarely dioicous, is unknown in the British Isles.

22 B. knowltonii Barnes, Bot. Gaz. (Crawfordsville), 1889 B. lacustre (F. Weber & D. Mohr) Blandow

(Fig. 180)

Synoicous. Pale green to reddish patches, to 1 cm high. Upper leaves more crowded than lower, sometimes in 2 or more successive comal tufts, erect, flexuose when dry, erect-patent to spreading when moist, concave, lower ovate, obtuse, upper ovate-lanceolate, acute, reddish at base; margins weakly bordered at least in upper leaves, recurved, entire; costa stout, reddish, ending below apex to percurrent, rarely excurrent; basal cells rectangular to narrowly rectangular, cells above narrowly rectangular to rhomboid-hexagonal, 14–24 μm wide in mid-leaf, 3–4 marginal rows narrower, forming ill-defined unistratose border. Capsules pendulous, broadly pyriform, abruptly narrowed into distinct neck, wide-mouthed when dry and empty; lid shortly conical; processes with oval perforations, cilia rudimentary; spores 20–26 μm. Capsules frequent, maturing in succession in late spring. n = 11. On damp basic soil and dune-slacks. Lowland. Rare and much decreased, in scattered localities from N. Devon and N. Essex north to Ross, very rare inland, Hertford, N. W. Yorkshire. 26. GB12 + 23∗ . European Boreal-montane. N., W. and C. Europe north to Svalbard, Iceland, Faeroes, Siberia, Himalayas, Canada, Alaska, Colorado, Greenland. This species can only be determined when mature capsules are present. Most likely to be confused with B. warneum from which it differs in the nature of the exostome teeth and the reddish leaf bases. It differs from related species in the not or only slightly excurrent costa. This species is treated as vulnerable in the Red List of British Mosses.

23 B. archangelicum Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 181) Synoicous. Compact green tufts, c. 0.5 cm high. Upper leaves forming dense comal tufts, erect and slightly spreading when moist and when dry, lanceolate or ovate-lanceolate, acuminate, reddish at base; margins poorly to distinctly bordered, recurved, ± denticulate towards apex; costa strong, yellowish brown to reddish brown, longly excurrent in upper leaves; basal cells quadrate to shortly rectangular, alar cells slightly swollen in upper leaves, cells above rhomboidhexagonal, 11–16 μm wide in mid-leaf, 2–4 marginal rows much narrower, incrassate, forming poorly to well defined unistratose border. Setae reddish, 12–14 mm long; capsules pendulous, pyriform, symmetrical, mouth red, neck tapering into seta; exothecial cells incrassate, 1–2 rows at mouth transversely rectangular, cells below larger, ± quadrate, 20–25 μm wide, then longitudinally rectangular; lid

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Fig. 180 1–3, Bryum knowltonii: 1, leaf; 2, mid-leaf cells; 3, capsule. 4–8, B. salinum: 4, leaf; 5, mid-leaf cells; 6, capsule; 7, lower part of exostome tooth; 8, exothecial cells at capsule mouth. 9–14, B. imbricatum: 9, leaves; 10, mid-leaf cells; 11, capsule; 12, lower part of exostome tooth; 13, portion of endostome; 14, exothecial cells near capsule mouth. Leaves ×25, cells ×280, capsules ×10, teeth ×175.

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Fig. 181 1–4, Bryum archangelicum: 1, leaves (×40); 2, mid-leaf cells; 3, capsule (×10); 4, lower part of exostome tooth and uppermost exothecial cells. 5–8, B. algovicum var. rutheanum: 5, leaves (×25); 6, mid-leaf cells; 7, capsule (×10); 8, lower part of exostome tooth (×175). Cells ×280, capsules ×10.

hardly convex, very shortly apiculate; exostome teeth yellowish, darker at base, not perforated, processes very longly and narrowly perforated, cilia rudimentary or absent; spores densely papillose, yellowish brown at maturity, soon becoming blackish, 26–30 μm. Capsules common. On damp basic rock ledges. 700 m. Very rare, Angus. 1. GB1. Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Iceland, northern Asia, arctic N. America, Greenland. This species can only be identified when mature capsules are present. Somewhat resembling B. arcticum macroscopically, but the in latter the leaves are concolorous, the costa is only

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shortly excurrent and the borders are stratose. May also be confused with B. imbricatum, which, however, is larger, the capsule lids are mamillate and the processes have wide gaping perforations. However, the most distinctive feature of B. archangelicum is the densely papillose blackish spores. For an account of the discovery of this plant in Scotland see C. C. Townsend. J. Bryol. 18, 277–80, 1994.

24 B. salinum I. Hagen ex Limpr., Laubm. Deutschl., 1892 (Fig. 180) Synoicous. Dull yellowish green patches, 1.0–1.5 cm high. Upper leaves forming comal tuft, erect-patent when moist, ovate-lanceolate, acuminate, reddish at base; margins bordered, recurved, entire or denticulate towards apex; costa strong, excurrent; cells somewhat incrassate, porose, basal rectangular, alar cells slightly swollen in comal leaves, cells above rhomboid-hexagonal, 16–30(–40) μm wide in mid-leaf, 3–4 marginal rows very narrow, more incrassate, forming distinct unistratose border. Capsules ± pendulous, narrowly pyriform, mouth red, neck tapering into seta; exothecial cells incrassate, 1–2 rows at mouth transversely rectangular, cells below larger, ± quadrate, 30–40 μm wide, then longitudinally rectangular; lid ± mamillate; exostome teeth reddish brown with perforated median groove on outer surface in some but not all teeth, processes uniformly finely papillose, cilia rudimentary; spores mostly 18–20 or 28–30 μm but in some capsules ranging in size from 18 to 36 μm. Capsules common, spring. A halophyte occurring in dune slacks, on soil by the sea and in upper reaches of salt-marshes. Lowland. Very rare, S. Somerset, Westmorland, Ayr, Kincardine, Jura, Ross, W. Sutherland, N. E. Galway. 7, H1. GB7 + 1∗ , IR1. European Boreo-arctic Montane. European coasts from Denmark north to Svalbard, Iceland, Poland, Canada, Alaska, Greenland. This species can only be determined when mature capsules are present. It is similar to B. imbricatum but differs in the neck of the capsule tapering into the seta, the colour of the mouth, the width of the exothecial cells at the mouth and the reddish brown perforated exostome teeth. For the occurrence of this plant in the British Isles see E. Nyholm & A. C. Crundwell, Trans. Br. Bryol. Soc. 3, 375–7, 1958. This species is treated as vulnerable in the Red List of British Mosses.

¨ 25 B. imbricatum (Schwagr.) Bruch & Schimp. in Bruch et al., Bryol. Eur., 1839 (Fig. 180) ¨ Hal., B. inclinatum (Brid.) Blandow, B. stenotrichum Mull. ¨ B. amblyodon Mull. Hal. Synoicous. Green patches or tufts, to c. 1 cm high. Leaves crowded above, sometimes in two or more successive comal tufts, appressed, straight or ± crisped when dry, erect-patent when moist, ovate to lanceolate or oblong-lanceolate, acuminate to longly acuminate, reddish at base; margins bordered, recurved, entire or obscurely denticulate towards apex; costa stout, yellowish to reddish brown, excurrent, longly so in upper leaves; basal cells rectangular, in comal leaves alar cells slightly swollen, cells above ± rhomboid-hexagonal, 12–20(–28) μm wide in

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mid-leaf, 3–4 marginal rows very narrow, more incrassate, forming distinct unistratose border. Capsules ± pendulous, narrowly ellipsoid or narrowly pyriform, symmetrical, neck abruptly narrowed into seta, mouth yellowish to orange; 2–4 rows exothecial cells incrassate, at mouth 1–2 rows transversely rectangular, cells below larger, ± quadrate, 20–25 μm wide then longitudinally rectangular; lid ± mamillate; exostome teeth yellow above, reddish below, not perforated, processes with wide gaping perforations, more strongly papillose at edges than down middle, cilia rudimentary; spores 16–18 or 22–30(–34) μm. Capsules common, spring to autumn. n = 10∗ , 20∗ , 30. On soil on banks, roadsides, in rock crevices, on walls, old buildings, sand-dunes, particularly where basic. Mainly lowland but ascending to 650 m in Caernarfon. Occasional to frequent throughout the British Isles. 83, H23, C. GB260 + 84∗ , IR17 + 12, C2 + 1∗ . Circumpolar Boreo-temperate. Temperate and cold regions of both hemispheres. This species can only be identified when mature capsules are present. The relationship between spore size and chromosome number requires further investigation, both in this plant and in B. salinum. Likely to be confused with B. archangelicum (q.v.) or B. salinum (q.v.).

¨ 26 B. intermedium (Brid.) Blandow, Uber Mecklenb. Moose, 1809 (Fig. 182) Synoicous. Greenish tufts or patches, to 2.5 cm high. Upper leaves forming comal tuft, imbricate, straight when dry, erect when moist, lanceolate to ovatelanceolate, acute to acuminate, reddish at base; margins obscurely bordered, revolute from base to apex, entire or nearly so; costa stout, reddish, excurrent in

Fig. 182 Bryum intermedium: 1, leaves (×25); 2, mid-leaf cells (×280); 3, capsule (×10); 4, part of endostome (×175).

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short to long point; basal cells narrowly rectangular, alar cells in comal leaves swollen, cells above rectangular to rhomboid-hexagonal, 12–20 μm wide in midleaf, 2–3 marginal rows narrower, forming ill-defined unistratose border. Capsules cernuous or pendulous, narrowly pyriform, slightly asymmetrical, slightly gibbous, mouth small, oblique; lid conical; peristome teeth brown, processes narrowly perforated, cilia nodulose; spores 18–24 μm. Capsules common, ripening in succession, summer, autumn. n = 20∗ , 24. On usually basic soil on roadsides, waste ground, rock ledges, hedge banks, walls, old buildings, sand-dunes. 0–310 m. Occasional in England and Wales, rare in Scotland, extending north to Caithness, very rare in Ireland and not seen recently. 66, H9. GB65 + 80∗ , IR10∗ . Eurasian Temperate. Europe north to Fennoscandia, Asia, N. Africa, Canada, Greenland. B. intermedium can only be identified when mature capsules are present. Unlike most other Bryum species, the capsules ripen successively rather than all at once. Confused with other Bryum species of similar leaf shape but distinguished, except from B. caespiticium, by the leaf margins weakly bordered and with revolute margins. B. caespiticium has smaller spores and is dioicous. The slightly asymmetrical capsules will distinguish it from B. imbricatum and B. algovicum in the field, and B. pallescens and B. creberrimum differ in the appendiculate cilia as well as in leaf characters.

Subsection 2 Pseudotriquetra Broth., Nat. Pflanzenfam., 1903 Upper leaves forming comal tuft or not, leaves with ± decurrent bases, bordered. Gemmae very rare. Processes broadly perforated, cilia nodulose or appendiculate; spores mostly 12–20 μm. 27 B. creberrimum Taylor, Lond. J. Bot., 1845 B. affine Lindb. & Arnell, B. lisae De Not.

(Fig. 183)

Synoicous. Dense tufts, green above, reddish brown and matted with tomentum below, 1–4 cm high. Leaves slightly twisted when dry, erect-patent when moist, ovate-lanceolate to lanceolate, often tapering from widest point to acuminate apex, base reddish; margins bordered, usually strongly recurved, entire or denticulate towards apex; costa reddish, excurrent; basal cells rectangular, alar cells of comal leaves slightly turgid, cells above rhomboid-hexagonal, 14–24 μm wide in mid-leaf, several marginal rows narrow, more incrassate, forming distinct unistratose border. Capsules inclined or pendulous, narrowly ellipsoid or narrowly pyriform, symmetrical; lid mamillate; processes with perforations about as long as wide, cilia appendiculate; spores 14–16 μm. Capsules common, summer. n = 10, 22, 30. On soil, roadside banks, waste ground, occasionally on sand-dunes and in rock and wall crevices. Lowland. Rare, widely scattered from N. Somerset east to W. Kent and north to E. Ross, Dublin. 28, H1. GB14 + 25∗ , IR1. Circumpolar Boreo-temperate. Europe north to Svalbard, Iceland, Turkey, N. America. B. creberrimum and B. pallescens are very close and have been confused in the past because of the statement in Dixon & Jameson (1924) that B. creberrimum is synoicous and B. pallescens

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Fig. 183 1–4, Bryum pallescens: 1, leaves (×15); 2, mid-leaf cells; 3, capsule; 4, part of endostome (×175). 5–8, B. creberrimum: 5, leaf (×15); 6, mid-leaf cells; 7, capsule; 8, part of endostome (×175). 9–10, B. funkii: 9, leaves (×40); 10, mid-leaf cells. Cells ×280, capsules ×10.

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autoicous. The latter may also be synoicous. The smaller spores and widely perforated processes will usually separate B. creberrimum from B. pallescens, but plants with spores of intermediate size occasionally occur. The gametophytes of B. pallescens are variable and some are inseparable from B. creberrimum, but plants with ± ovate, shortly pointed leaves belong to B. pallescens. Robust plants of either may be mistaken for B. bimum but differ in the more acuminate leaves with longly excurrent costae.

¨ 28 B. pallescens Schleich. ex Schwagr., Sp. Musc. Frond. Suppl. 1, 1816 (Fig. 183) B. obconicum Hornsch. Synoicous or autoicous. Tight tufts, green above, reddish brown and matted with tomentum below, 1.0–4.0(–7.5) cm high. Leaves slightly twisted when dry, erectpatent when moist, ovate to ovate-lanceolate, acuminate, reddish at base; margins bordered, recurved, sometimes strongly so, entire or denticulate towards apex; costa red, excurrent; basal cells rectangular, alar cells of comal leaves slightly turgid, cells above rhomboid-hexagonal, 14–24 μm wide in mid-leaf, several marginal rows narrow, more incrassate, forming distinct unistratose border. Capsules inclined to pendulous, narrowly ellipsoid to narrowly pyriform, symmetrical; lid mamillate; perforations of processes 1.5–2.0 times as long as wide, cilia with poorly to well developed appendages; spores 18–20(–22) μm. Capsules common, summer. n = 10, 12, 20. On soil, sand-dunes, in crevices in rocks and walls and on heavy-metal mine waste. 0–1205 m. Rare to occasional, generally distributed, extending north to W. Ross, rare in Ireland. 58, H8, C. GB54 + 43∗ , IR4 + 3∗ , C2. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Cyprus, N., C. and E. Asia, Tenerife, N., C. and S. America, Greenland, Falkland Islands. The type specimen of B. obconicum, a plant regarded by Dixon & Jameson (1924) as related to B. capillare, is a specimen of B. pallescens. Many British gatherings named B. obconicum are B. torquescens and some are B. creberrimum.

29 B. pseudotriquetrum (Hedw.) Gaertn. et al., Oeken. Fl. Wettenau, 1802 (Fig. 184) Dioicous. Glossy green to reddish tufts or patches, 1–10(–15) cm high, stems matted below with brown tomentum. Leaves not much crowded at stem apices, shrunken, flexuose when dry, erect-patent when moist, ovate to narrowly lanceolate, acuminate, base reddish with cells more deeply coloured than in rest of leaf; margins bordered, slightly recurved, entire or denticulate towards apex; costa stout, percurrent to shortly excurrent; basal cells shortly rectangular, cells above rhomboid-hexagonal, mostly (16–)20–24 μm wide in mid-leaf, several marginal rows longer and narrower, forming distinct unistratose border. Green filamentous uniseriate axillary gemmae, c. 30 μm wide, becoming very long and much branched with age, present very rarely. Capsules large, inclined or pendulous, narrowly ellipsoid, symmetrical, wide-mouthed and narrowed below mouth when

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Fig. 184 1–3, Bryum pseudotriquetrum: 1, leaf; 2, mid-leaf cells; 3, capsule; 4, axillary gemmae (×90). 5–6, B. neodamense: 5, leaves; 6, mid-leaf cells. 7–10, B. caespiticium: 7, leaves; 8, mid-leaf cells; 9, capsule; 10, part of endostome (×175). Leaves ×25, cells ×280, capsules ×10.

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dry and empty; lid mamillate; cilia appendiculate; spores 12–18 μm but sometimes variable in size within a capsule. Capsules occasional, summer, autumn. n = 10∗ , 10 + m. On wet ground in fens, dune-slacks, on wet heaths, in flushes, duneslacks, by streams and lakes. 0–1170 m. Occasional in lowland England, common elsewhere. 109, H39, C. GB1333 + 123∗ , IR231 + 6∗ , C5 + 2∗ . Circumpolar Wideboreal. Widely distributed in temperate and cold zones. B. pseudotriquetrum and B. bimum are usually easily recognised by the robust, glossy, usually red-tinged plants with rigid leaves. Although B. bimum has been treated as a variety of B. pseudotriquetrum, some recent authors accord it specific rank. It has been shown by F. Demaret & A. Empain (Bull. Jard. Bot. Nat. Belg. 55, 275–80, 1985) that the two taxa differ significantly in leaf cell size. It is likely that B. bimum (n = 20) is an autopolyploid derivative of B. pseudotriquetrum (n = 10) although there are some reports of n = 20 for the latter, but it is uncertain if these have been correctly named. There are thus good grounds for treating the two taxa as distinct species. Stunted forms of either may be mistaken for B. pallens, but that differs in the uniform colour of the leaf cells, the more shortly pointed leaf apex and the strongly recurved margins with bistratose borders.

30 B. bimum (Schreb.) Turner, Muscol. Hibern. Spic., 1804 B. pseudotriquetrum var. bimum (Schreb.) Lilj. Synoicous. Gametophyte plants morphologically similar to B. pseudotriquetrum but mid-leaf cells mostly 12–16 μm wide. Sporophytes similar to those of B. pseudotriquetrum; spores 15–25 μm. n = 20∗ , 22, 33. In similar habitats to B. pseudotriquetrum. Occasional to frequent. 65, H10, C. Circumpolar Wide-boreal. Europe north to Svalbard, Iceland, E. Asia, Middle East, Siberia, Macaronesia, Sudan, N. America, Australia, New Zealand. ¨ Hal., Syn. Musc. Frond., 1849 31 B. neodamense Itzigs in Mull. (Fig. 184) Dioicous. Reddish green tufts or patches, 1–10 cm high. Leaves very distant except at stem tips, curled when dry, spreading when moist, very concave, lower leaves broadly ovate, obtuse to rounded, ± cucullate, upper leaves ovate to lanceolate, obtuse to acute, base reddish, slightly decurrent; margins bordered, plane or slightly recurved, ± entire; costa ending below apex to percurrent; basal cells shortly rectangular, cells above rectangular to rhomboid-hexagonal, 16–30 μm wide in mid-leaf, 2–5 marginal rows narrow, forming distinct unistratose border. Capsules obovate-pyriform; very rare. In fens, dune-slacks and on wet limestone, calcicole. Lowland. Very rare, Caernarfon, S. Lancashire, Caithness, old records from N. W. Yorkshire and Angus, rare in Ireland. 5, H9. GB3 + 5∗ , IR10 + 2∗ . Circumpolar Boreal-montane. N., W. and C. Europe north to Svalbard, Iceland, Siberia, Altai, Alaska, Canada, Greenland. Likely to be mistaken for a form of B. pseudotriquetrum but recognised by the very concave leaves, the lower of which at least have rounded or obtuse and sometimes cucullate apices. This species is considered endangered in the Red List of British Mosses and is a protected plant under the Wildlife and Countryside Act.

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ˇ e Akˇed. Ved, Tˇr. 2, Vˇedy Pˇrı´r., 1901 Subsection 3 Caespitibryum Podp., Rozpr. Cesk´ Leaf bases not decurrent, border indistinct. Gemmae sometimes present. Processes broadly perforated, cilia appendiculate; spores 10–18 μm. 32 B. caespiticium Hedw., Sp. Musc. Frond., 1801 (Fig. 184) Dioicous. Dull green tufts or patches, to 1(–2) cm high. Upper leaves forming comal tufts, imbricate, slightly twisted when dry, erect or erect-patent when moist, ovate to ovate-oblong, widest below middle, tapering from below middle to acute apex, reddish or not at base, margins obscurely bordered, strongly recurved, entire; costa yellowish to reddish brown, in upper leaves excurrent in entire or slightly denticulate point; basal cells rectangular or shortly rectangular, alar cells swollen in comal leaves, cells above narrowly rhomboid-hexagonal or narrowly hexagonal, 12–16 μm wide in mid-leaf, 1–3 marginal rows narrower, forming poorly defined unistratose border. Sparse chocolate-brown rhizoidal gemmae occasionally present. Capsules pendulous, narrowly ellipsoid or narrowly pyriform, sometimes slightly asymmetrical, straight or slightly upcurved, wide-mouthed and narrowed below mouth when dry and empty, mouth reddish-brown; lid mamillate; exostome teeth pale brown, cilia appendiculate; spores 10–14 μm. Capsules common, summer. n = 9 + m, 10∗ , 10 + m∗ , 20, 20 + m∗ , 22, 30. On basic or neutral soil on waste ground, banks, rocks, old walls, in quarries and dune-slacks. Lowland. Common in England (except in the south-west), E. Wales and S. E. Scotland, occasional to very rare elsewhere, extending north to Orkney, rare in Iceland. 104, H8, C. GB743 + 91∗ , IR9 + 4∗ . Circumpolar Boreo-temperate. More or less cosmopolitan. Distinct from the preceding species in the scarcely bordered leaves with narrower cells, although it cannot be reliably identified unless the plants are fertile. An apparently calcicolous form with small red rhizoidal gemmae has been found in Suffolk and Cambridge (A. C. Crundwell in Hill et al., 1994). The hybrid B. caespiticium × B. algovicum occurs occasionally and may be recognised by the B. caespiticium-like gametophytes bearing B. algovicum-like capsules, but with the lines on the exostome teeth less thickened than in B. algovicum and the spores c. 20 μm.

¨ 33 B. funkii Schwagr., Sp. Musc. Frond. Suppl. 1, 1816 (Fig. 183) ¨ B. caespiticium var. imbricatum Bruch & Schimp., B. funckii auct. non Schwagr. Dioicous. Pale green patches to 1 cm high. Leaves of equal size and distribution along stems, erect, appressed when dry, imbricate when moist giving shoots julaceous appearance, strongly concave, ovate to broadly ovate, rapidly narrowed to fine acumen, reddish at base; margins very obscurely bordered, erect and plane or narrowly recurved below, entire or obscurely denticulate towards apex; costa strong, yellowish to pale brown, excurrent in fine acumen; basal cells rectangular, cells above narrowly hexagonal or narrowly rectangular, 12–16 μm wide in midleaf, 1–3 marginal rows narrower, forming very obscure border. Capsules inclined, narrowly ellipsoid; spores to c. 18 μm. Capsules unknown in Britain. n = 10.

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On calcareous rock ledges and thin calcareous turf in open habitats. Lowland. Rare, from N. Somerset and E. Sussex north to Durham but with recent records only from Shropshire, Montgomery, Caernarfon and Anglesey. 11. GB8 + 10∗ . submediterranean-subatlantic. W. and C. Europe north to Sweden, N. and C. Asia. B. funkii is unlikely to be mistaken for any other British Bryum species as it is distinctive in the julaceous shoots and very strongly concave, ± unbordered leaves. This is the plant known to British bryologists as B. caespiticium var. imbricatum, but it bears no resemblance to B. caespiticium and there are no intermediates. It is almost identical with the plant described from continental Europe as B. funkii, although unlike British material the plants are said to be bud-like (Nyholm, 1993). Whether the plants currently named B. funkii are the same as ¨ that described by Schwagrichen in 1816 is obscure and likely to remain so.

¨ Hal., Linnaea, 1875 Subsection 4 Soliolidium Mull. Small plants. Leaves obtuse or shortly pointed; border absent or poorly developed. Axillary bulbils frequent; gemmae sometimes present. Capsules short with thick neck; processes with narrow perforations, cilia appendiculate; spores 10–20 μm. 34 B. argenteum Hedw., Sp. Musc. Frond., 1801 B. argenteum var. lanatum (P. Beauv.) Hampe

(Fig. 185)

Dioicous. Small dense tufts, patches, mats or scattered plants among other bryophytes, hoary or not when dry, whitish or silvery above, brownish green below. Shoots slender, julaceous, fragile, to 1.5 cm long. Leaves imbricate when moist, scarcely altered when dry, concave, ovate to broadly ovate, narrowed to short to long acuminate apex, ± hyaline in upper part, base decurrent, reddish; margins unbordered, plane, entire; costa relatively thin, ending below apex to excurrent; basal cells quadrate with quadrate or rectangular cells extending to c. 1/3 way up margins, cells elsewhere rhomboid-hexagonal or narrowly rhomboidhexagonal, sometimes very incrassate, 10–16 μm wide in mid-leaf, cells in upper part of leaf pellucid with colourless walls, causing the whitish or silvery appearance of dry shoots, 1–2 marginal rows in upper part of leaf narrower but not forming border. Leafy axillary bulbils sometimes present. Setae short; capsules small, cernuous or pendulous, ellipsoid to pyriform, wide-mouthed and contracted below mouth when dry and empty; lid mamillate; processes narrowly perforated; cilia appendiculate; spores 8–14 μm. Capsules occasional, autumn to spring. n = 10∗ , 10 + m, 11, 20. Commonly in man-made habitats such as paving stone crevices, on concrete, by paths, roadsides, on waste ground, walls, mortar of old buildings, asphalt, also on banks of rivers and streams, rock outcrops, cliff slopes and sanddunes. 0–490 m. Very common in England and Wales, occasional to common in Scotland and Ireland. 112, H40, C. GB1761 + 80∗ , IR207 + 12∗ , C9. Circumpolar Wide-boreal. Cosmopolitan. Var. lanatum (P. Beauv.) Hampe is of doubtful taxonomic value and is not recognised here. For an account of the morphological and physiological variation of this species see R. E.

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Fig. 185 1–3, Bryum argenteum: 1, leaves (×35); 2, mid-leaf cells; 3, capsule (×10). 4–5, B. dixonii: 4, leaf; 5, marginal cells at middle of leaf. 6–10, B. gemmiferum: 6, 7, leaves of sterile and fertile stems (×50); 8, mid-leaf cells; 9, capsule (×10); 10, axillary bulbils (×90). Cells ×280.

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Longton, J. Bryol. 11, 501–20, 1981, and T. Hedderson & R. E. Longton, Bull. Br. Bryol. Soc. 72, 45–6, 1999.

35–39 B. dichotomum complex The bulbil-bearing species of the B. dichotomum aggregate, B. dichotomum, B. gemmilucens, B, gemmiferum and B. dunense, were shown by H. L. K. Whitehouse to retain their distinctive characteristics when grown under uniform conditions. More recently, however, it has been shown that B. dunense, and also what was thought to be the non-British species B. versicolor, intergrade with B. dichotomum to such an extent that they must be regarded as synonymous (see D. T. Holyoak, J. Bryol. in press). Similarly, B. barnesii, recognised as a distinct species by continental European bryologists but treated as synonymous with B. dichtomum in the first edition of this book, has been shown by D. T. Holyoak (pers. commun.) to intergrade completely with B. dichotomum. Recently, an additional taxon has been found in a number of coastal localities in England and Wales and has been described as a new species, B. dyffrynense (see D. T. Holyoak, J. Bryol., in press). All the species except B. dixonii regularly produce axillary bulbils and, at times, rhizoidal gemmae, except sometimes when bearing sporophytes. The nomenclature of the bulbil-bearing species described in the first edition of this book was based upon the descriptions of R. Wilczek & F. Demaret, Bull. Jard. Bot. Nat. Belq. 46, 511–51, 1976 and A. J. E. Smith & H. L. K. Whitehouse, J. Bryol., 10, 29–47, 1978. British specimens of B. gemmilucens do not correspond exactly with descriptions and illustrations of Belgian material. Plants of the B. dichotomum agg. differ from bulbilliferous Pohlia species in leaf and capsule shape, and the narrowly recurved usually entire leaf margins and relatively short cells. When plants are sterile the bulbils provide adequate distinguishing characters from all other Bryum species except B. gemmiparum (q.v.). 35 B. dixonii Cardot, Rev. Bryol., 1910 (Fig. 185) Dense patches or small tufts among other bryophytes, yellowish green above, reddish brown below when moist, yellowish white when dry, to c. 1 cm high. Leaves imbricate when dry, erect-patent when moist, concave, ovate and acute to broadly ovate and acuminate, cells near costa brownish but other basal cells not reddish; margins unbordered, plane, obscurely denticulate above; costa relatively thin, ending below apex to shortly excurrent; basal cells rectangular, cells above rhomboid-hexagonal, 10–16 μm wide in mid-leaf, 2–3 marginal rows narrower but not forming border. Small caducous axillary shoots sometimes present. Gametangia and sporophytes unknown. Damp basic montane rocks and soil on cliffs, in gullies and flushes. 30–850 m. Rare in the Scottish Highlands, W. and Mid Perth, Angus, W. Inverness, Argyll, Skye, E. Ross, W. Sutherland, St. Kilda. 9. GB15 + 1∗ . Suboceanic Boreal-montane. Switzerland. H. L. K. Whitehouse (J. Bryol. 17, 376–7, 1992) reports the occurrence of spherical rhizoidal gemmae similar to those of other members of the aggregate on plants grown in

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culture. These are likely to occur in nature although I have not found them in herbarium material. Likely to be mistaken only for other plants of the B. dichotomum agg., B. argenteum, Anomobryum filiforme or Plagiobryum species. Members of the B. dichotomum agg. have axillary bulbils and recurved leaf margins; B. argenteum differs in colour and hyaline leaf apices; Anomobryum differs in leaf shape and areolation and Plagiobryum in colour and areolation.

36 B. gemmiferum R. Wilczek & Demaret, Bull. Jard. Bot. Nat. Belgique, 1976 (Fig. 185) Dioicous. Yellowish green tufts, patches or scattered plants among other bryophytes, to 1.5 cm high. Stems often reddish. Leaves erect-patent when moist, strongly concave, base not reddish; leaves on sterile stems ovate, acute or subacute with costa ending in apex or, in taller stems, excurrent; leaves of fertile stems ovate-lanceolate, more tapering, acute, with costa excurrent; margins unbordered, narrowly recurved below, entire or obscurely denticulate; basal cells quadrate-rectangular, cells above rhomboid-hexagonal, 16–22 μm wide in midleaf, 1–3 marginal rows narrower, not forming a border. Sterile stems with usually orange or red axillary bulbils, (5–)20–30 per axil, 100–160(–200) μm long, base pointed, primordia 1/4 –2/3 total length of bulbil, restricted to apex of bulbils. Brown or reddish brown rhizoidal gemmae have been reported from Belgian plants. Capsules pendulous, ovoid, purplish, neck short, very abruptly narrowed into seta; lid conical and shortly apiculate; spores 14–18 μm. Capsules occasional, autumn. n = 10∗ . On soil, particularly where sandy, loamy or gravelly soil by pools, ditches, on damp ground, in dune-slacks and glasshouses. 0–350 m. Occasional to frequent in S. E. England, rare elsewhere in England and Wales, very rare in Scotland and Ireland but probably under-recorded. 68, H6, C. GB122, IR6, C1. Suboceanic Temperate. Belgium, Denmark, Germany, the Netherlands, Portugal, Spain, Lanzarote. Usually distinguished by the very small orange or red bulbils although old bulbils remaining on the stems may approach those of B. dichotomum in size but differ in their shorter primordia.

37 B. gemmilucens R. Wilczec & Demaret, Bull. Jard. Bot. Nat. Belgique, 1976 (Fig. 186) Dioicous. Tufts or scattered plants among other bryophytes, 0.5–1.0 cm high. Stems orange-red. Leaves erect-patent when moist, very concave, ovate or broadly ovate, acute, not reddish at base; margins ± unbordered, recurved below, entire or obscurely denticulate above; costa ending below apex to percurrent; basal cells rectangular, above rectangular to rhomboid-hexagonal, 10–16 μm wide in midleaf, 1–2 marginal rows narrower but not forming border. Bulbils c. 5 per axil, yellow, glossy, ± broadly ellipsoid, 120–200 μm long, base rounded, primordia very rudimentary or indistinct with bulbils often appearing similar at both ends, primordia where present restricted to bulbil apex. Gametangia and sporophytes unknown. On non-calcareous soil in arable fields, on roadsides and woodland rides.

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Fig. 186 1–5, Bryum dichotomum: 1, 2, leaves of sterile and fertile stems (×20); 3 basal cells; 4, mid-leaf cells; 5, capsule (×10). 6–8, B. gemmilucens: 6, leaves (×20); 7, mid-leaf cells; 8, axillary bulbils (×50). Leaves ×20, cells ×280.

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Lowland. Rare in southern England, N. E. and S. W. Yorkshire. 12. GB10 + 1∗ . European Temperate. Belgium, Corsica, Denmark, France, Germany, Hungary, Luxembourg, the Netherlands, Portugal, Spain, Turkey, La Gomera, Lanzarote, California. Recognised by the leaf primordia of the bulbils so poorly developed that the bulbils appear similar at both ends. Belgian plants are described as having the bulbils pyriform or obovoid but British material differs in having ovoid bulbils.

38 B. dichotomum Hedw., Sp. Musc. Frond., 1801 (Figs. 186, 187) B. atropurpureum Bruch & Schimp., B. barnesii J. B. Wood, B. bicolor Dicks., B. dunense A. J. E. Sm. H. Whitehouse, B. versicolor A. Braun ex Bruch & Schimp. Dioicous. Lax or compact pale green or green tufts or patches, reddish below, 0.5– 1.5 cm high. Stems green to reddish; rhizoids yellowish to brown, papillose. Leaves erect to erect-patent or imbricate, scarcely shrunken when dry, erect-patent when moist, very concave, not reddish at base; leaves on sterile stems broadly ovate to lanceolate, obtuse to acuminate; margins recurved below, rarely from base to apex, usually entire, usually unbordered; costa ending in or below apex to excurrent; leaves on fertile stems obovate-lanceolate, ovate-lanceolate or lanceolate, acuminate; costa ending in apex to longly excurrent, to 70 μm wide near base; basal cells quadrate-rectangular to rectangular, cells above rhomboid-hexagonal to rectangular, 10–20 μm wide in mid-leaf, 1–3 marginal rows narrower but only rarely forming poorly defined border. Bulbils 1–2(–several) per axil, yellowish green to green, ovoid to subcylindrical, (125–)200–480(–600) μm long with acute or subacute or rarely obtuse or rounded leaf primordia, c. 1/2 (–3/4 ) total length of bulbil, rarely costate, arising from upper 1/2 –2/3 of bulbil. Rarely yellowish brown rhizoidal gemmae present. Capsules pendulous, purplish red, ovoid, neck short, very abruptly narrowed into seta; lid conical and shortly apiculate; cilia appendiculate; spores 8–16 μm. Capsules occasional, spring, summer. n = 10∗ , 24∗ . On soil in fields, waste ground, in gardens, in flower pots and among rocks by streams and on sandy and gravelly soil. 0–490 m. Frequent or common throughout the British Isles. 111, H37, C. GB1569 + 87∗ , IR206 + 5∗ , C9. European Wide-temperate. Europe north to Fennoscandia, Faeroes, Caucasus, Turkey, Cyprus, N. W. India, Macaronesia, N. Africa, N. America. A very variable species and by far the commonest member of the complex. B. gemmiparum, which may be confused with B. dichotomum, differs in the broader costa and the frequent presence of reddish rhizoidal gemmae. Very vigorous plants with the general appearance of B. dichotomum, which have been mistaken for B. gemmiparum sometimes occur in rock crevices by rivers (e.g. by the East Lyn River, Somerset). The identity of such plants is not clear; the lower leaves have a distinct border and it is not certain whether the plants should be referred to B. dichotomum or to some as yet undescribed taxon.

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Fig. 187 Bryum dichotomum: axillary bulbils (×50).

There is another plant, known as B. barnesii, which was first described from a gathering from Levens, Westmorland. This was treated as a synonym of B. argenteum by Braithwaite (1888–1895) and of B. dichotomum by Dixon & Jameson (1924). In the first edition of this book I suggested that the plant could not be separated from B. dichotomum. However, continental European and N. American authors have treated it as a good species but it has

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Fig. 188 Bryum dyffrynense: 1, leaves (×55), mid-leaf cells (×280); 3, capsule (×30); 4, gemmae (×75); 5, old gemmae (×75). been shown that intermediates connect the two taxa and B. barnesii cannot be maintained (D. T. Holyoak, pers. commun.).

39 B. dyffrynense D. T. Holyoak, J. Bryol., in press (Fig. 188) Dioicous. Lax patches, 1–2 cm high, often partially immersed in sand. Fertile stems short, 3–5 mm high, innovating from below inflorescences to produce slender sterile bulbil-bearing shoots, with tips julaceous with imbricate leaves. Stem orangebrown, radiculose below. Rhizoids brown, papillose. Upper leaves on sterile stems imbricate when moist and when dry, concave, ovate-lanceolate, blunt to shortly acute or acuminate, often reddish or brown at base; margins unbordered or with poorly defined border above, plane or narrowly recurved below, entire or occasionally denticulate above; costa stout, reddish, extending ± to apex; cells thickwalled, basal rectangular to narrowly rectangular, alar cells of some but not all leaves enlarged or inflated and forming reddish brown shortly decurrent auricles, which may remain attached to stem when leaves are removed; cells above narrowly rectangular to elongate hexagonal, in mid-leaf 10–13 μm wide, becoming narrower towards margins and sometimes forming poorly defined border above. Bulbils of branches solitary in leaf axils, obloid to ovoid, mostly yellowish green but becoming brown below, 209–385 × 264–985 μm, primordia broad, concave, blunt, ecostate, occupying 1/2 –2/3 total length of bulbil; scattered bulbils present on

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30 Bryaceae

fertile stems, to 1 mm long, sometimes beginning to develop, lower part dark brown, primordia with rounded apices occupying 1/2 –2/3 total length of bulbil. Rhizoidal gemmae lacking. Capsules cernuous to pendulous, brown to orangebrown, ovoid-pyriform; neck short, abruptly narrowed into seta; spores (10–)12– 14(–15) μm. On damp calcareous sand in dune-slacks. Lowland. Rare in coastal habitats, E. Kent, Merioneth, Anglesey, S. Lancashire, Westmorland. 5. Endemic. The julaceous shoot tips provide a useful field character for separating B dyffrynense from other species of the complex. The frequent presence of auricles is unique in the group and it differs from all other members except B. dichotomum in the solitary bulbils. It differs from B. dichotomum in the red costa. For an account of this species see B. H. Holyoak, J. Bryol, in press.

ˇ e Akˇed. Ved. Tˇr. 2, Vˇedy ¨ Hal.) Podp., Rozpr. Cesk´ Subsection 5 Apalodictyon (Mull. Pˇrı´r., 1901 Small often reddish-tinged plants. Rhizoidal gemmae always present. Process perforations ovate, cilia appendiculate; spores mostly 8–16 μm. 40–48 B. erythrocarpum complex Except for B. radiculosum the members of this complex were treated by Dixon & ¨ This has been shown Jameson (1924) as a single species, B. erthrocarpum Schwagr. to consist of nine species in the British Isles and additional species elsewhere. For an account of the complex see A. C. Crundwell & E. Nyholm, Trans. Br. Bryol. Soc. 4, 597–637, 1964, and A. C. Crundwell & H. L. K. Whitehouse, J. Bryol. 23, 171–6, 2001. For naming to be meaningful, identification of plants of the B. erythrocarpum complex should be taken to the species level. 40 B. radiculosum Brid., Sp. Musc. Frond., 1817 B. murale Wilson ex Hunt, B. murorum (Schimp.) Berk.

(Fig. 189)

Dioicous. Plants densely tufted, 3–10 mm high. Rhizoids yellowish to brown, coarsely papillose. Leaves erect-patent when moist, lanceolate, acuminate, reddish at base, not or scarcely bordered; costa very strong, longly excurrent, yellow or sometimes reddish when old; basal cells quadrate or shortly rectangular, cells above incrassate, 10–12 × 40–60 μm, slightly narrower at margins but not forming a border. Rhizoidal gemmae always present although sometimes few, never axillary, ± spherical, bright red to brown, 120–180 μm diameter, cells not protuberant. Capsules cernuous, variable in shape and size, ± narrowly ellipsoid; lid convex, obtuse; spores 10–14 μm. Capsules frequent, early summer. On mortar, limestone and hard calcareous soil, calcicole. Lowland. Common in southern England and N. Wales, rare to occasional elsewhere, extending north to W. Sutherland and Monach Islands, rare in Ireland. 100, H29, C. GB457 + 47∗ , IR15 + 15∗ , C8. Submediterranean-Subatlantic. Europe north to Denmark, Caucasus, Turkey, Palestine, S. E. Asia, Japan, Madeira, Canary Islands, N. Africa, Bermuda. Most likely to be confused with B. subapiculatum but is a calcicole species differing in the larger less regularly spherical gemmae and the coarsely papillose rhizoids. Sometimes

105 Bryum

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Fig. 189 1–5, Bryum radiculosum: 1, leaves; 2, basal cells; 3, mid-leaf cells; 4, capsule (×10); 5, rhizoidal gemma. 6–9, B. violaceum: 6, leaf; 7, basal cells; 8, marginal cells at middle of leaf; 9, rhizoidal gemma. 10–13, B. ruderale: 10, leaf; 11, basal cells; 12, marginal cells at middle of leaf; 13, rhizoidal gemma. Leaves ×35, cells ×280, gemmae ×250.

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30 Bryaceae

mistaken for B. dichotomum agg. but differs in the narrower leaf cells and absence of axillary bulbils.

41 B. ruderale Crundw. & Nyholm, Bot. Not., 1963 (Fig. 189) Dioicous. Tufts or patches, to 8 mm high. Rhizoids distinctly papillose, deep bright violet, sometimes purple, rarely reddish and paler. Leaves erect-patent when moist, lanceolate or ovate-lanceolate, acuminate, base reddish; margins hardly bordered, recurved below, entire or faintly denticulate above; costa stout, excurrent in stout point; basal cells quadrate or shortly rectangular, cells above ± incrassate, narrowly rhomboid-hexagonal, 10–14 × 30–60 μm, narrower at margins but hardly forming a border. Gemmae on long rhizoids, never axillary, spherical, bright or pale purplish red, occasionally orange, 125–180(–200) μm diameter, cells scarcely protuberant. Capsules cernuous, pyriform; spores 9–11 μm. Capsules unknown in the British Isles. On strongly basic to slightly acidic soil in arable fields, on banks, by paths and roads, on sand-dunes. 0–310 m. Frequent or common in England and Wales, rare in Scotland, extending north to Shetland, rare to occasional in Ireland. 90, H24, C. GB498 + 2∗ , IR27, C2. European Temperate. Europe north to Denmark, Azerbaijan, Macaronesia, Egypt, S. Africa, N. America, New Zealand. The usually deep violet rhizoids render this species easily distinguishable in the field except from B. violaceum, which differs in the larger, regularly spherical gemmae and the distinctly papillose rhizoids.

42 B. violaceum Crundw. & Nyholm, Bot. Not., 1963 (Fig. 189) Dioicous. Tufts or scattered plants among other bryophytes, often in small quantity, 2–7 mm high. Rhizoids deep bright violet, smooth or finely papillose. Leaves erect when moist, lanceolate, acuminate, reddish at base; margins scarcely bordered, recurved, denticulate above; costa stout, excurrent; basal cells shortly rectangular, cells above narrowly hexagonal, 10–14 × 30–70 μm in mid-leaf, narrower at margins but hardly forming a border. Irregularly spherical gemmae numerous on long rhizoids, never axillary, bright pale purplish red or occasionally orange, 60–90(–110) μm diameter, cells not protuberant. Capsules pendulous, narrowly pyriform; spores 9–11 μm. Capsules unknown in the British Isles. On calcareous to slightly acid soil in arable fields, on earthy banks, roadsides and waste ground. Lowland. Occasional to frequent in England and Wales, rare in Scotland, extending north to Caithness, very rare in Ireland. 76, H10, C. GB242 + 1∗ , IR7 + 1∗ , C1. European Temperate. Western Europe from Spain north to Scandinavia and Poland, Turkey, Kashmir, Tenerife, N. America, Patagonia. Often mixed with other species of the aggregate, but distinguishable in the field from all except B. ruderale by the usually violet rhizoids and small paler gemmae. For the differences from B. ruderale see under that species. Plants with pale rhizoids may be confused with B. klingraeffii but that species differs in the gemmae being of a different colour and having protuberant cells.

105 Bryum

579

43 B. klinggraeffii Schimp. in H. Klinggr., Höh. Crypt. Pruess., 1858 (Fig. 190) Dioicous. Tufts or scattered plants among other bryophytes, 2–5 mm high. Rhizoids pale yellowish brown, smooth. Leaves erect or erect-patent when moist, lanceolate, acuminate, reddish at base; margins hardly bordered, recurved below, denticulate above; costa excurrent; basal cells rectangular, cells above rectangular to rhomboid-hexagonal, 10–14 × 45–60 μm in mid-leaf, narrower at margins but hardly forming a border. Bright crimson rhizoidal gemmae usually abundant, never axillary, irregularly spherical, (50–)60–100(–115) μm diameter, cells protuberant. Capsules broadly pyriform, slightly contracted below mouth when dry and empty; spores 8–12 μm. Capsules unknown in the British Isles. On highly calcareous to slightly acid soil in arable fields, on margins of ponds and reservoirs. Lowland. Occasional to common in England and Wales, rare in Scotland. extending north to Sutherland, rare in Ireland. 93, H24, C. GB395 + 1∗ , IR23. European Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Rajasthan, China, Japan, N. America, Patagonia. Only likely to be confused with B. violaceum or B. sauteri. The former has gemmae of a purplish red colour with scarcely protuberant cells and usually violet rhizoids, and the latter has smaller gemmae which are brown like the rhizoids.

44 B. sauteri Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 190) Dioicous in Britain. Small tufts or scattered plants among other bryophytes, c. 4 mm high. Rhizoids red-brown, finely papillose. Leaves erect-patent when moist, ovatelanceolate, acuminate, reddish at base; margins unbordered, recurved below, ± entire; costa stout, excurrent in short point; basal cells narrowly rectangular, cells above narrowly rectangular or narrowly rhomboid-hexagonal, c. 14 × 70 μm in mid-leaf, slightly narrower towards margins but not forming a border. Gemmae usually abundant, never axillary, pyriform, brown or red-brown, 40–60 × 60– 100 μm, cells not or slightly protuberant. Capsules narrowly pyriform, distinctly contracted below mouth when dry and empty; spores 16–20 μm. Only female plants known in the British Isles. On disturbed basic or acidic soil in arable fields, on earthy banks and molehills. Lowland. Occasional to frequent in S. W. and extreme S. E. England and in Wales, rare or very rare elsewhere, extending north to Shetland, rare in Ireland. 56, H10, C. GB192, IR13, C3. European Temperate. Europe north to Norway, Iceland, Caucasus, Tenerife, Madeira, S. Africa, Ecuador, Chile, New Zealand. Most of the material of B. sauteri from continental Europe is synoicous and produces sporophytes. It is possible that there are two taxa, one oceanic and dioicous and the other continental and synoicous.

45 B. tenuisetum Limpr., Jahresber. Schles. Ges. Vaterl. Kult., 1897 (Fig. 190) Dioicous but with occasional synoicous inflorescences. Rhizoids usually yellow, papillose. Leaves erect-patent when moist, lanceolate, acuminate, reddish at base;

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30 Bryaceae

Fig. 190 1–3, Bryum sauteri: 1, leaf; 2, marginal cells at middle of leaf; 3, rhizoidal gemmae. 4–7, B. klinggraeffii: 4, leaf; 5, basal cells; 6, marginal cells at middle of leaf; 7, capsule (×10); 8, rhizoidal gemmae. 9–13, B. tenuisetum: 9, leaf; 10, basal cells; 11, mid-leaf cells; 12, capsule (×10); 13, rhizoidal gemma. Leaves ×35, cells ×280, gemmae ×250.

105 Bryum

581

margins hardly bordered, recurved, denticulate above; costa stout, excurrent, becoming dark purple with age; basal cells narrowly rectangular, cells above rectangular or rhomboid-hexagonal, 12–14 × 50–60(–100) μm, narrower and more incrassate at margins but hardly forming a border. Gemmae yellowish, usually abundant, on long rhizoids, never axillary, spherical or slightly angular, 120–180 (–220) μm diameter, cells distinctly protuberant. Capsules narrowly ellipsoid; spores 12–16 μm. Capsules frequent. On acid sandy or peaty soil on heaths, margins of upland reservoirs, very rarely in arable fields. 0–350 m. Rare to occasional from Cornwall east to Surrey and north to Skye and W. Sutherland, W. Cork, Jersey. 30, H1, C. GB56 + 5∗ , IR1, C2. European Boreo-temperate. Austria, Belgium, Czechoslovakia, Denmark, Finland, France, Germany, Iceland, the Netherlands, Norway, Poland, Sweden, Tenerife, N. America. The yellowish gemmae will distinguish B. tenuisetum from all other European members of the aggregate.

46 B. subapiculatum Hampe, Vidensk. Meddel. Dansk Naturhist Foren. København, 1872 (Fig. 191) ¨ Hal. & Kindb. B. microerythrocarpum Mull. Dioicous. Tufts or patches, 4–10 mm high. Rhizoids brownish, papillose. Leaves erect to erect-patent when moist, lanceolate, acuminate, reddish at base; margins scarcely bordered, recurved below, denticulate above; costa strong, excurrent; basal cells rectangular, cells above narrowly rhomboid-hexagonal or narrowly hexagonal, 10–16 × 45–70 μm in mid-leaf, narrower and more incrassate at margins but hardly forming a border. Gemmae on long rhizoids and sometimes axillary, scarlet or brick red, spherical, 190–260 μm diameter, cells not or only slightly protuberant. Capsules narrowly ovoid-cylindrical; spores 10–12 μm. Capsules occasional, late spring. On mildly acidic, disturbed, usually peaty or sandy soil in arable fields, by paths, on cliffs, molehills, heaths, rarely on moorland. 0–310 m. Occasional to frequent in England and Wales, rare in Scotland, extending north to Shetland, rare in Ireland. 98, H13, C. GB438 + 4∗ , IR13, C3. European Temperate. Europe north to Scandinavia, Faeroes, Iceland, Israel, N. America, New Zealand. A very variable species which may consist of more than one taxon and may contain derivatives of hybrids with B. rubens or B. tenuisetum. Most likely to be confused with B. rubens, which, however, has the leaves distinctly bordered and the gemmae with very protuberant cells.

47 B. bornholmense Wink. & R. Ruthe, Hedwigia, 1899 (Fig. 191) Dioicous autoicous or synoicous. Plants 3–15 mm high. Rhizoids brown, papillose. Leaves ovate or ovate-lanceolate, acute, reddish at base; margins bordered, recurved, denticulate above; costa stout, longly excurrent, 65–100 μm wide at base; cells incrassate, basal rectangular, cells above rectangular or rhomboidhexagonal, 14–20 × 60–80 μm in mid-leaf, marginal rows narrower, more

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30 Bryaceae

Fig. 191 1–3, Bryum subapiculatum: 1, leaves; 2, basal cells; 3, marginal cells at middle of leaf; 4, capsule; 5, rhizoidal gemma. 6–10, B. bornholmense: 6, leaves; 7, basal cells; 8, mid-leaf cells; 9, capsule; 10, rhizoidal gemma. Leaves ×35, cells ×280; capsules ×10, gemmae ×250.

105 Bryum

583

incrassate with pigmented walls c. 3 μm thick, forming distinct unistratose border. Gemmae borne on long rhizoids, never axillary, not glossy, translucent in transmitted light, colour variable, orange to orange-red or orange-brown, pale to dark brown, dark red or reddish brown, ± spherical, to 330 μm diameter, cells slightly protuberant when dry, not protuberant when moist, cells (30–)45–60 μm diameter, walls 1–2 μm wide, gemmae turning orange in dilute HCl, red or dark red in dilute KOH. Capsules pyriform; spores 12–14 μm. Capsules rare. On disturbed peaty or sandy soil, on heaths, sides of ditches, ponds and reservoirs, not recorded from arable fields but tolerant of shade, calcifuge. 0–400 m. Occasional in Wales and the southern half of England, rare further north, extending to Shetland, S. Kerry, N. Tipperary, Meath. 50, H3. GB77 + 3∗ , IR3. European Temperate. Rare in Europe, Denmark, France, Greece, Norway, Sweden, Gran Canaria. This and the next species have not been properly understood until recently. The accounts are based on manuscript descriptions kindly provided by the late Dr H. L. K. Whitehouse. There is also a posthumous paper, A. C. Crundwell & H. L. K. Whitehouse, J. Bryol. 23, 171– 6, 2001. B. bornholmense differs from B. rubens in the leaves with thicker costa and more incrassate cells, in the gemmae never being axillary and not having protuberant cells when moist. The gemmae are variable in colour, whereas in B. rubens they are always reddish. Furthermore, B. bornholmense is calcifuge and has not been recorded from arable fields.

48 B. rubens Mitt., Hooker’s J. Bot. Kew Gard. Misc., 1856 (Fig. 192) Dioicous. Plants 2–15 mm high. Rhizoids brown, papillose. Leaves erect or erectpatent when moist, ovate-lanceolate, acute, reddish at base; margins bordered, recurved, denticulate above; costa shortly excurrent, 65–75 μm wide at base; basal cells rectangular, cells above rhomboid-hexagonal, 16–20 × 40–60 μm, walls 1–2 μm thick, marginal cells longer, narrower, more incrassate, pigmented, forming distinct unistratose border. Gemmae spherical, glossy bright crimson, red or dark red, opaque in transmitted light, usually on very short rhizoids clustered at base of stems but sometimes on long rhizoids only, also solitary, to 260(–300) μm diameter, cells strongly protuberant, 30–35(–40) μm, turning red in dilute HCl and almost black in dilute KOH. Capsules cylindrical; spores 8–10 μm. Capsules occasional. On slightly acid to highly basic disturbed soil in fields, especially stubble fields, on roadsides and woodland rides. 0–450 m. Common in most of England and Wales, becoming rarer northwards, extending to Shetland, occasional in Ireland. 108, H33, C. GB1071 + 4∗ , IR44, C8. European Temperate. Europe, Azerbaijan, India, Japan, S. Africa, N. America and New Zealand (probably introduced). ˇ e Akˇed. Ved, Tˇr. 2, Vˇedy Pˇrı´r., Subsection 6 Alpiniformia (Kindb.) Podp Rozpr. Cesk´ 1901 Usually glossy, often reddish or red-green variegated plants. Leaves often equidistant along stems, not forming comal tufts, not or hardly bordered. Rhizoidal gemmae present or not. Processes widely perforated, cilia appendiculate; spores 12– 16 μm.

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30 Bryaceae

Fig. 192 Bryum rubens: 1, leaves (×35); 2, basal cells (×280); 3, marginal cells at middle of leaf (×280); 4, capsule (×10); 5, gemma (×250).

49 B. riparium I. Hagen, Kongel. Norske Vidensk. Selsk. Forh., 1908 (Fig. 193) Dioicous. Dense tufts, pale green above, blackish below, to 3 cm high. Stems brownish, concealed by closely placed leaves, tomentose below. Leaves imbricate, slightly twisted at tips when dry, erect to erect-patent when moist, lanceolate or ovate-lanceolate, acuminate, abruptly narrowed into shortly excurrent costa, base reddish, decurrent; margins bordered above at least in upper leaves, plane or recurved, entire; costa green or reddish brown; basal cells lax, rectangular or quadrate-rectangular, 16–40 μm wide at extreme base, cells above rhomboidal to narrowly rhomboidal, incrassate, (8–)12–16(–20) μm wide in mid-leaf, marginal cells longer, narrower, forming ± distinct border. Reddish flattened lobed rhizoidal gemmae, 100–200 × 76–150 μm, present in tomentum on older parts of stems. Only female plants known. On intermittently moist soil, rocks and in rock crevices, especially in stream beds but also on peat, sides of ditches and in arable fields. 0–760 m. Rare to occasional in the mountains of Wales, N. W. England and Scotland, S. Kerry, Waterford, W. Galway, Mayo. 32, H5. GB52 + 4∗ , IR8 + 1∗ . Hyperoceanic Temperate. Norway. Confused in the past with B. mildeanum, from which it differs in the more closely placed narrower leaves concealing the brown, not reddish, stems, the distinct border, the green or

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Fig. 193 1–3, Bryum muehlenbeckii: 1, leaf; 2, mid-leaf cells; 3, rhizoidal gemma. 4–7, B. riparium: 4, leaf; 5, basal cells; 6, marginal cells at middle of leaf; 7, rhizoidal gemma. 8–10, B. mildeanum: 8, leaf; 9, basal cells; 10, marginal cells at middle of leaf. Leaves ×25, cells ×420, gemmae ×250.

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30 Bryaceae

brownish costa and the distinctive gemmae which will separate B. riparium from all other British and Irish Bryum species. For a detailed comparison of B. riparium and B. mildeanum see H. L. K. Whitehouse, Trans. Br. Bryol. Soc. 4, 389–403, 1963.

50 B. mildeanum Jur., Verh. Zool.-Bot. Ges. Wien, 1862 (Fig. 193) Dioicous. Tight yellow-green tufts, 0.5–2.5 cm high. Stems reddish, sometimes visible between distant leaves. Leaves imbricate, straight when dry, erect or erect-patent when moist, concave, ovate-lanceolate, acuminate, apex gradually tapering into shortly excurrent costa, base reddish, shortly excurrent; margins obscurely bordered, recurved, entire or obscurely denticulate above; costa reddish, at least at base; basal cells lax, rectangular to quadrate-rectangular, 14–25 μm wide at extreme base, cells above rhomboidal to narrowly rhomboidal, slightly incrassate, 8–16 μm wide in mid-leaf, marginal cells narrower, forming obscure border. Rhizoidal gemmae lacking. Capsules unknown in Britain. On rocks and sand by streams, in limestone crevices and on soil on limestone. 70–850 m. Rare, Hereford, S. Wales, Caernarfon, N. W. England and the Scottish Highlands north to Sutherland. 18. GB16 + 10∗ . European Boreal-montane. Montane and northern Europe north to Fennoscandia, Turkey, S. W. and S. E. Asia, Macaronesia, N. Africa. 51 B. muehlenbeckii Bruch & Schimp. in Bruch et al., Bryol. Eur., 1846 (Fig. 193) Dioicous. Dark greenish-red tufts or patches, to 7 cm high. Stems tomentose below. Leaves straight, imbricate when dry, erect-patent when moist, sometimes pink-tinged, concave, ovate, obtuse to acute, reddish at base; margins unbordered, plane or recurved, entire; costa reddish, ending in or below apex; basal cells quadrate or quadrate-rectangular, upper cells rhomboid-hexagonal, slightly incrassate, 20–24 μm wide in mid-leaf. Orange-red, ± spherical rhizoidal gemmae, c. 160 μm diameter, sometimes present in tomentum on older parts of stems. Capsules narrowly ellipsoid; spores 12–14 μm. Capsules unknown in Britain. On acidic rocks in and by water in montane habitats. To 800 m. Caernarfon, Mid Perth, Inverness, Mull, Ross, W. Sutherland. 9. GB9 + 5∗ . European Boreal-montane. Montane and northern Europe north to Fennoscandia, Caucasus, Madeira, N. Africa, N. America, Greenland, Peru, Chile. 52 B. gemmiparum De Not., Comment. Soc. Crittog. Ital., 1866 (Fig. 194) Dioicous. Dense tufts, green above, reddish below, to 3 cm high. Leaves ± straight and imbricate when dry, erect-patent when moist, concave, ovate-lanceolate or lanceolate, acute, not reddish at base; margins ± unbordered, plane or slightly recurved, entire; costa strong, 75–100 μm wide near base, ending in or below apex; basal cells ± quadrate, cells above rhomboidal or narrowly rhomboidal, 12–18(–28) μm wide in mid-leaf, marginal cells narrower, occasionally forming very poorly defined border. Green to reddish sessile bulbils, mostly

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Fig. 194 1–6, Bryum alpinum: 1, leaves; 2, mid-leaf cells; 3, capsule (×10); 4, rhizoidal gemma (×250); 5, 6, leaf and cells of green-coloured form. 7–9, B. gemmiparum: 7, leaf; 8, mid-leaf cells; 9, axillary bulbil (×100). Leaves ×25, cells ×420.

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30 Bryaceae

250–750 μm long, with rudimentary leaves, often present in upper leaf axils. Orange or pink, rarely red spherical rhizoidal gemmae, 100–160 μm diameter, sometimes present in tomentum of older parts of stems. Capsules narrowly ellipsoid; spores 12–14 μm. Capsules unknown in Britain. n = 9 + m, 20. In rock crevices by streams and rivers. Lowland. Very rare, Devon, Monmouth, Brecon. 4. GB4 + 3∗ . Mediterranean-Atlantic. Southern Europe, Cyprus, Turkey, N. Africa. Plants without axillary bulbils cannot be named. B. gemmiparum is intermediate in leaf form and areolation between B. muehlenbeckii and B. alpinum, but distinct when axillary bulbils are present. It has been confused with species of the B. dichotomum aggregate, but these differ in their relatively wider more concave leaves, the weaker costa and shorter ± narrowly hexagonal cells. This species is considered endangered in the Red List of British Mosses.

53 B. alpinum Huds. ex With., Syst. Arr. Brit. Pl., 1801 (Fig. 194) Dioicous. Glossy purplish red, red or more rarely bright green and red variegated tufts or patches with distinct metallic sheen, to 6 cm high. Stems rigid, tomentose below. Leaves ± equidistant, imbricate when dry, erect to erect-patent when moist, of uniform colour throughout, concave, lanceolate to narrowly lanceolate, and ± tapering from below middle to obtuse to acute apex, margins unbordered, recurved or revolute below, entire or denticulate, rarely toothed above; costa stout or very stout, pale red to purplish red, ending below apex to percurrent; basal cells ± quadrate, cells above narrowly rhomboidal to vermicular, very incrassate in older leaves, thinner-walled and wider in younger leaves, 8–12(–16) μm wide in mid-leaf, marginal cells not or hardly narrower. Purplish red to brownish red, ± spherical rhizoidal gemmae, 120–200 μm diameter, usually present in tomentum of older parts of stems. Capsules large, pendulous, narrowly ellipsoid to subcylindrical, symmetrical, neck short; lid mamillate; cilia appendiculate; spores 12–14 μm. Capsules rare, summer. On acidic to slightly basic wet rocks and soil by paths, lakes, on banks and moorland. Mainly at low altitudes but ascending to 920 m in S. Aberdeen. Frequent or common in western and northern Britain, very rare in lowland England, common in the west and occasional elsewhere in Ireland. 70, H29, C. GB533 + 63∗ , IR82 + 14∗ , C6 + 1∗ . European Temperate. Europe to 70◦ N in Norway, Asia, Macaronesia, Morocco, Uganda, southern Africa, Madagascar, N. America, Mexico, Peru, Argentina. The robust, usually purplish red, metallic-tinged glossy tufts and leaves with vermicular cells make this an easy plant to recognise. Variable in colour and degree of cell wall thickness, and two varieties have been recognised in the British Isles on the basis of these two characters. Green plants with wider cells and denticulate leaf apices have been named var. viride Husn., but this variety does not seem worth maintaining as the range in colour from green to purple-red can occur in a single tuft and purple-red plants can have toothed leaves. However, A. C. Crundwell (in Hill et al., 1994) suggests that the variety may have some

106 Rhodobryum

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validity. Deeply coloured plants usually have a very stout costa and strongly incrassate narrower cells; such plants have been named var. meridionale Schimp., but this seems merely to be a dry ground form.

Subfamily 2 RHODOBRYOIDEAE With the characters of the genus. 106 RHODOBRYUM (SCHIMP.) HAMPE, LINNAEA, 1874 Plants robust, underground rhizomatous stolons present. Lower leaves of erect stems small, distant, upper much larger, in a terminal rosette, obovate or spathulate; margins bordered or not, unistratose, toothed above; costa ending below apex to excurrent, in section with few or no stereids; basal cells narrow, cells above rhomboid-hexagonal. Often polysetous; capsules horizontal to pendulous, oblongcylindrical, slightly curved, neck short; exostome teeth finely papillose, processes perforated, cilia appendiculate. A ± world-wide genus of about 45 species. Derivation: meaning rose moss, alluding to the rose-like rosettes of leaves.

1 R. roseum (Hedw.) Limpr., Laubm. Deutschl., 1895 Bryum roseum Hedw.

(Fig. 195)

Dioicous. Green patches, 5 cm or more high. Stems arising from underground rhizomatous stems with scale leaves, simple or with a single branch from below perichaetium, terminating in a comal rosette of 16–21 leaves. Lower leaves of erect stems scale-like, comal leaves much larger, shrunken and contorted when dry, spreading when moist, outer leaves ovate, acute, middle spathulate, acute, inner spathulate, acuminate; margins unbordered, recurved to about widest part of leaf, dentate above; costa ending below apex; cells in lower part of leaf rectangular, at widest part and above rhomboidal, 24–36 μm wide at widest part, 1–2 marginal rows below narrower, more incrassate but not forming border. Costa of perichaetial leaves percurrent or excurrent. Setae long, red; capsules pendulous with short neck; lid conical; spores 16–24 μm. Capsules very rare, autumn. n = 10∗ , 11. On sheltered, base-rich soil in turf, on banks, mud-capped walls and rock ledges, in dune-slacks. Lowland. Rare in western and northern Scotland and Ireland, occasional but widely distributed elsewhere. 100, H21. GB184 + 102∗ , IR14 + 17∗ . Circumpolar Boreo-temperate. Europe from northern Spain to 73◦ N in Norway, west to Siberia, China, Japan, British Columbia, Alaska. ´ (R. ontariense (Kindb.) Paris), has been A second species, R. spathulatum (Hornsch.) Pocs recorded from Sweden, C. Europe and Spain (Z. R. Iwatsuki & T. Koponen, Acta Bot. Fenn. 96, 1–22, 1972), and could occur in the British Isles. It is distinguished from R. roseum by the more numerous comal leaves (18–52) which when dry are strongly twisted and turned upwards and the 1–2 rows of marginal cells forming a yellowish border.

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30 Bryaceae

Fig. 195 1–3, Rhodobryum roseum: 1, leaf (×10); 2, mid-leaf cells (×280); 3, capsule (×10). 4–6, Mielichhoferia mielichhoferiana: 4, leaf (×65); 5, mid-leaf cells (×420); 6, costa section (×420). 7–9, M. elongata: 7, leaves (×65); 8, mid-leaf cells (×420); 9, costa section (×420).

31 Mniaceae Dioicous or synoicous. All stems erect or fertile stems erect and sterile stems procumbent or arcuate; central strand present. Leaves pellucid, ovate to linearlanceolate, acuminate to rounded; margins unbordered or with 1–several-stratose border, entire or dentate with single or double teeth; costa with stereid band in section; cells ± quadrate to linear, smooth, sometimes in divergent rows. Female inflorescences bud-like, male discoid or not. Sporophytes sometimes more than one per perichaetium; setae long; capsules cernuous to pendulous, ovoid to cylindrical; peristome double; calyptrae cucullate. Fifteen genera. Except for the subfamily Pohlioideae the treatment of this family follows T. Koponen, Ann. Bot. Fenn. 5, 117–51, 1968. In a later work (J. Hattori Bot. Lab. 64, 37–46, 1988) T. Koponen

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divides the family into the Mniaceae (Mnium), Cinclidiaceae (Cinclidium, Rhizomnium) and Plagiomniaceae (Plagiomnium, Pseudobryum), but the genera as a whole form such a natural group that this treatment does not seem to be justified.

Subfamily 1 POHLIOIDEAE Leaf margins usually unbordered, usually denticulate above; costa usually ending in or below apex, rarely excurrent, in section usually with large median guide cells, usually with 2 stereid bands; lamina cells frequently elongate, marginal cells differentiated or not. 107 MIELICHHOFERIA HORNSCH., BRYOL. GERM., 1831 Plants slender, densely tufted. Leaves ovate or lanceolate, margins unbordered, entire or denticulate above; costa ending in or below apex. Capsules erect or pendulous with distinct neck; exostome lacking. A cosmopolitan genus of c. 140 species, which occur particularly on montane copper-bearing rocks. Derivation: named after M. Mielichhofer (1772–1847), an Austrian director of mines and bryologist.

Leaves c. 3 times as long as wide, acute to obtuse, costa c. 30 μm wide, basal cells c. 15 × 40 μm 1. M. elongata Leaves c. 4 times as long as wide, acuminate, costa c. 40 μm wide, basal cells c. 10 × 30 μm 2. M. mielichhoferiana

1 M. elongata (Hoppe & Hornsch.) Nees & Hornsch., Bryol. Germ., 1836 (Fig. 195) Oreas mielichhoferi Brid. var. elongata (Hoppe & Hornsch.) Bruch & Schimp. Dioicous. Plants slender, forming dense glossy green patches, sometimes extensive, to 1.5 cm high. Leaves erect, imbricate when moist, ovate to ovate-lanceolate, c. 0.7 mm long, c. 2 times as long as wide, acute to obtuse, margins plane, denticulate above; costa c. 30 μm wide near base, ending well below apex, in section with one layer of large adaxial cells; cells thin-walled, basal rectangular, c. 15 × 40 μm. cells above narrowly hexagonal, c. 10 × 60 μm in mid-leaf. Setae cygneous; capsules horizontal or cernuous, pyriform; spores c. 17 μm. Capsules very rare. On damp shaded highly acidic heavy-metal-containing rocks. 600–890 m. Very rare, N. E. Yorkshire, S. Aberdeen. 2. GB3. Suboceanic Boreal-montane. Rare in Europe from Spain, Italy and Yugoslavia north to Svalbard, Caucasus, E. Africa, N. America. This species is treated as vulnerable in the Red List of British Mosses.

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2 M. mielichhoferiana (Funck ex Hornsch.) Loeske, Stud. Morph. Syst. Laubm., 1910 (Fig. 195) M. mielichhoferi (Hook.) Wijk & Margad., M. nitida (Hook.) Nees & Hornsch. Dioicous. Plants slender, in glossy, yellowish green tufts, 0.5–1.5 cm high. Leaves erect to slightly falcate when moist, lanceolate, c. 0.9 mm long, c. 4 times as long as wide, acuminate; margins sometimes recurved at middle of leaf; costa c. 40 μm wide near base, extending almost to apex, in section with 2 rows large adaxial cells; cells incrassate, basal rectangular, c. 10 × 30 μm, cells above narrowly hexagonal to vermicular, somewhat incrassate, c. 7 × 45 μm in mid-leaf. Setae flexuose; capsules ± erect; spores c. 12 μm. Capsules unknown in Britain. On damp shaded heavymetal-containing rock, at one of its two sites occurring with M. elongata. 700– 800 m. Very rare, S. Aberdeen, Argyll. 2. GB2. European Boreal-montane. N. and C. Europe, Pyrenees, Caucasus, China, N. America. M. mielichhoferiana differs from M. elongata in leaf shape, width of the costa and cell size. For a discussion of the taxonomy of the two species see A. J. Shaw, Bryologist 97, 47–55, 1994 and for the occurrence of M. mielichhoferiana in Scotland see P. D. Coker, Trans. Br. Bryol. Soc. 5, 448–51, 1968. This species is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside act.

¨ ¨ 108 EPIPTERYGIUM LINDB., OFVERS FORH. KONGL. SVENSKA VETENSK-AKAD., 1863 Dioicous. Small gregarious or tufted terricolous plants. Leaves of sterile stems in 3–4 ranks, 2 lateral and 1–2 dorsal, lateral leaves spreading, plane, from narrow base broadly ovate-oblong or obovate, the dorsal leaves smaller and narrower, margins plane, entire or denticulate above; costa ending well below apex; cells very lax, thin-walled, elongate-rhomboidal to hexagonal, marginal cells narrow, forming distinct border; leaves of fertile shoots less differentiated. Capsules inclined or cernuous; endostome with tall basal membrane, processes perforated, cilia present, nodulose. A small genus of c. 18 species, most of which occur in C. and S. America. Derivation: meaning winged on top, referring to the dorsal stem leaves.

¨ 1 E. tozeri (Grev.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 196) Webera tozeri (Grev.) Schimp. Small pale green to reddish tufts, patches or scattered plants among other bryophytes, c. 5 mm high; stems reddish. Leaves distant, glossy, twisted when dry, spreading when moist, of two distinct sizes, lateral leaves larger, broadly ovate to ovate-lanceolate, obtuse and apiculate to acute, dorsal leaves smaller,

109 Pohlia

593

ovate-lanceolate to lanceolate, acute, base very narrow, slightly decurrent; margins plane, entire or obscurely denticulate above, bordered; costa reddish, ending well below apex; cells lax, narrowly hexagonal throughout except at margins, 20–40 μm wide in mid-leaf, 3–6 marginal rows long, narrow, thicker-walled, forming distinct sometimes reddish border. Spherical to ovoid bulbils, 100– 300 μm diameter usually present at stem bases and developing in situ into leafy shoots. Pale brown ellipsoid rhizoidal gemmae, 35–55 × 100–130 μm, composed of 5–10 thin-walled cells occasionally present. Capsules horizontal to pendulous, obovoid or pyriform, abruptly narrowed into neck, ± spherical when dry and empty; lid obtusely mamillate; endostome ciliate; spores 14–20 μm. Capsules rare, spring, n = 11. On acidic, particularly clayey soil on shaded banks in hedgerows, woods, by streams and rivers. Lowland. Frequent in S. W. England, becoming rarer eastwards to Kent and Essex and northwards in Wales and the Marches, very rare elsewhere, I. of Man, Argyll, Kintyre and Jura, rare in Ireland. 37, H9, C. GB204 + 24∗ , IR10 + 2∗ , C5 + 1∗ . Mediterranean-Atlantic. Mediterranean and western Europe north to western France, Caucasus, Turkey, Lebanon, Himalayas, Taiwan, Japan, Macaronesia, Algeria, Morocco, Tunisia, western N. America. Recognisable by the broad bordered leaves with lax cells and costa ending well below the apex, these characters serving to distinguish the plant from species of Pohlia and Bryum with which it might be confused. For an account of vegetative propagules, ecology and distribution of E. tozeri see T. Arts & G. Nordhorn-Richter, J. Bryol. 14, 91–97, 1986.

109 POHLIA HEDW., SP. MUSC. FROND., 1801 Dioicous, autoicous, paroicous, synoicous or polyoicous. Plants usually tufted. Leaves ovate to lanceolate, longer, narrower and more crowded towards stem apex; margins unbordered, usually denticulate; costa ending in or below apex; cells linear to narrowly hexagonal. Setae long; capsules erect to pendulous, ovoid to ellipsoid, neck short or long; annulus present or not; peristome double, cilia appendiculate, sometimes rudimentary; calyptrae small, cucullate. A ± cosmopolitan genus of about 155 species. Derivation: named after E. Pohl, a German physician. The species of Pohlia and Bryum may be confused, but usually those of Pohlia have narrower unbordered leaves with long narrow cells.

1 Plants with axillary bulbils Plants without axillary bulbils 2 Bulbils solitary in leaf axils in upper part of stems (but not necessarily present in all axils) Bulbils 2–numerous per leaf axil at least in upper part of stems

2 12 3 4

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31 Mniaceae

3 Bulbils reddish brown, 500–1000 μm long, primordia arising at least down to middle of bulbils 6. P. drummondii Bulbils yellowish, 350–500 μm long, primordia restricted to apex of bulbils 8. P. filum 4 Bulbils 2–6 per axil in upper leaves, ovoid or obconical, yellowish green or reddish brown 5 Bulbils numerous, mostly 10–35 per axil in upper part of stems, ovoid, clavate or vermiform, yellowish green or orange, only reddish in older part of stems 7 5 All except youngest bulbils reddish brown 9. P. andalusica Bulbils yellowish green 6 6 Bulbil leaf primordia incurved, forming dome-shaped cavity over apex of bulbil 10. P. bulbifera Primordia ± erect 11. P. annotina 7 Bulbils globose, ovoid or clavate, vermiform bulbils present or not 8 Only vermiform bulbils present 10 8 Bulbils translucent, yellowish green to bright orange, apex with small protuberances but without definite leaf primordia 14. P. flexuosa Bulbils opaque, green at least when young, with definite leaf primordia 9 9 Bulbils ovoid, sessile, with 2–4 uni- to multicellular peg-like or triangular 11. P. annotina primordia c. 1/4 length of bulbil Bulbils ± globose, usually with short filamentous stalks, with 2–3 unicellular primordia 13. P. camptotrachela 14. P. flexuosa 10 Leaf primordia to 1/10 total length of bulbils 11 Primordia more than 1/10 total length of bulbils 11 Plants dull when dry, bulbils with 2–4(–5) peg-like 2–multicellular primordia 11. P annotina Plants glossy when dry, bulbils with 1–2 peg-like usually unicellular primordia 12. P. proligera 12 Mid-leaf cells of upper leaves mostly more than 16 μm wide 13 Mid-leaf cells of upper leaves 6–14 μm wide 16 13 Leaf bases decurrent 5 P. ludwigii Leaf bases not decurrent 14 14 Plants pale glaucous green, to 6(–15) cm high, upper leaves ovate or ovate-lanceolate 19. P. wahlenbergii Plants darker, to 1.5 cm high, leaves lanceolate or narrowly lanceolate 15 15 Mid-leaf cells 16–30 × 120–200 μm 18. P. melanodon Mid-leaf cells 16–20 × 40–120 μm or if longer then 14–16 μm wide 19. P. wahlenburgii 16 Plants with metallic sheen 3. P. cruda Plants lacking metallic sheen 17

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17 Mid-leaf cells of upper leaves 6–8 μm wide, costa percurrent or excurrent in upper leaves 2. P. crudoides Mid-leaf cells of upper leaves 10–14 μm wide or if less then costa ending in or below apex of upper leaves 18 18 Plants autoicous or paroicous, neck 1/2 –1 length of body of capsule 1. P. elongata Plants dioicous, capsule neck shorter or capsules lacking 19 19 Plants less than 1 cm high, rhizoidal gemmae present 20 Plants 1 cm or more high, rhizoidal gemmae lacking 21 20 Perichaetial leaves linear-lanceolate, mid-leaf cells 6–10 × 70–180 μm, rhizoidal gemmae yellowish, ellipsoid, with knobbly outline 16. P. lutescens Perichaetial leaves narrowly lanceolate, mid-leaf cells 10–14 × c. 80 μm, rhizoidal gemmae pale brown, spherical to pyriform, not knobbly 17. P. lescuriana 21 Mid-leaf cells 6–10 μm wide; margins recurved almost to apex at least on one side of leaf 7. P. scotica Mid-leaf cells to 14(–20) μm wide; margins narrowly recurved below 22 22 Lower leaves hardly concave, acute, upper leaves with costa ending below or in apex, common plant 4. P. nutans Lower leaves concave, acute to obtuse, upper leaves with costa percurrent or excurrent, very rare montane plant 5. P. obtusifolia

Section 1 Pohlia Monoicous or dioicous. Comal leaves long and narrow; cells linear to linearrhomboidal. Capsules usually horizontal to pendulous, cylindrical with long neck; exothecial cells rectangular; stomata superficial; annulus of large cells; basal membrane low, processes entire or narrowly perforated, cilia rudimentary or absent. 1 P. elongata Hedw., Sp. Musc. Frond., 1801 ¨ Webera elongata (Hedw.) Schwagr. Plants dull or pale green, 0.5–5.0 cm high. Stems brown. Leaves erect, straight to flexuose, somewhat shrunken when dry, erect to erect-patent when moist, lower distant, lanceolate, acuminate, comal crowded, narrowly lanceolate to linearlanceolate, acuminate; margins plane or recurved, denticulate above; costa stout, ending in or below apex; cells except at extreme base linear, often ± vermicular, 8–12 × 40–110 μm in mid-leaf. Capsules inclined to cernuous, narrowly pyriform to fusiform, sometimes curved; lid conical or mamillate, acute to obtuse; spores finely or coarsely papillose, 16–24 μm. Capsules common, late summer, autumn.

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Comal leaves 2–4 mm long, cells in mid-leaf 60–110 μm long, capsules var. elongata 2.5–6.0 mm long, neck c. 1/2 total length of capsule Comal leaves 1.0–2.5 mm long, cells in mid-leaf c. 40 μm long, capsules 1.5–3.5 mm long, neck less than 1/3 total length of capsule var. polymorpha Var. elongata (Fig. 196) P. acuminata Hoppe & Hornsch., P. elongata var. acuminata (Hoppe & Hornsch.) Huebener Paroicous or autoicous. Green or yellowish green tufts, 0.5–5.0 cm high. Comal leaves 2–4 mm long; mid-leaf cells 60–110 μm long. Setae (1.0–)1.5–2.5 cm long; capsules inclined to horizontal, very narrow, ± fusiform, 2.5–6.0 mm long, neck as long as body of capsule; lid acute to obtuse; basal membrane c. 1/2 height of endostome, cilia present or not. n = 11∗ , 22. On thin usually acidic soil in shaded rock crevices, on ledges and on soil banks. 0–920 m. E. Cornwall, S. Devon, S. Somerset, S. Hampshire, occasional to frequent elsewhere in montane areas in Wales, N. England, and Scotland, rare in Ireland. 49, H11. GB161 + 13∗ , IR11 + 4∗ . Circumpolar Boreal-montane. Montane Europe north to Scandinavia, Faeroes, Iceland, Caucasus, Turkey, Asia, Macaronesia, Africa, N. America, Kerguelen Is. Var. polymorpha (Hoppe & Hornsch.) Nyholm, Ill. Moss Fl. Fennoskand., 1969 (Fig. 196) ¨ P. major Schwagr., P. polymorpha Hoppe & Hornsch., Webera polymorpha (Hoppe & Hornsch.) Schimp. Paroicous. Plants rarely more than 1 cm high. Comal leaves usually 1.0–2.5 mm long; mid-leaf cells c. 40 μm long. Setae rarely more than 1 cm long; capsules cernuous, narrowly pyriform, 1.5–3.5 mm long, neck shorter than body of capsule; lid conical or mamillate, obtuse; endostome with very short basal membrane, without cilia. On thin soil on rock ledges, among rocks and on mountain summits, usually at higher altitudes than var. elongata. 400–1050 m. Rare, Caernarfon, Northumberland, Scottish Highlands north to Sutherland, S. Kerry, S. Tipperary, W. Galway. 21, H3. GB25 + 11∗ , IR2 + 1∗ . Circumpolar Boreal-montane. Montane Europe north to Svalbard, Faeroes, Iceland, Turkey, Caucasus, Kashmir, Himalayas, China, N. America, Greenland. A very variable species requiring experimental study. Although autoicous plants are regarded by some authorities as a distinct species, P. acuminata, apart from the inflorescence, the characters separating it from paroicous plants are inconstant and I do not consider that it is worth maintaining even as a variety. However, the largest plants of var. elongata are always paroicous and the smallest always autoicous. Var. polymorpha is usually distinct in its smaller size and capsule shape, but intermediate forms do occur, hence its varietal status. P. cruda differs in its metallic sheen and glaucous green colour and the leaf cells 80–200 μm long. P. crudoides is dioicous, has narrower leaf cells and erect or inclined

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Fig. 196 1–6, Pohlia elongata var. elongata: 1–3, lower, upper and perichaetial leaves (×25); 4, mid-leaf cells (×280); 5, capsule; 6, capsule of plant referred to as P. elongata var. acuminata. 7, P. elongata var. polymorpha: capsule. 8–10, Epipterygium tozeri: 8, leaves (×17.5); 9, marginal cells at middle of leaf (×210); 10, capsule. Capsules ×10. ovoid capsules. P. nutans has relatively wider leaves with shorter cells and relatively shorter capsules.

2 P. crudoides (Sull. & Lesq.) Broth., Nat. Pflanzenfam., 1903 (Fig. 197) Dioicous. Glaucous green tufts, reddish below, c. 3.5 cm high in Britain (to 7 cm high in Fennoscandia). Stems red. Leaves erect, slightly shrunken when dry,

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Fig. 197 1–3, Pohlia crudoides: 1, 2, lower and upper leaves (×10); 3, mid-leaf cells. 4–8, P. cruda: 4, 5, upper and perichaetial leaves (×17.5); 6, 7, mid-leaf stem and perichaetial leaf cells; 8, capsule (×7.5). 9–13, P. nutans: 9, 10, stem and perichaetial leaves (×17.5); 11, 12, mid-leaf stem and perichaetial leaf cells; 13, capsule (×7). 14–19, P. obtusifolia: 14, 15 stem leaves (×17.5); 16, perichaetial leaves (×17.5); 17, 18, mid-leaf stem and perichaetial leaf cells; 19, capsule (×10). Cells ×280.

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erect-patent when moist, lower lanceolate, upper narrowly lanceolate; margins recurved, slightly denticulate above; costa ending below apex in lower leaves, percurrent or excurrent in upper; cells linear, ± vermicular, 6–8 × 40–100 μm in mid-leaf. Capsules erect or slightly inclined, ovate-ellipsoid with short neck. Only male plants known in Scotland. n = 11. In crevices of montane rocks. 900 m. Very rare, E. Inverness. 1. GB1. Circumpolar Arctic-montane. Norway, Sweden, Finland, Svalbard, N. Russia, N., C. and E. Asia, N. America, Greenland. May be distinguished from P. elongata, P. cruda, P. nutans and P. cucullata by the very narrow cells and dioicous inflorescence. For the occurrence of this plant in Scotland see E. C. Wallace, J. Bryol. 7, 157–9, 1972. This species is treated as vulnerable in the Red List of British Mosses.

Section 2 Lamprophyllum (Lindb.) Broth., Nat. Pflanzenfam., 1903 Dioicous or paroicous. Comal leaves narrow; cells narrowly hexagonal to linear. Capsules usually horizontal to pendulous, narrowly ovoid or pyriform, neck short; exothecial cells long; stomata superficial; annulus of large cells; basal membrane of medium height, processes perforated, cilia usually present, not appendiculate. 3 P. cruda (Hedw.) Lindb., Musci Scand., 1879 ¨ Webera cruda (Hedw.) Furnr.

(Fig. 197)

Dioicous, paroicous or autoicous. Glaucous green or pale green tufts with metallic sheen above, reddish below, to 4 cm high. Stems red. Leaves erect to erect-patent when moist, hardly altered when dry, reddish at base, lower ovate-lanceolate, acute with entire margins, upper lanceolate, comal narrowly lanceolate, acute; margins plane, denticulate above; costa reddish, ending below apex; extreme basal cells rectangular, cells elsewhere ± uniformly linear, 8–12 × 80–200 μm in midleaf, slightly narrower at margins. Capsules inclined to subpendulous, ± ellipsoid, neck c. 1/2 length of body of capsule; lid mamillate; endostome ciliate; spores 18– 24 μm. Capsules occasional, summer. n = 10, 10 + 4m, 11∗ , 22∗ , 40. Dry to moist slightly acidic to basic rock crevices and ledges, walls and coastal rocks. 0–1180 m. Frequent or common in montane areas from Wales and Derby northwards, Devon, rare in Ireland. 62, H14. GB317 + 30∗ , IR10 + 4∗ . Circumpolar Boreo-arctic Montane. Europe, Faeroes, Iceland, Asia, Azores, La Palma, Algeria, Morocco, southern Africa, N., C. and S. America, Kerguelen Is, Hawaii, Australia, New Caledonia, Antarctica. Readily recognised in the field by the glaucous green leaves with a metallic sheen.

4 P. nutans (Hedw.) Lindb., Musci Scand., 1879 Webera nutans Hedw.

(Fig. 197)

Synoicous. Dull dark green tufts or patches, sometimes extensive, brownish below, or scattered plants among other bryophytes, 1.0–7.5 cm high; stems reddish

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31 Mniaceae

brown with reddish brown tomenttum below. Lower leaves ± imbricate when dry, erect when moist, ovate-lanceolate, acute; margins plane or narrowly recurved; upper leaves shrunken, flexuose when dry, erect-patent when moist, narrowly lanceolate, acuminate; margins narrowly recurved, entire to sharply denticulate; costa reddish brown, ending in or below apex; basal cells incrassate, rectangular, reddish, elsewhere narrowly rectangular to elongate-hexagonal, in lower leaves 9–14 × 25–80 μm in mid-leaf, in upper leaves 10–16(–20) × 60–100 μm in midleaf. Setae flexuose, variable in length, 1–5 cm long; capsules horizontal to pendulous, narrowly pyriform to ovate-ellipsoid, neck conspicuous or not, less than 1/ length of body of capsule; lid mamillate; spores 18–28 μm. Capsules common, 2 spring, summer. n = 11, 11 + m, 12, 12 + m, 20, 21 + 2m, 22∗ , 22 + m, 32 + m, 33∗ . On peaty or gravelly soil, decaying wood, bark, in rock crevices, on heaths, in bogs, woods, relict industrial sites especially where heavy-metal polluted, in shaded or open, wet or dry habitats, calcifuge. 0–1340 m. Common except in basic areas, occasional to frequent in Ireland. 112, H38, C. GB1591 + 91∗ , IR151 + 6∗ . Circumpolar Wide-boreal. Europe north to Svalbard, Faeroes, Iceland, Asia, southern Africa, N. America, southern S. America, Australasia, Kerguelen Is., Antarctica. A usually easily recognised plant forming dark green tufts or patches, with relatively long setae, especially characteristic of acidic peaty or sandy soil. Very variable morphologically and cytologically. P. cruda differs in colour, metallic sheen and narrower leaf cells. A curious plant, reddish in colour and dioicous, has been found at several sites in Berkshire; these plants in other respects come within the range of P. nutans and it seems likely that they are a habitat form of that plant, but the matter requires experimental investigation.

5 P. obtusifolia (Villars ex Brid.) L. F. Koch, Leafl. W. Bot., 1950 ¨ ¨ P. cucullata (Schwagr.) Lindb., Webera cucullata (Schwagr.) Schimp.

(Fig. 197)

Paroicous. Glossy pale green tufts, 1.0–2.5 cm high. Stems reddish. Leaves appressed when dry, erect-patent when moist, concave, ovate to ovate-lanceolate, base somewhat decurrent, apex acute to obtuse, comal leaves larger, lanceolate, acute; margins plane or narrowly recurved, entire or denticulate above; costa stout, ending below apex in lower leaves, percurrent or excurrent in comal leaves; cells in lower leaves elongate-hexagonal except at base, 12–24 × 40–80 μm in midleaf, in comal leaves 10–14 × 70–130 μm in mid-leaf. Capsules pendulous, pyriform, short-necked; lid mamillate or conical; spores 30–36 μm. Capsules frequent, late summer. On flushed rocks and in bogs and flushes at high altitudes. Ascending to 1100 m. Very rare, Mid Perth, Inverness, W. Ross. 4. GB4 + 3∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Iceland, N. and C. Asia, Japan, N. America, Greenland. Similar in appearance to P. nutans but the leaves are relatively shorter and wider and less sharply pointed as well as being concave and with ± decurrent bases; the spores are larger. It also somewhat resembles P. drummondii but that species has reddish brown axillary bulbils. This species is considered endangered in the Red List of British Mosses.

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Section 3 Cacodon Broth., Nat. Pflanzenfam., 1903 Dioicous. Upper leaves ± similar to lower leaves not forming comal tuft; cells narrowly hexagonal to linear-rhomboidal. Capsules horizontal to pendulous, ovoid or pyriform with short neck; exothecial cells short; stomata superficial; annulus of large cells; processes perforated, cilia not appendiculate. 6–14 P. annotina complex It has been shown that all of the next nine species except P. scotica, which was not described until 1982, remain distinct in cultivation and produce axillary bulbils. They fall into two groups, those in which young bulbils are produced in clusters (species 9–14), and P. drummondii and P. filum in which the bulbils arise singly in the leaf axils. However, the number and morphology of the bulbils of the bulbilliferous species vary depending upon the time of year and the age of the plants. Whilst there are some differences in leaf shape and cell size, as between P. drummondii, P. scotica and P. filum, in the other species differences are not statistically significant and are not of much practical use in identification. Sporophytes are so rarely produced that they likewise are of little use. Bulbil descriptions are of bulbils from the upper 1/3 of stems. Bulbils frequently become detached in dried specimens but may usually be found in the detritus in the bottom of packets. The leaf-like outgrowths or projections on the bulbils are referred to for convenience as leaf primordia, but they are not necessarily homologous with such structures. For an account of the P. annotina complex in the British Isles see K. B. Lewis & A. J. E. Smith, J. Bryol. 9, 539–56, 1977 and 10, 9–27, 1978, and in N. America see A. J. Shaw, J. Hattori Bot. Lab. 59, 1–81, 1981. Lewis & Smith (1978) considered P. proligera to be synonymous with P. annotina, but had not seen authentic material of the former. ¨ Hal.) A. L. Andrews in Grout, Moss Fl. N. Am., 1935 6 P. drummondii (Mull. (Figs. 198, 199) Webera commutata Schimp. Dioicous. Lax or dense greenish tufts, 1–4(−10) cm high. Leaves appressed when dry, erect-patent when moist, ovate-lanceolate, acute, 1.0–1.6 × 0.4–0.7 mm, c. 2.5 times as long as wide; margins plane or narrowly recurved below, bluntly denticulate above; costa ending below apex; cells narrowly rhomboidal, 8–15(−18) × 33–90(−103) μm in mid-leaf. Bulbils one per axil but not regularly present in every axil, reddish brown, ovoid, 500–1000 × 150–400 μm, primordia (5−)6–8(−11), broad, green, arising at different levels on upper half of bulbil and sometimes 1–2 outgrowths from lower half; bulbils in tall montane plants may be longer and germinate in situ. Capsules cernuous or pendulous, narrowly pyriform; lid conical; spores 12–20 μm. Capsules summer, occasional in Scotland, rare elsewhere. In at least periodically moist habitats, on sandy soil and gravel by streams, rivers, waterfalls, on muddy tracks, cuttings, in old gravel pits and rock crevices. 0–1220 m. Rare in lowland England, rare to frequent in montane habitats,

602

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Fig. 198 1–3, Pohlia drummondii: 1, dry shoot; 2, leaves; 3, mid-leaf cells. 4–7, P. scotica: 4, 5, dry and moist shoots 6, leaves; 7, mid-leaf cells. 8–10, P. filum; 8, dry shoot; 9. leaves; 10. mid-leaf cells. Shoots ×15, leaves ×40, cells ×280.

109 Pohlia

603

Fig. 199 Axillary bulbils of Pohlia species. 1. Pohlia filum; 2, P. bulbifera: 3, P. andalusica: 4, P. drummondii. All ×100.

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extending from Cornwall east to W. Sussex and north to W. Sutherland, very rare in Ireland. 44, H7. GB158 + 10∗ , IR7. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Asia, N. America, Patagonia. Lowland forms of this plant have been mistaken for P. andalusica, which, however, is very rare in Britain. In P. andalusica, the leaf primordia of the bulbils arise from the same level on the flattened apex and the bulbils are smaller and mostly 3–6 per leaf axil. In P. filum, which like P. drummondii usually has solitary bulbils, the bulbils are yellowish.

7 P. scotica Crundw., J. Bryol., 1982 (Fig. 198) Sex unknown. Bright green tufts, 1–6 cm high; stems red or red-brown, with large central strand. Leaves erect or erect-patent when dry, little changed when moist, 1–2 × 0.3–0.6 mm, 3–4 times as long as wide, lanceolate; margins recurved almost to apex at least on one side, entire or denticulate towards apex; costa ending in or below apex; mid-leaf cells narrowly rhomboidal, 6–10 × 33–100 μm. Vegetative propagules, gametangia and sporophytes unknown. On silt among rocks, on damp sandy and stony ground by lakes and streams. 95–650 m. Very rare, Mid Perth, Argyll, Dunbarton, E. Ross. 4. GB8. Endemic Suboceanic Boreal-montane). Endemic to Scotland. Most likely to be mistaken for plants of P. drummondii lacking bulbils, but differing in the more longly tapering relatively narrower leaves. In dry plants of P. scotica, the leaves are narrower and more spreading than those of P. drummondii, giving the plants a different appearance. P. filum is intermediate between P. drumondii and P. scotica in leaf shape and cell size, but the leaves are erect and appressed when dry, are smaller and have the margins recurved 1/4 –1/2 way up the leaves on one side only. For an account of P. scotica see A. C. Crundwell, J. Bryol. 12, 7–10, 1982.

˚ 8 P. filum (Schimp.) Martensson, Kung. Svenska Vetenskapskad. Avh. ¨ Naturskyddsarenden, 1956 (Figs. 198, 199) P. gracilis (Bruch & Schimp.) Lindb., P. schleicheri Crum, Webera gracilis (Bruch & Schimp.) De Not. Dioicous. Lax or dense yellowish green tufts, becoming reddish or brownish with age, to 4 cm high. Leaves appressed when dry, erect when moist, ovatelanceolate to lanceolate, 0.8–1.2(−1.5) × 0.20–0.45 mm, 2.5–3.5 times as long as wide; margins plane or recurved to 1/4 –1/2 way up on one side only, denticulate above; costa ending below apex; cells narrowly rhomboidal, (7−)9–13(−15) × 45– 90(−110) μm in mid-leaf. Capsules cernuous to pendulous, pyriform; lid convex or mamillate; spores 12–22 μm. Capsules rare, late spring, early summer. In open habitats on wet sand, gravel and rocks by streams, rivers and roads, in sand-dunes. 0–330 m. Surrey, Carmarthen, N. Lancashire, rare in southern Scotland, occasional in the Highlands, extending north to Shetland, Waterford, W. Mayo, Tyrone,

109 Pohlia

605

Armagh. 23, H4. GB53 + 4∗ , IR5. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, Siberia, N. and C. America, Greenland. Differs from other related species in the erect leaves, bulbil morphology and pyriform capsules.

¨ 9 P. andalusica (Hohn.) Broth., Nat. Pflanzenfam., 1903 P. rothii (Correns) Broth.

(Fig. 199)

Dioicous. Light green tufts or patches, sometimes extensive, 1–3 cm high. Leaves lanceolate or ovate-lanceolate; margins plane, denticulate above; costa ending below apex; cells narrowly rhomboidal, 6–10 μm wide in mid-leaf. Bulbils in upper part of shoots 3–6(−12) per axil, yellowish green when young, soon becoming reddish brown, obconical or ovoid with flattened apex, 200–300 × 80–120 μm, primordia 3–5(−6), green, erect, broad, ± overlapping, arising at same level at apex, c. 1/3 total bulbil length, on older parts of stems bulbils fewer, larger, to 500 μm wide. Capsules horizontal to pendulous, oblong-ellipsoid; lid conical to rostellate; spores 14–24 μm. Capsules unknown in the British Isles. On damp sandy soil on tracks, china clay and mine waste. 0–600 m. Very rare, Cornwall, S. Devon, W. Ross, W. Cork, Waterford. 4, H2. GB12, IR2. Suboceanic Borealmontane. W. and C. Europe north to Norway, Faeroes, Iceland, N. Asia, Azores, N. America. Young plants with yellowish green bulbils may be confused with P. annotina, but differ in the larger overlapping primordia of the bulbils.

10 P. bulbifera (Warnst.) Warnst., Krypt.- Fl. Brandenburg, 1904 Webera annotina var. bulbifera (Warnst.) Correns ex Dixon

(Fig. 199)

Dioicous. Yellowish green tufts, 0.5–2.0 cm high. Leaves spreading when moist, lanceolate; margins plane, denticulate above; costa ending below apex; midleaf cells 7–11 μm wide. Bulbils (1−)3–5(−8) per axil, ovoid, yellowish green, (150−)200–300 × 120–200 μm, leaf primordia usually 4, incurved, forming a hollow cover over apex of bulbil, c. 1/3 total bulbil length. Capsules cernuous to pendulous, obovoid, lid conical to rostellate; spores 14–24 μm. Capsules rare, early summer. On damp alluvial soil by streams, rivers, lakes and reservoirs, in old quarries and on cliff ledges, usually in montane areas. 0–350 m. Occasional in western and northern Britain from E. Cornwall north to Orkney, rare in Ireland. 50, H11. GB129 + 8∗ , IR19 + 1∗ . Circumpolar Boreo-temperate. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Turkey, N. Asia, Azores, N. America, Greenland. Readily recognised by the distinctive bulbils. When dried specimens are moistened an air bubble is usually trapped by the leaf primordia over the apex of the bulbil, a feature not encountered in other species.

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11 P. annotina (Hedw.) Lindb., Musci Scand., 1879 P. proligera auct. angl., Webera annotina (Hedw.) Bruch

(Fig. 201)

Dioicous. Lax light green tufts to extensive patches, often mixed with other bryophytes, 1.5–3.0 cm high. Leaves erect-patent to spreading when moist, ovatelanceolate to lanceolate, acute; margins plane, denticulate above; costa ending below apex; cells (6−)8–10(−12) μm wide in mid-leaf. Bulbils light green, very variable in shape and size depending on position on stem and age of plants, of two types, vermiform and ovoid to oblong; in upper part of stem 10–25(−30) per axil, below and in older plants (1−)3–10 per axil; ovoid to oblong sessile bulbils (160−)200–300 × (80−)100–150 μm; vermiform bulbils (250−)300–450 × 50–60(−80) μm; both types with 2–4(−5) unicellular or multicellular, mostly narrowly rectangular to prong-like apical primordia, c. 1/4 length of ovoid bulbils. Capsules cernuous to pendulous, obovoid; lid conical; spores 14–22 μm. Capsules very rare, early summer. n = 11∗ . On loamy to gravelly acidic to mildly basic soil by ditches, streams and rivers, on waste ground, in gravel pits, on woodland rides, damp rocks and copper mine-waste. 0–800 m. Occasional to frequent in southern England from Cornwall east to Kent and Essex, and in western Britain from Wales north to Shetland, rare elsewhere, occasional in Ireland. 107, H30, C. GB850 + 71∗ , IR99 + 4∗ , C4. European Boreotemperate. Europe, Turkey, Asia Minor, Siberia, Azores, Madeira, N. America, Greenland. Bulbil shape is exceedingly variable. They are most numerous and small in young plants and young parts of stems; as bulbils are dislodged the remainder become larger, up to 4–5 times the original size. Small vermiform bulbils may be produced in the axils of new growth from old stems. Forms with only vermiform bulbils may be found on mud and wet soil in shaded situations in rock crevices, among boulders and in woods. Forms with few large bulbils may be mistaken for P. drummondii, P. filum or P. andalusica. The first differs in the solitary reddish brown bulbils and the primordia arising at different levels on the bulbils; P. filum also has solitary bulbils, and P. andalusica has reddish brown bulbils with larger wider overlapping primordia. P. camptotrachela and P. flexuosa have axillary bulbils which are often stalked. This is the plant referred to as P. proligera in the first edition of this flora.

12 P. proligera (Lindb.) Kindb. ex Arnell, Bot. Not., 1894 (Fig. 200) Dioicous. Lax green tufts, patches or scattered plants among other bryophytes, glossy when dry, 0.5–1.5 cm high. Leaves erect-patent when moist, lanceolate to ovate-lanceolate, acute; margins recurved below, denticulate above; costa ending below apex; mid-leaf cells 7–10 μm wide. Bulbils abundant in axils of upper leaves, vermicular, translucent, mostly green, becoming yellow to red with age, 150–300(−450) μm long, to 60 μm wide, with 1–2 usually unicellular, often bent primordia at apex. Capsules narrowly pyriform; spores 15–20 μm. Capsules unknown in the British Isles. On open disturbed mildly basic soil. Ascending to 800 m. Rare, in scattered localities from Warwick and Denbigh north to E. Ross,

109 Pohlia

607

Fig. 200 Axillary bulbils of Pohlia species. 1, Pohlia camptotrachela (×150). 2–3, P. flexuosa var. pseudomuyldermansii; 2, clavate bulbils (×150); 3, vermicular bulbils (×100). 4, P. flexuosa var. flexuosa: clavate bulbils (×250). 5–6, P. annotina: clavate and vermicular bulbils (×100). 7, P. proligera (×100).

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Londonderry. 14, H1. GB17, IR1. European Boreal-montane. Northern and montane Europe north to Svalbard, Azores, Madeira, N. America. Likely to be confused with forms of P. annotina in which only vermicular bulbils are present. The bulbils differ from those of P. proligera in being 2–multicellular and only having 2–4(−5) primordia per bulbil. Authentic material of this plant was not seen by K. B. Lewis & A. J. E. Smith (J. Bryol. 10, 9–27, 1978) and they concluded that it and P. annotina were conspecific. The two are, however, distinct – see under P. annotina.

13 P. camptotrachela (Renauld & Cardot) Broth., Nat. Pflanzenfam., 1903 (Fig. 200) Dioicous. Small pale green tufts, 0.5–2.0 cm high. Leaves spreading when moist, lanceolate, margins plane, denticulate above; costa percurrent; cells narrowly rhomboidal, 7–14 × 40–130 μm in mid-leaf. Bulbils 10–25(−30) per axil in upper part of stems, yellowish or light green, rarely orange or in old plants deep red, ± globose, 80–140(−180) × 80–120 μm, usually with short stalk, with 2–4 unicellular inflexed apical projections, c. 1/5 total length of bulbil, bulbils fewer and sometimes solitary and much larger in lower axils; vermicular gemmae never present. Capsules cernuous to pendulous, ± pyriform; spores 14–24 μm. Capsules unknown in the British Isles. On damp soil in fields, on banks by streams, rivers, pools and reservoirs, on paths and by tracks. 0–300 m. Occasional in western England and W. Wales, rare in Scotland, extending north to Shetland, rare in Ireland. 63, H11. GB148 + 17∗ , IR12. Suboceanic Boreal-montane. Europe north to Fennoscandia, Azores, Madeira, western N. America. Often occurs with P. bulbifera or P. annotina. It is distinct from other bulbilliferous Pohlia species in the smaller bulbils. Most likely to be confused with P. flexuosa, which has clavate, ovoid or ellipsoid bulbils without distinct apical projections.

14 P. flexuosa Hook., Icon. Pl., 1836 P. muyldermansii R. Wilczek & Demaret Dioicous. Lax or dense tufts or scattered plants, 0.5–2.0 cm high. Leaves erect when dry, spreading when moist, lanceolate, acute; margins plane, denticulate above; costa ending below apex; cells narrowly rhomboidal, 7–15(−20) μm wide in mid-leaf. Bulbils 15–25(−30) per axil in upper part of stems, of two types: vermicular, very caducous, pale green bulbils, 400–1000 × 25–50 μm, composed of spirally twisted cells with 2–4 finger-like apical projections less than 1/10 total bulbil length; clavate, ovoid or ellipsoid bulbils, yellowish green to bright orange, translucent, sessile or stalked, 60–170 × 35–80 μm, apex smooth or with protuberant cell walls or knobbly; both types may be present together or one or the other but the vermicular bulbils are soon lost; on older parts of stems the second type of bulbil may become cylindrical, 4–5 times larger, deep orange or reddish brown. Setae slender, flexuose; capsules obovoid. Capsules very rare.

109 Pohlia

609

Suboceanic Boreal-montane. W. and C. Europe, Sri Lanka, India, Bhutan, Nepal, China. Dense tufts, clavate bulbils smooth or with protuberant cell walls, without filamentous stalks var. flexuosa Lax tufts or scattered plants, clavate bulbils knobbly, with filamentous stalks var. pseudomuyldermansii Var. flexuosa (Fig. 200) Plants forming dense tufts. Leaves 2.0–2.9 times as long as wide; mid-leaf cells 10– 15(−20) × 35–130 μm, 4–6 times as long as wide. Short bulbils ovoid or ellipsoid, 60–140 × 35–70 μm, smooth or with bulging cell walls, not stalked, in culture vermicular bulbils produced before short bulbils. On moist stream banks, sides of ditches and roads, sometimes on heavy-metal polluted substrates, in areas with annual rainfall of 750–850 mm. Lowland. Not recorded from the British Isles but likely to occur in lowland England. Belgium, Germany, the Netherlands. Var. pseudomuyldermansii (T. Arts et al.) A. J. E. Sm., J. Bryol., AAA (Fig. 200) Lax tufts or scattered plants. Leaves 2.3–3.7 times as long as wide; mid-leaf cells 7.5–12.5 × 45–110 μm, 5–8 times as long as wide. Short bulbils clavate, 90–170 × 50–80 μm, often with filamentous stalks, knobbly and with short stubby apical protuberances; in culture short bulbils produced before vermicular bulbils. On shallow soil, gravel and fragmenting rocks in sheltered rocky places by waterfalls and streams, rarely by roadsides and in fields in montane areas with an annual rainfall of more than 1000 mm. Rare or occasional in western and northern Britain from E. Cornwall north to W Sutherland, South Lewis, rare in Ireland. 39, H9. GB78 + 2∗ , IR11. Suboceanic Boreal-montane. Austria, Switzerland. The differences between the two varieties are small but consistent and these, together with ecological differences, merit maintenance of varietal status (see A. J. E. Smith, J. Bryol. AAA). P. flexuosa is readily recognised by the dense clusters of small translucent yellowish green to orange bulbils. Var. flexuosa has not yet been found in Britain but is very likely to occur. It has been confused in continental Europe with P. camptotrachela but that species differs in never having vermicular bulbils and the clavate bulbils which have short stalks, being opaque and with 2–4 inflexed apical primordia. Plants with only vermicular gemmae may be mistaken for P. annotina or P. proligera, but in the former the bulbils have 2–4(−5) apical projections and in the latter they have usually unicellular primordia.

¨ 15 P. ludwigii (Sprengl. ex Schwagr.) Broth., Acta Soc. Sci. Fenn., 1892 (Fig. 201) ¨ Mniobryum ludwigii (Sprengl. ex Schwagr.) Loeske, Webera ludwigii (Sprengl. ¨ ¨ ex Schwagr.) Furnr. Dioicous. Lax or dense tufts or patches, sometimes extensive, bright green above, reddish below, (1−)2–10(−15) cm high. Leaves shrunken when dry, patent when

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Fig. 201 1–2, Pohlia annotina: 1, leaves (×35); 2, mid-leaf cells. 3–4, P ludwigii: 3, leaves (×25); 4, mid-leaf cells. 5–9, P. lutescens: 5, 6, lower and upper leaves; 7, 8, mid-leaf cells of lower and upper leaves; 9, rhizoidal gemmae (×250). 10–14, P. lescuriana: 10, 11, lower and upper leaves (×25); 12, 13, mid-leaf cells of lower and upper leaves; 14, rhizoidal gemmae (×175). Cells ×280.

109 Pohlia

611

moist, pink or red-tinged except the uppermost, distant, concave, lower broadly ovate, obtuse to acute, upper ovate, acute, base longly decurrent, margins narrowly recurved, sinuose or faintly denticulate towards apex; costa ending well below apex; cells lax, thin-walled, elongate-rhomboidal, 16–24 μm wide in midleaf, narrower towards margins. Perichaetial leaves larger and more acute than stem leaves. Capsules ± pendulous, pyriform. Capsules rare except in areas of late snow lie where they are frequent, summer. Soil on banks and by streams, on rock ledges, in areas of late snow-lie, montane flushes. Ascending to 1340 m. Occasional in the Scottish Highlands north to Sutherland, very rare elsewhere, N. W. Wales, N. England. 18. GB44 + 8∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Kenya, N. America, Greenland. 16 P. lutescens (Limpr.) H. Lindb., Acta Soc. Sci. Fenn., 1899 Mniobryum lutescens (Limpr.) Loeske

(Fig. 201)

Dioicous. Small glossy yellowish green tufts or patches or scattered plants among other bryophytes, 3–8 mm high. Leaves flexuose, shrunken when dry, patent or spreading when moist, lanceolate to linear-lanceolate, acuminate, margins plane or narrowly recurved below, denticulate, sometimes spinosely so from about middle of leaf; costa ending below apex in lower leaves to longly excurrent in perichaetial leaves; cells narrowly rhomboidal to linear, in upper leaves 6–10 × 70– 180 μm in mid-leaf, wider in lower leaves. Perichaetial leaves longer and narrower than stem leaves. Pale yellow, knobbly ellipsoid rhizoidal gemmae, 50–70 × 40– 50 μm, always although sometimes sparsely present. Green filamentous gemmae produced in leaf axils during March. Capsules unknown in the British isles. On clayey soil in open habitats, on banks by paths, ditches and streams. 0–450 m. Occasional to frequent in England and Wales, rare in Scotland, extending north to Caithness, very rare in Ireland. 79, H5, C. GB299, IR5, C2. European Temperate. European endemic extending from Italy and Yugoslavia north to Scandinavia. Differs from P. lescuriana in the usually sharply denticulate upper leaves, narrower perichaetial leaves, the narrower, longer cells and in the morphology of the rhizoidal gemmae. For an account of this plant in the British Isles see E. V. Watson, Trans. Br. Bryol. Soc. 5, 443–7, 1968.

17 P. lescuriana (Sull.) Ochi, J. Fac. Educ. Tattori Univ., Nat Sci., 1968 (Fig. 201) P. pulchella (Hedw.) Lindb., Mniobryum pulchellum (Hedw.) Loeske Dioicous. Dull green or pale green tufts or patches, c. 5 mm high; stems brownish. Leaves flexuose when dry, spreading when moist, lower ovate-lanceolate, upper lanceolate, margins plane or narrowly recurved below, obscurely toothed above; costa ending below apex; cells thin-walled, narrowly rhomboidal to linearrhomboidal, in upper leaves 10–14 × c. 80 μm in mid-leaf, wider in lower leaves. Perichaetial leaves narrowly lanceolate, acuminate; costa percurrent to excurrent. Pale brown spherical, ellipsoid or pyriform rhizoidal gemmae, 75–150 × 70–90 μm,

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always although sometimes sparsely present. Setae 1–2 cm long; capsules pendulous, ovoid, neck short; lid conical, apiculate; endostome with nodulose cilia; spores 12–15 μm. Capsules occasional, winter, spring. Usually on damp clayey soil on banks by streams, ditches, reservoirs, paths, on woodland rides and in fields. 0–400 m. Rare to occasional in England and Wales, very rare in Scotland, extending north to Caithness, W. and Mid Cork, Limerick. 38, H3. GB70, H3. Eurosiberian Temperate. Europe north to Fennoscandia, Japan, N. America. For the occurrence of this plant in British Isles see E. F. Warburg, Trans. Br. Bryol. Soc. 4, 760–2, 1965.

Section 4 Mniobryum (Schimp.) Nyholm, Ill. Moss Fl. Fennoscand., 1958 Dioicous. Capsules cernuous or pendulous, ovoid or pyriform, neck short; exothecial cells short; stomata immersed; basal membrane well enveloped, processes perforated, cilia simple or nodulose. 18 P. melanodon (Brid.) A. J. Shaw, Bryologist, 1981 (Fig. 202) Mniobryum delicatulum (Hedw.) Dixon, P. carnea (Schimp.) Lindb., P. delicatula (Hedw.) Grout, Webera carnea Schimp. Dioicous. Pale green to reddish lax to dense tufts or patches, 3–10 mm high; stems red. Leaves flexuose when dry, patent when moist, frequently reddish at base, ovate to lanceolate, acute to acuminate, margins plane, obscurely denticulate above; costa ending below apex; cells thin-walled to slightly incrassate, ± rhomboidal, 16–30 × 120–200 μm in mid-leaf, narrower at margins. Perichaetial leaves longer and narrower than stem leaves. Moniliform, colourless rhizoidal gemmae, (2−)4–8(−15) cells long, (20−)25–30(−40) μm wide, frequently present. Seta short, c. 1 cm long; capsules horizontal to pendulous, ovoid or pyriform, neck short; lid ± conical; endostome with appendiculate cilia; spores 14–22 μm. Capsules occasional, winter, spring. n = 11. On damp neutral to basic clay soil on steep banks by ditches, streams, rivers and paths, in fields and on woodland rides. Lowland. Common in England, Wales and S. E. Scotland, occasional elsewhere in Scotland, extending to Shetland, occasional in Ireland. 109, H24, C. GB1200 + 97∗ , IR77 + 9∗ , C4. Circumpolar Southern-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Cyprus, N. and C. Asia, Canaries, Azores, N. Africa, N. America. Moniliform gemmae have been reported by T. Arts, Bull. Soc. R. Bot. Belg., 119, 114–20, 1986, and A. J. Shaw, Bryologist 84, 505–14, 1981. These rhizoidal gemmae, which have not been reported from British plants, are very difficult to detect unless iodine solution, which stains starch grains in the cells of the gemmae, is used. P. lutescens and P. lescuriana differ in their narrower upper leaves and narrower cells and in the morphology of their rhizoidal gemmae. Leaf shape and cell size are too variable in juvenile plants to allow determination unless gemmae are present.

109 Pohlia

613

Fig. 202 1–5, Pohlia melanodon: 1, 2, stem and perichaetial leaves; 3, 4, mid-leaf stem and perichaetial leaf cells; 5, capsule. 6–9, P. wahlenbergii var. wahlenbergii: 6, 7, stem and perichaetial leaves; 8, mid-leaf cells; 9, capsule. 10–13, P. wahlenbergii var. calcarea: 10, 11, leaf and mid-leaf cells from broad-leaved form; 12, 13, leaf and mid-leaf cells from narrow-leaved form. Leaves ×25, cells ×280, capsules ×10.

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19 P. wahlenbergii (F. Weber & D. Mohr) A. L. Andrews in Grout, Moss Fl. N. Am., 1935 Mniobryum wahlenbergii (F. Weber & D. Mohr) Jenn., P. albicans (Wahlenb.) Lindb., Webera albicans (Wahlenb.) Schimp. Dioicous. Lax or dense tufts or patches, whitish or glaucous green when moist, sometimes reddish tinged, 0.5–15.0 cm high; stems bright red. Leaves shrunken when dry, erect-patent to patent when moist, narrowly lanceolate to ovate, acute to acuminate, base slightly decurrent, margins plane, denticulate above; costa reddish below, ending in or below apex; cells elongate-hexagonal, narrower towards margins with 2–3 marginal rows narrower. Perichaetial leaves longer and gradually tapering from base to apex; costa shortly excurrent. Setae pale red; capsules pendulous, pyriform, wide-mouthed when dry and empty; cilia nodulose spores 16–20 μm. Capsules rare, summer. 1 Plants whitish or glaucous green when moist, to 6 cm high, leaves ovate or ovate-lanceolate, cells in upper leaves mostly 12–24 μm wide var. wahlenbergii Plants pale green and to 15 cm high, leaf cells mostly 20–30 μm wide or plants dull green, to 1.5 cm high, leaves lanceolate or narrowly lanceolate 2 2 Robust plants, to 15 cm high, leaves ovate, cells mostly 20–30 μm wide in mid-leaf var. glacialis Plants small, to 1.5 cm high, leaves lanceolate or narrowly lanceolate, cells mostly 14–20 μm wide var. calcarea Var. wahlenbergii (Fig. 202) Plants forming soft whitish to glaucous green tufts or patches, reddish below, to 6 cm high. Leaves to ovate-lanceolate; mid-leaf cells in upper leaves mostly 12–24 μm wide but in lower leaves to 40 μm wide. n = 10, 11∗ . On damp soil by streams, ditches, paths, on woodland rides, waste ground and in montane springs. 0–1200 m. Frequent or common except in eastern England. 110, H40. GB1101 + 101∗ , IR225 + 12∗ . Circumpolar Wide-boreal. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Asia, La Palma, Algeria, Greenland, N. and S. America, Kerguelen Is, Australasia. Var. glacialis (Schleich. ex Brid.) E. F. Warb., Trans Br. Bryol. Soc., 1962 Large dull pale green tufts or patches, reddish below, to 15 cm high. Leaves distant, ovate; cells in mid-leaf mostly 20–30 μm wide. On damp ground among rocks, on ledges and in flushes at high altitudes. Rare, from Caernarfon, Derby and Westmorland north to E. Sutherland, Sligo. 18, H1. Circumpolar Boreal-montane. Montane and northern Europe north to Norway, Sweden and Finland, Iceland, Caucasus, Turkey, Asia, N. America.

110 Mnium

615

Var. calcarea (Warnst.) E. F. Warb., Trans. Br. Bryol. Soc., 1962 (Fig. 202) Dull green tufts, to 1.5 cm high. Leaves lanceolate or narrowly lanceolate; cells mostly 14–20 μm wide in mid-leaf. On chalky and calcareous soil in turf. Very rare and not seen recently, Cornwall, Dorset, I. of Wight, Surrey, Mid-West. Yorkshire, W. Galway, W. Donegal. 6, H2. Europe north to France and Germany. Usually easily recognised by the soft whitish or pale glaucous green tufts. Var. glacialis is probably no more than a luxuriant habitat form. The identity of var. calcarea is obscure. H. N. Dixon & W. E. Nicholson (J. Bot. Lond. 63, 126–7, 1925) describe two forms and this is borne out by observations on a limited number of specimens. One form has lanceolate leaves with cells mostly 16–20 × 40–140 μm and the other has narrowly lanceolate leaves with cells mostly 14–16 × 100–200 μm. Further investigation is required.

Subfamily 2 MNIOIDEAE Cells of stem epidermis incrassate; only macronemata present. Red pigment often present in cell walls. Leaves linear-lanceolate to elliptical; margins usually with bistratose border, toothed, teeth often double; costa ending below apex to excurrent, often toothed on abaxial side; cells mostly c. 15 μm.

110 MNIUM HEDW., SP. MUSC. FROND., 1801 Sterile and fertile shoots erect; reddish coloration often present. Sub-apical branching of stems rare; stem epidermis unistratose with cell walls heavily thickened; macronemata present, micronemata absent. Leaves mostly ovate or lanceolate, toothed on abaxial side above margins with 2–several-stratose border and double teeth; costa ending in apex, often toothed on abaxial side above, in section with two stereid bands; cells ± isodiametric, not much smaller at margins than by costa, rarely in rows. Sporophytes usually one per perichaetium; capsules erect, horizontal or pendulous, ovoid to ellipsoid; lid rostrate; peristome double, processes not joined, cilia nodulose. A north temperate genus of c. 14 species. Derivation: From the Greek word mnion meaning moss. For an account of the genus Mnium see T. Koponen, Abstr. Bot. 5 (suppl.) 63–73, 1979.

1 Leaves unbordered 6. M. stellare Leaves bordered 2 2 Leaf bases scarcely decurrent, costa ending below apex in upper leaves, toothed on abaxial side above, lid mamillate 1. M. hornum Leaf bases decurrent, costa reaching apex to excurrent at least in upper leaves or lacking teeth on abaxial side above, lid rostrate 3 3 Leaf cells in divergent rows, often somewhat elongate near costa 2. M. spinosum Leaf cells not in divergent rows nor elongate near costa 4

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4 Mid-leaf cells mostly 14–18 μm wide, not collenchymatous 3. M. thomsonii Mid-leaf cells mostly 18–28 μm wide, collenchymatous 5 5 Plants usually dioicous, costa of upper leaves percurrent or excurrent, with teeth on abaxial side above 4. M. ambiguum Plants synoicous, costa of upper leaves ending below apex except in fertile stems, usually lacking teeth on abaxial side above 5. M. marginatum Section 1 Mnium Leaf bases not decurrent; costa ending below apex, denticulate on both sides, in section with stereid bands; cells not collenchymatous. One sporophyte per perichaetium; capsules cernuous; lid conical. 1 M. hornum Hedw., Sp. Musc. Frond., 1801 (Fig. 203) Dioicous. Dark green tufts or patches, sometimes tinged with red in exposed habitats, paler in younger parts, 2–10 cm high. Sterile and fertile stems erect, red to brown with brown tomentum below. Leaves erect, twisted when dry, patent when moist, lower small, distant, upper larger, crowded, lanceolate or narrowly lanceolate, acute to acuminate, slightly decurrent at base; margins plane, strongly bordered, with spinose double teeth from below middle; costa ending well below apex, with a few teeth on abaxial side above; basal cells rectangular, cell above irregularly hexagonal, not in divergent rows, walls uniformly thickened, variable in size, (14−)18–24(−30) μm wide in mid-leaf, several marginal rows elongate, narrow, very incrassate, forming 2–4-stratose border. Sporophytes 1 per perichaetium; setae red; capsules horizontal to pendulous, ovoid to ovate-ellipsoid; lid mamillate; spores 26–35 μm. Capsules frequent, spring. n = 6∗ , 7, 12. On acidic soil in woods, on banks, sides of streams, tree boles, logs, rotting wood, rocks and in rock crevices, usually in shaded situations. Mostly lowland but ascending to 970 m in Mid Perth. Common and sometimes abundant except in basic habitats. 112, H39, C. GB2112 + 77∗ , IR263 + 5∗ , C8 + 1∗ . European Temperate. Europe north to northern Scandinavia, Faeroes, Iceland, Turkey, Japan, Azores, eastern N. America. Slender forms in rock crevices may be confused with M. marginatum or M. thomsonii, but these differ in having decurrent leaf bases and the costa extending to the apex or excurrent in the upper leaves (of fertile stems in M. marginatum). It may also be confused with Atrichum undulatum or A. crispum; the former has more longly tapering undulate leaves and costa with lamellae on the adaxial side; the latter has ovate to ovate-oblong leaves, a greenish border, larger cells and lamellae, albeit obscure, on the adaxial surface of the costa.

Section 2 Spinosa (Kindb.) T. J. Kop., Ann. Bot. Fenn., 1968 Leaf bases decurrent; costa percurrent or excurrent, toothed on abaxial side; cells not collenchymatous. Sporophytes 1-several per perichaetium; capsules horizontal to cernuous; lid rostrate.

110 Mnium

617

Fig. 203 1–4, Mnium spinosum: 1, leaves (×10); 2, leaf margin; 3, mid-leaf cells; 4, capsule (×10). 5–9, M. hornum: 5, lower and upper leaves (×15); 6, leaf margin; 7, mid-leaf cells; 8 section of leaf margin (×70); 9, capsule (×5). Cells ×280.

¨ 2 M. spinosum (Voit.) Schwagr., Sp. Musc. Frond. Suppl. 1., 1819 (Fig. 203) Dioicous. Lax dull green or dark green tufts or patches, reddish in older parts, 1.5–8.0 cm high. Sterile and fertile stems erect. Lower leaves distant, scale-like, appressed, upper large, crowded, twisted, undulate when dry, spreading when moist, similar on both sterile and fertile stems, ovate to ovate-lanceolate or oblanceolate, acute to subacute and apiculate, narrow, longly decurrent at base; margins plane, strongly bordered, spinosely double-toothed from half way or below; costa reddish, excurrent in upper leaves, toothed on abaxial side above

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or not; basal cells rectangular, cells above in divergent rows, irregularly hexagonal, somewhat elongate near costa, not collenchymatous, 16–40 μm wide in midleaf, several marginal rows elongate, narrow, strongly incrassate, forming severalstratose border. Sporophytes 1–several per perichaetium; setae red or orange; capsules horizontal to pendulous, narrowly ellipsoid; lid with curved beak; spores 20–28 μm. Capsules very rare, late summer. n = 6, 7. In turf among rocks, in rock crevices and on ledges in shaded, slightly basic habitats. 600–1100 m. Mid and E. Perth, Angus, S. Aberdeen, Inverness, Argyll. 7. GB9 + 2∗ . Circumpolar Borealmontane. Montane and northern Europe north to Svalbard, Iceland, east to the Caucasus and Urals, Turkey, N. and C. Asia, China, western N. America. 3 M. thomsonii Schimp., Syn. Musc. Eur. (ed. 2), 1876 M. orthorrhynchum auct. non Brid.

(Fig. 204)

Dioicous. Dense, dark green or pale green tufts or parches, reddish below, 1–6 cm high. Sterile and fertile stems erect. Leaves twisted and incurved when dry, patent when moist, distant below, more crowded, larger above, ovate to ovate-lanceolate

Fig. 204 1–3, Mnium ambiguum: 2, leaf (×15); 2, leaf margin; 3, mid-leaf cells. 4–6, M. thomsonii: 4, leaves (×15); 5, leaf margin; 6, mid-leaf cells. Margins ×70, cells ×280.

110 Mnium

619

on sterile stems, ovate-lanceolate to lanceolate on fertile stems, acute to acuminate, longly decurrent at base; margins plane, with strong reddish border, with double spinose teeth from below middle; costa reddish-brown, excurrent in upper leaves, toothed on abaxial side above; basal cells rectangular, cells above not in divergent rows, quadrate-hexagonal, not or hardly collenchymatous, variable in size, (12−)14–18(−20) μm wide in mid-leaf, several marginal rows elongate, narrow, forming strong several-stratose border. Sporophytes solitary; setae red; capsules cernuous to horizontal, ellipsoid; lid rostrate; spores 25–36 μm. Capsules very rare, summer. n = 6, 8, 12. In crevices and on ledges of basic rock. 600–900 m. Rare but locally frequent, Stafford, Caernarfon, Pennines, Lake District, Dumfries, central Scottish Highlands, Clare, W. Galway, Sligo, Leitrim, Fermanagh. 23, H5. GB54 + 11∗ , IR5 + 1∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Caucasus, Turkey, N and C. Asia, China, Japan, N. America, Greenland. Most likely to be confused with M. marginatum, from which it differs in the smaller noncollenchymatous leaf cells.

Section 3 Laevinervia Chen ex Li & Zang, Acta Bot. Yunnanica, 1979 Leaf bases decurrent; costa percurrent, toothed on abaxial side, in section with stereids; cells collenchymatous. Sporophytes one per perichaetium; capsules horizontal to cernuous; lid rostrate. ¨ 4 M. ambiguum H. Mull., Verh. Bot. Vereins Prov. Brandenburg, 1866 ¨ M. lycopodioides auct. non Schwagr.

(Fig. 204)

Dioicous. Green tufts, only occasionally reddish-tinted, 3–7 cm high. Sterile and fertile stems erect, reddish brown. Leaves twisted when dry, patent when moist, lower shorter and wider than upper, upper leaves crowded, ovate-oblong, acute and apiculate, longly decurrent at base; margins plane, with strong reddish brown border with double spinose teeth from below midway; costa percurrent to shortly excurrent at least in upper leaves, usually spinulose on abaxial side above; basal cells rectangular, cells above not in divergent rows, ± hexagonal, collenchymatous, variable in size, (15−)18–28(−32) μm wide in midleaf. Setae red; capsules cernuous to horizontal, ellipsoid to narrowly ellipsoid; lid rostrate; spores 22–24 μm. Capsules very rare, summer. n = 6, 7. In shaded crevices and on ledges of damp basic rock. 800–1200 m. Very rare, Mid Perth, Angus, S. Aberdeen. 3. GB5. Circumpolar Boreal-montane. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Siberia, N. America. Close to M. marginatum, but differing in the costa spinulose on the abaxial side and in the dioicous inflorescence. The leaves are usually toothed, more crowded, more sharply toothed and less conspicuously red-tinted than in M. marginatum, but these characters are not always constant.

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5 M. marginatum (With.) P. Beauv., Prodr. Aethéogam., 1805 M. serratum Schrad. ex Brid. Synoicous or dioicous. Light to dark green tufts or patches, deep red below, 3–4(−6) cm high. Sterile and fertile stems erect. Leaves twisted when dry, patent when moist, ovate to broadly ovate, acute to obtuse and apiculate on sterile stems, lanceolate, acute on fertile stems, decurrent at base; margins plane, with strong border, reddish brown in older leaves, toothed from half way or below with small double blunt or sharp teeth; costa reddish brown in older leaves, ending in apex of upper leaves of fertile stems, below apex in other leaves, rarely toothed on abaxial side above; basal cells rectangular, cells above not in divergent rows, ± hexagonal, collenchymatous, (14−)18–32(−36) μm wide in mid-leaf, several marginal rows narrow, elongate, incrassate, forming distinct 2–3-stratose border. Setae pale red; capsules subpendulous, ellipsoid; lid rostrate; spores 24–34 μm. Plants synoicous, capsules frequent Plants dioicous, capsules unknown in Britain

var. marginatum var. dioicum

Var. marginatum (Fig. 205) Synoicous. Capsules frequent, early summer. n = 6, 12. Tufts or patches on soil, rocks and in rock crevices in woods and shaded usually basic habitats. Usually lowland but ascending to 1170 m in Mid Perth. Frequent in N. W. England, rare or very rare in the rest of England and in Wales, occasional in central and western Scotland, rare in Ireland. 70, H10. GB166 + 60∗ , IR7 + 6∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Siberia, Himalayas, China, Greenland, N. America, Mexico, Guatemala, Hawaii. ¨ Var. dioicum (H. Mull.) Crundw., Trans. Br. Bryol. Soc., 1968 ¨ M. dioicum H. Mull., M. riparium Mitt. Dioicous. Capsules unknown in Britain. Scattered shoots and small patches on damp basic soil and rocks in woods and by streams. Lowland. Very rare, Denbigh, Derby, S. W. and N. W. Yorkshire, old records from W. Sussex, S. E. and N. W. Yorkshire and Mid Perth. 7. Europe north to Norway, Caucasus. The only difference between the two varieties is the nature of the inflorescence and it is doubtful if var. dioicum is worth maintaining; however, chromosome counts would be helpful. In its typical form, M. marginatum differs from the previous species in the costa only rarely being toothed on the abaxial side.

Section 4 Stellariformia (Kindb.) T. J. Kop., Ann. Bot. Fenn., 1968 Leaf bases not decurrent; costa ending below apex, not spinulose on abaxial side, in section without stereids. One sporophyte per perichaetium; capsules horizontal to cernuous; lid conical.

110 Mnium

621

Fig. 205 1–4, Mnium marginatum: 1, leaves (×10); 2, leaf margin (×70); 3, mid-leaf cells; 4, capsule (×5). 5–7, M. stellare: 5, leaves (×15); 6, marginal cells; 7, capsule (×10). 8–10, Cinclidium stygium: 8, leaf (×15); 9, mid-leaf cells: 10, leaf margin section. Cells ×280.

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6 M. stellare Hedw., Sp. Musc. Frond., 1801 (Fig. 205) Astrophyllum stellare (Hedw.) Lindb., Stellariomnium stellare (Hedw.) M. C. Bowers Dioicous. Dense tufts or patches, pale to bright green or sometimes bluish green above, dark green to brownish below, glossy when dry, bluish when dead; sterile and fertile shoots erect, 1–10 cm high. Lower leaves small, distant, upper larger, more crowded, slightly curled and undulate when dry, patent when moist, similar on both sterile and fertile stems, broadly ovate to ovate-lanceolate, acute to obtuse and apiculate, decurrent at base; margins plane, unbordered, irregularly dentate at least above with single or double blunt teeth; costa ending well below apex, not toothed on abaxial side; basal cells rectangular, cells above not in divergent rows, ± hexagonal, ± collenchymatous, 20–24 μm wide in mid-leaf, 1–2 marginal rows sometimes elongate, more incrassate but not forming border. Setae reddish; capsules cernuous to horizontal, ellipsoid; lid convex; spores 20–30 μm. Capsules very rare, spring. n = 6 + m∗ , 7. On damp shaded rocks and soil in woods, in rock crevices, on ledges, walls, in basic habitats. Mainly lowland but ascending to 490 m on Skye. Very rare in lowland England, frequent or common in parts of the west, north-west and in Wales, occasional to frequent in Scotland, rare in Ireland. 194, H16. GB462 + 66∗ , IR16 + 3∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Himalayas, Siberia, Japan, eastern N. America. Only likely to be passed over for M. hornum, but differing in its lighter paler green colour and unbordered leaves. The plants turn blue after death because of the development of mnioindigen in the cytoplasm and cell sap.

Subfamily 3 CINCLIDIOIDEAE Stem epidermal cells incrassate; macronemata present, micronemata present or not. Red pigment often present in cell walls. Leaves orbicular to ellipsoid; margins entire, with 1–several-stratose border; costa ending below apex to percurrent.

111 CINCLIDIUM SW., J. BOT. (SCHRADER), 1803 Synoicous or dioicous. Plants reddish. Sterile stems erect, subapical branching rare. Stem epidermis unistratose with cell walls heavily thickened; macronemata present, in rows on stems, micronemata lacking. Leaves elliptical to orbicular or obovate, base narrow and attenuate but not decurrent; margins plane, bordered, entire; costa reaching apex, not toothed on abaxial side, in section with stereid band; cells in divergent rows, elongate-hexagonal. Capsules pendulous with distinct neck; lid conical; processes of endostome fused into dome-like structure with irregular openings, cilia lacking. A mainly circumboreal genus of four species. Derivation: From the Greek for lattice, referring to the endostome. For a monograph of Cinclidium see G. S. Mogensen, Lindbergia 3, 49–80, 1973.

112 Rhizomnium

623

1 C. stygium Sw., J. Bot. (Schradeer), 1803 (Fig. 205) Synoicous. Green to reddish tufts or patches, purplish to blackish below, 3–8 cm high; stems reddish to black, covered with dense brown tomentum except in youngest parts. Leaves shrunken when dry, patent to spreading when moist, small below, larger, more crowded above, concave, elliptical to orbicular or obovate, apiculate, slightly decurrent at base; margins plane, with strong reddish border, entire; costa percurrent, red to blackish; cells in divergent rows, rectangularhexagonal, 15–35 μm wide in mid-leaf, 2–4 marginal rows elongate, narrow, forming unistratose border. Setae long, red; capsules pendulous, ovoid; lid conical; spores 25–35 μm. Capsules rare, summer. n = 7, 14. Calcareous springs, flushes, fens and marshes. Occasional in East Anglia and N. W. England, rare to occasional in the Scottish Highlands, Merioneth, Selkirk, Roxburgh, Westmeath, Sligo, Leitrim, Antrim. 25, H4. GB41 + 7∗ , IR3. Circumpolar Boreal-montane. Europe from the Alps north to Svalbard, Iceland, Altai, Kamchatka, N. America, Greenland, Patagonia. 112 RHIZOMNIUM (BROTH.) T. J. KOP., ANN. BOT. FENN., 1968 Plants with reddish coloration. Sterile stems erect, stem epidermis unistratose with thick cell walls; macronemata present, in bundles in the leaf axils, micronemata present or absent. Leaves ellipsoid, orbicular or obovate, apex rounded, sometimes emarginate and apiculate, narrowly decurrent at base; margins plane, entire with 1–several-stratose border; costa ending well below apex to percurrent, not toothed on abaxial side, in section without stereids; cells in divergent rows, elongate-hexagonal, decreasing in size from costa to margins. Capsules horizontal to pendulous; lid rostrate; processes of endostome not joined. A Northern Hemisphere genus of 13 species. Derivation: Meaning Mnium with rhizoids. For an account of Rhizomnium see T. Koponen, Ann. Bot. Fenn. 10, 1–26, 1973.

1 Stems without micronemata (see Fig. 206, 5), border cells 3 4-stratose, 12–20 μm wide at middle of leaf, prosenchymatous at apex 1. R. punctatum Stems with micronemata (see Fig. 206, 1), border cells usually unistratose, 15–40 μm wide at middle of leaf, with flat ends near apex 2 2 Dioicous, leaves often with small apiculus, costa extending almost to or to apex, capsules ovoid to ovate-ellipsoid 2. R. magnifolium Synoicous, leaves never apiculate, costa ending well below apex, capsules subglobose 3. R. pseudopunctatum 1 R. punctatum (Hedw.) T. J. Kop., Ann. Bot. Fenn., 1968 Mnium punctatum Hedw.

(Fig. 206)

Dioicous. Scattered plants, lax tufts or patches, dark green above, reddish to black below, 1–10 cm high; sometimes occurring as chocolate-brown protonemata with

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Fig. 206 1–4, Rhizomnium magnifolium: 1, part of stem (×10); 2, leaf (×7); 3, leaf apex (×115); 4, leaf margin section (×280). 5–9, R. punctatum: 5, part of stem (×10); 6, leaf (×7); 7, leaf apex (×115); 8, leaf margin section (×280); 9, capsule (×10). ma = macronemata; mi = micronemata.

112 Rhizomnium

625

depauperate shoots. Stems red or brown, macronemata present, micronemata absent (see Fig. 206); forming reddish brown or brown tomentum below. Leaves shrunken when dry, spreading when moist, distant below, larger, more crowded above, concave, elliptical to orbicular or broadly ovate, apex rounded, sometimes emarginate, usually apiculate, very narrowly decurrent at base; margins plane, entire with strong reddish to brownish border; costa ending below apex to percurrent; cells in divergent rows, elongate-hexagonal, 35–50 × 70–120 μm in mid-leaf, 3–4 rows marginal cells elongate, narrow, incrassate, forming 3–4-stratose border, border cells 12–20 μm wide at middle of leaf, at apex long, narrow and prosenchymatous. Setae orange-red; capsules cernuous, ellipsoid or ovate-ellipsoid; lid rostrate; exostome teeth pale yellow, with 20 or more articulations; spores 25–50 μm. Capsules frequent, autumn, winter. n = 6 + m, 7∗ . On soil in fens, marshes, damp woodland, on rotting logs, on wet rocks, damp rocks by streams and rivers, in slightly acid to strongly basic habitats. 0–1165 m. Common. 112, H37, C. GB1713 + 83∗ , IR193 + 4∗ , C5 + 1∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Iran, Siberia, Madeira, Azores, N. Africa. All the British species of Rhizomnium have macronemata (large dark brown rhizoids) c. 30 μm diameter at the base; these are confined to the leaf axils and appear as tufts on the stems except in the youngest parts. R. magnifolium and R. pseudopunctatum also have micronemata, much smaller pale brown rhizoids to c. 16 μm diameter. These arise all along the stems, although they may be absent from the youngest parts, and appear as a furry tomentum covering the stems, readily visible with a lens. R. punctatum is a distinctive plant likely to be confused only with other Rhizomnium species or Cinclidium stygium. The absence of micronemata, the border 3–4-stratose at the middle of the leaf and the shape of the border cells at the leaf apex distinguish R. punctatum from the next two species. Cinclidium stygium differs in the densely tomentose tufts or patches, purplish to blackish below, the smaller leaf cells and the unistratose border.

2 R. magnifolium (Hook.) T. J. Kop., Ann. Bot. Fenn., 1973 M. punctatum var. elatum Schimp., R. perssonii T. J. Kop.

(Fig. 206)

Autoicous. Loose tufts, dark green above, brown to black below, 2–7 cm high. Stems with micronemata and macronemata (see Fig. 206), the latter forming reddish brown tomentum below. Leaves shrunken when dry, patent to spreading when moist, concave, orbicular to broadly elliptical, ovate or obovate, apex rounded, emarginate, sometimes bluntly apiculate; margins plane, bordered; costa ending below or occasionally reaching apex; cells in divergent rows, narrowly hexagonal to elongate hexagonal, mostly 50–60 × 64–100 μm in mid-leaf, 3–4 rows marginal cells elongate, narrow, incrassate, forming border, 2–3-stratose at base, unistratose above, border cells 15–40 μm wide at middle of leaf, narrowly rectangular at apex. Setae orange-red; capsules horizontal to cernuous, ellipsoid to ovate-ellipsoid; exostome teeth yellowish to brown, with 25–42 articulations;

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spores 30–40 μm. Capsules unknown in Britain. n = 7, 14. In areas of late snowlie, sheltered gullies and below dripping rocks, calcifuge, also at lower altitudes in flushes, but sometimes in slightly basic habitats. 420–1020 m. Rare to occasional in the Scottish Highlands from Argyll, Mid Perth and Angus north to Ross and E. Sutherland. 11. GB19 + 1∗ . European Boreal-montane. Montane and northern Europe north to northern Norway, Siberia, Baikal, Sakhalin, Himalayas, Korea, Japan, northern N. America, Greenland. R. pseudopunctatum differs from R. magnifolium in the synoicous inflorescence, the leaves never apiculate, the costa never reaching the leaf apex and the subglobose capsules. In the British Isles, R. pseudopunctatum is a calcicole whereas R. magnifolium is a calcifuge except at lower altitudes where it may occur in slightly basic conditions. For the occurrence of this plant in Britain see A. C. Crundwell, J. Bryol. 10, 1–4, 1978, and D. G. Long, Bull. Br. Bryol. Soc. 39, 39–41, 1982.

3 R. pseudopunctatum (Bruch & Schimp.) T. J. Kop., Ann. Bot. Fenn., 1968 (Fig. 207) Mnium pseudopunctatum Bruch & Schimp., M. subglobosum Bruch & Schimp. Synoicous. Lax tufts or patches, dark green above, brown to blackish below, often tinged with red, 4–12 cm high. Stems black or brown, micronemata and macronemata present, the latter forming dense tomentum below. Leaves shrunken when dry, patent to spreading when moist, broadly ovate to ± orbicular, apex rounded, sometimes emarginate, very rarely with small blunt apiculus, narrowly decurrent at base; margins plane, entire, border pale or yellowish brown; costa ending well below apex; cells in indistinct rows, elongate-hexagonal, 35–50 × 60–140 μm in mid-leaf, 2–3 rows marginal cells elongate, narrow, incrassate, forming unistratose border, border cells 20–30 μm wide at middle of leaf, shortly rectangular to trapezoid at apex. Setae orange-red; capsules cernuous to pendulous, subglobose; lid with short thick beak; exostome teeth brownish; spores 30–50 μm. Capsules frequent, winter, spring. n = 13, 13 + m∗ , 14∗ . In fens, marshes, springs and flushes, calcicole. 0–970 m. Occasional in N. W. Wales and N. W. England, generally distributed but rare or very rare elsewhere, extending from S. Devon east to E. Sussex and north to Shetland, rare in Ireland. 69, H18. GB187 + 43∗ , IR11 + 11∗ . Circumpolar Boreal-montane. From central and western Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Siberia, Korea, Taiwan, northern N. America, Greenland.

Subfamily 4 PLAGIOMNIOIDEAE Sterile stems often arcuate or prostrate. Stem epidermal cells not incrassate; macronemata and micronemata present. Red pigment not present in cell walls of gametophytes. Leaves lanceolate to elliptical, acute to obtuse; margins with single row of teeth, with unistratose border or unbordered.

112 Rhizomnium

627

Fig. 207 1–4, Rhizomnium pseudopunctatum: 1, leaf (×7); 2, leaf apex (×115); 3, leaf margin section (×70); 4, capsule (×10). 5–8, Plagiomnium cuspidatum: 5, leaves (×15); 6, marginal cells 3 /4 way up leaf; 7, mid-leaf cells; 8, capsule (×10). 9–12, P. medium: 9, leaf (×10); 10, marginal cells at middle of leaf; 11, mid-leaf cells; 12, leaf base (×15). Cells ×280.

628

31 Mniaceae

113 PLAGIOMNIUM T. J. KOP., ANN. BOT. FENN., 1968 Plants lacking red pigment. Sterile stems arcuate, fertile stems erect; stem epidermis 2–several stratose with cell walls not much thickened; micronemata present, sometimes to stem apex. Leaf margins with unistratose border, dentate with single teeth; costa not toothed on abaxial side, in section with stereid band; cells in divergent rows or not, isodiametric or not. Capsules horizontal to pendulous; lid usually conical. A cosmopolitan genus of c. 20 species. Derivation: meaning oblique Mnium, alluding to the habit of the sterile stems.

1 Leaves narrowly lingulate, transversely undulate when moist, mid-leaf cells 10–16 μm wide 6. P. undulatum Leaves ± ovate, not or scarcely undulate, mid-leaf cells 15–50 μm wide 2 2 Leaf margins plane, sharply toothed from about middle of leaf to apex, cells not in rows 1. P. cuspidatum Leaves bluntly or sharply toothed from below middle or rarely teeth absent, cells in rows or not 3 4 3 Leaf bases decurrent1 Leaf bases not or hardly decurrent 6 4 Synoicous, mid-leaf cells ± hexagonal, 1.0–1.5 times as long as wide 3. P. medium Dioicous, mid-leaf cells narrowly hexagonal, 1.5–3.0 times as long as wide 5 5 Leaf bases narrowly decurrent, mid-leaf cells 30–45 μm wide, 1.5–2.0 times as long as wide, sterile shoots arcuate 2. P. affine Leaf bases broadly decurrent, mid-leaf cells 15–35 μm wide, 2–3 times as long as wide, sterile shoots sometimes erect 4. P. elatum 6 Dioicous, capsule lid conical, leaf cells increasing in size towards costa, walls distinctly porose 5. P. ellipticum Synoicous, lid rostrate, leaf cells hardly increasing in size towards costa, walls hardly porose 7. P. rostratum Section 1 Plagiomnium Leaves ovate-elliptical, acute, bases decurrent; margins plane, toothed from the middle, teeth sharp, formed of 1–2 cells; lamina cells ± hexagonal. 1 P. cuspidatum (Hedw.) T. J. Kop., Ann. Bot. Fenn., 1968 Mnium cuspidatum Hedw.

(Fig. 207)

Synoicous. Dark green tufts or patches with paler young growths. Sterile stems arcuate or erect, 1.4–4.0 cm long; fertile stems erect. Lower leaves distant, upper larger, more crowded, crisped when dry, patent to spreading when moist, broadly ovate to obovate, sharply pointed, decurrent at base; margins plane, bordered, sharply toothed from about half way to apex, teeth single, 1–2 cells long; 1

Decurrent bases are usually lost from detached leaves and are best viewed in situ on a piece of stem from which the leaves have been removed.

113 Plagiomnium

629

costa ending below apex to percurrent; cells not in rows, ± regularly hexagonal, collenchymatous, 30–34(−38) μm wide in mid-leaf, 2–4 rows marginal cells elongate, narrow, forming unistratose yellowish border. Setae reddish; capsules horizontal to subpendulous, ovoid; lid shortly conical; spores 18–36 μm. Capsules frequent, spring, early summer. n = 6, 12∗ . On damp basic soil, rocks, walls, tree boles in sheltered situations. Mainly lowland but ascending to 650 m in E. Perth. Occasional throughout Britain, rare in Ireland. 92, H21. GB289 + 73∗ , IR14 + 11∗ . Circumpolar Boreo-temperate. Europe north to northern Scandinavia, Faeroes, Iceland, Caucasus, Turkey, Siberia, Himalayas, E. Asia, N. Africa, Kenya, Uganda, Greenland, N. America, Mexico, Cuba. Differs from related species in the smaller size of the plants, the leaf margins plane, sharply toothed only from about the middle and the smaller cells. P. affine and P. rostratum may occur in similar habitats but have narrower, more shortly pointed and less decurrent leaves.

Section 2 Rosulatae (Kindb.) T. J. Kop., Ann. Bot. Fenn., 1967 Leaves elliptical to oblong, acute or obtuse and apiculate or mucronate, bases usually decurrent; margins plane, toothed ± from base to apex, teeth to 4 cells long; lamina cells mostly longer than wide. For a monograph of the section Rosulatae see T. Koponen, Ann. Bot. Fenn. 8, 305–67, 1971. The full range of leaf cell sizes are taken from this paper.

2 P. affine (Funck) T. J. Kop., Ann. Bot Fenn., 1968 Mnium affine Funck

(Fig. 208)

Dioicous. Lax spreading green patches or scattered plants. Stems angled in section, sterile stems arcuate, rooting at tips, often with complanate leaves, to 10 cm long; fertile stems erect 0.5–6.0 cm high, Leaves crisped when dry, spreading when moist, broadly ovate or obovate, obtuse or subobtuse, apiculate, longly decurrent at base; margins plane, bordered, toothed ± from base to apex, teeth single, usually sharp, 1–3(−4) cells long, at least some teeth ± perpendicular to margin at middle of leaf, but margins sometimes entire in plants in dry habitats; costa ending in or below apex; cells in rows, elongate-hexagonal, slightly collenchymatous, porose, mid-leaf cells mostly 30–45 μm wide, (22–57 × 45–100 μm), 1.5–2.0 times as long as wide, 3–4 marginal rows elongate, narrow, forming unistratose border. Sporophytes mostly 1–2(−3) per perichaetium; setae pale red; capsules subpendulous, ellipsoid, neck not distinct; lid shortly conical; spores 18–24 μm. Capsules very rare, spring. n = 6, 7, 12, 18. On damp basic to slightly acid soil in woods, in turf and by tracks. Lowland. Frequent to common in the southern half of Britain, rare further north, extending to Ross and Harris, rare in Ireland. 91, H9. GB572 + 63∗ , IR10 + 1∗ . European Temperate. Montane and northern Europe north to Fennoscandia, Faeroes, W. Russia, Caucasus, Turkey, Iran, Madeira. This and the next three species have been and are likely to be confused. P. medium is distinct in the leaf cells not arranged in rows and the usually present synoicous inflorescences. In P. ellipticum, the sterile stems are usually erect and the leaf bases not or scarcely decurrent,

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31 Mniaceae

Fig. 208 1–7, Plagiomnium affine: 1, 2, Leaf and marginal cells at middle of leaf of erect stem; 3, 4, leaf and marginal cells at middle of leaf of prostrate stem; 5, leaf margin section; 6, mid-leaf cells; 7, leaf base. 8–10, P. ellipticum: 8, leaf; 9, leaf base; 10, margin at middle of leaf. Leaves ×10, cells ×280, bases ×15.

113 Plagiomnium

631

the teeth are small or even lacking (but dry ground forms of P. affine may have entire leaf margins) and the cells are ± isodiametric. In P. elatum, the sterile stems may be erect, the leaves have widely decurrent bases and the cells are smaller and relatively longer than in typical P. affine. Poorly developed forms of the latter may, however, have smaller cells and it may be that such plants are forms of P. elatum growing in unfavourable habitats. P. rostratum differs from P. affine and the next three species in the leaf cells scarcely increasing in size towards the costa and hardly porose, the rostrate beak of the capsules and the stomata scattered over the whole capsule instead of concentrated near the base. Juvenile forms of P. undulatum with ovate non-undulate leaves differ in their smaller leaf cells.

3 P. medium (Bruch & Schimp.) T. J. Kop., Ann. Bot. Fenn., 1968 Mnium medium Bruch & Schimp.

(Fig. 207)

Synoicous. Lax bright green patches or tufts. Stems angled in section, sterile stems arcuate with complanate leaves, not rooting at tips, to 6 cm long; fertile stems erect, 3–9 cm high. Leaves crisped when dry, spreading when moist, ovate to ovatelanceolate, acute, subobtuse or obtuse and apiculate, broadly decurrent at base; margins plane, bordered, toothed ± from base to apex, teeth sharp, 1–2 cells long, set at an angle to margin at middle of leaf; costa ending below apex to excurrent; cells not in rows, hexagonal, collenchymatous, walls porose, in mid-leaf mostly 30–50 μm wide (25–70 × 45–102 μm), 1.0–1.5(−2.0) times as long as wide, 3–5 marginal rows elongate, narrow, forming unistratose border. Sporophytes 1–5(−8) per perichaetium; setae reddish; capsules subpendulous, ellipsoid; spores 19–27 μm, Capsules unknown in Britain. n = 6, 12. In basic flushes and on damp rock ledges. 800–1070 m. Very rare, Mid Perth, Angus, S. Aberdeen, Inverness, Argyll. 6. GB7 + 1∗ . Circumpolar Boreal-montane. Montane and boreal woodland in Europe from Spain north to northern Fennoscandia, Faeroes, Caucasus, Siberia, Korea, Japan, N. America, Greenland. For an account of this plant in Scotland see J. G. Duckett & E. R. B. Little, Trans. Br. Bryol. Soc. 5, 452–9, 1967.

4 P. elatum (Bruch & Schimp.) T. J. Kop., Ann. Bot. Fenn., 1968 (Fig. 209) Mnium seligeri auct. non Mitt., M. affine var. elatum Bruch & Schimp. Dioicous. Yellowish green tufts or patches. Stems angular in section, matted with rhizoids below; sterile stems erect or arcuate and rooting at tips, to 10 cm long; fertile stems erect, 4–10 cm high. Leaves crisped, at least some often squarroserecurved when dry, spreading when moist, broadly ovate to obovate or elliptical, obtuse or subobtuse, apiculate, broadly decurrent at base; margins plane, bordered, toothed ± from base to apex, teeth sharp, 1–3 cells long, at middle of leaf at an angle to margin; costa percurrent or excurrent; cells in rows, elongate-hexagonal to ± rectangular, walls porose, not collenchymatous, 15–35 × 40–70 μm, mostly 2–3 times as long as wide in mid-leaf, 2–4 marginal rows elongate, narrow, forming unistratose border. Sporophytes as in P. affine, produced in spring but probably unknown in the British Isles. n = 6, 12. In calcareous fens, marshes, by streams, springs and in seepage areas. Mainly lowland but ascending to 850 m in

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31 Mniaceae

Fig. 209 1–4, Plagiomnium elatum: 1, leaf; 2, leaf base (×15); 3, margin at middle of leaf; 4, mid-leaf cells. 5–8, P. rostratum: 5, leaf; 6, margin at middle of leaf; 7, mid-leaf cells; 8, capsule (×10). Leaves ×10, cells ×280.

113 Plagiomnium

633

Angus. Occasional throughout the British Isles. 100, H28. GB294 + 48∗ , IR35 + 4∗ . European Boreo-temperate. Montane Europe north to Scandinavia, Sicily, W. Russia, Faeroes, Iceland, Turkey. Frequently when dry at least some of the leaves of P. elatum are squarrose-recurved, distinguishing this plant from related species.

5 P. ellipticum (Brid.) T. J. Kop., Ann. Bot. Fenn., 1968 (Fig. 208) Mnium rugicum Laurer, M. affine var. rugicum (Laurer) Bruch & Schimp. Dioicous. Light green to dark green tufts or patches. Stems rounded or obscurely angled in section, covered with brownish tomentum below; sterile stems usually erect but sometimes arcuate and with complanate leaves, to 9 cm long, fertile stems erect, 1–10 cm high. Leaves crisped when dry, spreading when moist, ovate to orbicular, acute to obtuse, apiculate, scarcely decurrent at base; margins plane, bordered, toothed ± from base to apex, teeth sharp or blunt, 1(−2) cells long but sometimes lacking; costa percurrent to excurrent; cells in rows, ± hexagonal, walls porose, not collenchymatous, 20–35 μm wide, 1.0–1.5 times as long as wide in mid-leaf, 3–4 marginal rows elongate, narrow, forming unistratose border Sporophytes 1–3 per perichaetium; capsules pendulous, ellipsoid; spores 24–40 μm. Capsules very rare, summer. n = 6∗ , 12. By flushes, in springs, damp grassland and wet woodland. Mainly lowland but ascending to 550 m on Skye. Rare to occasional throughout the British Isles. 81, H17. GB167 + 22∗ , IR23 + 1∗ . Circumpolar Boreo-arctic Montane. N., W. and C. Europe, north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Japan, N. America, Greenland, Patagonia. A very variable species, dry ground forms of which may have entire leaf margins and are likely to be confused with similar forms of P. affine (q.v.). It differs from the preceding 3 species in the scarcely decurrent leaf bases and, except for P. medium, the ± hexagonal cells.

Section 3 Undulata T. J. Kop., Ann. Bot. Fenn., 1968 With the characters of P. undulatum. 6 P. undulatum (Hedw.) T. J. Kop., Ann. Bot. Fenn., 1968 Mnium undulatum Hedw.

(Fig. 210)

Synoicous. Lax light green tufts, patches or scattered plants. Sterile stems erect and dendroid to arcuate with frequently complanate leaves, to 15 cm long, branching frequently subapical; fertile stems erect, 2–11 cm high. Leaves crisped when dry, spreading when moist, strongly transversely undulate, lower distant, ovate to ovate-oblong, upper more crowded, much larger, narrowly lingulate, acute to obtuse or rounded, apiculate, decurrent at base; margins plane, bordered, toothed ± from base to apex, teeth spinose, 1(−2) cells long; costa percurrent or excurrent; cells not arranged in rows, hexagonal to elongate-hexagonal, ± incrassate, walls scarcely porose, mostly 10–16 μm wide in mid-leaf, 3–5 marginal rows elongate,

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31 Mniaceae

Fig. 210 Plagiomnium undulatum: 1, leaves (×20); 2, margin half way up leaf; 3, mid-leaf cells; 4, capsule (×7). 5–6, Pseudobryum cinclidiodes: 5, leaf (×15); 6, margin half way up leaf; 7, mid-leaf cells. Cells ×280.

114 Pseudobryum

635

narrow, forming unistratose border. Sporophytes 1–10 per perichaetium; capsules cernuous, ellipsoid; lid conical; spores 24–32 μm. Capsules rare but often abundant when present, spring. n = 6∗ , 7. Male plants less common than female. Damp basic or neutral soil in woodland, grassland, on lawns, boggy ground, in duneslacks, on sheltered dripping rocks. Mainly lowland but ascending to 850 m in W. Inverness. Common or very common throughout the British Isles. 112, H40, C. GB1971 + 72∗ , IR308 + 7∗ , C3 + 1∗ . European Temperate. Europe except the far north, Faeroes, Iceland, Caucasus, Turkey, S. W. Asia, Macaronesia, N. W. Africa, Ethiopia. An unmistakable and handsome plant when growing vigorously, sometimes forming miniature forests, but exceedingly variable. Stunted plants in dryish turf with shorter hardly undulate leaves may be mistaken for other species of Plagiomnium but differ in their smaller leaf cells.

Section 4 Rostratum (Kindb.) T. J. Kop., Ann. Bot. Fenn., 1968 With the characters of P. rostratum. 7 P. rostratum (Schrad.) T. J. Kop., Ann. Bot. Fenn., 1968 Mnium longirostrum Brid., M. rostratum Schrad.

(Fig. 209)

Synoicous. Lax green or dark green patches. Sterile stems arcuate, often with complanate leaves, to c. 5 cm long, fertile stems ± erect, 2–5 cm high. Leaves crisped when dry, spreading when moist, broadly ovate to ovate or ovate-oblong, obtuse or subobtuse, apiculate, hardly decurrent at base; margins plane, bordered, toothed from below middle with small blunt usually unicellular teeth which may sometimes be obsolete; costa ending in or below apex; cells in rows, irregularly hexagonal, not markedly larger towards costa, collenchymatous, sometimes strongly so, not or hardly porose, 20–35(−40) μm wide in mid-leaf, 2–5 marginal rows elongate, narrow, forming unistratose yellowish border. Sporophytes 1–5 per perichaetium; capsules cernuous, ellipsoid; stomata scattered over whole surface of capsule; lid rostrate; spores 18–30 μm. Capsules common, spring. n = 6, 6 + m, 12∗ , 14, 21. On sheltered basic soil, rocks and damp walls. Mainly lowland but ascending to 460 m in Caernarfon. Frequent or common in most of Britain but occasional in northern Scotland, rare to occasional in Ireland. 109, H37, C. GB914 + 101∗ , IR100 + 2∗ , C1 + 1∗ . European Boreo-temperate. Cosmopolitan. Easily recognised by the rostrate capsule lids but when sterile may be confused in the field with P. affine (q.v.).

114 PSEUDOBRYUM (KINDB.) T. J. KOP., ANN. BOT. FENN. 1968 Dioicous. All stems erect. Leaves orbicular to ovate-oblong, unbordered; costa without stereids; cells elongate-hexagonal or rhomboidal. Lid conical.

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32 Aulacomniaceae

Chromosomes longer and thinner than in preceding genera of the Mniaceae. Two species only, the second, P. speciosum (Mitt.) T. J. Kop., occurring in C. Asia. Derivation: Meaning resembling but not being a Bryum.

1 P. cinclidioides (Huebener) T. J. Kop., Ann. Bot. Fenn., 1869 Mnium cinclidioides Huebener

(Fig. 210)

Bright green patches or deep tufts, dark brown below, 3–10(−15) cm high; stems with brownish tomentum below. Leaves shrunken when dry, spreading and often slightly undulate when moist, ovate, obovate-oblong or orbicular, apex rounded, emarginate or apiculate, not decurrent at base; margins plane, unbordered, entire or obscurely denticulate above; costa stout, green to brown, ending well below apex; cells in rows, elongate-hexagonal, not collenchymatous, porose, 20– 30 × 70–125 μm, 3–4 times as long as wide in mid-leaf. Setae orange-red; capsules pendulous, ovoid; lid conical; spores 24–36 μm. Capsules very rare, early summer. n = 6, 7. In fen carr, marshes, wet woodland, by lakes, in flushes and springs. Ascending to 800 m. Occasional in N. W. Wales, rare or very rare elsewhere, from the Lake District and N. Northumberland north to Shetland. 33. GB44 + 11∗ . Circumpolar Boreal-montane. Montane and northern Europe north to northern Scandinavia, N. and C. Asia, Himalayas, China, Sakhalin, Japan, northern N. America, Greenland.

32 Aulacomniaceae Dioicous or autoicous. Stems with central strand. Leaves ovate to lanceolate; margins unbordered, entire to dentate; costa strong, ending below apex, with two stereid bands in section; extreme basal cells enlarged or elongate, cells elsewhere rounded-hexagonal, incrassate, mamillose. Stems sometimes terminating in gemma-bearing pseudopodia. Setae long; capsules suberect to horizontal, straight or curved, ovate-ellipsoid to shortly cylindrical, striate, when dry and empty sulcate; stomata superficial; exostome teeth finely papillose, endostome with long cilia; lid conical; calyptrae cucullate. One genus.

¨ 115 AULACOMNIUM SCHWAGR., SP. MUSC. FROND. SUPPL. 3, 1827 Eight species distributed through Europe, Asia, Africa, the Americas, Australasia. Derivation: meaning furrowed Mnium, with reference to the striate capsules.

1 Plants to 2.5 cm high, gemma-bearing pseudopodia common, leaf margins irregularly denticulate above, basal cells rectangular, greenish 3. A. androgynum Plants to 10 cm high, gemma-bearing pseudopodia occasional, leaf margins entire to finely denticulate above, basal cells enlarged, brownish 2

115 Aulacomnium

637

Fig. 211 1–6, Aulacomnium palustre: 1, dry shoot (×5); 2, leaf (×15); 3, mid-leaf cells; 4, gemma-bearing pseudopodium (×40); 5, capsule (×10); 6, leaf of dry ground form (×15). 7–10, A. androgynum: 7, shoot with pseudopodium (×15); 8, leaf (×30); 9, mid-leaf cells; 10, gemmae (×250). 11–13, A. turgidum: 11, dry shoot (×5); 12, leaf (×15); 13, mid-leaf cells. Cells ×420.

2 Stems with dense brown tomentum, leaves usually erect-patent when moist, cells mamillose, lumens rounded 1. A. palustre Stems not tomentose, leaves imbricate when moist, cells not or scarcely mamillose, lumens stellate 2. A. turgidum ¨ 1 A. palustre (Hedw.) Schwagr., Sp. Musc. Frond. Suppl. 3, 1827 A. palustre var. imbricatum Bruch & Schimp.

(Fig. 211)

Dioicous. Yellowish green to green tufts or patches, matted with brown tomentum below, to 10 cm or more high. Leaves variously crisped or twisted, rarely straight

638

32 Aulacomniaceae

and imbricate when dry, erect-patent when moist, lanceolate to lingulate, tapering to acuminate to obtuse or rarely rounded apex; margins recurved on one or both sides below, entire or finely denticulate above; costa stout, ending below apex, shining white on abaxial side when dry; extreme basal cells enlarged, brownish, 2–3-stratose, cells elsewhere unistratose, irregularly rounded to quadrate, incrassate with rounded lumens, with one conical mamilla on each face, 8–14 μm wide in mid-leaf. Stems occasionally producing terminal gemma-bearing pseudopodia; gemmae fusiform, c. 400 μm long. Capsules inclined, narrowly ovate-ellipsoid, ribbed, strongly sulcate when dry; lid bluntly rostrate; spores c. 14 μm. Capsules occasional, summer. n = 12∗ . Damp peaty more or less acidic ground on heaths, moorland, in bogs and damp fen carr. 0–975 m. Common on suitable terrain in lowland England, common and sometimes locally abundant elsewhere, occasional to frequent in Ireland. 112, H31, C. GB1202 + 101∗ , IR207 + 7∗ , C2. Circumpolar Wide-boreal. Throughout the Northern Hemisphere, extending north to Svalbard, Australia, Tasmania. New Zealand. A very variable species, some small forms of which approach A. androgynum in size, and it may occasionally have gemma-bearing pseudopodia. It differs, however, in habitat and the enlarged 2–3-stratose brownish cells at the extreme base of the leaves. A form with blunter leaves which are imbricate when dry, referred to as var. imbricatum Bruch & Schimp., appears to be a form of drier ground and is no longer recognised as distinct in Britain.

¨ 2 A. turgidum (Wahlenb.) Schwagr., Sp. Musc. Frond. Suppl. 3, 1827 (Fig. 211) Yellowish green tufts, to 10 cm high; shoots turgid when moist, stems not tomentose. Leaves somewhat crisped, appressed when dry, imbricate when moist, concave, obovate to ovate or lanceolate, obtuse to rounded, sometimes cucullate; margins recurved to above middle, entire; costa ending below apex; cells at extreme base swollen, brownish, 2–3-stratose; elsewhere unistratose, roundedhexagonal, with stellate lumens, not or scarcely mamillose, 10–16 μm wide in mid-leaf. Capsules ± curved; unknown in Britain. n = 12. In dwarf herb communities and Racomitrium heath over base-rich rocks, often on the edge of soil-creep terraces. (430−)700–1000 m. Rare to occasional on the higher Scottish mountains, Mid Perth, Inverness, Argyll, Skye, Ross, Sutherland, with an old record from N. W. Yorkshire. 10. GB23 + 7∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Faroes, Iceland, Himalayas, Japan, E. Africa, N. America, Mexico. Likely to be mistaken for A. palustre, but distinguished in the field by the concave leaves imbricate when moist. The ± smooth cells with stellate lumens will distinguish A. turgidum microscopically.

¨ 3 A. androgynum (Hedw.) Schwagr., Sp. Musc. Frond. Suppl. 3, 1827 (Fig. 211) Pale green to dark green tufts or patches, to 2.5(−3.5) cm high; stems slender, tomentose below. Leaves appressed, crisped when dry, patent when moist,

116 Plagiopus

639

ovate-lanceolate to narrowly lanceolate, acuminate; margins recurved or not below, irregularly denticulate above; costa ending below apex; cells incrassate, unistratose throughout, rectangular at base, elsewhere ± uniformly roundedhexagonal with tall conical mamillae, 10–12 μm wide in mid-leaf. Gemmabearing pseudopodia common, gemmae spherical to ovoid, to 55 μm long. Capsules ± erect, becoming inclined to horizontal with age, narrowly ellipsoid; spores c. 10 μm. Capsules very rare, spring, summer. n = 11–12, 12. On logs, twigs, in knot holes and crevices in trunks, on decaying wood and posts, sides of peat-cuttings, sheltered humus-rich banks and sheltered sandstone. Lowland. Rare or very rare in Scotland and Ireland, common elsewhere except S. W. and N. W. England and W. Wales, very rare in Ireland and seen recently only in Cavan, Louth and Fermanagh. 95, H9. GB775 + 45∗ , IR2 + 11∗ . European Temperate. Europe north to 63◦ N, Cyprus, Turkey, C. Asia, Japan, Korea, Canary Islands, N. America, Patagonia. A. androgynum has increased in parts of England, particularly in the past 40 years, possibly as a consequence of reduced atmospheric pollution and lowered competition from other epiphytic species unable to tolerate levels of pollution that still prevail.

33 Bartramiaceae Dioicous, autoicous or synoicous. Usually tufted plants; stems tomentose, with central strand. Leaves erect to ± spreading when moist, ovate-lanceolate to linearlanceolate, often with expanded basal part, shortly to longly acuminate; margins plane or recurved, denticulate to serrate above; costa ending below apex to excurrent; cells ± hexagonal to elongate, mamillose. Setae long, usually straight; capsules erect or inclined, globose; symmetrical or not with mouth often oblique, smooth when ripe, usually longitudinally furrowed when dry and empty; lid conical, sometimes shortly beaked; peristome double, rarely single, rudimentary or absent, exostome longer than endostome, processes bifid, cilia rudimentary or absent; calyptrae minute, cucullate. For a review of the family see D. Griffin III & W. R. Buck, Bryologist 92, 368–80, 1989.

Subfamily 1 BARTRAMIOIDEAE Rhizoids papillose. Axillary hairs usually up to 3 cells long, basal cell pigmented or hyaline. Leaves spirally arranged or 3-ranked. Lids conical; exostome teeth free. x = 8, 9.

116 PLAGIOPUS BRID., BRYOL. UNIV., 1826 Gametophyte similar to that of Bartramia but stem in section triangular and cells of outer layer elongate. Leaf cells finely papillose-striate and not mamillose. Setae long, flexuose; capsules ± globose, striate at maturity, furrowed when dry and

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33 Bartramiaceae

empty; peristome double. Only two species, the second of which occurs in New Zealand. Derivation: meaning curved, referring to the ± flexuose setae.

1 P. oederianus (Sw.) H. A. Crum & L. E. Anderson, Mosses E. N. Am., 1981 (Fig. 212) Bartramia oederi Brid., P. oederi (Brid.) Limpr. Synoicous. Loose or dense green tufts, to 6 cm high. Stems tomentose below. Leaves flexuose to crisped when dry, erect-patent when moist, narrowly lanceolate, acuminate, base not sheathing, margins recurved below, toothed above; costa ending in apex or excurrent; basal cells linear, cells at basal angles and short distance up margins quadrate-rectangular, cells above ± rectangular, smooth or faintly papillose, 8–10 μm wide in mid-leaf. Setae 5–15 mm long; capsules ± globose, asymmetrical with oblique mouth, finely striate at maturity, sulcate and curved when dry and empty; lid conical; spores 18–25 μm. Capsules common, spring, summer. n = 7∗ , 8. On shaded ledges and in crevices of calcareous rock in ravines, woods and on cliffs. 0–730 m. Occasional in Wales, Derby, Lake District, central Scottish Highlands, locally common in the Pennines, very rare elsewhere, W. Cornwall, Stafford, W. Gloucester, and north to Skye and W. Sutherland, Leitrim, old records from S. Kerry and Antrim. 36, H3. GB66 + 30∗ , IR1 + 4∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Iceland, Turkey, Iran, N. and C. Asia, China, Japan, N. America, Greenland, Hawaii. Similar to some Bartramia species, but the more slender plants with relatively shorter and more shortly pointed leaves without sheathing bases and smaller capsules will distinguish P. oederiana from Bartramia species in the field.

117 BARTRAMIA HEDW., SP. MUSC. FROND., 1801 Autoicous or synoicous. Plants often robust; stems tomentose below. Leaves erect to spreading when moist, linear-lanceolate or narrowly lanceolate from often sheathing basal part, subulate; margins plane or recurved below, denticulate above, teeth sometimes double; costa ending in apex to excurrent; basal cells elongate, thin-walled, cells above incrassate, quadrate to narrowly rectangular, mamillose. Setae straight or curved; capsules ± globose, striate, furrowed when dry and empty; lid shortly conical; peristome double, outer longer than inner. A world-wide genus of c. 75 species. Derivation: named after John Bartram (1699–1777), an early N. American botanist.

1 Leaves erect, rigid, straight when dry, capsules symmetrical 4. B. stricta Leaves flexuose or crisped when dry, capsules asymmetrical with oblique mouth 2

117 Bartramia

641

Fig. 212 1–4, Plagiopus oederianus: 1, leaf; 2, basal cells; 3, mid-leaf cells; 4, capsule (×10). 5–8, Bartramia ithyphylla: 5, leaves; 6, basal cells; 7, mid-leaf cells; 8, capsule (×7). 9–13, B. pomiformis: 9, leaf; 10, basal cells; 11, mid-leaf cells; 12, 13, mature and old capsules. Leaves ×20, cells ×420, capsules ×10.

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33 Bartramiaceae

2 Leaves with ± white sheathing bases, upper cells narrowly rectangular, opaque 3 B. ithyphylla Leaf bases if sheathing not whitish, upper cells hexagonal, quadrate or quadrate-rectangular, ± pellucid 3 3 Plants bright green above, brownish below, leaves ± crisped when dry, setae curved, 2–3 mm long, capsules usually concealed by leaves 1. B. halleriana Plants usually glaucous green, upper leaves flexuose to ± crisped when dry, setae straight, 5–25 mm long, capsules exserted above leaves 2. B. pomiformis Section 1 Bartramia Leaves erect-patent to spreading when moist, bases subsheathing or not; basal cells narrowly rectangular, cells above quadrate-rectangular, unistratose except at margins. Capsules asymmetrical. 1 B. halleriana Hedw., Sp. Musc. Frond., 1801 (Fig. 213) Autoicous or synoicous. Lax silky green or brownish green tufts, to 15 cm high; stems tomentose below. Upper leaves crisped when dry, erect-patent when moist, sometimes subsecund, from erect subsheathing basal part narrowly lanceolate, longly subulate; margins recurved below, dentate above, teeth sometimes double; costa excurrent, toothed on abaxial side above; cells incrassate, in basal part narrowly rectangular, a few alar cells rectangular, cells above quadrate-rectangular, bistratose at margins, unistratose elsewhere, mamillose, pellucid, 6–10 μm wide in mid-leaf. Sporophytes often 2 per perichaetium; setae curved, 2–3 mm long; capsules ± concealed by leaves, persisting and appearing lateral with age, inclined, globose with oblique mouth, striate at maturity, sulcate when dry and empty; lid shortly conical; spores 20–24 μm. Capsules common, summer. n = 8 + m, 9, 12∗ . On shaded calcareous rock ledges in woods, in ravines and on cliff ledges. 0–730 m. Occasional to frequent in W. Wales, N. W. England and the middle part of W. Scotland, rare elsewhere in the west and north, extending to W. Sutherland, formerly Derby, S. W. Yorkshire and Durham, recorded from 9 Irish vice-counties but seen recently only in S. Kerry. 36, H9. GB91 + 15, IR1 + 7∗ . European Borealmontane. Montane and northern Europe north to Fennoscandia, W. Russia, Caucasus, Turkey, Himalayas, Kashmir, Tibet, China, Kilimanjaro, N. America, southern S. America, Australia, New Zealand. Usually readily recognised by its large size and capsules, which are commonly present, immersed in the leaves. Successive generations of capsules may persist, older capsules appearing lateral because of continued growth of branches from below the perichaetia. It may be difficult to separate from some tall lax forms of B. pomiformis in which innovating shoots may overtop capsules but the setae are curved.

2 B. pomiformis Hedw., Sp. Musc. Frond., 1801 (Fig. 212) Autoicous or synoicous. Dense glaucous green or rarely green tufts, brownish below, 0.5–8.0 cm high; stems tomentose below. Leaves crowded, flexuose to crisped

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Fig. 213 1–4, Bartramia halleriana: 1, leaf (×15); 2, basal cells; 3, mid-leaf cells; 4, capsule (×10). 5–8, B stricta: 5, leaf (×15); 6, basal cells; 7, mid-leaf cells; 8, capsule (×10). 9–11, Conostomum tetragonum: 9, leaves (×20); 10, mid-leaf cells; 11, capsule (×10). 12–14, Philonotis cernua: 12, leaf (×55); 13, mid-leaf cells; 14, capsule (×15). Cells ×420.

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when dry, erect-patent to patent when moist, lanceolate or linear-lanceolate, tapering to subulate apex, basal part not or scarcely sheathing; margins recurved below, toothed above, teeth often double; costa excurrent, toothed on abaxial side above; basal cells narrowly rectangular, cells above incrassate, quadraterectangular, quadrate or hexagonal, mamillose, pellucid, bistratose at margins, unistratose elsewhere, 4–8 μm wide in mid-leaf. Setae straight, 5–25 mm long; capsules inclined, globose with oblique mouth, striate at maturity, glossy and sulcate when dry and empty; lid shortly conical; spores with large rounded papillae, 20–26 μm. Capsules common, spring, summer. n = 7 + m, 8∗ , 8 + m∗ . Sheltered soil banks, rock crevices, on ledges in ravines and woodland, on walls, in dry to moist acidic to slightly basic habitats. 0–900 m. Occasional to frequent in southern England from Cornwall east to Kent, rare elsewhere in lowland England, frequent or common in Wales, N. England and Scotland, occasional in Ireland. 105, H28, C. GB766 + 141∗ , IR43 + 9∗ , C7. Circumpolar Boreo-temperate. Europe north to Fennoscandia, Faeroes, Caucasus, Turkey, N. and C. Asia, Himalayas, China, Japan, La Palma, Tenerife, N. America, Greenland, Tierra del Fuego, New Zealand. B. pomiformis is a variable species, particularly in relation to size and degree of crowding and crisping of leaves. In damp or heavily shaded habitats the tufts may be green, laxer, the leaves longer, narrower and somewhat crisped when dry. Such forms have been treated as a variety (var. elongata Turner) but would appear to be a mere habitat form. B. stricta differs in the leaves being straight, rigid and appressed when dry and the capsules erect and symmetrical. B. ithyphylla may be distinguished in the field by the whitish leaf bases and microscopically by the long narrow leaf cells.

Section 2 Ithyphylliae Kindb., Eur. N. Am. Bryin., 1897 Leaves spreading when moist, bases sheathing; basal cells narrowly rectangular, cells above narrowly rectangular, bistratose except at margins. Capsules asymmetrical. 3 B. ithyphylla Brid., Muscol. Recent., 1802 (Fig. 212) Synoicous. Silky glaucous green tufts, 0.5–4.0 cm high; stems tomentose below. Leaves erect, flexuose or crisped when dry, spreading when moist, basal part white, rectangular, sheathing, widened at shoulders, then narrowly lanceolate, tapering to subulate apex; margins plane, serrulate above; costa excurrent; cells in sheathing base narrowly rectangular, hyaline, cells above smaller, narrowly rectangular, mamillose, opaque, unistratose at margins, bistratose elsewhere, 4–6 μm wide in mid-leaf. Setae straight, 1–3 cm long; capsules inclined, globose with oblique mouth, striate at maturity, glossy and sulcate when dry; lid shortly conical; spores mamillose, 34–40 μm. Capsules common, summer. n = 8∗ , 12∗ . On ± basic soil in montane rock crevices and on ledges, also on lowland hedge banks. 0–1170 m. Occasional in N. W. England, very rare elsewhere in England, occasional to frequent in Wales, common in the central and northern Scottish Highlands,

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occasional elsewhere in Scotland, rare in Ireland. 87, H14. GB323 + 57∗ , IR12 + 9∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faroes, Iceland, Caucasus, Turkey, N. and C. Asia, Himalayas, Yunnan, Taiwan, N. and E. Africa, Greenland, N. and C. America, Patagonia, Australia, New Zealand, sub-antarctic islands. Readily distinguished from other members of the genus in the field by the whitish sheathing leaf bases and under the microscope by the narrow opaque leaf cells.

Section 3 Strictidium (Mull. ¨ Hal.) Broth., Nat. Pflanzenfam., 1904 Leaves erect when moist, bases not sheathing; cells of similar shape ± throughout, 2–3-stratose above. Capsules symmetrical. 4 B. stricta Hedw., Sp. Musc. Frond., 1801 (Fig. 213) Synoicous. Dense glaucous green tufts, to 3 cm high; stems tomentose below. Leaves erect, rigid when dry, ± erect when moist, narrowly lanceolate, tapering almost from base to subulate apex, basal part not sheathing; margins plane or narrowly recurved below, denticulate above; costa excurrent; basal cells narrowly rectangular, hyaline, cells above incrassate, rectangular or narrowly rectangular, mamillose, opaque, 2(−3)-stratose in upper part of leaf, 4–8 μm wide in mid-leaf. Setae straight, c. 1 cm long; capsules erect, globose, symmetrical, finely striate at maturity, glossy and sulcate when dry; lid shortly conical; spores mamillose, 36– 42 μm. Capsules common, summer. n = 16. On soil in rock crevices and on ledges, on soil banks in basic habitats. Lowland. Very rare, W. Sussex (extinct), Radnor, Montgomery (probably extinct), Mid Perth, Jersey, Guernsey. 4, C. GB3 + 1∗ , C2. Mediterranean-Atlantic. Mediterranean and western Europe north to Britain, Caucasus, Turkey, Cyprus, Macaronesia, Algeria, Libya, Cameroon, N. America, Magellan Is., Australia, Tasmania. This species is regarded as critically endangered in the Red List of British mosses and is a protected species under the Wildlife and Countryside Act.

Subfamily 2 CONOSTOMOIDEAE With the characters of the genus. Derivation: meaning cone mouth, from the form of the peristome.

118 CONOSTOMUM SW. IN F. WEBER & D. MOHR, NATURH. REISE SCHWEDENS, 1804 Dioicous or autoicous. Plants densely tufted, stems fastigiately branched. Rhizoids smooth. Axillary hairs 2 cells long, basal cell often pigmented. Leaves imbricate, lanceolate, serrulate above; cells ± rectangular, mamillose. Capsules ± obloid, cernuous, striate; peristome single, the 16 teeth united at tips. x = 8. With the exception of C. tetragonum, a Southern Hemisphere genus, 15 species.

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¨ 1 C. tetragonum (Hedw.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1861 (Fig. 213) C. boreale Sw. Dioicous. Dense glaucous green to dark green tufts, to 2(−12) cm high. Leaves imbricate when moist and when dry, 5-ranked, narrowly lanceolate, acuminate; margins plane, denticulate above; costa excurrent; cells variable in shape, ± rectangular to narrowly rectangular, towards apex ± quadrate to elliptical, narrower at margins, mamillose, 8–13 μm wide in mid-leaf. Setae straight, to 12 mm long; capsules cernuous, ± obloid, asymmetrical, striate at maturity, sulcate when dry and empty; lid obliquely rostrate; spores c. 40 μm. Capsules occasional, summer. n = 16. On acidic soil in areas of late snow-lie, on mountain summits and in corries. (280−)800–1335 m. Formerly in Caernarfon and Westmorland, frequent and sometimes locally abundant on the higher Scottish mountains, extending north to Shetland. 21. GB50 + 12∗ . Circumpolar Arctic- montane. Montane and northern Europe north to Svalbard, Faroes, Iceland, N. Asia, N. America, Greenland.

Subfamily 3 BREUTELIOIDEAE Rhizoids papillose. Axillary hairs 2 or more cells long, apical cell globose, basal pigmented. Leaves spirally arranged. Lid convex or conical; exostome teeth free, x = 6.

119 PHILONOTIS BRID., BRYOL. UNIV., 1827 Dioicous, autoicous or synoicous. Plants very variable phenotypically, often tall. Stems innovating from below perigonium or perichaetium. Leaves ovate to lanceolate, acute to longly acuminate; margins plane or recurved, toothed, teeth single or double; costa usually strong, ending below apex to excurrent, in section with two stereid bands; at least upper cells usually mamillose. Fertile male shoots in species 4–8 with smaller more appressed and more shortly pointed leaves than sterile or female stems. Perigonial and perichaetial leaves differing markedly in shape from stem leaves or not. Setae long; capsules globose, inclined, striate at maturity, sulcate when dry and empty; endostome with well developed cilia. A world-wide genus of about 240 species of mainly damp habitats. Derivation: meaning loving moisture, referring to the habitat of most of the species. Most British species are very variable morphologically and experimental study, especially of plants coming within the range of variation of species 4–8, is required. Some species produce vegetative propagules (see E. Petit, Bull. Jard. Bot. Natn. Belg. 46, 221–6, 1976).

Notes on the identification of Philonotis species For purposes of identification it is important that mature late season leaves are examined as those produced earlier may not be fully developed and this may lead

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to misidentification. The most suitable leaves are those at the end of the previous year’s growth amongst the stem tomentum. 1 Plants 2–5 mm high, setae cygneous 9. P. cernua Plants 0.5–15.0 cm high, setae straight or sporophytes absent 2 2 Autoicous, capsules common, perigonia bud-like, leaves rigid, mamillae apparently on end-walls of cells 1. P. rigida Dioicous, capsules occasional, perigonia disciform, leaves soft, mamillae near end-walls of cells or absent 3 3 At least cells in upper part of leaves with mamillae only at distal ends of cells or cells smooth 4 Leaf cells with proximal and also sometimes distal mamillae 5 4 Most cells with distal mamillae, plants 1–5 cm high 2. P. marchica Cells in lower half of leaf smooth, upper cells smooth or with distal mamillae, plants slender, 0.5–1.0 cm high 3. P. arnellii 5 Leaves of mature growth not plicate, margins plane with single teeth, cells ± rectangular throughout 4. P. caespitosa Leaves of mature growth plicate at least near base, margins recurved, teeth double, upper cells much narrower than lower cells 6 6 Leaves spirally imbricate, costa coarsely mamillose ± from base to apex on abaxial side 7. P. seriata Leaves not spirally imbricate, costa smooth or only slightly mamillose on abaxial side 7 7 Leaves 1.8–3.0 mm long, costa (80−)128–240 μm wide near base, cells near costa at widest part of leaf mostly 48–88 μm long, inner perigonial bracts acute, plants robust 8. P. calcarea Leaves 0.5–1.5(−2.0) mm long, costa 64–128 μm wide, cells at widest part of leaf 24–40 μm long, inner perigonial bracts obtuse or if acute then plants slender 8 8 Plants slender to robust, tomentose below, leaves ± ovate, acute to acuminate, costa not or scarcely excurrent, inner perigonial bracts obtuse 5. P. fontana Plants slender, densely tomentose below, leaves narrowly lanceolate to ovate-lanceolate, acuminate or subulate, costa excurrent to longly excurrent, inner perigonial leaves acute 6. P. tomentella Section 1 Philonotula (Schimp.) Jaeger, Ber. Thatigk. St. Gallishen Naturwiss Ges., 1875 Small plants. Leaf margins plane or recurved, teeth single; mamillae apparently on end-walls of cells. Leaves below inflorescences similar to other leaves. Setae straight. 1 P. rigida Brid., Bryol. Univ., 1827 (Fig. 214) Autoicous. Green to brownish green tufts or patches, to 10(−12) mm high; stems radiculose. Leaves crowded, appressed, straight when dry, erect to erect-patent,

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Fig. 214 1–4, Philonotis rigida: 1, leaf (×25); 2, basal cells; 3, mid-leaf cells; 4, capsule (×10). 5–9, P. marchica: 5, male shoot (×10); 6, leaf (×25); 7, basal cells; 8, upper cells; 9, perigonial bract (×25). 10–13, P. arnellii: 10, male shoot (×10); 11, leaf (×40); 12, basal cells; 13, upper cells. 14–17, P. caespitosa: 14, leaf (×25); 15, basal cells; 16, upper cells; 17, perigonial bract (×25). Cells ×420.

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rigid when moist, lanceolate, acuminate; margins plane or narrowly recurved, toothed, teeth single; costa strong, excurrent; basal cells rectangular, shorter towards margins, cells above narrowly rectangular, mamillose, mamillae distal but apparently on end-walls of cells, cells 5–8 μm wide in mid-leaf. Leaves below inflorescences similar in shape to other leaves. Deciduous gemmiform propagules, 0.7–0.9 mm long, frequently produced, especially in late winter. Perigonia bud-like below perichaetia. Setae red, to 2 cm long; capsules inclined, globose, asymmetrical, striate at maturity, sulcate when dry and empty; spores ovoid, 28–32 μm long. Capsules common, spring. n = 6∗ , 12. On usually acidic damp soil or in crevices on wet cliffs and on stream banks. Lowland. Occasional in N. W. Wales, very rare elsewhere along the west coast from W. Cornwall north to Ayr, Radnor, W. Perth, very rare in western Ireland, Wicklow, Jersey. 10, H8, C. GB17 + 8∗ , IR4 + 6∗ , C2. Mediterranean-Atlantic. S. and W. Europe from Sicily and Crete north to the British Isles, Caucasus, Turkey, Lebanon, Macaronesia, Algeria. Recognised by the erect rigid narrow leaves and relatively large capsules. For a detailed account of this species see G. Raemaekers, Lindbergia 9, 29–33, 1983.

Section 2 Heteromorphae Kindb., Eur. N. Am. Bryin., 1897 Small to medium-sized plants. Stem leaves and leaves below inflorescences similar in shape; margins usually plane, with single teeth; mamillae distal. Setae straight. 2 P. marchica Brid., Bryol. Univ., 1827 (Fig. 214) Dioicous. Plants slender to robust, forming pale green tufts, 1–5(−9) cm high. Leaves erect-patent in slender plants to falcate-secund in robust plants, narrowly lanceolate to ovate-lanceolate, acute to acuminate, not plicate near base; margins plane, toothed, teeth single, blunt or sharp; costa ending below apex to shortly excurrent, 40–60 μm wide near leaf base; cells except at base with distal mamillae, basal cells rectangular, 10–16(−20) μm wide, cells above narrowly rectangular, 6–12 μm wide in mid-leaf, becoming ± linear towards apex. Leaves below inflorescences similar in shape to other leaves. Perigonial bracts from broad ± erect basal part narrowed to long acuminate apex. Capsules inclined, globose, asymmetrical, striate at maturity, sulcate when dry and empty. Capsules very rare, unknown in Britain. n = 6. On wet shale, moist soil and sandstone. Lowland. Very rare, I. of Wight, N. W. Yorkshire (1903). 2. GB1 + 1∗ . European Southern-temperate. S., C. and W. Europe north to England, Caucasus, Turkey, W. Asia, Japan, Korea, Azores, Madeira, Algeria, N. America. Whilst well grown specimens are distinct from P. arnellii in their larger size and secund leaves, the only reliable character for identifying small plants which are sterile is the presence of mamillae on the cells in the lower part of the leaf in P. marchica. For the occurrence of this plant in Britain see A. J. E. Smith, J. Bryol, 8, 5–8, 1974. This species is considered endangered in the Red List of British mosses.

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3 P. arnellii Husn., Muscol Gall., 1890 P. capillaris auct. non Lindb.

(Fig. 214)

Dioicous. Small green tufts or patches of slender plants, 0.5–1.0 μm high. Leaves erect or slightly secund when dry, patent, sometimes slightly secund when moist, 0.6–0.9 mm long, mostly 3–5 times as long as wide, lanceolate, acuminate to longly acuminate, not plicate at base; margins plane or narrowly recurved, toothed, teeth single; costa excurrent, 30–40 μm wide near leaf base; lower cells rectangular, smooth, 8–10 μm wide, cells above narrower, smooth or with distal mamillae, 7–10(−12) μm wide in mid-leaf. Leaves below inflorescences similar in shape to other leaves. Caducous axillary flagelliform branches frequently produced. Inner perigonial leaves squarrose, acute. Capsules inclined, ± globose, asymmetrical, striate at maturity, sulcate when dry and empty; spores c. 28 μm. Capsules very rare, summer. On periodically moist soil in rock crevices, on ditch and stream banks, on woodland rides and montane cliffs. 0–640 m. Rare to occasional in southern and western England and Wales, and northern England north to Caithness, W. Galway, Cavan, Tyrone (old record), Jersey. 47, H3, C. GB59 + 27∗ , IR1 + 1∗ , C1. European Temperate. Europe north to northern Scandinavia, Iceland, Caucasus, Turkey, N. America, Greenland. In both P. arnellii and P. marchica, depauperate specimens may be difficult to determine as mamillae may be difficult to detect, but careful study of well developed leaves of the latter will usually reveal distal mamillae on the cells in the lower part of the leaf. All the succeeding species except P. caespitosa have double teeth on the margins of mature leaves, but in immature or poorly developed leaves the teeth may be single. E. Petit (Bull. Jard. Bot. Natn. Belg., 36, 21–5, 1976) points out a character which might be useful in the separation of P. arnellii and P. marchica. The latter produces ellipsoid axillary gemmae, 0.5–1.0 mm long whilst the former has flagelliform axillary shoots c. 1 mm long.

Section 3 Philonotis Usually robust plants. Leaf margins recurved, teeth usually double; mamillae proximal and sometimes also distal. Leaves below inflorescences often differing from other leaves. Setae straight. 4 P. caespitosa Jur., Verh. Zool.-Bot. Ges. Wien, 1862 (Fig. 214) Dioicous. Slender light green plants in tufts or patches, to 5 cm high; older parts of stems tomentose. Leaves imbricate, ± straight or subsecund when dry, stem leaves erect-patent to falcate-secund when moist, 0.5–1.7 mm long, 1.5–3.0(−4.0) times as long as wide, ovate-lanceolate, acuminate, not plicate near base; margins plane or rarely slightly recurved, toothed, teeth single; costa narrow, ending below apex to shortly excurrent, not or scarcely mamillose on abaxial side; cells thin-walled to incrassate, rectangular ± throughout, mamillae proximal, cells in lower part of leaf 10–20 μm wide. Leaves below inflorescences erect, ovate or broadly ovate, sharply toothed, costa thick. Inner perigonial leaves acute. Capsules inclined, ± globose, asymmetrical, striate at maturity, sulcate when dry and empty; unknown in the

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British Isles. On damp or wet soil or rocks by ditches, streams, lakes and reservoirs, on damp tracks and marshy ground. 0–300 m. Widely distributed but rare or very rare, from Cornwall east to Sussex and north to Dunbarton and Mull, very rare in Ireland, Jersey. 47, H7, C. GB44 + 31∗ , IR5 + 2∗ , C1. Circumpolar Boreo-temperate. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Turkey, N., W. and C. Asia, Azores, N. America, Greenland. Differs from the next four species in the leaves not plicate below, the usually plane margins with single teeth and the cells of ± uniform shape throughout the leaf. It is likely that not all specimens named P. caespitosa belong to that species; small forms of P. fontana may be mistaken for P. caespitosa, especially if only young leaves are examined (see also under P. fontana). Plants with lax areolation and falcate leaves named P. caespitosa are not necessarily that plant.

5 P. fontana (Hedw.) Brid., Bryol. Univ., 1827 (Fig. 215) Dioicous. Slender to robust yellowish green, bright green or brownish green plants, forming tufts or patches, (0.5−)1.0–10.0(−15.0) cm high. Stems tomentose below. Leaves imbricate when dry, erect-patent or, especially in female plants, falcate and subsecund or secund, 0.8–1.5(−2.0) mm long, 2–3(−4) times as long as wide, from ovate or broadly ovate basal part rapidly narrowed to acuminate apex, plicate below; margins recurved with double teeth at least in mature leaves; costa stout, 64–128(−160) μm wide near base, ending below apex to shortly excurrent, not or scarcely mamillose on abaxial side; cells mamillose, mamillae proximal and sometimes also distal, cells in lower part of leaf ± rectangular, at widest part of leaf towards costa 8–15 × (16−)24–40 μm, cells becoming narrower above, towards apex narrowly rectangular. Leaves below male inflorescences imbricate, similar in shape to other leaves, below female inflorescences erect when moist. Deciduous axillary branchlets only rarely produced. Inner perigonial bracts reflexed from sheathing base, obtuse; margins sharply toothed. Setae to 5 cm long; capsules inclined, ± globose, asymmetrical, striate at maturity, horizontal, ovoid, furrowed when dry and empty; spores ovoid, 26–30 μm long. Capsules occasional, summer. n = 6∗ . On moist or wet soil on ditch and stream banks, by lakes, in springs and flushes, on woodland rides, on wet rocks and ledges. 0–1335 m. Rare to occasional in lowland England, common elsewhere, frequent in Ireland. 110, H36, C. GB1140 + 119∗ , IR184 + 4∗ , C1. Circumpolar Wide-temperate. Europe north to Svalbard, Faroes, Iceland, Caucasus, Turkey, Asia, Azores, Canary Islands, Algeria E. Africa, Mexico, N. America, Greenland. A very variable species, some forms of which may be confused with the previous species and others with P. calcarea or P. tomentella. Young leaves may have plane margins with single teeth and abnormally large cells. For this reason it is essential for the determination of Philonotis that leaves from the end of the previous year’s growth from amongst the tomentum are examined. P. rigida, P. arnellii and P. marchica differ in the narrower more tapering leaves and position of the cell mamillae. In P. caespitosa the leaves have wider, ± uniformly shaped cells and plane margins with single teeth. P. tomentella is close to P. fontana but has more

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Fig. 215 1–6, Philonotis fontana: 1, leaves; 2, cells near costa at widest part of leaf; 3, cells from upper part of leaf; 4, perigonial bract; 5, 6, mature and old capsules. 7–9, P. tomentella: 7, leaf; 8, perigonial bract; 9, capsule. 10–12, P. seriata: 10, leaf; 11, cells near costa at widest part of leaf; 12, cells from upper part of leaf. Leaves ×25, cells ×420, capsules ×10.

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slender stems with narrower leaves with long sometimes subulate points and acute inner perigonial leaves; these differences seem constant and the plant is worthy of specific status. P. seriata differs in the spirally arranged leaves with costae scabrous with mamillae on the abaxial side; the basal cells of the leaves in that species are also more heavily and coarsely mamillose. P. calcarea may sometimes be difficult to distinguish and occasional plants are encountered that cannot be named in the absence of perigonial leaves. P. calcarea usually has longer leaves (1.8–3.0 mm long compared with 0.8–1.5(−2.0) mm in P. fontana), the cells are frequently but not always wider (10–24 μm wide compared with 8–16 μm), and the longest cells in P. fontana (to 40 μm) do not reach the length of the longest cells in P. calcarea (48–88 μm), although it must be noted that in P. calcarea there are also scattered shorter cells. Cell length seems to be the most satisfactory character and I have only seen two gatherings in which, in the last resort, this has not served to name the plants.

6 P. tomentella Molendo in Lorch, Moosstududien, 1864 (Fig. 215) P. fontana var. tomentella (Molendo) Dixon, P. fontana var. pumila (Turner) Brid. Dioicous. Slender plants in densely tomentose tufts, patches or as straggling shoots, to 5(−9) cm high. Stems densely tomentose except youngest parts. Leaves imbricate when dry, erect-patent to subsecund when moist, 0.5–1.5 mm long, 3–4 times as long as wide, narrowly lanceolate to ovate-lanceolate, tapering to acuminate to subulate apex; margins plane or recurved with single or double teeth; costa longly excurrent, not or hardly mamillose on abaxial side; areolation as in P. fontana with mamillae proximal and sometimes also distal. Leaves below inflorescences wider than other leaves, below male inflorescences imbricate, below female inflorescences erect when moist. Inner perigonial bracts acute. Capsules as in P. fontana; very rare, spring. n = 6. In damp rock crevices on cliffs, on open ground by water, in basic habitats. (80−)400–1100 m. Very rare, in widely scattered localities from Caernarfon and N. W. Yorkshire north to Shetland. 16. GB13 + 6∗ . Circumpolar Arctic-montane. Europe north to Svalbard, Caucasus, Turkey, Iraq, Mongolia, N. America, Greenland. 7 P. seriata Mitt., J. Linn. Soc. Bot. Suppl., 1869 (Fig. 215) Dioicous. Green to yellowish green tufts or patches, reddish below, 3–12 cm high. Stems tomentose below. Leaves spirally imbricate, mostly 1–2 mm long. 1.5– 3.0(−3.5) times as long as wide, stem leaves straight to falcate, plicate below, broadly ovate and acute to ovate and shortly acuminate; margins narrowly recurved, teeth single or double; costa stout, ending below apex to shortly excurrent, coarsely mamillose on abaxial side; cells with proximal mamillae, in lower part of leaf rectangular to elongate-hexagonal, cells near costa at widest part of leaf 8–18 × 16–36 μm, towards apex narrowly rectangular. Leaves below inflorescences straight, wider than other leaves, below female inflorescences erect, below male inflorescences imbricate when moist. Capsules inclined, ± globose, asymmetrical, striate at maturity, sulcate when dry and empty. Capsules very rare, summer. n = 6. In acidic springs, flushes, by streams and on wet ground, especially in areas of late snow-lie, rarely in calcareous habitats. (450−)800–1000 m. Caernarfon, rare

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or occasional in the Scottish Highlands from Perth and Angus north to Sutherland, Orkney. 15. GB23 + 7∗ . Eurosiberian Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faroes, Iceland, Caucasus, Urals, Turkey, Iran, Siberia, Himalayas, N. Africa, Greenland. 8 P. calcarea (Bruch & Schimp.) Schimp., Coroll. Bryol. Eur., 1856 (Fig. 216) Plants ± robust, to 10(−20) cm high, forming pale green to bright green or yellowish green tufts or patches; older stems tomentose. Leaves appressed, secund when dry, erect-patent to falcate-secund when moist, 1.8–3.0 mm long, 2.5– 4.0 times as long as wide, usually falcate, lanceolate to ovate-lanceolate, rarely ovate, tapering to acuminate apex; margins strongly recurved, toothed, teeth double; costa stout, (80−)128–240 μm wide near base; cells with proximal mamillae, areolation variable, in leaves produced early in the season lower cells large, lax, ovate-rectangular, thin-walled, in leaves produced later lower cells ± narrowly rectangular, incrassate, cells towards costa at widest part of leaf 10–24(−32) × 48– 88(−108) μm, upper cells narrowly rectangular to ± linear. Leaves below inflorescences with broader bases and more longly pointed than other leaves, ± straight. Inner perigonial leaves narrowly triangular from ± erect base, acute. Setae to 4 cm long; capsules inclined, ± globose, asymmetrical, striate at maturity, horizontal, ovoid, furrowed when dry and empty; spores c. 25 μm. Capsules rare, summer. n = 6∗ . In permanently wet calcareous sites, in fens, springs, dune-slacks, on cliff ledges and dripping rocks. 0–640 m. Very rare to occasional in lowland and S. W. England, frequent in Wales and N. England, rare to frequent in Scotland, occasional in Ireland. 76, H30 GB282 + 48∗ , IR52 + 12∗ . European Boreo-temperate. Europe north to northern Scandinavia, Faroes, Caucasus, Turkey, Iran, N. Asia, Himalayas, Tibet, Algeria, N. America. Unlike other British species of Philonotis, P. calcarea is strongly calcicolous.

Section 4 Leiocarpus Broth., Nat. Pflanzenfam., 1904 Synoicous. Plants very small. Male inflorescence bud-like. Setae cygneous; peristome present or not. 9 P. cernua (Mitt.) D. G. Griffin & W. R. Buck, Bryologist, 1989 (Fig. 213) Bartramidula cernua (Wilson) Lindb., B. wilsonii Bruch & Schimp., P. wilsonii (Bruch & Schimp) Mitt. Synoicous, rarely autoicous or dioicous. Plants very small, slender, scattered or forming pale green patches, 2–5 mm high; stems branching from below perichaetium. Leaves erect-flexuose when dry, erect-patent, sometimes subsecund when moist, lanceolate to narrowly lanceolate, acuminate; margins plane, denticulate; costa usually ending in apex; basal cells rectangular, cells above narrowly rectangular, not or only faintly mamillose, c. 8 μm wide in mid-leaf. Setae flexuose when dry, arcuate when moist; capsules inclined to pendulous, globose, with shortly tapering neck, smooth at maturity, slightly sulcate when dry and

119 Philonotis

655

Fig. 216 1–5, Philonotis calcarea: 1, leaf; 2, cells near costa at widest part of leaf; 3, cells from upper part of leaf; 4, perigonial bract; 5, capsule. 6–8, Breutelia chrysocoma: 6, leaves; 7, mid-leaf cells; 8, capsule. Leaves ×25, cells ×420, capsules ×10.

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33 Bartramiaceae

empty; lid convex; peristome absent; spores 28–40 μm. Capsules common, summer, autumn. On periodically burnt peat or on soil in scree. 0–500 m. Very rare and sporadic in appearance, W. Inverness, Argyll, S. Kerry, W. Cork, W. Mayo, old records from Merioneth, Angus, W. Ross, S. Uist, Lewis, W. Galway. 6, H3. GB2 + 5∗ , IR3 + 1∗ . Hyperoceanic Temperate. Spain, Yunnan, Bioko (Fernando Po), N. Carolina, Tennessee, Mexico, Costa Rica. This species is regarded as critically endangered ion the Red List of British mosses.

120 BREUTELIA (BRUCH & SCHIMP.) SCHIMP. COROLL. BRYOL. EUR., 1856 Dioicous. Plants robust; stems tomentose. Leaves spreading, plicate, from broad sheathing base lanceolate, acuminate; costa thin, percurrent or excurrent; basal cells linear, cells above narrowly rectangular, sometimes widened at margins, mamillose. Setae long or short, flexuose to cygneous; capsules pendulous, ± globose or ovoid, furrowed when dry and empty; lid shortly conical; peristome double. A world-wide genus of about 140 species. Derivation: named after Johann C. Breutel, a German bryologist (1788–1855).

¨ 1 B. chrysocoma (Hedw.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 216) B. arcuata (Sw.) Schimp. Shoots procumbent or ascending, yellowish green above, brownish below, to 10(−15) cm long, forming tufts, patches or scattered plants; stems with brownish tomentum except near tips. Leaves spreading when moist, somewhat scarious when dry but otherwise unaltered, longitudinally plicate, from sheathing base reflexed, lanceolate, acuminate; margins plane or slightly recurved above, slightly denticulate above; costa thin, ending below apex; basal cells linear to narrowly rectangular, alar cells wider and shorter, cells above incrassate, rectangular to narrowly rectangular, slightly sinuose, mamillose, 6–8 μm wide in mid-leaf. Setae cygneous; capsules usually hidden in leaves, ovoid to globose, symmetrical, striate at maturity, furrowed when dry and empty; spores 24–30 μm. Capsules rare, autumn. n = 6. On open wet ground and near streams on heaths, moorland, banks, grassland, cliff ledges. 0–750 m. Common in western and north-western Britain, very rare in lowland England, occasional in eastern Scotland, frequent or common in western Ireland, rare elsewhere. 77, H33. GB614 + 66∗ , IR172 + 9∗ . Hyperoceanic Temperate. S. W. Norway, Faroes, very rare elsewhere in Europe, France, Germany, Switzerland, Spain, Italy, Corsica, W. Africa, C. America.

17 Orthotrichales Acrocarpous. Leaves ovate to lanceolate; costa with or without median guide cells; basal cells rectangular, upper cells rounded-hexagonal, often papillose,

121 Amphidium

657

unistratose. Setae straight, very short to long; capsules erect, immersed to longly exserted; peristome double, outer of 16 usually papillose or striate teeth, endostome thin or absent, or capsules gymnostomous.

34 Amphidiaceae Autoicous or synoicous. Plants forming dense cushions. Leaves twisted or crisped when dry, linear or linear-lanceolate, acute; margins recurved on one or both sides; costa ending below apex, in section with median guide cells, adaxial stereids sometimes absent; basal cells rectangular, thin- or thick-walled, cells above roundedquadrate, papillose, opaque, papillae of upper cells rounded, those of lower cells oval to linear. Perichaetial leaves elongate with sheathing bases. Setae short, straight; capsules gymnostomous, emergent to shortly exerted, narrowly pyriform, tapering into seta, striate, sulcate when dry and empty; stomata superficial; peristome absent; calyptrae cucullate, smooth. One genus with about 12 species with a ± world-wide distribution. One genus.

121 AMPHIDIUM SCHIMP., COROLL. BRYOL. EUR., 1885 Derivation: a modification of the original name, Amphoridium, meaning an urn, alluding to capsule shape. Amphidium is placed by some authorities in the Rhabdoweisiaceae, but it has been shown by J. Lewinsky (Lindbergia 3, 227–31, 1976) that, on the basis of capsule development, the closest affinities of the family are with the Orthotrichaceae. However, although morphologically similar to Zygodon, cytologically Amphidium shows affinities with Grimmia and Ptychomitrium and is best placed in its own family.

Basal cells of leaves thin-walled, upper cells strongly papillose, autoicous, capsules common, just emerging above leaves 1. A. lapponicum Basal cells thick-walled, upper faintly papillose, dioicous, capsules very rare, exserted 2. A. mougeotii 1 A. lapponicum (Hedw.) Schimp., Coroll. Bryol. Eur., 1856 Zygodon lapponicus (Hedw.) Bruch & Schimp.

(Fig. 217)

Autoicous. Dark green tufts, reddish brown below, to 5 cm high. Leaves crisped when dry, patent, flexuose when moist, ligulate to linear, acute or acuminate; margins recurved below, papillose-crenulate above; costa ending in or below apex; basal cells thick-walled, hyaline, cells above rounded-hexagonal, strongly papillose, 10–14 μm wide in mid-leaf. Setae short, 1.5–2.5 mm long; capsules just emergent above leaves, narrowly pyriform, striate at maturity, plicate when dry and empty, gymnostomous; spores smooth, 8–12 μm. Capsules common, summer. n = 13∗ . On basic cliffs and rock outcrops in exposed or sheltered situations and in rock crevices. 210–1070 m. Rare in Wales and southern Scotland, occasional in N. W. England and the Scottish Highlands, extending north to Sutherland. 30.

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34 Amphidiaceae

Fig. 217 1–4, Amphidium mougeotii: 1, leaf; 2, basal cells; 3, mid-leaf cells; 4, sporophyte. 5–8, A. lapponicum: 5, leaves 6, basal cells; 7, mid-leaf cells; 8, sporophyte. Leaves ×25, cells ×420, sporophytes ×10.

GB64 + 13∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, northern and eastern Asia, Canary Islands, N. and southern Africa, N. America, Chile, New Zealand. 2 A. mougeotii (Bruch & Schimp.) Schimp., Coroll. Bryol. Eur., 1856 (Fig. 217) Zygodon mougeotii Bruch & Schimp. Dioicous. Yellowish green to dark green or brownish green tufts or cushions, brownish below, to 8 cm high. Leaves flexuose-curled when dry, erect-patent, flexuose when moist, narrowly linear-lanceolate, acuminate; margins recurved below, entire or finely papillose-crenulate to denticulate towards apex; costa ending in or below apex; basal cells rectangular, incrassate, yellowish green, cells above rounded-hexagonal, incrassate, faintly papillose, pellucid, 8–10 μm wide in midleaf. Setae c. 3 mm long; capsules exserted above leaves, narrowly pyriform, striate at maturity, sulcate when dry and empty, gymnostomous; spores 10–12 μm. Capsules very rare, summer. On damp, especially vertical, usually acidic rocks and in rock crevices in ravines and woods, on montane and coastal cliffs. 0–2280 m. Frequent or common in western and northern Britain and western Ireland. 75, H28. GB672 + 77∗ , IR100 + 7∗ . Circumpolar Boreal-montane. Europe north to Fennoscandia, Caucasus, Turkey, N. and E. Asia, Macaronesia, N. America. A. lapponicum, which is commonly fertile, may be distinguished from A. mougeotii by its shorter, broader leaves with more papillose cells. Anoectangium aestivum, which may be

122 Zygodon

659

mistaken for A. mougeotii, differs in its vivid green colour, slender stems and shorter wider leaves with more strongly papillose cells.

35 Orthotrichaceae Plants usually tufted. Leaves ovate to narrowly lanceolate, usually acute; margins usually recurved; costa present, ending in or below apex or excurrent; basal cells rectangular to linear, upper cells rounded-hexagonal, often incrassate and papillose. Setae short or long; capsules immersed to longly exserted, ellipsoid, often with long neck, usually striate at maturity, sulcate when dry and empty; stomata superficial or immersed; peristome double, single or rarely absent; calyptrae mitriform or cucullate, often with coarse erect hairs. Mainly corticolous or saxicolous plants. Basic chromosome numbers of the family are x = 6, 10 + m, 11. Twenty-three genera. Subfamily 1 ZYGODONTOIDEAE Leaves denticulate or with an apiculus, acute or rarely obtuse; cells in upper part of leaf mostly with 3–6 clavate papillae. Gemmae usually present in leaf axils or on radicles, never on leaf surfaces. Capsules longly exserted; calyptrae cucullate, not plicate. 122 ZYGODON HOOK. & TAYLOR., MUSCOL. BRIT., 1818 Autoicous or dioicous. Leaves flexuose, twisted when dry, linear-lanceolate to ovate; margins plane or recurved below, entire, papillose-crenulate or toothed towards apex; costa ending below apex to excurrent; basal cells rectangular, hyaline, smooth, upper cells quadrate to hexagonal, papillose, often obscure. Gemmae in leaf axils and on radicles frequently present. Setae long; capsules ovoid to ellipsoid or pyriform, with 8 longitudinal striae at maturity; exostome teeth when present initially in pairs then separating. A ± world-wide genus of c. 50 species, the majority of which occur in Africa and America. Derivation: meaning united tooth, referring to the paired exostome teeth.

1 Plants 2–8 cm high, margins of upper leaves toothed towards apex 6. Z. gracilis Plants to 1(−2) cm high, leaf margins not toothed 2 2 Capsules narrowly pyriform, cells smooth, in leaf 14–20(−24) μm wide 1. Z. forsteri Capsules ovoid to ellipsoid, cells papillose, 6–12 μm wide in mid-leaf 3 3 Costa widened towards leaf apex, excurrent 3. Z. stirtonii Costa not widened above, ending below apex 4 4 Leaves patent when moist, cells 10–12 μm wide in mid-leaf, spores 18–20 μm, gemmae 7–8 cells long, without longitudinal cell walls, peristome double, teeth short, fugacious 5. Z. conoideus

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35 Orthotrichaceae

Leaves spreading-recurved when moist, leaf cells mostly 7–9 μm wide in mid-leaf, spores 14–16 μm, gemmae 4–6 cells long, with or without longitudinal cell walls, peristome rudimentary or absent 5 5 Gemmae 30–40 μm wide with some longitudinal cell walls, plants green to dark green 2. Z. viridissimus Gemmae mostly 20–30 μm wide, without longitudinal cell walls, plants yellowish green 4. Z. rupestris

1 Z. forsteri (Dicks. ex With.) Mitt., Ann. Mag. Nat. Hist., 1851 (Fig. 218) Autoicous. Small dark green cushions, to 5 mm high. Leaves flexuose when dry, erect-patent when moist, ovate to lanceolate or slightly ovate-spathulate, acute to acuminate; margins plane, entire; costa percurrent to excurrent; basal cells rectangular, cells above hexagonal, smooth, pellucid, 14–20(24) μm wide in mid-leaf. Gemmae lacking except on protonemata. Capsules narrowly pyriform; peristome present; spores c. 10 μm. On trunks and branches of trees, especially Fagus sylvatica, usually in seepage areas or below old scars, rarely on exposed roots. Lowland. Very rare, known from the New Forest, Epping Forest and Burnham Beeches, old records from S. Somerset and Worcester. 5. GB3 + 3∗ . Suboceanic Southern-temperate. Bulgaria, Croatia, Denmark, Greece, Italy, Portugal, Sardinia, Spain, Switzerland, Madeira, Algeria. First discovered new to science near Walthamsow, Essex, in 1817. For an account of the ecology of this species in Britain see M. C. F. Proctor, Trans. Br. Bryol. Soc. 4, 107–10, 1961. This species is considered endangered in the Red List of British mosses and is a protected plant under the Wildlife and Countryside Act.

2 Z. viridissimus (Dicks.) Brid., Bryol. Univ., 1826 Z. viridissimus var. occidentalis Malta

(Fig. 218)

Dioicous. Green or dark green tufts or patches, to 1(−2) cm high. Leaves twisted and often slightly homomallous when dry, spreading-recurved when moist, narrowly lanceolate or lanceolate, acute; margins plane, papillose; costa ending below apex, not widened in upper part of leaf; cells incrassate, basal shortly rectangular, hyaline, cells above rounded-hexagonal, papillose, obscure, 7–9(−12) μm wide in mid-leaf. Clavate to ovoid ± colourless stem and axillary gemmae, 30–40 μm wide at maturity, (4−)5–6 cells long, with some longitudinal cell walls, almost always sparsely present. Setae yellowish; capsules ovoid, smooth at maturity, plicate when dry and empty; peristome absent or rudimentary; spores papillose, 14–16 μm. Capsules occasional, spring. n = 12∗ . On bark and on shaded base-rich rocks and walls. 0–300 m. Common in southern and N. W. England, Wales, southeast and western Scotland, rare to occasional elsewhere, occasional to common in Ireland. 110, H39, C. GB1243 + 107∗ , IR175 + 6∗ , C9. European Temperate. Europe

122 Zygodon

661

Fig. 218 1–4, Zygodon viridissimus: 1, leaf; 2, mid-leaf cells; 3, gemmae; 4, capsule. 5, Z. stirtonii: leaf. 6–8, Z. rupestris: 6, leaf; 7, mid-leaf cells; 8, gemmae. 9–10, Z. gracilis: 9, leaf; 10, mid-leaf cells. 11–13, Z. forsteri: 11, leaf; 12, mid-leaf cells; 13, capsule. 14–17, Z. conoideus var. conoideus: 14, leaf; 15, mid-leaf cells; 16, gemma; 17, capsule. 18, Z. conoideus var. lingulatus: leaf apex. Leaves ×15, cells ×420, capsules ×10, gemmae ×250.

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35 Orthotrichaceae

north to Fennoscandia and east to Romania, Faeroes, Iceland, Macaronesia, eastern N. America. The tips of the leaves tending to be recurved when moist and the gemmae with some longitudinal cell walls will distinguish this species from Z. conoideus; the green or dark green colour and size of the gemmae will separate it from Z. rupestris.

3 Z. stirtonii Schimp. in Stirt., Trans. Bot. Soc. Edin., 1871 Z. viridissimus var. stirtonii (Schimp.) I. Hagen

(Fig. 218)

Dioicous. Dense dark green cushions or patches, to c. 1 cm high. Leaves twisted when dry, spreading when moist, lanceolate, acute and sometimes slightly asymmetrical at apex; margins plane, papillose; costa excurrent in stout point, expanded in upper part of leaf; cells incrassate, basal shortly rectangular, cells above roundedhexagonal, papillose, obscure, 7–9(−12) μm wide in mid-leaf. Gemmae similar to those of Z. viridissimus. Sporophytes similar to those of Z. viridissimus; rare. On base-rich rocks and occasionally on bark. Lowland. Occasional throughout the British Isles but sometimes frequent in coastal areas. 81, H24, C. GB194 + 23∗ , IR26 + 8∗ , C1 + 1∗ . Faeroes, France, Germany, Luxembourg, the Netherlands, Romania, Sweden. Although frequently treated as a form or variety of Z. viridissimus, this plant differs in the less acutely pointed leaves, the lamina sometimes extending further up one side of the costa than up the other rendering the leaf apex slightly asymmetrical, the costa expanded above and excurrent in a stout point and some ecological differentiation, providing reasonable grounds for treating the taxon as a distinct species.

4 Z. rupestris Schimp. in A. W. H. Walther & Molendo, Laubm. Oberfrank., 1868 (Fig. 218) Z. baumgartneri Malta, Z. vulgaris Nyholm Dioicous. Spreading yellowish green tufts or patches, to c. 1.5 cm high. Leaves twisted when dry, spreading when moist, linear-lanceolate to lanceolate, acute; margins plane, papillose; costa ending below apex, not widened in upper part of leaf; cells incrassate, basal shortly rectangular, cells above rounded-hexagonal, papillose, obscure, 7–9(−12) μm wide in mid-leaf. Brownish fusiform stem and axillary gemmae 20–30(−40) μm wide at maturity, 4–5 cells long, with brownish cell walls, without longitudinal walls, almost always sparsely present. Sporophytes similar to those of Z. viridissimus, occasional, spring. On bark, mainly of old trees and occasionally on base-rich rocks. 0–500 m. Occasional to frequent in southern England and Wales, rare or very rare elsewhere, extending north to Sutherland, rare in Ireland. 60, H8. GB175 + 17∗ , IR7 + 1∗ . Circumpolar Southern-temperate. Europe north to Fennoscandia, Caucasus, Turkey, C. Asia, Japan, Macaronesia, N. America. Sometimes growing with Z. viridissimus but distinct in its yellowish green colour and the morphology of the gemmae.

122 Zygodon

663

5 Z. conoideus (Dicks.) Hook. & Taylor, Musci Brit., 1818 Dioicous. Green or yellowish green tufts or patches, to 5 mm high. Leaves appressed when dry, patent when moist, narrowly lanceolate or lanceolate, acuminate or very rarely rounded; margins plane, entire, costa ending below apex; basal cells shortly rectangular, cells above rounded-hexagonal, papillose, obscure, 10–12 μm wide in mid-leaf. Fusiform ± colourless stem and axillary gemmae, 18–20 μm wide at maturity, 7–8 cells long, without longitudinal walls, almost always sparsely present. Setae yellowish green; capsules ovoid to ellipsoid, striate, sulcate when dry and empty; peristome teeth short, fugacious; spores papillose, (16−)18–20 μm. Capsules frequent, spring, summer. Leaf apices acute Leaf apices rounded

var. conoideus var. lingulatus

Var. conoideus (Fig. 218) Leaves acute. Epiphytic, particularly on Sambucus. Lowland. Occasional to frequent in southern England, Wales, the Lake District and parts of western Scotland, very rare elsewhere, extending north to Shetland, rare to occasional in Ireland. 89, H27, C. GB328 + 33∗ , IR32 + 2∗ , C2. Oceanic Temperate. W. and N. Europe from Spain north to S. Scandinavia and east to Switzerland, Macaronesia, Newfoundland, Nova Scotia. Var. lingulatus S. R. Edwards, J. Bryol., 2000 (Fig. 218) Leaves with rounded apices. On bark of Fagus sylvatica. Lowland. Very rare, one site in Surrey. 1. GB1. Endemic (Suboceanic Temperate). Distinguished from Z. viridissimus by the tips of the leaves not recurved when moist and in the morphology of the gemmae. Z. rupestris, which differs in colour, is slightly less frequent but has a similar distribution. Z. conoideus is increasing in frequency in parts of Britain, possibly as a consequence of pollution from engine exhausts reducing competition from other species. For an account of Z. conoideus var. lingulatus see S. R. Edwards & R. C. Stern, J. Bryol. 22, 35–42, 2000.

6 Z. gracilis Wilson in Berk., Handb. Brit. Mosses, 1863 (Fig. 218) Dioicous. Brownish green tufts, 2–8 cm high. Leaves incurved when dry, spreading to recurved when moist, lanceolate, tapering to acute to obtuse apex; margins plane, entire in lower leaves, toothed towards apex in upper leaves; costa ending below apex; basal cells narrowly rectangular, cells above rounded-hexagonal, papillose, obscure, 8–10 μm wide in mid-leaf. Gemmae lacking. Capsules shortly cylindrical, slightly inclined; peristome double; spores 12–14 μm. Capsules found only twice in Britain (1866). On dry-stone limestone walls or rarely on limestone rocks. (270−)380–400 (−425) m. Very rare and endangered, known only from the Malham and Ingleborough area of N. W. Yorkshire. 1. GB3 + 1∗ . European

664

35 Orthotrichaceae

Temperate. Rare in Europe, Austria, Czechoslovakia, France, Italy, Norway, Switzerland. The large size and the leaves incurved when dry will differentiate this plant from other British species of the genus. The leaves of stunted specimens and the lower leaves of others may have entire margins. For comments on Z. gracilis in Britain see G. A. Shaw, Trans. Br. Bryol. Soc. 4, 206–8, 1962. This species is considered endangered in the Red List of British Mosses and is a protected plant under the Wildlife and Countryside Act.

Subfamily 2 ORTHOTRICHOIDEAE Leaves never longly apiculate, rarely denticulate near apex; cells in upper part of leaf with 1–4 simple or forked papillae per cell. Gemmae produced only on leaf surfaces. Capsules immersed, emergent or shortly exserted; peristome present or absent; calyptrae mitrate, ± plicate.

123 ORTHOTRICHUM HEDW., SP. MUSC. FROND., 1801 Autoicous or dioicous. Leaves usually imbricate when dry, erect-patent to spreading when moist, lanceolate, acute to obtuse or rounded; margins usually strongly recurved; costa ending below apex; basal cells rectangular, shorter towards margins, cells above rounded to hexagonal, papillose, papillae simple or 2–3-fid. Setae short; vaginula glabrous or hairy, ochrea present; stomata superficial or immersed; peristome absent or of 8 or 16 teeth, teeth sometimes in pairs, 0, 8 or 16 processes present. x = 6, 10 + m, 11. A world-wide genus of c. 110 species, most of which are either epiphytic or saxicolous. Some species show considerable morphological variation. Whether this is environmental, genetic or due to hybridity is not known. Many species are highly susceptible to atmospheric pollution and have decreased markedly over the last 100 years. Species with superficial stomata have x = 6 and those with immersed stomata x = 10 + m or 11. For a synopsis of the genus, which the account below follows, see J. Lewinsky, Bryobrothera 2, 1–59, 1993. For a key to and illustrations of European species see J. LewinskyHaapasaari, Meylania 9, 1–56, 1995. Derivation: meaning upright hair from the erect hairs on the calyptrae.

1 Leaves with toothed hyaline apices 16. O. diaphanum Leaf apices not hyaline 2 2 Leaf margins plane or strongly incurved, apices obtuse or rounded 3 Leaf margins recurved at least below, apices 4 3 Leaf margins strongly incurved, cells with 2–3 papillae on each face 6. O. gymnostomum Margins plane or slightly incurved, cells with one papilla on each face 7. O. obtusifolium

123 Orthotrichum

665

4 Numerous brown simple or branched gemmae, 32–45 μm wide, present on adaxial surface of leaves, dioicous, capsules very rare 1. O. lyellii Gemmae lacking or if present not as above, autoicous, capsules common 5 5 Leaf apices broad, usually rounded 6 Leaves tapering to acute to obtuse apices 7 6 Plants 1–3 cm high, mid-leaf cells 10–14 μm wide 10. O. rivulare Plants 0.5–1.0 cm high, mid-leaf cells (14−)16–24 μm wide 11. O. sprucei 7 Stomata superficial 8 Stomata immersed 12 8 Capsules smooth or with faint striae just below mouth at maturity, ± smooth when dry and empty, exostome teeth 16 Capsules striate at maturity, at least some sulcate when dry and empty, exostome teeth in 8 pairs 10 9 Exostome teeth orange-brown, separate, not perforated, endostome present (best seen in newly ripened capsules), spores c. 20 μm 2. O. striatum Exostome teeth whitish, often partially united, often with longitudinal perforations, endostome rudimentary or absent, spores mostly 14–17 μm 3. O. shawii 10 Calyptrae hairy, exostome teeth erect or spreading when dry, spores 14–20 μm, usually saxicolous plants 17. O. rupestre Calyptrae glabrous or hairy, at least some capsules with reflexed exostome teeth, spores 18–26 μm, usually corticolous plants 11 11 Leaves acute to acuminate, setae c. 2 mm long, lower part of capsules smooth, striate only below mouth, calyptrae hairy, setae c. 2 mm long, spores 24–26 μm 4. O. speciosum Leaves acute to obtuse and apiculate, capsules striate from mouth to base, calyptrae glabrous or sparsely hairy, setae 0.4–1.2 mm long, spores 18–24 μm 5. O. affine 12 Plants 0.5–5.0 cm high, usually saxicolous, exostome teeth 16, erect to spreading when dry 13 Plants mostly 0.5–1.0 cm high, usually corticolous, at least some capsules with exostome teeth reflexed when dry, teeth in 8 pairs 14 13 Capsules exserted, reddish, setae (1.5−)2.0–4.0 mm long 18. O. anomalum Capsules emergent, pale brown, setae 1.0–1.6 mm long 19. O. cupulatum 14 Capsules exserted, exostome teeth usually orange-red, very rarely yellowish, leaves twisted when dry 15 Capsules immersed to emergent, exostome teeth pale to brownish, leaves ± straight when dry 16 15 Exostome orange-red, stomata in middle and upper half of capsule, plants occasional 8. O. pulchellum Exostome teeth yellowish, stomata in middle and lower half of capsule, only records dated 1846 9 O. consimile

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35 Orthotrichaceae

16 Calyptrae conspicuously dark-tipped, vaginula with numerous long hairs1 13. O. stramineum Calyptrae not dark-tipped, vaginula glabrous or with a few short hairs 17 17 Capsules orange-brown, narrowly ellipsoid or subcylindrical, stomata restricted to neck of capsule 12. O. tenellum Capsules pale, ellipsoid, stomata scattered at least in lower half of capsules 18 18 Calyptrae plicate, capsules gradually tapering into seta, stomata not obscured by overlying exothecial cells 14. O. pallens Calyptrae smooth, capsules abruptly narrowed into seta, stomata ± obscured by overlying exothecial cells 15. O. pumilum

Subgenus 1 Gymnosporus (Lindb. ex Braithw.) Limpr., Laubm. Deutschl., 1890 Usually autoicous. Stomata superficial; exostome of 8 or 16 teeth, reflexed or recurved when dry, endostome of 8 or 16 processes, lacking connecting membrane. Mainly epiphytic. Section 1 Leiocarpa Mol., Bayerns Laubm., 1887 Leaves erect, flexuose when dry, acute to acuminate; margins usually recurved or revolute; cells papillose. Capsules immersed to exserted; endostome well developed; spores 18–53 μm. Mainly Southern Hemisphere species. 1 O lyellii Hook. & Taylor, Muscol. Br., 1818 (Fig. 219) Dioicous. Dark green often straggling tufts, (0.5−)1.0–4.0 cm high, shoots often curved when dry. Leaves appressed to flexuose when dry, spreading when moist, narrowly lanceolate, acute; margins recurved on one or both sides below, entire; costa ending below apex; basal cells very thick-walled, cells above roundedhexagonal, papillose, 8–10 μm wide in mid-leaf. Brown 2- to many-celled uniseriate simple or branched gemmae present on adaxial side of leaves. Setae c. 1.4 mm long; capsules pale brown, immersed to emergent, ellipsoid, tapering into seta, striate when mature, narrower and sulcate when dry and empty; stomata superficial; exostome of 16 teeth, strongly recurved when dry, endostome of 16 papillose processes; spores 26–40 μm; calyptrae sparsely hairy. Capsules rare, summer. n = 6. On trunks, branches and twigs of trees, often in less humid places than other species of Orthotrichum, rarely saxicolous. Lowland. Frequent, generally distributed. 99, H25, C. GB526 + 51∗ , IR57 + 17∗ , C1 + 1∗ . Suboceanic Temperate. Europe north to southern Fennoscandia, Caucasus, Turkey, Cyprus, Madeira, Canary Islands, Algeria, Morocco, eastern N. America, Mexico, Hawaii. Spore size is very variable and as plants with sporophytes often occur with other Orthotrichum species this could be due to hybridity. The gemmae are sometimes so abundant 1

Not to be confused with paraphyses.

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Fig. 219 1–5, Orthotrichum lyellii: 1, leaves; 2, mid-leaf cells; 3, sporophyte with calyptra; 4, old sporophyte; 5, gemmae (×165). 6–11: O. affine: 6, leaf; 7, mid-leaf cells; 8, mature sporophyte; 9, calyptra; 10, old sporophyte; 11, stoma. 12–15, O. speciosum: 12, leaf; 13, mid-leaf cells; 14, calyptra; 15, mature sporophyte. Leaves ×15, sporophytes and calyptrae ×15, cells ×420. as to give the leaves a dusty brown appearance. Some other species of Orthotrichum may also have gemmae on the leaves, but these differ in colour and/or size from those fo O. lyellii.

2 O striatum Hedw., Sp. Musc. Frond., 1801 O. leiocarpum Bruch & Schimp.

(Fig. 220)

Autoicous. Dark green tufts, 0.5–3.0 cm high. Leaves erect-patent to spreading when moist, lanceolate, acute to acuminate; margins recurved; costa ending

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Fig. 220 1–6, Orthotrichum striatum: 1, leaf (×15); 2, mid-leaf cells; 3, calyptra (×15); 4, 5, mature and old sporophytes (×15); 6, exostome tooth ×220). 7–10, O. shawii: 7, leaf (×30); 8, mid-leaf cells; 9, mature sporophyte (×15); 10, exostome tooth (×220). 11–13, O. obtusifolium: 11, leaf (×25); 12, mid-leaf cells; 13, gemmae. 14–16, O. gymnostomum: 14, leaf (×25); 15, mid-leaf cells; 16, gemmae. Cells ×420, gemmae ×250.

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below apex; basal cells rectangular, thick-walled, nodulose, cells above roundedhexagonal, papillose, c. 10 μm wide in mid-leaf. Setae 0.5–1.5(−2.2) mm long; capsules immersed to emergent, pale brown, ellipsoid, tapering into seta, smooth when mature, ± smooth and never sulcate when dry and empty; stomata superficial; exostome teeth 16, strongly recurved when dry, orange-brown, densely papillose, transverse articulations not thickened, strongly recurved when dry, endostome of 16 irregular yellowish papillose processes; spores c. 30 μm; calyptrae hairy. On tree trunks, branches and twigs, very rarely on rock. Lowland. Occasional in the south-west and the extreme south of England, almost extinct in the rest of England, occasional in S. W. Wales, frequent in N. W. Wales, rare to occasional in Scotland, extending north to Caithness, occasional and widely distributed in Ireland. 93, H34, C. GB232 + 107∗ , IR23 + 10∗ , C2 + 1∗ . European Boreo-temperate. Europe to 70◦ N, Iceland, Caucasus, Turkey, N. W. China, Gran Canaria, Algeria, north-west N. America. Distinct from all species except the very rare O. shawii (q.v.) in the capsules smooth when dry and empty. O. speciosum may have some smooth capsules but there are usually some sulcate capsules present on the same tuft and the setae are longer with the capsules often exserted.

3 O. shawii Wilson in Schimp., Bryol. Eur. Suppl., 1864 (Fig. 220) Autoicous. Small dull green tufts. Leaves erect to erect-patent when moist, lanceolate, acute to acuminate; margins recurved ± from base to apex; costa usually percurrent; basal cells rectangular, thick-walled, cells above rounded-quadrate to shortly rectangular, incrassate, papillose, 8–16 μm wide in mid-leaf. Setae c. 0.3 mm long; capsules immersed to slightly emergent, pale brown, ovoid, tapering into seta, completely smooth or with 8 faint striae towards the mouth when dry and empty; exothecium with irregular longitudinal bands formed by thickened longitudinal cell walls; stomata superficial; exostome of 16 pale teeth, often only partially separated, often with longitudinal perforations, coarsely papillose, recurved when dry, endostome of 8 rudimentary processes or absent; spores 14–17(−20) μm. Capsules common. On Fraxinus ornus trunk. Lowland. Very rare, Ayrshire (1860–1873). 1. GB1∗ . Suboceanic Southern. Corsica, France, Germany, Sicily, Spain. Although previously treated as synonymous with O. striatum, O. shawii has recently been shown to be a distinct species (see V. Mazimpaka et al., J. Bryol. 22, 183–92, 2000). In the field O. shawii may be distinguished from O. striatum by peristome characters. In O. shawii the exostome teeth are whitish, often partially joined and sometimes have longitudinal perforations; in O. striatum the teeth are orange-brown, separate and entire. The endostome is rudimentary or absent in O. shawii although this can only be determined with certainty in ripe or recently dehisced capsules.

Section 2 Affinia Schimp., Syn. Musc. Eur (ed. 2), 1876 Autoicous. Leaves erect, appressed when dry, acute to acuminate; margins usually recurved or revolute, cells in upper part of leaf papillose. Endostome well developed or rudimentary; spores 13–30 μm. Mainly Northern Hemisphere species.

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35 Orthotrichaceae

4 O. speciosum Nees in Sturm., Deutschl. Fl. Abt. 2, Krypt., 1819 (Fig. 219) Autoicous. Yellowish green tufts, 0.5–4.0 cm high. Leaves erect-spreading when moist, lanceolate or narrowly lanceolate, acute or acuminate; margins recurved; costa ending below apex; basal cells strongly incrassate, cells above rounded, papillose, 10–12 μm wide in mid-leaf. Setae c. 2 mm long; capsules emergent or exserted, pale, ellipsoid to subcylindrical, tapering into seta, smooth or with 8 faint striae at maturity, at least some capsules sulcate when dry and empty; stomata superficial; exostome teeth in 8 pairs, pale, densely papillose, reflexed when dry, endostome of 8 papillose processes; spores 34–36 μm; calyptrae hairy. Capsules common, winter, spring. n = 6, 12, 12 + m. On trunks and branches of trees and shrubs, very rarely on rock. 0–350 m. Rare or occasional, M. Perth, Banff, Elgin, E. Inverness, old records from Sussex, N. E. Yorkshire, E. Perth and Angus. 10. GB12 + 15∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Iceland, Caucasus, Turkey, Asia, N. America. 5 O. affine Schrad. ex Brid., Muscol. Recent., 1801 O. affine var. fastigiatum (Brid.) Huebener

(Fig. 219)

Autoicous. Dark green tufts, 0.5–2.5 cm high. Leaves erect-patent to spreading when moist, lanceolate or broadly lanceolate, acute to obtuse and apiculate; margins recurved; costa ending below apex; basal cells rectangular, strongly incrassate, cells above rounded, papillose, 6–10 μm wide in mid-leaf. Gemmae occasionally present on the leaves. Capsules emergent to slightly exserted, greenish at maturity, becoming brown with age, ellipsoid to subcylindrical, tapering into seta, with 8 ribs, sulcate, narrower and of ± uniform width throughout or urceolate when dry and empty; vaginula glabrous; stomata superficial; exostome teeth in 8 pairs, yellowish, papillose, strongly reflexed at least in some capsules when dry, endostome of 16 smooth filiform processes; spores 16–24 μm; calyptrae greenish, naked or sparsely hairy. Capsules common, spring to autumn. On trunks, branches and twigs of shrubs and trees, especially Betula, Fraxinus, Salix and Sambucus in bright, sheltered or humid situations, on tree boles and exposed roots by streams and rivers, occasionally in quarries, on rocks, walls and concrete, 0–530 m. Rare in central and eastern England, frequent or common elsewhere in England and Wales, frequent in eastern and western Scotland, rare elsewhere, extending north to Caithness and Lewis, occasional in Ireland. 110, H34, C. GB1080 + 123∗ , IR118 + 4∗ , C1 + 1∗ . European Boreo-temperate. Europe north to Fennoscandia, Caucasus, Turkey, Cyprus, Siberia, Kamchatka, Kashmir, Canary Islands, Madeira, N. and E. Africa, western N. America. The commonest and most variable of corticolous species of Orthotrichum in the British Isles. The shape of the capsules, length of setae and hairiness of the calyptrae are particularly variable. A form, shorter and more compact, with shorter immersed capsules, referred to in Dixon & Jameson (1924) as var. fastigiatum (Brid.) Huebener, has sometimes been given specific status, but is now treated as a synonym of O. affine. O. affine is distinguished from most other corticolous species of the genus by the superficial stomata. O. striatum and O. shawii may be recognised by the smooth capsules, O. speciosum by the hairier calyptrae, larger

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spores and longer setae. When O. affine occurs on a rock substrate or O. rupestre on bark, the former may be distinguished from the latter by the glabrous or sparsely hairy calyptrae and the exostome teeth reflexed when dry. The greenish calyptrae provide a useful field character for separating O. affine from O. stramineum, which has yellow calyptrae with a dark apex.

Subgenus 2 Orthophyllum Delogne, Ann. Soc. Belg. Microscop., 1885 Dioicous. Leaves erect, appressed when dry, obtuse or rounded; margins plane or incurved; upper cells incrassate, papillose. Stomata superficial; peristome double or absent, outer of 8 teeth, reflexed when dry, endostome of 8 processes; spores 18–25 μm. Northern Hemisphere species. 6 O. gymnostomum Bruch ex Brid., Bryol. Univ., 1827 (Fig. 220) Nyholmiella gymnostoma (Bruch ex Brid.) Holmen & Warncke, Stroemia gymnostoma (Bruch ex Brid.) I. Hagen Dioicous. Small yellowish green tufts, 1–3 cm high (in Britain). Leaves imbricate when dry, spreading when moist, lanceolate or ovate, obtuse to rounded, sometimes slightly cucullate; margins strongly incurved; costa ending below apex; basal cells rectangular, strongly incrassate, nodulose, cells above rounded, with 2–3 papillae on each face, 12–14 μm wide in mid-leaf. Yellowish brown, clavate to cylindrical, 2–many-celled, simple or branched gemmae present on both sides of leaves. Setae c. 0.3 mm long; capsules immersed or slightly emergent, ellipsoid, ± abruptly narrowed into seta; stomata superficial; peristome absent; spores 18– 21 μm. Capsules not known in Britain. On bark of Populus tremula in birch–pine woodland. 240 m. E. Inverness, 1960, not seen since. 1. GB1. European Borealmontane. Europe north to Fennoscandia, Caucasus, Turkey, Afghanistan, Japan, Newfoundland. Distinguished from O. obtusifolium by the strongly incurved leaf margins and cells with 2–3 papillae on each face. Probably a casual rather than a genuine native, resulting from long-distance spore dispersal. For the occurrence of this plant in Britain see A. R. Perry & J. Dransfield, Trans. Br. Bryol. Soc. 5, 218–21, 1967.

7 O. obtusifolium Brid., Muscol. Recent., 1801 (Fig. 220) Nyhomiella obtusifolia (Brid.) Holmen & Warncke, Stroemia obtusifolia (Brid.) I. Hagen Dioicous. Yellowish green tufts or patches, c. 0.5 cm high (in Britain). Leaves appressed when dry, patent when moist, ovate, rounded; margins plane or slightly incurved; costa ending below apex; basal cells rectangular, thick-walled, cells above irregularly rounded, with a single large papilla on each face, 10–14 μm wide in mid-leaf. Green to brown clavate gemmae scattered over both sides of leaves. Setae c. 0.4 mm long; capsules slightly emergent, ellipsoid, gradually tapering into seta; stomata superficial; peristome double, exostome teeth in 8 pairs, finely papillose, reflexed when dry, endostome with 8 smooth simple processes; spores 16–20 μm. Capsules unknown in Britain. n = 6. On trunks, branches and twigs of

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35 Orthotrichaceae

trees and shrubs. Lowland. Seen recently only in W. Norfolk, Angus, N. Aberdeen and Elgin but formerly recorded from 9 other vice-counties. 13. GB4 + 23∗ . Circumpolar Boreal-montane. Europe north to Svalbard, Caucasus, Turkey, Siberia, C. Asia, N. America. In the nineteenth century, occasional in an area from Hereford, Worcester and Warwick to Oxford, Berkshire and Buckingham, but long gone, probably as a consequence of strong susceptibility to atmospheric pollution. This species is considered endangered in the Red List of British Mosses.

Subgenus 3 Pulchella (Schimp.) Vitt, Nova Hedwigia, 1971 Autoicous. Capsules emergent or exserted; stomata immersed; exostome of 8 or 16 teeth, reflexed or recurved when dry, endostome of 8 or 16 processes, rarely absent; spores 10–24 μm. Mostly epiphytes. Section 1 Pulchella Schimp. Syn. Musc. Eur. (ed. 2), 1876 Leaves usually flexuose, contorted or twisted when dry; margins recurved; upper cells usually papillose. Capsules emergent or exserted; peristome present or not, where present endostome of 16 or rarely 8 ornamented processes; spores 16– 34(−40) μm. Epiphytes. 8 O. pulchellum Brunton in Sm., Engl. Bot., 1807 (Fig. 223) Autoicous. Small tufts, to c. 1 cm high. Leaves flexuose and curved when dry, patent when moist, narrowly lanceolate, acute; margins recurved; costa ending below apex; basal cells rectangular, thick-walled; cells above rounded, papillose, 8–12 μm wide in mid-leaf. Setae 1.2–2.0 mm long; vaginula with or without hairs; capsules exserted, pale brown, ovoid to ovate-ellipsoid, abruptly narrowed into seta, with 8 ribs when mature, ± cylindrical, sulcate when dry and empty; stomata immersed, scattered over middle and upper half of capsule; exostome of 8 pairs of orange-red papillose teeth, reflexed when dry, endostome with 8 orange processes; spores 16–22 μm; calyptrae glabrous. Capsules common, late spring, early summer. n = 10 + m∗ . On bark in sheltered habitats, occasionally on rocks or walls. Lowland. Mostly occasional throughout the British Isles. 109, H35, C. GB295 + 71∗ , IR38 + 20∗ , C1 + 1∗ . Oceanic Temperate. W. and C. Europe, from Spain north to Scandinavia, N. America. Recognisable in the field by the leaves twisted when dry and the exserted capsules with orange-red peristome teeth.

9 O. consimile Mitt., J. Linn. Soc. Bot., Autoicous. Leaves flexuose and curved when dry, patent when moist, narrowly lanceolate, acute; margins recurved; costa ending below apex; basal cells rectangular, thick-walled; cells above rounded, papillose, 8–12 μm wide in mid-leaf. Setae 1.2–2.0 mm long; vaginula with or without hairs; capsules exserted, pale brown, ovoid to ovate-ellipsoid, abruptly narrowed into seta, with 8 ribs when mature, ±

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cylindrical, sulcate when dry and empty; stomata immersed, scattered over middle and lower half of capsule; exostome of 8 pairs yellowish papillose teeth, reflexed when dry, endostome with 8 processes; spores 16–22 μm; calyptrae glabrous. Capsules common. On bark of Fagus sylvatica in Sussex but recorded from other tree species in continental Europe. Lowland. W. Sussex (1846). 1. GB1∗ . Belgium, Germany, the Netherlands, N. Portugal, Spain, western N. America. Known in Britain from only two gatherings from Hurstpierpoint, W. Sussex, by W. Mitten in 1846. For the discovery of the occurrence of O. consimile in Britain see R. D. Porley, J. Bryol. 22, 293–4, 2000. Distinguished from O. pulchellum by the characters given in the key. It is probably extremely rare as of about 500 gatherings of O. pulchellum examined only two proved to be O. consimile. Thought to be extinct in Europe but recently found in Belgium, the Netherlands and N. Portugal so whether the two nineteenth century O. consimile finds represent casual occurrences or the plant is genuinely native is debatable.

Section 2 Rivularia Schimp., Syn. Musc. Eur. (ed. 2), 1876 Leaves erect when dry, obtuse or rounded; margins revolute, toothed or entire above; upper cells papillose. Capsules immersed to emergent; endostome with 16 processes with longitudinal ridges on outside and papillae on inside. 10 O. rivulare Turner, Muscol. Hibern. Spic., 1804 (Fig. 221) Lax dark green tufts, 1–3 cm high; shoots sometimes denuded below. Leaves loosely appressed when dry, erect-patent when moist, lanceolate or ovatelanceolate, obtuse or obtuse and apiculate, sometimes cucullate; margins recurved, sometimes toothed above; costa ending below apex; basal cells rectangular, moderately thick-walled, cells above rounded, papillose, 10–14 μm wide in mid-leaf. Setae 0.4–1.5 mm long; vaginula hairy; capsules emergent, dark brown, ovoid, with 8 ribs when mature, narrower, urceolate and sulcate when dry and empty; stomata immersed; exostome of 8 pairs of teeth, reflexed when dry, endostome with 16 papillose processes; spores 14–20 μm; calyptrae glabrous. Capsules common, spring, summer. n = 10 + m∗ . On trunks, branches, exposed roots and stones in the flood zone of rivers and large streams. Lowland. Very rare and mostly extinct in lowland England, occasional to frequent in S. W. and N. W. England, Wales and eastern Scotland, extending north to Moray and W. Inverness, rare in Ireland. 62, H16. GB157 + 55∗ , IR29 + 10∗ . Suboceanic Temperate. Austria, Belgium, France, Germany, the Netherlands, Spain, Yugoslavia, eastern N. America. Readily recognised from habitat and the leaves often toothed above and with obtuse or obtuse and apiculate apices. O. sprucei is a smaller plant with rounded entire leaf apices and larger cells.

11 O. sprucei Mont. in Spruce, Lond. J. Bot., 1845 (Fig. 221) Autoicous. Small tufts, often encrusted with alluvial matter, 0.5–1.0 cm high. Leaves loosely appressed when dry, erect-patent when moist, lanceolate to lingulate or oblanceolate, rounded and sometimes mucronate; margins recurved,

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Fig. 221 1–3, Orthotrichum rivulare: 1, leaf: 2, mid-leaf cells; 3, old sporophyte. 4–8, O. stramineum: 4, leaves; 5, mid-leaf cells; 6, 7, mature and old sporophytes; 8, stoma. 9–10, O. sprucei: 9, leaves; 10, mid-leaf cells. 11–14, O. tenellum: 11, dry shoot with old sporophyte (×10); 12, leaf; 13, mid-leaf cells; 14, mature sporophyte with calyptra. Leaves and sporophytes ×15, cells ×420.

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entire; costa ending below apex; basal cells rectangular, walls hardly thickened, cells above rounded, ± smooth, (14−)16–24 μm wide in mid-leaf. Pale brown, simple or branched gemmae, several cells long, 6–9 μm wide, sometimes present on leaves. Setae 0.6–0.8 mm long; capsules immersed to emergent, brown, ovateellipsoid, with 8 ribs when mature, narrower and sulcate when dry and empty; stomata immersed; exostome with 8 pairs of densely papillose teeth, reflexed when dry, endostome of 8 papillose processes; spores 14–16 μm; calyptrae glabrous. Capsules frequent, summer. On trunks, branches and exposed roots of trees and shrubs in the flood zone of usually slow-flowing silty streams and rivers. Very rare in lowland England, rare to occasional in S. W. and N. England and Wales, very rare in Scotland, extending north to Mid Perth, Waterford, Wexford, old records from N. Kerry, Down and Antrim. 51, H5. GB81 + 22∗ , IR2 + 3∗ . Oceanic Temperate. Belgium, France, the Netherlands, Spain. Rarer than but with a similar distribution to O. rivulare (for differences see under that species) and it rarely if ever occurs on rock.

Section 3 Diaphana Venturi in Husn., Muscol. Gall., 1887 Leaves erect, appressed or slightly flexuose when dry, obtuse, acute or acuminate, sometimes with hyaline points; margins usually recurved or revolute; upper cells smooth or papillose. Capsules immersed or emergent; endostome with 8 or 16 smooth processes, rarely absent; spores 10–21(−36) μm. Usually epiphytic. 12 O. tenellum Bruch ex. Brid., Bryol. Univ., 1827 (Fig. 221) Autoicous. Small dark green tufts, to 0.5 cm high. Leaves appressed, straight when dry, erect-patent to spreading when moist, lanceolate to oblong-lanceolate, acute to obtuse or obtuse and apiculate; margins recurved, entire; basal cells rectangular, thick-walled, cells above rounded, papillose, 10–12(−14) μm wide in mid-leaf. Setae 0.5–1.0(−1.6) mm long; vaginula glabrous or with a few short hairs; capsules emergent, golden brown, narrowly ellipsoid to subcylindrical, with 8 ribs at maturity, ± abruptly narrowed into seta, narrower and of ± uniform width throughout and sulcate when dry and empty; stomata immersed, partially obscured by overlying exothecial cells; exostome of 8 pairs of light brown finely papillose teeth, reflexed when dry, endostome of 8 ± smooth processes; spores 10–12 or 14–18 μm; calyptrae sparsely hairy. Capsules common, spring, summer. n = 10 + m, 11. On bark of trees and shrubs in open situations. Lowland. Rare and mostly extinct in lowland England except the extreme south, occasional in S. W. and N. W. England, frequent in N. Wales, very rare and mostly extinct in Scotland, extending north to Skye and W. Ross, rare to occasional in Ireland. 77, H21, C. GB159 + 79∗ , IR19 + 15∗ , C5. Submediterranean-Subatlantic. Europe north to southern Scandinavia, Caucasus, Turkey, N. Asia, Macaronesia, Morocco, western N. America. Similar in appearance to small forms of O. affine, but recognisable in the field by the leaves flexuose when dry, the exserted capsules and the orange peristome teeth.

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13 O. stramineum Hornsch. ex Brid., Bryol. Univ., 1827 (Fig. 221) Autoicous. Light green or yellowish green tufts, 0.5–1.0 cm high. Leaves erectpatent when moist, lanceolate, acute; margins recurved, entire; basal cells rectangular, moderately thick-walled, cells above rounded, papillose, 8–12 μm wide in mid-leaf. Setae 0.7–1.0(−1.5) mm long; vaginula with numerous long hairs; capsules emergent, orange-brown, ellipsoid, gradually tapering into seta, with 8 ribs of 4–5 rows of thick-walled cells when mature, narrower, often markedly constricted below mouth, sulcate when dry and empty; stomata restricted to lower half of capsule, immersed, obscured by overlying exothecial cells; exostome with 8 pairs of yellowish finely papillose teeth, reflexed when dry, endostome with 8 smooth processes; spores 12–14 μm; calyptrae yellowish with dark apex, plicate, glabrous or sparsely hairy. Capsules common, summer. n = 20 + 2m. On trunks and branches of trees and shrubs in sheltered situations. Mainly lowland. Absent from much of eastern England, occasional in other parts of England and in Scotland, extending north to Sutherland, frequent in Mid and N. Wales, very rare in Ireland and not seen recently. 85, H7. GB266 + 88∗ , IR8∗ . European Temperate. Europe to 66◦ N in Norway, Iceland, Caucasus, Turkey, Cyprus, China, N. Africa, Newfoundland (introduced?). The capsules markedly constricted below the mouth when dry and empty and the darktipped calyptrae provide useful field characters for identifying this species, although very old capsules are of uniform width throughout. The hairy vaginula, obscured stomata and the shape of the empty capsules will separate O. stramineum from O. pallens. O. patens Bruch ex Bruch (as O. stramineum var. patens (Bruch) Venturi) has been reported from four localities in Britain but the specimens I have seen are O. affine.

14 O. pallens Bruch ex Brid., Bryol. Univ., 1827 (Fig. 222) Autoicous. Small tufts, 0.5–1.0 cm high. Leaves erect-patent when moist, lanceolate, acute to obtuse; margins recurved, entire; costa ending below apex; basal cells rectangular, walls thickened, cells above rounded, papillose, 12–18 μm wide in mid-leaf. Setae 0.5–0.8 mm long; vaginula without hairs; capsules emergent, pale yellowish brown, ellipsoid, gradually tapering into seta, with 8 ribs at maturity, narrowed and of ± uniform thickness throughout when dry and empty; rim of lid red; stomata immersed, hardly obscured by exothecial cells; exostome with 8 pairs of yellowish to pale orange finely papillose teeth, reflexed when dry, endostome of 8 smooth processes; spores 10–16 μm; calyptrae plicate, glabrous. Capsules common, summer. n = 10 + m. On tree trunks in open habitats. Lowland. Very rare, seen recently only in Banff, W. Inverness and E. Mayo, old records from W. Lancashire, S. E., Mid-West and N. W. Yorkshire, E. Ross, Mid Cork, Wicklow and Dublin. 7, H4. GB3 + 8∗ , IR1 + 3∗ . European Boreo-temperate. Europe north to Svalbard, Caucasus, Turkey, Greenland, N. America, Mexico, Venezuela. This species is considered endangered in the Red List of British Mosses.

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Fig. 222 1–5, Orthotrichum pallens: 1, leaf; 2, mid-leaf cells; 3, mature sporophyte with calyptra: 4, old sporophyte; 5, stoma. 6–10, O. pumilum: 6, leaf; 7, mid-leaf cells; 8, mature sporophyte with calyptra; 9, old sporophyte; 10, stoma. 11–14, O. diaphanum: 11, leaves; 12, mid-leaf cells; 13, mature sporophyte with calyptra; 14, old sporophyte. Leaves and sporophytes ×15, cells ×420.

15 O. pumilum Sw., Monthly Rev., 1801 O. schimperi Hammar

(Fig. 222)

Autoicous. Small, tight, pale green tufts, c. 0.5 cm high. Leaves erect-patent when moist, lanceolate, acute to obtuse; margins recurved, entire; costa ending below

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apex; basal cells rectangular, walls moderately thickened, cells above rounded, papillose, 10–14 μm wide in mid-leaf. Setae c. 0.5 mm long; vaginula glabrous; capsules immersed, brown, ellipsoid, tapering into seta, with 8 ribs when mature, narrower and sulcate when dry and empty; stomata immersed; obscured by overlying exothecial cells; exostome of 8 pairs of orange-yellow faintly papillose teeth, reflexed when dry, endostome with 8 processes; spores 12–16 μm; calyptrae smooth, glabrous. Capsules common, spring. n = 10 + m, 11, 39. On bark. Lowland. Very rare, seen recently only in Kincardine, old records from W. Suffolk, E. Norfolk, Northampton. 5. GB1 + 4∗ . European Temperate. Europe to c. 64◦ N in Norway, Caucasus, Turkey, N. Asia, China, Canary Islands, Madeira, Algeria, Morocco, N. America. O. pumilum is distinguished by its small size, compact habit, immersed capsules and glabrous calyptrae. D. H. Vitt (Bryophyt. Biblth. 1, 1–208, 1971) says gemmae are sometimes produced on the leaves. This is a critically endangered species in the Red List of British Mosses.

16 O. diaphanum Brid., Muscol. Recent., 1801 (Fig. 222) Autoicous. Small grey-green tufts or patches, to c. 1 cm high. Leaves soft, slightly twisted when dry, patent when moist, ovate-lanceolate, with acuminate hyaline denticulate apex; margins recurved, entire; costa ending below apex, basal cells rectangular, thin-walled, cells above rounded-hexagonal, walls hardly thickened, smooth or slightly papillose, 10–16 μm wide in mid-leaf. Colourless uniseriate simple or branched gemmae, 2–9 cells long, 20–30 μm wide, sometimes present on leaves. Setae 0.4–0.6 mm long; capsules emergent, pale, ovoid to ellipsoid, abruptly narrowed into seta, with 8 striae when mature, narrower, smooth or sulcate when dry and empty; stomata immersed; exostome of 16 pale brown coarsely papillose teeth, recurved when dry, endostome of 16 papillose processes; spores 14–18 μm; calyptrae hairy towards apex. Capsules common, throughout the year but mainly winter and spring. n = 10 + m∗ , 10 + 2m, 11. On wood, damp fences, bark, man-made and natural rock surfaces, and detritus of various types. Lowland. Common in England, Wales and eastern Scotland, rare to occasional elsewhere in Scotland, extending north to Shetland, occasional to frequent in Ireland. 112, H40, C. GB1408 + 105∗ , IR65 + 12∗ , C9. European Southern-temperate. Europe north to southern Norway, Faeroes, Caucasus, Turkey, Siberia, Macaronesia, Africa, N. America, Mexico, Ecuador, southern S. America, Hawaii. Occurs on a greater variety of substrates than other members of the genus and has been found on such unlikely materials as old linoleum, corrugated iron and tarmac. Differing from other Orthotrichum species in the hyaline leaf apices and is more likely to be mistaken for a species of Schistidium from which it may be distinguished in the field by its soft leaves and striate capsules with a double peristome with pale exostome teeth.

Subgenus 4 Phaneroporum Delogne, Ann. Soc. Belg. Microscop., 1885 Leaves erect, appressed when dry, acute to acuminate; margins recurved or revolute; cells in upper part of leaf papillose. Capsules emergent or exserted; stomata

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superficial; peristome often present, exostome of 16 or rarely 8 teeth, erect to spreading when dry, endostome of 0 or 8 often reduced processes; spores 9–28 μm. ¨ 17 O. rupestre Schleich. ex Schwagr., Sp. Musc. Frond. Suppl. 1, 1816 (Fig. 223) Autoicous. Dark green or brownish green tufts, mostly 1–4 cm high. Leaves erectpatent to spreading when moist, lanceolate to broadly lanceolate, acute to obtuse; margins strongly recurved; basal cells rectangular, strongly incrassate, nodulose, cells above rounded, papillose, 8–10 μm wide in mid-leaf, often bistratose above. Setae 0.8–2.0 mm long; capsules immersed to emergent, pale brown, ellipsoid or ovoid, abruptly or gradually narrowed into seta, with 8 striae above when mature, narrower and of ± uniform width throughout and usually sulcate when dry and empty; stomata superficial; exostome with 8 pairs of pale papillose longitudinally cleft teeth, erect when dry, endostome of 8 processes; spores 14–20 μm; calyptrae very hairy. Capsules common, winter to summer. n = 6∗ , 12. On dry exposed usually basic rocks by rivers and lakes, on stonework, scree, rarely on tree trunks and exposed roots. 0–700 m. Rare in N. W. England and Wales, very rare elsewhere in northern England, occasional in Scotland, extending north to Shetland, rare in Ireland. 60, H16. GB175 + 41∗ , IR12 + 9∗ . European Boreo-temperate. Europe north to northern Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Cyprus, India, Canary Islands, Madeira, N. and E. Africa, western N. America, Greenland, S. America, Australasia. Distinguished from O. cupulatum by the very hairy calyptrae, old dry capsules being of ± uniform width throughout, only eight peristome teeth, and the superficial stomata. O. anomalum differs in the reddish sporophytes with exserted capsules. O. striatum and O. shawii differ in having 16 exostome teeth strongly reflexed when dry and the capsules smooth when dry. May be mistaken for muticous specimens of Schistidium, but they differ in capsule and leaf shape, areolation and the single reddish peristome. A number of varieties have been described but these appear to be habitat forms.

Subgenus 5 Orthotrichum Autoicous. Leaves erect, appressed when dry, obtuse to acute; margins usually recurved or revolute; cells smooth or papillose. Capsules immersed, emergent or exserted; stomata immersed; exostome teeth 16, erect or spreading when dry, processes 0, 8 or 16, often reduced; spores 9–19(−48) μm. Mainly saxicolous species. 18 O. anomalum Hedw., Sp. Musc. Frond., 1801 O. anomalum var. saxatile Mild.

(Fig. 223)

Autoicous. Dark green tufts, 0.5–5.0 cm high. Leaves erect-patent to spreading when moist, lanceolate, acute; margins recurved at least below; costa ending below apex; basal cells rectangular, thick-walled, cells above rounded, papillose, 9–10 μm wide in mid-leaf. Setae reddish, (1.5−)2.0–4.0 mm long; vaginula glabrous; capsules exserted, reddish brown, ovoid to ellipsoid, with 8 strong ribs alternating with 8 weaker shorter ruibs which may sometimes be lacking,

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35 Orthotrichaceae

Fig. 223 1–4, Orthotrichum anomalum: 1, leaf (×15) 2, mid-leaf cells; 3, mature sporophyte with calyptra (×10); 4, old sporophyte (×10). 5–10, O. rupestre: 5, leaf (×15); 6, mid-leaf cells; 7, mature sporophyte with calyptra (×15); 8, 9, old sporophytes (×15); 10, stoma. 11–14, O. pulchellum: 11, dry shoot with old sporophyte (×10); 12, leaf (×25); 13, mid-leaf cells; 14, mature sporophyte with calyptra (×15). Cells ×420.

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narrower and sulcate when dry and empty; stomata immersed; exostome of 16 or rarely 8 pairs of pale orange longitudinally striate teeth, erect to spreading when dry, endostome rudimentary or absent; spores 10–14 μm; calyptrae sparsely hairy. Capsules common, spring, early summer. n = 10 + m∗ , 11, 20 + 2m. On usually exposed basic rocks, especially limestone, and on man-made substrates. 0–630 m. Frequent or common in much of England and Wales, occasional to frequent in Scotland and Ireland. 112, H40, C. GB1015 + 105∗ , IR166 + 8∗ , C6. European Wide-temperate. Europe to c. 67◦ N, Iceland, Caucasus, Turkey, Cyprus, Kashmir, Himalayas, Hong Kong, Japan, Canary Islands, Madeira, N. and E. Africa, N. America, Greenland, Guatemala, Haiti. Readily recognised in the field by the reddish brown exserted capsules. The report of O. urnigerum Myrin from W. Inverness is based on a colony of O. anomalum growing on pine trunks liberally coated with limestone dust from a nearby quarry working (see T. L. Blockeel, J. Bryol. 14, 649–51, 1987).

19 O. cupulatum Brid., Muscol. Recent., 1801 (Fig. 224) O. cupulatum var. nudum (Dicks.) Braithw., O. cupulatum var. riparium Huebener Autoicous. Dark green to blackish tufts, 0.5–2.0 cm high. Leaves erect-patent to spreading when moist, lanceolate to broadly lanceolate, acute to obtuse; margins recurved; costa ending below apex; basal cells rectangular, thick-walled, cells above rounded, papillose, 8–10 μm wide in mid-leaf. Setae pale green to brown, 1.0–1.6 mm long; vaginula glabrous or sparsely hairy; capsules immersed to emergent or slightly exserted, ovoid to ellipsoid, pale brown, ± tapering into seta, smooth at maturity, narrowed, urceolate and sulcate when dry and empty; stomata immersed; exostome of 16, pale yellow longitudinally striate teeth, erect to spreading when dry, endostome absent; spores 14–16 μm; calyptrae plicate, glabrous or sparsely hairy. Capsules common, spring. n = 10 + m∗ , 11. On flat limestone rocks and base-rich man-made habitats such as wall tops and roofs and on limestone rocks in streams and by pools. 0–620 m. Occasional to frequent throughout much of the British Isles. 94, H25. GB301 + 73∗ , IR41 + 10∗ . Eurosiberian Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Cyprus, N. Asia, Kashmir, Madeira, La Palma, Tenerife, N. Africa, N. America, Australia, New Zealand. Frequently growing with O. anomalum, which differs in the exserted reddish capsules. For differences from O. rupestre see under that species. J. Lewinsky-Haapasaari (in Nyholm, 1998) says with regard to var. riparium ‘ . . . is most likely an environmental modification not worthy of any taxonomic status.’ I concur and for this reason do not accept the variety.

124 ULOTA D. MOHR EX BRID., MUSCOL. RECENT., 1819 Autoicous, rarely dioicous. Marginal branches of tufts often decumbent and sometimes creeping. Leaves linear or linear-lanceolate, usually curved or crisped when

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35 Orthotrichaceae

Fig. 224 1–7, Orthotrichum cupulatum: 1, leaf; 2. mid-leaf cells; 3, stoma; 4, calyptra (×15); 5, 6, mature and old sporophytes (×15); 7, mature sporophyte of plant referred to as var. riparium (×15). 8–12, Ulota drummondii: 8, dry shoot with sporophyte with calyptra (×5); 9, leaves; 10, mid-leaf cells; 11, dry old sporophyte (×10). 12–15, U. coarctata: 12, leaves; 13, mid-leaf cells; 14, capsule with calyptra (×10); 15, old sporophyte (×10). Leaves ×15, cells ×420.

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dry, erect-patent to spreading when moist; margins plane or recurved, entire; costa ending in or below apex; cells incrassate, basal often narrow and vermicular except towards margins, cells above ± rounded, papillose. Capsules exserted, 8-striate, neck long, usually narrowed and sulcate when dry and empty; stomata superficial; peristome double, endostome sometimes rudimentary or lacking; calyptrae hairy. About 35 species, mainly in temperate regions. Derivation: meaning curled, from the leaves curled when dry. Species sometimes grow mixed together, this often causing difficulty with identification. It is possible that hybridisation occurs between some species, as occasional gametophytes of an intermediate nature occur. As with Orthotrichum, species of Ulota are very susceptible to the effects of atmospheric pollution.

1 Costa excurrent, uppermost leaves with clusters of brownish fusiform gemmae at tips, dioicous, capsules very rare 7. U. phyllantha Costa ending in or below apex, gemmae absent, autoicous, capsules common 2 2 Leaves stiff, imbricate, ± straight when dry, cells very strongly incrassate with small lumens, saxicolous plants 6. U. hutchinsiae Leaves curved or crisped when dry, cells incrassate but lumens not very small, plants usually corticolous 3 3 Dry empty capsules whitish, inflated, smooth except immediately below mouth 1. U. coarctata Dry empty capsules fawn to brownish, not inflated, strongly furrowed 4 4 Calyptrae usually with a few sparse hairs, leaves strongly crisped when dry, basal part of leaves plicate, band of rectangular basal cells extending up margins 5. U. calvescens Calyptrae very hairy, leaves curled to strongly crisped when dry, basal part not plicate, rectangular basal cells not ascending up margins 5 5 Leaves curled when dry, exostome teeth whitish, erect to spreading when dry, endostome rudimentary or absent, plants often reddish tinged, marginal branches often creeping 2. U. drummondii Leaves moderately to strongly crisped when dry, exostome teeth pale brown, strongly reflexed when dry, endostome well developed, plants not reddish tinged, marginal branches not creeping 6 6 Dry empty capsules urceolate,1 1–4 rows of cells between mouth of capsule and end of ribs (see Fig. 226, 1–3) wider than long, with uniformly thickened walls, exostome teeth remaining in pairs when reflexed, exostome processes hyaline, persisting 3. U. crispa Dry empty capsules fusiform,1 cells of ribs extending to mouth of capsule (see Fig. 226, 4–6), exostome teeth splitting longitudinally when reflexed, processes opaque, not persisting 4. U. bruchii 1

Old capsules become cylindrical in both U. crispa and U. bruchii and in such instances is necessary to examine the cells at the mouth of the capsules.

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35 Orthotrichaceae

1 U. coarctata (P. Beauv.) Hammar, Mon. Orthotrich. Ulot. Suec. 1852 U. ludwigii Brid.

(Fig. 224)

Autoicous. Small dull green tufts, c. 1 cm high. Leaves slightly twisted when dry, patent when moist, lanceolate from enlarged concave basal part, acute to obtuse; margins plane or recurved, entire; costa ending below apex; basal cells narrowly rectangular to linear, towards margins quadrate-rectangular, cells above ovate or rounded, incrassate, slightly papillose, 10–12 μm wide in mid-leaf. Setae 4.0– 4.5 mm long; capsules 2.0–2.5 mm long, narrowly pyriform, very pale brown, smooth except immediately below very small mouth, whitish and inflated when dry and empty; spores finely papillose 18–24 μm; calyptrae hairy. Capsules common, autumn. n = 9+ m. On shrubs and small trees in sheltered situations by streams and in wet places. Lowland. Rare to occasional in western Scotland from Selkirk north to W. Ross, scattered localities in eastern Scotland, very rare elsewhere and probably largely extinct, S. Somerset, I. of Wight, S. Hampshire, W. Sussex, E. Norfolk, Worcester, Merioneth, Kerry. 16, H2. GB17 + 22∗ , IR1. Suboceanic Boreal-montane. Montane and northern Europe north to 66◦ N, Caucasus, eastern N. America. This species, readily recognised by its pale narrowly pyriform capsules with very small mouths, has decreased markedly although there are two post-1950 records from England.

2 U. drummondii (Hook. & Grev.) Brid., Bryol. Univ., 1827 (Fig. 224) Autoicous. Tufts or spreading patches, often tinged with red, 0.5–1.0 cm high; marginal branches creeping. Leaves curved when dry, erect-patent when moist, narrowly lanceolate to lanceolate from sometimes expanded but not plicate basal part, acute to acuminate; margins plane or recurved below, entire; costa ending below apex; basal cells linear, vermicular, 4–10 marginal rows shorter, rectangular, cells above rhomboidal to rounded, papillose, 8–10(−14) μm wide in mid-leaf. Setae 3–5 mm long; capsules 2–3 mm long, pale brown, ovoid to ellipsoid with long neck, striate at maturity, narrowly ellipsoid to cylindrical, narrowed at the mouth, sulcate when dry and empty; stomata 31–84 (mean 46), 28–36 μm diameter; exostome teeth white, erect to spreading when dry, endostome rudimentary or absent; spores 18–24 μm; calyptrae hairy. Capsules common, autumn. n = 9 + m. On branches and twigs of trees and shrubs in humid situations. 0–620 m. Rare to occasional in N. W. Wales, northern England and southern Scotland, occasional to frequent further north, extending to Orkney, rare in Ireland. 45, H12. GB161 + 22∗ , IR7 + 4∗ . Suboceanic Boreal-montane. N., W. and C. Europe north to c. 66◦ N, Japan, N. America. May be confused with the next two species but differs in the leaves, which are often wider, curved rather than crisped when dry, and in the white peristome teeth. The number of stomata, which has been used as a distinguishing character, is considered unreliable as it varies from year to year depending upon environmental conditions (see P. Erzberger,

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Lindbergia 28, 14–22, 2003). The reddish tinge and creeping branches are also often characteristic.

3 U. crispa (Hedw.) Brid., Muscol. Recent. Suppl., 1819 U. crispula Brid.

(Figs. 225, 226)

Autoicous. Small yellowish green tufts or patches, mostly 0.4–2.0 cm high. Leaves strongly crisped when dry, patent to spreading when moist, upper leaves 2.0– 3.5 mm long, linear-lanceolate to lanceolate from concave but not plicate basal part, acute to acuminate; margins plane or recurved below, entire; costa ending in or below apex; basal cells narrowly rectangular to linear and vermicular, 4–10 marginal rows rectangular, cells above oval or rounded, papillose, 8–14 μm wide in mid-leaf. Sporophytes 3.0–6.0(−7.5) mm; setae 2–4(−5) mm long; capsules 1–3 mm long, ellipsoid, abruptly narrowed to gradually tapering into seta, narrowed below mouth, urceolate, sulcate when dry and empty, becoming shortly cylindrical with age; narrow ring of 1–4 uniformly thickened transversely rectangular cells extending round mouth, longitudinally rectangular cells of ribs becoming abruptly shorter near to and not reaching mouth, or rarely when only a single row of transversely rectangular cells is present this may not be continuous across the middle part of each rib; stomata 8–57 (mean 21), 24–42 μm wide; exostome teeth brownish, regularly recurved when dry, remaining in pairs, inner surface (i.e. the surface exposed when the teeth are reflexed) smooth or almost so, outer surface (i.e. the surface concealed when teeth are reflexed) papillose; endostome well developed, processes persisting, triangular to subulate, narrowed at base, hyaline, almost smooth or with low papillae, occasionally with short lines; spores 20–26 μm; calyptrae hairy. Capsules common, summer. n = 10 + m∗ , 10 + 2m∗ , 19 + 2m, 20 + 2m∗ , 22. On trunks, branches and twigs of trees and shrubs, especially Corylus, Fraxinus, Salix and Sambucus in damp and humid woodland, copses, by water, rarely on rocks. Rare or very rare in lowland England, probably frequent or common elsewhere. 107, H27, C. European Temperate. Throughout most of Europe, Turkey, N. Asia, Far East, Canary Islands, Madeira, eastern N. America. Confused with U. bruchii (q.v.) which is about three times more frequent – more than half the specimens named U. crispa in a herbarium survey proved to be U. bruchii and a review of voucher specimens is required. Small plants with capsules abruptly narrowed into the seta have been named U. crispula, but there is such a degree of intergradation that the taxon cannot be maintained even as a variety.

4 U. bruchii Hornsch. ex Brid., Bryol. Univ., 1827 (Figs. 225, 226) ¨ U. crispa var. norvegica (Gronvald) A. J. E. Sm. & M. O. Hill, U. nicholsonii Culmann Autoicous. Small yellowish green tufts or patches, 0.5–2.0 cm high. Leaves usually moderately crisped when dry, patent to spreading when moist, upper leaves 2.6–4.0 mm long, narrowly lanceolate or lanceolate from concave but not plicate basal part, acute to acuminate; margins plane or recurved below, entire; costa

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35 Orthotrichaceae

Fig. 225 1–7, Ulota crispa: 1, dry shoot; 2, leaves; 3, basal marginal cells; 4, mid-leaf cells (×420); 5, capsule with calyptra; 6, dry empty capsule; 7, dry old empty capsule. 8–12, U. bruchii: 8, dry shoot; 9, leaves; 10, mid-leaf cells; 11, dry empty capsule; 12, dry old empty capsule. Shoots ×5, leaves ×20, cells ×420, capsules ×20.

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Fig. 226 1–3, Ulota crispa cells at capsule mouth. 4–6, U. bruchii: cells at capsule mouth. All ×160.

ending in or below apex; basal cells narrowly rectangular to linear and vermicular, 4–10 marginal rows rectangular, cells above oval to rounded, papillose, 8–14 μm wide in mid-leaf. Sporophytes 6–8 mm long; setae (3.0−)3.5–5.2 mm long; capsules 2.0–3.2 mm long, ellipsoid, tapering into seta, narrowed at the mouth, fusiform, sulcate when dry and empty, becoming shortly cylindrical with age; rectangular cells of ribs gradually becoming shorter towards and reaching to mouth; stomata mostly 6–40 (mean 27), 32–48 μm wide; exostome teeth brownish, irregularly reflexed when dry, tending to split longitudinally, inner surface (i.e. surface exposed when teeth are reflexed) with fine lines and coarse papillae, outer surface (i.e. surface concealed when teeth are reflexed) with an irregular pattern of mainly longitudinally or concentrically arranged lines; endostome processes linear, narrow at base, whitish, opaque, fragile; spores 20–26 μm; calyptrae hairy. Capsules common, summer. n = 9 + m, 19 + m, 20 + 2m. On trunks, branches and twigs of trees and shrubs, especially Corylus, Fraxinus, Salix and Sambucus, in damp or humid woodland, copses, by water, rarely on rock. Rare in lowland England, frequent or common elsewhere in the British Isles. 103, H34, C. European Temperate. Europe north to Fennoscandia. U. bruchii and U. crispa cannot be distinguished when mature capsules are lacking. The two species are very close and about 3% of specimens cannot be named. Plants with urceolate

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35 Orthotrichaceae

capsules are U. crispa and those with fusiform capsules longly tapering into the seta are U. bruchii, but old capsules lose their distinct shape as they age, becoming ± cylindrical, and it is necessary to examine the areolation of the capsule mouth to determine such specimens. The cells of the capsule ribs are longitudinally rectangular with heavily thickened longitudinal walls and thin transverse walls. In U. bruchii these cells gradually decrease in size towards the mouth and extend right to the mouth of the capsule. In U. crispa they decrease in size rapidly near the mouth, around which are 1–4 rows of uniformly thickened cells, which are wider than long. Rarely, if there is only a single row of these cells, the cells of the ribs may extend to the mouth but are recognisably those of U. crispa, decreasing in length rapidly near the mouth. For a detailed account of the differences between the two species see A. J. E. Smith & M. C. F. Proctor, J. Hattori Bot. Lab. 74, 171–82, 1993. R. Garileti et al. (J. Bryol. 22, 273–8, 2000) provide further information about peristome characters and consider that the nature of the endostome processes is particularly valuable in separating U. crispa and U. bruchii. The plant referred to as U. nicholsonii Culmann from Achill Island is large, golden yellow and very distinctive looking. However, the morphology of the leaves is indistinguishable from that of U. bruchii and the species cannot be maintained.

5 U. calvescens Wilson in Rabenh., Bryoth. Eur., 1862 U. vittata Mitt.

(Fig. 227)

Autoicous. Small tufts, 0.5–1.5 cm high. Leaves strongly crisped when dry, erectpatent when moist, narrowly lanceolate to linear-lanceolate, acute to acuminate, basal part not enlarged, with 2 plicae; margins plane or recurved, entire; costa ending below apex; basal cells narrowly rectangular to linear, towards margins quadrate-rectangular, a band of rectangular cells ascending some way up margins, cells above rounded-quadrate, papillose, 8–10 μm wide in mid-leaf. Setae 4–6 mm long; capsules 1.5–2.5 mm long, narrowly pyriform, striate at maturity, cylindrical and sulcate when dry and empty; spores 22–26 μm; calyptrae glossy with a few sparse hairs, rarely strongly hairy. Capsules common, autumn. On branches and twigs of trees and shrubs, especially Betula, Corylus and Sorbus, in woods and sheltered sites. 0–420 m. Frequent or common from W. Inverness to Skye, very rare elsewhere, Merioneth, Ayr, Stirling, Ross, W. Sutherland, Outer Hebrides, Shetland, occasional in western Ireland. 14, H15. GB71 + 8∗ , IR23 + 8∗ . Oceanic Southern-temperate. Portugal, Spain, Macaronesia. Recognisable in the field by the usually sparsely hairy calyptrae and the capsules relatively short in relation to the seta when compared with other species of Ulota. Plants of U. calvescens have been found in Ireland with strongly hairy calyptrae (see D. T. Holyoak, Bull. Br. Bryol. Soc. 70, 59–61, 2002). Sterile plants may be recognised by the areolation and plicae of the basal part of the leaves.

6 U. hutchinsiae (Sm.) Hammar, Mon. Orthotrich. Ulot. Suec., 1852 U. americana (P. Beauv.) Schimp.

(Fig. 227)

Autoicous. Dark green to brownish tufts or patches, 1–2(−3) cm high. Leaves rigid, imbricate, straight or slightly curved when dry, erect-patent when moist,

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Fig. 227 1–5, Ulota calvescens: 1, leaf; 2, mid-leaf cells (×420); 3, capsule with calyptra; 4, mature sporophyte; 5, dry empty capsule. 6–9, U.hutchinsiae: 6, dry shoot; 7, leaf; 8, mid-leaf cells (×420); 9, dry empty capsule. 10–13, U. phyllantha: 10, young leaf with apical gemmae; 11, older leaf; 12, mid-leaf cells (×420); 13, gemmae (×175). Shoots ×5, leaves ×15, sporophytes ×10.

lanceolate, acute to obtuse, basal part not enlarged or plicate; margins recurved; entire costa very strong, reddish or brownish ending below apex; basal cells narrowly rectangular to linear, upper cells rounded, sometimes very strongly incrassate, papillose, 8–10 μm wide in mid-leaf. Setae 3.5–4.0 mm long; capsules c. 2 mm long, clavate, striate at maturity, ellipsoid to subcylindrical, sulcate, hardly contracted at mouth when dry and empty; exostome teeth light brown, spreading when dry; spores coarsely papillose, 16–18 μm; calyptrae hairy. Capsules common, summer. n = 10, 10 + m. On dry or intermittently moist acidic or basic boulders and walls, especially by water, and in scree. 0–490 m. Common in western Scotland, rare elsewhere in western and northern Britain, extending from Cornwall north to Sutherland, occasional in Ireland. 35, H19. GB145 + 29∗ , IR43 + 8∗ .

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36 Hedwigiaceae

Suboceanic Boreal-montane. Europe north to c. 68◦ N in Norway, Faeroes, Caucasus, Turkey, N. America. The dark green to brownish tufts with leaves straight and imbricate when dry will distinguish this plant from all other Ulota species. More likely to be confused with Racomitrium ellipticum (q.v.).

7 U. phyllantha Brid., Muscol. Recent. Suppl., 1819 (Fig. 227) Dioicous. Small to large yellowish green to brownish green cushions, reddish to brown below, 0.5–2.5 cm high. Leaves strongly incurved and crisped when dry, erect-patent when moist, variable in shape, narrowly lanceolate to linearlanceolate or ligulate, basal part sometimes slightly expanded, not plicate, apex variable, often obtuse and apiculate or misshapen or malformed; margins plane or recurved below, entire; costa brownish, excurrent; basal cells narrowly rectangular, 4–10 marginal rows shorter, rectangular, cells above elliptical to rounded, strongly incrassate, papillose, 6–10 μm wide in mid-leaf. Clusters of fusiform brownish gemmae borne on the excurrent part of costa of uppermost leaves. Capsules ellipsoid, striate at maturity; calyptrae sparsely hairy. Capsules very rare, autumn. On trunks, branches and twigs of trees and shrubs inland, also saxicolous by the coast. Lowland. Frequent or common along the west coast and in the extreme west from Cornwall to the Shetlands, rare to occasional elsewhere, common in western Ireland, becoming rarer eastwards. 105, H37, C. GB670 + 86, IR282 + 14∗ , C6. Oceanic Boreo-temperate. Atlantic and Baltic coasts of Europe from Spain north to the Kola Peninsula, Faeroes, Iceland, Czechoslovakia, Poland, Russia, coasts of N. America, Tierra del Fuego, Australia, Antarctica. Capsules are very rare but the clusters of brownish gemmae at the tips of the upper leaves will immediately identify this plant. It is increasing in southern England, perhaps an indication of reduced atmospheric pollution since the 1950s.

18 Hedwigiales Acrocarpous. Stems procumbent, branching irregular to pinnate. Leaves ± imbricate when dry, ± spreading when moist, concave, sometimes longitudinally plicate, ovate or ovate-lanceolate; costa absent; alar cells enlarged or not, cells above quadrate to elongate, papillose. Perichaetia terminal on main stems or branches. Perichaetial leaves long, erect. Setae very short; vaginula hairy, ochrea lacking; capsules immersed, emergent or longly exserted, asymmetrical; stomata superficial; peristome absent; calyptrae very small or large, cucullate or mitriform, never plicate. Three families.

36 Hedwigiaceae Protonemata globular. Leaf cells pluripapillose. Calyptrae smooth, glabrous. Three genera.

125 Hedwigia

691

125 HEDWIGIA P. BEAUV., MAG. ENCYCLOP., 1804 Autoicous. Main stems not stoloniform, irregularly branched. Leaves concave, apex acuminate, hyaline or not; basal cells linear, extending up centre of leaf, alar cells transversely rectangular to rectangular, basal cell elongate, cells above papillose, rounded-quadrate towards apex and margins. Perichaetial leaf margins entire or ciliate. Capsules immersed to emergent, erect; peristome absent; calyptrae small, cucullate. Cosmopolitan; c. 10 species. Derivation: Named after Johann Hedwig (1730–1799) whose book, Species Muscorum Frondosorum (1801), is the starting point of moss nomenclature. ¨ J. Bryol. 18, 130–57. 1994. For For an account of the first two species see L. Hedenas, their distribution and ecology in the British Isles see A. C. Crundwell, J. Bryol. 18, 807–10, 1995.

1 Leaves apices not hyaline, margins recurved ± from base to apex 3. H. integrifolia 2 Leaf apices hyaline, margins plane or recurved to 2/3 way up leaf 2 Mid-leaf cells with 1–4(−5) papillae, apical cell of many leaves crowned with 2–5 papillae, dry leaf apices erect to patent 1. H. ciliata Mid-leaf cells with 1(−2) papillae, apical cell of leaves usually lacking apical papillae, dry leaf apices, especially of upper leaves, recurved or reflexed when dry 2. H. stellata 1 H. ciliata (Hedw.) P. Beauv., Prodr. Aethéogam., 1805 Tufts or patches, whitish to grey-green when dry, green or brown-green when moist. Stems ± decumbent, irregularly branched, shoot tips straight to downcurved when dry. Leaves imbricate or sometimes falcate-secund with apices erect to erect-patent when dry, erect-patent to patent or spreading, sometimes subsecund when moist, concave, ovate to broadly ovate, tapering to hyaline apex; margins recurved below, papillose; hyaline apex spinosely toothed, coarsely papillose, deeply furrowed to almost tubular below; costa absent; cells incrassate or very incrassate throughout, except at base, with 1–4(−5) papillae on each face, papillae on abaxial side branched, basal cells narrowly rectangular, orange-brown, ascending up middle of leaf, cells towards margins and apex ovate or rounded-quadrate, 10–16 × 10–33 μm in mid-leaf; apical cell of at least some leaves crowned with 2–5 papillae, other apical cells acute or forked. Perichaetial leaves erect, straight; margins ciliate above. Capsules subsessile, obloid; spores 19–35 μm. Capsules frequent, spring, summer. Hyaline points short (mostly 7–33% total leaf length), frequently not visible to the naked eye, ± greyish white when dry; papillose below, spores (23−)25–35 μm var. ciliata Hyaline points longer (mostly 22–55% total leaf length), usually visible to the naked eye, conspicuously white when dry; papillose almost to apex, spores 19–28(−30) μm var. leucophaea

692

36 Hedwigiaceae

Var. ciliata (Fig. 228) Plants greyish green when dry. Leaf margins recurved to 1/3 –2/3 way up leaf on both sides; hyaline points short, hardly contrasting with rest of leaf and usually not visible to the naked eye when dry, constituting (4−)7–33% total leaf length, usually strongly papillose only in basal part. Spores (23−)25–35 μm. On exposed or sheltered hard acidic rocks and boulders, usually by lakes, on walls and tiles. 0–720 m. Rare, scattered localities from N. Wiltshire and W. Sussex north to Skye and W. Sutherland, Waterford, old records from E. Sussex, Merioneth, Caernarfon, Westmorland, Kirkcudbright and Argyll. 17, H1. N. W. Europe, Faeroes, Poland, Japan, Algeria, Morocco. Var. leucophaea Bruch & Schimp. in Bruch et al., Bryol. Eur. 1846 (Fig. 228) Plants white or greyish white when dry. Leaf margins plane or recurved to 1/ (−2/ ) on one or both sides; hyaline point constituting (5−)22–55(−65)% total 2 3 leaf length, contrasting strongly with rest of leaf and visible to the naked eye when dry, papillose to middle and above although papillae towards apex may be obscure. Spores 19–28(−33) μm. On exposed acidic rocks and boulders. Old records from Kirkcudbright and W. Sutherland. 2. Oceanic temperate. N. W. Europe, Spain, Madeira, Algeria, Morocco, Tunisia. In the British Isles, var. ciliata is rare and var. leucophea exceedingly rare. The hyaline leaf points of var. ciliata are usually very short and often only visible with a hand lens. Var. leucophaea has longer, more strongly papillose hyaline leaf points than var. ciliata and because these points are whiter when dry this gives dry plants a hoarier appearance. However, specimens of var. ciliata from very exposed situations may be difficult to separate from forms of var. leucophaea from less exposed habitats.

¨ J. Bryol., 1994 2 H. stellata Hedenas, (Fig. 229) Tufts or patches, greyish green when dry, green or brownish when moist. Stems decumbent, irregularly branched, shoot tips straight or down-curved when dry. Leaves erect, straight to falcate with apices erect-patent to reflexed or recurved when dry, usually patent or spreading when moist, concave, ovate or broadly ovate, tapering to hyaline apex; margins recurved to 1/3 –2/3 way up leaf; hyaline apex papillose, denticulate, sometimes spinosely so, constituting (17−)20– 41(−44)% total leaf length, furrowed from base to about middle; costa absent; cells incrassate, basal cells orange-brown, narrowly rectangular, extending up middle of leaf, alar cells thinner-walled, cells above quadrate to rectangular, with 1(−2) papillae on each face, those on abaxial side branched and usually peltate, mid-leaf cells 10–16 × 10–27 μm; apical cells acuminate, sometimes with large subapical papilla or forked. Perichaetial leaves with ciliate margins. Capsules immersed, shortly obovoid; lid convex, mamillate; spores 23–30 μm. Capsules spring. n = 10∗ . On exposed acidic or more rarely ± basic rocks, walls and roof tiles. Absent from southern and eastern England, frequent or common elsewhere.

125 Hedwigia

693

Fig. 228 1–5, Hedwigia ciliata var. ciliata: 1, leaves; 2, leaf apices; 3, mid-leaf cells (×420); 4, perichaetial leaf; 5, sporophyte (×10). 6–7, H. ciliata var. leucophaea: 6, leaves; 7, leaf apices. Leaves ×30, apices ×280.

694

37 Rhizogoniaceae

70, H2, C. European Temperate. Denmark, Finland, Norway, Sweden, Turkey, Morocco, N. America, Mexico. Distinguished from H. ciliata by the leaf apices reflexed or recurved when dry, the sharply pointed leaf tips and the mostly unipapillose cells, with the abaxial papillae being peltate.

3 H. integrifolia P. Beauv., Prodr. Aethéogam., 1805 (Fig. 228) H. imberbis (Sm.) Spruce, Hedwigidium integrifolium (P. Beauv.) Dixon Tufts or patches, yellowish green above, brownish below. Stems procumbent, irregularly branched, sometimes with flagelliform branches with minute leaves. Leaves ± imbricate when dry, erect-patent when moist, concave, ovate, acute or acuminate; margins recurved ± from base to apex, entire; costa lacking; cells incrassate, papillose, basal cells narrowly rectangular and extending up middle of leaf, cells above and towards margins quadrate-rectangular or rounded-quadrate, sinuose, papillae simple, 2–5 on abaxial side, 0–5 on adaxial side, 6–9 μm wide in mid-leaf. Flagilliform branchlets sometimes present. Perichaetial leaves longer and narrower than stem leaves; margins entire. Setae c. 1 mm long; capsules scarcely emergent, obloid, faintly striate when dry and empty; spores c. 25 μm. Capsules rare, early summer. On dry exposed ± basic rocks, boulders and in scree on moorland and bases of cliffs, rarely on walls, almost always with H. stellata. 0–450 m. Frequent in N. W. Wales and the Lake District, occasional in western Scotland, extending north to Skye and W. Ross, S. Kerry, W. Cork, Waterford, Wicklow, Antrim. 23, H5. GB60 + 11∗ , IR5 + 6∗ . Oceanic Temperate. France, N. Italy, S. W. Norway, N. Spain, Tanzania.

19 Rhizogoniales Acrocarpous or pleurocarpous. Primary stems usually rhizomatous, secondary stems erect. Leaves oblong to lanceolate; costa present, heterogeneous in section; cells usually short, thick-walled.

37 Rhizogoniaceae Acrocarpous. Plants medium-sized to large. Stems with central strand. Leaf margins frequently with 2−multi-stratose border; costa often toothed above. Capsules smooth; annulus usually present; peristome perfect or exostome or endostome absent. Eight genera.

¨ 126 LEPTOTHECA SCHWAGR., SP. MUSC. FROND. SUPPL. 2, 1824 A small genus of two species differing in degree of papillosity of the rhizoids and in leaf shape. Derivation: meaning thin capsule, referring to the very narrowly cylindrical capsules.

126 Leptotheca

695

Fig. 229 1–6, Hedwigia stellata: 1, dry shoot (×8); 2 leaves; 3, leaf apices (×280); 4, mid-leaf cells; 5, perichaetial leaf; 6, sporophyte. 7–10, H. integrifolia 7, leaf; 8, mid-leaf cells; 9, perichaetial leaf; 10, sporophyte. Leaves ×30, cells ×420, sporophytes ×10.

696

38 Calomniaceae

¨ 1 L. gaudichaudii Schagr. var. gaudichaudii, Sp. Musc. Frond. Suppl. 2, 1824 (Fig. 230) Dioicous. Plants slender, light yellowish green, 5–10 mm high, forming small lax patches. Stems tomentose below. Leaves erect-flexuose with incurved tips when dry, patent when moist; lanceolate-lingulate, obtuse; margins plane, toothed near apex; costa strong, excurrent; cells uniform ± throughout leaf, strongly incrassate, irregularly rounded-hexagonal, smooth, 9–13 μm wide in mid-leaf. Brownish uniseriate axillary gemmae, 280–550 × c. 60 μm, composed of incrassate quadrate cells, present. Setae long; capsules erect, narrowly cylindrical; stomata superficial; annulus present, peristome double, perfect. Capsules unknown in Ireland. On tree-fern (Dicksonia antarctica) trunks. Very rare, S. Kerry. H1. IR1. Southern S. America, Falkland Islands, S. Georgia, Australia, Tasmania, New Zealand. In New Zealand this species grows on a number of substrates including tree-fern trunks and was clearly introduced with tree ferns imported into Ireland. The plant is present in very small quantity and should not be collected.

38 Calomniaceae Dioicous. Acrocarpous. Plants small, arising from persistent protonemata. Leaves dimorphic, in three rows, the dorsal rank smaller than the two lateral rows. Perichaetial leaves narrowly lanceolate. Setae long; capsules erect, shortly cylindrical, gymnostomous; annulus present. One genus with three species occurring in Australasia and Samoa.

127 CALOMNION HOOK F. & WILSON, FL.-NOV. ZEL., 1854 Derivation: meaning beautiful moss.

1 C. complanatum (Hook. f. & Wilson) Lindb., Contr. Fl. Crypt. As. 1872 (Fig. 230) Sex unknown. Plants pale green, slender, shoots decumbent to ascending, c. 1 cm long. Leaves dimorphic in three rows, two lateral rows, and one abaxial row covering the stem; lateral leaves oblong-elliptical, acute, base very narrow; margins plane, crenulate-denticulate; costa stout, reddish, ending just below or in apex; cells uniformly irregularly hexagonal, thick-walled, 7–12 μm wide in mid-leaf. Abaxial leaves ± circular, apiculate, base narrow; margins crenulate-denticulate; costa stout, ending in apiculus; cells as in lateral leaves; some leaves may be present at two semicircular half leaves on either side of the stem. Gametangia and sporophytes unknown in Ireland. On tree-fern (Dicksonia antarctica) trunks. Very rare, S. Kerry. H1. Ir1. Australia, Tasmania, New Zealand. This plant is most commonly found on tree-fern trunks in Australasia and was clearly introduced with tree ferns imported into Ireland. The plant is present in very small quantity and should not be collected.

127 Calomnion

697

Fig. 230 1–3, Calomnion complanatum: 1, lateral leaf; 2, abaxial leaf; 3, mid-leaf cells of lateral leaf (×420). 4–6, Leptotheca gaudichaudii: 4, leaf; 5, mid-leaf cells (×420); 6, gemmae (×280). 7–8, Achrophyllum dentatum: 7, leaves; 8, mid-leaf cells (×280). Leaves ×70.

698

39 Hookeriaceae

20 Hookeriales Pleurocarpous. Leaves often complanate and often asymmetrical, sometimes with border of elongate cells; costa single or double, long or short or absent; alar cells not differentiated. Setae often rough; capsules exserted, erect, inclined or horizontal; peristome double, exostome teeth long, tapering, often furrowed, usually with thickened lamellae on the inner face, basal membrane of endostome high, cilia absent; calyptrae conical, often hairy or fringed. Eight almost exclusively tropical or subtropical families.

39 Hookeriaceae Stems with central strand. Pseudoparaphyllia filamentous or absent. Rhizoids unbranched. Leaves ± complanate, often asymmetrical, often bordered; costa short and double or absent; cells large, lax, alar cells undifferentiated. Setae smooth or spinose; capsules inclined to pendulous; stomata usually superficial; lid conical; exostome teeth horizontally striate, endostome with high basal membrane, processes keeled, finely papillose, cilia sometimes present; calyptrae multistratose at middle, glabrous. A mainly tropical family of c. 6 genera. 128 HOOKERIA SM., TRANS. LINN. SOC. LONDON, 1808 Autoicous or dioicous. Plants medium-sized. Leaves complanate, large, succulent, ovate, ± asymmetrical, ± obtuse; margins plane, entire, not bordered; costa absent; cells very large, hexagonal, marginal hardly differing. Setae stout; capsules horizontal or pendulous, ellipsoid; peristome perfect, endostome with tall basal membrane; calyptrae mitrate. A mainly tropical or subtropical genus of 20– 25 species. Derivation: named after William J. Hooker (1785–1865), Director of the Royal Botanic Gardens, Kew.

1 H. lucens (Hedw.) Sm., Trans. Linn. Soc. London, 1808 Pterygophyllum lucens (Hedw.) Brid.

(Fig. 231)

Autoicous. Bright green glossy succulent patches. Shoots decumbent, to 6 cm long; stems sparsely branched. Leaves complanate, slightly shrunken and undulate when dry, broadly ovate, apex rounded or obtuse; margins plane, entire, unbordered; costa lacking; cells very large, translucent, interspersed with occasional smaller cells, irregularly hexagonal to elongate-hexagonal, 60–100 μm wide in mid-leaf, longer in mid-base, marginal cells undifferentiated or slightly narrower. Uniseriate chlorophyllous caducous filaments sometimes produced from small cells in upper part of leaf. Setae very stout, black, c. 2 cm long; capsules blackish, ± horizontal, ellipsoid; spores 12–16 μm. Capsules occasional to frequent, late autumn to spring. n = 12∗ . On damp shaded non-calcareous soil in humid situations, on banks by ditches, streams and rivers, in woods, on rock

128 Hookeria

699

Fig. 231 1–3, Daltonia splachnoides: 1, leaf (×40); 2, marginal cells at middle of leaf; 3, capsule (×15). 4–6, Hookeria lucens: 4, leaf (×15); 5, marginal cells at middle of leaf; 6, capsule (×10). 7–9, Cyclodictyon laetevirens: 7, leaf (×25); 8, marginal cells at middle of leaf; 9, capsule (×10). 10–11, Calyptrochaeta apiculata: 10, leaf (×25); 11, marginal cells at middle of leaf. Cells ×280.

700

40 Pilotrichaceae

ledges, in scree. 0–1000 m. Rare in lowland England except the extreme south, frequent or common elsewhere. 93, H36, C. GB850 + 277∗ , IR171 + 13∗ , C2 + 2∗ . Suboceanic Temperate. Europe, extending north to southern Scandinavia, Faeroes, Caucasus, Turkey, China, Azores, Madeira, western N. America. 129 ACHROPHYLLUM VITT & CROSBY, BRYOLOGIST, 1972 Stems with central strand. Costa single; cells smooth. Setae long, smooth; exothecial cells collenchymatous, stomata immersed, pustular; exostome teeth striate, lamellate, grooved; endostome with tall basal membrane. Two or more species. Derivation: referring to the almost colourless nature of the leaves of the type of the genus.

1 A. dentatum (Hook. f. & Wilson) Vitt & Crosby, Bryologist, 1972 (Fig. 230) Dioicous. Small to medium-sized vivid green succulent plants, becoming brownish with age, occurring as scattered shoots. Stems ascending to erect, sparsely branched, to 3.5 cm long. Leaves complanate, usually distant, much shrunken when dry, dorsal and ventral leaves appressed, elliptical, symmetrical, lateral larger, ovate-oblong, asymmetrical; margins plane, unbordered, ± entire; costa thin, often forked, extending to c. 1/3 way up leaf; cells large, thin-walled, hexagonal, 40–64 μm wide in mid-leaf of lateral leaves, a few marginal rows smaller but not forming border. Filamentous outgrowths from innermost smaller marginal cells usually present but not in Cornish material (see note below). Cornish plants female; sporophytes unknown in Britain. Associated with filamentous Trichomanes gametophytes in a permanently humid sheltered situation in a garden in W. Cornwall. 1. GB1. Southern S. America, Falkland Islands, Juan Fernandez, Australasia. A. dentatum has been recorded in glasshouses in a number of British botanical gardens but the Cornish record is the only one from outside. The Cornish plant is unusual in having ± entire leaves as the margins are usually dentate at least above. Also, in the Southern Hemisphere, filamentous gemmae arise from the innermost of the smaller marginal cells, sometimes so abundantly as to render plants shaggy; the gemmae are c. 6 cells long with 1–3-cell-long branches arising at right angles from the base of the filament. It is very likely that the plant was introduced with tree ferns imported from Australia. For an account of its occurrence in Cornwall see F. J. Rumsey, J. Bryol. 23, 341–4, 2001.

40 Pilotrichaceae Stems without central strand. Pseudoparaphyllia foliose or absent. Costa long or short, double. Calyptrae unistratose at middle, usually hairy. Twenty-four genera. 130 CYCLODICTYON MITT., J. LINN. SOC. BOT., 1864 Synoicous, autoicous or dioicous. Slender to moderately robust plants; stems sparsely to densely tomentose. Leaves not crowded, in 5–8 ranks, ± complanate, variable in size, concave, asymmetrical, usually ovate-oblong or oblong, abruptly

131 Calyptrochaeta

701

tapering to short to subulate point; costa double, extending c. half way up leaf; cells very lax, rounded-hexagonal, marginal linear, forming 1–2-stratose border. Setae smooth; capsules inclined to horizontal, ovoid to obloid; annulus a single row of fugacious cells; calyptrae mitriform. A largely tropical or subtropical genus of c. 110 species occurring mainly in C. and S. America and to a lesser extent in Africa. Derivation: referring to the large short leaf cells.

1 C. laetevirens (Hook. & Taylor) Mitt., J. Linn. Soc. Bot., 1864 (Fig. 231) Autoicous. Soft dark green patches. Shoots procumbent, to 8 cm long; stems pinnately branched. Leaves complanate, glossy, shrunken when dry, broadly ovate, acute to obtuse with large apiculus; margins recurved near base, finely denticulate near apex, bordered; costa thin, double, extending c. 3/4 way up leaf; cells large, hexagonal, thin-walled, 15–30 μm wide in mid-leaf, larger towards base, 3–4 marginal rows very narrow, forming distinct border. Setae stout; capsules horizontal, ovoid; spores 12–16 μm. Capsules rare, late summer, autumn. On deeply shaded wet rocks in ravines, caves, crevices by waterfalls and in block scree. 0–300 m. Very rare, W. Cornwall, Islay, Jura, Kerry, W. Cork, W. Mayo, Leitrim, old records from Mid Cork and Waterford. 2, H7. GB3, IR17 + 2∗ . Hyperoceanic Southern-temperate. Portugal, Spain, China, Madeira, Azores, tropical Africa, San ´ Tome. Only likely to be confused with Calyptrochaeta apiculata, which differs in habitat and leaves with very short costa and wider border. This species is considered endangered in the Red List of British Mosses and is a protected plant under the Wildlife and Countryside Act.

41 Daltoniaceae Stems lacking central strand. Pseudoparaphyllia absent. Rhizoids 1–3-pinnately branched. Leaves complanate, often bordered; costa single; cells rounded to elongate-hexagonal. Setae usually papillose above; exostome teeth papillose, endostome with low basal membrane, processes papillose, cilia absent; calyptrae mitrate, usually naked, fringed. Eight genera. 131 CALYPTROCHAETA DESV., MEM. SOC. LINN. PARIS, 1835 Autoicous or dioicous. Leaves usually ± complanate, asymmetrical, shortly pointed; margins entire; costa forked with unequal branches, short or rarely long; cells rounded to rhomboid-hexagonal, 2–5 marginal rows very narrow, forming distinct border. Setae usually prickly; capsules small, horizontal or pendulous, ovoid; annulus of large cells falling with lid; exostome teeth horizontally striate, endostome with tall basal membrane and finely papillose processes; calyptrae mitrate. A mainly tropical and Southern Hemisphere genus with c. 35 species. Derivation: meaning long hair calyptra, alluding to the hairs on the calyptra of some species.

702

41 Daltoniaceae

1 C. apiculata (Hook. f. & Wilson) Vitt, Can. J. Bot., 1979 Eriopus apiculatus (Hook. f. & Wilson) Mitt.

(Fig. 231)

Dioicous. Glossy green or yellowish green patches. Stems suberect, hardly branched, to 1.5–3.0 cm high. Lower leaves small, upper larger, twisted and slightly shrunken when dry, complanate when moist, broadly ovate or obovate, symmetrical or not, apex blunt and apiculate; margins plane, bordered, toothed above; costa very short, single or forked; cells large, irregularly hexagonal, incrassate or not, smooth, 25–40 μm wide in mid-leaf, larger towards base, smaller towards apex, (3−)5–10 rows marginal cells narrow, elongate, forming broad border. Uniseriate gemmae, mostly 4–8 cells long, to 200 × 20 μm, attached to protonemal filaments on the dorsal side of the stem, sometimes produced, apparently in April. Only female plants known in Britain. On sheltered soil or sandstone boulders near the sea. Lowland. Very rare, Scilly Isles, E. Sussex. 2. GB2. Introduced (Oceanic Southerntemperate). Chile, Tierra del Fuego, Australia, New Zealand. Almost certainly introduced from the Southern Hemisphere, possibly independently at the two sites from which it is known, with horticultural plants. For accounts of this plant see J. A. Paton, Trans., Br. Bryol. Soc. 6, 460–2, 1971, E. C. Wallace, Trans. Br. Bryol. Soc. 5, 2, 1968, R. C. Stern, J. Bryol. 16, 488–9, 1991, and R. D. Porley & H. W. Matcham, J. Bryol. 22, 61–2, 2000.

132 DALTONIA HOOK. & TAYLOR, MUSCOL. BRIT., 1818 Autoicous or dioicous. Small plants with procumbent or ascending stems with short ascending branches. Leaves erect-patent, keeled, base decurrent, from ovate basal part lingulate-lanceolate to lanceolate or linear-lanceolate; costa stout, single, ending below apex; cells rhomboidal or elongate-hexagonal, rarely roundedhexagonal, smooth, longer towards base, marginal cells elongate, thick-walled, forming yellowish border. Capsules erect or slightly inclined, ovoid or ellipsoid; annulus absent; calyptrae fringed or ciliate at base. A world-wide genus but with most of the 60 or so species occurring in the tropics or subtropics. Derivation: named after John Dalton (1764–1843), a British botanist.

1 D. splachnoides (Sm.) Hook. & Taylor, Muscol. Brit., 1818 (Fig. 231) Autoicous or synoicous. Small dark green tufts or patches, to 10 mm high. Stems ascending. Leaves appressed when dry, erect-patent when moist, keeled, linearlanceolate, acute to acuminate; margins plane, entire, bordered; costa stout, single, ending below apex; cells variable in shape, narrowly rectangular, narrowly rhomboidal or trapezoid in lower part of leaf, becoming rhomboid-hexagonal above, 6–12 μm wide in mid-leaf, several marginal rows long and narrow, forming stout yellowish border. Setae deep red, papillose; capsules erect, ovoid, with short neck; exothecial cells papillose; lid rostrate; calyptrae fringed; spores c. 16 μm. Capsules common, summer. Shaded rocks by streams in woods, on

133 Fontinalis

703

flushed rock faces, rotten logs, tree trunks and branches and humus by streams, in areas of high rainfall. 0–460 m. Very rare, W. Inverness, Argyll, W. Ross, Kerry, W. Cork, Limerick, Dublin (old record), W. Mayo, Leitrim, Cavan. 3, H8. GB6 + 1∗ , IR19 + 3∗ . Hyperoceanic Southern-temperate. China, Madeira, Azores, Bioko, western N. America, Mexico, Antilles, New Zealand. This species is treated as vulnerable in the Red List of British Mosses and is listed as vulnerable in the Red Data Book of European Bryophytes.

21 Hypnales Pleurocarpous. Very slender to robust plants. Primary stems usually creeping, secondary stems procumbent to erect, branching irregular to pinnate or dendroid. Paraphyllia and/or pseudoparaphyllia present or not. Leaves spirally arranged or complanate, linear-lanceolate to ± orbicular, apices rounded to longly acuminate; branch leaves similar to and smaller than stem leaves or differing in shape; costa long or short, single, double or absent; cells short to linear-vermicular, usually smooth, alar cells often differentiated. Setae long, smooth or papillose; capsules erect to horizontal, ovoid to cylindrical; lid convex to longly rostrate or subulate; peristome double, perfect or variously reduced, exostome teeth papillose, not furrowed, endostome with or without tall basal membrane, cilia present or not; calyptrae naked. Chromosome number frequently x = 10 + m or 11. About 43 families The limits between some of the families within the Hypnales at present are very problematical as are the limits between some of the constituent genera.

42 Fontinalaceae Dioicous or synoicous. Slender to robust aquatic or amphibious plants. Stems irregularly or pinnately branched, Leaves ± 3-ranked, ovate to lanceolate, tapering to acute apex, plane, concave or keeled; margins plane; costa single or absent; cells linear, marginal sometimes forming ill-defined border, cells at basal angles ± inflated, sometimes forming auricles. Perichaetial leaves convolute, forming tubular perichaetium. Capsules immersed or exserted, ovoid to cylindrical; stomata absent; lid conical; endostome processes and cilia united by transverse strands into conical lattice; calyptrae cucullate or mitriform. Three genera.

133 FONTINALIS HEDW., SP. MUSC. FROND., 1801 Plants robust, usually aquatic, stems long and irregularly branched. Stem and branch leaves of similar shape, plane, concave or keeled, ovate or lanceolate, acute; margins plane, entire, costa lacking; alar cells usually enlarged, forming ± distinct auricles, cells above linear. Setae very short, straight; capsules immersed or

704

42 Fontinalaceae

emergent; peristome double, exostome teeth entire or perforated, teeth of endostome united by transverse bars into lattice-like cone; calyptrae minute, smooth. About 20 mainly north temperate species. Derivation: meaning belonging to springs or water, a reference to habitat. For a monograph of the genus see W. H. Welch, A Monograph of the Fontinalaceae, 1969.

At least leaves of main stems markedly keeled, or if not then deeply channelled 1. F. antipyretica Leaves concave, not keeled or deeply channelled 2. F. squamosa 1 F. antipyretica Hedw., Sp. Musc. Frond., 1801 Glossy or dull green or dark green straggling tufts, to 80(−150) cm long. Stems tough, flexuose, irregularly branched. Leaves imbricate to spreading when moist, 3-ranked, giving stems trifarious appearance, soft or rigid, markedly keeled, rarely deeply channelled, ovate to ± orbicular when flattened, scimitar to halfmoon shaped when folded in half, apex acute to ± rounded; margins plane or reflexed and entire or obscurely denticulate near base; costa lacking; cells thin-walled, alar cells enlarged, quadrate-hexagonal, sometimes forming distinct auricles, elsewhere linear-rhomboidal to linear, 10–19 μm wide in mid-leaf. Sporophytes produced on emergent plants; capsules ± immersed, dark green to brown, ovoid; lid with stout conical beak; exostome teeth bright red; spores 10–12 μm. Capsules rare, spring. 1 Leaves distant or crowded, imbricate to spreading, keeled at least on main stems 2 Leaves distant, widely spreading, deeply channelled var. cymbifolia 2 Leaves from middle part of main stems 2–3 times as long as wide when folded in half var. gigantea Leaves from middle part of main stems 3–7 times as long as wide when folded in half 3 3 Leaves from middle part of main stems mostly 3.5–5.5 × 1.0 1.3 mm when folded in half, mid-leaf cells 12–19 μm wide var. antipyretica Leaves from middle part of main stems mostly 2.4–3.6 × 0.45–0.70 mm when folded in half, mid-leaf cells 10–12 μm wide var. gracilis Var. antipyretica (Fig. 232) Plants to 25–50 cm long; shoots trifarious. Stem and branch leaves keeled or apparently conduplicate, leaves from middle part of main stems (3.0−)3.5–8.5 × 2.0–2.6(−4.0) mm and ovate when flattened, half the width, and lanceolate when folded in half, keeled, apex acute; cells 12–19 μm wide in mid-leaf. n = 11∗ . Submerged or emergent in neutral or basic water on rocks, tree boles and exposed roots in and by rivers, streams and pools, in seepage areas on cliffs and in quarries,

133 Fontinalis

705

Fig. 232 1–5, Fontinalis antipyretica. 1–5, var. antipyretica: 1, 2, leaves in side and abaxial view; 3, leaf section; 4, mid-leaf cells; 5, shoot tip with sporophyte (×10). 6–8, var. cymbifolia: 6, leaf in side view; 7, leaf section; 8, mid-leaf cells. 9–12, var. gracilis: 9, 10, leaves in side and abaxial views; 11, leaf section; 12, mid-leaf cells. 13–15, var. gigantea: 13 leaf in side view; 14, leaf section; 15, mid-leaf cells. Leaves ×10, sections ×45, cells ×280.

706

42 Fontinalaceae

in Irish turloughs. Frequent or common throughout the British Isles, 112, H39, C. GB1449 + 92∗ , IR278 + 4∗ , C2 + 1 + . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Macaronesia, South Africa, California, Greenland. Var. gracilis (Hedw.) Schimp., Syn. Musc. Eur. (ed. 2), 1876 (Fig. 232) Plants to 40 cm long; shoots trifarious. Leaves crowded, keeled, obtuse, those from middle part of main stems 2.4–3.6(−4.0) × 0.9–1.4(−2.2) mm, ovate lanceolate when flattened, half the width and lanceolate or narrowly lanceolate when folded in half, keeled, acute; cells linear, mostly 10–12 μm wide in mid-leaf. Usually on rocks or stones in fast-flowing montane streams and rivers, rarely in lowland habitats or in pools. Rare in western and northern Britain, absent from lowland England, S. Tipperary, W. Galway, Londonderry. 42, H3. Eurosiberian Boreotemperate. Europe, Faeroes, Siberia, Japan, Korea. Var. gigantea (Sull.) Sull., Icon. Musc., 1864 (Fig. 232) Plants to 150 cm long; shoots usually conspicuously 3-ranked. Leaves crowded, keeled, obtuse, those from middle part of main stems 3.6–7.0(−8.0) × 3.2–6.0 mm, ± orbicular, when flattened, half the width and ovate when folded in half, keeled; mid-leaf cells 15–18 μm wide, Rocks in rivers, streams and waterfalls. Rare to occasional, widely distributed from Cornwall east to Surrey and north to Shetland. 35, H12. Eurasian Boreo-temperate. Western and central Europe north to Sweden, Caucasus, China, Algeria, N. America. Var. cymbifolia W. E. Nicholson, J. Bot. London, 1911 (Fig. 232) Dark green straggling tufts, to c. 15 cm long; shoots not trifarious. Leaves distant, spreading when dry, widely spreading when moist, deeply channelled but not keeled, those from middle part of main stems 3.0–5.5 × 1.5–4.5 mm, broadly ovate and 1.0–2.2 times as long as wide when folded in half. In sluggishly flowing water. Lowland. Very rare, not seen recently and probably extinct, Somerset, N. Wiltshire, E. Sussex, Buckingham, Huntingdon, Northampton, Derby, Mid-West Yorkshire, Clare. 8, H1. Mediterranean-Atlantic. France. A species subject to considerable morphological variation. The three varieties are of uncertain status but are probably more than mere habitat variants as they are not necessarily confined to one type of habitat. Thus, var. gracilis occurs in both fast-flowing streams and in pools in montane habitats. Welch (1960) recognises var. gracilis and var. gigantea, but reduces var. cymbifolia to synonymy with var. antipyretica – but that variety is more distinctive looking than the other two. F. dolosa Cardot, reported from Lembury, Bedford, appears merely to be a form of var. antipyretica.

2 F. squamosa Hedw. Sp. Musc. Frond. Glossy straggling tufts, to 40 cm long. Stems rigid or flexuose, often fasciculately branched, frequently denuded below. Stem leaves similar to or larger than branch leaves, imbricate or sometimes patent when moist, concave, ovate to lanceolate, acute to obtuse, base decurrent; margins plane or inflexed, entire or slightly denticulate towards apex; costa lacking; cells ± incrassate, alar cells inflated,

133 Fontinalis

707

forming ± distinct decurrent auricles, cells elsewhere linear-rhomboidal to linear, 12–14 μm wide in mid-leaf, 1–2(−3) marginal rows narrower, more incrassate, yellowish, sometimes forming slight border. Capsules immersed, yellowish brown, ovoid; lid conical; spores 18–28 μm. Capsules rare to occasional, autumn to spring. 1 Plants brownish, stem and branch leaves of similar size, leaf base and auricles yellowish to brown 2 Young parts of plants reddish brown, stem leaves larger and wider than branch leaves, auricles orange-brown var. dixonii 2 Perichaetial leaves with rounded or truncate, non-apiculate apices, widespread plant var. squamosa Perichaetial leaves with apiculate apices, Cornwall and Devon var. curnowii Var. squamosa (Fig. 233) Submerged glossy brownish straggling tufts. Stem and branch leaves not differing markedly in size, 2.0–4.3 mm long; base of similar colour to rest of leaf or

Fig. 233 1–3, Fontinalis squamosa. 1–3, var. squamosa: 1, 2, stem and perichaetial leaves; 3, mid-leaf cells (×280). 4, 5, var. curnowii: stem and perichaetial leaves. Leaves ×10.

708

43 Climaciaceae

brownish, auricles yellowish to brownish. Perichaetial leaves with rounded or truncate apices. Capsules slightly emergent; spores 20–28 μm. Capsules rare to occasional, spring. n = 11∗ . On rocks in fast-flowing acidic streams and rivers. 0– 880 m. Common in S. W. and N. W. England and Wales, occasional to frequent in Scotland, north to Caithness and Lewis, rare to occasional in Ireland, 60, H22. GB356 + 32∗ , IR48 + 4∗ . Suboceanic Temperate. Europe to c. 68◦ N, Algeria. Var. curnowii Cardot, Mém. Soc. Sci. Nat. Cherbourg, 1892 (Fig. 233) Similar to var. squamosa but perichaetial leaves with apiculate apices. Capsules immersed; spores 18–22 μm. n = 10∗ . On stones in acidic fast-flowing streams. Very rare, Cornwall, Devon. 4. Oceanic Temperate. Endemic. Var. dixonii (Cardot) A. J. E. Sm., J. Bryol., 1976 F. dixonii Cardot Straggling tufts with young shoots often with distinct reddish tint, older parts reddish brown or golden brown. Stem leaves longer than branch leaves, 3.5– 4.5 mm long, branch leaves 2.5–3.5 mm long; leaf base and auricles orange-brown. Sporophytes unknown. On rocks in fast-slowing acidic streams and rivers. Rare, Merioneth, Caernarfon, Cumberland, Fermanagh, old records from Derby, W. Inverness, Outer Hebrides. 6, H1. Oceanic Temperate. Portugal. Welch (1960) reduced F. dixonii to synonymy with F. squamosa but, whilst in Wales occasional intermediates are found, the plant is distinctive in appearance and is at least as good a taxon as the varieties of F. antipyretica. F. dalecarlica Bruch et al. (as F. seriata Lindb.) has been reported twice from the River Wye (see Dixon & Jameson, 1924) and Welch (1960) identified one of these as F. hypnoides Hartm. I have examined both specimens. They have the cell width, border cells, alar cells and perichaetial leaves of F. squamosa and they are clearly slender forms of that species (see A. J. E. Smith, J. Bryol. 9, 79–80, 1977).

43 Climaciaceae Dioicous. Primary stems rhizomatous with scale leaves, secondary stems erect, stout, with scale leaves and central strand, usually branched in dendroid fashion, Branches and upper parts of secondary stems with normal leaves. Paraphyllia abundant. Leaves ovate, acute or obtuse, plicate; margins toothed above; costa single, ending below apex; basal cells rhomboidal, porose, alar cells differentiated or not, cells above rhomboidal, smooth, linear. Perichaetial leaves appressed, elongate, lacking costa. Setae long, twisted; vaginula cylindrical, usually glabrous; capsules erect or inclined, cylindrical; stomata superficial; annulus not differentiated; peristome double, exostome teeth papillose or not, processes widely perforated; calyptrae cucullate. Two genera. Derivation: meaning staircase, referring to the appearance of the endostome processes.

135 Cryphaea

709

134 CLIMACIUM F. WEBER & D. MOHR, NATURH. REISE SCHWEDENS, 1804 Capsules erect, symmetrical; peristome teeth papillose, basal membrane very short, processes long, widely perforated; calyptrae large. Four species in Europe, N. E. and S. E. Asia, N. America and New Zealand. 1 C. dendroides (Hedw.) F. Weber & D. Mohr., Naturh. Reise Schwedens, 1804 (Fig. 234) Yellowish green or green, usually numerous dendroid shoots forming patches, 2–10 cm high. Primary stems rhizomatous, secondary stems erect, branching at top in dendroid fashion with crowded branches. Leaves of secondary stems appressed, scale-like, branch leaves imbricate, concave, plicate, scarcely altered when dry, lanceolate to lingulate, obtuse to acute, plicate, coarsely toothed above; costa strong below, faint above, extending almost to apex; cells incrassate, narrowly rhomboidal, 4–5 μm wide in mid-leaf, alar cells irregularly quadrate. Seta thin, flexuose, to 4 cm long; capsules erect, cylindrical, slightly curved; columella extending beyond mouth of capsule after dehiscence; spores very variable in size with many aborted, 16–24 μm. Capsules very rare but often abundant when present, autumn, winter. n = 11. In damp usually slightly basic habitats, particularly where there is a fluctuating water table, such as damp grassland, dune-slacks and marshy ground. 0–900 m. Occasional in S. W. and lowland England, frequent or common elsewhere in the British Isles. 110, H39. GB727 + 135∗ , IR140 + 9∗ . Circumpolar Wide-boreal. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N., C. and E. Asia, N. America, Greenland, Australia and New Zealand (probably introduced). C. dendroides shows considerable phenotypic variation; the drier the habitat the shorter the erect secondary stems and the more tightly crowded the branches.

44 Cryphaeaceae Autoicous. Primary stems creeping, stoloniform, secondary stems without central strand, ± elongate, erect or procumbent, occasionally pendulous, irregularly, pinnately or fastigiately branched. Paraphyllia lacking, pseudoparaphyllia present. Leaves imbricate when dry, spreading when moist, ovate or ovate-lanceolate, apex acute to longly acuminate, longitudinally plicate or not; costa single; cells mostly smooth with ovate or elliptical lumens, towards margins oblique, near costa elongate and porose. Setae usually very short; capsules immersed, symmetrical, with a few superficial stomata; annulus differentiated, peristome double, single or absent, basal membrane if present very short; calyptrae mitrate, smooth. Eleven genera. 135 CRYPHAEA D. MOHR IN F. WEBER, TAB. CALYPTR. OPERC., 1814 Secondary stems erect or ascending. Cells in upper part of leaves with rounded or oval lumens. Perichaetial leaves long. Sporophytes borne unilaterally on

710

44 Cryphaeaceae

Fig. 234 1–4, Climacium dendroides: 1, stem leaf (×25); 2, branch leaves (×25); 3, mid-leaf cells of branch leaf; 4, capsule (×10). 5–7, Cryphaea heteromalla: 5, shoot tip with sporophyte (×10); 6, stem leaves (×30); 7, mid-leaf cells. 8–9, Dendrocryphaea lamyana: 8, stem leaves (×30); 9, mid-leaf cells. Cells ×420.

136 Dendrocryphaea

711

secondary stems; capsules ellipsoid to cylindrical; stomata superficial; peristome double, exostome teeth finely papillose, basal membrane short, cilia rudimentary or absent. About 70 species, Europe, C. and E. Asia, Africa, Madagascar, N. and S. America, Australia, New Zealand, Oceania. Derivation: meaning hidden, alluding to the immersed capsules. For a monograph of the genus see P. Rao, Bryobrothera 7, 1–112, 2001.

1 C. heteromalla (Hedw.) D. Mohr in F. Weber, Tab. Calyptr. Operc., 1814 (Fig. 234) Lax dull or dark green patches. Primary stems ± procumbent with numerous ± erect branches. Branch leaves imbricate when dry, erect-patent when moist, concave below, ovate, tapering to acute to acuminate apex; margins narrowly recurved below, entire; costa stout, extending c. 3/4 way up leaf; cells smooth, incrassate, basal elliptical, cells above rounded to oval, 8–12 μm wide in mid-leaf, 1.0–1.25 times as long as wide. Dwarf female branches borne on one side of secondary stems and not on branches. Perichaetial leaves larger, tapering gradually or abruptly into longly excurrent costa; margins scarious; cells longer and narrower than in stem leaves. Capsules immersed, ellipsoid; lid with straight beak; exothecial cells thin-walled; peristome teeth long, lanceolate; spores c. 18 μm. Capsules common, late summer to winter. n = 10 + m∗ , 10 + 2m. On trunks and branches of trees and shrubs, particularly Sambucus nigra, in sheltered situations especially near water, by streams, in carr, never saxicolous. Lowland. Frequent or common in S. W. and southern England and Wales. Rare or very rare elsewhere, extending north to E. Ross and Harris, occasional to frequent in Ireland. 95, H36, C. GB617 + 128∗ , IR139 + 21∗ , C2 + 2∗ . Submediterranean-Subatlantic. Europe north to southern Sweden, Caucasus, Turkey, Israel, Macaronesia, N. Africa, N. America. The immersed capsules borne unilaterally on the secondary stems give this plant a characteristic appearance.

136 DENDROCRYPHAEA PARIS & SCHIMP. EX BROTH, NAT. PFLANZENFAM., 1905 Except for D. lamyana a Neotropical and Australasian genus. Derivation: meaning tree-like Cryphaea.

1 D. lamyana (Mont.) P. Rao, Bryobrothera, 2001 (Fig. 234) ¨ Hal.) Wilson, C. lamyana (Mont.), Cryphaea heteromalla var. aquatilis (Mull. ¨ Hal. Mull. Lax dull green silt-encrusted patches. Primary stems creeping, 5–10 cm long, simple or sparsely branched, branches erect, curved when dry. Pseudoparaphyllia

712

45 Leucodontaceae

filamentous. Leaves imbricate when dry, erect-patent when moist, concave, broadly ovate, obtuse; margins plane, entire; costa stout, extending c. 3/4 way up leaf; cells incrassate, smooth, basal elliptical, alar cells slightly enlarged, cells above rounded to oval, 1.0–1.5 times as long as wide, 8–12 μm wide, 1.0–1.5 times as long as wide in mid-leaf. Dwarf female branches borne on one side of secondary stems and not on branches. Outer perichaetial leaves similar to stem leaves, inner yellowish with excurrent costa, margins not scarious. Capsules immersed, shortly ellipsoid; exothecial cells incrassate, brown; lid with curved beak; peristome teeth short; spores c. 18 μm. Capsules common, autumn, spring. n = 10 + m∗ . On tree trunks and rocks in the flood-zone of rivers, Lowland. Rare, E. Cornwall, Devon, Carmarthen, Pembroke, Cardigan. 6. GB10. Oceanic Southern-temperate. France, Italy, Portugal, Spain, Switzerland. A coarser plant than Cryphaea heteromalla, differing in habit, stem leaf shape, perichaetial leaf and capsule characters, mentioned by older authorities but not recently (Dr D. T. Holyoak, in litt.). This species is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside act.

45 Leucodontaceae Dioicous. Stems nearly circular in section, with or without central strand. Paraphyllia and/or pseudoparaphyllia present or not. Primary stems stoloniform, rarely rhizomatous; secondary stems numerous, without rhizoids, erect or ascending, rarely pendulous, branched or not. Leaves ovate or lanceolate, with long or short acumen, often longitudinally plicate; costa single, double or absent; cells incrassate, usually smooth, rhomboidal above, at base and towards middle of leaf longer, narrower. Perichaetial leaves longer than stem leaves. Setae usually long; capsules usually erect, symmetrical, ovoid to cylindrical, stomata when present superficial; annulus usually undifferentiated; peristome double, exostome teeth smooth, papillose or striate or both, basal membrane very short; calyptrae cucullate, glabrous or hairy. Eleven genera. The three British genera belong within the subfamily Leucodontoideae. For an account of the family see M. G. Manuel, Bryologist 77, 531–50, 1975.

¨ 137 LEUCODON SCHWAGR, SP. MUSC. FROND. SUPPL. 1., 1816 Dioicous. Plants medium-sized to robust. Pseudoparaphyllia foliose. Leaves imbricate when dry, longitudinally plicate; costa absent; alar cells narrow, extending up margins, cells above smooth, upper elliptical. Capsules usually erect; exostome teeth perforated or cleft, endostome rudimentary; calyptrae large. Thirtyfive species in Eurasia, Africa, the Americas, Oceania. Derivation: meaning white tooth, referring to the pale peristome.

137 Leucodon

713

¨ 1 L. sciuroides (Hedw.) Schwagr. Sp. Musc. Frond. Suppl. 1, 1816 Plants medium-sized, yellowish green patches. Primary stems creeping, secondary stems decumbent to erect, straight or curved when dry, simple or sparsely branched. Leaves appressed when dry, erect when moist, longitudinally plicate, lanceolate to broadly ovate, acute to acuminate; margins plane, entire or denticulate above; costa lacking; cells incrassate, smooth, alar cells longer than wide to wider than long, extending some distance up margins, other basal cells linear, cells above shorter and wider, in middle of leaf linear to narrowly hexagonal, shorter above, 6–10 × 24–56 μm in mid-leaf, towards margins rounded. Deciduous axillary branchlets sometimes produced abundantly at ends of branches. Setae long, reddish brown; capsules ovoid and curved to ellipsoid or cylindrical and straight or curved; lid rostrate; spores 20–26 μm. Shoots 0.5–2.0(−2.5) cm long, 0.4–1.0 mm diameter when dry var. sciuroides Shoots (1.5−)2.0–5.0(−7.0) cm long, 1.2–1.8 mm diameter when dry var. morensis Var. sciuroides (Fig. 235) Secondary stems 0.5–2.0(−2.5) cm long, 0.4–1.0 mm diameter when dry. Capsules ovoid to cylindrical, straight or curved. Capsules very rare. n = 9, 10, 11. On trunks

Fig. 235 1–5, Leucodon sciuroides var. sciuroides: 1, leaf; 2, 3, mid-leaf and marginal cells; 4, capsules; 5, caducous shoot (×40). 6–8, Antitrichia curtipendula: 6, leaf; 7, mid-leaf cells; 8, capsule. Leaves ×25, cells ×420, capsules ×10.

714

45 Leucodontaceae

of trees, especially Fraxinus excelsior, in open habitats and on base-rich rocks, walls and tombstones. 0–730 m. Frequent in southern and S. W. England and E. Wales, largely extinct elsewhere in lowland England, occasional to frequent in N. W. England and E. Scotland, extending north to Sutherland, rare in Ireland. 96. H15, C. GB364 + 223∗ , IR13 + 4∗ , C1 + 1∗ . Eurosiberian Wide-temperate. Europe north to northern Fennoscandia, Iceland, Caucasus, Turkey, Cyprus, Asia, Macaronesia, Algeria. ¨ Var. morensis (Schwagr.) De Not., Syllab. Musc., 1838 Secondary stems (1.5−)2.0–5.0(−7.0) cm long, 1.2–1.8 mm diameter when dry. Capsules ellipsoid to cylindrical, straight or slightly curved; occasional. n = 10–11. On basic rocks and walls. Lowland. Rare, Cornwall, Dorset, Pembroke, E. Inverness, old records from Surrey and Kirkcudbright. 9. S. and W. Europe, extending north to Scandinavia, Iceland, Turkey, Cyprus, Macaronesia, N. Africa. Var. morensis is said to have relatively longer and narrower capsules than var. sciuroides, but in the British Isles there is considerable variation in capsule shape in var. sciuroides.

138 ANTITRICHIA BRID., MUSCOL. RECENT. SUPPL., 1819 Dioicous. Secondary stems elongate, irregularly and sparsely branched, Stem leaves imbricate when dry, ovate or broadly ovate, plicate; margins toothed above; costa present, single; cells smooth, alar cells irregularly rounded, extending up margins, cells above narrow, becoming rounded or wider than long towards margins. Perichaetial leaves without costa. Endostome well developed but lacking basal membrane. Four species: Europe, parts of Asia, Africa, the Americas. Derivation: meaning opposite filaments, from the incorrect assumption that the processes are opposite the exostome teeth.

1 A. curtipendula (Timm ex Hedw.) Brid., Muscol. Recent. Suppl., 1819 (Fig. 235) Plants robust, forming dull or yellowish green coarse wefts. Primary stems short, stoloniform, secondary stems to 20 cm long, irregularly pinnately branched, branches erect or spreading, Leaves subsecund when dry, patent when moist, concave, plicate, ovate with longly acuminate apex with spinose, often recurved teeth; margins narrowly recurved ± from base to apex; costa broad, branching below, weak above, extending to 3 /4 way up leaf; cells incrassate, ± rounded at base, basal angles and lower part of margins, elsewhere elliptical, smooth, in mid-leaf 6–10 μm wide, 2–3 times as long as wide, rounded towards margins. Perichaetial leaves longer than stem leaves, sheathing; costa lacking. Setae flexuose or arcuate; capsules inclined, ellipsoid; spores 34–36 μm. Capsules rare, spring. On bark, rocks, walls and cliffs, in open habitats, rarely in grassland, on sanddunes and shingle. 0–715 m. Formerly widely but sparsely distributed in England

139 Pterogonium

715

and S. Scotland but now extinct in most localities except in the south-west and north-west of England where it is occasional, occasional in N. W. Wales, occasional to frequent in the Scottish Highlands, rare in Ireland. 73, H12. GB212 + 128∗ , IR9 + 10∗ . European Boreo-temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Macaronesia, Morocco, Ethiopia, C. and southern Africa, N. America, Greenland, Patagonia. Possibly to be confused with Rhytidiadelphus loreus, which differs in the more distant, more longly pointed and less imbricate leaves. A. curtipendula has decreased markedly and vanished from sites where it was once abundant as a consequence of atmospheric pollution. A. californica Sull. was mentioned as occurring in Sussex by Wilson (1855) but this has been shown to have been based upon a misidentification of a slightly abnormal form of A. curtipendula (see A. C. Crundwell, Trans. Br. Bryol. Soc. 3, 174–9, 1957).

139 PTEROGONIUM SW., MONTHL. REV., 1801 Dioicous. Leaves imbricate when moist, not plicate, ovate, acute to acuminate; costa short, double or forked; cells papillose, elongate by costa, becoming oval towards margins and above. Capsules ovoid to cylindrical, straight or curved; peristome double. Five species: Europe, Middle East, Africa, N. America. Derivation: meaning wing shoot, possibly alluding to the axillary female branches.

1 P. gracile (Hedw.) Sm., Engl. Bot., 1803 (Fig. 236) Plants medium-sized, in dense dark green or brownish green parches. Primary stems stoloniform, secondary stems erect, to 4 cm long, with branches curved to one side; flagelliform branches often present. Branch leaves imbricate when dry, spreading when moist, concave, not plicate, broadly ovate, acute to obtuse; margins plane, dentate above; costa single or double, extending to c. 1/4 way up leaf; cells at extreme base transversely rectangular, at basal angles and extending up margins rounded, cells beyond end of costa elliptical, becoming oval above and towards margins, papillose on abaxial side, mid-leaf cells c. 10 μm wide, c. 1.5 times as long as wide. Perichaetial leaves longer than stem leaves, sheathing, with single costa. Capsules slightly inclined, narrowly ellipsoid; spores c. 30 μm. Capsules very rare, autumn. n = 11. On sloping or vertical, usually hard basic rocks and on tree boles, in sheltered or open sites. 0–500 m. Occasional to frequent from Cornwall east to W. Sussex and formerly Kent and W. Suffolk, Wales, N. W. England, W. Scotland, rare to occasional in E. Scotland and Ireland. 71, H18, C. GB274 + 47∗ , IR28 + 9∗ , C5 + 1∗ . Submediterranean-Subatlantic. S., W. and ´ C. Europe, Madeira, Canary Islands, Africa, Madagascar, Reunion, N. America. Readily recognised by the curved branches of the secondary stems pointing in the same direction and with leaves imbricate when dry. May be confused with Pterigynandrum filiforme var. minus, but that plant has linear-rhomboidal cells.

716

45 Leucodontaceae

Fig. 236 1–3, Pterogonium gracile: 1, leaves (×40); 2, mid-leaf cells; 3, capsule (×10). 4–7, Neckera pumila: 4, sporophyte (×10); 5, leaves (×25); 6, mid-leaf cells; 7, marginal cells near leaf apex. 8–11, N. pennata: 8, sporophyte (×10); 9. leaf (×25); 10, mid-leaf cells; 11, marginal cells near leaf apex. Cells ×420.

141 Leptodon

717

46 Myuriaceae Dioicous. Stems circular in section, without central strand. Primary stems stoloniform, with scale leaves, secondary stems stout, usually erect or ascending, simple or branched. Paraphyllia lacking. Leaves ovate to lanceolate, ± longly acuminate; costa absent; cells smooth, alar cells differentiated. Perichaetial leaves small. Setae long; capsules symmetrical, ellipsoid, smooth; stomata superficial; annulus not differentiated; peristome double; calyptrae cucullate. Two genera. For a monograph of the family see J. Maschke, Bryophyt. Biblth. 6, 1–218, 1976.

140 MYURIUM SCHIMP., SYN. MUSC. EUR., 1860 Leaves very concave, not plicate. Setae long, smooth; capsules ellipsoid; peristome teeth not papillose, basal membrane short, processes lacking. Fifteen species distributed through Europe, Asia, Macaronesia, Australia, Oceania. Derivation: meaning mouse-tailed, from the appearance of the branches.

1 M. hochstetteri (Schimp.) Kindb., Ottawa Nat., 1900 M. hebridarum Schimp.

(Fig. 238)

Dense golden yellow or yellowish green tufts or patches. Primary stems prostrate with numerous crowded erect branches, branches julaceous when moist, to 6 cm long. Leaves glossy, ± imbricate when moist, hardly altered when dry, strongly concave, ovate-oblong, abruptly narrowed into long apiculus; margins plane below, inflexed above, denticulate; costa absent or almost so; cells incrassate, porose, narrow, c. 6 μm wide, c. 6 times as long as wide in mid-leaf, alar cells shorter. Occasional vegetative propagation by caducous leaves, leaving c. 1 cm of the stem tip bare. Capsules ± horizontal, narrowly ellipsoid, curved; unknown in the British Isles. Rock crevices at base of sea cliffs and rocks, on humus on steep coastal slopes. 0–110 m. Frequent in the Outer Hebrides, occasional in the Inner Hebrides, very rare elsewhere, W. Inverness, W. Sutherland, W. Galway. 5, H1. GB37 + 14∗ , IR1. Hyperoceanic Southern-temperate. Azores, Madeira, Tenerife.

47 Leptodontaceae Secondary stems irregularly to bipinnately branched, stems and branches curled when dry. Costa single; alar cells numerous, other cells isodiametric or short, smooth or papillose. Capsules immersed or shortly exserted; exostome teeth pale, smooth or papillose, endostome rudimentary; calyptrae hairy. Four genera of mainly epiphytic species. 141 LEPTODON D. MOHR, OBSERV. BOT., 1803 Primary stems rhizomatous, secondary stems decumbent to erect, pinnately or bipinnately branched, stems and branches strongly inrolled when dry;

718

47 Leptodontaceae

Fig. 237 1–3, Leptodon smithii: 1, sporophyte; 2, leaves (×40); 3, marginal cells at middle of leaf. 4–7, Neckera crispa: 4, sporophyte; 5, leaves (×15); 6, mid-leaf cells; 7, marginal cells near leaf apex. 8–11, N. complanata: 8, sporophyte; 9, leaves (×25); 10, mid-leaf cells; 11, marginal cells near leaf apex. Sporophytes ×10, cells ×420.

142 Neckera

719

small-leaved innovations often present. Leaves oval or shortly lingulate, obtuse; costa single, slender; cells oval. Setae short; capsules exserted; exostome teeth papillose, endostome rudimentary; calyptrae hairy. A small genus of 5 species distributed through Europe, W. Asia, Africa, N. America, Chile, Australia. Derivation: meaning thin tooth, referring to the peristome.

1 L. smithii F. Weber & D. Mohr, Index Mus. Pl. Crypt., 1803 (Fig. 237) Dioicous. Bright green patches. Secondary stems decumbent to ascending, to c. 2.5 cm long, complanately 1–2-pinnately branched, stems and branches strongly inrolled when dry, curved when moist, sometimes bearing flagelliform branchlets. Linear paraphyllia present. Leaves appressed when dry, spreading when moist, ovate and often asymmetrical, apex rounded; margins recurved on one side, entire or subcrenulate; costa single, faint, extending 1/4 –1/2 way up leaf; basal cells near costa elongate-hexagonal, alar cells not differentiated, cells elsewhere ± hexagonal, smooth, 10–14 μm wide, about as long as wide in mid-leaf, basal cells longer, Perichaetial leaves longer than stem leaves, outer squarrose, inner erect. Setae straight or curved, 1.5–2.0 mm long; capsules ellipsoid; spores c. 16 μm. Capsules occasional. n = 11. On trees, especially Fraxinus excelsior, Acer pseudoplatanus and formerly Ulmus, in woods and open situations, rarely on basic walls and rocks. Lowland. Occasional to frequent in the extreme south of England, from Cornwall to Kent, very rare elsewhere, Glamorgan (extinct), Pembroke, Merioneth, Caernarfon, Anglesey, Cumberland, W. Cork, Waterford. 25, H2, C. GB100 + 53∗ , IR1 + 1∗ , C3∗ . Mediterranean-Atlantic. S. and W. Europe north to the British Isles, Caucasus, Turkey, Cyprus, S. W. Asia, Canary Islands, Madeira, N. Africa, Uganda, Tanzania, southern Africa, Chile, Australia, New Zealand.

48 Neckeraceae Dioicous, autoicous or synoicous. Primary stems stoloniform or rhizome-like; secondary stems decumbent or erect, 1–2-pinnately branched, branches complanate; central strand absent. Paraphyllia often present. Leaves complanate, usually asymmetrical, ovate-oblong to lingulate; costa absent or short and faint, single or double; cells linear-vermicular to rhomboidal, smooth. Capsules immersed, emergent or exerted, erect, symmetrical, with or without superficial stomata; annulus usually lacking; peristome double or endostome rudimentary; calyptrae cucullate, with or without hairs. Fifteen genera.

142 NECKERA HEDW., SP. MUSC. FROND., 1801 Dioicous or autoicous. Secondary stems pinnately or bipinnately branched, branches complanate. Paraphyllia usually absent. Leaves complanate, often subfalcate, ± lingulate; margins plane or recurved on one side, denticulate above;

720

48 Neckeraceae

costa faint, single, double or absent. Flagelliform caducous branches often present. Capsules immersed or exserted, erect, ovoid to ellipsoid, symmetrical; annulus usually undifferentiated; exostome teeth papillose or nearly smooth, endostome with 16 short processes and no cilia; calyptrae cucullate or mitriform. A ± worldwide genus of about 120 mainly tropical or subtropical species. Derivation: named after a German bryologist, Noel M. J. de Necker (1730–1793).

1 Leaves not undulate 4. N. complanata Leaves transversely undulate 2 2 Autoicous, capsules common, immersed, leaves gradually tapering to apex, seen only once in Britain 1. N. pennata Dioicous, capsules rare, exserted, leaves ± abruptly narrowed to apex, frequent or common plants 3 3 Secondary stems 4–20 cm long, mid-leaf cells 8–10 μm wide 2. N. crispa Secondary stems 1–4 cm long, mid-leaf cells 5–6(−8) μm wide 3. N. pumila 1 N. pennata Hedw., Sp. Musc. Frond., 1801 (Fig. 236) Autoicous. Glossy yellowish green patches. Secondary stems decumbent, 5–10 cm long, irregularly pinnately branched, branches complanate. Leaves complanate, undulate when moist and when dry, subfalcate, ovate to lanceolate, gradually tapering to acute apex; margins recurved, faintly denticulate towards apex; costa very short, single or bifid, faint or absent; cells incrassate, linear-vermicular, smooth, wider at base and basal angles, in mid-leaf c. 8 μm wide, 4–8 times as long as wide at extreme apex. Flagelliform branchlets sometimes present. Capsules immersed; spores c. 22 μm. Capsules common, autumn, winter. Found once in 1823 in Angus on the trunk of a Fagus sylvatica tree, not seen since. Lowland. 1. GB1∗ . Circumpolar Boreal-montane. Europe north to Fennoscandia, Caucasus, Siberia, C. Asia, Himalayas, China, Hong Kong, Japan, Bioko (Fernando Po), southern Africa, N. America, Tasmania, New Zealand. In Scotland known from only a single gathering, possibly the result of chance long-distance spore dispersal. This species has very greatly decreased in continental Europe as a consequence of atmospheric pollution and is considered an endangered species (Duell, 1992).

2 N. crispa Hedw., Sp. Musc. Frond., 1801 (Fig. 237) Dioicous. Robust lax glossy green, yellowish green to golden patches, sometimes extensive. Secondary stems procumbent to erect, often standing out ± horizontally from sloping or vertical substrates, 4–20 cm long, pinnately branched, branches complanate. Leaves complanate, transversely undulate when moist and when dry, often subfalcate, ovate-oblong, abruptly tapered to rounded, obtuse or obtuse and apiculate apex; margins recurved, obscurely denticulate towards apex; costa absent or very short, single or bifid, very faint; cells incrassate, linear-vermicular, smooth, 8–10 μm wide in mid-leaf, shorter and wider at base, alar cells irregularly

142 Neckera

721

rounded, very incrassate, cells towards apex 2–4 times as long as wide. Caducous flagelliform branchlets sometimes present. Setae slightly flexuose, 8–12 mm long; capsules exserted, erect, ellipsoid; spores 24–30 μm. Capsules very rare in lowland England, occasional elsewhere, spring. n = 10 + m. Sheltered dry or periodically moist calcareous rock faces, walls, in limestone pavement, stony calcareous turf and on tree trunks, 0–700 m. Frequent or common in chalk and limestone areas of England, frequent or common in Wales and parts of the Scottish Highlands, rare elsewhere, occasional to frequent in western Ireland. 88, H31. GB503 + 62∗ , IR80 + 11∗ . European Temperate. Europe north to Fennoscandia, Iceland, Turkey, S. W. Asia, Macaronesia, N. America. A large handsome moss readily recognised by the glossy yellowish green to golden green complanately pinnately branched shoots, which often grow out ± horizontally from the substrate, and the undulate leaves.

3 N. pumila Hedw., Sp. Musc, Frond., 1801 (Fig. 236) Dioicous, Glossy pale green to dark green patches. Secondary stems decumbent, 1–4 cm long, 1–2-pinnately branched, branches complanate. Leaves complanate, transversely undulate when moist and when dry, ovate, tapering to acute to acuminate apex or obtuse with long apiculus; one margin incurved below, the other narrowly reflexed, finely denticulate towards apex; costa faint, double, extending to c. 1/4 way up leaf; cells incrassate, linear-vermicular, smooth, 5–6(−8) μm wide in mid-leaf, basal cells shorter and wider, alar cells not differentiated, cells near apex 2–6 times as long as wide. Caducous short flagelliform branchlets with minute leaves often present. Setae 2–4 mm long; capsules exserted, erect, ellipsoid; spores 15–20 μm. Capsules very rare in lowland England, occasional elsewhere, winter. On bark, especially where smooth, in woods and sheltered situations, very rarely on rocks or walls. Lowland. Frequent or common in southern and south-west England, extinct in most other parts of England, frequent or common in W. Wales and S. W. Scotland, rare elsewhere, extending north to W. Ross, occasional in Ireland. 72, H37, C. GB396 + 78∗ , IR87 + 9∗ , C1. Suboceanic Temperate. Europe, extending north to Scandinavia, rare in the south, Caucasus, Turkey, Macaronesia. 4 N. complanata (Hedw.) Huebener, Musc. Germ., 1833 (Fig. 237) Dioicous. Glossy pale or yellowish green patches. Secondary stems decumbent, to 5 cm long, pinnately branched, branches complanate. Leaves complanate, not undulate when moist or dry, subfalcate, lanceolate-oblong to ovate-oblong, acute to obtuse and apiculate; margins finely denticulate above, one slightly incurved below; costa short, double, faint; cells incrassate, linear-vermicular, smooth, 6–8 μm wide in mid-leaf, basal cells shorter, alar cells ± quadrate, cells near apex 1–3 times as long as wide. Caducous flagelliform branchlets sometimes present and abundant. Setae flexuose, 8–10 mm long; capsules exserted, ovate-ellipsoid; spores very variable in size, 14–26 μm. Capsules occasional, spring. On shaded vertical

722

48 Neckeraceae

rocks and walls, on chalk banks and bark in calcareous areas. 0–600 m. Frequent or common in southern England and Wales but ± extinct in the rest of lowland England, common in parts of Scotland, extending north to Shetland, frequent or common in Ireland, 112, H38, C. GB1210 + 118∗ , IR284 + 5∗ , C3 + 2∗ . European Boreo-temperate. Europe north to northern Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Iran, Kashmir, Madeira, Canary Islands, Algeria, C. Africa, N. America. Flagelliform branchlets may sometimes be so abundant as to give the plants a wispy appearance and occasionally constitute the whole plant (as in the var. tenella Schimp. of Dixon & Jameson, 1924). It differs from N. pumila in the non-undulate more shortly pointed leaves and is more likely to be confused with Homalia trichomanoides, which has a stronger costa extending beyond the middle of the leaf and shorter cells and which may be recognised in the field by the stems with fewer less-regular branches and the leaves more strongly curved down on either side of the stems and branches.

143 HOMALIA (BRID.) SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1850 Autoicous. Gametophyte similar to that of Neckera but secondary stems irregularly branched. Paraphyllia and flagelliform branchlets lacking. Leaves not undulate; costa single, extending ± half way up leaf. Setae long; capsules erect or inclined; annulus of 2 rows of large cells; peristome well developed, exostome teeth densely papillose above, striate below; endostome with basal membrane c. 1/3 length of processes, rudimentary cilia sometimes present. About 25 mainly tropical or subtropical species. Derivation: meaning flattened, from the complanate leaves.

1 H. trichomanoides (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1850 (Fig. 238) Omalia trichomanoides auct. Plants medium-sized, in lax depressed glossy yellowish green or green patches. Secondary stems to c. 6 cm long, sparsely and irregularly branched, branches complanate. Leaves complanate, not undulate, curved down on either side of stems and branches, asymmetrical, ovate-oblong, apex rounded or rounded and apiculate; margins denticulate towards apex, incurved on one side; costa single, extending 1/2 –3/4 way up leaf; cells near costa narrowly rhomboidal, smooth, becoming rhomboidal towards margins, 6–10 μm wide near margins, cells in upper part of leaf narrowly hexagonal. Setae 1.0–1.5 cm long; capsules erect, shortly cylindrical; spores 14–16 μm. Capsules occasional to frequent, winter. n = 11∗ , 11 + m. On bark, especially in the flood zone of streams and rivers, on sheltered damp rocks and walls, soil banks. Lowland. Frequent in the southern half of England, Wales, N. W. England and the southern half of Scotland, rare to occasional elsewhere, extending north to Shetland, occasional in Ireland.

143 Homalia

723

Fig. 238 1–4, Homalia trichomanoides: 1, sporophyte (×7); 2, leaf (×40); 3, mid-leaf cells; 4, marginal cells near leaf apex. 5–6, Myurium hochstetteri: 5, leaf (×25); 6, mid-leaf cells. 7–10, Thamnobryum alopecurum: 7, 8, stem and branch leaves (×25); 9, marginal cells near apex of branch leaf; 10, capsule (×10). Cells ×420.

724

49 Thamnobryaceae

107, H39, C. GB820 + 115∗ , IR56 + 13∗ , C1. Circumpolar Boreo-temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Siberia, China, Japan, Madeira, N. America.

49 Thamnobryaceae Primary stems stoloniform, secondary stems ± erect, often dendroid; central strand present. Stem and branch leaves differing in shape; stem leaves triangular, branch leaves ovate or lingulate, acute to obtuse; margins entire to strongly toothed; costa single, ending below apex; cells mostly short, smooth or papillose, marginal elongate, forming border or not. Setae long or short; capsules inclined to horizontal, cylindrical, symmetrical or not; lid rostrate; peristome double, well developed; calyptrae cucullate, smooth or hairy.

144 THAMNOBRYUM NIEUWL., AM. MIDL. NAT., 1917 Dioicous. Usually robust dendroid plants; secondary stems often with numerous curved, homomallous branches. Stem leaves broadly triangular, branch leaves ovate; margins toothed; cells short, papillose. Capsules inclined, cylindrical, curved; exostome teeth papillose throughout or horizontally striate below. A ± world-wide genus of c. 40 species. Derivation: meaning shrubby moss, from the habit of the plants.

1 Branch leaves ovate to lanceolate, costa stout, well defined and occupying less 1. T. alopecurum than 1/4 width of leaf base, common plant Branch leaves lanceolate or ligulate to triangular-ligulate, costa poorly defined below, occupying more than 1/3 width of leaf base or indistinguishable below, very rare plants 2 2 Branch leaves widest 1/5 –2/5 from base, margins coarsely toothed, costa wide and thin below, cell lumens angular 2. T. angustifolium Branch leaves mostly widest at base, margins entire or denticulate, costa not or poorly defined below, cell lumens rounded 3. T. cataractarum 1 T. alopecurum (Hedw.) Gangulee, Mosses E. India, 1976 (Fig. 238) Porotrichum alopecurum (Hedw.) Dixon, Thamnium alopecurum (Hedw.) Schimp. Plants medium-sized to very robust, forming lax green to dark green or brownish green tufts or patches, sometimes extensive, to 8(−20) cm high. In wet or humid situations secondary stems stout, stiff and wiry, erect, dendroid and densely branched near apex, branches irregularly pinnately or bipinnately branched, spreading, secund or curved, short to flagelliform. Plants in drier habitats smaller, secondary stems poorly developed and less branched. Stem leaves distant, appressed, scale-like, broadly triangular, acute, about twice as long as wide or

144 Thamnobryum

725

more, lower scarious, upper chlorophyllous; margins coarsely dentate; costa well defined, occupying less than 1/4 total width of leaf base; cells elongate except near basal angles, unistratose. Uppermost stem leaves and branch leaves imbricate when dry, patent when moist, concave or not, ovate, widest c. 1/3 from base, tapering to acute apex; margins plane, subentire to coarsely toothed; costa single, strong, occupying less than 1/4 width of leaf base, narrower above, ending shortly below apex; cells thin-walled to incrassate, papillose, elliptical or roundedquadrate, 8–12 μm wide in mid-leaf. Leaves of ultimate branches smaller, narrower, lanceolate. Setae short, 1.0–1.5 cm long; capsules inclined, ovoid to ellipsoid, curved, asymmetrical; spores 10–12 μm. Capsules rare to occasional, autumn to spring. n = 11∗ . On humid shaded rock faces, spray zone of waterfalls, in scree, quarries, on soil and tree boles in woods, in humid mildly acidic to basic and especially calcareous sites. 0–500 m. Common in most parts of the British Isles. 112, H39, C. GB1366 + 100∗ , IR242 + 6∗ , C4. European Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Asia, Macaronesia, N. Africa. When growing in very humid situations T. alopecurum is dendroid in habit, forming miniature forests. However, it is markedly affected by the humidity of the habitat and plants growing in drier or more exposed places are very stunted and not dendroid in appearance.

2 T. angustifolium (Holt) Nieuwl., Am. Midl. Nat., 1917 (Fig. 239) Porotrichum angustifolium Holt, Thamnium angustifolium (Holt) Dixon Plants medium-sized, forming greenish patches, coated with calcareous matter below, c. 4 cm high. Secondary stems erect, stiff and wiry, branches slender, not crowded. Stem leaves scale-like, triangular, twice as long as wide or more, widest at base, acute, lower scarious, upper chlorophyllous; margins coarsely dentate; costa distinct, occupying c. 1/4 –1/3 width of leaf base; cells elongate, unistratose. Branch leaves loosely imbricate when dry, patent when moist, ligulate to lanceolate, widest 2 /5 –3 /5 from base, acute; margins very coarsely dentate above, teeth 20–40 μm long; costa wide but thin, occupying c. 1/3 –2 /5 width of leaf at base, c. 1/5 –1/4 width of leaf 1/3 from apex, ending below apex; mid-leaf cells ± isodiametric, pappilose, lumens angular, 6–12 μm wide in mid-leaf. Only male plants known. On sheltered periodically wet vertical limestone. Lowland. Very rare, Derby. 1. GB1. Endemic (Oceanic Temperate). Apart from an unsubstantiated record of T. angustifolium from Antrim this plant is known only from the type locality where it is present in only small quantity. Collections of T. angustifolium from the time of its discovery in 1883 show a gradual decrease in size of the plants. Whether this is due to changes in the habitat or to the activities of collectors is not clear. This species is regarded as critically endangered in the Red List of British Mosses and is a protected species under the Wildlife and Countryside Act. It is also on the European and World Red Lists.

726

49 Thamnobryaceae

Fig. 239 1–3, Thamnobryum angustifolium: 1, stem leaf; 2, branch leaves; 3, margin at middle of leaf. 4–6, T. cataractarum: 4, stem leaf; 5, branch leaves; 6, margin at middle of leaf. Leaves ×50, cells ×420. Doubts have been expressed as to its specific status, it being suggested that it is merely a habitat form of T. alopecurum. Cultivation studies have shown, however, that it is morphologically distinct (see S. B. Furness & O. L. Gilbert, J. Bryol. 11, 139–44, 1980).

3 T. cataractarum N. G. Hodgetts & Blockeel, J. Bryol., 1992 (Fig. 239) Plants medium-sized, forming dark green to blackish patches, 1.5–5.0 cm high, or with other aquatic bryophytes. Secondary stems stiff and wiry, dendroid or less frequently irregularly branched. Lower leaves on secondary stems appressed, scalelike, becoming narrowly triangular to elongate-triangular above, 1.5–3.0(−4.0) times as long as wide, obtusely pointed or sometimes ± subulate; margins entire

144 Thamnobryum

727

or obscurely toothed near apex; costa not differentiated or very obscure; cells linear, 2–several-stratose throughout or with marginal band of unistratose elongate to rectangular or rhomboidal cells. Leaves from upper part of secondary stems and from branches loosely imbricate when dry, erect to erect-patent when moist, narrowly lingulate or triangular-ligulate, widest at base, apex rounded or bluntly pointed; margins plane, sparsely denticulate, sometimes obscurely so, longest teeth to 9–18(−23) μm long; costa not differentiated or only obscurely so below, clearly differentiated above, sometimes with radiating streaks, c. 1/5 –1/4 leaf width 1/ from apex, weakly to strongly toothed on abaxial side towards apex; lower cells 3 elongate, cells above incrassate, 1(−2)-stratose, irregularly oblong to rhomboidal, sometimes isodiametric in patches, lumens rounded to elliptical, 6–12 μm wide, 1–4 times as long as wide in mid-leaf, papillose. Gametangia and sporophytes unknown. On vertical or steeply sloping acidic rocks in a ravine submersed to just above water level and in waterfalls in calcareous water. Lowland. Very rare, N. W. Yorkshire. 1. GB1. Endemic (Oceanic Temperate) This species, known only from the type locality, is closely related to T. angustifolium and the ´ Madeiran T. fernandesii C. Serg. It differs from the former in the cells of the lower leaves of the secondary stems being multistratose, the costae not or hardly discernible below, the margins entire or only obscurely toothed, the branch leaves mostly widest at the base, sparsely denticulate with teeth rarely more than 20 μm long and the mid-leaf cells with rounded lumens. For a detailed account of this plant and for differences from T. fernandesii see N. G. Hodgetts & T. L. Blockeel, J. Bryol. 17, 251–62, 1992. This species is treated as vulnerable in the Red List of British Mosses and is listed as vulnerable in the Red Data Book of European Bryophytes.

50 Pterigynandraceae Slender, patch-forming plants. Primary stems creeping or decumbent, irregularly, regularly or pinnately branched. Stem and branch leaves similar, broadly ovate to lanceolate, obtuse to acute or acuminate; margins plane, entire or denticulate; costa weak, single or double or absent; cells elliptical to rhomboidal, smooth or papillose. Setae short or long, smooth; capsules erect to horizontal, ± symmetrical; stomata superficial; annulus of small persistent cells; peristome single or double, exostome teeth often united at apex, smooth or papillose; calyptrae cucullate. Five genera. The constitution of this and the next two families appears to be very much a matter of opinion, depending upon which characters are selected and the method of analysis used. The problem is unlikely to be solved until DNA studies are carried out. In the meantime I have followed W. R. Buck & H. Crum (Contr. Univ. Mich. Herb. 17, 55–60, 1990) and J. R. Spence (J. Hattori Bot. Lab. 70, 261–71, 1997) in placing Habrodon, Heterocladium and Pterigynandrum in the Pterigynandraceae, next to the Leskeaceae, but have excluded Myurella for reasons given under that genus.

728

50 Pterigynandraceae

145 PTERIGYNANDRUM HEDW., SP. MUSC. FROND., 1801 Dioicous. Usually slender plants, stems creeping or ascending, branches crowded, often secund or flagelliform. Leaves imbricate to erect-patent, ovate, acute, obtuse or obtuse and apiculate; margins plane or recurved below, entire or denticulate above; costa slender, single or double, extending c. 1/2 way up leaf; cells 2–6 times as long as wide, each with a large solitary papilla on abaxial side, alar cells ± quadrate. Capsules erect, cylindrical, straight; annulus falling with lid; peristome teeth short; calyptrae cucullate. Four species, distributed through Europe, Asia, N. Africa, Macaronesia, N. and C. America. Derivation: meaning side, female and male, referring to the lateral perichaetia and perigonia.

1 P. filiforme Hedw., Sp. Musc. Frond., 1801 Plants slender or very slender, forming yellowish green, green or brownish mats. Stems prostrate, branches numerous, prostrate to ascending, often short or flagelliform, often curved and homomallous, to 5 cm long. Leaves appressed when dry, imbricate to erect-patent, sometimes subsecund when moist, stem and branch leaves ± similar, concave at base, ovate or broadly ovate, acute to obtuse or obtuse and apiculate; margins denticulate and plane or inflexed above; costa weak, single and extending c. 1/2 way up leaf or double and shorter; cells incrassate, basal narrowly rhomboidal, becoming rectangular to quadrate at basal angles, cells above narrowly rhomboidal, radiating from costa, shorter towards margins and apex, with large distal apically directed papilla on abaxial face of each cell, 5–8 × 16–28 μm, 2.5–5.0 times as long as wide in mid-leaf. Uniseriate 2–5-celled gemmae, 50–80 μm long, often present on stems. Setae reddish; capsules erect, cylindrical; lid obliquely rostrate, acuminate; spores c. 12 μm. Capsules very rare, summer. Branches straight or slightly curved, acute at tips, (120−)160–240(−320) μm diameter when dry var. filiforme Branches curved, especially at tips, obtuse, 320–480 μm diameter when dry var. majus Var. filiforme (Fig. 240) Branches very slender, acute at tips, straight or slightly curved, (120−)160– 240(−320) μm diameter when dry. On exposed basic rocks, rarely on tree bases, especially by mountain lakes. 10–1100 m. Very rare in Westmorland, Cumberland, Dumfries, Stirling, rare to occasional but sometimes locally frequent in the Scottish Highlands, north to Shetland, old records from Brecon, Caernarfon, Derby, Wicklow, Dublin, Down and Londonderry. 26, H4. GB54 + 35∗ , IR5∗ . Circumpolar Boreal-montane. Montane and northern Europe north to Svalbard, Faeroes,

145 Pterigynandrum

729

Fig. 240 1–3, Heterocladium dimorphum: 1, 2, stem and branch leaves (×40); 3, cells at middle of stem leaf. 4–7, Pterigynandrum filiforme var. filiforme: 4, leaves (×65); 5, mid-leaf cells; 6, gemmae (×420); 7, capsule (×10). 8–10, Habrodon perpusillus: 8, leaves (×40); 9, marginal cells at widest part of leaf; 10, mid-leaf cells. Cells ×420.

730


Iceland, Turkey, Cyprus, Siberia, Korea, Japan, Madeira, Algeria, N. America, Greenland. Var. majus (De Not.) De Not., Comment. Soc. Crittog. Ital., 1876 Branches obtuse, curved, especially at tips, 320–480 μm diameter when dry. On rocks and boulders by montane lakes. Very rare, Perth, S. Aberdeen, E. Ross, old records from Caernarfon, Angus, E. Inverness, Down. 6, H1. Montane and northern Europe north to Fennoscandia, Iceland, Caucasus, Cyprus, Kashmir, Punjab, Indo-China, Japan, N. America. The main differences between the two varieties are indicated above and I have been unable to find any correlated leaf characters. The varieties are poorly defined with many intermediates but in the absence of a more detailed study I have retained them.

146 HABRODON SCHIMP., SYN. MUSC. EUR., 1860 Dioicous. Plants very slender, primary stems creeping, branches ± erect. Leaves ovate, tapering to long or short acuminate apex; margins entire or crenulate; costa short and single or absent; cells smooth, narrowly elliptical up centre of leaf, ± quadrate at margins. Capsules ± erect, narrowly ellipsoid; annulus large, separating; peristome single, arising below mouth of capsule. Three mainly Northern Hemisphere species. Derivation: meaning delicate tooth, referring to the peristome.

¨ 1 H. perpusillus (De Not.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1863 (Fig. 240) H. notarisii Schimp. Small pale green patches or scattered plants growing through other bryophytes. Primary stems creeping, branches ± procumbent, homomallous. Leaves appressed with flexuose tips when dry, patent to spreading when moist, concave, ± ovate, tapering to short or long acuminate apex; margins plane, entire or finely crenulate; costa short or absent; cells smooth, incrassate, in mid-leaf rhomboidal, c. 10 μm wide, 1–2 times as long as wide, shorter towards margins and at basal angles, longer towards middle of leaf. Ovoid to shortly fusiform, (1−)2–5-celled brownish gemmae, 20–50 μm long, sometimes present on younger parts of branch stems. Setae short, 3–4 mm long; capsules narrowly ellipsoid; spores 16–24 μm. Capsules very rare, spring. On well illuminated trunks and branches of trees and shrubs, Lowland. Rare, scattered localities from Devon, Somerset and Dorset north to Argyll, Dunbarton and Arran but extinct in many sites, 21. GB15 + 29∗ . MediterraneanAtlantic. S. and W. Europe north to S. W. Norway, Turkey, Gran Canaria, Madeira, Algeria. This species has decreased considerably over the last 100 years, presumably as a consequence of atmospheric pollution and is considered endangered in the Red List of British Mosses.

147 Heterocladium

731

147 HETEROCLADIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1852 Dioicous. Primary stems stoloniform, secondary stems procumbent, irregularly branched. Paraphyllia few, simple, cells smooth. Stem leaves ovate, acute, base cordate, excavate, decurrent; margins entire or denticulate; costa short and double or longer and single; cells unipapillose, median elongate or not, towards margins and apex quadrate-hexagonal to rounded-quadrate. Branch leaves smaller, more bluntly pointed. Perichaetial leaves with sheathing base and long spreading to reflexed apex. Setae long; capsules inclined or horizontal, ellipsoid, straight or curved; annulus of large cells, separating; peristome double, endostome with cilia. A small genus of 8 species distributed through Europe, N. and E. Asia, Macaronesia, N. America, Brazil. Derivation: meaning different branch, alluding to the dimorphic leaves.

1 Stem leaves squarrose or squarrose-recurved, abruptly narrowed to acuminate to filiform apex 4. H. dimorphum Stem leaves patent or spreading, tapering to acute to acuminate apex 2 1/ 2 4 2 Costa usually single, extending 2 – /3 (− /5 ) way up leaf 3. H. wulfsbergii Costa absent or short, double or occasionally single, rarely reaching half way up leaf 3 3 Plants slender, stem leaves mostly 0.8–1.2 mm long, mid-leaf cells mostly 2–4 times as long as wide 1. H. heteropterum Plants very slender, stem leaves 0.24–0.40 mm long, mid-leaf cells 1–2 times as long as wide 2. H. flaccidum ¨ 1 H. heteropterum (Bruch ex Schwagr.) Schimp. in Bruch et al., Bryol. Eur., 1852 (Fig. 241) Slender plants forming dense dull green, bright green or rarely yellowish green tufts or patches or occurring as wefts amongst other bryophytes. Primary stems stoloniform, secondary stems procumbent to ascending, irregularly branched, branches often homomallous. Stem leaves often subsecund when moist, mostly 0.8–1.2 mm long, ovate, acute to acuminate; costa short, double or rarely single, or absent, extending 0–1/2 way up leaf, to 20 μm wide at widest part of leaf when single; cells papillose, in middle of leaf beyond costa elongate, in mid-leaf elliptical, 5–9 × 12–24 μm, 2–4 times as long as wide. Branch leaves smaller than stem leaves, often subsecund, ovate-lanceolate to ovate 0.3–1.0 mm long, ovate, acute; mid-leaf cells 5–8 × 8–16 μm. Perichaetial leaves from expanded basal part ± linear, entire. Setae purplish, erect or decumbent; capsules inclined to horizontal, narrowly ellipsoid; lid with stout straight or curved, blunt beak; spores 14–16 μm. Capsules rare, spring. On damp rocks, in rock crevices and occasionally on damp soil in humid woodland and ravines, especially by streams and rivers, in acidic situations. Mainly lowland or at moderate altitudes but ascending to 1150 m in E. Inverness. Occasional in S. E. England, almost absent elsewhere in lowland England, frequent or common in western and northern England and

732


Fig. 241 Heterocladium heteropterum: 1, 2, stem and branch leaves. 3, cells at middle of stem leaf; 4, capsule (×15); 5–6, H. wulfsbergii: 5, 6, stem and branch leaves). 7–8, H. flaccidum: 7, stem and branch leaves; 8, cells at middle of stem leaf. Leaves ×40, cells ×420.

147 Heterocladium

733

Wales, common in western Scotland, occasional elsewhere, occasional to frequent in Ireland. 82, H34, C. GB231 + 61∗ , IR145 + 6∗ . Suboceanic Temperate. N., W. and C. Europe, north to c. 68◦ N in Norway, Faeroes, Caucasus, Turkey, Macaronesia. For the differences from H. wulfsbergii see under that species. H. dimorphum differs in the squarrose stem leaves with a wider band of short cells on either side of the median band of elongate cells and the more bluntly pointed branch leaves. An American species, H. macounii Best, has been reported from Britain and other parts of Europe but E. F. Warburg (Trans. Br. Bryol. Soc. 3, 126–7, 1956) showed that this plant does not occur in Britain or continental Europe.

2 H. flaccidum (Schimp.) A. J. E. Sm., J. Bryol. (Fig. 241) H. heteropterum var. fallax Milde, H. heteropterum var. flaccidum Schimp. Plants very slender, forming thin dull green patches. Stem leaves of similar shape to branch leaves, 0.24–0.40 mm long, ovate-lanceolate to lanceolate, acute costa very short and double or absent; cells papillose, ± quadrate-hexagonal throughout leaf, median cells 5–8 × 8–16 μm, 1–2 times as long as wide. Branch leaves 0.15– 0.32 mm long. Sporophytes unknown. On deeply shaded, mildly to strongly basic rocks in woods and ravines, very rarely on soil. Lowland. Occasional to frequent in western Britain from Cornwall north to Shetland and in S. E. England, absent from the rest of lowland England, rare to occasional in Ireland. 72, H19, C. GB228 + 27∗ , Ir26 + 3∗ , C1. Suboceanic Temperate. Norway, Sweden, France, Germany, Silesia. Although merely regarded as a habitat form by many continental European authorities, H. flaccidum is a good species. Intermediates if they exist are extremely rare and it is ecologically distinct, occurring in more basic and in drier habitats than H. heteropterum (see A. C. Crundwell & A. J. E. Smith, J. Bryol. 22, 43–7, 2000).

3 H. wulfsbergii I. Hagen, K. Kongel. Norske Vidensk. Selsk. Forh., 1909 (Fig. 241) H. heteropterum var. wulfsbergii (I. Hagen) C. E. O. Jensen & H. Perss. Plants slender, forming dull green tufts or patches. Primary stems stoloniform, secondary stems procumbent to ascending, irregularly or subpinnately branched to almost unbranched. Stem leaves patent or spreading, those on the underside of the stem often curved downwards, concave, ovate-lanceolate to broadly ovate, gradually tapering to acute to acuminate apex; margins plane, irregularly denticulate; costa single or slightly branched above, extending 1/2 –2 /3 (−4 /5 ) way up leaf, 30– 50(−80) μm wide at widest part of leaf; cells weakly papillose, in mid-leaf, variable in shape from plant to plant, rectangular or elliptical to ± hexagonal, 8–14 × 10– 20(−22) μm, 1–2 times as long as wide, towards margins and apex ± isodiametric to wider than long. Branch leaves smaller and narrower than stem leaves; costa almost absent to reaching about half way up leaf, double or occasionally single; mid-leaf cells 4–9 × 6–14 μm, 1.0–1.5 times as long as wide. Capsules inclined to horizontal, narrowly ellipsoid; lid with stout straight or curved blunt beak; spores

734

51 Myriniaceae

14–16 μm. Capsules rare. On rocks in streams, on rock outcrops and steep rock faces in wet situations, often where subject to submergence. 0–315 m. Occasional in western Britain from Cornwall north to Jura and St. Kilda, N. Northumberland, Kintyre, rare in Ireland. 15, H10. GB21 + 15∗ , IR10 + 7∗ . Oceanic Temperate. France, Luxembourg, Norway, Portugal, Spain, Macaronesia. Probably more frequent than the number of records suggests as this species has only recently been recognised as occurring in the British Isles. It is distinguished from H. heteropterum by the wider longer single costa. It tends to occur in wetter places than H. heteropterum but the habitats overlap. In Macaronesia, where H. heteropterum is unknown, very slender plants of H. wulfsbergii occur which are indistinguishable from H. flaccidum but these grow in moist acidic habitats whereas H. flaccidum tends to occur in drier basic situations. Such slender forms of H. wulfsbergii have not been encountered in the British Isles. For an account of H. wulfsbergii in the British Isles see A. C. Crundwell & A. J. E. Smith, J. Bryol. 22, 43–7, 2000.

4 H. dimorphum Schimp. in Bruch et al., Bryol. Eur., 1852 H. squarrosulum Lindb.

(Fig. 240)

Slender plants forming dull green patches. Stems procumbent and sometimes stoloniform, pinnately branched. Stem leaves c. 0.9 mm long, squarrose or squarrose-reflexed, broadly ovate, abruptly narrowed to usually long acuminate to filiform acumen, base excavate, decurrent; margins sharply denticulate; costa short, double; cells unipapillose, median narrowly rectangular, 5–8 × 20–32 μm, 3–5 times as long as wide, towards margins ± abruptly rectangular, trapezoid or quadrate-hexagonal. Branch leaves smaller than stem leaves, concave, ovate, obtuse to acute; costa short or very short, double. Capsules unknown in Britain. On shaded montane rock ledges and boulders. To 1100 m. Very rare, W. and Mid Perth, formerly Angus and Dunbarton. 4. GB2 + 5∗ . European Boreal-montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Turkey, N. America, Greenland, Brazil. This species is treated as vulnerable in the Red List of British Mosses.

51 Myriniaceae Plants small. Costa single, often slender; alar cells weakly differentiated, other cells elongate, smooth. Capsules often erect; peristome reduced. Five genera of mostly epiphytic plants.

148 MYRINIA SCHIMP., SYN. MUSC. EUR., 1860 Slender patch-forming plants; branching irregular. Leaves ovate or ovatelanceolate, obtuse to shortly acute; costa single, extending about 1/2 way up leaf; cells small, rhomboid-hexagonal, marginal and alar cells quadrate. Perichaetial leaves sheathing. Capsules erect or slightly inclined; annulus not differentiated;

149 Leskea

735

peristome double. Two species occurring in Europe, N. Asia and N. America and a third in Brazil. ¨ G. Myrin (1803–1835). Derivation: named after the Swedish bryologist Claes

1 M. pulvinata (Wahlenb.) Schimp., Syn. Musc. Eur., 1860 Helicodontium pulvinatum (Wahlenb.) Lindb.

(Fig. 244)

Autoicous. Soft dull green patches, often silt encrusted; stems procumbent with ± erect branches. Leaves soft, appressed when dry, patent and sometimes secund when moist, ovate to ovate-lanceolate, acute to obtuse; margins entire; costa single, faint, extending to 1/3 (−2 /3 ) way up leaf, sometimes forked above; cells smooth, in mid-leaf rhomboidal, 12–16 μm wide, 2–3 times as long as wide, shorter towards margins, alar cells ± quadrate or rectangular. Capsules erect, ellipsoid, slightly asymmetrical; lid conical; spores 12–20 μm. Capsules common, summer. On tree boles and exposed roots in the flood zone of rivers, streams and ditches. Lowland. Rare, in scattered localities from Dorset and E. Sussex north to Perth. 24. GB20 + 8∗ . Circumpolar Boreal-montane. France, Italy, N. W. Europe, Urals, Siberia, C. Asia, Canada. Often accompanied by Leskea polycarpa but may be distinguished in the field by its smaller size, darker colour, leaves appressed when dry, faint costa and shorter capsules.

52 Leskeaceae Primary stems usually stoloniform, irregularly or pinnately branched, branches procumbent to erect; paraphyllia often present. Leaves appressed when dry, erect to spreading when moist, concave, sometimes plicate, ovate to lanceolate, obtuse to acuminate; margins plane or recurved, entire or denticulate; costa usually present, single or double, usually ending well below apex; cells smooth or papillose, usually 1–2 times as long as wide, quadrate or wider than long at basal angles. Setae long; capsules erect or inclined, straight or curved; stomata superficial; peristome usually double, inner often imperfect; lid conical; calyptrae cucullate. Twenty-one genera.

149 LESKEA HEDW., SP. MUSC. FROND. 1801 Autoicous. Primary stems creeping, branches erect or decumbent. Leaves ± ovate, obtuse to acute; margins recurved below, entire or denticulate above; costa usually ceasing below apex; cells ± quadrate or hexagonal, with central papilla on each face. Sporophytes arising from primary stems; setae long; capsules cylindrical, straight or curved; peristome double, without cilia. About 75 species occurring mainly in Europe, Asia and N. America. Derivation: named after a German professor, Nathaniel Gottfried Leske (1751–1786).

736

52 Leskeaceae

Fig. 242 1–3, Pseudoleskea incurvata: 1, leaves (×65); 2, mid-leaf cells; 3, capsule. 4–5, P. patens: 4, leaves (×65); 5, mid-leaf cells. 6–9, Leskea polycarpa: 6, leaves (×40); 7, marginal cells at widest part of leaf; 8, mid-leaf cells; 9, capsule. Cells ×420, capsules ×15.

150 Pseudoleskiella

737

1 L. polycarpa Hedw., Sp. Musc. Frond. 1801 (Fig. 242) Plants slender, forming dull dark green or brownish patches, often silt-encrusted. Primary stems creeping, irregularly branched, branches procumbent to erect. Paraphyllia sparse. Stem and branch leaves ± similar, patent, spreading or subsecund when moist, little altered when dry, not plicate, ovate to broadly ovate, acute to obtuse; margins recurved below, entire; costa strong below, ending well below apex; cells ± uniform throughout leaf, irregularly quadrate or quadrate-hexagonal, with central papilla on each face, in mid-leaf about as long as wide, 8–11 μm wide. Setae reddish brown; capsules erect or slightly inclined, cylindrical, straight or curved; lid conical; spores 12–16 μm. Capsules common, summer. n = 10∗ , 10 + m, 11, 11 + 2m. On exposed tree roots, trunks and branches, rocks, rarely on soil, by streams, rivers, lakes and pools. Lowland. Frequent or common in England and Wales, occasional in eastern Scotland, rare elsewhere, extending north to Shetland. 95, H25, C. GB511 + 78∗ , IR28 + 18∗ , C1∗ . Circumpolar Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Siberia, C. Asia, Japan, N. America. Easily recognized by the ± erect cylindrical capsules which are usually abundantly produced. For differences from Myrinia pulvinata see under that species.

150 PSEUDOLESKIELLA KINDB., EUR. N. AMER. BRYIN., 1896 Dioicous. Leaves ± patent when moist, ovate or lanceolate, obtuse to longly acuminate; costa single, forked or double; cells rounded or elongate, smooth or with papillae on distal walls. Setae elongate; capsules ovoid to cylindrical, straight or slightly curved; annulus separating; lid conical or rostrate. Eight or nine mainly arctic or alpine Northern Hemisphere species. Derivation: meaning small Pseudoleskea.

1 Stems and branches slightly wispy with flexuose leaf tips, when dry, mid-leaf cells mostly 3–4 times as long as wide 2. P. rupestris Leaves appressed when dry, cells mostly 1–2 times as long as wide 2 2 1. P. catenulata 2 Leaves acute, costa extending c. /3 way up leaf Leaf apices acuminate to filiform, costa extending to acumen 3. P. nervosa ¨ 1 P. catenulata (Brid. ex Schwagr.) Kindb., Eur. N. Am. Bryin.,1896 ¨ Pseudoleskea catenulata (Brid. ex Schwagr.) Schimp.

(Fig. 243)

Plants very slender, forming olive-green or brownish green mats. Primary stems creeping, irregularly pinnately branched, branches julaceous when dry. Paraphyllia sparse. Stem and branch leaves similar, appressed when dry, patent when moist, slightly concave, not plicate, ovate, acute; margins plane or narrowly recurved below, entire; costa extending to 1/2 (−3 /4 ) way up leaf, sometimes forked above; cells incrassate, smooth or slightly papillose, cells towards basal angles transversely rectangular, mid-leaf cells rounded or oval, 8–12 × 12–14 μm, 1–2 times as long as wide, cells near apex rounded. Capsules erect, curved; spores 16–18 μm. Capsules

738

52 Leskeaceae

Fig. 243 1–4, Pseudoleskiella catenulata: 1, leaves; 2, mid-leaf cells; 3, marginal cells at widest part of leaf; 4, leaf apex. 5–7, P. rupestris: 5, leaves; 6, mid-leaf cells; 7, leaf apex. 8–10, P. nervosa: 8, leaves; 9. mid-leaf cells; 10, leaf apex. Leaves ×65, cells ×420.

150 Pseudoleskiella

739

unknown in Britain. On exposed basic montane rocks. 250–1100 m. Caernarfon, occasional in the Pennines and Scottish Highlands, extending north to Sutherland. 15. GB24 + 12∗ . European Boreal-montane. Czechoslovakia, France, Germany, Hungary, Italy, Poland, Romania, Russia, Sweden, Switzerland. Usually recognisable in the field by the very slender shoots forming interwoven brownish green mats and under the microscope by the leaves with a single costa and short cells.

¨ & Soderstrom, ¨ 2 P. rupestris (Berggr.) Hedenas Lindbergia, 1991 (Fig. 243) P. catenulata var. acuminata (Culm.) J. J. Amann, P. sibirica (Arnold) P. Wilson & D. H. Norris, Pseudolaskea catenulata var. acuminata (Culm.) Crundw. Plants extremely slender, in green to reddish patches. Primary stems creeping, irregularly pinnately branched, stems and branches slightly wispy with flexuose leaf apices when dry. Stem and branch leaves similar, appressed-flexuose when dry, patent and often subsecund when moist, not plicate, ovate with long acuminate apex; margins denticulate towards apex; costa extending 1/2 –3 /4 way up leaf or sometimes percurrent, single or unequally forked above; cells incrassate, smooth, basal marginal cells transversely rectangular, cells in mid-leaf elliptical to narrowly elliptical, 5–8 × 20–30 μm, (2−)3–4 times as long as wide. Capsules erect, cylindrical, straight; spores 9–12 m. Capsules unknown in Britain. On exposed limestone rocks. 0–1100 m. Rare, Westmorland, Scottish Highlands. 12. GB12 + 2. Circumpolar Boreal-montane. Finland, France, Germany, Italy, Norway, Poland, Spain, Sweden, Switzerland, Svalbard, Siberia, N. America, Greenland. Distinctive in its extremely small size and leaves with long flexuose apices. For an account of this plant in Britain see A. C. Crundwell, Trans. Br. Bryol. Soc. 2, 278–82, 1953.

3 P. nervosa (Brid.) Nyholm, Moss Fl. Fennoscandia. 2. Musci, 1960 Leskea nervosa (Brid.) Myrin, Leskeella nervosa (Brid.) Loeske

(Fig. 243)

Plants very slender, in olive green to blackish patches. Primary stems prostrate, bearing erect branches. Paraphyllia lacking. Stem and branch leaves similar, appressed when dry, patent when moist, concave, not plicate, from a broad base ovate, tapering to long acuminate to filiform apex, acumen often turned to one side; margins plane, entire; costa stout below, reaching acumen but becoming obscure; cells incrassate, slightly papillose, at basal angles wider than long, in midleaf 8–10 μm wide, 1–2 times as long as wide. Dwarf axillary caducous branchlets often present. Capsules erect, obovoid, straight; spores 15–17 μm. Capsules unknown in Britain. On exposed calcareous rocks and possibly tree boles. 500– 1000 m. Very rare, S. Aberdeen. 1. GB1. Circumpolar Boreal-montane. Montane and northern Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Iran, N. and C. Asia, Japan, N. America. Recognisable in the field by the presence of caducous branchlets in the axils of the upper leaves of the branches. This species is treated as vulnerable in the Red List of British Mosses.

740

52 Leskeaceae

151 PSEUDOLESKEA SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1852 Dioicous. Stems creeping; stem and branch tips often curved when moist. Paraphyllia numerous. Stem leaves larger than branch leaves but otherwise similar, erect when dry, sometimes with falcate tips, patent when moist, obscurely plicate, from ovate base gradually or abruptly narrowed to acumen; margins recurved, serrulate above; costa single, ending below apex; basal cells short or long, alar cells quadrate, other cells rounded to elliptical, papillose. Capsules inclined and curved, rarely erect, shortly cylindrical; peristome double, cilia usually rudimentary or absent. Derivation: from the resemblance to Leskea.

Leaves ± uniformly spreading when moist, mid-leaf cells about as long as wide, each with a centrally conical papilla 1. P. patens Leaves falcate-secund when moist, cells 1–3 times as long as wide, papillae on end walls 2. P. incurvata 1 P. patens (Lindb.) Kindb., Canad. Rec. Sci., 1894 Lescuraea patens Lindb.

(Fig. 242)

Very slender plants forming dark green to brownish patches or wefts. Primary stems creeping, irregularly branched, branches decumbent, straight. Paraphyllia numerous. Stem and branch leaves similar, erect when dry, uniformly spreading, slightly secund when moist, slightly plicate, ovate to broadly ovate, tapering to acuminate to filiform apex; margins recurved on one or both sides below and sometimes above, crenulate-denticulate above; costa single, ending well below apex; cells incrassate, basal cells about as wide as long, marginal cells near base wider than long, cells above irregularly quadrate-hexagonal, each with a central conical papilla, in mid-leaf 8–10 × 10–14(−16) μm, 1(−2) times as long as wide. Setae brownish; capsules erect or inclined, ovoid, slightly curved; lid conical; spores 12–14 μm. Capsules rare, spring, summer. In exposed or sheltered, dry or damp situations, usually on basic rocks and soil in gullies, scree, on cliffs, by streams, pools and flushes. 600–1200 m. Rare, Mid Perth, Angus, S. Aberdeen, Inverness, Argyll, Ross. 8. GB17 + 1∗ . European Boreal-montane. Montane and northern Europe north to Jan Mayen, Faeroes, Iceland, Turkey, E. Asia. N. America. Confused in the past with P. incurvata but distinguished by the ± uniformly isodiametric cells with thinner walls and centrally placed papillae.

2 P. incurvata (Hedw.) Loeske, Hedwigia, 1911 Lescuraea incurvata (Hedw.) E. Lawton, P. atrovirens Schimp.

(Fig. 242)

Slender plants in dark green patches, often blackish in older parts. Primary stems creeping, irregularly branched, stem and branch tips curved or hooked. Paraphyllia numerous. Stem and branch leaves similar, appressed when dry, falcate-secund when moist, slightly plicate, ovate, tapering to acuminate apex; margins recurved,

153 Ptychodium

741

denticulate towards apex; costa single, ending in apex; cells incrassate, papillose, papillae near end walls, basal cells about as wide as long, in mid-leaf 4–8 × 10– 16(−20) μm, 1–3 times as long as wide. Setae brownish; capsules erect or inclined, ellipsoid, slightly curved; lid conical; spores 12–14 μm. Capsules very rare, spring. On sheltered montane rocks and on rocky banks in lowland river ravines. (80−)600–1100 m. Rare, Mid and E. Perth, Angus, Banff, W. Inverness, old records from Roxburgh, S. Aberdeen, W. Inverness. 8. GB7 + 9∗ . European Boreal-montane. Montane and northern Europe north to Svalbard, Iceland, Turkey, N. and C. Asia, Sakhalin, Japan, N. America, Greenland.

152 LESCURAEA SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1851 Dioicous. Primary stems creeping, branches erect. Paraphyllia numerous. Stem and branch leaves similar, ovate or ovate-lanceolate, acuminate; margins recurved, entire or denticulate above; costa extending almost to or to apex; basal cells elongate, alar cells quadrate, cells above linear, smooth or papillose. Capsules erect, straight; stomata present; annulus absent; exostome teeth smooth or papillose, united at base, endostome with short basal membrane, processes lanceolate, channelled, cilia lacking. Derivation: named after Charles E. Lesquereux(1806–1889), a North American botanist.

1 L. saxicola (Schimp.) Milde, Bryol. Siles., 1869 (Fig. 244) L. saxicola var. mutabilis (Schimp.) I. Hagen, Pseudoleskea striata var. mutabilis Schimp. Slender to small plants forming green or brownish green glossy patches. Primary stems creeping, ± pinnately branched, branches procumbent, often curved or with curved tips. Paraphyllia numerous. Stem and branch leaves similar, appressed when dry, subsecund when moist, plicate, lanceolate to ovate, tapering to acuminate apex; margins plane or recurved, denticulate towards apex; costa stout, ending in or below apex; cells incrassate, basal cells mostly c. 3 times as long as wide, alar cells quadrate, cells above ± linear, papillose with papillae at cell ends, in midleaf 6–8 × 30–40 μm, 6–8 times as long as wide. Capsules erect, oblong-ellipsoid, symmetrical; lid conical; spores c. 16 μm. Capsules unknown in Britain. On stones and pieces of rock. 700–950 m. Mid Perth, not seen since 1911. 1. GB1∗ . Circumpolar Boreal-montane. Montane and northern Europe north to Fennoscandia, Iceland, Caucasus, Turkey, N. and C. Asia, N. America.

153 PTYCHODIUM SCHIMP., SYN. MUSC. EUR., 1860 A small genus of two species, the second occurring in India, with similar characters to P. plicatum. Most recent authors place Ptychodium and Pseudoleskea in the Leskeaceae on the basis of gametophyte characters and I have followed this practice. However, J. R. Rohrer (Lindbergia

742

52 Leskeaceae

Fig. 244 1–3, Lescuraea saxicola: 1, leaf (×65); 3, mid-leaf cells; 3, marginal cells at widest part of leaf. 4–6, Ptychodium plicatum: 4, leaf (×30); 5, mid-leaf cells; 6, marginal cells at widest part of leaf. 7–10, Myrinia pulvinata: 7, leaves (×65); 8, marginal cells at widest part of leaf; 9, cells at centre of leaf; 10, capsule ×15. Cells ×420.

154 Anomodon

743

12, 33–40, 1986) considers that on the basis of capsule characters Ptychodium belongs in the Thuidiaceae. Derivation: meaning folds, from the plicate leaves.

1 P. plicatum (Schleich. ex F. Weber & D. Mohr) Schimp., Syn. Musc. Eur. 1860 (Fig. 244) Brachythecium plicatum (Schleich. ex F. Weber & D. Mohr) Schimp., Lescuraea plicata (Schleich. ex F. Weber & D. Mohr) Lindb. Dioicous. Medium-sized plants in lax yellowish green to brownish patches. Stems with central strand, creeping, ± pinnately and much branched, branches prostrate to suberect. Paraphyllia numerous. Leaves appressed when dry, patent and sometimes slightly secund when moist, stem leaves strongly plicate, ovate-lanceolate to broadly ovate, ± abruptly narrowed to long or short acuminate apex, recurved, entire or obscurely denticulate towards apex; costa reaching acumen; cells incrassate, smooth, basal shortly rectangular, alar cells shorter and wider, cells above elongate, 5–9 × 35–55 μm, 5–8 times as long as wide in mid-leaf. Branch leaves similar to stem leaves but smaller. Capsules ± horizontal, ellipsoid, curved; lid conical, apiculate; peristome double, exostome teeth cross striolate, cilia rudimentary or absent; spores 15–24 μm. Capsules very rare, late autumn. On wet or dry rocks or in rocky turf, usually in sheltered situations. 650–1200 m. Very rare, Mid and E. Perth, Angus, W. Inverness. 4. GB6. European Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Caucasus, N. America.

53 Anomodontaceae Dioicous. Plants small to large, usually forming mats. Primary stems creeping, secondary stems erect or erect-spreading, sparsely and irregularly branched. Paraphyllia absent. Leaves lanceolate and acuminate to abruptly narrowed from broad basal part, obtuse and apiculate; margins usually entire; costa single, ending below apex; cells ± isodiametric at least above, papillose. Perichaetia borne on main branches. Perichaetial leaves elongate from sheathing basal part. Capsules erect, oblong-ovoid to cylindrical; endostome rudimentary or absent; calyptrae cucullate. Three genera.

154 ANOMODON HOOK. & TAYLOR MUSCOL. BRIT., 1818 Dioicous. Primary stems stoloniform, with small leaves differing in shape from those of secondary stems, secondary stems ± erect, irregularly branched, branches sometimes flagelliform. Paraphyllia lacking. Leaves erect-patent to spreading, sometimes secund, ovate to lanceolate or lingulate, apex acute to rounded; margins papillose-crenulate, sometimes toothed above; costa single, ending below apex; cells incrassate, usually papillose, rounded-hexagonal except at base. Perichaetial leaves with sheathing base and reflexed apex. Setae long; capsules

744

53 Anomodontaceae

erect, cylindrical; cilia of endostome rudimentary or absent. About 30 species distributed through Europe, Asia, N. Africa, America, Australasia. Derivation: meaning not rule tooth, from the erroneous assumption that the processes arose from between the exostome teeth. For an account of Anomodon see I. Granzow-de la Cerda Contr. Univ. Michigan Herb. 21, 205–75, 1997.

1 Plants very slender, leaves acuminate, cells with single papilla on each face 1. A. longifolius Plants slender or robust, leaf apices usually rounded or obtuse, apiculate or not, cells with 2–3 papillae on each face 2 2 Plants slender, leaves 1.0–2.2 mm long, margins with a few teeth near apex 2. A. attenuatus Plants robust, leaves 2.0–3.5 mm long, margins untoothed 3. A. viticulosus 1 A. longifolius (Schleich. ex Brid.) Hartm., Handb. Skand. Fl. (ed. 2), 1838 (Fig. 245) Plants very slender, forming lax yellowish green patches, shoots to 2 cm long. Primary stems stoloniform, secondary stems erect, irregularly branched, sometimes flagelliform. Leaves loosely appressed when dry, patent when moist, 0.9– 2.4 mm long, ovate to lanceolate, tapering to acuminate apex, base decurrent, subsheathing; margins plane below, slightly denticulate towards apex; costa ending below apex; cells incrassate, alar cells slightly enlarged, marginal cells for some distance up lamina transversely rectangular, cells elsewhere rounded-hexagonal, conically unipapillose on each face, 8–10 μm wide in mid-leaf. Capsules ellipsoid; unknown in Britain. n = 11. On sheltered usually vertical limestone and basic sandstone rock in wooded valleys and ravines. 0–300 m but probably higher. Very rare, seen recently only in W. Gloucester, S. Lincoln, S. W. Yorkshire, Durham and Angus but old records from N. Somerset, Merioneth, Hereford, Mid West and N. W. Yorkshire and Mid Perth. 10. GB5 + 9∗ . Eurasian Boreo-temperate. Europe north to S. W. Norway, Caucasus, Siberia, Sakhalin, Japan. A. attenuatus and A. viticulosus differ in their larger size, leaf shape, rounded or obtuse leaf apices and cells with 2–3 papillae on each face. This species is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside Act.

2 A. attenuatus (Hedw.) Huebener, Musc. Germ., 1833 (Fig. 245) Plants slender, forming yellowish green patches, shoots to 5 cm long. Primary stems stoloniform, secondary stems erect, irregularly branched, some branches flagelliform. Leaves loosely appressed when dry, patent to spreading when moist, 1.0–2.2 mm long, from ovate basal part lingulate or broadly lingulate, apex obtuse, apiculate or not, base decurrent, subsheathing; margins papillose with a few teeth near apex; costa ending below apex; cells incrassate, basal elongate, alar cells

154 Anomodon

745

Fig. 245 1–3, Anomodon viticulosus: 1, leaves; 2, mid-leaf cells; 3, capsule (×15). 4–5, A. longifolius: 4, leaves; 5, marginal cells at middle of leaf. 6–7, A. attenuatus: 6, leaves (×25); 7, marginal cells at middle of leaf. Leaves ×25, cells ×420.

not enlarged, marginal cells near base slightly wider than long, cells elsewhere rounded-hexagonal, with 2–3 papillae on each face, 8–12 μm wide in mid-leaf. Capsules erect, cylindrical; unknown in Britain. On shaded bark, rotting wood and calcareous sandstone. Lowland. Very rare. Angus, Mid Perth (old record). 2. GB1 + 1∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Iceland, Caucasus, Cyprus, Iran, Kashmir, Japan, N. America, Mexico, Guatemala, Cuba, Jamaica. This species is considered endangered in the Red List of British Mosses.

746

54 Thuidiaceae

3 A. viticulosus (Hedw.) Hook. & Taylor, Muscol. Brit., 1818 (Fig. 245) Plants robust, forming large lax green or yellowish green tufts or turfs, dull green when dry, 2–12 cm high. Primary stems stoloniform, with numerous erect sparsely branched secondary stems. Leaves loosely appressed or incurved and curled when dry, spreading, sometimes secund, somewhat undulate when moist, 2.0–3.5 mm long, from ovate basal part lingulate-lanceolate, apex obtuse or rounded, base decurrent, subsheathing; margins plane or narrowly recurved, papillose-crenulate but not toothed; costa ending below apex; cells incrassate, basal cells rectangular, alar cells not enlarged, marginal cells near base wider than long, cells above rounded-hexagonal, with 2–3 papillae on each face, 7–10 μm wide in mid-leaf. Setae long; capsules erect or inclined, ± cylindrical, straight or slightly curved; lid obliquely rostrate; spores c. 16 μm. Capsules rare, winter. n = 11. On usually ± vertical rocks, rock faces, walls, particularly where shaded and basic, on tree boles and roots, on stone-work by streams and rivers. 0–300 m, but possibly higher. Common and sometimes locally abundant in basic areas of England and Wales, rare elsewhere, frequent in Scotland, extending north to W. Sutherland, occasional in Ireland. 103, H37, C. GB642 + 80∗ , IR78 + 4∗ , C1 + 1∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Caucasus, Turkey, Iran, Siberia, Kashmir, Nepal, China, La Palma, Algeria, N. America. Likely to be mistaken by the unwary for an acrocarpous moss. Easily recognised by its large size, and the bright green colour and spreading leaves when moist and the dull green colour and appressed crisped leaves when dry.

54 Thuidiaceae Dioicous or autoicous. Primary stems creeping, secondary stems procumbent or arcuate to erect, 1–3-pinnately branched, sometimes producing stoloniform innovations; central strand rudimentary or absent. Paraphyllia numerous. Stem and branch leaves often differing in shape; stem leaves often concave, plicate or not, with broad often decurrent base, ovate to ovate-lanceolate or lingulate, acute or occasionally obtuse; margins usually denticulate; costa well developed, single or rarely short and double; cells short at least towards margins, sometimes elongate or linear towards costa, papillose on one or both sides, rarely smooth. Perichaetia borne on main stems. Setae long; capsules horizontal, curved; stomata superficial; annulus differentiated; lid conical or convex and apiculate; peristome double, endostome with well developed basal membrane, processes and cilia; calyptrae cucullate. About 12 genera.

¨ 155 ABIETINELLA MULL. HAL., NUEVO GIORN. BOT. ITAL., 1896 Stems simply pinnate, branches not complanate, otherwise similar to Thuidium. Derivation: from the supposed resemblance to a miniature Abies.

155 Abietinella

747

1 A. abietina (Hedw.) Fleisch., Musci Buitenzorg, 1923 Thuidium abietinum (Hedw.) Schimp. Stems ± arcuate, simply pinnate, branches in four rows, not complanate. Paraphyllia abundant, simple or branched, ends truncate, cells papillose, walls ± transverse. Stem leaves patent, often curved, plicate, broadly ovate with broad base, tapering to long acuminate apex; margins recurved, denticulate; costa extending c. 3 /4 way up leaf; cells irregularly shaped, 1–2 times as long as wide, unipapillose. Branch leaves smaller, concave, broadly ovate to lanceolate, obtuse to acuminate; costa ending c. 2 /3 way up leaf; cells incrassate, unipapillose, rounded to elliptical, shorter towards margins, 8–10 μm wide in mid-leaf. Margins of perichaetial leaves not ciliate. Capsules suberect, cylindrical, curved; lid conical, acute; spores 16–18 μm. Stem leaves 1.0–1.4 mm long, mid-leaf cells of branch leaves 1.0–1.5(−2.0) times as long as wide var. abietina Stem leaves 1.5–2.0 mm long, mid-leaf cells of branch leaves 1.5–3.0 times as long as wide var. histricosa Var. abietina (Fig. 246) Lax yellowish green to brownish wefts or scattered plants growing through other vegetation. Stems and branches ± terete with appressed leaves when dry. Stem leaves ovate, acuminate, mostly 1.0–1.4 mm long, tapering to acuminate apex. Branch leaves ovate, acute, 0.6–1.0 mm long; margins entire; cells in mid-leaf 8–16 μm long, 1.0–1.5(−2.0) times as long as wide. Capsules very rare. In unimproved chalk and limestone grassland, dune-slacks, on basic montane rock ledges and slopes. 0–850 m. Occasional in East Anglia, rare or very rare elsewhere, from W. Cornwall east to E. Kent and north to E. Ross, very rare in Ireland. 40, H7, C. GB40 + 32∗ , IR4 + 6∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Iceland, Caucasus, Turkey, S. W. Asia, Himalayas, China, Japan, Lesotho, N. America, Greenland. Var. histricosa (Mitt.) Sakurai, Musci Jap. Exsic., 1954 A. histricosa (Mitt.) Broth., Thuidium histricosum Mitt.

(Fig. 246)

Yellowish green to brownish wefts. Branches with leaves somewhat patent so that branches are not terete when dry. Stem leaves ovate-lanceolate, longly acuminate, mostly 1.5–2.0 mm long. Branch leaves sometimes secund, mostly 0.9–1.3 mm long, 1.5–3.0 times as long as wide, ovate to lanceolate, shortly to longly tapering to acute to acuminate apex; margins entire to denticulate; mid-leaf cells 12–20 μm long, 1.5–3.0 times as long as wide. Capsules unknown in the British Isles. Chalk and limestone grassland. Lowland. Frequent on the chalk of southern England north to Bedford, old records from Mid West and N. W. Yorkshire, Mid Perth, W. Mayo, Sligo, Donegal, Londonderry. 18, H5. GB53 + 10∗ , IR1 + 4∗ . Austria,

748

54 Thuidiaceae

Fig. 246 1–4, Abietinella abietina ssp. histricosa: 1, branch (×20); 2, 3, stem and branch leaves; 4, mid-leaf cells of stem leaf. 5–8, A. abietina ssp. abietina: 5, branch (×10); 6, 7, stem and branch leaves; 8, mid-leaf cells of stem leaf. 9–13, Thuidium tamariscinum: 9, 10, stem and branch leaves; 11, mid-leaf cells of stem leaf; 12, apex of leaf of ultimate branch; 13, capsule (×15). Leaves ×40, cells ×420.

156 Thuidium

749

Belgium, Czechoslovakia, France, Germany, Italy, Poland, Romania, Russia, Spain, Switzerland. China. Although var. histricosa is usually distinct from var. abietina in appearance with the branch leaves patent when moist, with more longly tapering tips and longer cells, occasional forms intermediate between var. histricosum and var. abietina occur. For a detailed comparison of the two taxa see I. Duell-Hermanns, J. Bryol 11, 467–87, 1981.

156 THUIDIUM (HEDW.) SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1852 Dioicous. Primary stems stoloniform, secondary stems usually arcuate, irregularly 2–3-pinnately branched. Paraphyllia abundant, ends truncate, cells short, papillose, walls ± transverse. Stem leaves plicate, concave, broadly ovate to ovatetriangular with long or short acumen; margins plane or recurved, denticulate or serrulate; costa ending in or below apex; cells papillose, short, to 3 times as long as wide. Branch leaves smaller than and of different shape from stem leaves. Perichaetial leaves narrowly lanceolate, longly acuminate; margins ciliate or not. Setae long; capsules inclined or horizontal, cylindrical, curved; annulus present; peristome double, inner well developed with cilia. A world-wide genus of about 240 species. Derivation: so named because of the resemblance to the feathery branched conifer Thuja.

1 Apical cell of leaves of ultimate branches acute, not papillose 1. T. tamariscinum Apical cell of leaves of ultimate branches obtuse, crowned with 2–3 papillae 2 2 Cells beyond end of costa of stem leaves longer than neighbouring cells and extending into acumen, paraphyllia with papillae against distal walls of cells 4. T. recognitum Cells beyond end of costa similar in shape to neighbouring cells, cells of paraphyllia with median or subapical papillae 3 3 Stem leaf apices not reflexed when dry, acumen usually terminating in a single elongate cell, perichaetial leaf margins sparsely ciliate 2. T. delicatulum Stem leaf apices reflexed when dry, acumen usually ending in a uniseriate row of several elongate cells, perichaetial leaf margins not ciliate 3. T. assimile 1 T. tamariscinum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1852 (Fig. 246) Shoots to 25 cm or more long, forming bright green to rich golden brown wefts, sometimes extensive. Stems brownish with paraphyllia, arcuate, complanately and often regularly and neatly (2–)3-pinnately branched, branches sometimes in interrupted groups. Paraphyllia uniseriate, simple or branched, cells with papilla at middle. Leaves loosely appressed when dry, erect-patent to patent when moist; stem leaves concave, plicate, from wide base broadly ovate, rapidly narrowed to acuminate apex; margins recurved below, crenulate to denticulate above; costa

750

54 Thuidiaceae

strong, ending below apex; cells thin-walled to incrassate, unipapillose, rectangular or narrowly rectangular, 8–10 μm wide in mid-leaf. Branch leaves ovate, acute; ultimate branch leaves terminating in single smooth acute cell. Inner perichaetial leaves with ciliate margins. Capsules inclined, cylindrical, curved; lid with oblique beak; spores 12–20 μm. Capsules occasional in W. and N. Britain, very rare elsewhere, winter, spring. n = 10 + m, 11∗ . On damp ground, banks, tree boles, rotting logs and rocks in woods, in damp turf, on sand-dunes, heaths, montane cliffs and ledges. 0–880 m. Common. 112, H40, C. GB1796 + 85∗ , IR377 + 40∗ , C6. European Temperate. Europe north to southern Fennoscandia, Faeroes, Iceland, Cauca´ sus, Turkey, Sakhalin, Japan, Azores, Madeira, Reunion, Tanzania, Newfoundland (probably introduced), Colombia. One of the most attractive and common of our pleurocarpous mosses, easily recognised by the handsome tripinnate arcuate shoots. Stunted forms may be confused with T. delicatulum but in that species the branches are hardly complanate and more congested and the apical cell of ultimate branch leaves is crowned with 2–3 papillae.

2 T. delicatulum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1852 T. recognitum var. delicatulum (Hedw.) Warnst.

(Fig. 247)

Shoots to 20 cm or more long, forming green wefts. Stems arcuate, ± (2–)3pinnately branched, branches hardly complanate, sometimes in congested groups. Stems brownish with paraphyllia. Paraphyllia uniseriate, simple or branched, cells with median or subapical papillae. Stem leaves appressed to spreading with acumen rarely reflexed when dry, ± patent when moist, plicate, from broad base ovate-triangular, gradually or abruptly tapering to long or short acumen usually terminating in a single elongate cell; margins recurved below, crenulatedenticulate above; costa ending below acumen; cells beyond end of costa of similar shape to neighbouring cells, not incrassate, 1–2 times as long as wide, 30–50 μm long. Leaves of ultimate branches concave, oval, acute; cells unipapillose, apical cell obtuse with 2–3 apical papillae. Perichaetial leaves with ciliate margins. Capsules inclined, cylindrical, curved; spores 16–20 μm. Capsules occasional, winter. n = 11∗ . On rocks, banks and soil in woods, in damp turf, on damp montane cliff ledges, in bogs, on heaths and sand-dunes. 0–800 m. Occasional to frequent in S. W. and N. W. England, Wales, W. Scotland, rare elsewhere and ± absent from lowland England, rare to occasional in Ireland. 53, H27. GB376 + 28∗ , IR50 + 6∗ . Circumpolar Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia. China, Japan, N. America, Mexico, Jamaica, St. Vincent, Andes, Marion I. Although T. delicatulum and T. assimile are reduced to infraspecific taxa of T. recognitum by some authors, the differences between them are sufficient for the maintenance of specific status. T. assimile may usually be distinguished by the stem leaf apices ending in a uniseriate row of several cells and reflexed when dry. Stunted forms of T. assimile may, however, be impossible to distinguish from T. delicatulum. T. recognitum differs from both in the cells

156 Thuidium

751

Fig. 247 1–8, Thuidium delicatulum: 1, portion of dry stem (×15); 2, 3, stem and branch leaves; 4, mid-leaf cells of stem leaf; 5, stem leaf apex; 6, apex of ultimate branch leaf; 7, perichaetial leaf; 8, paraphyllia. 9–15, T. assimile: 9, portion of dry stem (×15); 10, 11, stem and branch leaves; 12, mid-leaf cells of branch leaf; 13, apex of stem leaf; 14, apex of ultimate branch leaf; 15, paraphyllia. Leaves ×40, cells ×420, paraphyllia ×280.

752

54 Thuidiaceae

beyond the end of the costa elongate and differing in shape from neighbouring cells and in the position of the papillae of the cells of the paraphyllia. For a discussion of these three species see J. Tallis, Trans. Br. Bryol. Soc. 4, 102–6, 1961.

¨ 3 T. assimile (Mitt.) A. Jaeger, Ber. Thatigk. St. Gallischen Naturwiss Ges., 1878 (Fig. 247) T. philibertii Limpr. Plants forming yellowish green wefts. Stems arcuate, (2–)3-pinnately branched, branches hardly complanate, sometimes congested. Stems brownish with paraphyllia. Paraphyllia uniseriate, simple or branched, cells with median or subapical papillae. Stem leaves appressed with apices reflexed or recurved when dry, ± patent when moist, plicate, from broad base ovate-triangular, gradually or abruptly tapering to filiform apex; margins recurved below, crenulate-denticulate above; costa ending in acumen; cells beyond end of costa of similar shape to neighbouring cells, not incrassate, 1–2 times as long as wide, 20–30 μm long, apex of 1–several elongate cells. Leaves of ultimate branches concave, ovate, bluntly pointed; cells unipapillose, apical cell obtuse, crowned with 2–3 apical papillae. Margins of perichaetial leaves not ciliate. Capsules inclined, cylindrical, curved; unknown in the British Isles. In chalk and limestone grassland, calcareous sanddunes, on damp basic rocks in woods and montane habitats. 0–800 m. Occasional, generally distributed, rare in Ireland. 86, H19. GB194 + 50∗ , IR21 + 4∗ . Circumpolar Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Kashmir, Altai, China, Algeria, N., C. and S. America. ¨ 4 T. recognitum (Hedw.) Lindb., Not. Sallsk. Fauna Fl. Fenn. Förh., 1874 (Fig. 248) Plants forming greenish wefts. Stems arcuate, (2–)3-pinnately branched, branches hardly complanate, sometimes congested. Stems brownish with paraphyllia. Paraphyllia uniseriate, simple or branched, cells with papillae against distal calls. Stem leaves appressed to spreading with reflexed or recurved apices when dry, ± patent when moist, concave, plicate, from broad base ovate-triangular, gradually or abruptly tapering to filiform acumen; margins recurved below, crenulatedenticulate above; costa extending almost to apex of acumen; cells of acumen incrassate, cells beyond end of costa elongate, longer than neighbouring cells. Leaves of ultimate branches concave, oval, acute; cells unipapillose, apical cell obtuse, crowned with 2–3 papillae. Margins of perichaetial leaves not ciliate. Capsules unknown in the British Isles. On basic rocks and banks in woods, limestone pavement, montane grassland, scree and on rock ledges. 0–670 m. Rare to occasional in the central Scottish Highlands, rare or very rare elsewhere, in widely scattered localities from N. Somerset north to Sutherland, Clare, W. Galway, E. Mayo, Leitrim, Londonderry. 21, H5. GB30 + 8∗ , IR3 + 1∗ . Circumpolar Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, N. and C. Asia, Japan, Azores, Madeira, N. America, Greenland, Peru.

156 Thuidium

753

Fig. 248 1–6, Thuidium recognitum: 1, portion of stem (×15); 2, 3, stem and branch leaves; 4, mid-leaf cells of stem leaf; 5, apex of stem leaf; 6, paraphyllia (×280). 7–11, Helodium blandowii: 7, 8, stem and branch leaves; 9, mid-leaf cells of stem leaf; 10, apex of ultimate branch leaf; 11, capsule (×15). Leaves ×40, cells ×420.

754

55 Helodiaceae

55 Helodiaceae Plants robust. Filamentous or narrowly foliose paraphyllia present, cells elongate, smooth. Costa single; alar cells differentiated or not, Outer peristome teeth crossstriolate. Four genera.

157 HELODIUM WARNST., KRYPT.-FL. BRANDENBURG, LAUBM., 1905 Autoicous. Primary stems stoloniform, secondary stems erect, usually regularly pinnately branched. Paraphyllia abundant, cells elongate, not papillose, with oblique walls, distal ends acute. Stem leaves larger than branch leaves, concave, plicate, ovate, acuminate; margins recurved at least below, entire or denticulate; costa extending half way up leaf to just below apex; cells thin-walled or incrassate, linear-rhomboidal, unipapillose on abaxial surface. Perichaetial leaves lanceolate, acuminate; margins not ciliate. Setae elongate; capsules inclined to horizontal, cylindrical, curved; annulus differentiated; lid conical and acute or convex and apiculate; peristome double, inner with well developed basal membrane and cilia; calyptrae cucullate. Four species of mainly marshy habitats; circumboreal. Derivation: referring to the marshy habitat.

1 H. blandowii (F. Weber & D. Mohr) Warnst., Krypt. –Fl. Brandenburg, Laubm., 1905 (Fig. 248) Thuidium blandowii (F. Weber & D. Mohr) Schimp. Dense yellowish green to golden brown tufts or patches. Primary stems stoloniform, secondary stems erect, usually regularly pinnately branched. Paraphyllia abundant at basal angles and on abaxial side of costa of leaves, long, uniseriate, much branched. Leaves loosely appressed when dry, patent when moist; stem leaves concave, plicate, broadly ovate, shortly tapering to acuminate apex; margins plane or recurved below, sharply denticulate; costa extending 1/2 –3/4 way up leaf; auricles lacking, cells elongate, unipapillose on abaxial side with papillae on distal walls, cells in mid-leaf 6–9 × 28–44 μm, 5–7 times as long as wide. Branch leaves ovate or lanceolate, acuminate. Capsules inclined, cylindrical, curved; spores 16–20 μm. Capsules common, spring. On boggy ground and in poor fen. 0–400 m. Extinct, last seen in Cheshire in 1885 and N. W. Yorkshire in 1894; there are earlier records from S. E. and Mid-West Yorkshire. 4. GB4∗ . Circumpolar Boreal-montane. N., W. and C. Europe, Iceland, Caucasus, N. Asia, Japan, N. America, Greenland.

158 PALUSTRIELLA OCHYRA, J. HATTORI BOT. LAB., 1989 A small genus with the characters of P. commutata, the other three species differing in leaf characters and stem tomentum.

158 Palustriella

755

Derivation: meaning diminutive marshy, referring to small plants of wet habitats. For an account of Palustriella see R. Ochyra, J. Hattori Bot. Lab., 67, 202–242, 1989.

1 Leaf cells with tall conical papillae at least in young leaves, cells (2.5−)3.0–6.0 times as long as wide in mid-leaf, very rare high altitude species 3. P. decipiens Leaf cells smooth or with low papillae, in mid-leaf (6−)9−15 times as long as wide, frequent or common widespread species 2 2 Stems regularly complanately pinnately branched, tomentose, stem leaves cordate-triangular 1. P. commutata Stems irregularly or subpinnately branched, not tomentose, stem leaves ovate to lanceolate 2. P. falcata 1 P. commutata (Hedw.) Ochyra, J. Hattori Bot. Lab., 1989 Cratoneuron commutatum (Hedw.) Roth, Hypnum commutatum Hedw. Dioicous. Plants usually medium-sized to robust, forming green or yellowish green dense or lax tufts or patches, yellowish brown and often encrusted with calcareous matter below. Shoots procumbent to erect; stems regularly complanately pinnately branched, with tomentum of brownish rhizoids and abundant linear-lanceolate or ciliate-lanceolate paraphyllia. Leaves falcate-secund, sometimes strongly so, strongly plicate; stem leaves cordate-triangular, sometimes widely so, gradually tapering from near base to acumen, not narrowed at base; margins plane or recurved below, denticulate below, not or obscurely so above; costa stout, extending 1 /2 –3 /4 way or more up leaf, rarely shorter; alar cells enlarged, forming yellowish to brownish auricles extending ± to costa, other cells linear-vermicular, lower smooth or prorate, in mid-leaf 5–7 × (30−)55–100 μm, (6−)9–15 times as long as wide. Branch leaves smaller and narrower. Setae elongate, flexuose; capsules ± horizontal, narrowly ellipsoid or subcylindrical, curved; annulus of 2–3 rows separating cells; lid with straight stout acute point; peristome perfect, exostome teeth transversely striolate below, faintly papillose and with scattered coarse papillae above, inner with well developed cilia; spores 26–30 μm. Plants medium-sized to robust, costa extending 3/4 or more way up leaf, mid-leaf cells mostly 9–15 times as long as wide var. commutata Plants slender, stem leaves with costa extending about half way up leaf, mid-leaf cells mostly 6–8 times as long as wide var. sulcata Var. commutata (Fig. 249) Plants usually robust. Costa stout, extending c. 3/4 way or more up leaf; mid-leaf cells 5–7 × 55–100 μm, 9–15 times as long as wide. Capsules rare, spring, summer. n = 10∗ . In and by calcareous springs and flushes, on wet basic rocks and in sanddunes. 0–900 m. Frequent or common except in lowland and S. W. England and S. W. Wales, occasional in N. W. Ireland, rare elsewhere. 107, H38, C. GB735 + 93∗ , IR73 + 13∗ , C1∗ . Circumpolar Boreo-temperate. Europe north to northern

756

55 Helodiaceae

Fig. 249 1–5, Palustriella commutata var. commutata: 1, 2, stem and branch leaves; 3, mid-leaf cells (×420); 4, paraphyllia (×85); 5, capsule (×10). 6–9, P. falcata: 6, 7, stem and branch leaves of typical plants; 8, alar cells (×210); 9. mid-leaf cells (×420). Leaves ×40.

158 Palustriella

757

Fig. 250 1, 2, Palustriella falcata, form referred to as P. commutata var. virescens: stem and branch leaves (×25). 3–5, P. commutata var. sulcata: 3, 4, stem and branch leaves (×40); 5, mid-leaf cells. 6–9, P. decipiens: 6, 7, stem and branch leaves (×40); 8, mid-leaf cells; 9, paraphyllia (×85). Cells ×420.

Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, W. Asia, Kashmir, Tibet, Japan, Korea, Kamchatka, Madeira, N. Africa. Var. sulcata (Lindb.) Ochyra, J. Hattori Bot. Lab., 1989 (Fig. 250) ¨ Cratoneuron commutatum var. sulcatum (Lindb.) Monk., Hypnum sulcatum Lindb. Plants slender, in golden brown patches. Costa extending 1/2 way up leaf; mid-leaf cells 6–7 × 30–40 μm, 6–8 times as long as wide. Capsules unknown. On moist base-rich high altitude rocks. To 1175 m. Very rare, Mid Perth, W. Inverness, Argyll, Mull (old record). 4. GB5 + 1∗ . Montane and northern Europe north to Fennoscandia, Iceland, N. Africa. The relationship between P. commutata and P. falcata is controversial. Both Dixon & Jameson (1924) and Nyholm (1954–69) say that plants of P. commutata occur with peripheral

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55 Helodiaceae

branches with the characters of P. falcata. Nyholm also reports the occurrence of individual shoots, P. commutata below and P. falcata above. On the other hand, P. R. Bell & E. Lodge (J. Ecol. 51, 113–22, 1963) say that the two varieties remain distinct in culture and that P. falcata will tolerate water much lower in bases than will P. commutata. The two are at least as distinct as many pairs of taxa that are now accepted as species. ¨ as Duell (1992) considers that var. sulcata is worthy of specific rank and quotes L. Hedenas ¨ (pers. commun., 2000) considers var. supporting this. However, more recently, L. Hedenas sulcata to be merely a form of var. commutata. However, var. sulcata has abundant paraphyllia, suggesting a relationship to P commutata; also, the difference in areolation seems unlikely to be just a response to environmental conditions and I have therefore maintained the plant as a variety of P. commutata.

¨ Bryophyt. Biblioth., 1992 2 P. falcata (Brid.) Hedenas, (Figs. 249, 250) ¨ Cratoneuron commutatum var. falcatum (Brid.) Monk., A. commutata var. virescens (Schimp.) Ochyra, Hypnum falcatum Brid., P. commutata var. falcata (Brid.) Ochyra Dioicous. Green or more usually yellowish green to orange-brown, rarely dark green or blackish, moderately robust or robust tufts or patches, often encrusted with calcareous matter. Stems erect or ascending, irregularly to subpinnately branched, with few or no rhizoids, paraphyllia sparse. Leaves falcate-secund, rarely ± straight, strongly plicate; stem leaves narrowly triangular, gradually tapering almost from base to acumen; margins plane or recurved below, denticulate below, not or obscurely so above; costa extending c. 3/4 way up leaf, rarely percurrent or excurrent; alar cells enlarged, forming yellowish to brownish auricles extending ± to costa, other cells linear-vermicular, lower smooth or prorate, mid-leaf cells 5–7 × 55–100 μm, 9–15 times as long as wide. Branch leaves lanceolate. Sporophytes as in P. commutata. Capsules rare, spring, summer. n = 7, 10. On wet calcareous rocks, in flushes, seepage areas, fens. 0–1070 m. Rare to occasional in lowland and S. W. England, frequent or common elsewhere, rare to occasional in Ireland. 97, H32. GB433 + 81∗ , IR61 + 12∗ . Circumpolar Boreo-temperate. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Himalayas, China, N. Africa, N. America. The plant referred to as Cratoneuron commutatum var. virescens (Fig. 250), which is dark green or blackish, with ± straight leaves with stout, percurrent or excurrent costa, is regarded as ¨ pers. commun.). a habitat form (L. Hedenas,

3 P. decipiens (De Not.) Ochyra, J. Hattori Bot. Lab., 1989 Cratoneuron decipiens (De Not.) Loeske, Hypnum decipiens De Not.

(Fig. 250)

Dioicous. Plants slender, forming bright green or yellowish green patches. Stems procumbent, pinnately branched and sometimes forked, densely tomentose with rhizoids and paraphyllia, stem and branch tips sometimes hooked. Leaves falcatesecund, concave, strongly plicate; stem leaves cordate-triangular, narrowed at insertion, tapering to long acumen; margins plane or recurved, denticulate below;

159 Cratoneuron

759

costa extending to 2/3 –3/4 way up leaf; basal cells narrowly rectangular, alar cells enlarged, forming distinct auricles extending to costa, other cells narrowly elliptical, with tall conical papillae on abaxial side at least in younger leaves, mid-leaf cells (5−)6–9 × 20–35 μm, (2.5−)3.0–6.0 times as long as wide. Branch leaves smaller, concave, ovate, acuminate; costa extending c. 1/2 way up leaf. In basic montane springs and flushes. 500–980 m. Rare in the Scottish Highlands, old records from S. E. and N. E. Yorkshire and Kincardine. 11. GB13 + 7∗ . European Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Turkey, C. Asia, Japan. Likely to he passed over as a small form of P. commutata but differing in the more abruptly tapered stem leaves, markedly narrowed at the insertion, and in the presence of conical papillae on the abaxial side of the leaves, best seen in side view in folded leaves.

56 Amblystegiaceae Autoicous or dioicous. Slender to robust lax tufts to dense mats; stems irregularly branched, stolons lacking. Paraphyllia present or not. Stem and branch leaves similar although the latter usually smaller with a weaker costa, patent to spreading, straight to falcate when moist, ovate-lanceolate or lanceolate, acute to acuminate; costa single; cells short, smooth, alar cells differentiated or not. Perichaetial leaves differentiated from stem leaves. Setae reddish, smooth; capsules inclined or horizontal, ellipsoid to cylindrical, frequently contracted below mouth when dry and empty; lid conical, mamillose or not; peristome double, exostome teeth yellowish brown, cross-striolate endostome with well developed basal membrane, processes broad, cilia entire; calyptrae cucullate, smooth. Fourteen genera of plants mainly of damp habitats.

159 CRATONEURON (SULL.) SPRUCE, CAT. MUSC., 1867 With the characters of the two species below. Derivation: meaning strong nerve, referring to the stout costa. R. Ochyra (J. Hattori Bot. Lab. 67, 203–42, 1989) places Cratoneuron filicinum in the monotypic family Cratoneuronaceae placed near the Thuidiaceae and C. curvicaule in the monotypic ¨ genus Callialaria Ochyra in the Amblystegiaceae, but the treatment here follows L. Hedenas, Lindbergia 22, 101–33, 1997.

Stem and branch tips usually hook-like with falcate leaves, brown tomentum present, mid-leaf cells mostly 2–4 times as long as wide, common plant 1. C. filicinum Stem and branch tips straight, tomentum absent, mid-leaf cells 6–10 times as long as wide, very rare plant 2. C. curvicaule

760

56 Amblystegiaceae

1 C. filicinum (Hedw.) Spruce, Cat. Musc., 1867 Amblystegium filicinum (Hedw.) De Not.

(Fig. 251)

Dioicous. Golden yellow to bright green plants varying from tight patches with regularly pinnately branched stems to erect tufts with sparsely branched stems. Stems and branches densely tomentose with brownish rhizoids and abundant lanceolate or narrowly lanceolate paraphyllia, apices hooked. Stem leaves erectpatent to spreading, straight with ± curved acumen, rarely falcate-secund, scarcely altered when dry, concave, not plicate, cordate-triangular, tapering from widest part to acuminate apex; margins plane, denticulate ± from base to apex with teeth most prominent at widest part of leaf; costa very stout, ending below acumen to excurrent; alar cells incrassate, inflated, forming decurrent auricles extending almost to costa, other basal cells irregularly rectangular, cells above shorter, ± elliptical, smooth, 6–8 × 16–24 μm, mostly 2–4 times as long as wide in midleaf. Branch leaves narrower, frequently falcate-secund. Capsules inclined, ellipsoid, curved; lid conical, obtuse; spores 12–14 μm. By calcareous springs and flushes, in damp grassland, on banks, rocks, cliffs, in dune-slacks, in ± basic sites. 0–850 m. Frequent or common throughout the British Isles. 112, H40, C. GB1625 + 116∗ , IR254 + 9∗ , C5. Circumpolar Wide-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Asia, La Palma, Madeira, Algeria, Kenya, Tanzania, Uganda, Zaire, South Africa, N. America, Mexico, Ecuador, New Zealand. An extremely variable species with a range in form from slender Amblystegium-like plants to lax coarse tufts 5–7 cm high. A number of varieties have been described but intergrade to such an extent that they are not recognised here. Coarse plants with erect stems differ markedly in appearance from the more usually procumbent plants with pinnately branched stems, but the stem and branch apices generally have the characteristic hooked appearance of C. filicinum. Plants with leaves with stout excurrent costa, referred to as var. fallax (Brid.) Roth (Amblystegium filicinum var. valliclausae auct.), are recognised by R. Ochyra, J. Hattori Bot. Lab. 67, 202–42, 1989 (as Callialaria filicinum var. atrovirens (Brid.) Ochyra), but they seem no more than phenotypic variants as I have seen plants with the characteristics of that variety organically attached to typical C. filicinum.

2 C. curvicaule (Jur.) Roth, Hedwigia, 1899 (Fig. 251) ¨ Amblystegium curvicaule (Jur.) Lindb., C. filicinum var. curvicaule (Jur.) Monk., Callialaria curvicaulis (Jur.) Ochyra Dioicous. Plants slender, forming lax or dense green to golden yellow mats, shoots to 10 cm long. Stems procumbent to ascending, irregularly to ± pinnately branched, 2–5(−15) cm long; rhizoids absent or very sparse. Paraphyllia absent. Leaves loosely imbricate when dry, erect-patent when moist; stem leaves ± straight, from cordate-triangular base abruptly narrowed to short or

159 Cratoneuron

Fig. 251 1–6, Cratoneuron filicinum: 1, 2, stem and branch leaves (×40); 3, alar cells (×210); 4, mid-leaf cells (×420); 5, paraphyllia (×85); 6, capsule (×10). 7–10, C. curvicaule: 7,8, stem and branch leaves (×50); 9, alar cells (×210); 10, mid-leaf cells (×420).

761

762

56 Amblystegiaceae

long, straight, sometimes filiform acumen; margins obscurely to strongly serrulate from base to apex; costa thin, ending from well below to reaching base of acumen, alar cells inflated, forming hyaline to orange-brown decurrent auricles extending to costa, other cells oblong-rhomboidal to linear-rhomboidal, 5–7 × 35– 50 μm, 6–10 times as long as wide in mid-leaf. Branch leaves similar to stem leaves but smaller. Only female plants known. On moist or wet basic rocks at high altitudes. Very rare, old records from Mid Perth and Skye. 2. Montane and N. Europe north to Svalbard, Novaya Zemlya, Kazakstan, Himalayas, Mongolia, China. Macroscopically similar to C. filicinum but differing in lack of stem and branch rhizoids and paraphyllia, the stem and branch tips usually straight, the leaves not falcate and with longer cells.

160 AMBLYSTEGIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1953 Autoicous, rarely dioicous. Very slender or slender, rarely robust plants. Stems procumbent, irregularly branched, branches few to numerous, procumbent to erect. Leaves erect-patent to spreading, sometimes subsecund, broadly ovate to lanceolate, gradually to abruptly tapering to longly acuminate, rarely obtuse apex; margins plane, entire or denticulate; costa thin, extending to 1/2 –3/4 way up leaf, rarely absent or strong and ending in apex or excurrent; basal cells quadrate or rectangular, alar cells scarcely differentiated, not forming auricles, other cells narrowly rhomboid-hexagonal to narrowly rhomboidal, mostly 5–6 times as long as wide, rarely linear, smooth. Capsules inclined, ellipsoid to cylindrical, curved, often horizontal and contracted below the mouth when dry and empty; annulus present; lid conical, sometimes apiculate; peristome double, inner with processes and nodulose or appendiculate cilia. A world-wide genus of c. 95 species occurring mainly in damp or wet habitats. Derivation: meaning blunt roof, referring to the capsule lids.

1 Plants exceedingly slender, stem leaves mostly 0.10–0.25 mm long, costa lacking, plants of sheltered situations 5. A. confervoides Plants mostly slender, stem leaves more than 0.25 mm long, costa present or if absent then plants occurring in exposed coastal habitats 2 2 Costa of stem leaves ± reaching apex 2. A. varium 3 Costa of stem leaves reaching to 3/4 way up leaf 3 Base of stem leaves longly decurrent, ± lanceolate paraphyllia often present 4. A. radicale Base of stem leaves not or scarcely decurrent, paraphyllia absent 4 4 Stem leaves 0.5–1.0 mm long, crowded, not markedly narrowed at insertion 1. A. serpens Stem leaves 1.2–2.2 mm long, distant, markedly narrowed at insertion 3. A. humile

160 Amblystegium

763

1 A. serpens (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1853 A. juratzkanum Schimp. Autoicous. Shoots slender, stems procumbent, irregularly branched, branches procumbent to erect. Paraphyllia lacking. Leaves appressed to patent or spreading when dry, erect-patent to spreading when moist, stem leaves ovate to lanceolate, tapering to ± long acuminate apex; margins plane, entire to denticulate; costa almost absent to extending to 3/4 way up leaf; basal cells quadrate or rectangular, marginal cells from base to widest part of leaf quadrate to rectangular, cells above ± incrassate, usually elliptical. Branch leaves smaller and narrower than stem leaves. Capsules inclined or occasionally suberect, narrowly ellipsoid to cylindrical, curved; lid conical with blunt apiculus; spores 8–15 μm; calyptrae whitish. Leaves 0.5–1.0 mm long, mid-leaf cells 3–6 times as long as wide, capsules inclined var. serpens Leaves 0.24–0.56 mm long, mid-leaf cells 2–3 times as long as wide, capsules suberect var. salinum Var. serpens (Fig. 252) Plants ± slender, forming dense intricate greenish patches, sometimes extensive. Leaves appressed to spreading when dry; stem leaves mostly 0.5–1.0 mm long; costa extending 1/2 –3/4 way up leaf; mid-leaf cells (6−)7–10 × 28–40(−48) μm, 3–5(−6) times as long as wide. Capsules inclined; common, spring to autumn. n = 10 + m, 11, 11 + m, 12, 12 + m, 13, 19∗ , 19 + m∗ , 19 + 2m, 20∗ , 20 + m∗ , 22, 24, 28. On soil, stones, rocks, masonry, dead wood, bark, in sheltered situations such as woodland and in open habitats, usually where moist, on acidic to basic substrata. Mainly lowland but ascending to 380 m in Mid West. Yorkshire. Rare to occasional in the Scottish Highlands, common elsewhere. 111, H38, C. GB1720 + 92∗ , IR200 + 13∗ , C8. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Siberia, Chitral, Tibet, Kashmir, Japan, Azores, Algeria, N. America, Greenland, Mexico, Ecuador, Peru, Tasmania, New Zealand. Var. salinum Carrington, Trans. Bot. Soc. Edinburgh, 1863 (Fig. 252) Plants very slender, forming dense yellowish green patches. Leaves appressed when dry; stem leaves (0.24−)0.34–0.56 mm long; costa ± absent to extending to half way up leaf; cells in mid-leaf 8–10 × 16–24 μm, 2–3 times as long as wide. Capsules suberect; occasional. In dune-slacks and on soil in coastal habitats. Lowland. Occasional on the west coast from W. Cornwall north to Shetland, rare to occasional along the east coast, occasional on Irish coasts. 28, H13, C. Denmark, Faeroes, Germany, Iceland, Norway, Poland, Sweden, Svalbard. Not all sand-dune plants of A. serpens belong to var. salinum, which is distinctive in its shorter leaf cells and suberect capsules. Sand-dune plants without capsules can only be determined microscopically.

764

56 Amblystegiaceae

Fig. 252 1–4, Amblystegium serpens var. serpens; 1, stem leaves; 2, alar cells from different plants (×420); 3, mid-leaf cells (×420); 4, capsule. 5–8, A. serpens var. salinum: 5, stem leaves; 6, alar cells (×420); 7, mid-leaf cells (×420); 8, capsule. 9–12, A. varium: 9, stem leaves; 10, alar cells (×210); 11, mid-leaf cells (×420); 12, capsule. Leaves ×65, capsules ×19.

160 Amblystegium

765

Although some authorities consider A. juratzkanum Schimp. to be a good species it is quite impossible to separate it from A. serpens. A. juratzkanum is described as having spreading leaves, a longer costa than A. serpens and rectangular basal marginal cells. Having examined a considerable number of gatherings of both I found that there is no correlation between the characters given. Several of the gatherings could well be small forms of A. varium but cannot be named with certainty. A. varium usually differs in the larger wider stem leaves and the leaf cells are relatively shorter than in larger forms of A. serpens.

2 A. varium (Hedw.) Lindb., Musci Scand., 1870 (Fig. 252) Plants slender, forming lax light green patches. Stems irregularly branched, stems and branches ± procumbent. Paraphyllia absent. Leaves patent to spreading when moist, hardly altered when dry; stem leaves mostly 1.0–1.4 mm long, ovate, tapering to long acumen; margins plane, ± entire; costa extending ± to apex; basal cells shortly rectangular, cells above rhomboidal, in mid-leaf 8–12 × 16–32(−44) μm, (1.3−)2.0–4.0(−4.5) times as long as wide, marginal cells from base to widest part of leaf quadrate to rectangular; branch leaves smaller, narrower, with costa extending to 3/4 way up leaf. Capsules erect or inclined, cylindrical, curved; lid with obtuse apiculus; spores 10–16 μm. Capsules occasional, summer. n = 10, 10 + m, 12 + m, 19 + m, 20, 40. On rocks, wood and soil, by streams and pools, in fens, carr and on marshy ground. Lowland. Rare to occasional in most of England and Wales, rare or very rare in Scotland, extending north to W. Sutherland and Barra, rare in Ireland. 76, H20, C. GB184 + 60∗ , IR17 + 15∗ , C1 + 1∗ . Circumpolar Temperate. Europe north to Fennoscandia, Caucasus, Turkey, Iran, Siberia, China, Tenerife, La Palma, Madeira, Azores, Algeria, Egypt, Morocco, N. America, Mexico, Haiti. Apparently very variable cytologically but in view of the difficulty of separating some forms of this species from A. serpens and A. humile (q.v.) this variation is open to question.

3 A. humile (P. Beauv.) Crundw., J. Bryol., 1981 (Fig. 253) A. kochii Schimp., Leptodictyium humile (P. Beauv.) Ochyra, L. kochii (Schimp.) Warnst., L. trichopodium (Schultz) Warnst. Plants slender to medium-sized, dull green straggling shoots or patches. Stems procumbent, irregularly branched, branches procumbent or ascending. Paraphyllia lacking. Leaves distant, patent to spreading, both when moist and when dry, stem leaves 1.2–2.2 mm long, ovate, narrowed at insertion, not decurrent, tapering to acuminate apex; margins plane, entire; costa extending 1/ –3/ way up leaf; basal cells rectangular, cells above ± rhomboidal, in mid2 4 leaf 8–12(−18) × 28–56(−72) μm, 2.5–5.0 times as long as wide. Branch leaves smaller, ovate-lanceolate. Capsules inclined, narrowly ellipsoid, curved; lid conical; spores 14–16 μm. On soil, rocks and tree bases by streams, in moist turf, carr and marshy ground. Lowland. Rare or occasional in lowland England, very rare in Wales and Scotland, extending north to Angus and Caithness, Roscommon,

766

56 Amblystegiaceae

Fig. 253 1–4, Amblystegium radicale: 1, stem leaves (×40); 2, alar cells (×210); 3, mid-leaf cells (×420); 4, capsule. 5–7, A. humile: 5, leaves (×40); 6, alar cells (×210); 7, mid-leaf cells (×420). 8–12, A. confervoides: 8, stem leaves (×63); 9, alar cells (×210); 10, leaf apex (×420); 11, perichaetial leaf (×63); 12, capsule. Capsules ×10.

160 Amblystegium

767

Antrim, Londonderry (old record). 52, H3. GB43 + 23∗ , IR2 + 1∗ . Circumpolar Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Iran, Himalayas, Siberia, New Guinea, N. America, Mexico. Probably under-recorded, often growing in similar habitats to and similar in appearance to A. radicale, A. serpens, A. varium and Leptodictyum riparium. A. radicale differs in the decurrent leaf bases. A. humile differs from A. serpens and A. varium in the larger stem leaves markedly narrowed at the base and from the former in the less crowded more spreading leaves and from the latter in the shorter costa. L. riparium has the leaves subcomplanate with longer cells.

4 A. radicale (P. Beauv.) Schimp. in Bruch et al., Bryol. Eur., 1853 A. saxatile Schimp., Campylium radicale (P. Beauv.) Grout

(Fig. 253)

Plants of moderate size, forming lax straggling yellowish green patches. Stems procumbent, irregularly branched. Lanceolate paraphyllia present. Leaves patent to spreading when moist and when dry, stem leaves 0.8–1.4 mm long, from ovate-cordate basal part rapidly tapering to long channelled acumen, base longly decurrent; margins sinuose with projecting cell ends; costa extending between half way up and base of acumen of leaf; alar cells enlarged, rectangular, decurrent but not forming auricles, cells above narrowly ellipsoid, in mid-leaf 6–9 × 32–64 μm, 4–7(−10) times as long as wide. Branch leaves smaller and narrower. Setae flexuose, orange to red, c. 4 cm long; capsules ± horizontal, ellipsoid, curved; lid conical, subacute; spores 10–18 μm. Capsules common, June. In damp stagnant conditions on decaying vegetation on marshy ground and in peat cuttings. Lowland. Very rare, E. Cornwall, Merioneth. 2. GB2. European Temperate. Europe north to Norway and Sweden, Iceland, Crimea, Japan, N. America, Ecuador. A. radicale may be confused with A. humile but sporophytes are frequently produced and the setae are conspicuously long and flexuose; the decurrent leaf bases are distinctive. For an account of the plant in Britain see A. C. Crundwell & E. Nyholm, Trans. Br. Bryol. Soc. 4, 638–41, 1964. This is a critically endangered species in the Red List of British Mosses.

5 A. confervoides (Brid.) Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 253) Amblystegiella confervoides (Brid.) Loeske, Platydictya confervoides (Brid.) Crum Autoicous. Plants exceedingly slender, forming dull green confervoid patches. Stems irregularly branched. Paraphyllia absent. Stem leaves minute, 0.10– 0.25(−0.42) mm long, appressed when dry, erect-patent, sometimes slightly curved when moist, lanceolate, acute; margins plane, entire or sinuose; costa absent; basal cells shortly rectangular, alar cells ± quadrate and extending short distance up margins, cells above ± rhomboidal, in mid-leaf 5–10 × 12–24 μm, 1.5– 4.0 times as long as wide, cells near apex 2–3 times as long as wide. Perichaetial

768

56 Amblystegiaceae

leaves with long acumens; margins entire or finely denticulate. Capsules ± horizontal, gibbous; spores 8–10 μm. Capsules frequent, summer. On calcareous, usually limestone rock, rarely chalk, in sheltered situations, in woodland, on vertical rock faces and clefts in rock faces. 0–300 m. Rare to occasional in scattered localities from E. Cornwall and S. Devon east to Surrey and north to Banff, very rare in Ireland. 26, H7. GB23 + 21∗ , IR2 + 5∗ . European Temperate. Europe north to southern Norway, Caucasus, Madeira, N. America. Likely to be confused with Platydictya jungermannioides (q.v.).

161 HYGROAMBLYSTEGIUM LOESKE, MOOSFL. HARZ., 1903 Dioicous. Shoots stiff, dark green. Stems simple or irregularly branched. Paraphyllia absent. Leaves straight, patent, sometimes weakly homomallous when moist, lanceolate or ovate-lanceolate, acute or bluntly acute; margins entire or denticulate above; costa stout, extending ± to apex to excurrent; cells thickwalled, prosenchymatous, alar cells not differentiated. Capsules ± horizontal, shortly cylindrical, curved; peristome double; lid conical. Plants of aquatic habitats. Plants forming ± elongate tufts, stems irregularly branched, leaf apices obtuse 1. H. fluviatile Plants forming intricate patches, stems ± pinnately branched, leaf apices ± acute 2. H. tenax 1 H. fluviatile (Hedw.) Loeske, Moosfl. Harz. I, 1903 Amblystegium fluviatile (Hedw.) Schimp.

(Fig. 254)

Plants slender to moderately slender, forming dark green ± elongate tufts. Stems sparsely and irregularly branched, branches long. Paraphyllia lacking. Leaves appressed when dry, erect-patent to patent when moist, concave; stem leaves ovate to lanceolate, sometimes slightly curved, obtuse; margins plane, entire or sometimes sinuose above with projecting cell ends; costa stout, brownish, 40–70 μm wide near base, ending in apex to shortly excurrent, basal cells quadrate-rectangular, cells above rhomboidal to narrowly rhomboidal, in midleaf 6–10 × (16−)20–44 μm, 2–4(−6) times as long as wide. Capsules inclined, cylindrical, curved; lid conical, acute; spores 12–18 μm. Capsules rare, late summer. n = 20∗ . On submerged or frequently inundated rocks, stones, tree boles and exposed roots in fast-flowing streams and rivers. Lowland. Occasional to common in S. W. and northern England and in Wales, occasional in southern and eastern Scotland, extending north to Caithness, Berkshire, Stafford, rare in Ireland. 67, H12, C. GB254 + 42∗ , IR8 + 8∗ , C1. European Boreo-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Madeira, Algeria, Morocco, N. and C. America, Andes.

161 Hygroamblystegium

769

Fig. 254 Hygroamblystegium tenax: 1, stem leaves (×40); 2, leaf apex (×100); 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule (×10). 6–10, H. fluviatile: 6, stem leaves (×40); 7, leaf apex (×100); 8, alar cells (×210); 9, mid-leaf cells (×420); 10, capsule (×10). 11–14, Conardia compacta: 11, stem leaves (×63); 12, alar cells (×420); 13, mid-leaf cells (×420); 14, gemmae (×210).

770

56 Amblystegiaceae

2 H. tenax (Hedw.) Jenn., Man. Mosses W. Pennsylvania, 1913 (Fig. 254) Amblystegium irriguum (Hook. & Wilson) Schimp., Amblystegium tenax (Hedw.) C. E. O. Jensen Plants slender, forming dark green intricate patches. Stems wiry, denuded below, irregularly pinnately branched, branches relatively short. Paraphyllia lacking. Leaves rigid, loosely appressed when dry, erect-patent, sometimes subsecund when moist, ± concave; stem leaves ovate to lanceolate, sometimes curved, tapering to ± acute apex; margins plane, entire or denticulate above; costa stout, brownish, ending just below apex to shortly excurrent, usually 50– 60 μm wide near base; basal cells quadrate-rectangular, cells above rhomboidhexagonal, in mid-leaf 8–11 × 16–28(−40) μm, 2–4 times as long as wide. Capsules inclined, ellipsoid to cylindrical, curved; lid conical, acute; spores 16–20 μm. Capsules frequent, spring, summer. n = 12, 20∗ , 30∗ . On submerged or frequently immersed rocks, stones and exposed roots in basic streams and rivers. 0–420 m. Occasional to frequent throughout most of England, Wales and S. E. Scotland, very rare further north, extending to Orkney, rare in Ireland. 89, H18, C. GB341 + 65∗ , IR13 + 9∗ , C1 + 1∗ . Circumpolar Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Siberia, Altai, Azores, Algeria, Morocco, N. America. H. fluviatile is a softer plant, the patches less intricate, the stems and branches forming congested tufts; the leaves are also relatively shorter with obtuse or rounded apices. A. varium has thinner costae, the leaves are ± spreading when dry, the whole plant is softer in texture and occurs in a different habitat.

162 LEPTODICTYUM (SCHIMP.) WARNST., KRYPT.-FL. BRANDENBURG, LAUBM., 1906 Autoicous. Plants slender to moderately robust. Stems procumbent to ascending, irregularly or subpinnately branched. Paraphyllia lacking. Leaves ± spreading, sometimes subcomplanate, lanceolate to ovate, tapering to long plane acumen; margins plane, entire or nearly so; costa single, thin, ending at or above middle of leaf; cells rhomboid-hexagonal to linear, thin-walled, smooth, alar cells slightly differentiated or not. Perichaetial leaves ± plicate. Capsules inclined, narrowly ellipsoid to subcylindrical, curved; annulus differentiated; lid obtuse or acute; peristome double, inner with nodulose cilia. Derivation: meaning with a fine network.

1 L. riparium (Hedw,) Warnst., Krypt.-fl. Brandenburg Laubm., 1906 Amblystegium riparium (Hedw.) Schimp., Hypnum riparium Hedw.

(Fig. 255)

Autoicous. Plants slender to moderately robust, forming bright or yellowish green, lax, sometimes extensive patches. Stems procumbent or rarely ascending,

162 Leptodictyum

771

Fig. 255 1–4, Campylium stellatum: 1, stem leaf (×40); 2, alar cells (×210); 3, mid-leaf cells (×420); 4, capsule. 5–8, C. protensum: 5, stem leaf (×40); 6, alar cells (×210); 7, mid-leaf cells (×420); 8, capsule. 9–12, Leptodictyum riparium: 9, stem leaves (×25); 10, alar cells (×210); 11, mid-leaf cells (×420); 12, capsule. Capsules ×10.

772

57 Campyliaceae

irregularly to subpinnately branched. Leaves usually subcomplanate, crowded to distant, divergent, sometimes falcate-secund towards stem and branch apices, hardly altered when dry, usually lanceolate or ovate-lanceolate, gradually tapering to long acuminate apex, but varying in shape from narrowly lanceolate with long filiform acumen to ovate-triangular and acuminate; margins entire or sometimes sinuose with projecting cell ends, occasionally faintly denticulate near apex; costa weak or strong, extending to 2/3 way up leaf to almost to apex, basal cells incrassate, rectangular, pellucid, alar cells not differentiated, not decurrent, cells above linear-rhomboidal, in mid-leaf 5–12 × 40–120 μm, (5−)7– 15 times as long as wide. Capsules inclined, narrowly ellipsoid to shortly cylindrical, curved; lid conical, obtuse; spores 12–16 μm. Capsules frequent, spring to autumn. n = 10∗ , 12, 20∗ , 21, 24, 40, 46. On moist logs, tree boles, exposed roots, stones and soil, on litter in fens, marshes and carr, by pools, canals and slowflowing streams and rivers. Lowland. Common in most of England, occasional to frequent in Wales and eastern Scotland, rare or very rare in the rest of Scotland, extending north to Shetland, occasional in Ireland. 103, H33, C. GB971 + 78∗ , IR43 + 13∗ , C3 + 2∗ . Circumpolar Temperate. Europe north to Fennoscandia, Caucasus, Turkey, Siberia, Tibet, Tonkin, Japan, Macaronesia, N. and southern Africa, N. America, Mexico, Guatemala, Cuba, Haiti, Australia, New Zealand, Kerguelen Is.

57 Campyliaceae Autoicous or dioicous. Slender to robust lax tufts to dense mats; stems irregularly to pinnately branched. Paraphyllia present or not. Stem and branch leaves similar although the latter usually smaller with a weaker costa, imbricate to spreading, sometimes secund or falcate-secund when moist, orbicular to narrowly lanceolate, apex rounded to longly and finely acuminate; costa well developed or faint, single, double or absent; cells prosenchymatous and hexagonal to linear, alar cells often differentiated, inflated or not. Perichaetial leaves differentiated from stem leaves. Setae reddish, smooth; capsules inclined or horizontal, ellipsoid to cylindrical, frequently contracted below mouth when dry and empty; lid conical, mamillose or not; peristome double, outer teeth yellowish brown, inner with well developed basal membrane, processes broad, cilia entire; calyptrae cucullate, smooth. Eighteen genera composed mainly of plants of damp or wet habitats.

163 CONARDIA H. ROB., PHYTOLOGIA, 1976 A monotypic genus with the characters of the species. Derivation: named after a N. American botanist, Henry Shoemaker Conard (1874– 1971).

164 Campylium

773

¨ Hal.) H. Rob., Phytologia, 1976 1 C. compacta (Mull. (Fig. 254) ¨ Hal.) Aust., Rhynchostegiella compacta (Mull. ¨ Hal) Amblystegium compactum (Mull. Loeske Dioicous in Europe. Plants very slender, forming dense green or yellowish green patches. Stems procumbent, irregularly branched. Paraphyllia lacking. Leaves appressed when dry, patent to spreading, often slightly secund when moist, stem leaves 0.3–0.7 mm long, lanceolate, ± acute; margins plane, strongly denticulate below, less so above, teeth at widest part of leaf often recurved; costa poorly defined, reaching acumen or percurrent; basal cells rectangular, cells above narrowly rhomboidal, in mid-leaf 5–10 × 28–45 μm, mostly 5–6 times as long as wide. Branch leaves smaller but otherwise similar to stem leaves. Uniseriate gemmae, to 100 μm long often present near leaf apex on abaxial surface. Capsules unknown in Europe. On deeply shaded basic rocks and soil, especially under overhangs. Lowland. Rare or very rare, from S. Devon and I. of Wight north to W. Sutherland, Sligo (old record). 23, H1. GB20 + 12∗ . IR1∗ . Circumpolar Boreal-montane. Europe north to northern Norway, Iceland, Turkey, Israel, Madeira, N. America, Greenland. The leaves sharply toothed below will distinguish C. compacta from species of Amblystegium. In Europe C. compacta is rare, is not known to produce sporophytes and occurs on basic rocks and soil; in N. America it is common, produces sporophytes frequently and occurs ¨ J. Bryol. 15, 779–83. on wood. For the systematic treatment of C. compacta see L. Hedenas, 1989.

164 CAMPYLIUM (SULL.) MITT., J. LINN. SOC. BOT., 1869 Stem cortex of 1–2(−3) layers small thick-walled sells, inner cells thin-walled, central strand present. Paraphyllia present or absent; pseudoparaphyllia foliose. Stem leaves crowded, gradually or abruptly narrowed to channelled acumen; margins plane, entire; costa short, single or double; basal cells ± linear, alar cells heterogeneous, lower enlarged, hyaline, upper clearly smaller, forming ovate or rectangular group extending up basal margins, forming auricles or not, not decurrent, cells above linear. Capsules contracted at mouth when dry; annulus of 2–3 rows of cells, separating; exostome teeth cross-striolate below, papillose above, endostome with nodulose or appendiculate cilia. A small genus of four species of mineral-rich wetlands. Derivation: meaning curved and alluding either to the curved leaves or the arcuate capsules. ¨ Bryologist 100, 65–88, For a description of this and the next two genera see L. Hedenas, ¨ for further information on the two British species 1997, and I am grateful to Dr L. Hedenas of Campylium.

Plants usually erect, stem leaves 2.0–3.6 mm long, acumen when leaves abruptly narrowed constituting 40–65% of leaf length, alar cells forming distinct auricles 1. C. stellatum

774

57 Campyliaceae

Plants usually procumbent, stem leaves 1.2–2.0 mm long, acumen when leaves abruptly narrowed constituting 55–75% of leaf length, alar cells hardly forming distinct auricles 2. C. protensum 1 C. stellatum (Hedw.) C. E. O. Jensen, Meddel. Greenland, 1887 Hypnum stellatum Hedw.

(Fig. 255)

Dioicous. Usually robust plants, forming yellowish green to greenish brown patches, tufts or turfs, to 10 cm high. Stems usually erect, irregularly and sparsely branched, older parts with tomentum of brown rhizoids. Paraphyllia absent. Leaves usually spreading when moist, scarcely altered when dry, rarely falcate, 2.0–3.6 mm long, from broadly cordate concave basal part gradually or abruptly tapering to fine channelled acumen, if abruptly narrowed then acumen constituting 40–65% of leaf length; margins plane, entire or obscurely denticulate at widest part of leaf; costa absent or short and single or double; basal cells linear, alar cells enlarged, quadrate or rectangular, thin-walled in young leaves, incrassate in older leaves, forming distinct hardly decurrent auricles; cells above linear-vermicular, incrassate, porose in lower part of leaf, 5–8 × 36–70 μm, (6−)8–15 times as long as wide in mid-leaf. Branch leaves smaller and narrower than stem leaves. Setae red; capsules inclined, subcylindrical, curved; lid conical with small acute apiculus; peristome double, outer teeth cross-striolate below, papillose above; spores smooth, 12–18 μm; calyptrae cucullate. Capsules rare, late spring, early summer. n = 10, 18 + 2m, 22. In moist or wet, open, base-rich habitats in turf, on tracks, by streams, in flushes, fens, marshes, dune-slacks and on rock ledges. 0–1070 m. Occasional to frequent in lowland England, frequent or common elsewhere, occasional to frequent in Ireland. 109, H38, C. GB983 + 144∗ , IR163 + 6∗ , C5 + 2∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, N., C. and E. Asia, N. America, Greenland, Mexico, Guatemala, New Zealand. 2 C. protensum (Brid.) Kindb., Canad. Rec. Sci., 1894 C. stellatum var. protensum (Brid.) Bryhn

(Fig. 255)

Dioicous. Slender or medium-sized plants, forming green or dull green patches. Stems procumbent, often irregularly pinnately branched, older parts with tomentum of brown rhizoids. Paraphyllia sparse. Leaves spreading and frequently squarrose when moist, scarcely altered when dry, 1.2–2.0 mm long, from concave very broadly cordate basal part gradually or abruptly tapering to fine channelled acumen, if abruptly narrowed then acumen constituting 55–75% of leaf length; margins plane, entire or obscurely denticulate at widest part of leaf; costa absent or short and single or double; basal cells linear, alar cells enlarged, quadrate or rectangular, thin-walled in young leaves, incrassate in older leaves, hardly forming auricles; cells above linear-vermicular, incrassate, porose in lower part of leaf, 5–8 × 36–70 μm, (6−)8–15 times as long as wide in mid-leaf. Branch leaves smaller and narrower than stem leaves. Capsules inclined, subcylindrical, curved;

165 Campyliadelphus

775

lid conical with small acute apiculus; exostome teeth cross-striolate below, papillose above; spores 16–20(−22) μm. Capsules very rare, early summer. n = 10. In ± moist neutral to basic sites in turf, quarries, on banks, woodland rides, on rock ledges in the mountains and in dry grassland and chalk pits. 0–750 m. Occasional to frequent in southern England, common in N. W. England and western Scotland, rare to occasional elsewhere, rare in Ireland. 98, H24. GB353 + 60∗ , IR26 + 6∗ . Circumpolar Boreo-temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Siberia, Altai, Kashmir, Punjab, N. America. Although C. protensum is treated as a variety of C. stellatum by many authors, apart from morphological differences, it tends to grow in drier and more markedly calcareous habitats ¨ (Bryologist 100, 65–88, 1997) I have treated it than C. stellatum and, following L. Hedenas as a distinct species.

165 CAMPYLIADELPHUS (KINDB.) R. S. CHOPRA, TAXON. INDIAN MOSSES, 1975 Plants small to medium-sized. Stem cortex or 2–3 layers small thick-walled cells, inner tissue of large thin or slightly thick-walled cells, central strand present. Paraphyllia absent; pseudoparaphyllia foliose. Stem leaves distant or crowded, from broad basal part gradually or abruptly narrowed to channelled acumen; margins plane to recurved, entire or denticulate; costa long, single; basal cells rectangular or narrowly rectangular, alar cells longly decurrent, homogeneous, small, rectangular to transversely rectangular, forming quadrate to broadly ovate or triangular group, cells above rectangular to linear. Branch leaf cells smooth. Capsules contracted below mouth when dry; annulus of 2–4(−5) rows of cells, separating; lid conical; exostome teeth cross-striolate below, papillose above, endostome with cilia mostly nodulose. Three species of periodically moist calcareous habitats. Derivation: meaning related to Campylium.

Alar cells hardly forming auricles, costa usually extending 1/2 –3/4 way up leaf; margins entire or obscurely denticulate near base 1. C. chrysophyllus Alar cells forming distinct auricles, costa usually extending into acumen; margins obscurely denticulate above 2. C. elodes 1 C. chrysophyllus (Brid.) R. S. Chopra, Taxon. Indian Mosses, 1975 (Fig. 256) Campylium chrysophyllum (Brid.) J. Lange, Hypnum chrysophyllum Brid. Plants slender, forming greenish to golden yellow patches or more rarely tufts. Stems procumbent, rarely ascending or erect, irregularly to subpinnately branched, branches usually ascending to erect. Paraphyllia present. Leaves patent, secund, rarely straight or falcate-secund, 0.9–1.5(−1.8) × 0.36–0.59 mm, from broad ovate-cordate basal part ± rapidly narrowed to long channelled acumen;

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Fig. 256 1–6, Campyliadelphus chrysophyllus 1, 2, stem and branch leaves: 3, alar cells (×210); 4, mid-leaf cells (×420); 5, paraphyllia (×86); 6, capsule. 7–10, C. elodes: 7, stem leaves; 8, alar cells (×210); 9, mid-leaf cells (×420); 10, capsule. Leaves ×40, capsules ×10.

165 Campyliadelphus

777

margins plane, entire or obscurely denticulate at widest part of leaf; costa usually single, extending 1/2 –3/4 way up leaf but sometimes absent; alar cells irregularly quadrate, incrassate, opaque, hardly forming auricles, not decurrent, cells elsewhere in basal part narrowly rhomboidal, 5–7 × 24–44 μm, (4−)5–8 times as long as wide. Capsules suberect to inclined, cylindrical, curved, lid conical; peristome double, outer teeth cross-striolate below, papillose above; spores smooth, c. 24 μm. Capsules rare, spring. Setae reddish; capsules rare, spring. n = 20. In chalk and limestone grassland, old quarries, scree, on rocks, cliffs, old buildings, sand-dunes. Lowland but ascending to 630 m in Angus. Frequent or common in chalk and limestone areas of England and Wales, rare to occasional elsewhere, extending north to Shetland, rare to occasional in Ireland. 94, H34, C. GB416 + 86∗ , IR40 + 18∗ , C2∗ . Circumpolar Boreo-temperate. Europe north to northern Fennoscandia, Iceland, Caucasus, Turkey, C. Asia, Himalayas, China, Korea, Japan, N. Africa, Mexico, Guatemala, Colombia, Patagonia, Greater Antilles. Similar to small forms of Campylium stellatum, especially those in which the leaves have a single costa reaching nearly half way up the leaf; Campyliadelphus chrysophyllus differs in the shorter leaf cells. Occasional plants of C. chrysophyllus may have leaves with the costa very short or lacking but there are always some leaves with well developed costae.

2 C. elodes (Lindb.) Kanda, J. Sci. Hiroshima Univ. ser. B, div. 2, Bot., 1975 (Fig. 256) Campylium elodes (Lindb.) Kindb., Hypnum elodes Spruce Lax or dense green to yellowish patches or straggling shoots. Stems procumbent to ascending, to 5–10 cm long, irregularly pinnately branched, branches ascending to erect. Leaves patent to spreading, sometimes falcate or falcate-secund at stem and branch tips; stem leaves 1.05–2.35 × 0.23–0.56 mm, concave, broadly lanceolate to lanceolate, varying from gradually tapering to abruptly narrowed to long fine channelled acumen; margins plane, obscurely denticulate; costa usually reaching acumen; basal cells quadrate to rectangular, alar cells enlarged, rectangular, forming distinct non-decurrent auricles, cells above linear, in mid-leaf 5–8 × 46– 100 μm, (7−)8–18 times as long as wide. Branch leaves smaller and narrower than stem leaves. Capsules inclined, ellipsoid, curved; lid with acute apiculus; spores 12– 17 μm. Capsules rare, early summer. In open or lightly shaded calcareous sites, in fens, marshes, wet woodland, on heaths, mixed with other bryophytes or on litter. Lowland. Rare to occasional but widely distributed throughout the British Isles. 55, H24. GB72 + 39∗ . IR18 + 11∗ . European Temperate. Europe north to Fennoscandia, Himalayas, Siberia, Japan. The relatively long costa and obscurely denticulate margins will distinguish this plant from C. chrysophyllus and Campylophyllum calcareum.

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57 Campyliaceae

¨ 166 DREPANOCLADUS (MULL. HAL.) ROTH, HEDWIGIA, 1899 Dioicous or autoicous. Plants medium-sized to robust, green, yellowish or brownish. Stems procumbent to ascending, irregularly to pinnately branched. Paraphyllia lacking. Leaves erect to spreading, straight or falcate, concave, not plicate, ovate to narrowly lanceolate, gradually tapering to acuminate apex; margins plane, entire or obscurely denticulate; costa single, extending 2/5 or more way up leaf, sometimes excurrent; basal cells narrowly rectangular, alar cells inflated, hyaline, forming auricles, cells above linear, ± vermicular, incrassate or not, smooth. Setae long, flexuose; capsules horizontal, shortly cylindrical, curved; lid conical, apiculate; annulus separating; peristome perfect, inner with nodulose or appendiculate cilia. A small genus of plants occurring mainly in moist or wet habitats. Derivation: meaning curved branches.

1 Alar cells not inflated, differentiated into yellowish to orange-brown poorly defined to distinct non-decurrent auricles, costa 60–100(−120) μm wide near base, extending into acumen 2. D. sendtneri Alar cells enlarged or inflated, forming hyaline decurrent auricles, costa to 2 60 μm wide near base, extending 1/2 –3/4 way up leaf 2 Basal cells porose, auricles extending to costa, mid-leaf cells 12–18 times as long as wide, leaf acumens long, fine, channelled 1. D. polygamus Basal cells not porose, auricles not extending to costa, mid-leaf cells mostly 9–12 times as long as wide, leaf acumens long but not fine or channelled 3. D. aduncus ¨ Bryologist, 1997 1 D. polygamus (Schimp.) Hedenas, (Fig. 257) Campyliadelphus polygamus (Schimp.) Kanda, Campylium polygamum (Schimp.) J. Lange & C. E. O. Jensen, Hypnum polygamum Schimp. Autoicous or synoicous. Plants slender to moderately robust, forming yellowish green to golden yellow patches or coarse wefts. Stems procumbent, ascending or scrambling, occasionally erect, irregularly branched. Leaves patent to spreading, sometimes subsecund, 1.6–3.0 mm long, narrowly to broadly lanceolate, tapering to long fine channelled acumen; margins plane, entire; costa thin, extending 1/2 –3/4 way up leaf; alar cells enlarged, quadrate to rectangular, forming decurrent auricles extending almost to costa, other cells in lower part of leaf linear, incrassate, porose, in mid-leaf 5–10(−12) × 100–120 μm, 12–18 times as long as wide. Capsules inclined, ellipsoid to subcylindrical, curved; lid with short acute apiculus; spores 20–24 μm. Capsules occasional to frequent, summer. In damp turf, flushes, gravel pits, and particularly along the coast in dune-slacks and salt-marshes, usually in open habitats where the ground water is calcareous or salty. Lowland but ascending to 850 m in Angus. Occasional throughout the British Isles. 84, H19. GB105 + 51∗ , IR13 + 11∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Asia, N. Africa, N. America, Greenland, New Guinea,

166 Drepanocladus

779

Fig. 257 1–4, Drepanocladus polygamus: 1, stem leaf (×25); 2, alar cells (×210); 3, mid-leaf cells (×420); 4, capsule (×10). 5–7, D. sendtneri: 5, stem leaves (×25); 6, 7, alar cells from slender and robust plants (×280); 8, mid-leaf cells (×420).

Tanzania, Bolivia, Peru, Colombia, S. Africa, Australia, New Zealand, Tristan da Cunha, S. Georgia, Antarctica (to c. 71 ◦ S). Likely to be confused with Campylium stellatum but differing in leaf shape, the costa extending 1/2 –3/4 way up the leaf and the longer cells.

2 D. sendtneri (Schimp.) Warnst., Beih. Bot. Centralbl., 1903 (Fig. 257) D. sendtneri var. wilsonii (Lindb.) Warnst., Hypnum sendtneri Schimp., H. wilsonii Lindb. Dioicous. Plants medium-sized to robust, forming green to greenish brown, reddish or golden brown patches. Stems procumbent, simple to pinnately branched.

780

57 Campyliaceae

Leaves secund, falcate to strongly falcate-secund; stem leaves 2.4–4.4 mm long, ovate-lanceolate to lanceolate, gradually tapering to long acuminate apex, base not decurrent; margins plane, entire; costa strong, extending into acumen, 60– 100(−120) μm wide near base; basal cells rhomboidal, incrassate, porose, orange to yellowish brown, alar cells differentiated into small non-decurrent auricles, not reaching costa, these auricles distinct in small plants, poorly defined in robust plants, cells above linear, in mid-leaf 6–7 × 56–80(−104) μm, 6–16 times as long as wide. Capsules suberect, cylindrical, curved; spores c. 16 μm. Capsules very rare, summer. In and at edges of pools on sand-dunes, in marl pits and periodically flooded hollows in limestone, in highly calcareous habitats. Lowland. Rare or very rare, widely distributed but now extinct in many sites, from W. Cornwall to E. Kent and north to Caithness and the Outer Hebrides, rare in Ireland. 48, H11. GB36 + 38∗ , IR8 + 4∗ . Circumpolar Boreo-arctic Montane. Europe north to Fennoscandia, Iceland, Caucasus, Siberia, Szechwan, northern N. America, Greenland, Kerguelen Is. The plant referred to as var. wilsonii is a large form with larger leaves and smaller auricles but the range of forms between this taxon and more typical plants is such as to make discrimination impossible. Large plants may be difficult to separate from Pseudocalliergon lycopodioides. That species has relatively wider leaves, thinner costae and hardly differentiated alar cells.

3 D. aduncus (Hedw.) Warnst., Beih. Bot. Centralbl., 1903 Hypnum aduncum Hedw.

(Fig. 258)

Dioicous. Plants medium-sized, soft in texture, forming dull green to yellowish green or brownish patches, sometimes extensive. Shoots to 30(−45) cm long; stems procumbent but often with upturned tips, irregularly to pinnately branched. Leaves patent, straight to falcate-secund; stem leaves ovate-triangular to ovatelanceolate, shortly to longly tapering to long acuminate apex, base cordate, slightly decurrent; margins plane, entire or slightly sinuose; costa 40–60 μm wide near base, extending 1/2 –3/4 way up leaf; basal cells irregularly rectangular, incrassate, not porose, alar cells inflated, hyaline to yellowish, forming distinct hardly decurrent auricles, not or scarcely reaching costa, cells above linear-rhomboidal to linear, in mid-leaf 5–10 × 35–80(−140) μm, (7−)9–12(−14) times as long as wide. Capsules inclined, cylindrical, curved; annulus separating; spores c. 16 μm. Capsules very rare, summer. n = 12. On wet ground, often submerged, in and by pools, marshes, upper reaches of salt-marshes, dune-slacks, ditches, damp tracks, usually where the ground water is base-rich and eutrophic. Lowland. Frequent or common in lowland England, rare to occasional elsewhere and in Ireland. 106, H27, C. GB501 + 103∗ , IR29 + 13∗ , C4. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, N. and C. Asia, Szechwan, N. America, Greenland, Mexico, Peru, Australia, New Zealand, Kerguelen Is. An extremely variable species which appears to be strongly subject to environmental modification. In a revision of D. aduncus, J. Zarnowiec (A Taxonomic Monograph of the

167 Warnstorfia

781

Fig. 258 Drepanocladus aduncus: 1, stem leaves (×25); 2, alar cells (×280); 3, mid-leaf cells (×420). ´ z Technical Drepanocladus aduncus Group (Bryopsida: Amblystegiaceae). Bielsko-Biala: tod´ University, 2001) recognised four species in the D. aduncus complex, three of which, D. aduncus, D. polycarpos (Bland ex Voit) Warnst. and D. stagnatus Zarnowiec, he reported from Britain. For a brief account of his observations see M. O. Hill, Bull. Br. Bryol. Soc. 78. 59–61. 2002. However, I found it impossible to separate D. stagnatum and D. aduncus using the characters given and Dr M. O. Hill (pers. commun.) has found D. aduncus and D. polycarpos physically joined, forming a single plant. On the basis of these observations I do not consider that the three taxa reported from Britain can be sustained. Most likely to be confused with Warnstorfia exannulata and W. fluitans, but differing in the entire leaves and the auricles hardly reaching the costa. D. sendtneri has less distinct, more opaque auricles, a stronger costa extending further up the leaf and porose basal cells.

167 WARNSTORFIA LOESKE, VERH. BOT. VEREINS PROV. BRANDENBURG, 1908 Dioicous or autoicous. Plants medium-sized to robust, yellowish green to reddish brown or brown. Stems irregularly branched. Paraphyllia lacking. Axillary hairs 1–7 cells long, abundant. Stem leaves straight or falcate, concave, triangular to narrowly ovate, apex longly or shortly acuminate, obtuse or rounded; margins plane, entire, sinuose or denticulate; costa single, weak or strong, extending from

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57 Campyliaceae

2/ 3

way up leaf to excurrent; basal cells narrowly rectangular, alar cells quadrate or rectangular or inflated, thin-walled to incrassate, forming distinct or indistinct group, not or scarcely decurrent, cells above linear. Branch leaves smaller and sometimes narrower. Setae flexuose; capsules inclined to horizontal, shortly cylindrical, curved; annulus not separating; lid conical; peristome perfect, endostome with nodulose cilia; calyptrae cucullate. A small genus of 13–20 species.

Derivation: named after Carl Friedrich Warnstorf (1837–1921), a German bryologist. ¨ J. Bryol. 17, 447–79, For a discussion of this and the next two genera see L. Hedenas, 1993.

1 Leaves oblong-lanceolate, apices obtuse to rounded, apiculate or not 3. W. sarmentosa Leaves ovate-lanceolate to narrowly lanceolate, gradually tapering to acuminate apex 2 2 Costa extending to 3/4 way up leaf, plano-convex in section, alar cells to 50(−60) μm long and hardly forming distinct auricles 1. W. fluitans Costa reaching acumen, biconvex in section, largest alar cells 70–150 μm long, forming distinct auricles 2. W. exannulata 1 W. fluitans (Hedw.) Loeske in Nitardy, Hedwigia, 1907 (Fig. 259) Drepanocladus fluitans (Hedw.) Warnst., D. fluitans var. falcatus (Sanio ex C. E. O. Jensen) Roth, D. h-schulzei (Limpr.) Loeske, Hypnum fluitans Hedw. Autoicous. Plants medium-sized, forming dull green to greenish brown or reddish brown tufts or patches. Shoots to 16 cm long, usually soft in texture; stems irregularly or rarely pinnately branched. Pseudoparaphyllia mostly longer than wide. Leaves straight to subfalcate, rarely falcate; stem leaves narrowly lanceolate to ovate-lanceolate, gradually tapering to acuminate to longly acuminate apex; margins plane, denticulate; costa single, extending 1/2 –3/4 way up leaf, 40–60 μm wide near base, in section plano-convex (plane on adaxial side, convex on abaxial side) or biconvex; basal cells irregularly rectangular, alar cells enlarged, to 50(−60) μm long thin-walled to incrassate, hyaline to orange-brown, not or scarcely forming auricles, not decurrent, extending to costa, cells above linear, 4–10 × 80–160 μm, 10–20 times as long as wide. Setae 1–12 cm long; capsules inclined to horizontal, shortly cylindrical, curved; annulus lacking; spores 16–24 μm. Capsules occasional, summer, autumn. n = 22, 22 + 2m, 24. In acidic, nutrient-poor pools and seepage areas on wet heath and blanket bog. 0–870 m. Occasional to frequent throughout Britain, rare in Ireland. 108, H18. GB521 + 103∗ , IR21 + 6∗ . Circumpolar Boreotemperate. More or less cosmopolitan. A very variable species. Although var. falcatus has been shown to have a genetic basis (see E. Lodge, Svensk. Bot. Tidskr. 54, 468–86, 1960), no consistent differences exist between it and var. fluitans and it is not recognised here. The alar cells of W. fluitans extend to the costa and may be mistaken for basal cells but are considerably shorter and wider than the basal

167 Warnstorfia

783

Fig. 259 1–4, Warnstorfia exannulata: 1, stem leaves (×25); 2, 3, alar cells from different plants (×280); 4, mid-leaf cells (×420). 5–8, W. fluitans: 5, leaves (×25); 6, 7, alar cells from different plants (×280); 8, mid-leaf cells (×420).

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57 Campyliaceae

cells. Forms of W. fluitans with incrassate alar cells may be mistaken for W. exannulata which, however, has pronounced auricles which are lacking in W. fluitans. The latter species also shorter alar cells and occurs in more acidic habitats. The alar cells of both species extending to the costa and the denticulate leaf margins will distinguish both from Drepanocladus species.

2 W. exannulata (Schimp.) Loeske in Nitardy, Hedwigia, 1907 (Fig. 259) Drepanocladus exannulatus (Schimp.) Warnst., D. exannulatus var. rotae (De Not.) ¨ Monk., Hypnum exannulatum Schimp. Dioicous. Plants medium-sized, forming dull green to brownish or deep red tufts or patches. Shoots 20–30 cm long; stems sparsely to regularly pinnately branched. Pseudoparaphyllia mostly wider than long. Leaves straight or more usually falcate or falcate-secund; stem leaves ovate to narrowly lanceolate, tapering to long acumen; margins plane, denticulate; costa single, stout, biconvex, usually reddish or brownish, 50–100 μm wide near base, extending into acumen; basal cells rectangular, alar cells inflated or elongate, hyaline to reddish or brownish, largest 70–150 μm long, forming distinct non-decurrent auricles, cells above linear-rhomboidal, in mid-leaf 4–8 × 40–80 μm, (6−)7–12(−17) times as long as wide. Capsules inclined, shortly cylindrical, curved; spores 16–20 μm. Capsules rare, summer. In mildly acidic, nutrient-poor sites on wet heaths, edges of pools, in springs, fens and bogs in lowland and upland habitats. 0–1335 m. Locally frequent in some parts of lowland England but rare or absent in others, frequent or common in S. W. and N. W. England, Wales and Scotland, occasional in Ireland. 82, H28. GB512 + 64∗ , IR42 + 8∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Altai, Kashmir, Yunnan, Japan, N. America, Greenland, Falkland Islands, New Zealand. Although the plant referred to as var. rotae has been shown to have a genetic basis (E. Lodge, Svensk Bot. Tidskr. 54, 368–86, 1960) the variety is not recognised here because of the number of intermediates.

¨ J. Bryol. 17, 1993 3 W. sarmentosa (Wahlenb.) Hedenas, (Fig. 260) Acrocladium sarmentosum (Wahlenb.) P. W. Richards & E. C. Wallace, Calliergon sarmentosum (Wahlenb.) Kindb., Hypnum sarmentosum Wahlenb., Sarmentypnum sarmentosum (Wahlenb.) Tuom. & T. J. Kop. Dioicous. Plants of moderate size, forming deep purplish red tufts, sometimes variegated with green or yellow. Shoots to 12 cm long; stems irregularly branched, branches short, stem and branch tips sometimes cuspidate. Leaves imbricate to erect-patent when moist and when dry; stem leaves concave, ovate-triangular to ovate-oblong, apex obtuse or rounded and apiculate, sometimes subcucullate; margins entire, plane below, ± erect above; costa extending 3/4 or more way up leaf; alar cells inflated, hyaline when young, reddish in older leaves, forming distinct decurrent auricles, cells above incrassate, linear, 5–7 × 44–80 μm, 8–14 times as long as wide. Branch leaves small and narrow. Capsules inclined, narrowly

167 Warnstorfia

785

Fig. 260 1–2, Warnstorfia sarmentosa: 1, 2, stem and branch leaves (×25); 3, alar cells (×210); 4, mid-leaf cells (×420). 5–10, Straminergon stramineum: 5, shoot (×2); 6, 7, stem and branch leaves (×25); 8, alar cells (×210); 9, mid-leaf cells (×420); 10, capsule (×10).

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ellipsoid; spores c. 16 μm. Capsules very rare, summer. In flushes, springs and on dripping rock faces in open habitats with some trace of base. 0–1070 m. Occasional to frequent in S. W. and N. W. England, Wales and the Scottish Highlands, occasional in the west of Ireland. 55, H10. GB382 + 71∗ , IR38 + 18∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, N. and C. Asia, New Guinea, C. Africa, N. America, Greenland, Patagonia, New Zealand, Subantarctic islands, Antarctica. ¨ J. BRYOL., 1993 168 STRAMINERGON HEDENAS, A monotypic genus with the characters of the species. Derivation: meaning straw yellow.

¨ J. Bryol., 1993 1 S. stramineum (Brid.) Hedenas, (Fig. 260) Acrocladium stramineum (Brid.) P. W. Richards & E. C. Wallace, Calliergon stramineum (Brid.) Kindb., Hypnum stramineum Brid. Dioicous. Plants medium-sized, forming pale yellowish green tufts, patches or straggling mats, patches or scattered shoots among other bryophytes. Shoots procumbent to ascending, to 25 cm long; stems simple or sparsely branched. Paraphyllia absent. Leaves closely imbricate when moist and when dry; stem leaves concave, ovate to ovate-lanceolate, widest near base, apex obtuse or rounded, often subcucullate; margins entire, plane below, erect or sometimes slightly inflexed above; costa extending 3/4 or more way up leaf; basal cells narrowly rectangular, alar cells inflated, hyaline, forming distinct decurrent auricles, cells above, linear, incrassate, smooth, 5–8 × 50–80 μm, (6−)9–14 times as long as wide. Branch leaves smaller than stem leaves. Capsules inclined, cylindrical, curved; lid with blunt apiculus; peristome perfect, inner with nodulose cilia; spores 12– 16 μm. Capsules rare, summer. On acid peaty wet ground by streams and pools, in flushes, marshes, carr and bogs, often ± submerged. 0–1260 m. Rare to occasional in lowland England, frequent or common elsewhere in England and in Wales, occasional to frequent in Scotland, occasional in Ireland. 104, H30. GB585 + 82∗ , IR29 + 13∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Japan, Kenya, N. America, Greenland, Australia. 169 CALLIERGON (SULL.) KINDB., CANAD. REC. SCI., 1894 Autoicous or dioicous. Large green to brownish plants. Stems sparsely to much branched, branches not complanate; hyalodermis lacking. Paraphyllia lacking. Stem leaves concave, ± broadly ovate, apex obtuse to rounded; margins plane, ± entire; costa stout, single, sometimes forked, extending from 2/3 way up to almost to apex; basal cells narrowly rectangular, incrassate, alar cells rectangular or inflated and hyaline, forming ± well defined broadly decurrent auricles, cells above

169 Calliergon

787

linear. Perichaetial leaves not plicate. Setae long; capsules ± horizontal, ellipsoid, curved; lid conical; annulus not separating; peristome perfect, exostome teeth dotted below, cilia nodulose; calyptrae cucullate. Six or seven species. Derivation: referring to an elegance of appearance.

Stems irregularly to sparsely pinnately branched, leaves without distinct auricles 1. C. cordifolium Stems closely pinnately branched, leaves with distinct decurrent auricles 2. C. giganteum 1 C. cordifolium (Hedw.) Kindb., Canad. Rec. Sci., 1894 (Fig. 261) Acrocladium cordifolium (Hedw.) P. W. Richards & E. C. Wallace, Hypnum cordifolium Hedw. Autoicous. Plants medium-sized, forming light green or yellowish green tufts or patches or scattered shoots among other bryophytes. Shoots procumbent or ascending, to 15 cm long; stems irregularly to sparsely pinnately branched, branches short, branch and stem tips cuspidate. Leaves ± spreading when dry, patent to spreading when moist, concave, broadly ovate to ovate-lanceolate, apex rounded; margins plane, entire; costa single, extending almost to apex; alar cells enlarged, decurrent down stem but not forming distinct auricles, cells above linear, incrassate, in mid-leaf 8–12(−16) × (64−)80–160 μm, (5−)7–20 times as long as wide. Capsules horizontal, ellipsoid, gibbous; spores 10–16 μm, Capsules rare, spring, summer. n = 10, 21∗ , 22∗ . In sheltered or open mildly acidic, particularly swampy situations, by streams, ditches and pools, in marshes, flushes, wet woodland, often submerged. Mainly lowland but ascending to 910 m in E. Inverness. Occasional to frequent throughout the British Isles. 108, H32. GB487 + 101∗ , IR46∗ + 14∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Japan, N. America, Greenland, New Zealand. Straminergon stramineum and Pseudocalliergon trifarium differ in the leaves imbricate when moist and when dry; the former differs in the well defined auricles and the latter in its frequent brownish tinge.

2 C. giganteum (Schimp.) Kindb., Canad. Res. Sci., 1894 (Fig. 261) Acrocladium giganteum (Schimp.) P. W. Richards & E. C. Wallace, Hypnum giganteum Schimp. Dioicous. Plants yellowish green, green or brownish, in dense tufts or patches. Shoots procumbent or ascending, to 20 cm long; stems closely pinnately branched, branches short, of varying length, stem and branch tips usually cuspidate. Leaves, except at stem and branch tips, patent to spreading when dry, patent when moist; stem leaves broadly ovate to ovate-triangular, apex obtuse or rounded, apiculate or not; margins plane, entire; costa single, strong, reddish brown below in older

788

57 Campyliaceae

Fig. 261 Calliergon cordifolium: 1, shoot (×2); 2, stem leaf (×25); 3, alar cells (×210); 4, mid-leaf cells (×420). 5–8, C. giganteum: 5, 6, stem and branch leaves (×25); 7, alar cells (×210); 8, mid-leaf cells (420).

leaves, ending below apex; alar cells inflated, hyaline, forming distinct decurrent auricles, cells above linear, incrassate, 5–10 × 52–100 μm, 7–16 times as long as wide. Branch leaves smaller and narrower. Capsules horizontal, ellipsoid, gibbous; spores 16–20 μm. Capsules very rare, summer. In usually base-rich sites on wet ground, by streams and pools, in fens, marshes and flushes. 0–910 m. Occasional to frequent throughout the British Isles. 88, H36. GB283 + 53∗ , IR62 + 9∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Altai, Siberia, Colorado, Greenland. Sometimes confused with C. cordifolium but that plant is only sparsely branched and although the alar cells are differentiated and decurrent down the stem they do not form distinct auricles.

170 Scorpidium

789

170 SCORPIDIUM (SCHIMP) LIMPR., LAUBM. DEUTSCHL., 1899 Dioicous or autoicous. Plants medium-sized to robust. Stems with weak central strand. Paraphyllia lacking; pseudoparaphyllia broad, foliose, sparse. Stem leaves straight to falcate, concave, broadly ovate to ovate-lanceolate, acuminate to rounded; margins plane, entire or finely denticulate towards apex; costa long and single, short and double or absent; basal cells incrassate, porose, alar cells inflated, forming distinct, hardly decurrent auricles, supra-alar cells not or hardly distinct from other basal cells, cells above linear. Inner perichaetial leaves erect, straight, plicate, ovate to lanceolate, gradually or abruptly narrowed to acuminate apex; margins entire or denticulate. Setae long; vaginula hairy; capsules ± horizontal, cylindrical, curved; annulus separating; peristome perfect, inner with high basal membrane, processes not or narrowly perforated, cilia nodulose; calyptrae cucullate. Three species in Europe. Derivation: so called because of the similarity to a scorpion. ¨ For a description of North European species of this genus and Hamatocaulis see L. Hedenas, Lindbergia 15, 8–36, 1989.

1 Leaf apices rounded to acute, costa usually absent or short and double, rarely reaching half way up leaf 1. S. scorpioides Leaves tapering to acuminate apex, costa single, extending beyond middle of leaf 2 2 Mid-leaf cells 14–96(−120) μm long, with transverse or shortly tapered ends 2. S. cossonii Mid-leaf cells of stem leaves 60–140(−180) μm long, with longly tapered ends 3. S revolvens

1 S. scorpioides (Hedw.) Limpr., Laubm. Deutschl., 1899 Hypnum scorpioides Hedw. (Fig. 262) Dioicous. Robust, dark green to yellowish brown, reddish brown or purplish plants patches. Shoots tumid with imbricate leaves, procumbent, often mud-encrusted and worm-like in appearance, to 15(−25) cm long; stems sparsely branched. Leaves imbricate, falcate-secund, concave, often rugose, ovate, shortly tapered to obtuse or rounded apex with fragile apiculus or more rarely tapering to acute apex; margins plane, entire; costa absent or very short and double, very rarely long and single; basal cells elongate, strongly incrassate, a few alar cells sometimes inflated, thin-walled, forming very small fragile fugacious non-decurrent auricles, cells above linear, in mid-leaf 4–7 × 48–120 μm, 10–20 times as long as wide. Capsules suberect to inclined, cylindrical, curved; spores 18–22 μm. Capsules rare, spring, summer. n = 8, 11∗ . In basic habitats on mud, sometimes submerged, by pools, in fens, marshes, springs, flushes and dune slacks. 0–770 m. Rare in lowland areas, frequent elsewhere in the west and north of Britain, frequent in the west of Ireland, rare elsewhere. 87, H33. GB515 + 83∗ , IR94 + 12∗ .

790

57 Campyliaceae

Fig. 262 1–4, Scorpidium scorpioides: 1, stem leaves (×25); 2, alar cells from very young leaf with inflated thin-walled cells still present (×210); 3, mid-leaf cells (×420); 4, capsule (×10). 5–9, S. revolvens: 5, stem leaves (×30); 6, alar cells from very young leaf with inflated thin-walled cells still present (×210); 7, mid-leaf cells (×420)); 8, leaf base with cortical cells attached (×210); 9, segment of stem section (×420). 10–11, S. cossonii: 10, stem leaf (×30); 11, mid-leaf cells (×420).

170 Scorpidium

791

Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, N. Asia, N. America, Greenland, Andes. ¨ Lindbergia, 1989 2 S. cossonii (Schimp.) Hedenas, (Fig. 262) Drepanocladus cossonii (Schimp.) Loeske, D. revolvens var. intermedius (Lindb.) R. Wilson, Hypnum intermedium (Brid.) F. Web. & D. Mohr, Limprichtia cossonii (Schimp.) Anderson et al. Dioicous. Plants slender to robust, forming yellowish green to green, rarely red or reddish brown tufts or patches. Shoots often ± 2 mm wide; stems procumbent to ascending, irregularly or more usually pinnately branched; outer layer of cortex of large cells. Leaves strongly falcate-secund, concave; stem leaves from ovate or broadly ovate basal part tapering to channelled acumen; margins plane, usually finely denticulate towards apex; costa single, extending c. 3/4 way up leaf; basal cells linear to narrowly rectangular, incrassate, porose, alar cells shorter, wider, less thick-walled, with 2–10(−16) inflated hyaline cells, forming small fragile nondecurrent auricles which are soon lost, cells above linear, shortly tapered or with transverse end walls, 4–8 μm wide, 20–90 μm long, 5–10(−12) times as long as wide. Branch leaves smaller than stem leaves. Setae long; capsules ± horizontal, cylindrical, curved; lid conical; peristome perfect, lower part of outer teeth ± dotted all over, papillose above, cilia nodulose; spores 14–20 μm. Capsules rare, summer. n = 10 + m∗ . In base-rich mires, fens, dune-slacks. Frequency and attitudinal range uncertain because of confusion with S. revolvens but more common in lowland areas than that species. 37, H26. Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Caucasus, N. America. S. cossonii is a plant of more base-rich habitats then S. revolvens. Whilst S. cossonii is a usually more slender plant than S. revolvens, frequently pale green or yellowish green, the two have been considered synonymous by many recent authors because of intermediate forms. ¨ (Lindbergia 15, 8–36, 1989). However, they have been shown to be distinct by L. Hedenas S. cossonii is dioicous, the mid-leaf cells are shorter and have ± transverse or only shortly tapered ends. There is also a difference in patterning of the peristome tenth but this is not of great practical use as capsules are rare. For further information on the two species in the British Isles see T. L. Blockeel, Bull. Br. Bryol. Soc. 75, 32–40, 2000. This and the next species may be confused with Hamatocaulis vernicosus, but they differ in the relatively longer, narrower, non-plicate leaves with the basal cells not pigmented brown and the large epidermal cells of the stem. Parts of these epidermal cells may tear off with the leaf base and form a useful distinguishing character from H. vernicosus, which may sometimes lack plicate leaves and/or brownish basal cells.

¨ Lindbergia, 1989 3 S. revolvens (Sw.) Hedenas, (Fig. 262) Drepanocladus revolvens (Sw.) Warnst., Hypnum revolvens Sw., Limprichtia revolvens (Sw.) Loeske Autoicous. Plants medium-sized to robust, forming glossy reddish green to purplish black patches, rarely green. Shoots often c. 3 mm wide; stems procumbent

792

57 Campyliaceae

to ascending, irregularly branched; outer layer of cortex of large cells. Leaves strongly falcate-secund to circinate, unaltered or sometimes crisped at tips when dry; stem leaves from ovate base tapering to long channelled acumen, base not decurrent; margins plane, entire or finely denticulate near apex; costa single, extending c. 3/4 way up leaf; basal cells elongate, very incrassate, porose, alar cells shorter, wider, less thick-walled, with 2–10 cells inflated, hyaline, forming small very fragile non-decurrent auricles, usually lost except in young leaves, cells above linear-vermicular, tapering at ends, 4–9 × 60–140(−280) μm, 9–15(−18) times as long as wide. Capsules inclined, shortly cylindrical, curved; lid conical; peristome perfect, outer teeth 60–80(−100)% cross-striolate in lower part, papillose above, cilia nodulose; spores 12–16 μm. Capsules rare, summer. n = 20∗ , 23. In mires, fens, wet peaty rocks and wet gravelly ground. Frequency and altitudinal range uncertain because of confusion with S. cossonii. 17, H17. Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Faeroes, Iceland, Caucasus, N. America, New Guinea, Bolivia, Colombia, southern S. America, New Zealand.

¨ LINDBERGIA, 1989 171 HAMATOCAULIS HEDENAS, A small genus with characters of the two species which differ in leaf morphology. Derivation: meaning bearded stem

¨ Lindbergia, 1989 1 H. vernicosus (Mitt.) Hedenas, (Fig. 263) Drepanocladus vernicosus (Mitt.) Warnst., Hypnum vernicosum Mitt., Scorpidium vernicosum (Mitt.) Tuom. Plants medium-sized, forming green to yellowish green or brown, rarely reddish brown patches, shoot tips often hooked. Stems procumbent to ascending, pinnately branched; central strand lacking, epidermal cells small, incrassate. Paraphyllia lacking; pseudoparaphyllia broad, foliose, sparse. Leaves strongly falcatesecund, finely longitudinally plicate especially when dry; stem leaves ovate, tapering from 1/4 –1/3 way up leaf; margins plane, entire; costa single, extending 1/ –3/ way up leaf; basal cells elongate, incrassate, porose, 1–2 basal rows brown, 2 4 sometimes conspicuously so, a few alar cells rectangular but otherwise not differentiated, not decurrent, in young leaves a few hyaline, very thin-walled inflated fragile cells present, cells above linear, incrassate or not, in mid-leaf (3−)4–7 × 32– 72(−140) μm, (8−)10–20 times as long as wide. Perichaetial leaves erect, straight, ovate-lanceolate; margins entire or slightly denticulate. Setae long; capsules inclined, shortly cylindrical, curved; lid conical, peristome perfect, exostome teeth dotted or dotted-striolate on outer surface below, endostome with high basal membrane, processes entire or narrowly perforated, cilia nodulose; spores 14–18 μm; calyptrae cucullate. Capsules very rare, summer. In bogs, fens and flushes, rarely by streams, in base-rich situations mainly in the uplands. 0–450 m. Occasional

172 Tomentypnum

793

Fig. 263 1–4, Hamatocaulis vernicosus: 1, stem leaves (×50); 2, alar cells (×210); 3, mid-leaf cells (×420); 4, segment of stem section (×210). 5–7, Tomentypnum nitens: 5, stem leaf (×25); 6, mid-leaf cells (×420); 7, capsule (×15).

to frequent in Wales and N. W. England, rare elsewhere from S. Hampshire and Norfolk north to Skye, rare in Ireland. 34, H7. GB70 + 34∗ , IR16 + 5∗ . Circumpolar Boreal-montane. Montane and northern Europe north to Siberia, China, Japan, Algeria, N. America, Greenland, Hispaniola, Venezuela. For some obscure reason H. vernicosus is on the list of species protected under the Wildlife and Countryside Act, 1981. Whilst it is not a common plant it has about twice the frequency of either Drepanocladus sendtneri or Pseudocalliergon lycopodioides, neither of which is even listed as vulnerable in the Red List of British Mosses, let alone in need of protection.

172 TOMENTYPNUM LOESKE, DEUTSCHE BOT. MONATSCHR. 1911 Plants often golden yellow. Stems tomentose, with central strand, branches complanate. Leaves straight, longitudinally plicate, stem leaves with rhizoids arising

794

57 Campyliaceae

on abaxial side at base, base not decurrent; costa well developed; alar cells similar to other basal cells. Setae smooth; capsules horizontal, curved; stomata long; peristome perfect, exostome teeth brownish yellow, pitted below processes and cilia tall. Four species. Derivation: meaning Hpnum with a tomentum. For the reasons for placing this genus in the Amblystegiaceae next to Sanionia see L. ¨ J. Bryol. 14, 729–36, 1987. Hedenas,

1 T. nitens (Hedw.) Loeske, Deutsche Bot. Monatschr., 1911 (Fig. 263) Camptothecium nitens (Hedw.) Schimp., Homalothecium nitens (Hedw.) H. Rob. Dioicous. Moderately robust, yellowish green to golden brown plants, forming patches or occurring as scattered shoots. Stems ascending or erect, tomentose with brown rhizoids, irregularly branched. Leaves erect, strongly plicate when moist and when dry; stem and branch leaves similar, lanceolate-triangular, tapering ± from base to long acuminate apex; margins plane or narrowly recurved, entire or sinuose; costa extending c. 3/4 way up leaf; basal cells rounded-rectangular, incrassate, porose, a few alar cells larger but not forming auricles, not decurrent, cells above linear-vermicular, c. 6 × 48–90 μm, 9–18 times as long as wide. Setae purple; capsules horizontal, cylindrical, curved; lid conical; peristome perfect, outer teeth dotted, cilia nodulose; spores 16–20 μm. Capsules rare, summer. n = 12. In calcareous fens, flushes and wet fields. 0–840 m. Occasional from East Anglia and N. W. Wales north to E. Inverness, Limerick, W. Galway, Kildare, Westmeath, W. Mayo, Tyrone, W. Donegal. 37, H7. GB45 + 28∗ , IR4 + 1∗ . Circumpolar Boreoarctic Montane. A declining species in northern and montane Europe extending north to Svalbard, Iceland, Caucasus, N. and C. Asia, N. America (New Mexico), Greenland.

173 PSEUDOCALLIERGON (LIMPR.) LOESKE, HEDWIGIA, 1907 Dioicous. Plants medium-sized to robust, green to yellowish green or brownish green. Stems simple or pinnately branched. Paraphyllia lacking. Stem leaves weakly to strongly concave, from broadly ovate to ovate-lanceolate basal part abruptly narrowed to rounded or acuminate apex, base decurrent or not; margins plane, entire or denticulate; costa short and double or single and long; alar cells inflated or hardly so, thin-walled or incrassate, cells above linear. Capsules inclined to horizontal, cylindrical, curved; peristome perfect or with teeth of inner narrow. Five North European species. Derivation: meaning resembling Calliergon. ¨ Lindbergia 16, 80–99, 1990. For the treatment of North European taxa see L. Hedenas,

1 Stems leaves tapering to acuminate apex Stem leaf apices rounded or obtuse, apiculate or not

l. P. lycopodioides 2

173 Pseudocalliergon

795

2 Stem leaves ovate or broadly ovate with obtuse apices 2. P. turgescens Stem leaves suborbicular or ovate-orbicular with rounded apices 3. P. trifarium ¨ Lindbergia, 1990 1 P. lycopodioides (Brid.) Hedenas, (Fig. 264) Drepanocladus lycopodioides (Brid.) Warnst., Hypnum lycopodioides Brid., Scorpidium lycopodioides (Brid.) H. K. G. Paul Plants robust, forming greenish brown to yellowish brown patches. Shoots to 25 cm long; stems sparsely branched. Leaves crowded, falcate, concave, rugose when dry; stem leaves 2.6–5.0 mm long, ovate, tapering to acuminate apex; margins plane, entire or obscurely denticulate below; costa single, thin, 40– 60 μm wide near base, ending in acumen; basal cells rhomboidal, incrassate, porose, alar cells quadrate, incrassate, not forming auricles, cells above linear, 5–7 × 56–104 μm, 10–15(−20) times as long as wide. Capsules suberect, cylindrical, curved, lid mamillate; spores 12–18 μm. Usually submerged, in pools in calcareous habitats, turloughs and dune-slacks. Mainly lowland but ascending to 520 m in S. Aberdeen. Rare or very rare but sometimes locally abundant, from Devon, S. Hampshire and E. Anglia north to the Outer Hebrides and Orkney, rare in Ireland. 31, H10. GB37 + 23∗ , IR7 + 5∗ . European Boreo-temperate. Europe north to S. Norway and Finnish Lapland, Iceland, east to Ukraine. 2 P. turgescens (T. Jensen) Loeske, Hedwigia, 1907 (Fig. 264) Hypnum turgescens T. Jensen, Scorpidium turgescens (T. Jensen) Loeske Plants robust, in green to greenish brown patches, sometimes extensive. Shoots ± erect, to 25 cm long, tumid with imbricate leaves; stems sparsely branched. Leaves straight or very slightly secund at shoot tips, imbricate, very concave; stem leaves ovate or broadly ovate, obtuse, sometimes with recurved apiculus, sometimes cucullate; margins entire, inflexed above; costa single or double, extending 1/5 – 2 /5 way up leaf; basal cells rectangular, porose, alar cells quadrate to rectangular, not forming auricles, cells above linear, 7–10 × 48–64 μm, 5–8 times as long as wide. Vegetative propagation by deciduous shoot tips. Capsules inclined, cylindrical, curved; spores 12–18 μm. Capsules unknown in Britain. Locally abundant in mires of pH 6.0–6.1. 1000 m. Very rare, Mid Perth. 1. GB1. Circumpolar Arcticmontane. Montane and northern Europe north to northern Fennoscandia, Caucasus, Turkey, Siberia, Yunnan, N. America, Greenland, Ecuador, Bolivia. Although occurring in only one locality in Britain P. turgescens is locally abundant there (see H. J. B. Birks & J. Dransfield, J. Bryol. 11, 129–33, 1980). A few stems of this species were found amongst other bryophytes collected on Cader Idris, Merioneth in 1922 but the plant has not been seen there since and the source of the alleged Welsh specimens is questionable. This species is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside Act.

796

57 Campyliaceae

Fig. 264 1–4, Pseudocalliergon lycopodioides: 1, Stem leaves; 2, segment of stem section (×210); 3, alar cells (×210); 4, mid-leaf cells (×420); 5–8, P. trifarium: 5, shoot (×2); 6, stem leaf; 7, alar cells (×210); 8, mid-leaf cells (×420). 9–11, P. turgescens: 9, stem leaves; 10, mid-leaf cells (×420); 11, alar cells (×210). Leaves ×25.

174 Sanionia

797

3 P. trifarium (F. Weber & D. Mohr) Loeske, Hedwigia, 1907 (Fig. 264) Acrocladium trifarium (F. Weber & D. Mohr) P. W. Richards, & E. C. Wallace, Calliergon trifarium (F. Weber & D. Mohr) Kindb., Hypnum trifarium F. Weber D. Mohr Plants medium-sized, in yellowish brown to brownish patches. Shoots julaceous, to 25 cm long; stems procumbent, sparsely branched. Leaves imbricate when moist and when dry, concave; stem leaves suborbicular to ovate-orbicular, apex rounded, sometimes subcucullate; margins plane, entire; costa single, extending from 2/3 way up to almost to apex; basal cells rectangular, alar cells inflated, hyaline, hardly forming slightly decurrent auricles, cells above linear, incrassate, in midleaf 5–8 × 52–80 μm, (6−)9–14 times as long as wide. Capsules inclined, cylindrical, curved; lid with blunt apiculus; spores 12–16 μm. Capsules not known in the British Isles. In basic montane flushes, fens and in and by streamlets, turloughs. 0–450 m. Rare to occasional in the Scottish Highlands from Stirling and Perth north to Sutherland, Clare, W. Galway. 17, H2. GB46 + 4∗ , GB2. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, Altai, N. America, Greenland, Haiti, Venezuela.

174 SANIONIA LOESKE, HEDWIGIA, 1907 Autoicous. Plants small to robust. Paraphyllia absent. Stem leaves straight, falcate or circinate, concave, smooth to plicate, tapering from ovate or lanceolate basal part to apex; margins finely to strongly denticulate; costa single, extending to acuminate apex; alar cells thin-walled, hyaline, not or hardly decurrent, cells above linear. Capsules horizontal and curved to erect and straight, cylindrical or subcylindrical; lid conical; peristome perfect or exostome and endostome reduced; calyptrae cucullate. Three North European species. Derivation: named after Carl Gustav Sanio (1832–1891). ¨ Ann. Bot. Fenn. For an account of the North European species of Sanionia see L. Hedenas, 26, 399–419, 1989.

Plants closely pinnately branched, supra-alar cells in smaller group than alar cells, costa clearly defined, walls not porose 1. S. uncinata Plants sparsely and irregularly branched, costa in deep furrow and often hidden, supra-alar cell group as large as or larger than alar group, walls ± porose 2. S. orthothecioides 1 S. uncinata (Hedw.) Loeske, Hedwigia, 1907 (Fig. 265) Drepanocladus uncinatus (Hedw.) Warnst., Hypnum uncinatum Hedw. Autoicous. Plants slender to medium-sized, in pale green to yellowish green patches. Shoots to 10 cm long; stems procumbent to ascending, closely regularly

798

57 Campyliaceae

Fig. 265 1–4, Sanionia uncinata: 1, leaves (×30); 2, alar cells (×210); 3, mid-leaf cells (×420); 4, capsule (×10). 5–7, S. orthothecioides: 5, leaves (×30); 6, alar cells (×210); 7, mid-leaf cells (×420).

174 Sanionia

799

pinnately branched. Leaves falcate-secund to circinate, concave, plicate; stem leaves from broad base longly tapering to ± filiform acumen; margins plane or rarely partly recurved, denticulate above; costa in shallow broad groove, usually readily visible, extending far into acumen; basal cells rectangular, porose, alar cells strongly inflated, forming non- or hardly decurrent auricles, suupra-alar cells forming group usually smaller than alar group, walls not porose, cells above linear, incrassate, in mid-leaf 5–7 × 48–72 μm, 10–14 times as long as wide. Capsules ± horizontal, shortly cylindrical, curved; peristome perfect, inner brownish yellow, basal membrane more than 1/3 total length, cilia well developed; spores 12–16 μm. Capsules frequent to common, spring, summer. n = 10∗ , 11, 12, 20. On tree boles, logs, soil and leaf litter, on rocks by streams and in fens and carr, on flushed rocks, on cliffs and in ravines, in basic and acidic often sheltered habitats. 0–1230 m. Rare to occasional and much reduced in lowland England, frequent or common in S. W. and N. England, Wales and Scotland, rare to occasional in Ireland. 90, H29. GB572 + 86∗ , IR40 + 13∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Kashmir, China, N. America, Greenland, Mexico. Hamatocaulis vernicosus has longitudinally plicate leaves but the leaves are relatively shorter and wider, the plicae fine and the habitat different.

2 S. orthothecioides (Lindb.) Loeske, Hedwigia, 1907 (Fig. 265) Autoicous. Yellow-green glossy patches or scattered shoots among other mosses. Shoots ± procumbent to ascending or erect, 5–8 cm long; stems irregularly and sparsely branched. Leaves strongly falcate, strongly longitudinally plicate; stem leaves ovate-lanceolate, widest above ovate-triangular base, tapering to long acuminate apex; margins recurved for part or whole of length, subentire to sparsely denticulate above; costa strong but sometimes ± concealed in longitudinal furrow, extending to acumen, basal cells incrassate, rectangular, alar cells inflated, hyaline, forming distinct hardly decurrent auricles, supra-alar cells forming a group as large as or larger than alar group, cells above thin-walled or slightly thickened, 5–8 × 37–60 μm, 10–20 times as long as wide. Capsules erect or inclined, cylindrical, straight or slightly curved, lid conical; endostome reduced, yellow, basal membrane 1/4 –1/3 total length of endostome, cilia rudimentary or absent; spores 13–18 μm. Sporophytes not known in Scotland. In sloping mossy turf, on banks and partially buried rocks, in coastal areas. 0–350 m. Very rare, W. Sutherland, St. Kilda, Orkney, Fair Isle, Shetland. 3. GB5. Circumpolar Boreo-arctic Montane. Northern Europe, especially the Arctic coasts, Faeroes, Finland, Iceland, Jan Mayen, Norway, Svalbard, N. Russia, Canada, Alaska. Likely to be confused with S. uncinata but differing in the sparsely irregularly branched stems, the costa often concealed in a deep furrow, and the supra-alar cells in a group as large as or larger than the alar group. S. uncinata has horizontal curved capsules. For an

800

57 Campyliaceae

account of this plant in Scotland see D. G. Long, J. Bryol. 17, 111–17, 1992 and 17, 513–14, 1993.

175 HYGROHYPNUM LINDB., ACTA SOC. SCI. FENN., 1872 Autoicous or dioicous. Slender to robust plants. Stems procumbent to erect, sometimes denuded below, with or without sparse rhizoids. Leaves usually crowded, imbricate to spreading, sometimes secund or falcate-secund, ± concave, plicate, ovate-lanceolate and acuminate to ± orbicular; margins, entire or denticulate, costa short or long, single, forked above, or double or absent; alar cells shorter and wider than elsewhere, sometimes enlarged or inflated, hyaline or coloured, thin-walled to incrassate, other cells incrassate, blunt-ended, smooth, shorter near apex. Setae red; capsules inclined to horizontal, ovoid to cylindrical, curved, contracted below mouth when dry and empty; annulus present; peristome perfect; lid conical. A small genus of c. 38 species, distributed through Europe, Asia, central Africa, the Americas. Derivation: meaning a Hypnum of aquatic habitats.

1 Leaves ovate-oblong to ovate-lanceolate, gradually or abruptly tapering to apex 2 Leaves broadly ovate-orbicular, apex wide, obtuse or rounded or leaves broadly ovate and abruptly narrowed to apiculus 5 2 Alar cells inflated, thin-walled, hyaline, forming distinct small but fragile 1. H. ochraceum decurrent auricles1 Alar cells inflated or not, usually coloured at least in older leaves, not forming decurrent auricles 3 3 Costa ending in leaf apex or percurrent 2. H. polare 4 Costa absent or single or double, not extending more than 3/4 way up leaf 4 Costa extending to (1/2 −)3/4 way up leaf, alar cells with granulose contents 3. H. luridum Costa rarely extending more than 1/4 way up leaf, alar cells without granulose contents 5. H. eugyrium 5 Leaves ± abruptly narrowed to acuminate apex 4. H. styriacum Leaf apices obtuse or rounded 6 6 Costae single or sometimes forked above, only occasional leaves with double costa, mid-leaf cells 4–7 times as long as wide, leaves not subsecund, margins entire except near apex 6. H. smithii Costae double, mid-leaf cells 7–14 times as long as wide, leaves subsecund or if not then margins denticulate from middle of leaf or below 7 7 Leaves straight, margins denticulate from middle or below 7. H. molle Leaves subsecund, margins entire or faintly denticulate near apex 8. H. duriusculum 1

Auricles frequently remain attached to stem when leaves are removed.

175 Hygrohypnum

801

Fig. 266 1–4, Hygrohypnum ochraceum: 1, stem leaves (×40); 2, alar cells (×210); 3, mid-leaf cells (×420); 4, capsule (×10). 5–7, H. polare: 5, stem leaves (×40); 6, alar cells (×210); 7, mid-leaf cells (×420).

1 H. ochraceum (Turner ex Wilson) Loeske, Moosfl. Harz, 1903 Hypnum ochraceum Turner ex Wilson

(Fig. 266)

Dioicous. Plants medium-sized to robust, in green to yellowish green or brownish green flaccid mats. Shoots 1–8 cm long; stems procumbent, irregularly branched, branches usually parallel to main stems. Leaves shrunken, glossy when dry, straight or more usually falcate-secund when moist, sometimes slightly undulate, concave; stem leaves ovate-oblong to ovate-lanceolate, gradually or shortly tapering to rounded, obtuse or subacute apex; margins plane below, erect or inflexed

802

57 Campyliaceae

above, entire or minutely denticulate towards apex; costa single or double, extending 1 2 (−3/4 ) way up leaf; basal cells narrowly rhomboidal, alar cells larger, rectangular, incrassate, with a few inflated, thin-walled, hyaline, forming very fragile decurrent auricles, cells above ± linear, 5–7 × 40–64 μm, 9–13 times as long as wide. Capsules inclined, ellipsoid, curved; lid conical, acute; spores 16– 23 μm. Capsules very rare. n = 10, 11. On rocks in acidic fast-slowing streams and rivers and by waterfalls. 0–1200 m. Frequent or common in hilly and montane areas, very rare elsewhere and absent from lowland England, rare to occasional in Ireland. 71, H23. GB542 + 71∗ , IR36 + 5. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, C. Asia, Korea, Japan, N. Africa, N. America, Greenland. Very variable and often resembling other species of Hygrohypnum but differing in the large hyaline alar cells; it is softer in texture than the next four species.

2 H. polare (Lindb.) Loeske, Verh. Bot. Vereins Prov. Brandenburg, 1905 (Fig. 266) Dioicous. Medium-sized or robust plants forming green cushions or tufts, brownish below. Shoots 3.5 cm long; stems procumbent, irregularly branched, branches erect or ascending. Lower leaves imbricate, towards stem and branch tips falcatesecund when moist; stem leaves ovate, obtuse to rounded; margins entire, plane below, inflexed above; costa single, stout, ending near apex or percurrent; basal cells narrowly rectangular, alar cells quadrate to rectangular, hyaline or in older leaves brownish, forming small decurrent auricles, cells above linear, in mid-leaf 5–7 × 35–56 μm, 5–10 times as long as wide. Sporophytes unknown. On basic lakeside boulders. 670 m. Very rare, W. Ross. 1. GB1. Circumpolar Arctic-montane. In mainly arctic parts of Europe, Asia and N. America, Greenland. Distinct from other British species of Hygrohypnum in the stout costa extending to the leaf apex. The Scottish plants appear to have more strongly falcate-secund leaves than plants from northern Europe. For the occurrence of the plant in Scotland see E. C. Wallace, J. Bryol. 7, 157–9, 1972. This species is considered endangered in the Red List of British Mosses and is a protected plant under the Wildlife and Countryside Act.

3 H. luridum (Hedw.) Jenn., Man. Mosses W. Pennsylv., 1913 Hypnum palustre Huds. Autoicous. Medium-sized plants, in yellowish green to green or brownish green, sometimes red-tinged patches, Stems procumbent, irregularly branched, branches ascending, ± parallel to main stems. Leaves straight and imbricate to strongly falcate-secund, concave; stem leaves ovate-lanceolate to ovate-oblong, gradually or abruptly tapering to obtuse to acute apex; margins plane below, erect or inflexed above, minutely denticulate towards apex; costa single, usually forked above or double, extending (1/2 −)3/4 way up leaf and sometimes almost to apex;

175 Hygrohypnum

803

basal cells narrowly rhomboidal, alar cells ellipsoid to quadrate, not inflated, incrassate, opaque with granular contents, brownish in older leaves, not forming auricles, cells above linear, in mid-leaf 4–7 × 40–56 μm, 7–14 times as long as wide. Capsules inclined, ovoid to ellipsoid, curved; lid mamillate; spores 16–21 μm. Leaves straight to subfalcate, costa extending (1/2 −)3/4 way up leaf, capsules ellipsoid, curved var. luridum Leaves falcate-secund, costa extending almost to apex, capsules ovoid or shortly ellipsoid, gibbous var. subsphaericarpon Var. luridum (Fig. 267) Leaves straight to subfalcate; costa single, forked or double, extending (1/2 −)3/4 way up leaf. Capsules ellipsoid, curved. Capsules common, summer. n = 10, 10 + 1∗ , 11∗ . On rocks in and by fast-flowing basic streams, rivers and waterfalls. 0–910 m. Occasional to frequent in lowland and S. W. England and Ireland, frequent or common elsewhere. 104, H34. GB619 + 98∗ , IR49 + 20∗ . Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Siberia, Kashmir, Tibet, Yunnan, Japan, N. America. Var. subsphaericarpon (Schleich. ex Brid.) C. E. O. Jensen in Podp., Consp. Musc. Eur., 1956 (Fig. 267) Leaves falcate-secund; costa single, extending almost to apex. Capsules ovoid or shortly ellipsoid, gibbous. In similar habitats to the type. Very rare, seen recently only in W. Lancashire, N. W. Yorkshire and E. Perth, but also recorded from Merioneth, Cheshire, Mid-West Yorkshire, S. Northumberland, and Fife. 8. Baltic region, Portugal, Spain, Caucasus, Tibet, Japan. Whether var. subsphaericarpon is worth maintaining is very much open to question. H. luridum differs from H. eugyrium in the leaves with longer costae and granulose alar cells. H. polare has a stronger costa and non-granulose alar cells.

4 H. styriacum (Limpr.) Broth., Nat. Pflanzenfam., 1908 (Fig. 267) Pseudoparoicous (one perigonium and 1–4 perichaetia, with 2–3 bracts in the axil of a leaf). Shoots to 2 cm long; stems irregularly pinnately branched. Leaves patent, scarcely altered when dry; stem leaves 0.8–1.0 mm long, concave, broadly ovate, abruptly narrowed to long tapering channelled acumen occupying 20–25% total leaf length, sometimes reflexed; margins plane or narrowly recurved in lower half of leaf, usually denticulate at base; costa single, double or forked, reaching about 1/2 (−3/4 ) way up leaf; basal cells quadrate-rectangular to shortly rectangular, alar cells quadrate to shortly rectangular but otherwise not differentiated, not forming auricles, broadly and shortly decurrent, cells above elongate-rhomboidal, in mid-leaf 4–7 × 27–35 μm, (4−)5–7 times as long as wide. Branch leaves similar to but narrower than stem leaves. Setae orange below, paler above; capsules inclined, shortly cylindrical, nearly straight (in Scottish plant); spores 14–17 μm.

804

57 Campyliaceae

Fig. 267 1–4, Hygrohypnum luridum var. luridum: 1, stem leaves; 2, alar cells (×210); 3, mid-leaf cells (×420); 4, capsule. 5–6, H. luridum var. subsphaericarpon: 5, stem leaves. 6, capsule. 7–10, H. styriacum: 7, leaves; 8, alar cells ×210); 9, mid-leaf cells (×420); 10, capsule. Leaves ×40, capsules ×10.

175 Hygrohypnum

805

One capsule found on only British gathering. In cracks in granite retaining wall from which base-rich water seeps. 1075 m. In very small quantity at one site in E. Inverness. 1. GB1. European Arctic-montane. Alps, Tatra, Carpathians, Norway, Sweden, Iceland, N. America. Leaves somewhat similar to those of Pictus scoticus but that species differs in habitat, the leaves more shortly pointed and the differentiated alar cells. H. styriacum differs from other British species of Hygrohypnum in leaf shape and the pseudoparoicous inflorescence. For an account of this plant see M. F. V. Corley & G. P. Rothero, J. Bryol. 17, 107–10, 1992. This is a critically endangered species in the Red List of British Mosses.

5 H. eugyrium (Schimp.) Broth., Nat. Pflanzenfam., 1908 Hypnum eugyrium Schimp.

(Fig. 268)

Autoicous. Medium-sized plants, forming yellowish green to brownish green patches. Shoots 0.5–2.0 cm long. Stems procumbent, irregularly branched, branches procumbent to erect. Leaves falcate to falcate-secund, concave; stem leaves ovate to ovate-lanceolate, shortly tapering to short obtuse to acuminate apex; margins erect or inflexed above, entire or denticulate towards apex; costa absent or thin and double, hardly extending 1/4 way up leaf; basal cells narrowly rectangular, alar cells enlarged, incrassate, hyaline in younger leaves, orangebrown and opaque in older leaves, forming small non-decurrent excavate auricles, cells above linear, in mid-leaf 3–5 × 35–52 μm, 8–16 times as long as wide. Capsules inclined, shortly ellipsoid, curved; lid conical, acute; spores c. 20 μm. Capsules common, spring. n = 8∗ , 11. On usually at least slightly basic rocks in fast-flowing streams and in waterfalls. 0–800 m. Frequent in N. Wales, the Lake District and western Scotland, rare to occasional elsewhere in western and northern Britain, rare in Ireland. 43, H16. GB137 + 9∗ , IR19 + 6∗ . Suboceanic Borealmontane. W. and C. Europe north to C. Sweden, Faeroes, E. Asia, Japan, eastern N. America. 6 H. smithii (Sw.) Broth., Nat. Pflanzenfam., 1908 Hypnum arcticum (Sommerf.) Loeske

(Fig. 268)

Autoicous. Stiff olive green to brownish tufts. Shoots 3–12 cm long; stems stiff, procumbent, often denuded below, sparsely branched. Leaves closely imbricate when dry, spreading when moist, not secund, 0.7–1.2 mm long, concave, ovate to orbicular with obtuse apex; margins plane, entire; costa single, sometimes forked above, extending 1/2 –3/4 way up leaf; basal cells narrowly rectangular, alar cells shorter, wider, yellowish, not forming auricles, cells above ± ellipsoid or narrowly ellipsoid, in mid-leaf 4–10 × 28–36 μm, 4–7 times as long as wide. Perichaetial leaves narrowly lanceolate, costa extending to apex. Capsules inclined, ellipsoid, curved; lid mamillate; spores 14–20 μm. Capsules rare but sometimes abundant when produced. On rocks in mountain streams in basic habitats. 700–1000 m. Very rare, Mid and E. Perth, Angus, S. Aberdeen, Inverness, Argyll, W. Ross.

806

57 Campyliaceae

Fig. 268 1–4, Hygrohypnum eugyrium: 1, stem leaves (×40); 2, alar cells (×320); 3, mid-leaf cells (×420); 4, capsule (×10). 5–7, H. smithii: 5, stem leaf (×40); 6, alar cells (×210); 7, mid-leaf cells (×420). 8–10, H. molle: 8, stem leaf (×40); 9, mid-leaf cells (×420); 10, alar cells (×210).

175 Hygrohypnum

807

8. GB7 + 5∗ . European Boreal-montane. Montane and northern Europe north to northern Fennoscandia, Faeroes, Caucasus, N. and C. Asia, Kashmir, China, Japan, N. America, Greenland. 7 H. molle (Hedw.) Loeske, Moosfl. Harz, 1903 Hypnum molle Hedw.

(Fig. 268)

Autoicous. Plants forming soft green or yellowish green tufts or cushions. Shoots crowded, 2–8 cm long; stems slender, brittle, often denuded below, not or sparsely branched. Leaves imbricate, soft when moist, 1–2 mm long, concave, broadly ovate, apex rounded, obtuse or occasionally ± acute; margins plane, denticulate, ± straight at middle part of leaf; costa double, extending 1/3 –1/2 way up leaf; basal cells narrowly rectangular, alar cells only slightly enlarged, hyaline, not forming auricles, not decurrent, cells above linear, in mid-leaf 4–7 × 40–52 μm, (6−)7–12 times as long as wide, cells towards apex not differing in shape from cells below. Capsules inclined, ovoid; spores 16–20 μm. Capsules unknown in Britain. On wet rocks and rocks in streams at high altitudes. 950–1250 m. Very rare but sometimes locally abundant, S. Aberdeen, Banff, Inverness. 4. GB4 + 1∗ . Suboceanic Boreal-montane. Montane and northern Europe north to Norway, Sweden and Finland, Siberia, C. Asia, Japan, N. America. Crum & Anderson (1981) and P. Geissler, Candollea 40, 191–200, 1985, treat this plant as a synonym of H. duriusculum, but in Britain the two species seem perfectly distinct. In the field H. molle is a soft plant with appressed leaves that are difficult to see. H. duriusculum is more rigid with visible leaves. The leaf cells of H. duriusculum are longer and narrower than in H. molle except near the apex where the cells are ± isodiametric, unlike the situation in H. molle. This species is treated as vulnerable in the Red List of British Mosses.

8 H. duriusculum (De Not.) Jamieson, Taxon, 1980 (Fig. 269) H. dilatatum (Wilson) Loeske, Hypnum dilatatum Wilson ex Schimp. Dioicous. Green or yellowish green tufts. Shoots somewhat stiff, not crowded, 2–6 cm long; stems sparsely branched, often denuded below, irregularly branched. Leaves patent, subsecund when moist, 1.0–1.8 mm long concave, ovate-orbicular, apex obtuse to rounded; margins plane, entire or faintly denticulate near apex, curved from base to apex; costa double, extending 1/3 –1/2 way up leaf; basal cells narrowly rectangular, alar cells enlarged, somewhat incrassate, orange or brownish at least in older leaves but not forming auricles, cells above linear, in mid-leaf 4–7 × 44–72 μm, (7−)9–14 times as long as wide, cells towards apex ± isodiametric. Capsules inclined, ellipsoid, curved; lid conical, obtuse; spores c. 20 μm. Capsules very rare, summer. n = 11. In fast-flowing mountain streams and rivers. 60–400 m. Rare but sometimes locally abundant, N. W. Wales, N. W. England, N. Northumberland, Mid Perth, Angus, Kincardine, Banff, Inverness, W. Ross, W. Sutherland, Kerry (not seen recently). 16, H2. GB18 + 5, IR2∗ .

808

57 Campyliaceae

Fig. 269 1–4, Hygrohypnum duriusculum: 1, stem leaves ×; 2, alar cells (×210); 3, mid-leaf cells (×420); 4, capsule (×10). 5–9, Pictus scoticus (from C. C. Townsend, J. Bryol. 12, 1–4, 1982): 5, stem leaves; 6, alar cells (×375); 7, cells from upper part of leaf (×375); 8, branch leaves; 9, capsule (×20). Leaves ×40.

176 Pictus

809

Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, N. and C. Asia, Kashmir, China, Japan, N. America, Greenland.

176 PICTUS C. C. TOWN., J. BRYOL., 1982 A monotypic genus with the characters of the species. Derivation: a tongue-in-cheek name for a plant from the land of the Picts and the Scots.

1 P. scoticus C. C. Towns., J. Bryol., 1982 (Fig. 269) Autoicous. Golden brown ± shining compact mat. Shoots to 3 cm long; stems irregularly branched, branches divergent, to 6 mm long. Leaves moderately to strongly appressed or laxer and subsecund when dry, erect-patent when moist; stem leaves 1.0–1.2 mm long, broadly ovate, abruptly narrowed to short point, orange at base; margins plane, entire; costa short and double or longer, single, forked above and reaching middle of leaf; basal cells rectangular, alar cells hexagonal, slightly incrassate, forming distinct excavate orange-brown group, not forming auricles, not decurrent, cells above linear-vermicular, 4–6 × 35–42(−56) μm, 10–16 times as long as wide. Branch leaves slightly larger than stem leaves, oblong-lanceolate, ± abruptly contracted to short broad acute apex, base yellowish; margins entire; costa single or forked, variable in length, reaching to about middle of leaf; alar cells hexagonal, slightly incrassate, forming narrow group, cells above linear, 4–6 × (42−)53–63 μm. Inner perichaetial leaves linear, plicate, ± abruptly narrowed into slender acumen; costa absent. Setae slender, reddish brown, c. 12 mm long; capsules reddish brown, inclined, asymmetrically ellipsoid, curved, widemouthed when dry and empty; annulus a single ring of cells, not separating; peristome perfect, processes filiform, cilia present; spores c. 12 μm. On bark of a small tree on limestone outcrop. 500 m. Very rare, E. Perth. 1. GB1. Endemic (Suboceanic Boreal-montane). Only known from a single gathering. Most closely resembling a small form of Pterigynandrum filiforme, but that species, which produces sporophytes only very rarely, has erect capsules and gemmae are often present. It is also saxicolous. For the original description of Pictus scoticus in Britain see C. C. Townsend, J. Bryol., 12, 1–6, 1982. Anacamptodon Brid., Muscol. Recent. Suppl., 1818 ¨ A. splachnoides (Frohl. ex Brid.) Brid., Muscol. Recent Suppl., 1818 In the Swedish Museum of Natural History there is a specimen of Anacamptodon splachnoides (collected by P. Dreesen apparently from Westmorland, England, in 1873). Whether this ¨ Bryological Times specimen really came from Westmorland is debatable (see L. Hedenas, 90, 9, 1999), the species being known from C. Europe from eastern France to Romania. The plants are autoicous, slender, leaves c. 1.5 cm long, lanceolate, acuminate; costa single, extending c. 2/3 way up leaf; cells c. 12 μm wide, 2–4 times as long as wide. Capsules ellipsoid; peristome double; lid rostrate, Capsules common. In knot holes of trees such as Fagus sylvatica.

810

58 Brachytheciaceae

58 Brachytheciaceae Slender to robust plants usually forming mats, patches or wefts. Stems creeping to ascending, sparsely and irregularly to closely and pinnately branched, branches straight or curved, complanate or not, spreading to erect. Paraphyllia usually absent. Leaves imbricate to spreading, rarely complanate, stem and branch leaves similar or not, plane or concave, plicate or not, broadly ovate to narrowly lanceolate, apex obtuse or rounded to longly acuminate; costa single, sometimes ending in a small projection on abaxial side of leaf, rarely forked or double; cells elongatehexagonal to linear-vermicular, usually smooth, basal cells shorter, often porose, alar cells differentiated or not, forming auricles or not. Setae long, usually reddish, smooth or papillose with projecting cell ends; capsules erect, inclined or horizontal, ovoid to cylindrical, straight, curved or gibbous; annulus differentiated or not; lid conical, with or without rostrate to subulate beak; peristome double, exostome teeth horizontally striate below, papillose above, endostome with tall basal membrane and usually well developed cilia; calyptrae cucullate, naked. Whilst the Brachytheciaceae is a reasonably natural family, delimitation of some of the genera (e.g. Brachythecium, Eurhynchium, Rhynchostegium, Scleroopdium) is not at all clear and this creates difficulties for the beginner, especially in the absence of sporophytes. DNA studies (e.g. M. Stech & J.-P. Frahm, Bryobrothera 5, 203–11, 1999) are beginning to provide information on relationships, but unfortunately are unlikely to help in identification.

177 ISOTHECIUM BRID., BRYOL. UNIV., 1827 Dioicous. Primary stems creeping, secondary stems procumbent to erect, sparsely to closely branched, branches sometimes secund. Paraphyllia lacking. Leaves imbricate to erect-patent, concave; stem leaves ovate to cordate-triangular, obtuse or obtuse and apiculate to longly acuminate; margins denticulate at least above; costa single or occasionally forked above or double; basal cells rhomboidal to rectangular, alar cells incrassate, opaque, forming distinct yellowish to brownish group, cells above rhomboidal to narrowly rhomboidal, shorter towards margins and apex; branch leaves ovate to lanceolate, obtuse to acuminate. Setae reddish, smooth; capsules erect to inclined, ellipsoid, straight or curved; lid obliquely rostrate; peristome perfect, endostome with or without cilia. A mainly Northern Hemisphere genus with c. 20 species. Derivation: meaning symmetrical capsules.

1 Stem leaves shortly pointed, denticulate only towards apex, capsules ± erect 3. I. alopecurioides Stem leaves with long or short acumen or abruptly tapered to acute apex, obscurely denticulate to dentate ± from base to apex, capsules inclined 2

177 Isothecium

811

2 Stem leaves tapering to long or short acumen, plants pale green 1. I. myosuroides Stem leaves gradually or abruptly tapering to acute apex, plants often tinged orange-brown 2. I. holtii 1 I. myosuroides Brid., Bryol. Univ., 1827 Eurynchium myosuroides (Brid.) Schimp. Plants slender to medium-sized. Primary stems creeping, secondary stems relatively short, erect and branching in a subdendroid fashion to procumbent, elongate and irregularly branched; stoloniferous branches arising from base of secondary stems. Leaves of secondary stems concave, ovate or obovate to cordate-triangular, tapering to long or short fine acumen; margins plane or inflexed above, obscurely to strongly denticulate; costa single, sometimes forked or double, rarely absent; extreme basal and alar cells shortly rectangular, incrassate, opaque, forming distinct group extending to costa, alar cells often excavate, cells above linearrhomboidal, in mid-leaf 5–9 × 28–48 μm, 4–8 times as long as wide. Branch leaves differing in shape from stem leaves or not. Setae curved; capsules inclined, ellipsoid. straight; lid obliquely rostrate; spores 16–24 μm. Secondary stems ± erect, relatively short, subdendroid, leaves erect-patent when moist var. myosuroides Secondary stems procumbent, long, irregularly and distantly branched, leaves imbricate when moist var. brachythecioides Var. myosuroides (Fig. 270) Dense pale green to green rough mats or patches. Secondary stems ascending to erect, subdendroid with branches crowded near tips, branches short or long, often curved and homomallous. Leaves imbricate when dry, erect-patent when moist; stem leaves ovate to cordate-triangular, tapering to long sometimes fine apex; margins denticulate to dentate from near base. Branch leaves smaller, lanceolate to ovate, tapering to long sometimes twisted acumen. Capsules rare in lowland England, frequent or common elsewhere. n = 11∗ , 11 + m∗ . On well drained substrates, on tree trunks, branches, exposed roots, stumps, logs, rocks, walls, especially in woodland but also in ± exposed habitats. 0–950 m. Rare to occasional in parts of eastern England, common elsewhere in the British Isles. 111, H39, C. GB1620 + 108∗ , IR284 + 178∗ , C8. Suboceanic Boreo-temperate. Europe north to C. Scandinavia and east to the Carpathians, Faeroes, Iceland, Turkey, Macaronesia, Algeria, China. Var. brachythecioides (Dixon) C. E. O. Jensen, Denmarks Mosser, 1923 (Fig. 270) Yellowish green to green patches. Secondary stems to 10 cm long, procumbent, irregularly and distantly branched, branches procumbent, straight. Leaves imbricate

812

58 Brachytheciaceae

Fig. 270 1–5, Isothecium myosuroides var. myosuroides: 1, 2, stem and branch leaves; 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule (×10). 6, 7, I. myosuroides var. brachythecioides: stem and branch leaves. 8–10 I. holtii: 8, 9, stem and branch leaves; 10, mid-leaf cells (×420). Leaves ×25.

177 Isothecium

813

when moist; stem leaves ovate to broadly ovate, tapering to long or short acumen; margins obscurely denticulate. Branch leaves ± similar to stem leaves but with more pronounced denticulations. Saprophytes unknown. On acidic usually well drained substrates, on sheltered rock faces, in rock crevices and in sloping turf. 50– 920 m. Occasional in N. W. Wales and from Arran north to Shetland, Dumfries, Berwick, I. of May, rare in western Ireland, S. Tipperary. 26, H13. GB102 + 6∗ , IR17 + 4∗ . Hyperoceanic Temperate. Faeroes, Iceland, Norway, Spain, Switzerland, Tenerife. I. myosuroides var. myosuroides is an abundant species in woodland in western and northern Britain, easily recognised by the pale green subdendroid shoots with frequently homomallous branches forming rough patches. Var. brachythecioides in its typical form is a very different looking plant, more resembling a Brachythecium species but differing in the shorter leaf cells. However, it is linked to the type by intermediates, as for example on the Shetland Islands.

2 I. holtii Kindb., Rev. Bryol., 1895 I. myosuroides var. rivulare Holt ex Limpr.

(Fig. 270)

Plants medium-sized, forming green to orange-brown rough patches. Secondary stems ascending, irregularly to subpinnately branched, branches long, subcomplanate. Leaves imbricate when moist; stem leaves ovate to cordate-triangular, tapering gradually or abruptly to acute apex; margins inflexed above, obscurely denticulate; costa strong, extending almost to apex; extreme basal and alar cells shortly rectangular, incrassate, opaque, forming group extending to costa, cells above narrowly rhomboidal, in mid-leaf 5–8 × 28–48 μm, 4–8 times as long as wide. Capsules inclined, ellipsoid; spores 16–21 μm. Capsules rare, winter. On shaded rocks, boulders and exposed tree roots by fast flowing streams and rivers in sheltered humid situations and in the spray zone of waterfalls. 0–300(−550) m. Locally frequent in S. W. England, common in Mid and N. Wales, rare to occasional from the Lake District north to Sutherland and Caithness, Derby, Mid-West Yorkshire, rare in Ireland. 32, H7. GB126 + 6∗ , IR18. Oceanic Temperate. Atlantic Europe from S. Spain to S. Norway, Czechoslovakia, France, Germany, Luxembourg, Switzerland. I. holtii differs from I. myosuroides in the longer branches, more shortly pointed stem leaves and the frequently orange-brown tint. Superficially resembling small forms of Thamnobryum alopecurum, but that species differs in the stronger costae and short papillose leaf cells. The specific status of this plant has been questioned as intermediates between it and I. myosuroides are said to exist and the situation requires further study. However, Duell (1992) says ‘Also occurring far away from streams and therefore not only a variety’.

3 I. alopecurioides (Dubois) Isoviita, Ann. Bot. Fenn., 1981 Eurhynchium myurum (Brid.) Dixon, I. myurum Brid.

(Fig. 271)

Medium-sized to robust plants forming pale green to yellowish green tufts or patches, sometimes extensive. Secondary stems procumbent, irregularly

814

58 Brachytheciaceae

Fig. 271 1–6. Isothecium alopecuroides: 1, 2, stem and branch leaves; 3, mid-leaf cells (×420); 4. capsule (×10). 5–7, Scorpiurium circinatum: 5, 6, stem and branch leaves; 7, mid-leaf cells (×420). Leaves ×25.

branched, not dendroid, branches straight or curved, often homomallous. Leaves imbricate when moist, strongly concave; stem leaves ovate to broadly ovate or obovate, shortly acute to obtuse or obtuse and apiculate; margins inflexed at least above middle of leaf, entire below, denticulate towards apex; costa extending 2/3 way up leaf, single, sometimes forked above or double; extreme basal and alar cells quadrate to rectangular, incrassate, opaque, forming distinct group extending to costa, alar cells often excavate, cells above narrowly rhomboidal, shorter towards margins and apex, in mid-leaf 5–8 × 20–40 μm, 4–6 times as long as wide. Branch leaves smaller, more shortly pointed. Capsules ± erect and symmetrical, ellipsoid to

178 Scorpiurium

815

shortly cylindrical; lid rostrate; spores 12–16 μm. Capsules occasional to frequent, winter. n = 10, 11, 11 + m∗ , 12. On tree boles, exposed roots, stumps, logs and rocks in woods, by streams and rivers, on cliffs, shaded rocks and scree. 0–650 m. Occasional in the northern half of lowland England and parts of Scotland, common elsewhere, occasional to common in Ireland. 112, H38, C. GB1219 + 122∗ , IR189 + 9∗ , C2 + 2∗ . European Boreo-temperate. Europe north to C. Scandinavia, Faeroes, Iceland, Caucasus, Turkey, W. Asia, Azores, La Palma, W. Africa, Ontario. Distinguished in the field from I. myosuroides by the erect capsules and shortly pointed leaves.

178 SCORPIURIUM SCHIMP., SYN. MUSC. EUR. (ed. 2), 2, 1876 Dioicous. Relatively slender plants. Primary stems creeping, rhizoids in tufts; secondary stems ascending to erect with numerous short curved branches. Leaves of secondary stems distant, weakly plicate, ovate-triangular, acuminate, base decurrent; costa extending to apex; cells rhomboidal to narrowly rhomboidal, at base and basal angles quadrate-hexagonal. Branch leaves ovate or ovate-lanceolate; costa extending to apex. Setae purple, smooth; capsules inclined, ellipsoid, curved; lid with long oblique beak; peristome perfect, endostome with tall basal membrane and nodulose cilia. Three species: Europe, Middle East, E. Asia, N. Africa, Macaronesia. Derivation: meaning scorpion-tailed.

1 S. circinatum (Brid.) M. Fleisch. & Loeske, Allg. Bot. Zeitschr., 1907 (Fig. 271) Eurhynchiunm circinatum (Brid.) Schimp. Slender plants forming tight green to yellowish green rough patches. Primary stems creeping, secondary stems erect, curved, branches short, curved, crowded at ends of stems. Stem leaves erect when dry, erect-patent to spreading when moist, triangular to ovate-triangular, rapidly narrowed to long acuminate apex; margins plane, entire or denticulate; costa very stout, reaching acumen; basal and alar cells ± hexagonal, opaque, cells above rhomboidal to narrowly rhomboidal, in mid-leaf 5–8 × 20–36 μm, 4–6 times as long as wide. Branch leaves larger, narrower, imbricate when dry, erect-patent when moist, curved, ovate to lanceolate, acuminate; margins denticulate or dentate; costa reaching nearly to apex; areolation as in stem leaves. Setae smooth; capsules inclined, ellipsoid, curved; lid with subulate beak. Capsules not known in the British Isles. On shaded or exposed calcareous rocks, walls and soil, rarely in open turf, on banks, rocks and sanddunes, usually but not exclusively in chalk and limestone areas. Lowland. Rare to frequent in southern and south-west England and South Wales, very rare elsewhere, Radnor, Denbigh, Anglesey, rare in the western half of Ireland. 24, H10, C. GB101 + 23∗ , IR16 + 3∗ , C6. Mediterranean-Atlantic. Mediterranean and Atlantic

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58 Brachytheciaceae

Europe north to the British Isles, Belgium and Germany, Crimea, Turkey, Cyprus, Asia Minor, Iran, Macaronesia, N. Africa.

179 HOMALOTHECIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1851 Dioicous. Medium-sized to robust plants. Stems procumbent to erect, radiculose or not, irregularly to subpinnately branched. Leaves appressed or erect when dry. Erect or erect-patent when moist, deeply longitudinally plicate, narrowly lanceolate-triangular, tapering from base to long acumen; margins entire or denticulate, plane or narrowly recurved; costa single, extending c. 3/4 way up leaf; cells ± uniformly linear-vermicular except at basal angles, porose or not. Outer perichaetial leaves recurved, inner erect. Setae smooth or papillose; capsules erect to horizontal, ovoid to cylindrical, straight or curved; lid conical, obtuse or acute; endostome with or without cilia. A mainly temperate or warm temperate genus of eight species. Derivation: meaning upright capsule. For a monograph of the genus see H. Hofmann, Lindbergia 23, 119–59, 1998.

Branches short, erect, very crowded, curved when dry, basal margins of branch leaves strongly denticulate with often curved teeth 1. H. sericeum Branches long, not crowded, ± straight, basal margins of leaves denticulate 2. H. lutescens 1 H. sericeum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1851 Camptothecium sericeum (Hedw.) Kindb.

(Fig. 272)

Plants moderately robust, glossy yellowish green to golden brown, in dense rough mats or patches, sometimes extensive. Stems creeping, 5–10 cm long, attached to substrate for most of their length by rhizoids, closely pinnately branched, branches ± erect, usually curved, especially when dry. Axillary hairs 24–42 μm long. Leaves appressed when dry, erect-patent when moist, strongly longitudinally plicate; stem leaves very narrowly triangular, tapering from near base to long acumen; margins plane or narrowly recurved below, denticulate at base, entire or faintly denticulate above; costa thin, extending c. 3/4 way up leaf; basal cells usually not porose, alar cells ± quadrate, incrassate, forming small decurrent auricles, cells elsewhere linear-vermicular, walls not porose, cells in mid-leaf 4–8 × 56–90 μm, 10–16 times as long as wide. Branch leaves with 4–6 decurrent cells at base, basal margins conspicuously denticulate, often with recurved teeth at base. Setae reddish, papillose; capsules erect, cylindrical, somewhat tapering from near base to mouth, straight or slightly curved; lid shortly rostrate to narrowly conical; endostome lacking cilia; spores 11–22 μm. Capsules occasional, winter. n = 8∗ , 9∗ , 10∗ , 10 + m∗ , 11∗ , 11 + 2m∗ , 12. On dry exposed to slightly sheltered horizontal to vertical substrates such as tree trunks, branches, rocks, walls, roofs, especially

179 Homalothecium

817

Fig. 272 1–4, Homalothecium sericeum: 1, stem leaf; 2, alar cells (×420); 3, mid-leaf cells (×420); 4, capsule. 5–8, H. lutescens: 5, stem leaf; 6. alar cells (×280); 7, mid-leaf cells (×420); 8, capsule. Leaves ×25, capsules 10.

where basic. 0–610 m. Common and sometimes locally abundant throughout the British Isles. 112, H39, C. GB1843 + 78∗ , IR321 + 8∗ , C7 + 1∗ . Eurosiberian Southern-temperate. Europe north to northern Scandinavia, Faeroes, Iceland, Turkey, Cyprus, Middle East, Kashmir, China, Macaronesia, N. Africa, N. America. 2 H. lutescens (Hedw.) H. Rob., Bryologist, 1962 Camptothecium lutescens (Hedw.) Schimp.

(Fig. 272)

Moderately robust plants in glossy, yellowish green to golden brown, lax patches, sometimes extensive. Male plants dwarf or of similar size to female plants. Shoots to 5–10 cm; stems procumbent to ascending with sparse rhizoids, not attached to substrate except at base, irregularly branched, branches not crowded, straight, long, erect to procumbent and directed forwards. Axillary hairs 40– 100 μm long. Stem and branch leaves similar, erect when dry, erect-patent when moist, strongly longitudinally plicate, very narrowly triangular, tapering ± from base to long filiform often twisted acumen; margins plane or narrowly recurved below, denticulate ± from base to apex; costa thin, extending c. 3/4 way up leaf; alar

818

58 Brachytheciaceae

cells ± quadrate, incrassate, forming small decurrent auricles, cells elsewhere linear-vermicular, walls of basal cells porose, cells in mid-leaf 5–7 × 48–80 μm, c. 10 times as long as wide. Branch leaves with costa sometimes ending in spine on abaxial side; with 2–4 decurrent cells at base. Setae purple, papillose; capsules erect or inclined, subcylindrical, straight or slightly curved; lid narrowly conical to rostrate; processes as long as exostome teeth, short cilia present; spores 16–20 μm. Capsules rare, winter. n = 8, 10, 11∗ , 12, 14. In exposed situations in chalk and limestone grassland, on cliff tops and sand-dunes, rarely directly on rocks or walls. 0–400 m. Common in basic areas in England and Wales, rare to occasional elsewhere, extending north to Shetland, occasional to frequent in Ireland. 105, H35, C. GB709 + 92∗ , IR136 + 9∗ , C6 + 1∗ . European Southern-temperate. Europe north to S. Scandinavia, Faeroes, Iceland, Caucasus, Turkey, Iran, Madeira, Morocco. May sometimes be difficult to separate from H. sericeum which, however, usually differs in the short curved branches, the basal margins strongly toothed, non-porose basal cells and shorter axillary hairs. It may also be mistaken for Brachythecium albicans, but is larger, has the basal cells of the leaves hardly differentiated from the cells above and has erect or inclined rather than horizontal capsules. There is a form of H. lutescens which blackens on drying, then resembling H. sericeum, and it has been suggested that this may be H. lutescens var. fallax (Philib.) Duell, but H. Hofmann (loc. cit.) considers that this is probably a hybrid between H. lutescens and H. sericeum.

180 BRACHYTHECIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1853 Dioicous or autoicous, rarely synoicous. Slender to robust plants. Stems creeping, ascending or erect, irregularly to pinnately branched, branches short or long, straight or curved. Leaves imbricate to spreading, stem leaves similar or not to branch leaves, concave or plane, smooth or plicate, cordate-triangular to ovatelanceolate, acute to longly acuminate, base decurrent or not; margins plane or recurved, entire or denticulate; costa single, extending 1/2 –3/4 way up leaf or to apex; basal cells rhomboidal or rectangular, porose or not, alar cells usually shorter, sometimes enlarged and forming auricles, cells above narrowly rhomboidal or linear-rhomboidal. Setae deep red, papillose or not; capsules inclined to horizontal, ovoid to cylindrical, symmetrical, gibbous or curved; annulus separating; lid conical; peristome perfect, endostome with tall basal membrane and nodulose or appendiculate cilia. A large cosmopolitan genus of c. 300 species. Derivation: meaning short capsule. Although a straightforward genus in the British Isles, in continental Europe the distinctions between some of the species are very blurred.

1 Stem leaves longitudinally plicate, tapering to long or filiform acumen, margins entire or denticulate, setae smooth Stem leaves more shortly pointed or if longly acuminate then not or only slightly plicate, margins denticulate, setae papillose at least above

2 6

180 Brachythecium

819

2 Stem leaves with long twisted filiform acumens 3. B. glareosum Acumens of stem leaves not filiform or twisted 3 3 Stem leaves curved, with tufts of reddish brown rhizoids arising from bases 2. B. erythrorrhizon Stem leaves straight, without tufts of reddish brown rhizoids arising from bases 4 4 Dioicous, leaves imbricate when dry, giving shoots string-like appearance 1. B. albicans Autoicous, leaves erect-flexuose or appressed-flexuose when dry, stems not string-like 5 5 Leaves plicate, margins entire to denticulate ± from base to apex, mid-leaf cells of stem leaves 6–9 μm wide, woodland plants 4. B. salebrosum Leaves weakly plicate, margins ± entire, mid-leaf cells 7–12 μm wide, plants of open habitats 5. B. mildeanum 6 Stem leaves broadly ovate to lanceolate or lanceolate-triangular, alar cells not forming or if auricles present then plants robust 7 Plants slender, stem leaves cordate-triangular to broadly ovate, alar cells forming decurrent auricles 14 7 Alar cells inflated, forming distinct decurrent auricles 7. B. rivulare Alar cells not forming auricles 8 8 Plants medium-sized to robust, stem leaves usually more than 1.5 mm long 9 Plants slender, stem leaves to 1.4 mm long, rarely more 11 9 Setae smooth below, papillose above, leaves ± secund when moist, on rocks in and by water and on flushed rocks 15. B. plumosum Setae papillose throughout, leaves straight, habitat not as above 10 10 Stem leaves longly tapering to fine acuminate apices, margins ± entire, setae smooth 5. B. mildeanum Stem leaves ovate or ovate-lanceolate, apices acute to acuminate but not fine, margins denticulate, setae coarsely papillose 6. B. rutabulum 11 Setae smooth below, papillose above, costa extending into acumen or almost to apex of stem leaves 14. B. populeum Setae papillose throughout, costa of stem leaves shorter 12 12 Stem leaves tapering from near base, branch leaves often subfalcate 12. B. velutinum 1 1 13 Stem leaves tapering from /4 – /3 from base, branch leaves ± straight 13 Stem leaves ovate-triangular, costa extending 2/3 –4 /5 way up leaves, branch leaves ovate to lanceolate, lowland plant 11. B. appleyardiae Stem leaves lanceolate-triangular, costa extending about half way up leaf, branch leaves narrowly lanceolate, montane plant 13. B. trachypodium 14 Costa of stem leaves extending into longly acuminate channelled acumens 10. B. reflexum Costa extending c. half way up leaves, acumen shorter, not channelled 15

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58 Brachytheciaceae

15 Leaf margins plane or slightly recurved at base, alar cells rectangular 8. B. starkei Margins strongly recurved near base, alar cells quadrate 9. B. glaciale Section 1 Albicans Nyholm, Ill. Moss Fl. Fennoscandia. 2. Musci, 1965 Stem leaves concave, ovate-lanceolate, longitudinally plicate; alar cells quadrate or rectangular, forming usually broadly decurrent marginal group; cells in mid-leaf up to 30–80 μm long. Setae smooth; cilia of endostome nodulose. 1 B. albicans (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1853 Chamberlainia albicans (Hedw.) H. Rob.

(Fig. 273)

Dioicous. Slender to medium-sized plants forming yellowish green or whitish green silky patches. Shoots to 8 cm long, string-like in appearance when dry; stems ascending, irregularly branched, rhizoids sparse. Leaves imbricate, plicate, concave; stem leaves ovate-lanceolate to ovate or ovate-triangular, tapering rapidly to long filiform acumen, acumen not twisted; margins recurved below, entire or obscurely denticulate above; costa extending 1/2 –3/4 way up leaf; basal cells shortly rectangular, alar cells quadrate, less translucent, forming a ± triangular group ± distinct from other cells but not forming auricles, cells above linear-rhomboidal, in mid-leaf 6–9 × 48–90 μm, 7–11 times as long as wide. Branch leaves narrower than stem leaves, ovate-lanceolate to lanceolate; cells longer and narrower. Setae smooth; capsules inclined, ovoid, gibbous; lid conical; spores 12–14 μm. Capsules rare, autumn, winter. n = 5, 9. On soil, particularly where sandy or gravelly, in grassland, old gravel pits, on heaths, sand-dunes, on rocks and walls, in exposed neutral or acidic habitats. 0–350 m. Frequent or common in most of England and Wales, in Scotland and Ireland frequent along the coast, rare to occasional elsewhere. 111, H29, C. GB974 + 95∗ , IR48 + 9∗ , C10. Circumpolar Boreo-temperate. Europe north to Jan Mayen, Faeroes, Iceland, Caucasus, Turkey, Azores, Madeira, N. America, Greenland, introduced in Australia and New Zealand. Readily recognised in the field by the pale silky patches and string-like shoots with imbricate plicate leaves.

2 B. erythrorrhizon Schimp. in Bruch et al., Bryol. Eur., 1853 Chamberlania erythrorrhizon (Schimp.) H. Rob.

(Fig. 273)

Dioicous. Scottish plants slender, in small glossy yellowish green patches. Stems procumbent with tufts of reddish brown rhizoids arising at leaf bases on older parts, pinnately branched, branches procumbent to ascending. Leaves erect when dry; stem leaves plicate, patent, subsecund when moist, often curved, ovate, gradually tapering to long acumen, base decurrent; margins plane or recurved below, finely denticulate above; costa extending c. 3/4 way up leaf; basal cells linear-rhomboidal, alar cells irregularly hexagonal, forming a ± triangular group ± distinct from other

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Fig. 273 1–5, Brachythecium albicans: 1, 2, stem and branch leaves; 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule. 6–8, B. erythrorrhizon: 6, 7, stem and branch leaves; 8, mid-leaf cells (×420). 9–13, B. salebrosum: 9, 10, stem and branch leaves; 11, alar cells (×210); 12, mid-leaf cells (×420); 13, capsule. Leaves ×15, capsules ×10.

822

58 Brachytheciaceae

cells but not forming auricles, cells above linear, in mid-leaf 6–10 × 48–72 μm, 6– 10 times as long as wide. Branch leaves smaller and more shortly pointed than stem leaves, erect-patent to patent, straight to subsecund when moist. Setae ± smooth; capsules inclined, ellipsoid; spores c. 16 μm. Capsules unknown in Britain. Lowland. Very rare, on sand-dunes amongst Dryas, W. Sutherland. 1. GB1. Circumpolar Boreal-montane. Montane and northern Europe, Siberia, N. America. The Scottish plant is very depauperate but differs from very slender forms of B. albicans in the frequently curved stem leaves and tufts of reddish brown rhizoids. For the discovery of this plant in Britain see J. J. Barkman, Trans. Br. Bryol. Soc. 2, 568–70. 1955. The plant has been seen twice since its original discovery, in 1956 and again in 1988.

Section 2 Plicata Kindb., Eur. N. Am. Bryin., 1897 Stem leaves strongly plicate, ovate-lanceolate; alar cells ± quadrate, somewhat decurrent, mid-leaf cells 70–100 μm or more long. Setae smooth; cilia of endostome nodulose. 3 B. glareosum (Spruce) Schimp. in Bruch et al. Bryol. Eur., 1853 (Fig. 274) Dioicous. Plants medium-sized, in silky pale green to yellowish green patches. Shoots to 8(−10) cm long; stems creeping, irregularly pinnately branched, branches procumbent to ascending. Leaves appressed-flexuose when dry, erectpatent when moist, plicate, concave; stem leaves ovate to ovate-triangular, tapering to long twisted filiform acumen, base not decurrent; margins plane or recurved, entire or finely denticulate above; costa extending 1/2 –3/4 way up leaf; basal cells rhomboidal, alar cells shortly rectangular to rounded-quadrate, forming ± triangular group ± distinct from other cells but not forming auricles, cells above linearrhomboidal, 5–10 × 64–90 μm, 8–11(−13) times as long as wide. Setae smooth; capsules inclined, ovate-ellipsoid, slightly curved or gibbous; lid conical; spores 14–20 μm. On dry basic soil, rocks, banks, in turf and open woodland. 0–1065 m. Occasional to frequent in much of England and eastern Wales, rare in Scotland, extending north to W. Sutherland, rare in Ireland. 87, H22, C. GB300 + 15∗ , IR16 + 10, C3∗ . Eurasian Boreo-temperate. Europe north to northern Fennoscandia, Iceland, Caucasus, Turkey, Siberia, Yunnan, Korea, Japan, Morocco, N. America. Recognisable in the field by the yellowish green colour and the silky shoots with leaves with long twisted acumens. It differs from the preceding species in the rectangular supra-alar cells hardly ascending up the leaf margins.

4 B. salebrosum (F. Weber & D. Mohr) Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 273) Chamberlainia salebrosa (F. Weber & D. Mohr) H. Rob. Autoicous, rarely synoicous. Plants medium-sized to robust in yellowish green or green patches. Stems procumbent to ascending, irregularly branched, branches ascending to erect. Leaves erect-flexuose, sometimes subsecund when dry, erectpatent when moist, plicate, ± concave; stem leaves ovate-lanceolate tapering to

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Fig. 274 Brachythecium glareosum: 1, 2, stem and branch leaves; 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule. 6–10, B. mildeanum: 6, 7 stem and branch leaves; 8, alar cells (×210); 9, mid-leaf cells (×420); 10, capsule. Leaves ×15, capsules ×10.

long flexuose acumen; margins recurved near base, entire to denticulate ± from base to apex; costa ascending 1/2 –2/3 way up leaf; basal cells rhomboidal, incrassate, porose, alar cells rectangular, a few enlarged, ± hyaline, hardly forming decurrent auricles, rectangular supra-alar cells ascending up margins, cells above narrowly rhomboidal to linear-rhomboidal, 6–9 × 56–100 μm, 9–13 times as long as wide. Branch leaves narrower than stem leaves. Setae smooth; capsules inclined, shortly

824

58 Brachytheciaceae

cylindrical, curved; lid conical; spores 12–18 μm. Capsules occasional, autumn, winter. n = 13. In damp woodland on tree boles, rotting logs, rocks, wet heaths. Lowland. Rare to occasional in England, very rare in Scotland, Roxburgh, Angus, 25. GB30 + 19∗ . Circumpolar Wide-boreal. Europe north to Scandinavia, Caucasus, C. Asia, Macaronesia, Algeria, Libya, Morocco, Greenland, Australia, New Zealand, Kerguelen Is. Although ecologically distinct, B. salebrosum and B. mildeanum have been confused in the British Isles because of the similarity of their gametophytes, but B. salebrosum has more strongly plicate leaves with slightly wider cells. Also confused with B. glareosum and B. rutabulum. The former differs in the leaves with long filiform twisted acumens and in the dioicous inflorescence. B. salebrosum differs from B. rutabulum in the silky appearance of the plants, the more longly tapering plicate leaves and smooth setae; it may, however, be passed over for B. rutabulum and is almost certainly under-recorded.

Section 3 Brachythecium Broth., Nat. Pflanzenfam., 1908 Stem leaves concave, often slightly plicate, broadly ovate; alar cells rectangular, sometimes inflated, ± decurrent; mid-leaf cells 70–100 μm or more long. Setae smooth or papillose; cilia of endostome nodulose. 5 B. mildeanum (Schimp.) Schimp. in Milde, Bot. Zeit., 1862 B. salebrosum var. palustre Schimp.

(Fig. 274)

Autoicous. Plants medium-sized to robust, in yellowish green patches. Stems procumbent, irregularly branched, branches spreading to ascending. Leaves erectflexuose when dry, erect-patent when moist, plicate but sometimes only slightly so, plane or concave; stem leaves narrowly triangular to ovate-lanceolate, tapering to fine acumen, base not decurrent; margins entire to sinuose, costa extending 1/ −2/ way up leaf; basal cells rhomboidal, incrassate, porose, alar cells rectangular, 2 3 not much differentiated from neighbouring cells, not forming auricles, cells above narrowly hexagonal to linear-rhomboidal, 7–12 × 80–120 μm, 9–18 times as long as wide. Setae smooth; capsules inclined, shortly cylindrical, curved; lid conical; spores 12–18 μm. Capsules occasional, autumn. In open damp basic habitats, by pools, on river banks, in fens, dune-slacks and on woodland tracks. Lowland. Occasional but sometimes locally abundant in England and Wales, rare in Scotland, extending north to Sutherland, rare in Ireland. 74, H15, C. GB75 + 60∗ , IR12 + 6∗ , C1. Circumpolar Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Turkey, N. and C. Asia, Azores, N. America. Differs from B. rutabulum and B rivulare in the smooth setae and the stem leaves tapering to a long fine acumen and the margins ± entire.

6 B. rutabulum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 275) Autoicous. Lax glossy bright green or yellowish green tufts or patches. Shoots to 12 cm long; stems creeping, branches erect, ascending or arcuate, often curved.

180 Brachythecium

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Fig. 275 1–5, Brachythecium rutabulum: 1, 2, stem and branch leaves; 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule. 6–10, B. rivulare: 6, 7 stem and branch leaves; 8, alar cells (×210); 9, mid-leaf cells (×420); 10, capsule. Leaves ×15, capsules ×10.

826

58 Brachytheciaceae

Leaves erect-patent, smooth or ± plicate or rugose when dry, erect-patent, sometimes plicate when moist, concave; stem leaves ovate or ovate-cordate, gradually or abruptly tapering to acute to acuminate apex, base decurrent; margins plane or recurved below, denticulate above; costa extending 1/2 –2/3 way up leaf; basal cells rhomboidal, porose, alar cells rectangular, decurrent but not forming auricles, cells above linear-rhomboidal, in mid-leaf 6–10 × 56–100 μm, 8–14 times as long as wide. Setae coarsely papillose; capsules inclined, ellipsoid, curved or gibbous; lid conical; spores 16–24 μm. Capsules common, late autumn to spring. n = 5, 6, 10, 10 + 1, 11∗ , 12∗ , 13, 20, 22. A fast-growing species, especially of damp woodland in base-rich situations, on tree boles, branches, logs, soil, rocks, by streams and rivers, on walls and cliffs, amongst herbaceous vegetation, rare or absent on acidic nutrient-poor substrates, shade tolerant. 0–1344 m. Common or very common. 112, H40, C. GB2159 + 73∗ , IR3 + 7∗ , C7 + 3∗ . European Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Asia, Macaronesia, N. and C. Africa, N. America, Greenland, Guatemala, Colombia, Australia, New Zealand, Hawaii. One of the commonest pleurocarpous mosses, very variable in size and habit, but usually recognised by the glossy, often yellowish green shoots, the stem and branch tips often somewhat cuspidate, the leaves erect-patent both when moist and when dry and the coarsely papillose setae.

7 B. rivulare Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 275) Dioicous. Plants robust, forming lax glossy pale green to green or yellowish green, patches. Shoots to 12 cm long; stems creeping, irregularly and distantly to closely branched, branches long, ascending to erect. Leaves erect or imbricate when dry, imbricate to patent when moist, concave; stem leaves broadly ovate to ovateoblong, obtuse and apiculate to shortly acuminate; margins plane or recurved below, sinuose to denticulate above; costa extending 3/4 or more way up leaf; basal cells rhomboidal, alar cells enlarged, lax, hexagonal, hyaline or brownish, forming distinct decurrent auricles, cells above linear-rhomboidal, in mid-leaf 6–10 × 64–128 μm, 9–20 times as long as wide. Setae coarsely papillose; capsules inclined, ovoid, gibbous; lid conical, obtuse and apiculate; spores 16–20 μm. Capsules occasional, autumn to spring. On rocks, logs and tree boles in and by fastflowing streams and rivers, in damp woodland, damp turf, springs and flushes. 0–960 m. Frequent or common except in parts of lowland England, occasional to frequent in Ireland. 112, H37, C. GB1488 + 83∗ , IR144 + 8∗ , C7. Circumpolar Boreotemperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Asia, Macaronesia, Kenya, S. America, Greenland, Chile, Australia, Kerguelen Is. B. rivulare differs from B. rutabulum in its often pale green colour and the more shortly pointed leaves which are imbricate rather than erect-patent when dry but the two cannot always be distinguished in the field. Microscopically the auricles are distinctive.

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Section 4 Reflexa Broth., Nat. Pflanzenfam., 1908 Stem leaves plane or concave, hardly plicate, cordate-triangular to broadly ovate; alar cells quadrate or rectangular, longly decurrent; mid-leaf cells mostly to 80 μm long. Setae papillose; cilia of endostome ± appendiculate. 8 B. starkei (Brid.) Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 276) Autoicous. Plants slender, forming yellowish green tufts or patches. Stems irregularly branched. Leaves patent, ± plicate below when moist and when dry; stem leaves plane, cordate-triangular, narrowed to long or short acumen, base longly decurrent; margins plane or slightly recurved at base, spinosely denticulate from base to apex; costa extending c. 1/2 way up leaf; basal cells rhomboidal, alar cells rectangular, thin-walled, hyaline, forming narrow, decurrent, very fragile auricles, cells above linear-rhomboidal, in mid-leaf 5–7 × 44–80 μm, 7–14 times as long

Fig. 276 1–4, Brachythecium starkei: 1, 2, stem and branch leaves; 3, alar cells (×210); 4, mid-leaf cells (×420). 5–7, B. reflexum: 5, 6, stem and branch leaves; 7, mid-leaf cells (×420). 8–11, B. glaciale: 8, 9, stem and branch leaves; 10, alar cells (×210); 11, mid-leaf cells (×420). Leaves ×25.

828

58 Brachytheciaceae

as wide. Branch leaves ± concave, ovate-lanceolate, acute. Perichaetial leaves squarrose. Setae slightly papillose; capsules inclined to horizontal, ovate-ellipsoid; lid conical; spores 12–15 μm. Capsules common in Angus, unknown elsewhere in Scotland. n = 20. In basic rock crevices, flushes and on pool-side rocks. 500– 960 m. Very rare, Mid Perth, Angus, Ross. 4. GB2 + 2. Circumpolar Boreal-montane. Montane and northern Europe north to Fennoscandia, Iceland, Caucasus, Turkey, N. and C. Asia, Japan, eastern N. America. This species is treated as vulnerable in the Red List of British Mosses.

9 B. glaciale Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 276) Autoicous. Plants slender, forming green wefts. Stems irregularly branched. Leaves imbricate when dry, imbricate to patent when moist, concave, plicate or not below; stem leaves cordate-triangular to broadly ovate, narrowed to ± filiform acumen, base longly decurrent; margins strongly recurved near base, denticulate from about widest part; costa extending c. 1/2 way up leaf; basal cells rhomboidal, alar cells ± quadrate, thick-walled, forming decurrent auricles, cells above narrowly rhomboidal, in mid-leaf 6–10 × 44–66 μm, 6–8 times as long as wide. Branch leaves ovate, acuminate. Perichaetial leaves erect. Setae papillose; capsules inclined, ovate-ellipsoid; lid conical; spores c. 16 μm. Capsules rare, summer. In crevices of sheltered basic rock and scree. 710–1200 m. Rare in the Scottish Highlands, Mid Perth, Angus, S. Aberdeen, Inverness, Argyll, Ross. 9. GB14 + 2∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, N. and C. Asia, N. America, Greenland, southern S. America, S. Georgia. B. glaciale and B. starkei have been confused in Britain (see A. C. Crundwell, Trans. Br. Bryol. Soc. 3, 565–7, 1959, for further information). B. glaciale differs from B. starkei in the leaf margins strongly recurved near the base and less strongly denticulate, the ± quadrate alar cells, other cells shorter and straight perichaetial leaves. B. reflexum differs from these two species in the much longer stem leaf apices and the costa reaching the leaf acumen.

10 B. reflexum (Starke) Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 276) Autoicous. Slender plants in greenish wefts. Stems irregularly branched. Stem leaves distant, flexuose-spreading when dry, patent to reflexed when moist, cordate-triangular, narrowed to long, channelled, sometimes filiform acumen; margins plane, denticulate above; costa extending into acumen; basal cells rhomboidal, alar cells quadrate, longly decurrent, cells above narrowly rhomboidal, in mid-leaf 5–9 × 32–60 μm, 5–9 times as long as wide. Branch leaves more crowded, patent when dry, patent to spreading when moist, lanceolate; margins denticulate to dentate. Setae papillose; capsules horizontal, ellipsoid; lid conical; spores c. 16 μm. Capsules rare but locally abundant. In sheltered rock crevices. 700– 1080 m. Rare in the Scottish Highlands, Mid and E. Perth, Angus, S. Aberdeen,

180 Brachythecium

829

Inverness, Argyll, Ross, E. Sutherland. 10. GB14 + 4∗ . Circumpolar Boreal-montane. Europe north to Svalbard, Caucasus, Turkey, N. and C. Asia, Kashmir, Japan, N. America. In continental Europe this species also occurs at low altitudes on rocks and tree boles in woodland.

Section 5 Velutina De Not., Atti Reale Univ. Genova, 1869 Stem leaves ± concave, not or scarcely plicate, usually ovate-triangular or lanceolate-triangular, longly tapering, alar cells usually shortly decurrent, midleaf cells to 30–74 μm long; setae ± papillose; endostome with ± appendiculate cilia. 11 B. appleyardiae S. V. McAdam & A. J. E. Sm., J. Bryol., 1981 (Fig. 277) Dioicous. Small pale green to yellowish green rough mats. Stems procumbent, c. 4 cm long. Branches numerous, crowded, ascending. Leaves imbricate, shrunken when dry, patent when moist; stem leaves ovate-triangular to ovate-lanceolate, occasionally longitudinally plicate, acuminate; margins plane or narrowly recurved below, entire or obscurely denticulate above; costa extending 2/3 –4 /5 way up leaf, ending in small tooth on abaxial side; cells at extreme base and basal angles rhomboid-rectangular, elsewhere linear, in mid-leaf (4−)9–12(−14) × (23−)28– 74(−106) μm. (3−)9–12(−14) times as long as wide. Branch leaves smaller, concave, ovate to lanceolate; margins finely denticulate above, costa single, rarely forked, ending in small tooth on abaxial side. Setae papillose; capsules inclined, shortly cylindrical, curved; lid conical, blunt; spores 10–14 μm. n = 11∗ . Sporophytes not known in the wild. On thin soil on sheltered limestone rock and mortared sandstone. Lowland. Very rare, S. Somerset, S. Wiltshire, Derby, Cavan. 3, H1. GB5, IR1. Suboceanic Temperate. Germany. A somewhat variable plant originally thought to be a form of Eurhynchium pulchellum and briefly described as such in the first edition of this book. In its small size B. appleyardiae resembles other members of the section Velutina but the leaves are relatively shorter and wider. For an account of this plant see S. V. McAdam & A. J. E. Smith, J. Bryol. 11, 591–8. 1981. This plant is listed as vulnerable in the Red Data Book of European Bryophytes.

12 B. velutinum (Hedw.) Schimp. in Bruch et al. Bryol. Eur., 1853 Chamberlainia velutina (Hedw.) H. Rob.

(Fig. 278)

Autoicous. Plants slender, in green or yellowish green patches. Stems prostrate, irregularly to subpinnately and closely branched, branches short, ascending or erect. Leaves imbricate to spreading when dry, erect-patent to patent, sometimes subsecund when moist, plane or slightly concave, plicate or not near base; stem leaves lanceolate-triangular, tapering from near base to long slender acumen, base hardly decurrent; margins sinuose to denticulate ± from base to apex; costa

830

58 Brachytheciaceae

Fig. 277 1–5, Brachythecium appleyardiae (from V. McAdam & A. J. E. Smith, J. Bryol. 11, 591–8, 1981): 1, 2, stem and branch leaves (×40); 3, alar cells (×350); 4, mid-leaf cells (×350); 5, capsule, grown in culture (×20). 6–9, B. trachypodium: 6, 7, stem and branch leaves (×40); 8, alar cells (×210); 9, mid-leaf cells (×420).

180 Brachythecium

831

Fig. 278 1–5, Brachythecium velutinum: 1, 2, stem and branch leaves (×35); 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule. 6–10, B. populeum: 6, 7, stem and branch leaves (×35); 8, alar cells (×210); 9, mid-leaf cells (×420); 10, capsule. 11–15, B. plumosum: 11, 12, stem and branch leaves (×25); 13, alar cells (×210); 14, mid-leaf cells (×420); 15, capsule. Capsules ×10.

832

58 Brachytheciaceae

extending 1/2 –2/3 way up leaf; basal cells rhomboidal, alar cells rounded-quadrate, thin-walled, 8–11 μm wide, not forming auricles, cells above linear, in mid-leaf 5–7 × 48–70 μm, 9–18 times as long as wide. Branch leaves lanceolate to narrowly lanceolate, apex filiform; costa often ending in small tooth on abaxial side. Setae papillose; capsules inclined, ellipsoid, symmetrical or gibbous; lid conical with stout obtuse beak; spores 13–16 μm. Capsules frequent, winter, spring. n = 10∗ , 10 + 2m, 11, 12∗ . In sheltered situations, on tree boles, stumps, on rocks, in rock crevices, on walls crevices and hedgebanks, but also on more exposed walls and stones in urban areas. Lowland. Common in England, Wales and S. E. Scotland, rare to occasional elsewhere in Scotland and in Ireland. 108, H24, C. GB1038 + 90∗ , IR124 + 19∗ , C5. Circumpolar Temperate. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, Cyprus, Iran, N. Asia, Japan, Macaronesia, Algeria, Morocco, N. America. A variable species, forms of which may be confused with B. populeum. That species has the leaves appressed when dry, whereas B. velutinum often has them patent or spreading. B. populeum also bas a longer costa and shorter leaf cells, setae smooth below and a more sharply pointed capsule lid.

13 B. trachypodium (Brid.) Schimp. in Bruch et al., Bryol. Eur. 1853 (Fig. 277) Autoicous. Plants slender, forming golden green patches. Stems with orangebrown rhizoids, irregularly pinnately branched. Leaves imbricate to spreading when dry, erect-patent to patent when moist; stem leaves ± straight, often slightly plicate, concave, lanceolate-triangular to ovate-lanceolate, tapering from c. 1/3 from base to ± slender acumen; margins plane or rarely narrowly recurved near base, denticulate throughout and becoming serrulate in acumen; costa reaching c. 1/2 way up leaf, often branched; basal cells rectangular, incrassate, alar cells ± quadrate, 7–10 μm wide, walls slightly thickened, not forming auricles and only slightly decurrent, cells above linear, in mid-leaf 4–7 × 37–70 μm, 7–16 times as long as wide. Branch leaves c. 1 mm long, somewhat falcate, narrowly lanceolate; costa sometimes ending in tooth on abaxial side. Setae papillose; capsules inclined to horizontal, ovoid, slightly curved; lid conical; spores 10–12 μm. Capsules unknown in Britain. On montane calcareous rocks. 1050 m. Very rare, Mid Perth (old record), W. Inverness. 2. GB1 + 1∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Caucasus, Turkey, Afghanistan, Siberia, Algeria, Alaska, Canada, Greenland. B. trachypodium is similar to B. velutinum but differs in its golden yellow colour, the leaves tapering from about one third from the base, the alar cells with slightly thickened walls and the branch leaves hardly falcate. In Scotland, B. trachypodium is a high-altitude species whereas B. velutinum is lowland. For the occurrence of this plant in Scotland see M. F. V. Corley, J. Bryol. 16, 173–7, 1990. This is a critically endangered species in the Red List of British Mosses.

181 Pseudoscleropodium

833

14 B. populeum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 278) Autoicous. Plants slender, forming yellowish green to green, sometimes brownishtinged patches. Stems procumbent, pinnately branched, branches ascending to erect. Leaves appressed when dry, erect-patent when moist, not plicate; stem leaves ovate-triangular, tapering to long filiform acumen; margins plane or recurved below, sinuose or denticulate above; costa extending to acumen and sometimes almost to apex; basal cells rhomboidal, alar cells rounded-quadrate to rectangular, not forming auricles and scarcely decurrent, cells above linearrhomboidal, in mid-leaf 5–8 × 32–56 μm, 5–9 times as long as wide. Branch leaves narrowly lanceolate, longly acuminate. Setae smooth below, papillose above; capsules inclined, ellipsoid, symmetrical or gibbous; lid conical, acute; spores 12–20 μm. Capsules frequent, autumn to spring. n = 9, 10∗ , 10 + 1, 11. On rocks, walls, tree boles and stumps and on soil banks in sheltered situations but also occasionally in more exposed habitats. 0–580 m. Occasional to frequent in lowland England and Scotland, common elsewhere, rare to occasional in Ireland. 110, H32, C. GB1028 + 90∗ , IR12 + 19∗ , C5. Circumpolar Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Iran, Kashmir, Himalayas, Japan, Macaronesia, Morocco, Algeria, N. America. 15 B. plumosum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1853 (Fig. 278) Autoicous. Medium-sized to robust plants forming yellowish green to brownish green or golden brown patches. Stems procumbent, closely branched, branches ascending to erect. Leaves ± imbricate to erect-patent when dry, usually secund when moist, very concave; stem leaves curved or straight, broadly ovate to ovate-lanceolate, acuminate; margins recurved near base, one margin sometimes inflexed above, denticulate; costa extending c. 3/4 way up leaf; basal cells rectangular, incrassate, sometimes opaque or brownish, alar cells quadrate-rectangular, ± opaque, decurrent but not forming auricles, cells above linear-rhomboidal, in midleaf 6–8 × 48–72 μm, 7–11 times as long as wide. Branch leaves straight or curved, ovate-lanceolate to oblong-lanceolate, acuminate. Setae smooth below, papillose above; capsules inclined, ovoid to ellipsoid, gibbous; lid conical; spores 16–24 μm. Capsules frequent, winter. On rocks and tree roots subject to submergence by fast-flowing streams and rivers, on rocks by lakes and pools, on flushed rocks and ledges away from water. 0–1205 m. Almost absent from lowland England except the extreme south, common elsewhere, rare to occasional in Ireland. 82, H31, C. GB1053 + 68, IR149 + 7∗ , C2 + 1∗ . Circumpolar Boreo-temperate. Almost cosmopolitan.

181 PSEUDOSCLEROPODIUM (LIMPR.) M. FLEISCH. IN BROTH., NAT. PFLANZENFAM., 1925 A monotypic genus with the characters of the species. Derivation: meaning resembling Scleropodium.

834

58 Brachytheciaceae

Fig. 279 Pseudoscleropodium purum: 1, stem leaves (×25); 2, mid-leaf cells (×420); 3, capsule (×10). Placed by some authorities in the Entodontaceae, but on cytological grounds P. purum is very closely related to Brachythecium.

1 P. purum (Hedw.) M. Fleisch. in Broth., Nat. Pflanzenfam., 1925 (Fig. 279) Brachythecium purum (Hedw.) Dixon, Scleropodium purum (Hedw.) Limpr. Dioicous. Plants robust, in lax pale green to yellowish green or more rarely brownish, green patches or coarse wefts, often extensive. Shoots to 15 cm long. Stems and branches tumid, julaceous, stems procumbent to ascending, often with well defined annual growth zones, ± regularly pinnately branched, branches complanate. Leaves imbricate, very concave, ovate-orbicular to broadly ovate, apex obtuse or rounded with acuminate apiculus; margins plane or recurved near base, finely denticulate above; costa thin, single, extending c. 1/3 –1/2 way up leaf or sometimes double and shorter; basal cells rhomboidal, incrassate, porose, alar cells larger, quadrate to rectangular, more pellucid but not forming auricles, not decurrent, cells above linear-vermicular, in mid-leaf 4–6 × 56–100 μm, 14–25 times as long as wide. Setae smooth; capsules horizontal, cylindrical, curved or gibbous; lid rostrate; peristome perfect, inner with tall basal membrane and appendiculate cilia; spores 12–16 μm. Capsules rare, autumn, winter. n = 7, 11∗ . In calcareous to mildly acidic situations, on soil and in turf in grassland, on roadsides, banks, heaths, in marshes, quarries, woods, on cliff ledges. Usually lowland but ascending to 1000 m in Mid Perth. Very common, 112, H40, C. GB1909 + 79∗ , IR368 + 8∗ , C6 + 1∗ . European Temperate. Europe north to southern Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Macaronesia; also reported from Japan,

182 Scleropodium

835

Taiwan, Sri Lanka, S. Africa, N. and S. America, Australia, New Zealand, but probably introduced. Although the type specimen of the genus Pseudoscleropodium comes from Argentina, it is likely to have been an introduction there as the species is thought to be indigenous to Europe and Macaronesia. The plant is often used as packing material and readily establishes in suitable habitats, hence its now ± world-wide distribution. See B. H. Allen & M. R. Crosby, J. Bryol. 14, 523–5, 1987, for comments on the distribution of P. purum.

182 SCLEROPODIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1853 Dioicous. Slender to medium-sized plants. Secondary stems ascending, closely branched, branches spreading or ascending, long or short. Paraphyllia lacking. Laves very concave; stem leaves broadly ovate, gradually to abruptly narrowed to acute or obtuse apex, apiculate or not, entire or denticulate above; costa extending 1/2 –3/4 way up leaf, single or forked; cells narrowly rhomboidal to linearvermicular, basal cells shorter, alar cells quadrate to rectangular. Setae deep red, papillose; capsules erect to horizontal, cylindrical to ovate-ellipsoid; annulus separating; lid conical or rostrate; peristome perfect, inner with tall basal membrane, cilia nodulose or appendiculate. A small genus of c. 9 species found in Europe, Asia, N. Africa, Macaronesia, N. and C. America. Derivation: meaning hard footed.

Shoots not julaceous when moist, stem leaves broadly ovate, cells (4−)6–12 times as long as wide, capsules erect or slightly inclined 1. S. cespitans Shoots julaceous with imbricate strongly concave leaves, stem leaves ovate-oblong to cordate-triangular, cells 10–20 times as long as wide, capsules inclined to horizontal 2. S. tourettii ¨ Hal.) L. F. Koch, Leafl. West Bot., 1950 (Fig. 280) 1 S. cespitans (Wilson ex Mull. Brachythecium caespitosum (Wilson) Dixon, S. caespitosum (Wilson) Schimp. Plants medium-sized, forming pale green patches. Primary stems creeping, secondary stems ascending with numerous, erect, often curved branches. Leaves imbricate when dry, erect-patent when moist, strongly concave; stem leaves broadly ovate, acute or obtuse or abruptly narrowed to apex of varying length; margins plane, entire or denticulate above; costa single, sometimes forked above, extending 1/2 –2/3 way up leaf, often ending in tooth on abaxial side; basal and alar cells quadrate or rectangular, cells above narrowly rhomboidal to linearrhomboidal, in mid-leaf 5–7 × 28–68 μm, (4−)6–12 times as long as wide. Branch leaves ovate, obtuse to acute; margins denticulate; cells longer than in stem leaves. Setae papillose; capsules erect or slightly inclined, narrowly ellipsoid to cylindrical, straight or curved; lid rostrate; spores 12–24 μm. Capsules rare, winter. On tree trunks, roots, rocks, walls and soil in the flood zone of silty streams, also in

836

58 Brachytheciaceae

Fig. 280 1–4, Scleropodium cespitans: 1, 2, stem and branch leaves; 3, mid-leaf cells; 4, capsule. 5–8, S. tourettii: 5, 6, stem and branch leaves; 7, mid-leaf cells; 8, capsule. Leaves ×40, cells ×420, capsules ×10.

woodland, on concrete and tarmac. Lowland. Occasional to frequent in the southern half of England and in eastern Wales, rare and mostly extinct further north but extending to Argyll and Dunbarton, rare in Ireland. 52, 9, C. GB274 + 86∗ , IR6 + 2∗ , C7. Suboceanic Temperate. Belgium, Corsica, France, Italy, the Netherlands, Portugal, Sardinia, Spain, Turkey, Tenerife, western N. America. May be confused with Cirriphyllum crassinervium or Rhynchostegium murale. Both these species have capsule lids with subulate beaks; C. crassinervium is a larger plant and the

183 Cirriphyllum

837

leaves have shorter cells; in R. murale sporophytes are common, the setae are smooth, the lids longly, and the leaves have poorly defined auricles.

2 S. tourettii (Brid.) L. F. Koch, Rev. Bryol. Lichénol., 1948 (Fig. 280) S. tourretii auct., S. illecebrum auct. non Schimp., Brachythecium illecebrum auct. non (Schimp.) De Not. Slender or medium-sized plants forming green patches. Primary stems rhizomatous, secondary stems ascending, pinnately branched, branches short, spreading, stems and branches julaceous with imbricate leaves. Leaves very concave; stem leaves ovate-oblong to ovate-triangular, acute to obtuse, with or without blunt apiculus; margins plane, sinuose or finely denticulate above; costa single, stout, extending c. 3/4 way up leaf or forked and shorter; basal cells rhomboidal, alar cells rectangular, pellucid, not forming auricles, cells above linear-vermicular, in mid-leaf 4–7 × 52–80 μm, 10–15(−20) times as long as wide. Branch leaves ovate, acute to obtuse, apiculate or not. Setae papillose; capsules inclined to horizontal, ovate-ellipsoid; lid rostrate, obtuse; spores 12–15 μm. Capsules rare. In exposed situations on soil or rocks on cliffs, paths, sand-dunes, banks, also in woodland, usually coastal but sometimes also inland. Lowland. Frequent or common along south and west coasts east to E. Kent and north Anglesey and I. of Man, very rare further north, Wigtown, Ayr, rare inland in southern England where it has much decreased, Berwick, Mid Perth, very rare on Irish coast and seen recently only in E. Cork and Waterford. 42, H10, C. GB144 + 78∗ , IR2 + 11∗ , C10. MediterraneanAtlantic. Mediterranean and western Europe extending north to Scotland and Denmark, Turkey, Cyprus, China, Macaronesia, N. Africa, western N. America. Recognisable by the stems and branches julaceous with very concave imbricate leaves. Pseudoscleropodium purum is a much larger plant,

183 CIRRIPHYLLUM GROUT, BULL. TORREY BOT. CL., 1898 Dioicous, Medium-sized to robust plants; stems creeping or ascending, irregularly or pinnately branched, branches erect or ascending. Leaves concave, sometimes strongly so, stem leaves ovate to ovate-oblong, gradually or abruptly narrowed to acute to acuminate apex or obtuse with long piliferous acumen, base decurrent; margins recurved near base, entire to denticulate; costa single or forked above, extending 1/3 –3/4 way up leaf; cells rhomboidal to linear, alar cells quadrate to rectangular, forming decurrent auricles. Setae deep red or brownish red, strongly papillose; capsules inclined, ovoid to ellipsoid, gibbous or curved; annulus separating; lid conical with long subulate beak; peristome perfect, inner with tall basal membrane with nodulose or appendiculate cilia. Probably 4 or 5 species. Derivation: meaning curl of hair leaf, referring to the filiform acumen of the leaves of some species. For an account of Cirriphyllum see K. Karttunen, Taxon 19, 312–22, 1990.

838

58 Brachytheciaceae

1 Leaves moderately concave, apices acuminate 3. C. crassinervium Leaves strongly concave, apices rounded with long piliferous acumen 2 2 Stems pinnately branched, mid-leaf cells 10–15 μm wide, frequent or common mainly lowland plant 1. C. piliferum Stems irregularly branched, mid-leaf cells 6–8 μm wide, very rare high-altitude plant 2. C. cirrosum

1 C. piliferum (Hedw.) Grout, Bull. Torrey Bot. Cl., 1898 (Fig. 281) Brachythecium piliferum (Hedw.) Kindb., Eurhynchium piliferum (Hedw.) Schimp. Dioicous. Plants robust, bright green, forming lax patches, coarse wefts or as scattered shoots, to 15 cm long. Stems procumbent, complanately pinnately branched, branches spreading. Paraphyllia lacking. Leaves erect, apices flexuose, shrunken or not when dry, loosely imbricate when moist, strongly concave, plicate or not; stem leaves ovate-oblong, apices rounded or obtuse with long piliferous acumen; margins recurved near base, sinuose or finely denticulate above; costa extending c. 3/4 way up leaf; basal cells elongate-rectangular, alar cells enlarged, rectangular, sometimes forming auricles, decurrent, cells above linear-rhomboidal, in mid-leaf 10–15 × 60–100 μm, 8–12 times as long as wide. Branch leaves similar to stem leaves or narrower. Setae strongly papillose; capsules inclined, ovate-ellipsoid or ellipsoid, curved or gibbous; lid conical with long subulate beak; exostome teeth yellowish; spores 12–16 μm. Capsules rare, autumn, winter. In moist turf in woodland, scrub, sheltered river and roadside banks, fens, in basic or neutral situations. Mainly lowland but ascending to 800 m in W. Ross. Frequent or common in most of England and Wales, occasional to frequent in Scotland, occasional in Ireland. 109, H35, C. GB1066 + 132∗ , IR97 + 9∗ , C2 + 2∗ . Circumpolar Boreo-temperate. From the mountains of southern Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Iran, N. and C. Asia, Japan, Algeria, Morocco, N. America, Greenland. ¨ 2 C. cirrosum (Schwagr.) Grout, Bull. Torrey Bot. Cl., 1898 (Fig. 281) ¨ ¨ Brachythecium cirrosum (Schwagr.) Schimp., Eurynchium cirrosum (Schwagr.) Husn. Dioicous. Plants robust, in lax or tight, pale green patches. Shoots to 10 cm long; stems procumbent, irregularly branched. Paraphyllia lacking. Leaves erect, with flexuose apices when dry, loosely imbricate when moist, very concave, plicate or not; stem leaves ovate–oblong, apices obtuse or rounded with long piliferous acumen; margins recurved near base, sinuose or finely denticulate above; costa extending 1/3 –1/2 way up leaf; basal cells narrowly rhomboidal, alar cells quadrate to rectangular, sometimes forming auricles, decurrent, cells above linearrhomboidal, incrassate, 5–8 × 56–84 μm, 8–13 times as long as wide. Capsules similar to those of C. piliferum but lid conical with rostrate beak. Capsules unknown in Scotland. On basic rock ledges on cliffs. 730–1170 m. Very rare, Mid Perth,

183 Cirriphyllum

839

Fig. 281 1–4, Cirriphyllum piliferum: 1, 2, stem and branch leaves; 3, mid-leaf cells (×420); 4, capsule. 5–7, C. cirrosum: 5, 6, stem and branch leaves; 7, mid-leaf cells (×420). 8–11, C. crassinervium: 8, 9, stem and branch leaves; 10, alar cells (×210); 11, mid-leaf cells (×420); 12, capsule. Leaves ×25, capsules ×10.

840

58 Brachytheciaceae

Argyll, Ross. 4. GB5. Circumpolar Arctic-montane. Montane and arctic Europe north to Svalbard, Caucasus, Atlas Mountains, Himalayas, N. America, Greenland. Similar to C. piliferum but differing in the irregularly branched stems and narrower leaf cells. Although the two species overlap in their altitudinal ranges, C. piliferum is a mainly lowland species whilst C. cirrosum is a very rare plant occurring exclusively at high altitudes in Scotland.

3 C. crassinervium (Taylor) Loeske & M. Fleisch., Allg. Bot. Zeitschr., 1907 (Fig. 281) Eurhynchium crassinervium (Taylor) Schimp. Dioicous. Medium-sized plants in dense, green or bright green tufts or patches. Primary stems creeping or ascending, closely branched, branches short, straight or curved, often homomallous. Leaves erect-flexuose when dry, patent when moist, concave, stem leaves ovate, rapidly narrowed to acuminate apex; margins plane, entire below or denticulate ± from base to apex; costa extending 1/2 –2/3 way up lea; basal cells narrowly rectangular, slightly porose, alar cells rectangular, cells above rhomboidal to narrowly rhomboidal, in mid-leaf 6–8 × 36–56 μm, 5–8 times as long as wide. Branch leaves similar to or narrower than stem leaves; costa ending in small tooth on abaxial side. Setae strongly papillose; capsules inclined, ovate-ellipsoid to ellipsoid, curved or gibbous; lid conical with long subulate beak; spores 16–22 μm. Capsules occasional, winter. n = 11. On shaded rocks, soil and tree boles in woodland and by streams and rivers, on bases of walls, in usually basic situations. Lowland. Frequent or common in England and Wales, becoming rare in Scotland, extending north to Shetland, occasional in Ireland. 95, H31, C. GB571 + 84∗ , H65 + 9∗ , C1 + 2∗ . European Temperate. Europe north to Scandinavia, Iceland, Caucasus, Turkey, Iran, Japan, Algeria. Easily recognised by the numerous short branches and strongly concave acuminate leaves. K. Kartunen (Taxon 39, 312–22, 1990) puts forward reasons for transferring this species to Eurhynchium, but it seems better retained in Cirriphyllum.

184 PLATYHYPNIDIUM M. FLEISCH., MUSCI BUITENZORG, 1923 Autoicous. Plants robust. Stem and branch leaves hardly differing, concave, ovate to ± orbicular, not striate; costa of branch leaves not ending in abaxial tooth; alar cells somewhat enlarged but not forming auricles. Setae smooth. About 20 species. Although included by most recent authors in Rhynchostegium, it has been shown using DNA sequencing (M. Stech & J.-P. Frahm, Bryobrothera 5, 203–12, 1999) that P. riparioides is distinct from Rhynchostegium and also from Eurhynchium. An additional species, P. mutatum Ochyra & Vanderpoorten, was recently described from Germany; this seems merely to be a mutant form of P. riparioides (see M. Stech & J.-P. Frahm, J. Bryol. 21, 191–5, 1999).

Leaves imbricate to spreading when moist, mid-leaf cells 6-11 μm wide 1. P. riparioides

184 Platyhypnidium

841

Fig. 282 1–4, Platyhypnidium riparioides: 1, 2, stem and branch leaves (×15); 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule. 6–8, P. alopecuroides: 6, stem leaf; 7, mid-leaf cells (×420); 8, capsule. Capsules ×10.

Shoots julaceous with closely imbricate leaves when moist, mid-leaf cells 4–8 μm wide 2. P. alopecuroides 1 P. riparioides (Hedw.) Dixon, Rev. Bryol. Lichén., 1934 (Fig. 282) Eurhynchium riparioides (Hedw.) P. W. Richards, E. rusciforme Milde, P. rusciforme (Schimp.) M. Fleisch., Rhynchostegium riparioides (Hedw.) Cardot, R. rusciforme Schimp. Plants robust, rigid or soft, bright green or dark green to brownish tufts or patches, often blackish below, with glossy metallic sheen when dry, sometimes extensive. Shoots to 15 cm long, procumbent or pendulous, often denuded below; stems

842

58 Brachytheciaceae

irregularly branched, branches long or short, sometimes attenuate. Leaves slightly shrunken or not when dry, imbricate to spreading, sometimes subsecund when moist, concave, ovate or broadly ovate, acute to obtuse; margins plane, denticulate to dentate ± from base to apex; costa strong, extending c. 3/4 way up leaf; basal cells narrowly rhomboidal, alar cells rectangular, not forming auricles, not decurrent, cells above linear, in mid-leaf 6–11 × 48–100(−136) μm, (6−)8–13 times as long as wide. Setae smooth; capsules inclined to cernuous, ovate-ellipsoid to ellipsoid; lid with subulate beak; spores 16–22 μm. Capsules frequent, autumn, winter. n = 8∗ , 10, 11∗ , 20. On rocks and tree roots subject to submergence or submerged in and by fast-flowing streams and rivers, in waterfalls, on weirs, sluices and locks, flushes on cliffs and in quarries. Mainly lowland but ascending to 950 m in E. Inverness. Common in Britain, frequent in Ireland. 112, H38, C. GB1565 + 84, IR165 + 4∗ , C6. Circumpolar Southern-temperate. Europe north to southern Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Tibet, Kashmir, Nepal, Manchuria, China, Japan, Macaronesia, Algeria, Morocco, N. America, Mexico, Guatemala, northern S. America. A very variable species, small plants tending to grow in drier habitats, large plants submerged or floating. May be confused with Hygrohypnum and submerged Brachythecium species. Differs from the former in leaf shape and sharply denticulate leaf margins. Brachythecium rivulare has distinct decurrent hyaline auricles and B. plumosum differs in leaf shape. P. alopecuroides is usually brownish in colour, the shoots julaceous with closely imbricate leaves and the leaf cells are narrower.

2 P. alopecuroides (Brid.) A. J. E. Sm., J. Bryol., in press (Fig. 282) Eurhynchium alopecuroides (Brid.) P. W. Richards & E. C. Wallace, E. alopecurum err. orth. pro E. alopecuroides, E. rusciforme var. alopecuroides (Brid.) Dixon, R. alopecuroides (Brid.) A. J. E. Sm., Hygrohypnum lusitanicum (Schimp.) Corb., R. lusitanicum (Schimp.) A. J. E. Sm. Plants medium-sized, forming dense, brownish green to brownish patches. Shoots decumbent or floating; stems sparsely branched, stems and branches julaceous with imbricate leaves. Leaves very concave, ovate, obtuse to acute; margins denticulate ± from base to apex; costa reaching 3/4 or more way up leaf; basal cells narrowly rhomboidal, alar cells quadrate-rectangular or rectangular, not forming auricles, not decurrent, cells above linear-vermicular, in mid-leaf 4–8 × 56– 112 μm, 12–17 times as long as wide. Capsules ellipsoid; lid with subulate beak; spores 16–20 μm. Capsules usually very rare but frequent in N. Wales, winter. On submerged rocks in fast-slowing streams and rivers. Usually at low altitudes but ascending to 450 m in Montgomery. Occasional in S. W. England, Mid and N. Wales, Lake District, I. of Man, rare elsewhere in scattered localities north to W. Sutherland, rare in Ireland. 26, H8. GB60 + 11∗ , IR12 + 2∗ . Oceanic Temperate. France, Germany, Portugal, spain.

185 Rhynchostegium

843

185 RHYNCHOSTEGIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1852 Autoicous. Plants slender to robust. Stems ± irregularly branched. Paraphyllia lacking. Stem leaves similar to branch leaves or smaller, usually concave, ovatelanceolate to broadly ovate, shortly tapering to acute to obtuse apex; margins entire or denticulate; costa extending 1/2 way or more up leaf, not ending in a tooth on abaxial side in branch leaves; basal cells rhomboidal or narrowly rhomboidal, alar cells quadrate to rectangular, sometimes forming poorly defined auricles, cells above narrowly rhomboidal to linear. Setae reddish, smooth; capsules inclined to horizontal, ovoid to shortly cylindrical, curved or gibbous; annulus present; lid with long subulate beak; peristome perfect, inner with tall basal membrane and nodulose or appendiculate cilia; calyptrae cucullate. A mainly Northern Hemisphere genus of about 195 species. Derivation: meaning lid with long beak. Rhynchostegium is somewhat intermediate between Eurhynchium and Brachythecium. It differs from the former in the stem and branch leaves being of ± similar shape and often strongly concave, the costa not ending in a tooth on the abaxial side of branch leaves and in being autoicous; it differs from Brachythecium in the capsules with lids with subulate beaks.

1 Mid-leaf cells 10–16 μm wide, 3–5 times as long as wide, very rare plant 4. R. rotundifolium Mid-leaf cells 4–10 μm wide, 6–17 times as long as wide 2 2 Leaf margins ± entire or only denticulate above, alar cells forming poorly defined auricles 1. R. murale Leaf margins denticulate ± from base to apex, alar cells not forming auricles 3 3 Plants slender, stems attached to substrate for most of length by rhizoids, leaf apices acute, rarely acuminate, not twisted 2. R. confertum Plants medium-sized, stems only attached to substrate at base, leaf apices acuminate, twisted 3. R. megapolitanum 1 R. murale (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1852 Eurhynchium murale (Hedw.) Milde

(Fig. 283)

Medium-sized plants in glossy light green or yellowish green patches. Stems creeping, irregularly pinnately branched, branches short, obtuse, erect or ascending, Stem and branch leaves ± similar, imbricate to erect-patent when moist, hardly altered when dry, very concave, ovate, obtuse or obtuse and apiculate; margins plane or inflexed above, obscurely denticulate above; costa extending 1/2 –3/4 way up leaf; basal cells rhomboidal, alar cells enlarged, shortly rectangular, forming poorly defined auricles, cells above narrowly rhomboidal to linear-rhomboidal, in mid-leaf 5–8 × 48–72 μm, 7–12 times as long as wide. Inner perichaetial leaves with entire margins, ecostate. Setae short, smooth; capsules inclined or horizontal, cylindrical, curved; lid with long subulate beak; spores 12–16 μm. Capsules

844

58 Brachytheciaceae

Fig. 283 1–5, Rhynchostegium murale: 1, 2, stem and branch leaves; 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule. 6–8, R. rotundifolium: 6, stem leaf; 7, mid-leaf cells (×420); 8, capsule. 9–13, R. confertum: 9, 10 stem and branch leaves; 11, alar cells (×210); 12, mid-leaf cells (×420); 13, capsule. Leaves ×15, capsules ×10.

185 Rhynchostegium

845

common, winter, spring. n = 10, 10 + m, 11∗ . On shaded rocks, walls, stony ground and tree boles, calcicole. Mainly lowland but ascending to 730 m in Mid West Yorkshire. Frequent or common in basic sites in England and Wales, rare to occasional in Scotland, extending north to Shetland, rare to occasional in Ireland. 101, H28, C. GB584 + 87∗ , H24 + 11∗ , C2 + 1∗ . European Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Syria, Japan, Macaronesia, Afghanistan, Algeria. Recognisable in the field from the dense glossy patches with short ± obtuse branches which are frequently julaceous with ± imbricate strongly concave obtuse leaves.

2 R. confertum (Dicks.) Schimp. in Bruch et al., Bryol. Eur., 1852 Eurhynchium confertum (Dicks.) Milde

(Fig. 283)

Slender plants forming dull green patches. Stems procumbent, irregularly branched, branches short, spreading to erect. Stem and branch leaves ± similar, spreading, sometimes subsecund or complanate when moist, somewhat shrunken when dry, concave, ovate or ovate-lanceolate, acute, rarely acuminate; margins plane, denticulate ± from base to apex; costa extending c. 3/4 way up leaf; basal cells rhomboidal, alar cells shortly rectangular, not forming auricles, cells above linear, in mid-leaf 5–7 × 48–60 μm, 9–11(−13) times as long as wide. Perichaetial leaves with denticulate margins, costate. Setae short, smooth; capsules inclined, ellipsoid; lid with long subulate beak; spores c. 15 μm. Capsules common, winter. n = 10∗ , 10 + m, 11∗ , 11 + m, 12∗ . On rocks, stones, damp walls and bark in sheltered habitats, mildly calcicolous. Mainly lowland but ascending to 350 m in N. W. Yorkshire and 950 m in Westmorland. Common in England and Wales, becoming rare in Scotland except in the south-east, extending to Shetland, occasional in Ireland. 107, H33, C. GB1279 + 92∗ , IR72 + 2m∗ , C8. European Temperate. Europe north to southern Scandinavia, Iceland, Caucasus, Turkey, Cyprus, China, Macaronesia, Algeria. A nondescript moss with no obvious distinguishing features but recognisable in the field by its relatively small size, the concave, ovate or ovate-lanceolate, uncrowded leaves and the usually abundant sporophytes with smooth setae and longly rostrate lids. It differs from small Brachythecium species in its wider shortly pointed leaves; from R. murale by its spreading, less concave leaves with margins denticulate ± from base to apex, and from Rhynchostegiella pumila in the longer narrower leaf cells and the costa not ending in a small tooth on the abaxial side of branch leaves.

3 R. megapolitanum (Bland. ex F. Weber & D. Mohr) Schimp. in Bruch et al, Bryol. Eur., 1852 (Fig. 284) Eurhynchium megappolitanum (Bland ex F. Weber & D. Mohr) Milde Medium-sized pale green or yellowish green plants forming straggling patches or wefts. Stems procumbent to ascending, irregularly branched. Stem and branch leaves ± similar, shrunken when dry, erect to patent when moist, ovate to broadly

846

58 Brachytheciaceae

Fig. 284 1–5, Eurhynchium striatum: 1, 2, stem and branch leaves; 3, alar cells (×280); 4, mid-leaf cells (×420); 5, capsule (×10). 6–9, E. meridionale: 6, 7, stem leaves from different plants; 8, alar cells (×280); 9, mid-leaf cells (×420). 10–11, Rhynchostegium megapolitanum: 10, stem leaf; 11, mid-leaf cells (×420). Leaves ×20.

186 Eurhynchium

847

ovate, gradually to abruptly tapering to acuminate apex, apex twisted; margins plain, denticulate ± from base to apex; costa extending c. 2/3 way up leaf; basal cells shortly rectangular or rhomboidal, alar cells shortly rectangular, not forming auricles, cells above linear, 6–10 × 56–128 μm, 8–13 times as long as wide. Setae long, flexuose, smooth; capsules inclined, subcylindrical; lid with subulate beak; spores 12–16 μm. Capsules frequent, autumn, winter. n = 10∗ , 11, 11 + m. On sandy or chalky soil in turf, on banks, on cliff tops and sand-dunes, calcicole. Lowland. Occasional to frequent in southern and central England, rare elsewhere, S. and N. Wales and scattered localities north to Angus, S. Kerry, Waterford, Wicklow, Dublin, Westmeath. 54, H5, C. GB189 + 40∗ , IR3 + 1∗ , C6 + 1∗ . SubmediterraneanSubatlantic. S. and W. Europe north to Denmark and S. Sweden, Turkey, Cyprus, Iran, Syria, Lebanon, Macaronesia, Algeria, Morocco. May be overlooked as Brachythecium rutabulum but that species differs in the tighter patches and narrower more shortly pointed leaves.

4 R. rotundifolium (Scop. ex Brid.) Schimp. in Bruch et al., Bryol. Eur., 1852 (Fig. 283) Eurhynchiium rotundifolium (Scop. ex Brid.) Milde Medium-sized plants forming dull green patches. Stems creeping, irregularly branched, branches erect or ascending, short. Leaves soft, not crowded, shrunken and flexuose when dry, patent to spreading when moist, slightly concave, broadly ovate, acute; margins plane, bluntly denticulate above; costa extending c. 1/2 way up leaf; cells lax, narrowly hexagonal to rhomboidal, narrower at base, not differentiated at basal angles, in mid-leaf 10–16 × 48–60 μm, 3–5 times as long as wide. Setae short, smooth; capsules inclined, ovoid; spores 14–16 μm. capsules common, winter. n =10 + m, 11∗ . On tree boles and exposed roots in sheltered situation in hedgerows. 0–230 m. Very rare and endangered, N. Somerset (1887), E. Sussex, E. Gloucester. 3. GB2 + 1∗ . European Temperate. Central and western Europe, Caucasus, Japan. This species is regarded as critically endangered in the Red List of British Mosses and is a protected species under the Wildlife and Countryside Act.

186 EURHYNCHIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1854 Usually dioicous. Plants slender to robust, forming mats, patches or wefts. Stems creeping, procumbent, arcuate or ascending, irregularly to pinnately branched, branches spreading. Paraphyllia seldom present. Leaves imbricate to spreading, often plicate; stem leaves broadly ovate-triangular to lanceolate-triangular, obtuse to acute or longly acuminate, base decurrent or not; margins usually denticulate ± from base to apex; costa extending 3/4 way or more up leaf; basal cells narrowly rhomboidal, alar cells usually shorter and wider, sometimes enlarged and forming auricles, cells above narrowly rhomboidal to linear. Branch leaves differing

848

58 Brachytheciaceae

in shape from stem leaves, ovate to lanceolate; costa ending in a small tooth on abaxial side. Setae reddish, smooth; capsules inclined to horizontal, ovoid to shortly cylindrical, curved or gibbous; annulus present; lid with long subulate beak; peristome perfect, inner with tall basal membrane and nodulose or appendiculate cilia; calyptrae cucullate. Derivation: Meaning finely beaked, referring to the longly rostrate lids. DNA studies (M. Stech & J.-P. Frahm, Bryobrotheria 5, 203–11, 1999) support the separation of Oxyrrhynchium and Kindbergia from Eurhynchium and I have accepted this.

1 Plants forming coarse wefts, branches not crowded, alar cells of stem leaves rectangular 1. E. striatum Plants forming mats or patches, branches crowded, alar cells ± rounded-quadrate 2 2 Branches curved and often homomallous, alar cells of stem leaves forming opaque auricles extending to costa, cells above 4–8 times as long as wide 3. E. striatulum Branches not curved or homomallous, alar cells not forming auricles, cells above 8–12 times as long as wide 3 3 Plants medium-sized, leaves strongly plicate and undulate when moist 2. E. meridionale Plants small or very small, leaves not or only slightly plicate when moist 4. E. pulchellum 1 E. striatum (Schreb. ex Hedw.) Schimp., Coroll. Bryol. Eur., 1856 (Fig. 284) Dioicous. Plants medium-sized to robust, rigid, forming glossy bright green, green or yellowish green coarse wefts. Stems procumbent to ascending or arcuate, irregularly to subpinnately branched, branches not crowded, spreading to erect, obtusely pointed, stout to somewhat slender. Leaves erect-patent to spreading, strongly longitudinally plicate; stem leaves cordate-triangular to lanceolatetriangular, tapering from near base to acuminate apex; margins narrowly recurved below, denticulate to dentate ± from base to apex; costa extending 3/4 way or more up leaf; basal cells narrowly rhomboidal, ± porose, alar cells larger, rectangular, forming shortly decurrent poorly defined auricles, cells above linear, in mid-leaf 4–6 × 36–72 μm, 10–14 times as long as wide. Branch leaves smaller, ovate to lanceolate, acute; costa ending in a small tooth on abaxial side. Setae smooth; capsules inclined, subcylindrical, slightly curved; lid with long subulate beak; spores c. 14 μm. Capsules rare in lowland England, occasional elsewhere, autumn, winter. n = 6, 11∗ , 12. In basic or neutral situations on soil, rocks and logs in woods, on cliff ledges, banks, by streams, in damp turf and among rocks in calcareous grassland. 0–780 m. Occasional in N. E. Scotland, common elsewhere. 112, H39, C. GB14550 + 92∗ , IR273 + 6∗ , C7. European Temperate. Europe to c. 66◦ N, Iceland, Caucasus, Turkey, Altai, Siberia, Japan, Macaronesia, Algeria.

186 Eurhynchium

849

2 E. meridionale (Schimp.) De Not. in Piccsine, Comm. Soc. Crittog. Ital., 1863 (Fig. 284) Plasteurhynchiunm meridionbale (Schimp.) M. Fleisch. Dioicous. Plants medium-sized, forming dense bright yellowish green patches. Stems creeping, closely branched, branches erect or ascending. Leaves spreading, flexuose when dry, patent when moist, longitudinally plicate, undulate, stem leaves cordate-triangular, acuminate; margins plane, denticulate ± from base to apex; costa extending c. 3/4 way up leaf; basal cells elongate-rhomboidal, incrassate, porose, alar cells rounded-quadrate, strongly incrassate, cells above linearrhomboidal, incrassate, in mid-leaf 5–6 × 48–56 μm, c. 10 times as long as wide. Branch leaves similar to stem leaves; costa ending in a small tooth on abaxial side. Setae smooth; capsules inclined, subcylindrical; unknown in Britain. n = 11∗ . On limestone rocks and boulders in old quarries and on cliff slopes. Lowland. Very rare, Dorset, 1, GB2. Mediterranean-Atlantic. Mediterranean region of Europe, Caucasus, Turkey, Macaronesia, Azores, Algeria. Although the leaves are similar in shape to those of E. striatum, the habits of the two plants are so different that they cannot be confused. However, robust forms of E. striatulum have been mistaken for E. neridionale; they differ in the imbricate leaves, the alar cells extending to the costa and in the other basal cells being shortly rectangular. This species is treated as vulnerable in the Red List of British Mosses.

3 E. striatulum (Spruce) Schimp. in Bruch et al, Bryol. Eur., 1852 (Fig. 285) Isothecium striatulum (Spruce) Kindb., Plasteurhynchium striatulum (Spruce) M. Fleisch. Dioicous. Plants slender to medium-sized, forming yellowish green patches. Primary stems creeping, secondary ascending to erect, branching subdendroid to irregularly pinnate, branches often curved and homomallous. Leaves imbricate to erect-patent when moist, not much altered when dry, plicate but sometimes only faintly so, ± concave; stem leaves cordate-triangular, rapidly tapering to long channelled acumen in large plants to broadly ovate and acuminate in small forms; margins denticulate ± from base to apex; costa extending c. 3/4 way up leaf; extreme basal and alar cells shortly rectangular to rounded-quadrate, incrassate, forming distinct group extending to costa, other basal cells narrowly rectangular, cells above rhomboidal to narrowly rhomboidal, in mid-leaf 5–8 × 30– 48 μm, 4–8 times as long as wide. Branch leaves lanceolate to ovate-lanceolate, acute; margins denticulate to dentate; costa ending in small tooth and with 2–3 teeth on abaxial side. Setae smooth; capsules inclined, ellipsoid, slightly curved to gibbous; lid with oblique subulate beak; spores 14–20 μm. Capsules rare, winter. n = 11. On shaded limestone and chalk rocks, stones and walls and on tree roots, calcicole. Lowland. Rare to occasional in south and S. W. England, S. and N. Wales, N. W. England, Argyll, and W. Ireland. 28, H12. GB42 + 16∗ , IR13 + 2∗ .

850

58 Brachytheciaceae

Fig. 285 1–4, Eurhynchium striatulum: 1, 2, stem and branch leaves; 3, mid-leaf cells 4, capsule (×10). 5–7, E. pulchellum var. diversifolium: 5, 6, stem and branch leaves from different plants; 7, mid-leaf cells from different plants (×420). Leaves ×40, cells ×420.

Submediterranean-Subatlantic. Europe north to southern Scandinavia, Caucasus, Turkey, Tenerife, Azores, Algeria. The correct taxonomic position of E. striatulum is debatable as habit and leaf areolation closely resembles that of Isothecium, but it is placed by recent authorities in Eurhynchium because of the costa ending in a small tooth on the abaxial side of branch leaves, a character which I consider to be of relatively little importance. It differs from Isothecium species in the longitudinally plicate leaves.

187 Kindbergia

851

4 E. pulchellum (Hedw.) Jenn. var. diversifolium (Schimp.) C. E. O. Jensen, Skand. Bladmossfl., 1929 (Fig. 285) E. strigosum var. diversifolium (Schimp.) Anzi Dioicous. Female plants small or very small, forming green or yellowish green patches; male plants bud-like on female plants. Stems procumbent, densely and often subpinnately branched, branches erect, short, obtuse. Leaves crowded, imbricate to erect-patent when moist and when dry, concave, ± plicate or not; stem leaves slightly complanate, ovate-triangular and tapering to acuminate apex; margins plane, denticulate ± from base to apex; costa slender, extending c. 3/4 way up leaf; basal cells rhomboidal, incrassate, often ± porose, alar cells oval to rounded-quadrate, incrassate, not forming auricles, cells above linear, 5–7 × 36–56 μm, 8–12 times as long as wide in mid-leaf. Branch leaves ovate, acute to obtuse; costa ending in a small tooth on abaxial side. Setae smooth; capsules ovoid to ellipsoid, curved; unknown in the British Isles. n = 10∗ . In dry basic situations, on rock faces, cliff ledges and on calcareous soil. 0–500 m. Very rare, W. Suffolk, Angus (old record) Skye, Londonderry. 3, H1. GB3 + 1∗ , IR1. Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Caucasus, Turkey, Arctic Asia, Afghanistan, N. America, N. America, Greenland. Three varieties of E. pulchelllum have been recorded from the British Isles, var. diversifolium (Bruch et al.) C. E. O. Jensen, var. praecox (Hedw.) Dixon and var. pulchellum, but after examination of herbarium specimens, M. O. Hill (J. Bryol. 17, 683–684, 1993) concluded that all the material belonged to var. diversifolium. The status of this variety is open to question as Duell 1992) suggests that var. diversifolium is synonymous with var. praecox and Nyholm (1954–1969) suggests that these two varieties are not genetically distinct and might merely be dry habitat forms of var. pulchellum. This species is considered endangered in the Red List of British Mosses.

187 KINDBERGIA OCHYRA, LINDBERGIA, 1982 Stem leaves broad, squarrose, strongly decurrent, strongly differentiated from branch leaves. Capsules strongly inclined to horizontal, narrower than in other genera of the family. A small genus of 7 species. Derivation: Named after Nils Conrad Kindberg ((1832–1910), a Finnish bryologist.

1 K. praelonga (Hedw.) Ochyra, Lindbergia, 1982 (Fig. 286) Eurhynchium praelongum (Hedw.) Schimp., E. praelongum var. stokesii (Turner) Dixon, E. stokesii (Turner) Schimp., Oxyrrhynchium praelongum (Hedw.) Warnst., Stokesiella praelonga (Hedw.) H. Rob. Dioicous. Plants very slender to medium-sized, forming light green to dark green patches or wefts or straggling plants creeping through vegetation and litter. Shoots

852

58 Brachytheciaceae

Fig. 286 1–6, Kindbergia praelonga: 1, 2, stem and branch leaves (×40); 3, mid-leaf cells (×420); 4, 5, end of costa on abaxial side of branch leaf, surface and side views (×210); 6, capsule (×10). 7–11, Oxyrrhynchium hians: 7, 8 stem and branch leaves (×25); 9, alar cells (×210); 10, mid-leaf cells (×420); 11, capsule (×10).

188 Oxyrrhynchium

853

to 12 cm long; stems procumbent or arcuate, interruptedly pinnately or sometimes bipinnately branched, branches subcomplanate, ± curved. Paraphyllia sometimes present. Leaves ± patent, somewhat shrunken when dry; stem leaves somewhat distant to crowded, patent to spreading or squarrose when moist, widely cordatetriangular to ovate-triangular, rapidly or abruptly narrowed to usually long acumen, base longly decurrent; margins plane, denticulate ± from base to apex; costa extending 1/2 –3/4 way up leaf; basal cells narrowly rhomboidal, alar cells rectangular forming poorly defined auricles, cells above becoming narrower, towards acumen linear, 5–7 × 24–60 μm, 5–12 times as long as wide. Branch leaves patent to spreading, markedly differing from stem leaves, ovate to lanceolate, acute to acuminate. Setae papillose; capsules green with small black blotches at maturity, ± horizontal, ellipsoid to subcylindrical, curved; lid with long subulate beak; spores 11–13 μm. Capsules frequent, winter. n = 7, 8∗ , 9∗ , 9 + m∗ , 9 + 2m∗ , 9 + 4m∗ , 10, 10 + m∗ , 11∗ , 12. In sheltered or exposed, dry or damp situations, on soil, rocks, litter, logs, tree boles in woodland, on hedgebanks, by streams and rivers, in turf, on cliff ledges and in scree, in marshes, usually on neutral to acidic terrain. 0–500(−1050) m. Very common throughout the British Isles. GB112, H40, C. GB2172 + 79∗ , IR338 + 9∗ , C7 + m∗ . European Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, N. Asia, Yunnan, Japan, Macaronesia, Tunisia, Morocco, Tanzania, S. Africa (introduced), N. America, Australia and New Zealand (introduced ?). A very variable species. Larger forms with bipinnately branched stems have been known as var. stokesii (Turner) Ochyra (Eurhynchium praelongum var. stokesii (Turner) Dixon) and have even been recognised at the specific level, but so many intermediates exist between this variety and typical plants that it is not recognised here. Oxyrrhynchium hians differs in its yellowish colour, the stem and branch leaves only differing slightly in shape. Some authorities treat K. praelonga and Oxyrrhynchium as synonymous but Dixon & Jameson (1924) give good reasons for treating the two as distinct species.

188 OXYRRHYNCHIUM (SCHIMP.) WARNST., KRYPT. FL. BRANDENBURG, LAUBM., 1905 Usually dioicous. Plants usually medium-sized, forming mats, patches or wefts, often glossy when dry. Stems creeping, procumbent, arcuate or ascending, irregularly branched, branches spreading; Paraphyllia absent. Leaves imbricate to spreading, not plicate; stem leaves broadly ovate to lanceolate, acute to acuminate, base decurrent or not; margins denticulate ± from base to apex; costa single, extending 1/2 way or more up leaf; basal cells narrowly rhomboidal, alar cells usually shorter and wider, sometimes enlarged and forming auricles, cells above narrowly rhomboidal to linear. Branch leaves similar in shape to stem leaves or narrower; costa ending in a small tooth on abaxial side of leaf (except in O. speciosum). Setae reddish, papillose; capsules inclined to horizontal, ovoid to shortly cylindrical, curved or gibbous; annulus present; lid with long subulate

854

58 Brachytheciaceae

beak; peristome perfect, endostome with tall basal membrane and nodulose or appendiculate cilia; calyptrae cucullate. Derivation: Meaning provided with a sharp beak, referring to the subulate beak of the capsule lid.

1 Primary stems rhizomatous, subterranean, branches short, crowded, mid-leaf cells 3–5 μm wide. Leaf apices often twisted through 180◦ 3. O. schleicheri Stems not rhizomatous or subterranean, branches of various length, not crowded, mid-leaf cells 6–9 μm wide, leaf apex not twisted 2 2 Dioicous, plants usually yellowish or yellowish green, stem leaves often complanate, mid-leaf cells of stem leaves 48–60 μm long 1. O. hians Autoicous or synoicous, plants dark green, stem leaves not complanate, mid-leaf cells 40–90 μm long 2. O. speciosum 1 O. hians (Hedw.) Loeske, Ver. Bot. Vereins Prov. Brandenburg, 1907 (Fig. 286) Eurhynchium hians (Hedw.) Sande Lac., E. swartzii (Turner) Curn., E. swartzii ´ var. rigidum (Boulay) Ther. Dioicous. Plants slender or medium-sized, in yellowish or yellowish green, occasionally green, lax patches or straggling shoots. Stems prostrate, distantly to closely irregularly branched, branches straight, spreading or erect. Leaves complanate or not, ± shrunken when dry, patent to spreading when moist, stem leaves ovate to broadly ovate, acute to acuminate, base shortly decurrent; margins plane, denticulate to dentate ± from base to apex; costa strong, extending c. 4/5 way up leaf; basal cells narrowly rhomboidal, alar cells rectangular, not forming auricles, cells above linear, in mid-leaf 6–9 × 48–80 μm, 4–11 times as long as wide. Branch leaves narrower than stem leaves, ovate-lanceolate to ovate, acute to acuminate; costa ending in tooth on abaxial side. Setae strongly papillose; capsules greenish with small black blotches at maturity, inclined, ellipsoid, gibbous or slightly curved; lid with long subulate beak; spores 12–16 μm. Capsules rare, winter. n = 7∗ , 7 + 2m, 10, 11. On damp soil in fields, grassland, by streams, roadsides, banks, in woodland, on rocks and walls, in neutral to basic habitats. 0–450 m. Common in England and Wales and parts of Scotland, becoming rarer in the north, extending to Shetland, frequent in Ireland. 111, H37, C. GB1431 + 91∗ , IR154 + 7∗ , C6 + 1∗ . Circumpolar Temperate. Europe north to northern Norway, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Lebanon, C. Asia, Japan, Madeira, Azores, St. Helena, N. America. The plant known as O. hians var. rigidum (Boulay) Duell (Eurhynchium swartzii var. ´ is said to be distinguished by its crowded, non-complanate leaves rigidum (Boulay) Ther) but is poorly defined with intermediates and is not recognised here. However, Duell (1992) considers it a good variety characteristic of stream valleys in forest in continental Europe.

188 Oxyrrhynchium

855

Fig. 287 1–4, Oxyrrhynchium speciosum: 1, 2, stem and branch leaves (×25); 3, mid-leaf cells (×420); 4, capsule (×10). 5–8, O. schleicheri: 5, 6 stem and branch leaves; 7, mid-leaf cells (×420); 8, capsule (×10).

2 O. speciosum (Brid.) Warnst., Krypt. fl. Brandenburg, Laubm., 1905 (Fig. 287) Eurhynchium speciosum (Brid.) Jur. Autoicous or synoicous. Medium-sized plants in dull or dirty green lax straggling patches. Stems procumbent to ascending, irregularly branched, branches erect or spreading. Leaves ± distant, spreading and shrunken when dry, spreading when moist; stem leaves not complanate, ovate to broadly ovate, acute to acuminate, base narrowly decurrent; margins plane, sharply dentate ± from base to apex; costa strong, extending c. 4/5 way up leaf or sometimes nearly to apex; basal cells rhomboidal, alar cells rectangular, decurrent but not forming auricles, cells above linear, in mid-leaf 6–9 × 40–90 μm, (6−)8–16 times as long as wide. Branch leaves subcomplanate or complanate, similar to or narrower than stem leaves; costa not terminating in tooth on abaxial side. Setae papillose; capsules inclined

856

58 Brachytheciaceae

or horizontal, slightly gibbous; lid with subulate beak; spores c. 16 μm. Capsules frequent, winter. n = 15. On muddy ground and tree boles by streams, rivers and pools, on waterlogged soil and wet muddy rock ledges, in fens, carr, flushes and on marshy ground, usually in sheltered situations. Lowland. Occasional throughout England and Wales, rare and mainly coastal in Scotland, extending north to Kincardine and Scarba (102), rare in Ireland. 67, H17, C. GB161 + 53∗ , IR11 + 7∗ , C2. European Temperate. Europe north to southern Sweden, Caucasus, Turkey, Cyprus, Iran, Saudi Arabia, China, Macaronesia. Readily identified when well grown by the dull green or dirty green colour, the distant and complanate branch leaves with coarsely toothed margins. It is probably underrecorded, especially in southern England, being mistaken for other Brachythecium and other Oxyrrhynchium species. It differs from members of both genera in the coarsely toothed leaf margins, from the former in leaf shape and the latter in the costa of branch leaves not ending in a tooth on the abaxial side. Depauperate specimens may be mistaken for O. hians but that species differs in its dioicous inflorescence and shorter leaf cells as well as in its usually yellowish colour and somewhat complanate stem leaves. It may also be confused with Brachythecium rutabulum growing in similar habitats, but that species differs in leaf shape and the leaves with denticulate margins and shorter costa. O. speciosum is closely related to O. hians and is thought to have evolved from that species by polyploidy (see V. McAdam, J. Bryol. 12, 233–58, 1982).

¨ Hedwigia, 1915 3 O. schleicheri (R. Hedw.) Roll, (Fig. 287) Eurhynchium abbreviatum (Turner) Brockm., E. schleicheri (R. Hedw.) Milde Dioicous. Plants medium-sized, in dense yellowish green tufts or patches. Primary stems ± subterranean, rhizomatous, secondary stems creeping, densely branched, branches erect or ascending, short, obtuse. Stem and branch leaves ± similar, crowded, erect, somewhat shrunken when dry, erect-patent to patent when moist, not complanate, ± concave, irregularly plicate, ovate-oblong to ovate, acute, apex often twisted through 180◦ ; margins plane or recurved below, denticulate ± from base to apex; costa extending c. 2/3 way up leaf; basal cells narrowly rhomboidal, alar cells shortly rectangular, not forming auricles, cells above linear or linearvermicular, in mid-leaf 3–5 × 32–80 μm, 10–16 times as long as wide. Branch leaves sometimes subcomplanate, ovate-lanceolate. Setae papillose; capsules inclined to horizontal, ellipsoid to shortly cylindrical, curved or gibbous; lid with long subulate beak; spores 10–14 μm. Capsules rare, winter. n = 7, 8, 11∗ , 20. On well drained, usually but not necessarily calcareous soil on banks in woods, by roads, streams and rivers. Lowland. Frequent in southern England and S. E. Wales, rare or very rare elsewhere, extending north to Roxburgh and Berwick, N. Tipperary. 41, H1. GB143 + 91∗ , IR1. Submediterranean-Subatlantic. Europe, extending north to southern Scandinavia, Caucasus, Turkey, Iran, Gran Canaria, La Palma, Madeira. Possibly to be confused with O. hians, but differing in the crowded branches and leaves which are not complanate, the leaf apices often twisted through 180◦ and the narrower cells.

189 Rhynchostegiella

857

189 RHYNCHOSTEGIELLA (SCHIMP.) LIMPR., LAUBM. DEUTSCHL., 1896 Autoicous, rarely dioicous. Plants slender. Stems creeping, with tufts of rhizoids, irregularly branched. Paraphyllia absent. Stem leaves small, not plicate, linearlanceolate to oblong-lanceolate or lanceolate, acute to acuminate; margins plane, denticulate above; costa single; alar cells little differentiated, cells above narrowly rhomboidal to linear. Branch leaves ± similar to or smaller than stem leaves; costa not ending in a tooth on abaxial side (except in R. pumila). Setae deep red, usually papillose, somewhat curved; capsules inclined or horizontal, ovoid or ellipsoid; annulus differentiated; lid rostrate; peristome perfect, endostome with tall basal membrane and nodulose or shortly appendiculate cilia; Almost world-wide but absent from America and Antarctica, about 50 species. Derivation: Meaning diminutive Rhynchostegium. For an account of Rhynchostegiella in Europe and Macaronesia see R. Duell, Bryol, Beitr. 6, 91–105, 1986.

1 Stem leaves linear-lanceolate, 6–10 times as long as wide, with long acuminate apices, setae smooth or papillose 2 Stem leaves ovate to lanceolate or oblong-lanceolate, 2–5 times as long as wide, acute to subobtuse, setae papillose 3 2 Setae smooth, axillary hairs 3.5–6.5 μm wide in upper part, usually saxicolous plants 1. R. tenella Setae papillose, axillary hairs 4–10 μm wide in upper part, plants usually corticolous 2. R. litorea 3 Stem leaves ovate to ovate-lanceolate, mid-leaf cells 2–5 times as long as wide 5. R. pumila Stem leaves lanceolate to oblong-lanceolate; mid-leaf cells mostly 5–10 times as long as wide 4 4 Costa extending 1/2 –2/3 way up leaf, mid-leaf cells 44–72 μm long, 8–10 times as long as wide 3. R. curviseta Costa extending 3/4 or more way up leaf, mid-leaf cells 32–48 μm long, 5–7 times as long as wide 4. R. teneriffae 1 R. tenella (Dicks.) Limpr., Laubm. Deutschl., 1896 Eurhynchium tenellum (Dicks.) Milde

(Fig. 288)

Autoicous. Slender plants forming yellowish green or green patches. Stems creeping, closely irregularly pinnately branched, branches erect. Axillary hairs 2–4 cells long, upper 1–2 cells 3.5–6.5 μm wide. Leaves patent or erect-patent, sometimes subsecund; stem leaves linear-lanceolate, tapering from near base to very long acuminate apex, 5–10 times as long as wide; margins plane, entire or sinuose; costa extending 1/2 –2/3 way up leaf into acumen; basal cells narrowly rhomboidal, a few alar cells rectangular, cells above linear, in mid-leaf 5–8 × 56–100 μm, 10–20 times as long as wide. Branch leaves similar to stem leaves but with narrower bases.

858

58 Brachytheciaceae

Fig. 288 1–3, Rhynchostegiella tenella: 1, stem leaf (×40); 2, mid-leaf cells; 3, capsule. 4–6, R. litorea: 4, stem leaf (×40); 5, mid-leaf cells; 6, capsule. 7–9, R. teneriffae: 7, stem leaf (×40); 8, mid-leaf cells; 9, capsule. 10–13, R. pumila: 10, 11, stem and branch leaves (×50); 12, mid-leaf cells; 13, capsule. 14–16, R. curviseta: 14, stem leaf (×40); 15, mid-leaf cells; 16, capsule. Cells ×420, capsules ×10.

Perichaetial leaves erect. Setae smooth; capsules ± horizontal, ovoid; lid with obliquely subulate beak; spores 10–15 μm. Capsules common, autumn to spring. n = 11∗ , 22∗ . On sheltered basic rocks and walls, coastal cliffs, rarely on tree boles. 0–500 m. Frequent or common in the southern half of England, Wales and parts of N. W. England, rare to occasional elsewhere, extending north to W. Sutherland, frequent in Ireland. 99, H38, C. GB802 + 92∗ , IR166 + 7∗ , C5. SubmediterraneanSubatlantic. Europe to 60◦ N, Caucasus, Turkey, Cyprus, Lebanon, Sinai, China, Macaronesia, N. and C. Africa.

189 Rhynchostegiella 2 R. litorea (De Not.) Limpr., Laubm Deutschl., 1896 R. tenella var. litorea (De Not.) P. W. Richards & E. C. Wallace

859 (Fig. 288)

Autoicous. Slender plants forming yellowish green or green patches. Stems creeping, closely irregularly pinnately branched, branches erect. Axillary hairs 2–3 cells long, upper cell 6–10 μm wide. Leaves patent or erect-patent, sometimes subsecund; stem leaves linear-lanceolate, tapering from near base to long acuminate apex, 5–10 times as long as wide; margins plane, ± entire below, denticulate above; costa extending 1/2 –2/3 way up leaf; basal cells narrowly rhomboidal, a few alar cells rectangular, cells above linear, in mid-leaf 5–8 × 56–100 μm, 10–20 times as long as wide. Branch leaves smaller and with more longly tapering apices than stem leaves. Perichaetial leaves erect-patent. Setae sparsely to moderately papillose; capsules ± horizontal, ovoid; lid with oblique subulate beak; spores 10–15 μm. Capsules common, autumn to spring. On tree stumps and boles, occasionally on stones, in basic habitats. Lowland. Rare, scattered localities from S. Devon east to Kent and north to Oxford and Cambridge. 16. European Southern-temperate. Widely distributed in the Mediterranean region of Europe, Caucasus, Turkey, Cyprus, Madeira, Morocco, Algeria, S. Africa. Very similar to R. tenella and likely passed over for that species as the papillose setae are only detectable on inspection with a hand lens. The leaves of R. litorea are less longly tapering than those of R. tenella, the margins less distinctly denticulate, the axillary hairs wider. It does, however, usually occurs on bark, a habitat on which R. tenella rarely occurs.

3 R. curviseta (Brid.) Limpr., Laubm. Deutschl., 1896 Eurhynchium curvisetum (Brid.) Husn.

(Fig. 288)

Autoicous. Plants slender, in small dense yellowish green or green mats. Stems creeping, irregularly pinnately branched, branches ascending. Leaves patent to spreading, 3–5 times as long as wide, lanceolate to oblong-lanceolate, acute to subobtuse; margins plane, faintly denticulate above; costa extending 1/2 –2/3 way up leaf; basal cells rectangular, cells above narrowly rhomboidal to linearrhomboidal, in mid-leaf (4−)5–7(−9) × 40–72 μm, (6−)8–10(−13) times as long as wide. Branch leaves similar to stem leaves. Perichaetial leaves suberect. Setae strongly papillose; capsules ± horizontal, ovoid; lid with oblique subulate beak; spores 13–16 μm. Capsules frequent, winter, spring. On damp rocks and stones, tree boles, walls by streams, rivers, canals and lakes, shaded banks. Lowland, occasional in the southern half of England, Fermanagh, old records from S. Kerry, Leitrim and Londonderry. 30, H4, C. GB73 + M7∗ , IR1 + 3∗ , C1∗ . MediterraneanAtlantic. S. and W. Europe, extending north to the Netherlands and Germany, Turkey, Cyprus, Palestine, Iraq, China, Azores, Morocco. Usually distinct from R. teneriffae in the shorter costa and longer leaf cells but in S. W. England plants occur that are intermediate between the two. It is not clear whether such plants are intermediates or of hybrid origin, but if it is the former it is possible that the two species would be better treated as subspecies of a single species.

860

59 Entodontaceae

4 R. teneriffae (Mont.) Dirske & Bouman, Lindbergia, 1996 Eurhynchium teesdalei (Schimp) Milde, R. teesdalei (Schimp.) Limpr.

(Fig. 288)

Autoicous. Plants slender, forming dense dull green or dark green mats. Stems creeping, irregularly branched, branches ± procumbent. Leaves patent to spreading, 3–5 times as long as wide, lanceolate to oblong-lanceolate, subobtuse or occasionally acute; margins plane, faintly denticulate above; costa extending c. 3/4 or more way up leaf; basal cells shortly rectangular, cells above linear-rhomboidal, in mid-leaf 5–8 × 32–48 μm, (4−)5–7(−8) times as long as wide. Branch leaves similar to stem leaves. Setae strongly papillose; capsules ± horizontal; lid with long or short subulate beak; spores 13–16 μm. Capsules frequent, winter, spring. On wet rocks or stones, usually by running water, especially on limestone but also on sandstone and shale. 66, H18, C. GB16547∗ , IR18 + 5∗ , C1. SubmediterraneanSubatlantic. Europe north to S. W. Norway, Caucasus, Turkey, Tenerife, Algeria. 5 R. pumila (Wilson) E. F. Warb., Trans. Br. Bryol. Soc., 1962 (Fig. 288) Eurhynchium pumilum (Wilson) Schimp., Oxyrrhynchium pumilum (Wilson) Loeske, R. pallidirostra (Brid.) Loeske Dioicous. Plants slender, forming dull green mats. Stems irregularly branched, branches filiform. Leaves spreading, often subcomplanate, stem and branch leaves of ± similar shape, 2–3 times as long as wide, ovate to ovate-lanceolate, acute, base not decurrent, margins plane, denticulate above; costa extending 1/2 –4/5 way up leaf, in branch leaves ending in small tooth on abaxial side, cells rhomboidal or narrowly rhomboidal, ± similar throughout, 6–8 × 16–36 μm, 2–5 times as long as wide. Setae papillose; capsules ± horizontal, ovoid to ellipsoid; lid with subulate beak; spores 12–15 μm. Capsules frequent, autumn, winter. n = 10∗ , 10 + m∗ , 11. On deeply shaded soil in woodland, on hedgebanks, by streams and ditches, in chalk pits and on basic rocks, also spreading onto tree boles and exposed roots, Lowland. Frequent or common in Wales and the southern half of England, occasional to frequent in parts of northern England, rare elsewhere, extending north to Caithness and Orkney, rare to occasional in Ireland. 101, H28, C. GB717 + 81∗ , IR29 + 12∗ , C6 + 1∗ . Submediterranean-Subatlantic. Europe north to S. W. Norway, Caucasus, Turkey, Canary Islands, Madeira, Algeria. R. pumila is a very slender plant, only likely to be mistaken for R. curviseta or Amblystegium serpens. The former species has relatively longer and narrower leaves with longer cells and is autoicous. It differs from Amblystegium serpens in its shorter leaves, papillose setae and dioicous inflorescences. DNA studies have shown that R. punila belongs in Rhynchostegiella rather than in Eurhynchium (see Stech & J.-P. Frahm, Bryobrothera 5, 203–11, 1999).

59 Entodontaceae Plants slender to robust, forming mats. Stems creeping, usually irregularly branched; central strand present or not. Paraphyllia absent; pseudoparaphyllia

190 Entodon

861

foliose. Stem and branch leaves similar, ovate to lanceolate, acuminate, usually concave, margins plane, denticulate above; costa short and double or absent; alar cells ± quadrate, not forming auricles, other basal cells incrassate, porose, cells above narrowly elliptical to linear-vermicular. Setae elongate, smooth; capsules erect, cylindrical; annulus present, separating or not; exostome teeth perforated papillose or striate, basal membrane very low or absent, cilia lacking; calyptrae cucullate, glabrous or sparsely hairy. Four genera. ¨ 190 ENTODON MULL. HAL., LINNAEA, 1845 Usually dioicous. Plants slender to robust, forming mats or patches or wefts; stems creeping to ascending, irregularly to pinnately branched, branches short. Leaves imbricate, sometimes ± complanate, concave, ovate-oblong; margins plane or recurved below, entire or denticulate above; costa short and double or absent; cells linear vermicular, porose, shorter at base, at basal angles ± quadrate, hyaline. Setae yellow or red; capsules erect, cylindrical, straight or curved; annulus papillose, striate or smooth, endostome without basal membrane, cilia absent or rudimentary. A world-wide genus of about 190 species, concentrated particularly in eastern Asia. Derivation: referring to the peristome teeth being inserted below the mouth of the capsule.

1 E. concinnus (De Not.) Paris, Ind. Bryol. (ed. 2), 1904 (Fig. 290) E. orthocarpus (Brid.) Lindb., Cylindrothecium concinnum (De Not.) Schimp. Plants medium-sized or large, in yellowish green to brownish green loose patches or as scattered shoots. Shoots procumbent to ascending, to c. 10 cm long, stems irregularly divided, irregularly pinnately branched, branches crowded. Leaves loosely imbricate when moist and dry, concave, stem leaves broadly ovate or ovateoblong, obtuse or obtuse and apiculate, often ± cucullate; margins erect or inflexed above, entire; costa very short and double or absent; cells linear-vermicular, incrassate, shorter and wider towards base, alar cells quadrate, extending short distance up margins, forming poorly defined auricles, cells at apex shorter and wider, in mid-leaf 5–7 × 46–82 μm, 7–12 times as long as wide. Branch leaves narrower. Capsules erect, cylindrical; unknown in the British Isles. n = 11. On well drained soil in open situations in turf, amongst rocks and in scree, on sand-dunes, calcicole. 0–1175 m. Frequent in chalk and limestone areas of southern England, rare or occasional elsewhere, extending north to Shetland, occasional in W. Ireland, very rare elsewhere. GB196 + 46∗ , IR31 + 7∗ . Circumpolar Boreal-montane. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Asia, New Guinea, N. and S. America, Ecuador. Often present in small quantity. Superficially resembling Pleurozium schreberi or small forms of Pseudoscleropodium purum. The former is a calcifuge and differs in the red stems and large hyaline alar cells and the latter has costate leaves.

862

60 Plagiotheciaceae

60 Plagiotheciaceae Autoicous or dioicous. Plants very slender to robust. Primary stems usually procumbent, branches easily detached, procumbent to erect. Pseudoparaphyllia present or not. Rhizoids usually axillary or on lower part of abaxial side of leaves, sometimes purple and granular-papillose when young. Leaves strongly complanate to imbricate, when dry slightly to strongly shrunken, symmetrical to strongly asymmetrical, ovate or lanceolate, shortly to longly tapering to acute to acuminate apex; margins entire or denticulate; costa short and double, rarely absent; alar cells often enlarged, sometimes decurrent, forming distinct auricles or not, cells elsewhere linear-vermicular, rarely shorter and wider. Vegetative propagation by axillary or leaf-tip gemmae of various types frequent. Perichaetial leaves small, not plicate. Setae long, straight, often reddish; capsules erect or inclined, ellipsoid to cylindrical, straight or curved; annulus separating or not; lid conical to rostrate; exostome teeth pale whitish yellow, striate below, papillose above, border gradually narrowed upwards, endostome with or without basal membrane and cilia; calyptrae cucullate. An apparently heterogeneous family with nine European genera (but see below). ¨ (J. Bryol. 14, 429–39, 1987) considers that on the basis of a number of morphoL. Hedenas logical and anatomical characters Myurella, Platydictya jungermannioides and Orthothecium belong in the Plagiotheciaceae. They possess a number of characters in common which are unlikely to have evolved in combination in unrelated genera and are therefore placed in the same family. Most recent authorities consider that only Plagiothecium belongs in the Plagiotheciaceae and that the remaining genera (genera 195–198) traditionally placed in the ¨ (loc. cit.) lists a number of correlated Plagiotheciaceae belong in the Hypnaceae. L. Hedenas characters clearly separating all the genera concerned from members of the Hypnaceae and supporting his contention that they all belong in the Plagiotheciaceae. However, the family now appears heterogeneous and DNA studies would be helpful in supporting or refuting ¨ suggestions. Hedenas’s

191 MYURELLA SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1853 Dioicous. Plants slender; stems irregularly branched, branches julaceous, ascending or erect. Rhizoids axillary, purple, granular-papillose. Paraphyllia lacking. Leaves imbricate, concave, obtuse; costa faint and double or absent; cells lax, hexagonal or rhomboidal, papillose. Capsules erect or inclined; exostome teeth lanceolate-subulate, striate below, papillose above, cilia present; calyptrae minute. An arctic-alpine genus of four species occurring in the Northern Hemisphere. Derivation: referring to the mouse tail-like appearance of the branches of Myurella julacea.

Plants blue-green, leaves without or with short straight apiculus, margins denticulate 1. M. julacea Plants pale green or yellowish green, leaves with reflexed apiculus, margins crenulate above 2. M. tenerrima

192 Platydictya ¨ 1 M. julacea (Schwagr.) Schimp. in Bruch et al., Bryol. Eur., 1853 M. julacea var. scabrifolia Lindb. ex Limpr.

863 (Fig. 289)

Scattered shoots among other bryophytes or small patches, younger parts bluish green, older parts pale reddish brown. Shoots slender, to 10(−15) mm long; stems fragile, older parts with long thin rhizoids. Leaves closely imbricate, scarcely altered when dry, very concave, broadly ovate, apex obtuse or rounded, with or without short straight apiculus; margins, denticulate to spinosely denticulate below; costa short, double or single and forked, very indistinct; cells elliptical, with low rounded obscure to conical obvious papillae, in mid-leaf 4–6 μm wide, 1.5–3.0 times as long as wide. Setae curved; capsules obovoid; lid conical, obtuse; spores c. 10 μm. Capsules rare, late summer. On soil among rocks, in rock crevices and on rock ledges, in basic situations. 450–1200 m. Caernarfon (old record), rare in the Pennines, occasional in the central Scottish Highlands, very rare elsewhere, Leitrim, Londonderry, old records from Waterford and W. Galway. 17, H4. GB32 + 1∗ , IR3. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Kashmir, China, N. America, Greenland, Patagonia. Plants with non-apiculate leaves, margins denticulate below and low papillae have been named var. julacea and those with apiculate leaves with margins spinosely denticulate below and cells with conical papillae have been referred to as var. scabuifolia. The two grow together and intergrade completely and are not worthy of separation.

2 M. tenerrima (Brid.) Lindb., Musci Scand., 1879 M. apiculata (Huebener) Schimp.

(Fig. 289)

Pale green or yellowish green scattered shoots among other bryophytes. Shoots very slender, to 10(−15) mm long; stems fragile. Leaves somewhat imbricate when dry, somewhat spreading when moist, concave, broadly ovate, apex obtuse or rounded with long reflexed apiculus; margins crenulate-denticulate; costa short, double or single and forked, very indistinct; cells elliptical, papillose, in mid-leaf 4–6 μm wide, 1.5–3.0 times as long as wide. Setae curved; capsules obovoid; lid conical, obtuse; spores c. 10 μm. Capsules unknown in Britain. n = 9. On dry soil in rock crevices and on rock surfaces, in basic situations at high altitudes. 700– 1180 m. Very rare, Mid Perth, Angus (old record). GB4 + 2∗ . Circumpolar Arcticmontane. Montane and northern Europe north to Svalbard, Iceland, Caucasus, Turkey, N. and C. Asia, N. America, Greenland. This species is considered endangered in the Red List of British Mosses and is protected under the Wildlife and Countryside Act.

192 PLATYDICTYA BERK., HANDB. BR. MOSSES, 1863 Plants exceedingly slender. Stems creeping, irregularly branched, without central strand. Paraphyllia absent. Leaves lanceolate or linear-lanceolate, acuminate;

864

60 Plagiotheciaceae

Fig. 289 1–3, Myurella julacea: 1, leaves (×65); 2, marginal cells near leaf base; 3, mid-leaf cells. 4–6, M. tenerrima: 4, leaf (×65); 5, marginal cells near leaf base; 6, mid-leaf cells. 7–11, Platydictya jungermannioides: 7, leaves (×65); 8, basal cells; 9, leaf apex; 10, perichaetial leaf (×65); 11, capsule (×10); 12–14, Orthothecium rufescens: 12, leaf (×25); 13, mid-leaf cells; 14, capsule (×10). 15–16, O. intricatum: 15, leaves (×25); 16, mid-leaf cells. Cells ×420.

193 Orthothecium

865

margins plane, entire or denticulate; costa very short and double or absent; alar cells differentiated or not, other cells rhomboidal or narrowly rhomboidal. Setae long; capsules erect and straight or inclined and curved, ovoid to shortly cylindrical; annulus of large cells; lid conical, apiculate to rostrate; peristome perfect, outer teeth cross-striolate below, papillose above. About 10 species distributed through Eurasia and N. America. Derivation: meaning network formed by the outline of the leaf cells.

1 P. jungermannioides (Brid.) Crum, Michigan Bot., 1964 (Fig. 289) Amblystegiella jungermannioides (Brid.) Giacom., A. Sprucei (Bruch) Schimp., Amblystegium jungermannioides (Brid.) Schimp. Plants exceedingly slender, forming yellowish green patches. Stems irregularly branched. Stem leaves minute, 0.12–0.32(−0.36) mm long, erect-patent when dry, erect-patent, often subfalcate when moist, acute; margins plane, entire or in well developed leaves denticulate above; costa absent; basal cells shortly rectangular, alar cells scarcely differentiated, cells elsewhere rhomboidal, in mid-leaf 6–9 × 16–32 μm, 2.5–4.0 times as long as wide near apex 3–4 times as long as wide. Small axillary gemmae, 100–230 μm long, sometimes present. Perichaetial leaves larger than stem leaves; margins spinosely denticulate above. Capsules ± inclined, ellipsoid; spores c. 14 μm. Capsules very rare, summer. On damp shaded rocks and soil on rocks and in rock crevices, often in woods, in basic crevices, often in woods, in basic habitats. Ascending to 1175 m. Absent from lowland England, rare to occasional elsewhere, from N. Somerset north to W. Sutherland and Outer Hebrides, S, Kerry, Sligo, Leitrim, Fermanagh (old record). 37, H4. GB51 + 30∗ , IR3 + 1∗ . Circumpolar Boreo-arctic Montane. Europe north to Svalbard, Iceland, Caucasus, N. and C, Asia, Yunnan, Japan, N. America, Greenland. May be confused with Amblystegium confervoides. That species, which is autoicous and frequently produces sporophytes, has leaves with ± entire margins and perichaetial leaf margins obscurely denticulate. In P. jungermannioides the leaves are not appressed when dry and have long fine apices.

193 ORTHOTHECIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR. 1851 Dioicous. Plants slender to robust. Primary stems creeping, secondary stems irregularly branched, branches prostrate to ascending. Rhizoids axillary, purple, granular papillose. Leaves erect-patent to secund when moist, often plicate, lanceolate or lanceolate-triangular, longly acuminate; margins plane or recurved, ± entire; costa very poorly developed or absent; cells ± uniformly linear-vermicular, shorter at base, alar cells not differentiated. Setae reddish, smooth; capsules erect or slightly inclined, ellipsoid or cylindrical, straight or slightly curved; annulus separating; exostome teeth striate below, papillose above, basal membrane low or high, cilia

866

60 Plagiotheciaceae

present or not; calyptrae cucullate. A small genus of about 10 species occurring in Eurasia, N. Africa and N. America. Derivation: meaning small upright vessel, from the erect capsule.

Plants robust, leaves 2–4 mm long, plicate Plants slender, leaves 0.5–2.0 mm long, not plicate

1. O. rufescens 2. O. intricatum

1 O. rufescens (Dicks. ex Brid.) Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 289) Plants robust, forming dense sometimes extensive glossy greenish red to vinous red patches. Stems irregularly branched, stems and branches procumbent to ascending. Stem and branch leaves similar, ± erect when dry, erect-patent, sometimes slightly secund when moist, strongly plicate, 2–4 mm long, narrowly lanceolatetriangular, tapering ± from base to long acuminate apex, margins recurved, ± entire; costa ± absent; cells at extreme base rhomboidal, strongly incrassate, porose, cells above linear-vermicular, 5–8 × 80–128 μm, (10−)12–20 times as long as wide. Setae long, pale red; capsules ± erect, ellipsoid to subcylindrical; lid with short conical beak; spores c. 12 μm. Capsules rare, summer. On damp or flushed sheltered usually vertical basic rock faces in montane habitats and low altitude ravines. 10–1250 m. Merioneth (old record), Caernarfon, occasional in the Pennines, Scottish Highlands and extreme west of Scotland, extending to Sutherland and Orkney, Clare, Sligo, Leitrim, W. Donegal. 22, H4. GB76 + 6∗ , IR6. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to northern Norway, Iceland, Caucasus, Siberia, China, Japan, N. America, Greenland. 2 O. intricatum Schimp. in Bruch et al., Bryol. Eur., 1851 O. intricatum var. abbreviatum Dixon

(Fig. 289)

Plants slender, in green to reddish small to extensive patches. Stems irregularly branched, stems and branches procumbent to ascending. Leaves appressed when dry, secund when moist, 0.5–2.0 mm long, concave, not plicate, lanceolate or ovate-lanceolate, longly acuminate or in stunted forms acute; margins plane, entire; costa ± absent; cells narrowly rhomboidal to linear-vermicular, long in well grown plants, shorter in stunted forms, in mid-leaf 4–8 × 32–88 μm, (4−)6–18 times as long as wide. Capsules ovate-ellipsoid; very rare, summer. On sheltered dry or damp usually vertical rock faces and in rock crevices on cliffs and in ravines. 0–1180 m. Occasional in Wales, occasional to frequent in northern England and the Scottish Highlands, extending from N. Devon (old record) and N. Somerset to Orkney and Shetland (old record), rare to occasional in far western Ireland, very rare elsewhere. 55, H13. GB102 + 18∗ , IR23 + 4∗ . European Boreo-arctic montane. Montane and northern Europe north to Svalbard,

194 Plagiothecium

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Faeroes, Iceland, Caucasus, Turkey, N. Asia, Punjab, N. Africa, N. America, Greenland. Very small forms with acute leaves have been referred to as var. abbreviatum but these intergrade with larger forms and the variety cannot be maintained.

194 PLAGIOTHECIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1851 Plants slender to robust. Stems simple or branched, branches procumbent to erect, epidermal cells large, thin-walled. Paraphyllia and pseudoparaphyllia lacking. Rhizoids not axillary, in narrow-celled species purple at least when young, granular-papillose. Stem and branch leaves similar in shape, imbricate to strongly complanate, concave or not, symmetrical to strongly asymmetrical, acute to acuminate, apices acute to acuminate, often directed downwards; margins plane or recurved, entire or denticulate towards apex; costa double or sometimes ± lacking; basal cells rhomboidal, alar cells decurrent, cells elsewhere narrowly rhomboidal to linear-vermicular. Fusiform axillary gemmae often present. Capsules erect to inclined, ellipsoid to cylindrical, straight or curved; annulus of large cells, separating; peristome perfect, outer teeth striate below, papillose above, basal membrane high, cilia in groups of 2–3, nodulose; lid conical; calyptrae cucullate. A world-wide genus of about 110 species. Derivation: meaning inclined capsule. All British species belong in subgenus Plagiothecium except P. latebricola, which belongs in subgenus Plagiotheciella Broth.

1 Plants large, shoots 5–10 cm long, whitish when dry, pale green when moist, leaves 2–5 mm long, transversely undulate 10. P. undulatum Plants small to medium-sized, shoots rarely more than 5 cm long, yellowish to dark green, leaves to 3.2 mm long, rarely undulate 2 2 leaf apices abruptly narrowed to long filiform acumen 2. P. piliferum Leaves gradually tapering to acuminate to obtuse apex 3 3 Mid-leaf cells mostly less than 10 μm wide 4 Mid-leaf cells mostly more than 10 μm wide 6 4 Leaves symmetrical 1. P. latebricola Leaves strongly asymmetrical with one side ± straight 5 5 Leaf apices curved downwards, capsules inclined to horizontal, curved 4. P. curvifolium Leaf apices not curved downwards, capsules ± erect, straight 5. P. laetum 6 Leaves mostly asymmetrical or if symmetrical then obtuse, decurrent alar cells1 rounded to rounded-rectangular, forming distinct auricles 3. P. denticulatum 1

The decurrent cells usually remain attached to the stem when the leaves are removed and are best viewed in situ on a portion of stem from which the leaves have been removed.

868

60 Plagiotheciaceae

Leaves mostly symmetrical, acute to acuminate, decurrent alar cells rectangular, not forming distinct auricles 7 7 Shoots julaceous with imbricate concave leaves 7. P. cavifolium Shoots not julaceous, leaves complanate, not or only slightly concave 8 8 Leaf margins sharply denticulate near apex, group of thin-walled cells often eroded away near apex 6. P. platyphyllum Margins entire or denticulate near apex, cells near apex with walls of similar thickness throughout 9 9 Leaves tapering to narrow entire acuminate apex, cells 10–20 × 100–200 μm, 6–10 times as long as wide, not in transverse rows 8. P. succulentum Leaves shortly tapering to entire or denticulate acute apex, cells 16–22 × 80–120 μm, 4–6 times as long as wide in ± transverse rows 9. P. nemorale 1 P. latebricola Schimp. in Bruch et al., Bryol. Eur., 1851 Plagiotheciella latebricola (Schimp.) Fleisch.

(Fig. 290)

Autoicous. Slender plants in pale green or yellowish green flattish patches. Shoots prostrate, to c. 2 cm long. Leaves somewhat shrunken when dry, complanate, spreading when moist, ± symmetrical, ovate-lanceolate, tapering to long acuminate apex; margins plane or narrowly recurved below, entire or faintly denticulate near apex; costa very short and double or absent; alar cells enlarged, decurrent down stem in single row of rectangular cells, cells elsewhere linear, in mid-leaf 6–8 × 80–150 μm, 11–17 times as long as wide. Fusiform gemmae, 30–100 μm long, often present in leaf axils and on leaf tips. Capsules erect, narrowly ellipsoid, smooth when dry; lid conical-rostrate; spores c. 12 μm. Capsules rare, spring. n = 10, 11. On decaying logs, fern and sedge tussock bases, rarely on soil or tree boles, in damp shaded habitats. Usually lowland but ascending to 350 m in Denbigh. Occasional to frequent in the southern half of England, rare in Wales and the rest of England, extending north to Yorkshire, old records from Berwick and Stirling, Leitrim. 35, H1. GB171 + 43∗ , IR1. Circumpolar Temperate. Europe north to central Scandinavia, Turkey, Japan, eastern N. America. 2 P. piliferum (Schwartz) Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 290) Isopterygium piliferum (Schwartz) Loeske, Plagiotheciella pilifera (Schwartz) M. Fleisch. Autoicous. Small plants in glossy light green patches. Shoots prostrate, to c. 2.5 cm long. Leaves somewhat shrunken when dry, complanate, spreading when moist, ± symmetrical, very concave, ovate, abruptly narrowed to long filiform acumen; margins narrowly recurved ± from base to apex, entire; costa short and double or lacking; alar cells rectangular, hyaline, decurrent, cells elsewhere linear, in mid-leaf 4–8 × 48–100 μm, 10–15 times as long as wide. Gemmae absent. Capsules erect, cylindrical, straight; lid conical; spores 13–15 μm. Capsules common,

194 Plagiothecium

869

Fig. 290 1–4, Plagiothecium latebricola: 1, Leaves (×40); 2, decurrent alar cells (×175); 3, mid-leaf cells (×280); 4, capsule. 5–8, P. piliferum: 5, leaf (×40); 6, decurrent alar cells (×175); 7. mid-leaf cells (×280); 8, capsule. 9–11, Entodon concinnus: 9, 10, stem and branch leaves (×25); 11, mid-leaf cells (×420). Capsules ×10.

870

60 Plagiotheciaceae

summer. n = 11. On shaded acidic rock ledges at high altitudes. c. 800 m. Very rare and not seen since 1930, Mid Perth, Angus. 2. GB2∗ . Montane and northern Europe north to northern Norway, northern Asia, N. America, Greenland. P. piliferum is listed as critically endangered in the Red List of British Mosses and is protected under the Wildlife and Countryside Act.

3–9. P. denticulatum–nemorale complex Although the species of this complex were reviewed by S. W. Greene (Trans. Br. Bryol. Soc. 3, 181–90, 1957) the complex is in urgent need of experimental study as there is a great divergence of opinion as to the validity of many of the taxa as these frequently appear to intergrade to a greater or lesser extent. 3 P. denticulatum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1851 Autoicous. Plants medium-sized, shoots prostrate, c. 5 cm long. Leaves 1.4–2.6 mm long, slightly shrunken when dry, strongly complanate, spreading, rarely imbricate, occasionally transversely undulate, often curving down when moist, slightly to strongly concave, ovate to ovate-lanceolate, mostly asymmetrical with one side more strongly curved than the other or one side ± straight, shortly pointed, acuminate to obtuse; margins plane, entire or denticulate towards apex; costa double, extending to 1/4 –1/2 way up leaf, rarely wanting; alar cells inflated, hyaline, rounded or rounded-rectangular, rarely rectangular, forming distinct decurrent auricles, cells elsewhere linear-vermicular, in mid-leaf 10–17 × 80–176 μm, 8–12 times as long as wide. Axillary fusiform gemmae, 70–180 μm long, sometimes present. Capsules inclined, shortly cylindrical, curved, longitudinally furrowed when dry; lid conical-rostellate; spores 8–12 μm. 1 Leaves mostly with one side straight, margins entire var. undulatum Most leaves with both sides curved, margins often denticulate near apex 2 2 Leaves acute var. denticulatum Leaves obtuse var. obtusifolium Var. denticulatum (Fig. 291) Glossy pale green to dark green patches. Leaves 1.4–2.4 mm long, strongly complanate, ovate, with one side more strongly curved than the other, acute; margins plane, entire or denticulate towards apex; mid-leaf cells 10–16 × 96–140 μm, 8–12 times as long as wide. Capsules common, late spring, summer. n = 10, 11∗ , 20, 25. In sheltered humid situations, on soil, banks, decaying logs, tree boles and rocks in woods, on marshy ground at low altitudes, usually calcifuge, among boulders and on cliff ledges in montane habitats. 0–1085 m. Common in England and Wales, frequent to common in Scotland, rare to occasional in Ireland. 110, H16, C. GB1195 + 81∗ , IR25 + 5∗ , C3. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, N., C. and E. Asia, Azores, N. America, Greenland, Mexico.

194 Plagiothecium

871

Fig. 291 1–5, Plagiothecium denticulatum var. denticulatum: 1, leaves (×40); 2, decurrent alar cells (×175); 3, mid-leaf cells (×280); 4, gemmae (×80); 5, capsule (×10). 6, P. denticulatum var. obtusifolium: leaf (×25).

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60 Plagiotheciaceae

Var. obtusifolium (Turner) Moore, Proc. Roy. Irish Acad. Sci., 1873 (Fig. 291) Glossy pale green to dark green patches. Leaves ovate, obtuse, weakly concave, strongly complanate and asymmetrical, with one side more strongly curved than the other, or strongly concave, imbricate and symmetrical with both sides ± equally curved, obtuse; margins plane, entire or denticulate towards apex. Capsules common, summer. Among boulders and in rock crevices in montane habitats. (330−)600–1205 m. Rare in N. W. Wales and N. England, occasional to frequent in the Scottish Highlands, very rare in Ireland. 27, H6. GB75 + 6∗ , IR5. Montane and northern Europe, Iceland, Sikkim, N. America. Var. undulatum Ruthe ex Geheeb, Rev. Bryol., 1877 P. ruthei Limpr.

(Fig. 292)

Leaves strongly complanate, sometimes transversely undulate when moist, 2.0– 2.6 mm long, ovate to ovate-lanceolate, mostly with one side ± straight, acute to acuminate; margins plane, usually entire; mid-leaf cells 10–17 × 80–176 μm, 7–11(−14) times as long as wide. Capsules occasional, spring. n = 11. In sheltered humid situations on damp soil, litter, rocks, on bases of tussocks in reed swamp, marshes and carr, by streams, calcifuge. Occasional in England and Wales, rare in Scotland, from Cornwall and Kent north to W. Ross. 48. Europe north to Fennoscandia, Japan, N. America. Distinct from other Plagiothecium species in the rounded or rounded-rectangular alar cells forming distinct auricles. Var. undulatum has been treated as a distinct species (P. ruthei) in the British Isles but it is a very poorly defined taxon and I have followed Z. Iwatsuki (J. Hattori Bot. Lab. 33, 331–80, 1979) in treating it as a variety of P. denticulatum. In the literature var. obtusifolium is said to differ from var. denticulatum mainly in the obtuse leaf apices, but in the British Isles there are two forms with obtuse apices. One has complanate hardly concave leaves and the other has imbricate strongly concave leaves. The relationship between these two forms and their relationship to var. denticulatum require further investigation.

4 P. curvifolium Schlieph. ex Limpr., Laubm. Deutschl., 1897 P. denticulatum var. aptychus (Spruce) Lees

(Fig. 292)

Autoicous. Plants small, forming glossy pale green patches, shoots to ca 2 cm long. Leaves 1.0–2.6 mm long, somewhat complanate with tips usually down-curved when moist, hardly altered when dry, mostly strongly asymmetrical with one side curved and the other ± straight, lanceolate, shortly tapering to acute to acuminate apex; margins plane, entire or slightly denticulate near apex; costa double, from almost absent to extending to 1/2 way up leaf; alar cells enlarged, narrowly rectangular, decurrent down stem in 1–4 rows but not forming auricles; cells elsewhere linear-vermicular, in mid-leaf 6–8(−10) × 80–140 μm, 12–19 times as long as wide. Fusiform axillary gemmae sometimes present. Capsules almost horizontal, narrowly ellipsoid to cylindrical, strongly, curved, longitudinally furrowed when

194 Plagiothecium

873

Fig. 292 1–3, Plagiothecium denticulatum var. undulatum: 1, leaves (×25); 2, decurrent alar cells (×176); 3, mid-leaf cells (×280). 4–7, P. curvifolium: 4, leaves (×25); 5, decurrent alar cells (×175), 6, mid-leaf cells (×280); 7, capsule (×10).

874

60 Plagiotheciaceae

dry; lid conical-rostrate; spores c. 12 μm. Capsules frequent, late spring, early summer. n = 11∗ . On tree stumps, logs, litter and soil in woodland, particularly conifer woodland, calcifuge. Lowland but ascending to 400 m in Wales. Frequent or common in lowland England, rare or occasional elsewhere, extending north to E. Ross and E. Sutherland, Wicklow. 87, H1, C. GB459 + 22∗ , IR1, C3. European Temperate. Europe north to southern Fennoscandia, Japan. Very close to and treated by many authorities, especially in N. America, as a synonym of P. laetum. The best character separating the two is the form of the capsule. In P. cuvifolium the capsules are almost horizontal and strongly curved, whereas in P. laetum they are ± erect and only slightly curved. The shoots of P. curvifolium are less strongly complanate than those of P. laetum and the tips of the larger leaves usually curve downwards. However, all these characters are subject to variation, making determination difficult at times.

5 P. laetum Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 293) Autoicous. Small plants forming pale green patches. Leaves to c. 1.5 mm long, strongly complanate, tips not turned downwards, scarcely altered when dry, strongly asymmetrical with one side curved and the other ± straight, ovatelanceolate, shortly tapering to acute apex; margins plane, entire or obscurely denticulate near apex; costa double, almost absent to extending to 2/5 way up leaf; alar cells enlarged, narrowly rectangular, decurrent down stem in 1–2 rows but not forming auricles, other cells linear-vermicular, 6–8(−10) × 76–144 μm, 11–17 times as long as wide. Fusiform gemmae sometimes present in leaf axils and on leaf tips. Capsules narrowly ellipsoid, ± erect, ± straight, furrowed when dry; lid conical-rostellate; spores c. 10 μm. Capsules frequent autumn. n = 8, 10, 11. On tree boles and stumps, logs and soil in deciduous woodland, rarely in conifer woodland, in lowland habitats, on soil among boulders in montane habitats. Mainly lowland but ascending to 440 m in Westmorland. Very rare in lowland and S. W. England, rare to occasional elsewhere, extending north to Caithness, Dublin, Fermanagh. 51, H2. GB64 + 1∗ , IR2. Circumpolar Boreal-montane. Spain, N. and C. Europe north to northern Scandinavia, Caucasus, Siberia, N. America. For the occurrence of this plant in Britain see A. C. Crundwell, Trans. Br. Bryol. Soc. 3, 562–4, 1960.

¨ 6 P. platyphyllum Monk., Laubm. Eur., 1927 P. denticulatum var. majus sensu Dixon

(Fig. 293)

Autoicous. Large plants in glossy or dull pale green to dark green patches. Shoots procumbent to erect, 5–12 cm long. Leaves 2.0–2.5 mm long, shrunken when dry, complanate, spreading on prostrate shoots, often subsecund on erect shoots when moist, symmetrical or weakly asymmetrical, ovate to ovate-lanceolate, tapering from about 1/2 way to acute apex; margins plane, sharply denticulate near apex; costa double, extending up to c. 1/2 way up leaf; alar cells rectangular, decurrent in 2–4 rows down stem, ± forming auricles, cells elsewhere linear-rhomboidal,

194 Plagiothecium

875

Fig. 293 1–4, Plagiothecium laetum: 1, leaves; 2, decurrent alar cells (×175); 3, mid-leaf cells (×280); 4, gemmae (×250). 5–7, P. platyphyllum: 5, leaves; 6, decurrent alar cells (×175); 7, mid-leaf cells (×280). 8–10, P. cavifolium: 8, leaves; 9, decurrent alar cells (×175); 10, mid-leaf cells (×280). Leaves ×25.

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60 Plagiotheciaceae

in mid-leaf 10–15 × 80–160 μm, group of cells near apex very thin-walled and sometimes eroded away. Propagules lacking. Capsules inclined, narrowly ellipsoid, curved, furrowed when dry; lid conical-rostellate; spores c. 12 μm. Capsules frequent, summer. n = 20, 22∗ . In rock crevices by waterfalls and streams, in flushes, in montane habitats, calcifuge. To 850 m. Rare or very rare, Caernarfon, Westmorland, Cumberland, Scottish Highlands north to W. Sutherland, Wicklow. 16, H1. GB18, IR1. European Boreal-montane. Montane and northern Europe north to Svalbard, Caucasus, Turkey, Kashmir, N. America. Likely to be confused in the field with large forms of P. succulentum. It differs from that species and P. nemorale in the narrower leaf cells and in leaf shape. Some forms resemble P. denticulatum in the alar cells forming auricles, but the cells of these are rectangular rather than rounded. P. platyphyllum is, however, most distinct in the group of cells near the leaf apex with very thin walls and which are frequently eroded away; the leaf margins are also sharply denticulate above. Treated as a synonym of P. cavifolium by some N. American authorities.

7 P. cavifolium (Brid.) Z. Iwats., J. Hattori Bot. Lab., 1970 P. roeseanum Schimp.

(Fig. 293)

Dioicous. Medium-sized plants in glossy yellowish green patches; shoots ± julaceous or sometimes subcomplanate, ascending to erect. Leaves 1.1–2.2 mm long, scarcely shrunken when dry, imbricate to subcomplanate but not complanate, very concave, symmetrical, ovate to broadly ovate, shortly tapering to acute often reflexed apiculate apex; margins plane, usually entire; costa double, extending to 1/2 –2/3 way up leaf; alar cells enlarged, rectangular, decurrent in 1–3 rows down stem, not forming auricles, other cells linear-rhomboidal, in mid-leaf 10– 16 × 76–144 μm, 6–13 times as long as wide. Fusiform axillary gemmae occasionally present. Capsules erect or inclined, cylindrical, straight or curved; lid rostrate; spores c. 12 μm. Capsules rare. n = 11. On moist usually basic rock ledges in montane areas. 0–1205 m. Rare or very rare, N. Wales, N. England, Scottish Highlands north to W. Sutherland, W. Mayo, old records from S. Kerry and W. Donegal. 21, H3. GB28 + 3∗ , IR1 + 2∗ . Circumpolar Boreal-montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, N. Asia. Japan, N. America, Greenland, Falkland Is. In its typical form with shoots julaceous with very concave leaves and narrowly decurrent alar cells distinct from other British species of Plagiothecium. It is, however, very close to P. succulentum and sometimes apparently intergrading with it. Some N. American authorities reduce it to synonymy with P. succulentum.

8 P. succulentum (Wilson) Lindb., Bot. Not., 1865 (Fig. 294) Dioicous or autoicous. Very glossy usually golden green patches; shoots prostrate to ascending. Leaves 2.0–3.2 mm long, moderately to strongly shrunken when dry, complanate, spreading when moist, symmetrical, ovate to ovate-lanceolate,

194 Plagiothecium

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Fig. 294 1–4: Plagiothecium succulentum: 1, leaf (×25); 2, decurrent alar cells (×175); 3, mid-leaf cells (×280); 4, capsule (×10). 5–7, P. nemorale: 5, leaves (×25); 6, decurrent alar cells (×175); 7, mid-leaf cells (×280).

878

60 Plagiotheciaceae

tapering to narrow acuminate apex; margins plane, usually entire; costa extending up to 1/2 way up leaf; alar cells enlarged, rectangular, decurrent down stem in 1–3 rows of cells, not forming auricles, other cells linear-rhomboidal, overlapping, not in transverse rows, in mid-leaf 10–22 × (80−)100–208 μm, 6–10 times as long as wide. Fusiform axillary gemmae sometimes present. Capsules inclined, cylindrical, curved, smooth when dry; lid conical; spores 12–14 μm. Capsules occasional, summer. n = 10, 11. On tree boles, soil in woods, hedgerows, quarries, and by streams in lowland habitats, among boulders, on cliff ledges and in springs in montane situations. 0–1160 m. Frequent or common throughout most of Britain, occasional in Ireland. 109, H30, C. GB1172 + 69∗ , IR73 + 1∗ , C4. Eurosiberian Boreo-temperate. Europe north to northern Scandinavia, Faeroes, Iceland, Siberia, N. Africa, N. America. P. succulentum and P. nemorale cannot be distinguished from one another in the field. In P. succulentum the overlapping leaf cells will separate it from P. nemorale, in which the cells are in transverse rows. However, some continental European authors treat the two species as synonymous and in N. America some authorities treat P. succulentum as a synonym of P. cavifolium.

9 P. nemorale (Mitt.) A. Jaeger, Ber. Rhatigk. St. Gallishen Naturwiss Ges., 1878 (Fig. 294) ¨ P. neglectum Monk., P. sylvaticum auct. non Hypnum sylvaticum Brid. Dioicous. Medium-sized plants forming usually dull dark green patches; shoots prostrate to ascending. Leaves (1.4−)1.8–3.0 mm long, shrunken when dry, complanate, spreading, symmetrical, ± ovate, acute; margins entire or denticulate near apex; costa extending up to 1/2 way up leaf; alar cells enlarged, narrowly to broadly decurrent down stem in 1–3 rows of cells, not forming auricles, other cells narrowly hexagonal, in ± transverse rows, scarcely overlapping, in mid-leaf 16–22 × 80–120(−140) μm, 4–6 times as long as wide. Fusiform axillary gemmae sometimes present. Capsules inclined, cylindrical, curved, smooth when dry; lid rostrate; spores c. 12 μm. Capsules occasional, summer, autumn. n = 8, 10, 11∗ , 12. On tree boles and soil in woods, hedgebanks, streamsides. Mainly lowland but ascending to 460 m on Skye. Common in the southern half of England, occasional to frequent in the rest of England and in Wales, frequent or common in the far west of Scotland, rare elsewhere, rare to occasional in Ireland. 99, H26, C. GB877 + 68∗ , IR38 + 1∗ , C9. European Temperate. Europe north to C. Scandinavia, Faeroes, Caucasus, Turkey, Iran, N. Africa, Macaronesia, Algeria, Tunisia, N. America. Treated by some N. American authors as a synonym of P. cavifolium.

10 P. undulatum (Hedw.) Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 295) Dioicous. Plants robust, pale green when moist, whitish when dry, in soft patches. Shoots prostrate, sometimes with attenuate tips, to 10 cm long. Leaves 2.3–4.0 mm

194 Plagiothecium

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Fig. 295 1–3, Plagiothecium undulatum: 1, leaf (×25); 2, mid-leaf cells (×280); 3, capsule. 4–5, Isopterygiopsis muelleriana: 4, leaves (×40); 5, mid-leaf cells (×420). 6–8, Taxiphyllum wissgrillii: 6, leaves (×40); 7, mid-leaf cells (×420); 8, capsule. 9–11, Isopterygiopsis pulchella: 9, leaves (×40); 10, mid-leaf cells (×420); 11, capsule. Capsules ×10.

880

60 Plagiotheciaceae

long, complanate, strongly undulate, scarcely altered when dry, symmetrical to slightly asymmetrical, ovate, shortly pointed, acute to obtuse; margins plane, denticulate near apex; costa double, extending up to 1/3 way up leaf; basal and alar cells rhomboid-hexagonal, alar cells decurrent in narrow band down stem, cells elsewhere linear, 7–10 × (80−)120–160 μm, (8−)13–18 times as long as wide. Gemmae lacking. Capsules inclined, cylindrical, curved, furrowed when dry; lid rostrate; spores 10–15 μm. Capsules frequent in wetter parts, rare elsewhere, spring, summer. n = 11∗ . On soil, rocks and logs in deciduous and conifer woods, on shaded hedgebanks, by ditches and streams, on moorland under heather, on cliff ledges, in wet grassland, strongly calcifuge. 0–1100 m. Frequent or common in southern England, rare to occasional elsewhere in lowland England, common in other parts of Britain, common in western Ireland, occasional elsewhere. 110, H32, C. GB1296 + 89∗ , IR1516, C1 + 1∗ . Suboceanic Boreo-temperate. N., W. and C. Europe extending to about 70◦ N in Norway, Faeroes, Turkey, Iran, Siberia, N. America 195 ISOPTERYGIOPSIS Z. IWATS., J. HATTORI BOT. LAB., 1970 Close to Pseudotaxiphyllum but without flagelliform branches or only with gemmae. Epidermal cells large and thin-walled or small and incrassate. Pseudoparaphyllia lacking. Rhizoids axillary, purple, granular-papillose. Three species. Derivation: meaning similar to Isopterygium (meaning equal wings).

Shoots to 5 cm long, leaves complanate, epidermal cells of branches thin-walled, 16–20 μm wide, mid-leaf cells 4–6 μm wide 1. I. muelleriana Shoots to 1.25 cm long, leaves scarcely complanate, epidermal cells thick-walled, 7–12 μm wide, mid-leaf cells 5–8 μm wide 2. I. pulchella 1 I. muelleriana (Limpr.) Z. Iwats., J. Hattori Bot. Lab, 1970 (Fig. 295) Isopterygium muellerianum (Schimp.) A. Jaeger, Plagiothecium muellerianum Schimp. Dioicous. Plants slender, in glossy pale green or yellowish green patches or as scattered shoots. Stems procumbent, sometimes stoloniform, to 5 cm long, with long branches; epidermal cells large, thin-walled, 16–20 μm wide. Pseudoparaphyllia lacking. Leaves distant or close, complanate, directed forwards and sometimes upwards, hardly altered when dry, symmetrical or slightly asymmetrical, ovate to ovate-oblong, rapidly contracted to narrow or filiform acumen; margins plane, entire; costa short and double or absent; 1–2 alar cells green, quadrate, not enlarged or decurrent, cells elsewhere linear, 4–6 × (56−)72–130 μm, 14–20 times as long as wide. Clusters of axillary gemmae, 60–100 μm long, occasionally present. Capsules inclined, cylindrical, curved; unknown in the British Isles. n = 11. Crevices in scree and at the base of crags, in moist or humid slightly basic situations. 300–1070 m. Caernarfon, rare or occasional in the Scottish Highlands

196 Pseudotaxiphyllum

881

from Perth north to Sutherland, S. Kerry. 14, H1. GB31 + 3∗ , IR1. Suboceanic Borealmontane. Montane and northern Europe north to southern Norway, Iceland, Caucasus, Turkey, Siberia, China, Japan, N. America, New Zealand. May be mistaken for a slender form of Pseudotaxiphyllum elegans but differs in the larger epidermal cells of the stems and the leaves with entire margins and very narrow cells. Dixon & Jameson (1924) report flagelliform branches in this species, but I have seen these only in misnamed specimens of P. elegans.

2 I. pulchella (Hedw.) Z. Iwats., J. Hattori Bot. Lab., 1987 (Fig. 295) Isopterygium pulchellum (Hedw.) A. Jaeger, Plagiothecium pulchellum (Hedw.) Schimp. Autoicous. Plants slender, pale green or yellowish green, glossy, sometimes with a metallic sheen when dry, growing through other bryophytes or in tufts. Shoots to 1.25 cm long. Stems creeping, with numerous erect or spreading branches; epidermal cells thick-walled, 7–12 μm wide. Leaves spreading, often secund, hardly complanate when moist, hardly altered when dry; symmetrical or slightly asymmetrical, narrowly triangular to narrowly lanceolate-triangular, tapering ± from base to filiform acumen; margins plane, entire or with 1–2 small blunt teeth at basal angles; costa short and double or absent; alar cells green, rectangular, not inflated or decurrent, cells elsewhere linear, in mid-leaf 5–8 × 56–120 μm, 10–20 times as long as wide. Fusiform or cylindrical axillary gemmae, 2–5 cells long, occasionally present. Capsules slightly inclined, ovate-ellipsoid to ellipsoid, straight or slightly curved; lid conical, with or without short beak; spores 8–10 μm. Capsules common, late spring, early summer. n = 10 + 2m, 11, 22∗ . Usually in small quantity on humus on damp shaded rock and cliff ledges, in rock crevices, on streambanks, in ravines, in at least slightly basic montane habitats. 0–1170 m. S. Devon (old record), S. Somerset, occasional to frequent in Wales, N. England and the Scottish Highlands, extending north to Orkney, rare to occasional in Ireland. 61, H18. GB228 + 39∗ , IR21 + 8∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. Asia, Kashmir, N. America, Greenland, Australia, New Zealand. A somewhat variable species of which var. nitidulum (Wahlenb.) Broth. has been recorded from Britain, but this seems to be no more than a minor variant intergrading with the type. I. muelleriana has longer shoots, larger and thin-walled epidermal cells and complanate leaves with entire margins and narrower cells.

196 PSEUDOTAXIPHYLLUM Z. IWATS., J. HATTORI BOT. LAB., 1987 Autoicous or dioicous. Epidermal cells of stems small, thick-walled. Rhizoids attached below leaf insertions. Pseudoparaphyllia present or not. Leaves complanate or not, tips often upcurved or downcurved, ± symmetrical, not plicate, ovate to lanceolate, gradually tapering to acuminate to filiform apex; margins plane, entire or denticulate; costa short and double or absent; alar cells green, quadrate

882

60 Plagiotheciaceae

to rectangular or hardly distinct from other basal cells, not decurrent down stem, other cells linear. Axillary gemmae or flagelliform branchlets often present. Setae straight; capsules suberect to inclined, ovoid to cylindrical; lid with or without beak; annulus cells large, separating; peristome perfect. A small genus of 7 species. Derivation: meaning resembling Taxiphyllum.

1 P. elegans (Brid.) Z. Iwats., J. Hattori Bot. Lab., 1987 (Fig. 296) Isopterygium elegans (Brid.) Lindb., Plagiothecium elegans (Brid.) Schimp. Dioicous. Small to medium-sized plants in glossy pale green patches, sometimes extensive. Shoots to 3 cm long. Stems procumbent, branches numerous, procumbent, all pointing in same direction. Epidermal cells of stem small, thick-walled, 10–12 μm side. Leaves complanate, tips often pointing downward when moist, hardly altered when dry, ovate to ovate-oblong, abruptly to gradually tapering to filiform apex; margins plane, nearly entire or denticulate near apex; costa short and double; alar cells green, hardly differentiated, not inflated or decurrent, other cells linear, in mid-leaf 5–7 × 76–112 μm, 13–23 times as long as wide. Caducous axillary filiform branchlets with minute leaves often present and sometimes so abundant as to render plants fluffy in appearance. Capsules inclined, ovoid, wide-mouthed, smooth when empty; lid conical; spores 10–14 μm. Capsules very rare. spring, summer. On soil in woods, on banks, tree boles, rocks, in rock crevices, scree, on moorland, sometimes occurring in deeply shaded situations, calcifuge. 0–980 m. Rare in parts of eastern and central England, common or very common elsewhere, occasional to frequent in Ireland. 112, H37, C. GB1417 + 84∗ , IR143 + 6∗ , C5. Suboceanic Boreo-temperate. Europe north to the Arctic Circle, Faeroes, Iceland, Caucasus, W. Asia, N. Africa, Azores, Madeira, N. America, New Zealand. For the differences from Taxiphyllum wissgrillii see under that species.

197 HERZOGIELLA BROTH., NAT. PFLANZENFAM., 1925 Autoicous. Epidermal cells of stem large, thin-walled. Pseudoparaphyllia lacking. Rhizoids axillary, purplish, granular-papillose at least when young. Leaves spreading, sometimes secund, not or scarcely complanate, ± symmetrical, ovate to ovate-oblong or ovate-lanceolate, apex acuminate or filiform; margins denticulate in upper half of leaf; costa usually short and double; alar cells quadrate to rectangular, inflated or not, decurrent or not, other cells linear. Vegetative propagules lacking. Capsules inclined, ovoid to cylindrical, curved; annulus not persisting; lid conical; peristome perfect; calyptrae cucullate. Five or six species occurring in Europe, Asia, N. Africa and N. America. Derivation: named after the German bryologist Theodor Herzog, 1889–1961.

Alar cells inflated, forming decurrent auricles Alar cells not inflated or decurrent, auricles lacking

1. H. striatella 2. H. seligeri

197 Herzogiella

883

Fig. 296 1–4, Pseudotaxiphyllum elegans: 1, leaves (×40); 2, mid-leaf cells (×420); 3, propagules; 4, capsule. 5–7, Herzogiella seligeri: 5, leaf (×25); 6, mid-leaf cells (×420); 7, capsule. 8–11, H. striatella: 8, leaf (×25); 9, decurrent alar cells (×175); 10, mid-leaf cells (×420); 11, capsule. Capsules ×10.

884

60 Plagiotheciaceae

1 H. striatella (Brid.) Z. Iwats., J. Hattori Bot. Lab., 1970 (Fig. 296) Dolichotheca striatella (Brid.) Loeske, Plagiothecium muehlenbeckii Schimp., P. striatellum (Brid.) Lindb., Sharpiella striatella (Brid.) Z. Iwats. Very slender to medium-sized plants in glossy yellowish green to green patches. Shoots to 5 cm long. Stems procumbent irregularly branched, branches ascending; epidermal cells large, thin-walled, 16–28 μm wide. Leaves somewhat shrunken and flexuose when dry, ± complanate, often secund with upturned tips when moist, concave, ovate-lanceolate to ovate-triangular, tapering to long fine acumen; margins plane, denticulate ± from base to apex; costa short, faint, double; alar cells inflated, hyaline, decurrent, forming distinct auricles, cells elsewhere linear-rhomboidal, in mid-leaf 5–7(−8) × 40–64(−72)μm, 6–11 times as long as wide. Propagules lacking. Capsules inclined, subcylindrical, curved, irregularly furrowed when dry; lid conical; spores 10–12 μm. Capsules common, summer. n = 11, 11 + m. On soil in rock crevices, among boulders, on soil and tree boles in woods, in montane areas. 0–950 m. I. of Man, rare to occasional in the Scottish Highlands from Perth north to Sutherland. 15. GB31 + 3∗ . European Boreal-montane. Montane and northern Europe north to Fennoscandia, N. Asia, N. America, Greenland. Distinctive among related species occurring in northern Britain in the leaves with margins denticulate ± from base to apex and the relatively short leaf cells.

2 H. seligeri (Brid.) Z. Iwats., J. Hattori Bot. Lab., 1970 (Fig. 296) Dolicotheca seligeri (Brid.) Loeske, Isopterygium seligeri (Brid.) Dixon, Plagiothecium silesiacum auct. non (F. Weber & D. Mohr) Schimp., Sharpiella seligeri (Brid.) Z. Iwats. Plants slender, in pale green or yellowish green glossy patches; shoots to 2.5 cm long. Stems procumbent, irregularly branched; epidermal cells small, thick-walled, 9–12 μm wide. Leaves spreading, hardly complanate, tips often upcurved or down curved when moist, less spreading, flexuose when dry, ± symmetrical, ovate, lanceolate or lanceolate-triangular, tapering to long fine apex; margins plane, denticulate ± from base to apex; costa short, double; alar cells not inflated or decurrent, green, cells elsewhere linear, in mid-leaf 5–9 × 56–100(−112) μm, 10–16 times as long as wide. Propagules lacking. Capsules inclined, cylindrical, curved, not furrowed when dry; lid shortly conical; spores 9–12 μm. Capsules common, summer. n = 10 + m, 11. On rotten logs and tree stumps, more rarely on soil or tree boles in shaded situations, especially Castanea sativa coppice or associated with other introduced tree species. Lowland. Occasional to frequent in S. E. England, very rare elsewhere, N. Lincoln, S. E. Yorkshire (old record), N. E. Yorkshire. 29. GB49 + 13∗ . European Boreo-temperate. Europe north to southern Scandinavia, Caucasus, Turkey, Manchuria, Kashmir, Hunan, Japan, N. Africa, Tanzania, N. America. It has been suggested that as H. seligeri is often associated with plantations of introduced tree species it is perhaps an introduction. However, the species is widespread in Europe, extending north to southern Scandinavia, so this seems debatable.

198 Taxiphyllum

885

198 TAXIPHYLLUM M. FLEISCH., MUSCI BUITENZORG, 1923 Dioicous. Epidermal cells of stems small, thick-walled. Rhizoids smooth. Foliose pseudoparaphyllia present. Leaves usually complanate, not secund, ± symmetrical, ovate to oblong-lanceolate, acute to acuminate; margins plane, denticulate above and sometimes almost to base; costa short and double or absent; alar cells quadrate to rectangular, not inflated or decurrent, green, cells elsewhere linear. Propagules lacking. Capsules erect to horizontal, ovoid, straight or curved; annulus persisting; lid with long beak; peristome perfect; calyptrae cucullate. About 35 species occurring mainly in eastern Asia but also found in N. and C. Africa, N and S. America, Australia and Hawaii. 1 T. wissgrillii (Garov.) Wijk & Margad., Taxon, 1960 (Fig. 295) T. depressum (Brid.) Reim., Isopterygium depressum (Brid.) Mitt., I. wissgrillii (Garov.) Gillet-Lefebvre, Plagiothecium depressum (Brid.) Spruce Plants small to medium-sized, in pale green glossy flat patches. Shoots to 3 cm long. Stems pinnately branched; epidermal cells thick-walled, 10–15 μm wide. Leaves spreading, complanate, slightly secund, hardly altered when dry, ovate, narrowed to short acute apex; margins denticulate above and sometimes almost to base; costa short and double or absent; alar cells green, quadrate to shortly rectangular, not inflated or decurrent, cells elsewhere linear, in mid-leaf 6–10 × (52−)64– 80 μm, 8–10 times as long as wide. Propagules absent. Capsules inclined, ovateellipsoid; lid with long beak; 8–10 times as long as wide. Capsules inclined, ovateellipsoid; lid with long beak; spores 10–12 μm. Capsules very rare. n = 10, 11. On soil, tree roots and boles, stones and porous rock in shaded situations, calcicole. Mainly lowland but ascending to 400 m in Mid-West Yorkshire. Occasional to frequent, mainly in chalk and limestone districts, in England and Wales, rare in Scotland, extending north to W. Sutherland, rare in Ireland. 74, H13. GB214 + 46∗ , IR13 + 4. European Temperate. Europe north to C. Scandinavia, Iceland, Caucasus, Turkey. Likely to be confused with Pseudotaxiphyllum elegans which is, however, calcifuge, often produces filiform axillary branches and has more longly tapering leaves with longer narrower cells.

61 Sematophyllaceae Plants slender to robust, usually glossy, often yellowish-tinged. Stems creeping, procumbent or ascending, irregularly to pinnately branched. Paraphyllia usually absent. Stem and branch leaves usually similar, sometimes secund or complanate, usually symmetrical, ovate to lanceolate, acute to acuminate; costa short and double or absent; alar cells enlarged or inflated, other cells linear or linear-rhomboidal. Setae long, smooth or papillose; capsules erect or more usually inclined or pendulous, ovoid to cylindrical, straight or curved; lid conical; peristome perfect or not; calyptrae cucullate or rarely mitriform. A mainly tropical and subtropical family of c. 45 genera.

886

61 Sematophyllaceae

199 SEMATOPHYLLUM MITT., J. LINN. SOC. BOT., 1864 Dioicous or autoicous. Stems creeping or procumbent. Leaves erect-patent or patent, sometimes subcomplanate or subsecund, ovate to lanceolate, acute to acuminate; a few alar cells enlarged or inflated, forming small auricles, other cells linear to linear-rhomboidal; Setae smooth or papillose; capsules relatively small, erect to horizontal; lid with long beak. A world-wide genus of c. 160 species. 1 Leaves with long filiform acumen Leaves acute to acuminate 2 Leaves lanceolate, margins ± entire Leaves ovate, margins denticulate above

3. S. substrumulosum 2 1. S. demissum 2. S. micans

1 S. demissum (Wilson) Mitt., J. Linn. Soc. Bot., 1864 (Fig. 297) Autoicous. Plants slender, forming tight glossy yellowish green to golden patches. Stems creeping, pinnately branched, branches short, procumbent, often curved. Leaves shrunken when dry, erect-patent to patent, sometimes subsecund when moist, 0.9–1.2 mm long, sometimes slightly asymmetrical, lanceolate, tapering to acuminate apex, base narrow; margins plane or recurved below, ± entire; costa short, single or double or absent; basal cells often orange, a few hyaline alar cells hyaline, inflated, forming small auricles, a few marginal cells above rectangular, cells elsewhere linear-rhomboidal, in mid-leaf (5−)6–9 × 44–94 μm, 7–16 times as long as wide. Setae reddish, flexuose; capsules inclined to horizontal, narrowly ellipsoid, slightly curved; lid longly rostrate; spores 12–18 μm. Capsules common, summer. On lightly shaded ± horizontal rock in humid situations and by streams in deciduous woodland, very rarely on more exposed vertical rock. 0–320 m. Very rare in Merioneth, Caernarfon and W. Galway, occasional in Kerry with an old record from W. Cork. 2, H4. GB4 + 1, IR14 + 1∗ . Oceanic Temperate. Belgium, France, Germany, Italy, Norway, Switzerland, Turkey, Japan, N. Africa, eastern N. America. S. demissum is listed as endangered in the Red List of British Mosses.

2 S. micans (Hedw.) Braithw., Brit. Moss Fl., 1902 (Fig. 297) Hygrohypnum micans (Mitt.) Broth., S. novae-caesareae (Aust) E. Britton Dioicous. Plans very slender, forming green patches or mixed with other bryophytes. Stems procumbent, pinnately branched, branches long, sometimes filiform, procumbent. Leaves patent, sometimes subsecund when moist, slightly shrunken when dry, concave, sometimes slightly asymmetrical, ovate, acute to acuminate; margins recurved below, denticulate above; costa double, extending 1/ –1/ way up leaf; a few alar cells enlarged, forming small auricles, a few marginal 3 2 cells above rectangular, cells elsewhere linear-rhomboidal, in mid-leaf 5–7 × 44– 72 μm, 7–12 times as long as wide. Setae flexuose, capsules ellipsoid; lid rostrate. Sporophytes unknown in the British Isles. On lightly to moderately shaded damp

199 Sematophyllum

887

Fig. 297 1–3, Sematophyllum micans: 1, stem leaves (×40); 2, alar cells (×280), 3, mid-leaf cells (×420). 4–7, S. demissum: 4, stem leaves (×40); 5, alar cells (×280); 6, mid-leaf cells (×420); 7, capsule (×10). 8–11. S. substrumulosum: 8, stem leaves (×50); 9, alar cells (×280); 10, mid-leaf cells (×420); 11, capsule (×12.5).

acidic to slightly basic rocks in woodland and on intermittently flushed rocks in wooded ravines and by waterfalls. 0–400 m. Merioneth (old record), Cumberland, occasional to frequent in the far west of Scotland from Stirling north to W. Ross, occasional in Kerry, W. Cork (old record), W. Galway. 11, H4. GB33 + 5∗ , IR15 + 2∗ . Oceanic Temperate. Belgium, France, Germany, British Columbia, eastern N. America, Mexico, S. America. Some authors place this species in Hygrohypnum, but whether this is the correct position is questionable (see Crum & Anderson, 1981).

888

62 Hypnaceae

3 S. substrumulosum (Hampe) E. Britton, J. Bot., 1902 (Fig. 297) Autoicous. Slender to medium-sized plants, forming slightly glossy yellowish green mats. Stems creeping, irregularly and sparsely branched, branches procumbent to ascending. Leaves erect-patent when dry, erect-patent to patent, sometimes slightly secund when moist, 1.2–1.7 mm long, base conspicuously brownish yellow, concave, lanceolate, narrowed at base, tapering to long filiform acumen; margins narrowly recurved at middle, entire; costa very short and double or lacking; cells porose throughout at least in some leaves, a few alar cells inflated, forming distinct auricles, marginal cells above rectangular to quadrate, cells above linear, 4–6 × 60–95 μm, c. 15 times as long as wide. Capsules inclined, narrowly ellipsoid to shortly cylindrical, curved; lid longly rostrate; spores mostly 12–16 μm. Capsules common, September. On Pinus radiata trunks and peaty soil on and amongst rocks in heather. Lowland. Frequent on the Scilly Islands. 1. Southern Europe east to Greece and north to Charente maritime, France, N. Africa, Azores, Madeira, Canary Islands, Superficially similar to Hypnum resupinatum, with which it is frequently associated, but differing in its inclined capsules and small auricles. First discovered on the Scilly Island of Tresco in 1995 (see D. T. Holyoak, J. Bryol. 19, 341–5, 1996), but now known from most of the islands, both on Pinus radiata and on peaty soil on and amongst rocks in heather. The Scilly Isles have been intensively studied for many years so the recent discovery of S. substrumulosum on Tresco with its many introduced plants suggests the species may be a recent introduction. However, that it is widespread suggests that it might be a natural colonist.

62 Hypnaceae Autoicous to dioicous. Small to robust pleurocarpous mosses in tight mats to lax coarse wefts. Stems creeping to erect, usually forked, frequently complanately pinnately branched, branches firmly attached. Rhizoids attached below leaves, brown or reddish brown, smooth. Paraphyllia absent; pseudoparaphyllia foliose or filamentous. Leaves often falcate-secund, stem leaves larger than branch leaves, of similar shape or not, lanceolate to cordate-triangular, abruptly or gradually tapering to usually acuminate apex; margins usually denticulate at least above; costa short and double; basal cells often porose, alar cells usually differentiated, sometimes forming auricles, cells above narrowly ellipsoid to linear. Perichaetial leaves usually well developed and plicate. Setae long, usually smooth; capsules erect to horizontal, ovoid to cylindrical, straight or curved; annulus usually separating; lid conical to mamillate or with rostrate to subulate beak; peristome double, exostome teeth usually yellowish brown, striolate below, papillose above, sometimes with pale border distinctly widened at transition zone, endostome usually with tall basal membrane, keeled processes and nodulose cilia; calyptrae cucullate. About 50 genera.

200 Campylophyllum

889

Subfamily 1 CAMPYLOPHYLLOIDEAE Leaves straight or falcate; margins entire or denticulate above; alar cells differentiated or not. Capsules ± horizontal, curved. Plants of damp or aquatic habitats.

200 CAMPYLOPHYLLUM (SCHIMP.) M. FLEISCH., NOVA GUINEA., 1914 Dioecious. Plants small or minute. Stems irregularly pinnately branched; central strand present. Paraphyllia sparse or absent; pseudoparaphyllia filiform or foliose. Stem leaves recurved or squarrose from erect to spreading ovate-cordate or ovate basal part abruptly narrowed to long channelled acumen; margins plane or recurved below, entire or denticulate; costa short and double, sometimes ending in small spine on abaxial side; alar cells homogeneous, not inflated, forming quadrate to broadly ovate group extending up basal margins, decurrent or not, cells above narrowly rectangular to linear. Branch leaves smaller and sometimes narrower than stem leaves; at least some cells prorate on abaxial side. Setae reddish; capsules ± horizontal, cylindrical, curved; peristome double, exostome teeth cross-striolate below, papillose above, basal membrane tall, cilia well developed. Plants of dry calcareous or organic substrates. Ten species. Derivation: meaning Campylium leaf.

Leaves spreading to subsquarrose, acumen constituting 1/2 –3/4 total leaf length, alar cells forming small auricles, lowland plant 1. C. calcareum Leaves squarrose from ± erect base, acumen constituting 1/3 –1/2 total leaf length, alar cells not forming auricles, high altitude plant 2. C. halleri ¨ Bryologist, 1997 1 C. calcareum (Crundw. & Nyholm) Hedenas, (Fig. 298) Campylium calcareum Crundw. & Nyholm, Campylium sommerfeltii auct. eur., Hypnum hispidulum var. sommerfeltii auct eur. Plants slender, forming dense dull green or yellowish green patches. Stems decumbent, irregularly branched, branches usually long. Paraphyllia absent. Stem and branch leaves similar, spreading or subsquarrose when moist, 0.6–0.9 mm long, basal part concave, broadly ovate-cordate or cordate-triangular, abruptly tapering to long fine channelled acumen constituting 1/2 –3/4 total leaf length; margins plane, denticulate below, sinuose to sharply and sparsely denticulate above; costa absent or short and double; basal cells rectangular, alar cells slightly enlarged, quadrate to rectangular, ± forming non-decurrent auricles, other cells narrowly elliptical, variable in size, prorate on abaxial side, in mid-leaf 5–8 × 24–56 μm, 4–7(−9) times as long as wide. Capsules inclined, ellipsoid to subcylindrical; lid conical; spores 10–16 μm. Capsules rare, early summer. On hard-packed soil, chalk and limestone rocks, tree boles and logs, often in deeply shaded sites, strongly calcicolous.

890

62 Hypnaceae

Fig. 298 1–4, Campylophyllum calcareum: 1, stem leaves; 2, alar cells (×280); 3, mid-leaf cells (×420); 4, capsule. 5–7, C. halleri: 5, stem leaves; 6, alar cells (×280); 7, mid-leaf cells (×420). 8–12, Calliergonella cuspidata: 8, 9, stem and branch leaves; 10, alar cells (×210); 11, mid-leaf cells (×420); 12, capsule. Leaves ×40, capsules ×10.

201 Calliergonella

891

Lowland. Occasional in chalk and limestone areas of the southern half of England, rare elsewhere, extending north to Banff and Inverness, W. Mayo, Londonderry, old records from W. Galway, E. Mayo and Antrim. 59, H5. GB85 + 35∗ , IR1 + 4∗ . European Temperate. W. and C. Europe north to S. Fennoscandia, Caucasus, Turkey, Kenya. 2 C. halleri (Sw. ex Hedw.) M. Fleisch., Nova Guinea, Bot., 1914 (Fig. 298) Campylium halleri (Sw. ex Hedw.) Lindb., Hypnum halleri Sw. ex Hedw. Slender plants forming dense golden patches. Stems procumbent, ± pinnately branched, branches ascending or erect. Paraphyllia often sparsely present. Stem and branch leaves similar, 0.4–1.0 mm long, squarrose when moist, basal part oblong or broadly ovate, ± abruptly narrowed to fine channelled acumen constituting 1/3 –1/2 total leaf length; margins plane, denticulate; costa ± absent; basal cells rectangular, a few alar cells ± quadrate, not forming auricles, not decurrent, other cells linear, in mid-leaf 4–5 × 32–52 μm, 8–12 times as long as wide. Capsules inclined, subcylindrical, slightly curved; spores 10–13 μm. Capsules produced sporadically, late summer. On basic boulders and rock faces. 850–1000 m. Very rare, Mid Perth, Angus, W. Inverness. 3. GB4 + 1∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Fennoscandia, Caucasus, Himalayas, Yunnan, N. America. Very distinctive in the dense patches and squarrose leaves, resembling miniature patches of Rhytidiadelphus squarrosus. C. halleri is treated as critically endangered in the Red List of British Mosses.

201 CALLIERGONELLA LOESKE, HEDWIGIA, 1911 A small genus with the characters of its two species. Derivation: meaning diminutive Calliergon. ¨ Lindbergia 16, 161–8, 1890, for an account of the genus. See L. Hedenas,

Stem and branch tips cuspidate, leaves straight Stem and branch tips hooked, leaves subfalcate, secund

1. C. cuspidata 2. C. lindbergii

1 C. cuspidata (Hedw.) Loeske, Hedwigia, 1911 (Fig. 298) Acrocladium cuspidatum (Hedw.) P. W. Richards & E. C. Wallace, Callliergon cuspidatum (Hedw.) Kindb., Hypnum cuspidatum Hedw. Dioecious. Moderately robust yellowish green to greenish brown plants forming tufts or patches, sometimes extensive, or occurring as scattered shoots growing through other bryophytes. Shoots procumbent to erect, to 12 cm long, stem and branch tips cuspidate with appressed leaves; stems green to reddish brown, ± regularly pinnately branched; hyalodermis present. Paraphyllia absent;

892

62 Hypnaceae

pseudoparaphyllia broad. Leaves, except at stem and branch tips, erect-patent to patent when moist and when dry; stem leaves ovate-triangular to ovate-oblong, obtuse or obtuse and apiculate, sometimes subcucullate; margins entire, plane below, ± erect above; costa absent or very short and double, faint; basal cells narrowly rectangular, alar cells inflated, hyaline or coloured, forming very distinct decurrent auricles, cells above linear, thin-walled to incrassate, in mid-leaf 4–7 × 55–88 μm, 10–18 times as long as wide. Branch leaves smaller and narrower than stem leaves. Perichaetial leaves plicate; margins entire or obscurely denticulate. Capsules ± horizontal, cylindrical, curved, furrowed when dry; exothecial cells slightly collenchymatous; annulus separating; peristome perfect, exostome teeth cross-striolate below, papillose above, cilia appendiculate; spores 16–24 μm. Capsules occasional, spring. n = 11∗ . In fens, marshes, bogs, flushes, moist turf, by pools, streams, on woodland rides, damp walls, in chalk and limestone grassland, mountain ledges and flushes, in open or slightly shaded situations, usually but not necessarily where the substrate is moist and basic, sometimes submerged. 0–900 m. Common or very common throughout the British Isles. 112, H40, C. GB2126 + 75∗ , IR297 + 7∗ , C9 + 1∗ . Circumpolar Temperate. Europe north to Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Asia, Macaronesia, C. Africa, N. America, Jamaica, Argentina, Australia, New Zealand. An extremely common moss occurring in a very wide range of habitats; at one extreme it occurs as a submerged aquatic, at the other it is found in chalk and limestone grassland. It is readily recognised by the cuspidate stem and branch tips and is only likely to be confused with Pleurozium schreberi, which differs in its bright red stems and ± curved branches.

¨ Lindbergia, 1990 2 C. lindbergii (Mitt.) Hedenas, Hypnum lindbergii Mitt., H. patientiae Lindb. ex Milde

(Fig. 299)

Dioecious. Plants medium-sized, forming glossy pale green to yellowish green patches or tufts. Stems procumbent to ascending, irregularly and sparsely branched; epidermal cells large (often coming off when leaves are removed). Paraphyllia lacking. Leaves falcate-secund, secund, more strongly so at tips of stems and branches, ± in two rows but not complanate; stem leaves ovate or broadly ovate, shortly tapering to subacute to acuminate apex; margins plane, finely denticulate above; costa short and double, one branch often shorter than the other, or lacking; basal cells narrowly rhomboidal, porose, alar cells inflated, hyaline, forming small distinct decurrent auricles, cells above linear, ± vermicular, 5.0–6.5 × 52–112 μm, 10–20 times as long as wide. Branch leaves smaller, with rounded to acute apices. Capsules inclined, obloid, curved, furrowed when dry, mouth slightly oblique; exothecial cell walls of uniform thickness; peristome perfect, cilia appendiculate; spores 14–16 μm. Capsules unknown in the British Isles. n = 10, 10 + m. On damp sandy or gravelly soil on paths, in quarries, by streams, in woods, on heaths and on sand-dunes. Mainly lowland but ascending to 900 m in Angus. Frequent in southern and N. W. England and Wales, rare elsewhere in

201 Calliergonella

893

Fig. 299 1–3, Calliergonella lindbergii: 1, stem leaves (×30); 2, alar cells (×280); 3, mid-leaf cells (×420). 4–8, Platygyrium repens: 4, 5, stem and branch leaves (×40); 6, alar cells (×280), 7, mid-leaf cells (×420); 8, gemmae (×75). 9–14, Pylaisia polyantha: 9, 10, stem and branch leaves (×40); 11, alar cells (×280), 12, mid-leaf cells (×420); 13, capsule (×10); 14, exothecial cells (×280).

894

62 Hypnaceae

England, rare to occasional in Scotland, extending north to W. Sutherland, occasional in Ireland. 92, H34. GB392 + 72∗ , IR71 + 16∗ . Circumpolar Wideboreal. Europe north to northern Fennoscandia, Iceland, Caucasus, Turkey, Asia, N. America, Greenland. Likely to be mistaken for a species of Hypnum, but differing in the shortly pointed leaves, inflated alar cells forming distinct hyaline auricles and large epidermal cells (also found in H. callichroum and H. hamulosum). Hypnum callichroum has distinct auricles but differs in the stems complanately pinnately branched and in leaf shape.

Subfamily 2 PYLAISIOIDEAE Leaves straight or slightly falcate, erect-spreading or imbricate; margins entire; alar cells numerous, quadrate or shortly rectangular. Capsules ± straight. Plants of dry habitats. 202 PYLAISIA SCHIMP., BRYOL. EUR., 1851 Autoicous. Plants slender. Stems creeping, closely irregularly or pinnately branched, branches erect or ascending. Stem and branch leaves ± similar, ± straight, ovate, tapering to long acuminate apex; margins entire; costa short and double or ± absent; alar cells quadrate, not inflated or forming auricles. Perichaetial leaves not plicate. Capsules erect, shortly cylindrical, ± straight; exothecial cell walls uniformly thickened; annulus present or not; exostome teeth striate below, papillose above, endostome with well developed basal membrane and rudimentary cilia; calyptrae naked. A mainly Southern Hemisphere genus of about 40 species. Derivation: named in honour of a French bryologist, Auguste Bachelot de la Pylaie (1786– 1856).

1 P. polyantha (Hedw.) Schimp. in Bruch et al., Bryol Eur., 1851 Pylaisiella polyantha (Hedw.) Grout

(Fig. 299)

Plants slender, in yellowish green or green patches. Stems creeping, pinnately branched, branches erect or ascending, dwarf fertile branches usually abundant. Leaves appressed, flexuose when dry, erect or subsecund and upturned when moist, lanceolate to ovate-lanceolate, narrowed to long fine acumen; margins plane, entire; costa very short and double or absent; basal cells thin-walled, not porose, narrowly rectangular, frequently with flat ends, intergrading with alar cells which intergrade with cells above, forming ill-defined group about 1.5 times as long as wide, cells above linear-rhomboidal, in mid-leaf 5–8 × 56–92 μm, 8–12(−14) times as long as wide. Capsules erect, narrowly ellipsoid, straight; exothecial cell walls of uniform thickness; lid conical, acute, 1.0–1.2 mm long; spores 13–16 μm. Capsules common, autumn, winter, two generations often present. n = 11. On bark in hedgerows and open woodland. Lowland. Rare, from

203 Platygyrium

895

N. Somerset and E. Kent north to Kincardine, Kerry, E. Cork (old record). 43, H3, C. GB36 + 38∗ , IR2 + 1∗ , C1∗ . Circumpolar Temperate. Europe north to northern Scandinavia, Caucasus, Turkey, Kashmir, Japan, N. Africa, Tenerife, La Gomera, southern United States, Mexico. Superficially similar to Hypnum resupinatum and possibly overlooked for that species. It differs in the shape of the capsule lid and the frequent occurrence of two generations of capsules, the numerous fertile branches and the uniformly heavily thickened exothecial cell walls. It also differs in the basal cells of the leaves often having flat ends. Homomallium incurvatum occurs on calcareous rocks and has inclined curved capsules; Platygyrium repens is dioicous, has sparse fertile branches, the leaves have recurved margins, the alar cells extend further up the margins and it has axillary gemmiferous branchlets.

203 PLATYGYRIUM SCHIMP., BRYOL. EUR., 1851 Dioicous. Stems creeping, closely pinnately branched, branches erect or ascending; Pseudoparaphyllia absent. Stem and branch leaves of similar shape, straight, ovate or ovate-lanceolate, tapering to acuminate apex; margins recurved, ± entire; costa short and double or absent; alar cells quadrate or rectangular, cells above linear-rhomboidal. Deciduous axillary branches frequently present. Setae smooth, reddish; capsules erect, cylindrical, straight; exothecial cells thin-walled; annulus persisting; exostome teeth transversely striate below, papillose above, endostome with very short basal membrane, cilia lacking; calyptrae naked. About 10 species distributed through Europe, Asia, N. and C. America and the Caribbean. 1 P. repens (Brid.) Schimp. in Bruch et al., Bryol. Eur., 1851 (Fig. 299) Plants slender, in dark green often coppery-tinged mats. Stems creeping, closely branched, branches ascending to erect, Leaves ± erect, scarcely altered when dry, ovate-lanceolate to lanceolate, tapering to long acuminate apex, stem leaves slightly curved, not concave; margins recurved on one or both sides below, ± entire; costa very short and double or absent; basal cells narrowly rhomboidal, not porose, alar cells quadrate to trapezoid, extending some distance up margins, forming a group of cells about twice as long as wide, cells above linearrhomboidal, shorter at margins and apex, in mid-leaf 5–9 × 56–80 μm, 8–12 times as long as wide. Branch leaves straight, concave. Axillary propaguliferous branchlets, c. 250 μm long, present at tips of branches. Capsules erect, subcylindrical, straight; exothecial cell walls of ± uniform thickness; lid rostrate; spores 16– 20 μm. Capsules very rare. n = 11. On trunks and branches of deciduous trees and shrubs, on logs, in woodland. Lowland. Rare to occasional in the southern half of England and in Wales, Lincoln, Berwick, E. Lothian. 29. GB39. Circumpolar Temperate. Europe north to central Scandinavia, Caucasus, Turkey, Mongolia, Japan, Algeria, N. America. Likely to be mistaken for Hypnum resupinatum but is usually darker green, and the branches are ± erect and produce axillary branchlets at the branch tips. First collected in England in

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1945 but not recognised until 1962 (see E. F. Warburg & A. R. Perry, Trans. Br. Bryol. Soc., 4, 422–5, 1963). Possibly a recent arrival but as it often persists only as a single colony for a short time its occurrence in Britain may be of longer standing.

Subfamily 3 HYPNOIDEAE Autoicous or dioicous. Leaves ± straight to circinate, ovate to lanceolate, acuminate; margins plane or recurved, entire or denticulate; costa short and double or absent; alar cells ± quadrate, few to numerous, forming distinct group, occasionally inflated and hyaline. Capsules usually inclined, curved; peristome perfect.

204 HOMOMALLIUM (SCHIMP.) LOESKE, HEDWIGIA, 1907 Autoicous. Leaves straight or secund, concave, ovate or ovate-lanceolate, gradually or abruptly narrowed to acumen; margins plane, entire or denticulate above; alar cells numerous, quadrate, basal cells not porose, cells elsewhere linear-rhomboidal. Perichaetial leaves not plicate. Setae smooth; capsules curved; exothecial cells thin-walled; annulus cells inflated, separating; lid shortly rostrate; peristome perfect. Four species in Europe, Asia, N. and C. America. 1 H. incurvatum (Schrad. ex Brid.) Loeske, Hedwigia, 1907 Hypnum incurvatum Schrad. ex Brid.

(Fig. 300)

Plants very slender, in small glossy yellowish green or green patches. Stems creeping, irregularly pinnately branched, branches ascending or erect. Leaves erect when dry, patent to spreading, ± upturned when moist, concave, straight or curved, lanceolate to narrowly lanceolate, rapidly tapering to long acumen, margins plane, entire; costa short and double or absent; alar cells quadrate, reaching nearly to costa, grading into rhomboidal basal cells and forming group of cells c. 1.5 times as long as wide, cells above linear-rhomboidal to linear, shorter towards margins and apex, in mid-leaf 5.5–8.0 × 48–68 μm, 9–12 times as long as wide. Capsules inclined to horizontal, oblong-ellipsoid, curved; exothecial cell walls of ± uniform thickness; lid conical, rostrate; spores 8–14 μm. Capsules common, summer. n = 12. On rocks, walls and soil, calcicole. Lowland. Rare and much decreased, Mid-West Yorkshire, Durham, Cumberland, Mid Perth, old records from Derby, N. W. Yorkshire, Westmorland, W. and E. Perth. 9. GB4 + 18∗ . Eurasian Boreal-montane. Europe north to northern Norway, Caucasus, Turkey, Iran, Siberia, Yenesei, Altai, Kashmir, Japan, N. America. The reason for the marked decline in this species is unknown, It is possible that it has been overlooked as Hypnum resupinatum, but that species is calcifuge and has erect usually straight capsules. H. incurvatum is treated as critically endangered in the Red List of British Mosses.

204 Homomallium

897

Fig. 300 1–4, Homomallium incurvatum: 1, stem leaves; 2, alar cells (×280); 3, mid-leaf cells (×420); 4, capsule (×10). 5–8, Hypnum vaucheri: 5, stem leaves; 6, alar cells (×280); 7, mid-leaf cells (×420); 8, pseudoparaphyllia (×90). 9–11, Hypnum revolutum var. revolutum: 9, stem leaf; 10, alar cells (×280); 11, mid-leaf cells (×420). 12, Hypnum revolutum var. dolomiticum: stem leaf. Leaves ×40.

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205 HYPNUM HEDW., SP. MUSC. FROND., 1801 Autoicous or dioicous. Stems creeping to erect, ± unbranched to closely pinnately branched. Branches long or short. Pseudoparaphyllia usually present. Stem leaves straight to falcate or circinate, secund, narrowly lanceolate to broadly ovate, gradually or abruptly narrowed to acute to filiform apex; margins plane or recurved, entire or denticulate; costa short and double or absent; basal cells usually narrowly rhomboidal, incrassate, porose or not, alar cells distinct, quadrate to rectangular, thin-walled to incrassate, hyaline or not, cells above elliptical to linear-vermicular. Branch leaves of ± similar shape to stem leaves but smaller. Setae long, reddish, smooth; capsules erect to horizontal, obloid to cylindrical, straight or curved; lid mamillate to conical with subulate beak; exostome teeth transversely striate below, longitudinally point-striate, papillose or smooth above, endostome with tall basal membrane and cilia. A cosmopolitan genus with c. 200 species. Derivation: from the Greek word h˘ypnon for a moss or some similar plant. The genus has been monographed in a series of excellently illustrated papers by H. Ando. His first paper was J. Sci. Hiroshima Univ., Ser. B, Div. 2, 14, 53–73, 1972, and the most recent was Hikobia 12, 9–17, 1996.

1 Capsules present 2 Capsules lacking 4 2 Capsules ± erect, straight, 7. H. resupinatum Capsules variously inclined and curved 3 3 Capsules with mamillate lids 5. H. andoi Capsules with rostrate lids 8 4 Epidermal cells of stems narrow, incrassate, not usually coming off with leaf bases when leaves are removed 5 Epidermal cells wide, thin-walled, often coming off with leaf bases when leaves are removed 14 5 Leaf margins recurved from near base to about half way up leaf on one or both sides, very rare high-altitude plant 1. H. revolutum Leaf margins plane or recurved below 6 6 Stems reddish brown, leaves circinate-secund, cells porose throughout, alar cells few but forming distinct group 10. H. bambergeri Stems greenish or if reddish brown then leaves falcate-secund, cells porose only in basal part of leaves, alar cells ± numerous 7 7 Largest alar cells hardly more than 10 μm wide, pseudoparaphyllia rounded, very rare high-altitude plant 2. H. vaucheri Largest alar cells 12–20 μm wide, pseudoparaphyllia linear to lanceolate, mostly widespread and common plants 8 8 Stems pinnately branched, at least some stem leaves with alar cells enlarged or inflated 9 Branching irregular, alar cells not markedly enlarged 10

205 Hypnum

899

9 Plants pale green when fresh, stems green except oldest parts, pseudoparaphyllia narrowly or linear-lanceolate, sometimes bilobed, margins entire 8. H. jutlandicum Plants yellowish green to brown, stems reddish brown except at tips, pseudoparaphyllia lanceolate to narrowly triangular, not bilobed, margins toothed 9. H. imponens 10 Plants robust, stems ± julaceous when moist with strongly concave imbricate leaves 4. H. lacunosum Plants very slender to medium-sized, stems not julaceous, leaves concave or weakly concave 11 11 Leaves homomallous, tips often directed obliquely upwards, stem leaves ovate or ovate-lanceolate; margins of branch leaves and often of stem leaves usually entire 7. H. resupinatum Leaves weakly to strongly falcate-secund; leaf margins usually denticulate above 12 12 Alar cells usually excavate, often brownish, row of 5–8 rectangular supra-alar marginal cells present, very rare Irish plant 6. H. uncinulatum Alar cells not or only weakly excavate, not brownish, 7–15 rectangular supra-alar marginal cells present except in very slender plants, very common plants 13 13 Leaves weakly falcate-secund or falcate-secund, occasionally straight in very slender forms, mid-leaf cells of branch leaves averaging 59–74 μm long, alar cells not increasing in size towards basal angles 3. H. cupressiforme Leaves falcate-secund, often strongly so in slender plants, mid-leaf cells of branch leaves averaging 35–53 μm long, alar cells often increasing in size and sometimes inflated towards basal angles 5. H. andoi 14 Alar cells few, only 0–2 inflated and hyaline 12. H. hamulosum Alar cells inflated, hyaline, forming distinct auricles 15 15 Plants greenish, complanately pinnately branched, leaves circinate-secund, tapering to filiform apex 11. H. callichroum Plants reddish brown, irregularly branched, leaves subfalcate, shortly tapering to apex Calliergonella lindbergii (p. 892)

Section 1 Revolutohypnum Monk., ¨ Laubm. Eur., 1927 Plants small to medium-sized. Epidermal cells of stems narrow, thin- or thickwalled. Stem and branch leaves only differing slightly in shape; alar cells homogeneous, nor enlarged, not excavate. Perichaetial leaves plicate. Setae twisted dextrorsely proximally, sinistrorsely distally when dry; endostome cilia 2–3. Capsules ripe summer, autumn.

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¨ 1 H. revolutum (Mitt.) Lindb., Ofvers Förh. Kongl. Svenska Vetensk-Akad., 1867 Dioicous. Plants slender, in yellowish to brownish mats. Stems yellowish to orange, erect or ascending, pinnately branched; epidermal cells narrow, thin-walled. Pseudoparaphyllia lanceolate, toothed. Leaves falcate-secund, concave, weakly to strongly plicate; stem leaves ovate to lanceolate, gradually tapering or abruptly narrowed to acuminate apex; margins plane or recurved on one or both sides from base up to c. 3/4 way up leaf or nearly to apex, denticulate towards apex; costa short and double; basal cells rhomboidal, alar cells few, rectangular, poorly defined, cells above narrowly elliptical with rounded ends, in mid-leaf 5.0–6.5 × 24–40 μm, 4–7 times as long as wide. Branch leaves smaller and narrower. Capsules inclined, subcylindrical, curved, unknown in Britain. Stem leaves lanceolate or ovate-lanceolate, strongly plicate, margins revolute on var. revolutum both sides to c. 3/4 way up leaf Stem leaves ovate, weakly plicate, margins plane or recurved on one or both sides below var. dolomiticum Var. revolutum (Fig. 300) Stem strongly plicate, lanceolate or ovate-lanceolate, gradually tapering to acumen; margins revolute from base to c. 3/4 way up leaf; costa usually distinct. n = 14. On basic montane rocks. c. 1000 m. Very rare, Mid Perth. 1. GB1 + 1∗ . Circumpolar Arctic-Montane. Montane and northern Europe north to Svalbard, Turkey, Siberia, Mongolia, China, Himalayas, N. America, Greenland, Mexico, Patagonia, New Zealand, Antarctica. ¨ Var. dolomiticum (Milde) Monk., Laubm. Eur., 1927 H. dolomiticum Milde

(Fig. 300)

Stem leaves weakly plicate, ovate, ± rapidly tapering to acumen; margins plane or recurved on one or both sides below; costa very faint. On basic montane rocks. c. 1000 m. Very rare, Mid Perth. 1. GB1∗ . Austria, Czechoslovakia, France, Germany, Italy, Spain, Switzerland, N. America, Antarctica. I have seen three Scottish specimens, one typical var. revolutum, one typical var. dolomiticum and one intermediate. For this reason I did not recognise var. dolomiticum in the first edition of this book. However, many authorities in C. Europe treat var. dolomiticum as a species. H. Ando (J. Sci. Hiroshima Univ. 2, series B, Div. 2, 14, 165–207, 1973), because of the existence of intermediates treats it as a variety and I have followed him. Var. dolomiticum was first reported from Scotland by E. C. Wallace in 1932, (see J. B. Duncan, Rep. Br. Bryol. Soc. for 1932, 3, 47, 1933). H. revolutum is listed as endangered in the Red List of British Mosses.

ˆ 2 H. vaucheri Lesq., Mem. Soc. Sci. Nat. Neuchatel, 1846 (Fig. 300) Dioicous. Primary stems stoloniform, secondary stems erect or ascending, irregularly pinnately branched, stems and branches subjulaceous. Pseudoparaphyllia

205 Hypnum

901

rounded, about as wide as long. Leaves imbricate when dry, erect or erect-patent when moist, straight or curved above, concave, ovate or ovate-oblong, ± abruptly narrowed to long ± channelled acuminate apex; margins plane, entire; costa short and double; basal cells irregularly rectangular, alar cells numerous, ± quadrate, c. 10 μm wide, forming well defined group about twice as long as wide, cells above narrowly rhomboidal, (6−)8–10 × 24–44 μm, 3.5–7.0 times as long as wide. Capsules erect or inclined, shortly cylindrical, curved; lid conical, acute. Sporophytes unknown in Britain. n = 6. On exposed basic montane rocks. c. 800 m. Very rare, Mid and E. Perth. 2, GB2. Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard, Turkey, Asia, Eritrea, N. America, Greenland. Likely to be confused with members of the H. cupressiforme complex but differing in several features. The epidermal cells have thinner walls and sometimes remain attached to leaf bases when leaves are stripped off the stem, the pseudoparaphyllia are roundish, the leaf margins plane and the alar cells smaller and numerous. For the discovery of this plant in Scotland see A. R. Perry & R. D. Fitzgerald, Trans. Br. Bryol. Soc. 4, 418–21, 1963. H. vaucheri is treated as vulnerable in the Red List of British Mosses and is protected under the Wildlife and Countryside Act.

Section 2 Hypnum Plants small to large. Stem epidermal cells narrow. Alar cells heterogeneous, enlarged towards leaf base, sometimes excavate. Perichaetial leaves not plicate. Setae twisted dextrorsely when dry; endostome cilia mostly 1–2. Capsules ripening autumn to winter. For an account of the Hypnum cupressiforme complex in the British Isles see A. J. E. Smith, J. Bryol. 19, 751–74.1997.

3–9 Hypnum cupressiforme complex In the H. cupressiforme complex leaf shape may be very variable on any one stem or branch. Shape referred to in the descriptions of these species is of leaves intermediate between the least falcate and the most falcate on a stem or branch. 3 H. cupressiforme Hedw., Sp. Musc. Frond., 1801 (Fig. 301) Dioicous. Plants very slender to medium-sized, light to dark green, often glossy when dry, usually forming smooth mats. Stems irregularly branched. Pseudoparaphyllia narrowly lanceolate or linear-lanceolate or deeply 2–3-lobed with linearlanceolate lobes, 225–450 μm long. Stem leaves weakly falcate to falcate-secund, weakly concave, or concave, lanceolate to ovate-lanceolate, gradually tapering from 1/4 –1/3 from base, 1.0–2.1 × 0.3–0.6(−0.8) mm; margins recurved below, entire or denticulate above; costa very short and double or absent; cell walls usually slightly thickened, basal cells rhomboidal, alar cells ± colourless to pale brown, numerous except in small plants, quadrate, hardly increasing in size towards basal angles, not excavate, marginal row of 8 or more quadrate to rectangular supraalar present except in very small plants, mid-leaf cells 4–7(−8) × 48–88(−96) μm,

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62 Hypnaceae

Fig. 301 Hypnum cupressiforme: 1, shoot (×8); 2, 3, stem and branch leaves (×30); 4, alar cells (×210); 5, mid-leaf cells (×420); 6, capsule (×10) 7, pseudoparaphyllia (×90).

205 Hypnum

903

averaging 57–76 μm long. Branch leaves smaller and narrower than stem leaves; margins denticulate above; mid-leaf cells 48–96 μm long, averaging 59–74 μm. Capsules cylindrical, curved and somewhat inclined, body of capsule 1.7–2.4 mm long; lid rostrate, 0.6–0.9 mm long. Capsules frequent, autumn. n = 10∗ , 10 + m, 11. On trunks and lower branches of trees, logs, rocks, walls, tombstones, very rarely on soil, in dry exposed or sheltered situations, calcifuge, 0–760 m. Common throughout the British Isles except in heavily polluted areas. 112, H40, C. GB2283 + 78∗ , IR396 + 16∗ , C9 + 1∗ . Circumpolar Wide-temperate. More or less cosmopolitan. In the field H. cupressiforme is only likely to be confused with H. andoi, larger forms of which have less strongly falcate and less complanate leaves, and microscopic examination of such plants is necessary for determination if capsules are absent. In lowland Britain, H. cupressiforme is the commonest species of the complex except on basic substrata but in the west and north H. andoi is more frequent and produces sporophytes much more abundantly. I have seen about 20 gatherings of a plant from S. E. England, Germany and Austria that macroscopically resembles H. cupressiforme, and one German gathering that had typical H. cupressiforme capsules. However, the leaves tended to be almost plane, somewhat flaccid and ± straight or only slightly falcate, and had cells of the length of those of H. andoi. The identity of these gatherings is obscure as on morphological grounds they are clearly neither H. cupressiforme s.s. nor H. andoi and they are likely to belong to an undescribed taxon. H. Ando (Hikobia 11, 111–23, 1992) recognises very slender forms with parallel branches and straight leaves as H. cupressiforme var. filiforme Brid. but, as he points out, the plants intergrade with and may be physically joined to larger forms of H. cupressiforme, thus the variety cannot be maintained. Very slender forms of H. andoi with parallel branches and strongly falcate complanate leaves have often named H. cupressiforme var. filiforme and are the basis for the acceptance of this plant as occurring in the British Isles. H. heseleri Ando & Higuch, described as a species of the H. cupressiforme complex (H. Ando & M. Higuchi, J. Hattori Bot. Lab. 75, 97–105, 1994), is of somewhat doubtful status. It is known from five continental European localities and may well be found in southern England. It has the following characteristics. Stems subpinnately or irregularly branched. Pseudoparaphyllia filiform or lanceolate, entire. Stem leaves appearing crumpled, straight or slightly falcate, ovate-cordate, 0.7–1.1(−1.2) × 0.45–0.70 mm, ± abruptly acuminate, acumen 1(−2) twisted, mid-leaf cells 30–45(−60) μm long. Branch leaves smaller. However, B. O. van Zanten & A. Hofman (J. Hattori Bot. Lab. 75, 107–17, 1994) present convincing evidence that this plant is an abnormal form of H. cupressiforme.

4 H. lacunosum (Brid.) G. F. Hoffman ex Brid., Muscol. Recent. Suppl., 1819 Dioicous. Plants moderately robust to robust, forming loose mats or wefts, sometimes extensive, with ± ascending branches. Shoots julaceous when moist. Pseudoparaphyllia simple, lanceolate to narrowly lanceolate, 125–400 μm long, Leaves ovate-lanceolate to broadly ovate, acuminate or longly acuminate; margins recurved below, entire or denticulate above; costa very short and double or absent; cells walls slightly to strongly thickened, basal rhomboidal, alar cells numerous,

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62 Hypnaceae

Fig. 302 Hypnum lacunosum var. lacunosum: 1, shoot (×8); 2, 3, stem and branch leaves (×30); 4, alar cells (×210); 5, mid-leaf cells from different plants (×420); 6, capsule (×10); 7, pseudoparaphyllia (×90).

205 Hypnum

905

not or hardly increasing in size towards basal angles, cells above very variable in length, width and degree of wall thickening from plant to plant. Plants yellowish green to golden or bronze, leaves falcate, sometimes strongly so, mostly 2–3 mm long var. lacunosum Plants olive to brownish green, leaves ± straight or falcate only at tips, usually less than 2 mm long var. tectorum Var. lacunosum (Fig. 302) H. cupressiforme var. lacunosum Brid., H. cupressiforme var. elatum Schimp. Plants robust, glossy yellowish green to golden brown. Stem leaves falcate, strongly or very strongly concave, lanceolate or ovate-lanceolate, gradually tapering from about 1/3 from base, 1.8–3.0 × 0.6–1.2 mm; mid-leaf cells 6–9 × 40–76(−90) μm, averaging 54–78 μm long. Branch leaves smaller and narrower; margins denticulate above; mid-leaf cells 48–80(−88) μm long, averaging 54–78 μm. Capsules inclined, curved, body of capsule 1.7–2.9(−3.3) mm long; lid rostrate, 0.70– 0.89 mm long. Capsules occasional, autumn. n = 10. In calcareous grassland, on sand-dunes and on usually but not exclusively base-rich rocks, common and sometimes locally abundant throughout much of the British Isles. 111, H36, C. Circumpolar Boreo-temperate. Europe north to Svalbard, Cyprus, Turkey, Caucasus, Ethiopia, southern Africa, Gran Canaria, Tenerife, N., C. and S. America south to Tierra del Fuego, Australia, Tasmania, New Zealand. Var. tectorum (Brid.) J.-P. Frahm, Herzogia, 1976 H. cupressiforme var. tectorum Brid.

(Fig. 303)

Plants robust or moderately robust, hardly glossy, forming olive-green to greenish brown wefts or loose mats. Shoots julaceous when moist. Stem leaves straight or falcate only at tips, strongly or very strongly concave, ovate-lanceolate to broadly lanceolate, narrowed, sometimes abruptly from about the middle or higher, to short or long often filiform point; margins entire or denticulate above; mid-leaf cells 5–8 × 40–80 μm, averaging 48–70 μm long. Branch leaves smaller and narrower; mid-leaf cells 40–80 μm long, averaging 41–72 μm. Capsules not seen. On basic to acidic rocks and soil, common on sand-dunes. 0–950 m. Rare to occasional, widely distributed, extending from Cornwall east to Sussex and north to Shetland; certainly overlooked as var. lacunosum. 36, H8. World distribution uncertain. Unlike other members of the group, H. lacunosum nearly always occurs on base-rich substrata. H. lacunosum var. lacunosum is close to H. cupressiforme, but may usually be recognised by the large size, golden colour and glossiness of the plants with strongly falcate concave leaves. The often brownish colour and very julaceous shoots distinguish var. tectorum from var. lacunosum. However, the two varieties have been totally confused by bryologists in

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62 Hypnaceae

Fig. 303 1–3, Hypnum lacunosum var. tectorum: 1, shoot (×8); 2, 3, stem and branch leaves (×30). 4–10, H. uncinulatum: 4, 5, stem and branch leaves (×30); 6, alar cells (×210); 7, mid-leaf cells from different plants (×420); 8, 9, mature and dry empty capsules (×10); 10, pseudoparaphyllia (×90).

205 Hypnum

907

Fig. 304 Hypnum andoi: 1, shoot (×8); 2, 3, stem and branch leaves (×30); 4, alar cells from different plants (×210); 5, mid-leaf cells from different plants (×420); 6, 7, mature and dry empty capsule (10); 8, pseudoparaphyllia (×90). Britain and elsewhere and for this reason the two are often treated as synonymous. Interestingly, Watson (1981) clearly understood the difference between the two.

5 H. andoi A. J. E. Sm., J. Bryol., 1981 (Fig. 304) H. mammillatum (Brid.) Loeske, H. cupressiforme var. mammillatum Brid. Dioicous. Plants very slender to medium-sized, yellowish green to golden green, glossy or not, forming sometimes extensive smooth mats. Stems irregularly branched. Pseudoparaphyllia narrowly lanceolate or linear-lanceolate or deeply bilobed, 150–250 μm long. Stem leaves falcate-secund or strongly falcate-secund especially in slender forms, weakly concave, ovate or ovate-lanceolate, gradually

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62 Hypnaceae

tapering from 1/5 –1/4 from base to channelled apex, 0.5–2.0 × 0.15–0.60 mm; margins recurved below, usually denticulate above; costa very short and double or absent; cells rarely thick-walled, basal rhomboidal, alar cells occasionally excavate, often becoming larger towards basal angles, colourless to brownish, marginal row of 8 or more quadrate or rectangular supra-alar cells present except in very small plants, cells in mid-leaf 4–7 × 24–60 μm, averaging 35–53 μm long. Branch leaves similar to stem leaves but smaller; margins denticulate above; mid-leaf cells 32–56 μm long, averaging 35–53 μm. Capsules shortly cylindrical to narrowly ellipsoid, symmetrical, slightly inclined, ± curved, not wide-mouthed or asymmetrical when dry and empty, body of capsule 1.6–2.4 mm long; lid mamillate, 0.41–0.57 mm long. Capsules common and sometimes abundant in the west and north, occasional to frequent elsewhere, autumn. n = 10∗ . On bark and rocks in sheltered situations, calcifuge. 0–760 m. Common in southern England, Wales, the Lake District and western Scotland, rare elsewhere, rare to occasional in Ireland. 96, H20, C. GB479 + 23∗ , IR28 + 5∗ , C1. Suboceanic Temperate. Mainly in western Europe extending north to Fennoscandia, Faroes, Macaronesia, N. America. Probably under-recorded, being mistaken for H. cupressiforme especially when capsules with lids are absent. Small plants of H. andoi are readily identified in the field by the strongly falcate often complanate leaves and the golden yellow colour of the plants. Very slender plants occur on vertical tree trunks, have long parallel shoots forming dense often long mats and are of very distinctive appearance – such plants have frequently been named, incorrectly, var. filiforme Brid. Larger plants have less strongly falcate leaves and if not yellowish in colour or when lacking capsules may require microscopic examination to separate them from H. cupressiforme. H. andoi occurs in more sheltered and humid habitats than H. cupressiforme, forming extensive patches on tree branches and trunks, less commonly occurring on rocks. H. cupressiforme usually occurs in less humid and less sheltered and sometimes in exposed situations. H. andoi usually produces abundant sporophytes and is readily identifiable on sight from about June to December; H. cupressiforme produces fewer sporophytes and, especially in exposed situations, lacks them altogether. Separating H. andoi and H. uncinulatum in the field is difficult when the plants are sterile. Mixed colonies are common on the Canary Islands and when only one has sporophytes confusion may result from examination of the gametophyte of one species and a sporophyte of the other. Gametophytes of H. andoi growing with H. resupinatum have been found in Cornwall with capsules intermediate between those of the two species and are presumably of hybrid origin (S. R. Edwards, pers. commun.).

6 H. uncinulatum Jur., Bot. Zeit., 1886 H. canariense Mitt.

(Fig. 303)

Dioicous. Plants slender to medium-sized, greenish, sometimes tinged brown, forming smooth mats. Stems irregularly branched. Pseudoparaphyllia simple or deeply bilobed, narrowly lanceolate or linear-lanceolate, 125–275 μm long. Stem leaves falcate-secund, often weakly so, concave, lanceolate, gradually tapering from near base, apex only occasionally channelled, 1.0–1.8 × 0.25–0.56 mm;

205 Hypnum

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margins recurved below, entire to spinosely denticulate above; costa very short and double or absent; cells often strongly incrassate, basal rhomboidal, alar cells relatively few, usually excavate, often reddish brown, enlarged towards basal angles, marginal row of 4–8 quadrate to rectangular supra-alar cells present, mid-leaf cells 4–7 × 42–96 μm, averaging 57–76 μm long. Branch leaves smaller and more falcate; margins denticulate to spinose-denticulate above; mid-leaf cells 52–88 μm long, averaging 62–76 μm. Capsules ellipsoid to shortly cylindrical, curved, widemouthed and sometimes somewhat gibbous when dry and empty; lid shortly rostrate. Capsules occasional in Ireland. Rocks (also on bark in Macaronesia). Lowland. very rare, N. Kerry, H1. IR1∗ . Hyperoceanic Southern-temperate. Portugal, Spain, Macaronesia. Close to H. andoi with capsule lid intermediate in shape between those of H. andoi and H. cupressiforme. The capsules are often ellipsoid and curved, differing in shape from those of the other two species and frequently wide-mouthed – a distinctive feature – when dry and empty. This species was omitted from the first edition of this flora but the independent rediscovery of a specimen collected by William Wilson in 1829 by H. Ando and by C. C. Townsend led to the reinstatement of H. uncinulatum to the Irish list (see H. Ando & C. C. Townsend, J. Bryol. 11, 185–9, 1980). There are five specimens from the same locality collected in the 1920s in the National Museum of Wales.

7 H. resupinatum Taylor, Ann. Mag. Nat. Hist., 1849 H. cupressiforme var. resupinatum (Taylor) Schimp.

(Fig. 305)

Dioicous. Plants very slender to small, ranging from pale green to dull green smooth mats with upwardly directed leaves to dark olive-green patches with short erect branches. Stems irregularly branched, branches prostrate to erect. Stem leaves homomallous, sometimes pointing upwards, ± straight or with weakly falcate tips, concave, ovate or ovate-lanceolate, gradually tapering from 1/4 –1/2 from base to ± abruptly narrowed to apex; margins recurved below, plane, usually entire above; costa very short and double or absent; basal cells rhomboidal, with pointed ends, sometimes porose, alar cells rarely increasing in size towards basal angles, not excavate, cells in mid-leaf 4.5–7.5 × (28−)32–76(−88) μm, averaging 39–69 μm long. Branch leaves similar to stem leaves but smaller; margins plane, usually entire; mid-leaf cells 32–80 μm long, averaging 39–69 μm. Capsules erect, straight or occasionally slightly curved, narrowly ovoid to cylindrical, body of capsule 1.1–2.2 mm long; exothecial cells with heavily thickened longitudinal walls; lid rostrate, 0.83–1.17 mm long. Capsules frequent, autumn. n = 10∗ . On bark, rocks and walls, calcifuge, 0–920 m. Frequent or common throughout the British Isles. 112, H40, C. Circumpolar Temperate. Europe north to Fennoscandia, N. America, Macaronesia, Cyprus. Except for very slender plants, which may be difficult to separate from slender H. cupressiforme, this plant is easily identified in the field even when sterile by the ovate

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Fig. 305 1–8. Hypnum resupinatum: 1, shoot (×12); 2, 3, stem and branch leaves (×30); 4, alar cells (×210); 5, mid-leaf cells (×420); 6, capsule (×10); 7, pseudoparaphyllia (×90). 8–11, H. callichroum: 8, stem leaf (×40); 9, alar cells (×280); 10, mid-leaf cells (×420); 11, capsule (×10).

205 Hypnum

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or ovate-lanceolate, relatively shortly pointed, homomallous leaves, often pointing upwards. There are two variants of H. resupinatum, one with numerous, often crowded ascending straight or curved branches and upward pointing leaves. This gives well grown specimens the appearance of dark olive-green coarse velvet. The second form has long prostrate branches, the plants forming dull green to yellowish brown smooth mats. The two are very distinctive in appearance but a complete range of intermediates exists.

8 H. jutlandicum Holmen & Warncke, Bot. Tidskr., 1969 (Fig. 306) H. cupressiforme var. ericetorum Schimp., H. ericetorum (Schimp.) Nyholm Dioicous. Medium-sized plants forming pale green lax patches or wefts. Stems complanately pinnately branched, green. Pseudoparaphyllia simple or deeply bilobed, narrowly lanceolate or linear-lanceolate, occasionally with 1–2 teeth, 125–300 (−400) μm long. Stem leaves weakly to strongly falcate, concave, ovate or ovate-lanceolate, 1.4–2.3 × 0.5–0.8 mm; margins entire or denticulate above; costa very short and double or absent; basal cells rhomboidal, alar cells relatively few, colourless to pale brown, often deeply excavate, enlarged and sometimes much inflated towards basal angles, mid-leaf cells 4–7 × 40–88 (−96) μm, averaging 43–85 μm. Branch leaves smaller and narrower; margins denticulate above; mid-leaf cells 48–88 μm long, averaging 54–78 μm. Capsules curved, strongly inclined to ± horizontal, body of capsule 1.4–2.1 mm long, lid rostrate, 0.60– 0.79 μm long. Capsules occasional, autumn. n = 10. Very common and sometimes abundant on dry to damp heath, upland Racomitrium heath, drier parts of bogs, on moorland, in scree, open birch woodland and conifer plantations, in exposed to deeply shaded situations, calcifuge, 0–1040 m. Common except in central and eastern England. 112, H40, C. GB1512 + 67∗ , IR323 + 9∗ , C11. Suboceanic Temperate. Montane and western Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, Cyprus, Asia, La Palma, Tenerife, Madeira, Azores, Newfoundland. Only likely to be confused with H.imponens, but differing in its pale green colour, green stems and shape of the pseudoparaphyllia.

9 H. imponens Hedw., Sp. Musc. Frond., 290, 1801 (Fig. 307) Dioicous. Medium-sized plants, yellowish green to reddish brown lax patches. Stems regularly pinnately branched, dark reddish brown. Pseudoparaphyllia narrowly triangular to lanceolate, toothed, 175–450 μm long. Stem leaves strongly falcate-secund, concave, gradually tapering from c. 1/5 –1/4 from base, ovatelanceolate or lanceolate, 1.6–2.6 × 0.4–1.0 mm; margins entire or denticulate above; costa very short and double or absent; cells in mid-leaf 4–7 × 56–96 μm, alar cells relatively few, colourless or more usually pinkish to dark reddish brown, enlarged and sometimes inflated, not or only slightly excavate. Branch leaves smaller, narrower, more strongly falcate with margins denticulate above. Capsules inclined, oblong-ellipsoid, slightly curved; lid shortly rostrate. Capsules very rare (I have only seen old capsules once in British material). n = 7, 11. On wet heath,

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Fig. 306 1–6, Hypnum jutlandicum: 1, 2, stem and branch leaves (×30); 3, alar cells from different plants (×210); 4, mid-leaf cells from different plants (×420); 5, capsule (×10) 6, pseudoparaphyllia (×90). 7–9, H. bambergeri: 7, stem leaf (×40); 8, alar cells (×280); 9, mid-leaf cells (×420).

205 Hypnum

913

Fig. 307 Hypnum imponens: 1, 2, stem and branch leaves (×30); 3, alar cells (×210); 4, mid-leaf cells (×420); 5, capsule (×10) 6, pseudoparaphyllia (×90).

raised, valley and blanket bog. 0–600 m. Rare but sometimes locally frequent from S. Devon (old record) and E. Kent north to W. Ross, Laois. 29, H1. GB46 + 19∗ , IR1, IR1. European Temperate. Temperate and montane Europe north to about 67◦ N, Cyprus, Azores, N. America. Sporophytes are exceedingly rare and I have only once seen British material with old capsules. Only likely to be confused with H. jutlandicum in the field, but differing in the yellowish green to reddish brown colour of the plants and the reddish brown stems.

Section 3 Banbergeri Ando, J. Sci. Hiroshima Univ. B, Div. 2, Bot., 1973 Plants large. Stem epidermal cells narrow. Alar cells homogenous, thick-walled, excavate. Perichaetial leaves plicate. Setae twisted dextrorsely proximally and sinistrorsely distally; cilia 2–3.

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10 H. bambergeri Schimp., Syn. Musc. Eur., 1860 (Fig. 306) Dioicous. Plants small to medium-sized, in yellowish green to orange-brown tufts or patches. Stems creeping, irregularly pinnately branched, branches short or long, erect or ascending. Leaves circinate-secund, lanceolate to ovate-lanceolate, gradually tapering to long fine acumen; margins plane, entire or sinuose; costa short and double or absent; cells porose, basal narrowly rectangular, alar cells quadrate or rectangular, very incrassate, orange-brown, forming small but distinct group. cells above elliptical to linear, in mid-leaf 5–8 × 32–64 μm, 5–11 times as long as wide. Sporophytes very rare and unknown in Britain. On sheltered basic montane rocks and in rock crevices. 920–1175 m. Rare to occasional in the central Scottish Highlands; Mid and E. Perth, Angus, S. Aberdeen, Inverness, Argyll, W. Sutherland. 8. GB14 + 2∗ . Circumpolar Arctic-montane Montane and northern Europe north to Svalbard, Iceland, Turkey, Altai, northern Siberia, northern N. America, Greenland. More robust and less regularly pinnate than H. hamulosum; the alar cells are much more distinct and the cells above more porose. In H. hamulosum the epidermal cells of the stems are large and thin-walled and frequently partially tear off with leaf bases when leaves are removed.

Section 4 Hamulosa Schimp. emend. Ando, J. Sci. Hiroshima Univ., Series B, Div. 2, 1973 Plants small to medium-sized. Stems with large thin-walled epidermal cells. Alar cells heterogeneous, excavate, sometimes differing in stem and branch leaves, some enlarged, hyaline towards base. Perichaetial leaves plicate. Setae twisted dextrorsely proximally, sinistrorsely distally. Cilia 2–3. Capsules ripe spring to summer. 11 H. callichroum Brid., Bryol. Univ., 1827 (Fig. 305) Dioicous. Plants medium-sized, forming glossy green sometimes extensive patches. Stems procumbent to ascending, complanately pinnately branched; epidermal cells large, thin-walled. Pseudoparaphyllia lanceolate-triangular. Leaves circinate-secund, lanceolate, gradually tapering to filiform acumen; margins plane, entire or bluntly denticulate near base; costa lacking; basal cells narrowly rhomboidal, alar cells inflated, hyaline, forming distinct auricles, cells above linear, ± vermicular, in mid-leaf 5–7(−8) × 48–88 μm, (6−)10–16 times as long as wide. Setae yellowish green; capsules inclined to horizontal, oblong-ellipsoid, curved; exothecial cell walls of uniform thickness; spores 12–16 μm. Capsules rare, summer. n = 10∗ . In damp shaded situations on rocks and ledges, in turf, ravines, on cliffs and among boulders, often in basic habitats. 0–1225 m. Frequent or common in N. W. Wales, the Lake District and the Scottish Highlands, north to Orkney, rare to occasional in the far west of Ireland. 37, H8. GB209 + 22∗ , IR19 + 1∗ . Circumpolar Boreo-arctic Montane. Montane and northern Europe north to Svalbard,

205 Hypnum

915

Fig. 308 1–4, Hypnum hamulosum: 1, leaf (×40); 2, alar cells (×280); 3, mid-leaf cells (×420); 4, capsule (×10). 5–7, Ptilium crista-castrensis: 5, 6, stem and branch leaves (×40); 7, capsule (×10).

Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Yunnan, Japan, Canada, Greenland. 12 H. hamulosum Schimp. in Bruch et al., Bryol. Eur., 1854 (Fig. 308) Autoicous. Plants slender, in yellowish green to golden brown patches. Primary stems creeping, secondary stems procumbent to ascending, pinnately branched, branches short, stem and branch tips hooked; epidermal cells large, thin-walled. Leaves falcate-secund to circinate-secund, ovate, longly tapering to filiform apex; margins plane or recurved, entire or sparsely denticulate from base to apex; costa short and double or absent; basal cells narrowly rectangular to narrowly rhomboidal, alar cells very few, quadrate to trapezoid, intergrading with other cells,

916

62 Hypnaceae

not forming distinct group, cells above linear, vermicular or not, in mid-leaf 4–8 × (24−)40–64(−80) μm, 6–11 times as long as wide. Capsules inclined, narrowly ellipsoid, slightly curved; lid conical, obtuse; spores 12–14 μm. Capsules occasional, summer. On sheltered basic montane rocks, rock faces, ledges, in crevices and in rocky turf. 0–1125 m. Rare in N. W. Wales, occasional in the Lake District and the Scottish Highlands, north to Sutherland. 13. GB68 + 18∗ . Circumpolar Arctic-montane. Montane and northern Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. Asia, Szechwan, Japan, N. America, Greenland.

Subfamily 4 CTENIDIOIDEAE Usually pinnately or plumosely branched plants. Pseudoparaphyllia lanceolate. Leaves often plicate; stem leaves from cordate-triangular basal part rapidly narrowed to long fine acumen; margins entire to denticulate from base to apex; costa short and double or absent; alar cells differentiated, other cells ± linear. Capsules horizontal, curved; exothecial cells incrassate.

206 PTILIUM DE NOT., COMMENT. SOC. CRITTOG. ITAL., 1867 With the characters of P. crista-castrensis. There is a second species occurring in the Caribbean region. Derivation: meaning plume-like habit.

1 P. crista-castrensis (Hedw.) De Not., Comment. Soc. Crittog. Ital., 1867 (Fig. 308) Hypnum ptilium crista-castrensis Hedw. Plants medium-sized, forming lax green or yellowish green patches or coarse wefts. Shoots very elegant, 5–8(−20) cm long; stems procumbent to erect, closely complanately pinnately branched, branches of ± equal length. Pseudoparaphyllia abundant, narrowly lanceolate. Leaves circinate-secund, plicate; stem leaves ovate or ovate-lanceolate, longly tapering to filiform acumen; margins plane, entire or sinuose; costa short and double or absent; basal cells linear-rhomboidal, alar cells inflated, hyaline, forming small very distinct longly decurrent auricles, cells above linear-vermicular, in mid-leaf 4–5 μm wide. Setae thin, reddish; capsules horizontal, ovoid or obloid, curved or gibbous; lid mamillate; spores 11–13 μm. Capsules rare, autumn. n = 10, 10 + m. 11. On acid humus-rich soil in woodland, especially coniferous woodland, more rarely under Calluna or Erica, or on soil among boulders, in humid habitats. 0–850 m. W. Suffolk and W. Norfolk (probably introduced), rare or occasional in N. W. Wales, N. England and S. Scotland, occasional to frequent in the Scottish Highlands, extending north to Sutherland, W. Mayo. 41, H1. GB242 + 49∗ , IR1. Circumpolar Boreal-montane. Montane and northern Europe

207 Ctenidium

917

north to Fennoscandia, Caucasus, N. Asia, Siberia, Sikkim, Yunnan, N. America, Greenland.

207 CTENIDIUM (SCHIMP.) MITT., J. LINN. SOC. BOT., 1869 Dioicous. Slender to robust plants. Primary stems creeping, secondary stems prostrate to erect, pinnately and frequently plumosely branched. Pseudoparaphyllia sparse. Leaves straight to circinate-secund, plicate or not; stem leaves from cordate-triangular base rapidly narrowed to acuminate apex, base broadly decurrent; costa short and double or absent; alar cells differentiated, other cells linear. Branch leaves narrower, more gradually tapering than stem leaves. Setae smooth or papillose; capsules inclined to horizontal, curved; cilia nodulose; calyptrae hairy. About 20 species of which two occur in Europe. Derivation: referring to the comb-like manner of branching. For a revision of the genus see N. Nishimura, J. Hattori Bot. Lab. 58, 1–82, 1985.

Leaf margins denticulate, often strongly so, ± from base to apex, common and widespread plant 1. C. molluscum Leaf margins entire or faintly denticulate above, very rare high-altitude plant 2. C. procerrimum 1 C. molluscum (Hedw.) Mitt., J. Linn. Soc. Bot., 1869 Hypnum molluscum Hedw. Plants slender to robust, forming dense yellowish green to golden brown patches. Stems creeping, pinnately branched or variously branched with divisions plumosely pinnately to fastigiately branched, these procumbent to erect, branches crowded. Leaves undulate or flexuose when dry, usually plicate, falcate-secund to circinate-secund, cordate-triangular, rapidly narrowed to long acumen; costa double and extending to up to 1/4 way up leaf or absent; basal cells rhomboidal, porose, alar cells enlarged, ± incrassate, forming poorly defined auricles, other cells linear. Capsules inclined, ellipsoid, gibbous; lid conical, acute or mamillate; spores 13–15 μm. Capsules rare, spring. 1 Plants very slender to medium-sized, branch tips strongly hooked or not 2 Plants robust, stem tips strongly hooked, high-altitude plants 4 2 Plants very slender, stems erect, stems fastigiately branched, stem leaves 0.8–1.3 mm long, high-altitude plant var. fastigiatum Plants slender to medium-sized, stems closely regularly pinnately branched, leaves 1.0–2.1 mm long 3 3 Branch tips not strongly hooked, branches slender, crowded var. molluscum Branch tips strongly hooked, branches stout, not crowded var. sylvaticum

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4 Plants forming patches, stems creeping, pinnately branched var. condensatum Plants forming tufts, stems erect, to 10 cm high, irregularly branched var. robustum Var. molluscum (Fig. 309) Plants slender to medium-sized, in dense soft glossy yellowish green to golden, sometimes bronze-tinged mats or patches, sometimes extensive, or straggling through other vegetation. Shoots procumbent to erect, when erect rarely more than 2 cm high. Stems creeping, forked, divisions procumbent to ascending, usually closely regularly pinnately branched, plumose, but sometimes ± fastigiately branched, branches crowded, stem and branch tips not markedly hooked. Leaves crowded in dry habitats, distant in moist ones; stem leaves usually plicate, flexuose when dry, 1–2 mm long, strongly falcate-secund to circinate-secund, rarely almost straight, cordate-triangular to broadly cordate-triangular, rapidly narrowed to long acumen; margins often strongly denticulate almost from base to apex; midleaf cells 5–7 × 36–76 μm, 6–12 times as long as wide. Branch leaves smaller and narrower, 0.7–1.4 mm long. n = 5, 8∗ . On compacted soil in grassland, on rocks, cliffs, in flushes, fens and marshes, in weakly to strongly calcareous situations. 0–1295 m. Occasional in eastern England, common elsewhere in Britain, common in the western half of Ireland, occasional to frequent in the eastern half. 112, H40, C. GB1459 + 122∗ , IR297 + 7∗ , C2 + 2∗ . European Boreo-temperate. Europe north to northern Norway, Faeroes, Iceland, Caucasus, Turkey, N. Asia, Kamchatka, Algeria, Azores, Canary Islands, N. W. North America. Var. fastigiatum (Bosw.) Braithw., Brit. Moss Fl., 1902 (Fig. 309) Plants very slender, in very dense golden green to golden brown tufts or deep patches, to 3 cm high. Primary stems creeping, secondary stems erect, forked, fastigiately branched, branches very crowded. Leaves not plicate, sometimes flexuose when dry; stem leaves 0.8–1.3 mm long, ovate-cordate to cordate-triangular, shortly tapering to filiform acumen; mid-leaf cells 4.0–8.5 × 26–48 μm, (4−)5–7 times as long as wide. Branch leaves smaller, more longly tapering than stem leaves, ovate-lanceolate, 0.5–0.9 mm long. On dry basic montane rocks. Rare, N. Devon (old record) and Somerset north to W. Sutherland (old record), S. Kerry, Leitrim, Sligo. 18, H3. Apparently endemic. Var. condensatum (Schimp.) C. Britton, Mem. Torrey Bot. Cl., 1894 (Fig. 309) Plants moderately robust, in glossy green to golden brown patches. Shoots to 8 cm long but with branches rarely more than 1 cm high. Stems creeping, forked, pinnately branched, branches spreading to erect, stem and branch tips strongly hooked. Leaves strongly plicate, irregularly flexuose or undulate when dry; stem leaves (1.1−)1.4–2.0 mm long, falcate-secund, cordate-triangular, shortly tapering to filiform acumen, margins denticulate ± from base to apex; mid-leaf cells 5.5– 8.0 × 40–50(−72) μm, 6–10(−12) times as long as wide. Branch leaves of similar

207 Ctenidium

919

Fig. 309 Ctenidium molluscum: 1–5, var. molluscum: 1, 2, stem and branch leaves (×40); 3, alar cells (×280); 4, mid-leaf cells (×420); 5, capsule (×10). 6–7, var. fastigiatum: 6, stem leaf (×40); 7, mid-leaf cells (×420). 8–9, var. condensatum: 8, stem leaf (×40); 9, mid-leaf cells (×420). 10–11, var. robustum: 10, stem leaf (×30); 11, mid-leaf cells (×420). 12–14, var. sylvaticum: 12, 13, stem and branch leaves (×40); 14, mid-leaf cells (×420).

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62 Hypnaceae

length to stem leaves but narrower and more gradually tapering. On flushed shaded montane cliffs, in scree and flushes. Occasional, W. Cornwall, Hereford and Worcester north to Shetland, rare in Ireland. 44, H8. From Sicily and Spain north to Belgium and Poland, Faeroes. Var. robustum Boulay in Braithw., Brit. Moss Fl., 1902 (Fig. 309) Plants robust, forming golden brown, often reddish-tinged tufts, to 10 cm high, stem and branch tips strongly hooked. Primary stems creeping, secondary stems erect, distantly and irregularly branched, branches erect, long. Leaves strongly plicate, falcate-secund; stem leaves mostly 1.5–3.0 mm long, ovate-cordate, tapering to filiform acumen; margins denticulate ± from base to apex; mid-leaf cells 5–10 × (40−)72–150 μm, (7−)9–20 times as long as wide. Branch leaves smaller, narrower, more strongly plicate, more strongly falcate and more gradually tapering than stem leaves, 1.2–2.0 mm long, ovate-lanceolate. On sheltered flushed basic montane rocks. Rare, Merioneth and from Mid-West Yorkshire and Westmorland (old records) north to W. Sutherland, Down (old record). 14, H1. Europe from Spain, Italy and Roumania north to Fennoscandia. Var. sylvaticum F. Rose & A. J. E. Sm. In press (Fig. 309) Plants medium-sized, in dense yellowish green to golden green patches, rarely more than 1 cm high, with glossy pale-tipped stems and branches. Primary stems creeping, secondary stems prostrate, forked, ± pinnately branched, branches short, erect, ± fastigiate, with strongly hooked pale tips. Leaves plicate, often undulate above when dry; stem leaves 1.3–2.1 mm long, falcate-secund, ovatetriangular, shortly tapering to filiform acumen; margins denticulate ± from base to apex; mid-leaf cells 5.5–7.0 × (32−)40–64 μm, 5–10 times as long as wide. Branch leaves 1.0–1.6 mm long, strongly falcate to falcate-circinate, ovate, gradually tapering to filiform apex. On acidic soil and humus in woodland. Lowland. Frequent in Cornwall and south-east England, rare elsewhere, Pembroke, Caernarfon. 14. France (Brittany), Spain. A very variable species for which about 20 varieties have been described. Var. sylvaticum is distinctive in its habit and preference for a substrate with a pH of about 5.5. Var. sylvaticum may be worthy of subspecific or even specific status, but before any firm conclusions can be drawn further study is necessary. The status of the other varieties is uncertain and they may or may not be mere habitat modifications but experimental investigation is required.

2 C. procerrimum (Molendo) Lindb., Bot. Not., 1882 (Fig. 310) Hypnum procerrimum Molendo, Pseudostereodon procerrimum (Molendo) M. Fleisch. Medium-sized plants forming dense dull green to yellowish green flat patches. Stems prostrate, ± interruptedly very closely pinnately or sometimes subpinnately branched, branches strongly complanate. Leaves similar moist and dry, not flexuose at tips, concave; stem leaves falcate-secund, from ovate-lanceolate basal part

207 Ctenidium

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Fig. 310 1–4, Ctenidium procerrimum: 1, 2, stem and branch leaves (×40): 3, alar cells (×280); 4, mid-leaf cells (×420). 5–8, Hyocomium armoricum: 5, 6, stem and branch leaves (×40): 7, mid-leaf cells (×420); 8, capsule (×7). 9–10, Rhytidium rugosum: 9, stem leaf (×10); 10, mid-leaf cells (×420).

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62 Hypnaceae

gradually tapering to acuminate apex; margins plane, entire or slightly denticulate above; costa double, extending to up to 1/3 way up leaf; alar cells numerous, quadrate to rectangular, incrassate, often opaque, ± orange, forming conspicuous but ill-defined group of cells, cells elsewhere ± linear, in mid-leaf 4–6 × 32–64 μm, 7–13 times as long as wide. Branch leaves smaller and narrower than stem leaves, strongly falcate-secund or circinate-secund, from lanceolate or narrowly lanceolate basal part tapering to acuminate apex. Sporophytes unknown. On basic montane rocks. 450–900 m. Very rare, Mid Perth, E. Inverness. 2. GB3. C. Circumpolar Arctic-montane. Europe Norway, Caucasus, Siberia, C. Asia, Yunnan, Sinkiang, arctic N. America. Somewhat intermediate between Hypnum species and Ctenidium molluscum, distinguished from the former by the ± orange often opaque alar cells and from the latter by the ± entire leaf margins C. procerrimum is on the Red List of British Mosses as vulnerable.

Subfamily 5 HYOCOMIOIDEAE With the characters of the species.

208 HYOCOMIUM SCHIMP. IN BRUCH ET AL., BRYOL. EUR., 1853 A monotypic genus with the characters of the species. Derivation: from a Greek word meaning lover of moisture.

1 H. armoricum (Brid.) Wijk & Margad., Taxon, 1961 H. flagellare Schimp.

(Fig. 310)

Autoicous. Plants small to robust, in golden green to golden brown patches, sometimes extensive. Shoots to 15 cm long; primary stems creeping, secondary stems ascending to procumbent or pendulous, forked, regularly or irregularly pinnately branched, branches short to attenuate. Paraphyllia and pseudoparaphyllia absent. Leaves mostly patent to spreading, plicate, sometimes rugose when dry, erect to erect-patent, sometimes slightly secund when moist; stem leaves broadly cordatetriangular, shortly tapering to acute to filiform apex, decurrent; margins plane, irregularly dentate from base to apex; costa short and double or absent; cells thinwalled to incrassate, porose, basal rhomboidal to narrowly rhomboidal, alar cells numerous, ± narrowly hexagonal, opaque, decurrent, not forming auricles, cells above variable in shape, narrowly rhomboidal, trapezoid to linear, in mid-leaf 6–9 × 40–84 μm, 7–10 times as long as wide. Branch leaves smaller, on ultimate branches ovate, acute. Setae purplish red, papillose; capsules ± horizontal, obloid, slightly curved; spores c. 16 μm. Capsules rare, winter. n = 8. On rocks, tree roots and boles in flood zone of streams and rivers, on damp shaded rocks, cliff ledges and by waterfalls, usually in woodland or ravines but also in moorland streams.

209 Rhytidium

923

0–360(−770) m. S. Hampshire, Sussex, Kent, frequent or common in western and northern England, Wales, the western Highlands of Scotland, rare to occasional elsewhere in Scotland, frequent or common in W. Ireland, rare to occasional elsewhere. 75, H33. GB630 + 40∗ , IR127 + 7∗ . Oceanic Temperate. W. and C. Europe north to western Norway, Faeroes, Azores, Madeira, Japan. Thamnobryum alopecurum and Isothecium holtii grow in similar habitats to and are sometimes mixed with H. armoricum. Both the former species have narrower costate leaves.

63 Hylocomiaceae Dioicous. Plants medium-sized to robust, forming mats to lax wefts, sometimes extensive. Stems procumbent to erect, irregularly to pinnately or bipinnately branched. Paraphyllia present or not; pseudoparaphyllia usually present, foliose. Leaves erect to spreading or squarrose, plicate or not, broadly ovate to lanceolate, acuminate to rounded, base sometimes decurrent; margins often recurved below, usually denticulate to dentate; costa usually double, rarely single; alar cells differentiated or not, basal cells incrassate, porose, cells above narrowly elliptical to linear, sometimes prorate. Branch leaves smaller, narrower and often more sharply toothed than stem leaves. Setae smooth; capsules erect to pendulous; annulus of 1–3 rows of cells or absent; lid conical to longly rostrate; exostome teeth variously ornamented, endostome with high basal membrane, cilia 1–4, rarely absent; calyptrae cucullate. Twelve genera distributed in cool temperate and arctic areas. For a generic revision of the Hylocomiaceae see J. R. Rohrer, J. Hattori Bot. Lab. 59, 241– 78, 1985. He points out that many authors have placed the last four species of this family treated here in Hylocomium for convenience as the number of species in Europe, N. America and Japan is small. However, Rohrer puts forward good reasons for accepting M. Fleischer’s treatment in Brotherus (1924–1925) and I have followed his recommendations.

209 RHYTIDIUM (SULL.) KINDB., BIH. KONGL. SVENSKA VETENSK. – ACAD. HANDL., 1882 A monotypic genus with the characters of the species. Derivation: from a Greek word meaning wrinkled, referring to the rugose leaves.

1 R. rugosum (Hedw.) Kindb., Bih. Kongl. Svenska Vetensk. – Acad. Handl., 1882 (Fig. 310) Hylocomium rugosum (Hedw.) De Not. Dioicous. Robust plants in yellowish green to golden brown coarse lax patches. Shoots to 10 cm long; stems procumbent to ascending, forked and irregularly pinnately branched, branches erect to spreading. Paraphyllia absent;

924

63 Hylocomiaceae

pseudoparaphyllia lanceolate-subulate. Leaves imbricate, concave, rugose, falcatesecund; stem leaves ovate, tapering to acuminate apex; margins recurved ± from base to near apex, denticulate above; costa single, forked above, reaching 1/2 – 3/ way up leaf; cells porose, basal rhomboidal, alar cells numerous, quadrate to 4 trapezoid, not forming auricles, ascending up margins and intergrading with other cells, cells above narrowly elliptical, papillose on abaxial side above, in mid-leaf 5.5–8.0 × 28–56 μm, 4–7 times as long as wide. Branch leaves smaller, ovatelanceolate to lanceolate, otherwise similar to stem leaves. Setae long, smooth; capsules horizontal, shortly cylindrical, curved; exothecial cell walls of uniform thickness; annulus of 3 rows of separating cells; lid obliquely rostellate; exostome teeth cross-striolate below, papillose above, basal membrane high, cilia 1–3; spores c. 16 μm; calyptrae almost covering capsules. Sporophytes unknown in the British Isles. In dry basic grassland, in dune pasture, on inland cliff ledges and in quarries, calcicole. 0–850 m. Very rare in lowland England, Caernarfon, occasional in the Pennines, rare to occasional in Scotland, extending north to W. Sutherland, Londonderry. 32, H1. GB54 + 29∗ , IR2. Circumpolar Boreo-arctic Montane. Europe north to northern Scandinavia, Iceland, Caucasus, Turkey, N. and C. Asia, Mongolia, China, Japan, Morocco, N. America, Greenland, Mexico, Guatemala.

210 PLEUROZIUM MITT., J. LINN. SOC. BOT., 1869 A monotypic genus with the characters of the species. Derivation: probably referring to the pinnate branching of the stems.

1 P. schreberi ((Willd. ex Brid.) Mitt., J. Linn. Soc. Bot., 1869 Hypnum schreberi Willd. ex Brid

(Fig. 311)

Plants medium-sized, in pale green to yellowish green patches or coarse wefts, sometimes extensive. Shoots to 12 cm long; stems deep red, procumbent to erect, complanately pinnately branched, branches short and of uniform length along stems, often slightly down-curved. Paraphyllia and pseudoparaphyllia absent. Leaves loosely imbricate, making stems and branches somewhat julaceous; stem leaves ovate or broadly ovate, obtuse or rounded; margins incurved above, entire; costa very short, double; cells incrassate, porose, basal trapezoid to elliptical, alar cells rectangular, brown, forming distinct auricles, cells above linear, in mid-leaf 6.5–10.0 × 60–132 μm, 8–16 times as long as wide. Branch leaves smaller, obtuse to acuminate. Setae long, thin, smooth, red; capsules inclined, ovoid, curved; lid conical, obtuse or apiculate; exostome teeth finely papillose throughout, endostome with tall basal membrane, processes keeled with widely gaping perforations, cilia well developed; spores 12–18 μm. Capsules occasional in N. Wales and northern Scotland, very rare elsewhere. n = 5∗ . On heaths, upland moorland, in coniferous and upland deciduous woodland, in acid grassland, scree, on sand-dunes. 0–1210 m. Common and sometimes abundant in suitable habitats,

211 Rhytidiadelphus

925

Fig. 311 1–4. Pleurozium schreberi: 1, stem leaf (×25); 2, alar cells (×280); 3, mid-leaf cells (×420); 4, capsule (×10). 5–7. Rhytidiadelphus triquetrus: 5, stem leaf (×10); 6, mid-leaf cells (×420); 7, capsule (×10).

frequent in central and eastern England and Ireland, common or very common elsewhere in Britain. 112, H40, C. GB1505 + 101∗ , IR252 + 14∗ , C1. Circumpolar Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Japan, Ethiopia, Madeira, Azores, N., C. and northern S. America, Greenland. Readily recognised by the bright red stems and the neatly pinnately branched shoots, the branches of which are often slightly down-curved.

211 RHYTIDIADELPHUS (WARNST.) WARNST., KRYPT. FL. BRANDENBURG, LAUBM., 1906 Dioicous. Robust or very robust plants, often forming coarse wefts. Shoots procumbent to erect; stems usually very long, irregularly to pinnately branched; central

926

63 Hylocomiaceae

strand present. Paraphyllia absent; pseudoparaphyllia if present broadly ovate or suborbicular. Stem and branch leaves ± similar or not, plicate or not, spreading to squarrose, from broad sometimes sheathing basal part gradually or abruptly narrowed to acumen; margins denticulate at least above; costa short and double or absent; cells ± incrassate, porose or not, alar cells differentiated or not, cells above linear-elliptical, smooth to coarsely prorate on abaxial side. Setae long, flexuose, deep red; capsules ± horizontal, ovoid or obloid, gibbous; 2–3 rows annular cells present; lid conical or mamillate; endostome with nodulose cilia. Five species occurring in Europe, Asia, N. America and Australasia. Derivation: meaning related to Rhytidium.

1 Stem leaves spreading or falcate-secund, plicate, alar cells not much differentiated 2 Stem leaves squarrose or strongly reflexed, not plicate, alar cells forming distinct group 3 2 Shoots erect, branches not complanate, leaves scarious when dry, ± spreading 1. R. triquetrus Shoots arcuate, procumbent, or stoloniform, branches ± complanate, leaves falcate-secund, not scarious when dry 4. R. loreus 3 Stem leaves squarrose with erect sheathing basal part, completely concealing stems, stem tips stellate with crowded leaves 2. R. squarrosus Stem leaves reflexed from erect-patent or patent non-sheathing basal part, stem often visible between leaves, stem tips hardly stellate 3. R. subpinnatus 1 R. triquetrus (Hedw.) Warnst., Krypt. Fl. Brandenburg, Laubm., 1906 (Fig. 311) Hylocomium triquetrum (Hedw.) Schimp. Plants very robust, forming coarse green or yellowish green tufts or patches, reddish brown below. Shoots to 20 cm long; stems erect or ascending, orangebrown to brown, irregularly branched, branches not complanate, short or sometimes attenuate. Leaves ± spreading, plicate and sometimes rugose when moist, scarious but otherwise hardly altered when dry; stem leaves from ± erect subsheathing cordate basal part tapering to acute apex, base decurrent; margins plane, denticulate to dentate above; costa double, extending up to 3/4 way up leaf; basal cells elliptical, alar cells shorter, wider, thinner-walled but hardly distinct, cells above linear-elliptical, upper prorate on abaxial side, in mid-leaf 6–9 × 48–72 μm, 7–11 times as long as wide. Branch leaves smaller, tapering from cordate-triangular basal part. Capsules ± horizontal, obloid, gibbous; lid conical, acute; spores 14–21 μm. Capsules rare, winter. n = 6∗ . On grassy banks, in damp turf, open places in woodland, on moorland, cliff ledges and slopes, sand-dunes, in basic to acidic habitats. 0–980 m. Occasional to frequent in central and eastern

211 Rhytidiadelphus

927

England and Ireland, common and sometimes locally dominant elsewhere. 111, H39, C. GB1417 + 111∗ , IR264 + 8∗ , C5 + 2∗ . Circumpolar Boreo-temperate. Europe north to northern Fennoscandia, Faeroes, Iceland, Caucasus, Turkey, Asia, C. Africa, Madeira, N. America. 2 R. squarrosus (Hedw.) Warnst., Krypt. Fl. Brandenburg, Laubm., 1906 (Fig. 312) Hylocomium squarrosum (Hedw.) Schimp. Plants robust, pale green to yellowish, in coarse tufts or wefts, sometimes extensive, often brownish below. Shoots to 15 cm long; stems erect or ascending at least at tips, towards ends reddish, elsewhere reddish brown, concealed by sheathing leaf bases, irregularly or sometimes sparsely pinnately branched, branches short or sometimes long and attenuate. Leaves not plicate; stem leaves strongly squarrose, at stem tips crowded rendering tips stellate in appearance, from sheathing broadly ovate basal part narrowed to long acuminate apex; margins plane, denticulate above; costa double, extending 1/4 –1/3 way up leaf; basal cells narrowly rhomboidal, alar cells enlarged, hyaline or coloured, forming distinct group, cells above linear-elliptical, smooth, in mid-leaf 6–9 × 40–80(−86) μm, 7–10(−12) times as long as wide. Lower leaves of branches of similar shape to but smaller than stem leaves, towards ends of branches ovate-lanceolate, tapering to long fine denticulate acumen. Setae long, flexuose, sometimes bent or twisted; capsules horizontal, ovoid, gibbous; lid conical, acute; spores 18–20 μm. Capsules rare, winter. n = 8, 10. In turf, lawns, on banks, streamsides, roadsides, in open woodland, on heaths, marshy ground, usually where damp. 0–1225 m. Very common. 112, H40, C. GB1969 + 71∗ , IR462 + 9∗ , C7. European Boreo-temperate. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. and E. Asia, Azores, Madeira, N. America. 3 R. subpinnatus (Lindb.) T. J. Kop., Hikobia, 1971 (Fig. 312) R. calvescens (Lindb.) Broth., R. squarrosus ssp. calvescens (Lindb.) Giacom., R. squarrosus var. calvescens (Lindb.) Warnst. Plants moderately robust, pale green to yellowish, in coarse wefts, Shoots to 12 cm long; stems ascending, reddish brown almost to tips, only partially concealed by leaf bases, irregularly or sometimes sparsely pinnately branched. Leaves not plicate; stem leaves weakly squarrose, at stem tips not rendering tips stellate in appearance, from patent or ± erect but not sheathing broadly ovate or ovate-cordate basal part ± abruptly narrowed to acuminate upper part; margins plane, denticulate above; costa double, extending up to 1/3 way up leaf; basal cells narrowly rhomboidal, alar cells enlarged, hyaline or coloured, forming distinct group, cells above linear-elliptical, smooth, in mid-leaf 6–9 × 40–80(−86) μm, 7–10(−12) times as long as wide. Lower leaves of branches ovate-lanceolate, tapering to acuminate apex, towards ends of branches ovate abruptly narrowed or shortly tapering denticulate acumen. Sporophytes as in R. squarrosus; not

928

63 Hylocomiaceae

Fig. 312 1–5, Rhytidiadelphus squarrosus: 1, stem leaves; 2, leaf from base of branch; 3, leaf from upper part of branch; 4, mid-leaf cells; 5, capsule (×10). 6–9, R. subpinnatus: 6, stem leaves; 7, leaf from base of branch; 8, leaf from upper part of branch; 9, mid-leaf cells. Leaves ×25, cells ×420.

212 Loeskeobryum

929

known in the British Isles. n = 10. On damp soil in grassy places and stream banks in deciduous woodland. Lowland. Very rare, Merioneth, W. Lancashire, Waterford, old records from Carmarthen, Derby, Cheshire, Mid-West and N. W. Yorkshire, Westmorland. 9, H1. GB2 + 10∗ , IR1. Circumpolar Boreal-montane. W. and C. Europe north to Fennoscandia, Iceland, Caucasus, Turkey, N. Asia, Japan, Azores, N. America. Confused with slender forms of R. squarrosus for which it may well be overlooked. Variously treated as a species or as a subspecies or variety of or synonymous with R. squarrosus. R. subpinnatus is recognised by its softer appearance; the leaves are reflexed from an erect non-sheathing base, this giving the leaves a less rigid appearance and also revealing the stem in places. The leaves of R. subpinnatus may have a broader basal part more abruptly narrowed into the acumen but not always so. Depauperate plants of R. squarrosus may be difficult or impossible to separate from R. subpinnatus. There is a report of a hybrid sporophyte, the result of crossing between R. subpinnatus (female) and R. loreus (male) from a locality in Merioneth (see D. T. Holyoak, Bull. Br. Bryol. Soc. 76, 56–8, 2001). R. subpinnatus is listed as endangered in the Red List of British Mosses.

4 R. loreus (Hedw.) Warnst., Krypt. Fl. Brandenburg, Laubm., 1906 Hylocomium loreum (Hedw.) Schimp.

(Fig. 313)

Plants very robust in yellowish green lax coarse wefts or straggling patches. Shoots ascending, arcuate to procumbent, to 30(−50) cm long. Stems reddish brown or orange-brown, ± pinnately branched, branches short, spreading. Leaves patent, falcate-secund, hardly altered when dry; stem leaves from concave ovate plicate basal part gradually tapering to long channelled acumen; margins plane or narrowly recurved near base, denticulate from middle or below; costa short, double, faint or absent; basal cells linear-rhomboidal, alar cells shorter, wider, more incrassate, sometimes coloured but not forming distinctive group, cells above linear-elliptical, smooth, in mid-leaf 6–8(−10) × 40–80 μm, 8–10 times as long as wide. Branch leaves smaller and narrower than stem leaves. Capsules horizontal, ovoid, gibbous; lid mamillate or conical; spores 14–18 μm. Capsules rare. On rocks, boulders, fallen logs, soil, banks, on cliff ledges, in scree, damp moorland, in humid situations, calcifuge. 0–1225 m. Rare in lowland England except the far south, there and elsewhere common, common in western Ireland, occasional elsewhere. 106, H37, C. GB1505 + 101∗ , IR183 + 6∗ , C2 + 2∗ . Suboceanic Boreo-temperate. W. and C. Europe north to N. Norway, Faeroes, Azores, Madeira, N. America. 212 LOESKEOBRYUM M. FLEISCH. IN BROTH., NAT. PFLANZENFAM., 1925 Plants medium-sized to robust. Stems with central strand. Paraphyllia abundant, branched, branches uniseriate; pseudoparaphyllia similar. Stem and branch leaves different; stem leaves plicate; costa short and double. Branch leaves with costa double, stronger than in stem leaves, extending 1/3 –1/2 way up leaf. Setae smooth;

930

63 Hylocomiaceae

Fig. 313 1–3, Rhytidiadelphus loreus: 1, stem leaves (×18); 2, mid-leaf cells; 3, capsule (×10). 4–8, Loeskeobryum brevirostre: 4, 5, stem and branch leaves (×25); 6, mid-leaf cells; 7, capsules (×10); 8. paraphyllia (×180). Cells ×420.

213 Hylocomiastrum

931

capsules inclined to horizontal, with short neck; annulus of 1–2 rows large cells; lid rostrate; exostome teeth cross-striolate below, papillose above, basal membrane tall, cilia 2–3, nodulose. Three species distributed through Europe, N. Asia, N. Africa, N. and C. America, Caribbean. Derivation: a combination of the name of the bryologist Leopold Loeske (1854–1935) and the Greek word bryon meaning a cryptogamic plant. Close to Rhytidiadelphus but differing in the presence of paraphyllia.

1 L. brevirostre (Brid.) M. Fleisch. in Broth., Nat. Pflanzenfam., 1925 (Fig. 313) Hylocomium brevirostre (Brid.) Schimp., Rhytidiadelphus brevirostris (Brid.) Nyholm Medium-sized to robust plants in lax dull green or yellowish green patches or coarse wefts. Shoots to 12 cm long; stems reddish brown, ascending, arcuate or stoloniform, forked and irregularly pinnately branched, branches spreading. Paraphyllia abundant, small, 70–130 μm long, irregularly and often substellately branched. Leaves weakly plicate, sometimes rugose at tips especially when dry; stem leaves patent to spreading or squarrose, cordate-orbicular to broadly ovatecordate or cordate-triangular, abruptly narrowed to frequently falcate channelled acumen; margins plane, bluntly to coarsely toothed above; costa double, thin, extending c. 1/3 way up leaf; basal cells narrowly rhomboidal, brownish, incrassate, strongly porose, alar cells thinner-walled, rhomboidal, forming large rounded sometimes decurrent auricles, cells above linear-rhomboidal, smooth, in mid-leaf 5–8 × 28–64 μm, 4–8(−11) times as long as wide. Branch leaves ovate to ovatelanceolate, ± abruptly narrowed to usually straight acumen; margins coarsely dentate; costa double, stronger than in stem leaves, extending 1/2 –3/4 way up leaf. Capsules inclined, ellipsoid, curved; lid with stout obtuse beak; spores 22–26 μm. Capsules rare, winter. n = 6, 7, 10 + m. On banks, rocks, wall tops, tree boles, logs and branches in shaded humid situations, on cliff ledges, especially where basic. 0– 650 m. Frequent or common in S. W. England, Wales, N. W. England and western Scotland, extending north to Sutherland and Lewis, rare elsewhere, frequent or common in W. Ireland, rare elsewhere. 75, H37, C. GB379 + 73∗ , IR117 + 6∗ , C1∗ . European Temperate. Europe north to southern Scandinavia, Faeroes, Turkey, N. Asia, Kamchatka, Tunisia, Algeria, Azores, N. America, Greenland. In habit L. brevirostre resembles a species of Rhytidiadelphus rather than any of the next three species with which it is usually placed, but is readily recognised by the abundant paraphyllia. It differs from the next three species in the large auricles of the stem leaves. The small substellate paraphyllia are also characteristic.

213 HYLOCOMIASTRUM M. FLEISCH. IN BROTH., NAT. PFLANZENFAM., 1925 Stems with central strand. Paraphyllia multiseriate at base, becoming biseriate then uniseriate above, cell ends projecting as spines; pseudoparaphyllia similar

932

63 Hylocomiaceae

but larger. Leaves plicate; stem leaves often distant; costa strong, single or double, extending 1/3 –3/4 way up leaf. Branch leaves with single costa extending 1/2 –3/4 way up leaf. Setae smooth; capsules without distinct neck, gibbous; annulus absent; lid conical, apiculate; exostome teeth cross-striolate below, densely papillose above; basal membrane tall, cilia 2–3, nodulose. Three species occurring in Eurasia, N. Africa and N America. Derivation: meaning having an incomplete likeness to Hylocomium. Well separated from other genera of the family. Differing from Hylocomium in branching pattern, presence of a central strand, morphology of the paraphyllia, strongly plicate leaves with well developed costa and capsule lacking a distinct neck and annulus among other things.

Stems sparsely or irregularly pinnately branched, stem leaves abruptly narrowed to acumen 1. H. pyrenaicum Stems regularly pinnately branched, sometimes bipinnate, stem leaves ± tapering to acumen 2. H. umbratum 1 H. pyrenaicum (Spruce) M. Fleisch. in Broth., Nat. Pflanzenfam., 1925 (Fig. 314) Hylocomium pyrenaicum (Spruce) Lindb. Plants medium-sized, in yellowish green patches or more usually scattered. Stems reddish brown, procumbent to ascending, occasionally forked, irregularly and sparsely pinnately branched, branches spreading. Paraphyllia abundant, 130– 600 μm long, cell ends projecting as spines. Leaves loosely imbricate, concave, strongly plicate; stem leaves distant or not, ovate, abruptly narrowed to apiculus to ± gradually narrowed to acute twisted apex; margins recurved below, coarsely toothed; costa single or rarely double, faint, extending to 1/2 way up or more up leaf; basal cells yellowish, rhomboidal, incrassate, porose, alar cells not differentiated, cells above narrowly rhomboidal to linear-rhomboidal, smooth, in mid-leaf 5–7 × 32–64 μm, (4−)5–11 times as long as wide. Branch leaves ovate, shortly pointed, obtuse and apiculate; margins coarsely toothed; costa single, extending 1/ –3/ way up leaf. Capsules inclined, ovate-ellipsoid; lid conical, acute; spores 2 4 c. 20 μm. Sporophytes unknown in Britain. n = 12. In turf below cliffs, on ledges and in scree and at edges of stony flushes in basic situations. 670–1180 m. Rare, Scottish Highlands. 11. GB21 + 3∗ . Circumpolar Boreal-montane. Montane and northern Europe north to northern Fennoscandia, Faeroes, Iceland, Caucasus, N. and C. Asia, Japan, N. America, Greenland. 2 H. umbratum (Hedw.) M. Fleisch. in Broth., Nat. Pflanzenfam., 1925 (Fig. 314) Hylocomium umbratum (Hedw.) Schimp Somewhat slender plants forming pale green to yellowish green, sometimes brownish-tinged coarse tufts, 10–20 cm high. Stems reddish brown, ascending,

213 Hylocomiastrum

933

Fig. 314 1–4, Hylocomiastrum pyrenaicum: 1, 2, stem and branch leaves; 3, mid-leaf cells; 4, paraphyllia (×180). 5–9, H. umbratum: 5, 6, stem and branch leaves; 7, mid-leaf cells; 8, capsule (×10); 9, paraphyllia (×180). Leaves ×40, cells ×420.

934

63 Hylocomiaceae

forked, 1–2-pinnate, branches subcomplanate, sometimes crowded, variable in length, sometimes attenuate. Paraphyllia abundant, variable in size, 240–1000 μm long, linear and irregularly branched into lanceolate-subulate segments, cell ends projecting as spines. Leaves strongly plicate; stem leaves ± distant, erect to erectpatent, ovate-cordate, tapering to acute apex, base decurrent; margins plane, coarsely toothed; costa double, extending up to 1/2 way or more up leaf; basal cells yellowish, rhomboidal, porose, alar cells hardly differentiated, decurrent, cells above narrowly linear-rhomboidal, smooth, in mid-leaf 5–7 × 40–64 μm, 6–11 times as long as wide. Branch leaves ± imbricate, concave, ovate to broadly ovate or ovate-triangular; margins coarsely toothed; costa single, extending 1/2 –3/4 way up leaf, ending in a spine on abaxial side. Capsules horizontal, ovate-ellipsoid, gibbous; lid conical, obtuse; spores 14–18 μm. Capsules rare, autumn. n = 7. On soil, humus and rocks in open humid woodland, wooded valleys, rocky turf, on rock ledges and in scree. 0–1170 m. Frequent or common in N. W. Wales, the Lake District and western Scotland north to W. Sutherland and the Outer Hebrides, rare elsewhere in Scotland, frequent or common in the far west of Ireland. 36, H8. GB209 + 8∗ , IR28. European Boreal-montane. Montane and northern Europe north to northern Fennoscandia, Faeroes, Caucasus, Kamchatka, Korea, Japan, Algeria, Tunisia, N. America. Hylocomium splendens is a larger plant and has regularly complanately pinnately branched stems and much less plicate leaves.

214 HYLOCOMIUM SCHIMP. IN BRUCH ET AL., BRYOL EUR., 1852 A monotypic genus with the characters of the species. Derivation: according to Schimper 1852 meaning an inhabitant of woods.

1 H. splendens (Hedw.) Schimp. in Bruch et al., Bryol Eur., 1852 (Fig. 315) Plants medium-sized to large, in yellowish green to brownish green coarse wefts or patches. Stems bright red, procumbent, often with annual growth zones, giving plants a layered appearance, 10–20 cm long, forked, complanately bipinnate, very rarely simply pinnate, not attenuate; central strand lacking. Paraphyllia abundant, 200–1000 μm long, multiseriate at base, with several long ultimately uniseriate filiform branches. Leaves loosely imbricate, plicate below, concave; stem leaves not plicate, somewhat distant, ovate-oblong, abruptly narrowed to acute, rarely obtuse channelled sometimes crimped acumen, not falcate, not decurrent; margins plane or recurved near base, denticulate or dentate; costa double, extending up to 1/2 −2/3 way up leaf; basal cells narrowly rhomboidal, porose, orangebrown, alar cells not or hardly differentiated, cells above narrowly rhomboidal to linear, sparsely prorate on abaxial side above, in mid-leaf 5–7 × (26−)40– 80 μm, (5−)7–14 times as long as wide. Leaves of primary branches similar to but smaller than stem leaves, weakly plicate; costa variable, ranging from absent

214 Hylocomium

935

Fig. 315 Hylocomium splendens: 1, 2, stem and branch leaves; (×40) 3, mid-leaf cells (×420); 4, capsule (×10); 5, paraphyllia (×180).

to extending to halfway up leaf; leaves of ultimate branches much smaller, ovateellipsoid, acute. Capsules inclined to horizontal, ovoid to ellipsoid, gibbous, neck distinct; annulus of 1–2 rows large cells; lid with rostrate beak; exostome teeth reticulate below, papillose above, endostome with tall basal membrane, cilia 2–4, nodulose spores 14–17 μm. Capsules rare, spring. n = 10, 11∗ , 12. In usually acidic habitats on soil, in turf on banks, on heaths, moorland, sand-dunes, cliff ledges, roadsides, stream banks, in chalk and limestone grassland where leached, calcifuge. 0–1180 m. Occasional in central and eastern England, common and sometimes locally abundant elsewhere, frequent to common in Ireland. 111, H40, C. GB1487 + 238∗ , IR314 + 9∗ , C1 + 2∗ . Circumpolar Wide-boreal. Europe north to Svalbard, Faeroes, Iceland, Caucasus, Turkey, N. and C. Asia, Japan, Sakhalin, Kuriles, Morocco, Azores, Madeira, La Gomera, N. America, Greenland, New Zealand. Differs from bipinnate Thuidium species in its larger size, leaf shape and areolation. Simply pinnate forms may be confused with Pleurozium schreberi or Hylocomiastrum umbratum. The former differs in its obtuse leaves and lack of paraphyllia. In the latter the branching is less regularly bipinnate, less complanate and the stem leaves are plicate and more triangular in shape.

Geographical relationships of British and Irish mosses Hill & Preston (1998) carried out an analysis of the bryophytes of the British Isles in terms of world distribution, habitat and distribution in the British Isles. They established a system of elements based on distribution in northern and western Eurasia, dividing the flora up first into latitudinal categories and secondly into longitudinal ones. They recognised four major biomes (large, naturally occurring zones of dominant vegetation adapted to the particular conditions in which they occur) and these are listed below. Many species occur in more than one major biome and five composite categories, also listed below, were recognised. The floristic element/eastern limit category or biome to which each species belongs is given in italics in the distribution data of that species.

Major biomes Arctic-montane. Species with their main distribution either to the north of or (on mountains) above the tree line, or both. Boreal-montane. Species with their main distribution in the coniferous forest zone. They may occur in the Boreal zone and/or in the coniferous forest zone of mountains to the south. Temperate. Species with their main distribution in the cool temperate, broad-leaved deciduous forest zone. May occur on mountains to the south or in cool steppes in continental interiors. Southern. Species with their main distribution in the warm temperate zone south of the broad-leaved deciduous forest zone.

Composite categories Boreo-arctic Montane. Species occurring in both Arctic-montane and Boreal-montane zones. Boreo-temperate. Occurring more or less equally in the Boreal and Temperate zones or, if absent from the Boreal Zonobiome, ascending to the subalpine zone on mountains. Southern-temperate. Species which are found more or less equally in the Temperate and Southern (Mediterranean) zones. 936

Geographical relationships

937

Wide-boreal. Species with a distribution centered on the Boreal zone or its montane equivalent but also occurring widely in the tundra and the Temperate zone. Wide-temperate. Species with a distribution that is centered on the Temperate zone but which also occur widely in the Boreal zone and Mediterranean region.

Eastern limit categories Circumpolar. Species that are found in Europe, Asia and North America or at least discontinuously so. Eurasian. Species with a distribution extending across Asia to an eastern limit east of 120◦ E. European. Species with a mainly European distribution but sometimes extending east to the Caucasus, Pontic Asia and the Middle East but not occurring east of 60◦ E. Eurosiberian. Species with a main distribution reaching its eastern limit between 60◦ E and 120◦ E. Hyperoceanic. Species that are markedly western within the Oceanic zone, found especially in Western Ireland, Scotland and Norway. Oceanic. Species occurring in western Europe extending east to Norway, Denmark and Central France. Suboceanic. Species with a western distribution but extending further east than oceanic species, to Italy, Central Europe and Sweden.

Red List of British Mosses

Species in bold type are protected under the Provisions of the Wildlife and Countryside Act, 1981.

Extinct Bryum lawersianum1 Bryum turbinatum Cynodontium fallax Encalypta brevicollis4 Grimmia anodon Grimmia elatior Gyroweisia reflexa Helodium blandowii Lescuraea saxicola

Neckera pennata4 Orthotrichum gymnostomum Paludella squarrosa Pterygoneurum lamellatum4 Sphagnum obtusum Tortella limosella1 Trematodon ambiguus Weissia × mittenii

Critically endangered Amblystegium radicale Aplodon wormskjoldii Bartramia stricta Brachythecium trachypodium Bryum mamillatum Bryum schleicheri Bryum uliginosum Dicranum elongatum Didymodon glaucus Didymodon mamillosus4 Ephemerum cohaerens3

Homomallium incurvatum Hygrohypnum styriacum Micromitrium tenerum4 Orthotrichum pumilum Philonotis cernua Plagiothecium piliferum Rhynchostegium rotundifolium Seligeria carniolica Tayloria tenuis Tetrodontium repandum Thamnobryum angustifolium5

Endangered Acaulon triquetrum Anomodon attenuatus

Atrichum angustatum Blindia caespiticia

938

Red List of Mosses Bryum cyclophyllum Bryum gemmiparum Bryum marratii Bryum neodamense Buxbaumia viridis4 Campylophyllum halleri Ceratodon conicus Cyclodictyon laetevirens Ditrichum cornubicum 2,5 Ephemerum stellatum4 Eurhynchium pulchellum Habrodon perpusillus Hygrohypnum polare Hypnum revolutum Myurella tenerrima Orthotrichum obtusifolium Orthotrichum pallens

Philonotis marchica Physcomitrium eurystomum Plagiobryum demissum Pohlia obtusifolia Rhytidiadelphus subpinnatus Sematophyllum demissum Sphagnum balticum Tayloria lingulata Timmia austriaca Tortula cernua Tortula wilsonii Weissia levieri Weissia multicapsularis3 Weissia squarrosa Zygodon forsteri Zygodon gracilis

Vulnerable Andreaea frigida Anomodon longifolius Brachythecium starkei Bryum calophyllum Bryum knowltonii Bryum salinum Bryum stirtonii Bryum warneum Cinclidotus riparius Ctenidium procerrimum Daltonia splachnoides4 Dendrocryphaea lamyana4 Dicranum bergeri Dicranum leioneuron Dicranum spurium Didymodon cordatus Eurhynchium meridionale Fissidens serrulatus Grimmia ovalis Grimmia tergestina Grimmia ungeri

Grimmia unicolor Heterocladium dimorphum Hygrohypnum molle Hypnum vaucheri Leptodontium gemmascens Mielichhoferia elongata Mielichhoferia mielichhoferiana Orthodontium gracile3 Paraleucobryum longifolium Pohlia crudoides Pseudoleskiella nervosa Saelania glaucescens4 Scorpidium turgescens Seligeria brevifolia Sphagnum majus Syntrichia norvegica Thamnobryum cataractacum4 Tortula cuneifolia Tortula leucostoma Weissia condensa

939

Red List of Mosses

940

Species not on the Red List but protected under the Wildlife and Countryside Act, 1981 Hamatocaulis vernicosus

Moss species listed as vulnerable in the Red Data Book of European Bryophytes but not on the British list Brachythecium appleyardiae Ditrichum plumbicola Tortula freibergii

1 2 3 4 5

In the List of 4 extinct moss species in the Red Data Book of European Bryophytes. In the List of 9 critically endangered moss species in the Red Data Book of European Bryophytes. In the List of 17 endangered moss species in the Red Data Book of European Bryophytes. In the List of 80 vulnerable moss species in the Red Data Book of European Bryophytes. In the IUCN world List of Bryophytes.


The British and Irish Watsonian vice-counties or botanical districts mentioned in the text are listed below and illustrated in Fig. 316. The British vice-counties were delimited in 1852 and the Irish in 1901, but because of political boundary changes since those dates many of these bear little relation to current administrative counties. The numbers by which the Irish vice-counties are usually known are given in brackets after the names. A large-scale version (1/4 inch to 1 mile) was published in 1969 (J. E. Dandy, Watsonian Vice-Counties of Great Britain. London: The Ray Society, 1969. No ISBN number).

England and Wales 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

W. Cornwall E. Cornwal S. Devon N. Devon S. Somerset N. Somerset S. Wiltshire N. Wiltshire Dorset Isle of Wight S. Hampshire N. Hampshire W. Sussex E. Sussex E. Kent W. Kent Surrey S. Essex N. Essex Hertford Middlesex Berkshire Oxford

24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 941

Buckingham E. Suffolk W. Suffolk E. Norfolk W. Norfolk Cambridge Bedford Huntingdon Northampton E. Gloucester W. Gloucester Monmouth Hereford Worcester Warwick Stafford Shropshire Glamorgan Brecon Radnor Carmarthen Pembroke Cardigan

942


Fig. 316 British and Irish vice-county map based upon the New Naturalist Vice-County map of the British Isles. For key to numbers see text.

British and Irish vice-counties 47 48 49 50 51 52 53 54 55 56 57 58 59

Montgomery Merioneth Caernarfon Denbigh Flint Anglesey S. Lincoln N. Lincoln Leicester Nottingham Derby Cheshire S. Lancashire

60 61 62 63 64 65 66 67 68 69 70 71

W. Lancashire S. E. Yorkshire N. E. Yorkshire S. W. Yorkshire Mid-West Yorkshire N. W. Yorkshire Durham S. Northumberland N. Northumberland Westmorland Cumberland Isle of Man

Scotland 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92

Dumfries Kirkcudbright Wigtown Ayr Renfrew Lanark Peebles Selkirk Roxburgh Berwick E. Lothian Midlothian W. Lothian Fife Stirling W. Perth Mid Perth E. Perth Angus Kincardine S. Aberdeen

93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112

N. Aberdeen Banff Moray (Elgin) E. Inverness W. Inverness Argyll Dunbarton Clyde Islands, incl. Arran) Kintyre S. Ebudes (Islay, etc.) Mid Ebudes (Mull, etc.) N. Ebudes (Skye, etc.) W. Ross E. Ross E. Sutherland W. Sutherland Caithness Outer Hebrides Orkney Shetland

117 118 119 120

E. Cork (H5) Waterford (H6) S. Tipperary (H7) Limerick (H8)

Ireland 113 114 115 116

S. Kerry (H1) N. Kerry (H2) W. Cork (H3) Mid Cork (H4)

943


944 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136

Clare (H9) N. Tipperary (H10) Kilkenny (H11) Wexford (H12) Carlow (H13) Laois (H14) S. E. Galway (H15) W. Galway (H16) N. E. Galway (H17) Offaly (H18) Kildare (H19) Wicklow (H20) Dublin (H21) Meath (H22) Westmeath (H23) Longford (H24)

C Channel Islands

137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152

Roscommon (H25) E. Mayo (H26) W. Mayo Sligo (H28) Leitrim (H29) Cavan (H30) Louth (H31) Monaghan (H32) Fermanagh (H33) E. Donegal (H34) W. Donegal (H35) Tyrone (H36) S. Antrim (H37) Down (H38) N. Antrim (H38) Derry (Londonderry) (H40)

English names for British and Irish mosses Most bryophyte taxa do not have common or English names. The Wildlife and Countryside Act, 1981 requires that such names are used for protected species of plants and animals. These names also feature in Biological Action Plans. The following list has therefore been extracted from Edwards (1999). I do not, however, recommend that such names are otherwise used unless the Latin names are given as well as these have no botanical nomenclatural basis and are meaningless to bryologists abroad. Abietinella abietina ssp. abietina: Fir Tamarisk-moss abietina ssp. hystricosa: Prickly Tamarisk-moss Acaulon muticum var. mediterraneum: Spiny-spored Pygmy-moss muticum var. muticum: Rounded Pygmy-moss triquetrum: Triangular Pygmy-moss Achrophyllum dentatum: Toothed Clear-leaf Moss Aloina aloides: Common Aloe-moss ambigua: Tall Aloe-moss brevirostris: Short-beaked Aloe-moss rigida: Rigid Aloe-moss Amblyodon dealbatus: Short-tooth Hump-moss Amblystegium confervoides: Tiny Feather-moss humile: Constricted Feather-moss radicale: Swamp Feather-moss serpens var. salinum: Salt Feather-moss serpens var. serpens: Creeping Feather-moss varium: Willow Feather-moss Amphidium lapponicum: Lapland Yoke-moss mougeotii: Mougeot’s Yoke-moss Andreaea alpestris: Slender Rock-moss alpina: Alpine Rock-moss blyttii: Blytt’s Rock-moss frigida: Icy Rock-moss megistospora: Big-spored Rock-moss mutabilis: Changeable Rock-moss nivalis: Snow Rock-moss 945

946

English names

rothii: Dusky Rock-moss rothii ssp. falcata: Hunt’s Rock-moss rupestris var. papillosa: Rough Rock-moss rupestris var. rupestris: Black Rock-moss sinuosa: Small-spored Rock-moss Anoectangium aestivum: Summer-moss Anomobryum julaceum var. concinnatum: Neat Silver-moss julaceum var. julaceum: Slender Silver-moss Anomodon attenuatus: Slender Tail-moss longifolius: Long-leaved Tail-moss viticulosus: Rambling Tail-moss Antitrichia curtipendula: Pendulous Wing-moss Aongstroemia longipes: Sprig-moss Aphanorrhegma patens: Spreading Earth-moss Aplodon wormskjoldii: Carrion-moss Archidium alternifolium: Clay Earth-moss Arctoa fulvella: Arctic Fork-moss Atrichum angustatum: Lesser Smoothcap crispum: Fountain Smoothcap tenellum: Slender Smoothcap undulatum var. gracilisetum: Side-stalk Smoothcap undulatum var. undulatum: Common Smoothcap Aulacomnium androgynum: Bud-headed Groove-moss palustre: Bog Groove-moss turgidum: Mountain Groove-moss Barbula convoluta: Lesser Bird’s-claw Beard-moss sardoa: Sardinian Bird’s-claw Beard-moss unguiculata: Bird’s-claw Beard-moss Bartramia halleriana: Haller’s Apple-moss ithyphylla: Straight-leaved Apple-moss pomiformis: Common Apple-moss stricta: Upright Apple-moss Blindia acuta: Sharp-leaved Blindia caespiticia: Dwarf Blindia Brachydontium trichodes: Bristle-leaf Brachythecium albicans: Whitish Feather-moss appleyardiae: Appleyard’s Feather-moss erythrorrhizon: Redfoot Feather-moss glaciale: Snow Feather-moss glareosum: Streaky Feather-moss mildeanum: Sand Feather-moss plumosum: Rusty Feather-moss

English names populeum: Matted Feather-moss reflexum: Reflexed Feather-moss rivulare: River Feather-moss rutabulum: Rough-stalked Feather-moss salebrosum: Smooth-stalk Feather-moss starkei: Starke’s Feather-moss trachypodium: Lawers Feather-moss velutinum: Velvet Feather-moss Breutelia chrysocoma: Golden-head Moss Bryoerythrophyllum caledonicum: Scottish Beard-moss ferruginascens: Rufous Beard-moss recurvirostrum: Red Beard-moss Bryum algovicum var. rutheanum: Drooping Thread-moss alpinum: Alpine Thread-moss archangelicum: Archangelic Thread-moss arcticum: Arctic Thread-moss argenteum: Silver-moss barnesii: Barnes’ Bryum bimum: Bimous Marsh Bryum bornholmense: Potato Bryum caespiticium: Tufted Thread-moss calophyllum: Blunt Bryum canariense: Canary Thread-moss capillare var. capillare: Capillary Thread-moss capillare var. rufifolium: Rufous Thread-moss creberrimum: Tight-tufted Thread-moss cyclophyllum: Round-leaved Bryum dichotomum: Bicoloured Bryum dixonii: Dixon’s Thread-moss donianum: Don’s Thread-moss dyffynense: Dyffryn Moss elegans: Blushing Bryum funkii: Funk’s Bryum gemmiferum: Small-bud Bryum gemmilucens: Yellow-bud Bryum gemmiparum: Welsh Thread-moss imbricatum: Small-mouthed Thread-moss intermedium: Many-seasoned Thread-moss klinggraeffii: Raspberry Bryum knowltonii: Knowlton’s Thread-moss laevipilum: Syed’s Thread-moss lawersianum: Lawers Thread-moss

947

948

English names

mamillatum: Sand Thread-moss marratii: Baltic Bryum mildeanum: Milde’s Thread-moss muehlenbeckii: Muehlenbeck’s Thread-moss neodamense: Long-leaved Thread-moss pallens: Pale Thread-moss pallescens: Tall-clustered Thread-moss pseudotriquetrum: Marsh Bryum radiculosum: Wall Thread-moss riparium: River Thread-moss rubens: Crimson-tuber Thread-moss ruderale: Pea Bryum salinum: Saltmarsh Thread-moss sauteri: Sauter’s Thread-moss schleicheri var. latifolium: Schleicher’s Thread-moss stirtonii: Stirton’s Thread-moss subapiculatum: Lesser Potato Bryum subelegans: Flabby Thread-moss tenuisetum: Yellow-tuber Thread-moss torquescens: Twisting Thread-moss turbinatum: Topshape Thread-moss uliginosum: Cernuous Thread-moss violaceum: Pill Bryum warneum: Warne’s Thread-moss; Sea Bryum weigelii: Duval’s Thread-moss Buxbaumia aphylla: Brown Shield-moss viridis: Green Shield-moss Calliergon cordifolium: Heart-leaved Spear-moss giganteum: Giant Spear-moss Calliergonella cuspidata: Pointed Spear-moss lindbergii: Lindberg’s Plait-moss Calomnion complanatum: Tree-fern Beauty-moss Calyptrochaeta apiculata: Southern Hookeria Campyliadelphus chrysophyllum: Golden Feather-moss elodes: Fine-leaved Marsh Feather-moss Campylium protensum: Dull Starry Feather-moss stellatum: Yellow Starry Feather-moss Campylophyllum calcareum: Chalk Feather-moss halleri: Haller’s Feather-moss Campylopus atrovirens var. atrovirens: Bristly Swan-neck Moss atrovirens var. falcatus: Sickle Swan-neck Moss atrovirens var. gracilis: Slender Swan-neck Moss brevipilus: Compact Swan-neck Moss

English names flexuosus: Rusty Swan-neck Moss fragilis: Brittle Swan-neck Moss gracilis: Schwarz’s Swan-neck Moss introflexus: Heath Star Moss pilifer: Stiff Swan-neck Moss pyriformis var. azoricus: Azorean Swan-neck Moss pyriformis var. pyriformis: Dwarf Swan-neck Moss schimperi: Schimper’s Swan-neck Moss setifolius: Silky Swan-neck Moss shawii: Shaw’s Swan-neck Moss subporodictyon: Rusty Bow-moss subulatus: Awl-leaved Swan-neck Moss Campylostelium saxicola: Bent-moss Catoscopium nigritum: Down-looking Moss Ceratodon conicus: Scarce Redshank purpureus: Redshank Cheilothela chloropus: Rabbit Moss Cinclidium stygium: Lurid Cupola-moss Cinclidotus fontinaloides: Smaller Lattice-moss riparius: Fountain Lattice-moss Cirriphyllum cirrosum: Tendril Feather-moss crassinervium: Beech Feather-moss piliferum: Hair-pointed Feather-moss Climacium dendroides: Tree-moss Conardia compacta: Compact Feather-moss Conostomum tetragonum: Helmet-moss Coscinodon cribrosus: Sieve-tooth Moss Cratoneuron curvicaule: Bent-stem Hook-moss filicinum: Fern-leaved Hook-moss Cryphaea heteromalla: Lateral Cryphaea Ctenidium molluscum var. condensatum: Dense Comb-moss molluscum var. fastigiatum: Slender Comb-moss molluscum var. molluscum: Chalk Comb-moss molluscum var. robustum: Vinous Comb-moss molluscum var. sylvaticum: Wood Comb-moss procerrimum: Alpine Comb-moss Cyclodictyon laetevirens: Bright-green Cave-moss Cynodontium fallax: False Dog-tooth jenneri: Jenner’s Dog-tooth polycarpon: Many-fruited Dog-tooth strumiferum: Strumose Dog-tooth tenellum: Delicate Dog-tooth Daltonia splachnoides: Irish Daltonia

949

950

English names

Dendrocryphaea lamyana: Multi-fruited Cryphaea Dialytrichia mucronata: Pointed Lattice-moss Dichodontium flavescens: Yellowish Fork-moss palustris: Marsh Forklet-moss pellucidum: Transparent Fork-moss Dicranella cerviculata: Red-neck Forklet-moss crispa: Curl-leaved Forklet-moss grevilleana: Greville’s Forklet-moss heteromalla: Silky Forklet-moss rufescens: Rufous Forklet-moss schreberiana: Schreber’s Forklet-moss staphylina: Field Forklet-moss subulata: Awl-leaved Forklet-moss varia: Variable Forklet-moss Dicranodontium asperulum: Orange Bow-moss denudatum: Beaked Bow-moss uncinatum: Curve-leaved Bow-moss Dicranoweisia cirrata: Common Pincushion crispula: Mountain Pincushion Dicranum bergeri: Waved Fork-moss bonjeanii: Crisped Fork-moss elongatum: Dense Fork-moss flagellare: Whip Fork-moss flexicaule: Bendy Fork-moss fuscescens: Dusky Fork-moss leioneuron: Fuzzy Fork-moss majus: Greater Fork-moss montanum: Mountain Fork-moss polysetum: Rugose Fork-moss scoparium: Broom Fork-moss scottianum: Scott’s Fork-moss spurium: Rusty Fork-moss tauricum: Fragile Fork-moss Didymodon acutus: Pointed Beard-moss australasiae var. umbrosus: Shady Beard-moss cordatus: Cordate Beard-moss fallax: False Beard-moss ferrugineus: Rusty Beard-moss glaucus: Glaucous Beard-moss icmadophilus: Slender Beard-moss insulanus: Cylindric Beard-moss luridus: Dusky Beard-moss mamillosus: Perthshire Beard-moss maximus: Irish Beard-moss

English names nicholsonii: Nicholson’s Beard-moss rigidulus: Rigid Beard-moss sinuosus: Wavy Beard-moss spadiceus: Brown Beard-moss tomaculosus: Sausage Beard-moss tophaceus: Olive Beard-moss vinealis: Soft-tufted Beard-moss Diphyscium foliosum: Nut-moss Discelium nudum: Flag-moss Distichium capillaceum: Fine Distichium inclinatum: Inclined Distichium Ditrichum cornubicum: Cornish Path-moss flexicaule: Bendy Ditrichum gracile: Slender Ditrichum heteromallum: Curve-leaved Ditrichum lineare: Dark Ditrichum plumbicola: Lead-moss pusillum: Brown Ditrichum subulatum: Awl-leaved Ditrichum zonatum var. scabrifolium: Scabrous Ditrichum zonatum var. zonatum: Alpine Ditrichum Drepanocladus aduncus: Kneiff’s Hook-moss polygamus: Fertile Feather-moss sendtneri: Chalk Hook-moss Encalypta alpina: Alpine Extinguisher-moss brevicollis: White-mouthed Extinguisher-moss ciliata: Fringed Extinguisher-moss rhaptocarpa: Ribbed Extinguisher-moss streptocarpa: Spiral Extinguisher-moss vulgaris: Common Extinguisher-moss Entodon concinnus: Montagne’s Cylinder-moss Entosthodon attenuatus: Thin Cord-moss fascicularis: Hasselquist’s Hyssop muhlenbergii: Muhlenberg’s Cord-moss obtusus: Blunt Cord-moss pulchella: Pretty Cord-moss Ephemerum cohaerens: Clustered Earth-moss minutissimum: Minute Earth-moss recurvifolium: Strap-leaved Earth-moss serratum var. praecox: Early Earth-moss serratum var. serratum: Serrated Earth-moss sessile: Sessile Earth-moss spinulosum: Prickly Earth-moss stellatum: Starry Earth-moss

951

952

English names

Epipterygium tozeri: Tozer’s Thread-moss Eucladium verticillatum: Whorled Tufa-moss Eurhynchium meridionale: Portland Feather-moss pulchellum var. diversifolium: Elegant Feather-moss striatulum: Lesser Striated Feather-moss striatum: Common Striated Feather-moss Fissidens adianthoides: Maidenhair Pocket-moss bryoides: Lesser Pocket-moss celticus: Welsh Pocket-moss crassipes: Fatfoot Pocket-moss curnovii: Curnow’s Pocket-moss curvatus: Portuguese Pocket-moss dubius: Rock Pocket-moss exiguus: Tiny Pocket-moss exilis: Slender Pocket-moss gracilifolius: Narrow-leaved Pocket-moss incurvus: Short-leaved Pocket-moss limbatus: Herzog’s Pocket-moss monguillonii: Atlantic Pocket-moss osmundoides: Purple-stalked Pocket-moss polyphyllus: Many-leaved Pocket-moss pusillus: Petty Pocket-moss rivularis: River Pocket-moss rufulus: Beck Pocket-moss serrulatus: Large Atlantic Pocket-moss taxifolius var. pallidicaulis: Great Pocket-moss taxifolius var. taxifolius: Common Pocket-moss viridulus: Green Pocket-moss Fontinalis antipyretica var. antipyretica: Greater Water-moss antipyretica var. cymbifolia: Boat-leaved Water-moss antipyretica var. gigantea: Robust Water-moss antipyretica var. gracilis: Lesser Water-moss squamosa var. curnowii: Curnow’s Water-moss squamosa var. dixonii: Dixon’s Water-moss squamosa var. squamosa: Alpine Water-moss Funaria hygrometrica: Common Cord-moss Glyphomitrium daviesii: Black-tufted Moss Grimmia alpestris: Alpine Grimmia alpestris: Mountain Grimmia anodon: Toothless Grimmia arenaria: Sand Grimmia atrata: Copper Grimmia crinita: Hedgehog Grimmia decipiens: Great Grimmia

English names dissimulata: Dissimulating Grimmia donniana: Donn’s Grimmia elatior: Large Grimmia elongata: Brown Grimmia funalis: String Grimmia hartmanii: Hartman’s Grimmia incurva: Black Grimmia laevigata: Hoary Grimmia lisae: Lisa’s Grimmia longirostris: North Grimmia montana: Sun Grimmia orbicularis: Round-fruited Grimmia ovalis: Flat-rock Grimmia pulvinata: Grey-cushioned Grimmia ramondii: Spreading-leaved Grimmia tergestina: Dapple-mouthed Grimmia torquata: Twisted Grimmia trichophylla: Hair-pointed Grimmia ungeri: Unger’s Grimmia unicolor: Dingy Grimmia Gymnostomum aeruginosum: Verdigris Tufa-moss calcareum: Blunt-leaf Tufa-moss viridulum: Luisier’s Tufa-moss Gyroweisia reflexa: Reflexed Beardless-moss tenuis: Slender Stubble-moss Habrodon perpusillus: Lesser Squirrel-tail Moss Hamatocaulis vernicosus: Varnished Hook-moss Hedwigia ciliata var. ciliata: Fringed Hoar-moss ciliata var. leucophaea: Dusky Hoar-moss integrifolia: Green Hoar-moss stellata: Starry Hoar-moss Helodium blandowii: Blandow’s Tamarisk-moss Hennediella heimii: Heim’s Pottia macrophylla: Short Pottia stanfordensis: Stanford Screw-moss Herzogiella seligeri: Silesian Feather-moss striatella: Muhlenbeck’s Feather-moss Heterocladium dimorphum: Dimorphous Tamarisk-moss flaccidum: Slender Tamarisk-moss heteropterum: Wry-leaved Tamarisk-moss wulfsbergii: Wulfsberg’s Tamarisk-moss Homalia trichomanoides: Blunt Feather-moss Homalothecium lutescens: Yellow Feather-moss sericeum: Silky Wall Feather-moss

953

954

English names

Homomallium incurvatum: Incurved Feather-moss Hookeria lucens: Shining Hookeria Hygroamblystegium fluviatile: Brook-side Feather-moss tenax: Fountain Feather-moss Hygrohypnum duriusculum: Broad-leaved Brook-moss eugyrium: Western Brook-moss luridum var. luridum: Drab Brook-moss luridum var. subsphaericarpon: Fat-fruit Brook-moss molle: Soft Brook-moss ochraceum: Claw Brook-moss polare: Polar Brook-moss smithii: Arctic Brook-moss styriacum: Snow Brook-moss Hylocomium splendens: Glittering Wood-moss Hylocomiastrum pyrenaicum: Oake’s Wood-moss Hylocomiastrum umbratum: Shaded Wood-moss Hymenostylium insigne: Robust Tufa-moss recurvirostrum: Hook-beak Tufa-moss Hyocomium armoricum: Flagellate Feather-moss Hypnum andoi: Mamillate Plait-moss bambergeri: Golden Plait-moss callichroum: Downy Plait-moss cupressiforme: Cypress-leaved Plait-moss hamulosum: Hook-leaved Plait-moss imponens: Pellucid Plait-moss jutlandicum: Heath Plait-moss lacunosum var. lacunosum: Great Plait-moss lacunosum var. tectorum: Roof Plait-moss resupinatum: Supine Plait-moss revolutum: Revolute Plait-moss uncinulatum: Hooked Plait-moss vaucheri: Vaucher’s Plait-moss Isopterygiopsis muelleriana: Mueller’s Silk-moss pulchella: Neat Silk-moss Isothecium alopecuroides: Larger Mouse-tail Moss holtii: Holt’s Mouse-tail Moss myosuroides var. brachythecioides: Thicker Mouse-tail Moss myosuroides var. myosuroides: Slender Mouse-tail Moss Kiaeria blyttii: Blytt’s Fork-moss falcata: Sickle-leaved Fork-moss glacialis: Snow Fork-moss starkei: Starke’s Fork-moss Kindbergia praelonga: Common Feather-moss Leptobarbula berica: Beric Beard-moss

English names Leptobryum pyriforme: Golden Thread-moss Leptodictyum riparium: Kneiff’s Feather-moss Leptodon smithii: Prince-of-Wales Feather-moss Leptodontium flexifolium: Bent-leaved Beard-moss gemmascens: Thatch-moss Leptohascum leptophyllom: Vectis-moss Leptophylum gaudichaudii: Gaudichaud’s Slender-fruited Moss Lescuraea saxicola: Rock Feather-moss Leskea polycarpa: Many-fruited Leskea Leucobryum glaucum: Large White-moss juniperoideum: Smaller White-moss Leucodon sciuroides var. morensis: Larger Squirrel-tail Moss sciuroides var. sciuroides: Squirrel-tail Moss Loeskeobryum brevirostre: Short-beaked Wood-moss Meesia triquetra: Three-ranked Hump-moss uliginosa: Broad-nerved Hump-moss Microbryum curvicolle: Swan-necked Earth-moss floerkeanum: Floerke’s Phascum. rectum: Upright Pottia Micromitrium tenerum: Millimetre Moss Mielichhoferia elongata: Elongate Copper-moss mielichhoferiana: Alpine Copper-moss Mnium ambiguum: Ambiguous Thyme-moss hornum: Swan’s-neck Thyme-moss marginatum var. dioicum: Stream Thyme-moss marginatum var. marginatum: Bordered Thyme-moss spinosum: Spinose Thyme-moss stellare: Starry Thyme-moss thomsonii: Short-beaked Thyme-moss Molendoa warburgii: Warburg’s Moss Myrinia pulvinata: Flood-moss Myurella julacea: Small Mouse-tail Moss tenerrima: Dwarf Mouse-tail Moss Myurium hochstetteri: Hare-tail Moss Neckera complanata: Flat Neckera crispa: Crisped Neckera pennata: Feathered Neckera pumila: Dwarf Neckera Octodiceras fontanum: Fountain Pocket-moss Oedipodium griffithianum: Gouty-moss Oligotrichum hercynicum: Hercynian Haircap Oncophorus virens: Green Spur-moss wahlenbergii: Wahlenberg’s Spur-moss Oreoweisia bruntonii: Brunton’s Dog-tooth

955

956

English names

Orthodontium gracile: Slender Thread-moss lineare: Cape Thread-moss Orthothecium intricatum: Fine-leaved Leskea rufescens: Red Leskea Orthotrichum affine: Wood Bristle-moss anomalum: Anomalous Bristle-moss consimile: Mitten’s Bristle-moss cupulatum var. cupulatum: Hooded Bristle-moss diaphanum: White-tipped Bristle-moss gymnostomum: Aspen Bristle-moss lyellii: Lyell’s Bristle-moss obtusifolium: Blunt-leaved Bristle-moss pallens: Pale Bristle-moss pulchellum: Elegant Bristle-moss pumilum: Dwarf Bristle-moss rivulare: River Bristle-moss rupestre: Rock Bristle-moss shawii: Shaw’s Bristle-moss speciosum: Showy Bristle-moss sprucei: Spruce’s Bristle-moss stramineum: Straw Bristle-moss striatum: Smooth Bristle-moss tenellum: Slender Bristle-moss Oxyrrhynchium hians: Swartz’s Feather-moss schleicheri: Twist-tip Feather-moss speciosum: Showy Feather-moss Paludella squarrosa: Tufted Fen-moss Palustriella commutata var. commutata: Curled Hook-moss commutata var. sulcata: Lawers Hook-moss decipiens: Lesser Curled Hook-moss falcata: Claw-leaved Hook-moss Paraleptodontium recurvifolium: Drooping-leaved Beard-moss Paraleucobryum longifolium: Long-leaved Fork-moss Phascum cuspidatum var.cuspidatum: Cuspidate Earth-moss cuspidatum var. papillosum: Rough Earth-moss cuspidatum var. piliferum: Bearded Earth-moss cuspidatum var. schreberianum: Schreberian Earth-moss Philonotis arnellii: Arnell’s Apple-moss caespitosa: Tufted Apple-moss calcarea: Thick-nerved Apple-moss cernua: Swan-necked Apple-moss fontana: Fountain Apple-moss marchica: Bog Apple-moss

English names rigida: Rigid Apple-moss seriata: Spiral Apple-moss tomentella: Woolly Apple-moss Physcomitrium eurystomum: Norfolk Bladder-moss pyriforme: Common Bladder-moss sphaericum: Dwarf Bladder-moss Pictus scoticus: Pict-moss Plagiobryum demissum: Alpine Hump-moss zieri: Zierian Hump-moss Plagiomnium affine: Many-fruited Thyme-moss cuspidatum: Woodsy Thyme-moss elatum: Tall Thyme-moss ellipticum: Marsh Thyme-moss medium: Alpine Thyme-moss rostratum: Long-beaked Thyme-moss undulatum: Hart’s-tongue Thyme-moss Plagiopus oederianus: Oeder’s Apple-moss Plagiothecium cavifolium: Round Silk-moss curvifolium: Curved Silk-moss denticulatum var. denticulatum: Dented Silk-moss denticulatum var. obtusifolium: Donnian Silk-moss denticulatum var. undulatum: Swamp Silk-moss laetum: Bright Silk-moss latebricola: Alder Silk-moss nemorale: Woodsy Silk-moss piliferum: Hair Silk-moss platyphyllum: Alpine Silk-moss succulentum: Juicy Silk-moss undulatum: Waved Silk-moss Platydictya jungermannioides: Spruce’s Leskea Platygyrium repens: Flat-brocade Moss Platyhypnidium alopecuroides: Portuguese Feather-moss riparioides: Long-beaked Water Feather-moss Pleuridium acuminatum: Taper-leaved Earth-moss subulatum: Awl-leaved Earth-moss Pleurochaete squarrosa: Side-fruited Crisp-moss Pleurozium schreberi: Red-stemmed Feather-moss Pogonatum aloides: Aloe Haircap nanum: Dwarf Haircap urnigerum: Urn Haircap Pohlia andalusica: Roth’s Thread-moss annotina: Pale-fruited Thread-moss bulbifera: Blunt-bud Thread-moss

957

958

English names

camptotrachela: Crookneck Nodding-moss cruda: Opal Thread-moss crudoides: Lapland Thread-moss drummondii: Drummond’s Thread-moss elongata var. elongata: Long-fruited Thread-moss elongata var. polymorpha: Changeable Thread-moss filum: Fat-bud Thread-moss flexuosa: Orange-bud Thread-moss lescuriana: Pretty Nodding-moss ludwigii: Ludwig’s Thread-moss lutescens: Yellow Thread-moss melanodon: Pink-fruited Thread-moss nutans: Nodding Thread-moss obtusifolia: Blunt-leaved Thread-moss proligera: Bent-bud Thread-moss scotica: Scottish Thread-moss wahlenbergii var. calcarea: Chalk Thread-moss wahlenbergii var. glacialis: Mountain Thread-moss wahlenbergii var. wahlenbergii: Pale Glaucous Thread-moss Polytrichastrum alpinum: Alpine Haircap formosum: Bank Haircap longisetum: Slender Haircap sexangulare: Northern Haircap Polytrichum commune var. commune: Common Haircap commune var. humile: Clustered Haircap commune var. perigoniale: Dense Haircap juniperinum: Juniper Haircap piliferum: Bristly Haircap strictum: Strict Haircap Pottia davalliana: Smallest Pottia starckeana ssp. starckeana: Starke’s Pottia Pottiopsis caespitosa: Round-fruited Pottia Protobryum bryoides: Tall Pottia Pseudephemerum nitidum: Delicate Earth-moss Pseudobryum cinclidioides: River Thyme-moss Pseudocalliergon lycopodioides: Large Hook-moss trifarium: Three-ranked Spear-moss turgescens: Turgid Scorpion-moss Pseudocrossidium hornschuchianum: Hornschuch’s Beard-moss revolutum: Revolute Beard-moss Pseudoleskea incurvata: Brown Mountain Leskea patens: Patent Leskea Pseudoleskiella catenulata: Chained Leskea

English names nervosa: Nerved Leskea rupestris: Wispy Leskea sibirica: Siberian Leskea Pseudoscleropodium purum: Neat Feather-moss Pseudotaxiphyllum elegans: Elegant Silk-moss Pterigynandrum filiforme var. filiforme: Capillary Wing-moss Pterigynandrum filiforme var. majus: Blunt Wing-moss Pterogonium gracile: Bird’s-foot Wing-moss Pterygoneurum lamellatum: Spiral Chalk-moss ovatum: Oval-leaved Pottia Ptilium crista-castrensis: Ostrich-plume Feather-moss Ptychodium plicatum: Plaited Leskea Ptychomitrium polyphyllum: Long-shanked Pincushion Pylaisia polyantha: Many-flowered Leskea Racomitrium aciculare: Yellow Fringe-moss affine: Lesser Fringe-moss aquaticum: Narrow-leaved Fringe-moss canescens: Hoary Fringe-moss ellipticum: Oval-fruited Fringe-moss elongatum: Long Fringe-moss ericoides: Dense Fringe-moss fasciculare: Green Mountain Fringe-moss heterostichum: Bristly Fringe-moss himalayanum: Himalayan Fringe-moss lanuginosum: Woolly Fringe-moss macounii ssp. alpinum: Macoun’s Fringe-moss sudeticum [affine sensu A. J. E. Smith 1978]: Slender Fringe-moss Rhabdoweisia crenulata: Greater Streak-moss crispata: Toothed Streak-moss fugax: Dwarf Streak-moss Rhizomnium magnifolium: Large-leaf Thyme-moss pseudopunctatum: Felted Thyme-moss punctatum: Dotted Thyme-moss Rhodobryum roseum: Rose-moss Rhynchostegiella curviseta: Curve-stalked Feather-moss litorea: Scabrous Feather-moss pumila: Dwarf Feather-moss tenella: Tender Feather-moss teneriffae: Teesdale Feather-moss Rhynchostegium confertum: Clustered Feather-moss megapolitanum: Indian-feather-moss murale: Wall Feather-moss rotundifolium: Round-leaved Feather-moss

959

960

English names

Rhytidiadelphus loreus: Little Shaggy-moss squarrosus: Springy Turf-moss subpinnatus: Scarce Turf-moss triquetrus: Big Shaggy-moss Rhytidium rugosum: Wrinkle-leaved Feather-moss Saelania glaucescens: Blue Dew-moss Sanionia orthothecioides: St Kilda Hook-moss uncinata: Sickle-leaved Hook-moss Schistidium agassizii: Water Grimmia apocarpum [agg.]: Sessile Grimmia atrofuscum: Black Mountain Grimmia confertum: Compact Grimmia crassipilum: Thickpoint Grimmia dupretii: Dupret’s Grimmia elegantulum ssp. elegantulum: Elegant Grimmia elegantulum ssp. wilsonii: Wilson’s Grimmia flaccidum: Goblet Grimmia frigidum: Frigid Grimmia maritimum: Seaside Grimmia papillosum: Rough Grimmia platyphyllum: Broadleaf Grimmia pruinosum: Mealy Grimmia rivulare: River Grimmia robustum: Robust Grimmia strictum: Upright Brown Grimmia trichodon: Stook Grimmia Schistostega pennata: Luminous Moss Scleropodium cespitans: Tufted Feather-moss tourettii: Glasswort Feather-moss Scopelophila cataractae: Tongue-leaf Copper-moss Scorpidium cossonii: Intermediate Hook-moss revolvens: Rusty Hook-moss scorpioides: Hooked Scorpion-moss Scorpiurium circinatum: Curving Feather-moss Seligeria acutifolia: Sharp Rock-bristle brevifolia: Short Rock-bristle calcarea: Chalk Rock-bristle calycina: English Rock-bristle campylopoda: Bentfoot Rock-bristle carniolica: Water Rock-bristle diversifolia: Long Rock-bristle donniana: Donn’s Rock-bristle oelandica: Irish Rock-bristle

English names patula: Outspread Rock-bristle pusilla: Dwarf Rock-bristle recurvata: Recurved Rock-bristle trifaria: Trifid Rock-bristle Sematophyllum demissum: Prostrate Signal-moss micans: Sparkling Signal-moss substrumulosum: Bark Signal-moss Sphagnum affine: Imbricate Bog-moss angustifolium: Fine Bog-moss austinii: Austin’s Bog-moss balticum: Baltic Bog-moss capillifolium ssp. capillifolium: Acute-leaved Bog-moss capillifolium ssp. rubellum: Red Bog-moss compactum: Compact Bog-moss contortum: Twisted Bog-moss cuspidatum: Feathery Bog-moss denticulatum: Cow-horn Bog-moss fallax: Flat-topped Bog-moss fimbriatum: Fringed Bog-moss flexuosum: Flexuous Bog-moss fuscum: Rusty Bog-moss girgensohnii: Girgensohn’s Bog-moss inundatum: Lesser Cow-horn Bog-moss lindbergii: Lindberg’s Bog-moss magellanicum: Magellanic Bog-moss majus: Olive Bog-moss molle: Blushing Bog-moss obtusum: Obtuse Bog-moss palustre var. centrale: Enclosed Bog-moss palustre var. palustre: Blunt-leaved Bog-moss papillosum: Papillose Bog-moss platyphyllum: Flat-leaved Bog-moss pulchrum: Golden Bog-moss quinquefarium: Five-ranked Bog-moss riparium: Cleft Bog-moss russowii: Russow’s Bog-moss skyense: Skye Bog-moss squarrosum: Spiky Bog-moss strictum: Pale Bog-moss subnitens var. ferrugineum: Brownish Bog-moss subnitens var. subnitens: Lustrous Bog-moss subsecundum: Slender Cow-horn Bog-moss tenellum: Soft Bog-moss

961

962

English names

teres: Rigid Bog-moss warnstorfii: Warnstorf’s Bog-moss Splachnum ampullaceum: Cruet Collar-moss sphaericum: Round-fruited Collar-moss vasculosum: Rugged Collar-moss Stegonia latifolia: Hood-leaved Screw-moss Straminergon stramineum: Straw Spear-moss Syntrichia amplexa: Clay Screw-moss intermedia: Intermediate Screw-moss laevipila: Small Hairy Screw-moss latifolia: Water Screw-moss norvegica: Norway Screw-moss papillosa: Marble Screw-moss princeps: Brown Screw-moss ruralis var. ruraliformis: Sandhill Screw-moss ruralis var. ruralis: Great Hairy Screw-moss virescens: Lesser Screw-moss Taxiphyllum wissgrillii: Depressed Feather-moss Tayloria lingulata: Tongue-leaved Gland-moss tenuis: Slender Gland-moss Tetraphis pellucida: Pellucid Four-tooth Moss Tetraplodon angustatus: Narrow Cruet-moss mnioides: Slender Cruet-moss Tetrodontium brownianum: Brown’s Four-tooth Moss repandum: Small Four-tooth Moss Thamnobryum alopecurum: Fox-tail Feather-moss angustifolium: Derbyshire Feather-moss cataractarum: Yorkshire Feather-moss Thuidium assimile: Philibert’s Tamarisk-moss delicatulum: Delicate Tamarisk-moss recognitum: Lesser Tamarisk-moss tamariscinum: Common Tamarisk-moss Timmia austriaca: Sheathed Timmia megapolitana: Indian-feather Moss norvegica: Norway Timmia Tomentypnum nitens: Woolly Feather-moss Tortella densa: Clint Crisp-moss flavovirens var. flavovirens: Yellow Crisp-moss flavovirens var. glareicola: Gravel Crisp-moss fragilis: Brittle Crisp-moss inclinata: Bent Crisp-moss inflexa: Sassari Crisp-moss limosella: Arisaig Crisp-moss

English names nitida: Neat Crisp-moss tortuosa: Frizzled Crisp-moss Tortula atrovirens: Rib-leaf Moss canescens: Dog Screw-moss cernua: Flamingo-moss cuneifolia: Wedge-leaved Screw-moss freibergii: Freiberg’s Screw-moss lanceola: Lance-leaved Pottia leucostoma: Alpine Pottia marginata: Bordered Screw-moss modica: Blunt-fruited Pottia muralis var. aestiva: Summer Screw-moss muralis var. muralis: Wall Screw-moss solmsii: Solms’ Screw-moss subulata var. angustata: Upright Screw-moss subulata var. graeffii: Graeff’s Screw-moss subulata var. subinermis: Spathulate Screw-moss subulata var. subulata: Awl-leaved Screw-moss truncata: Common Pottia vahliana: Chalk Screw-moss viridifolia: Bristly Pottia wilsonii: Wilson’s Pottia Trematodon ambiguus: Ambiguous Long-necked Moss Trichodon cylindricum: Cylindric Ditrichum Trichostomum brachydontium: Variable Crisp-moss crispulum: Curly Crisp-moss hibernicum: Irish Crisp-moss tenuirostre: Narrow-fruited Crisp-moss tenuirostre var. holtii: Holt’s Crisp-moss Ulota bruchii: Bruch’s Pincushion calvescens: Balding Pincushion coarctata: Club Pincushion crispa: Crisped Pincushion drummondii: Drummond’s Pincushion hutchinsiae: Hutchins’ Pincushion phyllantha: Frizzled Pincushion Warnstorfia exannulata: Ringless Hook-moss fluitans: Floating Hook-moss sarmentosa: Twiggy Spear-moss Weissia brachycarpa var. brachycarpa: Small-mouthed Beardles moss brachycarpa var. obliqua: Oblique-mouthed Beardless-moss condensa: Curly Beardless-moss controversa var. controversa: Green-tufted Stubble-moss

963

964

English names

controversa var. crispata: Crisped Stubble-moss controversa var. densifolia: Thick-leaved Earth-moss controversa var. wimmeriana: Wimmer’s Stubble-moss levieri: Levier’s Beardless-moss longifolia var. angustifolia: Narrow-leaved Beardless-moss longifolia var. longifolia: Crisp Beardless-moss × mittenii: Mitten’s Beardless-moss multicapsularis: Many-fruited Beardless-moss perssonii: Persson’s Stubble-moss rostellata: Beaked Beardless-moss rutilans: Pointed-leaved Stubble-moss squarrosa: Spreading-leaved Beardless-moss sterilis: Sterile Beardless-moss Zygodon conoideus var. conoideus: Lesser Yoke-moss conoideus var. lingulatus: Tongue-leaved Yoke-moss forsteri: Knothole Yoke-moss gracilis: Slender Yoke-moss rupestris: Park Yoke-moss stirtonii: Stirton’s Yoke-moss viridissimus: Green Yoke-moss

Glossary

abaxial The dorsal side of a leaf (i.e. underside), the side away from the stem when the leaf is folded upwards against the stem. acrocarpous Mosses in which the gametophyte usually produces sporophytes at the apex of stems or main branches with further vegetative growth continued by lateral branch(es) or innovation(s). Acrocarpous mosses usually form turfs or cushions or occur as scattered individuals. acumen Tapering apex of leaf, with angle at apex less than 15◦; adj., acuminate (Fig. 318, 5). acute Sharp point with an angle of 15–90◦ (Fig. 318, 4). adaxial The ventral side (i.e. upper side), the side facing the stem when the leaf is folded upwards. agg., aggregate A group of closely related species previously considered to be a single species from which the aggregate derives its name (e.g. the Hypnum cupressiforme agg. is now thought to consist of six closely related species including H. cupressiforme s.s.). alar cells at basal angles of leaf, sometimes referred to as angular cells (Figs. 259, 3; 291, 2). amphithecium Outer tissue of a sporophyte embryo giving rise to all the tissues of the capsule except the columella in the Sphagnopsida, and to the outer layers and outer wall of the spore sac in other mosses. angular cells Alar cells, cells at basal angles of leaf. annulus Ring(s) of cells at mouth of capsule associated with dehiscence of lid; adj., annular. antheridium (pl. antheridia) Male gametangium, structure containing male gametes, ± spherical in the Sphagnopsida, fusiform to cylindrical in other mosses. apical lamina In the Fissidentales, that part of the leaf extending beyond the sheathing lamina (Fig. 73, 3b). apiculus Short abrupt point (Fig. 318, 3); adj., apiculate. apogamy The production of a haploid sporophyte from an egg cell without fusion between it and a male gamete; adj., apogamous. appendiculate With transverse bars (Fig. 179, 10). appressed Pressed upwards against stem.

965

966

Glossary

Fig. 317 1–5, Distribution of gametangia: 1 and 2, dioicous; 3, autoicous; 4, paroicous; 5, synoicous. 6–11, leaf postures: 6, erect; 7, erect-patent; 8, patent; 9, spreading; 10, recurved; 11, squarrose. 12–21, leaf shape: 12, orbicular; 13, ovate; 14, elliptical; 15, oblong; 16, lanceolate; 17, linear; 18, lingulate; 19, ligulate; 20, spathulate; 21, panduriform. 22–27, leaf margins: 22, entire; 23, crenulate; 24, papillose-crenulate; 25, papillose; 26, denticulate, serrulate; 27, dentate, serrate.

Glossary

967

Fig. 318 1–9, leaf apices: 1, rounded; 2, obtuse; 3, obtuse and apiculate; 4, acute; 5, acuminate; 6, cuspidate; 7, subulate; 8, setaceous; 9, emarginate. 10–15, leaf margins as seen in section: 10, plane; 11, recurved; 12, revolute; 13, inflexed; 14, incurved; 15, involute. 16–26, cell shape: 16, quadrate; 17, rectangular; 18, hexagonal; 19, rounded; 20, rhomboidal; 21, linear; 22, linear, vermicular; 23, rectangular, sinuose; 24, rounded, papillose; 25, rectangular, porose; 26, rounded, lax. 27–35 capsules: 27, erect, cylindrical; 28, inclined, ellipsoid; 29, ovoid; 30, obloid; 31, globose; 32, horizontal, cylindrical, curved; 33, cernuous, narrowly pyriform; 34, pendulous, pyriform; 35, inclined, gibbous, strumose. 36–41, capsule lids: 36, subulate; 37, rostrate; 38, rostellate; 39, mamillate; 40, conical; 41, convex.

968

Glossary

archegonium (pl. archegonia) The female gametangium, a flask-shaped structure consisting of a swollen basal part or venter, containing the egg cell, and a tubular upper part or neck. archesporium Tissue in the spore sac from which spore mother cells are derived. arcuate Curved (Fig. 154, 12); of capsules, curved like a bow (Fig. 318, 32). areolation The pattern or form and arrangement of cells. arista Fine bristle-like point; adj., aristate. arthrodontous With reference to mosses having articulate peristome teeth. articulations Thickened joints between the segments of the peristome teeth of arthrodontous mosses (Fig. 174, 4); adj., articulate. ascending Growing upwards at an angle from the substrate. Latitude because of proximity of the sea. auct Abbreviation for auctor(es), meaning author(s) who applied a name to a plant differing from that intended by the original author(s). auricle A group of enlarged or otherwise differentiated alar cells at each corner of a leaf base forming a distinctive group (Fig. 259, 3; 291, 2); adj., auricular. auriculate Having auricles. autoecious A term used by some authorities for autoicous but considered inappropriate for the situation in haploid gametophytes as it applies strictly only to sporophytic or diploid sexuality. autoicous Having antheridia and archegonia borne on different branches of the same plant (Fig. 317, 3). axil The upper angle formed between an axis and a leaf; adj., axillary. axillary hairs Uniseriate hairs in axils, usually of the uppermost leaves. basal membrane Cylinder of tissue at base of the endostome bearing processes (endostome teeth) and cilia. beak Projection from lid of a capsule. bifid Divided into two ± equal parts. biflagellate With two flagella. bipinnate Twice-pinnately branched. bistratose Two cells thick. blade Flat green portion of a leaf, differentiated or not from basal part of leaf. body That part of the capsule (theca or urn) containing the spore sac, distinct from the neck or hypophysis. border Of leaves, margins differentiated in structure or cell shape from the rest of the leaf (Fig. 206, 6); or peristome teeth, having a narrow pale margin (Fig. 46, 9); adj., bordered. boreal Pertaining to the cool or cold regions of the Northern Hemisphere. bract Leaf-like structure, similar to or differentiated from vegetative leaves, associated with gametangia; cf. perichaetial and perigonial bracts. bulbiform Bulb-like; a rosette of leaves imbricate to form a bulb-like plant.

Glossary

969

bulbil Bulb-like vegetative propagule often with apical and sometimes lateral projections or ‘leaf primordia’ (Fig. 199); adj., bulbilliferous. C-shaped papilla Crescent-shaped papilla. caducous Readily falling off, usually referring to vegetative propagules in the form of leaflets or branchlets. caespitose Tufted. calcicole Plant of basic habitats such as limestone or chalk; adj., calcicolous. calcifuge Plants of acidic habitats, intolerant of base. calyptra (pl. calyptrae) Structure developed from the venter of the archegonium covering a developing capsule and at least the lid of older capsules, falling or not as capsule matures. campanulate Bell-shaped. capitulum Mass of crowded branches at the apex of the stems of Sphagnum. capsule The spore-bearing structure or sporangium of the moss sporophyte, usually differentiated into capsule body or theca and sterile basal part or neck. carinate Keeled, with a V-shaped channel in transverse section. cartilaginous Thick and tough, of a border of incrassate elongate cells. catenulate Chain-like. central strand Column of elongate cells, thin-walled in transverse section, running through the centre of a stem. cernuous Drooping at an angle between horizontal and vertically downwards (Fig. 318, 33). channelled With reference to leaves, with a U-shaped groove formed by upturned margins. chlorocyst Green photosynthetic cell in Sphagnum leaf. chlorophyllous Containing chloroplasts. cilia Uniseriate hair-like structures alternating with processes of the inner peristome; adj., ciliate. circinate Very strongly curved and ± forming a circle (Fig. 308, 5). circumboreal Distributed round northern boreal regions. cladocarpous The situation in pleurocarpous mosses where the archegonia are borne terminally on short branches rather than dwarf lateral branches. clavate Usually of gemmae, club-shaped (Fig. 211, 10). cleistocarpous Pertaining to capsules that do not dehisce; spores are released by rupture or decay of the capsule wall. clone A population of genetically uniform plants produced by vegetative propagation (e.g. Atrichum crispum in the British Isles). cochleariform Very concave, like a spoon. collenchymatous With walls more heavily thickened at the corners than elsewhere. columella The central dome or column of sterile tissue in the centre of the moss capsule. coma Group of more crowded, usually larger leaves, at stem apex; adj., comal.

970

Glossary

commissural pores Pores situated along the commissures in Sphagnum leaves. commissure In Sphagnum, the junction between hyaline and green cells. complanate Of leaves or branches, arranged ± in one plane (Fig. 74, 7). concolourous Of uniform colour throughout. conduplicate Folded together face to face, as with the two portions of the sheathing lamina of the Fissidentales leaf (Fig. 74, 2). confervoid Fine and wispy. confluent Merging together. conical Cone-shaped (Fig. 318, 40). conspecific Belonging to the same species. constricted Narrowed, often abruptly. convolute Clasping, enfolding, sheathing. copprophilous Occurring on dung or decaying animal remains cordate Heart-shaped. coriaceous Of a leathery texture. cortex In mosses the layer of cell(s) between the epidermis and the central strand; in Sphagnum the outer layer of thin-walled cells around the cells of the central strand of stems and branches; adj., cortical. corticolous Growing on bark. costa Midrib or nerve of leaf, always more than one cell thick; adj., costate. crenate With rounded teeth. crenulum (pl. crenulae) Minute rounded projection usually formed from bulging cell wall (Fig. 317, 23); adj., crenulate. cribrose With numerous perforations (Fig. 125, 5). crisped Strongly curled and twisted (Fig. 225, 1). cucullate Of calyptrae, hood-shaped and split down one side (Fig. 165, 15); of leaves, hooded at the apex by incurving of the margins (Fig. 3, 1; 86, 5). cuneate Wedge-shaped. cupruliferous Occurring on a copper-bearing substrate. cushion A ± hemispherical life-form in which the shoots radiate from a central point (e.g. Grimmia pulvinata). cuspidate Of leaves, with a thick point formed by stout excurrent costa (Fig. 318, 6); of stems, with a bud-like apex formed by imbricate concave leaves. cygneous Strongly curved in the upper part like a swan’s neck (Fig. 68, 4). cylindrical Cylinder-shaped (Fig. 318, 27). deciduous Falling, being lost at maturity. decumbent Prostrate with ascending tips. decurrent The basal angles or alar cells of a leaf running down the stem, sometimes forming wings (Fig. 291, 2). dehisce Open by loss of lid or opening of valves; adj., dehiscent. dendroid Having a life-form like a miniature tree (e.g. Thamnobryum alopecurum).

Glossary

971

dentate Strongly toothed, teeth usually composed of two or more cells (Fig. 317, 27). denticulate Finely toothed, teeth usually composed of only part of a cell projecting from leaf margin (Fig. 317, 26). denuded Eroded or torn away. depauperate Small, stunted, poorly developed. dextrorsely Twisted clockwise when viewed from above. diaphanous Colourless and transparent. dichotomous Regularly branching in a Y-like fashion with each branch of a pair of ± equal size. dimorphic Of two shapes or sizes. dioecious A term used by some authorities for dioicous but considered inappropriate for the situation in haploid gametophytes as it applies strictly only to sporophytic or diploid sexuality. dioicous Antheridia and archegonia borne on different plants (Fig. 317, 1). diploid Having two sets of chromosomes. diplolepideous With a double articulated peristome, i.e. with two concentric rows of articulated teeth. disciform Saucer-shaped. discoid Of gemmae, disc-shaped and thickest in the middle (Fig. 38, 4). distal End or portion furthest from base or point of origin. distant Well spaced, not crowded. distichous Of branches or leaves, in two ranks, one on either side of the stem (Fig. 45, 1). divergent Spreading away from. dorsal With reference to leaves, the abaxial side (i.e. underside). dorsal lamina In the Fissidentales, that part of the leaf opposite the sheathing lamina, on the abaxial side of the costa (Fig. 73, 3c). ecostate Without a costa. ellipsoid The three-dimensional equivalent of elliptical (Fig. 318, 28). elliptical Symmetrical shape with convex sides (Fig. 317, 14). emarginate With a small indentation at the apex (Fig. 318, 9). emergent Partially emerging above perichaetial leaves. endemic Limited to a single country or geographical area. endostome Inner ring of teeth or processes of the double peristome of diplolepideous mosses. endothecium Inner core of cells of a sporophyte embryo giving rise to the columella in the Sphagnopsida, and to the archesporium, inner spore sac and columella of other mosses. entire Smooth, without papillae, crenulae or teeth (Fig. 317, 22). ephemeral Short-lived. epilith Plant growing on rock; adj., epilithic.

972

Glossary

epiphragm Circular membrane at the mouth of a capsule, attached to tips of peristome teeth or mouth of capsule, derived from the top of the columella. epiphytic Growing on another plant, usually on bark. erect Of leaves, pointing upwards but not pressed against the stem (Fig. 317, 6); of branches, growing parallel to main stem or vertically upwards; of margins, curved upwards; of capsules, upright (Fig. 318, 27). erect-patent Pointing upwards at an angle of about 20–45◦ to the stem (Fig. 317, 7). eroded Worn away. erose Irregularly notched or partially eroded away. esinuose Not sinuose. eutrophic Rich in mineral nutrients. excavate Of auricles with a concave group of cells. excurrent Of costae, projecting beyond the end of the lamina (Fig. 109, 1). exostome Outer ring of teeth of a double peristome. exothecium Epidermis or superficial layer of cells of a capsule; adj., exothecial. exserted Carried well above the perichaetial leaves. falcate Curved like a sickle (Fig. 265, 1). falcate-secund Curved and pointing in one direction. fascicle A bunch or group of branches arising from a single point on the stem (Fig. 4, 1). fastigiate Branches erect and reaching ± the same height. fibril Fibre-like thickenings of the walls of hyaline cells in Sphagnum; adj., fibrillose. filamentous Thread-like. filiform Fine or thread-like. fimbriate Of Sphagnum leaves, fringed with the radiating walls of partially eroded marginal cells (Fig. 7, 1). flagelliform Of usually propaguliferous shoots, long and thin with small distant leaves (Fig. 296, 3). flaccid Soft, limp. flexuose Wavy, irregularly bent. foot Basal part of sporophyte embedded in gametophyte. fringed With a shortly ciliate margin or edge. fruit Colloquial term for sporophyte or capsule. fugacious Readily or quickly falling. fusiform Tapering at either end, spindle-shaped (Fig. 218, 16). gametangium (pl. gametangia) Structure containing gametes, i.e. antheridium and archegonium. gametophyte The haploid sexual phase of the moss life-cycle, the leafy plant. gemma (pl. gemmae) Vegetative propagule, brood body, borne on various parts of the gametophyte plant (Figs. 38, 4; 41, 9–12; 189, 5, 9, 13; 218, 16; 219, 5).

Glossary

973

gemma cup Cup-shaped structure, formed from rosette of modified leaves, containing gemmae. gemmiferous Bearing gemmae. gemmiform Bud-shaped. geniculate Sharply bent, as in a knee (Fig. 166, 4). gibbous Pertaining to asymmetrical capsules with the upper side swollen and larger than the lower side (Fig. 318, 35). gigas Exceptionally large. glabrous Smooth, not hairy. glaucous With whitish, greyish or bluish bloom. globose More or less spherical in shape (Fig. 318, 31). granulose Grainy, with minute blunt projections. green cells Of Sphagnum, the long narrow leaf cells containing chloroplasts and separating the hyaline cells. gregarious Growing close together but not crowded in turfs or mats. growth-form The genetically determined morphology of an individual moss plant (see life-form). guard cells The two epidermal cells surrounding the opening of a stoma (Fig. 219, 11). guide cells The large, elongate, thin-walled cells in the costa of many mosses (Figs. 64, 65). gymnostomous Without a peristome. habit Aspect or appearance of a plant. hair-point Fine, usually hyaline leaf tip, usually whitish when dry, formed by excurrent costa (Fig. 109, 1). halophyte A plant growing in a saline habitat, e.g. near the sea. haploid Having a single set of chromosomes. haplolepideous Of mosses having a single ring of articulated peristome teeth. heteroecious A term used by some authorities for heteroicous but considered inappropriate for the situation in haploid gametophytes as it applies strictly only to sporophytic or diploid sexuality. heteroicous With various arrangements of antheridia and archegonia in a single species. hexagonal Six-sided (Fig. 318, 18). hispid Rough with projecting papillae or mamillae. hoary Whitish or greyish in appearance. homomallous Pointing in one direction. hyaline Colourless and transparent when moist, usually white when dry. hyaline cells The large empty cells of Sphagnum leaves. hyaline point Usually colourless leaf apex, mostly whitish when dry, formed from the whole leaf apex as distinct from a hair-point, which is formed by an excurrent costa. hyalocyst Large empty water-storage cell in Sphagnum leaf.

974

Glossary

hyalodermis Differentiated outer layer of cells or epidermis of stems. hypophysis Sterile basal part of a capsule strongly differentiated from the body of the capsule. imbricate Of leaves, closely appressed and overlapping. immersed Of capsules, overtopped by the perichaetial leaves of stomata, sunken below the level of the exothecial cells of the capsule wall (Fig. 224, 3). imperfect peristome In haplolepideous mosses where the peristome teeth are poorly developed or truncate (Fig. 79, 8); in diplolepideous mosses where the endostome is absent or not fully developed. imperforate Of Sphagnum pores, pore-shaped wall thinnings not opening to the exterior. inclined Of capsules, inclined at an angle to the vertical of 20–60◦ (Fig. 318, 35). incrassate Of cells, with thick walls (Fig. 219, 7). incurved Of leaf margins, curved upwards and inwards (Fig. 318, 14). indehiscent Of capsules that do not shed a lid or open by slits. inflated Swollen, enlarged. inflexed Of leaf margins, turned upwards and inwards (Fig. 318, 13). inflorescence The structure composed of gametangia and surrounding bracts. innovation A new branch, usually arising from below an inflorescence. innovating Producing new branches. insertion Line of attachment of a leaf. involute Of margins, strongly rolled upwards and inwards (Fig. 318, 15). isodiametric Radially symmetrical, ± as long as wide. isophyllous Stem and branch leaves of similar shape or all leaves of a stem similar. julaceous Of stems and branches, cylindrical because of closely imbricate concave leaves. keeled Of leaves, sharply longitudinally folded like the keel of a boat, V-shaped in transverse section. KOH Potassium hydroxide; leaves are mounted in a 2% solution of potassium hydroxide and the resultant colouration observed. lacuna A hole; adj., lacunose. lamellae Flat plates of unistratose cells (Fig. 37, 6); adj., lamellate. lamina Blade of leaf as distinct from costa and/or differentiated basal part if present. lanceolate Shaped like the head of a spear, about three times as long as wide (Fig. 317, 16). lax Of cells, large with thin often bulging walls (Fig. 318, 26); of plants, with shoots loosely arranged. lid Operculum, dehiscent top of capsule. life-form The gross morphology of a moss colony resulting from the interaction between the genetically determined growth-form of the individual plants making up the colony and the environment.

Glossary

975

ligulate Strap-shaped, narrow and parallel-sided (Fig. 317, 19). limb Upper part of leaf when leaf is differentiated into green upper part and usually enlarged, often hyaline basal part. line Archaic unit of measurement used by Dixon & Jameson (1924), 1 inch (approximately 2 mm). representing 12 linear Of leaves, long and narrow like a grass leaf (Fig. 317, 17); of cells, long and narrow, more than six times as long as wide (Fig. 318, 21). lingulate Tongue-shaped, broad and ± parallel-sided (Fig. 317, 18). lithosol A stony shallow soil, composed of imperfectly weathered rock. longitudinal Parallel to the long axis. lumen Cell cavity. m-chromosomes Microchromosomes or small chromosomes, one half or less the size of the next smallest member of the complement, not to be confused with accessory chromosomes, which are of doubtful occurrence in mosses. macronema (pl. macronemata) Large branched rhizoids produced around branch primordia and at leaf insertions. mamilla (pl. mamillae) Protuberance from cell surface into which the lumen projects (Fig. 48, 20), in surface view indistinguishable from papillae; adj., mamillose. mamillate Convex or hemispherical with a short point (Fig. 318, 39). mat A life form composed of tightly interwoven stems and branches forming a flat patch adhering to the substrate with rhizoids; smooth mat with stems and branches in the same plane (e.g. Hypnum cupressiforme); rough mat, with short branches projecting upwards (e.g. Homalothecium sericeum). membrane gap An irregular opening in the walls of a hyaline cell of stem leaves of Sphagnum. mesotrophic Having intermediate levels of mineral nutrients. microphyllous Bearing minute leaves. micron, micrometre (μ μm) One-millionth of a metre, one-thousandth of a millimetre, referred to colloquially as mu. micronema (pl. micronemata) Thin rhizoids arising between the leaves. mid-leaf Position half way up leaf and midway between margin and costa or equivalent position if costa is lacking. midrib Costa. mitrate, mitriform Conical and without splits, like a bishop’s mitre (Fig. 166, 4). moniliform Consisting of a chain of cells like a string of beads. monoecious A term used by some authorities for monoicous but considered inappropriate for the situation in haploid gametophytes as it applies strictly only to sporophytic or diploid sexuality. monoicous Having antheridia and archegonia on the same plant. monopodial With the main stem of unlimited growth, the situation characteristic of pleurocarpous mosses.

976

Glossary

monotypic With only one taxon; e.g. a monotypic genus contains only a single species. morphology General appearance or structure of a plant; adj. morphological. mucro An abrupt relatively broad short point at a leaf apex; adj., mucronate. multifid Divided many times. muticous Lacking a hyaline point, often of lower leaves when a hyaline point is present in upper leaves. n The functionally haploid chromosome number of the gametophyte, as opposed to x, the basic number; n may equal x or it may be a multiple of it in polyploid plants. Where a number such as n = 10 + m is given, +m indicates the presence of a microchromosome. naked Hairless. neck Of capsules, the sterile portion at the base of a capsule between the body of the capsule and the top of the seta; of retort cells in Sphagnum, a projection from the surface of a cell terminating in a pore. nematodontous Peristomes with solid non-articulated teeth. nodulose With bead-like thickenings (Fig. 146, 14); of cilia, with bead-like thickenings corresponding in position to the articulations of the processes. obclavate Inverted club-shaped. obcuneate Inverted wedge-shaped. oblanceolate As lanceolate but widest above the middle. oblate Wider than long. obloid Three-dimensional equivalent of oblong, but with reference to capsules with rounded edges and corners (Fig. 318, 30). oblong Rectangular, but with reference to leaves, with rounded corners (Fig. 317, 15). obovate Egg-shaped in outline but widest above the middle. obscure Indistinct, difficult to see. obsolete Almost absent. obtuse Bluntly pointed, angle formed by apex more than 90◦ (Fig. 318, 2). ochrea Cylinder of thin tissue surrounding the base of the seta derived from the top of the venter of the archegonium. (Fig. 221, 6). oligotrophic Having low levels of nutrients. ombrotrophic Obtaining water and nutrients mainly from precipitation. opaque Not transparent. operculum Lid of capsule; adj., operculate. orbicular More or less circular in outline (Fig. 317, 12). outer peristome The outer ring of teeth of a double peristome, the exostome. ovate Egg-shaped in outline and widest below the middle, about twice as long as wide (Fig. 317, 13). ovoid Egg-shaped, a three dimensional shape about twice as long as wide (Fig. 318, 29). paludal Growing in marshy places.

Glossary

977

panduriform Shaped like the body of a violin (Fig. 317, 21). papilla (pl. papillae) Solid projection from cell surfaces (Figs. 317, 25; 318, 24) adj., papillose. paraphyllia Minute filamentous to leaf-like or variously divided structures between the leaves on stems of some pleurocarpous mosses (Fig. 249, 4). paraphyses Uniseriate hairs mixed with antheridia and archegonia. parenchymatous More-or-less hexagonal cells with uniformly thin walls. paroecious A term used by some authorities for paroicous but considered inappropriate for the situation in haploid gametophytes as it applies strictly only to sporophytic or diploid sexuality. paroicous Having antheridia in the axils of the leaves immediately below the perichaetium (Fig. 317, 4). patent At an angle to the stem of ca 45◦ (Fig. 317, 9). pellucid Translucent, clear. peltate Umbrella-shaped. pendent Hanging. pendulous Hanging downwards (Fig. 318, 34). percurrent Extending to the apex (Fig. 121, 7). perfect peristome In haplolepideous mosses with the peristome teeth fully developed; in diplolepideous mosses with both the exostome and endostome fully developed. perichaetium A structure usually composed of modified leaves (perichaetial bracts) surrounding or enclosing the archegonia; the female ‘inflorescence’. perigonium A structure composed of frequently modified leaves (perigonial bracts) surrounding or enclosing the antheridia; the male ‘inflorescence’. peristome The single or double ring of teeth at the mouth of a capsule revealed after fall of the lid. In genera with a double peristome (diplolepideous mosses) the endostome is homologous with the single peristome of haplolepideous mosses. persistent Not falling or deciduous. photosynthetic Containing chloroplasts and carrying out photosynthesis. phyllotaxy The order of spirally arranged leaves; e.g. 2 /5 phyllotaxy means that 5 leaves occupy 2 complete turns of the spiral. piliferous hair-like. pinnate Branches produced ± regularly on each side of the stem; adj., pinnately. plane Flat (Fig. 318, 10). pleurocarpous Mosses with monopodial main stems and inflorescences produced on dwarf lateral branches, plants often forming mats or wefts. plica (pl. plicae) Longitudinal fold or ridge; adj., plicate. plumose Feathery in appearance. pluripapillose With several papillae. point-striate With rows of minute papillae.

978

Glossary

polymorphic With more than one form, variable. polyploid Of gametophytes with two or more chromosome complements. polysetous With more than one sporophyte produced from a single perichaetium. pore In Sphagnum, openings to the exterior in walls of hyaline cells (Fig. 4, 4); in other mosses, pits in cell walls (Fig. 60, 6, 7); adj., porose (Fig. 318, 25). primary stem The main stem of most pleurocarpous mosses, usually creeping, often with rhizoids and reduced leaves. primordium (pl. primordia) An organ, e.g. leaf, at a very early stage of development. processes The thin teeth of the endostome (inner peristome) alternating with the exostome teeth (Fig. 174, 12, 13). procumbent Prostrate. propagule A vegetative reproductive structure, e.g. gemma, bulbil; adj., propaguliferous. pro parte Part prorate With papillae formed by projecting cell ends. prosenchymatous Of cells with pointed ends. protonema (pl. protonemata) The filamentous or rarely thalloid structure produced after spore germination and from which the gametophyte shoots develop. proximal End or part nearest to point of origin. pseudodioicous Separate male and female gametophyte plants arising from the same protonema so that the gametophyte plants appear dioicous. pseudoparaphyllia Minute leaf-like or filamentous structures surrounding branch primordia of many pleurocarpous mosses (Fig. 302, 7). pseudopodium Leafless prolongation of stem bearing gemmae; in Sphagnum and Andreaea, elongated stalk of archegonium pushing capsule above the perichaetial bracts. pseudopore A thinning of the wall of a hyaline cell in Sphagnum shaped like a pore but not opening to the exterior. pyriform Pear-shaped (Fig. 318, 34). quadrate With four sides of ± equal length, square (Fig. 318, 16). radicle Rhizoid; adj., radiculose, with usually numerous long rhizoids. rectangular About twice as long as wide (Fig. 318, 17). recurved Curved outwards from stem (Fig. 317, 10); of leaf margins, curved downwards and inwards (Fig. 318, 11). reflexed Of leaves or margins, bent down. remote distant, widely separate. reniform Kidney shaped. resorbed Eroded parts of cell walls of Sphagnum. resorption Erosion of cell walls of Sphagnum. resorption furrow Furrow formed by the erosion of the outer cell wall of an elongate marginal cell of a leaf in some species of Sphagnum (Fig. 4, 6).

Glossary

979

retort cell Cortical cells in some species of Sphagnum shaped like a glass retort and ending in a projection with a pore (Fig. 20, 6). retuse Broad with a slight indentation. revoluble Cells separating in a curled row. revolute Strongly rolled downwards and under (Fig. 318, 12). rhizoid Uniseriate branched structure, usually arising from stems, often anchoring plant to substrate; adj., rhizoidal. rhizoid wick Mass of rhizoids at base of a stem forming a wick which transports water. rhizomatous Horizontal and underground, analogous to rhizomes in higher plants. rhomboidal More-or-less narrowly diamond-shaped (Fig. 318, 20). ribs Raised vertical lines of cells on the walls of capsules (Fig. 68, 9; 160, 5); adj., ribbed. riparian Growing beside streams and rivers. ringed Of Sphagnum pores, surrounded by a fibril ring. rosette Whorl of leaves, usually forming the whole plant, or terminal rosette, whorl of usually enlarged leaves at tops of stems. rostellate With a short beak (Fig. 318, 38). rostrate With a beak (Fig. 318, 37). rudimentary Poorly developed, vestigial. rugose With irregular undulations. sac A sack or container, i.e. spore sac which contains spores. sacculus Minute sac-like projection from the epiphragm between the peristome teeth of some members of the Polytrichales. saxicolous Growing on rocks. scabrous Rough, usually with papillae. scale leaf Small scale-like leaf with little or no chlorophyll. scarious Thin and papery in texture. sclerodermis A cylinder of heavily thickened cells inside the hyalodermis in the stems of some mosses. secund Turned to one side. semiterete Rounded on one side, flat on the other. s.s, sensu stricto In the strict sense. Used after the name of a species (e.g. Schistidium apocarpum s.s.) to indicate that is the species as recognised by the original author to distinguish the name from that of an aggregate of two or more species having the same name (e.g. Schistidium apocarpum agg.). septate Having cell walls; of Sphagnum, hyaline cells having septa or partitions within the cells. Estimates of the percentage of septate cells are based upon regarding two hyaline cells not separated by a green cell as a single cell and it is the number of such cells relative to the total number of hyaline cells that constitute the percentage. septum Cell wall. seriate In rows.

980

Glossary

serrate Regularly toothed (like a saw) with the teeth composed of one or more cells (Fig 317, 27). serrulate Minutely regularly toothed with each tooth composed of part of a single cell (Fig. 317, 26). sessile Without a seta. seta (plur. setae) The stalk of a sporophyte between the foot and the capsule. setaceous Bristle-like (Fig. 318, 8). sheath Of stem leaves, expanded often hyaline basal part clasping stem; of perichaetial leaves, surrounding the lower part of the seta; adj., sheathing. sheathing lamina The conduplicate portion (vaginant lamina) of the leaves of the Fissidentales (Fig. 73, 3a). shoulder Distal portion of the basal part of a leaf where the base narrows, often abruptly, into the upper part of the leaf. siliceous Of rocks containing more than 66% silica (SiO2 ) by weight and usually poor in bases, i.e. acidic. sinestrorsely Twisted anticlockwise when viewed from above. sinuose Of leaf margins, wavy with curved indentations; of cells, with wavy walls (Fig. 318, 23). smooth Pertaining to cells, without mamillae or papillae; to capsules, not ribbed or rugose. soligenous Of mires or bogs, fed by ground water. spathulate Spatula-shaped, narrow below and broad above (Fig. 317, 20). spinose With sharply pointed teeth (Fig. 203, 5, 6, 8). spinulose With minute sharply pointed teeth. sporophyte The asexual diploid phase of the moss life cycle, consisting of foot embedded in the gametophyte, seta or stalk and capsule which produces spores following meiosis. spreading Held ± at right angles to the stem (Fig. 317, 9). spreading branches In Sphagnum, those branches of a fascicle growing away from the stem. squarrose Strongly curved away from the stem (Fig. 317, 11). stegocarpous Dehiscing by means of a lid. stellate Star-shaped. stereids, stereid cells Long, narrow, very thick-walled, fibre-like cells occurring in the costa of the leaves of some mosses, appearing in transverse section as almost solid with a spot in the middle representing the lumen. sterile Technically, without gametangia but, used loosely, meaning without sporophytes. stoloniform Arching and touching the substrate at the tips, analogous to the stolons of higher plants. stoma (pl. stomata) Pore surrounded by two guard cells in the epidermis of the capsule wall (Fig. 219, 11).

Glossary

981

stratose In layers, e.g. bistratose, cells in two layers. striae Small lines or ridges on the walls of capsules or on peristome teeth; adj., striate. striolations Very fine ridges on peristome teeth; adj., striolate. struma Swelling at the base of the neck of a capsule; adj., strumose (Fig. 318, 35). subula Long slender point; adj., subulate (Fig. 318, 7, 36). sulcate Deeply furrowed. superficial Of stomata, in the same plane as the other cells of the exothecium (Fig. 219, 11). supra-alar cells Leaf cells immediately above the alar cells. sympodial The main stem of limited growth, further growth continuing by means of lateral branch(es). A characteristic feature of acrocarpous mosses resulting in the cushion and turf growth forms. synoecious A term used by some authorities for synoicous but considered inappropriate for the situation in haploid gametophytes as it applies strictly only to sporophytic or diploid sexuality. synoicous With antheridia and archegonia mixed together (Fig. 317, 5). taxon (pl. taxa) Any taxonomic category. teeth Divisions of the peristome; serrations of the leaf margin. terete Rounded in transverse section. terrestrial Growing on dry land, not aquatic. terricolous Growing on a soil substrate. tetrad Group of four spores derived from a single spore mother cell by meiosis. thalloid Composed of a flat plate of tissue. tomentum Felt-like covering of long rhizoids on the stems of some mosses; adj., tomentose. transverse At right angles to the long axis. trapezoid, trapeziform Of cells, quadrilateral with only two sides parallel. trifarious In three ranks. triradiate With a three-pronged scar, a characteristic feature of the spores of land plants. tristichous Trifarious, in three ranks. truncate Cut off, ending abruptly (Fig. 79, 8). tuber Rhizoidal gemma. tubular Inrolled and overlapping to form a tube. tufa A porous calcareous rock formed by the deposition of calcium carbonate from a super-saturated solution, usually onto plant material. tuft A clump of ± erect shoots. tumid Swollen. turbinate Top-shaped (Fig. 175, 4). turf Life form of a colony with closely growing erect shoots like the pile of a carpet.

982

Glossary

undulate Wavy. unilateral One-sided. unipapillose With one papilla on the face of a cell. uniseriate Cells in a single row, e.g. as in rhizoids or moniliform gemmae. unistratose One cell thick. urceolate Urn-shaped, narrowed below the mouth and then widened below (Fig. 225, 6). vaginula Sheath at the base of a seta developed from the venter of the archegonium. ventral The adaxial or upper surface of a leaf. vermicular Worm-like, long, narrow and wavy (Fig. 318, 22). verrucose Roughened with wart-like projections. weft A life form of loosely interwoven shoots. whorled Arranged in a ring. x The basic haploid chromosome number of a taxonomic group as opposed to n, the functional haploid number, which may be a multiple of x. xeromorphic With morphological features characteristic of plants of dry habitats.

Bibliography

Works referred to in the text or freely consulted in the compilation of the flora are listed here. References dealing with specific taxa are given in the text where appropriate. Beever, J., Allison, K. W. & Child, J. The Mosses of New Zealand. 2nd edn. Otago: University of Otago Press. 1992. Blockeel, T. L. & Long, D. G. A Check-list and Census Catalogue of British and Irish Mosses. Cardiff: British Bryological Society. 1998. Blom, H. H. A revision of the Schistidium apocarpum complex in Norway and Sweden. Bryophytorum Bibliotheca 49, 1–333. 1996. Braithwaite, R. The British Moss Flora. London: L. Reeve & Co. 1887–1905. Brotherus, V. F. Musci (Laubmoose). In A. Engler & R. Prantl, Die Naturlichen Pflanzenfamilien, zweite Auflag. TL 10, 11. Leipzig: W. Engelmann. 1924–1925. British Bryological Society Reports. Harlech, Berwick-on-Tweed. 1923–1945. Brummitt, R. K. & Powell, C. E. (eds.). Authors of Plant Names. Kew: Royal Botanic Gardens. 1992. Bulletin of the British Bryological Society. Cardiff. 1974–. Bryologist, The, 1898–. Church, J. M., Hodgetts, N. G., Preston, C. D. & Stewart, N. F. British Red Data Books. 2. Mosses and Liverworts. Peterborough: Joint Nature Conservation Committee. 2001. Clarke, G. C. S. & Duckett, J. G (eds.). Bryophyte Systematics. London: Academic Press. 1979. Corley, M. F. C. & Crundwell, A. C. Additions and amendments to the mosses of Europe and the Azores. Journal of Bryology 16, 337–56. 1991. Corley, M. F. V., Crundwell, A. C., Dull, ¨ R., Hill, M. O. & Smith, A. J. E. Mosses of Europe and the Azores: an annotated list of species with synonyms from the recent literature. Journal of Bryology. 11, 609–89. 1981. Crosby, M. R. Index of Mosses, 1996–1998. Monographs in Systematic Botany from the Missouri Botanical Garden 80, 1–65. 2000. Crosby, M. R. Vade Mecum Bryologiae I. St. Louis Hedwigian Soc. 1999. Crosby, M. R. & Magill, R. E. A Dictionary of Mosses. St. Louis: Missouri Botanical Garden. 1977. Crosby, M. R., Magill, R. E. & Bauer, C. R. Index of Mosses, 1963–1989. Monographs in Systematic Botany from the Missouri Botanical Garden 42, 1–646. 1992. Crosby, M. R. & Magill, R. E. Index of Mosses, 1990–1992. Monographs in Systematic Botany from the Missouri Botanical Garden 50, 1–87. 1994. Crosby, M. R. & Magill, R. E. Index of Mosses, 1993–1995. Monographs in Systematic Botany from the Missouri Botanical Garden 62, 1–106. 1997.

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984

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Index

Synonyms and excluded taxa are in italics; page numbers of illustrations are in italics. ¨ Hal., 746 Abietinella Mull. abietina (Hedw.) M. Fleisch., 747; var. abietina, 747, 748; var. histricosa (Mitt.) Saakurai, 747, 748 histricosa (Mitt.) Broth., 747 ¨ Hal., 376 Acaulon Mull. minus (Hook. & Taylor) A. Jaeger, 376 ¨ Hal., muticum (Schrad. ex Hedw.) Mull. 376; var. mediterraneum (Limpr.) ´ Sergio, 378; var. muticum, 376, 377 ¨ Hal., 377, 378 triquetrum (Spruce) Mull. Achrophyllum Vitt & Crosby, 700 dentatum (Hook. f. & Wilson) Vitt & Crosby, 697 Acrocladium cordifolium (Hedw.) P. W. Richards & E. C. Wallace, 787 cuspidatum (Hedw.) P. W. Richards & E. C. Wallace, 891 giganteum (Schimp.) P. W. Richards & E. C. Wallace, 787 sarmentosum (Wahlenb.) P. W. Richards & E. C. Wallace, 784 stramineum (Brid.) P. W. Richards & E. C. Wallace, 786 trifarium (F. Weber & D. Mohr) P. W. Richards & E. C. Wallace, 797 Aloina Kindb., 339 aloides (D. J. Koch ex Schultz) Kindb., 340, 342; var. ambigua (Bruch & Schimp.) F. J. Craig., 342 ambigua (Bruch & Schimp.) Limpr., 340, 342 brevirostris (Hook. & Grev.) Kindb., 339, 340

¨ Hal.) Broth., 341 obliquifolia (Mull. rigida (Hedw.) Limpr., 340, 341; var. mucronulata (Bruch & Schimp.) Lindb., 341 Amblyodon P. Beauv., 523 dealbatus (Sw. ex Hedw.) Bruch & Schimp., 522, 523 Amblystegiaceae, 759 Amblystegiella confervoides (Brid.) Loeske, 767 jungermannioides (Brid.) Giacom., 865 sprucei (Bruch) Loeske, 865 Amblystegium Schimp., 762 ¨ Hal.) Aust., 773 compactum (Mull. confervoides (Brid.) Schimp., 766, 767 curvicaule (Jur.) Lindb., 760 filicinum (Hedw.) De Not., 760; var. valliclausae auct., 760 fluviatile (Hedw.) Schimp., 768 humile (P. Beauv.) Crundw., 765, 766 irriguum (Hook. & Wilson) Schimp., 770 jungermannioides (Brid.) Schimp., 865 juratzkanum Schimp., 763 kochii Schimp., 765 radicale (P. Beauv.) Schimp., 766, 767 riparium (Hedw.) Schimp., 770 saxatile Schimp., 767 serpens (Hedw.) Schimp., 763; var. salinum Carrington, 763, 764; var. serpens, 763, 764 sprucei (Bruch) Schimp. tenax (Hedw.) C. E. O. Jensen, 770 varium (Hedw.) Lindb., 764, 765 Amphidiaceae, 657

986

Index Amphidium Schimp., 657 lapponicum (Hedw.) Schimp., 657, 658 mougeotii (Bruch & Schimp.) Schimp., 658, 658 Anacamptodon Brid., 809 ¨ splachnoides (Frohlich ex Brid.) Brid., 809 Andreaea Hedw., 103 alpestris (Thed.) Schimp., 105, 108 alpina Hedw., 104, 105 blyttii Schimp., 115, 116, 116 crassinervia auct., 111 crassinervia Bruch. 113; var. huntii (Lindb.) Braithw., 111 frigida Huebener, 113, 114 hartmanii Thed., 116 megistospora B. M. Murray, 114, 114 mutabilis Hook. f. & Wilson, 108, 109 nivalis Hook., 116, 116 obovata Thed., 116; var. papillosa (Lindb.) Nyholm, 106; var. sparsifolia auct., 108 petrophila Ehrh., 106; var. alpestris Thed., 108 rothii F. Weber & D. Mohr, 110; ssp. falcata (Schimp.) Lindb. 111, 112; ssp. frigida (Huebener) Schultze-Motel, 113; ssp. rothii, 111, 112 rupestris Hedw., 106; var. alpestris (Thed.) Sharp, 108; var. papillosa (Lindb.) Podp., 106, 107; var. rupestris, 106, 107 sinuosa B. M. Murray, 109, 110 Andreaeaceae, 103 Andreaeales, 103 Andreaeopsida, 103 Anisothecioideae, 184 Anisothecium grevilleanum (Brid.) H. Arnell & C. E. O. Jensen, 186 palustre (Dicks.) I. Hagen, 181 rufescens (With.) Lindb., 190 scheberianum (Hedw.) Dixon, 186 staphylinum (H. Whitehouse) Sipman et al., 190 vaginale (Dicks. ex With.) Loeske, 188 varium (Hedw.) Mitt., 188 ¨ Anoectangium Schwagr., 304–306 aestivum (Hedw.) Mitt., 304, 305

987

¨ compactum Schwagr., 304 warburgii Crundw. & M. O. Hill, 311 Anomobryum Schimp., 530 concinnatum (Spruce) Lindb., 531 filiforme (Dicks.) Husn., 531 julaceum (Schrad. ex Gaertn. et al.) Schimp., 531; var. concinnatum (Spruce) Zetterst., 529, 531; var. julaceum, 529, 531 juliforme Solms-Laub., 531 Anomodon Hook. & Taylor, 743 attenuatus (Hedw.) Huebener, 744, 745 longifolius (Schleich. ex Brid.) Hartm., 744, 745 viticulosus (Hedw.) Hook. & Taylor, 745, 746 Anomodontaceae, 743 Antitrichia Brid., 714 californica Sull., 715 curtipendula (Timm ex Hedw.) Brid., 713, 714 Aongstroemia Bruch & Schimp., 184 longipes (Sommerf.) Bruch & Schimp., 179 Aphanorhegma auct., 513 Aphanorrhegma Sull., 513 patens (Hedw.) Lindb., 512, 513 Aplodon (R. Br.) Rohl, 517 wormskjoldii (Hornem.) Kindb., 517, 517 Archidiaceae, 144 Archidiales, 144 Archidium Brid., 144 alternifolium (Dicks. ex Hedw.) Mitt., 145, 146 Arctoa (Dicks.) Bruch & Schimp., 194 fulvella (Dicks.) Bruch & Schimp., 194, 195 Astomum crispum (Hedw.) Hampe, 276 crispum var. sterilis (W. E. Nicholson) ¨ Monk., 275 levieri Limpr., 275 mittenii Bruch & Schimp., 273 multicapsularis (Sm.) Bruch & Schimp., 273 rostellatum (Brid.) Bruch & Schimp., 272

988

Index

Astrophyllum stellare (Hedw.) Lindb., 622 Atrichum P. Beauv., 133 angustatum (Brid.) Bruch & Schimp., ¨ 134, 136; var. rhystophyllum (Mull.) P. W. Richards & E. C. Wallace, 137 crispum (Hampe) Sull. & Lesq., 133, 134 ¨ tenellum (Rohl.) Bruch & Schimp., 134, 135 undulatum (Hedw.) P. Beauv., 135; var. gracilisetum Besch., 136; var. haussknechtii (Jur. & Milde) Frye, 136; var. minus auct. 132; var. undulatum, 132, 136 Aulacomniaceae, 636 ¨ Aulacomnium Schwagr., 636 ¨ androgynum (Hedw.) Schwagr., 637, 638 ¨ palustre (Hedw.) Schwagr., 637, 637; var. imbricatum Bruch & Schimp., 637 ¨ turgidum (Wahlenb.) Schwagr., 637, 638 Barbula Hedw., 312 acuta (Brid.) Brid., 317 asperifolia Nitt., 334 ¨ botelligera Monk., 299 convoluta Hedw., 312, 313; var. commutata (Jur.) Husn., 314 cordata (Jur.) Braithw., 327 cylindrica (Taylor) Schimp., 325 fallax Hedw., 331 ferruginascens Stirt., 299 ¨ glauca (Ryan) H. Moller, 322 ¨ gracilis (Schleich.) Schwagr., 317 hornschuchiana Schultz, 295 ¨ Hal, 317 icmadophila Schimp. ex Mull. lurida (Hornsch. ex Spreng.) Lindb., 325 mamillosa Crundw., 319 maxima Syed & Crundw., 333 nicholsonii Culm., 321 recurvifolia Schimp., 333 recurvirostra (Hedw.) Dixon, 297 reflexa (Brid.) Brid., 333; var. robusta Braithw., 333 revoluta Brid., 295 rigidula (Hedw.) Mitt., 319 rubella (Huebener) Mitt., 297; var. ruberrima Ferguson, 299 rufa (Lor.) Jur., 334

sardoa (Schimp.) J.-P. Frahm 313, 314 sinuosa (Mitt.) Gravat, 327 spadicea (Mitt.) Braithw., 329 tomaculosa Blockeel, 331 tophacea (Brid.) Mitt., 329 trifaria (Hedw.) Mitt., 325 unguiculata Hedw., 313; var. cuspidata (Schultz) Brid., 315 vinealis Brid., 324; ssp. cylindrica (Taylor) Podp., 325 Bartramia Hedw., 640 halleriana Hedw., 642, 643 ithyphylla Brid., 641, 644 oederi Brid., 640 pomiformis Hedw., 641, 642; var. elongata Turner, 644 stricta Hedw., 643, 645 Bartramiaceae, 639 Bartramidula cernua (Wilson) Lindb., 654 wilsonii Bruch & Schimp., 654 Bartramioideae, 639 Blindia Bruch & Schimp., 477 acuta (Hedw.) Bruch & Schimp., 478, 478 ¨ caespiticia (F. Weber & D. Mohr) Mull. Hal., 478, 478 ¨ Brachydontium Furnr., 493 ¨ trichodes (F. Weber) Furnr., 492, 493 Brachyodus trichodes (F. Weber) Nees & Hornsch., 493 Brachytheciaceae, 810 Brachythecium Schimp., 818 albicans (Hedw.) Schimp., 820, 821 appleyardiae S. V. McAdam & A. J. E. Sm., 829, 830 caespitosum (Wilson) Dixon, 835 ¨ cirrosum (Schwagr.) Schimp., 838 erythrorrhizon Schimp., 820, 821 glaciale Schimp., 827, 828 glareosum (Spruce) Schimp., 822, 823 illecebrum auct., 837 mildeanum (Schimp.) Schimp., 823, 824 piliferum (Hedw.) Kindb., 838 plicatum (Schleich. ex F. Weber & D. Mohr) Schimp., 743 plumosum (Hedw.) Schimp., 831, 833 populeum (Hedw.) Schimp., 831, 833

Index purum (Hedw.) Dixon, 834 reflexum (Starke) Schimp., 827, 828 rivulare Schimp., 825, 826 rutabulum (Hedw.) Schimp., 824, 825 salebrosum (F. Weber & D. Mohr) Schimp., 821, 822; var. palustre Schimp., 824 starkei (Brid.) Schimp., 827, 827 trachypodium (Brid.) Schimp., 830, 832 velutinum (Hedw.) Schimp., 829, 831 Breutelia (Bruch & Schimp.) Schimp., 656 arcuata (Sw.) Schimp., 656 chrysocoma (Hedw.) Lindb., 655, 656 Breutelioides, 646 Bruchiaceae, 166 Bryaceae, 528 Bryales, 526 Bryideae, 513 Bryoideae, 528 Bryoerythrophyllum P. C. Chen, 297 caledonicum D. G. Long, 296, 299 ferruginascens (Stirt.) Giacom., 298, 299 recurvirostrum (Hedw.) P. C. Chen, 297, 298 recurvifolium (Taylor) R. H. Zander, 292 Bryophyta, 1 Bryopsida, 143 Bryum Hedw., 532 affine Lindb. & Arnell, 562 algovicum Sendtn. var. rutheanum (Warnst.) Crundw., 556, 559 alpinum Huds. ex With., 587, 588; var. meridionale Schimp., 589; var. viride Husn., 588 ¨ Hal., 560 amblyodon Mull. angustirete Kindb., 556 archangelicum Bruch & Schimp., 557, 559 arcticum (R. Br.) Bruch & Schimp., 541, 542 argenteum Hedw., 568, 569; var. lanatum (P. Beauv.) Hampe, 568 atropurpureum Bruch & Schimp., 573 barnesii J. B. Wood, 573 bicolor Dicks., 573 bimum (Schreb.) Turner, 566

989 bornholmense Wink. & R. Ruthe, 581, 582 caespiticium Hedw., 565, 567; var. imbricatum Bruch & Schimp., 567 calophyllum R. Br., 539, 540 canariense Brid., 554, 555; var. provinciale (H. Philib.) Huebener, 554 capillare Hedw., 548; var. capillare, 549, 550; var. elegans (Nees) Husn. 551; var. rufifolium (Dixon) Podp., 549, 550; var. torquescens (Bruch ex De Not.) Husn., 554 cernuum (Hredw.) Lindb., 543 creberrimum Taylor, 562, 563 ¨ cyclophyllum (Schwagr.) Bruch & Schimp., 545, 547 dichotomum complex, 570 dichotomum Hedw., 572, 573 dixonii Cardot, 569, 570 donianum Grev., 547, 548 dunense A. J. E. Sm. & H. Whitehouse, 573 duvalii Voit, 546 dyffrynense D. T. Holyoak, 575, 575 elegans Nees, 551, 555 erythrocarpum complex, 576 filiforme Dicks., 531 flaccidum auct., 551 funckii auct., 567 ¨ funkii Schwagr., 563, 567 gemmiferum R. Wilczek & Demaret, 569, 571 gemmilucens R. Wilczec & Demaret, 571, 572 gemmiparum De Not., 586, 587 ¨ imbricatum (Schwagr.) Bruch & Schimp., 558, 560 inclinatum (Brid.) Blandow., 560 intermedium (Brid.) Blandow, 561, 561 klinggraeffii Schimp., 579, 580 knowltonii Barnes, 557, 558 lacustre (F. Weber & D. Mohr) Blandow, 557 laevifilum Syed, 551, 552 lawersianum H. Philib., 543, 548 lisae De Not., 562 mamillatum Lindb., 538, 539

990

Index

Bryum Hedw. (cont.) marratii Wilson, 538, 539 ¨ Hal. & Kindb., microerythrocarpum Mull. 581 mildeanum Jur., 585, 586 muehlenbeckii Bruch & Schimp., 585, 586 murale Wilson ex Hunt, 576 murorum (Schimp.) Berk., 576 neodamense Itzigs., 565, 566 obconicum Hornsch., 564 pallens Sw., 542, 544; ssp. lawersianum (H. Philib.) Podp., 543; var. fallax Jur., 544 ¨ pallescens Schleich. ex Schwagr., 563, 564 pendulum (Hornsch.) Schimp., 556 provinciale H. Philib., 554 pseudotriquetrum (Hedw.) Gaertn. et al., 564, 565; var. bimum (Schreb.) Lilj., 566 purpurascens (R. Br.) Bruch & Schimp., 543 radiculosum Brid., 576, 577 riparium I. Hagen, 584, 585 roellii H. Philib., 556 roseum Hedw., 589 rubens Mitt., 583, 584 ruderale Crundw. & Nyholm, 577, 578 rufifolium (Dixon) Demaret & R. Wilczek, 549 salinum I. Hagen ex Limpr., 558, 560 sauteri Bruch & Schimp., 579, 580 ¨ schleicheri Schwagr. var. latifolium ¨ (Schwagr.) Schimp., 545, 546 ¨ Hal., 560 stenotrichum Mull. stirtonii Schimp., 551, 552 subapiculatum Hampe, 581, 582 subelegans auct., 551 subelegans Kindb., 553 tenuisetum Limpr., 579, 580 torquescens Bruch ex De Not., 554, 555 tortifolium Brid., 547 turbinatum (Hedw.) Turner, 545, 545; ¨ var. latifolium (Schwagr.) Bruch & Schimp., 546

uliginosum (Brid.) Bruch & Schimp, 542, 543 versicolor A. Braun ex Bruch & Schimp., 573 violaceum Crundw. & Nyholm, 577, 578 ¨ warneum (Rohl.) Brid., 539, 540 weigelii Spreng., 545, 546 Buxbaumia Hedw., 141 aphylla Hedw., 141, 141 indusiata Brid., 142 viridis (Moug. ex DC) Brid. ex Moug. & Nestl., 141, 142 Buxbaumiaceae, 141 Buxbaumiales, 140 Callialarisa curvicaulis (Jur.) Ochyra, 760 Calliergon (Sull.) Kindb., 786 cordifolium (Hedw.) Kindb., 787, 788 cuspidatum (Hedw.) Kindb., 891 giganteum (Schimp.) Lindb., 787, 788 sarmentosum (Wahlenb.) Kindb., 784 stramineum (Brid.) Kindb., 786; trifarium (F. Weber & D. Mohr) Kindb., 797 Calliergonella Loeske, 891 cuspidata (Hedw.) Loeske, 890, 891 ¨ 892, 893 lindbergii (Mitt.) Hedenas, Callomniaceae, 696 Callomnion Hook. f. & Wilson, 696 complanatum (Hook. f. & Wilson) Loeske, 696, 697 Calyptrochaeta Desv., 701 apiculata (Hook. f. & Wilson) Vitt, 699, 702 Camptothecium lutescens (Hedw.) Schimp., 817 nitens (Hedw.) Schimp., 794 sericeum (Hedw.) Kindb., 816 Campyliaceae, 772 Campyliadelphus (Kindb.) R. S. Chopra, 775 chrysophyllus (Brid.) R. S. Chopra, 775, 776 elodes (Lindb.) Kanda, 776, 777 polygamus (Schimp.) Kanda, 778

Index Campylium (Sull.) Mitt., 773 calcareum Crundw. & Nyholm, 889 chrysophyllum (Brid.) J. Lange, 775 elodes (Lindb.) Kindb., 777 halleri (Sw. ex Hedw.) Lindb., 891 polygamum (Schimp.) J. Lange & C. E. O. Jensen, 778 protensum (Brid.) Kindb., 771, 774 radicale (P. Beauv.) Grout, 767 sommerfeltii auct. eur., 889 stellatum (Hedw.) C. E. O. Jensen, 771, 774; var. protensum (Brid.) Bryhn, 774 Campylophylloideae, 889 Campylophyllum (Schimp.) M. Fleisch., 889 calcareum (Crundw. & Nyholm) ¨ 889, 890 Hedenas, halleri (Sw. ex Hedw.) M. Fleisch., 890, 891 Campylopodioideae, 213 Campylopus Brid., 216 atrovirens De Not., 229; var. atrovirens, 230, 231; var. falcatus Braithw., 230, 231; var. gracilis Dixon, 230, 231 azoricus Mitt., 224 brevipilus Bruch & Schimp., 234, 235 flexuosus (Hedw.) Brid., 219, 226, 227 fragilis (Brid.) Bruch & Schimp., 219, 221, 222; var. pyriformis (Schultz) Agst., 223, 224 gracilis (Mitt.) A. Jaeger, 219, 221, 222 introflexus (Hedw) Brid., 232, 233, 235; var. polytrichoides (De Not.) Giacom., 232 paradoxus Wilson, 226 pilifer Brid., 232, 233, 235 polytrichoides De Not., 232 pyriformis (Schultz) Brid., 223; var. azoricus(Mitt.) M. F. V. Corley, 224, ´ M. F. V. 225; var. fallaciosus (Ther.) Corley, 226; var. pyriformis, 219, 225 schimperi Milde, 219, 220, 221 schwarzii Schimp., 219; var. huntii (Stirt.) Dixon, 222 setifolius Wilson, 219, 227, 228; var. ¨ shawii (Wilson) Monk, 229

991

shawii Wilson, 219, 229, 230 subporodictyon (Broth.) B. H. Allan & R. Ireland, 214, 215, 236 subulatus Schimp. in Rabenh., 218, 219, 227; var. schimperi (Milde) Husn., 220 Campylostelium Bruch & Schimp., 476 saxicola (F. Weber & D. Mohr) Bruch & Schimp., 475 Catharinea angustata (Brid.) Brid., 136 crispa Hampe, 133 ¨ tenailla Rohl., 135 undulata (Hedw.) F. Weber & D. Mohr, 135 Catoscopiaceae, 526 Catoscopium Brid., 526 nigritum Brid., 522 Ceratodon Brid., 163 chloropus (Brid.) Brid., 166 conicus (Hampe) Lindb., 164, 165 purpureus (Hedw.) Brid., 163, 164; ssp. conicus (Hampe) Dixon, 165; var. conicus (Hampe) Husn., 165 Chamberlania albicans (Hedw.) H. Rob., 820 erythrorhizon (Schimp.) H. Rob., 820 salebrosa (F. Weber & D. Mohr) H. Rob., 822 velutina (Hedw.) H. Rob., 829 Cheilothela (Lindb.) Broth., 165 chloropus (Brid.) Broth., 164 ¨ Hal.) R. H. Zander, Chenia leptophylla (Mull. 378 Cinclidioideae, 622 Cinclidium Sw., 622 stygium Sw., 621, 623 Cinclidotaceae, 388 Cinclidotus P. Beauv., 388 brebissonii (Brid.) Husnot, 294 fontinaloides (Hedw.) P. Beauv., 388, 389 mucronatus (Brid.) Molendo, 294 riparius (Host ex Brid.) Arnott, 389, 390 Cirriphyllum Grout, 837 ¨ cirrosum (Schwagr.) Grout, 838, 839 crassinervium (Taylor) Loeske & M. Fleisch., 839, 840 piliferum (Hedw.) Grout, 838, 839 Climaciaceae, 708

992

Index

Climacium F. Weber & D. Mohr, 709 dendroides F. Weber & D. Mohr., 709, 710 Conardia H. Rob., 772 ¨ Hal.) H. Rob., 769 compacta (Mull. Conostomoideae, 645 Conostomum Sw., 645 boreale Sw., 643 tetragonum (Hedw.) Lindb., 643, 646 Coscinodon Spreng., 397 cribrosus (Hedw.) Spruce, 398, 398 Cratoneuron (Sull.) Spruce, 759 commutatum (Hedw.) Roth, 755; var. ¨ falcatum (Brid.) Monk., 758; var. ¨ sulcatum (Lindb.) Monk., 757 curvicaule (Jur.) Roth, 760, 761 decipiens (De Not.) Loeske, 758 filicinum (Hedw.) Spruce, 760, 761; var. atrovirens (Brid.) Ochyra, 760; var. ¨ curvicaule (Jur.) Monk., 760; var. fallax (Brid.) Roth, 767 Cryphaea D. Mohr, 709 heteromalla (Hedw.) D. Mohr, 710, 711; ¨ Hal.) Wilson, 711 var. aquatilis (Mull. ¨ Hal., 711 lamyana (Mont.) Mull. Cryphaeaceae, 709 Ctenidioideae, 916 Ctenidium (Schimp.) Mitt., 917 molluscum (Hedw.) Mitt., 917; var. condensatum (Schimp.) E. Britton, 918, 919; var. fastigiatum (Bosw.) Braithw., 918, 919; var. molluscum, 918, 919; var. robustum Boulay, 919, 920; var. sylvaticum F. Rose & A. J. E. Sm., 919, 920 procerrimum (Molendo) Lindb., 920, 921 Cyclodictyon Mitt., 700 laetevirens (Hook. & Taylor) Mitt., 699, 701 Cylindrothecium concinnum (De Not.) Schimp., 861 Cynodontium Bruch & Schimp., 171 bruntonii (Sm.) Bruch & Schimp., 170 fallax Limpr., 172, 175 gracilescens (D. Weber & F. Mohr) Schimp., 172, 175 jenneri (Schimp.) Stirt., 173, 174

polycarpon (Hedw.) Schimp., 172, 173; var. strumiferum (Hedw.) Schimp., 171 strumiferum (Hedw.) Lindb., 171, 172 tenellum (Bruch & Schimp.) Limpr., 174, 175 virens(Hedw.) Schimp., 176 wahlenbergii (Brid.) Hartm., 176 Daltonia Hook. & Taylor, 702 splachnoides (Sm.) Hook. & Taylor, 699 Daltoniaceae, 701 Dendrocryphaea Paris & Schimp. Ex Broth., 711 lamyana (Mont.) P. Rao, 710 Desmatodon cernuus (Huebener) Bruch & Schimp., 355 convolutus (Brid.) Grout, 357 heimii (Hedw.) Mitt., 375 leucostoma (R. W. Br.) Berggr., 355 suberectus (Hook.) Limpr., 355 Dialytrichia (Schimp.) Limpr., 292 mucronata (Brid.) Broth., 293, 294 Dichodontium Schimp., 178 flavescens (Dicks. ex With.) Lindb., 179, 180 palustre (Dicks.) M. Stech, 181, 182 pellucidum (Hedw.) Schimp., 178, 179; var. fagimontanum (Brid.) Schimp., 180; var. flavescens (Dicks. ex With.) Kindb., 180 Dicranaceae, 183 Dicranales, 145 ¨ Hal.) Schimp., 184 Dicranella (Mull. cerviculata (Hedw.) Schimp., 191, 193 crispa (Hedw.) Schimp., 188, 189 curvata (Hedw.) Schimp., 192 grevilleana (Brid.) Schimp., 186, 187 heteromalla (Hedw.) Schimp., 193, 193; var. sericea (Schimp.) Schimp., 194 howei Renauld & Cardot, 189 palustris (Dicks.) Crundw. & E. F. Warb., 181 rufescens (With.) Schimp., 190, 191 schreberi (Hedw.) Schimp., 186 schreberiana (Hedw.) Hilfarty ex H. A. Crum & L. E. Anderson, 186, 187

Index secunda Lindb., 192 squarrosa (Schrad.) Schimp., 181 staphylina H. Whitehouse, 190, 191 subulata (Hedw.) Schimp., 187, 192 varia (Hedw.) Schimp., 188, 189; var. callistoma Renauld & Cardot, 188, 189 Dicranoideae, 194 Dicranodontium Bruch & Schimp., 213 asperulum (Mitt.) Broth., 214, 215, 215 denudatum (Brid.) E. Britton, 214, 215, 216; var. alpinum (Schimp) I. Hagen, 216 longirostre (F. Weber & D. Mohr) Bruch & Schimp., 216 subporodictyon Broth., 236 uncinatum (Harv.) A. Jaeger, 213, 214, 215 Dicranoideae, 144 Dicranoweisia Lindb., 181 cirrata (Hedw.) Lindb., 181, 182 crispula (Hedw.) Milde, 182, 183 Dicranum Hedw., 200 affine Funck, 206 asperulum Mitt., 215 bergeri Blandow, 206, 207 blyttii Bruch & Schimp., 198 bonjeanii De Not., 202, 203 congestum auct., 209 ¨ elongatum Schleich. ex Schwagr., 207, 209 falcatum Hedw., 196 flagellare Hedw., 211, 212 flexicaule Brid., 207, 209 fulvellum (Dicks.) Sm., 194 fuscescens Turner, 207, 208; var. congestum auct., 209 glaciale Berggr., 199 leioneuron Kindb., 202, 203 longifolium Hedw., 237 majus Turner, 203, 206 montanum Hedw., 211, 212 polysetum Sw., 201, 205 rugosum (Dicks.) Hoffm. ex Brid., 201 scoparium Hedw., 203, 204 scottianum Turner, 210, 211 spurium Hedw., 206, 207 starkei F. Weber & D. Mohr, 199

993

strictum(Dicks.) Sm., 210 subporodictyon (Broth.) Gao et al., 236 tauricum Sapjegin, 210, 211 uncinatum (Dicks.) Sm., 213 undulatum F. Weber & D. Mohr, 201 undulatum Schrad. ex Brid., 206 Didymodon Hedw., 315 acutus (Brid.) K. Saito, 317, 318; var. ¨ Hal) icmadophilus (Schimp. Ex Mull. R. H. Zander, 317 asperifolius (Mitt.) H. A. Crum et al., 334 ¨ Hal) australasiae var. umbrosus (Mull. R. H. Zander, 322, 323 cordatus Jur., 327, 328 fallax (Hedw.) R. H. Zander, 331, 332 ferrugineus (Schimp. & Besch.) M. O. Hill, 332, 333 glaucus Ryan, 320, 322 ¨ Hal.) K. icmadophilus (Schimp. ex Mull. Saito, 317, 318 insulanus (De Not.) M. O. Hill, 325, 326 luridus Hornsch. Ex Spreng., 325, 326; var. nicholsonii (Culm.) Loeske, 321 mamillosus (Crundw.) M. O. Hill, 319, 320 maximus (Syed & Crundw.) M. O. Hill, 330, 333 nicholsonii Culm., 320, 321 reedii H. Rob., 325 rigidulus Hedw., 318, 319; var. glaucus (Ryan) Wijk & Margad., 322; var. gracilis (Schleich.) R. H. Zander, 317; ¨ var. icmadophilus (Schimp. ex Mull. Hal.) R. H. Zander, 317 sinuosus (Mitt.) Delogne, 327, 328 spadiceus (Mitt.) Limpr., 329, 330 subandraeaoides (Kindb.) R. H. Zander, 318 tomaculosus (Blockeel) M. F. V. Corley, 330, 331 tophaceus (Brid.) Lisa, 328, 329 ¨ trifarius (Hedw.) Rohl., 325 ¨ Hal.) R. H. Zander, 322 umbrosus (Mull. vinealis (Brid.) R. H. Zander, 324, 326; var. flaccidus (Bruch & Schimp.) R. H. Zander, 325; var. luridus, (Hornsch.) R. H. Zander, 325; var. nicholsonii (Culm.) R. H. Zander, 317

994

Index

Diphysciaceae, 143 Diphysciales, 143 Diphysciideae, 143 Diphyscium D. Mohr, 143 foliosum (Hedw.) D. Mohr, 141, 144 Disceliaceae, 504 Discelium Brid., 504 nudum (Dicks.) Brid., 504, 505 Distichium Bruch & Schimp., 160 capillaceum (Hedw.) Bruch & Schimp., 160, 161 inclinatum (Hedw.) Bruch & Schimp., 161, 162 Ditrichaceae, 145 Ditrichum Hampe, 149 cornubicum Paton, 153, 154 ¨ Hal.) Paris, 158 crispatissimum (Mull. cylindricum (Hedw.) Grout, 149 flexicaule auct., 158; var. densum (Bruch & Schimp.) Braithw., 157 ¨ flexicaule (Schwagr.) Hampe, 157, 159 gracile (Mitt.) Kuntze, 158, 159 heteromallum (Hedw.) E. Britton, 150, 155 homomallum (Hedw.) Hampe, 155; var. zonatum (Brid.) Lindb., 156 lineare (Sw.) Lindb., 153, 154 plumbicola Crundw., 154, 155 pusillum (Hedw.) Hampe, 151, 152 subulatum Hampe, 150, 157 tenuifolium Lindb., 149 tortile (Schrad.) Brockm., 151 vaginans (Sull.) Hampe, 157 zonatum (Brid.) Kindb., 156; var. scabrifolium Dixon, 150; var. zonatum, 150 Dolichotheca seligeri (Brid.) Loeske, 884 striatella (Brid.) Loeske, 884 ¨ Hal.) Roth, 778 Drepanocladus (Mull. aduncus (Hedw.) Warnst., 780, 781 cossonii (Schimp.) Loeske, 791 exannaulatus (Schimp.) Warnst., 784; var. ¨ rotae (De Not.) Monk., 784 fluitans (Hedw.) Warnst., 782; var. falcatus, 782 h-schulzei (Limpr.) Loeske, 782

lycopodioides (Brid.) Warnst., 795 polycarpos (Blandow ex Voit.) Warnst., 781 ¨ 778, 779 polygamus (Schimp) Hedenas, revolvens (Sw.) Warnst., 791; var. intermedius (Lindb.) P. Wilson, 791 sendtneri (Schimp.) Warnst., 779, 779; var. wilsonii (Lindb.) Warnst., 779 stagnatus Zanowiec, 781 uncinatus (Hedw.) Warnst., 797 vernicosus (Mitt.) Warnst., 792 Dryptodon patens (Dicks. ex Hedw.) Brid., 456 Encalypta Hedw., 497 alpina Sm., 500, 501 brevicollis (Bruch & Schimp.) Ångstr., 500, 501 ciliata Hedw., 501, 503 commutata Nees & Hornsch., 500 ¨ rhabdocarpa Schwagr., 502 ¨ rhaptocarpa Schwagr., 499, 502 streptocarpa Hedw., 498, 499 vulgaris Hedw., 499, 502 Encalyptaceae, 497 Encalyptales, 497 ¨ Hal., 860 Entodon Mull. concinnus (De Not.) Paris, 861, 869 orthocarpus (Brid.) Lindb., 861 Entodontaceae, 860 ¨ Entosthodon Schwagr., 506 attenuatus (Dicks.) Bryhn, 508, 509 ¨ Hal., 508, 510 fascicularis (Hedw.) Mull. muhlenbergii (Turner) Fife, 505, 507 obtusus (Hedw.) Lindb., 508, 509 ´ pulchellus (H. Philib.) Brugees, 507, 508 Ephemeraceae, 391 Ephemerella recurvifolia (Dicks) Schimp., 393 sessilis (Bruch) Nyholm, 393 Ephemerum Hampe, 391 cohaerens (Hedw.) Hampe, 392, 394 intermedium Braithw., 396 minutissimum Lindb., 395, 396 recurvifolium (Dicks.) Boulay, 392, 393 serratum (Hedw.) Hampe, 396; var. angustifolium auct., 396; var.

Index minutissimum (Lindb.) Grout, 396; var. praecox A. W. H. Walther & Molendo, 395, 396; var. serratum, 395, 396 ¨ Hal., 392 sessile (Bruch) Mull. spinulosum Bruch & Schimp. ex Schimp. 394, 395 stellatum H. Philib., 392, 394 Epipterygium Lindb., 592 tozeri (Grev.) Lindb., 592, 597 Eriopus apiculatus (Hook. f. & Wilson) Mitt., 702 Eucladium Bruch & Schimp., 262 verticillatum (Brid.) Bruch & Schimp., 262, 263 Eurhynchium Schimp., 847 abbreviatum (Turner) Brockm., 856 alopecuroides (Brid.) P. W. Richards & E. C. Wallace, 842 alopecurum err. orth., 842 circinatum (Brid.) Schimp., 815 ¨ cirrosum (Schwagr.) Husn., 838 confertum (Dicks.) Milde, 845 crassinervium (Taylor) Schimp., 840 curvisetum (Brid.) Husn., 859 hians (Hedw.) Sande Lac., 854 megapolitanum (Bland ex F. Weber & D. Mohr) Milde, 845 meridionale (Schimp. De Not., 846, 849 murale (Hedw.) Milde, 843 myosuroides (Brid.) Schimp., 811 myurum (Brid.) Dixon, 813 piliferum (Hedw.) Schimp., 838 praelongum (Hedw.) Schimp., 851; var., stokesii (Turner) Dixon., 851 pulchellum (Hedw.) Jenn. var. diversifolium (Schimp.) C. E. O. Jensen, 850, 851; var. praecox (Hedw.) Dixon, 851; var. pulchellum pumilum (Wilson) Schimp., 860 riparioides (Hedw.) P. W. Richards, 841 rotundifolium (Scop. ex Brid.) Milde, 847 rusciforme Milde, 841; var. alopecuroides (Brid.) Dixon, 842 schleicheri (R. Hedw.) Milde, 856 speciosum (Brid.) Jur., 855 stokesii (Tunrer) Schimp., 851

995 striatulum (Spruce) Schimp, 849, 850 striatum (Schreb. ex Hedw.) Schimp., 846, 848 strigosum var. diversifolium (Schimp.) Anzi, 851 swartzii (Turner) Curn., 854; var. rigidum ´ 854 (Boul.) Ther, teesdalei (Schimp.) Milde, 860 tenellum (Dicks.) Milde, 857

Fissidens Hedw., 241 adianthoides Hedw., 257, 258 algarvicus Solms, 254 bryoides Hedw., 247, 248; ssp. incurvus ¨ (Starke ex Rohl.) Bertsch, 247 ssp. viridulus (Sw.) Kindb., 243 var. caespitans Schimp. 249 celticus Paton, 253, 254 crassipes Wilson ex Bruch & Schimp., 251, 252 cristatus Wilson ex Mitt., 256 curnovii Mitt., 248, 249 curvatus Hornsch., 253, 254 decipiens De Not., 256 dubius P. Beauv., 256, 257 exiguus Sull., 243, 248 exilis Hedw., 252, 253 fontanus (Bach. Pyl.) Steud., 260 gracilifolius Brugg.-Nann. & Nyhholm, 244, 247 herzogii Ruthe ex Herzog, 245 ¨ incurvus Starke ex Rohl., 247, 248 limbatus Sull., 244, 245 mildeanus Schimp. ex Milde, 252 minutulus auct., 246 minutulus Sull., 245 ´ 250, 251 monguillonii Ther., osmundoides Hedw., 253, 255 pallidicaulis Mitt., 256 polyphyllus Wilson ex Bruch & Schimp., 259, 260 pusillus (Wilson) Milde, 244, 246; var. tenuifolius Boulay, 247 rivularis (Spruce) Schimp., 250, 251; var. ´ Podp., 250 monguillonii (Ther.) rufulus Bruch & Schimp., 251, 252

996

Index

Fissidens Hedw. (cont.) serrulatus Brid., 258, 259 taxifolius Hedw., 255; ssp. pallidicaulis ¨ (Mitt.) Monk., 256; var. pallidicaulis (Mitt.) Corb., 256, 257; var. taxifolius, 257 viridulus (Sw.) Wahlenb., 243, 244; var. bambergeri (Schimp.) Waldh., 243; var. lylei Wilson, 246; var. tenuifolius (Boulay) A. J. E. Sm., 247 Fissidentaceae, 240 Fontinalaceae, 703 Fontinalis Hedw., 703 antipyretica Hedw, 704; var. antipyretica, 704, 705; var. cymbifolia W. E. Nicholson, 705, 706; var. gigantea (Sull.) Sull., 705, 706; var. gracilis (Hedw.) Schimp., 705, 706 dalecarlica Bruch et al., 708 dixonii Cardot, 708 dolosa Cardot, 706 hypnoides Hartm., 708 seriata Lindb., 708 squamosa Hedw., 706, 707; var. curnowii Cardot, 707, 708; var. dixonii (Cardot) A. J. E. Sm., 708; var. squamosa, 707, 707 Funaria Hedw., 506 attenuata (Dicks.) Lindb., 509 calcarea Wahlenb., 507 ericetorum (Bals.-Criv. & De Not.) Dixon, 509 fascicularis (Hedw.) Lindb., 510 hygrometrica Hedw., 505, 506 mediterranea Lindb., 507 muhlenbergii Turner, 507 obtusa (Hedw.) Lindb., 509 pulchella H. Philib., 507 templetonii Sm., 509 Funariaceae, 504 Funariales, 504 Funariideae, 494 Glyphomitrium (Dicks.) Brid., 476 daviesii (Dicks.) Brid., 475 Grimmia Hedw., 427 affinis Bornsch., 442

agassizii (Sull. & Lesq.) A. Jaeger, 407 alpestris auct., 438 alpestris (F. Weber & D. Mohr) Schleich., 438 alpicola var. rivularis (Brid.) Wahlenb, 403 andraeaoides Limpr., 319 anodon Bruch & Schimp., 430, 431 apocarpa Hedw., 408; var. alpicola auct., ¨ 406; var. gracilis Rohl., 413; var. homodictyon (Dixon) Crundw., 416 arenaria Hampe, 440, 441 atrata Miel. ex Hornsch., 443, 444 atrofusca Schimp., 421 austrofunalis auct., 449 britannica A. J. E. Sm., 449 campestris Burchell ex Hook., 432 commutata Huebener, 434 conferta Funck, 417; var. pruinosa (Wilson) Braithw., 412 cribrosa Hedw., 398 crinita Brid., 431, 431 curvata (Brid.) De Sloover, 456 decipiens (Schultz) Lindb., 454, 455 dissimulata E. Maier, 451 donniana Sm., 439, 440; var. arenaria (Hampe) Loeske, 441; var. curvula Spruce, 441 elatior Bruch ex Bals.-Criv. & De Not., 455, 456 elongata Kaulf., 440, 442 ¨ funalis (Schwagr.) Bruch & Schimp., 447, 448 hartmanii Schimp., 453, 453 homodictyon Dixon, 416 ¨ incurva Schwagr., 448, 449 laevigata (Brid.) Brid., 432, 433 leucophaea Grev., 432 lisae De Not., 452, 453 longirostris Hook., 442, 443 maritima Turner, 403 meuhlenbeckii Schimp., 451 montana Bruch & Schimp., 436, 437 orbicularis Bruch ex Wilson, 445, 446 ovalis (Hedw.) Lindb., 434, 435 ovalis auct., 442 ovata F. Weber & D. Mohr, 434 ¨ ovata Schwagr., 442

Index patens (Dicks. ex Hedw.) Bruch & Schimp., 456 pulvinata (Hedw.) Sm., 445, 445; var. africana (Hedw.) Hook. f. & Wilson, 445 ramondii (Lam. & DC) Margad., 455, 456 ¨ Hal., 438 reflexidens Mull. retracta Stirt., 452 sessitana auct., 438 sessitana De. Not., 438 stirtonii Schimp., 449 stricta Turner, 413 subsquarrosa Wilson, 452 tergestina Tomm. ex Bruch & Schimp., 433, 433 torquata Hornsch. ex Drumm., 447, 448 trichodon Brid., 408 trichophylla Grev., 449, 450; var. robusta (Ferg. Ex Braithw.) A. J. E. Sm., 449; ¨ var. stirtonii (Schimp.) Moll.; var. subsquarrosa (Wilson) A. J. E. Sm., 452; var. tenuis (Wahlenb.) Wijk & Margad., 451 umgeri Jur., 437, 438 unicolor Hook., 434, 435 Grimmiaceae, 397 Grimmialaes, 397 Gymnostomum Nees & Hornsch., 307 aeruginosum Sm., 310, 311 calcareum Nees & Hornsch., 308, 309 insigne (Dixon) A. J. E. Sm., 303 recurvirostrum Hedw., 303; var. cataractacum (Schimp.) Podp., 303; var. insigne (Dixon) P. W. Richards & E. C. Wallace, 303 ´ ´ luisieri (Sergio) Sergio & Crundw., 308 viridulum Brid., 308, 309 Gyroweisia Schimp., 306 ´ luisieri Sergio, 308 reflexa (Brid.) Schimp., 305, 307 tenuis (Schrad. ex Hedw.) Schimp., 305, 306 Habrodon Schimp., 730 notarisii Schimp., 730 perpusillus (De Not.) Lindb., 729, 730

997

¨ 792 Hamatocaulis Hedenas, ¨ 792, 793 vernicosus (Mitt.) Hedenas, Haplodon wormskjoldii auct., 517 Hedwigia P. Beauv., 691 ciliata (Hedw.) P. Beauv., 691; var. ciliata, 692, 693; var. leucophaea Bruch & Schimp., 692, 693 imberberbis (Sm.) Spruce, 694 ¨ 692, 695 stellata Hedenas, integrifolia P. Beauv., 694, 695 Hedwigiaceae, 690 Hedwigiales, 690 Hedwigidium integrifolium (P. Beauv.) Dixon, 694 Helicodontium pulvinatum (Wahlenb.) Lindb., 735 Helodiaceae, 754 Helodium Warnst., 754 blandowii (F. Weber & D. Mohr) Warnst., 753, 754 Hennediella Paris, 372 heimii (Hedw.) R. H. Zander, 371, 375 macrophylla (R. M. Br.) Paris, 373, 374 stanfordensis (Steere) Blockeel, 372, 374 Herzogiella Broth., 882 seligeri (Brid.) Z. Iwats., 883, 884 striatella (Brid.) Z. Iwats., 883, 884 Heterocladium Schimp., 731 dimorphum Schimp., 729, 734 flaccidum (Milde) A. J. E. Sm., 732, 733 ¨ heteropterum (Bruch ex Schwagr.) Schimp., 731, 732; var. fallax Milde, 733; var. flaccidum Schimp., 733; var. wulfsbergii, (I. Hagen) C. E. O. Jensen & H. Perss., 733 macounii Best, 733 squarrosulum Lindb., 734 wulfsbergii I. Hagen., 732, 733 Homalia (Brid.) Schimp., 722 trichomanoides (Hedw.) Schimp., 722, 723 Homalothecium Schimp., 816 lutescens (Hedw.) H. Rob., 817, 817; var. fallax (H. Philib.) Duell, 818 nitens (Hedw.) H. Rob., 794 sericeum (Hedw.) Schimp., 816, 817

998

Index

Homomallium (Schimp.) Loeske, 896 incurvatum (Schrad. ex Brid.) Loeske, 896, 897 Hookeria Sm., 698 lucens (Hedw.) Sm., 698, 699 Hookeriaceae, 698 Hookeriales, 698 Hygroamblystegium Loeske, 768 fluviatile (Hedw) Loeske, 768, 769 tenax (Hedw.) Jenn., 769, 770 Hygrohypnum Lindb., 800 dilatatum (Wilson)Loeske, 807 duriusculum (De. Not.) Jamieson, 807, 808 eugyrium (Schimp.) Broth., 805, 806 luridum (Hedw.) Jenn., 802; var. luridum, 803, 804; var. subsphaericarpon (Schleich. ex Brid.) C. E. O. Jensen, 803, 804 lusitanicum (Schimp.) Corb., 842 micans (Mitt.) Roth, 886 molle (Hedw.) Loeske, 806, 807 ochraceum (Turner ex Wilson) Loeske, 801, 801 polare (Lindb.) Loeske, 801, 802 smithii (Sw.) Broth., 805, 806 styriacum (Limpr.) Broth., 803, 804 Hylocomiaceae, 923 Hylocomiastrum M. Fleisch., 931 pyrenaicum (Spruce.) M. Fleisch., 932, 933 umbratum (Hedw.) M. Fleisch., 932, 933 Hylocomium Schimp., 934 brevirostre (Brid.) Schimp., 931 loreum (Hedw.) Schimp., 929 pyrenaicum (Spruce.) Lindb., 932 rugosum (Hedw.) De Not., 923 splendens (Hedw.) Schimp., 934, 935 squarrosum (Hedw.) Schimp., 927 triquetrum (Hedw.) Schimp., 926 umbratum (Hedw.) Schimp., 932 Hymenostomum microstomum (Hedw.) R. Br., 270 rostellatum (Brid.) Schimp., 272 squarrosum Nees & Hornsch., 272 ¨ tortile (Schwagr.) Bruch & Schimp., 269

Hymenostylium Brid., 302 insigne (Dixon) Podp., 301, 303 recurvirostrum (Hedw.) Dixon, 301, 303 Hyocomioideae, 922 Hyocomium Schimp., 922 armoricum (Brid.) Wijk & Margad., 921, 922 flagellare Schimp., 922 Hyophila stanfordensis (Steere) A. J. E. Sm. & H. Whitehouse, 373 Hypnaceae, 888 Hypnales, 703 Hypnoideae, 896 Hypnum Hedw., 898 aduncum Hedw., 780 andoi A. J. E. Sm., 907, 907 arcticum (Sommerf.) Loeske, 805 bambergeri Schimp., 912, 914 callichroum Brid., 910, 914 canariense Mitt., 908 chrysophyllum Brid., 775 commutatum Hedw., 755 cordifolium Hedw., 787 crista-castrensis Hedw., 916 cupressiforme Hedw., 901, 902; var. elatum Schimp., 905; var. ericetorum Schimp., 911; var. filiforme Brid., 903; var. lacunosum Brid., 905; var. mammillatum Brid., 907; var. resupinatum (Taylor) Schimp., 909; var. tectorum Brid., 905 cupressiforme complex, 901 cuspidatum Hedw., 891 decipiens De Not., 758 dilatatum Wilson ex Schimp., 807 dolomiticum Milde, 900 elodes Spruce, 777 ericetorum (Schimp.) Loeske, 911 eugyrium Schimp., 805 exannulatum Schimp., 784 falcatum Brid., 758 fluitans Hedw., 782 giganteum Schimp., 787 halleri Sw. ex Hedw., 891 hamulosum Schimp., 915, 915 heseleri Ando & Higuchi, 903 hispidulum var. sommerfeltii auct., 889

Index imponens Hedw., 911, 913 incurvatum Schrad. ex Brid., 896 intermedium (Brid.) F. Weber & D. Mohr, 791 jutlandicum Holmen & Warncke, 911, 912 lacunosum (Brid.) G. F. Hoffman ex Brid., 903; var. lacunosum, 904; var. tectorum (Brid.) J. P. Frahm, 905, 906 lindbergii Mitt., 892 lycopodioides Brid., 795 mammillatum (Brid.) Loeske, 907 molle Hedw., 807 molluscum Hedw., 917 ochraceum Turner ex Wilson, 801 palustre Huds., 802 patientiae Lindb, ex Milde, 892 polygamum Schimp., 778 procerrimum Molendo, 920 resupinatum Taylor, 909, 910 revolutum (Mitt.) Lindb., 900; var. ¨ dolomiticum (Milde) Monk., 897; var. revolutum, 897, 900 revolvens Sw. riparium Hedw., 770 sarmentosum Wahlenb., 784 schreberi Willd. Ex Brid., 924 scorpioides Hedw., 789 sendtneri Schimp., 779 stellatum Hedw., 774 stramineum Brid., 786 sulcatum Lindb., 757 trifarium F. Weber D. Mohr, 797 turgescens T. Jensen, 795 uncinatum Hedw., 797 uncinulatum Jur., 906, 908 vaucheri Lesq., 897, 900 vernicosum Mitt., 792 wilsonii Lindb., 779 Isopterygiopsis Z. Iwats., 880 muelleriana (Limpr.) Z. Iwats., 879, 880 pullchella (Hedw.) Z. Iwats., 879, 881 Isopterygium depressum (Brid.) Mitt., 885 elegans (Brid.) Lindb., 882 muellerianum (Schimp.) A. Jaeger, 880 piliferum (Schwartz) Loeske, 868

999

pulchellum (Hedw.) A. Jaeger, 881 seligeri (Brid.) Dixon, 884 wissgrillii (Garov.) Gillet-Lefebvre, 885 Isothecium Brid., 810 alopecuroides (Dubois) Isoviita, 813, 814 holtii Kindb., 812, 813 myosuroides Brid. 811; var. brachythecioides (Dixon) C. E. O. Jensen, 811, 812; var. myosuroides, 811, 812; var. rivulare Holt ex Limpr., 813 myurum Brid., 813 striatulum (Spruce) Kindb., 849 Kiaeria I. Hagen, 196 blyttii (Bruch & Schimp.) Broth., 195, 197, 198 falcata (Hedw.) I. Hagen, 195, 196, 197 glacialis (Berggr.) I. Hagen, 195, 197, 199 starkei (F. Weber & D. Mohr) I. Hagen, 195, 197, 199 Kindbergia Ochyra, 851 praelonga (Hedw.) Ochyra, 851, 852 Leptobarbula Schimp., 343 berica (De Not.) Schimp., 343, 344 Leptobryum (Bruch & Schimp.) Wilson, 524 pyriforme (Hedw.) Wilson, 524, 525 Leptodictyum (Schimp.) Warnst., 770 humile (P. Beauv.) Ochyra., 765 kochii (Schimp.) Warnst. 765 riparium (Hedw) Warnst., 770, 771 trichopodium (Schultz) Warnst., 765 Leptodon D. Mohr, 717 smithii F. Weber & D. Mohr, 718, 719 Leptodontaceae, 717 ¨ Hal.) Limpr., 300 Leptodontium (Mull. flexifolium (Dicks.) Hampe, 300, 301 gemmascens(Mitt.) Braithw., 301, 302 recurvifolium (Taylor) Lindb., 292 ¨ Hal.) J. Guerra & M. Leptophascum (Mull. Cano, 378 ¨ Hal.) J. Guerra & M. leptophylum (Mull. Cano, 378, 379 ¨ Leptotheca Schwagr., 694 ¨ gaudichaudii Schwagr., 696, 697

1000

Index

Lescuraea Schimp., 741 incurvata (Hedw.) E. Lawton, 740 patens Lindb., 740 plicata (Schleich. ex F. Weber & D. Mohr) Lindb., 743 saxicola (Schimp.) Milde, 741, 742; var., mutabilis (Schimp.) I. Hagen, 741 Leskea Hedw., 735 nervosa (Brid.) Myrin, 739 polycarpa Hedw., 736, 737 Leskeaceae, 735 Leskeella nervosa (Brid.) Loeske, 739 Leucobryaceae, 239 Leucobryum Hampe, 239 albidum (Brid. ex P. Beauv.) Lindb., 240 glaucum (Hedw.) Ångstr., 238, 239 ¨ Hal., 238, juniperoideum (Brid.) Mull. 240 minus (Hampe) Sull., 240 ¨ Leucodon Schwagr, 712 ¨ sciuroides (Hedw.) Schwagr., 713; var. ¨ morensis (Schwagr.) De Not., 714; var. sciuroides, 713, 713 Leucodontaceae, 712 Limprichtia cossonii (Schimp.) Anderson et al., 791 revolvens (Sw.) Loeske, 791 Loeskeobryum M. Fleisch., 929 brevirostre (Brid.) M. Fleisch., 930, 931 Meesia Hedw., 521 trichodes Spruce, 523 trifaria (Hedw. F.) Crum et al., 523 triquetra (A. Richter) Ångstr., 522, 523 tristicha Bruch, 523 uliginosa Hedw., 522, 523 Meesiaceae, 521 Merceyoideae, 292 Microbryum Schimp., 369 curvicolle (Hedw.) R. H. Zander, 370, 371 davallianum (Sm.) R. H. Zander, 369 floerkeanum (F. Weber & D. Mohr) Schimp., 371, 372 rectum (With.) R. H. Zander, 370, 371 starkeanum (Hedw.) R. H. Zander, 367

Micromitrium Austin, 391 tenerum (Bruch & Schimp.) Crosby, 391, 392 Mielichhoferia Hornsch., 591 elongata (Hoppe & Hornsch.) Nees & Hornsch., 590, 591 mielichhoferi (Hook.) Wijk & Margad., 592 mielichhoferiana (Funck ex Hornsch.) Loeske, 590, 592 nitida (Hook.) Nees & Hornsch., 592 Mniaceae, 590 Mniobryum delicatulum (Hedw.) Dixon, 612 ¨ ludwigii (Sprengl. ex Schwagr.) Loeske, 609 lutescens (Limpr.) Loeske, 611 pulchellum (Hedw.) Loeske, 611 wahlenbergii (F. Weber & D. Mohr) Jenn., 614 Mnioideae, 615 Mnium Hedw., 615 affine Funck 629; var. elatum Bruch & Schimp., 631; var. rugicum (Laurer) Bruch & Schimp., 633 ¨ ambiguum H. Mull., 618, 619 cinclidioides Huebener, 636 cuspidatum Hedw., 628 ¨ dioicum H. Mull., 620 hornum Hedw., 616, 617 longirostrum Brid., 635 lycopodioides auct., 619 marginatum (With.) P. Beauv., 620; var. ¨ dioicum (H. Mull.) Crundw., 620; var. marginatum, 620, 621 medium Bruch & Schimp., 631 orthorrhynchum auct., 618 pseudopunctatum Bruch & Schimp., 626 punctatum Hedw., 623; var. elatum Schimp., 625 riparium Mitt., 620 rostratum Schrad., 635 rugicum Laurer, 633 seligeri auct., 631 serratum Schrad. ex Brid., 620 ¨ spinosum (Voit.) Schwagr., 617, 617 stellare Hedw., 621, 622

Index subglobosum Bruch & Schimp., 626 thomsonii Schimp., 618, 618 undulatum Hedw., 633 Molendoa Lindb., 310 warburgii (Crundw. & M. O. Hill) R. H. Zander, 311, 311 Myrinia Schimp., 734 pulvinata (Wahlenb.) Schimp., 735, 742 Myriniaceae, 734 Myurella Schimp., 862 apiculata (Heubener) Schimp., 863 ¨ julacea (Schwagr.) Schimp., 863, 864; var. scabrifolia Lindb. ex Limpr., 863 tenerrima (Brid.) Lindb., 863, 864 Myuriaceae, 717 Myurium Schimp., 717 hochstetteri (Schimp.) Kindb., 717, 723 hebridarum Schimp., 717 Nanomitrium tenerum (Bruch & Schimp.) Lindb., 391 Neckera Hedw., 719 complanata (Hedw.) Huebener, 718, 721; var. tenella Schimp., 722 crispa Hedw., 718, 720 pennata Hedw., 716, 720 pumila Hedw., 716, 721 Neckeraceae, 719 Nyholmiella gymnostoma (Brid.) Holmen & Warncke, 671 obtusifolia (Brid.) Holmen & Warncke, 671 Octodiceras Brid., 260 fontanum (Bach. Pyl.) Lindb., 259, 260 julianum Brid., 260 Oedipodiaceae, 140 ¨ Oedipodium Schwagr., 140 ¨ griffithianum (Dicks.) Schwagr., 138, 140 Oligotrichum Lam. & DC., 131 hercynicum (Hedw.) Lam. & DC., 131, 132 Omalia trichomanoides auct., 722 Oncophorus (Brid.) Brid. 176 virens (Hedw.) Brid., 176, 177 wahlenbergii Brid., 176, 177

1001

Oreas mielichhoferi var. elongata (Hoppe & Hornsch.), Bruch & Schimp., 591 Oreoweisia De Not., 170 bruntonii (Sm.) Milde, 170, 174 Orthodicranum flagellare (Hedw.) Loeske, 212 montanum (Hedw.) Loeske, 212 scottianum (Turner) Roth, 210 strictum (Dicks.) Broth., 210 Orthodontiaceae, 526 ¨ Orthodontium Schwagr., 526 ¨ gracile (Wilson) Schwagr. ex Bruch & Schimp., 525, 527; var heterocarpum W. Watson, 527 ¨ lineare Schwagr., 525, 527 Orthothecium Schimp., 865 intricatum Schimp., 864, 866; var. abbreviatum Dixon, 866 rufescens (Dicks. ex Brid.) Schimp., 864, 866 Orthotrichaceae, 659 Orthotrichales, 656 Orthotrichoideae, 664 Orthotrichum Hedw., 664 affine Schrad. ex Brid., 667, 670; var. fastigiatum (Brid.) Heubener, 670 anomalum Hedw., 679, 680; var. saxatile auct., 679 consimile Mitt., 672 cupulatum Brid., 681, 682; var. nudum (Dicks.) Braithw., 681; var. riparium Huebener, 681, 682 diaphanum Brid., 677, 678 gymnostomum Bruch ex Brid., 668, 671 leiocarpum Bruch & Schimp., 667 lyellii Hook. & Taylor, 666, 667 obtusifolium Brid., 668, 671 pallens Bruch ex Brid., 676, 677 patens Bruch ex Bruch, 676 pulchellum Brunton, 672, 680 pumilum Sw., 677, 677 rivulare Turner, 673, 674 ¨ rupestre Schleich. ex Schwagr., 679, 680 schimperi Hammar, 677 shawii Wilson, 668, 669 speciosum Nees, 667, 670 sprucei Mont., 673, 674

1002

Index

Orthotrichum Hedw. (cont.) stramineum Hornsch. ex Brid., 674, 676; var. patens (Bruch) Venturi, 676 striatum Hedw., 667, 668 tenellum Bruch ex. Brid., 674, 675 urnigerum Myrin, 681 Oxyrrhynchium (Schimp.) Warnst., 853 hians (Hedw.) Loeske, 852, 854 praelongum (Hedw.) Warnst., 851 pumilum (Wilson) Loeske, 860 ¨ 855, 856 schleicheri (R. Hedw.) Roll, speciosum (Brid.) Warnst., 855, 855 Oxystegus hibernicus (Mitt.) Hilp., 290 sinuosus (Mitt.) Hilp., 327 tenuirostis (Hook. & Taylor) A. J. E. Sm., 288 Paludella Brid., 521 squarrosa (Hedw.) Brid., 521, 522 Palustriella Ochyra, 754 commutata (Hedw.) Ochyra, 755; var. commutata, 755, 756; var. falcata (Brid.) Ochyra, 758; var. sulcata (Lindb.) Ochyra, 757, 757; var. virescens (Schimp.)Ochyra, 758 decipiens (De Not.) Ochyra, 757, 758 ¨ 756, 758 falcata (Brid.) Hedenas, Paraleptodontium D. G. Long, 292 recurvifolium (Taylor) D. G. Long, 292, 293 Paraleucobryum (Limpr.) Loeske, 237 longifolium (Ehrh. ex Hedw.) Loeske, 237, 238 Phascum Hedw., 362 curvicolle Hedw., 370 cuspidatum Hedw., 362; ssp. papillosum (Lindb.) Guerra & Ros, 364; var. curvisetum Nees & Hornsch., 362; var. cuspidatum, 363, 364; var. maximum auct., 365; var. papillosum (Lindb.) Roth, 363, 364; var. piliferum (Hedw.) Hook. & Taylor, 363, 364; var. schreberianum (Dicks.) Brid., 363 floerkeanum F. Weber & D. Mohr., 372 ¨ Hal., 378 leptophyllum Mull.

Philonotis Brid., 646 arnellii Husn., 648, 650 caespitosa Jur., 648, 650 calcarea (Bruch & Schimp.) Schimp., 653, 655 capillaris auct., 650 cernua (Mitt.) D. G. Griffin & W. R. Buck, 643, 654 fontana (Hedw.) Brid., 651, 652; var. pumila (Turner) Brid., 653; var. tomentella (Molendo) Dixon, 653 marchica Brid., 648, 649 rigida Brid., 647, 648 seriata Mitt., 652, 653 tomentella Molendo, 652, 653 wilsonii (Bruch & Schimp.) Mitt., 654 Physcomitrella patens (Hedw.) Bruch & Schimp., 513 Physcomitrium (Brid.) Brid., 510 eurystomum Sendtn., 511, 512 pyriforme (Hedw.) Hampe, 511, 512 ¨ sphaericum (C. E. Ludw.) Furnr., 512, 513 Pictus C. C. Towns., 809 scoticus C. C. Towns., 808, 809 Pilotrichaceae, 700 Plagiobryum Lindb., 528 demissum (Hook.) Lindb., 529, 530 zieri (Dicks. ex Hedw.) Lindb., 528, 529 Plagiomnioideae, 626 Plagiomnium T. J. Kop., 628 affine (Funck) T. J. Kop., 629, 630 cuspidatum (Hedw.) T. J. Kop., 627, 628 elatum (Bruch & Schimp.) T. J. Kop., 631, 632 ellipticum (Brid.) T. J. Kop., 630, 633 medium (Bruch & Schimp.) T. J. Kop., 627, 631 rostratum (Schrad.) T. J. Kop., 632, 635 undulatum (Hedw.) T. J. Kop., 633, 634 Plagiopus Brid., 639 oederi (Brid.)Limpr., 640 oederiana (Sw.) H. A. Crum & L. E. Anderson, 640, 641

Index Plagiotheciaceae, 862 Plagiotheciella latebricola (Schimp.) M. Fleisch., 868 pilifera (Schwartz) M. Fleisch., 868 Plagiothecium Schimp., 867 cavifolium (Brid.) Z. Iwats., 875, 876 curvifolium Schlieph. ex Limpr., 872, 873 denticulatum (Hedw,) Schimp., 870; var. aptychus (Spruce) Lees, 872; var. denticulatum, 870, 871; var. majus sensu Dixon, 874; var. obtusifolium (Turner) Moore, 871, 872; var. undulatum Ruth ex Geheeb, 872, 873 denticulatum–nemorale complex, 870 depressum (Brid.) Spruce, 885 elegans (Brid.) Schimp., 882 laetum Schimp., 874, 875 latebricola Schimp., 868, 869 muehlenbeckii Schimp., 884 muellerianum Schimp., 880 ¨ neglectum Monk., 878 nemorale (Mitt.) A. Jaeger, 877, 878 piliferum (Schwartz) Schimp., 868, 869 ¨ platyphyllum Monk., 874, 875 pulchellum (Hedw.) Schimp., 881 roseanum Schimp., 876 ruthei Limpr., 872 silesiacum auct., 884 striatellum (Brid.) Lindb., 884 succulentum (Wilson) Lindb., 876, 877 sylvaticum auct., 878 undulatum (Hedw.) Schimp., 878, 879 Plasteurhynchium meridionale (Schimp.) M. Fleisch., 849 striatulum (Spruce) M. Fleisch., 849 Platydictya Berk., 863 confervoides (Brid.) Crum, 767 jungermannioides (Brid.) H. A. Crum, 864, 865 Platygyrium Schimp., 895 repens (Brid.) Schimp., 893, 895 Platyhypnidium M. M. Fleisch., 840 alopecuroides (Brid.) A. J. E. Sm., 841, 842 riparioides (Hedw.) Dixon, 841, 841 rusciforme (Schimp.) M. Fleisch., 841

1003

Pleuridium Rabenh., 147 acuminatum Lindb., 146, 147 alternifolium Dixon, 147 axillare (Sm.) Lindb., 148 subulatum (Hedw.) Rabenh., 146, 147 subulatum F. Weber & D. Mohr, 147 Pleurochaete Lindb., 291 squarrosa (Brid.) Lindb., 291, 293 Pleurozium Mitt., 924 schreberi (Willd. ex Brid.) Mitt., 924, 925 Pogonatum P. Beauv., 118 aloides (Hedw.) P. Beauv., 120, 121; var. minimum (Chrome) Molendo, 122 ¨ alpinum (Hedw.) Rohl., 123 nanum (Schreb. ex Hedw.) P. Beauv., 120, 121 urnigerum (Hedw.) P. Beauv., 121, 122 Pohlia Hedw., 593 acuminata Hoppe & Hornsch., 596 albicans (Wahlenb.) Lindb., 614 ¨ andalusica (Hohn.) Broth., 603, 605 annotina (Hedw.) Lindb., 606, 610 annotina complex, 601 bulbifera (Warnst.) Warnst., 603, 605 camptotrachela (Renauld & Cardot) Broth., 607, 608 carnea (Schimp.) Lindb, 612 cruda (Hedw.) Lindb., 598, 599 crudoides (Sull. & Lesq.) Broth., 597, 598 ¨ cucullata (Schwagr.) Lindb., 600 delecatula (Hedw.) Grout, 612 ¨ Hal.) A. L. Andrews, drummondii (Mull. 601, 602 elongata Hedw., 595; var. acuminata (Hoppe & Hornsch.) Heubener, 596, 597 var. elongata, 596, 597; var. polymorpha,(Hoppe & Hornsch.) Nyholm, 596, 597 filiforme (Dicks) A. L. Andrews, 531 ˚ filum (Schimp.) Martensson, 602, 604 flexuosa Hook., 608; var. flexuosa, 607; var. pseudomuyldermansii (Arts et al.) A. J. E. Sm., 607, 609 gracilis (Bruch & Schimp.) Lindb., 604 lescuriana (Sull.) Ochi, 610, 611

1004

Index

Pohlia Hedw. (cont.) ¨ ludwigii (Sprengl. ex Schwagr.) Broth., 609, 610 lutescens (Limpr.) H. Lindb., 610, 611 ¨ major Schwagr., 596 melanodon (Brid.) J. Shaw, 612, 613 muyldermansii R. Wilczek & Demaret, 608 nutans (Hedw.) Lindb., 598, 599 obtusifolia (Brid.) L. F. Koch, 598, 600 polymorpha Hoppe & Hornsch., 596 proligera auct., 606 proligera (Lindb.) Lindb. ex Arnell, 606, 607 pulchella (Hedw.) Lindb., 611 rothii (Correns) Broth., 605 schleicheri Crum, 604 scotica Crundw., 602, 604 wahlenbergii (F. Weber & D. Mohr) A. L. Andrews, 614; var. calcarea (Warnst.) E. F. Warb., 613, 615; var. glacialis (Schleich. ex Vrid) E. F. Warb., 614; var. wahlenbergii, 613, 614 Pohlioideae, 591 Polytrichaceae, 118 Polytrichales, 118 Polytrichastrum G. L. Sm., 122 alpinum (Hedw.) G. L. Sm., 123, 124; var. septentrionale, 124 formosum (Hedw.) G. L. Sm., 125, 126 longisetum (Sw. ex Brid.) G. L. Sm., 123, 124 ¨ sexangulare (Florke ex Brid.) G. L. Sm., 125, 127 Polytrichopsida, 118 Polytrichum Hedw., 128 aloides Hedw., 120 alpestre Hoppe, 130 alpinum Hedw., 123; var. septentrionale (Sw.) Lindb., 123 aurantiacum Brid., 123 commune Hedw., 128; var. commune, 126, 129; var. humile Sw., 126, 129; var. minus De Not., 129; var. perigoniale (Michx.) Hampe, 126, 129 formosum Hedw., 125 gracile Metnz., 123

juniperinum Hedw., 127, 130; ssp. ¨ 130 strictum (Brid.) Nyl. & Sal., longisetum Sw. ex Brid., 123 nanum Schreb. ex Hedw., 120 norvegicum auct., 125 perigoniale Milde, 129 piliferum Hedw., 127, 130 ¨ sexangulare Florke ex Brid., 125 strictum Brid., 127, 130 urnigerum Hedw., 122 Porotrichum alopecurum (Hedw.) Dixon, 724 angustifolium Holt, 725 ¨ Pottia (Rchb.) Furnr., 365 asperula Mitt., 358 bryoides (Dicks.) Mitt., 362 ¨ Hal., caespitosa (Bruch ex Brid.) Mull. 290 commutata Limpr., 369 crinita Wilson ex Bruch & Schimp., 358 davalliana (Sm.) C. E. O. Jensen, 366, 369 ¨ heimii (Hedw.) Furnr., 375 ¨ 359 intermedia (Turner) Furnr., ¨ Hal., 357 lanceolata (Hedw.) Mull. ¨ ¨ Hal., 336 latifolia (Schwagr.) Mull. littoralis Mitt, 359 ¨ ¨ minutula (Schwagr.) Furnr., 369 recta (With.) Mitt., 370 ¨ Hal., 366, 367; starkeana (Hedw.) Mull. ¨ ssp. commutata (Schwagr.) D. F. ¨ Chamb. 369; ssp. conica (Schwagr.) D. F. Chamb., 369; ssp. minutula, ¨ (Schwagr.) D. F. Chamb., 369; var. ¨ brachyodus (Bruch & Schimp.) Mull. Hal., 367 truncata (Hedw.) Bruch & Schimp., 361; var. major (F. Weber & D. Mohr) Bruch & Schimp., 359 ¨ truncatula (With.) Buse, 361 viridifolia Mitt., 358 wilsonii (Hedw.) Schimp., 358; var. crinita (Wilson ex Bruch & Schimp.) Warnst., 358 Pottiaceae, 262 Pottiales, 261 Pottioideae, 335 Pottiopsis Blockeel & A. J. E. Sm., 290

Index caespitosa (Bruch ex Brid.) Blockeel & A. J. E. Sm., 289, 290 Protobryum (Limpr.) J. Guerra & M. J. Cano, 361 bryoides (Dicks.) J. Guerra & M. J. Cano, 362, 363 Pseudephemerum (Lindb.) I. Hagen, 148 nitidum (Hedw.) Loeske, 146, 148 Pseudobryum (Kindb.) T. J. Kop., 635 cinclidioides (Huebener) T. J. Kop., 634, 636 Pseudocalliergon (Limpr.) Loeske, 794 ¨ 795, 796 lycopodioides (Brid.) Hedenas, trifarium (F. Weber & D. Mohr) Loeske, 796, 797 turgescens (T. Jensen) Loeske, 795, 796 Pseudocrossidium R. S. Williams, 294 hornschuchianum (Schultz) R. H. Zander, 295, 296 revolutum (Brid.) R. H. Zander, 295, 296 Pseudoleskea Schimp., 740 atrovirens Schimp., 740 ¨ catenulata (Brid. ex Schwagr.) Schimp., 737; var. acuminata (Culm.) Crundw., 739 incurvata (Hedw.) Loeske, 736, 740 patens (Lindb.) Kindb., 736, 740 striata var. mutabilis Schimp., 741 Pseudoleskeella Kindb., 737 ¨ catenulata (Brid. ex Schwagr.) Kindb., 737, 738 var. acuminata (Culm.) J. J. Amann, 739 nervosa (Brid.) Nyholm, 738, 739 ¨ & rupestris (Berggr.) Hedenas ¨ Soderstrom, 738, 739 sibirica (Arnold) P. Wilson & D. H. Norris, 739 Pseudoscleropodium (Limpr.) M. Fleisch., 833 purum (Hedw.) M. M. Fleisch., 834, 834 Pseudostereodon procerrimum (Molendo) M. Fleisch., 920 Pseudotaxiphyllum Z. Iwats., 881 elegans (Brid.) Z. Iwats., 882, 883 Pterigynandraceae, 727 Pterigynandrum Hedw., 728

1005

filiforme Hedw. 728; var. filiforme, 728, 729; var. majus (De Not.) De Not., 730 Pterogonium Sw., 715 gracile (Hedw.) Sm., 715, 716 Pterygoneurum Jur., 336 lamellatum (Lindb.) Jur., 337, 338 ovatum (Hedw.) Dixon, 337, 338 Pterygophyllum lucens (Hedw.) Brid., 698 Ptilium De Not., 916 crista-castrensis (Hedw.) De Not., 915, 916 Ptychodium Schimp., 741 plicatum (Schleich. ex F. Weber & D. Mohr) Schimp., 742, 743 Ptychomitriaceae, 474 ¨ Ptychomitrium Furnr., 474 polyphyllum (Sw.) Bruch & Schimp., 474, 475 Pylaisia Schimp., 894 polyantha (Hedw. Schimp., 893, 894 Pylaisiella polyantha (Hedw.) Grout, 894 Pylaisioideae, 894 Racomitrium Brid., 457 aciculare (Hedw.) Brid., 460, 467 affine (Schleich. ex F. Weber & D. Mohr) Lindb., 463, 464 affine auct., 462 aquaticum (Brid. ex Schrad.) Brid., 460, 467 canescens (Hedw.) Brid., 472, 473; var. ericoides (F. Weber ex Brid.) Hampe, 470 ellipticum (Turner) Bruch & Schimp., 458, 460 elongatum Ehrh. ex Frisvoll, 471, 472 ericoides (F. Weber ex Brid.) Brid., 470, 470 fasciculare (Hedw.) Brid., 468, 469 heterostichum (Hedw.) Brid., 463, 464; var. alopecurum Huebener, 463; var. gracilescens Bruch & Schimp., 463 himalayanum (Mitt.) A. Jaeger, 465, 466 lanuginosum (Hedw.) Brid., 468, 469 macounii Kindb. ssp. alpinum (E. Lawton) Frisvoll, 458, 461 microcarpon auct., 465 microcarpon (Hedw.) Brid., 466

1006

Index

Racomitrium Brid. (cont.) obtusum (Brid.) Brid., 463 patens (Dicks. ex Hedw.) Huebener, 456 protensum (A. Braun) Huebener, 467 sudeticum (Funck) Bruch & Schimp., 461, 462 Rhabdoweisia Bruch & Schimp., 167 crenulata (Mitt.) H. Jameson, 168, 169 crispata (Dicks. ex With.) Lindb., 168, 169 denticulata (Brid.) Bruch & Schimp., 169 fugax (Hedw.) Bruch & Schimp., 167, 168 Rhabdoweisiaceae, 167 Rhacomitrium auct., 457 Rhizogoniaceae, 694 Rhizogoniales, 694 Rhizomnium (Broth.) T. J. Kop., 623 magnifolium (Hook.) T. J. Kop., 624, 625 perssonii T. J. Kop., 625 pseudopunctatum (Bruch & Schimp.) T. J. Kop., 626, 627 punctatum (Hedw.) T. J. Kop., 623, 624 Rhodobroideae, 589 Rhodobryum (Schimp.) Hampe, 589 ontariense (Kindb.) Paris, 589 roseum (Hedw.) Limpr., 589, 590 ´ spathulatum (Hornsch.) Pocs, 589 Rhynchostegiella (Schimp.) Limpr., 857 ¨ Hal.) Loeske., 773 compacta (Mull. curviseta (Brid.) Limpr., 858, 859 litorea (De Not.) Limpr., 858, 859 pallidirostra (Brid.) Loeske, 860 pumila (Wilson) E. F. Warb., 858, 860 teesdalei (Schimp.) Limpr., 860 tenella (Dicks.) Limpr., 857, 858; var. litorea (De Not.) P. W. Richards & E. C. Wallace, 859 teneriffae (Mont.) Dirske & Bouman, 858, 860 Rhynchostegium Schimp., 843 alopecuroides (Brid.) A. J. E. Sm., 842 confertum (Dicks.) Schimp., 844, 845 lusitanicum (Schimp.) A. J. E. Sm., 842 megapolitanum (Bland. ex F. Weber & D. Mohr) Schimp., 845, 846

murale (Hedw.) Schimp., 843, 844 riparioides (Hedw.) Cardot, 841 rotundifolium (Scop. ex Brid.) Schimp., 844, 847 rusciforme Schimp., 841 Rhytidiadelphus (Warnst.) Warnst., 925 brevirostris (Brid.) Nyholm, 931 calvescens (Lindb.) Roth, 927 loreus (Hedw.) WArnst., 929, 930 squarrosus (Hedw.) Warnst., 927, 928; ssp. calvescens (Lindb.) Giacom.), 927, 928; var. calvescens (Lindb.) Warnst., 927, 928 subpinnatus (Lindb. T. J. Kop., 927, 928 triquetrus (Hedw.) Warnst., 925, 926 Rhytidium (Sull.) Kindb., 923 rugosum (Hedw.) Kindb., 921, 923 Saelania Lindb., 158 caesia (Villars ex P. Beauv.) Lindb., 160 glaucescens (Hedw.) Broth., 160, 164 Sanionia Loeske, 797 orthothecioides (Lindb.) Loeske, 798, 799 uncinata (Hedw.) Loeske, 797, 798 Sarmentypnum sarmentosum (Wahlenb.) Tuom. & T. J. Kop., 784 Schistidium Brid., 399 agassizii Sull. & Lesq., 404, 407 alpicola auct., 406; var. rivulare (Brid.) Limpr., 403 apocarpum (Hedw.) Bruch & Schimp., 408, 409; var. confertum (Funck) H. ¨ Moller, 417; var. homodictyon (Dixon) Crundw. & Nyholm, 416 atrofuscum (Schimp.) Limpr., 421, 422 boreale Poelt, 413, 426 canariense Wint., 417 confertum (Funck) Bruch & Schimp., 416, 417 confusum H. H. Blom, 426 crassipilum H. H. Blom., 422, 423 ´ W. A. Weber, 415, 416 dupretii (Ther.) elegantulum H. H. Blom, 424; ssp. elegantulum, 424, 425; ssp. wilsonii H. H. Blom, 425, 426

Index flaccidum (De Not.) Ochyra, 418, 419 flexipile (Lindb. ex Broth.) Broth., 426 ¨ gracile (Rohl.) Limpr., 413 frigidum H. H. Blom, 420; var. frigidum, 419, 420; var. havaasii H. H. Blom, 419, 421 latifolium (J. E. Zetterst.) Weim, 406 lancifolium (Kindb.) H. H. Blom, 426 maritimum (Turner) Bruch & Schimp., 403, 404 papillosum Culm., 410, 411 platyphyllum (Mitt.) H. Perss., 405, 406 pruinosum (Wilson ex Schimp.) Roth, 411, 412 pulchrum H. H. Blom, 427 pulvinatum (Hedw.) Brid., 418 rivulare (Brid.) Podp., 403, 405; ssp. latifolium (J. E. Zetterst.) B. Bremer, 406 robustum (Nees & Hornsch.) H. H. Blom, 414, 416 singarense (Schiffn.) Laz., 427 ˚ strictum (Turner) Loeske ex Martensson, 413, 414 subjulaceum H. H. Blom, 427 trichodon (Brid.) Poelt, 408, 409; var. nutans H. H. Blom, 410, 426; var. trichodon, 410 umbrosum (Zetterst.) H. H. Blom, 427 venetum H. H. Blom., 427 Schistostega D. Mohr, 261 osmundacea D. Mohr, 261 pennata (Hedw.) F. Weber & D. Mohr, 259, 261 Schisostegaceae, 261 Scleropodium Schimp., 835 caespitosum (Wilson) Schimp., 835 ¨ Hal.) L. Koch, cespitans (Wilson ex Mull. 835, 836 illecebrum auct., 837 purum (Hedw.) Limpr., 834 tourettii (Brid.) L. F. Koch, 836, 837 tourretii auct., 837 Scopelophila (Mitt.) Lindb., 334 cataractae (Mitt.) Broth., 334, 335 Scorpidium (Schimp) Limpr., 789

1007

¨ 790, 791 cossonii (Schimp.) Hedenas, lycopodioides (Brid.) H. K. G. Paul, 795 ¨ 790, 791 revolvens (Sw.) Hedenas, scorpioides (Hedw.) Limpr., 789, 790 turgescens (T Jensen) Loeske, 795 vernicosum (Mitt.) Tuom., 792 Scorpiurium Schimp., 815 circinatum (Brid.) M. Fleisch. & Loeske, 814, 815 Seligeria Bruch & Schimp., 479 acutifolia Lindb., 482, 483; var. longiseta Lindb., 483 brevifolia (Lindb.) Lindb., 482, 483 calcarea (Hedw.) Bruch & Schimp., 487, 488 calycina Mitt. ex Lindb., 486, 487 campylopoda Kindb., 484, 485 carniolica (Breidl. & Beck) Nyholm., 491, 492 diversifolia Lindb., 484, 485 ¨ Hal., 487, 488 donniana (Sm.) Mull. lapponica Nyman & Uggla, 491 oelandica C. E. O. Jensen & Medelius, 491, 492 patula (Lindb.) Broth., 490, 490 paucifolia auct., 486 pusilla (Hedw.) Bruch & Schimp., 481, 482 recurvata (Hedw.) Bruch &. Schimp., 485, 486 trifaria (Brid.) Lindb., 489, 490 tristicha (Brid.) Bruch & Schimp., 489 Seligeriaceae, 477 Seligeriales, 477 Sematophyllaceae, 885 Sematophyllum Mitt., 886 demissum (Wilson) Mitt., 886, 887 micans (Hedw.) Braithw., 886, 887 novae-caesaraeae (Aust.) E. Britton, 886 substrumulosum (Hampe) E. Britton, 887, 888 Sharpiella seligeri (Brid.) Z. Iwats., 884 striatella (Brid.) Z. Iwats., 884 Sphagnaceae, 43 Sphagnales, 43 Sphagnopsida, 43

1008

Index

Sphagnum L. 44; section Acutifolia Wilson, 59; section Cuspidata (Lindb.) Schlieph. ex Schimp., 86; section Rigida (Lindb.) Schlieph. ex Limpr., 75; section Sphagnum, 46; section Squarrosa (Russow) Schimp., 55; section Subsecunda (Lindb.) Schlieph. ex Schimp., 78 acutifolium Ehrh. ex Schrad., 68; var. fuscum Schimp., 70; var. gracile Russow, 66; var. quinquefarium Lindb. ex Braithw., 65; var. subnitens (Russow & Warnst.) Dixon, 70 affine Renauld & Cardot, 49, 50 angustifolium (C. E. O. Jensen ex Russow) C. E. O. Jensen, 97, 98 auriculatum Schimp., 82; var. inundatum (Russow) M. O. Hill, 80 austinii Sull. ex Aust., 48, 49 balticum (Russow) Russow ex C. E. O. Jensen, 92, 93 bavaricum Warnst, 80 ¨ brevifolium (Lindb. ex Braithw.) Roll emend. Flatberg, 96 capillaceum (Weiss) Schrank, 68 capillifolium (Ehrh.) Hedw., 68; ssp. capillifolium, 68, 69; ssp. rubellum (Wilson) M. O. Hill, 68, 69; var., tenellum (Schimp.) Crum, 68 centrale C. E. O. Jensen, 52 compactum Lam. & DC., 77, 78 contortum auct., 82 contortum Schultz, 84, 85; var. platyphyllum (Lindb. ex Braithw.) Åberg, 86 cuspidatum Ehrh. ex Hoffm., 89, 90; var. majus Russow, 91 cymbifolium Hedw., 52 denticulatum Brid., 82, 83 dusenii Warnst., 91 fallax (H. Klinggr.) H. Klinggr., 96, 97 fimbriatum Wilson, 61, 61 flexuosum Dozy & Molk., 98, 99 fuscum (Schimp.) H. Klinggr., 67, 70 girgensohnii Russow, 62, 62; var. robustum (Russow) Dixon, 63

imbricatum Hornsch. ex Russow ssp. affine (Renauld & Cardot) Flatberg, 50; ssp. austinii (Sull. ex Aust.) Flatberg, 48 intermedium auct. non Hoffm., 95; var. riparium (Ångstr.) Lindb., 100 inundatum Russow, 80, 81 isoviitae Flatberg, 96 laricinum (Wilson) Spruce, 84; var. platyphyllum Lindb. ex Braithw., 86 lescurii Sull., 82 lindbergii Schimp. ex Lindb., 100, 101 majus (Russow) C. E. O. Jensen, 91, 92 magellanicum Brid., 54, 55 medium Limpr., 54 molle Sull., 73, 74 molluscum Bruch, 88 nemoreum auct., 68 obtusum Warnst., 95, 99 palustre L., 52; var. centrale (C. E. O. Jensen) A. Eddy, 51, 52; var. palustre, 52, 53 papillosum Lindb., 50, 51 parvifolium (Warnst.) Warnst., 98 platyphyllum (Lindb. ex Braithw.) Sull. ex Warnst., 85, 86 ¨ 70 plumulosum Roll, pulchrum (Lindb. ex Braithw.) Warnst., 94, 95 quinquefarium (Lindb. ex Braithw.) Warnst., 65, 65 recurvum agg., 95 recurvum var. amblyphyllum (Russow) Warnst., 98; var. balticum Russow, 93; var. brevifolium (Lindb. ex Braithw.) Warnst., 96; var. mucronatum (Russow) Warnst., 96; var. tenue H. Klinggr., 98 rigidum (Nees & Hornsch.) Schimp., 78 riparium Ångstr., 100, 101 ¨ 63 robustum Roll, rubellum Wilson, 68 rufescens (Nees & Hornsch.) Limpr., 82 russowii Warnst., 63, 64 skyense Flatberg, 72, 73 squarrosum Crome, 56, 57; var. teres Schimp. 58 strictum Sull., 76, 77 subbicolor auct. 52

Index subfulvum auct. Hib., 71 ¨ 72 subfulvum Sjors, subnitens Russow & Warnst., 70; ssp. ferrugineum Flatberg, 71; var. ferrugineum (Flatberg) M. O. Hill, 71; var. subnitens, 71, 72 subsecundum auct. Angl., 82 subsecundum Nees, 80, 81; var. bavaricum (Warnst.) Åberg, 80; var. inundatum (Russow) C. E. O. Jensen, 80 tenellum (Brid.) Bory, 88, 89 teres (Schimp.) Ångstr. 57, 58 viride Flatberg, 90 warnstorfianum Du Rietz, 66 warnstorfii Russow, 66, 67 Splachnaceae, 514 Splachnales, 514 Splachnum Hedw., 518 ampullaceum Hedw., 519, 520 ovatum Dicks. ex Hedw., 518 sphaericum Hedw., 518, 519 vasculosum Hedw., 519, 520 wormskjoldii Hornem., 517 Stegonia Venturi, 335 ¨ latifolia (Schwagr.) Venturi ex Broth., 336, 337 Stellariomnium stellare (Hedw.) M. C. Bowers, 622 Stokesiella praelonga (Hedw.) H. Rob., 851 ¨ 786 Straminergon Hedenas, ¨ 785, 786 stramineum (Brid.) Hedenas, Stroemia gymnostoma (Bruch ex Brid.) I. Hagen, 671 obtusifolia (Brid.) I. Hagen, 671 Stylostegium caespiticium (F. Weber & D. Mohr) Bruch & Schimp, 479 Swartzia inclinata (Hedw.) P. Beauv., 162 montana Lindb., 160 Syntrichia Brid., 380 amplexa (Lesq.) R. H. Zander, 386, 388 calcicola J. J. Amann, 381 calcicolens (W. A. Kramer) Duell, 381 intermedia Brid., 383, 384 laevipila Brid., 385, 386; var. laevipiliformis (De Not.) Amann, 385

1009 latifolia (Bruch ex Hartm.) Huebener, 386, 387 norvegica F. Weber & D. Morh, 379, 382 papillosa (Wilson) Jur., 386, 387 princeps (De Not.) Mitt., 383, 384 ruraliformis (Besch.) Cardot, 382 ruralis (Hedw.) F. Weber & D. Mohr, 381; var. ruraliformis (Besch.) Husn. ex T. Durand, 379, 382; var. ruralis, 379, 381 virescens (De Not.) Ochyra, 384, 385

Taxiphyllum M. Fleisch., 885 depressum (Brid.) Reim., 885 wissgrillii (Garov.) Wijk & Margad., 879, 885 Tayloria Hook., 514 lingulata (Dicks.) Lindb., 515, 516 longicollis (Dicks.) Dixon, 514 serrata var. tenuis (Dicks. ex With.) Bruch & Schimp., 514 tenuis (Dicks. ex With.) Schimp., 514, 515 Tetraphidaceae, 137 Tetraphidales, 137 Tetraphis Hedw., 137 browniana (Dicks.) Grev., 139; var. repanda (Funck) Hampe, 139 pellucida Hedw., 137, 138 Tetraplodon Bruch & Schimp., 516 angustatus (Sw. ex Hedw.) Bruch & Schimp., 515, 516 mnioides (Hedw.) Bruch & Schimp., 515, 516 wormskjoldii (Hornem.) Lindb., 517 ¨ Tetrodontium Schwagr., 139 ¨ brownianum (Dicks.) Schwagr., 138, 139 ¨ repandum (Funck) Schwagr., 138, 139 Thamnium alopecurum (Hedw.) Schimp., 724 angustifolium (Holt) Dixon, 725 Thamnobryaceae, 724 Thamnobryum Nieuwl., 724 alopecurum (Hedw.) Gangulee, 723, 724 angustifolium (Holt) Nieuwl., 725, 726 cataractacum N. G. Hodgetts & Blockeel, 726, 726 ´ fernandesii C. Serg., 727

1010

Index

Thuidiaceae, 746 Thuidium (Hedw.) Schimp., 749 abietinum (Hedw.) Schimp., 747 assimile (Mitt.) A. Jaeger, 751, 752 blandowii (F. Weber & D. Mohr) Schimp., 754 delicatulum (Hedw.) Schimp., 750, 751 histricosum Mitt., 747 philibertii Limpr., 752 recognitum (Hedw.) Lindb., 752, 753; var. delicatulum (Hedw.) Warnst., 714 tamariscinum (Hedw.) Schimp., 748, 749 Timmia Hedw., 494 austriaca Hedw., 494, 495 norvegica T. E. Zetterst., 495, 496 megapolitana Hedw., 495, 496 Timmiaceae, 494 Timmiales, 494 Tomentypnum Loeske, 793 nitens (Hedw.) Loeske, 793, 794 Tortella Limpr., 278 densa (Lorentz & Molendo) Crundw. & Nyholm, 281, 282 flavovirens (Bruch). Broth., 282, 284; ssp. limosella (Stirt.) Podp., 284; var. glareicola (A. Chr.) Crundw. & Nyholm, 282 fragilis (Hook. & Wilson) Limpr., 280, 281 inclinata (R. Hedw.) Limpr., 282, 283 inflexa (Bruch) Broth., 277, 283 limosella (Stirt.) P. W. Richards & E. C. Wallace, 282, 284 nitida (Lindb.) Broth., 280, 283 tortuosa (Hedw.) Limpr., 279, 280; fo. curta Albertson, 281 Tortula Hedw., 344 acaulon (With.) R. H. Zander, 362; var. papillosa (Lindb.) R. H. Zander, 364; var. pilifera (Hedw.) R. H. Zander, 364; var. schreberiaana (Dicks.) R. H. Zander, 365 aloides (D. J. Koch ex Schultz) De Not., 342 ambigua (Bruch & Schimp.) Ångstr., 342 amplexa (Lesq.) Steere, 388 angustata Limpr., 347 atherodes R. H. Zander, 362

atrovirens (Sm.) Lindb., 356, 357 brevirostris Hook. & Grev., 339 brevis H. Whitehouse & M. E. Newton, 373 calcicolens W. A. Kramer, 381 canescens Mont., 352, 353 cernua (Huebener) Lindb., 355, 356 crinita (De Not.) De Not., 383 cuneifolia (Dicks.) Turner, 348, 349 freibergii Dixon & Loeske, 349, 350 intermedia (Brid.) De Not., 383 ¨ laevipila (Brid.) Schwagr., 385 lamellata Lindb., 338 lanceola R. H. Zander, 357, 360 latifolia Bruch ex Hartm., 387 leucostoma (R. W. Br.) Hook. & Grev., 355, 356 marginata (Bruch & Schimp.) Spruce, 351, 352 modica R. H. Zander, 359, 360 mutica Lindb., 387 muralis Hedw., 354; var. aestiva Hedw., 352, 354; var. muralis, 352; var. rupestris Chev., 354 norvegica (F. Weber) Wahlenb. ex Lindb., 382 papillosa Wilson, 387 princeps De Not., 383 protobryoides R. H. Zander, 362 pulvinata (Jur.) Limpr., 385 pusilla Mitt., 338 rhizophylla (Sakurai) Z. Iwats. & M. Saito, 378 rigida ((Hedw.) Schrad. ex Turner, 341 ruraliformis (Besch.) Ingham, 382 ruralis (Hedw.) P. Gaertn. et al.; ssp. ruraliformis (Besch.) Dixon, 382; var. alpina Wahlenb., 382; var. arenicola Braithw., 382 solmsii (Schimp.) Limpr., 350, 351 stanfordensis Steere, 373 suberecta Hook., 355 subulata Hedw., 346; var. angustata (Schimp.) Limpr., 347, 348; var. graeffii Warnst., 347, 348; var. subinermis (Bruch & Schimp.) Wilson 347, 348; var. subulata, 347, 348

Index truncata (Hedw.) R. H. Zander, 360, 361 vahliana (Schultz) Mont., 350, 353 vectensis E. F. Warb. & Crundw., 378 virescens (De Not.) De Not., 385 viridifolia (Mitt.) Blockeel & A. J. E. Sm., 358, 359 wilsonii (Hook.) R. H. Zander, 358, 359 Trematodon Michx., 166 ambiguus (Hedw.) Hornsch., 161, 166 Trematodontoideae Trichodon Schimp., 149 cylindricus (Hedw.) Schimp., 149, 150 Trichostomoideae, 262 ¨ Hal.) Trichostomopsis umbrosus (Mull. H. Rob., 322 Trichostomum Bruch, 285 brachydontium Bruch, 286, 286; var. cophocarpum (Schimp.) Cout., 287; var. littorale (Mitt.) C. E. O. Jensen, 287 caespitosum (Bruch ex Brid.) Jur., 290 crispulum Bruch, 286, 287; var. ¨ Hal.) brevifolium (Schimp. ex Mull. Bruch & Schimp., 287; var. elatum Schimp., 287; nigroviride (Braithw.) Dixon, 287; var. viridulum (Bruch) Dixon, 287 ¨ Hal., 288 cylindricum (Brid.) Mull. flavovirens Bruch, 284 ¨ Hal., 281 fragile (Hook. & Wilson) Mull. hibernicum (Mitt.) Dixon, 289, 290 inclinatum (R. Hedw.) Dixon, 283 limosellum (Stirt.) Dixon, 284 mutabile Bruch, 286 nitidum (Lindb.) Schimp., 283 recurvifolium (Taylor) R. H. Zander, 292 ¨ Hal., 327 sinuosum (Mitt.) Mull. tenuirostre (Hook. & Taylor) Lindb., 288; var. gemmiparum (Schimp.) R. H. Zander, 290; var. holtii (Braithw.) Dixon, 75, 289; var. tenuirostre, 288, 289 tortuosum (Hedw.) Dixon, 279 Trochobryum carniolicum Breidl. & Beck, 491 Ulota D. Mohr ex Brid., 681 americana (P. Beauv.) Schimp., 688 bruchii Hornsch. ex Brid., 685, 686

1011 calvescens Wilson, 688, 689 coarctata (P. Beauv.) Hammar, 682, 684 crispa (Hedw.) Brid., 685, 686; var. ¨ norvegica (Gronvald) A. J. E. Sm. & M. O. Hill, 685 crispula Brid., 684 drummondii (Hook. & Grev.) Brid., 682, 684 hutchinsiae (Sm.) Hammar, 688, 689 ludwigii Brid., 684 nicholsonii Culman, 685 phyllantha Brid., 689, 670 vittata Mitt., 688

Warnstorfia Loeske, 781 exannulata (Schimp.) Loeske, 783, 784 fluitans (Hedw.) Loeske, 782, 783 ¨ 784, sarmentosa (Wahlenb.) Hedenas, 785 Webera albicans (Wahlenb.) Schimp., 614 annotina (Hedw.) Bruch, var., 606; var. bulbifera (Warnst.) Correns ex Dixon, 605 carnea Schimp., 612 commutata Schimp., 601 ¨ cruda (Hedw.) Furnr., 599 ¨ cucullata (Schwaaegr.) Schimp., 600 ¨ elongata (Hedw.) Schwagr., 595 gracilis (Bruch & Schimp.) De Not., 604 ¨ ¨ ludwigii (Sprengl. ex Schwagr.) Furnr., 609 nutans Hedw., 599 polymorpha (Hoppe & Hornsch.) Schimp., 596 tozeri (Grev.) Schimp., 592 Weissia Hedw., 264 brachycarpa (Nees & Hornsch.) Jur., 270; var. brachycarpa, 270, 271; var. obliqua (Nees & Hornsch.) M. O. Hill, 270, 271 ¨ Hal., 308 calcarea (Nees & Hornsch.) Mull. condensa (Voit.) Lindb., 268, 269 controversa Hedw., 266; ssp. perssonii (Kindb.) Podp., 267; var. controversa, 263, 266; var. crispata (Nees & Hornsch.) Nyholm, 263, 266; var. densifolia (Bruch & Schimp.) Wilson, 263, 267

1012

Index

Weissia Hedw. (cont.) var. wimmeriana (Sendtn.) Blockeel & A. J. E. Sm., 263, 267 crispa auct., 278 crispa (Hedw.) Mitt., 276 var. aciculata (Hedw.) Dixon, 276 ¨ Hal., crispata (Nees & Hornsch.) Mull. 266 ¨ Hal., 303; var. curvirostris (Erhr.) Mull. insigne (Dixon) H. Schmidt, 303 fallax Sehlm., 266 levieri (Limpr.) Kindb., 274, 275 longifolia Mitt., 276; var. angustifolia (Baumgartner) Crundw. & Nyholm, 277, 278; var. longifolia, 276, 277 ludwigii Crum, 270 ¨ Hal., 270; var. microstoma (Hedw.) Mull. ¨ brachycarpa (Nees & Hornsch.) Mull. Hal., 270 var. microstoma, 270 mucronata Bruch & Schimp., 269 mittenii (Bruch & Schimp.) Mitt., 273 × mittenii (Bruch & Schimp.) Mitt. emend. A. J. E. Sm., 271, 273 multicapsularis (Sm.) Mitt., 273, 274 perssonii Kindb., 267, 268 reflexa Brid., 307 rostellata (Brid.) Lindb., 271, 272

¨ Hal., 310 rupestris (Schwaegr.) Mull. rutilans (Hedw.) Lindb., 268, 269 ¨ Hal., squarrosa (Nees & Hornsch.) Mull. 271, 272 sterilis W. E. Nicholson, 274, 275 ¨ Hal., 306 tenuis (Schrad. ex Hedw.) Mull. ¨ ¨ Hal., 269 tortilis (Schwagr.) Mull. verticillata Brid., 262 wimmeriana (Sendtn.) Bruch & Schimp., 267 Zygodon Hook. & Taylor., 659 baumgartneri Malta, 662 conoideus (Dicks.) Hook. & Taylor, 663; var. conoideus, 661, 663; var. lingulatus S. R. Edwards, 661, 663 forsteri (Dicks. ex With.) Mitt., 660, 661 gracilis Wilson, 661, 663 lapponicus (Hedw.) Bruch & Schimp., 657 mougeotii Bruch & Schimp., 658 rupestris Schimp., 661, 662 stirtonii Schimp., 661, 662 viridissimus (Dicks.) Brid., 660, 661; var. occidentalis Malta, 660; var. stirtonii (Schimp.) I. Hagen, 662 vulgaris Nyholm, 662 Zygodontoideae, 659

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