Flowering Plants. Eudicots: Berberidopsidales, Buxales, Crossosomatales, Fabales p.p... (The Families and Genera of Vascular Plants, Volume 9)

THE FAMILIES AND GENERA OF VASCULAR PLANTS Edited by K. Kubitzki Volumes published in this series Volume I Pteridop...

Author: Klaus Kubitzki

45 downloads 964 Views 31MB Size Report

This content was uploaded by our users and we assume good faith they have the permission to share this book. If you own the copyright to this book and it is wrongfully on our website, we offer a simple DMCA procedure to remove your content from our site. Start by pressing the button below!
Report copyright / DMCA form

DOWNLOAD PDF

THE FAMILIES AND GENERA OF VASCULAR PLANTS

Edited by K. Kubitzki

Volumes published in this series Volume I

Pteridophytes and Gymnosperms Edited by K.U. Kramer and P.S. Green (1990) Date of publication: 28.9.1990

Volume II

Flowering Plants. Dicotyledons. Magnoliid, Hamamelid and Caryophyllid Families Edited by K. Kubitzki, J.G. Rohwer, and V. Bittrich (1993) Date of publication: 28.7.1993

Volume III

Flowering Plants. Monocotyledons: Lilianae (except Orchidaceae) Edited by K. Kubitzki (1998) Date of publication: 27.8.1998

Volume IV

Flowering Plants. Monocotyledons: Alismatanae and Commelinanae (except Gramineae) Edited by K. Kubitzki (1998) Date of publication: 27.8.1998

Volume V

Flowering Plants. Dicotyledons: Malvales, Capparales and Non-betalain Caryophyllales Edited by K. Kubitzki and C. Bayer (2003) Date of publication: 12.9.2002

Volume VI

Flowering Plants. Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales Edited by K. Kubitzki (2004) Date of publication: 21.1.2004

Volume VII

Flowering Plants. Dicotyledons: Lamiales (except Acanthaceae including Avicenniaceae) Edited by J.W. Kadereit (2004) Date of publication: 13.4.2004

Volume VIII Flowering Plants. Eudicots: Asterales Edited by J.W. Kadereit and C. Jeffrey (2007) Volume IX

Flowering Plants. Eudicots: Berberidopsidales, Buxales, Crossosomatales, Fabales p.p., Geraniales, Gunnerales, Myrtales p.p., Proteales, Saxifragales, Vitales, Zygophyllales, Clusiaceae Alliance, Passifloraceae Alliance, Dilleniaceae, Huaceae, Picramniaceae, Sabiaceae Edited by K. Kubitzki (2007)

The Families and Genera of Vascular Plants Edited by K. Kubitzki

IX

Flowering Plants · Eudicots Berberidopsidales, Buxales, Crossosomatales, Fabales p.p., Geraniales, Gunnerales, Myrtales p.p., Proteales, Saxifragales, Vitales, Zygophyllales, Clusiaceae Alliance, Passifloraceae Alliance, Dilleniaceae, Huaceae, Picramniaceae, Sabiaceae

Volume Editor: K. Kubitzki in Collaboration with C. Bayer and P. F. Stevens

With 174 Figures

123

Professor Dr. Klaus Kubitzki Universität Hamburg Biozentrum Klein-Flottbek und Botanischer Garten Ohnhorststraße 18 22609 Hamburg Germany

Library of Congress Control Number: 2006928744

ISBN-10 3-540-32214-0 Springer Berlin Heidelberg New York ISBN-13 978-3-540-32214-6 Springer Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permissions for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. Springer is a part of Springer Science+Business Media springer.com © Springer-Verlag Berlin Heidelberg 2007 The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Cover design: WMXDesign, Heidelberg, Germany Typesetting and production: LE-TEX Jelonek, Schmidt & Vöckler GbR, Leipzig, Germany Printed on acid-free paper

31/3150/YL – 5 4 3 2 1 0

Preface

The present volume contains treatments of various eudicot orders which all are strongly supported in molecular analyses. A first group comprises Proteales, Buxales and the enigmatic Sabiaceae which, together with Ranunculales and Trochodendrales, treated earlier in Vol. II of this series, represent the basal grade of early-diverging eudicots. Although all of them have clearly tri-orate pollen, making them eudicots, they otherwise lack the strict eudicot floral organisation, particularly with regard to flower merosity, phyllotaxis and perianth structure. The same is true for the order Gunnerales which, however, according to findings of molecular systematics, forms part of the strongly supported core eudicots. All these orders to some extent bridge the morphological gap between basal angiosperms and typical core eudicots. Plesiomorphic floral traits, although less pronounced, are also found among the isolated but clearly core eudicotyledonous Saxifragales, treated in this volume, and particularly in the early-diverging woody families of this order. Some of these latter families were included in Vol. II, which followed a classification used prior to the discovery of the modern concept of Saxifragales. The exact interrelationships among the early-diverging eudicot orders still remain largely unresolved. This is even more true for many of the core eudicot orders included in the present volume, i.e. Vitales, Crossosomatales, Geraniales, Zygophyllales and Myrtales, and also for two of the families not assigned to order, i.e. Huaceae and Picramniaceae. A possible relationship between Dilleniaceae and woody Caryophyllales, as suggested by recent studies, opens an interesting new perspective on the evolution of this family. Included in this volume are two subclades of the vast Malpighiales. These are Passifloraceae with two satellite families, and Clusiaceae/Hypericaceae with Podostemaceae, which recently have been identified as very close relatives. My deep thanks go to all authors of this volume, who have provided such highly interesting and scholarly contributions, and to all those who have freely shared additional information and/or have commented on earlier drafts of the contributions. These include B.G. Briggs, T. Clifford, G. Jordan, B. Makinson, P. Olde, R. Barker, J.A. Doyle, P.J. Rudall and C.A. Furness (Proteaceae); H. Manitz (Aphanopetalaceae); A.E. Orchard (Haloragaceae); P.H. Linder and M. Weigend (Geraniales); A. Bernhard and W.J.J.O. de Wilde (Passifloraceae); the late M. Ricardi S. (Malesherbiaceae); I. Jäger-Zürn and T. Philbrick (Podostemaceae); and S. Renner, P.G. Wilson and J. Schönenberger (Myrtales). I am also grateful to M.L. Matthews and P.K. Endress for showing me their papers prior to publication elsewhere. Mark C. Chase is thanked for always making available the newest results of his pathbreaking studies. The copyright holders of the illustrations included in this volume are thanked for their generous permission to use their valuable material. As always, it is a pleasure to acknowledge the agreeable collaboration with the staff of Springer-Verlag, who kindly responded to all requests I had in connection with the production of this volume, and to thank Monique T. Delafontaine for her meticulous copy editing of the manuscript. Hamburg, September 2006

K. Kubitzki

Contents

Introduction to the Groups Treated in this Volume K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Berberidopsidales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Buxales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to the Clusiaceae Alliance (Malpighiales) . . . . . . . . . . . . . . . . . Introduction to Crossosomatales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Fabales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Geraniales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Gunnerales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Myrtales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to the Passifloraceae Alliance (“Passiflorales” = Malpighiales) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Proteales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Saxifragales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Vitales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Zygophyllales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Families Unassigned to Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General References

1 1 2 3 3 5 5 7 7 12 12 15 18 19 20

............................................

21

Aextoxicaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23

Alzateaceae

S.A. Graham . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

Aphanopetalaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29

Aphloiaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31

Berberidopsidaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

33

Bonnetiaceae

A.L. Weitzman, K. Kubitzki and P.F.Stevens . . . . .

36

Buxaceae

E. Köhler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40

Clusiaceae-Guttiferae

P.F. Stevens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

48

Combretaceae

C.A. Stace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67

Crassulaceae

J. Thiede and U. Eggli . . . . . . . . . . . . . . . . . . . . . . . .

83

Crossosomataceae

V. Sosa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Crypteroniaceae

S.S. Renner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Daphniphyllaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

VIII

Contents

Didymelaceae

E. Köhler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Dilleniaceae

J.W. Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

Geissolomataceae

F. Forest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

Geraniaceae

F. Albers and J.J.A. Van der Walt . . . . . . . . . . . . . . 157

Grossulariaceae

M. Weigend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

Gunneraceae

H.P. Wilkinson and L. Wanntorp . . . . . . . . . . . . . . 177

Haloragaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184

Huaceae

C. Bayer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

Hypericaceae

P.F. Stevens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

Iteaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

Ixerbaceae

J.V. Schneider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

Krameriaceae

B.B. Simpson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

Ledocarpaceae

M. Weigend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

Leeaceae

J. Wen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

Lythraceae

S.A. Graham . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

Malesherbiaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247

Melianthaceae

H.P. Linder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250

Oliniaceae

M. von Balthazar and J. Schönenberger . . . . . . 260

Paeoniaceae

M. Tamura . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

Passifloraceae

C. Feuillet and J.M. MacDougal . . . . . . . . . . . . . . 270

Penaeaceae

J. Schönenberger, E. Conti and F. Rutschmann . 282

Penthoraceae

J. Thiede . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292

Peridiscaceae

C. Bayer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

Picramniaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301

Podostemaceae

C.D.K. Cook and R. Rutishauser . . . . . . . . . . . . . . . 304

Polygalaceae

B. Eriksen and C. Persson . . . . . . . . . . . . . . . . . . . . 345

Proteaceae

P.H. Weston . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364

Pterostemonaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405

Quillajaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407

Rhynchocalycaceae

J. Schönenberger . . . . . . . . . . . . . . . . . . . . . . . . . . . 409

Sabiaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413

Saxifragaceae

D.E. Soltis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418

Stachyuraceae

J.V. Schneider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436

Staphyleaceae

S.L. Simmons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440

Strasburgeriaceae

W.C. Dickison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446

Contents

IX

Surianaceae

J.V. Schneider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449

Tetracarpaeaceae

K. Kubitzki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456

Turneraceae

M.M. Arbo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458

Vitaceae

J. Wen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467

Vochysiaceae

M.L. Kawasaki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480

Zygophyllaceae

M.C. Sheahan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488

Additions and Corrections to Volumes II–VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501 Index to Scientific Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503

List of Contributors

Albers, Focke

Botanischer Garten, Universität Münster, Schlossgarten 3, 48149 Münster, Germany

Arbo, María M.

Instituto de Botánica del Nordeste, Casilla de Correo 209, 3400 Corrientes, Rep. Argentina

Balthazar, Maria von

Swedish Museum of Natural History, Division of Palaeobotany, P.O. Box 50007, 10405 Stockholm, Sweden

Bayer, Clemens

Palmengarten der Stadt Frankfurt, Siesmayerstr. 61, 60323 Frankfurt/Main, Germany

Conti, Elena

Institut für Systematische Botanik und Botanischer Garten, Universität Zürich, Zollikerstr. 107, 8008 Zürich, Switzerland Institut für Systematische Botanik und Botanischer Garten, Universität Zürich, Zollikerstr. 107, 8008 Zürich, Switzerland (deceased)

Cook, Christopher D.K. Dickison, W.C. Eggli, Urs Eriksen, Bente

Sukkulenten-Sammlung, Mythenquai 88, 8002 Zürich, Switzerland Department of Botany, University of Göteborg, P.O. Box 461, 40530 Göteborg, Sweden

Feuillet, Christian

Department of Botany, Smithsonian Institution, P.O. Box 37012, Washington, DC 20013-7012, USA

Forest, Felix L.

School of Biological Sciences, Plant Sciences Laboratories, The University of Reading, Reading RG6 6AS, UK

Graham, Shirley A.

Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166-0299, USA

Horn, James W.

Department of Biology, Duke University, P.O. Box 90338, Durham, NC 27708-0338, USA. Present address: Fairchild Tropical Botanic Garden, 11935 Old Cutler Road, Miami, FL 33156-4242, USA

Kawasaki, M. Lúcia

Department of Botany, Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605-2496, USA

Köhler, Egon

Spezielle Botanik und Arboretum, Humboldt-Universität, Späthstr. 80/81, 12437 Berlin, Germany

Kubitzki, Klaus

Biozentrum Klein-Flottbek und Botanischer Garten, Universität Hamburg, 22609 Hamburg, Germany

XII

Linder, H. Peter

MacDougal, John M.


Institut für Systematische Botanik und Botanischer Garten, Universität Zürich, Zollikerstr. 107, 8008 Zürich, Switzerland Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166-0299, USA

Persson, Claes

Department of Botany, University of Göteborg, P.O. Box 461, 40530 Göteborg, Sweden

Renner, Susanne S.

Botanische Staatssammlung, Menzinger Str. 67, 80638 München, Germany

Rutishauser, Rolf

Institut für Systematische Botanik und Botanischer Garten, Universität Zürich, Zollikerstr. 107, 8008 Zürich, Switzerland Institut für Systematische Botanik und Botanischer Garten, Universität Zürich, Zollikerstr. 107, 8008 Zürich, Switzerland Spezielle Botanik, Universität Leipzig, Johannisallee 21–23, 04103 Leipzig, Germany

Rutschmann, Frank

Schneider, Julio V. Schönenberger, Jürg

Department of Botany, University of Stockholm, Lilla Frescativägen 5, 10691 Stockholm, Sweden

Sheahan, Mary C.

Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond SRY TW9 3DS, UK

Simmons, Sara L.

Department of Integrative Biology, University of Texas, Austin, TX 78712, USA

Simpson, Beryl B.

University of Texas, Section of Integrative Biology, 1 University Station A 6700, Austin, TX 78712, USA

Soltis, Douglas E.

Department of Botany, University of Florida, Gainesville, FL 32611-7800, USA

Sosa, Victoria

Instituto de Ecología, A.C., Apartado Postal 63, 91000 Xalapa, Veracruz, México

Stace, Clive A.

Department of Botany, University of Leicester, University Road, Leicester LE1 7RH, UK

Stevens, Peter F.

Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166-0299, USA

Tamura, Michio

4-25-7 Ao-gein, Mino, Osaka 562-0025, Japan

Thiede, Joachim

Schenefelder Holt 3, 22589 Hamburg, Germany

Van der Walt, J.J.A.

(deceased)

Wanntorp, Livia

Department of Botany, University of Stockholm, Lilla Frescativägen 5, 10691 Stockholm, Sweden

Weigend, Maximilian

Institut für Biologie/Systematische Botanik, Freie Universität Berlin, Altensteinstr. 6, 14195 Berlin, Germany

Weitzman, Anna L.



Wen, Jun


Weston, Peter

Royal Botanic Gardens, Mrs Macquaries Road, Sydney, NSW 2000, Australia

Wilkinson, Hazel P.

Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond SRY TW9 3DS, UK

XIII

Introduction to the Groups Treated in this Volume K. Kubitzki

Introduction to Berberidopsidales 1. Dioecious tree, young parts covered with ferrugineous scales; leaves conduplicate, entire; flowers 5(6)merous, enveloped in bud by firm calyptrate bract; stamens 5, alternating with nectary glands; gynoecium 1-carpellate; ovules 2, pendulous from apex of locule; style apically bifid; fruit dry, indehiscent; seed with ruminate endosperm and embryo of about half the length of seed. 1/1, S Chile and adjacent Argentina Aextoxicaceae – Scandent shrubs, largely glabrous; leaves involute (Berberidopsis), spiny-toothed or entire; flowers hermaphrodite, acyclic and with disk, or cyclic, pentamerous and without disk; gynoecium 3–5-carpellate; ovules several to many, each on 3–5 placentas; style not bifid; fruit berry-like; embryo small. 2/3, S Chile and SE Australia Berberidopsidaceae

A close relationship between Berberidopsidaceae and Aextoxicaceae has never been considered until gene sequence studies provided strong support for a relationship between them (see family treatments). In the four-gene analysis of eudicots (Soltis et al. 2003), Gunnerales and subsequently Berberidopsidales are sister to all other core eudicots, the latter being strongly supported by molecular data and isolated from all other clades (Fig. 1). Aextoxicum has long been known for its peculiar wood anatomy, particularly the high number of bars of the vessel element perforations. A recent study by Carlquist (2003) has revealed many important similarities in the wood anatomy of the two families, although these are plesiomorphic. Pollen grains are relatively small and tricolpate to indistinctly colporate. The two families share encyclocytic stomata (Soltis et al. 2005), a rare character in angiosperms, stout filaments, and a ring of vascular bundles in the petiole (Judd and Olmstead 2004). Unfortunately, many important characters are not known for both taxa but available information shows that Berberidopsidales are very plastic in their floral structure, combining (even within the same family, Berberidospidaceae) both spiral and whorled patterns, and 1-, 3- and 5-merous

gynoecia. The spiral sequence of initiation of floral organs in Berberidopsis, with a tendency of arrangement in alternating groups of five, may represent an incipient case of pentamery (Ronse DeCraene 2004) but this is problematic, in view of the firmly established pentamerous floral structure characteristic for core eudicots which exists in parts of Berberidopsidaceae and in the closely related Aextoxicum (see Berberidopsidaceae and Aextoxicaceae, this volume).

Fig. 1. A phylogenetic hypothesis of eudicot relationships, based on a four-gene dataset (Soltis et al. 2003)

2

K. Kubitzki

Morphologically, basal eudicots exhibit considerable structural disjunctions, which underlines their relict nature. This is also corroborated by the remarkable angiospermous fossil from the Early Cretaceous, Teixeira lusitanica, which shows affinities to members of Ranunculales, and to Berberidopsidaceae, Hamamelidaceae and Daphniphyllaceae (von Balthazar et al. 2005). Characters such as the dimerous floral structure, known from Gunnera, and presumably plesiomorphic traits (decurrent stigmas, antepetalous stamens, etc.), known from other basal eudicot families such as Proteaceae and Sabiaceae, are not found in Berberidopsidales.

References Balthazar, M. von, Pedersen, K.R., Friis, M.E. 2005. Teixeira lusitanica, a new fossil flower from the Early Cretaceous of Portugal with affinities to Ranunculales. Pl. Syst. Evol. 255:55–75. Carlquist, S. 2003. Wood anatomy of Aextoxicaceae and Berberidopsidaceae is compatible with their inclusion in Berberidopsidales. Syst. Bot. 28:317–325. Judd, W.S., Olmstead, R.G. 2004. A survey of tricolpate (eudicot) phylogenetic relationships. Amer. J. Bot. 91:1627–1644. Ronse DeCraene, L.P. 2004. Floral development of Berberidopsis corallina: a crucial link in the evolution of flowers in the core eudicots. Ann. Bot. 94:741–751. Soltis, D.E. et al. 2003. See general references. Soltis, D.E. et al. 2005. See general references.

Introduction to Buxales 1. Dioecious trees; flowers apetalous, male with one stamen pair, female often paired, a single carpel; pollen grains tricolpo-di-orate; seeds exalbuminous. 1/2, Madagascar Didymelaceae – Monoecious, rarely dioecious shrubs or herbs; flowers with weakly differentiated perianth, male with decussate tepals and 4, 6 or more stamens, female with spiral tepals and a 2–4-carpellate, syncarpous gynoecium; pollen grains 3–7-colporate with 3–6 pores per colpus, or pantoporate; seeds albuminous. 5/c. 100, all continents, except Australia Buxaceae

Buxales comprise Buxaceae and Didymelaceae, grouped together by traits such as cyclocytic stomata, leaf venation pattern, wood anatomical peculiarities including many sclereids, racemose inflorescences, small, imperfect, often dimerous flowers with decurrent stigmas extending the entire length of the stylodia, stamens with more or less basifixed anthers and conspicuous connective anther protrusions, and the occurrence of very

peculiar steroidal pregnan alkaloids. The most obvious trait of Buxales is the plasticity and simplicity of perianth organisation. In some of their members (Didymeles, male Styloceras), a perianth is completely lacking and, in Buxaceae, the tepals hardly differ from vegetative bracts below the flower (von Balthazar and Endress 2002a) and in female flowers they are spirally arranged, making the delimitation of flowers difficult. The stamens are always antesepalous and the stamen-sepalum complex of Buxaceae is similar to that of Proteaceae, also in the supply of the sepals by a single trace. Stamens, when occurring in low number, are arranged in dimerous whorls but, for higher numbers (in Notobuxus 6, 8, and up to more than 40), less regular arrangements prevail. Palynologically, Buxales are highly diverse (Bessedik 1983; Doyle 1999). An early fossil attributable to Buxales (Doyle 1999) is a pollen from the Aptian/Albian of northern Gondwana, which has simple colpate apertures and a striate(-reticulate) sculpture and has been related to the buxaceous megafossil Spanomera (Drinnan et al. 1991). In the late Albian of Gabon and Brazil, the tricolpodiorate pollen Hexaporotricolpites (Boltenhagen 1967) appears. This pollen type may be related to extant Didymeles from Madagascar (cf. Fig. 36), which has left a fossil record in the southern Indian Ocean, Australia, New Zealand and New Caledonia. Similar pollen grains with an increasing number of pores and meridional colpi, later in pantocolporate and eventually pantoporate configuration, the latter combined with a crotonoid exine pattern (cf. Fig. 11D), appear both in the fossil record and in extant Buxus (Köhler 1981; Köhler and Brückner 1982; Bessedik 1983). Buxales form part of the grade of earlydiverging tricolpate(-derived) dicots or eudicots, which also comprises Ranunculales, Sabiaceae, Proteales and Trochodendraceae (cf. Fig. 1). With several early-diverging eudicots, and partly also with some basal core eudicots (Gunneraceae, Myrothamnaceae and some basal families of Saxifragales), Buxales share characters which are known also from the eumagnoliids. Particularly remarkable are the dimerous flowers, the supply of the sepals by a single trace, and the stamensepalum complex, in which Buxaceae agree with Proteaceae. Conspicuous connective protrusions are known from other early-diverging eudicots and some basal core eudicots, including Proteaceae, Platanaceae, Trochodendraceae, Myrothamnaceae; basifixed anthers are widespread in early-diverging

Introduction to the Groups Treated in this Volume

eudicots. Elongate stigmas decurrent in two crests are shared with Platanaceae, Myrothamnaceae and Trochodendraceae but are also found in some Saxifragales. Nectary disks are rare in early-diverging eudicots and, apart from the intrastylodial nectariferous structures in Buxaceae, are known only from Proteaceae and Sabiaceae.

References Doyle, J.A. 1999. The rise of angiosperms as seen in the African Cretaceous pollen record. In: Heine, K. (ed.) Palaeoecology of Africa and the surrounding islands. Rotterdam: Balkema, pp. 3–29. For other references, see the selected bibliographies of Buxaceae and Didymelaceae, and the General References (this volume).

3

now well established (Soltis et al. 2000; Savolainen, Fay et al. 2000), and Podostemaceae appear sister to Hypericaceae or perhaps nested inside this family (Gustafsson et al. 2002). As the sinking of Podostemaceae in the broadly delimited Clusiaceae would lead to a highly heterogeneous unit, it appears preferable to “save” an independent family Podostemaceae by segregating Hypericaceae from Clusiaceae s.l., following the approach of many earlier authors such as Takhtajan (1997), although the separation in terms of contrasting characters between the latter two is not very strong. Characters common to the three families include resin cells and secretory ducts, containing xanthones, and bitegmic and tenuinucellate ovules.

References Introduction to the Clusiaceae Alliance (Malpighiales) 1. Annual cataract-dwellers with unclear differentiation of stems, roots and leaves (roots often crustaceous, ribbon-like; leaves sometimes terminal and doublesheathed); fertile pollen and fertilisable embryo sacs developed underwater; [pollination autogamous or cleistogamous, rarely allogamous; female gametophyte reduced Allium type; no double fertilisation and no endosperm; seed set high]. 49/c. 280, worldwide, tropical and warm-temperate regions Podostemaceae – Woody or herbaceous land plants 2 2. Leaves alternate, serrulate, initially setulose, convolute; latex 0; stamen connective glands 0; capsule with persistent column. 3/40, northern South America, West Indies, and SE Asia to New Guinea Bonnetiaceae – Leaves opposite or alternate, entire, not setulose, not convolute; latex often present in glands or secretory canals; stamen connectives often with glands producing oil or resin; fruit, if capsular, then rarely with persistent column 3 3. Stylodia free, at least distally; flowers perfect; sepals and petals 3–5; aril 0; trichomes, if multicellular, then stellate; woody or herbaceous. 9/540, worldwide Hypericaceae – Stylodia free or fused to form a simple style; flowers perfect or unisexual; sepals 2–20, petals 0–8; aril sometimes present; stellate hairs very rare (Caraipa, Marila); woody. 27/1090, pantropical Clusiaceae

Although these families have been intensely studied by generations of botanists, recent work has considerably modified our understanding of their phylogenetic relationships and details of their family and tribal delimitation. Molecular studies have revealed one enigma of long standing – the systematic position of Podostemaceae. Their close relationship with Clusiaceae s.l. (i.e. including Hypericaceae) is

For references, see the Selected Bibliography of ClusiaceaeGuttiferae and the General References (this volume).

Introduction to Crossosomatales 1. Perianth biseriate 2 – Perianth uniseriate; [flowers solitary] 6 2. Leaves opposite, pinnately compound, rarely unifoliolate; embryo green; [ovary syncarpous or apocarpous; ovules anatropous]. 2/40–50, temperate to tropical regions, mainly of the northern hemisphere Staphyleaceae – Leaves alternate, simple (if opposite and simple to slightly trilobate and gynoecium apocarpous, see Apacheria in Crossosomataceae); embryo achlorophyllous 3 3. Flowers solitary 4 – Flowers in panicles, racemes or spikes 5 4. Sepals 4–10; stamens 5 + 5; anthers dorsifixed; pistil 4–7-carpellate; style simple; ovules 1 per locule, anatropous; fruit indehiscent, fibrous; seed with rudimentary aril; embryo straight; vessel element perforation scalariform; T-shaped unicellular trichomes present. 1/1, New Caledonia Strasburgeriaceae – Sepals (3)4–5(6); stamens 4–50 (flower haplostemonous, diplostemonous or polystemonous); anthers basifixed; gynoecium apocarpous, 1–5(–9)-carpellate; ovules 1–many per carpel, campylotropous; fruit follicular; seed arillate; embryo curved; vessel element perforation mostly simple; T-shaped trichomes 0. 4/10, North America, with Mexico Crossosomataceae 5. Flowers strictly 5-merous; ovules 2 per locule; pollen 4(5)-colporate; fruit capsular; aril rudimentary; vessel element perforation scalariform; T-shaped unicellular trichomes present. 1/1, New Zealand Ixerbaceae – Flowers strictly 4-merous; ovules many per locule; pollen 3-colporate; fruit berry-like; seed with soft

4

K. Kubitzki funicular aril; vessel element perforation simple; T-shaped trichomes 0. 1/c. 16, E Asia Stachyuraceae 6. Leaves decussate, entire; tepals 4; stamens 4 + 4; anthers dorsifixed; ovary 4-locular, with 4 twisted stylodia; ovules anatropous; fruit capsular; seeds with swollen funicle; embryo straight; T-shaped unicellular trichomes present. 1/1, South Africa Geissolomataceae – Leaves alternate, serrate; tepals 4–5(6); stamens many; anthers basifixed; ovary unilocular; style simple; ovules campylotropous; fruit a berry; seeds arillate, incurved with hippocrepiform embryo. 1/1, E and southern Africa, islands of Indian Ocean Aphloiaceae

Until very recently, these apparently disparate families had been placed in different rosid orders and some had been “dumped” in larger families such as the broadly construed Saxifragaceae (Ixerba) or Flacourtiaceae (Aphloia). The taxonomic history of the individual families is briefly described in the family treatments, and has been treated in more depth by Matthews and Endress (2005). Although Takhtajan (1987) for the first time used the name of the order Crossosomatales which, in his approach, comprised only the name-giving family, a broader concept of the order was not achievable in the pre-molecular era largely because the characters traditionally used in higher-level classification are very variable in these seven families (see Conspectus). During recent years, several molecular studies have contributed to the recognition of the relationships in the entourage of Crossosomataceae. In their rbcL and combined morphological and rbcL studies, Nandi et al. (1998) found a clade of {[(Crossosoma + Stachyurus) Staphylea] Geissoloma}, albeit without significant support. Strong support for [(Crossosoma + Stachyurus) Staphylea] was adduced by further rbcL studies (Savolainen, Fay et al. 2000; Sosa and Chase 2003) and multigene analyses (Soltis et al. 2000; Cameron 2003), and for Ixerba + Strasburgeria by rbcL (Savolainen, Fay et al. 2000; Sosa and Chase 2003) and multigene studies (Cameron 2003). When included in the analysis, Ixerba + Strasburgeria, Aphloia and Geissoloma usually appeared in the same clade as Crossosoma, Stachyurus and Staphylea, although statistical support for this was low. The concept of Crossosomatales proposed by Savolainen, Fay et al. (2000) and Soltis et al. (2000), comprising Crossosomataceae, Stachyuraceae and Staphyleaceae, has later been extended to include all seven aforementioned families (see also Stevens 2005). This concept is now confirmed by the broad-based comparative study of Matthews and Endress (2005), which has revealed structural traits, particularly previ-

ously neglected floral characters, which are shared in different constellations by groups of two, three or more families of the whole alliance. The group as a whole is only weakly characterised. Stomata are usually anomocytic. Leaf margins are usually toothed. Stipules are lacking only in Ixerbaxceae and some Crossosomataceae. Vessel elements have scalariform perforation, Crossosomataceae and Stachyuraceae excepted. Sepal and petal aestivation is imbricate throughout, and stamens are always incurved in bud; anthers are tetrasporangiate; nectary disks are present. Ovules are bitegmic and crassinucellar, mostly anatropous; Aphloiaceae and Crossosomataceae have campylotropous ovules. Pollen grains are colporate and usually have lalongate endoapertures; the gynoecium is often stalked; the carpel tips are often postgenitally united to form a compitum. The seed coat is testal. Sieve element plastids are S type throughout. Ellagitannins and gallotannins, but no proanthocyanidins, are known from Crossosomataceae. More restricted are the following traits. Ixerbaceae and Strasburgeriaceae have large flowers with petals forming a tight, pointed cone in bud, stamens with sagittate anthers, and a rudimentary aril. These families share with Geissolomataceae T-shaped unicellular trichomes and a punctiform stigma on postgenitally united and twisted carpel tips, and only one or two ovules per carpel. Aphloiaceae, Geissolomataceae, Ixerbaceae and Strasburgeriaceae share pollen grains with pronounced protruding endoapertures (“pollen buds”). Crossosomataceae, Stachyuraceae and Staphyleaceae have polygamous or functionally unisexual flowers, and Crossosomataceae and Aphloiaceae (although not resolved as sisters in molecular studies) share polyandrous flowers, basifixed anthers, a stigma with two or more decurrent crests, campylotropous ovules and reniform seeds (data from Matthews and Endress 2005). Crossosomatales are core eudicots but otherwise their relationships are still unclear: they appear at the base of eurosids II (Savolainen, Fay et al. 2000; Soltis et al. 2000) or eurosids I (Hilu et al. 2003), or in a polytomy with Geraniales, Myrtales, eurosids I and eurosids II (APG II 2003), but always with low statistical support.

References For references, see the General References (this volume).


Introduction to Fabales 1. Stylodia gynobasic; [woody; flowers regular; gynoecium apocarpous, 1–5-carpellate; ovule unitegmic (only Suriana known); endosperm 0 or sparse; nectary only rarely present; vestured pits in Recchia]. 5/8, in warm-temperate and tropical regions, widely distributed Surianaceae – Style or stylodia not gynobasic 2 2. Gynoecium syncarpous, 2–8-carpellate (sometimes 1locular); pollen grains 7–28-colporate; seeds mainly endotestal; leaves estipulate; [woody or herbaceous; nodes unilacunar with a single trace; vessel element perforations usually simple; vestured pits sometimes present; flowers actinomorphic to zygomorphic; nectary a disk, a gland, or 0; seeds often arillate]. n = 6–23. 21/800–1,000, widely distributed in tropical, subtropical and temperate regions Polygalaceae – Gynoecium (nearly) apocarpous; pollen grains mostly 3-aperturate; seeds exotestal; leaves stipulate; [nectariferous disk usually present] 3 3. Flowers strictly actinomorphic; carpels 5, only basally connate; pollen grains in monads; seeds exarillate; endosperm thin; cotyledons convolute; stipules small; nodes unilacunar; vessel elements with simple and scalariform perforation; vestured pits 0; [woody; bark strongly saponiferous]. n = 14. 1/2, warm-temperate southern South America Quillajaceae – Flowers actinomorphic to zygomorphic; carpel usually 1 or very rarely more (and then each carpel with a terminal stylodium); pollen grains in monads, tetrads or polyads; seeds arillate or not; endosperm usually 0, rarely sparse or even copious; stipules sometimes modified into prickles or spines; nodes tri-(penta-)lacunar; vessel elements with simple perforations, the lateral pits often vestured; [roots very often with N-fixing root nodules]. 640/1800, widely distributed throughout the world Leguminosae–Fabaceae s.l. (not treated in this volume)

A clade comprising these four families was resolved as belonging to eurosids I by early molecular studies (Chase et al. 1993; Fernando et al. 1993; Morgan et al. 1994) and is strongly supported in several multigene analyses (e.g. Soltis et al. 1999, 2000). Morphologically, the four families have little in common, apart from the basically core eudicot floral organisation. Stevens (2005) notes green embryos and often fluorescent wood, and absence of ellagitannins (which are, however, present in Leguminosae) as common traits.

References Chase, M.W. et al. 1993. See general references. Fernando, E.S. et al. 1993. See selected bibliography of Surianaceae. Morgan, D.R. et al. 1994. See selected bibliography of Quillajaceae.

5

Soltis, P.S., Soltis, D.E., Chase, M.W. 1999. Angiosperm phylogeny inferred from multiple genes as a tool for comparative biology. Nature 402:402–404. Soltis, D.E. et al. 2000. See general references. Stevens, P.F. 2005. See general references.

Introduction to Geraniales 1. Embryo small, straight, achlorophyllous; endosperm copious; secondary xylem always with rays; [either (sub)shrubs or small trees with mostly 5-merous flowers and simple leaves and regular flowers (Greyia), or with pinnate leaves and ± zygomorphic flowers (Melianthus, Bersama), or herbs with mostly 4-merous flowers and commissural stigmas (Francoa, Tetilla)]. 5/19, subsaharan Africa, southern South America Melianthaceae – Embryo large, circinate, twisted, or cochlear, rarely (Rhynchotheca) straight, chlorophyllous; endosperm usually scant; secondary xylem often rayless 2 2. Pollen grains tricolp(or)ate; style elongate, with 5 style branches or (Hypseocharis) unbranched with capitate stigma; fruits schizocarpic with 1-seeded awned mericarps or (Hypseocharis) loculicidal capsules; seed coat with crystalliferous endotesta and thickened but not lignified exotegmen. 5/c. 835, nearly worldwide Geraniaceae – Pollen grains pantoporate or inaperturate; style very short, with 5–3 elongate stigmatic branches; fruits septicidal or septifragous capsules with 1–many-seeded locules; seed coat usually lacking mechanical layers (Viviania, exotegmic); Balbisia with mucilaginous exotesta. 4/c. 18, South America, mostly Andean Ledocarpaceae

The former, broadly construed concept of the order Geraniales (e.g. Engler 1892) comprised 15–20 families including disparate groups such as Oxalidaceae, Tropaeolaceae, Zygophyllaceae, Rutaceae and Euphorbiaceae. Based on the work of many authors, notably Takhtajan (e.g. 1959, 1987) and Dahlgren (e.g. 1980), Geraniales were stepwise restricted by the exclusion of orders such as Rutales, Polygalales and Malpighiales. Yet, in a still more recent survey of dicotyledon families, Thorne (2001) merged Geraniales with Linales (= Malpighiales), mainly on account of these sharing a tendency for obdiplostemonous flowers with 10–15 stamens and a 5-partite gynoecium. It is difficult to understand why Oxalidaceae, for instance, were for so long considered to belong to Geraniales, although the former differ in possessing traits such as free stylodia, abundant endosperm, and capsular fruits (see treatment of Oxalidales in Vol. VI of this series). In the pioneering molecular studies of Price and Palmer (1993), Morgan and Soltis (1993) and

6

K. Kubitzki

Chase et al. (1993), the five genera of Geraniaceae s.str. grouped with Hypseocharis and, in some analyses, also with Viviania, Greyia and Francoa, and often also with Crossosoma, whereas other families of the erstwhile Geraniales were clearly excluded. More recent molecular work (Soltis et al. 2000; Savolainen, Fay et al. 2000; Sosa and Chase 2003) has resolved Geraniales and Crossosomatales (see treatment in this volume) as sister groups placed at the base of eurosid II orders, but the statistical support is tenuous and the Angiosperm Phylogeny Group (APG II 2003) lists both orders among the unresolved rosids. Evidence for a sister group relationship of Melianthaceae and Ledocarpaceae and, in turn, of both of these with Geraniaceae is provided by the rbcL analyses of Savolainen, Fay et al. (2000) and Sosa and Chase (2003). This is notable, as morphologically Ledocarpaceae and Geraniaceae seem to have more in common than any of them have with Melianthaceae (see below). Support is also strong for recognising Melanthiaceae and Geraniaceae in the circumscription adopted in this volume but it is less strong for the morphologically more diverse Ledocarpaceae. Biebersteinia, a Eurasian monotype which often had been related to Geraniaceae (e.g. Knuth 1931), agreeing with this family in some details of fruit and seed morphology (Boesewinkel 1988), in molecular studies is resolved as sapindalean (APG II 2003). A morphological characterisation of Geraniales is difficult because the genera of Melianthaceae and, less so, of Ledocarpaceae are diverse. It is true that all Geraniales have anomocytic stomata, vessels with simple perforation, 5- or 4-merous hypogynous flowers with a persistent calyx, and either haplostemonous or more often obdiplostemonous androecia with paired antepetalous stamens, 5(–3)-carpellate syncarpous gynoecia with simple styles (extremely short in Balbisia) terminating in 3–5 stigmatic lobes or branches, axile or rarely basal placentation, anatropous to campylotropous bitegmic and crassinucellar ovules and, where known, a Polygonum type embryo sac and Nuclear endosperm. All Melianthaceae have copious endosperm, and Melianthus, Bersama and Greyia share multilacunar nodes. Francoa and Tetilla, formerly included in Saxifragaceae, differ from this family in the commissural stigma, the 4-merous flowers, Nuclear endosperm and the lack of myricetin. Otherwise, multilacunar nodes are not known in Geraniales, and the endosperm is absent or scanty in Geraniaceae. Ledocarpaceae and

Geraniaceae agree, however, in numerous traits, such as rayless wood, acuminate to awned sepals, broadened filaments and sometimes basal nectariferous appendages, tanniniferous seed coats, green embryos and (Rhynchotheca excepted) curved or cochlear embryos. Differences between the two families exist in growth habit, pollen morphology and seed coat anatomy (Boesewinkel 1997). Anthecologically, Geraniales families are diversified. Nectaries are present in all families, and Geraniaceae depend on a broad variety of insect groups as pollinators and only occasionally on bird, whereas Melianthaceae rely strongly on bird pollination. In Ledocarpaceae, Viviania produces copious nectar as reward for insect and other pollinators whereas the remaining genera, Balbisia and Rhynchotheca, lack nectaries. Balbisia has pollen flowers, and its showy corolla indicates that it is also zoophilous; one species, B. gracilis, may be anemophilous. Rhynchotheca has apetalous flowers with large, pendulous anthers and shows synchronous mass-flowering, all indicative of anomophily (Weigend 2005). Thus, the morphological disparity of Ledocarpaceae appears to be related to their range of pollination syndromes, which may explain the difficulties morphological workers had in recognising the circumscription and affinities of the family. Phytochemically, Geraniales are characterised by the typical presence of ellagitannins; ellagic acid has been recorded from all genera (Tetilla not studied); gallotannins are also present in Geranicaeae, and geraniin, an ellagitannin based on dehydroxyhexahydroxydiphenic acid, is a prominent compound in Geranium. Proanthocyanidins are uniformly lacking from aerial parts but occur in seed coats and are recorded also from the rootstocks of Geraniaceae. Other biodynamic compounds include the bufodienolides and pentacyclic triterpenoids in Melianthaceae (Hegnauer 1969, 1989).

References APG II 2003. See general references. Boesewinkel, F.D. 1988. The seed structure and taxonomic relationships of Hypseocharis Remy. Acta Bot. Neerl. 37:111–120. Boesewinkel, F.D. 1997. Seed structure and phylogenetic relationships of the Geraniales. Bot. Jahrb. Syst. 119:277– 291. Chase, M.W. et al. 1993. See general references. Dahlgren, R. 1980. A revised system of classification of the angiosperms. Bot. J. Linn. Soc. 80:91–124.

Introduction to the Groups Treated in this Volume Engler, A. 1892. Syllabus der Vorlesungen über spezielle und medizinisch-pharmazeutische Botanik. Berlin: Gebr. Borntraeger. Hegnauer, R. 1969, 1989. See general references. Knuth, R. 1931. Geraniaceae. In: Engler, A., Harms, H. (eds) Die natürlichen Pflanzenfamilien, ed. 2, 19a. Leipzig: W. Engelmann. Kubitzki, K. (ed.) 2004. Flowering plants. Dicotyledons. Celastrales, Oxalidales, Rosales, Cornales, Ericales. The Families and Genera of Flowering Plants, VI. Berlin Heidelberg New York: Springer. Morgan, D.R., Soltis, D.E. 1993. See general references. Price, R.A., Palmer, J.D. 1993. See general references. Savolainen, V., Fay, M.F. et al. 2000. See general references. Soltis, D.E. et al. 2000. See general references. Sosa, V., Chase, M.W. 2003. See general references. Takhtajan, A.L. 1959. Die Evolution der Angiospermen. Stuttgart: G. Fischer. Takhtajan, A. 1987. See general references. Thorne, R.F. 2001. See general references. Weigend, M. 2005. Notes on the floral morphology in Vivianiaceae (Geraniales). Pl. Syst. Evol. 253:125–131.

Introduction to Gunnerales 1. Poikilohydric shrubs; nodes trilacunar; axial parenchyma 0; rays uniseriate; leaves opposite; flowers unisexual, hypogynous; perianth of up to 4 scales; stamens 3–8; ovary 3–4-locular; stylodia 3–4, broad, recurved, with ventrally decurrent stigma; pollen in tetrads; embryo sac Allium type (bisporic, 8-celled); fruit a septicidal capsule; sieve-element plastids S type. 1/2, E and South Africa, Madagascar Myrothamnaceae (see Vol. II) – Perennial herbs, often giant and nearly acaulescent, with endosymbiontic Nostoc cells; nodes multilacunar; vascular system nearly always polystelic; leaves alternate; flowers epigynous, 2-merous; ovary 1-locular; stylodia subulate; pollen in monads; embryo sac Peperomia type (tetrasporic, 16-celled); stylodia 2; fruit a drupe; ellagitannins present; sieve-element plastids Pcf type. 1/c. 60, mainly in southern hemisphere Gunneraceae

Traditionally, Gunneraceae were included in Haloragaceae; Takhtajan (1997) placed them in Saxifraganae. Numerous molecular studies recovered the family in close association with the desert shrub Myrothamnus at the base of core eudicots, where they form a strongly supported clade. There is also evidence for the position of this clade as sister to all remaining core eudicots (cf. Fig. 1), a grouping indicated in various analyses and strongly supported particularly by Soltis et al. (2000, 2003) and Hilu et al. (2003). Gunnera very probably has dimerous flowers and the same may apply to Myrothamnus (see Conspectus). Dimery is not only widespread in early-diverging eudicots such as Proteaceae and

7

many Ranunculaceae but usually also co-occurs with trimery in basal angiosperms (Kubitzki 1987) or even with pentamery in early-diverging eudicots (Soltis et al. 2003). This is not seen in character reconstructions if only a single exemplar per family is included in a tree, as in the reconstruction of perianth merosity in Fig. 3 of Soltis et al. (2003). Indeed, both in basal angiosperms and early-diverging eudicots, there is pronounced variation in floral merosity, and the stereotyped pentamerous floral structure with diplostemony or haplostemony occurs only above the node to Gunnerales. Thus, in Ranunculaceae, pentamery, where it occurs, is restricted to the perianth and, in pentamerous Sabia (Sabiaceae), the sepals, petals and stamens stand on the same radius, a clear violation of Hofmeister’s rule but quite common in “basal” eudicots, as in Gunnera itself (see also Doust and Stevens 2005). Yet, following the node to Gunnerales, the typical pentamerous eudicot pattern is strictly conserved, and further variation is limited to processes such as fusion, reduction and multiplication of stamens and/or carpels and of perianth parts. Gunnerales, although forming part of the core eudicot clade, have not achieved (or have lost?) the pentamerous pattern, but agree with many core eudicots in possessing potent allelochemicals based on ellagic acid.

References Doust, A.W., Stevens, P.F. 2005. A reinterpretation of the staminate flowers of Haptanthus. Syst. Bot. 30:779–785. Hilu, K.W. et al. 2003. See general references. Kubitzki, K. 1987. Origin and significance of trimerous flowers. Taxon 36:21–28. Kubitzki, K., Rohwer, J.G., Bittrich, V. (eds) Flowering plants. Dicotyledons. Magnoliid, Hamamelid and Caryophyllid families. The Families and Genera of Vascular Plants, II. Berlin Heidelberg New York: Springer. Soltis, P.S., Soltis, D.E. 2004. The origin and diversification of angiosperms. Amer. J. Bot. 91:1614–1626. Soltis, D.E. et al. 2000. See general references. Soltis, D.E. et al. 2003. See general references. Takhtajan, A. 1997. See general references.

Introduction to Myrtales 1. Ovary unilocular with apical placentation, inferior (half-inferior in Strephonema); indumentum almost always of slender, unicellular, thick-walled, pointed hairs with a distinctive basal compartment; inflorescences indeterminate; [stamen whorls 1 or 2, the

8

K. Kubitzki

–

2.

– 3.

–

4.

– 5.

– 6. – 7.

–

1

outer sometimes with 2 or 3 times the normal number of stamens; pseudocolpi + (0 in Strephonema); intrastaminal disk often +; fruit 1-seeded, a drupe, usually flattened, ridged and/or winged; cotyledons twisted (massive and hemispheric in Strephonema)]. 14/500, pantropical Combretaceae Ovary usually multilocular with axile placentation, more or less inferior; fruit 1–many-seeded, usually a capsule or berry; indumentum various but not as above 2 Leaves with secretory cavities usually containing essential oils (0 in Psiloxylon), spirally arranged or opposite; pollen oblate, brevi- to longicolpate, lacking pseudocolpi; style base often sunken in apex of gynoecium 3 Leaves lacking secretory cavities, not aromatic; pollen often with pseudocolpi; style base generally not sunken (sunken in some Vochysiaceae) 4 Dioecious; leaves spiral; stamens ≥ 10, erect in bud; anthers tetralocular at anthesis, dehiscing by slits; embryo sac bisporic. 2/4, south-eastern Africa, Mascarenes Myrtaceae–Psiloxyloideae∗1 Flowers bisexual, rarely andromonoecious; leaves spiral or opposite; stamens (few–)usually many, inflexed in bud; anthers bilocular at anthesis, dehiscing with longitudinal or apical slits or pores; embryo sac monosporic; [ovary (nearly superior–)inferior, (1)2– 4(–18)-locular; fruits capsular, indehiscent, or fleshy]. c. 140/over 5,500, tropical to warm-temperate regions mainly of southern hemisphere, with greatest diversity in the Australasian region Myrtaceae–Myrtoideae∗ Flowers strongly mono- or asymmetric; fertile stamen 1, staminodes 0–several; pollen without pseudocolpi; [petals (0)1–3(5); style base ± sunken in apex of gynoecium; fruit a loculicidal capsule or samaroid]. 8/200, most neotropical, 2/5 of them in West Africa Vochysiaceae Flowers usually not strongly zygomorphic; stamens > than 1; pollen often with peudocolpi 5 Pollen with viscin threads on proximal surface and unique paracrystalline beaded exine, the central body of the grain circular to triangular with (2)3(–6) protruding apertures, pseudocolpi 0; embryo sac monosporic, 4-nucleate; endosperm diploid; [flowers (2)4(5, 7)-merous; stamens usually arising from rim of the well-developed hypanthium; fruit a capsule, or dry and indehiscent; interxylary phloem often present; vegetative parts rich in oxalate raphides; exotegmen fibrous]. 17–24/675, widely distributed from tropics to arctic-alpine regions Onagraceae∗ Viscin threads 0, exine different; pollen apertures usually not protruding but pseudocolpi often present; embryo sac 8-nucleate, endosperm triploid 6 Pollen grains 3-porate, lacking pseudocolpi; [ovary superior to partly inferior; branched foliar sclereids +] 7 Pollen grains (2)3-colporate; pseudocolpi present or not 8 Gynoecium 4–8-carpellate and -locular; petals shortly clawed; stamens 12 or numerous; tall trees with drooping, 4-angled ultimate branches. x = 10. 1/2, Southeast Asia, New Guinea Lythraceae p.p. (Duabanga) Gynoecium 10–20-carpellate and -locular; petals linear(-lanceolate) or 0; stamens numerous; swamp

The asterisk denotes taxa not treated in this volume.

8.

– 9.

– 10. – 11.

– 12.

–

13.

–

and mangrove trees with pneumatophores. x = 12. 1/5, coastal Africa to Pacific islands Lythraceae p.p. (Sonneratia) Annual aquatic with floating leaves and submerged filiform-dissected stipules; flowers emergent, 4merous; sepals basally connate into a tube, 2 or 4 of them accrescent in fruit as hornlike or spine-like projections; stamens 4, alternipetalous; gynoecium 2-carpellate, ovary partly inferior; fruits 1-seeded; endosperm 0 but one cotyledon starchy, very large, retained within the fruit. 1/3 (or 15?), temperate to tropical regions of Old World, except Australia Lythraceae p.p. (Trapa) Terrestrial 9 Endothelium present (at least, in Axinandra); [glabrous trees, often with quadrangular twigs; inflorescences indeterminate; flowers hypogynous to perigynous, 4–5-merous, obhaplostemonous or rarely diplostemonous; anther endothecium ephemeral; pollen tricolporate-pseudocolpate or (Crypteronia) bisyncolporate; petals 0 or (Axinandra) small and connate apically, falling off as a cup when the flower opens; ovary ± inferior, 2–6-locular; capsule woody or chartaceous]. 3/10, South and Southeast Asia, Malaysia Crypteroniaceae Endothelium 0 10 Flowers strictly obhaplostemonous; [plants woody; anther endothecium ephemeral] 11 Flowers usually diplostemonous or multistaminate; Melastomataceae and Lythraceae rarely (ob)haplostemonous 14 Hypanthium rim ending with some blunt teeth (“epicalyx”); ovary inferior, 3–5-locular; pollen heteropolar with unequal colpi and “half pseudocolpi” restricted to one polar face; sepals conspicuous, white or pinkish, inserted on margin of hypanthium; petals scale-like, minute, closing the hypanthium in bud; [stamens inserted on inner rim of tube below petals; fruit drupaceous]. x = 10. 1/c. 8, southern and eastern Africa, from Ethiopia to South Africa Oliniaceae Epicalyx 0; ovary superior; pollen isopolar; petals, if present, not closing the hypanthium 12 Flowers (5)6(7)-merous; hypanthium stellate; petals minute, hood-like, lobate and unguiculate, arising from hypanthial rim; septum between the two microsporangia of each theca persistent; pollen 3-colporate with pseudocolpi; gynoecium 2(3)carpellate, ovary 1-locular/partly bilocular; embryo sac monosporic/8-nuclear; fruit capsular. n = 10. 1/1 Rhynchocalycaceae Flowers 4–5(6)-merous; hypanthium tubular; petals strongly reduced or 0; septum between the two microsporangia not persistent; embryo sac bisporic or tetrasporic 13 Flowers 4-merous; nodes unilacunar; foliar sclereids 0; hypanthium large, often conspicuously coloured; ovary 4-locular; pollen with pseudocolpi isomerous with apertures; embryo sac tetrasporic, 16-nucleate. n = 10. 7/23, Cape Province of South Africa Penaeaceae Flowers 5(6)-merous; nodes trilacunar; branched foliar sclereids +; pollen without pseudocolpi; hypanthium green to yellow, 4–6 mm long; ovary 2-locular; embryo sac bisporic. 1/1, Costa Rica to Bolivia Alzateaceae

Introduction to the Groups Treated in this Volume 14. Stamen connectives dorsally enlarged and often massive; anther dehiscence often ± poricidal; [pollen with pseudocolpi; leaves opposite; crystal druses and/or styloids +] 15 – Stamen connectives dorsally not enlarged; anther dehiscence by longitudinal slits 16 15. Leaf venation pinnate or brochidodromous (very rarely, acrodromous); plants woody; flowers strictly epigynous, diplostemonous; stamen connectives generally provided with depressed elliptic terpenoidproducing dorsal glands; anthers with fibrous endothecium, dehiscing by slits (sometimes short and functioning as pores); terminal leaf sclereids +; stomata paracytic; secondary xylem with axially included phloem islands; fruit baccate; seed coat with fibrous exotegmen; seeds 1–few, generally with welldeveloped storage cotyledons. x =? 6/440, pantropical Memecylaceae∗ – Leaf venation acrodromous (very rarely, pinnate); plants woody or herbaceous; flowers actino- to zygomorphic, wholly or partly epigynous, diplostemonous or (ob)haplostemonous; stamen connectives without dorsal glands; anthers mostly poricidal, endothecium 0; terminal leaf sclereids 0; stomata anemocytic, polycytic or encyclocytic; secondary xylem generally without included phloem islands; fruit capsular or baccate; seed coat without fibrous exotegmen; seeds many, with small cotyledons; [indumentum very diverse, trichomes multicellular, scale-like]. x = 17. 185/4,500, mainly in tropical and subtropical regions of the world, with greatest diversity in South America Melastomataceae∗ 16. Herbaceous or woody; ovary superior (to inferior); flowers usually diplostemonous or flowers (ob)haplostemonous; petals crumpled in bud; stamens inserted at the base of floral tube or above, whorls of unequal length; heterostyly widespread; pollen grains tricolporate, pseudocolpi 0 or isomerous with or double the number of apertures; fruit capsular or baccate. 30/c. 600, worldwide, mainly in subtropical and tropical regions Lythraceae p.m.p. – Woody; ovary inferior; stamens many, covering the inner floral tube surface from the rim to the ovary; homostylous; pollen tricolporate, with indistinct pseudocolpi; ovary 7–9(–15)-loculate, carpels in 1 whorl or in 2–3 superposed layers; fruit a leathery berry; seeds many, with translucent sarcotesta. 1/2, from Balkan Peninsula to Himalayas and on Soqotra Lythraceae p.p. (Punica)

Earlier hypotheses on the composition of the order Myrtales are partly congruent with modern concepts. A.P. de Candolle, for instance, in 1828 in the third volume of his Prodromus, combined all major myrtalean families, such as Combretaceae, Onagraceae, Memecylaceae, Melastomataceae, Myrtaceae and, surprisingly, also Vochysiaceae into Myrtales. In addition, he included Alangiaceae, Rhizophoraceae and Lecythidaceae. This and similar circumscriptions of Myrtales persisted in most classifications up to the second half of the 20th century. Mainly due to the work of Briggs

9

and Johnson (1979) and Dahlgren and Thorne (1984), heterogeneous elements were subsequently excluded. Since then, the circumscription of the order has remained unchanged, the only exception being the reinsertion of Vochysiaceae which, based on their unique floral morphology, had not been included by most authors. Rather, they had associated it with families such as Polygalaceae and Euphroniaceae. However, phylogenetic analyses of molecular data as well as morphological evidence strongly supports the inclusion of Vochysiaceae into the order (Conti et al. 1996). In the present circumscription, the order comprises 12 families (see Fig. 2 for a phylogenetic hypothesis) and more than 9,000 species, representing about 6% of core eudicot diversity. Myrtales

Fig. 2. A phylogenetic hypothesis of relationships of Myrtales families, mainly based on Clausing and Renner (2001), Sytsma et al. (2004) and Wilson et al. (2005)

10

K. Kubitzki

are characterised by the combination of vestured pits and bicollateral vascular bundles in the primary xylem, resulting in the appearance of phloem included within the secondary xylem (van Vliet and Baas 1984), and also by several embryological features (Tobe and Raven 1983). Additional characters found in part throughout the order include opposite leaves with undivided laminas, even in the aquatic members; small or rudimentary stipules; short to elongate hypanthia; stamens incurved in bud; vessel elements with simple perforations, paratracheal axial parenchyma and usually nonseptate fibres; secondary phloem stratified in young twigs; unilacunar nodes; simple styles; pollen with subsidiary “colpi” (“pseudocolpi”, i.e. meridional invaginations in the intercolpial regions, apparently with a harmomegathic function); 2-celled pollen; a crystalliferous endotesta; scarce or no endosperm; and copious amounts of galloand ellagitannins, the latter often methylated. Morphological studies significantly contributed to our knowledge of Myrtales in the 1970s and 1980s, and many of these appear in the Myrtales symposium volume published in the Annals of the Missouri Botanic Garden (vol. 71, 1984). Following the comparative analysis of inflorescence structure by Briggs and Johnson (1979), Weberling (1988) analysed the inflorescences from a typological point of view. Monotelic thyrsopaniculate inflorescences, postulated to be basic in the order, predominate in Myrtaceae, Melastomataceae, Oliniaceae and other smaller families whereas Combretaceae and Onagraceae are polytelic throughout. Nevertheless, the aspect of character polarity of inflorescences is yet not completely settled, and recent work shows that within Lythraceae alone the monotelic condition is derived at least four times from the polytelic (Graham et al. 2005). The so-called pseudocolpi are a peculiar character of the pollen grains of many Myrtales, and the distribution and different expressions of these structures are problematic. The absence of pseudocolpi from part of Lythraceae is striking, as is the occurrence of “double” pseudocolpi in another part (Patel et al. 1984). Their complete absence from Onagraceae and the Myrtaceae clade have led earlier authors (Dahlgren and Thorne 1984; see also Johnson and Briggs 1984) to postulate the origin of the pseudocolpi after the branching off of these two families. In view of recent phylogenetic hypotheses (Fig. 2), however, it seems more parsimonious to consider pseudocolpi as ancestral for the order as a whole.

Modern phylogenetic studies in Myrtales started with the seminal work of Johnson and Briggs (1984), and many of their findings have later been confirmed by molecular studies (Conti et al. 1996, 1997, 2002; Clausing and Renner 2001; Sytsma et al. 2004; Wilson et al. 2005). Molecular analyses generally provided strong support for the monophyly of individual families, and also interfamilial relationships have been greatly clarified. The morphological circumscription of families and larger clades turned out to be more difficult (see Conspectus of families). The exact position of the order within the eudicots is not clear and, together with Crossosomatales and Geraniales, Myrtales are left unplaced within the rosids (APG II 2003; see also the angiosperm-wide analysis of matK sequences by Hilu et al. 2003). Combretaceae often appear to be sister to the rest of the order but statistical support for this is still tenuous. Onagraceae and Lythraceae are sister taxa, the former possessing raphides, the latter alkaloids. Onagraceae are highly autapomorphic (see Conspectus). Among the remaining families, Melastomataceae, Memecylaceae and their sister group, the CAROP families (Crypteroniaceae, Alzateaceae, Rhynchocalycaceae, Oliniaceae and Peneaeaceae), are characterised by dorsally massive anther connectives. Renner (1993) and Clausing and Renner (2001) determined the acrodromous leaf venation and lack of a fibrous anther endothecium as being synapomorphic for Melastomataceae, and the terpenoid-producing connective glands as synapomorphic for Memecylaceae. The few genera of Melastomataceae which lack the peculiar, arching leaf venation are nested within the family and thus are clearly derived, and the occurrence of an anther endothecium in the basal melastom genus Pternandra is interpreted as a plesiomorphy (Clausing and Renner 2001). Interestingly, Pternandra also has the interxylary phloem islands (included phloem) which generally occur in Memecylaceae. This trait is interpreted as parallelism, and not as plesiomorphy, because Pternandra agrees with Melastomataceae in most other wood characters. The CAROP families share the loss of an anther endothecium (probably evolved independently from Melastomataceae) with obhaplostemonous flowers (Schönenberger and Conti 2003) and the presence of stipules (Johnson and Briggs 1984). Apart from these features, the four families are strongly diversified. Particularly Crypteroniaceae, with their variable androecium and gynoecium


structure, defy any attempt for a sound morphological family characterisation; the circumscription of this family follows largely molecular findings. The melastom/CAROP clade is sister to the Myrtaceae/Vochysiaceae clade. Myrtaceae represent the largest, most diverse family of the order, for which a detailed classification has recently been established (Wilson et al. 2005). The inclusion of the somewhat aberrant genera Psiloxylon and Heteropyxis in Myrtaceae increases the support for the monophyly of the family, compared to a separate treatment of these two taxa as monogeneric families. The great size of Myrtaceae encompasses much variation in inflorescence, floral and fruit structure, which has been explored by numerous studies subsequent to the seminal contributions by Briggs and Johnson (1979) and Johnson and Briggs (1984). Until the advent of molecular systematics, the close relationship of Vochysiaceae and Myrtaceae had been camouflaged by the distinct floral organisation of the former family but Vochysiaceae have many myrtalean traits, and share the plesiomorphic (see the hypothetic “Protomyrtalis” of Johnson and Briggs 1984) sunken styles and 1–2-celled hairs with many Myrtaceae (Stevens 2005). Much work has been dedicated to the elucidation of the biogeographic history of Myrtales. This task is complicated due to the ancient origin of the order and its poor fossil record (see Sytsma et al. 2004). Recent dating analyses have estimated the crown group of Myrtales to be 107 (Wikström et al. 2001) or 110 million years old (Sytsma et al. 2004), corresponding to the Albian of the Lower Cretaceous. The split between the Myrtaceae/Vochysiaceae clade and the Melastom/CAROP clade may also have occurred in the Albian. This implies that Gondwanan vicariance was an important factor in the biogeographic history of this lineage, as seems reflected by, for instance, the disjunct distribution of the CAROP families and the out-of-India dispersal of Crypteroniaceae (Rutschmann et al. 2004). As for Myrtaceae, Sytsma et al. (2004) could not unambiguously determine the place of their initial diversification, although the extant members of the family are clearly Australasian in origin and a more recent move to South America occurred in the early Eocene, possibly using the temperate Antarctic land bridge. Vochysiaceae are clearly neotropical; the African representatives of the family are nested within a South American clade and may have reached Africa by long-distance

11

dispersal in the Neogene, when the Atlantic had already rifted c. 80 million years ago in the equatorial region (Sytsma et al. 2004). The initial radiation of Melastomataceae is hypothesised to have occurred during the Palaeocene/Eocene along the northern shore of the Sea of Tethys (Renner et al. 2001). From there, the family may have dispersed to North America and throughout Eurasia, later also to South America and from there with repeated long-distance dispersal events to Africa, Madagascar, India and Indochina.

References APG II 2003. See general references. Briggs, B.G., Johnson, L.A.S. 1979. Evolution in the Myrtaceae – evidence from inflorescence structure. Proc. Linn. Soc. New South Wales 102:157–256. Candolle, A.P. de 1828. Prodromus systematis naturalis regni vegetabilis. Pars III. Paris: Treuttel & Würtz. Clausing, G., Renner, S.S. 2001. Molecular phylogenetics of Melastomataceae and Memcylaceae: implications for character evolution. Amer. J. Bot. 88:486–498. Conti, E. et al. 1996. See general references. Conti, E. et al. 1997. See general references. Conti, E. et al. 2002. See general references. Dahlgren, R., Thorne, R.F. 1984. The order Myrtales: circumscription, variation, and relationships. Ann. Missouri Bot. Gard. 71:633–699. Graham, S.A. et al. 2005. See general references. Hilu, K.W. et al. 2003. See general references. Johnson, L.A.S., Briggs, B.G. 1984. Myrtales and Myrtaceae – a phylogenetic analysis. Ann. Missouri Bot. Gard. 71:700–756. Patel, V.C., Skvarla, J.J., Raven, P.H. 1984. Pollen characters in relation to the delimitation of Myrtales. Ann. Missouri Bot. Gard. 71:858–969. Renner, S.S. 1993. Phylogeny and classification of the Melastomataceae and Memecylaceae. Nordic J. Bot. 13:519– 540. Renner, S.S., Clausing, G., Meyer, K. 2001. Historical biogeography of Melatomataceae: the roles of Tertiary migration and long-distance dispersal. Amer. J. Bot. 88:1290–1300. Rutschmann, F., Eriksson, T., Schönenberger, J., Conti, E. 2004. Did Crypteroniaceae disperse out of India? Molecular dating evidence from rbcL, ndhF, and rpl16 intron sequences. Intl J. Pl. Sci. 165, suppl. 4:S69–S83. Schmid, R. 1980. Comparative anatomy and morphology of Psiloxylon and Heteropyxis, and the subfamilial and tribal classification of Myrtaceae. Taxon 29:559–595. Schönenberger, J., Conti, E. 2003. Molecular phylogeny and floral evolution of Penaeaceae, Oliniaceae, Rhynchocalycaceae, and Alzateaceae (Myrtales). Amer. J. Bot. 90:293–309. Stevens, P.F. 2005. See general references. Sytsma, K.J. et al. 2004. See general references. Tobe, H., Raven, P.H. 1983. An embryological analysis of the Myrtales: its definition and characteristics. Ann. Missouri Bot. Gard. 70:71–94.

12

K. Kubitzki

Vliet, G.J.C.M. van, Baas, P. 1984. Wood anatomy and classification of the Myrtales. Ann. Missouri Bot. Gard. 71:783–800. Weberling, F. 1988. The architecture of inflorescences in the Myrtales. Ann. Missouri Bot. Gard. 75:226–310. Wikström, N. et al. 2001. See general references. Wilson, P.G., O’Brien, M.M., Heslewood, M.M., Quinn, C.J. 2005. Relationships within Myrtaceae sensu lato based on matK phylogeny. Pl. Syst. Evol. 251:3–19.

Introduction to the Passifloraceae Alliance (“Passiflorales” = Malpighiales) 1. (Andro)gynophore 0; petal aestivation contorted; corona rarely present and then weakly developed; calyx and corolla separating from developing fruit and falling together; seeds arillate, pitted. 10/+200, Africa, America Turneraceae – (Andro)gynophore usually present; petal aestivation cochlear; corona often present and strikingly coloured 2 2. Stylodia inserted beneath the top of ovary; stamens 5; pollen grains 3-colporate; seeds exarillate; calyx persistent in fruit; tendrils 0. 1/24, Chile, Peru Malesherbiaceae – Stylodia inserted on top of ovary; stamens 4, 5, or many; pollen grains 3–12-colporate or -foraminate; seeds arillate; tendrils often present. 17/700–750, pantropical Passifloraceae

These three families are closely related and also could be merged into one, as suggested as an option by the Angiosperm Phylogeny Group (APG II 2003); here, they are treated separately because their authors prefer the traditional family circumscription. Whereas the molecular data of Chase et al. (2002) confirm that these families form a clade, at the time of writing of these accounts and this introduction (Sept. 2005), it still remains unclear whether the separation of these families involves paraphyly. They share important characters such as an extrastaminal corona, exotestal seeds, cyclopentenoid cyanogenic glucosides and/or cyclopentenyl fatty acids, and biparental or paternal transmission of plastids (the latter not observed in Malesherbiaceae). Whereas seed structure and chemical make-up appear quite constant in the group, a corona is not always present and its expression is quite diverse. It is developed in its full-fledged form in Passifloraceae, mainly Passiflora, but is only weakly in the possibly basal Adenias and also in Turneraceae and Malesherbiaceae; it is difficult to decide whether this represents an anagenetic or reductional transformation. Accessory or superposed buds, as in Passifloraceae, are found also in various

members of Salicaceae and Achariaceae (de Wilde 1971b, at that time included in Flacourtiaceae) where, however, no cyanogens are present; still, a corona is known from Abatia, which led earlier researchers to include the genus in Passifloraceae. Its placement in Salicaceae on the basis of molecular evidence (Chase et al. 2002) is corroborated by morphological evidence. Thus, in contrast to Passifloraceae, Abatia has opposite leaves, valvate calyx aestivation and extrorse anthers, and both the coronal threads and stamens are irregularly arranged whereas in Passifloraceae the corona elements are in distinct whorls and the stamens in the polystemononous genera of this family are in a single whorl (Bernhard 1999); the corona may not be homologous in both groups.

References For references, see the Selected Bibliography of Passifloraceae and the General References (this volume).

Introduction to Proteales 1. Herbaceous, cambial activity 0; sepals 2, stamens numerous, spirally arranged; carpel closure by secretion; ovule 1 per carpel, anatropous; pollen grains variously furrowed or rarely sulcate or tricolpate; simple benzylisoquinoline alkaloids (aporphines) present; myricetin and condensed tannins 0; carpel closure by secretion; flowers thermogenic]. 1/1 or 2, North America, Asia, Australia Nelumbonaceae (see Vol. II) – Woody; sepals or tepals > 2, stamens whorled; carpels postgenitally fused; ovules 1 or 2, rarely more per carpel, usually orthotropous; pollen grains triaperturate(-derived); benzylisoquinoline alkaloids 0; myricetin and condensed tannins present but gallate 0; [seeds lacking starch but containing fat oil and protein] 2 2. Stipules 2, often fused; flowers small, unisexual, in globular heads; perianth 3–4(–7)-merous, the petals vestigial; carpels 3–8, distinct, ovules 1(2); pollen grains tricolpate; triterpenes +. 1/c. 7, North America and Asia Minor to East Asia Platanaceae (see Vol. II) – Stipules 0; flowers usually bisexual, in racemes, panicles, or condensed, often paired; perianth of 4 (very rarely 3 or 5) valvate tepals; stamens antetepalous, often adnate to tepals, alternating with hypogynous nectar secreting glands; carpel 1; ovules 1–2(–many); pollen grains triporate, rarely tricolporoidate or diporate; triterpenes 0. 80/1,700, mainly southern hemisphere, best developed in Australia Proteaceae

The three families united in this order form an unexpected alliance, which was discovered by early molecular work and since has received support in


various multigene analyses. Sabiaceae, here left unplaced as to ordinal allocation (see family treatment), are also often found together with Proteales (cf. Fig. 1). As is evident from the characters given in the Conspectus, Nelumbonaceae appear quite out of place in this alliance. Their ranunculalean chemistry (see Gottlieb et al. 1993) is accompanied by completely ascidiate carpels without any postgenital fusion, which Nelumbo shares only with Berberidaceae; the ovules are anatropous (Igersheim and Endress 1998). Nelumbo has a dimerous calyx (Hayes et al. 2000; in contrast to information given erroneously by Kubitzki 1993), but dimerous whorls are widespread in basal eudicots (Drinnan et al. 1994; Doyle and Endress 2000; Soltis et al. 2003) and are by no means exclusive for earlydiverging eudicots. Nelumbonaceae are remarkable with regard to pollen development. Whereas in basal angiosperms (monosulcates) there is much variation between the simultaneous and successive type of microsporogenesis, almost all eudicots (triaperturates) have simultaneous microsporogenesis, with the notable exception of Nelumbonaceae (Kreunen and Osborn 1999) and Proteaceae (Furness et al. 2002; including the diporate proteaceous pollen: Blackmore and Barnes 1995). The co-occurrence of putatively monosulcate and triaperturate pollen in Nelumbo (Kuprianova 1979; Blackmore et al. 1995) raised great phylogenetic interest but later (Borsch and Wilde 2000) was found to be part of an extensive, regular variation pattern influenced by factors such as a delay in aperture ontogeny (Kreunen and Osborn 1999). Platanaceae and Proteaceae, which are resolved as sister taxa in most molecular analyses, have much in common morphologically, including the presence of five carpellary bundles (rather than three in most Ranunculales and in the early-branching Proteacea Bellendena), ample tanniniferous tissue in the carpels, mostly one or two large, orthotropous ovules of which the upper is pendent, and floral organs which may be arranged in dimerous whorls. Traditionally, Proteaceae had been interpreted as tetramerous but the ontogenetic work of Douglas and Tucker (1996a) supports the interpretation of their perianth and androecium as dimerous. Possibly, Proteaceae are primarily apetalous; the nectarial hypogynous scales, which alternate with the tepals, are positioned inside the stamen whorl and their initiation takes places after that of all other floral organs (Douglas and Tucker 1996),

13

which is inconsistent with their interpretation as erstwhile petals. Both extant and fossil Platanaceae show considerable variability in the number of floral parts. Some of their mid-Cretaceous and early Tertiary representatives had strictly pentamerous perianths with five stamens and five carpels respectively (Friis and Crane 1989), but clear tetramery existed, for instance, in the Late Cretaceous Quadriplatanus (Magallón et al. 1997), in which the female flowers had two perianth whorls and eight carpels. Proteaceae pollen is known for differing from the widespread developmental pattern in eudicots, in which apertures are formed in pairs at six points in the developing tetrad, following Fischer’s Rule. In Proteaceae, the apertures are formed in groups of three at four points in the tetrad (Garside 1946). Furness and Rudall (2004), who quoted Illiciales, Proteaceae and Olacaceae as the only examples in angiosperms for pore orientation according to Garside’s Rule, argued for origins of this developmental mode of triaperturate pollen independent from the developmental pattern following Fischer’s Rule which characterises the majority of the eudicots. Illiciales are, however, irrelevant in this context because their “tricolpate” condition is an extension of the trichotomosulcate arrangement, which is often found among monosulcates in which Illiciales are embedded (Huynh 1976; Doyle et al. 1990). The pollen grains of some Olacaceae, which are formed according to Garside’s Rule, appear autapomorphic because this family is deeply embedded within the triaperturate group. Also for Proteaceae, it is difficult to envisage a completely independent origin of the triaperturate condition from a monosulcate/trichotomosulcate ancestor: even if Proteales were basal in eudicots, Proteaceae are nested within Proteales, in which Platanaceae and Nelumbonaceae produce “normal” triaperturates. Any hypothesis of an independent origin within this order would then require one or two additional origins of the normal Fischer’s Rule tricolpate type, a non-parsimonious assumption. Rather, these considerations all favour an origin of the proteaceous condition from normal tricolpates, much as concluded for Olacaceae. This view is shared by Blackmore and Crane (1998) who tend to view the Garside’s Rule arrangement in Proteaceae as derived. A triporate fossil pollen from the Cenomanian (mid-Cretaceous) of the Northern Gondwana Province, Triorites africaensis, has often been related to Proteaceae. The ultrastructural analysis of

14

K. Kubitzki

Triorites by Ward and Doyle (1994) suggests that Triorites pollen is not tricolporate-derived, as usually is the case with triporates, but perhaps directly from tricolpate. Ward and Doyle (1994) considered this as an additional piece of evidence against a derivation of the family from a rosid ancestor – of course, amply confirmed by molecular data. A number of Late Cretaceous (Late Santonian-Early Campanian) follicular fruits from southern Sweden (Leng et al. 2005) exhibit several similarities with Proteaceae, particularly with the first branching lineages in the family. These include a plicate carpel structure with a vascular system of three bundles, several anatropous, probably bitegmic ovules, and a more or less sessile stigmatic area which is located at the distal-most part of the ventral slit and extends over the topological apex to the abaxial side of the follicle. Although these fossils differ from extant Proteaceae in having unisexual and obviously perianth-free flowers and several ovules, they represent an extinct lineage of basal eudicots which probably was close to modern Proteaceae. Johnson and Briggs (1975), with admirable intuition, anticipated that Proteaceae are not only an “isolated” but also a fairly basal family, rather than belonging somewhere in the rosids, this having been fully confirmed by the evidence available 30 years later.

References Blackmore, S., Barnes, S.H. 1995. Garside’s rule and the microspore tetrads of Grevillea rosmarinifolia A. Cunningham and Dryandra polycephala Bentham (Proteaceae). Rev. Palaeobot. Palynol. 85:111–121. Blackmore, S., Crane, P.R. 1998. The evolution of apertures in the spores and pollen grains of embryophytes. In: Owens, S.J., Rudall, P.J. (eds) Reproductive biology. Royal Botanic Gardens, Kew, pp. 159–182. Blackmore, S., Stafford, P., Persson, V. 1995. Palynology and systematics of Ranunculiflorae. Pl. Syst. Evol. suppl. 9:71–82. Borsch, T., Wilde, V. 2000. Pollen variability within species, populations, and individuals, with particular reference to Nelumbo. In: Harley, M.M., Morton, C.M., Blackmore, S. (eds) Pollen and spores: morphology and biology. Royal Botanic Gardens, Kew, pp. 285–299. Douglas, A.W., Tucker, S.C. 1996. Comparative floral ontogenies among Persoonioideae including Bellendena (Proteaceae). Amer. J. Bot. 83:1528–1555. Doyle, J.A., Endress, P.K. 2000. Morphological phylogenetic analysis of basal angiosperms: comparisons and combination with molecular data. Intl J. Pl. Sci. 161, suppl. 6:S121–S153. Doyle, J.A., Hotton, C.L., Ward, J.V. 1990. Early Cretaceous tetrads, zonasulculate pollen, and Winteraceae. II.

Cladistic analysis and implications. Amer. J. Bot. 77:1558–1568. Drinnan, A.N., Crane, P.R., Hoot, S.B. 1994. Patterns of floral evolution in the early diversification of non-magnoliid dicotyledons (eudicots). Pl. Syst. Evol. suppl. 8:93–122. Endress, P.K., Igersheim, A. 1999. Gynoecium diversity and systematics of the basal eudicots. Bot. J. Linn. Soc. 130:305–393. Friis, E.M., Crane, P.R. 1989. Reproductive structures of Cretaceous Hamamelidae. In: Crane, P.R., Blackmore, S. (eds) Evolution, systematics and fossil history of the Hamamelidae, 1. Oxford: Clarendon Press, pp. 155– 174. Furness, C.A., Rudall, P.J. 2004. Pollen aperture evolution – a crucial factor for eudicot success? Trends Pl. Sci. 9:154–158. Furness, C.A., Rudall, P.J., Sampson, F.B. 2002. Evolution of microsporogenesis in angiosperms. Intl J. Pl. Sci. 163:235–260. Garside, S. 1946. The developmental morphology of the pollen of Proteaceae. J. S. African Bot. 12:27–34. Gottlieb, O.R., Kaplan, M.A.C., Zocher, D.H.T. 1993. A chemosystematic overview of Magnoliidae, Ranunculidae, Caryophyllidae and Hamamelidae. In: Kubitzki, K. (ed.) The Families and Genera of Vascular Plants, 2. Berlin Heidelberg New York: Springer, pp. 20–31. Hayes, V., Schneider, E.L., Carlquist, S. 2000. Floral development of Nelumbo nucifera (Nelumbonaceae). Intl J. Pl. Sci. 161, suppl. 6:S183–S191. Hoot, S.B., Magallón, S., Crane, P.R. 1999. Phylogeny of basal eudicots based on three molecular data sets: atpB, rbcL, and 18S nuclear ribosomal DNA sequences. Ann. Missouri Bot. Gard. 86:1–32. Huynh, K.-L. 1976. L’arrangement du pollen du genre Schisandra (Schisandraceae) et sa signification phylogénique chez les Angiospermes. Beitr. Biol. Pflanzen 52:227–253. Igersheim, A., Endress, P.K. 1998. Gynoecium diversity and systematics of the paleoherbs. Bot. J. Linn. Soc. 127:289–370. Johnson, L.A.S., Briggs, B. 1975. See general references. Kreunen, S.S., Osborn, J.M. 1999. Pollen and anther development in Nelumbo (Nelumbonaceae). Amer. J. Bot. 86:1662–1676. Kubitzki, K. 1993. Platanaceae. In: Kubitzki, K., Rohwer, J.G., Bittrich, V. (eds) Flowering plants. Dicotyledons. Magnoliid, Hamamelid and Caryophyllid families. The Families and Genera of Vascular Plants, II. Berlin Heidelberg New York: Springer, pp. 521–522. Kubitzki, K., Rohwer, J.G., Bittrich, V. (eds) Flowering plants. Dicotyledons. Magnoliid, Hamamelid and Caryophyllid families. The Families and Genera of Vascular Plants, II. Berlin Heidelberg New York: Springer. Kuprianova, L.A. 1979. On the possibility of the development of tricolpate pollen from monosulcate. Grana 18:1–4. Leng, Q., Schönenberger, J., Friis, E.M. 2005. Late Cretaceous follicular fruits from southern Sweden with systematic affinities to early diverging dicots. Bot. J. Linn. Soc. 148:377–407. Magallón, S., Herendeen, P.S., Crane, P.R. 1997. Quadriplatanus georgianus gen. et sp. nov.: staminate and pis-

Introduction to the Groups Treated in this Volume tillate platanaceous flowers from the Late Cretaceous (Coniacian-Santonian) of Georgia, U.S.A. Intl J. Pl. Sci. 158:373–394. Ressayre, A., Dreyer, L., Triki-Teurtroy, S., Forchioni, A., Nadot, S. 2005. Post-meiotic cytokinesis and pollen aperture pattern ontogeny: comparison of development in four species differing in aperture pattern. Amer. J. Bot. 92:576–583. Soltis, D.E. et al. 2003. See general references. Ward, J.V., Doyle, J.A. 1994. Ultrastructure and relationships of mid-Cretaceous polyforate and triporate pollen from northern Gondwana. In: Kurmann, M.H., Doyle, J.A. (eds) Ultrastructure of fossil spores and pollen. Royal Botanic Gardens, Kew, pp. 161–172.

– 9.

–

Introduction to Saxifragales 10. 1. Trees; stigmas decurrent; pollen colpate or pantoporate; [anthers with protruding connectives] 2 – Trees or herbs; stigmas subulate, capitate or spatulate; pollen colpor(oid)ate, rarely porate 5 2. Flowers mostly hermaphroditic; anthers mostly dehiscing with valves; [trichomes mostly stellate or tufted; flowers (2–)4–5(–7)-merous, calyx rarely 0, petals often adaxially circinate; ovary inferior to superior, 2-carpellate with straight stylodia; iridoids 0]. n = 8, 12, 18. 27/82, tropical to temperate, C and E North America, SE Europe through S, E and SE Asia to New Guinea and NE Australia Hamamelidaceae (see Vol. II) – Dioecious; anthers dehiscing with slits or rudimentary valves 3 3. Ovary unicarpellate with abaxial suture [but the solitary carpels (= female flowers) united into pseudanthia]; iridoids 0; [fruit a samara; seed with large embryo]. n = 19. 1/2, China and Japan Cercidiphyllaceae (see Vol. II) – Ovary bicarpellate; no pronounced shoot dimorphism; iridoids present 4 4. Female flowers in globose heads, male in terminal globose racemes; stipules present; pollen pantoporate; embryo > half the length of the seed; secretory ducts in all vegetative tissues. n = 8. 1/13, C America, E Mediterranean, E Asia to Malesia Altingiaceae (see Vol. II under Hamamelidaceae) – Flowers in elongate racemes; stipules 0; pollen tricolpate; embryo minute; secretory ducts 0. n = 8. 1/10, E Asia, Malesia Daphniphyllaceae 5. Flowers polyandrous 6 – Flowers haplostemonous or diplostemonous. Core Saxifragales 7 6. Apocarpous; stamens in 5 fascicles; seeds with shining sarcotesta; perennial herbs or (half)shrubs. 1/40, northern hemisphere Paeoniaceae – Syncarpous, ovary unilocular; stamens not distinctly fasciculate; seeds with black crustaceous coat; trees. 3/11, South America, Africa Peridiscaceae 7. Flowers essentially 4-merous; [leaves estipulate; nodes unilacunar] 8 – Flowers essentially 5 >-merous 10 8. Ovary superior, nearly apocarpous; anther wall without fibrous endothecium; [pollen tricolporate; fruit fol-

– 11.

– 12.

–

13.

– 14.

–

15

licular; seeds very small, winged; low glabrous shrub]. 1/1, Tasmania Tetracarpaeaceae Ovary inferior or semi-inferior, the carpels at least basally connate; anther wall with fibrous endothecium 9 Leaves alternate, opposite, or verticillate; ovary inferior, 4(–2)-carpellate; stylodia free with penicillate stigmas; vessel elements with simple perforation; pollen 4– 6(–20)-colpate or -porate, often aspidiate; [tanniniferous terrestrial or aquatic herbs, shrubs or small trees]. n = 7 (6, 9, 21, 29). 8/150, worldwide but mainly Australia Haloragaceae Leaves opposite; ovary semi-inferior, 4-carpellate; style shortly 4-lobed; stigmas papillate; vessel elements with scalariform perforation; pollen tricolporate; [petals small or 0; climbing shrubs]. 1/2, Australia Aphanopetalaceae Shrubs; [leaves alternate; vessel element perforation mainly scalariform; ovary syncarpous] 11 Herbs; [seeds exotestal] (but see Crassulaceae) 13 Gynoecium 5-carpellate; style shortly 5-lobed; [ovary largely inferior with 4–6 ascending ovules/locule; stigmas radiate; stipules minute; pollen 3-colporate; vessel elements also with simple perforations]. 1/3, Mexico Pterostemonaceae Gynoecium 2-carpellate; style cleft or not 12 Ovary inferior, 1-locular; fruit a berry; seeds usually numerous, small, mucilaginous; embryo small; pollen 8-zonocolporate, pentacolpo-di-orate, or pantoporate; erect, arching, trailing or prostrate shrubs often with 3- or 2-forked or simple nodal spines and smaller internodal bristles, and long-petiolate, basally 2-veined leaves; [seed coat with exotestal mucilaginous palisade, endotesta crystalliferous]. n = 8. 1/150–200 Grossulariaceae Ovary nearly superior to 3/4 inferior, 2-locular; fruit a capsule; seeds few to many, dry; embryo large, curved; pollen bilateral, 2-porate; unarmed shrubs or small trees with short-petiolate, pinnately veined leaves; [anthers with globular protrusion of the connective; stylodia separate to fused but apically coherent with globular stigmas]. n = 11. 1/c. 27, E and SE Asia, one sp. in Africa, one in North America Iteaceae Fruit a 5–7-carpellate and -beaked stellate capsule, the beak of each carpel circumscissile above the syncarpous region; nodes unilacunar; vessel element perforation scalariform; [rhizomatous perennials; petals 0 or very small]. n = 8, 9. 1/2, E North America, E and SE Asia Penthoraceae Fruiting carpels not dehiscing along a circumscissile suture; nodes uni-, tri- or multilacunar; vessel element perforation simple 14 Succulent herbs, subshrubs or rarely shrubs; stipules 0; nodes trilacunar or unilacunar; leaves usually simple and entire; gynoecium isomerous with perianth; nectariferous scale near base of each carpel (petaloid in Monanthes and some Sedum). n = 4–22+. 33/1,410, widely distributed mostly in arid temperate or warm regions, and centred in Mexico and South Africa Crassulaceae Not succulent, perennial and annual herbs; stipules present or leaf basis sheathing; nodes trilacunar or multilacunar; leaves simple or pinnately or

16

K. Kubitzki palmately compound or decompound; gynoecium 2(– 5)-carpellate; nectariferous disk mostly present. n = (5, 6)7(11, 12, 15, 17, 18). 33/1,410, nearly cosmopolitan but mainly in northern temperate zone and centred in North America Saxifragaceae

Saxifragales, in the circumscription followed in this volume, are the result of a series of molecular analyses carried out over the past 15 years or so (Chase

Fig. 3. A phylogenetic hypothesis of relationships of Saxifragales families, based on Fishbein et al. (2001), Fishbein and Soltis (2004) and, for Peridiscaceae, on Davis and Chase (2004). Note that resolution among the basal woody families is weekly supported. Hamamelidaceae, Altingiaceae and Cercidiphyllaceae were treated in Vol. II (Kubitzki et al. 1993) of this series

et al. 1993; Morgan and Soltis 1993; Soltis and Soltis 1997; Fishbein et al. 2001; APG II 2003; Davis and Chase 2004; Fishbein and Soltis 2004, among others). The monophyly of this clade is strongly supported. Moreover, there is a 1 bp insertion common to all members of the order (Soltis and Soltis 1997). In addition to the Core Saxifragales traditionally considered to belong to this order (see Fig. 3), it comprises also Haloragaceae, the controversial Paeoniaceae, some woody “hamamelidid” families (Cercidiphyllaceae, Hamamelidaceae, Altingiaceae, Daphniphyllaceae), and the enigmatic Peridiscaceae. Outgroup relationships of Saxifragales are weakly supported (Savolainen, Chase et al. 2000; Soltis et al. 2000) but the group is often found together with Vitaceae at the base of the large eurosid clade. A group comprising the families now constituting the order Saxifragales has never before been recognised in traditional systematic studies. In comparison with older concepts such as of those of Bentham (1865), Engler (1891, 1930) and Cronquist (1981), and partly also with the more recent but essentially morphologically based classifications by Huber (1991), Takhtajan (1997) and Thorne (2001), the present circumscription differs in three major points, first, in the exclusion of the lineages having tenuinucellate ovules and containing iridoids; second, in the inclusion of Haloragaceae, Peridiscaceae and Paeoniaceae (included in Saxifragales by Huber 1991); and third, in the addition of several woody families showing presumably plesiomorphic characters such as valvate anther dehiscence, apiculate connective protrusions and tricolpate pollen, some of which persist here and there in the Core Saxifragales. ad 1. The first to recognise the systematic significance of ovules was Warming (1878), and the bitegmic ovules of Itea led van Tieghem (1898) to propose the transfer of Itea from Escalloniaceae to Saxifragaceae. He later (van Tieghem 1901) used the distinction between bitegmic and unitegmic ovules as a rigorous criterion in the classification of the whole plant kingdom, which resulted in a system containing inconsistent and unnatural groupings, discrediting the use of this character. Consequently, his views were wholly rejected by other botanists and Engler (1930), when commenting on Hydrangioideae and Escalloniodeae which he included in his Saxifragaceae, argued that the number of integuments had little systematic significance because, among otherwise clearly related genera of Ranunculaceae, their number


can be variable. However, Mauritzon (1933), in his embryological studies of Saxifragales, found ovule characters to be useful, and Philipson (1974) suggested that a distinction be made between families in which the ovular characters are constant, as opposed to those in which some variation in this respect occurs sporadically. Taxa such as Escalloniaceae, Hydrangeaceae, Phyllonoma, Montinia and Eremosyne, transferred to the asterids by Soltis and Soltis (1997) on the basis of molecular evidence, are all unitegmic and iridoid-positive. Some unitegmic genera (Darmera, Micranthes) persist in Saxifragaceae but these are embedded in broader bitegmic lineages and lack iridoids, whereas the few iridoid-positive Saxifragales are bitegmic. ad 2. Haloragaceae traditionally have been related with Myrtales but Takhtajan (1997) demonstrated that they have more characters in common with Saxifragales. Peridiscaceae have often been related to Flacourtiaceae but the three-gene analysis of Davis and Chase (2004) adds the family, with the inclusion of Soyauxia, to the Saxifragales where they come out with Daphniphyllaceae and the other woody groups at the base of the Saxifragales clade, albeit with low support (M.W. Chase, pers. comm. Nov. 2003). A close relationship between these three taxa is not reflected by morphological traits, although the anther flaps of Soyauxia are found in some basal Saxifragales families as well. Paeoniaceae, large-flowered, apocarpous, with striking seed-presentation and strongly autapomorphic2 , in the analysis of Fishbein and Soltis (2004) are basal to Core Saxifragales. ad 3. Within the Saxifragales, but outside the Core Saxifragales, iridoids occur in two families, Altingiaceae and Daphniphyllaceae, where they are poorly diversified chemically (Kaplan and Gottlieb 1982), perhaps due to the small size of these families. These are the only reports of iridoids outside the asterids. The tricolpate pollen predominating in Cercidiphyllaceae, Hamamelidaceae and Daphniphyllaceae is likely to be a plesiomorphic trait; in fact, the apertures of Cercidiphyllum appear quite archaic, and are intermediate between the poroidate and colpoidate condition (Praglowski 1975); however, there are transitions to compound (colporoidate or colporate) apertures known from within Daphniphyllum. In the Core Saxifragales, elabo2 The record of iridoids sometimes indicated for Paeonia (e.g. in Stevens 2005) may be based on Nekratova et al. (1988, in Rast. Resur. 24:392–399), who may have mistaken monoterpene glucosides of the Paeoniflorin type for iridoids (Hegnauer 1990).

17

rate compound apertures (with well-differentiated exo- and endoapertures) are the rule but sometimes (Saxifragaceae) they are not fully developed. On the whole, the woody basal families of (“nonCore”) Saxifragales appear as isolated remnants of formerly more richly developed, archaic lineages, as is particularly well documented for Cercidiphyllaceae. Resolution within the Core Saxifragales is better supported, mainly due to the efforts of Fishbein et al. (2001), and even a cursory glance at the topology reproduced in Fig. 3 reveals that a broader concept of Saxifragaceae (with the inclusion of Tetracarpaea and Penthorum) is untenable, unless Crassulaceae and Haloragaceae were to be incorporated, too. The topology of Fig. 3 is also useful for a comparison with character transformations which can be recognised in the Core Saxifragales. The transition from woody to herbaceous growth, usually accompanied by the loss of scalariform perforation plates of the vessel elements, has taken place some five times within Saxifragales – in Paeoniaceae, Saxifragaceae, Crassulaceae (the few woody members of which are definitely secondarily woody; see Crassulaceae, this volume), Penthoraceae and the woody/herbaceous Haloragaceae. Penthoraceae are remarkable for having “retained” scalariform perforation in spite of being herbaceous. Grossulariaceae are strictly woody whereas their sister group Saxifragaceae is largely herbaceous – a remarkable difference, although both agree in details of shoot morphology and growth dynamics, as is well described by Weigend under “Affinities” of Grossulariaceae (this volume). Anthers in Saxifragales are remarkably uniformly basifixed but gynoecium structure, particularly in Core Saxifragales, is labile. Pterostemonaceae stand out with an isomerous and apocarpous gynoecium within an otherwise 2–3-carpellate Saxifragaceae alliance; the gynoecia of Crassulaceae and Tetracarpaeaceae are also (nearly) apocarpous. Free stylodia are widespread, and most groups with this character seem to lack a compitum. The functionally advantageous fusion of stylodia into a common style is uncommon (Grossulariaceae, Iteaceae, Aphanopetalaceae). Although there is no indication that apocarpy here, or in the (other) eurosids where it also occurs, is due to a reversal, it is difficult to imagine that this character expression should be plesiomorphic in these groups. Minute embryos characterise Peridiscaceae, Daphniphyllaceae, Paeoniaceae, Grossulariaceae and Tetracarpaeaceae; all other groups have medium-sized or large embryos.

18

K. Kubitzki

References APG II 2003. See general references. Bentham, G. 1865. Ordo LIX. Saxifrageae. In: Bentham, G., Hooker, J.D., Genera Plantarum, I, ii. London: Reeve, pp. 629–655. Chase, M.W. et al. 1993. See general references. Cronquist, A. 1981. See general references. Cutler, D.F., Gregory, M. (eds) 2000. Anatomy of the Dicotyledons, 2nd edn. Vol. 4, Saxifragales. Oxford: Clarendon Press. Davis, C.C., Chase, M.W. 2004. Elatinaceae are sister to Malpighiaceae; Peridiscaceae belong to Saxifragales. Amer. J. Bot. 91:262–273. Engler, A. 1891. Saxifragaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 2a. Leipzig: W. Engelmann, pp. 41–93. Engler, A. 1930. Saxifragaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 18a. Leipzig, W. Engelmannn, pp. 74–226. Fishbein, M., Soltis, D.E. 2004. Further resolution of the rapid radiation of Saxifragales (Angiospetrms, Eudicots) supported by mixed-model Bayesian analysis. Syst. Bot. 29:883–891. Fishbein, M. et al. 2001. See general references. Hegnauer, R. 1990. See general references. Huber, H. 1991. Angiospermen. Leitfaden durch die Ordnungen und Familien der Bedecktsamer. Stuttgart: G. Fischer. Kaplan, M.A.C., Gottlieb, O.R. 1982. Iridoids as systematic markers in dicotyledons. Biochem. Syst. Ecol. 10:329– 347. Kubitzki, K., Rohwer, J.G., Bittrich, V. (eds) Flowering plants. Dicotyledons. Magnoliid, Hamamelid and Caryophyllid families. The Families and Genera of Vascular Plants, II. Berlin Heidelberg New York: Springer. Mauritzon, J. 1933. Studien über die Embryologie der Familien Crassulaceae und Saxifragaceae. Ph.D. Thesis, Lund University. Morgan, D.R., Soltis, D.E. 1993. Phylogenetic relationships among members of Saxifragaceae sensu lato based on rbcL sequence data. Amer. J. Bot. 80:631–660. Nemirovich-Danchenko, E.N. 1994. Morphology and anatomy of the seeds of Iteaceae (in Russian). Bot. Zhurn. (Moscow & Leningrad) 79:83–87. Philipson, W.R. 1974. Ovular morphology and the major classification of the dicotyledons. Bot. J. Linn. Soc. 68:89–108. Praglowski, J. 1975. Pollen morphology of the Trochodendraceae, Tetracentraceae, Cercidiphyllaceae and Eupteleaceae with reference to taxonomy. Pollen Spores 16:449–467. Savolainen, V., Chase, M.W. et al. 2000. See general references. Soltis, D.E., Soltis, P.S. 1997. Phylogenetic relationships in Saxifragaceae sensu lato: a comparison of topologies based on 18S rDNA and rbcL sequences. Amer. J. Bot. 84:504–522. Soltis, D.E. et al. 2000. See general references. Stevens, P.F. 2005. See general references. Takhtajan, A. 1997. See general references. Thorne, R.F. 2001. See general references.

Tieghem, Ph. van 1898. Structures de quelques ovules et parti qu’on en peut tirer pour améliorer la classification. J. Bot. (Paris) 12:197–220. Tieghem, Ph. van 1901. L’œuf des plantes considéré comme base de leur classification. Ann. Sci. Nat., Bot. VIII, 14:213–390. Walker, J.W. 1974. Aperture evolution in the pollen grains of primitive angiosperms. Amer. J. Bot. 61:1112–1136. Warming, E. 1878. De l’ovule. Ann. Sci. Nat. VI, 5:177–266.

Introduction to Vitales 1. Small trees, shrubs, or herbs; tendrils 0; stipular wings conspicuous, sheathing; inflorescences terminal; floral disk tubular, not producing nectar; due to secondary septation, ovary 4–6(–8)-locular, ovule 1 per locule. 1/34, mainly southern Asia, extending to Africa/Madagascar and Australia Leeaceae – Woody lianas usually with leaf-opposite tendrils, rarely succulent small trees or erect herbs; stipules not sheathing the petiole margins; inflorescences often leaf-opposed; floral disk intrastaminal, ring-shaped, cupular, or gland-shaped, usually nectariferous; ovary 2-locular, ovules 2 per locule. 14/c. 750, pantropical Vitaceae

Traditionally, Vitales were included in Rhamnales – both have antepetalous stamens – but Takhtajan (1997) dismembered this association because Vitaceae and Leeaceae differ from Rhamnaceae in their berry-like fruits and seed structure, and in having raphide sacs in the parenchymatous tissue; he placed them as “Vitalanae” close to his Proteanae at the end of his Rosidae. Corner (1976) was much impressed by the thick, lignified endotesta and small embryo of the seeds of Vitaceae, which he found “scarcely improved on that of Magnolia and. . . even more primitive”. Vitales also have a tracheidal exotegmen, which is a rare feature in angiosperm seeds – apart from Dilleniaceae; it is listed only for Cunoniaceae by Nandi et al. (1998). Vitaceae, Leeaceae and Dilleniaceae are the only angiosperm families which share the lignified endotesta and tracheidal exotegmen. The first to find an association between Vitaceae and Dilleniaceae were Nandi et al. (1998) in a combined rbcL/morphological analysis. In an rbcL analysis (Savolainen, Fay et al. 2000), Vitales and Dilleniaceae appear in a sister position to Caryophyllales. The two-gene analysis of Savolainen, Chase et al. (2000) and the three-gene analysis of Soltis et al. (2000) place Vitales at the base of the rosid clade. In the matK analysis of Hilu et al. (2003), the rosids are sister to Vitis and Tetracera (in turn, sister taxa) and to other taxa


including Berberopsidales, Santalales (relative positions were uncertain), and Caryophyllales plus asterids. In the four-gene study of Soltis et al. (2003), Vitales occupy a position at the base of a Caryophyllales/Saxifragales clade. None of these associations is strongly supported. Thus, a closer relationship between Vitaceae/Leeaceae and Dilleniaceae can not be ruled out. Perhaps both families branched off at the base of the core eudicot tree and both, but Dilleniaceae more probably than Vitaceae/Leeaceae, may be related to Caryophyllales. Evidence for placing Vitales in rosids is tenuous because the molecular data are not convincing. Note, however, that Stevens (2005), citing Oxelman et al. (2004), mentions that the RPB2 gene may not be duplicated in Vitales, perhaps suggesting a position outside core eudicots. Summarising, one may agree with Stevens (2005, on Vitales) that Vitales have no firm position as yet, although a more strongly supported association with Dillenaceae and Caryophyllales would not come as a surprise.

References Corner, E.J.H. 1976. See general references. Hilu, K.W. 2003. See general references. Nandi, O.I. et al. 1998. See general references. Oxelman, B., Yoshikawa, N., McConaughy, B.L., Luo, J., Denton, A.L., Hill, B.D. 2004. RPB2 gene phylogeny in flowering plants, with particular emphasis on asterids. Mol. Phylog. Evol. 32:462–479. Savolainen, V., Chase, M.W. et al. 2000. See general references. Savolainen, V., Fay, M.F. et al. 2000. See general references. Soltis, D.E. et al. 2000. See general references. Soltis, D.E. et al. 2003. See general references. Stevens, P.F. 2005. See general references. Takhtajan, A. 1997. See general references.

Introduction to Zygophyllales 1. Hemiparasitic; stipules 0; flowers solitary or in botryoid panicles, zygomorphic; the two abaxial petals lipid-secreting, the three adaxial ones forming a flag; stamens ± as many as petals; ovary 1-locular; pollen 3-porate; vessels with non-vestured pits; axial parenchyma usually with one cell per strand; storying absent or nearly so; crystals many per cell, mostly in axial phloem parenchyma; n = 6. 1/18, New World Krameriaceae – Autotrophic; stipules +; flowers solitary, paired or in few-flowered cymes, regular or rarely slightly zygomorphic; nectar-secreting disk often +; stamens 1 or

19

2 times as many as petals; ovary (2–)5(–12)-locular; vessels with vestured pits; axial parenchyma usually with 2–4 cells per strand; storying present in axial parenchyma, sometimes in rays; crystals one per cell or septate portion of cell in wood or secondary phloem; x = 6–15. 22/230–240, in hot dry regions all over the world Zygophyllaceae

Previously, Krameriaceae and Zygophyllaceae were placed in different orders, and no close relationship between them had been recognised. Molecular studies, particularly the multigene analyses of Soltis et al. (2000) and Savolainen, Chase et al. (2000), revealed a strongly supported clade consisting of the two families within eurosids I. Ordinal status for this clade, which appears not to fit in any other rosid order, was suggested by Soltis et al. (2000). Zygophyllaceae and Krameriaceae are quite diverse but have more or less pentamerous and (ob-)diplostemonous(-derived) flowers, bitegmic/crassinucellate ovules, and simple styles, and thus conform to a generalised rosid pattern. They agree in various wood characters such as simple perforation plates in vessels, and the presence of tracheids (vasicentric, in the case of Zygophyllaceae), which are considered as plesiomorphous within eurosids whereas other characters, listed by Carlquist (2005) and partly included in the Conspectus above, are autapomorphous; the paedomorphic rays of Krameria are probably related to its hemiparasitism. The presence of anthraquinones may indicate their relationship to the nitrogen-fixing clade (Cucurbitales, Fagales, Fabales, Rosales) where these compounds are more often found (Savolainen, Chase et al. 2000), and to which they appear close in some analyses, although with low support. Apart from the presence of harman alkaloids in both families, the remarkable diversification of lignans and neolignans is a strong link between them (see “Phytochemistry” in family treatments) although, according to our present knowledge, these compounds in Krameriaceae are localised in the roots but in Zygophyllaceae on the leaf surface and in the wood.

References Carlquist, S. 2005. Wood anatomy of Krameriaceae with comparisons with Zygophyllaceae: phylesis, ecology and systematics. Bot. J. Linn. Soc. 149:257–270. Savolainen, V., Chase, M.W. et al. 2000. See general references. Soltis, D.E. et al. 2000. See general references. Stevens, P.F. 2005. See general references.

20

K. Kubitzki

Families Unassigned to Order Four families are treated in this volume which are not assigned to order: Dilleniaceae, Huaceae, Picramniaceae and Sabiaceae. By and large, they do appear related to groups contained in this volume but, currently, evidence is not sufficient for including them into a specific order, and elevating them to monotypic orders does not seem appropriate because it would not convey any phylogenetic information. Apart from the following brief comments, a fuller discussion of the relationships of these families is found in the family treatments. Dilleniaceae. In the past, this family was considered a central group from which others radiated. This has not been confirmed by recent phylogenetic studies. Dilleniaceae have resisted attempts of molecular studies to determine their closest relative but it seems that they have some affinity with Caryophyllales. In his treatment of the family (this volume), J.W. Horn describes several important characters uniting Dilleniaceae and (woody) Caryophyllales such as Rhabdodendraceae. In the light of the internal topology of Dilleniaceae, with the genera showing anomalous secondary growth at the base of the family tree, this connection between Dilleniaceae and Caryophyllales gains weight. Molecular support for this relationship is, however, still weak (see also Introduction to Vitales, this volume).

Huaceae. This family has rare features, including the sepaline glands, cristarque cells, odour of garlic, and folds in the polar areas of the peroblate pollen grains. All existing morphology-based hypotheses for the placement of Huaceae are untenable (see family treatment, this volume), and the results of molecular studies, pointing to an association with Oxalidales/Malpighiales, have no strong support. The affinity of the family remains obscure. Picramniaceae. The two genera forming this pinnate-leaved family do not show particularly striking morphological features and traditionally have been considered an aberrant element of Simaroubaceae, from which they differ in structural and chemical traits (see family treatment, this volume). Molecular data point, albeit with low support, to a position of the family either sister to all rosids or sister to Zygophyllales. Sabiaceae. This family, formerly included either in Sapindales or in Ranunculales, is now clearly placed in the early-diverging eudicots. In molecular analyses it diverges after, before, or with Proteales but the support uniting these two groups is nearly always low. The pentamerous floral structure is quite different from the stereotyped pentamerous pattern of core eudicots; it is unique within eudicots. Available molecular evidence is not sufficient for an inclusion of Sabiaceae in Proteales, apart from the limited anatomical similarities between them. For further details, see treatment of Sabiaceae and Introduction to Gunnerales (this volume).

General References

Morphology, Anatomy, Embryology, Chromosomes and Palynology Behnke, H.-D. 1991. Distribution and evolution of forms and types of sieve-element plastids in the dicotyledons. Aliso 13:167–182. Carlquist, S. 2003. Wood anatomy of Aextoxicaceae and Berberidopsidaceae is compatible with their inclusion in Berberidopsidales. Syst. Bot. 28:317–325. Corner, E.J.H. 1976. The seeds of dicotyledons, 2 vols. Cambridge: Cambridge University Press. Davis, G.L. 1966. Systematic embryology of the angiosperms. New York: Wiley. Eichler, A.W. 1875–1878. Blüthendiagramme, 2 vols. Leipzig: W. Engelmann. Erdtman, G. 1952. Pollen morphology and plant taxonomy. Stockholm: Almquist & Wiksell. Fedorov, A.A. (ed.) 1969. Chromosome numbers of flowering plants (in Russian). Leningrad: Nauka. Hideux, M.J., Ferguson, I.K. 1976. The stereostructure of the exine and its evolutionary significance in Saxifragaceae sensu lato. In Ferguson, I.K., Muller, J. (eds) The evolutionary significance of the exine. Linnean Society Symposium Series no. 1:327–378. London: Academic Press. Johri, B.M., Ambegoakar, K.B., Srivastava, P.S. 1992. Comparative embryology of angiosperms, 2 vols. Berlin Heidelberg New York: Springer. Matthews, M.L., Endress, P.K. 2005. Comparative floral structure and systematics in Crossosomatales (Crossosomataceae, Stachyuraceae, Staphyleaceae, Aphloiaceae, Geissolomataceae, Ixerbaceae, Strasburgeriaceae). Bot. J. Linn. Soc. 147:1–46. Metcalfe, C.R., Chalk, L. 1950. Anatomy of the dicotyledons, 2 vols. Oxford: Clarendon Press (2nd edn 1979 onwards). Netolitzky, F. 1926. Anatomie der Angiospermen– Samen. In: Linsbauer, K. (ed.) Handbuch der Pflanzenanatomie, 2. Abt., 2. Teil, vol. 10. Berlin: Borntraeger. Takhtajan, A. (ed.) 1991–2000. Anatomia seminum comparative (in Russian). Leningrad St. Petersburg: Nauka/Mir et Semja (Vol. 3: CaryophyllidaeDilleniidae; Vol. 4: Dicotyledons Dilleniidae; Vol. 5: Rosidae I; Vol. 6: Rosidae II).

Systematics and Classification APG (Angiosperm Phylogeny Group) 1998. An ordinal classification for the families of flowering plants. Ann. Missouri Bot. Gard. 85:531–553.

APG (Angiosperm Phylogeny Group) II 2003. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants. Bot. J. Linn. Soc. 141:399–436. Cronquist, A. 1981. An integrated system of classification of flowering plants. New York: Columbia University Press. Cronquist, A. 1988. The evolution and classification of flowering plants, 2nd edn. Bronx, NY: New York Botanical Garden. Johnson, L.A.S., Briggs, B. 1975. On the Proteaceae – the evolution and classification of a southern family. Bot. J. Linn. Soc. 70:83–182. Johnson, L.A.S., Briggs, B.G. 1984. Myrtales and Myrtaceae – a phylogenetic analysis. Ann. Missouri Bot. Gard. 71:700–756. Stevens, P.F. 2005. Angiosperm Phylogeny website, version 5. http://www.mobot.org/MOBOT/research/ APweb/welcome.html Takhtajan, A. 1980. Plant life, vol. 5, 1. Leningrad: Nauka. Takhtajan, A. (ed.) 1981. Plant life, vol. 5, 2. Leningrad: Nauka. Takhtajan, A. 1987. Systema Magnoliophytorum. Leningrad: Nauka. Takhtajan, A.L. (ed.) 1996. Anatomia seminum comparativa, vol. 5 (in Russian). St. Petersburg: Mir et Semja. Takhtajan, A. 1997. Diversity and classification of flowering plants. New York: Columbia University Press. Thorne, R.F. 2001. The classification and geography of the flowering plants: dicotyledons of the class Angiospermae. Bot. Rev. 66:441–647. Thorne, R.F. 2004. An updated classification of the class Angiospermae (8/9/2004). Xeroxed and privately distributed.

Phytochemistry Bate-Smith, E.C. 1962. The phenolic constituents of plants and their taxonomic significance. I. Dicotyledons. J. Linn. Soc. Bot. 58:95–173. Gibbs, R.D. 1974. Chemotaxonomy of flowering plants, 4 vols. Montreal: McGill-Queen’s University Press. Hegnauer, R. 1962–1992. Chemotaxonomie der Pflanzen. Basel: Birkhaeuser (Vol. 1: 1962; Vol. 2: 1963; Vol. 3: 1964; Vol. 4: 1966; Vol. 5: 1969; Vol. 6: 1973; Vol. 7: 1986; Vol. 8: 1989; Vol. 9: 1990; Vol. 10: 1992). Nandi, O.I., Chase, M.W., Endress, P.K. 1998. A combined cladistic analysis of angiosperms using rbcL and non-molecular data. Ann. Missouri Bot. Gard. 85:137–212.

22

Palaeobotany Knobloch, E., Mai, D. 1986. Monographie der Früchte und Samen in der Kreide Mitteleuropas. Rozpravy ústredního ústavu geologického svazek 47. Praha: Czechoslovachian Academy. Krutzsch, W. 1989. Paleogeography and historical phytogeography (paleochorology) in the Neophyticum. Pl. Syst. Evol. 162:5–61. Muller, J. 1981. Fossil pollen records of extant angiosperms. Bot. Rev. 47:1–142.

Molecular Systematics Albach, D.C., Soltis, P.S., Soltis, D.E., Olmstead, R.G. 2001. Phylogenetic analysis of asterids based on sequences of four genes. Ann. Missouri Bot. Gard. 88:163–212. Anderberg, A.A., Rydin, C., Källersjö, M. 2002. Phylogenetic relationships in the order Ericales s.l.: analyses of molecular data from five genes from the plastid and mitochondrial genomes. Amer. J. Bot. 89:677–687. Anderson, C.L., Bremer, K., Friis, E.M. 2005. Dating phylogenetically basal eudicots unsing rbcL sequences and multiple fossil reference points. Amer. J. Bot. 92:1737– 1748. Cameron, K.M. 2003. On the phylogenetic position of the New Caledonian endemic families Paracryphiaceae, Oncothecaceae, and Strasburgeriaceae: a comparison of molecules and morphology. Bot. Rev. 68:428–443. Chase, M.W., Soltis, D.E., Olmstead, R.G., Morgan, D., Les, D.H. and 37 others 1993. Phylogenetics of seed plants: an analysis of nucleotide sequences from the plastid gene rbcL. Ann. Missouri Bot. Gard. 80:528–580. Chase, M.W., Zmarzty, S., Lledo, M.D., Wurdack, K.J., Swensen, S.M., Fay, M.F. 2002. When in doubt, put it in Flacourtiaceae: a molecular phylogenetic analysis based on plastid rbcL DNA sequences. Kew Bull. 57:141–181. Conti, E., Litt, A., Sytsma, K.J. 1996. Circumscription of Myrtales and their relationships to other rosids: evidence from rbcL sequence data. Amer. J. Bot. 83:221–233. Conti, E., Litt, A., Wilson, P.G., Graham, S.A., Briggs, B.G., Johnson, L.A.S., Sytsma, K.J. 1997. Interfamilial relationships in Myrtales: molecular phylogeny and patterns of morphological evolution. Syst. Bot. 22:629– 647. Conti, E., Eriksson, T., Schönenberger, J., Sytsma, K.J., Baum, D.A. 2002. Early Tertiary out-of-India dispersal of Crypteroniaceae: evidence from phylogeny and molecular dating. Evolution 56:1931–1942. Davis, C.C., Webb, C.O., Wurdack, K.J., Jaramillo, C.A., Donoghue, M.J. 2005. Explosive radiation of Malpighiales supports a Mid-Cretaceous origin of modern tropical rain forests. Amer. Naturalist 165: E36–E65. Fishbein, M., Hibsch-Jetter, C., Soltis, D.E., Hufford, L. 2001. Phylogeny of Saxifragales (angiosperms, eudicots): analysis of a rapid, ancient radiation. Syst. Biol. 50:817–847.

Graham, S.A., Hall, J., Sytsma, K., Shi, S.-H. 2005. Phylogenetic analysis of the Lythraceae based on four gene regions and morphology. Intl J. Pl. Sci. 166:995– 1017. Hilu, K.W., Borsch, T., Müller, K., Soltis, D.E., Soltis, P.S., Savolainen, V. and 10 others 2003. Angiosperm phylogeny based on matK sequence information. Amer. J. Bot. 90:1758–1776. Morgan, D.R., Soltis, D.E. 1993. Phylogenetic relationships among members of Saxifragaceae sensu lato based on rbcL sequence data. Ann. Missouri Bot. Gard. 80:631–660. Price, R.A., Palmer, J.D. 1993. Phylogenetic relationships of the Geraniaceae and Geraniales from rbcL sequence comparisons. Ann. Missouri Bot. Gard. 80:661–671. Savolainen, V., Chase, M.W., Hoot, S.B., Morton, C.M., Soltis, D.E., Bayer, C., Fay, M.F., de Bruijn, A.Y., Sullivan, S., Qiu, Y.-L. 2000. Phylogenetics of flowering plants based on combined analysis of plastid atpB gene sequences. Syst. Biol. 49:306–362. Savolainen, V., Fay, M.F., Albach, D.C., Backlund, A., van der Bank, M., Cameron, K.M., Johnson, S.A., Lledó, M.D., Pintaud, J.C., Powell, M., Sheahan, M.C., Soltis, D.E., Soltis, P.S., Weston, P., Whitten, W.M., Wurdack, K.J., Chase, M.W. 2000. Phylogeny of the eudicots: a nearly complete familial analysis based on rbcL gene sequences. Kew Bull. 55:257–309. Soltis, S.E., Soltis, P.S., Nickrent, D.L., Johnson, L.A., Hahn, W.J., Hoot, S.B., Sweere, J.A., Kuzoff, R.K., Kron, K.A., Chase, M.W., Swensen, S.M., Zimmer, E.A., Chaw, S.M., Gillespie, L.J., Kress, W.J., Sytsma, K.J. 1997. Angiosperm phylogeny inferred from 18S ribosomal DNA sequences. Ann. Missouri Bot. Gard. 84:1–49. Soltis, D.E., Soltis, P.S., Chase, M.W., Mort, M.E., Albach, D.C., Zanis, M., Savolainen, V., Hahn, W.H., Hoot, S.B., Fay, M.F., Axtell, M., Swensen, S.M., Prince, L.M., Kress, W.J., Nixon, K.C., Farris, J.S. 2000. Angiosperm phylogeny inferred from 18S rDNA, rbcL, and atpB sequences. Bot. J. Linn. Soc. 133:381–461. Soltis, D.E., Senters, A.E., Zanis, M.J., Kim, S., Thompson, J.D., Soltis, P.S., Ronse deCraene, L.P., Endress, P.K., Farris, J.S. 2003. Gunnerales are sister to other core eudicots: implications for the evolution of pentamery. Amer. J. Bot. 90:461–470. Soltis, D.E., Soltis, P.S., Endress, P.K., Chase, M.W. 2005. Angiosperm phylogeny, classification, and evolution. Washington, DC: Smithsonian Institution Press. Sosa, V., Chase, M.W. 2003. Phylogenetics of Crossosomataceae based on rbcL sequence data. Syst. Bot. 28:96–105. Sytsma, K.J., Litt, A., Zjhra, M.L., Pires, C., Nepokroeff, M., Conti, E., Walker, J., Wilson, P.G. 2004. Clades, clocks and continents: historical and biogeographical analysis of Myrtaceae, Vochysiaceae and relatives in the southern hemisphere. Intl J. Pl. Sci. 165 suppl.:85– 105. Wikström, N., Savolainen, V., Chase, M.W. 2001. Evolution of the angiosperms: calibrating the family tree. Proc. Roy. Soc. London B, 268:2211–2220.

Aextoxicaceae1 Aextoxicaceae Engler & Gilg in Engler, Syllabus, ed. 8:250 (1920), nom. cons.

K. Kubitzki

Dioecious trees; twigs, the lower side of leaves, inflorescences and flowers including the ovary covered with ferrugineous scales. Leaves alternate to subopposite, simple, entire, conduplicate and sometimes minutely peltate, pinnately veined, estipulate. Inflorescences racemes or botryoids usually in groups of 3 or more, branching from axils of basal prophylls, the male ones longer and more abundant than the female ones; bracts very small, rounded. Flowers (4)5(6)-merous, hypogynous, regular, enveloped in bud by a firm calyptrate bract; sepals orbicular, free, thin, strongly imbricate, caducous; petals broadly clawed, incurved in bud, oblong, with thick midrib, imbricate, persistent; male flowers: stamens 5, antesepalous, alternating with well-developed fleshy, reniform nectary glands; anthers dorsifixed, introrse, opening by short slits towards the apex, with persistent septum between pollen sacs; gynoecium vestigial; female flowers: staminodia fleshy, alternating with the nectary glands; gynoecium 1-carpellate, style short, strongly deflexed to one side and appressed to the ovary, apically bifid; ovary with 2 pendulous ovules; ovules anatropous, with a long extended endostome. Fruits dry, indehiscent, oneseeded; endosperm ruminate, oily-proteinaceous; embryo well-developed, cotyledons flattened, cordate-orbicular. n = 16. Monotypic, Aextoxicon punctatum Ruiz & Pav., a tree of the coastal and lake region of southern Chile and adjacent Argentina. Morphology and Anatomy. On young shoots, the far-advanced conduplicate leaf primordia appear the year before they unfold (Fig. 4). They are densely covered by stellate scales and overwinter without being enclosed in a bud. Such “naked buds” are characteristic of several trees of the humid-temperate Valdivian rainforest and are also well-developed in young shoots of Proteaceae such 1

Including personal observations by P.F. Stevens and W. Stuppy.

Fig. 4. Aextoxicaceae. Aextioxicon punctatum, “naked bud” in February (early fall), the conduplicate leaf primordia densely covered by stellate scales; note also the minute peltation. (Photograph B. Fiebig)

as Gevuina avellana (pers. obs.). In the unfolded leaves, the cover of stellate scales is restricted to the lower leaf surface. Between the scales, short glands are interspersed. The plants are strongly tanniniferous but lack ethereal oil cells. The leaves are sometimes minutely peltate; on the adaxial side, the mesophyll tissue is uninterrupted at the base. Phellogen is superficial, and there are cortical sclereids, pericyclic fibres, and a strikingly heterogeneous pith. Nodes are trilacunar, and the peti-

24

K. Kubitzki

ole bundle is annular, although slightly flatter on the adaxial surface. Stomata are actinocyclic with 5–7 accessory cells. There are two layers of palisade tissue. Prismatic crystals, but no druses, are present in the stem, petiole and lamina, as are sclereids; in the lamina, they are quite spectacular, being as tall as about half the thickness of the blade. The wood of Aextoxicon is remarkable for its long vessel elements and tracheids (mean length 1,357 and 1,528 µm respectively), the former with perforation plates showing various degrees of pit membrane remnants and 49–84 bars per plate. Axial parenchyma is diffuse; rays are multiseriate and uniseriate, the uniseriate rays and uniseriate portions of multiseriate rays composed of upright cells, the central portion of multiseriate rays composed of markedly procumbent cells (Carlquist 2003). The morphological interpretation of the firm cover enclosing the flower buds has always been contentious. Some authors thought that it might represent the fused prophylls or a transformed sepal. The latter view was favoured by Pax and Hoffmann (1917), who found cross sections of the flower cover to consist of a single leaf organ. In contrast to all earlier descriptions, the ovary is 1-carpellate, not 2-carpellate. Embryology. The ovules are bitegmic and crassinucellate; the outer integument 2–3 cells thick, the inner 5–7. The endostome projects beyond the exostome. The ovules have a massive nucellar beak and numerous parietal layers (Mauritzon 1936). Several authors characterised the ovule as apotropous, which is inappropriate by definition, as the monomerous ovary has no central axis. Pollen Morphology. Pollen grains are spheroidal, tricolporate, with lalongate ora, 17 × 18 µm (Erdtman 1952). Fruit and Seed. The drupes have a coriaceous pericarp, and the endocarp cracks along two lines. The solitary seed is campylotropous, the seed coat is undifferentiated, about 6 cells thick, and tanniniferous, the endosperm is ruminate, and the embryo is slightly curved and seems to be horizontaloblique in the seed. Phytochemistry. Aextoxicon is strongly tanniniferous.

Fig. 5. Aextoxicaceae. Aextoxicon punctatum. A Flowering and fruiting branch. B Two leaves with axillary raceme. C Stellate scale. D Flower bud. E Same, calyptrate bract removed. F Male flower, one petal removed. G Female flower showing disk, staminodes, scaly gynoecium and deflexed style, petals removed. H Fruit with seed. (Drawn by M. Raspini; Dimitri 1972)

Aextoxicaceae

Affinities. The position of Aextoxicon has been disputed by many authors (see, e.g. Pax and Hoffmann 1917; Takhtajan 1997), and placements in or close to Euphorbiaceae, Celastrales, Sapindales and Icacinaceae have been proposed. More recently, gene sequence analyses established a sister relationship with Berberidopsidaceae at the basis of the core eudicots (Angiosperm Phylogeny Group, APG II 2003). This is supported also by anatomical data, although these refer mostly to plesiomorphies, as emphasised by Carlquist (2003). Distribution and Habitat. Aextoxicon is member of the temperate Valdivian rainforest in Chile and adjacent border with Argentina, growing preferentially at localities with high air humidity. In coastal habitats, it is a small tree and wind-shorn shrub on dunes and rocks and, further inland in the lake region, a medium-sized tree. Aextoxicon extends from 36 to 44◦ S and, further north at about 30◦ S, has a relic occurrence in the Chilean Coastal Cordillera.

25

One monotypic genus: 1. Aextoxicon Ruiz & Pav.

Figs. 4, 5

Aextoxicon Ruiz & Pav., Prodr.: 131, t. 29 (1794).

Selected Bibliography APG II (2003). See general references. Carlquist, S. 2003. Wood anatomy of Aextoxicaceae and Berberidopsidaceae is compatible with their inclusion in Berberidopsidales. Syst. Bot. 28:317–325. Dimitri, M.J. (ed.) 1972. La región de los bosques andinopatagónicos. Buenos Aires: INTA. Erdtman, G. 1952. See general references. Mauritzon, J. 1936. Die Embryologie und systematische Abgrenzung der Reihen Terebinthales und Celastrales. Bot. Notiser 1936:161–212. Pax, F., Hoffmann, K. 1917. Systematische Stellung der Gattung Aextoxicon. Jahresber. Schles. Gesell. für vaterländ. Cultur 1916, II. Abt., Zool.-bot. Sekt.: 17–21. Radcliffe-Smith, A. 1987. Segregate families from the Euphorbiaceae. Bot. J. Linn. Soc. 94:47–66. Takhtajan, A. 1997. See general references.

Alzateaceae Alzateaceae S.A. Graham, Ann. Missouri Bot. Gard. 71:775 (1985).

S.A. Graham

Small evergreen trees or shrubs, sometimes hemiepiphytic; young stems and axes of the inflorescence quadrangulate. Leaves opposite or whorled, simple, entire; blades oblong-obovate or elliptical, coriaceous, glabrous, venation brochidodromous; stipules 2–a few. Inflorescences thyrsoidal, axillary at the ends of branches, 10–30-flowered; flowers actinomorphic, bisexual, barely hemi-epigynous, 5(6)-merous, apetalous or possibly petals rudimentary; floral tube campanulate; sepals valvate, thick, irregularly fleshy on the adaxial surface; stamens 5, fleshy, inserted below the sinus of adjacent sepals at the margin of a broad lobed nectary, filaments short with large cordate connective, the anthers dorsifixed, introrse, the sporangia terminal; ovary superior, bilaterally compressed, bilocular; placentation parietal; ovules 40–60, horizontally imbricate in staggered vertical rows. Fruits bilaterally compressed dry capsules dehiscing loculicidally. Seeds flattened, oblong to lunate, thin, encircled by a fragile membranous wing; embryo central, straight; endosperm 0. n = 14. A single species, Alzatea verticillata Ruiz & Pav. with two narrowly separated subspecies from Central and South America. Vegetative Anatomy. Anatomy agrees with generalized characteristics of the Myrtales but does not indicate close affinities to any one family. Leaves include sclereids of the same shape as the spongy mesophyll cells; stomates are anomocytic and cyclocytic (Keating 1984). Uniquely, among the families to which Alzatea has been previously related, Alzatea has trilacunar three-trace nodes, rather than unilacunar one-trace nodes (Graham 1984). Wood anatomy (Baas 1979; Baas and Zweypfenning 1979) is characterized by diffuse vessels, solitary or in radial multiples of 2–4 with inter-vessel pits vestured and end walls oblique with simple perforations; septate fibers with thin walls; very scanty paratracheal parenchyma; rays of type heterogeneous I-II, 1–3-seriate; crystals

absent. Internal phloem forms a continuous ring, and druses are abundant in chambered phloem parenchyma. Flower Structure. The fleshy flowers are small, 4–6 mm long. They are obhaplostemonous, a synapomorphy that unites members of the clade Alzatea + Rhynchocalycaceae + Oliniaceae + Penaeaceae (Schönenberger and Conti 2003). van Beusekom-Osinga and van Beusekom (1975) report rudimentary petals that are scarcely visible and already mucilaginous in bud, although even these are not always present (Graham, pers. obs.). The stamens are easily mistaken for petals, due to enlarged heart-shaped, pinkish connectives that are conspicuously exserted between the sepals at anthesis. Embryology. Tobe and Raven (1984) investigated the embryological development of Alzatea and compared it to that of related families. The anthers are tetrasporangiate; the endothecium and the middle layers of the anther wall degenerate early; dehiscence is accomplished by rupture of thin-walled epidermal cells. Ovules are anatropous, crassinucellate, and bitegmic. Embryo sac formation is of the bisporic Allium type, a type unknown elsewhere in the order. The archesporium is multicelled. The inner integument remains two-layered, and ultimately elongates beyond the outer integument to form the micropyle. Endosperm is probably of the Nuclear type and cotyledons are planar. Embryology of Alzatea is most similar to that of Rhynchocalycaceae, and in general agreement with other Myrtales (Tobe and Raven 1984, 1987). Pollen Morphology. Pollen grains are circular in outline, tricolporate; the ektexine bridges over a circular pore; the exine is psilate bordering the colpi, thinner and verrucate-aerolate in the mesocolpal regions, thus suggesting faint sub-

Alzateaceae

sidiary colpi; diameter 18–22 µm (Graham 1984; Patel et al. 1984; Graham et al. 1985). The external morphology of the exine is relatively generalized whereas the internal structure shares a zigzag columellar layer with Dactylocladus and Axinandra in the Crypteroniaceae (Patel et al. 1984).

27

and South America. Considered restricted to Peru and Bolivia until it was discovered in Costa Rica in 1936, subsequent discoveries in Panama in 1978 and Colombia in 1986 revealed a more continuous distribution than previously known (Silverstone-Sopkin and Graham 1986). Increased

Karyology. A haploid chromosome number of n = 14 has been counted from A. verticillata subsp. amplifolia (Almeda 1997). Given a basic number for the order Myrtales of x = 12 (Raven 1975), the basic number of Alzateaceae may have arisen from x = 12 as an ascending dysploid or alternatively, it may represent a tetraploid from an ancestral base of 7 (Almeda 1997). Clarification may come when chromosome numbers of Crypteroniaceae, considered ancestral to Alzateaceae (Schönenberger and Conti 2003), become known. Phytochemistry. Ellagic acid and flavonoid mono- and di-glycosides, including quercetin 3-Oglucoside and quercetin 3-O-diglucoside, have been detected in leaves of Alzatea (Graham 1984; Graham and Averett 1984). The profile is in keeping with that of the order, which is rich in ellagic acid and tannins (Hegnauer 1969). It differs from the common pattern by the absence of myricetin and C-glycoflavones (Graham and Averett 1984). Affinities. In the past, Alzatea has been aligned with eight families in five orders, among them, Lythraceae and Crypteroniaceae in Myrtales (Lourteig 1965; van Beusekom-Osinga and van Beusekom 1975). Graham (1984) elevated Alzatea to family status after comparison of extensive non-molecular data that determined that Alzatea was distinctly separated from its nearest living relative, Rhynchocalyx. Phylogenetic analyses of cpDNA sequences from several genes and chloroplast spacer regions now affirm the monophyly of Alzateaceae as a member of Myrtales in a lineage with the Southeast Asian Crypteroniaceae sister to Alzateaceae + the African families Rhynchocalycaceae, Oliniaceae, and Penaeaceae. Alzateaceae, in turn, are sister to Rhynchocalycaceae–Oliniaceae + Penaeaceae, a position supported by bootstrap values varying from ≤ 50 to 92%, depending on the analysis (Conti et al. 1997, 2002; Clausing and Renner 2001; Schönenberger and Conti 2003). Distribution and Habitats. Alzatea grows in mid- to low-montane forests along the eastern slopes of the Andes and mountains of Central

Fig. 6. Alzateaceae. Alzatea verticillata. A Flowering twig. B Flower bud. C Flower. D Disk. E Three stamens. F Transversal section of ovary. G Fruit. H Transversal section of fruit. I Seed. (Lourteig 1965)

28

S.A. Graham

collections have diminished the morphological differences between subspecies (Graham 1995). Only one genus: Alzatea Ruiz & Pav.

Fig. 6

Alzatea Ruiz & Pav., Prodr.: 40 (1794).

Description as for family.

Selected Bibliography Almeda, F. 1997. Chromosomal observations on the Alzateaceae (Myrtales). Ann. Missouri Bot. Gard. 84:305– 308. Baas, P. 1979. The anatomy of Alzatea Ruiz & Pav. (Myrtales). Acta Bot. Neerl. 28:156–158. Baas, P., Zweypfenning, R.C.V.J. 1979. Wood anatomy of the Lythraceae. Acta Bot. Neerl. 28:117–155. Clausing, G., Renner, S.S. 2001. Molecular phylogenetics of Melastomataceae and Memecylaceae: implications for character evolution. Amer. J. Bot. 88:486–498. Conti, E. et al. 1997. See general references. Conti, E. et al. 2002. See general references. Graham, S.A. 1984. Alzateaceae, a new family of Myrtales in the American Tropics. Ann. Missouri Bot. Gard. 71:757–779. Graham, S.A. 1995. Two new species in Cuphea (Lythraceae), and a note on Alzateaceae. Novon 5:272–277.

Graham, S.A., Averett, J.E. 1984. Flavonoids of Alzateaceae (Myrtales). Ann. Missouri Bot. Gard. 71:855–857. Graham, A., Nowicke, J., Skvarla, J.J., Graham, S.A., Patel, V., Lee, S. 1985. Palynology and systematics of the Lythraceae. I. Introduction and genera Adenaria through Ginoria. Amer. J. Bot. 72:1012–1031. Hegnauer, R. 1969. See general references. Keating, R.C. 1984. Leaf histology and its contribution to relationships in the Myrtales. Ann. Missouri Bot. Gard. 71:801–823. Lourteig, A. 1965. On the systematic position of Alzatea verticillata R. & P. Ann. Missouri Bot. Gard. 52:371– 378. Patel, V.C., Skvarla, J.J., Raven, P.H. 1984. Pollen characters in relation to the delimitation of Myrtales. Ann. Missouri Bot. Gard. 71:858–969. Raven, P.H. 1975. The bases of angiosperm phylogeny: cytology. Ann. Missouri Bot. Gard. 62:724–764. Schönenberger, J., Conti, E. 2003. Molecular phylogeny and floral evolution of Penaeaceae, Oliniaceae, Rhynchocalycaceae, and Alzateaceae (Myrtales). Amer. J. Bot. 90:293–309. Silverstone-Sopkin, P.A., Graham, S.A. 1986. Alzateaceae, a plant family new to Colombia. Brittonia 38:340–343. Tobe, H., Raven, P.H. 1984. The embryology and relationships of Alzatea Ruiz & Pav. (Alzateaceae, Myrtales). Ann. Missouri Bot. Gard. 71:844–852. Tobe, H., Raven, P.H. 1987. The embryology and relationships of Dactylocladus (Crypteroniaceae) and a discussion of the family. Bot. Gaz. 148:103–111. van Beusekom-Osinga, R.J., van Beusekom, C.F. 1975. Delimitation and subdivision of the Crypteroniaceae (Myrtales). Blumea 22:255–266.

Aphanopetalaceae Aphanopetalaceae Doweld, Prosyllabus tracheophytorum: XXVII (2001).

K. Kubitzki

Scrambling or viny shrubs, glabrous throughout; nodes unilacunar, 1(+ 2) trace; stems with conspicuous raised lenticels. Leaves opposite, simple, serrate to mostly entire, shortly petiolate; stipules 0 but with minute colleters at each side of the nodes. Inflorescences lax axillary panicles, or flowers solitary; pedicels at the mid with 2 prophylls. Flowers regular, hermaphrodite, tetramerous, half-inferior; sepals largely separate, imbricate at lower level, greatly enlarged in fruit and persistent, borne in pairs at slightly different levels, their basal parts coalescing with basal portions of petals (when present) and stamens into a short floral tube which is adnate to the lower half of the ovary wall; petals minute with reduced blade or completely absent (even within the same individual); stamens 8; anthers oblong, 2-lobed at base, almost basifixed, tetrasporangiate, with connective protrusion, dehiscing with longitudinal slits, latrorse-introrse; gynoecium of 4 laterally concrescent carpels; ovary one quarter- to half-inferior, 4-locular, deeply 4-furrowed, gradually tapering into a 4grooved, apically 4-lobed style with 4 canals; stigmas terminal, highly papillate; ovules 1 per locule, descending, suspended on axile placenta with long, thick funiculus, bitegmic, anatropous. Fruit nut-like, hard, 1-locular and 1-seeded, with the sepals persistent; seed hippocrepiform or reniform; embryo curved; endosperm fleshy. A family comprising a single genus with two species in Australia. Anatomy and Morphology. (All data from Dickison 1980b, Dickison et al. 1994, and Dickison and Rutishauser 1990). Between the opposite leaves, small non-vascular colleters are present, which perhaps are reduced stipules. The innermost layer of the cortex is formed by a well-defined endodermis. Nodes are unilacunar and the single large trace diverges to produce dorsally or laterally situated petiolar bundles. Stomata are anomocytic. The leaves are bifacial; the epidermis is uniseriate.

Dark deposits have been found in the mesophyll of both species. Leaf teeth are weakly vascularized and non-glandular. In mature stems, prominent lenticels develop on the cortex. Cork is surficial. Vessels are solitary or rarely in radial multiples; vessel elements with scalariform perforation plates with 2–6 thick, fully bordered bars; fibre-tracheids non-septate, thick-walled, pitted, rays homocellular, uniseriate and heterocellular, multiseriate, the latter 2–4 cells wide and composed of procumbent and upright cells. Axial parenchyma is scarce and apotrachealdiffuse. Floral Structure. Apart from the details given in the family description, information on the vascular anatomy of Aphanopetalum can be found in Dickison (1975) and Dickison et al. (1994). Pollen Morphology. Pollen of Aphanopetalum is tricolporate, prolate, fully tectate; the endoaperture is simple-diffuse; the rugulate-stellate sculpture is unique in Saxifragaceae/Cunoniaceae (Hideux and Ferguson 1976). Embryology. The anther has a fibrous endothecium and a tapetum of 2–3 cells. The ovules have a long, thick funiculus, and are bitegmic and anatropous. Affinities and Phylogeny. Until recently, the systematic relationships of Aphanopetalum were unclear. Hoogland (1960) and Dickison (1980b) noted that this genus was out of place in Cunoniaceae. It differs from Cunoniaceae in having unilacunar nodes and lacking stipules, and from Saxifragaceae in having opposite leaves and lacking foliar trichomes, and is unique in possessing a pronounced endodermis. However, tetramerous flowers and single (or 2) ovules per carpel are known elsewhere in woody Saxifragales. This is consistent with the results of molecular studies, particularly with the topology of Fishbein et al. (2001), in which

30

K. Kubitzki

Fig. 7. Aphanopetalaceae. Aphanopetalum resinosum. A Habit. B, C Flower. D Androecium and gynoecium.

E Stamen. F Pistil. G Carpel, vertical section. (Drawing F. Bauer; Endlicher 1841)

Aphanopetalum is part of the “Haloragis clade”, which is sister to the “Saxifragaceae clade”.

Dickison, W.C. 1975. Studies on the floral anatomy of the Cunoniaceae. Amer. J. Bot. 62:433–447. Dickison, W.C. 1980a. Diverse nodal anatomy of the Cunoniaceae. Amer. J. Bot. 67:975–981. Dickison, W.C. 1980b. Comparative wood anatomy and evolution of the Cunoniaceae. Allertonia 2:281–321. Dickison, W.C., Rutishauser, R. 1990. Developmental morphology of stipules and systematics of the Cunoniaceae and presumed allies. II. Taxa without interpetiolar stipules and conclusions. Bot. Helv. 100:75–95. Dickison, W.C., Hils, H.M., Lugansky, T.W., Stern, W.L. 1994. Comparative anatomy and systematics of woody Saxifragaceae. Aphanopetalum Endl. Bot. J. Linn. Soc. 114:167–182. Endlicher, S. 1841. Iconographia generum plantarum, II, tabula 39. Wien: F. Beck. Fishbein, M. et al. 2001. See general references. Hideux, M.J., Ferguson, I.K. 1976. See general references. Hoogland, R.D. 1960. Studies in the Cunoniaceae. I. The genera Ceratopetalum, Gillbeea, Aistopetalum, and Calycomis. Austral. J. Bot. 8:318–341.

Only one genus: Aphanopetalum Endl.

Fig. 7

Aphanopetalum Endl., Gen. Pl.: 818 (1839), and Iconogr. t. 96 (1839); Bentham, Fl. Austral. 2:441–442 (1864).

Description as for family. Two species in Australia, A. resinosum Endl. in river scrubs of temperate southern Queensland and New South Wales, and A. clematideum Domin in crevices of limestone rocks in south-western Australia.

Selected Bibliography Bailey, F.M. 1990. The Queensland flora. Queensland: H.J. Diddams.

Aphloiaceae Aphloiaceae Takht., Bot. Zhurn. (Moscow & Leningrad) 70:1691 (1985).

K. Kubitzki

Evergreen shrubs or slender trees, entirely glabrous. Leaves persistent, alternate, serrate or serrulate, rarely subentire, penninerved, petiolate; stipules minute, caducous. Flowers hermaphrodite, axillary, solitary or in few-flowered racemes or fascicles, sweet-scented; bracts scale-like, minute; pedicels with 1–3 scaly bracteoles in the lower half; perianth uniseriate; sepals 4–5(6), white, turning yellowish, free except at the base, imbricate, orbicular, the inner 3 more membranous and petaloid; petals 0; stamens very numerous, free, inserted towards the outer edge of a glandular disk; filaments filiform; anthers small, orbicular, introrse, basifixed near the base; gynoecium monomerous; ovary superior, ellipsoid, sessile or shortly stipitate, 1-locular; placentation lateral with 6–8 alternating ovules in 2 rows; ovules campylotropous; stigma sessile, large, capitate-bilobed and somewhat decurrent on ventral side. Fruit a fleshy, white berry with persistent perianth and about 6 obovate seeds; testa crustaceous, smooth, whitish, glossy; embryo incurved; endosperm sparse. A monogeneric family with a single polymorphic (or 8?) species in eastern and South Africa, Madagascar including the Comores, and the Mascarenes and Seychelles. Vegetative Morphology and Anatomy. Aphloia theiformis is a shrub or slender tree; the branchlets are drooping and longitudinally striate with a stronger line decurrent from a stipulate cushion. Leaves are distichous. Friedmann and Cadet (1976) observed that juvenile plants growing in xeric habitats on Réunion have pinnatisect leaves, whereas these are undivided in adult specimens. The cork is pericyclic; stomata are anisocytic; nodes are 3-lacunar (Stevens 2005). In the wood, growth rings are poorly defined. The vessel elements are mostly very long (1,051–2,416 µm) and have scalariform perforation plates. Rays are unicellular with upright cells, and multiseriate heterocellular with long uniseriate extensions. Fibre-

tracheids are present, and the axial parenchyma is vasicentric and apotracheal-diffuse (Miller 1975). Reproductive Structures. van Tieghem (1899) found the vascular supply of the stamens originating from five antesepalous trunk bundles. A detailed analysis of the floral morphology and anatomy was given by Matthews and Endress (2005). The bitegmic, crassinucellate and campylotropous ovule develops into an incurved seed with a hippocrepiform embryo. The seeds are exotestal. In the mature seeds, the testa is multiplicative with several outer, strongly thickened lignified layers and the tegmen crushed (Trifonova 1992).

Fig. 8. Aphloiaceae. Aphloia theiformis. A Flowering branch. B Flower bud. C Flower. D Stamen. E Pistil, vertical section. F Same, transversal section. G Fruit. H, I Seed. (Engler 1910)

32

K. Kubitzki

Pollen Morphology. The pollen grains are spheroidal, 20–25 µm long and wide, striate, tricolporate with large, elliptical, lalongate endoapertures, the colpi diffuse, weakly costate; the exine is 1.5–2 µm thick (Keating 1973). Phytochemistry. Bate-Smith (1965) recorded mangiferin from Aphloia. Affinities. Takhtajan (1987) placed Aphloiaceae in his Violales, along with Berberidopsidaceae and Flacourtiaceae. Since then, various molecular studies have recovered Aphloia together with Ixerba in association with the Crossosomatales clade (see Soltis et al. 2000; Savolainen, Fay et al. 2000; Cameron 2003). Distribution and Habitats. In submontane forest, mist forest and riverine forest, and in upland riverine bushland, 1,300–2,900 m. A single genus: Aphloia (DC.) Benn.

Fig. 8

Aphloia (DC.) Benn. in Benn. & Br., Pl. Jav. Rar. 2:192 (1838). Neumannia A. Rich. (1845).

A problematic, polymorphic species, Aphloia theiformis (Vahl) Benn., see above.

Selected Bibliography Bate-Smith, E.C. 1965. Recent progress in the chemical taxonomy of some phenolic constituents of plants. Mém. Soc. Bot. France 1965:16–28. Cameron, K.M. 2003. See general references. Engler, A. 1910. Die Pflanzenwelt Afrikas, 1. Leipzig: W. Engelmann. Friedmann, F., Cadet, T. 1976. Observation sur l’hétérophyllie dans les îles Mascareignes. Adansonia II, 15:423– 440. Keating, R.C. 1973. Pollen morphology and relationships of the Flacourtiaceae. Ann. Missouri Bot. Gard. 60:273– 305. Krishnan, N. 1981. Pollen morphology of some Flacourtiaceae. Proc. Ind. Acad. Sci., Pl. Sci. 90:163–168. Matthews, M.L., Endress, P.K. 2005. See general references. Miller, R.B. 1975. Systematic anatomy of the xylem and comments on the relationships of Flacourtiaceae. J. Arnold Arb. 56:20–102. Savolainen, V., Fay, M.F. et al. 2000. See general references. Soltis, D.E. et al. 2000. See general references. Stevens, P.F. 2005. See general references. Takhtajan, A. 1987. See general references. Tieghem, P. van 1899. Sur le genre Neumannia considéré comme type d’une famille nouvelle, les Neumanniacées. J. Bot. (Morot) 13:361–367. Trifonova, W.I. 1992. Aphloiaceae. In: Takhtajan, A. (ed.) Anatomia seminum comparativa, 4. St. Petersburg: Nauka, p. 80. Wild, H. 1960. Flacourtiaceae. In: Exell, A.W., Wild, H. (eds) Flora Zambesiaca 1, 1:261–298. London: Crown Agents.

Berberidopsidaceae Berberidopsidaceae A.L. Takhtajan, Bot. Zhurn. (Moscow & Leningrad) 70:1691 (1985).

K. Kubitzki

Scandent shrubs with sympodial branching and collateral axillary buds. Leaves spiral, simple, sub-3–5-pli-nerved, entire to coarsely dentate, estipulate, petioles pulvinate or not. Flowers in racemes or solitary, hypogynous, hermaphrodite (always?); pedicels with prophylls; petals welldeveloped, either distinct from sepals, or outer sepaloid tepals grading into inner petaloid ones; disk extra-staminal, persistent in fruit, or 0; stamens either in a single whorl of 6–13, or numerous and densely packed on torus; anthers (sub)basifixed, dehiscing longitudinally laterointrorse; ovary 1-locular, placentas parietal, 3 or 5, ovules epitropous, 2 or more per placenta. Fruit berry-like, indehiscent, with persistent style; seeds with fleshy or leathery exotesta, with chalazal arilloid (only Streptothamnus); endosperm copious, oily-proteinaceous; embryo minute. Two genera, one monotypic in Australia, the other with one species in Australia, another in Chile. Vegetative Anatomy. The leaves are hypostomatic, and the stomata are cyclocytic and surrounded by one or two rings of subsidiary cells. Other leaf anatomical features are restricted to the two species of Berberidopsis, such as the possession of 1–3-celled uniseriate hairs, druses and solitary crystals in the petiole, and sclerenchyma accompanying major leaf veins. In the c. 4 mm thick twigs of both genera, cork is not developed; growth rings are present; rays in secondary xylem are 1–multi-seriate, composed of procumbent cells, the uniseriate portions composed of upright cells; vessels are exclusively solitary and have scalariform perforations with 18–41 bars; a faint spiral thickening is present only in vessels of Berberidopsis corallina; fibres have distinctly bordered pits in radial and tangential walls and are non-septate (fibre-tracheids); axial parenchyma is mostly diffuse (Miller 1975; Baas 1984; Carlquist 2003).

Floral Morphology. Whereas Streptothamnus (and the closely related Aextoxicum) have cyclic pentamerous flowers with persistent calyx lobes and five caducous petals, the flowers of Berberidopsis are acyclic and fully spiral, with all floral organs following a regular sequence in a 2/5 pattern (Ronse De Craene 2004) and tending to appear in alternating groups of five. Pollen Morphology. Pollen grains are spheroidal to prolate and tricolpate to tricolporate, and tectate-columellate with an imperforate to microperforate tectum the sculpture of which varies from foveolate to rugulate and striate; those of Berberidopsis are 20–30 µm and of Streptothamnus smaller than 15 µm (Keating 1973, 1975; van Heel 1984). Seed. The seeds of Berberidopsidaceae have a peculiar protruding, “sausage-shaped” raphe. They are endotestal; the inner epidermis of the testa has strongly lignified pitted cells each containing a crystal. There are also indications of a less pronounced fibrous exotegmen. The embryo is very small. All these features distinguish Berberidopsidaceae from Flacourtiaceae (= Salicacaceae plus Achariaceae), in which they formerly were included and the seeds of which are exotegmic and have a sarcotesta formed by the outer integument (van Heel 1979, 1984); the embryo in those families is also larger. Affinities. The recognition of a second species of Berberidopsis (formerly included in Streptothamnus) by Veldkamp (1984) has prompted the anatomical studies of van Heel (1984) and Baas (1984), which have provided evidence for the restriction of the formerly more broadly circumscribed tribe Berberidopsideae to Berberidopsis and Streptothamnus. Takhtajan (1985) elevated this tribe to family rank but retained the narrowly circumscribed Berberidopsidaceae

34

K. Kubitzki

in Violales, along with Flacourtiaceae (Takhtajan 1987, 1997). Nandi et al. (1998), on the basis of a combined morphological/rbcL analysis, were the first to suggest a relationship between Berberidospsidaceae and Aextoxicaceae – never even considered in pre-molecular times – and Carlquist (2003) pointed to the great similarities in the wood anatomy of the two families, all of which, however, are plesiomorphic. The association of Berberidospidaceae with Aextoxicaceare has received such strong molecular support that Soltis et al. (2000) and Savolainen, Fay et al. (2000) suggested that the two families be placed in the same order. A four-gene analysis of eudicots (Soltis et al. 2003) has provided a resolution of the major core eudicot lineages, in which Gunnerales and subsequently Berberidopsidales are sister to all major core eudicot lineages. However, the relation of Berberidopsidales to other core eudicots is unclear.

Ronse DeCraene (2004) analysed the spiral sequence of initiation of perianth members and stamens in Berberidopsis corallina, and found a tendency of these organs to occur in alternating groups of five which, according to him, may represent an incipient case of pentamery. At first glance, this might appear convincing, particularly in view of the position of Berberidopsidaceae at the basis of the core eudicots above the node leading to (dimerous) Gunnerales, but it is problematic with regard to various structural aspects of the relatives of Berberidopsis, and of Berberidopsis itself. Berberidopsis has a tepaline perianth of 13–17 members whereas in Streptothamnus, which has five sepals and five petals, the androecium consists of numerous stamens which are densely packed but do not show any particular arrangement – evidently a derived condition. The paracarpous gynoecium in both genera of Berberidopsidaceae is also probably derived. These traits would hardly be expected in a group in which the transition from the spiral to the whorled condition took place quasi before our eyes, because then a less derived gynoecium structure would be expected, too. Even more pertinent seems the fact that the flowers of closely related Aextoxicon, with their fixed pentamery and haplostemony, are quite typically core eudicot. For these reasons, the spiral arrangement in Berberidopsis is probably a derived, rather than the original condition. Uses. Berberidospsis corallina has very showy, coral red or scarlet flowers, and has been introduced into gardens in Chile and Great Britain. Key to the Genera 1. Flowers acyclic; tepals 13–17, spirally set, caducous; disk present, persistent; stamens 6–13, filaments short, connective broad, muriculate, anthers muriculate 1. Berberidopsis – Flowers cyclic; sepals 5, persistent, petals 5, caducous; disk 0; stamens numerous, filaments longer than anthers, filiform, connective inconspicuous except for terminal lobe, anthers smooth 2. Streptothamnus

1. Berberidopsis Hook. f.

Fig. 9

Berberidopsis Hook. f. in Curtis, Bot. Mag. III, 18: t. 5343 (1862); Gunckel, Bol. Univ. Chile 46: 24:24–27, fig. (1964); Veldkamp, Blumea 30:24–28 (1984). Fig. 9. Berberidospidaceae. Berberidopsis corallina. A Flowering branch. B Flower buds. C Androecium. D Pistil with nectary disk. E Pistil, vertically cut. (Schneider 1912)

Leaf blades ovate to hastiform, entire to coarsely dentate. Flowers solitary or in many-flowered racemes; disk with as many lobes as stamens; style

Berberidopsidaceae

club-shaped with inconspicuous stigma; ovary with 3 or 5 placentae. Fruit with thin pericarp; seeds numerous; raphe a narrow, sausage-shaped lateral wing. Two species, B. beckleri (F. Muell.) Veldk., in montane rainforest of Queensland and New South Wales, Australia, and B. corallina Hook. f., in gorges by streams in the Coastal Cordillera of southern Chile from Prov. Talca to Osorno. 2. Streptothamnus F. Muell. Streptothamnus F. Muell., Fragm. Phyt. Austral. 3:27 (1862); Jessup in Fl. Australia 8:76 (1982).

Leaf blades ovate to elliptic, entire; flowers solitary or in a ± leafy raceme; disk 0; anthers basifixed; stigma mushroom-shaped; ovary 1-locular, placentas indistinct, probably 3. Fruit with thickish pericarp; seeds up to 25 per fruit, with median-lateral chalazal aril. One species, S. moorei F. Muell., in montane rainforest of Queensland and New South Wales, Australia, sometimes together with Berberidopsis beckleri F. Muell.

Selected Bibliography Baas, P. 1984. Vegetative anatomy and taxonomy of Berberidopsis and Streptothamnus (Flacourtiaceae). Blumea 30:39–44.

35

Carlquist, S. 2003. Wood anatomy of Aextoxicaceae and Berberidopsidaceae is compatible with their inclusion in Berberidopsidales. Syst. Bot. 28:317–325. Heel, W.A. van 1979. Flowers and fruits in Flacourtiaceae. IV. Hydnocarpus spp., Kiggelaria africana L., Casearia spp., Berberidopsis corallina Hook. f. Blumea 25:513–529. Heel, W.A. van 1984. Flowers and fruits in Flacourtiaceae. V. The seed anatomy and pollen morphology of Berberidopsis and Streptothamnus. Blumea 30:31–37. Keating, R.C. 1973. Pollen morphology and relationships of the Flacourtiaceae. Ann. Missouri Bot. Gard. 60:273–305. Keating, R.C. 1975. Trends in specialization in pollen of Flacourtiaceae with comparative observations of Cochlospermaceae and Bixaceae. Grana 15:29–49. Miller, R.B. 1975. Systematic anatomy of the xylem and comments on the relationships of the Flacourtiaceae. J. Arnold Arb. 56:20–102. Nandi, O.I. et al. 1998. See general references. Ronse DeCraene, L.P. 2004. Floral development of Berberidopsis corallina: a crucial link in the evolution of flowers in the core eudicots. Ann. Bot. 94:741–751. Savolainen, V., Fay, M.F. et al. 2000. See general references. Schneider, C.K. 1912. Illustriertes Handbuch der Laubholzkunde, 2. Jena: G. Fischer. Soltis, D.E. et al. 2000. See general references. Soltis, D.E. et al. 2003. See general references. Takhtajan, A. 1987. See general references. Takhtajan, A. 1997. See general references. Veldkamp, J.F. 1984. Berberidopsis (Flacourtiaceae) in Australia. Blumea 30:21–29. Warburg, O. 1894. Flacourtiaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 6a. Leipzig: W. Engelmann. pp. 1–56.

Bonnetiaceae Bonnetiaceae (Bartl.) L. Beauvis. ex Nakai in Bull. Tokyo Sci. Mus. 22:25 (1948).

A.L. Weitzman, K. Kubitzki, and P.F. Stevens

More or less subpachycaulous small to mediumsized trees and shrubs. Leaves convolute, spiral, crowded towards apex of branches, with close, ascending lateral veins, margins serrulate, initially setulose, estipulate; petiole short or 0. Flowers single, or more or less cymose inflorescences; pedicels with 2 prophylls or several bracts; flowers bisexual, cyclic; sepals 5, unequal, free, quincuncial; petals 5, contorted, free; stamens numerous; filaments slender, free, or basally connate into 5 antepetalous bundles; anthers short, basifixed; fasciclode + or 0; ovary 3(–5)-locular, with numerous orderly arranged ovules on biseriate axile placentae; stylodia free or united into a branched or simple style; stigmas papillate. Fruits septicidal capsules with a persistent central column; seeds with scanty endosperm; embryo straight. Three genera and about 40 species, northern South America, West Indies, Southeast Asia, West Malesia, Moluccas and New Guinea. Vegetative Morphology and Anatomy. Bonnetiaceae are stout-stemmed shrubs or usually small trees with few branches. The smallest species, Bonnetia ahogadoi, is notable for its trailing and rooting inflorescence axis which also acts as a stolon (Fig. 10), whereas Ploiarium alterniflorum, a small, stilt-rooted tree, may grow up to 25 m high on swampy peat soil in Johore (Corner 1978). The terminal bud usually lacks scales, axillary buds are small, and branching appears to be sylleptic, although in B. ahogadoi growth of the main axis appears to be rhythmic (Steyermark 1984) and there are scales at the base of flagelliform inflorescence shoots. The leaves remain rolled up as the bud elongates, and are more or less sessile and usually have a distinct but not very prominent midrib. The plants are completely glabrous, except for tiny colleters found in the leaf axils. The leaf margin is usually minutely serrulate and only rarely entire but, in the juvenile stage, it is always provided with minute setae which fall off during leaf expansion

but persist in the tiny, revolute leaves of Bonnetia roraimae. Archytaea and Ploiarium have vascularised, disciform structures borne immediately inside the margin and on the lower surface of the blade and in its upper one-third. Venation is often eucamptodromous, sometimes more or less brochidodromous or parallelodromous. The phellogen in the stem is surficial in origin, that in the root is initiated 3 or 4 layers deep in the cortex. There are brachysclereids in the stem cortex, a sheath of fibres in the pericyclic position, and groups of fibres in the secondary phloem (see also van Tieghem 1885). The heartwood is dark reddish brown and heavy. Vessel elements are solitary, of medium length, and their perforations are simple/transverse; uniseriate rays are of upright cells, and multiseriates (2–4 cells wide) consist of procumbent cells with uniseriate extensions of upright cells; axial parenchyma is scanty paratracheal, and fibres are mostly thick-walled. Xylem parenchyma forms an adaxial cap on the vessels. Nodes are trilacunar in Bonnetia, unilacunar in Archytaea and Ploiarium. The separate traces are visible in leaf scars although, in taxa such as Bonnetia ahogadai, traces are more or less confluent in the outer part of the cortex. Ploiarium has an arcuate midrib bundle, that of other taxa is more complex, the tissue on the adaxial side in particular being irregularly arranged. Vascular bundles are embedded, and the marginal setae of Archytaea and Ploiarium, but not those of Bonnetia, are associated with vascular tissue. Stomata are anomocytic and an adaxial hypodermis is sometimes present. The leaf anatomy of Bonnetia is remarkable: the epidermis is often mucilaginous and its cells bulge and intrude between the mesophyll cells; foliar sclereids are widespread in the mesophyll; and the leaf midrib and all veins including the terminal veinlets are surrounded by an endodermis of thin-walled cells provided with Casparian strips (Maguire 1972; Dickison and Weitzman 1996; Weitzman and Stevens 1997).

Bonnetiaceae

Inflorescence and Flowers. Inflorescences are lateral, and several species appear to have axillary flowers. However, these are probably reduced inflorescences, and the “pedicels” bear 2–several bracts along their length, sometimes very close to the calyx. The sepals of Bonnetia, and perhaps also Ploiarium, are terminated by setae very like those found on the leaf margins. The petals are predominantly white or pink. Whether or not the androecium of Bonnetia is fasciculate needs study; fascicles have been reported (e.g. Steyermark 1984) but their existence – at least, as evident in later bud or flower – has been questioned (Kobuski 1948; PFS, pers. obs.). It is not known if the fasciclodes of Ploiarium secrete nectar; otherwise, there are no reports of nectar from the family (Dickison and Weitzman 1998). Pollen Morphology. Pollen is 28 to almost 60 µm long, oblate-spheroidal, tricolporate with wide colpi and circular ora. Sometimes, as in B. lancifolia, the colpi are fused at the poles, leaving a triangular polar space. There are costal colpi in Archytaea and Ploiarium, and all taxa have costal pori. The nexine, 0.5–4 µm thick, is thicker than the sexine, which is finely reticulate (Erdtman 1952; Maguire 1972; Steyermark 1984; Salgado-Laboriau and Villar de Seoane 1992). Seed. The seeds are quite small, and Corner (1976) suggested that the seed coat of Ploiarium is probably endotestal, although its development has not been studied. Exotestal cells are thin-walled and polygonal, endotestal cells are usually isodiametric, low, and with sinuous anticlinal walls, lignification is extensive and there are numerous narrow plasmodesmata. Ploiarium alternifolium has rather elongated endotestal cells, and the anticlinal walls of those of Archytaea are almost straight. There is a thin, persistent layer of endoperm surrounding the straight embryo. Although the cotyledons are generally small, those of Bonnetia range from 1/2–1/6 the length of the embryo. Germination is epigeal (Ploiarium). Phytochemistry. Bonnetiaceae are rich in xanthones with various substitution patterns, and bixanthones and anthraquinone xanthones have been reported from Ploiarium (Kubitzki et al. 1978; Bennett et al. 1990). Xanthones are also richly diversified in Clusiaceae and Hypericaceae (Bennett and Lee 1989).

37

Family Circumscription and Affinities. When the exudate-producing genus Neotatea and the anther gland-bearing genera around Kielmeyera and Caraipa are removed from Bonnetiaceae, as suggested by Weitzman and Stevens (1997), the family becomes very homogeneous. Although in the past members of the family have been included in the “intermediate” zone between Theaceae and Clusiaceae/Hypericaceae, the former are now in Ericales, and possession of xanthones, floral morphology, testa anatomy, etc., all link Bonnetiaceae with Clusiaceae/Hypericaceae. The combination of characters of wood anatomical characters presented above sets Bonnetiaceae apart from Theaceae, with which Baretta-Kuipers (1976) compared them, and also Guttiferae and Hypericaceae. Gene sequence analyses by Savolainen, Fay et al. (2000) and Gustafsson et al. (2002) confirm the close relationship of Bonnetiaceae with Clusiaceae/Hypericaceae. The inclusion of Ploiarium in Malvales (Savolainen, Fay et al. 2000) was probably due to a mistaken identification, since i.a. the distinctive seed coat anatomy of Archytaea is quite unlike that of Malvales. Elatinaceae have also often been considered as possibly related to Bonnetiaceae, agreeing in testa anatomy and a number of other features, but molecular data place them sister to Malpighiaceae (Davis and Chase 2004); whether or not that family is close to Bonnetiaceae, etc., is unclear. Distribution and Habitats. The two closely related, small genera Archytaea and Ploiarium are disjunct between Southeast Asia/Malesia and northern South America, whereas Bonnetia is restricted to continental South America, with one species on Cuba. Archytaea prefers open habitats, often by creeks, always on nutrient-poor soil, ranging from lowland to mid-altitudes. Bonnetia is most speciose in the Guayana Highland and its surroundings, where 27 species are found, all but one (B. paniculata) of which are endemic to this region. Most of them have only a limited altitudinal range, with the majority preferring the mesothermic/submicrothermic belt (1,200–2,700 m; Huber 1988), but Bonnetia crassa spans a belt of 2,000 m. With increasing altitude, the bonnetias tend to be of lower stature. Bonnetia ahogadoi is a low shrublet growing at localized sites on peat in rock depressions of the Chimatá Massif in Venezuela

38

A.L. Weitzman, K. Kubitzki, and P.F. Stevens

Fig. 10. Bonnetiaceae. Bonnetia ahogadoi. A Habit. B Leaf. C Flower. D Androecium and gynoecium. E Anther. F Ovary, transversal section. G Capsule at beginning of dehiscence.

H Two valves of dehiscent capsule with adherent seeds and persistent columella. I Seeds, various positions. (Drawing by B. Manara; Steyermark 1984)

at an altitude of about 2,100 m (Huber 1992). Ploiarium grows in the lowland, often close to the sea, and on swampy peaty soil (Corner 1978) or on nutrient-poor white sand in the heath forests of Borneo.

Genera of Bonnetiaceae

Uses. The wood is durable and in Asia/Malesia locally used for constructions, but is not a commercial timber.

Key to the Genera 1. Androecium not fasciculate; ovary 3(4)-locular 3. Bonnetia – Androecium 5-fasciculate; ovary 5-locular 2 2. Flowers in 3–many-flowered inflorescences; sepals and stamens caducous; style simple 2. Archytaea – Flowers solitary; sepals and stamens persistent; stylodia 5, free to base 1. Ploiarium

1. Ploiarium Korthals Ploiarium Korthals, Verh. Nat. Gesch. Bot., ed. Temminck: 135 (1840); Kobuski, J. Arnold Arb. 31:196–207 (1950), rev.

Trees, sometimes vast, or shrubs. Flowers solitary; pedicels ancipitous, increasing in diameter towards apex; sepals caducous; nectary glands 5, alternating with petals; stamens numerous, caducous, in 5 antesepalous fascicles; ovary 5-locular; stylodia 5, free to base, persistent. Capsule dehiscing from the base; seeds linear; endosperm fleshy. Three species, from Cambodia through Malay Peninsula to Sumatra, Borneo and Halmahera. 2. Archytaea Mart. Archytaea Mart. in Mart. & Zucc., Nov. Gen. Sp. Pl. 1:116 (1826); Weitzman & Stevens, BioLlania Esp. 6:556–557 (1997); Weitzman, Fl. Venez. Guayana 9:310–313 (2005).

Bonnetiaceae

Small trees or shrubs. Inflorescences axillary, 3– many-flowered; peduncles ancipitous, increasing in diameter towards apex; pedicels midway with prophylls; sepals persistent; nectary glands 5, alternate with petals; stamens numerous, persistent, in 5 antesepalous fascicles; ovary 5-locular; style simple, persistent. Seeds numerous, linear, imbricate, exalbuminous. Two species, in the Guayana sandstone region and adjacent lowlands of northern South America. 3. Bonnetia Mart.

Fig. 10

Bonnetia Mart. in Mart. & Zucc., Nov. Gen. Sp. Pl. 1:114 (1826), nom. cons.; Kobuski, J. Arnold Arb. 29:393–413 (1948), rev.; Weitzman, Fl. Venez. Guayana 9:313–324 (2005). Neblinaria Maguire (1972). Neogleasonia Maguire (1972) except N. duidae (Kobuski & Steyerm.) Maguire Acopanea Steyerm. (1984).

Trees or shrubs. Flowers solitary or up to three on axillary peduncles or occasionally arranged in loose panicles with ancipitous or terete peduncles; sepals persistent; stamens very numerous, persistent, the filaments adnate to the base of the ovary and otherwise free; anthers dehiscing longitudinally or by two pores at the base; ovary 3(4)-celled; stylodia 3, or style simple and then sometimes apically branched. Seeds linear, elongated above and below into a small membranous wing. About 29 species, mainly in the Guayana highland and adjacent regions, with B. paniculata Spr. ex Benth. extending along the Andes to Peru, B. stricta (Nees) Nees & Mart. along the Atlantic coast southwards to Rio de Janeiro, and B. cubensis (Britton) Howard in Cuba.

Selected Bibliography Baretta-Kuipers, T. 1976. Comparative wood anatomy of Bonnetiaceae, Theaceae and Guttiferae. In: Baas, P., Bolton, A.M., Catling, D.M. (eds) Wood structure in biological and technological research. Leiden Botanical Series 3, pp. 76–101.

39

Bennett, G.J., Lee, H.-H. 1989. Xanthones from Guttiferae. Phytochemistry 28:967–998. Bennett, G.J., Lee, H.-H., Lowrey, T.K. 1990. Novel metabolites from Ploiarium alternifolium: a bixanthone and two anthraquinolyxanthones. Tetrahedron Lett. 31:751–754. Corner, E.J.H. 1976. See general references. Corner, E.J.H. 1978. The freshwater swamp-forest of South Johore and Singapore. Gard. Bull. suppl. 1. Singapore: Government Printers. Davis, C.C., Chase, M.W. 2004. Elatinaceae are sister to Malpighiaceae, and Peridiscaceae are members of Saxifragales. Amer. J. Bot. 91:262–273. Dickison, W.C., Weitzman, A.L. 1996. Comparative anatomy of the young stem, node and leaf of Bonnetiaceae, including observations on a foliar endodermis. Amer. J. Bot. 83:405–418. Dickison, W.C., Weitzman, A.L. 1998. Floral morphology and anatomy of Bonnetiaceae. J. Torrey Bot. Soc. 125:268–286. Erdtman, G. 1952. See general references. Gustafsson, M.H.G., Bittrich, V., Stevens, P.F. 2002. Phylogeny of Clusiaceae based on rbcL sequences. Intl J. Pl. Sci. 163:1045–1054. Huber, O. 1988. Guayana highlands versus Guayana lowlands, a reappraisal. Taxon 37:595–614. Huber, O. 1992. La vegetación. In: Huber, O. (ed.) El macizo de Chimatá. Caracas: Todtmann, pp. 161–177. Kobuski, C.E. 1948. Studies in the Theaceae, XVII. A review of the genus Bonnetia. J. Arnold Arb. 29:393–413. Kubitzki, K., Mesquita, A.A.L., Gottlieb, O.R. 1978. Chemosystematic implications of xanthones in Bonnetia and Archytaea. Biochem. Syst. Ecol. 6:185–187. Maguire, B. 1972. Bonnetiaceae. In: The Botany of the Guyana Highland. Part IX. Mem. New York Bot. Gard. 23:131–165. Prakash, N., Lau, Y.Y. 1976. Morphology of Ploiarium alternifolium and the taxonomic position of Ploiarium. Bot. Notiser 129:279–285. Salgado-Laboriau, M.L., Villar de Seoane, L. 1992. Contribución a la flora polínica de los tepuyes. In: Huber, O. (ed.) El macizo de Chimatá. Caracas: Todtmann, pp. 219–236. Savolainen, V., Fay, M.F. et al. 2000. See general references. Steyermark, J.A., 1984. Theaceae (Bonnetiaceae), pp. 323– 330. In: Flora of the Venezuelan Guayana, I. Ann. Missouri Bot. Gard. 71:297–340. van Tieghem, Ph. 1885. Second mémoire sur les canaux sécréteurs des plantes. Ann. Sci. Nat. VII, Bot. 1:5–96; see particularly Ternstroemiacées, pp. 43–46. Weitzman, A.L., Stevens, P.F. 1997. Notes on the circumscription of Bonnetiaceae and Clusiaceae, with taxa and new combinations. BioLlania Edic. Esp. 6:661– 564.

Buxaceae Buxaceae Dumort., Comment. Bot.: 54 (1822), nom. cons.

E. Köhler

Evergreen shrubs or trees, rarely subshrubs or rhizomatous perennial herbs, glabrous, sometimes with uni- or multicellular hairs, monoecious, rarely dioecious. Leaves alternate or decussate, petiolate, rarely sessile, entire, rarely dentate, pinnately veined, less often tripliveined, estipulate. Flowers in axillary or terminal botryoids or spikes, the male above the female ones, or one female above the male, subtended by decurrent bracts, the female with prophylls. Flowers actinomorphic, hypogynous; male: tepals 4, decussate, rarely wanting; stamens free, 4, 6 or 8, antetepalous, or rarely up to 45 in a more complex arrangement, if 6, then two pairs opposite the inner tepals, often inserted around a pistillode; anthers dorsifixed, dithecal, tetrasporangiate, longitudinally dehiscent, borne on long filaments, rarely sessile; pistillode present or wanting; female: often larger than the male, fewer or solitary; tepals 4–6; ovary syncarpous with free stylodia, (2)3(4)-carpellate, sometimes with false septa; placentation axile; stylodia subulate, divergent, rarely connate at the base, stigmatic area decurrent along the ventral fold; ovules usually 2 per locule, anatropous. Fruit a dry capsule with persistent stylodia, loculicidally dehiscent into 2-horned valves, or indehiscent, subdrupaceous or berry-like. Seeds black or dark, frequently carunculate; endosperm copious, fleshy, oily; embryo straight, cotyledons flat. A family comprising 5 genera with c. 100 species, distributed in the Northern Hemisphere of the Old and New World, extending to Andean South America and its Caribbean coast, to South Africa and Madagascar, and to peninsular Malaysia. Vegetative Morphology. Most Buxaceae are evergreen shrubs or trees up to 15 m tall. Only Pachysandra comprises erect or prostrate subshrubs and perennial herbs. Its sympodial rhizomes have adventitious roots and develop simple or sympodially branched stems with alternate, apically clustered leaves. The leaves are alternate in

Styloceras, Sarcococca and Pachysandra, decussate in Buxus and Notobuxus, where decurrent leaf bases form lateral internodal folds (Fig. 12A). In some Cuban Buxus, distichous leaves are interspersed with decussate pairs of very small ones inserted on short shoots. The leaves are usually entire but toothed in Pachysandra. Brochidodromous venation, occurring in Sarcococca, Notobuxus and Buxus, and variously modified in the latter, is regarded as basic. Styloceras and Asian Buxus species possess eucamptodromous venation. Cladodromous patterns are found in South African and Malagasy Buxus; Pachysandra has craspedodromous venation. Whereas the brochidodromous type prevails in the tropics, the derived patterns occur in subtropical and temperate regions of both hemispheres (Köhler 1993). Species of Buxus possess a grey, deeply fissured bark. Vegetative Anatomy. Old World Buxus and Notobuxus species have a cortical vascular bundle in each angle of the branchlets, accompanied by fibre strands in the Eurasian taxa. Both are wanting in New World Buxus and the remaining genera (van Tieghem 1897; Mathou 1940). Elongated fibres and large stone cells are frequent in the primary cortex. Chains of small, irregularly thickened sclereids with oxalate crystals, surrounding a larger fibre (‘Kristallkammerfasern’), occur in Pachysandra, Sarcococca and Styloceras. Secretory cells, often arranged in longitudinal rows, are frequent in Buxus, Pachysandra and Sarcococca, less prominent in Styloceras (Metcalfe and Chalk 1950). Vessels are mostly solitary and of small diameter, rather wide in Styloceras. They are of medium length in Buxus and Notobuxus but exceptionally long in Sarcococca and Styloceras, reflecting a continuous occupation of mesic sites (Carlquist 1982). They have scalariform perforations with a great range of numbers of bars (Köhler, unpubl. data). The fibrous elements are tracheids with bordered

Buxaceae

pits similar to vessels. The axial parenchyma is diffuse apotracheal throughout the family. Uniseriate rays are as frequent as multiseriate ones. The heterogeneous rays of Styloceras, which are up to four cells wide, are most primitive. Styloceras is an unspecialized, highly mesic type, followed by Sarcococca, whereas Notobuxus and especially Buxus are more specialized in adaptation to xeric conditions. The sieve element plastids represent a specific subtype, PVIc, with a globose protein crystal (Behnke 1982). Leaf epidermis cells are thin to strongly cutinized in Buxus, and covered with epicuticular waxes. Their anticlinal walls are sometimes extremely thickened, confining lumina to a central canal or basal rests in Cuban Buxus (Köhler and Schirarend 1989). The indumentum comprises thick-walled hairs of one to several cells. Stomata are usually abaxial and are laterocytic, occasionally cyclocytic (Baranova 1980); they have prominent outer ledges which sometimes bear a peristomal rim. A hypodermis is present only in Styloceras. The mesophyll contains prominent secretory cells, which sometimes form a continuous hypodermal layer and may be interspersed with brachy- , osteoor astrosclereids. Druses and solitary oxalate crystals are frequent; cells with coarse crystal sand are rarer. The vascular bundles are accompanied by arc-shaped or ring-like sclerenchymatous sheaths. The petiole is supplied by a median and two lateral bundles, the latter being replaced by fibre strands in Eurasian Buxus. The nodes are unilocular with one trace. Inflorescence Structure. Inflorescences are axillary or terminal, rarely borne at the base of the stem (Pachysandra procumbens), and shortly pedunculate or sessile. In Buxus, Notobuxus and Styloceras kunthianum, they are usually botryoids with lateral male flowers and a terminal female flower. Pachysandra and some Sarcococca have open spikes with lateral male flowers in the upper part of the inflorescence and female flowers below. In the dioecious species of Styloceras, male flowers form long spikes sometimes terminated by a peloric flower; female flowers are solitary or in thyrses (von Balthazar and Endress 2002b). Flower Structure. The bracts preceding the reproductive organs of male flowers are always arranged in a decussate pattern whereas the uppermost four, bract-like phyllomes are tepal-like and inconspicuous or whitish (Sarcococca) and creamy

41

petaloid (Buxus). There are typically four stamens, in Notobuxus six or up to ten; in Styloceras, they are numerous. Filaments are long-exserted, stout, sometimes clavate. Anthers are introrse, dorsifixed with a protruding, ± coloured connective tip. The stamens are frequently inserted around a pistillode, which is quadrangular to 4-lobed, sometimes truncate in Buxus and Pachysandra or urceolate in Sarcococca, but very reduced in Notobuxus and absent in Styloceras. It possesses a nectariferous structure (Daumann 1974; Vogel 1998). In the female flowers the carpels are usually preceded by a pair of prophylls and several spirally arranged bracts which are only weakly differentiated towards tepals (von Balthazar and Endress 2002b). The locules of the ovary contain two collateral ovules and are separated by spurious septa in Pachysandra and Styloceras. The stylodia are rather long, slender and recurved in Styloceras, erectsubulate in Pachysandra, more stout in Sarcococca, and short-divergent in Notobuxus and Buxus. Protuberances between the bases of the stylodia function as nectaries and are considered to be of androecial derivation (Daumann 1974). Embryology. The anther wall has a 1-layered fibrous endothecium. The tapetum is secretory and its cells become binucleate. Pollen meiosis is simultaneous, resulting in tetrahedral or isobilateral tetrads. Pollen is 2-celled when shed (Davis 1966). The ovules are anatropous, pendulous, with the micropyle towards the axis in Buxus and Notobuxus or averted in Sarcococca. They are bitegmic, crassinucellate with a pronounced nucellar cap; the micropyle is made up by the inner integument (Wunderlich 1967; Corner 1976). Protuberances of the placenta form an obturator in Pachysandra. A proliferation of the outer integument, forming a hood over the nucellus, develops a prominent caruncle in the latter (Channel and Wood 1987). The megaspores are arranged in linear (Sarcococca, Pachysandra) or T-shaped tetrads (Buxus and Notobuxus), the chalazal one developing into a Polygonum type embryo sac. The synergids have a filiform apparatus. The antipodes persist into postfertilization stages and a small degree of secondary multiplication has been reported. Endosperm formation is cellular, but nuclear in Sarcococca (Wiger 1935). Embryogeny follows the Onagrad type. Occasionally, parthenocarpy has been reported for Buxus, and some Sarcococca species seem to be obligate apomicts (Naumova 1980). Nucellar polyembryogeny is recorded for S. humilis.

42

E. Köhler

Pollen Morphology. Pollen grains are ± spheroidal and vary in the size range 20–50 µm. Apertures range from 3-colporate in Notobuxus to 3–7-colporate, 5–12-pantocolporate and 12–40pantoporate in Buxus (Fig. 11A–C), whereas only pantoporate grains occur in Sarcococca, Pachysandra and Styloceras (Köhler 1981; Köhler and Brückner 1982). The colpi of Buxus pollen contain 3–6 circular ora, the number of ora decreasing in pantocolporate forms (Fig. 11B), eventually giving

rise to pantoporate grains (Fig. 11C). The pores are roundish with sculptured membranes (Brückner 1993), which also occur in Styloceras. The exine sculpture, providing taxonomically significant characters in Buxus and Notobuxus, comprises comparatively free, interlaced ridges and a coarse or fine reticulum, which sometimes bears small spinulae. Others have supratectal pilate-verrucate elements. The exine of Styloceras is finely reticulate with pointed spinulae and, in Sarcococca and

Fig. 11. Buxaceae, pollen grains. A Buxus arborea, tricolpo4-orate grain showing one colpus, ×3,500. B Buxus benguellensis, pantocolpo-2-orate grain, ×2,700. C Buxus

cochinchinensis, pantoporate grain, ×2,600. D Sarcococca wallichii, pantoporate grain with crotonoid exine pattern, ×1,800. (Orig. Köhler)

Buxaceae

Pachysandra, a ‘crotonoid’ pattern is observed with reticulately arranged triangular and linear units based on a ledge, which is supported by bacula (Fig. 11D). Karyology. Chromosome numbers of the family are mainly multiples of x = 7 (Hans 1973). With the exception of a tetraploid record for Buxus sinica (Huang et al. 1986), the Eurasian and New World species of Buxus share 2n = 28 (Köhler, unpubl. data). For Sarcococca, diploids with 2n = 28 (less frequently, tetraploids) are recorded. An aberrant number of n = 12 is given by Singh et al. (1982). In Pachysandra, a wider range with n = 12, 13, 24, 27 is found (Raven 1975; Kurosawa 1981). Notobuxus diverges with 2n = 20. Pollination and Reproductive System. (See also the summary by von Balthazar and Endress 2002a). In male flowers of Buxus, Sarcococca and Pachysandra and, perhaps, also of Notobuxus, rudiments of a pistil are present but the flowers are functionally unisexual. In female flowers, no rudiments of stamens are found. The mixed inflorescences of Buxus, Sarcococca and Pachysandra are protogynous. Self-fertility is reported for Pachysandra procumbens by Robbins (1962). Since the tepals are commonly inconspicuous, pollinator attraction is by other floral parts. Sarcococca and Pachysandra have showy tepals with white filaments and red or yellow anthers; the filaments emit a strong, sweet scent. In the centre of the male flowers of Sarcococca and Pachysandra, a nectary is present but, in their female flowers, attractants are lacking. Pollination depends on the strict foraging behaviour of insect visitors, which always move from the base to the apex of the inflorescence and thereby inadvertently touch the female flowers (Vogel 1998). The flowers in many Buxus attract bees and flies by a faint scent, and nectar is produced by the pistillode in male flowers or on nectariferous structures between the carpels in the female flowers (Fig. 12C). In African Buxus and the closely related Notobuxus, no nectariferous pistillodes nor pistils are found, and wind pollination was suggested for these species (Vogel 1998), which would be compatible with their increased number of stamens, although the pollen is well-sculptured and does not suggest wind pollination (Köhler and Brückner 1982). Fruit and Seed. The fruit of Buxus and Notobuxus is a dry, loculicidal capsule with leathery exocarp and persistent stylodia, dehiscing basipetally

43

into three spreading, 2-horned valves. The detached cartilaginous endocarp partly encloses both seeds and ejects them forcibly. In Pachysandra, transitions from indehiscent capsules to subdrupaceous white and pulpy fruits occur. In Sarcococca and Styloceras, the fruit is sub- to fully drupaceous, with a pulpy mesocarp and a thin crustaceous endocarp in the former, and a cartilaginous endocarp divided in 4–6 pyrenes in the latter. The seeds are oblong, trigonal, with a smooth, shining black, brown or blue coat. The raphe is scarcely discernible, showing a slight postchalazal ramification of bundles in Buxus. There is a caruncle, rather prominent in Pachysandra, and reduced to two small, white lobes on either side of the micropyle in Buxus. Seeds of Sarcococca and Styloceras are ecarunculate. The family has an exomesotestal seed coat, with a multiplicative testa in Sarcococca and Pachysandra but not in Buxus. These genera share a palisade of thick-walled, prismatic cells in the outer epidermis, followed by crushed parenchymatous cells (Melikian 1968). In Buxus, the inner epidermis is shortly palisadic and lignified at the micropyle, forming a false endostome (Corner 1976). The embryo is slightly curved with a long radicle in Buxus, but straight with a short radicle in Sarcococca. The cotyledons are thin and flat and the endosperm is fleshy and oily. Dispersal. The ejection mechanism of Buxus and Notobuxus may suffice for localized seed dispersal; abiotic agents such as rain or flowing water may account for dispersal over larger distances. The caruncle is related to ant dispersal, which has been observed in B. sempervirens and is likely to act also in Pachysandra procumbens, where the carunculate seeds are released on the ground. The drupaceous fruits of Sarcococca and Pachysandra terminalis are indicative of endozoochory, probably by birds. This seems to be true also for Styloceras, where the tardily dehiscing fruit exposes a gelatinous pulp surrounding the blue seeds (Gentry and Foster 1981). Phytochemistry. Buxus, Sarcococca and Pachysandra contain a series of highly elaborated steroidal alkaloids of the aminopregnan type, which are derived from triterpenoids (Hegnauer 1964, 1989) and are shared with Didymelaceae. More than 150 alkaloids, mainly pregnan and irehdiamine derivatives, have been isolated from Buxus, Sarcococca and Pachysandra, whereas those of Styloceras are unknown. Condensed tannins

44

E. Köhler

have been found in some Buxus but are not prominent. Seventeen Cuban Buxus species have been recognized as nickel-hyperaccumulators, reaching nickel contents of 1,000 to 25,000 µg g−1 dry weight (Reeves et al. 1996), which might be of taxonomic interest. Relationships Within the Family. Two major clades can be recognized within the family (von Balthazar and Endress 2000, 2002a), one comprising Pachysandra, Sarcococcus and Styloceras, and another of Buxus with Notobuxus. Pachysandra and Sarcococcus are strongly supported as monophyletic groups in a sister relationship to Styloceras. American and Eurasian Buxus each represent a strongly supported clade, with Notobuxus embedded among the African members of Buxus. von Balthazar and Endress (2002a) suggest either to sink Notobuxus in Buxus, or to keep Notobuxus at generic level and integrate all African Buxus in this genus. Shared characters among Sarcococcus, Pachysandra and Styloceras include the occurrence of two (rarely three) carpels, the lack of interstylar nectaries, a micropyle formed by both integuments, attractive stamens in male flowers, and fleshy fruits. In addition, Styloceras and Pachysandra share a secondary partition of the ovary. Notobuxus shares with Buxus a similar inflorescence and perianth structure, 3-carpellate female flowers, interstylodial nectaries, micropyles formed by the inner integument, rudimentary arils, and capsular fruits; in male flowers, stamens are sessile and the pistillode is lacking in some species (von Balthazar and Endress 2002a). Affinities. Until very recently, the phylogenetic position of Buxaceae has remained problematic (see Webster 1987 and Jarvis 1989 for reviews). The family has frequently been associated with Euphorbiaceae and also Celastrales, but Hamamelidales and Pittosporales have also been considered. Recent morphological, molecular and combined data analyses (Nandi et al. 1998; Soltis et al. 2000, 2003; The Angiosperm Phylogeny Group, APG II 2003) place Buxaceae as sister to Didymelaceae (Buxales) together with Ranunculales, Sabiaceae, Proteales and Trochodendraceae in a grade at the base of the eudicots. Palaeobotany. Early fossil records (Spanomera) from the Albian/Cenomanian of the Potomac

Group are closely related to Buxaceae (Drinnan et al. 1991). Among fossil pollen attributable to Buxaceae, the ‘crotonoid’ Pachysandra-Sarcococca type appeared initially in the Upper Cretaceous of central Europe and, in the Palaeogene, subsequently extended westwards and then eastwards along the north-Tethyan warm-temperate vegetation belt; by the Miocene, it had arrived in East Asia (Krutzsch 1989). Macrofossils of Pachysandra are known from the Upper Eocene and of Sarcococca from the Upper Oligocene/Miocene of central Europe (Mai and Walther 1985). Colporate Buxus pollen is known from the Lower Eocene (Kedves 1962), followed by a succession of types (Bessedik 1983) which document the coherence with pantoporate Buxus pollen of the Lower Miocene (Krutzsch 1966). Fruits and leaf remains of Buxus with Eurasian-type venation have been found in the Miocene of Bohemia (Kvacek et al. 1982) and the Oligocene of East Asia (Uemura 1979). Styloceras pollen is recorded from the Eocene of Argentina and the Pliocene of Colombia (van der Hammen 1974). Distribution and Habitats. The genus Buxus has a disjunct intercontinental distribution with a centre of diversity in tropical to temperate East Asia and another in the Caribbean, whereas only few species, including the most primitive taxa, occur in Africa from Ethiopia to the eastern Cape in South Africa and in Madagascar. The genus has a wide ecological range and grows in dry scrub forests, on limestone cliffs, in the understorey of montane rainforests, occasionally in cloud forests, sometimes above 3,000 m; it frequently grows on ultramafic soils. Notobuxus has a scattered distribution in coastal forests between Kenya and the eastern Cape, and in equatorial forests from Sierra Leone to Nigeria. Sarcococca is widely distributed in tropical and subtropical Asia from Afghanistan to China, Indonesia and the Philippines, growing in the understorey of montane forests, often at higher altitudes. A single New World species occurs in Guatemala. Three species of Pachysandra are native to China, Japan and Taiwan, and one to south-eastern North America, growing in rich mesophytic forests in mountain regions. Species of Styloceras are confined to the Andes of South America from Venezuela to Bolivia, growing in forests between 2,500 and 3,800 m. A recently discovered species from Amazonian Peru suggests that the genus may be an old lowland forest element (Gentry and Foster 1981).

Buxaceae

45

3. Male flowers with 4 stamens opposite the tepals, longexserted; pistillode present 1. Buxus – Male flowers with 6(–10) stamens, two pairs opposite the inner tepals; anthers sessile; pistillode as a flat disk, or absent 2. Notobuxus 4. Woody shrubs or small trees with entire leaves; fruit ± drupaceous 3. Sarcococca – Perennial herbs with procumbent stems, leaves ± coarsely toothed; flowers borne at the base of the stem or terminal; fruit an indehiscent capsule or subdrupaceous 4. Pachysandra

Genera of Buxaceae 1. Buxus L.

Fig. 12

Buxus L., Sp. Pl. 2:983 (1753); Hatusima, J. Dept. Agric. Kyusyu Imp. Univ. 6:261–342 (1942), Asiatic spp.; Friis, Kew Bull. 44:293–299 (1988), African spp.; Schatz & Lowry II, Adansonia III, 24:179–196 (2002), Malagasy spp.

Fig. 12. Buxaceae. Buxus moctezumae. A Portion of branch with decurrent leaf bases. B Inflorescence with a terminal female flower and lateral male flowers. C Nectaries of female flower, surrounded by stylodia. D Dehisced fruit. (Köhler et al. 1993)

Economic Importance. The family is economically important for its horticultural value. The genus Buxus has yielded more than 150 registered cultivars, mainly of B. sempervirens and B. microphylla (Batdorf 1995), which are used for edging, as hedges suitable for pruning and topiary work. The hard, closely grained wood is employed for turning, engraving and manufacturing instruments. Pachysandra terminalis is widely grown as ornamental ground cover. Styloceras provides firstclass timber for joinery.

Key to the Genera 1. Tepals absent in male flowers, stamens numerous; rudiment of ovary wanting; ovary 2(3)-carpellate 5. Styloceras – Tepals present; stamens usually 4, rarely 6–10 2 2. Leaves decussate; female flowers terminal in racemes or clusters; fruit a 3-valved capsule 3 – Leaves alternate; female flowers at base of racemes or spikes; fruit ± drupaceous 4

Shrubs or trees with tetragonal branchlets, leaves decussate. Inflorescences lax to glomerate botryoids of male flowers with a terminal female. Male flowers 4-merous, tepals decussate, stamens antetepalous, inserted around a pistillode. Female flowers with 4–6 tepals, ovary 3-carpellate, with divergent stylodia, stigmas 2-lobed, decurrent along the ventral fold. Fruit a 3-horned capsule, loculicidally dehiscing into 2-horned valves, ejecting trigonal black seeds. 2n = 28, (56). About 90 species in Central America, West Indies, northern and southern Africa, Madagascar, East Asia. For the relationship between the African Buxus and Notobuxus, see below. 2. Notobuxus Oliv. Notobuxus Oliv. in Hook, Ic. Pl. 14:78, t. 1400 (1882); Friis, Kew Bull. 44:293–299 (1989); Phillips, J. S African Bot. 9:138– 140 (1943).

Shrubs or small trees; leaves decussate. Inflorescences subfasciculate botryoids with few male and a terminal female flower. Male flowers tepals 4, stamens 6(–10), two pairs opposite the inner tepals; anthers sessile, pistillode minute or wanting. Female flowers tepals 4–6, ovary 3-carpellate with short, recurved stylodia; stigmas decurring. Fruit a greenish-brown, red or black, loculicidal capsule with persistent stylodia. Seeds oblong-ovoid to trigonal, black, 2n = 40. Five species, equatorial West and Central Africa, east to South Africa. This genus is close to Buxus, of which it is treated as a subgenus by Friis, but it differs in the number of stamens, chromosome number and traits of the exine.

46

E. Köhler

3. Sarcococca Lindl. Sarcococca Lindl., Bot. Reg.: t. 1012 (1826); Sealy, Bot. J. Linn. Soc. 92:117–159 (1986), rev.

Small trees or shrubs; leaves alternate, ± triplinerved. Inflorescences androgynous botryoids or spikes, sometimes unisexual. Male flowers above, 4merous, with pale or white tepals, whitish stamens and an urceolate pistillode. Females bracteolate, 4– 6 tepals, ovary 3–2-carpellate, with stout recurved stylodia, stigma sulcate, ventrally decurrent. Fruit purplish red or black, indehiscent, subdrupaceous or with dry mesocarp, stylodia persistent. Seeds often solitary, hemispherical to subglobose, brownish black. 2n = 28, less frequent 2n = 56. Eleven species, Southeast Asia. The affiliation of S. conzattii (Standley) I.M. Johnst. from Guatemala is doubtful. 4. Pachysandra Mich. Pachysandra Mich., Fl. Bor. Amer. 2:177 (1803); Robbins, Sida 3:211–248 (1968), rev.

Procumbent rhizomatous subshrubs or perennial herbs, branches ascending, leaves alternate, coarsely dentate to nearly entire. Inflorescences axillary or terminal spikes, male flowers above, few females below, male 4-merous, with pale tepals, whitish stamens, attached around a rectangular to truncate pistillode; female subtended by prophylls, with 4–6 tepals, ovary 2–3-carpellate, with spurious septa, stylodia erect to recurved, stigma sulcate, decurrent. Fruit reddish brown to black, indehiscent 3-horned capsules or subdrupaceous, white and pulpy. Seeds trigonal, dark brown or black. 2n = 24, 26, 48, 54. Five species, Atlantic North America, China, Taiwan. 5. Styloceras Adr. Juss. Styloceras Adr. Juss., Euph. Tent. 53: t. 17 (1824).

Trees or shrubs, dioecious, rarely monoecious, leaves alternate. Male inflorescences short, pendent spikes, sometimes bisexual, tepals wanting, numerous subsessile stamens inserted in a triangular bract, pistillode absent. Female flowers solitary, tepals 3–5, bract-like, ovary 2–3-carpellate, divided by secondary septae, with long, basally distant stylodia, recurved at the tip, and long, decurrent stigmas. Fruit yellow, globose, drupaceous, ± fleshy, indehiscent or tardily dehiscent, stylodia persisting as subapical horns. Seeds oblong, dark blue. Five species, Andean South America.

Selected Bibliography APG II 2003. See general references. Balthazar, M. von, Endress, P.K. 2002a. Reproductive structures and systematics of Buxaceae. Bot. J. Linn. Soc. 140:193–228. Balthazar, M. von, Endress, P.K. 2002b. Development of inflorescences and flowers in Buxaceae and the problem of perianth interpretation. Intl J. Pl. Sci. 163:847–876. Balthazar, M. von, Endress, P.K., Qiu, Y.-L. 2000. Phylogenetic relationships in Buxaceae based on nuclear internal transcribed spacers and plastid ndhF sequences. Intl J. Pl. Sci. 161:785–792. Baranova, M.A. 1980. Comparative stomatographic studies in the family Buxaceae and Simmondsiaceae (in Russian). In: Zhilin, S.G. (ed.) Systematics and evolution of higher plants. Leningrad: Nauka, pp. 68–75. Batdorf, L.R. 1995. Boxwood handbook. Boyce: American Boxwood Society. Behnke, H.-D. 1982. Sieve-element plastids, exine sculpturing and the systematic affinities of the Buxaceae. Pl. Syst. Evol. 139:257–266. Bessedik, M. 1983. Le genre Buxus L. (Nagyipollis Kedves 1962) au Tertiaire en Europe occidentale: évolution et implications paléogéographiques. Pollen Spores 25:461–486. Brückner, P. 1993. Pollen morphology and taxonomy of Eurasiatic species of the genus Buxus (Buxaceae). Grana 32:65–78. Carlquist, S. 1982. Wood anatomy of Buxaceae: correlations with ecology and phylogeny. Flora 172:463–491. Channell, R.B., Wood, C.E. 1987. The Buxaceae in the southeastern United States. J. Arnold Arb. 68:241–257. Corner, E.J.H. 1976. See general references. Daumann, E. 1974. Zur Frage nach dem Vorkommen eines Septalnektariums bei Dikotyledonen. Zugleich ein Beitrag zur Blütenmorphologie und Bestäubungsökologie von Buxus L. und Cneorum L. Preslia 46:97–109. Davis, G.L. 1966. See general references. Drinnan, A.N., Crane, P.R., Friis, E.M., Raunsgaard Pedersen, K. 1991. Angiosperm flowers and tricolpate pollen of Buxaceous affinity from the Potomac group (MidCretaceous) of Eastern North America. Amer. J. Bot. 78:153–176. Gentry, A.H., Foster, R. 1981. A new Peruvian Styloceras (Buxaceae): discovery of a phytogeographical missing link. Ann. Missouri Bot. Gard. 68:122–124. Gibbs, R.D. 1974. Chemotaxonomy of flowering plants, 2. Montreal: McGill-Queen’s University Press. Hans, A.S. 1973. Chromosomal conspectus of the Euphorbiaceae. Taxon 22:591–636. Hardman, R. 1987. Recent developments in our knowledge of steroids. Pl. Medica 53:233–238. Hegnauer, R. 1964, 1989. See general references. Huang, S.F., Chen, S.J., Shi, X.H. 1986. Plant chromosome count (2). Subtrop. For. Sci. Tech. 3:41–47. Jarvis, Ch.E. 1989. A review of the family Buxaceae Dumortier. In: Crane, P.R., Blackmore, S. (eds) Evolution, systematics, and fossil history of the Hamamelidae, 1. Oxford: Clarendon Press, pp. 273–278. Kedves, M. 1962. Nagyipollis, a new pollen fgen. from the Hungarian Lower Eocene. Szeged: Acta Biol. 8:83–84.

Buxaceae Köhler, E. 1981. Pollen morphology of the West IndianCentral American species of the genus Buxus L. (Buxaceae) with reference to taxonomy. Pollen Spores 23:37–91. Köhler, E. 1993. Blattnervatur-Muster der Buxaceae Dumortier und Simmondsiaceae van Tieghem. Feddes Repert. 104:145–167. Köhler, E., Brückner, P. 1982. Die Pollenmorphologie der afrikanischen Buxus- und Notobuxus-Arten (Buxaceae) und ihre systematische Bedeutung. Grana 21:71– 82. Köhler, E., Brückner, P. 1990. Considerations on the evolution and chorogenesis of the genus Buxus (Buxaceae). Mem. New York Bot. Gard. 55:153–168. Köhler, E., Schirarend, C. 1989. Zur Blattanatomie der neotropischen Buxus-Arten und ihre Bedeutung für die Systematik. Flora 183:1–38. Köhler, E., Fernández, R., Zamudio, S. 1993. Buxus moctezmae Köhler, Fernández et Zamudio (Buxaceae) una especie nova de Estado de Querétaro, México. Feddes Repert. 104:295–305. Krutzsch, W. 1966. Zur Kenntnis der präquartären periporaten Pollenformen. Geologie 15:16–71. Krutzsch, W. 1989. Palaeogeography and historical phytogeography (palaeochorology) in the Neophyticum. Pl. Syst. Evol. 162:5–61. Kurosawa, S. 1981. Notes on chromosome numbers of Spermatophytes. J. Jap. Bot. 56:245–251. Kvacek, Z., Buzek, C., Holý, F. 1982. Review of Buxusfossils and a new large-leaved species from the Miocene of Central Europe. Rev. Palaeobot. Palynol. 37:361–394. Mai, D.H., Walther, H. 1985. Die obereozänen Floren des Weißelster-Beckens und seiner Randgebiete. Abh. Staatl. Mus. Mineral. Geol. Dresden 33:1–260. Martin-Sans, E., Ponchet, J. 1930. Sur l’appareil sécréteur des Buxus. Bull. Soc. Hist. Nat. Toulouse 60:231–232. Mathou, Th. 1940. Recherches sur la famille des Buxacées. Toulouse: Douladoure. Melikian, A.P. 1968. On the position of the families Buxaceae and Simmondsiaceae in the system (in Russian). Bot. Zhurn. (Moscow & Leningrad) 53:1043–1047. Metcalfe, C.R., Chalk, L. 1957. See general references. Nandi, O.I. et al. 1998. See general references.

47

Naumova, T.N. 1980. Nucellar polyembryony in the genus Sarcococca (Buxaceae) (in Russian). Bot. Zhurn. (Moscow & Leningrad) 65:230–240. Pax, F. 1896. Buxaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 5. Leipzig: W. Engelmann, pp. 7–23. Raven, P.H. 1975. The bases of angiosperm phylogeny: cytology. Ann. Missouri Bot. Gard. 62:724–764. Reeves, R.D., Baker, A.J.M., Borhidi, A., Berazaín, R. 1996. Nickel-accumulating plants from the ancient serpentine soils of Cuba. New Phytol. 133:217–224. Robbins, H.C. 1962. A monographic study of the genus Pachysandra (Buxaceae). Ph.D. Thesis, Vanderbilt University, Nashville, TN. Sealy, J.R. 1986. A revision of the genus Sarcococca (Buxaceae). Bot. J. Linn. Soc. 92: 117-159. Singh, G., Bir, S.S., Gill, B.S. 1982. In: Löve, A. (ed.) IOPB Chromosome number reports LXXVII. Taxon 31:761– 777. Smets, E. 1988. La présence des ‘nectaria persistentia’ chez les Magnoliophytina (Angiospermes). Candollea 43:709–716. Soltis, D.E. et al. 2000. See general references. Soltis, D.E. et al. 2003. See general references. Uemura, K. 1979. Leaf compressions of Buxus from the upper Miocene of Japan. Bull. Nat. Sci. Mus. Tokyo, C, 5:1–8. van der Hammen, T. 1974. The Pleistocene changes of vegetation and climate in tropical South America. J. Biogeogr. 1:3–26. van Tieghem, P. 1897. Sur les Buxacées. Ann. Sci. Nat. Bot. VIII, 5:289–338. Vogel, S. 1998. Remarkable nectaries: structure, ecology, organophyletic perspectives, IV. Miscellaneous cases. Flora 193:225–248. Webster, G.L. 1987. The saga of the spurges: a review of the classification and relationships in the Euphorbiales. Bot. J. Linn. Soc. 94:3–46. Wiger, J. 1935. Embryological studies on the families Buxaceae, Meliaceae, Simaroubaceae and Burseraceae. Thesis, Lund University. Wunderlich, R. 1967. Some remarks on the taxonomic significance of the seed coat. Phytomorphology 17:301– 311.

Clusiaceae-Guttiferae Guttiferae Jussieu, Gen. Pl.: 255 (1789), nom. cons. Clusiaceae Lindl., Nat. Syst. Bot., ed. 2: 74 (1836), nom. cons., nom. alt.

P.F. Stevens

Evergreen shrubs or trees, epiphytic or not, glands and/or canals in most parts of the plant; xanthones widespread; plants glabrous or with uni- or multicellular hairs, colleters common; terminal bud scaly or naked. Leaves opposite, sometimes whorled or alternate, entire, estipulate, but paired ‘glands’ sometimes found at base. Inflorescences terminal or axillary, rarely flowers single, often modified cymose. Flowers perfect or unisexual, actinomorphic, usually with prophylls, sepals free, occasionally fused, 2(3)4, or 5(–20); petals (0, 3)4–5(–8), free; stamens (4–)∞, free or variously fasciculate, phalangiate, or otherwise connate, fascicles or phalanges opposite the petals, anthers dithecate, extrose to introrse, opening by slits, rarely pores, connective often with glands of various types; receptacular nectary absent; ovary superior, 1–5(–20)-locular, placentation axile or parietal, apical or basal, ovules (1)2–∞/carpel, anatropous, sometimes amphitropous, bitegmic, tenuinucellate; free stylodia or simple style long to short or 0, stigmas more or less expanded, smooth and sticky or minutely porate, rarely papillose or ± punctate; fruit a berry or septicidal or -fragal capsule, seeds small to large, winged or arillate or not, testa with epidermis and exotegmen alone, the latter lignified and with sinuous anticlinal walls, or more complex and with vascular bundles permeating a many-layered testa, distinctive exotegmen then often absent; embryo large to small, cotyledons massive to almost absent; endosperm initially free nuclear, often absent at maturity; germination epigeal or hypogeal, if latter, then radicle may die early, replaced by adventitious roots. A family of 27 genera and 1,090 species; largely restricted to lowland tropics. Characters of Rare Occurrence. Exudate black (surrounding embryo of Chrysochlamys, floral resin of Clusia scrobiculata); leaves lacking free glands or canals (some Kielmeyera, Kayea);

bracts enveloping partial inflorescences and falling off like a calyptra (Tovomita calodictyos); flowers zygomorphic by abortion of fascicles (Marila sp.); petals and sepals 3 (some Garcinia); abaxial glands on prophylls and calyx (Clusiella); corolla tubular (Clusia gundlachii) or absent (Calophyllum); anthers with porose dehiscence (Poeciloneuron, some Marila, Clusia, and Garcinia); staminodes of the pistillate flower more strongly adnate to the corolla than phalanges of the staminate flower (Garcinia hollrungii) or staminodes opposite the sepals; pollen in tetrads (Kielmeyera spp.); fruits drupaceous (some Garcinia); seeds papillate (Neotatea); testa soft, with disorganized xylem (Kayea kunstleri, Symphonia); cotyledons fused (Mammea spp.). Vegetative Morphology. Clusiaceae are all woody plants. The trunk may be buttressed (some Calophyllum), or there may be knee (some Symphonia) or prop (Dystovomita) roots; the latter are strongly diageotropic initially. Clusia and its relatives are often epiphytes that only secondarily establish contact with the ground; adventitious roots commonly develop along the stem, and in epiphytic species of Clusia they may encircle and even strangle the host. Kielmeyera, a plant of rather drier areas, may develop a lignotuber, from which it resprouts after fire or drought; root suckering occurs in Mammea acuminata and Garcinia griffithii and layering in Chrysochlamys. Some species of Kielmeyera, Neotatea and Mammea have relatively stout, little- or unbranched stems and large leaves, although the three genera grow in very different habitats. Growth of most taxa is initially monopodial, the lateral branches being orthotropic to plagiotropic (in Garcinia and Symphonia, these may be rigidly plagiotropic). The terminal bud may lack scales, and then the flush may have only one (frequent in Garcinia, Clusia, and Calophyllum) or more pairs of leaves; branches develop from the axils of the uppermost


pair of leaves of the last flush as the terminal bud grows out. Symphonieae, Mammea, some species of Calophyllum, etc., have terminal buds with two or more pairs of scales (Garcinia may approach this condition); branches here usually arise in the axils of the uppermost scales (Mammea) or the lowest pair of expanded leaves (Symphonia). In Mesua, the apical bud aborts at the seedling stage (at least, in M. ferrea), and all growth is by axillary branches; apical buds also abort in some Calophyllum, Lebrunia, etc. In several (?all) species of Kayea, the apical bud of each orthotropic innovation grows on as a plagiotropic lateral shoot, and an axillary bud produces the next orthotropic leader. Tovomita has lateral branches that are plagiotropic by substitution; axillary shoots there may be truly sylleptic. Clusiaceae are often glabrous (Mammea, many Clusioideae); taxa with unicellular hairs are scattered throughout the family. Stellate hairs characterize Caraipa, and branched or stellate hairs occur in Marila; Calophyllum has irregular multicellular hairs. Colleters are common. Buds in taxa that lack perulae are sometimes covered with dense indumentum, as in Calophyllum (it lacks colleters). Terminal and axillary buds in Garcinia, Dystovomita, Poeciloneuron, and elsewhere are often enclosed in deep excavations of the petiole bases; colleters are usually present as well. In Mesua, axillary buds are immersed in stem tissue, and in Mammea they are small and lie almost flush with the stem; they are usually more prominent. There are no stipules, but paired ‘glands’ on either side of the leaf base are quite common. In Mahurea exstipulata, these occur immediately above the insertion of the leaf and appear to be modified colleters. Garcinia commonly has small, glandular or eglandular stipuliform structures immediately below the leaf insertion, while in Endodesmieae and Symphonieae similar structures are lateral and more delicate; they may even be peltate. In Montrouziera, Garcinia, and Mahurea (the only taxa examined), they lack a vascular supply. The lamina is usually petiolate and the midrib is nearly always obvious. Venation is commonly eucamptodromous or brochidodromous, rarely acrodromous, and is more or less reticulodromous in Kayea, Mammea, and Caraipa in particular. The secondary veins are often rather close together and are joined by a submarginal vein; in Calophyllum, the marginal vein is embedded in marginal thickening and usually cannot be seen, while in

49

Garcinieae, Symphonieae and Endodesmieae the submarginal vein is within 2 mm of the margin. Tertiary venation is notably scalariform in many species of Mahurea, Caraipa, and Marila; in Calophyllum and Neotatea in particular, tertiary venation is apparently absent. Seedlings of Calophyllum and Mammea can show substantial variation in leaf arrangement and rate of growth that is not evident in adults, in Calophyllum some species even having alternate leaves (all adults have opposite leaves; Stevens 1980). Vegetative Anatomy. Vesque (1889, 1892) provides a general survey of leaf anatomy that has still not been surpassed; Metcalfe and Chalk (1950) summarize other early literature; more recent studies include those of Schofield (1968), and Paula (1976 and references therein). A distinctive feature of Clusiaceae is the exudate-containing glands and canals found throughout the plant (hence the alternative name, Guttiferae), although this has not been surveyed at even a gross level. Canals are associated with the vascular tissue and are also found in both the cortex and pith. Systematically important variation is found in the secretory tissues of the appendicular organs of the plant. These are commonly more or less independent of the vascular tissue, and are probably schizogenous glands or canals. All cotyledons that I have seen possess canals, whatever the condition in the foliage leaves. Clusiella has both glands and canals in its leaves, a combination found in some species of Mammea, Garcinia (probably independently derived in sections Tagmanthera and Daedalanthera), and perhaps also in Symphonieae (particularly poorly known). However, a genus usually has either glands or canals. Glands are notably elongated in Endodesmia and some species of Mammea and Marila. Black glands, perhaps containing hypericin, occur in Mammea, Marila, etc. (these can be confused with spots caused by fungal infections). Most Clusieae and Garcinieae have two or more series of canals in the mesophyll, one near the adaxial side of the lamina and the other near the abaxial; they pursue a more admedial course than the secondary veins (and are more admedial on the adaxial side of the lamina than on the abaxial). Canals are dendritic in Clusia (Pilosperma), and branched canals occur in some species of Garcinia, Clusia, and possibly in Symphonieae such as Pentadesma. Calophyllum has distinctive leaves with closely set secondary veins alternating with canals; the latter are interpreted as being modified veins

50

P.F. Stevens

(Ramji 1967). Neotatea is similar, and there are tendencies toward this condition in Kayea. Canals commonly occur in petals and filaments (not all genera have been surveyed); in Clusia, for example, the stout filaments may consist very largely of resin-containing glands and canals. Nodes are single trace from a single gap. In Montrouziera, the single trace divides in the bottom of the petiole into several, normally oriented bundles. In some species of Mammea, too, the trace divides, but the additional petiole bundles are inverted. The petiole bundle is usually simple, either arcuate (Calophyllum) or more or less circular, or more complex (Marila). The midrib bundle is arcuate when the petiole bundle is arcuate, or more or less circular, with phloem toward the outside. However, in Mammea, Mesua, and some species of Marila, the adaxial layer of vascular tissue is inverted, the adaxial tissue being xylem, while in many genera there are three or more layers of xylem and phloem (the phloem of the adaxial layer is itself adaxial). In Endodesmieae, xylem and phloem of the midrib bundle do not form large blocks of tissues. The vascular bundles of even the higherorder veinlets are often transcurrent, being joined to at least one surface of the lamina by echlorophyllous and often lignified tissue, but in Clusioideae in particular the vascular bundles – sometimes even the midrib, too – are embedded. Hypodermes are common, although their presence is rarely entirely consistent within genera of any size. The abaxial or near-abaxial layers of spongy mesophyll may become thick-walled and lignified; again, this is usually not completely consistent in a genus. Isolated mesophyllar sclereids are rare, but most species of Mammea have fibers, either in a subepidermal sheet, as vertically elongated bundles in the palisade mesophyll, or, less frequently, isolated and wandering through the mesophyll (Dunthorn 2002). Epidermal cells have straight to sinuous anticlinal walls (the latter especially on the abaxial surface). Leaves are overwhelmingly hypostomatic; stomata are paracytic. Lignification of the echlorophyllous tissue in the lamina margin is common in Kielmeyeroideae. The position of initiation of the phellogen in the root is taxonomically very important; it may be superficial, (sub)epidermal, or deep-seated, interior to the pericycle. The phellogen in the stem is superficial. There are fairly extensive data on wood anatomy, but inconsistencies in the use of descriptive terms and a number of contradictions in the literature present problems. Vessels are

either single or in multiples, being in oblique lines in large-seeded Kielmeyeroideae. Perforation plates are usually simple, although they are sometimes scalariform. Vasicentric tracheids have been recorded from a number of taxa. Wood parenchyma usually occurs; it is paratracheal (in a variety of configurations) or apotracheal, diffuse or banded. Fiber tracheids and libriform fibers have both been recorded; both may occur within the one genus (Kayea, Marila). Septate fibers occur, but their distribution is very sporadic; septate and non-septate fibers can be found in the same individual (Baretta-Kuipers 1976). A variety of ray types have been reported and there may be variation of systematic interest – thus, the rays of Mesua are largely uniseriate, those of Kayea largely multiseriate. Silica may occur in the rays. Inflorescence Structure. Inflorescences are terminal or axillary, rarely ramiflorous. In Clusiella, the terminal inflorescence is evicted by the vigorous growth of an axillary shoot from immediately below the inflorescence, and hence appears axillary. The inflorescence is usually modified cymose or thyrsiform, and a terminal flower is nearly always present. Single, terminal flowers are common in Symphonieae. In Mesua ferrea there are single, axillary flowers, perhaps the terminal flowers of a reduced inflorescence, but in other species of the genus the few-flowered inflorescences lack terminal flowers. Marila has racemiform inflorescences in which the often numerous flowers open more or less simultaneously; again, there is no obvious terminal flower. Fasciculate inflorescences are common (e.g., Garcinia, Symphonia, Mammea); they are usually modified cymes. Flowers normally have both bracts and prophylls, but the latter are absent in Calophyllum, Lebrunia, and Kayea lepidota. Bracts, prophylls and sepals intergrade in some Clusieae (see also Gustaffsson 2000), and the lowermost pair of sepals in genera such as Tovomitopsis may in fact be prophyllar. Floral Structure. Sepals and petals are nearly always present and are usually free; they can be difficult to distinguish (Gustafsson 2000). Sepals are commonly five in number and quincuncial in aestivation, four and decussate, or two and valvate or even connate. When there are five petals, they are often contorted, when four, then decussate aestivation is common; petal numbers in Mammea increase by the division of the innermost petals. Clusia gundlachii has a remarkable, undivided tube


surrounding the androecium; it shows no evidence of being a composite structure, even when very young (Gustafsson 2000). Pubescence of the calyx and corolla is uncommon. The androecium may be basically fasciculate or phalangiate, the numerous stamens found in most species representing the products of five, antepetalous primordia (Figs. 14, 16, 17, 19). In pistillate flowers, structures that are usually in the antepetalous position may represent these fascicles. Kielmeyeroideae have slender, free (rarely fused – some species of Mammea) stamens with no evidence of fasciculation, although in the monosymmetric flowers of an undescribed species of Marila there are no stamens opposite two petals, suggesting that two fascicles are missing. Anther glands are common and diverse: they may be absent (Calophyllum, Poeciloneuron); barely perceptible, sometimes paired and apical (Mammea); single and more prominent (Mammea, Marila, Kayea); strongly crateriform, presumably after the contents are removed (Marila; in Caraipa, they contain a highly aromatic oil and the covering ruptures during anthesis); or relatively long and apparently tubular (Marila). Clusioideae show extreme androecial variation, although our knowledge is based almost entirely on general surveys from over a century ago (e.g., Pierre 1883–1885; Engler 1888, 1925; Vesque 1889, 1892, 1893, but see Gustafsson and Bittrich 2002 for Clusia). The filaments are stout, the anthers even being embedded in them. Garcinieae and Symphonieae often have clearly phalangiate androecia; in the latter, they occur at the end of a long tube. Decaphalangium (= Clusia) was described as having ten phalanges; it is best interpreted as having ten locellate anthers; some other Clusia, Kielmeyera, and Poeciloneuron also have locellate anthers. In both Garcinia and Clusia, androecial fusion may obscure the limits of individual stamens (see below), although epidermides delimiting the stamens can at least sometimes be seen in transverse section. Although an exudate may cover the whole androecium in Clusia and its relatives, or the whole filaments may consist of massive glands, distinct anther glands are rare in Clusioideae. There is no nectary at the base of the ovary. In Symphonia, however, there is a nectariferous disc surrounding the staminal tube that may represent the antesepalous whorl of the androecium (Fig. 19C); nectar is also secreted by other Symphonieae. Nectar may be secreted at the base of the androecium, as in some species of Clusia.

51

Some species of Garcinia produce an almost mucilaginous secretion from the center of the flower (P. Sweeney, pers. comm.). There are usually 2–5 carpels; when equal in number to the perianth whorls, they are opposite the sepals. Calophyllum has several vascular bundles in the style, the stigma is often definitely 2or more-lobed, and the single-ovulate gynoecium is multicarpellary. However, how many carpels make up the gynoecium in Endodesmia and Lebrunia, with its single, apical ovule and punctate stigma, is not clear. There is an apparent increase in carpel number within Garcinia, Clusia, and Mammea (Paramammea); in the latter, there may also be twice as many ovary loculi as stigmatic lobes. Placentation is basically axile, although the placentae may fail to meet in the middle, as in Mesua and Mammea; Clusiella has laminar placentation (Notis 2004), and Allanblackia has parietal placentation. Basal ovules occur in Kayea and Calophyllum, apical ovules in Endodesmieae. Ovules are anatropous, bitegmic, bistomal and tenuinucellate, although Mammea americana apparently has a single, massive integument some 26 cells across (Mourão and Beltrati 2000), while the micropyle of Garcinia mangostana is described as being exostomal (Lim 1984). Embryo sac development is of Polygonum type. However, little is known of ovule morphology and embryo sac development. Most Clusioideae have short stylodia representing the separate tips of carpels; the stigmas are usually distinct. The sessile stigmas of Garcinia are more nearly connate; Kielmeyeroideae often have long, simple styles, whether free or fused. The stigma is often more or less expanded, and the surface is smooth or variously sculptured (the latter especially in Garcinia). However, in Kayea, Poeciloneuron, and Endodesmieae it is punctate, while the expanded stigmas of Clusia section Cordylandra have stout, pointed hairs and those of C. section Criuva are papillate. There is a small aperture at the apex of the style branches in Symphonieae through which the pollen enters, but no exposed stigmatic surface at all. Floral Anatomy and Development. Little is known about floral anatomy and development. Stamen initiation is centrifugal in those few taxa in which this feature has been observed (e.g., Kubitzki 1978). Androecial development in Garcinia and Clusia shows extreme variability, in some species of the latter the normal parts of the stamen be-

52

P.F. Stevens

ing unrecognizable (Bittrich and Amaral 1996). The two antesepalous phalanges in species of Garcinia section Tagmanthera (Exell and Robson 1960) may result from fusion of phalanges in pairs (cf. Hypericaceae, this volume). The vascular tissue of the stamen phalanges of Lorostemon and its relatives is siphonostelic (Kawano 1965); siphonosteles, or close approximations to them, are found in the stout filaments of some species of Clusia (pers. obs.). Pollen Morphology. Seetharam (1985) surveyed the pollen of the family using a light microscope (see also Yi 1979; Barth 1980; Jones 1980; Seetharam and Maheshwari 1986; GonçalvesEsteves and Mendonça 2001). Extensive pollen variation in Madagascan species of Mammea (Presting et al. 1983) is caused by cryptic dioecy (Dunthorn 2004, see below). Pollen is usually in monads, although Kielmeyera may have tetrads. The grains are usually tricolporate, sometimes triporate; Garcinieae and Symphonieae often have more than three apertures. Costae colpi are usually present, and there is considerable variation in endaperture type and orientation. The pollen surface may be reticulate, rugulose, fossulate, foveolate, psilate or scabrate; supratectal elements occur in some genera, notably Chrysochlamys, and some species of Garcinia are densely spinulate. In most taxa, the nexine is < 1 µm thick, but in many Symphonieae it is > 1.5 µm thick. Karyology. There is extensive infraspecific variation within Garcinia xanthochymus (Chennaveeraiah and Radzan 1980). However, there may be little cytological variation within Clusia, gametic numbers of 30 having been recorded for several unrelated taxa (da Cruz et al. 1990). The few counts known from Clusioideae show high base numbers of 28–48, and comparable numbers for Kielmeyeroideae are 16–21 (Carr and McPherson 1986). Pollination and Reproductive Systems. Dioecy is common in Clusieae and Garcinieae, but is only sporadic elsewhere. The breeding system of Mammea, often described as being androdioecious, is cryptically dioecious (Dunthorn 2004) – hence the bizarre pollen morphology of some species, usually reported from ‘perfect’ flowers (see above). A few Calophyllum are dioecious; andromonoecy is common in Kielmeyera (Saddi 1989). Garcinia and Clusia need more study. Ag-

amospermy is known from Clusia rosea, C. minor, and Garcinia mangostana; in the latter, adventive embryony in particular occurs (Maguire 1976; Lim 1984; Richards 1990a, b, c). Furthermore, in some species of Clusia there are three flower types – staminate, pistillate, and perfect (Bittrich and Amaral 1997; Lopes and Machado 1998) – while C. minor has perfect flowers (B. Hammel, pers. comm.); in neither Garcinia nor Clusia is dioecy strict. Apomixis is sporadic elsewhere in Clusiaceae, possibly occurring in Calophyllum (Stevens 1980); polyembryony is known from a few species in Calophyllum, Kayea, and Garcinia, including G. magostana. There is little information about hybridization in Clusiaceae (for Calophyllum, see Stevens 1980); fairly extensive artificial crosses have been made in Clusia (V. Bittrich, pers. comm.). The predominant petal color in the family is white or yellow; pink, purple or red being less common. Many Clusiaceae from the New World tropics produce resins – in particular, polyisoprenylated benzophenones mixed with fatty acids – or other exudates from distinctive anther glands, secretions by the whole staminal mass, the stigmatic surface, or the staminode or pistillode (Ramirez B. and Gomez 1978; Armbruster 1984; Rodrigues C. et al. 1999; Mesquita and Franciscon 1995; Bittrich and Amaral 1996, 1997; Oliveira et al. 1996; Porto et al. 2000; Carmo and Franceschinelli 2002). In Clusia in particular, the secretions are collected by megachilid and other resin-collecting bees, and such pollination mechanisms have evolved more than once (including in Clusiella, see especially Gustafsson and Bittrich 2002). The aromatic oils in the filaments of Tovomita are collected by euglossine bees, and different fragrances may be involved in species barriers (Noguiera et al. 1998). Some Clusia are night-flowering and pollinated by beetles (including the banana-scented C. flava; B. Hammel, pers. comm.), with pistillate flowers perhaps mimicking staminate flowers (Correia et al. 1993); Clusia growing at higher elevations tends to produce nectar, rather than resin (Armbruster 1984). Little is known about what the various anther glands produce, although resins and/or hypericin and similar substances are likely candidates. Pollen may be a major reward, e.g., Calophyllum; buzz pollination is reported from Kielmeyera (Oliveira and Sazima 1990) and some Clusia, Mahurea, and Caraipa (Bittrich and Amaral 1996). Symphonia and its relatives have large, often red flowers and produce nectar; birds, butterflies, monkeys, and in Madagascar,


also lemurs are reported to visit the flowers (e.g., Perrier de la Bâthie 1951; Croat 1978; Pascarella 1992). Platonia insignis is bird-pollinated (Maués and Venturieri 1996), Moronobea coccinea was observed to be pollinated exclusively by parrots (Vicentini and Fischer 1999), while Pentadesma butyracea is bat-pollinated (Petterson et al. 2004). Fruit and Seed. Fruits are commonly capsular, dehiscence being septicidal or septifragal (Mesua, Clusieae). In Kayea, the calyx is often massively accrescent, in some species quite surrounding the capsule; the fruits are then indehiscent. Berries with a single seed and a woody testa occur in Mammea and Calophyllum; similar fruits of Endodesmieae have a thinner testa and the pedicels may be swollen. In Mammea americana, the inner part of the endocarp often becomes firmly attached to the seed coat (Mourão and Beltrati 2000; pers. obs.), and there is a well-developed periderm. Garcinieae and Symphonieae have several-seeded berries, while in Clusiella the berries may contain thousands of minute seeds. In Platonia insignis, the fleshy inner part of the pericarp becomes attached to the testa and covers it when the seeds are released after dehiscence of the fruit (Mourão and Beltrati 1996a). The endocarp is notably massive and sclerified in some species of Garcinia (largely east Malesian), the surface being strongly ridged. Clusiaceae with seeds less than 4 mm long usually have a testa with an epidermis, as well as a low, lignified exotegmen with sinuous anticlinal walls developing from the outer epidermis of the inner integument (see also Corner 1976). There is a single, chalazal vascular bundle. In many larger-seeded taxa, the testa is thicker and the vascular bundle proliferates (in Dystovomita it is braided, but restricted to the chalazal position); the exotegmen is then often absent. The exotegmen in large-seeded taxa such as Allanblackia is tall (Delay and Mangenot 1960), although it is difficult to equate the massive lignified layer in the seed coat of genera such as Lorostemon with an exotegmen. Platonia insignis has a testa of unthickened cells and a few brachysclereids in the tegmen (Mourão and Beltrati 1996b). The seed coat of Symphonia consists of a mass of almost cottony and unlignified fibers, while there is a layer of cells with scalariform thickenings in that of Kielmeyera. In Clusieae, the seed is more or less surrounded by a red or white aril, the latter in some Chrysochlamys, and in Tovomita the fruits are also red inside (V. Bittrich, pers. comm.). In Tovomita, the aril appears to be vascularized.

53

The endosperm may persist in small-seeded taxa as a thin layer around the embryo; it has largely disappeared by maturity in larger-seeded taxa. The proportions of cotyledon, hypocotyl and radicle vary greatly. Kielmeyeroideae such as Marila and Clusiella have small embryos less than 3 mm long and with cotyledons 30–60% of their lengths, but most genera have seeds over 6 mm long that are made up largely of cotyledons; in Caraipa, Haploclathra, and Kielmeyera, the cotyledons are strongly cordate whereas in Kayea they are more or less peltate. In Clusioideae, on the other hand, the cotyledons are minute (e.g., Clusia) or almost invisible (many species of Garcinia, Symphonieae), the often large embryo being made up of a grossly swollen hypocotylar region, the tigellus (e.g., Brandza 1908). Axes of such embryos are usually straight, but are S-shaped in Platonia insignis (Mourão and Beltrati 1996b) and some species of Garcinia. The embryo is usually white, but in Caraipa, Kielmeyera, and Clusieae it is often green, while in Calophyllum suberosum it is a rather violent purple. There is much variation in germination (La Mensbruge 1966 provides some information). Species with seeds under 10 mm long are usually epigeal and phanerocotylar, even when the cotyledons are relatively minute, c. 1/10 the seed in length, as in Clusia. Larger seeds over 10 mm long and consisting of proportionally huge cotyledons are either hypogeal and cryptocotylar (Calophyllum, Mammea), or epigeal and phanerocotylar (Caraipa, Kielmeyera); there is infrageneric variation in Poeciloneuron. Larger seeds consisting mostly of tigellus often develop adventitious roots in the epicotylar region, the hypocotyl does not elongate, the cotyledons do not develop further, and the radicle eventually dies, or at least becomes inconspicuous (Garcinia-type germination – see Brandza 1908; also in Symphonia, Tovomita, etc.). However, in other taxa with such seeds, the hypocotyl elongates, the tigellus becomes erect, and the cotyledons expand (Garcinia section Macrostigma, Chrysochlamys), while germination in Platonia is hypogeal, but adventitious roots do not develop. Dispersal. Mammea odorata, with its thick, woody, but not notably dense seed coat, and Calophyllum inophyllum, with a spongy layer immediately surrounding the seed, are strand plants that are water-dispersed. Fruits of the latter species may also be eaten by bats, as are some other

54

P.F. Stevens

species of the genus; the many blue-fruited species of Calophyllum (primarily from east of Wallace’s Line) may be dispersed by birds (Stevens 1980). The large, fleshy fruits of Mammea seem to be attractive to mammals, being eaten by a variety of lemurs in Madagascar, and seeds of the arillate New World Clusieae are dispersed by birds (e.g., Spruce 1855), although ants subsequently affect the distribution and germination of seeds of the primarily bird-dispersed Clusia criuva (Passos and Oliveira 2002). Taxa with small, dry seeds, and those with winged seeds, are probably wind-dispersed, although seeds of Haploclathra and Caraipa, with their proportionally very small wings, may be water-dispersed (Kubitzki 1989: the seeds certainly float well). Symphonia, whose fruits are eaten by animals, has dispersed across water to achieve its present-day distribution (Dick et al. 2003). Phytochemistry. Clusiaceae are noted for producing a wide array of isoprenylated xanthones, biflavonoids and anthraquinones (e.g., Xu et al. 2001 and references therein), 80 new xanthone structures having been reported in the years 1980–1988 alone (Bennett and Lee 1989). Most xanthones have a restricted distribution, although macluroxanthone and in particular mangiferin are more widespread. Interestingly, few xanthones are known from Clusieae, although benzophenones, their precursors, have been isolated from them. Prenylated benzophenones are known from Clusia, Tovomita, Tovomitopsis, and Moronobea (Delle Monache et al. 1991; A. Marsaioli, pers. comm.). 1,3,5,6-tetraoxygenated xanthones are known only from African species of Garcinia and from species of Rheedia (= Garcinia), but not in Asian species of Garcinia (Bennett and Lee 1989). Biflavonoids with 3-8 , 3 -8 and 8-8 linkages also show distributions of potential systematic interest (Owen and Scheinmann 1974; Waterman and Husain 1983), while there are distinctive coumarin derivates substituted at position 4 in Kielmeyeroideae (Taylor and Brooker 1969). Tocotrienolic acids and terpenes are also found in Clusia exudates (A. Marsaioli, pers. comm.). Relationships Within the Family. Planchon and Triana (1860, 1862 and references therein) laid the foundation of our knowledge of the family, while Vesque (1893) was its last monographer; he also made extensive anatomical observations. Mahurea, Kielmeyera, Marila, and their relatives are here included in Clusiaceae, although usually

placed in Bonnetiaceae or Theaceae, often having been considered to be ‘linking’ genera (e.g., Maguire 1972; Baretta-Kuipers 1976; Field 1978; Cronquist 1981). Hypericaceae are here excluded from Clusiaceae (Stevens, this volume). Within Clusiaceae, Kielmeyeroideae (as Calophylloideae – Robson 1978) form one major clade. Phylogenetic relationships between genera are unclear, taxa with cordate cotyledons apparently forming a paraphyletic group in some family-level morphological analyses (own unpubl. data), although monophyletic in a three-gene molecular study (Notis 2004). Although Clusiella is sister to Clusioideae in morphological analyses, molecular data place it firmly within Kielmeyeroideae, where it is a fascinating example of general ecological convergence with Clusia (Gustafsson et al. 2002); it may be associated with other small-seeded Kielmeyeroideae, especially when morphological data are included (Notis 2004). Within Kielmeyeroideae, Endodesmia may be sister to all other taxa, with Mammea sister to the remaining taxa; within the latter, Calophyllum + Mesua and Kayea + Poeciloneuron are two pairs of sister taxa (Notis 2004). (Endodesmieae are vegetatively like Clusioideae, they have fruits like Calophyllum (Kielmeyeroideae), and a unique gynoecium; their germination, chromosome number, root anatomy, etc., are all unknown.) Clusioideae, also monophyletic, are made up of Clusieae, Symphonieae, and Garcinieae. Evidence from both the androecium and gynoecium (the stigma) suggests that Symphonieae are monophyletic, but most genera are poorly known; Montrouziera and Moronobea in particular are very similar. Molecular data do not find a strongly supported Symphonieae (Gustafsson et al. 2002). Tovomita (Clusieae) has Garciniatype germination, while some species of Garcinia section Macrostigma germinate like Clusia, as well as apparently having seeds with an exotegmen. Garcinieae and Clusieae are clearly distinguished, and Garcinia germination type may have evolved twice. Clusia includes Decaphalangium and Renggeria, which with Clusia section Cordylandra make a clade (Gustafsson and Bittrich 2002) characterized i.a. by their stigmas, which have stout hairs. Other genera have been synonymized under Clusia (Gustafsson and Bittrich 2002); they were based on slight differences in the androecium, e.g., generally having few anthers (and also ovules). Pilosperma has distinctive branching canals in the leaf; it, too, is best included in Clusia. Tovomitopsis is poorly known, but it may be sister to


Chrysochlamys (Gustafsson and Bittrich 2002), and so it is recognized here (cf. Gustafsson et al. 2002). Affinities. In the past, Clusiaceae have been linked to the heterogeneous Theaceae by ‘intermediate’ genera such as Kielmeyera (e.g., Baretta-Kuipers 1976). Although both have numerous, centrifugally developing stamens and bitegmic, tenuinucellate ovules (e.g., Erbar 1986), Sladeniaceae, Theaceae, and Pentaphylacaceae, into which Theaceae are currently divided (Stevens and Weitzman 2004; Stevens et al. 2004; Weitzman et al. 2004 [as Ternstroemiaceae]), are now all well established as members of the asterid Ericales (e.g., Anderberg et al. 2002). Clusiaceae are part of Malpighiales (e.g., Chase et al. 1993; Davis and Chase 2004). Within Malpighiales, the immediate relatives of Clusiaceae seem well established. Clusiaceae are close to Bonnetiaceae (e.g., Gustaffson et al. 2002) and in particular Hypericaceae (see also Crepet and Nixon 1998). At least some members of all three families have distinctive xanthones (Kubitzki et al. 1978), similar, exotegmic seeds, and antepetalous staminal fascicles or phalanges. However, Bonnetiaceae have long, terminal buds, trilacunar nodes (most taxa), and minutely serrate leaves, although the polarities of these characters are unclear. A rather low base number of n = 11 from Ploiarium is most like numbers in Hypericaceae; Hypericaceae-Hypericeae and Bonnetiaceae also both have papillate stigmas, although Bonnetiaceae apparently lack glands or canals. It has caused something of a stir to find that Podostemaceae are also part of this group, and they, too, have tenuinucellate ovules and at least some xanthones; for further details, see Hypericaceae (this volume). The relationships of the Clusiaceae group of families are unclear. Elatinaceae have often been associated with them, but they are probably sister to Malpighiaceae (Davis and Chase 2004). Although Elatinaceae have exotegmic seeds rather like those of Clusiaceae, xanthones have not been detected in them (Hegnauer 1966), and there are a number of similarities between them and Malpighiaceae (Davis and Chase 2004; Stevens 2005). The Clusiaceae group may be close to families such as Ochnaceae (Davis and Chase 2004); interestingly, Malpighiaceae + Elatinaceae may in turn be close to that group. Distribution and Habitats. Clusiaceae are mostly plants of moist, tropical, lowland or

55

lower montane forests. Most genera occur in primary forest, where they may be rheophytes (e.g., Calophyllum rupicola) or grow in peat swamps (C. sundaicum) or black-water floodplains (Caraipa, Haploclathra spp.). Kielmeyera in South America grows in more open and drier vegetation. Epiphytic or lianescent taxa are found almost exclusively in Clusieae and Clusiella, both tropical American. Crassulacean acid metabolism occurs in Clusia, which shows considerable flexibility in carbon metabolism (Lüttge 1999, 2002). Pending a more detailed phylogeny, little can be said about the biogeography of the family. Bonnetiaceae, close to Clusiaceae, includes the New World Bonnetia and the Malesian-American Ploiarium and Archytaea. Within Clusiaceae, Kielmeyeroideae have many neotropical taxa, e.g., Marila, Caraipa, Neotatea, and Mahurea; Endodesmia and Lebrunia are from the African mainland. Other genera are primarily IndoMalesian, although Mammea is notably diverse in Madagascar; it and Calophyllum are also poorly represented in America. The African and American species of Mammea are notably more similar to each other than to other species in the genus. Within Clusioideae, Symphonieae occur in Africa-Madagascar, America, and New Caledonia (Montrouziera). Symphonia has an amphi-Atlantic distribution, and shows strong molecular differentiation within S. globulifera s.l. (Dick et al. 2003); at least three dispersal events across marine barriers seem necessary, given the age of the genus and its current geographic distribution. Clusieae are restricted to America, while Garcinieae are largely Old World (Garcinia in America is not at all diverse). The diversification of both Clusia and Garcinia may be linked to the extreme variation of their androecium. Fossil Record. The fossil record of Clusiaceae is poor. Fossil pollen such as Kielmeyeropollenites eoceni is known from the Eocene of India, and pollen ascribed to genera such as Symphonia, Pentadesma, and Calophyllum is known from the middle Eocene onward in the regions the genera currently inhabit (Muller 1981). Pachydermites diederexii, fossil pollen of Symphonia, is used for stratigraphic dating by the oil industry (R.J. Morley, in Dick et al. 2003). Some fossil woods have been identified as Clusiaceae, including Symphonioxylon from the lower Miocene in Egypt, the Middle Tertiary of India, and Cretaceous rocks of Somalia; woods similar to those of Calophyllum,

56

P.F. Stevens

Kayea, and Mesua have less-startling distributions (Müller-Stoll and Mädel-Angeliewa 1986). Flowers of Paleoclusia, recently described from the Turonian (c. 90 Ma b.p.) in New Jersey, USA, show signs of producing resins and being pollinated by meliponine or similar bees (see above); note, however, that unlike at least some Clusia, the outer anticlinal walls of the exotesta are well developed and there are hairs on the flower (Crepet and Nixon 1998). A few Pleistocene fossils are also known, e.g., of Garcinia in the New Hebrides (Fosberg 1977). Economic Importance. Garcinia mangostana, the mangosteen, is one of the finest tropical fruits; the inner part of the pericarp (the ‘aril’ of some) is eaten. Other species of the genus also produce tasty fruits, often more acid than those of the mangosteen, and the young leaves of some are edible. The pericarp of Mammea americana (the mammey apple) is another tropical delicacy, and fruits of Moronobea coccinea and in particular Platonia insignis (‘bacuri’; Maués and Venturieri 1996) are also esteemed. The flowers of Mammea siamensis yield a scent. Garcinia twigs are commonly used as chew sticks in West Africa (M. Cheek, pers. comm.). The wood of Mesua ferrea, the ironwood, is very hard; the plant has very ornamental flowers and foliage, and has long been cultivated in India and Java in particular. Species of Symphonia are also spectacular when in flower; the stiff leaves of Clusia rosea have been sent as postcards through the U.S. mail (C.E. Wood Jr., pers. comm.). Many of the larger trees in the family provide useful timber. Thus, Calophyllum is logged through much of Malesia (as ‘bintangor’ or Calophyllum); the wood of C. inophyllum was formerly much valued for the building of canoes and boats. Oils and fats, valuable as medicines and for household activities such as lighting, cooking and making soap, can be obtained from the seeds of species of Calophyllum, Pentadesma, and Garcinia. Moronobea can be weedy. Gamboge (the name is derived from ‘Cambodia’) is extracted from the resin of species of Garcinia; it is a pigment giving a bright yellow color, and also a potent purgative. Several species are important in local pharmacopeias, while in western medicine anti-tumor activity has been detected in xanthones and benzophenones (Bennett and Lee 1989); Calophyllum show some promise as a source of anti-AIDS drugs (McKee et al. 1996). A methanolic extract of Clusia exudate is active against bacteria and fungi (A. Marsaioli, pers. comm.).

Classification of Clusiaceae I. Subfamily Kielmeyeroideae Engler (1888). 1. Tribe Calophylleae Choisy (1824). Genera 1–12 2. Tribe Endodesmieae Engler (1921). Genera 13–14 II. Subfamily Clusioideae Engler (1888). 1. Tribe Clusieae Choisy (1824). Genera 15–18 2. Tribe Garcinieae Choisy (1824). Genera 19–20 3. Tribe Symphonieae Choisy (1824). Genera 21–27

Key to the Genera 1. Leaves alternate; androecium not obviously fasciculate or phalangiate; fruit capsular 2 – Leaves opposite, if alternate, then androecium fasciculate and fruit a berry 5 2. Secondary veins closely parallel, tertiary veins not evident 1. Neotatea – Secondary veins not closely parallel, tertiary veins well developed 3 3. Anthers lacking obviously crateriform glands; seeds with wing > 2 mm wide 5. Kielmeyera – Anthers usually with crateriform glands; seeds with wing < 2 mm wide 4 4. Plants lacking stellate hairs; capsules longer than wide, seeds numerous 3. Mahurea – Plants with (minute) stellate hairs; capsules about as long as wide, seeds < 3 6. Caraipa 5. Styles simple, often longer than the ovary (Poeciloneuron with free stylodia), filaments long, much more slender than the anthers; stigma papillate or smooth; plants rarely dioecious 6 – Free stylodia or simple styles usually shorter than the ovary; filaments none, or at least half the width of the anthers; stigmas not papillate; plants often dioecious 14 6. Lamina with prominent, close secondary veins almost at right angles to midrib; fruit baccate, seed single, large 7 – Lamina with often inconspicuous secondary veins leaving midrib at acute angle; fruit usually capsular, with few to many seeds 9 7. Stipuliform structures absent; indumentum well developed, at least on buds; stamens free 12. Calophyllum – Stipuliform structures present; indumentum none or slight; stamens fused and/or fasciculate 8 8. Lamina with glands and short canals; inflorescences terminal; sepals 5, quincuncial 13. Endodesmia – Lamina with canals, but not crossing secondary veins; inflorescences axillary; sepals 4, decussate 14. Lebrunia 9. Terminal bud aborting; axillary buds immersed in stem 9. Mesua – Terminal bud functional; axillary buds more or less evident 10 10. Inflorescences racemose, flowers opening simultaneously; capsules with ∞ seeds < 3 mm long 2. Marila – Inflorescences not racemose, flowers usually opening successively; capsules with < 4(–8) seeds > 8 mm long 11

Clusiaceae-Guttiferae 11. Terminal buds without perulae; hairs multicellular; cotyledons cordate 7. Haploclathra – Terminal buds perulate; hairs unicellular or plant glabrous; cotyledons not cordate 12 12. Anthers porose; stylodia long, free 8. Poeciloneuron – Anthers dehiscing by slits; style very short to long, more or less fused 13 13. Inflorescence usually with axis; style long; fruit capsular, and/or calyx massively accrescent 10. Kayea – Inflorescence fasciculate; style short; fruit a fibrous berry; calyx deciduous 11. Mammea 14. Lamina clearly with glands and canals; large gland on abaxial surface of prophylls and often sepals; fruit a many-seeded berry; cotyledons 1/2 length of embryo 4. Clusiella – Lamina rarely with both glands and canals; prophylls and calyx lacking surface glands; fruit capsular, or if baccate, then seeds few; cotyledons < 1|10 length of embryo 15 15. Terminal bud perulate; flowers perfect; anthers 1.7– 40 mm long; stigmas minute, porose 16 – Terminal bud usually not perulate; flowers rarely perfect; anthers usually < 2 mm long; stigmas much expanded 22 16. Filaments connate into a tube; seed with hairyappearing testa 28. Symphonia – Filaments not connate into a tube; seeds lacking hairy testa 17 17. Stamens 15+/phalange; anthers more or less locellate 18 – Stamens 3–13/phalange, anthers rarely locellate 19 18. Inflorescences with single flowers; filaments well fused 24. Platonia – Inflorescences with 3–15 flowers; filaments barely fused 22. Pentadesma 19. Petals ligulate, usually spreading at anthesis 20 – Petals usually broadly elliptic and erect at anthesis 21 20. Anthers 10–40 mm long; ovules 12–∞/carpel; tall, lignified exotegmen usually present 26. Lorostemon – Anthers 8–9 mm long; ovules c. 4/carpel; exotegmen absent 27. Thysanostemon 21. Style usually shorter than ovary; stamens twisted; ovules 3–10/carpel 23. Moronobea – Style as long as or longer than ovary; stamens straight; ovules 12–∞/carpel 25. Montrouziera 22. Stipuliform structures present or not; androecium often fasciculate; fruit nearly always baccate (capsular, drupaceous) 23 – Stipuliform structures absent; androecium not obviously fasciculate; fruit capsular 24 23. Placentation parietal; ovules 12–∞/carpel 21. Allanblackia – Placentation axile; ovule 1/carpel 20. Garcinia 24. Ovules 1–2(–4)/loculus; aril vascularized 25 – Ovules (1–)4–∞/loculus; aril not vascularized 27 25. Petiole base only slightly if at all excavated; axillary branches lacking long basal internode; stylodia none 19. Chrysochlamys – Petiole base often strongly excavated; axillary branches with a distinctively long basal internode; stylodia often distinct 26 26. Stylodia distinct; outer sepals enveloping bud 17. Tovomita – Stylodia none; outer sepals not enveloping bud 18. Tovomitopsis

57

27. Leaf base deeply excavated; inflorescences axillary 16. Dystovomita – Leaf base not or slightly excavated; inflorescences usually terminal 15. Clusia

Genera of Clusiaceae Basic Characters Plant woody; leaves opposite, ± coriaceous, entire, stipules 0; inflorescence ± cymose; stamens free, anthers extrorse, ovary superior, placentation axile, stigma wet; fruit dehiscing down septal radius; seed exarillate. I. Subfam. Kielmeyeroideae Engler (1888). Leaves with ± spherical glands, veins usually transcurrent; flowers perfect; filaments much narrower than the anthers; style simple; cotyledons > 1/3 length of seed; phellogen in root deep-seated. I.1. Tribe Calophylleae [No characters for the tribe.] 1. Neotatea Maguire Neotatea Maguire, Mem. New York Bot. Gard. 23:161 (1972).

Sparsely branched small trees; hairs unicellular; terminal bud not perulate, no colleters; leaves spiral, secondary veins closely parallel, alternating with canals; inflorescences terminal, 1–5-flowered; sepals 5, quincuncial; petals 5, contorted; anthers 5–6 mm long, glands large, spherical; carpels 3, ∞ ovules/carpel, style short, stigma expanded; fruit septicidal; seed papillate, testa simple, exotegmen present; embryo c. 2.5 mm long, cotyledons 1/3– 1/2 its length, endosperm present; germination unknown. Four species, northern South America; colline. 2. Marila Swartz Marila Swartz, Prodr. veg. ind. occ.: 84 (1788).

Trees; hairs stellate or branched, also often uniseriate; terminal bud not perulate, no colleters; secondary veins distant, tertiaries often scalariform, glands sometimes elongated; inflorescences with (2–)∞ flowers, racemiform, terminal, branched, or axillary, branched or unbranched, flowers opening simultaneously; sepals 5, quincuncial; petals 5, aestivation various,

58

P.F. Stevens

anthers 1–5.5 mm long, porose or not, glands large, spherical, or becoming strongly crateriform, or tubular; carpels 3–6, ∞ ovules/carpel, style short, stigma moderately expanded; fruit septicidal, seeds often with a tuft of hairs at one end, testa simple, exotegmen present, embryo < 1 mm long, cotyledons 1/2–2/3 its length; germination epigeal. Circa 40 species, many undescribed, Central America, the Caribbean, and northwestern South America; usually below 1,000 m. 3. Mahurea Aublet Mahurea Aublet, Hist. Pl. Guiane 1:558 (1775); Kubitzki, Mem. New York Bot. Gard. 29:131–138 (1978).

Trees; hairs unicellular; terminal bud perulate, colleters present; leaves spiral, secondary veins distant, tertiaries often scalariform; inflorescences terminal, with ∞ flowers; sepals 5, quincuncial; petals 5, contorted; anthers 1.2–2 mm long, gland large, becoming deeply crateriform; carpels 3(4), ∞ ovules/carpel, stigma moderately expanded; fruit septicidal, seeds winged, testa simple, exotegmen present, embryo c. 1.5 mm long, cotyledons 1/2–2/3 its length; germination unknown. Two species, the Guyanas, Venezuela and northern Brazil; low to moderate alt. 4. Clusiella Planchon & Triana Clusiella Planchon & Triana, Ann. Sci. Nat. Bot. IV, 14:253 (1860); Hammel, Novon 9:349 (1999), rev.

Trees, epiphytes or lianes; glabrous; terminal bud perulate, single interpetiolar stipuliform structure; secondary veins rather close, tertiaries obscure, also canals; plant dioecious; inflorescences pseudo-axillary, with 1–15 flowers, prophylls and all or some sepals with a prominent abaxial gland; sepals 5, quincuncial; petals 5, contorted; anthers < 1 mm long, gland 0; carpels 5–15, placentation laminar, ∞ ovules/loculus, funicles long, style 0, stigmas expanded, ± separate; fruit a many-seeded berry, testa simple, exotegmen present, embryo < 2 mm long, cotyledons ± 2/3 its length; germination unknown. Seven species, Central America and tropical South America; low alt. 5. Kielmeyera Mart. Kielmeyera Mart. & Zucch., Flora 8:30 (1825); Saddi, Comp. ext. morph. studies genus Kielmeyera (1989); Saddi, O genero Kielmeyera na flora de Mato Grosso (1996).

Small trees, sometimes little branched, or sprouting from a enlarged rootstock; glabrous, or hairs unicellular, sometimes fasciculate or uniseriate; terminal bud perulate, colleters present; leaves spiral, secondary veins distant, fine venation reticulate; inflorescences terminal, 3–∞ flowers; sepals 5, quincuncial; petals 5, contorted; anthers 1–2.5 mm long, locellate or not, gland sometimes subcrateriform, present or not; carpels (2)3, ∞ ovules/carpel, stigma expanded; fruit septicidal; seeds winged, testa with scalariform layer, exotegmen absent, embryo 10–25 mm long, flattened, cotyledons huge, cordate; germination epigeal (?always). Forty-seven species, overwhelmingly Brazilian; low alt. 6. Caraipa Aublet Caraipa Aublet, Hist. Pl. Guiane 1:561 (1775); Kubitzki, Mem. New York Bot. Gard. 29:82–131 (1978).

Trees; hairs stellate, sometimes unicellular or uniseriate; terminal bud perulate or not, colleters present; leaves spiral or distichous, secondary veins distant, tertiaries often scalariform. Inflorescences terminal and axillary, with 3–∞ flowers; sepals 5, quincuncial; petals 5, contorted; anthers < 2.5 mm long, gland large, becoming crateriform, rarely absent; carpels 3, 1–4 ovules/carpel, style long, stigma expanded; fruit septifragal; seeds narrowly winged or not, embryo > 6 mm long, flattened, exotegmen 0, cotyledons huge, cordate; germination epigeal. Circa 28 species, from Brazil (most) to Peru, Colombia, Venezuela and the Guianas; low to moderate alt. One undescribed species lacks glands on the anthers. 7. Haploclathra Bentham Haploclathra Bentham, J. Proc. Linn. Soc., Bot. 5:58 & 64 (1860); Lleras, Mem. New York Bot. Gard. 22:129–136 (1972).

Trees; hairs unicellular, branched or multicellular, uniseriate; terminal bud not perulate, colleters present; secondary veins distant, tertiaries scalariform; inflorescences terminal, with ∞ flowers; sepals 5, quincuncial; petals 5, contorted; anthers 1.5–5 mm long, locellate, eglandular; carpels 3, 1–2 ovules/carpel, style short, stigma expanded; fruit septifragal; seeds narrowly winged, testa complex, exotegmen absent, embryo > 9 mm long, flattened, cotyledons huge, cordate. Four species, Brazilian Amazonas and Peru; low alt.


8. Poeciloneuron Beddome Poeciloneuron Beddome, J. Linn. Soc., Bot. 8:267, pl. 17 (1865).

Trees; hairs unicellular; stipuliform structures present; terminal bud perulate, colleters present or not; petiole base excavated; secondary veins distant, fine venation reticulate; inflorescences axillary or terminal, with 1–∞ flowers; sepals 4, decussate, or 5, imbricate; petals 6, ± imbricate, or 5, contorted; anthers 2.5–6 mm long, porose, locellate or not, eglandular; carpels 2, 2 ovules/carpel, stylodia free, long, stigma punctiform; fruit septicidal (?septifragal); testa complex, exotegmen absent, embryo 1–3 cm long, cotyledons huge, germination hypogeal or epigeal. Three species, Western Ghats of India; medium alt. P. pauciflorum Beddome very distinct, but poorly known. 9. Mesua L. Mesua L., Sp. Pl.: 515 (1753).

Trees; plant glabrous or hairs unicellular; terminal bud aborting, axillary buds immersed, colleters not obvious; secondary veins rather close, fine venation closely reticulate. Flowers single, axillary, or in 2–6-flowered axillary inflorescences; sepals 4, decussate, or 5, quincuncial; petals 4 or 5; anthers 1.5–4 mm long, with obscure glands in connective or not; carpels 2, 2 ovules/carpel, style long, stigma peltate; fruit septifragal, septae woody, persistent; testa complex, exotegmen absent, embryo 1.2–2.5 cm long, cotyledons huge, germination hypogeal. Five species, Sri Lanka and the Western Ghats of India (4 spp. only from there) to Sumatra; usually low alt. M. ferrea L. throughout the range, long introduced (and problematic taxonomically) in Java, widely cultivated elsewhere. 10. Kayea Wall. Kayea Wall., Pl. Asiat. Rar. 3:5, t. 10 (1832).

Tree; plant glabrous, but stem often papillate; terminal bud perulate, colleters present; secondary veins usually distant, fine venation closely reticulate. Inflorescences terminal and axillary, (1–)5–∞ flowers; sepals 4, decussate, outer pair connate or not; petals 4, aestivation various; anthers < 1 mm long, gland large or absent; carpels (3)4, 1–3 ovules/carpel, basal, septae not developed, style long, usually shortly divided at the apex, stigmas

59

punctate; fruit capsular, usually surrounded by massively accrescent calyx; testa complex, exotegmen absent, embryo > 5 mm long, cotyledons huge, (sub)peltate, germination hypogeal. Circa 75 species, many undescribed, one species in Sri Lanka, the rest northeast India to Australia; low (moderate) alt. Most diverse in western Malesia.

11. Mammea L. Mammea L., Sp. Pl.: 512 (1753). Paramammea Leroy (1977).

Trees, sometimes unbranched and schopfbaum; plant glabrous; terminal bud perulate; colleters present; leaves rarely spiral, secondary veins distant, fine venation reticulate, resin canals also rarely present; plant dioecious, inflorescences axillary, fasciculate; sepals 2, connate; petals 4–6, aestivation various; anthers 0.6–4 mm long, glands large and single, to small or absent; carpels 2(4), 2(4) ovules/carpel (ovary 8-locular), style short, stigma peltate; fruit a fibrous berry, rarely a septifragal capsule; testa complex, exotegmen absent, embryo ≤ 1.2 cm long, cotyledons massive, sometimes connate, germination hypogeal. Circa 75 species, many undescribed, 2 species in Central America, 3 species in Africa, the others from Madagascar (the center of diversity) to the Pacific and New Caledonia; low to medium alt. The plants appear to be andromonoecious.

12. Calophyllum L.

Fig. 13

Calophyllum L., Sp. Pl.: 513 (1753); Stevens, J. Arnold Arb. 61:117–699 (1980), rev.

Trees; hairs multicellular; terminal bud perulate or not, colleters absent; secondary veins closely parallel, alternating with canals, glands 0; inflorescences axillary, rarely terminal, (1–)3–∞ flowers, prophylls absent; sepals 4, decussate; petals like sepals, 0–8, aestivation various; anthers 0.4–2.5 mm long, gland absent; carpels ?2–?4, ovule single, basal, septae absent, style usually long, stigma moderately expanded to peltate; fruit a fibrous one-seeded berry; testa complex, exotegmen absent, embryo (3–)6 mm long, cotyledons massive; germination hypogeal. Circa 186 species, c. 10 species in the American tropics, the rest from Madagascar to the Pacific; low (moderate) alt.

60

P.F. Stevens

sate; petals 4, contorted; stamens 9–12/fascicle, filaments free; embryo ?1.5–2.2 cm long. One species, L. bushaie Staner, western tropical Africa; low alt. II. Subfam. Clusioideae Engler (1888). Plant usually glabrous; lamina with canals (glands), veins usually embedded; plant dioecious (flowers perfect); anthers usually lacking glands; filaments usually stout; style or stylodia short or none; cotyledons 1 cm long, cotyledons < 1|20 its length. 22. Pentadesma Sabine Pentadesma Sabine, Trans. Hort. Soc. 4:457 (1824); van Meer, Bull. Jard. Bot. Etat Brux. 35:411–433 (1965).

Inflorescence with 3–15 flowers; petals broad; ∞ stamens/fascicle, filaments smooth, only slightly connate, anthers 7–16 mm long, locellate; ∞ ovules/carpel; exotegmen absent; germination garcinioid. Five species, Mali to Zaire and Ruanda; low alt. 23. Moronobea Aublet Fig. 16. Clusiaceae. Garcinia hunsteinii. A Flowering branch. B Flower. C Male flower, perianth removed. D Two stamen fascicles. E Anther. F Pistil of female flower. G Stigma, seen from above. H Ovary, transversally sectioned. I Branchlet with two fruits, one of which vertically sectioned. J Seed. (Lauterbach 1922)

Moronobea Aublet, Hist. Pl. Guiane 2:788, t. 313 (1775).

Flowers single; petals usually broad, erect; 3–4 stamens/fascicle, spiral, filaments papillate, anthers 18–25 mm long, locellate; 3–10 ovules/carpel, style medium; exotegmen present; germination


hypogeal. Seven species, Brazil, the Guyanas, Venezuela, Colombia; low to medium alt. 24. Platonia Mart.

63

papillate or not, anthers 4–20 mm long; 12–∞ ovules/carpel; exotegmen present; germination unknown. Five species, New Caledonia; low alt.

Fig. 17

Platonia Mart., Nov. Gen. Sp. 3:168, t. 289 (1829).

26. Lorostemon Ducke

Fig. 18

Flowers single; petals broad; ∞ stamens/fascicle, filaments papillate, anthers 8–11 mm long, ± locellate; ∞ ovules/carpel, style long; exotegmen absent, germination hypogeal. One species, P. insignis Mart., Guyanas, Brazil; low alt.

Lorostemon Ducke, Arq. Int. Biol. Veg. Rio de Janeiro 1:210 (1935).

Montrouziera Planchon & Triana, Ann. Sci. Nat. IV, Bot. 14:292 (1860).

Flowers single; petals narrow; 3–13 stamens/fascicle, filaments papillate or not, anthers 10–40 mm long; ovary long-stipitate or not, 12–∞ ovules/carpel; style not branched; exotegmen usually present; germination not known. Five species, South America; low (moderate) alt. Poorly known.

Inflorescence with 1–5 flowers, sometimes axillary; petals broad; 3–10 stamens/fascicle, filaments

27. Thysanostemon Maguire

25. Montrouziera Planchon & Triana

Thysanostemon Maguire, Mem. New York Bot. Gard. 10:132 (1964).

Fig. 17. Clusiaceae. Platonia insignis. A Flower buds. B Flower in anthesis. C Flower with perianth removed, showing phalanges and style with style branches. D Vegetative branch tip. E Two fruits, in one the pericarp partly removed. F Seed. (Cavalcante 1972)

Fig. 18. Clusiaceae. Lorostemon bombaciflorum. A Flowering branch. B Flower. C Stamen fascicle, ventral and dorsal view. D Pistil. E Ovary, transversally sectioned. F Fruit. G Seed. (Ducke 1935)

64

P.F. Stevens

Stipuliform stuctures not seen; flowers single; petals narrow; 4–6 stamens/fascicle, filaments papillate, anthers 8–9 mm long; c. 4 ovules/carpel; exotegmen absent; germination not known. Two species, Venezuela; low to moderate alt. Poorly known.

ovules/carpel; testa fibrous, exotegmen absent; germination garcinioid. Circa 23 species, tropical America, Africa, most diverse in Madagascar, S. globulifera L. f. widespread and variable; low to medium alt.

28. Symphonia L. f.

Selected Bibliography

Fig. 19

Symphonia L. f., Suppl.: 49 & 303 (1781); H. Perrier, Fl. Madag. Comores 135e & 136e fam.: 13–31 (1951).

Inflorescences with 3–9 flowers (axillary); petals broad; androgynophore absent; fascicles connate, 3–6 stamens/fascicle, filaments smooth, anthers 1.7–5 mm long, extrorse, connective with glands, a low annular nectary outside androecium; 4–8

Fig. 19. Clusiaceae. Symphonia globulifera. A Flowering branch. B Flower. C Flower with petals removed. D Same with perianth and most of staminal tube removed. E As D, but showing ovary in transversal section. F Fruit. G Seed. (Robson 1961)

Anderberg, A.A., Rydin, C., Källersjö, M. 2002. Phylogenetic relationships in the order Ericales s.l.: analyses of molecular data from five genes from the plastid and mitochondrial genomes. Amer. J. Bot. 89:677–687. Armbruster, W.S. 1984. The role of resin in angiosperm pollination: ecological and chemical considerations. Amer. J. Bot. 71:1149–1160. Baretta-Kuipers, T. 1976. Comparative wood anatomy of Bonnetiaceae, Theaceae and Guttiferae. In: Baas, P., Bolton, A.M., Catling, D.M. (eds), Wood structure in biological and technological research. Leiden Botanical Series 3, pp. 76–101. Barth, O.M. 1980. Morfologia do pólen e palinotaxinomia do género Kielmeyera (Guttiferae). Rodriguesia 32, 55:105–133. Bennett, G.J., Lee, H.-H. 1989. Xanthones from Guttiferae. Phytochemistry 28:967–998. Bittrich, V., Amaral, M. do C.E. 1996. Flower morphology and pollination biology of some Clusia species from the Gran Sabana (Venezuela). Kew Bull. 51:681–694. Bittrich, V., Amaral, M. do C.E. 1997. Flower biology of some Clusia species from Central Amazonia. Kew Bull. 52:617–635. Brandza, G. 1908. Recherches anatomiques sur la germination des Hypéricacées et des Guttifères. Ann. Sci. Nat. IX, Bot. 8:221–300, pls 5–15. Carmo, R.M., Franceschinelli, E.V. 2002. Pollinação e biologia floral de Clusia arrudea Planchon & Triana (Clusiaceae) na Serra da Calçada, município de Brumadinho, MG. Revista Brasil. Bot. 25:351–360. Carr, G.D., McPherson, G. 1986. Chromosome numbers of New Caledonian plants. Ann. Missouri Bot. Gard. 73:486–489. Cavalcante, P.B. 1972. Frutas comestiveis da Amazônia, I. Belém, Pará: Museu Paraense Museu Goeldi. Chase, M.W. et al. 2003. See general references. Chennaveeraiah, M.S., Radzan, M.K. 1980. Karyomorphological and phytochemical studies in evaluating species relationships in Garcinia L. and systematic position of the G. xanthochymus complex. J. Indian Bot. Soc. 59:251–262. Corner, E.J.H. 1976. See general references. Correia, M.C.R., Ormond, W.T., Pinheiro, M.C.B., De Lima, H.A. 1993. Estudo de biologia floral de Clusia criuva Camb. Um caso de mimetismo. Bradea 6:209–219. Crepet, W.L., Nixon, K.C. 1998. Fossil Clusiaceae from the Late Cretaceous (Turonian) of New Jersey and implications regarding the history of bee pollination. Amer. J. Bot. 85:1122–1133. Croat, T.B. 1978. Flora of Barro Colorado Island. Stanford: Stanford University Press. Cronquist, A. 1981. See general references.

Clusiaceae-Guttiferae da Cruz, N.D., Sellito Boaventura, V.M., Sellito, Y.M. 1990. Cytological studies on some species of the genus Clusia L. (Guttiferae). Revista Brasil. Genet. 13:335–345. Davis, C.R., Chase, M.C. 2004. Elatinaceae are sister to Malpighiaceae; Peridiscaceae belong to Saxifragales. Amer. J. Bot. 91:262–274. Delay, C., Mangenot, G. 1960. Le développement de la graine chez Allanblackia floribunda Oliv. Ann. Sci. Nat. XII, Bot. 1:387–440. Delle Monache, F., Delle Monache, G., Gáes-Baitz, E. 1991. Chemistry of the Clusia genus. Part 6. Prenylated benzophenones from Clusia sandiensis. Phytochemistry 30:2003–2005. Dick, C.W., Abdul-Salim, K., Bermingham, E. 2003. Molecular systematic analysis reveals cryptic Tertiary diversification of a widespread tropical rain forest tree. Amer. Naturalist 162:691–703. Ducke, A. 1935. Plantes nouvelles ou peu connues de la région amazonienne (VIIème série). Arq. Inst. Biol. Veg. Rio de Janeiro 1:205–212. Dunthorn, M.S. 2002. Anatomy and palynology of Mammea L. (Clusiaceae). M.Sc. Thesis, University of Missouri, St. Louis. Dunthorn, M.S. 2004. Cryptic dioecy in Mammea (Clusiaceae). Pl. Syst. Evol. 249:191–196. Engler, A. 1888. Guttiferae and Quiinaceae. In: Urban, I. (ed.) Flora Brasiliensis, vol. 12, 1. Leipzig: Fleischer, pp. 382–486, pls 79–110. Engler, A. 1925. Guttiferae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, vol. 21. Leipzig: W. Engelmann, pp. 154–237. Erbar, C. 1986. Untersuchungen zur Entwicklung der spiraligen Blüte von Stewartia pseudocamellia (Theaceae). Bot. Jahrb. Syst. 106:391–407. Exell, A.W., Robson, N.K.B. 1960. New species of Polygala and Garcinia from tropical Africa. Bol. Soc. Brot. II, 34:93–97. Field, B.S. 1978. Theaceae. In: Heywood, V.H. (ed.) Flowering plants of the world. New York: Mayflower Press, pp. 82–83. Fosberg, F.R. 1977. A fossil Garcinia fruit from the New Hebrides, Melanesia. Pacific Sci. 31:293–297. Gonçalves-Esteves, V., Mendonça, C.B.F. 2001. Estudo polínico em plantas de restinga do Estado do Rio de Janeiro – Clusiaceae Lindl. Revista Brasil. Bot. 24:527–536. Gustafsson, M.H.G. 2000. Floral morphology and relationships of Clusia gundlachii with a discussion of floral organ identity and diversity on the genus Clusia. Intl J. Pl. Sci. 161:43–53. Gustafsson, M.H.G., Bittrich, V. 2002. Evolution of morphological diversity and resin secretion in flowers of Clusia (Clusiaceae): insights from ITS sequence variation. Nordic J. Bot. 22:183–203. Gustafsson, M.H.G., Bittrich, V., Stevens, P.F. 2002. Phylogeny of Clusiaceae based on rbcL sequences. Intl J. Pl. Sci. 163:1045–1054. Hegnauer, R. 1966. See general references. Jones, S.J. 1980. Morphology and major taxonomy of Garcinia (Guttiferae). Ph.D. Thesis, University of Leicester. Kawano, S. 1965. Anatomical studies on the androecia of some members of the Guttiferae – Moronoboideae. Bot. Mag. Tokyo 78:97–108.

65

Kubitzki, K. 1978. Caraipa and Mahurea (Bonnetiaceae). In: Maguire, B. and Collaborators, The botany of the Guyana Highlands, part X, pp. 82–138. Mem. New York Bot. Gard. 29:1–832. Kubitzki, K. 1989. The ecogeographical differentiation of Amazonian inundation-forests. Pl. Syst. Evol. 162:285– 304. Kubitzki, K., Mesquita, A.A.L., Gottlieb, O.R. 1978. Chemosystematic implications of xanthones in Bonnetia and Archytaea. Biochem. Syst. Ecol. 6:185–187. La Mensbruge, G. de 1966. La germination et les plantules des essences arborées de la fôret dense humide de la Côte d’Ivoire. Nogent-sur-Marne: Centre Technique Forestier Tropical. Lauterbach, C. 1922. Beiträge zur Flora von Papuasien. IX. Die Guttiferen Papuasiens. Bot. Jahrb. Syst. 58:1–49. Lim, A.L. 1984. The embryology of Garcinia mangostana L. (Clusiaceae). Gard. Bull. Singapore 37:93–103. Lopes, A.V., Machado, I.C. 1998. Floral biology and reproductive ecology of Clusia nemorosa (Clusiaceae) in northeastern Brazil. Pl. Syst. Evol. 213:71–90. Lüttge, U. 1999. One morphotype, three physiotypes: sympatric species of Clusia with obligate C3 photosynthesis, obligate CAM, and C3-CAM intermediate behavior. Pl. Biol. 1:138–148. Lüttge, U. 2002. The genus Clusia L.: molecular evidence for independent evolution of photosynthetic flexibility. Pl. Biol. 4:86–93. Maguire, B. 1972. Bonnetiaceae and Tetrameristaceae. In: Maguire, B. and Collaborators, The botany of the Guyana Highlands, part IX, pp. 131–192. Mem. New York Bot. Gard. 23:1–832. Maguire, B. 1976. Apomixis in the genus Clusia (Clusiaceae) – a preliminary report. Taxon 25:241–244. Maués, M.M., Venturieri, G.C. 1996. Ecologia de polinização do Bacurizeiro (Platonia insignis Mart.) Clusiaceae. Bol. Pesquisa 170:1–24. McKee, A.C., Covington, C.D., Fuller, R.W., Bokesch, H.R., Young, S., Cardellina, J.H. II, Kadushin, M.R., Soejarto, D.D., Stevens, P.F., Cragg, G.M., Boyd, M.R. 1996. Pyranocoumarins from tropical species of the genus Calophyllum: a chemotaxonomic study of extracts in the National Cancer Institute collection. J. Nat. Prod. 61:1252–1256. Melchoir, H. 1930. Decaphalangium, eine neue Gattung der Guttiferen aus Peru. Notizbl. Bot. Gart. Mus. BerlinDahlem 10:946–950. Mesquita, R. de C.G., Franciscon, C.H. 1995. Flower visitors of Clusia nemorosa G.F.W. Meyer (Clusiaceae) in an Amazonian white-sand campina. Biotropica 27:254– 257. Metcalfe, C.R., Chalk, L. 1950. See general references. Mori, S.A., Cremers, G., Gracie, C., de Granville, J.J., Heald, S.V. et al. 2002. Guide to the vascular plants of central French Guiana. Part 2. Dicotyledons. Mem. New York Bot. Gard. 76, 2:1–900. Mourão, K.S.M., Beltrati, C.M. 1996a. Morfologia dos frutos, sementes e plântulas de Platonia insignis Mart. (Clusiaceae). I. Aspectos anatômicos dos frutos e sementes em desenvolvimento. Acta Amazonia 25:11–31. Manaus: Instituto Nacional de Pesquisas da Amazônia. Mourão, K.S.M., Beltrati, C.M. 1996b. Morfologia dos frutos, sementes e plântulas de Platonia insignis Mart.

66

P.F. Stevens

(Clusiaceae). II. Morfo-anatomia dos frutos e sementes maduros. Acta Amazonia 25:33–46. Manaus: Instituto Nacional de Pesquisas da Amazônia. Mourão, K.S.M., Beltrati, C.M. 2000. Morphology and anatomy of developing fruits and seeds of Mammea americana L. (Clusiaceae). Revista Brasil. Biol. 60:701–711. Muller, J. 1981. Fossil pollen records of extant angiosperms. Bot. Rev. 47:1–142. Müller-Stoll, W.R., Mädel-Angeliewa, E. 1986. Ein neues Guttiferenholz aus dem Tertiär von Java, Calophylloxylon intermedium sp. nov. Feddes Repert. 97:225–233. Nogueira, P.C. de L., Marsaioli, A.J., Amaral, M. do C.E., Bittrich, V. 1998. The fragrant oils of Tovomita species. Phytochemistry 49:1009–1112. Notis, C. 2004. Phylogeny and character evolution of Kielmeyeroideae (Clusiaceae) based on molecular and morphological data. M.Sc. Thesis, University of Florida, Gainesville. Oliveira, P.E.A.M. de, Sazima, K. 1990. Pollination biology of two species of Kielmeyera (Guttiferae) from Brazilian cerrado vegetation. Pl. Syst. Evol. 172:35–49. Oliveira, C.M.A., Porto, A.L.M., Bittrich, V., Vencato, I., Marsaioli, A.J. 1996. Floral resins of Clusia spp.: chemical composition and biological function. Tetrahedron Lett. 37:6427–6430. Owen, P.T., Scheinmann, F. 1974. Extractives from Guttiferae, XXVI. Isolation and extraction of six xanthones, a biflavanoid, and triterpenoids from the heartwood of Pentaphalangium solomonse [sic]. J. Chem. Soc. Perkins Trans. 1 1974:1018–1021. Pascarella, J.B. 1992. Notes on flowering phenology, nectar robbing, and pollination of Symphonia globulifera L. f. (Clusiaceae) in a lowland rain forest in Costa Rica. Brenesia 38:83–96. Passos, L., Oliveira, P.S. 2002. Ants affect the distribution and performance of seedlings of Clusia criuva, a primarily bird-dispersed rain forest tree. J. Ecol. 90:517– 528. Paula, J.E. de 1976. Anatomia de Lorostemon coelhoi Paula, Caraipa valioli Paula e Clusia aff. macropoda Klotzsch (Guttiferae da Amazônica). Acta Amazonia 6:273–291. Manaus: Instituto Nacional de Pesquisas da Amazônia. Perrier de la Bâthie, H. 1951. 136e famille Guttifères (Guttiferae). In: Humbert, H. (ed.) Flore de Madagascar et des Comores. Paris: Firmin-Didot. Petterson, S., Ervik, F., Knudsen, J.T. 2004. Floral scent of bat-pollinated species: West Africa vs. the New World. Biol. J. Linn. Soc. 82:161–168. Pierre, J.B.L. 1883–1885. Flore forestière de la Cochinchine, fasc. 5-7. Paris: Octave Doin. Planchon, J.E., Triana, J. 1860. Mémoire sur la famille des Guttifères. Ann. Sci. Nat. IV, Bot. 13:306–376, pls 15, 16. Planchon, J.E., Triana, J. 1862. Ibid. Ann. Sci. Nat. IV, Bot. 16:263–308. Porto, A.M., Machado, S.M.F., Oliveira, C.M.A., Bittrich, V., Amaral, M.C.E., Marsaioli, A.J. 2000. Polyisoprenylated benzophenones from Clusia floral resins. Phytochemistry 55:755–768. Presting, D., Straka, H., Friedrich, B. 1983. Palynologica Madagassica et Mascarenica. Familien 128 bis 146. Trop.-subtrop. Pflanzenwelt 44, 93 pp. Mainz: F. Steiner.

Ramirez, B.W., Gomez, P.L.D. 1978. Production of nectar and gums by flowers of Monstera deliciosa (Araceae) and some species of Clusia (Guttiferae) collected by New World Trigona bees. Brenesia 14–15:407–412. Ramji, M.V. 1967. Morphology and ontogeny of the foliar venation of Calophyllum inophyllum L. Austral. J. Bot. 15:437–443. Richards, A.J. 1990a. Studies in Garcinia, dioecious tropical forest trees: agamospermy. Bot. J. Linn. Soc. 103:233– 250. Richards, A.J. 1990b. Studies in Garcinia, dioecious tropical forest trees: the phenology, pollination biology and fertilization of G. hombroniana Pierre. Bot. J. Linn. Soc. 103:251–261. Richards, A.J. 1990c. Studies in Garcinia, dioecious tropical forest trees: the origin of the mangosteen (G. mangostana L.). Bot. J. Linn. Soc. 103:301–308. Robson, N.K.B. 1961. Guttiferae. In: Exell, A.W., Wild, H. (eds) Flora Zambesiaca, vol. 1, 2. London: Crown Agents for Oversea Governments and Administrations, pp. 378–404. Robson, N.K.B. 1978. Guttiferae. In: Heywood, V.H. (ed.) Flowering plants of the world. New York: Mayflower Books, pp. 85–87. Rodrigues, C.M.C., Teixeira Osmond, W., Pinheiro, M.C.B., Lima, H.A. de 1999. Biologia de reprodução de Clusia lanceolata Camb. Hohnea 26:61–73. Saddi, N. 1989. Comparative external morphological study in the genus Kielmeyera Martius (Guttiferae). Publ. Avuls. Herb. Central 2, Cuiabá. Schlechter, R. 1906. Beiträge zur Flora von Neu-Kaledonien. Bot. Jahrb. Syst. 39:1–274. Schofield, E.K. 1968. Petiole anatomy of the Guttiferae and related families. Mem. New York Bot. Gard. 18:1–55. Seetharam, Y.N. 1985. Clusiaceae: palynology and systematics. Institut Franç. Pondichéry: Travaux de la section Scientifique et Technique, t. 21. Seetharam, Y.N., Maheshwari, J.K. 1986. Scanning electron microscopic studies on the pollen of some Clusiaceae. Proc. Indian Acad. Sci. (Pl. Sci.) 96:217–226. Spruce, R. 1855. Note on Clusiaceae. Hooker’s J. Bot. Kew Gard. Misc. 7:347–348. Stevens, P.F. 1980. A revision of the Old World species of Calophyllum (Guttiferae). J. Arnold Arb. 61:117–699. Stevens, P.F. 2005. See general references. Stevens, P.F., Weitzman, A.L. 2004. Sladeniaceae. In: Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. VI. Flowering Plants: Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales. Berlin Heidelberg New York: Springer, pp. 431–433. Stevens, P.F., Dressler, S., Weitzman, A.L. 2004. Theaceae. In: Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. VI. Flowering Plants: Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales. Berlin Heidelberg New York: Springer, pp. 473–471. Taylor, H.L., Brooker, R.M. 1969. Isolation of uliginosin A and uliginosin B from Hypericum uliginosum. Lloydia 32:217–219. Vesque, J. 1889. Epharmosis, sive materiae ad instruendam anatomiam systematis naturalis. 2. Genitalia foliaque Garcinearum et Calophyllearum. Vincennes: Delapierre.

Combretaceae Combretaceae R. Br., Prodr.: 351 (1810), nom. cons.

C.A. Stace

Trees, shrubs, subshrubs or lianes, sometimes mangroves, rarely spiny. Indumentum almost always of unicellular, slender, thick-walled, pointed hairs with a distinctive basal compartment (‘Combretaceous hairs’) alone or with glandular hairs of one (or rarely both) of two types – short, capitate stalked glands, and subsessile peltate scales. Leaves opposite (or whorled) or spiral, petiolate, simple, entire, with pinnate venation, often with a pair of petiolar glands or domatia; stipules 0 or vestigial. Inflorescence axillary or terminal, capitate to expanded, of simple or paniculate spikes or less often racemes. Flowers with simple, usually caducous bracts, bisexual, or bisexual and male in same inflorescence, or rarely dioecious, 4- to 5-merous, actinomorphic, or sometimes weakly zygomorphic, epigynous or rarely semi-epigynous; hypanthium (receptacle) surrounding ovary (lower hypanthium) and extended beyond into saucer- to tube-shaped upper hypanthium, with 2 prophylls fused to lower hypanthium in Laguncularieae; sepals 4–5(–8), borne at tip of upper hypanthium, sometimes vestigial, rarely accrescent; petals 4–5, usually borne at or near tip of upper hypanthium, often small, sometimes conspicuous, or often 0; stamens usually twice as many as sepals (rarely to 16), borne inside upper hypanthium usually at two levels, sometimes as many as sepals, rarely second whorl represented by staminodes, exserted or included, with dorsifixed, usually versatile, rarely adnate, 4-locular anthers; nectariferous disk often present at base of upper hypanthium; ovary 1-locular; ovules (1)2–7(–20) (usually 2), apical, pendulous, anatropous, bitegmic, crassinucellate; style simple, with usually punctiform stigma. Fruit 1-seeded, indehiscent or rarely tardily dehiscent, with dry or spongy to succulent wall, often with 2–5 papery to leathery wings; endosperm absent in mature seed; cotyledons usually 2(–5) or fused to appear 1, variously folded or twisted in seed, rarely flat or hemispherical.

A pantropical family with 14 genera and c. 500 species. Characters of Rare Occurrence. Mangroves: Lumnitzera, Laguncularia (Conocarpus mangrove-associate) Branches spiny: Terminalia (former Bucida), some Combretum Semi-inferior ovary: Strephonema Slightly zygomorphic flowers: some Combretum (including former Calopyxis), Lumnitzera littorea, Dansiea Dioecious flowers: Combretum rupicola, Conocarpus (± so), Laguncularia (± so) Andromonoecious flowers: many Terminalia, Pteleopsis Markedly accrescent calyx: Calycopteris Only one whorl of stamens: Terminalia tetrandra, some Combretum (former Thiloa and Meiostemon) Staminodes representing one whorl of stamens: Combretum gracile, some flowers of the variably dioecious species and of Lumnitzera littorea Stamens with adnate anthers: Buchenavia Ovules often more than 8: Macropteranthes, Dansiea Tardily dehiscent fruits: Combretum (former Quisqualis) Fruit-wings derived from prophylls: Macropteranthes, Dansiea Cotyledons flat, not folded: Strephonema, Combretum sects. Cacoucia (some) and Calopyxis (some) Cotyledons fused: some Combretum Three or more cotyledons: some Terminalia Vegetative Morphology. All species of Combretaceae are woody, varying from tall timber trees or lianes (mostly in forest) to short shrubs or subshrubs (in savannah). A few species possess stem thorns. In the fire-prone savannahs of Africa and India, there are about 20 species of subshrub in the genus Combretum: plants with large underground ‘trunks’ putting up annual aerial shoots

68

C.A. Stace

which are burnt to the ground during the dry season. These species belong to four different sections of the genus (Keay 1950), in two cases together with forest scandent shrub and liane species, and in the other two cases together with savannah tree and shrub species. Some of the shrubs develop into lianes or ‘scrambling shrubs’ if left ungrazed and provided with a support. The lianes often climb over 30 m high, especially in the genus Combretum, while the smallest subshrubs do not exceed 20 cm. Combretum species are mostly subshrubs, shrubs or lianes, with very few trees (exceptionally, C. leprosum and C. glaucocarpum up to 25 m in Brazil). The largest trees are over 50 m tall and are found in the genera Terminalia and Buchenavia; buttresses are present in several species. Corner (1940) described the characteristic ‘pagoda-trees’ of Malaya, belonging to nine different families, in which the main branches are held in horizontal tiers with the leaves in flat bunches dispersed over the top side of each tier. This growth habit is so characteristic of several species of Terminalia (notably, T. catappa) that Corner termed the sympodial branching pattern which gives rise to it as “Terminalia-branching”. Two genera are true mangroves: Lumnitzera from East Africa to Australia and Laguncularia in West Africa and East and West America. Both develop characteristic pneumatophores – in Lumnitzera, these are looped above the mud (‘knee-roots’) whereas in Laguncularia they are simple or branched projections from the mud

Fig. 20. Combretaceae. Old specimen of Conocarpus erectus in a dune-valley of Peninsula de Paraguaná, Caribbean. (Phototograph K. Kubitzki)

(‘peg-roots’). Fruit-vivipary is, however, scarcely exhibited; in Laguncularia, the radicle is reported barely to pierce the seed-coat while the fruit is still on the tree. In addition, Conocarpus erectus, with a distribution similar to Laguncularia, is often considered a mangrove, but its lack of vivipary or pneumatophores suggests that it is best considered a ‘mangrove-associate’ (Fig. 20). Some Terminalia species are also mangrove-associates. Terminalia cuneata (India) is not one of these, but it sometimes produces erect pneumatophore-like aerial roots when the root-system is submerged (Adamson 1910). The leaves of Combretaceae are evergreen or deciduous, according to the vegetation type the plants inhabit. In some genera, notably Buchenavia, they are clustered in dense spirals at the swollen tips of twigs. A pair of sessile secretory glands is present in many species, particularly Terminalia, Buchenavia, Laguncularia and Conocarpus; their presence and position are of diagnostic value. Klucking (1991) presented an extensive survey of leaf venation in the family, providing many excellent illustrations, covering 11 genera and 223 species. His study, however, lacks an analytical element and, in several cases, specimens under different names for the same species (e.g. Terminalia amazonia and T. obovata) fell into different categories of venation pattern. Alwan (1983) covered 144 species in all 13 genera. Using the terminology of Hickey (1973), he recognized six major types within this broad pattern, five of them representing grades from brochidodromous to eucamptodromus, and the sixth being craspedodromous. There seems to be no taxonomic correlation of these types as high as genus level; all six types occur in Terminalia, and craspedodromous only in that genus. Many species bear foliar domatia – small pocket- or bowl-shaped pits in the axils of the main lateral leaf-veins on the lower leaf surface; they are particularly common in Terminalia, Buchenavia and Conocarpus, in which their presence and structure are species-constant. Pocket-shaped (‘marsupiiform’) domatia occur widely in Combretinae and Terminaliinae, but bowl-shaped (‘lebetiform’) ones are found only in the above three genera of Terminaliinae. In Strephonema, the leaves have marginal revolute domatia. Stipules are said in all floristic accounts to be absent from Combretaceae. Weberling, in Dahlgren

Combretaceae

and Thorne (1984), stated that they are present in “nearly all families of Myrtales”, although in Combretaceae he found them only as tiny “rudimentary finger-like projections” near the petiole base and only in a few of the species examined. Vegetative Anatomy. Leaves are usually dorsiventral, with no hypodermis but with 1–2 adaxial palisade layers and a broader spongy mesophyll (Tilney 2002). In the mangroves Laguncularia and Lumnitzera, in the related Macropteranthes and Dansiea to a slight degree (abaxial palisade weakly developed), in the mangrove-associate Conocarpus, and in a few other scattered taxa, the leaves have an isobilateral organization, with palisade on both sides and a central large-celled water-storage tissue; this is clearly an anatomical syndrome correlated with physiological drought (Stace 1966). Midrib structure is described by Keating (1984) and Tilney (2002). Stomata are usually present only on the lower epidermis, but are on both upper and lower surfaces in the species with fully isobilateral leaves and also in some species of Terminalia and other genera with coriaceous dorsiventral leaves. Stomata are basically anomocytic throughout the family, except in Strephonema where they are paracytic (Stace 1965). In the mangroves Lumnitzera and Laguncularia, the anomocytic stomata are cyclocytic. The trichomes of the Combretaceae are diagnostic. Non-glandular hairs are almost always in the form of ‘Combretaceous hairs’ – unicellular, pointed, very thick-walled hairs (leaving virtually no lumen) which possess a distinctive, often swollen basal compartment. Apart from Strephonema, these occur in all species (over 300) examined to date, except for the apparently completely glabrous Lummitzera littorea (but they do occur in L. racemosa). In Strephonema, they occur in S. mannii but not in the other two species (S. sericeum and S. pseudocola), where only 2armed thin-walled hairs usually with a basal compartment, as well as some intermediate forms, are present (Stace 1965). The 2-armed hairs were described by Heiden (1893) from Conocarpus, but I have been unable to confirm this. A few (taxonomically scattered) species possess some simple thin-walled hairs, among a predominance of Combretaceous hairs. Combretaceous hairs have elsewhere been reported only from a few Myrtaceae and Cistaceae (Solereder 1908). Glandular trichomes are of two main types: glandular hairs with a short uniseriate stalk (rarely

69

longer and multiseriate) and clavate or capitate head; and peltate scales, with a very short uniseriate stalk and a 1-cell-thick plate-like head consisting of eight to a few hundred cells (Fig. 24; Stace 1965). One or other type (extremely rarely both) is present in every species of all genera of subtribe Combretinae. The presence of these glandular trichomes, and the cell-delimitation of the scales, are extremely important taxonomic characters in this subtribe. Dome-shaped sessile glandular structures are found in Laguncularia at the base of deep, narrow-orificed pits found on both leaf surfaces, usually visible as a mound on the leaf surface. The superficially similar pits on the lower epidermis of Conocarpus do not contain glands and are best considered as domatia. In the latter genus, however, small stalked glands occur sparsely on both leaf surfaces; these resemble those of the Combretinae but they are perhaps related to the saline habitat of Conocarpus. In young twigs, the vascular bundles are bicollateral in almost all species examined (Dahlgren and Thorne 1984; Tilney 2002). Phloem islands (‘included phloem’) are present in the wood of only four of the six genera studied of subtribe Combretinae (van Vliet 1979). den Outer and Fundter (1976) found that both the periderm and the secondary phloem of Strephonema resemble those of the rest of the family in many characters, but differ in having type I sieve-tubes (types II or III in other genera) with longer elements than in all other genera. The sieve-tube element plastids are S-type throughout the family, as in the rest of Myrtales (Behnke 1984). Wood anatomy has been thoroughly surveyed by van Vliet (1979) and van Vliet and Raven (1984). Growth-rings are distinct or not, the wood being usually diffuse- but sometimes ring-porous, with parenchyma mostly paratracheal but often apotracheal or marginal, the first type varying from scanty to confluent-banded. Hence, virtually the whole spectrum of possibilities is covered. More interesting or unusual characters are the vestured pits, fibre-tracheids, radial vessels, ray-types, vessels of two distinct sizes, and included phloem. Strephonema differs from the other genera in having distinct aggregates (tangential bands) of apotracheal parenchyma, heterocellular rays of types II–III, vestured pits of type A (type B in rest of family) and fibre-tracheids (fibres with distinctly bordered pits, absent from rest of family). Subtribe Combretinae (all species examined) is characterized by two characters absent from the rest of the

70

C.A. Stace

family: vessels of two very distinct diameters, and uniseriate rays containing radial vessels with perforations in their tangential walls, those in the terminal elements connecting with very narrow axial vessels or tracheids. These radial vessels are, in fact, unique among all plants. Anatomy of the peg-roots of Laguncularia is described by Jeník (1970), and of normal roots of Combretum by Verhoeven and van der Schijff (1974). Inflorescence Structure. Weberling (1988) described the inflorescences as “polytelic throughout”, i.e. with indefinite growth, the inflorescence lacking a terminal flower. The commonest type of inflorescence is the spike, occurring in most genera including the two largest, Combretum and Terminalia (Figs. 22–24). Usually, the flowers are more or less sessile but in some cases they are shortly pedicellate, conspicuously so in Strephonema and Pteleopsis, forming a raceme. In most cases, the bracts are small and caducous but sometimes they persist and occasionally are large and conspicuous, presumably to attract pollinators, e.g. red in Combretum mussaendiflorum, white in C. racemosum. Variations occur in two directions. Firstly, the spikes (or racemes) are often branched, sometimes forming quite large compound spikes/racemes; this is common in several genera, including Combretum, but rare or absent in others, e.g. Terminalia and Buchenavia respectively. Secondly, the spikes may be congested (Exell 1962), in extreme cases forming apparent umbels (e.g. many Combretum, Guiera, some Terminalia, Pteleopsis) or cone-like structures (Conocarpus, Anogeissus, Finetia). Flower Structure. The common flower organization in the family includes an inferior 1-celled ovary with (1)2–7(–20) apical ovules leading to a 1seeded fruit and a tetramerous or pentamerous perianth with both 1-whorled calyx and corolla and an androecium of 1 or 2 stamen whorls. The hypanthium is usually divided into two parts: a lower one surrounding and fused to the ovary, and sometimes extended above it as a stalk-like support for the next (or the latter might be part of the next), and an upper one extended above it and bearing the sepals, petals and stamens. In Laguncularieae, there is scarcely any distinction between an upper and lower hypanthium. In Dansiea, the lower hypanthium is fused to the ovary only on one side.

Variation from this pattern is in four main directions: (1) loss of petals in virtually all Terminaliinae and some Combretinae; (2) loss of one whorl of stamens in some Combretum (former Thiloa, where the missing whorl is replaced by staminodes in 1/3 species, and former Meiostemon) and Terminalia tetrandra (former Terminaliopsis); (3) elaboration of the upper hypanthium into an attractive campanulate to tubular structure in some Combretum; and (4) a trend towards unisexuality – the plants andromonoecious in Terminalia and Pteleopsis, and flowers/plants variably bisexual, monoecious or dioecious (probably mainly functionally dioecious) in Conocarpus, Laguncularia and Combretum rupicola. The petals are rarely large and attractive; exceptions are a few Combretum species and Lumnitzera. In some Combretum, it is the antepetalous stamens which are missing (Stace 1968) whereas in other Combretum and Terminalia tetrandra it is the antesepalous ones (Capuron 1967). In two of the three species of Combretum sect. Thiloa, there are glandular outgrowths (caruncles) on the connectives. In some taxa, e.g. Lumnitzera littorea, variable numbers of stamens are aborted or sterile, giving a total of 5–10 functional ones. In most taxa, the disk is a continuous ring of nectariferous tissue at the base of the upper hypanthium, but sometimes it is vestigial or absent. In Lumnitzera littorea, the ring is broken at the most ventral point, where the stamen is usually lacking. In Dansiea, the nectary is reduced to a bilobed outgrowth only on the dorsal side. The style is adnate to the upper hypanthium for various distances in Lumnitzera littorea and some Combretum (including former Quisqualis). In Strephonema, the flowers are only semiepigynous, the lower hypanthium extending less than halfway up the ovary and the upper hypanthium arising from it at that point as a short ‘calyxtube’, and bearing the sepals, petals and stamens (Fig. 21). Floral anatomy, particularly vascular architecture, was treated by Venkateswarlu and Rao (1970). The pattern in Lumnitzera, with three traces to each sepal, was considered ancestral to the situation in Combretinae and Terminaliinae, with only one trace to each. Moreover, Lumnitzera has 8 traces in the style, said to represent the ancestral polycarpellary state, whereas the rest of the family have 2–5, and it was the only genus studied to have traces to the nectariferous disk. Subsequent work by Fukuoka et al. (1986) did not wholly confirm these earlier findings, and they concluded that

Combretaceae

Lumnitzera represents a separate line of development, rather than an ancestral state. Embryology. Male and female embryological details have been summarized by Tobe and Raven (1983); seven genera have been examined. Virtually all details agree with the common situation in the Myrtales (see family description), and little variation within the family is known. The ovules lack integumental vasculature, and the embryo sac is of the Polygonum type but usually with ephemeral antipodals. Guiera, however, was found by Venkateswarlu and Rao (1972) to have persistent antipodal cells and a micropyle formed from only the inner integument, both being unique character-states in the whole of Myrtales. Endosperm formation is Nuclear but an endosperm is absent in the mature seed. Pollen Morphology. Data presented here come from work of J.H. Tallis (1963, unpubl. data), B. Batts (1969, unpubl. data), A.-R.A. Alwan (1983, and unpubl. data), Patel et al. (1985), El Ghazali (1993) and El Ghazali et al. (1998); all current genera except Finetia and Dansiea were covered. In Strephonema, Buchenavia and Laguncularia, the grains are tricolporate; these genera are not related and this type of pollen does not occur in the genera most closely related to the latter two genera (Strephonema is isolated). These three can easily be distinguished by their surface sculpturing: reticulate, echinate and psilate respectively. The grains of the other nine studied genera are heterocolpate, i.e. the three colpi (each with a central pore) alternating with three pore-less subsidiary colpi (or pseudocolpi), and exhibit a similar range of surface sculpturing. Heterocolpate grains are found in 8 of the 14 families of Myrtaceae but in very few non-Myrtalean families (Dahlgren and Thorne 1984). Apart from this important feature, it can be concluded that pollen characters are very useful at generic and lower levels, but scarcely contribute to an understanding of generic relationships in Combretaceae. Probably too much was made by Patel et al. (1985) of the distinctive reticulate grains of Strephonema, since the strikingly striate grains of Combretum rhodanthum figured by El Ghazali (1993) appear no less distinctive. Some of the other generic characteristics summarized by Patel et al. (1985) break down when more species are surveyed, e.g. echinate grains are not constant in Anogeissus, but others do not, e.g. tricolporate echinate grains in Buchenavia (quite unlike

71

those in the presumably related Terminalia). The ranges found in the large genera Combretum (El Ghazali) and Terminalia (Alwan) suggest that their infrageneric classification might be reinforced by pollen morphology. Fruit and Seed Structure and Germination. Strictly spoken, the ‘fruit’ is a 1-seeded pseudocarp formed from the inferior ovary and surrounding the lower hypanthium, except in Strephonema where the semi-inferior ovary is mostly exposed from the hypanthium at fruiting, the latter remaining adherent to the base of the fruit. Where there is a stalk-like extension at the tip of the lower hypanthium, this may or may not persist as a fruit-beak. The fruit wall (pericarp plus hypanthium) may be thin and hard, or become differentiated as spongy or succulent tissue, or develop 2–5 wings. All situations are common, often within one genus. The inner part of those pericarps which become succulent may be very hard and woody, forming a pseudodrupe, as in many Terminalia and all Buchenavia. In some cases, the fruits are aggregated into compact heads, the Alnus-like ‘cones’ of Conocarpus representing the extreme. In Calycopteris, the 5 wings are developed from the accrescent calyx, and in Macropteranthes and Dansiea the 2 wings are accrescent prophylls. Fruit anatomy in Laguncularia and Combretum is described by Valente et al. (1989, 1994). An endosperm is absent and the embryo fills the seed. In Strephonema, the two cotyledons are massive and hemispherical (conduplicate). Those of Combretum sect. Calopyxis approach this condition. In Combretum sect. Cacoucia, the cotyledons are less massive but still not folded (also conduplicate) but in all other Combretaceae they are folded, although they can be thick and succulent, e.g. Terminalia megalocarpa (Coode 1973). Folding is either convolute (spiralled together) or irregularly complicate (folded upon themselves, often complexly). The distribution of these three types in the tribes and subtribes is as follows: Strephonematoideae – conduplicate (hemispherical) Combretoideae Laguncularieae – spirally convolute Combreteae Combretinae – irregularly complicate (mostly), spirally convolute or conduplicate Terminaliinae – spirally convolute

Both epigeal and hypogeal germination is common and seems to have little taxonomic significance

72

C.A. Stace

above species level; both types are found in both Combretum (Jackson 1974) and Terminalia. Strephonema shows hypogeal germination (Jongkind 1995b). Of the two mangroves, Laguncularia is epigeal and Lumnitzera hypogeal (Tomlinson 1986) whereas Macropteranthes, a close relative of the latter, is epigeal (N. Byrnes, pers. comm.). Tomlinson reported Conocarpus and Terminalia catappa to be hypogeal, as did Brandis (1893) for T. bellirica, but several Southeast Asian species of Terminalia are epigeal. Terminalia megalocarpa, like some others from Southeast Asia, has 3–4(–5) cotyledons (Coode 1969, 1973). Species of Combretum from African fire-prone savannah, e.g. C. viscosum, C. molle and C. bauchiense, have two epigeal cotyledons with long, fused petioles arising from below the soil and protecting the subterranean plumule bud (Jackson 1974, Onyekwelu 1990). In some seedlings of C. viscosum, the cotyledons are also fused, forming a deep cup with a circular rim (C.A. Stace, unpubl. data). When the shoot grows, it breaks laterally from the base of the fused petioles and emerges from the soil some centimetres from the cotyledons. This peculiar mode of germination has been termed ‘cryptogeal’, and is exhibited by pyrophytic species in other families. Karyology. About 112 chromosome counts for c. 47 species in 7 genera have been reported. By far the commonest counts are 2n = 24 and 26, the former being characteristic for Terminalia, Conocarpus, Anogeissus and Guiera and the latter for Combretum (including former Quisqualis), Calycopteris and Lumnitzera. The base numbers thus appear to be x = 12 and 13, the former in Terminaliinae and the latter in Combretinae and Laguncularieae. In addition, in both Terminalia and Combretum triploids, tetraploids, hexaploids and octoploids have been reported, the highest numbers being 2n = 96 for T. bellirica and 2n = 104 for C. celastroides. Some of the variation in ploidy level is infraspecific, e.g. 2n = 24, 48 and 72 in Terminalia chebula. Ohri (1996) reported DNA C-values for six species of Terminalia. For three diploids, 2C-values were 3.6 to 7.13 pg, for a triploid 10.19 pg, and for two tetraploids 7.3 to 12.8 pg. This gives an almost twofold variation (1.8 to 3.56 pg) in 2C-value per basic genome. In five Indian taxa, the 2C-value was 8.01 to 9.66 pg (Srivastava et al. 2001). These values are above average for tropical hardwoods (Ohri and Kumar 1986).

Pollination. Three major adaptations relevant to pollination are evident in the family: loss of petals; enlargement of upper hypanthium; and clustering of flowers into groups. Large coloured petals, as in a few Combretum species, especially those formerly in Quisqualis (Fig. 25), are rare. In C. indicum the flowers are sweetly scented, especially in the evening, and the long narrow hypanthium shows this to be a typical hawkmothpollinated flower. In nearly all other Combretaceae, the petals are relatively small and inconspicuous, or lacking, and three major pollination syndromes can be detected. Firstly, scentless flowers with large, red to yellow upper hypanthia, found in Combretum (including former Calopyxis) in West Africa and Madagascar, are presumably pollinated by sunbirds, although no direct observations have been made. The same is true of C. cacoucia regarding hummingbirds in America. Secondly, small whitish or pale fragrant flowers are the commonest situation throughout the family, and are pollinated by a wide range of insects, including beetles, flies, bees and butterflies. They usually have very well-developed nectaries inside the hypanthium, and are frequently grouped into larger clusters. In India, Srivastava (1993) found that four species of Terminalia were self-incompatible, and were visited by these orders of insects for both pollen and nectar. Thirdly, in tropical America the very widespread Combretum fruticosum and several related species (sect. Combretum) exhibit the ‘bottle-brush’ syndrome (cf. Australian Callistemon), with sessile, scentless, nectariferous flowers crowded on an elongated axis and possessing long, rigid stamens, with the stigma and anthers at the same level. The whole flower, of which the filaments are the most conspicuous part, starts yellow and then changes to red. These are pollinated primarily by hummingbirds (many direct observations), but other birds, butterflies and monkeys also play their part (Schemske 1980; Prance 1980). The species has been shown to be self-incompatible (Bernardello et al. 1994). In the self-compatible mangrove genus Lumnitzera, L. littorea has red flowers with well-exposed anthers and is pollinated mainly by sunbirds and honeyeaters whereas L. racemosa has white flowers and less-exposed anthers and is pollinated by various insects (Tomlinson 1986). Combretum lanceolatum is remarkable for producing a sweet, gelatinous secretion in form of pellets, rather than liquid nectar, which attracts a great diversity of bird visitors (Sazima et al. 2001).

Combretaceae

Dispersal. Present evidence suggests that species with winged fruits (mostly in savannah) are wind-dispersed, and those with succulent fruits (often riverine or in forest) are animal- or waterborne. In African savannah species of Combretum with large fruits, e.g. C. zeyheri, the wings probably act as sails as the fruit is blown along on the ground (Exell and Stace 1972). In Southeast Asia, Terminalia catappa is dispersed by both seawater and fructivorous bats (Exell 1954). Many species of Terminalia, as well as the two mangrove genera, have spongy rather than succulent fruits, often with airspaces in the mesocarp, and are well adapted for sea-dispersal. Phytochemistry. Ample phytochemical data on Combretaceae indicate that little insight is gained into relationships within the family, but that the position of the family in the Myrtales is strongly confirmed (Dahlgren and Thorne 1984). Particularly characteristic are condensed tannins, gallyol-and ellagi-tannins; among the flavonoids, the flavonol myricetin, various O-methyl flavonols, C-glycoflavones and proanthocyanidins (but no other flavones or iridoids); only few alkaloids; and triterpene saponins. Skoczylas et al. (1994) reported long-chain rubber-like polyisoprenoid alcohols in leaves of Lumnitzera. Anderson and Bell (1977) found differences in the composition of gum exudates in seven African Combretum taxa, and Carr and Rogers (1987) described a method of identifying species of this genus from southern Africa by TLC ‘fingerprints’ of polar constituents of leaf extracts. Laguncularia possesses gums similar to those of Combretum (Léon de Pinto et al. 1993). Large cells containing a single calcium oxalate druse are characteristic of the mesophyll of most (?all) genera; they frequently cause a pimple-like mound on the epidermis and/or pellucid dots when the leaf is held against the light. Subdivision and Relationships Within the Family. Strephonema, originally tentatively assigned to Lythraceae, differs from the rest of the genera in several characters and was separated as the subfamily Strephonematoideae by Engler and Diels (1899). Others have suggested a distinct family for it, but it possesses the diagnostic Combretaceous hairs and it consistently fell into the same single clade as the rest of the family in all the cladograms figured by Johnson and Briggs (1984). Most of the rest of the family (Combretoideae) forms two major groups based around Combretum

73

and Terminalia respectively, first recognized by de Candolle (1828), and later by Engler and Diels (1899, 1900) as the tribes Combreteae and Terminalieae. These have been variously distinguished (cotyledon folding, de Candolle 1828 and Engler and Diels 1899, 1900; presence of petals, Don 1832; presence of glandular trichomes, Stace 1965). Two groups of closely related, traditionally recognized genera form the cores of these two tribes respectively: Combretum, Meiostemon, Thiloa, Quisqualis and Calopyxis; and Terminalia, Terminaliopsis, Ramatuellea and Bucida. In addition, Buchenavia, Conocarpus, Anogeissus and Finetia also clearly belong to Terminalieae. Three other genera have variously been placed in tribes or subtribes of their own or subsumed into one of the above two: Guiera, tribe Guiereae (nom. nud.) (Venkateswarlu and Rao 1972); Calycopteris, tribe Calycopterideae (Engler and Diels 1899); and Pteleopsis, subtribe Pteleopsidinae (Exell and Stace 1966). All three have been placed in the Combreteae, and Pteleopsis also in Terminalieae (Vollesen 1981). In my view, Calycopteris is clearly a member of Combretinae, Pteleopsis of Terminaliinae, and Guiera is of uncertain affinity. I have retained Guiera in Combretinae, as it possesses scales and petals, but it might almost equally belong to Terminaliinae or a separate subtribe; DNA sequences are highly desirable. Four additional genera, Laguncularia, Lumnitzera, Macropteranthes and Dansiea, form a well-defined group which was once placed in Terminalieae or Combreteae, according to the character used to separate these tribes, but which was separated as a third tribe Laguncularieae by Engler and Diels (1899). Exell and Stace (1966) recognized 20 of the above 21 genera (Dansiea was not then described) in two subfamilies: the unigeneric Strephonematoideae and the Combretoideae. They considered Laguncularieae, with two prophylls fused to the hypanthium, to be more distinct than the rest of Combretoideae, which formed an enlarged Combreteae divided into three subtribes: Combretinae, Terminaliinae and the unigeneric Pteleopsidinae, which they thought did not fall into either of the other subtribes. Since then, Vollesen (1981) has presented clear evidence for merging the latter two subtribes. I have been unable to confirm Johnson and Briggs’s (1984) assertion that Strephonema has a pair of prophylls, and therefore consider that those of Laguncularieae do indeed represent a synapomorphy. Despite this advanced character, it is likely

74

C.A. Stace

that Laguncularieae are not an advanced group; the presence of petals, the floral vasculature and the hypanthium not separated into upper and lower portions are indicative of this. The main argument in Combretaceae classification today is how many genera should be recognized among the five and four core genera listed above in Combretinae and Terminaliinae. A conservative classification would recognize only one genus in each group, and it is probably true that separating any of the genera from Combretum or Terminalia respectively would leave the latter two paraphyletic. The types and taxonomic distribution of glandular trichomes in Combretinae support this view. Jongkind (1991, 1995a) argued for the inclusion of Quisqualis and Calopyxis in Combretum, just as Engler and Diels (1899, 1900) had done for Poivrea and Exell (1953) had done for Cacoucia, not on any theoretical basis but because the supposed differences could not be sustained; in fact, Cacoucia is as distinct from Combretum as is Calopyxis. The genera Thiloa and Meiostemon remain distinct, but they are probably no less closely evolutionarily related to Combretum subg. Combretum than are Cacoucia, Poivrea, Quisqualis and Calopyxis to Combretum subg. Cacoucia. In Terminaliinae, Terminaliopsis and Ramatuellea have few claims for separation from Terminalia, each representing specialized parts of the latter. Describing an apetalous species in the erstwhile petaliferous genus Pteleopsis, Vollesen (1981) considered that it could still be separated by the male flowers being at the base of the inflorescence, not at the apex, as in Terminalia. However, there are species of Terminalia with basal male flowers (sect. Ramatuellea), so there is no single character diagnosing Pteleopsis, although it remains a very distinctive taxon. The genus Bucida is traditionally separated from Terminalia by the retention of the upper hypanthium and calyx on the fruit. This character is, however, also found in three Madagascan Terminalia species of quite different facies (Capuron 1967), and in two other species from the Solomon Islands of yet different affinity (Exell 1935), and one species of Bucida does not possess it constantly. In my view, only Combretum, Terminalia and Pteleopsis of the above 12 should be recognized at generic level. Molecular studies (plastid and rDNA ITS sequences) on eight genera and 18 species by Tan et al. (2001, 2002) have largely confirmed the current suprageneric treatment. Strephonema is sister to the rest, and within the latter Laguncularieae (Lumnitzera, Laguncularia) are sister to the

remainder, which divide into Combretinae (Combretum including former Quisqualis, Calycopteris) and Terminaliinae (Terminalia, Anogeissus, Conocarpus). More recently, Sytsma et al. (2004) sequenced four genera (three at present recognized) and obtained rather different results, Conocarpus being sister to Terminalia (including Bucida) plus Combretum (as Quisqualis). Clearly, much more molecular work is required. Affinities. Combretaceae were considered one of 14 “core families of Myrtales” by Dahlgren and Thorne (1984), but “any close connections [to any of the other 13 families] are not obvious”. In Johnson and Briggs’s (1984) main cladograms, based on 77 morphological and anatomical characters, the sister clade to a clade containing only Combretaceae contained seven of the other core families: Penaeaceae, Alzateaceae, Oliniaceae, Rhynchocalycaceae, Crypteroniaceae, Memecylaceae and Melastomataceae. Despite the possession of Combretaceous hairs by some of their members, Myrtaceae were more distant. In Conti et al.’s (1996) cladistic analysis of rbcL sequence data, a different result was obtained: Combretaceae formed a clade along with Onagraceae and Lythraceae which was sister to all the other Myrtales (the above seven plus four other families). Similarly, Soltis et al.’s (2000) analysis of seven of the families using 18S rDNA, rbcL and atpB sequences revealed three unresolved subclades – Combretaceae, Onagraceae and Lythraceae – and four other families. The Angiosperm Phylogeny Group classification (APG II 2003) recognizes the Myrtales with 14 families, 13 of which are the same as those of Dahlgren and Thorne (1984) (Trapaceae merged into Lythraceae; Vochysiaceae added). Sytsma et al. (2004) found Combretaceae to be sister to all the other 13 families combined. There is thus agreement that Combretaceae are a distinct family which diverged early (perhaps first) in the evolution of Myrtales. Distribution and Habitats. Combretaceae occur throughout the tropics, with short extensions into warm temperate zones, i.e. to 37◦ 15 S in Argentina, 33◦ 46 S in South Africa and c. 26◦ S in Australia, and to 28◦ 30 N in Florida, 29◦ N in Baja California, 32◦ 20 N in Bermuda, 29◦ 30 N in China and c. 31◦ N in India. The two large genera, Combretum and Terminalia, occur in all continents (Combretum not discovered in Australia until 1980). The greatest genetic diversity of Combretum is in Africa, that of Terminalia in Southeast Asia.

Combretaceae

One mangrove, Laguncularia, occurs in both America (east and west coasts) and West Africa, and the other, Lumnitzera, from East Africa to Australia. The mangrove-associate, Conocarpus, has a similar distribution to Laguncularia, but there is also a second non-mangrove species (C. lancifolius) in northeast Africa and Arabia. Anogeissus occurs in both Africa and Asia, but the other seven genera are confined to one continent. There are only three amphi-Atlantic species: Laguncularia racemosa, Conocarpus erectus and Terminalia lucida. Combretaceae can be important constituents of forest, savannah and mangrove-swamp, and occur from sea level to (in Southeast Asia) over 3,000 m altitude. In parts of southern Africa, several species of Combretum, viz. C. zeyheri, C. molle, C. apiculatum, C. hereroense and C. mossambicense (Exell 1978), are characteristic and hence indicators of cupriferous soils. Palaeobotany. Friis et al. (1992) described flowers (Esgueiria adenocarpa E.M. Friis, K.R. Pedersen & P.R. Crane and E. miraensis E.M. Friis, K.R. Pedersen & P.R. Crane) from the Late Cretaceous of Portugal which they ascribed to Combretaceae. They had an inferior unilocular ovary with three stylodia and up to six apical anatropous ovules, five sepals and five sepals borne on the top of the ovary, and eight stamens (in two whorls of three and five) borne on the top of the ovary. The ovary and sepals had abundant simple hairs and peltate scales. Overall, there is good concordance between the features of Esgueiria and Combretaceae, but confirmation of the family status could only be made from anatomical analysis of the hairs; the photographs provided suggest that they might be Combretaceous. Primitive characters would be the three stylodia and the absence of an upper hypanthium. There are many earlier records of fossil supposed Combretaceae, involving wood, leaves, flowers, fruits and pollen from the Mid-Cretaceous (c. 100 Ma b.p.) onwards, all ascribed to modern genera or to fossil genera based on modern names. However, the evidence of them belonging to Combretaceae is tenuous and based on gross morphology only, except perhaps in the case of the Late Cretaceous and Tertiary wood Terminalioxylon (Friis et al. 1992). Economic Importance. Combretaceae are not of great worldwide economic importance. The larger species of Terminalia are valued as timber trees, mostly for local uses but in some cases in

75

the European and American markets, e.g. the West African T. ivorensis (‘idigbo’) and T. superba (‘afara’), the American T. amazonia (‘nargusta’ or ‘roblé coral’) and T. oblonga (‘sura’), and the Asian T. elliptica (‘Indian laurel’), T. cuneata (T. arjuna, ‘kumbuk’) and T. bialata (‘chuglam’). In the West Indies, Laguncularia is valued for fence-posts and Conocarpus for fuel. The fruit of several species of Terminalia (e.g. T. catappa, ‘Indian almond’) have edible kernels, as do species of Combretum sect. Calopyxis in Madagascar; in South America, Asia and Africa, several species of Combretum and Terminalia are commercial sources of gums; in Asia, the fruits of certain species (e.g. T. chebula) known collectively as ‘myrobalans’ are important for dyeing and tanning. Dalziel (1937) has 11 pages of entries for Combretaceae. Species of Terminalia, especially T. catappa throughout the tropics, are much grown as shade plants, and of Combretum (including former Calopyxis and Quisqualis) as ornamentals.

Key to the Genera 1. Ovary semi-inferior, the calyx-tube arising from its sides; seeds with massive hemispherical cotyledons 1. Strephonema – Ovary inferior, the hypanthium extended from its apex; seeds with flattened, usually variously folded cotyledons 2 2. Hypanthium with 2 adnate prophylls (sometimes developed as wings) 3 – Hypanthium without adnate prophylls 6 3. Prophylls not accrescent and not forming wings to the fruit; thick-leaved mangroves 4 – Prophylls accrescent to form 2 wings to the fruit; plants not mangroves 5 4. Leaves opposite, with minute narrow-orificed pits on both surfaces; hypanthium (above ovary) < 5 mm; petals pubescent, < 2 mm 2. Laguncularia – Leaves spiral, without surface pits; hypanthium (above ovary) > 5 mm; petals glabrous, > 3 mm 3. Lumnitzera 5. Hypanthium adnate to ovary all round; nectariferous disk forming an intrastaminal ring at base of hypnthium 4. Macropteranthes – Hypanthium adnate to ovary on ventral side only; nectary a 2-lobed outgrowth on inner dorsal side of hypanthium 5. Dansiea 6. Fruits aggregated into ‘cones’ (Alnus-like but without persistent bracts) 7 – Fruits not aggregated into Alnus-like ‘cones’ 9 7. Fruits without terminal beak, strongly recurved at apex 11. Conocarpus – Fruits with terminal beak, not recurved at apex 8 8. Ovary and fruit 2-winged; beak of fruit formed from whole of distal stalk-like part of lower hypanthium 9. Anogeissus

76

C.A. Stace

– Ovary and fruit 4-ridged; beak of fruit formed from only lower half of distal stalk-like part of lower hypanthium 10. Finetia 9. Calyx-lobes accrescent, forming 5 terminal fruit-wings 13. Calycopteris – Calyx-lobes not or scarcely accrescent, not forming fruit-wings 10 10. Petals usually present, rarely absent; leaves and inflorescences with glandular trichomes (stalked glands and/or scales) 11 – Petals usually absent, sometimes present; leaves and inflorescences without glandular trichomes 12 11. Fruits in radiating capitate clusters, linear to narrowly fusiform, with persistent upper hypanthium 14. Guiera – Fruits not in radiating clusters, not linear, without persistent upper hypanthium 12. Combretum 12. Anthers adnate to filaments; fruit a wingless pseudodrupe 8. Buchenavia – Anthers dorsifixed and versatile; fruit various 13 13. Andromonoecious, with bisexual flowers restricted to apex of rhachis; all flowers long-stalked 7. Pteleopsis – All flowers bisexual or, if andromonoecious with bisexual flowers restricted to apex of rhachis, at least bisexual flowers sessile or more or less so 6. Terminalia

Genera of Combretaceae I. Subfam. Strephonematoideae Engl. & Diels (1899). Trees; ovary semi-inferior; cotyledons conduplicate, hemispherical, massive; stomata paracytic; wood with tangential bands of apotracheal parenchyma; pollen tricolporate; one- and twoarmed Combretaceous hairs present; glandular trichomes absent; petals present. 1. Strephonema Hook. f.

Fig. 21

Strephonema Hook. f. in Benth. & Hook. f., Gen. Pl. 1:782 (1867); Jongkind, Ann. Missouri Bot. Gard. 82:535–541 (1955), rev.

Characters of subfamily; leaves spiral, without petiolar glands, with basal revolute domatia; inflorescences axillary, subumbellate to elongated simple to compound racemes; flowers (4–)5merous, bisexual, pedicellate; stamens 10, with versatile anthers; ovules 2; germination hypogeal. Three species, western tropical Africa. II. Subfam. Combretoideae Engl. & Diels (1899). Trees, shrubs, mangroves or lianes; ovary inferior; cotyledons flattened, variously folded or rarely

Fig. 21. Combretaceae. Strephonema sericea. A Flowering branch. B Flower with subtending bract. C Flower, vertical section. D Fruit. E Fruit, half of pericarp and seed-coat removed. (Engler and Diels 1900)

conduplicate; stomata anomocytic (or cyclocytic); wood without tangential bands of apotracheal parenchyma; pollen tricolporate or heterocolpate; only one-armed Combretaceous hairs present; glandular trichomes present or absent; petals present or absent. II.1. Tribe Laguncularieae Engl. & Diels (1899). Trees, shrubs or mangroves; stomata anomocytic or cyclocytic; cotyledons spirally convolute; leaves with isobilateral or weakly isobilateral anatomy; stalked glandular trichomes absent; hypanthium with 2 adnate prophylls; upper and lower hypanthia scarcely differentiated; petals present; anthers versatile; chromosome base number 13 (as far as is known). 2. Laguncularia C.F. Gaertn.

Fig. 22

Laguncularia C.F. Gaertn., Suppl. Carp. 209, t. 217 (1807); Exell, Ann. Missouri Bot. Gard. 45:162–164 (1958); Stace, Fl. Venez. Guayana 4:344 (1998).

Mangroves, often with pneumatophores; leaves opposite, with pair of petiolar glands, with sessile glands in minute sunken pits, without marginal

Combretaceae

77

or pedicellate; nectary a disk; petals glabrous; stamens 5–10; ovules 2–5; fruit unwinged; germination hypogeal. Two species, East tropical Africa to Australia. 4. Macropteranthes F. Muell. Macropteranthes F. Muell., Fragm. 3:151 (1863); Pedley, Fl. Australia 18:256–260 (1990).

Trees or shrubs; leaves spiral or opposite, without petiolar glands, with glands on margin near base; inflorescence axillary, of (1–)2 flowers; hypanthium adnate all round ovary, its prophylls accrescent to form winged fruit; flowers 5-merous, bisexual, sessile or pedicellate; nectary a disk; petals pubescent; stamens 10; ovules 6–12; germination epigeal. Five species, Australia. 5. Dansiea Byrnes Dansiea Byrnes, Austrobaileya 1:385 (1981); Pedley, Fl. Australia 18:260–262 (1990).

Fig. 22. Combretaceae. Laguncularia racemosa. A Fruiting branch. B Flower buds with bracts. C Petal and stamen. D Style, disk and ovules (below). E Immature fruits. F Fruit, vertical section. G Fruit, transverse section. h = hypocotyl, c = cotyledons. (Engler and Diels 1900)

glands; inflorescence a terminal panicle of spikes; hypanthium adnate all round ovary, its prophylls not accrescent; flowers 5-merous, bisexual to dioecious, sessile; nectary a disk; petals pubescent; stamens 10; ovules 2; fruit unwinged; germination epigeal. One species, L. racemosa (L.) C.F. Gaertn., eastern and western tropical America, western tropical Africa. 3. Lumnitzera Willd. Lumnitzera Willd., Gesell. Naturf. Freunde Berlin N. S. 4:186 (1803); Exell, Fl. Males. I, 4:585–589 (1954); Gangopadhyay & Chakrabarty, J. Econ. Tax. Bot. 21:325–329 (1997), rev.

Mangroves, often with pneumatophores; leaves spiral, without petiolar glands, with glands on margin; inflorescence a terminal raceme or axillary spike; hypanthium adnate all round ovary, its prophylls not accrescent; flowers 5-merous, bisexual, sessile

Trees; leaves spiral to subopposite, without petiolar glands, with glands on margin near base; inflorescence axillary, of (1–)2 flowers; hypanthium adnate to ovary on ventral side only, its prophylls accrescent to form winged fruit; flowers 5-merous, bisexual, subsessile; nectary a dorsal outgrowth; petals pubescent; stamens 10; ovules 14–20; germination? Two species, Australia. II.2. Tribe Combreteae DC. (1828). Trees, shrubs or lianes; stomata anomocytic; cotyledons conduplicate, spirally convolute or irregularly complicate; leaves usually with dorsiventral, sometimes with isobilateral, anatomy; stalked glandular trichomes present or absent; hypanthium without adnate prophylls; upper and lower hypanthia well differentiated; petals 4–5 or 0; anthers versatile or adnate; chromosome base number 12 or 13. II.2. a. Subtribe Terminaliinae (DC.) Exell & Stace (1966). Terminalieae [Terminaliées] DC. (1828). Pteleopsidinae Exell & Stace (1966).

Trees or shrubs; leaves usually spiral, usually with dorsiventral, sometimes with isobilateral, anatomy; petiolar glands often present; scales absent; stalked glands usually absent; flowers bisexual or andromonoecious, rarely dioecious,

78

C.A. Stace

sessile; petals usually absent, sometimes present; anthers versatile or adnate; cotyledons spirally convolute; fruit usually with hard sclerenchymatous endocarp; wood without vessels of 2 very distinct diameters and without rays with radial vessels; chromosome base number usually 12. 6. Terminalia L.

Fig. 23

Terminalia L., Syst. Nat., ed. 12, 2:674 (1767) & Mant. Pl. 21 (1767), nom. cons.; Alwan, Taxonomy Terminalia (Combretaceae) & related genera (1983), reg. rev.; Capuron, Combretacées arbust. arbor. Madagascar: 9–96 (1967); Coode, Man. forest trees Papua New Guinea, 1, Combretaceae: 5–78 (1969); Exell, Fl. Males. I, 4:548–584 (1954); Exell, Fl. Zambesiaca 4:166–181 (1978); Gangopadhyay & Chakrabarty, J. Econ. Tax. Bot. 21:334–362 (1997), reg. rev.; Griffiths, J. Linn. Soc., Bot. 55:818–907 (1959), reg. rev. Bucida L. (1759), nom. cons. Ramatuellea Kunth in Humb. (1825) (‘Ramatuela’, ‘Ramatuella’). Terminaliopsis Danguy (1923).

Trees. Leaves spiral, often with pocket-shaped or bowl-shaped domatia, frequently with petiolar glands; stalked glands 0; inflorescence an axillary lax to congested spike, the spikes often clustered

at branchlet-ends, rarely the spikes branched; flowers bisexual or plants andromonoecious, the male flowers basal, apical or mixed, at least the bisexual ones sessile, 5- or rarely 4-merous; upper hypanthium sometimes persistent in fruit; petals absent; stamens usually (4–5, 8)10; anthers versatile; fruit 2- to 5-winged or -ridged or ± terete, radially symmetrical or flattened, dry or succulent; chromosome base number usually 12. About 190 species, pantropical. 7. Pteleopsis Engl. Pteleopsis Engl., Abh. Königl. Akad. Wissensch. Berlin 1894: 25 (1894); Exell, Fl. Zambesiaca 4:162–166 (1978).

Leaves spiral, subopposite or opposite, without domatia, without petiolar glands; stalked glands 0; inflorescence an axillary congested spike, the spikes often clustered at branchlet-ends; plants andromonoecious, flowers long-stalked, 5- or 4-merous; upper hypanthium deciduous before fruiting; petals usually present (absent in P. apetala Vollesen); stamens 10 or 8; anthers versatile; fruit 2-winged, flattened, dry. About 10 species, Africa. 8. Buchenavia Eichler Buchenavia Eichler, Flora 49:164 (1866), nom. cons.; Exell & Stace, Bull. Brit Mus. (Nat. Hist.), Bot. 3:1–46 (1963), rev.; Alwan, Taxonomy Terminalia (Combretaceae) & related genera (1983).

Leaves spiral, often with pocket-shaped or rarely bowl-shaped domatia, usually with petiolar glands; stalked glands 0; inflorescence an axillary lax to congested spike, the spikes usually clustered at branchlet-ends; flowers bisexual, sessile, 5-merous; upper hypanthium deciduous before fruiting; petals absent; stamens 10; anthers adnate to filaments; fruit 5-ridged or ± terete, radially symmetrical or rarely slightly flattened, succulent. Twenty species, tropical America. 9. Anogeissus (DC.) Wall. Anogeissus (DC.) Wall., Numer. List no. 4014 (1831); Scott, Kew Bull. 33:555–566 (1979), rev. Conocarpus sect. Anogeissus DC. (1828).

Fig. 23. Combretaceae. Terminalia brownii. A Flowering branch. B Flower, vertical section. C Part of infructescence. D Fruit, transverse section. (Engler and Diels 1900)

Leaves spiral, opposite or subopposite, usually with dorsiventral anatomy, sometimes with pocket-shaped domatia, without petiolar glands; stalked glands absent; inflorescence a solitary or a raceme or compound raceme of compact conelike spikes; flowers bisexual, sessile, 5-merous; upper hypanthium deciduous before fruiting;

Combretaceae

petals absent; stamens 10; anthers versatile; fruit 2-winged, flattened, dry and achene-like, retaining whole of distal stalk-like part of lower hypanthium at fruiting; chromosome base number 12. Seven species, western tropical Africa to Southeast Asia.

Finetia Gagnep., Notul. Syst. (Paris) 3:278 (1917); Scott, Kew Bull. 33:555–566 (1979), rev. Anogeissus sect. Finetia (Gagnep.) A.J. Scott (1979).

Leaves opposite or subopposite, without domatia, without petiolar glands; stalked glands 0; inflorescence a solitary or a raceme of compact cone-like spikes; flowers bisexual, sessile, 5-merous; upper hypanthium deciduous before fruiting; petals absent; stamens 10; anthers versatile; fruit 4-ribbed, slightly flattened, dry and achene-like, retaining only lower half of distal stalk-like part of lower hypanthium at fruiting. One species, F. rivularis (Gagnep.) Lecomte, Thailand and Laos. 11. Conocarpus L.

or irregularly complicate; fruit without hard sclerenchymatous endocarp; wood with vessels of 2 very distinct diameters and with rays with radial vessels; chromosome base number 12 or 13. 12. Combretum Loefl.

10. Finetia Gagnep.

Fig. 20

Conocarpus L., Sp. Pl.: 176 (1753); Exell, Ann. Missouri Bot. Gard. 45:161–162 (1958), reg. rev.

Mangrove-like shrubs or trees, without pneumatophores; leaves spiral with bowl-shaped domatia and petiolar glands; minute stalked glands present; inflorescence a raceme or compound raceme of compact cone-like spikes; flowers bisexual to dioecious, sessile, 5-merous; upper hypanthium deciduous before fruiting; petals 0; stamens (5–)10; anthers versatile; fruit 2-winged, flattened, dry; chromosome base number 12. Two species, one (C. erectus L.) a mangrove-associate in western and eastern tropical America and western tropical Africa, the other (C. lancifolius Engl.) a tree of sandy soils in Northeast Africa and southern Yemen. II.2. b. Subtribe Combretinae Exell & Stace (1966). Calycopterideae Engl. & Diels (1899).

Trees, shrubs or lianes; leaves usually opposite, usually with dorsiventral anatomy; petiolar glands 0; stalked glandular trichomes (stalked glands and/or scales) present; flowers bisexual (dioecious, one species of Combretum), usually sessile; petals usually present; anthers versatile; pollen heterocolpate; cotyledons conduplicate, spirally convolute

79

Figs. 24, 25

Combretum Loefl., Iter Hispan. 308 (1758), nom. cons.; Engler & Diels, Monographieen afrikanischer PflanzenFamilien und -Gattungen, III & IV (1899–1900), reg. rev.; Exell, J. Bot. 69:116–124 (1931), part. rev.; Exell, J. Linn. Soc., Bot. 55:103–141 (1953), reg. rev.; Exell & Stace, Bol. Soc. Brot. II, 40:19 (1966), part. rev.; Gangopadhyay & Chakrabarty, J. Econ. Tax. Bot. 21:297–325, 329–334 (1997), reg. rev.; Jongkind, Bull. Mus. Natl Hist. Nat., B, Adansonia 17:191–200 (1995), reg. rev.; Stace, Bull. Torrey Bot. Club 95:156–165 (1968), part. rev. Quisqualis L. (1762). Cacoucia Aubl. (1775). Poivrea Comm. ex Thouars (1811). Calopyxis Tul. (1856). Thiloa Eichler (1866). Meiostemon Exell & Stace (1966).

Shrubs or lianes, rarely trees. Leaves opposite, sometimes verticillate; stalked glands and/or scales present; flowers 4-or 5-merous, usually sessile, sometimes stalked; upper hypanthium and calyx deciduous before fruiting; petals usually present, sometimes 0; stamens usually 8 or 10 (rarely more), sometimes 4; fruit 4- to 5-winged or -ridged or ± terete, dry or succulent, not achene-like; cotyledons conduplicate, spirally convolute or irregularly complicate; chromosome base number usually 13. About 255 species, pantropical except Pacific islands and most of Australia. Three subgenera are recognized: subg. Combretum, with peltate scales and usually with petals (about 150 spp. in about 33 sections, including Meiostemon and Thiloa); subg. Cacoucia (Aubl.) Exell & Stace, with stalked glands and usually with petals (about 104 spp. in about 17 sections, including Poivrea, Cacoucia, Quisqualis and Calopyxis); subg. Apetalanthum Exell & Stace, with stalked glands and scales, and without petals (one species). 13. Calycopteris Lam. Calycopteris Lam., Tabl. Encycl. 1:485, t. 357 (1793); Exell, Fl. Males. I, 4:584–585 (1954). Getonia Roxb. (1798).

Scrambling shrubs. Leaves opposite or subopposite; scales present; flowers 5-merous, ± sessile; upper hypanthium persistent in fruit, with accrescent

80

C.A. Stace

Fig. 25. Combretaceae. Combretum poggei (subg. Cacoucia). A Flowering branch. B Flower, vertical section. C Fruit. D Fruit, transverse section. (Engler and Diels 1899) Fig. 24. Combretaceae. Combretum bongense (subg. Combretum). A Flowering branch. B Flower bud. C Flower, vertical section. D Leaf underside. E Leaf, transverse section, showing a scale. (Engler and Diels 1899)

calyx forming 5 wings; petals absent; stamens 10; fruit dry, achene-like; cotyledons irregularly complicate; chromosome base number 13. One species, C. floribunda (Roxb.) Lam., Southeast Asia.

Shrubs; leaves opposite or subopposite; scale-like glandular trichomes present; flowers 5-merous, sessile; upper hypanthium persistent in fruit; petals present; stamens 10; fruit dry, achene-like; cotyledons spirally convolute; chromosome base number 12. One species, G. senegalensis J.F. Gmel., western tropical Africa.

Selected Bibliography 14. Guiera Adans. ex Juss. Guiera Adans. ex Juss., Gen. Pl.: 320 (1789).

Adamson, R.S. 1910. Note on the roots of Terminalia arjuna Bedd. New Phytol. 9:150–156.

Combretaceae Alwan, A.-R.A. 1983. The taxonomy of Terminalia (Combretaceae) and related genera. Ph.D. Thesis, University of Leicester. Anderson, D.M.W., Bell, P.C. 1977. The composition of the gum exudates from some Combretum species; the botanical nomenclature and systematics of the Combretaceae. Carbohyd. Res. 57:215–221. APG II 2003. See general references. Behnke, H.-D. 1984. Ultrastructure of sieve-element plastids of Myrtales and allied groups. Ann. Missouri Bot. Gard. 71:824–831. Bernardello, L., Galetto, L., Rodgriguez, I.G. 1994. Reproductive biology, variability of nectar features and pollination of Combretum fruticosum (Combretaceae) in Argentina. Bot. J. Linn. Soc. 114:293–308. Brandis, D. 1893. Combretaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 7. Leipzig: W. Engelmann, pp. 106–130. Candolle, A.P. de 1828. Combretaceae. In: Prodromus systematis naturalis regni vegetabilis, 3. Paris: Treuttel & Würtz, pp. 9–24. Capuron, R. 1967. Les Combretacées arbustives ou arborescentes de Madagascar. Madagascar: Centre Technique Forestier Tropicale. Carr, J.D., Rogers, C.B. 1987. Chemosystematic studies of the genus Combretum (Combretaceae), I. A convenient method of identifying species of this genus by a comparison of the polar constituents extracted from leaf material. S. African J. Bot. 53:173–176. Conti, E. et al. 1996. See general references. Coode, M.J.E. 1969. Manual of the forest trees of Papua and New Guinea. Part 1, revised. Combretaceae. Lae: Department of Forests. Coode, M.J.E. 1973. Notes on Terminalia L. (Combretaceae) in Papuasia. Contr. Herb. Austral. 2:1–33. Corner, E.J.H. 1940. Wayside trees of Malaya. Singapore: Government Printing Office. Dahlgren, R., Thorne, R.F. 1984. The order Myrtales: circumscription, variation and relationships. Ann. Missouri Bot. Gard. 71:633–699. Dalziel, J.M. 1937. The useful plants of West Tropical Africa. London: Crown Agents. Don, G. 1832. Combretaceae. In: A general history of the dichlamydeous plants, 2. London: Rivington, pp. 655– 668. El Ghazali, G.E.B. 1993. A study on the pollen flora of Sudan. Rev. Palaeobot. Palynol. 76:99–345. El Ghazali, G.E.B., Tsuji, S., El Ghazali, G.A., Nilsson, S. 1998. Combretaceae. In: Nilsson, S. (ed.) World Pollen and Spore Flora, 21. Oslo: Scandinavian University Press. Engler, A., Diels, L. 1899. Monographien afrikanischer Pflanzen-Familien und -Gattungen, III. Combretaceae africanae (I) Combretum. Leipzig: W. Engelmann. Engler, A., Diels, L. 1900. Monographien afrikanischer Pflanzen-Familien und -Gattungen, IV. Combretaceae africanae (II) excl. Combretum. Leipzig: W. Engelmann. Exell, A.W. 1931. The genera of Combretaceae. J. Bot. 69:113–128. Exell, A.W. 1935. Species of Terminalia from the Solomon Is. J. Bot. 73:131–134. Exell, A.W. 1953. The Combretum species of the New World. J. Linn. Soc., Bot. 55:103–141.

81

Exell, A.W. 1954. Combretaceae. In: Steenis, C.G.G.J. van (ed.) Flora Malesiana I, 4:533–628. Djakarta: Noordhoff-Kolff. Exell, A.W. 1962. Space problems arising from the conflict between two evolutionary tendencies in the Combretaceae. Bull. Soc. Roy. Bot. Belgique 95:41–49. Exell, A.W. 1978. Combretaceae. In: Launert, E. (ed.) Flora Zambesiaca 4:100–183. London: Flora Zambesiaca Managing Committee. Exell, A.W., Stace, C.A. 1966. Revision of the Combretaceae. Bol. Soc. Brot. II, 40:5–25. Exell, A.W., Stace, C.A. 1972. Patterns of distribution in the Combretaceae. In: Valentine, D.H. (ed.) Taxonomy, phytogeography and evolution. London: Academic Press, pp. 307–323. Friis, E.M., Pedersen, K.R., Crane, P.R. 1992. Esgueiria gen. nov., fossil flowers with combretaceous features from the Late Cretaceous of Portugal. Biol. Skr. 41:1–45. Fukuoka, N., Ito, M., Iwatsuki, K. 1986. Floral anatomy of the mangrove genus Lumnitzera (Combretaceae). Acta Phytotax. Geobot. 37:69–81. Griffiths, M.E. 1959. A revision of the African species of Terminalia. J. Linn. Soc., Bot. 55:818–907. Heiden, H. 1893. Anatomische Characteristik der Combretaceen. Bot. Centralbl. 55:353–360, 385–391; 56:1–12, 65–75, 129–136, 163–170, 193–200, 225–230. Hickey, L.J. 1973. Classification of the architecture of dicotyledonous leaves. Amer. J. Bot. 60:17–33. Jackson, G. 1974. Cryptogeal germination and other seedling adaptations to the burning of vegetation in savanna regions: the origin of the pyrophytic habit. New Phytol. 73:771–780. Jeník, J. 1970. Root system of tropical trees, 5. The pegroots and the pneumathodes of Laguncularia racemosa Gaertn. Preslia 42:105–113. Johnson, L.A.S., Briggs, B.G. 1984. Myrtales and Myrtaceae –a phylogenetic analysis. Ann. Missouri Bot. Gard. 71:700–756. Jongkind, C.C.H. 1991. Novitates Gabonenses, 6. Some critical observations on Combretum versus Quisqualis (Combretaceae) and description of two new species of Combretum. Bull. Mus. Natl Hist. Nat., B, Adansonia 12:275–280. Jongkind, C.C.H. 1995a. Prodromus for a revision of Combretum (Combretaceae) for Madagascar. Bull. Mus. Natl Hist. Nat., B, Adansonia 17:191–200. Jongkind, C.C.H. 1995b. Review of the genus Strephonema (Combretaceae). Ann. Missouri Bot. Gard. 82:535–541. Jongkind, C.C.H. 1998. Combretaceae. In: Morat, P. (ed.) Flore du Gabon, 35. Paris: Association de Botanique Tropicale. Keating, R.C. 1984. Leaf histology and its contribution to relationships in the Myrtales. Ann. Missouri Bot. Gard. 71:801–823. Keay, R.W.J. 1950. The systematic position of suffrutescent species of Combretum Loefl. Kew Bull. 5:255–257. Klucking, E.P. 1991. Leaf Venation Patterns, 5. Combretaceae. Berlin: J. Cramer. Léon de Pinto, G., Nava, M., Martínez, M., Rivas, C. 1993. Gum polysaccharides of nine specimens of Laguncularia racemosa. Biochem. Syst. Ecol. 21:463–466. Ohri, D. 1996. Genome size and polyploidy variation in the tropical hardwood genus Terminalia (Combretaceae). Pl. Syst. Evol. 200:225–232.

82

C.A. Stace

Ohri, D., Kumar, A. 1986. Nuclear DNA amounts in some tropical hardwoods. Caryologia 39:303–307. Onyekwelu, S.S.C. 1990. Germination, seedling morphology and establishment of Combretum bauchiense Hutch. & Dalz. (Combretaceae). Bot. J. Linn. Soc. 103:133– 138. Outer, R.W. den, Fundter, J.M. 1976. The secondary phloem of some Combretaceae and the systematic position of Strephonema pseudocola A. Chev. Acta Bot. Neerl. 25:481–493. Patel, V.C., Skvarla, J.J., Raven, P.H. 1985. Pollen characters in relation to the delimitation of Myrtales. Ann. Missouri Bot. Gard. 71:858–969. Pedley, L. 1990. Combretaceae. In: George, A.S. (ed.) Flora of Australia 18:255–293. Canberra: AGPS Press. Prance, G.T. 1980. A note on the probable pollination of Combretum by Cebus monkeys. Biotropica 12: 239. Sazima, M., Vogel, S., Prado, A.L. do, Oliveira, D.M. de, Franz, G., Sazima, I. 2001. The sweet jelly of Combretum lanceolatum flowers (Combretaceae): a cornucopia resource for bird pollinators in the Pantanal, western Brazil. Pl. Syst. Evol. 227:195–208. Schemske, D.W. 1980. Floral ecology and hummingbird pollination of Combretum farinosum in Costa Rica. Biotropica 12:169–181. Skoczylas, E., Swiezewska, E., Chojnacki, T., Tanaka, Y. 1994. Long-chain rubber-like polyisoprenoid alcohols in leaves of Lumnitzera racemosa. Pl. Physiol. Biochem. (Montrouge) 32:1–5. Solereder, H. 1908. Systematic anatomy of the dicotyledons. Transl. Boodle, L.A., Fritsch, F.E.; revised Scott, D.H. Oxford: Clarendon Press. Soltis, D.E. et al. 2000. See general references. Srivastava, P.K. 1993. Pollination mechanisms in genus Terminalia Linn. Indian Forester 119:147–150. Srivastava, P.K., Raina, S.N., Thangalevu, K. 2001. Nuclear DNA and fruit (seed) variation in section Pentaptera of genus Terminalia Linn. Indian Forester 128:289– 295. Stace, C.A. 1965. The significance of the leaf epidermis in the taxonomy of the Combretaceae, I. A general review of tribal, generic and specific characters. J. Linn. Soc., Bot. 59:229–252. Stace, C.A. 1966. The use of epidermal characters in phylogenetic considerations. New Phytol. 65:304–318. Stace, C.A. 1968. A revision of the genus Thiloa (Combretaceae). Bull. Torrey Bot. Club 95:156–165.

Stace, C.A. 1981. The significance of the leaf epidermis in the taxonomy of the Combretaceae; conclusions. Bot. J. Linn. Soc. 81:327–339. Sytsma, K.J. et al. 2004. See general references. Tan, F.-X., Shi, S.-H., Huang, Y.-L., Du, Y.-Q., Wang, Y.-G., Gong, X. 2001. Analysis of nrDNA ITS sequences in the subfamily Combretoideae (Combretaceae) and its systematic significance. Acta Bot. Yunnanica 23:239– 242. Tan, F.-X., Shi, S.-H., Zhong, Y., Gong, X., Wang, Y.-G. 2002. Phylogenetic relationships of Combretoideae (Combretaceae) inferred from plastid, nuclear gene and spacer sequences. J. Pl. Res. 115:475–481. Tilney, P.M. 2002. A contribution to the leaf and young stem anatomy of the Combretaceae. Bot. J. Linn. Soc. 138:163–196. Tobe, H., Raven, P.H. 1983. An embryological analysis of Myrtales: its definition and characteristics. Ann. Missouri Bot. Gard. 70:71–94. Tomlinson, P.B. 1986. The Botany of mangroves. Cambridge: Cambridge University Press. Valente, M. da C., Marquete Ferreira da Silva, N., Guimarães, D.J. 1989. Morfologia e anatomia do fruto de Combretum rotundifolium Rich. (Combretaceae). Rodriguésia 67:45–51. Valente, M. da C., Marquete Ferreira da Silva, N., Guimarães, D.J. 1994. Morfologia e anatomia do fruto de Laguncularia racemosa (L.) Gaertn. f. (Combretaceae). Arch. Jard. Bot. Rio de Janeiro 32:39–50. Venkateswarlu, J., Rao, P.S.P. 1970. The floral anatomy of Combretaceae. Proc. Indian Natl Sci. Acad., B, 36:1–20. Venkateswarlu, J., Rao, P.S.P. 1972. Embryological studies in some Combretaceae. Bot. Notiser 125:161–179. Verhoeven, R.L., Schijff, H.P. van der 1974. Anatomical aspects of Combretaceae in South Africa. Phytomorphology 24:158–164. Vliet, C.J.C.M. van 1979. Wood anatomy of the Combretaceae. Blumea 25:141–223. Vliet, C.J.C.M. van, Raven, P.H. 1984. Wood anatomy and classification of the Myrtales. Ann. Missouri Bot. Gard. 71:783–800. Vollesen, K. 1981. Pteleopsis apetala sp. nov. (Combretaceae) and the delimitation of Pteleopsis and Terminalia. Nordic J. Bot. 1:329–332. Weberling, F. 1988. The architecture of inflorescences in the Myrtales. Ann. Missouri Bot. Gard. 75:226–310.

Crassulaceae Crassulaceae DC. in Lam. & DC., Fl. Franç., ed. 3, 4, 1: 382 (1805), nom. cons. J. Thiede and U. Eggli1

Perennial or rarely annual or hapaxanthic herbs to (sub)shrubs, rarely aquatics, treelike, epiphytic or scandent, with ± succulent leaves, sometimes with succulent stems, rhizomes, underground caudices or succulent roots; indumentum of unior multicellular, often glandular hairs, or plants glabrous. Leaves (sub)sessile or rarely petiolate, usually alternate and spiral, or opposite-decussate or rarely whorled, frequently aggregated into rosettes, simple, rarely compound, usually entire or crenate to lobed, rarely dissected, estipulate. Inflorescences usually terminal, bracteate, usually many-flowered, basically thyrsoids, also pleio-, di-or monochasia (cincinni) or rarely true panicles, racemes or spikes. Flowers hermaphrodite, rarely unisexual, actinomorphic or very rarely zygomorphic, usually proterandrous, (3–)5(–32)merous; sepals free or connate at base, sometimes distinctly unequal in size; petals free or connate to a short to long corolla tube; stamens as many as or usually twice as many as petals; filaments free or ± connate with a tubular corolla; anthers basifixed in basal pit, 4-sporangiate, 2-locular at anthesis, dehiscence latrorse or slightly introrse by longitudinal slits; ovary usually ± superior to semi-inferior; carpels as many as petals, usually free or almost so, sessile or sometimes stipitate, tapering gradually to abruptly into short to long, erect to divergent stylodia, basally with a small to conspicuous dorsal nectary scale; stigma small, (sub)apical, often poorly differentiated; ovules usually many, rarely few to one, anatropous, crassi- or tenuinucellate, bitegmic, on parietal to marginal placentae. Fruits usually follicles, and usually ± completely dehiscent along the ventral suture, rarely few-seeded, indehiscent and nutlike; seeds smallish, usually 0.5–1 mm long, elongate-fusiform, longitudinally ridged (costate) or papillate (uni-or rarely multipapillate), rarely 1

U. Eggli provided the key and generic descriptions extracted from Eggli (2003) which were largely revised here.

(nearly) smooth, usually brownish; embryo small, straight; endosperm cellular, scanty. A family of 34 genera with c. 1,410 species distributed worldwide, usually in arid and/or rocky habitats, with centres of diversity in Mexico and South Africa. Vegetative Morphology. Crassulaceae are usually perennial herbs to (sub)shrubs, rarely small trees (the Malagasy Kalanchoe beharensis and K. dinklagei reach 8–10 m). The epicotyl is usually well developed; rarely does it remain very small (’t Hart 1982). In most perennials, the whole shoot system and at least some leaves survive unfavourable periods (frost, drought). Leaves are shed only when additional storage organs are present: succulent, ± elongated stems (e.g. Tylecodon) or small, tuber-like swollen stems (e.g. Dudleya subg. Hasseanthus). Rhizomes are usually sympodial, rarely monopodial (Rhodiola). In Aeonium, the modular growth form correlates with sectional classification (Jorgensen and Olesen 2000). Some highly reduced annual Crassula are morphologically aberrant: flowers of C. pageae are embedded in a short ‘disc’ derived from connate side shoots (coenosom, described in detail by Jäger-Zürn 1989), and C. aphylla forms leafless, ± globular shoots reaching maturity at about 3 mm Ø; it may represent the smallest succulent plant. Few Sedum from the Mediterranean and the Mexican Sierra Madre (Clausen 1977) are strictly biennial. Facultative annuals to perennials are found in Mediterranean Sedum and Macaronesian Aichryson and Monanthes icterica. Root apices often contain anthocyanins and are reddish. Roots are usually fibrous, rarely thickened-fusiform (Villadia p.p., Hylotelephium p.p.) or tuberous. Tuberous rhizomes or rootstocks may develop from the hypocotyl (Rhodiola rosea), the upper part of the main root and hypocotyl (Dudleya caespitosa), or the hypo- and epicotyl (Umbilicus). Sedum obtusifolium forms subter-

84

J. Thiede and U. Eggli

ranean runners with tuberous thickenings, and S. amplexicaule forms propagules from the swollen leaf bases clasping the stems. Secondary growth in roots and root tubers of Sedum and Hylotelephium is described by ’t Hart (1994a). Adventitious roots are formed by many prostrate to suberect shoots (e.g. many Sedum) or ± upright shoots of shrubs, especially under conditions of high air humidity (e.g. Aeonium); this ability is used for vegetative propagation in horticulture. Thickened short roots in Sempervivum, Sedum and some other genera which are inhabited by mycorrhizal symbionts (hyphomycetes, Berger 1930) need re-study. The root-nodules recently reported for Sinocrassula (Akiyama et al. 2001) may belong here. Germination is epigaeal and cotyledons are fleshy, usually petiolate and long persistent. Adult leaves are usually simple and only rarely pinnately compound (some Kalanchoe, e.g. K. pinnata), palmately lobed (Crassula alcicornis), laciniate (Kalanchoe laciniata) or peltate (Umbilicus sect. Umbilicus and a few Kalanchoe). The leaves are ± flat to subulate and often ± flat above and semi-terete below, partly with a ± developed keel. The leaf margin is usually entire or ± crenate (e.g. Umbiliceae), partly with cilia (e.g. many Aeonium). Heterophylly is found in some Orostachys and Rosularia (summer vs. winter rosette; Eggli 1988; Ebel et al. 1991a) and in Sedum diversifolium and S. greggii (sterile vs. flowering). Leaves typically break off easily and form adventitious shoots at the place of separation, a means of vegetative propagation in nature (e.g. Adromischus) which is widely used in horticulture. Many Kalanchoe species of sect. Bryophyllum form adventitious shoots (gemmae) on leaf margins. Sedum viviparum and S. gemmiferum form gemmae in the vegetative region, and Crassula multicava, Kalanchoe miniata, etc. within the inflorescences. The leaf arrangement is usually alternate (most Kalanchoideae and Sempervivoideae) or decussate (most Crassuloideae), rarely whorled (e.g. a few Sedum). Leaf aggregation in ± dense rosettes evolved independently in many genera of nearly all major clades (except Umbiliceae), especially within Sempervivoideae. In spirally arranged rosettes, the number of spirostichies may be of systematic value (e.g. Monanthes; Nyffeler 1992). The rosettes may be ± stem-less, with the leaves remaining attached to the stem at least for some time, or terminal at the shoot tips of (sub)shrubs, with dried leaves being usually shed. Stolons are a means of vegetative propagation in some rosettes (e.g. Semper-

vivum, Orostachys). The rosettes become ‘closed’ and form bud-like structures (‘resting rosettes’) during drought periods in some Aeonium (Ebel et al. 1991b), Orostachys (Ebel et al. 1991a) and Rosularia (Eggli 1988). Vegetative Anatomy. A detailed account was provided by Gregory (1998, with many references), from which data were taken if not cited otherwise. Soil root hairs are usually unicellular; those of aerial adventitious roots may be uni- or biseriately multicellular. The leaves are generally bifacial, succulent (weakly so in some Crassula (Tillaea) and few Sedum with small and thin scale-like leaves) and typically centric or intermediate between centric and dorsiventral. Palisade parenchyma is normally absent; the adaxial cells are sometimes palisade-like. Most leaves are thickish and exhibit a mesophyll with continuous transition from outer chlorenchyma to inner water-storage parenchyma with large achlorophyllous, highly vacuolated cells. Thinner leaves lack this differentiation and are chlorenchymatous throughout. Vascular bundles are collateral and in flat leaves in one row, in terete leaves in a circle, or irregular. Tissues often contain copious tannin. Solitary crystals and druses are common; crystal sand is found in Adromischus, Cotyledon, Kalanchoe and Umbilicus (also within secondary growth). The nodes were studied for few species only and vary even within genera (1-lacunar:1-trace; 1:2 or 1:3, 3:3, 3–multi:3–multi, or multi:3–8). Hydathodes of the ‘epithem’ type are present in many (all?) Crassulaceae. Crassuloideae typically have numerous hydathodes along the margin and/or on the leaf surface of one or both faces (Toelken 1977; Martin and von Willert 2000; see also under Physiology). Kalanchoideae and Sempervivoideae typically have one (sub)apical hydathode only (e.g. Rosularia, Eggli 1988); marginal hydathodes are rare, e.g. Aichryson p.p. (Caballero and Jiménez 1977) or Phedimus (’t Hart and Bleij 2003). The venation is pinnate or palmate and camptodromous or reticulate, usually with a distinct intramarginal vein. In ± flat leaves, the midvein typically protrudes at least on parts of the lower face. The leaf epidermis is usually one-, occasionally two- (to three)-layered. Outer walls are thin (mesomorphic) to extremely thick (xeromorphic), the anticlinal walls straight (especially in xeromorphic types) or wavy to markedly sinuous (especially in mesomorphic types). Some Crassula, Monanthes

Crassulaceae

and Tylecodon species exhibit enlarged epidermal cells (bladder-cell idioblasts). The cuticle is usually smooth or with fine striations (e.g. Aichryson) or distinct ridges (e.g. Aeonium). Epicuticular wax deposits are in rods, irregularly lobed platelets, threads, smooth platelets or a very thick layer fissured into platelets (Fehrenbach and Barthlott 1988). Stomata are usually superficial to somewhat sunken (some Crassula) or raised (some Sedum), and usually anisocytic or rarely helicocytic (Kalanchoe and Sedum) and mesogenous with 3–8(–10) subsidiary cells. Stomata are usually ± equally numerous on both faces, or more numerous abaxially (rarely adaxially) and usually irregularly orientated. The stomatal density is low, similarly to other leaf succulents, and about 5–80 per mm2 . Cystoliths are reported for Orostachys japonicus. Hairs occur usually on both leaf surfaces when present, with six types: (1) unicellular, simple, thick-walled; (2) unicellular swollen bladder-cell idioblasts with constricted base sometimes covering the epidermis completely; (3) most common are multicellular simple hairs with biseriate stalk which may be non-glandular or glandular with ± spherical heads of 2–12 secretory cells; (4) multicellular stellate hairs with 3(–6) apical arms (only in Malagasy Kalanchoe with dense-felty tomentum, e.g. K. beharensis; Boiteau and Allorge-Boiteau 1995); (5) multicellular sessile hairs with 2–3 basal cells and small head; and (6) multicellular uniseriate, simple or capitate hairs. On young stems, the periderm arises usually in the subepidermis, also in the epidermis or more deeply in the cortex and forms continuous rings or separate groups of cork cells. Additional cambia from the outer cortex sometimes lead to thick periderms (e.g. Kalanchoe beharensis). The cork is impregnated with resin in some Malagasy Kalanchoe. A peeling outer bark occurs in stem-succulent pachycauls (Tylecodon p.p., Aeonium smithii, some Sedum). The epidermal cells are thin-walled. Subepidermal collenchyma layer(s) are reported for some genera. The cortex is parenchymatous, sometimes with chlorophyll, and aerenchymatous in the semi-aquatic Crassula inanis (Moteetee and Nagendran 1997). A distinct endodermis is recorded for some genera. Secondary growth typically yields vessels, parenchyma and lignified fibres in distinct bands, layers, or as ground mass. The pith is parenchymatous, later sometimes lignified. Medullar bundles

85

are reported for some genera. Stem succulents often have secondary growth dominating in the parenchyma of cortex and pith. Growth rings are absent. The phloem is poorly developed. The wood structure is rather similar between unrelated genera and conspicuous in its juvenile features (raylessness, short vessels without variation in length and shape within the radius, and with secondary thickenings characteristic of the primary xylem), and differs strongly from the secondary wood of ‘normal’ woody plants. These differences were interpreted by ’t Hart and Koek-Noorman (1989) as resulting from paedomorphosis and were thought to indicate secondary woodiness derived from a primarily herbaceous ancestor (see also Phytochemistry). Vessel elements are moderately short (100–229 µm) with slightly inclined end walls. Perforation plates are simple (rarely reticulate in Sedum). Vessels have helical and annular lateral wall thickenings and/or scalariform(-reticulate) pitting. Libriform fibres are non-septate with simple pits and thin to thick walls, and form the major part of the wood in most species. Axial parenchyma is usually scanty paratracheal, but may rarely constitute the entire ground tissue, as in Crassula arborescens and some Monanthes. Cortical bundles are reported for some thick-stemmed taxa but are merely leaf-traces running ± vertically for some distance. The rhizome anatomy of Sedum tuberosum and Rhodiola rosea was described by ’t Hart (1982, 1994b). Ultrastructure. Crassulaceae exhibit the S0 type of sieve element plastids (without protein inclusions and without starch) not found elsewhere in Saxifragales (Behnke 1991). Chloroplast ultrastructure differs between C3 and CAM species (Teeri and Overton 1981). Inflorescence structure. Detailed data can be found in Troll (1964, 1969) and especially in Troll and Weberling (1989). Inflorescences are usually thyrsoids (monotelic, i.e. with a terminal flower). Rarely, the terminal flower may be reduced, partly together with the distal part of the inflorescence (Adromischus, Umbilicus). The partial inflorescences are dichasia (frequent in Crassuloideae, Kalanchoideae, Telephieae, Umbiliceae), monochasia (double or simple cincinni; frequent in Semperviveae, Aeonieae and Sedeae) or thyrsoids. They are sometimes concaulescent and thus branch off above their subtending bracts (e.g.

86


Aeonium), or the bracts are recaulescently shifted onto the partial inflorescences (e.g. Tylecodon reticulatus). Rarely, intercalar inhibition zones with bracts not subtending partial inflorescences are found (Aichryson, some Crassula). Some species produce pleiochasia (pseudowhorls of three or more distal partial inflorescences below the terminal flower); proximal partial inflorescences are absent or consist of few to single flowers only (e.g. Sempervivum tectorum). Cymoids with one cincinnus or two cincinni below the terminal flower are also frequent. In uniflowered species, only the terminal flower is developed. Obligately uniflowered inflorescences appear to be rare (e.g. Sedum humifusum). In Kalanchoe, all intermediates from manyflowered thyrsoids over racemes to solitary flowers occur. True panicles (some Adromischus and Umbilicus), racemes (some Umbilicus), double racemes (Umbilicus oppositifolius) or spikes (some Adromischus) are rare. The presence of prophylls, as in the botryoids (e.g. Villadia imbricata), is interpreted as derived from thyrsoids. Lateral inflorescences occur in some Sedum, Aichryson, Aeonium, Rosularia, Prometheum and throughout in Afrovivella, Meterostachys, Rhodiola, Dudleya and the Echeveria group. Flower Structure. Pedicels are distinct to (nearly) wanting. Either two, one or no prophylls are present. The flowers are usually upright to spreading, rarely pendent (then, again upright in the fruiting stage) and nearly always hermaphrodite (plants dioecious in Rhodiola p.p.). The length of the flowers ranges from a few mm (some Crassula [Tillaea]) to 140 mm (Kalanchoe marmorata). Flowers are actinomorphic, slightly zygomorphic only in Tylecodon grandiflorus, Kalanchoe elizae and K. robusta, (3–)5(–32)merous, and differ strongly in the degree of sympetaly (see, for instance, Figs. 28, 30). The sepals are usually green, (nearly) free or ± connate and usually much shorter than the corolla. They are usually equal and basally connate with the receptacle, or (in Sedum subg. Sedum) often free and ± spurred at base and unequal in size. Petal aestivation is quincuncial, cochlear, or contorted in Sedum (’t Hart 1990), imbricate or contorted in Crassula, convolute in Dudleya, imbricate in Sedella, Thompsonella and most Echeveria, and valvate in a few Echeveria. The petals are typically thin-textured (rarely membranous in annual Crassula), rarely thickish-succulent (e.g. Echeve-

ria), frequently dorsally keeled and sometimes papillose to hairy, and completely free or slightly to nearly completely connate to a corolla tube. Sympetaly is found in all Kalanchoideae and is frequent in many Sempervivoideae where it is of multiple origins (’t Hart et al. 1999; Mort et al. 2001). Petals are yellow, red, white, greenish to brownish with intermediates, very rarely blue (e.g. Sedum caeruleum), often unicoloured, partly bi- to rarely tricoloured (e.g. many Echeveria), sometimes with dots (some Pachyphytum) or irregular spottings (most Graptopetalum). Petals rarely have subapical unifacial precursory tips (‘Vorläuferspitzen’; e.g. Crassula subg. Crassula, many Sedum, some Villadia). Leinfellner (1954) studied the basal petal scales of Pachyphytum, which are also found in some Echeveria. The androecium is obhaplostemonous (Crassuloideae; then, antesepalous stamens only) or more frequently obdiplostemonous (most Kalanchoideae and Sempervivoideae). In obdiplostemonous androecia, the antesepalous stamens are typically longer. In sympetalous corollas, the stamens are ± connate with the tube; the antepetalous (always?) inserted somewhat higher than the antesepalous ones. The filaments are free from each other, usually ± thin-filiform, rarely broadened or thickened. The anthers are usually about 1 mm long, but are longer in long-tubed flowers. Anther colours are usually yellow or red, but also orange, purple, brown, black, white, pink and green with nearly all intermediates and partly infraspecific variation; they are of some taxonomic value (Thiede, unpubl. data). The gynoecium is nearly exclusively isomerous with the perianth (oligomerous only in Sedum tricarpum and S. bonnieri). The ovary is usually superior and the carpels are (nearly) completely free, rarely connate higher up and completely connate only in Crassula pageae (Jäger-Zürn 1989). Soltis et al. (2003) suggested that the ovary in Crassulaceae is secondarily superior, according to a characterstate reconstruction based on molecular data. The carpels narrow gradually to abruptly into separate, erect to divergent stylodia which are usually short to very long in long-tubed flowers. The stigma is small, often poorly differentiated, usually terminal (lateral in some Crassula, Toelken 1977). A compitum is recorded from some Echeveria. The carpels nearly always exhibit nectary scales at their dorsal bases (absent in a few Crassula, Sedum and Aeonium), which are usually less than 1 mm long and very diverse in shape and colour.

Crassulaceae

In Monanthes, Sedum surculosum, S. longipes and S. pentastamineum, the large, petaloid nectary scales are more obvious than the petals. Floral Development and Anatomy. Floral anatomy, vasculature and development have been described in general by Wassmer (1955), Jensen (1966) and Quimby (1971), for Sedum, Crassula and Phedimus by Eckert (1966), for Kalanchoe by Tillson (1940), for Hylotelephium by ’t Hart (1985c) and for Crassula pageae by Jäger-Zürn (1989). During ontogenesis, sepals develop much earlier than petals (Wassmer 1955). The haplostemonous Crassula dejecta lacks antepetalous (outer) stamens and otherwise develops as the obdiplostemonous Sedum acre, thus indicating that flowers in Crassulaceae are probably basically obdiplostemonous (Eckert 1966). The anthers are median-sagittate in shape (transverse-sagittate in other Saxifragales studied by Endress and Stumpf 1991). Anthers are basifixed, and the filament is attached to the connective with its very thin upper end in the basal pit (dorsifixed only in Rhodiola hobsonii). Anthers are usually latrorse, slightly introrse only in Crassula, Sinocrassula yunnanensis and Umbilicus rupestris (as U. pendulinus; Wassmer 1955) and usually caducous. The anther epidermis is astomate and shows different types (Endress and Stumpf 1991). Apical connective protrusions with different shapes were found in several genera (Wassmer 1955; Endress and Stumpf 1991); in Kalanchoe they may function as secretory glands (Raadts 1979). The carpels are open in early developmental stages and postgenitally connate and are mainly plicate. Carpels within a flower are congenitally connate at least for a short distance below and postgenitally above; completely free carpels have not been found. Ontogenetic studies suggest that the nectary scales represent emergences of the carpels (Wassmer 1955). They exude nectar through stomata (Said 1982). Embryology. Embryology was studied especially by Mauritzon (1930, 1933), and also by Rocén (1928), Souèges (1936) and Fétré and Lebègue (1964). Reviews are by Davis (1966) and Johri et al. (1992), from which most data were taken. The anther wall comprises a persistent epidermis, a one-layered fibrous endothecium, two ephemeral middle layers, and the secretory, uninucleate tapetum. Microsporogenesis is simultaneous. Pollen is shed in monads. It is binucleate and sometimes contains starch grains. The ovules are

87

anatropous, bitegmic and crassinucellate in Kalanchoideae and Sempervivoideae, and tenuinucellate in Crassuloideae. The micropyle is usually formed by both integuments which are both 2-layered. The embryo sac is usually of the normal Polygonum type. In Hylotelephium, an embryo sac of the bisporic Allium type develops from the chalazal dyad. In Prometheum, haustoria are given off from the megaspores and pass through the nucellus into the integuments; such megaspore haustoria are a rather unusual feature. The embryo sac generally contains starch grains. Endosperm formation is ab initio cellular, usually with a chalazal endosperm haustorium, and differs between Crassuloideae and Kalanchoideae/Sempervivoideae (Mauritzon 1933). The endosperm is scanty, fleshy and typically reduced to a 1-layered cap surrounding the hypocotyl (Krach 1976). The zygote divides into embryo, suspensor and a suspensor-haustorium within the nucellus (Mauritzon 1933). The embryogeny conforms to the Caryophyllad type. The embryo is small, long and straight, without a plumula, and stores aleuron as well as oil (Krach 1976). Pollen Morphology. The pollen is usually 3-colporate and subspheroidal to prolate in equatorial view, ± convex-triangular in polar view, and 13–38 µm long. Apertures are lalongate. The sexine is about as thick as the nexine. The tectum is complete and usually striate, reticulate, rugulate or cerebroid (Hideux 1981). The striae have a straight or rarely irregular margin (Monanthes). More rarely, the tectum is (nearly) completely smooth (Sempervivum sect. Jovibarba; Rosularia p.p., Prometheum) or has a fine OL-pattern. Colpi are tenuimarginate, with the thin exine usually protruding at the equatorial part of the colpi (Erdtman 1952). Pollen morphology may vary within the same inflorescence and is thus of restricted systematic applicability (Kim 1994). Data are based on an overview SEM study by Hideux (1981), more focused SEM studies for Sempervivum (incl. Jovibarba; Parnell 1991), European Sedum (’t Hart 1975), Rosularia and Prometheum (Eggli 1988), Monanthes (Nyffeler 1992), Korean Sedum (Kim 1994) and Korean Crassulaceae (Sin et al. 2002), and on light microscopy for Aeonium (Pérez de Paz 1980). Pollen morphology of Crassulaceae is similar to that of Saxifragaceae (Erdtman 1952). Karyology. Crassulaceae display an extensive variation in chromosome numbers among and often within genera and often among species,

88


and possibly represent the karyologically most diverse family of angiosperms. The base number for the family and subfamilies Crassuloideae and Sempervivoideae, x(n) = 8, is also found in outgroups (Penthoraceae, Haloragaceae). The basic chromosome numbers for the major clades have been reconstructed by Mort et al. (2001). Many studies have been conducted on North American taxa (Graptopetalum and Thompsonella, Uhl 1970; Pachyphytum, Uhl and Moran 1973; Sedum, Uhl 1976–1992; Echeveria, Uhl 1994–2005; intergeneric hybrids, Uhl 1993–1995; Lenophyllum, Uhl 1996; Villadia, Uhl and Moran 1999), on European Sedum by ’t Hart (especially 1985a, 1991), on European and Macaronesian Semperviva by Uhl (1961), on Rosularia by ’t Hart and Eggli (1998), on Crassula by Merxmüller et al. (1971) and Friedrich (1973), and on Kalanchoideae by Uhl (1948). The Asian taxa are less thoroughly studied (Uhl and Moran 1972; Wakabayashi and Ohba 1999). Karyotypes are typically rather symmetrical and the chromosomes small (less than 1 or 2 µm), so that pairs and structural details can hardly be recognised. Satellites are present in Crassula subg. Crassula (Friedrich 1973) and some other genera (Sharma and Gosh 1967). Most larger and also some smaller genera exhibit different base numbers and few to many polyploids, partly including high polyploids. Closely related genera often, but not always, exhibit different base numbers. Karyological variability reaches an extreme in Sedum and especially in the Echeveria group (Uhl 1992). Among the 62 studied European/Mediterranean Sedum species, about 140 cytotypes with all base numbers from 5 to 18 and some higher ones (20, 22, 24, 25, 29, 37) have been found. The data show that 64% of these cytotypes are polyploid, and nearly half of the species exhibit polyploids among diploids, some of them high polyploids (S. rubens: 20×) or complete series (S. forsterianum: 2 to 8×), partly also dysploids (’t Hart 1991). The high degree of polyploidy is attributed at least partly to allopolyploidy (’t Hart 1991), which was demonstrated experimentally (’t Hart et al. 1993). The Mexican Sedum suaveolens exhibits the highest chromosome number in angiosperms, n = 320 (= 40×). See also under Reproductive Systems. Pollination and Reproductive Systems. Flower induction in Kalanchoe is under short-day conditions (Engelmann 1960), whereas Hylotelephium telephium is a long-day plant (’t Hart and

van Arkel 1985). In Echeveria, short- as well as long-day plants are found (Rünger and Wehr 1969). Flowers are usually proterandrous, with the anthers of the antesepalous (inner) stamens releasing pollen before the anthers of the antepetalous (outer) ones. Sometimes, anthers dehisce already within the floral bud (Wassmer 1955). Proterogyny and homogamy are rare (e.g. some European Sedum). Differentiation among the two whorls for allogamy (stamens of outer whorl bending over petals) and autogamy (inner whorl remaining erect or bending over stylodia), respectively, is common in European Sedum and Sempervivum (Günthart 1902). Stamen movements are extreme in Graptopetalum, where the stamens curve back towards the sepals and petals during anthesis (Moran 1949). Crassula (Tillaea) muscosa is autogamous, and C. aquatica appears to be cleistoand autogamous (Berger 1930); some tendency towards cleistogamy has also been observed in Sempervivum sect. Jovibarba (Günthart 1902:61). Crassulaceae appear to be usually selfincompatible but Sedum sect. Gormania shows self-compatibility in varying degrees (Denton 1979). Fecundity in Echeveria gibbiflora is limited by pollen and resource availability (Parra et al. 1998). In Hylotelephium telephium, di-, tri- and tetraploid cytotypes are sympatric (’t Hart 1985b). Studies on the conservation genetics of Rhodiola integrifolia subsp. leedyi (Olfelt et al. 1998, 2001) and Dudleya multicaulis (Marchant et al. 1998) revealed a high intrapopulation genetic variation, indicating little gene flow among the isolated populations. Floral biology is poorly studied and largely restricted to the establishment of floral types and pollination syndromes. The carpellary nectary scales exude nectar in large quantities, which often forms glistening droplets. The few Crassulaceae without nectary scales may have deceptive flowers. Five major pollination syndromes are found (mostly taken from Vogel 1954). 1. Melittophily is assumed for taxa with a free, rotately spreading (e.g. most Sedum, many Telephieae and Umbiliceae, Aeonium, Sempervivum) or short tubular corolla (e.g. many Crassula species, Kalanchoe p.p., Tylecodon p.p. (Gess et al. 1998), Umbilicus). It represents the most frequent and least specialised, possibly plesiomorphic syndrome in Crassulaceae. 2. Psychophily corresponds to long-tubed salvershaped flowers (Adromischus, Pistorinia,

Crassulaceae

Kalanchoe, e.g. K. rotundifolia) or flowers with at least connivent petals forming a tube-like structure (e.g. Crassula coccinea) and intensive colouration (red, yellow) and scent production over the day. This floral type has earlier led to artificial generic segregations (e.g. Rochea for long-‘tubed’ Crassula species such as C. coccinea). 3. The sphingophilous syndrome (long, whitish corolla tubes, nocturnal scent) appears to be restricted to a few Crassula (e.g. C. fascicularis; detailed study by Johnson et al. 1993) and some Kalanchoe (e.g. K. marmorata), and thus to Africa. 4. Ornithophilous flowers (red, long-tubed corollas, lack of odour, abundant nectar production, exserted anthers) are found in species of Kalanchoe, Cotyledon, Tylecodon, Echeveria (Parra et al. 1993) and Dudleya. There appears to be a gradual transition from psycho- or melittophily to ornithophily. The psychophilous Crassula coccinea is also visited by nectar birds (Vogel 1954). In Dudleya, the gradual shift from bee to hummingbird pollination has been demonstrated to be accompanied by changes in nectar amount, increase in tube length, colour shift to reddish corollas, and shift from low to high auto-fertility (Levin and Mulroy 1985). 5. Myophily is assumed for Monanthes (open flowers with darkish colours, freely accessible nectar produced by large nectary scales; Vogel 1954). Carrion flies are possible pollinators for the fade-coloured and foetid flowers of most Graptopetalum (Moran and Meyrán 1974). In both genera, the darkish to fade flower colours are accompanied by corresponding anther colours (Thiede, unpubl. data). Some Crassula and Sedum species with small, insignificant whitish flowers with a musky scent are probably also fly-pollinated. The report of effective ant pollination for Sedum pusillum is one of the few known cases of ant pollination in angiosperms (Wyatt and Stoneburger 1981). When exploiting the freely accessible nectar from the nectary scales, the ants ‘accidentally’ transfer pollen over the dense stands of the plant, but bee pollination also occurs. Flower visits by ants were also reported for Kalanchoe (Bahadur et al. 1986) and may be more frequent, at least accidentally. Melittophily is widespread and dominates in the northern temperate region, whereas psycho-,

89

sphingo- and ornithophily are restricted to (sub)tropical or southern temperate regions. Pollination syndromes in southern Africa are more diversified than in North America. The derived pollination syndromes are certainly of multiple origin within Crassulaceae, possibly from the plesiomorphic melittophily. Hybridisation patterns in European Sedeae are strictly correlated with the presence or absence of four morphological character states (see Subdivision). Species can be hybridised only when they agree in all four character states, but not all hybrids are possible (’t Hart and Koek-Noorman 1989). In Aeonieae, hybridisation patterns correspond to present generic boundaries between Aichryson, Monanthes and Aeonium (incl. Greenovia): no hybrids between genera, but many within these genera are possible. The c. 200 species of the Echeveria group appear to be fully interfertile (though natural hybrids are rare) and form the largest comparium known among angiosperms (Uhl 1992). Fruit and Seed. Fruits are usually many-seeded follicles which dehisce xerochastically; hygrochastic opening is rare (e.g. Sedum acre). Fruit dehiscence is sometimes reversible under humid conditions (Phedimus aizoon; Huber 1961) or, vice versa, the suture opens fully only under humid conditions but closes again when drying out (Sedum acre and S. annum; Stopp 1957). The ripe follicles either remain upright (orthocarpic) or become divergent to stellate-patent (kyphocarpic). An earlier classification of Sedum based on these features (Fröderström 1930–1935) proved to be artificial. Follicles of most genera dehisce completely along the ventral suture; other types are more rare: the suture mainly opens apically or basally only, or the plicate carpel part breaks off as a whole (Aeonium sect. Greenovia). Some species of Crassula sect. Glomeratae have only 1- or 2-seeded follicles from which the upper part breaks off with circumscissile splits and encloses one or two seeds (Stopp 1957; Toelken 1977). Similar fruits are found in Hypagophytum and some Sedum. Sedella and Sedum microcarpum have one-seeded, non-dehiscent nutlike fruits, and the fruits of Sedum smallii dehisce with a tear-shaped flap unique within the family (Clausen 1975). In European Sedum, kyphocarpic follicles usually exhibit carpel walls broadened to ± distinct ‘lips’ (possibly favouring splash-cup dispersal by rain), whereas orthocarpic follicles are without lips (’t Hart 1991).

90


Fig. 26. Crassulaceae. Seed surface structures. A Crassula streyi. Sinuate (unipapillate) (‘Puzzle-Modell’ of Knapp 1994): anticlinal walls sinuate, periclinal walls usually convex to centrally papillate or rarely almost smooth (Crassuloideae). Types B–D Anticlinal walls straight. B Kalanchoe brachyloba. Costate (bipapillate) (‘Leitermodell’): cells with two papillae at each distal end. The papillae remain ± free or are mostly fused to form distinct costae with those of the neighbouring cells, partly with transverse connections (Kalanchoideae and all Sempervivoideae,

except for the following). C Umbilicus horizontalis. Multipapillate (‘Warzenmodell’): cells with 2–3(–5) small papillae which are usually unequal in size and form small groups with those of adjacent cells (only genus Umbilicus within tribe Umbiliceae). D Sedum wrightii. Reticulate (unipapillate) (‘Wabenmodell’): the lateral cell-walls are always thickened and form a distinct reticulate pattern, usually with a central papilla (Acre clade). Scale: A 100 µm, B 1,000 µm, C, D 10 µm. (A, C From Knapp 1997 and B, D from Knapp 1994)

The seeds are ± oblong-fusiform, ± brownish, usually 0.5–1 mm long and weighing c. 0.02 mg (Sempervivum). The East African Sedum epidendrum and the Mexican S. botteri and related species exhibit seeds up to 3 mm in length, a possible adaptation to their epiphytic habitats (Clausen 1959: 46; Gilbert 1985). The seed coat is 4-layered: the exotestal cells have a ± thickened outer wall, the inner exotegmic cell layer is pigmented, and the two middle layers are completely crushed (Krach 1976). The chalazal region is obtusely

rounded or elongated to acute (apiculate; Fig. 26B; Knapp 1994: 163). The micropylar region is partly surrounded by the outcurved testa which forms a distinct corona (Fig. 26B; Kalanchoideae, some Sedum; ’t Hart and Koek-Noorman 1989; Knapp 1994: 163). In SEM studies of testa structures (’t Hart and Berendsen 1980, for Sedum; Knapp 1994, 1997), four main types are distinguished, differing mainly in the number and position of papillae and concurring well with phylogenetic patterns (Fig. 26A–D): A sinuate-unipapillate with

Crassulaceae

sinuate anticlinal walls, or B costate-bipapillate, C multipapillate and D reticulate-unipapillate with straight anticlinal walls. Specific SEM datasets have been published for Crassula (Bywater 1980; Wickens and Bywater 1980; Bywater and Wickens 1983), Sedum sect. Ternata (Calie 1981), Sedum sect. Gormania (Denton 1982), Rosularia and Prometheum (Eggli 1988), Monanthes (Nyffeler 1992) and East Asian taxa (Gontcharova 1999). Dispersal. The follicles usually release the seeds immediately after ripening. The seeds are dispersed by gravity and wind, but are much larger than typical anemochorous dust seeds (e.g. orchids, many parasites). Nakanishi (2002) recorded splash-cup dispersal by raindrops for the divergent follicles of two Japanese Sedum spp.; this mechanism may be more frequent. The seed number in Crassulaceae may be very high (an old inflorescence of Aeonium nobile was estimated to produce about 50,000 flowers (Burchard 1929) and 500,000 or even much more seeds). Most seeds are dispersed over short distances as anemochorous seed rain around the mother plant (Parra et al. 1993). Anemochorous long-distance dispersal appears to be rare, as evidenced, e.g. by the closely related island vicariants on the Canary Islands, and the rarity of pronounced disjunctions. Evidence for long-distance dispersal comes from molecular data (van Ham and ’t Hart 1998; Mort et al. 2001). Berger (1930) suggested the possibility of secondary dispersal by water and ants, but evidence is wanting. Ripe seeds typically remain viable for a few years only or even less. On wet soil, seeds typically germinate within a few days (in cultivation) and generally in light. Studies on the germination ecology of the winter annuals Sedum pulchellum and S. smallii from the eastern USA revealed after-ripening of the seeds during summer, which is interpreted as an adaptation to summer-dry habitats (Baskin and Baskin 1972, 1977). Phytochemistry. Reviews are given by Hegnauer (1964, 1989) and Stevens (1995a, b). Crassulaceae accumulate large amounts of sedoheptulose, which is the most abundant sugar in most species. In contrast to many other succulents, nearly all species investigated to date contain isocitrate (Hegnauer 1964). Proanthocyanidins (condensed tannins) have been found in all clades, except for the Acre clade

91

where they are absent or at least rare and replaced by alkaloids (Stevens et al. 1992, 1995; Stevens 1995a). Proanthocyanidins are widespread both in woody and herbaceous Crassulaceae. The lack of exclusivity in the woody representatives supports the hypothesis that Crassulaceae are primarily herbaceous (Stevens 1995a), which is also supported by wood anatomy (see there). Galloyl esters are common, but ellagitannins are absent, in contrast to Saxifragaceae and Penthoraceae (Jay 1971). Flavonols and flavones, both unmethylated and methylated, are known to occur in Crassulaceae, but myricetin is rare (Denton and Kerwin 1980; Hegnauer 1989; Stevens et al. 1996). Wax composition (in particular, alkane and triterpene profiles) has been studied by Eglinton et al. (1962), Manheim et al. (1979), Bowman (1983) and Stevens et al. (1994). Since the isolation of sedamin from Sedum acre in 1939, many different pyrrolidine and piperidine alkaloids have been detected in Sedum subg. Sedum (several studies on Sedum acre; see Hegnauer 1989; Stevens et al. 1993) and in Echeveria. Alkaloids thus seem to be restricted to the Acre clade, but they are absent in its more derived members (except Echeveria; Stevens et al. 1992, 1995). Cyanogenic substances have been found in some, but not all Crassulaceae studied. Cyanogenesis is weak especially in Sedum, and several species appear to be polymorphic in this respect (Hegnauer 1989). The South African Tylecodon paniculatus contains toxic bufadienolides which may cause a lethal cattle disease (‘krimpsiekte’). Structurally similar poisons occur in Tylecodon grandiflorus, Cotyledon and Kalanchoe (incl. Bryophyllum; Hegnauer 1989). Bufadienolides from Kalanchoe (Bryophyllum) are reported as potent, novel antitumor agents (Yamagishi et al. 1989) and insecticidal compounds (Supratman et al. 2001). Subdivision and Relationships Within the Family. The infrafamilial classification is under debate over the last 200 years (review by ’t Hart and Eggli 1995). Most classifications relied heavily on a few trivial characters such as habit, leaf arrangement, number of floral parts, degree of petal fusion, number of stamens, and position of ripe follicles. However, most of these characters are of restricted value due to extensive homoplasy (’t Hart 1995; van Ham and ’t Hart 1998; Mort et al. 2001). Molecular data (’t Hart et al. 1999) indicated

92


that sympetaly originated six times independently in European Crassulaceae of the Leucosedum clade. The widely accepted classification by Berger (1930) suffered strongly from such inadequacies. For instance, subfamily Cotyledonoideae, which includes Berger’s African/Eurasian sympetalous Crassulaceae, has long been revealed as artificial (e.g. Uhl 1948). ’t Hart and Koek-Noorman (1989) and ’t Hart (1991) discovered hitherto largely unrecognised characters of considerable systematic value in European Sedum and related genera: interspecific crossbreeding is possible only between species which agree in the character states for testa ornamentation (costate vs. reticulate-papillate), shape of the micropylar region (coronate vs. apiculate), sepal insertion (free vs. connate at base), and presence or absence of glandular hairs. Groups characterised by these long-overlooked characters usually agree well with those of molecular studies. Many other, such more cryptic characters have been established as synapomorphies for the major clades by Thiede (unpubl. data). Molecular data (cpDNA trnL-trnF spacer sequences: ’t Hart 1995; cpDNA RFLPs: van Ham and ’t Hart 1998; cpDNA matK sequences: Mort et al. 2001) led to the recognition of seven major clades; an eighth clade has recently been found (nuclear ITS and trnL-trnF sequences; Mayuzumi and Ohba 2004). From the six subfamilies of Berger, only the largely monogeneric Crassuloideae (Crassula) and Kalanchoideae (Kalanchoe s.l.) were found to be monophyletic. Here, the revised classification of Thiede (unpubl. data) is adopted, which largely follows the sequencing convention (Fig. 27), i.e. it assigns the same rank to clades which branch off subsequently (three major clades: subfamilies; five major clades within Sempervivoideae: tribes). This contrasts with a previous proposal by ’t Hart (1995), who followed the ranking convention and classified the two sister-clades of subsequent di-

chotomies with formal ranks in descending order. Here, three subfamilies are recognised, as suggested earlier by Thorne (1983, 1992): the two morphologically well-supported Crassula and Kalanchoe clades are recognised as Crassuloideae (Crassula clade) and Kalanchoideae (Kalanchoe clade) respectively, and the remaining six clades are subsumed as Sempervivoideae (formerly Sedoideae). Within the latter, five tribes are recognised (Fig. 27): the Hylotelephium clade as tribe Telephieae, the Rhodiola clade as tribe Umbiliceae, the Sempervivum “clade” as tribe Semperviveae, the Aeonium clade as tribe Aeonieae, and the Leucosedum and Acre clades together as tribe Sedeae. It should be noted that the Crassula and Kalanchoe clades, which preferentially are (sub)tropical, are morphologically highly derived (see diagnoses of subfamilies Crassuloideae and Kalanchoideae), whereas the predominantly temperate Sempervivoideae largely retain the basic features of the family which have been recognised by outgroup comparison. For this reason, the taxonomic treatment starts with subfamily Sempervivoideae characterised by the basic features of the family. Molecular data (’t Hart 1995; van Ham and ’t Hart 1998; ’t Hart et al. 1999; Mort et al. 2001) indicated that Sedum, by far the largest genus of Crassulaceae, is highly paraphyletic. Sedum encompasses the least specialised species groups within the Semperviveae, Aeonieae and Sedeae, and is definable with plesiomorphic features only. All other genera in these tribes are derived from within Sedum and form a monophyletic lineage together with the latter. This implies that many segregates of Sedum are closely related to other genera in the Sempervivum, Aeonium, Acre and Leucosedum clades. In order to reflect phylogenetic relations within Semperviveae, Aeonieae and Sedeae, the segregates of Sedum identified to date by molecular studies are placed according to these molecular data. For most segregates, no generic names other than Se-

Fig. 27. Summary tree of Crassulaceae, showing the eight major clades, their number of genera/species (incl. Sedum), their main distribution, and the formal classification. The number of synapomorphies for the major clades (if any) is indicated above the branches; bootstrap support below the branches (∗ = 50–70%; ∗∗ = 71–90%; ∗∗∗ = 91–100%). The genus Pistorinia of tribe Sedeae is not included. Further explanations are provided in the text. Combined from molecular data of van Ham and ’t Hart (1998), cpDNA restriction sites, Sempervivum clade; Mayuzumi and Ohba (2004) and

Mayuzumi (unpubl. data), ITS and trnL-F sequences, Hylotelephium and Rhodiola clades; Mes et al. (1995), trnLF sequences, Aeonium clade; Mort et al. (2002), matK, trnL-F, psbA-trnH and ITS sequences, Aeonium clade; and Mort et al. (2001), matK sequences, all other clades. Abbreviations: Appendic. = subsect. Appendiculatae, S. = Sedum with [G] = subg. Gormania and [S] = subg. Sedum, Medit. = Mediterranean, Eur. = Europe, N. East = Near East, Umbilic. = Umbiliceae, Semper. = Semperviveae, Kalan. = Kalanchoideae, Cras. = Crassuloideae

Crassulaceae

93

94


dum are available (except for Petrosedum or perhaps Oreosedum, Amerosedum, etc.). However, the phylogenetic status of most of these segregates is insufficiently known, not to mention the dearth of morphological characters which could define them. Therefore, they are all classified here under Sedum but mentioned in the respective clades along with the genera most closely related to them. It is unlikely, and not intended, that any of these segregates will ever be elevated to generic status. The inclusion of all genera derived from within Sedum into a broadly defined, then monophyletic Sedum would be highly impractical because of the dramatic morphological heterogeneity of the resulting taxon. The other course, splitting Sedum into numerous constituent monophyletic taxa, would result in a tremendous increase of very small genera usually ill-defined morphologically; most of these can not be identified with present knowledge. A third option would be the inclusion of the segregates of Sedum into the existing, cladistically contiguous genera. Again, apart from presently insufficient knowledge and lack of morphological characters of these clades, several consist only of species of Sedum and do not contain a genus with which these could be united taxonomically (see particularly the molecular data for European Sedum by ’t Hart et al. 1999). Here, we follow ’t Hart’s (1995) suggestion to accept Sedum as a paraphyletic grouping. Genera derived from within Sedum should be monophyletic and for practical reasons not monospecific, and morphologically well defined (cf. ’t Hart 1995: 165), but this is not yet achieved for all genera (see especially the Echeveria group). A molecular clock model dates the origin of Crassulaceae at 69–77 Ma B.P., of the Crassuloideae/Kalanchoideae+Sempervivoideae split at 39–41 Ma B.P., of the Kalanchoideae/Sempervivoideae split at 25–29 Ma B.P., and of the split between the Leucosedum and Acre clades at 13–18 Ma B.P. (Wikström et al. 2001; cf. Fig. 27). A complete species-level taxonomic synopsis is provided by Eggli (2003). Affinities. Crassulaceae were usually placed next to Saxifragaceae and the monogeneric Penthoraceae, either within Rosales (Cronquist 1968; Thorne 1968) or Saxifragales (Takhtajan 1969; Thorne 1992). The circumscription of Crassulaceae is nearly undisputed, except for the inclusion of Penthorum by some authors (de Candolle 1828; Torrey and Gray 1838; Schönland 1894; Hutchinson

1973). Molecular data (Morgan and Soltis 1993; Soltis and Soltis 1997; Fishbein et al. 2001) establish the monophyly of Crassulaceae. Putative morphological synapomorphies are leaf succulence, anisocytic stomata and carpellary nectary scales. Homoplasious synapomorphies are thyrsoid inflorescences, papillate seeds and obdiplostemony, which are shared with Saxifragaceae; papillate seeds are also found in Penthoraceae. Penthorum, formerly included in Crassulaceae, approaches some Phedimus species and its peculiar fruit is similar to that of Sedum (Diamorpha), but it differs clearly from Crassulaceae in its non-succulent leaves with anomocytic stomata, its vessel and fibre structure, its diplostemonous flowers, in having the follicles connate almost to the middle, the lack of carpellary nectary scales, the presence of an operculum, and in its chemistry (see Penthoraceae, this volume). Saxifragaceae differ primarily in their oligomerous gynoecium, the presence of a nectariferous disc and of non-succulent leaves with stipules or sheathing leaf bases, and usually anomocytic stomata (see Saxifragaceae, this volume). According to molecular data, Crassulaceae belong to a distinct clade within Saxifragales, from which Crassulaceae, Aphanopetalaceae, Tetracarpaeaceae, Penthoraceae and Haloragaceae branch off successively. Stevens (2005) lists an axis with endodermis, nodes 1:1 and the lack of stipules as putative morphological synapomorphies. This clade is in turn sister to a clade which includes Saxifragaceae, Grossulariaceae, Iteaceae and Altingiaceae (Savolainen, Chase et al. 2000; Savolainen, Fay et al. 2000; Soltis et al. 2000; Fishbein et al. 2001). Distribution and Habitats. Crassulaceae occur almost worldwide. General distribution patterns and centres of diversity are described by ’t Hart (1997a); for North America, a detailed survey is given by Thiede (1995), and climatic correlations are presented by Teeri et al. (1978). More focused datasets have been published for Sedum (Böttcher and Jäger 1984), European taxa (Meusel et al. 1965; Jalas et al. 1999), Mediterranean Sedum (’t Hart 1997b), Crassula (Jürgens 1995), Tylecodon and Cotyledon (van Jaarsveld 1994), and Rhodiola (Ohba 1989). Crassulaceae are often viewed as a typical northern temperate element, but species diversity is concentrated in Mexico (about 325 species) and South Africa (about 250 species). The taxa of the eastern USA and especially the Mexican upland regions represent a distinct terminal clade within

Crassulaceae

the Acre clade, including the majority of North American Crassulaceae (van Ham and ’t Hart 1998; Mort et al. 2001). Southern African Crassulaceae belong exclusively to Crassuloideae (Crassula) and Kalanchoideae (van Ham and ’t Hart 1998; Mort et al. 2001). Genera of the latter are predominantly distributed in either the winter-rainfall (Tylecodon, Adromischus) or the summer-rainfall region (Kalanchoe). Cotyledon and Crassula are distributed in both regions, but many sections in the latter are specialised (Jürgens 1995). Diversity centres of secondary importance are the wider Californian winter-rainfall region (lineage within the Leucosedum clade with Sedella, Dudleya and the American Sedum subg. Gormania), Macaronesia (Aeonieae and a few Sedum species of the Acre clade), the Mediterranean (mainly Leucosedum clade: Sedum subg. Gormania, Pistorinia and Rosularia, and a few Sedum subg. Sedum in the Acre clade), the wider Himalayan region (Telephieae and Umbiliceae and the Asian Sedum subg. Sedum), East and Northeast Africa (Crassula, Kalanchoe, Sedum, Cotyledon, Hypagophytum, Afrovivella), and Madagascar (Kalanchoe, Perrierosedum, a few Crassula). All these centres, except for the Himalayan one, exhibit at least one or two (near-)endemic genera. Crassulaceae are poorly represented in the humid tropics as well as in South America (Thiede 1995) and Australia (Toelken 1986). Most genera are confined to a single continent. Exceptions are Sedum, Kalanchoe, the circumboreal Rhodiola and Hylotelephium, and the semi-aquatic Crassula (Tillaea), the worldwide distribution of which is attributed to long-distance dispersal by birds (Bywater and Wickens 1983). Of the genera restricted to the New World, only Echeveria and Villadia extend to South America, separated by a broad gap in Central America; all others are confined to North America and Guatemala (Thiede 1995). Migration and diversification of Crassulaceae principally followed the route (southern) Africa → Asia → Europe-Mediterranean → (northern) America (Fig. 27; see also van Ham and ’t Hart 1998 and Mort et al. 2001). Since Crassuloideae and Kalanchoideae are mainly southern African (Fig. 27), a first major diversification in southern Africa is assumed. The next branching clades, Telephieae and Umbiliceae, are mainly Asian, with Umbilicus and Phedimus extending to the eastern Mediterranean. Semperviveae extend from the Middle East to the Mediterranean and parts of Europe. Aeonieae and Sedeae are basically

95

European-Mediterranean. Aeonieae are diversified in Macaronesia, and Sedeae include distinct northern American lineages within the Leucosedum and Acre clades. The northern temperate clades are poor in species; whereas northern American and southern African lineages are highly diversified (Fig. 27). Growth form zonation reflects the climatic conditions: hemicryptophytes (Hylotelephium, many Umbiliceae) are restricted to northern temperate regions, annuals occur in climates with short vegetation periods, especially in winter-rainfall regions (’t Hart 1997b) and in alpine regions especially in East Asia, and subshrubs are restricted to regions without severe frosts. In contrast, small, often rooting and/or mat-forming herbs as well as stem-less rosette plants occur nearly throughout all regions (cf. also Böttcher and Jäger 1984 for Sedum). Crassulaceae generally prefer azonal sites, usually with more moderate temperatures and higher air humidity. Most taxa grow in arid habitats such as rocks and rock fissures under otherwise more humid climatic conditions, or in mountain regions in moderately arid areas, and are largely absent from hot deserts and arid lowlands. An exception is the arid coast of California, where many Dudleya species occur under moderate temperatures on coastal rocks exposed to sea breezes and fog (Thiede 2004), and the arid southern African Succulent Karoo, which exhibits a considerable species richness. Many rock plant communities with Crassulaceae have been described for Tenerife (Rivas-Martínez et al. 1993), Europe (Ellenberg 1996), Africa (Knapp 1973) and Arabia (Deil 1991). More unusual habitats are wet bogs (e.g. Sedum villosum), ephemeral water ponds where many Crassula (Tillaea) occur nearly hydrophytic, seasonally wet rock pools (e.g. Sedella), or moist forests with a few epiphytic Echeveria (Mexico, Central America), Sedum (Central and East Africa) and Kalanchoe (Madagascar). Edaphic specialisation is rare, e.g. Sempervivum dolomiticum is found only on dolomite, and Sedum alpestre occurs on siliceous and Sedum atratum on calcareous soil (Huber 1961). Germination and seedling establishment in rock habitats often occur within lichen or moss covers (e.g. Dudleya; Riefner et al. 2003). Crassulaceae frequently represent a first pioneer vegetation on shallow soils (e.g. Braun-Blanquet and Sutter 1982). Parasites. Specific crassulacean fungal parasites, the powdery mildews Erysiphe sedi and

96


Microsphaera umbilici (Braun 1987) and the rusts Puccinia umbilici and P. rhodiolae and Uromyces sedi, are all restricted to Telephieae and/or Umbiliceae. For further data on specific Puccinia, see Huber (1961). The rust fungi Endophyllum sempervivi and the mildews Fusarium solani and Phytophthora nicotianae var. parasitica occur on Sempervivum leaves (Ph. Neeff; in litt. 2004). The mildew Oidium kalanchoeae is known only from cultivated Kalanchoe (Braun 1987). Within angiosperms, Cuscuta campestris (Convolvulaceae) and Tapinanthus oleifolius (Loranthaceae) are unspecific parasites on Cotyledon (Visser 1981). Cuscuta spp. are occasionally found on European/Mediterranean Sedum, Petrosedum and Aeonium (U. Eggli, pers. obs.). Several mining insect larvae feed specifically on Crassulaceae: Sandia xami (Lepidoptera) on Mexican species (Jiménez and Soberón 1989), Phytomyza sedi (Diptera) and Glyphipteryx equitella (Lepidoptera) on European Sedum, and Phytomyza rhodiolae (Diptera), P. sedicola, Yponomeuta vigintipunctatus (Lepidoptera) and Apion sedi (Coleoptera) on European Telephieae and/or Umbiliceae (Huber 1961; Bland 1995). Thuleaphis sedi is a specialist aphid on Rhodiola rosea (Jacob 1964). Physiology. Nocturnal CO2 fixation based on the Crassulacean acid metabolism (CAM) pathway was first detected in Crassulaceae and named after this family, although it is now known to occur in many succulent taxa and a few non-succulents. CAM is expressed in many Crassulaceae and is either constitutive or facultatively induced under certain environmental conditions, especially under drought stress, and is found even in the weakly succulent semi-aquatic Crassula (Tillaea; Keeley 1998). Detailed data on CAM have been published for Sedum and Aeonium (Pilon-Smits 1992), Macaronesian Aeonieae (Lösch 1990), and Kalanchoe (Kluge and Brulfert 1996). Crassulaceae and other CAM plants are often highly endopolyploid (de Rocher et al. 1990), but the reason for this is unknown. Most Crassula studied by Martin and von Willert (2000) absorb water deposited on the leaf surfaces via hydathodes (see Vegetative Anatomy), which may subsequently stimulate CO2 fixation rates. Palaeobotany. Probably no fossil remains are known (Thomas Bolliger, pers. comm.); leaf fossils ascribed to Crassulaceae (e.g. Crassulaceophyllum) are doubtful.

Economic Importance. Apart from their horticultural value, Crassulaceae have minimal economic importance. Kalanchoe blossfeldiana cultivars are annually produced in large quantities as popular pot plants. Species of Hylotelephium, Phedimus, Sedum and Sempervivum are frequently cultivated in rock gardens and increasingly used for ‘green roofs’. Most perennial taxa of the family are choice collectors’ plants and commonly grown by succulent plant enthusiasts. Overviews of genera and species of horticultural importance are given by Cullen (1995) and Huxley et al. (1997). Several species, especially Kalanchoe pinnata, are aggressive invaders in the tropics. Nowadays, Crassulaceae are not used for food, although especially Petrosedum rupestre (vernacular name ‘Trip-Madame’) was recommended for salad in medieval herbals (’t Hart 1997a) and has locally been used as salad or pot-herb (Lippert 1995). The fleshy leaves may appear appealing in arid environments, but they are completely tasteless or bitter and are generally avoided even by cattle (’t Hart 1997a). Rhizomes of Rhodiola rosea have some use in folk medicine and were used officinally (‘Rose Root’; Radix Rhodiolae); an ethnobotanical review for Norway lists many uses (Alm 2004). For further data on folk uses and folk names of Central European taxa, see Huber (1961). Several Asian species of Rhodiola have been the subject of intense phytochemical and pharmacological studies (e.g. Kurkin and Zapesochnaya 1986; many older Russian references listed by Clausen 1975: 531). The medicinal properties of their rhizomes were known for a long time, and recent investigations have identified a vast array of different chemical compounds (e.g. Yoshikawa et al. 1996). There exist attempts for the large-scale cultivation of at least R. sachalinensis for the improved production of certain bioactive compounds (e.g. Xu et al. 1998). Conservation. Most Crassulaceae occur in rocky places not prone to habitat destruction (’t Hart 1997a). Narrow endemics (frequent in California, Mexico, Africa, Madagascar and Macaronesia) may be seriously threatened by land development and tourism. For example, two of three accessible populations of the Madeiran Sedum fusiforme have been destroyed during the construction of tourist accommodations (’t Hart 1997a). Legal and illegal trade and collecting of wild plants do occur but appear to be rather restricted,

Crassulaceae

compared to other succulents, due to low demands and easy vegetative and generative propagation (data for South Africa: Newton and Chan 1998). Genera popular in horticulture are typically protected under state laws (e.g. Sempervivum, Aeonium and Aichryson). Sedella leiocarpa and eight Dudleya taxa are listed as endangered in the USA (U.S. Fish and Wildlife Service 2004). Many data (general and per country listings with IUCN categories) are included in Oldfield (1997). Golding (2002) lists the IUCN Red Data List categories for many southern African species per country. Studies on the conservation biology (reproduction, life history, population genetics) are available for Rhodiola integrifolia and Dudleya multicaulis (see Reproductive Systems). Special ex situ propagation programs have been initiated for some endangered local endemics (e.g. the Madeiran Aichryson dumosum, Fernandes 1997). Most genera and species of horticultural appeal appear to be cultivated in specialised public and private collections.

97

Stamens equal in number to petals 2. Leaves usually decussate, rarely verticillate; with hydathodes along margins and/or leaf face; seeds sinuatepapillate (Crassula type) 3 – Not as above; leaves spiral 4 3. Perennial tuberous herbs, flowers 10–12-merous; fruits 2-seeded, breaking transversely (Ethiopia) 34. Hypagophytum – Not as above; when plants tuberous or flowers polymerous, then fruits not few-seeded 33. Crassula 4. Plants with persistent or monocarpic rosettes 5 – Plants without rosettes 7 5. Monocarpic rosette-forming herbs (Asia) 6 – Perennial shrublets with lax rosettes at branch tips (Mexico) 25. Graptopetalum p.p. 6. Inflorescences broad, flat-topped, corymboid thyrsoids 1. Sinocrassula – Inflorescences narrow-elongate thyrsoids 2. Kungia 7. Plants tuberous; leaves peltate; inflorescences elongate racemes 7. Umbilicus p.p. (U. heylandianus) – Not as above, annual to perennial herbs 8 8. Annual to perennial herbs; fruits many-seeded follicles (N hemisphere) 22. Sedum p.p. (e.g. S. rubens) – Minute annual herbs; fruits 1-seeded nutlets (USA: California) 20. Sedella p.p.

Stems frail or leaves caducous Conspectus of Crassulaceae I. Subfam. Sempervivoideae Arn. (1832). 1. Tribe Telephieae (’t Hart) Ohba and Thiede ined. (= Hylotelephium clade). Genera 1–5 Incertae sedis: genus 6 2. Tribe Umbiliceae Meisn. (1838) (= Rhodiola clade). Genera 7–10 3. Tribe Semperviveae Dumort. (1827) (= Sempervivum clade). Genera 11–12 and Sedum subg. Gormania p.min.p. (S. assyriacum, S. mooneyi) 4. Tribe Aeonieae Thiede ined. (= Aeonium clade). Genera 13–15 and Sedum subg. Gormania p.min.p. (series Caerulea, Pubescens and Monanthoidea) 5. Tribe Sedeae Fr. (1835). a. Leucosedum clade Genera 16–21 and Sedum subg. Gormania p.maj.p. b. Acre clade Genera 22–28 and Sedum subg. Sedum II. Subfam. Kalanchoideae A. Berger (1930) (= Kalanchoe clade). Genera 29–32 III. Subfam. Crassuloideae Burnett (1835) (= Crassula clade). Genera 33–34

Perennials with monocarpic rosettes with terminal inflorescences

Key to the Genera 1. Stamens equal in number to petals – Stamens double in number to petals

9. Perennials, but leaves or aboveground stems annually caducous 10 – Annual or biennial, or perennial and then with at least some perennating leaves 17 10. Stems perennial, succulent, ± elongated; leaves crowded at branch tips (southern Africa) 31. Tylecodon – Stems annual, not succulent; perennials with underground tubers, rhizomes or thickened roots (usually outside Africa) 11 11. Plants with tuberous stems 12 – Plants with rhizomes, caudices or thickened roots 13 12. Leaves not peltate; inflorescences axillary, cymose (W USA and Baja California) 21. Dudleya p.p. (D. sect. Hasseanthus) – Leaves usually distinctly peltate; inflorescences terminal, racemes or panicles 7. Umbilicus p.p. 13. Plants with thickened roots; leaves terete-subulate (America) 23. Villadia p.p. – Plants with rhizomes or caudices; leaves flat 14 14. Carpels narrowed at base (stipitate-attenuate) 5. Hylotelephium – Carpels with broad base 15 15. Rhizomes thin; inflorescences pleiochasia 10. Phedimus p.p. – Plants with very thick rhizome; inflorescences thyrsoids 16 16. Petals free; flowers often unisexual (plants monoecious or dioecious) 9. Rhodiola – Corolla connate at base for 1/3–2/3 8. Pseudosedum

2 9

17. Plants with perennial monocarpic rosettes with terminal inflorescences 18

98


– Plants annual (rarely biennial or triennial), or perennial and then not with monocarpic rosettes with terminal inflorescences 24 18. Nectary scales larger than the insignificant petals (Canary Islands) 14. Monanthes p.p. (M. sect. Monanthes) – Nectary scales inconspicuous, much smaller than the showy petals 19 19. Flowers 5(rarely 6)-merous; inflorescences corymboid to much elongated and spike-like thyrsoids 20 – Flowers (5)6–32-merous; inflorescences corymboid to dome-shaped thyrsoids or with several cincinni, never spike-like 22 20. Inflorescences flat-topped, corymboid thyrsoids, or cymose, few-flowered (eastern Mediterranean, W Asia) 18. Prometheum p.p. – Inflorescences elongate, many-flowered 21 21. Partial inflorescences helicoid (Turkey, Iraq, Turkmenistan) 17. Rosularia p.p. (R. elymaitica) – Partial inflorescences never helicoid (C to E Asia) 4. Orostachys 22. Leaves semi-terete, not apiculate; flowers 5-merous; white (Europe/Mediterranean) 22. Sedum p.p. (e.g. S. hirsutum) – Leaves usually flat and apiculate; flowers 6–32-merous 23 23. Rosettes sessile, usually < 10 cm; inflorescences pleiochasia; flowers 6–18-merous, often pink to purple, rarely white or yellow; carpels (sub)erect (Europe to Caucasus) 11. Sempervivum – Rosettes sessile or at branch tips, often > 10 cm; inflorescences thyrsoids or pleiochasia; flowers (6–)10–32merous, often yellow or whitish, rarely reddish; carpels spreading (mainly Macaronesia, also N and NE Africa and SW Arabia) 15. Aeonium 24. Leaves decussate throughout length of stems 25 – Leaves alternate at least in upper stem parts, or in rosettes, rarely verticillate 32

Leaves decussate 25. Annual to biennial, glabrous to glandular-hairy herbs, to 15 cm; flowers (4)5-merous, white, pink or purplish; petals 4–5 mm (Mediterranean) 26 – Perennial herbs (rarely monocarpic), or shrubs or small trees, or lianas; flowers 4–6-merous; petals > 5 mm, in various colours 27 26. Annual glabrous herbs; inflorescences to 5 cm 10. Phedimus p.p. (P. stellatus) – Annual to biennial, glandular-hairy herbs; inflorescences to 60 cm 22. Sedum p.p. (e.g. S. cepaea) 27. Flowers 4-merous; herbs (rarely monocarpic) to shrubs or small trees, or lianas 30. Kalanchoe – Flowers 5- or 6-merous; shrublets or herbs 28 28. Flowers (5)6-merous, white 29 – Flowers 5-merous, not white (Africa, Caucasus, North America) 30 29. Shrublets to 80 cm tall (Madagascar) 6. Perrierosedum – Dwarf herbs to 10 cm tall (Europe/Mediterranean) 22. Sedum p.p. (e.g. S. dasyphyllum) 30. Herbs with creeping stems; leaves petiolate, flat and thin; inflorescences arching over; flowers yellow, narrowly urceolate (Caucasus) 7. Umbilicus p.p. (U. oppositifolius)

– Not as above 31 31. Shrubs; leaves not easily detached; flowers 2–3 cm, usually pendent; corolla connate at base (Africa, Arabia) 32. Cotyledon – Herbs; leaves often easily detached; flowers to 1 cm, ± upright; petals free (USA, Mexico) 24. Lenophyllum 32. Leaves verticillate (Africa) 22. Sedum p.p. (e.g. S. epidendrum) – Leaves alternate at least in upper stem parts, or in rosettes 33 33. Annual (to rarely biennial or triennial) herbs 34 – Perennial herbs to shrublets 40

Annuals 34. Flowers 6–7-merous, dirty white; nectary scales conspicuous, larger than the insignificant petals (Canary Islands) 14. Monanthes p.p. (M. icterica) – Flowers 5–12-merous; nectary scales inconspicuous and never larger than the showy petals 35 35. Flower 5-merous; corolla distinctly connate (Iberian Peninsula, N Africa) 36 – Flower 5–12-merous; petals (nearly) free 37 36. Filaments inserted at the base of the corolla tube; stylodia ±1 mm 22. Sedum p.p. (S. mucizonia) – Filaments inserted slightly below the mouth of the corolla tube; stylodia 2.5–5 mm 16. Pistorinia 37. Annual to biennial herbs; leaves flat; young plants with conspicuous basal rosettes (E Mediterranean) 22. Sedum p.p. (S. lampusae, etc.) – Young plants without basal rosettes 38 38. Fruits 1-seeded nutlets (USA: California) 20. Sedella p.p. – Fruits many-seeded follicles opening at ventral suture 39 39. Annual to triennial herbs; leaves flat, often ± rosulate near branch tips; flowers yellow; nectary scales 2–5-fid (Macaronesia) 13. Aichryson p.p. (A. sect. Aichryson) – Annual herbs; leaves ± semi-terete; nectary scales entire (northern hemisphere to E Africa) 22. Sedum p.p.

Perennials with large nectary scales 40. Nectary scales conspicuous, larger than the insignificant petals 41 – Nectary scales inconspicuous, much smaller than the showy petals 43 41. Leaves with bladder-cell idioblasts (Canary Islands) 14. Monanthes p.p. – Leaves without bladder-cell idioblasts 42 42. Flowers 5-merous; stems elongate, repent (Mexico) 22. Sedum p.p. (S. longipes) – Flowers 5–7-merous; stems short and thick; leaves in rosettes (Morocco) 22. Sedum p.p. (S. surculosum) 43. Inflorescences terminal; leaves not in rosettes 44 – Inflorescences lateral; leaves usually in distinct rosettes, or at least crowded at branch tips 49

Perennials without rosettes and with terminal inflorescences 44. Plants herbaceous, at highest slightly woody at base 45 – Plants shrubby 47 45. Corolla connate (Mexico, Peru) 23. Villadia p.p. (V. imbricata, etc.)

Crassulaceae – Petals free 46 46. Leaves ± densely imbricate and acuminate; flowers yellow(ish); fruits erect (Europe/Mediterranean) 12. Petrosedum – Leaves not densely imbricate nor acuminate; fruits erect to spreading (northern hemisphere to E Africa) 22. Sedum p.p. (p.max.p.) 47. Stems distinctly succulent, with ± flaking papery bark; inflorescences pleiochasia; petals free 22. Sedum p.p. (e.g. S. frutescens) – Stems not distinctly succulent, without flaking papery bark; inflorescences elongate; corolla connate 48 48. Leaves usually soft fleshy, semi-terete; inflorescences thyrsoids; filaments glabrous (America) 23. Villadia p.p. – Leaves firmly fleshy; inflorescences thyrses or spikes without terminal flower; filaments papillate where connate with corolla (southern Africa) 29. Adromischus

Perennials with rosettes, lateral inflorescences, and the corolla connate for most of its length 49. Corolla connate for most of its length; petals distinctly fleshy (America) 50 – Petals free or corolla connate for less than 1/2 of its length; petals membranous 51 50. Leaves usually very thick and with strong wax bloom; inflorescences cincinnoid; bracts usually very large and ± covering the flowers at anthesis; petals with basal scale on each margin (Mexico) 28. Pachyphytum – Inflorescences racemose, cymose-paniculate, spicate thyrsoids, or cincinnoid; petals usually without, rarely with small scales (southern USA to Argentina) 27. Echeveria

Perennials with rosettes, shrubby habit and lateral inflorescences, and petals free or corolla connate for 10 mm, some with uniseriate ends 1 or few cells high. Mature secondary stems producing successive cambia (except Curatella and perhaps also suffruticose Davilla spp.). Nodes (3)5(7)-lacunar; nodes bearing inflorescence axes, or in Davilla the primary inflorescence axis itself, producing subsequent flushes of inflorescences via proleptic proliferation buds. Inflorescences without prophylls, or prophylls irregularly produced in a few large-flowered species of Davilla; stigma conspicuously peltate, the margin annuliform and even; ovules 2 per carpel, typically 1 epitropous and 1 apotropous but the direction of ovule curvature variable among flowers of a given individual. When gynoecium apocarpous, fruits or partial fruits globose. Aril margin mostly entire; fleshy. 2. Davilla Vand.

Fig. 40. Dilleniaceae. Tetracera boiviniana. A Flowering branch. B Stamens. C Gynoecium, vertical section. D Carpel, transverse section. E Fruit. F Arillate seed. (Gilg and Werdermann 1925)

145

Fig. 41

Davilla Vand., Fl. Lusit. Brasil.: 35 (1788); Kubitzki, Mitt. Bot. Staatssamml. München 9:1–105 (1971), rev.; Aymard in Fl. Venez. Guayana 4:671–685 (1998).

Scandent shrubs or lianas. Leaves sometimes with amplexicaul petiolar wings. Inflorescence a pani-

146

J.W. Horn

abaxial sides of the carpels. Sepals reflexing after anthesis and hardly accrescent. 3. Curatella Loefl.

Fig. 38

Curatella Loefl., It. Hispan.: 260 (1758); Kubitzki, Mitt. Bot. Staatssamml. München 9:1–105 (1971), rev.

Fig. 41. Dilleniaceae. Davilla flexuosa. A Flowering branch. B Petal. C Androecium and gynoecium. D Stamen. E Carpel, vertical section. F Same, transverse section. G Fruit enclosed by inner sepals. H Same after removal of one sepal. I Arillate seed. (Gilg and Werdermann 1925)

cle with ultimate paraclades of triads or (less often) monads, never ramiflorous; sepals 5, free, the innermost 2 deeply concave, oppositely arranged, conspicuously larger than the ± flattened outer 3, and prominently accrescent; petals (3–)5; stamens 25–300, free; carpels 1–2(3). Fruit irregularly dehiscent, with very thin, papery walls, completely and indefinitely enclosed by the inner 2 accrescent sepals. Seeds partially or completely enclosed by a membranous, white aril. About 25 species, from southern Mexico to southern Brazil, Bolivia, and Paraguay; Antilles. Section Homalochlaena Kubitzki, inner sepals with their margins pressed against each other; sect. Davilla, innermost sepals with reflexed margin and overlapped at margin by the second innermost sepal.

A small to medium-sized tree. Vestiture also including fasciculate trichomes. Leaves coarsely scabrous, owing to the presence of silicified epidermal cells and trichomes. Sepals (3)4(5), subequal, free; petals (3–)5, the median petal adaxial, or occasionally reduced or missing; stamens c. 80, free; carpels covered with fasciculate and hispid, simple trichomes. Pericarp outer surface green, inner surface scarlet. Seed completely enclosed by a membranous to slightly fleshy white aril. n = 13. One species, C. americana L., a tortuous savanna tree widespread from southern Mexico to southern Brazil and Bolivia, Antilles. 4. Pinzona Mart. & Zucc. Pinzona Mart. & Zucc., Abh. Math.-Phys. Kl. Königl. Bayer. Akad. Wissensch. 1:371 (1832); Kubitzki, Mitt. Bot. Staatssamml. München 9:1–105 (1971), rev.; Aymard & Miller, Candollea 49:169–182 (1994).

A high-climbing liana, largely glabrous at maturity except for inflorescence axes. Sepals 3–4, subequal, shortly basally connate; petals (2)3; stamens 25–35, free; carpels glabrous. Seed completely enclosed within a fleshy orange aril. One species, P. coriacea Mart. & Zucc., throughout Central and South America from Belize to northeastern Brazil; Antilles. 5. Doliocarpus Rol.

Other Doliocarpoideae: Inflorescences exclusively axillary and (mostly) ramiflorous (possibly terminal in one Neodillenia sp.). Fruits with fleshy or leathery, typically brightly colored pericarps.

Curatella + Pinzona: Leaf lamina decurrent on the petiole. Inflorescence a panicle. Gynoecium hemisyncarpous; carpels 2. Fruit a fleshy or leathery capsule, the stylodia crossing as the fruit matures on account of an unequal amount or rate of growth between the adaxial and

Doliocarpus Rol., Kong. Svenska Vetensk. Acad. Handl. 17: 260 (1756); Kubitzki, Mitt. Bot. Staatssamml. München 9:1– 105 (1971), rev.; Aymard & Miller, Candollea 49:169–182 (1994); Aymard, Anales Jard. Bot. Madrid 55:17–30 (1997); Aymard in Fl. Venez. Guayana 4:671–685 (1998).

Shrubs, mostly scandent, or lianas. Inflorescence a panicle, botryoid, or uncommonly a monad; the inflorescences at each node often appearing fasciculate due to the large number of accessory buds produced; sepals 3–6, free; petals 3–7; stamens c. 25– 250, free; carpel 1(2). Fruit typically ripening red, baccate, dehiscing along both the dorsal and ventral side of the carpel (sometimes irregularly so), or indehiscent and berry-like. Seeds with a fleshy, entire, white aril. About 45 species, from southern Mexico

Dilleniaceae

and the Antilles to southern Brazil and Paraguay, with the center of species diversity in Brazil. In sect. Calinea Eichl., the stamens are straight to slightly contorted in bud; in sect. Doliocarpus, the stamens are all reflexed in bud.

Genus dubium 5a. Neodillenia Aymard Neodillenia Aymard, Harvard Pap. Bot. 10:121–131 (1997); Aymard in Fl. Venez. Guayana 4:671–685 (1998).

Lianas with successive cambia. Trichomes simple. Inflorescences axillary (and sometimes also ramiflorous) and consisting of a solitary flower or botryoid, or terminal and consisting of a solitary flower or impoverished panicle (botryoid). Flowers large; sepals 3–6, unequal; corolla unknown; stamens 80–300, free; gynoecium apocarpous or merely shortly synovarious of (1)2–5 carpels; ovules (1)2 per carpel, said to be orthotropous (but, confusingly, also with a ventral raphe), though in N. peruviana Aymard they are clearly campylotropous, with one ovule epitropous and the other apotropous in each carpel. Seeds enclosed in a fleshy, entire, red aril. Fruit an aggregate of follicles, unknown in N. venezuelana Aymard. Three species, in the Amazonian regions of Colombia, Ecuador, Peru, and Venezuela. Note that the stamens are entirely free (not shortly basally connate into a ring) and the ovules campylotropous (not orthotropous, cf. the orig. description). Neodillenia is clearly a member of subfamily Doliocarpoideae, as evidenced by its successive cambia, conspicuously peltate stigma with an even, annuliform margin, and ovular details. Neodillenia coussapoana and N. peruviana appear to be closest to large-flowered species of Doliocarpus sect. Doliocarpus, particularly D. grandiflorus and D. magnificus. The anther connectives of Neodillenia are of the same thickness as those of Doliocarpus magnificus and contain abundant raphid idioblasts, like Doliocarpus anthers. The only features that keep these two species separated from Doliocarpus are their red arils and gynoecia with typically 4–5 carpels. The monocarpellate N. venezuelana would be readily referable to Doliocarpus, except that it (apparently) has terminal inflorescences. Further work is needed to clarify both the structure and phylogenetic position of these plants.

147

Rest: Vessel elements with exclusively scalariform perforation plates, or rarely also with few simple plates in a few xeromorphic Hibbertia species. Multiseriate wood rays with uniseriate ends always extended into long wings 4 or more cells in height (Kribs Type I). When inflorescences consisting of more than 1 flower, the β-prophyll often displaced onto the branch borne in its axil. Perianth nearly always 5-merous. Pollen grains uniformly with simple, colpate apertures, typically 3-aperturate. III. Subfam. Hibbertioideae J.W. Horn (2005). 6. Hibbertia Andrews

Figs. 42–44

Hibbertia Andrews, Bot. Rep.: t. 126 (1800); Bentham, Fl. Austral. 1:17–41 (1863); Hoogland, Fl. Males. I, 4:141–174 (1951); Stanley in Stanley & E.M. Ross, Fl. SE Queensland 1:185–189 (1983); Jessop in Jessop & Toelken, Fl. S. Australia 4th edn, 1:354–358 (1986); J.R. Wheeler in N.G. Marchant et al., Fl. Perth Region 1:119–133 (1987); G.J. Harden & J. Evrett in G.J. Harden, Fl. New South Wales 1:293–303 (1990); Veillon in Fl. Nouv.-Caléd. Dépend. 16:3–86 (1990); Craven & Dunlop, Austral. Syst. Bot. 5:477–500 (1992), rev. of subg. Pachynema, p.p.; Wheeler in Fl. Kimberley Region 151–155 (1992); Toelken in Walsh & Entwisle, Fl. Victoria 3:300–313 (1996); Lewington & Cobb in Grieve, How to know Western Australian wildflowers, 2nd edn, 2:35–56 (1998); Murray in Fl. New South Wales suppl. 1:32–36 (2000); Wheeler in Fl. South West: Bunbury-Augusta-Denmark 2:570–579 (2002); Wheeler, Nuytsia 15:311–320 (2004), key to W. Austral. spp. Hemistema Thouars (1804). Candollea Labill. (1806). Pleurandra Labill. (1806). Adrastaea DC. (1817). Pachynema R. Br. ex DC. (1817). Trisema Hook. f. (1857).

Shrubs, uncommonly small to medium-sized trees, or subshrubs, sometimes rhizomatous, with mostly or only cataphylls and with photosynthetic function transferred to the stems, rarely vines or lianas; nodes 1- or 3-lacunar. Leaves frequently ericoid, sometimes also with fasciculate, rarely peltate trichomes; venation semicraspedromous to brochidodromous, very rarely craspedromous, secondaries only occasionally parallel, and tertiaries rarely percurrent and never scalariform; areolation typically incomplete or lacking. Inflorescence commonly a monad, infrequently a cincinnus or thyrsoid with serial,

148

J.W. Horn

cincinnate partial inflorescences, terminal and often also axillary, or infrequently apparently only axillary, uncommonly most of the plant body overtly inflorescence-like, and then a compound thyrsoid or panicle; sepals 5, unequal to ± equal, free or shortly fused; petals (3–)5, free; androecium of (1–)5–100(–300+) members, sometimes partly staminodial, basically polysymmetric or monosymmetric; polysymmetric androecia with the stamens all free, rarely all shortly basally connate, and ± evenly distributed around the carpels, or the stamens grouped into 3 or 5 distinct fascicles in which the stamen filaments may be all free, all shortly connate, or sometimes with 1 stamen free and the others in the fascicle connate; staminodes (when present) external to the fertile stamens, or (rarely) internal (subg. Pachynema); monosymmetric androecia always have the fertile stamens presented in the median plane of the flower and exclusively opposite the median petal, where they are free or fused into a single fascicle; staminodes, when present, external to and/or lateral to the fertile androecium, and uncommonly partly to entirely encircling the fertile stamens as a unit; anthers dehiscence via longitudinal slits or, sometimes, via apical pores; carpels 1–5(–10), glabrous or pubescent; ovules 1–25 per carpel. Seeds 1–8 per follicle; aril subfleshy or pulpy and oily or waxy, whitish, subentire, or rarely red and fleshy. About 225 species, from Madagascar (1 sp.) to Fiji (1 sp.), c. 200 species in Australia incl. Tasmania, 24 species in New Caledonia, 2 species in New Guinea. The division into four subgenera, presented here, is strongly supported by both molecular and morphological data (Horn 2005; J.W. Horn, unpubl. data). 6a. Hibbertia subg. Pachynema (R. Br. ex DC.) J.W. Horn (2005). Fig. 42 Subshrubs, sometimes rhizomatous; true leaves (if present) confined to basalmost nodes of a shoot, with craspedromous venation (the only instance of this within the genus); aerial axes green and photosynthetic, often caespitose and sometimes dimorphic, provided with mostly or (typically) only cataphylls. Inflorescence (which constitutes nearly the whole of the shoot system) a compound thyrsoid or panicle, commonly with serial branches or flowers; androecium typically bicyclic, with an outer whorl of 7(–10) fertile stamens and an inner whorl of 2 stamens or staminodes in the transverse plane of the flower; infrequently the androecium unicyclic and

Fig. 42. Dilleniaceae. A Hibbertia (subg. Pachynema) dilatatum, flowering shoot. B Hibbertia (subg. Pachynema) junceum, flowering shoot. C–F Hibbertia (subg. Pachynema) complanatum. C Flower bud. D Same seen from below. E Flower. F Androecium and gynoecium, vertical section. (Gilg and Werdermann 1925)

consisting of 4–5 stamens, apparently by reduction; carpels 2, ovules 2 per carpel. n = 12; 2n = 30. Nine species, including all species recognized by Craven and Dunlop (1992) in Pachynema, plus Hibbertia conspicua (Harv.) Gilg and H. goyderi F. Muell., in Australia, mostly confined to the Northern Territory (especially the Arnhem Plateau) and adjacent regions of the Kimberley of Western Australia, and in the Geraldton sandplains of the Southwest Botanical Province of Western Australia. 6b. Hibbertia subg. Hemistema (Thouars) J.W. Horn (2005). Fig. 43 Small shrubs to medium-sized trees; mature axes non-photosynthetic. Leaves moderately large and broad to (frequently) small and ericoid; vestiture frequently also including fasciculate trichomes (sometimes only), or infrequently including multiradiate to peltate trichomes. Inflorescence commonly a terminal monad (often also axillary, or terminal on sometimes exclusively axillary short shoots), less often a terminal (and also often axillary) cincinnus or thyrsoid; androecium monosymmetric or less frequently polysymmetric and then the stamens not aggregated into either clearly defined cycles or fascicles; carpels basi-

Dilleniaceae

Fig. 43. Dilleniaceae. Hibbertia (subg. Hemistema) baudouini. A Flowering branch. B Androecium spread out and gynoecium. C Stamen. D Carpel, vertical section. E Carpel, transverse section. F Arillate seed. (Gilg and Werdermann 1925)

149

Fig. 44. Dilleniaceae. Hibbertia (subg. Hibbertia) scandens. A Flowering branch. B Flower bud. C Androecium and gynoecium, vertical section. D Stamen. E Gynoecium, transverse section. F Fruit. G Seed enclosed by aril. H Same, vertical section. (Gilg and Werdermann 1925)

just south of Sydney north to the Bundaberg area in southeastern Queensland. cally and commonly 2, uncommonly 3–5 due to a secondary increase in number, rarely 1; ovules 1–25 per carpel. n = 9; 2n = 26, 36. Estimated 160 species, including all species with monosymmetric androecia, all New Caledonian species, all species included in, or attributable to, Gilg and Werderman’s (1925) section Cyclandra series Ochrolasiae, Tomentosae, and Vestitae, plus Hibbertia arcuata J.R. Wheeler, H. graniticola J.R. Wheeler, and the H. exasperata group (Wheeler 2004b), which has been previously associated with section Candollea. Distribution equivalent to that of the whole genus.

6c. Hibbertia subg. Adrastaea (R. Br. ex DC.) J.W. Horn (2005). A wiry shrub, becoming scandent with age; mature axes non-photosynthetic. Leaves laminar, small and linear. Inflorescence a terminal monad; flowers initially produced on axillary short shoots, later on sympodial long shoots consisting mostly of 1-flowered, 2-prophyllate modules; stamens 10 in 2 cycles, obdiplostemonous; carpels 2, ovule 1 per carpel. Only one species, H. salicifolia (DC.) F. Muell., in wallum heath near the coast of temperate to subtropical eastern Australia, from

6d. Hibbertia subg. Hibbertia Fig. 44 Shrubs or, uncommonly, vines or lianas; mature axes non-photosynthetic. Leaves laminar, or ericoid in the Hibbertia hemignosta species complex within sect. Candollea. Stamens not aggregated into obvious cycles, or rarely 1 cycle in the few cases where there are 3 stamens, but sometimes grouped into 3 or 5 alternipetalous fascicles; carpels (1–)3(4)5(–15), fundamentally and commonly 3 or 5; ovules 1–10 per carpel. n = 4, 5, 8, 16, 32, 64; 2n = 20. Estimated 80–90 species, containing all species included in or attributable to the series of Gilg and Werdermann’s (1925) sect. Cyclandra not accounted for above, plus those in or attributable to their sect. Candollea (except the H. exasperata group, see above). Occurring throughout Australia, but particularly concentrated in the southeast and southwest, New Guinea. IV. Subfam. Dillenioideae Burnett (1835) (‘Dillenidae’). Nodes multilacunar (7–27), or probably secondarily trilacunar in the Sri Lankan species of Acrotrema. Leaves with persistent or deciduous,

150

J.W. Horn

amplexicaul petiolar wings (perhaps secondarily lost in one Dillenia clade).

8. Didesmandra Stapf

Schumacheria + Didesmandra:

Vestiture also including fasciculate trichomes. Inflorescence a terminal (less often also axillary) thyrsoid with cincinnate partial inflorescences, at least some of which represent supernumerary branches; sepals 5; petals 5; stamens grouped in 2 fascicles presented in the median plane of the flower, opposite the median petal with the filaments in each fascicle connate to form a ± cylindrical staminal column, the two stamen fascicles very shortly connate with one another at their base; each of the two stamen fascicles consists of 1 larger stamen with a conspicuously uncinate anther with dehiscence by longitudinal slits and 4 smaller stamens with unbent anthers that dehisce by apical pores; carpels 2, presented in the transverse plane of the flower. Fruit an aggregate of nutlets. Seed with a membranous aril. One species, D. aspera Stapf, endemic to Sarawak, Borneo.

Shrubs to small, spindly trees; androecium monosymmetric; pollen commonly 4-aperturate; ovule 1 per carpel, campylotropous, apotropous; vascularized by a massive bundle of traces that remain in the floral receptacle above the point where the ventral carpel bundles depart. 7. Schumacheria Vahl

Fig. 45

Schumacheria Vahl, Skr. Naturhist.-Selsk. 6:122 (1810); Wadhwa, Rev. Handb. Fl. Ceylon 10:109–135 (1996).

Inflorescence both terminal and axillary, a thyrsoid with a paniculate arrangement of cincinnate partial inflorescences in S. castaneifolia, or consisting of axillary cincinni in the other species. Sepals 5; petals 3–5; androecium of c. 20–35 stamens, grouped in a single fascicle located opposite the abaxial-median petal; stamen filaments nearly fully connate, forming a liguliform column; anthers with a vestiture of simple trichomes and with a short, mucronate, apical appendage, dehiscing by 2 apical pores; carpels (2)3. Seed with small, membranous aril. Three species, endemic to Sri Lanka.

Fig. 45. Dilleniaceae. Schumacheria castaneifolia. A Flowering branch. B Flower bud. C Androecium and gynoecium. D Anther. E Carpel, vertical section. F Carpel, transverse section. G Seed. (Gilg and Werdermann 1925)

Didesmandra Stapf in Hooker’s Ic. Pl.: t. 2646 (1900); Hoogland, Fl. Males. I, 4:152, Fig. 7 (1951).

Acrotrema + Dillenia: Gynoecium hemisyncarpous. Ovules 2 or more per carpel. 9. Acrotrema Jack

Fig. 46

Acrotrema Jack, Mal. Misc. 1, 5:36 (1820); Hoogland, Fl. Males. I, 4:141–174 (1951); Hoogland, Fl. Thailand 2, 2:95– 108 (1972); Wadhwa, Rev. Handb. Fl. Ceylon 10:109–135 (1996).

Rhizomatous herbs with leaves in a basal rosette or terminal on a very short, erect stem. Leaves simple, pinnatisect, or pinnate, sometimes variegated, the base sometimes auriculate; vestiture of simple, unicellular or multicellular trichomes. Inflorescence terminal, or sometimes also axillary, a raceme, or the flower solitary; sepals 5; petals 5; androecium of 15–50 free stamens, usually grouped in 3 fascicles positioned alternate with the carpels, or stamens evenly distributed around the gynoecium; anthers short and dehiscing via longitudinal slits, or long, linear, and dehiscing via 2 apical pores; carpels (2)3; ovules 2–6(–20) per carpel. Fruit an aggregate of basally coherent follicles, dehiscing irregularly at maturity. Seed with a white and membranaceous aril. n = 28 (Mathew 1972). About 9 species, c. 7 in Sri Lanka, 1 in the Western Ghats of India, and 1 in southern Myanmar, southern Thailand, Malay Peninsula, and northern Sumatra.

Dilleniaceae

151

with indehiscent fruits. n = 13, 16, 24, 27. About 65 species, from Madagascar and the Seychelles to Fiji, c. 45 species in Malesia, 1 in Australia. The non-amplexicaul species group, recognized by Hoogland (1952), is monophyletic (Horn 2005), but some of the amplexicaul species group (e.g., D. triquetra of Madagascar and Sri Lanka; possibly D. ferruginea of the Seychelles) may be most closely related to Acrotrema.

Fig. 46. Dilleniaceae. A Acrotrema thwaitesii. B Acrotrema lanceolatum. (Gilg and Werdermann 1925)

Further work is needed to determine whether this genus is derived within, or is sister to, Dillenia. 10. Dillenia L.

Figs. 47, 48

Dillenia L., Sp. Pl. 1:535 (1753); Hoogland, Fl. Males. I, 4:141–174 (1951), in Blumea 7:1–145 (1952), rev., ibid. 9:577–589 (1959), and Fl. Thailand 2, 2:95–108 (1972).

Trees, rarely shrubs, mostly evergreen, rarely deciduous. Leaves with or without persistent or deciduous amplexicaul petiolar wings. Inflorescences 1–10(–30)-flowered, a cincinnus, thyrsoid with (apparently) cincinnate partial inflorescences, panicle (often depauperate), or monad, terminal or rarely axillary; flowers infrequently borne on cataphyll-bearing short shoots; sepals (4)5(–18), unequal to ± equal; petals (0, 4)5(–7); androecium of (60–)100–700(–900) members, sometimes partly staminodial; fertile stamens often distinctly heterantherous (the inner group of stamens bearing anthers overtly longer than those of the outer group); anthers dehiscence frequently via 2 apical or subapical pores, less frequently via 2 longitudinal slits; staminodes, when present, typically external to the fertile androecium, rarely internal; gynoecium typically (always?) hemisyncarpous; carpels (4)5–15(–20), forming one whorl on a conical, centrally protruding part of the receptacle; ovules 5–80 per carpel, borne in 2(4) vertical rows on submarginal placentae. Fruit an aggregate of basally coherent follicles, or the fruit indehiscent and completely enclosed by the fleshy, accrescent calyx. Seeds with a white or red, fleshy aril, or the aril vestigial in some species

Fig. 47. Dilleniaceae. Dillenia excelsa. A Flowering branch. B Flower. C Dehiscing fruit. (Koorders and Valeton 1913)

152

J.W. Horn

Fig. 48. Dilleniaceae. Dillenia indica. A Flowering branch. B Androecium and gynoecium, vertical section. C Half gynoecium, transverse section. D Outer and inner stamen. E Fruit enclosed by fleshy sepals. F Same, vertical section. G Seed. H Same, vertical section. (Gilg and Werdermann 1925)

Selected Bibliography APG II 2003. See general references. Ashton, P.S., Gunatilleke, C.V.S. 1987. New light on the plant geography of Ceylon. I. Historical plant geography. J. Biogeogr. 14:249–285. Aymard, C., G.A. 1997. Dilleniaceae novae Neotropicae IX: Neodillenia, a new genus from the Amazon basin. Harvard Pap. Bot. 10:121–131. Aymard, C., G.A. 2002. Davilla papyracea (Dilleniaceae), a new species from Brazil. Kew Bull. 57:487–490. Baillon, H.E. 1865. Remarques sur les Dilléniacées. Adansonia 6:255–281. Baretta-Kuipers, T. 1972. Some remarks on the wood structure of Pinzona and allied genera of the subfamily Tetraceroideae (Dilleniaceae). Acta Bot. Neerl. 21:573– 577.

Berg, R.Y. 1975. Myrmecochorous plants in Australia and their dispersal by ants. Austral. J. Bot. 23:475–508. Bernhardt, P. 1984. The pollination biology of Hibbertia stricta (Dilleniaceae). Pl. Syst. Evol. 147:267–277. Bernhardt, P. 1986. Bee-pollination in Hibbertia fasciculata (Dilleniaceae). Pl. Syst. Evol. 152:231–241. Bernhardt, P. 1996. Anther adaptation in animal pollination. In: D’Arcy, W.G., Keating, R.C. (eds) The anther: form, function, and phylogeny. Cambridge: Cambridge University Press, pp. 192–220. Conti, E. et al. 2002. See general references. Corner, E.J.H. 1946. Centrifugal stamens. J. Arnold Arb. 27:423–437. Corner, E.J.H. 1976. See general references. Corner, E.J.H. 1978. The inflorescence of Dillenia. Notes Roy. Bot. Gard. Edinburgh 36:341–353. Craven, L.A., Dunlop, C.R. 1992. A taxonomic revision of Pachynema (Dilleniaceae). Austral. Syst. Bot. 5:477– 500. Croat, T. 1978. Flora of Barro Colorado Island. Stanford: Stanford University Press. Cronquist, A. 1981. See general references. Cronquist, A. 1988. The evolution and classification of flowering plants, 2nd edn. Bronx: New York Botanical Garden. Cuénoud, P., Savolainen, V., Chatrou, L.W., Powell, M., Grayer, R.J., Chase, M.W. 2002. Molecular phylogenetics of Caryophyllales based on 18S rDNA and plastid rbcL, atpB, and matK DNA sequences. Amer. J. Bot. 89:132–144. Dahlgren, R.M.T. 1983. General aspects of angiosperm evolution and macrosystematics. Nordic J. Bot. 3:119– 149. de Candolle, A.P. 1824. Prodromus systematis naturalis regni vegetabilis, I. Paris: Treuttel et Würtz. Dickison, W.C. 1967a. Comparative morphological studies in Dilleniaceae, I. Wood anatomy. J. Arnold Arb. 48:1– 29. Dickison, W.C. 1967b. Comparative morphological studies in Dilleniaceae, II. The pollen. J. Arnold Arb. 48:231– 240. Dickison, W.C. 1968. Comparative morphological studies in Dilleniaceae, III. The carpels. J. Arnold Arb. 49:317– 333. Dickison, W.C. 1969. Comparative morphological studies in Dilleniaceae, IV. Anatomy of the node and vascularization of the leaf. J. Arnold Arb. 50:384–410. Dickison, W.C. 1970a. Comparative morphological studies in Dilleniaceae, V. Leaf anatomy. J. Arnold Arb. 51:89– 113. Dickison, W.C. 1970b. Comparative morphological studies in Dilleniaceae, VI. Stamens and young stem. J. Arnold Arb. 51:403–422. Dickison, W.C. 1971. Comparative morphological studies in Dilleniaceae, VII. Additional notes on Acrotrema. J. Arnold Arb. 52:319–333. Dickison, W.C. 1979. A note on the wood anatomy of Dillenia (Dilleniaceae). IAWA Bull. 2/3:57–60. Dickison, W.C. 1984. On the occurrence of silica grains in the woods of Hibbertia (Dilleniaceae). IAWA Bull. II, 5:341–343. Dickison, W.C., Rury, P.M., Stebbins, G.L. 1978. Xylem anatomy of Hibbertia (Dilleniaceae) in relation to ecology and evolution. J. Arnold Arb. 59:32–49.

Dilleniaceae Dickison, W.C., Nowicke, J.W., Skvarla, J.J. 1982. Pollen morphology of the Dilleniaceae and Actinidiaceae. Amer. J. Bot. 69:1055–1073. Dyer, A.G. 1996. Reflection of near-ultraviolet radiation from flowers of Australian native plants. Austral. J. Bot. 44:473–488. Eichler, A.W. 1878. Blüthendiagramme, II. Leipzig: W. Engelmann. Endress, P.K. 1997. Relationships between floral organization, architecture, and pollination mode in Dillenia (Dilleniaceae). Pl. Syst. Evol. 206:99–118. George, A.S. 2002. The south-western Australian flora in autumn: 2001 Presidential Address. J. Roy. Soc. W. Australia 85:1–15. Gilg, E., Werdermann, E. 1925. Dilleniaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 21. Leipzig: W. Engelmann, pp. 7–36. Gottsberger, G. 1977. Some aspects of beetle pollination in the evolution of flowering plants. Pl. Syst. Evol., suppl. 1:211–226. Gurni, A.A., Kubitzki, K. 1981. Flavonoid chemistry and systematics of the Dilleniaceae. Biochem. Syst. Ecol. 9:109–114. Hegnauer, R. 1966. Chemotaxonomie der Pflanzen, 4, pp. 19–23. Basel: Birkhäuser. Hickey, L.J., Wolfe, J.A. 1975. The bases of angiosperm phylogeny: vegetative morphology. Ann. Missouri Bot. Gard. 62:538–589. Hoogland, R.D. 1952. A revision of the genus Dillenia. Blumea 7:1–145. Hoogland, R.D. 1953. The genus Tetracera (Dilleniaceae) in the eastern Old World. Reinwardtia 2:185–225. Hoogland, R.D. 1959. Additional notes on Dilleniaceae 1–9. Blumea 9:577–589. Horn, J.W. 2005. The phylogenetics and structural botany of Dilleniaceae and Hibbertia Andrews. Ph.D. Thesis, Duke University, Durham, NC, 171 p. Hutchinson, J. 1964. The genera of flowering plants, 1. Oxford: Clarendon. Imaichi, R., Kato, M. 1996. A scanning electron microscopic study of ovule development in Dillenia suffruticosa (Dilleniaceae). Phytomorphology 46:45–51. Ioffe, M.D., Zhukova, G.Y. 1974. Modification of zygote cell wall during its development in Dillenia Dilleniaceae. Bot. Zhurn. (Moscow & Leningrad) 59:1409–1416. Keighery, G.J. 1975. Pollination of Hibbertia hypericoides (Dilleniaceae) and its evolutionary significance. J. Nat. Hist. 9:681–684. Keighery, G.J. 1991. Pollination of Hibbertia conspicua (Dilleniaceae). W. Austral. Naturalist 18:163–165. Koorders, S.H., Valeton, T. 1913. Atlas der Baumarten von Java, 1. Leiden: P.W.M. Trap. Kubitzki, K. 1968. Flavonoide und Systematik der Dilleniaceen. Ber. Deutsch. Bot. Gesell. 81:238–251. Kubitzki, K. 1970. Die Gattung Tetracera (Dilleniaceae). Mitt. Bot. Staatssamml. München 8:1–98. Kubitzki, K. 1971. Doliocarpus, Davilla und verwandte Gattungen (Dilleniaceae). Mitt. Bot. Staatssamml. München 9:1–105. Lakshmanan, J.D.E., Lakshmanan, K.K. 1984. Further contributions to the embryology of Dillenia suffruticosa (Griff.) Martelli. J. Indian Bot. Soc. 63:353–359. Mathew, P.M. 1972. Cytology of Acrotrema. Curr. Sci. 41:751.

153

Momose, K., Yumoto, T., Nagamitsu, T., Kato, M., Nagamasu, H., Sakai, S., Harrison, R.D., Itioka, T., Hamid, A.A., Inoue, T. 1998. Pollination biology in a lowland dipterocarp forest in Sarawak, Malaysia. I. Characteristics of the plant-pollinator community in a lowland dipterocarp forest. Amer. J. Bot. 85:1477–1501. Ozenda, P. 1949. Recherches sur les dicotylédons apocarpiques. Publications des laboratoires de l’École Normale Supérieure, Série Biologie, fasc. 2. Paris: Jouve. Paetow, W. 1931. Embryologische Untersuchungen an Taccaceen, Meliaceen und Dilleniaceen. Planta 14:441– 470. Parmentier, M.P. 1895. Contribution à l’étude de la famille des Dilléniacées. C. R. Assoc. Franç. Avancem. Sci. pt. 2:626–630. Pavanasasivam, G., Sultanbawa, M.U.S. 1974. Betulinic acid in the Dilleniaceae and a review of its natural distribution. Phytochemisty 13:2002–2006. Prance, G.T. 2003. Rhabdodendraceae. In: Kubitzki, K., Bayer, C. (eds) The Families and Genera of Vascular Plants, 5. Flowering plants, dicotyledons: Malvales, Capparales and non-betalain Caryophyllales. Berlin Heidelberg New York: Springer, pp. 339–341. Rao, A.N. 1957. A contribution to the embryology of Dilleniaceae. Proc. Iowa Acad. Sci. 64:172–176. Rao, T.A., Das, S. 1979. Comparative typology and taxonomic value of foliar sclereids in Hibbertia Andr. (Dilleniaceae). Proc. Indian Acad. Sci., B 88:161–174. Rury, P.M., Dickison, W.C. 1977. Leaf venation patterns of the genus Hibbertia (Dilleniaceae). J. Arnold Arb. 58:209–256. Sastri, R.L.N. 1958. Floral morphology and embryology of some Dilleniaceae. Bot. Notiser 111:495–511. Schatral, A. 1995. The structure of the seed in some Western Australian species of the genus Hibbertia (Dilleniaceae). Bot. J. Linn. Soc. 119:257–263. Schatral, A. 1996. Dormancy in seeds of Hibbertia hypericoides (Dilleniaceae). Austral. J. Bot. 44:213–222. Schatral, A., Kailis, S.G., Fox, J.E.D. 1994. Seed dispersal of Hibbertia hypericoides (Dilleniaceae) by ants. J. Roy. Soc. W. Australia 77:81–85. Soltis, D.E. et al. 2003. See general references. Stebbins, G.L., Hoogland, R.D. 1976. Species diversity, ecology and evolution in a primitive angiosperm genus: Hibbertia (Dilleniaceae). Pl. Syst. Evol. 125:139–154. Steppuhn, H. 1895. Beiträge zur vergleichenden Anatomie der Dilleniaceen. Bot. Centralbl. 62:337–342, 369–378, 401–413. Swamy, G.L., Periasamy, K. 1955. Contributions to the embryology of Acrotrema arnottianum. Phytomorphology 5:301–314. Takhtajan, A. 1997. See general references. Thorne, R.F. 2000. The classification and geography of flowering plants: dicotyledons of the class Angiospermae. Bot. Rev. (Lancaster) 66:441–647. Toelken, H.R. 1998. Notes on Hibbertia (Dilleniaceae): 2. The H. aspera–empetrifolia complex. J. Adelaide Bot. Gard. 18:107–160. Toelken, H.R. 2000. Notes on Hibbertia (Dilleniaceae): 3. H. sericea and associated species. J. Adelaide Bot. Gard. 19:1–54.

154

J.W. Horn

Tucker, S.C., Bernhardt, P. 2000. Floral ontogeny, pattern formation, and evolution in Hibbertia and Adrastaea (Dilleniaceae). Amer. J. Bot. 87:1915–1936. Veillon, J.-M. 1990. Dilleniaceae. In: Morat, P., MacKee, H.S. (eds) Flore de la Nouvelle-Calédonie et Dépendances, 16, pp. 3–86. Paris: Muséum National d’Histoire Naturelle. Vyshenskaya, T.D., Oganezova, G.G. 1991. Dilleniaceae. In: Takhtajan, A. (ed.) Anatomia seminum comparativa (in Russian), 3, pp. 163–171. Leningrad: Nauka. Wagner, R. 1906a. Über den Bau der Rispen des Trisema Wagapii Vieill. Sitzungsber. Kaiserl. Akad. Wissensch., Math.-Naturwissensch. Kl., Abt. 1, 115:857– 880. Wagner, R. 1906b. Untersuchungen über den morphologischen Aufbau der Gattung Pachynema R. Br. Sitzungsber. Kaiserl. Akad. Wissensch., Math.-Naturwissensch. Kl., Abt. 1, 115:1039–1080.

Wheeler, J.R. 1984. New species of Hibbertia (Dilleniaceae) from the northern wheatbelt area of Western Australia. Nuytsia 9:427–437. Wheeler, J.R. 2002. Miscellaneous new species of Hibbertia (Dilleniaceae) from the wheatbelt and pastoral areas of Western Australia. Nuytsia 15:139–152. Wheeler, J.R. 2004a. A review of Hibbertia hemignosta and its allies (Dilleniaceae) from Western Australia. Nuytsia 15:277–298. Wheeler, J.R. 2004b. An interim key to the Western Australian species of Hibbertia (Dilleniaceae). Nuytsia 15:311–320. Wilson, C.L. 1937. The phylogeny of the stamen. Amer. J. Bot. 24:686–699. Wilson, C.L. 1965. The floral anatomy of the Dilleniaceae. I. Hibbertia Andr. Phytomorphology 15:248–274. Wilson, C.L. 1973. The floral anatomy of the Dilleniaceae. II. Genera other than Hibbertia. Phytomorphology 23:25– 42.

Geissolomataceae Geissolomataceae Endl., Ench. Bot.: 214 (1841), nom. cons.

F. Forest

Densely leafy low shrub, 50–120 cm high, aluminium-accumulating. Leaves coriaceous, decussate, subsessile, simple, entire, ovate, base cordate, apex acute, margin thickened; stipules small, subulate, situated on the sides of the short, petiole-like leaf base. Flowers solitary, terminal on lateral short shoots, subtended by 3 pairs of decussate, persistent bracts, these increasing in size and petaloid above; vestigial flower buds often present in axils of uppermost bracts. Flowers with short, sharply 4-angled pedicels, hermaphrodite, actinomorphic, monochlamydeous, hypogynous; tepals 4, decussate, basally shortly connate, persistent, pink, turning carmine when older; stamens 4 + 4, attached basally to the floral tube; filaments slender, free; anthers 4-sporangiate, dorsifixed, introrse, longitudinally dehiscent; nectary intrastaminal on floral cup with 4 nectary recesses opposite the tepals; gynoecium 4-carpellate; ovary superior, 4-lobate in transection, sessile, 4-locular; stylodia 4, free above the base but, at anthesis in apical part, postgenitally fused and twisted; stigma common to the four stylodia and punctiform; ovules 2 per locule, anatropous, pendulous from the apex. Fruit a hard, 4-lobed, loculicidal capsule enclosed in the persistent perianth; seeds 1 per locule, reniform, oblong, whitish, smooth; endosperm present; embryo straight, central; cotyledons long and linear. A single genus and species, Geissoloma marginatum (L.) A. Juss., restricted to the southern Langeberg mountains in the Cape of South Africa from the Swellendam to Riversdale divisions, on moist south-facing sandstone slopes at elevations of 600–1,200 m in “fynbos” scrub; flowering from June to September. Vegetative Anatomy. The leaves of Geissoloma have a multiple epidermis with intracellular pectates found in the epidermal cells. The thickened margin consists of large epidermal cells and thickwalled mesenchymatous cells, some of which con-

tain druses. Stomata are anomocytic and restricted to the abaxial side of the leaf. The abaxial surface of the leaf is covered with waxy scales or strands, and young leaves have dense, unicellular T-shaped trichomes (Dahlgren and Rao 1969; Carlquist 1990). The wood of Geissoloma, as studied by Carlquist (1975), has long vessel elements with oblique scalariform perforation plates. The imperforate elements of the axial secondary xylem is made up of tracheids only. Axial parenchyma is diffuse and scanty; rays are multiseriate and uniseriate, the former with procumbent and square to erect cells, the latter lacking procumbent cells. One or two large or several small calcium oxalate crystals are present in ray cells. Floral Structure. Dahlgren and Rao (1969) found little resemblance between Geissoloma and Penaeaceae, and could not find vestigial traces of other perianth whorls in Geissoloma. The stylodia are twisted (Fig. 49G) and thus form a compitum comparable to the situation in some Malvaceae. Matthews and Endress (2005) gave a detailed analysis of the floral morphology of Geissoloma and compared it with that of the other members of Crossosomatales. Embryology (from Stephens 1910). The ovules are anatropous, bitegmic and crassinucellate; the micropyle is formed by the outer integument. The embryo sac is 8-nucleate and probably formed according to the Polygonum type. The antipodals early decrease in size and lose their staining properties. The copious endosperm is partly resorbed by the developing embryo. No endosperm haustoria develop. In the ripe seed, the endosperm is fleshy. The funicular part of the seed becomes whitish and swollen and forms a collar-like caruncle. Seed coat structure is unknown. Pollen Morphology. The pollen grains are 3-colporate, ± spheroidal, and the exine is

156

F. Forest

baculate-tectate and finely perforate (Erdtman 1952; Dahlgren and van Wyk 1988). Karyology. The chromosome number is unknown. Attempts to germinate seeds in order to determine the chromosome number from root tips failed because of the low seed production and viability. Because of a sticky opaque substance produced by the pollen grains, chromosome counting from germinating pollen also failed (McDonald 1998). Affinities. The single species, first described as Penaea marginata by Linnaeus, was placed in Penaeaceae or Celastraceae by early botanists. After elevation to family rank, placements in Pittosporales, close to Bruniaceae and Grubbiaceae (Thorne 1983), Geissolomatales (Dahlgren 1983; Takhtajan 1987) and Celastrales (Cronquist 1981) were suggested. In recent phylogenetic analyses based on the plastid gene rbcL (Savolainen, Fay et al. 2000), Geissolomataceae emerged as the sister-group to the monotypic Ixerbaceae (New Zealand) and Strasburgeriaceae (New Caledonia). Savolainen, Fay et al. (2000) suggested that these three families could be included in an expanded order Crossosomatales. A single genus: Geissoloma Lindl. ex Kunth

Fig. 49

Geissoloma Lindl. ex Kunth, Linnaea 5:678 (1830).

Characters as for the family. Monotypic, see above.

Selected Bibliography Carlquist, S. 1975. Wood anatomy and relationships of the Geissolomataceae. Bull. Torrey Bot. Club 102:128–134. Carlquist, S. 1990. Leaf anatomy of Geissolomataceae and Myrothamnaceae as a possible indicator of relationship to Bruniaceae. Bull. Torrey Bot. Club 117:420–428. Cronquist, A. 1981. See general references. Dahlgren, R. 1983. General aspects of angiosperm evolution and macrosystematics. Nordic J. Bot. 3:119–149. Dahlgren, R., Rao, V.S. 1969. A study of the family Geissolomataceae. Bot. Notiser 122:207–227.

Fig. 49. Geissolomataceae. Geissoloma marginatum. A Flowering branch. B Leaf. C Leaf base with stipules. D Flower. E Stamen. F Anthers in dorsal and ventral view. G Pistil. H Upper part of ovary and bases of stylodia. I Apices of stylodia. J Young capsule. K Seed. L Hair from young leaf. (Dahlgren and van Wyk 1988)

Dahlgren, R., van Wyk, A.E. 1988. Structures and relationships of families endemic to or centred in South Africa. Monogr. Syst. Bot. Missouri Bot. Gard. 25:1–94. Erdtman, G. 1952. See general references. Matthews, M.L., Endress, P.K. 2005. See general references. McDonald, D.J. 1998. The enigma of the Geissolomataceae. Veld & Flora 84:122–123. Savolainen, V., Fay, M.F. et al. 2000. See general references. Stephens, E.L. 1910. The embryo-sac and embryo of Geissoloma marginata. New Phytol. 8:345–348. Takhtajan, A. 1987. See general references. Thorne, R.F. 1983. Proposed new realignments in the angiosperms. Nordic J. Bot. 3:85–117.

Geraniaceae Geraniaceae Adans., Fam. Pl. 2:384 (1763), nom. cons. Hypseocharitaceae Wedd. (1861).

F. Albers and J.J.A. Van der Walt

Herbs, sometimes shrublets or shrubs, occasionally with succulent stems, sometimes geophytic. Leaves alternate or opposite, mostly palmately or pinnately lobed or compound, lobes deeply serrate or lobulate; stipules present or (Hypseocharis) absent. Inflorescences pseudoumbellate, or flowers solitary. Flowers perfect, actinomorphic or zygomorphic, pentamerous; sepals free or united at base, imbricate with valvate tips, persistent; petals 5 (4, 2 or 0), free, imbricate; stamens 5 or 10 and 15, then in two whorls, sometimes a few sterile, filaments free or more or less connate at base; gynoecium of 5(4) carpels; style with 5 stigmatic branches (unbranched with capitate stigma in Hypseocharis); ovary 5-lobed, with 1–2(–12) pendulous, anatropous ovules in each locule; placentation axile. Fruits schizocarps with five 1-seeded awned mericarps which separate elastically from a central beak (rostrum), or (Hypseocharis) with five 1–few-seeded mericarps not connected by a central column or loculicidal capsules; seeds with a more or less curved embryo with green cotyledons or (Hypseocharis) with a cochlear embryo with spirally folded cotyledons; endosperm absent or scanty. A family of five genera and about 835 species, sub-cosmopolitan but mainly in temperate and subtropical regions. Vegetative Morphology. Erodium and Geranium are generally annual or perennial herbs, often with a basal rosette, occasionally subshrubs. Tall shrubs (to 4 m) are found only in the Hawaiian endemic Geranium sect. Neurophyllodes. Monsonia and Pelargonium exhibit a wide range of different growth forms. Monsonia comprises small xerophytic shrubs, geophytes, perennials and ephemeral annual herbs. Pelargonium exhibits a wide range of growth habits, from short-lived annuals to scrambling herbs and tall shrubs (Van der Walt 1977; Van der Walt and Vorster 1981, 1988), but xerophytes, stem succulents and

geophytes are the dominant type (Albers 2002). Leafless stem succulents are unknown in Erodium and Geranium. Species of Erodium and Geranium usually have fusiform roots or, more rarely, root tubers. In some sections of Geranium, the branched rootstock is covered with pale brown stipules and petiole bases. Xerophytic Monsonia and Pelargonium are characterised by fusiform roots, roots with a series of small tubers or thick rhizomes. Pelargonium sect. Hoarea has tubers with a cover of paper-like sheaths of exfoliating periderm. Hypseocharis forms thick taproots or large tubers. Most of the species of Erodium and Geranium are small herbaceous plants with numerous erect or decumbent stems, except for a few higher-growing species in Geranium with a single vegetative axis. Hypseocharis is an acaulescent or short-stemmed hemicryptophyte. In some Pelargonium, the stem is very short (e.g. P. sect. Polyactium) or totally reduced (P. sect. Hoarea). The differential development of the hypocotyl, internode elongation and branching system of various life forms in Pelargonium have been studied by Jones and Price (1996). The species of Monsonia sect. Sarcocaulon are short-stemmed, semi-erect to decumbent shrublets whereas the remaining sections of Monsonia are herbaceous; only the perennials are woody at the base. A few annuals form carpets by producing stolons. The shape and size of the leaves vary extremely within genera, subgenera and even sections. The leaves are opposite or alternate, not rarely changing position on the same stem. Especially in Pelargonium, a high diversity in leaf shapes and patterns occurs. The margin can be entire, toothed or lobed. The adaxial and abaxial leaf blades can differ in being glabrous or carrying non-glandular and/or glandular hairs of different types. Leaves are stipulate, except in Hypseocharis. Especially in Monsonia sect. Sarcocaulon, long petioles can persist as blunt or sharp spines.

158


Vegetative Anatomy. In most genera, the vascular bundles are arranged in one ring, which is often surrounded by a sheath of sclerenchyma. The pith parenchyma contains starch granules. Starch storage sometimes also occurs in the cortical parenchyma. Clustered crystals are frequent. In addition to the primary growth, a continuous vascular cambium produces secondary elements in a normal way. In woody pelargoniums, the secondary xylem contains vessels with simple perforations plates; reticulate plates seem to be rare. Living and septate fibres as well as both paratracheal and apotracheal axial parenchyma are present. The rays are heterogeneous, consisting mainly of square and upright cells (Van der Walt et al. 1987). Especially in Pelargonium sect. Hoarea, a phellogen originating in the outermost cortical parenchyma produces numerous periderm layers. In Monsonia sect. Sarcocaulon, a thick, waxy bark develops from the periderm, which is flammable and therefore called “bushmen candle”. Stem succulence in Pelargonium cotyledonis is mainly brought about through the production of parenchyma, whereas in Pelargonium sect. Otidia and sect. Cortusina primary and secondary tissues take part in its formation (Jones and Price 1996). Leaves are bifacial, rarely aequifacial. Stomata are anomocytic throughout. Roots are mainly diarch or less often triarch. Inflorescences. In Erodium and Pelargonium, normally a cluster of several pedicels arises from a single point, producing a pseudoumbel of two to many flowers, with the younger flowers at the periphery. In Pelargonium, the inflorescences are sometimes borne on a peduncle, which is often branched and forms a compound inflorescence with several pseudoumbels. In most species of Geranium and Hypseocharis, the inflorescence is cymose, composed of axillary, two-flowered cymules. Often, the cymules arise on aerial, leafy or leafless stems. In some geraniums and Hypseocharis, flowers arise directly from the short hypocotyl or rootstock. In Monsonia sect. Sarcocaulon, the flowers are solitary and the peduncles axillary. Floral Structure. Flowers are usually actinomorphic, apart from some Erodium and most Pelargonium. Petal aestivation is usually contort in bud. The corolla is usually pentamerous, but the number of petals can be reduced to two in

the zygomorphic flowers of Pelargonium. The androecium is obdiplostemonous with 5 + 5 stamens in Erodium, Geranium and Pelargonium, whereas Monsonia has 15 (10 staminodial in one species) and Hypseocharis has 5 or 15 stamens. In Erodium, only 5 and in Pelargonium 2–7 stamens are fertile. In Monsonia and Hypseocharis, the 15 stamens are arranged in two whorls, and in both genera the outer (and later developing) stamens form five antepetalous pairs (Ronse Decraene and Smets 1995) and are shorter than the antesepalous stamens. In one Hypseocharis, the androecium is reduced to 5 antepetalous stamens (Slanis and Grau 2001), whereas Aldasoro et al. (2001) report a reduction to 5 fertile antesepalous stamens for one species of Monsonia. In Erodium, Geranium and Monsonia, generally five hemispherical nectaries are present which alternate with the filaments of the outer staminal whorl. In some Geranium there is a ring-like disk, rather than isolated nectaries. Some Erodium and Monsonia have five nectaries more or less deeply submerged into antesepalous hypanthial tubes. In Pelargonium, there is usually only one nectary concealed in an adaxial-episepalous area in the hypanthium (Link 1990; Vogel 1998). A lobed extrastaminal nectary disk is well developed in Hypseocharis (Slanis and Grau 2001). Embryology. The tapetum in the mature anthers is glandular. Pollen grains are shed at the two-celled stage in Erodium and Monsonia and at the three-celled stage in Erodium, Pelargonium and Geranium. The ovules are anatropous, bitegmic and crassinucellate. Embryo sac development is of the Polygonum type; the early endosperm conforms to the Nuclear type, and both endosperm and nucellus are later resorbed by the embryo. The endospermless seeds of most Geraniaceae contain a large embryo which is bent in the region of the hypocotyl, so that the radicle is folded against one of the cotyledons. The embryo in Geranium is chlorophyllous and has a particularly long radicle (Yeo 1990). Erodium and Monsonia in principle share this morphology whereas in Pelargonium the cotyledons are flat (Aedo et al. 1998). The seeds of Hypseocharis have cochlear embryos with spirally folded cotyledons and scanty endosperm. Pollen Morphology. Pollen is tricolpate (Monsonia, Hypseocharis) or tricolporate (Erodium, Geranium and Pelargonium). The exine sculpture

Geraniaceae

is reticulate in Monsonia (Verhoeven and Venter 1986), reticulate-striate in Hypseocharis (Huynh 1969) and Erodium, or reticulate with supratectal processes in Geranium (Bortenschlager 1967; Verhoeven and Marais 1990). Exine sculpture of Pelargonium varies from striate-reticulate, reticulate-striate to striate (Stafford and Gibby 1992), and only a few subgroups can be identified by differences in their reticulum and ornamentation. The ultrastructure of the exine of some

Fig. 50. Geraniaceae. Diversity of flower morphs and coadapted pollinators in Pelargonium. A P. magenteum (long-proboscid hovering flies). B P. ternifolium (bees). C P. longiflorum (?long-proboscid hovering flies). D P. bowkeri (hawkmoths). E P. lobatum (hawkmoths). F P. scabrum (hemiphilic). G P. fulgidum (birds). H P. grossularioides (facultatively or obligatorily autogamous). I P. triandrum (long-proboscid hovering flies). J P. laxum (bees). K P. multicaule (bees). L P. rapaceum (bees). (Drawn by U. Meeve; Struck 1997)

159

Erodium and Geranium was studied by Stafford and Blackmore (1991). The surface of the exine is covered by pollenkitt and underlain by a compact layer of pollen-coating vesicles (Weber 1996). Karyology. Geraniaceae are karyologically highly diverse, well studied (except Hypseocharis), and illustrate the taxonomic importance of karyology at the generic and subgeneric level. The four genera present different patterns of basic chromosome numbers, with one dominating base number and several derived numbers (Albers 1990): Erodium: 8, 9, 10 (e.g. Guittonneau 1990). Geranium: 9, 10, 11, 13, 14 (e.g. Van Loon 1984a, b). Monsonia: 8, 9, 10, 11, 12 (Albers 1990; Touloumenidou et al., in prep.). Pelargonium: 4, 7, 8, 9, 10, 11 (e.g. Albers et al. 1992; Gibby et al. 1996). Additional numbers have resulted from losses of chromosomes in higher polyploids or from hybridization of polyploids with different chromosome numbers (e.g. in the Pelargonium alchemilloides complex: 32 × 36 = 34). Polyploidy ascends sometimes to dodekaploidy (Erodium tocranum 2n = 12x = 120; Pelargonium schizopetalum 2n = 10x = c. 108; Geranium canariense, G. rubescens 2n = 8x = 128; Monsonia ignorata 2n = 6x = 60). Pelargonium is the karyologically best known genus in the family, and base numbers and chromosome sizes are often indicators for natural groups within the genus and have led to several taxonomic rearrangements at sectional level (e.g. Albers et al. 1992), although morphological features are sometimes not congruent with the karyological results. Albers and Van der Walt (1984) proposed x = 11 as the basic chromosome number of Pelargonium; this was confirmed by Bakker et al. (2000). Most of the other base numbers in infrageneric groups of Pelargonium are derived from x = 11 (e.g. in sect. Hoarea 11 → 10 → 9, Gibby et al. 1996); such changes have taken place several times independently. Pollination. All genera are protandrous. In Erodium and Geranium, most of the species are pollinated by insects but self-pollination is frequent. Only the Hawaiian G. arborescens is ornithophilous. The two main groups of insects observed in Europe visiting Erodium are Diptera and Hymenoptera. Monsonia seems to be mostly pollinated by beetles (Albers, pers.

160


obs.). Pelargonium species predominantly have protandrous-allogamous flowers, which appear to be essentially pollinated by long-tongued bees and long-tongued flies (Fig. 50). The more basal sections of the genus show exclusively hemiphilous to melittophilous syndromes. Sphingophilous floral syndromes are expressed in the night-scented Pelargonium sect. Polyactium. Bird pollination is known only from P. fulgidum (Struck 1997). Autogamy is frequent in Pelargonium, and the different forms of self-pollination systems involved were treated by Meve (1995). Fruit and Seed. In Geranium, Erodium, Monsonia and Pelargonium, the five carpels form a syncarpous ovary maturing into a schizocarp. The mature fruit falls into five, usually one-seeded mericarps. The central column consists of the fused septa. Awned mericarps are capable of hygroscopic movements. Mericarps in Pelargonium as well as some Erodium and Monsonia develop hairs on the adaxial side of the awns. Awn morphology is of high diagnostic value (Guittonneau 1972; Yeo 1984, 1990). Most Hypseocharis have loculicidal capsules with several small seeds in each locule; H. tridentata has a schizocarp but the mericarps are not beaked; they contain one to few seeds (Slanis and Grau 2001). The seeds are strongly campylotropous with large embryos and strongly folded coytyledons, when viewed in transverse section. They are rich in lipid substances and poor in starch. Seed coat structure is uniform throughout the family, and characterised by a crystalliferous endotesta and a strongly thickened but scarcely lignified exotegmen (Corner 1976; Boesewinkel and Ben 1979; Boesewinkel 1988). For the light line of the endotesta, see Meisert et al. (2001). Dispersal. Most Geraniaceae are autochorous, active ballists, some are (exo)zoochorous or anemochorous. Based on beak morphology, three main seed-dispersal mechanisms can be distinguished (Yeo 1990). In the Erodium type, the entire mericarp including the awn is ejected, and the mericarps are able to bury themselves in the soil by hygroscopic movements of the twisted awn. This type is found in Pelargonium, Erodium, Monsonia and some Geranium. Two additional types are found in Geranium: in the carpel-projection type, the basal part of the mericarp containing the seed is thrown whereas the awn remains attached to the beak; in the seed-ejection type, the seed is ejected

by curving of the awn, and the entire mericarp remains on the plant. The diaspores of Erodium and Geranium are dispersed by cattle, birds and ants whereas the disapores of Pelargonium, Erodium subg. Erodium and Monsonia sections Monsonia and Plumosa have plumose awns and are wind-dispersed. The small, papillose seeds of Hypseocharis may also be anemochorous (Boesewinkel 1988). Vegetative Reproduction. Sexual reproduction predominates but asexual propagation occurs as well. In sprawling species of Erodium, Geranium and Pelargonium, rooting at the nodes is frequent and gives rise to new individuals. Pelargonium crassicaule, P. articulatum and others produce rhizomes from which new aerial shoots are formed. If individual tubers of Pelargonium sipthorpiifolium become separated, they give rise to new plantlets (F. Albers, pers. obs.). The propagation of Pelargonium species and cultivars by cuttings in commercial horticulture is being superseded by cell culture techniques. Phytochemistry. Common flavonols, proanthocyanidins, free ellagic acid and ellagitannins are widely distributed in the family; myricetin, C-glycosyl flavones and flavones have been less frequently recorded (Bate-Smith 1973; Williams et al. 2000). Their distribution was often found to be in accord with sectional classification, and has led to the reinstatement of the sect. Reniformia which had long been sunken in sect. Cortusina (Dreyer and Marais 2000). Alkaloids are less important as chemotaxonomic markers. Whereas most Pelargonium accumulate high quantities of tartaric acid, all studied species of Erodium and Geranium lack this compound or contain only small amounts of it. Bauer (1991) used flavonol glycosides and hydroxycinnamic acid derivatives for the identification of Pelargonium cultivars. High polyploids and cultivars of Pelargonium contain large amounts of “geranium oil” composed of citronellol, geraniol, citronellyl, and geranyl formate and citronellic acid (Demarne 1990). Subdivision and Relationships Within the Family and Affinities. Geraniaceae in their traditional circumscription have been revealed as a heterogeneous assemblage. Morphological evidence (Hallier 1923; Bortenschlager 1967; Boesewinkel 1997) and molecular data (Price and

Geraniaceae

Palmer 1993) have led to the segregation of several elements. Ledocarpaceae are still included in Geraniales, whereas Biebersteiniaceae are part of Sapindales, and Dirachmaceae belong to Rosales (see volume VI of this series). Geraniaceae in the restricted sense are supported as monophyletic by molecular analyses of various plastid and nuclear genes (Price and Palmer 1993; Savolainen, Fay et al. 2000; Soltis et al. 2000; see also Angiosperm Phylogeny Group APG II 2003). Hypseocharis, formerly included in a monotypic family, is sister to the remaining four genera, Erodium, Geranium, Pelargonium and Monsonia incl. Sarcocaulon. The fusion of the latter two genera was suggested by Price and Palmer (1993) and formally carried out by Albers (1996; see also Aldasoro et al. 2001; Touloumenidou et al., in prep.), but the taxonomic changes were rejected by Moffett (1997) and by Dreyer et al. (1997). The infrageneric subdivision in Geraniaceae is based mainly on flower morphology, fruit-discharge mechanisms and karyology. Comprehensive molecular studies are available only for Monsonia (Touloumenidou et al., in prep.) and Pelargonium (Bakker et al. 2000). A cladistic analysis of morphological characters showed two major clades in Monsonia: one is formed by Monsonia sect. Monsonia including Sarcocaulon, the other contains species of Monsonia sect. Olopetalum (Aldasoro et al. 2001). On the basis of a molecular study, Touloumenidou et al. (in prep.) propose five sections in Monsonia, with Sarcocaulon included at sectional rank. The subdivision of Pelargonium is based on morphology and different chromosome numbers and sizes. The basal split into two clades, as proposed by Albers (1988), is supported by molecular studies (Bakker et al. 2000) and led to the recognition of two subgenera, Pelargonium and Ciconium. Within these subgenera, the established sections represent natural entities. The subdivision of Erodium and Geranium is based exclusively on morphology. The limited rbcL data of six species of Geranium (Price and Palmer 1993) showed that Neurophyllodes (incl. Geranium grandiflorum) does not deserve generic status, since it is embedded in Geranium. The monospecific genus California newly described by Aldasoro et al. (2002) is not accepted until a complete molecular study of Erodium is available. The authors argued in terms of the unique androecium of the species (total reduction of the sterile stamens) but their trnL-F analysis provides low bootstrap support.

161

As a consequence of extensive molecular studies, Geraniales are restricted to Geraniaceae, Melianthaceae and Ledocarpaceae, which are the sister group of Crossosomatales. The position of these two orders within rosids is still unresolved (see Introduction to Geraniales, this volume). Distribution and Habitats. Erodium subg. Erodium has a Saharo-Sindian distribution but is absent from southern Europe; small annual and perennial anemochorous herbs predominate. Subg. Barbata is distributed all around the Mediterranean and extends to Central Asia, southern North America, southern Africa and Australia (Carolin 1958). Subg. Barbata is restricted to more mesic habitats than the more xerotolerant subg. Erodium. Erodium incarnatum, the only indigenous South African species of the genus, has been transferred into Pelargonium. Geranium is the most pronouncedly mesophytic genus of the family and is largely restricted to north temperate regions. The distribution of Geranium subg. Erodioideae is circumMediterranean, whereas subg. Robertium extends from Macaronesia to the Far East. Most sections of subg. Geranium consist of perennials of the east Mediterranean region but extend to the western Himalayas. Other subgenera contain annuals, biennials and summer-dormant tuberous species. Geranium sect. Geranium, by far the largest subgroup of the genus, is mesophytic and is worldwide in distribution, but is most speciose in tropical and subtropical mountain regions (Asia, Australia, Indonesia, Hawaiian Islands: e.g. Carolin 1964; North and South America: e.g. Robertson 1972, and Correa 1988; East and southern Africa: Laundon 1963, Müller 1963, Kokwaro 1971, Hilliard and Burtt 1985, and Gilbert and Vorster 2000). Three further sections comprise low, often acaulescent perennials restricted to higher altitudes of the Central and Northern Andes (Aedo et al. 2002). Today, several ruderal species of Erodium and Geranium are cosmopolitan weeds. Monsonia is mainly southern African; members of some sections including sect. Sarcocaulon show remarkable adaptations to arid conditions, especially in the Namib region. Their distribution extends from southern Africa via North Africa to India (Venter 1990). The vast majority of the species of Pelargonium occurs in Africa, whereas Australia has only few species. About 90% are endemic to the winter rainfall region of the western part of southern Africa.

162


The centre of diversity lies in the Cape Floristic Region. Most of the sections are confined to regions with regular rainfall and are part of the Coastal Fynbos. Several species survive in mountainous areas up to the alpine zone in the Drakensberg Mts., in karroid vegetation types and even in extremely dry areas in the north-western parts of southern Africa. Here, they are deciduous or die back and become dormant for the duration of the unfavourable season (Van der Walt and Vorster 1983). Species occurring in tropical East Africa are often associated with cooler highlands; those of Australia prefer regions of temperate to Mediterranean climate close to the southern coast. Hypseocharis occurs in the sub-alpine zone of the Andes from Peru through Bolivia into North Argentina at altitudes of about 2,000–4,000 m. This Andean genus may be a relic of the ancestors of Geraniaceae s.str. which occurred in Gondwana before South America separated from Africa (Boesewinkel 1988). Palaeobotany. Pollen attributed to Geranium and Pelargonium is known from the Upper Miocene of Spain, and to Pelargonium from the Pliocene of south-eastern Australia (Muller 1981). Parasites. Xanthomonas campestris pv. Pelargonii (Proteobacteria subcl. “beta/gamma”) infects both Pelargonium and Geranium species. This bacterial blight is the most serious disease of the garden geraniums (Dunbar and Stephens 1992). Economic Importance. Species and cultivars of Pelargonium and, to a lesser extent, of Geranium and Erodium are of high commercial value as ornamentals worldwide. Pelargoniums were introduced into The Netherlands and England at the beginning of the 17th century. Only five of the c. 280 species are the ancestors of the thousands of hybrids and cultivars now available. The “Royal Geraniums” are the result of crossings of P. cucullatum and P. grandiflorum. P. zonale and P. inquinans are the ancestors of the “Zonal Geraniums”. Different varieties of P. peltatum form the “Ivy Geraniums”. The food industry utilizes geranium oil as flavour or fragrance in non-alcoholic beverages, ice-cream, candy, baked goods, puddings, jams and chewing gums (Lis-Balchin 1990). Leaf extracts of Pelargonium species show antimicrobial effects. The scented-leaf pelargoniums are highly important for the perfume industry. The reported use of Pelargonium and Monsonia species as

Fig. 51. Geraniaceae. Hypseocharis tridentata. A Habit. B Flower, with petals removed. C Schizocarp. D Same, transverse section. E Mericarp, outer and inner view. F Seed. (Slanis and Grau 2001)

antispasmodics, antidysenterics, astringents and abortifacients is mainly limited to folk medicine. Only an extract of P. sidoides and P. reniforme roots is successfully employed in modern phytotherapy in Europe to cure infectious diseases of the respiratory tract (Kolodziej and Kayser 1998). Some efforts have been made concerning genetic transformation in Pelargonium species/cultivars (Boase et al. 1998). Conservation. Pelargonium cotyledonis, endemic to the St. Helena Islands, is one of the most endangered species of this genus. Hilton-Taylor (1997) listed four Pelargonium and three Monsonia sect. Sarcocaulon species for the southern African region which are under threat. The conservation status of the latter is also reported by Craib (1995). Species of the Pelargonium sect. Hoarea which mainly occur in the southwest of South Africa are becoming rare or are already extinct due to the extensive agriculture in that area, and other species of that genus are under threat by the extension of residential areas in the coastal regions.

Geraniaceae

Key to the Genera 1. Style simple, stigma capitate; fruits not beaked; leaves estipulate 1. Hypseocharis – Style with stigmatic style branches; fruits beaked; leaves stipulate 2 2. Flowers with hypanthium and a nectariferous tube in the hypanthium 5. Pelargonium – Flowers without hypanthium and without a nectariferous tube 3 3. Perfect stamens 5, flowers actinomorphic or zygomorphic 4 – Perfect stamens 10 or 15, flowers actinomorphic 5 4. Stamens free 3. Erodium – Each stamen grouped with two staminodes and connate with them at the base 4. Monsonia 5. Perfect stamens 10, free 2. Geranium – Perfect stamens 15, connate at base 4. Monsonia

163

Amer. spp.; Aedo, Syst. Bot. 26:205–215 (2001), rev. sect. Brasilensia; Aedo et al., Blumea 47:205–297 (2002), rev. sects. Azorelloideae, Neoandina and Paramensia; Aedo et al., Brittonia 55:93–126 (2003), rev. sect. Gracilia.

Annual or perennial herbs, occasionally subshrubs; stems herbaceous, erect to decumbent. Leaves opposite or alternate, palmatifid to palmatisect, segments entire to variously lobed, stipulate. Inflorescences 1–3-flowered pedunculate cymes. Flowers actinomorphic, only G. arboreum zygomorphic; petals white to purple, with markings; stamens 5 + 5, all fertile, connate at base; nectar glands 5, alternating with outer stamen whorl;

Genera of Geraniaceae 1. Hypseocharis J. Remy

Fig. 51

Hypseocharis J. Remy in Ann. Sci. Nat., Bot. III, 8:238– 240 (1847); Knuth, Bot. Jahrb. Syst. 41:170–174 (1908); MacBride, Field Mus. Nat. Hist. Chicago, Bot. 13, 3, no. 2:606–608 (1949); Slanis & Grau, Darwiniana 39:343–352 (2001).

Perennial acaulescent herbs with thick taproots or tubers. Leaves rosulate, pinnatifid, or upper ones pinnately incised, the leaflets subentire or 3-lobulate or pinnate-incised, estipulate. Inflorescences 1–many-flowered pedunculate cymes. Flowers actinomorphic; petals white, yellow, orange, brilliant red; nectary disk well developed, extrastaminal, lobed; stamens 5 or 15, all fertile, 10 short, antepetalous, 5 longer, antesepalous; ovary 5-lobed, 5-locular; ovules many per locule, axile, biseriate, anatropous to campylotropous; style simple, with capitate stigma. Fruit a tardily and irregularly loculicidal capsule, many small (c. 2 mm) seeds (schizocarpic); H. tridentata with unbeaked schizocarp, mericarps without awns, each with 1–few seeds. Six described species in high altitudes of the Andes, from Peru to northern Argentina. 2. Geranium L.

Fig. 52

Geranium L., Sp. Pl.: 676 (1753); Aedo et al., Anales Jard. Bot. Madrid 56:211–252 (1998), checklist; Knuth in Pflanzenreich IV, 129 (1912); Yeo, Bot. J. Linn. Soc. 67:285– 346 (1973), rev. sects. Anemonifolia and Ruberta; Aedo, Syst. Bot. Monogr. 49:1–104 (1996), rev. subg. Erodioidea; Aedo et al., Ann. Missouri Bot. Gard. 85:594–630 (1998), rev. sects. Batrachioidea and Divaricata; Aedo, Anales Jard. Bot. Madrid 58:39–82 (2000), et ibid. 59:3–65 (2001), N.

Fig. 52. Geraniaceae. Geranium maculatum. A Plant with annual shoot and perennial rhizome. B Flower at anthesis, with whorl of inner stamens dehiscing and style branches still closed. C Stamen of outer whorl. D Gynoecium with recurved style branches and nectar glands on receptacle below pubescent ovary. E Same, semidiagrammatic vertical section to show placentation. F Dehisced fruit with mericarps attached to recurved hygroscopic awns. G Transverse section of ovary, with two superposed ovules in each locule. H Seed. I Embryo. J Same, transverse section to show folding of cotyledons. (Robertson 1972)

164


ovary 5-lobed, 5-locular, 2 ovules per locule. Fruit beaked, of 5 mericarps, these 1-seeded, with a spirally twisted awn; seeds ellipsoidal, keeled with two growes. About 430 species, distributed throughout the world. Yeo (1990) proposed three subgenera which are based on the mode in which the fruit break at maturity: subg. Geranium (3 sections with more than 380 species), subg. Robertium (Picard) Rouy (8 sections with 30 species) and subg. Erodioidea (Picard) Yeo (3 sections with 19 species). 3. Erodium L’Hérit. Erodium L’Hérit. in Ait. Hort. Kew. ed. 1, 2:414 (1789). California Aldasoro, Navarro, Vargas, Sáez & Aedo, Anales Jard. Bot. Madrid 59:213 (2002).

Annual or perennial herbs, rarely subshrubs; stems herbaceous, erect to decumbent. Leaves opposite or alternate, simple to pinnatisect to pinnate, stipulate. Inflorescences 1–many-flowered pedunculate cymes. Flowers actinomorphic, rarely zygomorphic; petals white to purple, equal but sometimes unequal, when equal, then all petals often with a central marking, when unequal, then only the upper petals with markings; stamens 5, antesepalous, alternating with 5 staminodes; nectar glands 5, antesepalous; ovary 5-lobed, 5-locular, 2 ovules per locule. Fruit beaked, of 5 mericarps, these 1-seeded, with a spirally twisted and hairy awn; seeds oblongate, keeled with two grooves. About 80 species, with fairly cosmopolitan distribution and a high concentration in Mediterranean climate regions worldwide, often synanthropic. Two subgenera: subg. Erodium, anemochorous mericarps with long plumose fibres on the inner surface of the awn; subg. Barbatum (Boiss.) Guitt., zoochorous mericarps, awn with unequal but rigid fibres; 2 or 3 sections with subsections (Guittonneau 1990).

Fig. 53. Geraniaceae. Monsonia patersonii. A Habit. B Lateral branch armed with petioles of fallen leaves. C Leaf blade. D Flower. E Fruit. (Knuth 1912)

persisting as spines, stipulate. Inflorescences 1–15-flowered pedunculated cymes, or flowers solitary. Flowers actinomorphic; petals white to yellow, pink, mauve, bluish, often only with faint markings; stamens 15, in groups of 3, all fertile, or rarely (in one sp.) 10 sterile; nectar glands 5, alternating with outer stamen whorl; ovary 5-lobed, 5-locular, 2 ovules per locule. Fruit beaked, of 5 mericarps, these 1-seeded with a spirally twisted and, in several species, hairy awn; seeds oblongate, keeled with two grooves. About 40 species, Africa, Madagascar and southwest Asia, but most species in the drier parts of southern Africa. Albers (1996) demonstrated that Monsonia and Sarcocaulon are congeneric, and considered Sarcocaulon as a section of Monsonia. 5. Pelargonium L’Hérit.

4. Monsonia L.

Fig. 53

Monsonia L., Mant.: 14 (1767); Venter, Meded. Landbouwhogesch. Wageningen 79:1–128 (1979); Albers, S. African J. Bot. 62:345–347 (1996). Sarcocaulon (DC.) Sweet, Hort. Brit. ed. 1:73 (1826); Rehm in Bot. Jahrb. Syst. 67:264–274 (1935); Moffett, Bothalia 12:581–613 (1979); Craib, Hystrix 1:1–60 (1995).

Prostrate, decumbent or erect annual herbs or perennial subshrubs; stems herbaceous, succulent or woody. Leaves alternate or opposite, simple or rarely pinnately incised, petioles sometimes

Fig. 54

Pelargonium L’Hérit. in Ait. Hort. Kew. ed. 1, 2:417 (1789).

Perennial shrubs, subshrubs, herbs, geophytes with root tubers (rhizomes, climbers or annual herbs); stems herbaceous, subsucculent, succulent or woody, erect to decumbent. Leaves alternate, petiolate, entire to much divided to compound, often heteroblastic, petioles rarely persisting as spines; stipules membranous, herbaceous or spiny, caducous or persistent. Scape often branched with several inflorescences; inflorescences 1-manyflowered, pedunculate pseudoumbels. Flowers zy-

Geraniaceae

165

the Arabian Peninsula, Asia Minor, Madagascar and Australia incl. New Zealand. One species on Tristan da Cunha and one on St. Helena. Two subgenera, supported by chromosomal and molecular data: subg. Pelargonium and subg. Ciconium (Bakker et al. 2000), both with several sections and subsections.


Fig. 54. Geraniaceae. Pelargonium squamulosum. (Kunth 1912)

gomorphic, receptacle modified in a hypanthium with a nectariferous tube; sepals connate at base; petals 5(2, 4), usually unequal, white, cream, yellowish, greenish, pinkish, pink, pinkish-purple or red, upper 2 petals often with markings; androecial members 10, connate at base, 3–8 staminodial; ovary 5-lobed, 5-locular, 2 ovules per locule. Fruit beaked, of 5 mericarps, these 1-seeded, with a spirally twisted and hairy awn; seeds ellipsoidal, keeled with 2 grooves. About 280 species, of which more than 200 occur in southern Africa. The remaining are spread over East Africa,

Aedo, C., Muñoz-Garmendia, F., Pando, F. 1998. World checklist of Geranium. Anales Jard. Bot. Madrid 56:211–252. Aedo, C., Aldasoro, J.J., Navarro, C. 2002. Revision of Geranium sections Azorelloidea, Neoandina, and Paramensia (Geraniaceae). Blumea 47:205–297. Albers, F. 1988. Strategies in chromosome evolution in Pelargonium (Geraniaceae). Monogr. Syst. Bot. Missouri Bot. Gard. 25:499–502. Albers, F. 1990. Comparative karyological studies in Geraniaceae on family, genus, and section level. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 115–122. Albers, F. 1996. The taxonomic status of Sarcocaulon (Geraniaceae). S. African J. Bot. 62:345–347. Albers, F. 2002. Geraniaceae. In: Eggli, U. (ed.) Illustrated Handbook of Succulent Plants. Dicotyledons, pp. 241– 272. Berlin Heidelberg New York: Springer. Albers, F., Van der Walt, J.J.A. 1984. Untersuchungen zur Karyologie und Mikrosporogenese von Pelargonium sect. Pelargonium (Geraniaceae). Pl. Syst. Evol. 147:177–188. Albers, F., Gibby, M., Austmann, M. 1992. A reappraisal of Pelargonium sect. Ligularia (Geraniaceae). Pl. Syst. Evol. 179:257–276. Aldasoro, J.J., Navarro, C., Vargas, P., Aedo, C. 2001. Anatomy, morphology, and cladistic analysis of Monsonia L. (Geraniaceae). Anales Jard. Bot. Madrid 59:75–100. Aldasoro, J.J., Navarro, C., Vargas, P., Saez, L., Aedo, C. 2002. California, a new genus of Geraniaceae endemic to the southwest of North America. Anales Jard. Bot. Madrid 59:209–216. APG II 2003. See general references. Bakker, F.T., Culham, A., Pankhurst, C.E., Gibby, M. 2000. Mitochondrial and chloroplast DNA-based phylogeny of Pelargonium (Geraniaceae). Amer. J. Bot. 87:727– 734. Bate-Smith, E.C. 1973. Chemotaxonomy of Geranium. Bot. J. Linn. Soc. 67:347–359. Bauer, H. 1991. Untersuchungen zur Anwendbarkeit von Phenol-Bestimmungen bei der Charakterisierung von Genotypen unter dem Aspekt des Sortenschutzes. Ph.D. Thesis, Technische Universität München, 196 p. Boase, M.R., Bradley, J.M., Borst, N.K. 1998. An improved method for transformation of regel pelargonium (Pelargonium X domesticum Dubonnet) by Agrobacterium tumefaciens. Pl. Sci. 139:59–69. Boesewinkel, F.D. 1988. The seed structure and taxonomic relationships of Hypseocharis Remy. Acta Bot. Neerl. 37:111–120.

166


Boesewinkel, F.D. 1997. Seed structure and phylogenetic relationships of the Geraniales. Bot. Jahrb. Syst. 119:277– 291. Boesewinkel, F.D., Ben, W. 1979. Development of ovule and testa of Geranium pratense L. and some other representatives of the Geraniaceae. Acta Bot. Neerl. 28:335– 348. Bortenschlager, S. 1967. Vorläufige Mitteilungen zur Pollenmorphologie in der Familie der Geraniaceen und ihre systematische Bedeutung. Grana Palynol. 7:400– 468. Carolin, R.C. 1958. The species of the genus Erodium L’Hér. endemic to Australia. Proc. Linn. Soc. New South Wales 83:92–100. Carolin, R.C. 1964. The genus Geranium L. in the south western Pacific area. Proc. Linn. Soc. New South Wales 89:326–361. Corner, E.J.H. 1976. See general references. Correa, M.N. 1988. Geraniaceae. In: Flora Patagonica 5:30– 39. Buenos Aires: INTA. Craib, C. 1995. The sarcocaulons of southern Africa. Hystrix 1:1–60. Demarne, F.-E. 1990. Essential oils in Pelargonium, sect. Pelargonium. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 245–268. Dreyer, L.L., Marais, E.M. 2000. Section Reniformia, a new section in the genus Pelargonium (Geraniaceae). S. African J. Bot. 66:44–51. Dreyer, L.L., Leistner, O.A., Burgoyne, P., Smith, G.F. 1997. Sarcocaulon: genus or section of Monsonia (Geraniaceae)? S. African J. Bot. 63: 240. Dunbar, K.B., Stephens, C.T. 1992. Resistance in seedlings of the family Geraniaceae to bacterial blight caused by Xanthomonas campestris pv. pelargonii. Pl. Disease 76:693–695. Gibby, M., Hinnah, S., Albers, F., Marais, E.M. 1996. Cytological variation and evolution within Pelargonium sect. Hoarea. Pl. Syst. Evol. 203:111–142. Gilbert, M.G., Vorster, P. 2000. Geraniaceae. In: Edwards, S., Tadesse, M., Demissew, S., Hedberg, I. (eds) Flora of Ethiopia and Eritrea, vol. 2, 1, pp. 364–378. Addis Ababa: Ethiopian National Herbarium. Guittonneau, G.-G. 1972. Contribution à l’étude biosytématique du genre Erodium L’Hér. dans le bassin méditerranéen occidental. Boissiera 20:9–154. Guittonneau, G.-G. 1990. Taxonomy, ecology, and phylogeny of the genus Erodium L’Hér. in the Mediterranean region. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 69–91. Hallier, H. 1923. Beiträge zur Kenntnis der Linaceae (DC. 1819) Dumort. 25. Lepidobotrys Engl., die Oxalidaceen und die Geraniaceen. Beih. Bot. Centralbl. 39, 2:1– 178. Hilliard, O.M., Burtt, B.L. 1985. A revision of Geranium in Africa south of the Limpopo. Notes Roy. Bot. Gard. Edinburgh 42:171–225. Hilton-Taylor, C. 1997. Threatened succulents recorded for the Flora of Southern Africa (FSA) region. In: Oldfield, S. (comp.) Cactus and succulent plants. Status Survey and Conservation Action Plan. IUCN/SSC Cactus and Succulent Specialist Group, IUCN, Gland, Switzerland, 212 pp.

Huynh, K.-L. 1969. Etude du pollen des Oxalidaceae, 1. Bot. Jahrb. Syst. 89:272–303. Jones, C.S., Price, R.A. 1996. Diversity and evolution of seedling Baupläne in Pelargonium (Geraniaceae). Aliso 14:281–295. Knuth, R. 1912. Geraniaceae. In: Pflanzenreich IV, 129. Leipzig: W. Engelmann. Kokwaro, J. 1971. Geraniaceae. In: Milne, E., Polhill, R.M. (eds) Flora of Tropical East Africa. London: Government Printer, pp. 1–24. Kolodziej, H., Kayser, O. 1998. Pelargonium sidoides DC. Neueste Erkenntnisse zum Verständnis des Phytotherapeutikums Umckaloabo. Zeitschr. Phytotherapie 19:141–151. Laundon, J.R. 1963. Geranium. In: Exell, A.W., Fernandes, A., Wild, H. (eds) Flora Zambesiaca 2:131–136. Royal Botanic Gardens, Kew. Link, D. 1990. The nectaries of Geraniaceae. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 215–225. Lis-Balchin, M. 1990. The commercial usefulness of the Geraniaceae, including their potential in the perfumery, food manufacture, and pharmacological industries. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 269–277. Meisert, A. Schulz, D., Lehmann, H. 2001. The ultrastructure and development of the light line in the Geraniaceae seed coat. Pl. Biol. 3:351–356. Meve, U. 1995. Autogamie bei Pelargonium-Wildarten. Palmengarten 59:100–108. Moffett, R.O. 1997. The taxonomic status of Sarcocaulon. S. African J. Bot. 63:239–240. Müller, T. 1963. Pelargonium. In: Exell, A.W., Fernandes, A., Wild, H. (eds) Flora Zambesiaca 2:140–149. Royal Botanic Gardens, Kew. Muller, J. 1981. See general references. Price, R.A., Palmer, J.D. 1993. Phylogenetic relationships of the Geraniaceae and Geraniales from rbcL sequence comparisons. Ann. Missouri Bot. Gard. 80:661–671. Robertson, K.R. 1972. The genera of Geraniaceae in the southeastern United States. J. Arnold Arb. 53:182–201. Ronse DeCraene, L.P., Smets, E.F. 1995. The distribution and systematic relevance of the androecial character oligomery. Bot. J. Linn. Soc. 118:193–247. Savolainen, V., Fay, M.F. et al. 2000. See general references. Slanis, A.C., Grau, A. 2001. El genero Hypseocharis (Oxalidaceae) en la Argentina. Darwiniana 39:343–352. Soltis, D.E. et al. 2000. See general references. Stafford, P.J., Blackmore, S. 1991. Geraniaceae. In: Punt, W., Blackmore, S. (eds) The Northwest European Pollen Flora 6:49–78. Amsterdam: Elsevier. Stafford, P.J., Gibby, M. 1992. Pollen morphology of the genus Pelargonium (Geraniaceae). Rev. Palaeobot. Palynol. 71:79–109. Struck, M. 1997. Floral divergence and convergence in the genus Pelargonium (Geraniaceae) in southern Africa: ecological and evolutionary considerations. Pl. Syst. Evol. 208:71–97. Van der Walt, J.J.A. 1977. Pelargoniums of Southern Africa. Cape Town: Purnell. Van der Walt, J.J.A., Vorster, P.J. 1981. Pelargoniums of Southern Africa, vol. 2. Cape Town: Juta.

Geraniaceae Van der Walt, J.J.A., Vorster, P.J. 1983. Phytogeography of Pelargonium. Bothalia 14:517–523. Van der Walt, J.J.A., Vorster, P.J. 1988. Pelargoniums of Southern Africa, vol. 3. Kirstenbosch: National Botanical Gardens. Van der Walt, J.J.A., Werker, E., Fahn, A. 1987. Wood anatomy of Pelargonium (Geraniaceae). IAWA Bull. N.S. 8:95–108. Van Loon, J.C. 1984a. Chromosome numbers in Geranium from Europe. I. The perennial species. Proc. Koninkl. Ned. Akad. Wetensch. C, 87:263–277. Van Loon, J.C. 1984b. Chromosome numbers in Geranium from Europe. II. The annual species. Proc. Koninkl. Ned. Akad. Wetensch. C, 87:279–296. Venter, H.J.T. 1990. An account of Monsonia. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 331–351. Verhoeven, R.L., Marais, E.M. 1990. Pollen morphology of the Geraniaceae. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 137–173.

167

Verhoeven, R.L., Venter, H.J.T. 1986. Pollen morphology of Monsonia. S. African J. Bot. 52:361–368. Vogel, S. 1998. Remarkable nectaries: structure, ecology, organophyletic perspectives, IV. Miscellaneous cases. Flora 193:225–248. Weber, M. 1996. The existence of a special exine coating in Geranium robertianum pollen. Intl J. Pl. Sci. 157:195– 202. Williams, Ch.A., Newman, M., Gibby, M. 2000. The application of leaf phenolic evidence for systematic studies within the genus Pelargonium (Geraniaceae). Biochem. Syst. Ecol. 28:119–132. Yeo, P.F. 1973. The biology and systematics of Geranium, sections Anemonifolia Knuth and Ruberta Dum. Bot. J. Linn. Soc. 67:285–346. Yeo, P.F. 1984. Fruit-discharge-type in Geranium (Geraniaceae): its use in classification and its evolutionary implications. Bot. J. Linn. Soc. 89:1–36. Yeo, P. 1990. The classification of Geraniaceae. In: Vorster, P. (ed.) Proc. 1st International Geraniaceae Symposium, Stellenbosch University, South Africa, pp. 1–22.

Grossulariaceae Grossulariaceae DC. in Lam. & DC., Fl. Franç., ed. 3., 4, 2:405 (1805), nom. cons.

M. Weigend

Shrubs, sometimes dioecious, 0.1–7 m tall, erect, prostrate or lianescent with regular and very short internodes, unarmed or with simple or ternate nodal and/or simple internodal spines, stem initially with white pith, terete, bark dark brown to black, later often exfoliating in strips; horizontal underground stems often present; indumentum of subsessile and/or unicellular and pluriseriate, glandular or eglandular trichomes on young shoots, leaves, flowers and fruits. Leaves deciduous or evergreen, alternate, petiolate, rarely subsessile; stipules usually dry, brown and fimbriate; bud scales dry and brown, rarely membranaceous, usually pubescent and/or glandular; lamina ovate to subcircular, rarely flabellate, membranaceous to coriaceous, 0.5–25 cm in diameter, base cuneate to deeply cordate, usually trilobate, or subpalmately lobed, rarely undivided; margin irregularly lobulate and coarsely serrate with hydathode teeth, rarely subentire, usually pubescent at least abaxially, sometimes densely covered with resin or wax; venation palmate with usually three major veins; ptyxis mostly plicate, rarely convolute. Inflorescences usually on short shoots, racemose, pendulous, or rarely erect, (1–)5–50-flowered, axis sometimes with very short, sometimes distally contracted and inflorescence appearing corymbose, each flower with a pubescent and often fimbriate bract and usually two smaller prophylls, rarely with a single, amplexicaul prophyll. Flowers hermaphroditic or unisexual, chasmogamous, proterandric or protogynous, erect or pendulous, actinomorphic, (4)5-merous; hypanthium distinct, patelliform to long-cylindrical and usually persistent in fruit; calyx lobes usually oblong-acuminate, erect, spreading or reflexed, rarely erect with reflexed apex, green, white, yellow or red; petals distinct, rarely absent, erect or spreading, margin entire, ovate or oblong with narrowed base, rarely filiform or flabellate, flat or sometimes involute, membranaceous, green, white, yellow or red, aestivation apert; androecium haplostemonous, stamens an-

tesepalous, all fertile or all staminodial; filaments filiform, insertion episepalous; anthers included or long-exserted, basifixed, with 4 microsporangia; connective undifferentiated or with distal nectary, staminodia undifferentiated with poorly developed thecae, or fully developed thecae but without viable pollen; nectary a well-developed, often 5-lobed disc; ovary in hermaphroditic and female flowers well developed, completely inferior to 1/3 superior, conical to globose, glabrous to densely glandular and/or pubescent, with 2 parietal, slightly intrusive placentae, in male flowers very small, undifferentiated or with poorly developed ovules; style conical to filiform with two stigmatic branches and two papillose stigmas, included or exserted, basally often densely pubescent; ovules numerous, anatropous, bitegmic, crassinucellar with well-developed chalazal haustoria. Fruit a soft berry crowned with the persistent perianth, often covered with unicellular or glandular trichomes, yellow, orange, red, black, rarely white and/or covered with waxy bloom, acidic or insipid; seeds (3–)10–60, with outer mucilaginous layer and a hard, brown to black seed coat; embryo small, straight, embedded in copious starch-free, oily endosperm; seedlings with 2 ovate to elliptical cotyledons, these apically emarginate with midvein ending in hydathode tooth, often pubescent and glandular. One genus with 150–200 species in the northern temperate zone and South America, with outliers in northern Africa, Southeast Asia and Central America. Vegetative Morphology. Ribes consists exclusively of shrubs typically differentiated into short shoots and long shoots. The vast majority of taxa branches at the base and has numerous strong, self-supported, widely spaced branches. Prostrate stems or underground runners are occasionally found in all major groups of Ribes but are particularly typical of subg. Symphocalyx and subg. Ribes sect. Heritiera. Many species form large clonal

Grossulariaceae

stands in this way. Species with this type of growth are especially abundant in riparian forests and swamps (R. glandulosum, R. nigrum) and in alpine habitats (e.g. R. nitidissimum in Patagonia). At least one species forms dwarf shrubs only c. 15 cm high in high Andean habitats, some species have very dense and squarrose branching (i.e. many short shoots: R. cuneifolium), while others make very long internodes on thin shoots and thus climb in cloud forests (R. incarnatum and allied South American taxa). The epidermis of the shoots often exfoliates in long strips in the second year, and is then replaced by a well-developed periderm. Exfoliation is particularly striking in many species of subg. Ribes (sect. Berisia and sect. Ribes). Ribes subg. Ribes sect. Berisia, subg. Grossularioides and subg. Grossularia have spines, which are usually found at the leaf nodes (nodal spines) but also scattered over the entire shoot (internodal spines, e.g. R. horridum). Spines seem to have evolved twice independently, once in the Berisia lineage and once in the Grossularioides/Grossularia lineage. They are typical emergences developing from the epidermis and the subjacent parenchyma; internodal spines are sometimes gland-tipped (especially in R. subg. Grossularioides) and are derived from conical setae (see below). Foliage of Ribes is mostly deciduous, rarely evergreen. Evergreen species are found in alpine habitats in the Himalayas (R. laurifolium, R. davidii) and in Mediterranean habitats in California (R. viburnifolium), semi-evergreen species in South America (R. cuneifolium, R. ovalifolium) and East Asia (R. fasciculatum). Evergreen and semievergreen taxa generally have coriaceous and undivided or shallowly lobed leaves, while most Ribes have 3–5-lobed laminas. This leaf type is found in all infrageneric groups and can be considered as plesiomorphic. Leaf venation is always palmate with three veins entering the lamina, irrespective of leaf outline. Vegetative Anatomy. The plants are usually covered with different types of trichomes, some of which are informative in classification (Weigend and Binder 2001). Unicellular trichomes are usually white and lack a glandular apex. Glandular trichomes are very widespread and always have a pluricellular head. Sessile glands are disc-shaped, rarely globose, and are found in two different subtypes: sessile resin glands (surrounded by a persistent layer of resinous secretion) and non-resinous sessile glands (lacking any visible secretion in the

169

Fig. 55. Grossulariaceae. Ribes viburnifolium. Sessile nonresinous gland and unicellular trichomes from inferior portion of ovary, SEM micrograph. (Orig.)

dry stage and with at most a clear secretion at their tip in the living stage; Fig. 55). Subsessile glands are non-resinous and have a short, pluriseriate stalk which is shorter than or equal in length to the diameter of the glandular head of the trichome; they are often characteristic of certain species (cf. ovary of R. andicola). Stalked glands are pluriseriate trichomes c. 1 mm long with a well-developed secretory head. Conical setae differ in having a conical stalk 2–10 mm long. The tip of the conical setae is usually glandular, but the development of the apical gland can be retarded or suppressed. They are not usually found on leaf surfaces but are frequently present on stipules and stems, and the entire distal margin of the stipule can be laciniate and divided into conical setae. Plumose setae are conical setae which are densely covered with unicellular trichomes and are thus compound trichomes. There is a more or less gradual transition from conical setae to internodal spines in a few species (e.g. sect. Grossularioides, sect. Berisia). Nodal spines are apparently of different derivation, but their ontogeny has not been studied so far. The nodes are always trilacunar, and three veins enter the lamina. The lamina is usually hypostomatic, very rarely amphistomatic (R. cereum); stomata are anomocytic. Both the adaxial and abaxial epidermis is uniseriate. The mesophyll has usually 1–2, rarely up to 4 layers of palisade parenchyma with a few interspersed tanniniferous cells. Crystal druses 6–35 µm in diameter are found in the spongy and palisade parenchyma and the collenchyma along the leaf veins. Hydathodes are universally present at the leaf teeth.

170

M. Weigend

The stem anatomy of Ribes has been studied in a few, mostly North American and European taxa (Janczewski 1907; Metcalfe and Chalk 1950; Stern et al. 1970). Young shoots are filled with a distinct white pith of spongy parenchyma. Growth rings are usually present in the wood, but not very distinct. The xylem cylinder is interspersed with clear narrow, medullary or lignified rays. The xylem has scalariform perforation plates, rarely also simple plates and transitional to opposite intervascular pitting; axial xylem parenchyma is usually absent. Vessels are very narrow (25–50 µm in diam.) and form a tangential pattern in some species. Both homocellular and heterocellular vascular rays are present, as are more or less distinctly septate fibre tracheids. Underground stems have a well-differentiated endodermis. The hypodermis is usually massively developed, and has either thickened cells walls (subg. Grossularia) or consists of thin-walled cells (all other subgenera, Weigend et al. 2002). Tanniniferous cells are common in the leaves, petiole, cortex, phloem, pith and medullary rays. Cystoliths are frequently present in non-lignified tissues of the stems (Stern et al. 1970). Inflorescence and Flower Structure. The inflorescences of Ribes are very uniform and usually racemose (Fig. 56A); additional racemes arise very rarely from the usually sterile bracts on the main axis, but reductions to few-flowered racemes and apparently axillary flowers are pronounced in some Asian taxa (R. ambiguum, R. fasciculatum) and most gooseberries (R. subg. Grossularia, Fig. 56K). Ribes viburnifolium from California has very short internodes in the inflorescence, and these appear corymbose. The inflorescences usually arise on short shoots but the terminal bud on long shoots also usually produces an inflorescence, albeit not in subg. Ribes sects. Ribes and Heritiera. The inflorescences are nearly universally pendulous, irrespective of size, but both dioecious groups in Ribes (subg. Parilla sect. Andina and subg. Ribes sect. Berisia) have a few species with stiffly erect inflorescences elevated above the foliage. The bracts are typically ovate to narrowly ovate and more or less equal to the pedicel in length, but in subg. Ribes they are often much shorter than the pedicel and have a truncate apex. Prophylls are usually present. The flowers of Ribes are simple and uniform. The petals are always small and often included in the calyx (Fig. 56D), so that the attractive function of the perianth is usually shared by, or com-

Fig. 56. Grossulariaceae. A–D Ribes incarnatum. A Flowering shoot. B Vegetative shoot. C Stipulate petiole base. D Flower. E–G R. sanguineum, heteroblastic series from bud scale to foliage leaf, with gradually reduced stipular portion. H R. roezlii, flowering branch. I R. triste, flower, nectary dotted. R. speciosum. J Spiny fruit. K Flower. (A–D Weigend and Binder 2001; E–K orig.)

pletely relegated to the calyx. Flower colours are highly variable and most major groups have a wide range of colours. The hypanthium is sometimes very short and flat (Fig. 56I, typically in subg. Ribes, subg. Grossularioides, and individual species in all other subgenera except Grossularia), bowl-shaped (all groups), or rarely long and more or less cylindrical (subg. Symphocalyx, subg. Grossularia). The only structural variation of the hypanthium is the occurrence of small invaginations above the point of petal insertion and sometimes the point of fil-

Grossulariaceae

171

1977). The inner integument is usually 2–3-layered, and the outer 3–5-layered. The outer epidermis of the outer integument and sometimes also the inner epidermis of the inner integument consist of tanniniferous cells. The exact fate of the different integumentary layers during seed ontogeny is still unknown. Endosperm formation is ab initio cellular in subg. Ribes (R. orientale, R. rubrum, R. spicatum) and helobial in subg. Grossularia (R. burejense, R. uva-crispa, R. divaricatum, R. missouriense, R. oxyacanthoides; Davis 1966), but has not been studied for the other groups.

Fig. 57. Grossulariaceae. Ribes multiflorum. Hypanthium with filament bases, tiny petals and wide calyx lobes and the invaginations of the nectary, SEM micrograph. (Orig.)

ament insertion (Fig. 57, R. multiflorum, R. manshuricum). The calyx lobes are usually spreading or reflexed, occasionally erect and forming a tube (R. speciosum, Fig. 56K). Many species of subg. Grossularia have reflexed calyx lobes and porrect petals (Fig. 56H), and some species of subg. Ribes have porrect calyx lobes with a strongly ciliate margins (e.g. R. meyeri). Petals are often ovate or oblong with a narrowed base (most species), rarely flabellate (e.g. subg. Ribes, subg. Grossularioides), long-acuminate (some species of subg. Coreosma), filiform (R. fasciculatum) or involute (many species of subg. Grossularia). The anthers are usually included when a long hypanthium is present, but often distinctly exserted (e.g. subg. Symphocalyx, Grossularia, Fig. 56H). The presence of nectar glands on the connective has been used as an important character in classification (Janczewski 1907), but its systematic relevance has yet to be critically evaluated. The ovary is usually completely inferior and the receptacle is planar, but one group in subg. Ribes has a 1/3 superior ovary with a conical style. The nectary is very strongly developed and forms an extensive disc or cup; nectar is secreted from modified stomata. Embryology. Only a few species of Ribes have been subject to embryological studies. Ovules are anatropous, crassinucellar and bitegmic, and have a distinct chalazal haustorium. The funicle develops an obturator opposite the micropyle (Weigend et al. 2002), which has been termed “aril” (Krach

Pollen Morphology. Pollen morphology of Ribes has not been extensively studied with SEM, and relatively few useful data have been published. Verbeek-Reuvers (1980) studied the pollen of European species corresponding to three subgenera (subg. Grossularia, subg. Ribes sects. Ribes and Berisia, subg. Coreosma). These are here supplemented by a few original observations from the other subgenera. The pollen grains are 15–40 µm in diameter, prolate, ellipsoidal or globose in outline, and always have characteristic ectoapertures (i.e. rugose areas around the endoapertures). The apertures are rarely symmetrical and regular; more often they are of different sizes and without clear symmetry. The pollen grains are pantoporate with 5–6 pori (R. alpinum, R. nigrum), zonocolporate with 8 or more pori (R. uva-crispa), pantoporate with (6–)8–14 pori

Fig. 58. Grossulariaceae. Ribes multiflorum. Pollen grain, SEM micrograph. (Orig.)

172

M. Weigend

(R. rubrum, R. spicatum, R. petraeum, Fig. 58), or pentacolpo-di-orate (R. divaricatum). The exine is either nearly smooth (R. alpinum), shallowly and irregularly rugulose to punctate (most species), or reduced to irregularly rugulose remnants (R. inebrians) or distinct spines (R. lacustre). Karyology and Hybridization. Chromosome counts are available for c. two thirds of the species and uniformly show a chromosome complement of 2n = 16 (compiled in Sinnott 1985). The chromosomes are small (c. 1.5–2.5 µm long) and relatively uniform. Natural polyploidy has not been documented. Hybridization has been extensively studied both in artificial and natural hybrids. Natural hybridization has been documented mostly within narrowly related species groups such as the subg. Coreosma (Andersson 1943) and the “western gooseberries” of subg. Grossularia (Mesler et al. 1991). Natural hybridization is locally important in the South American Andes, where as many as three distinct species may locally form complex hybrid swarms (pers. obs.). Some degree of pollen sterility is observed even in hybrids between closely related species (Mesler et al. 1991). Various horticultural hybrids have been successfully established, and hybrid viability and fertility depend strongly on the closeness of the phylogenetic relationship between parental species (Janczewski 1907; Keep 1962). Hybrids between distantly related taxa often die at the seedling stage (Keep 1962), or have an irregular meiosis and strongly reduced pollen viability (Meurman 1928). Pollination and Breeding systems. The flowers of Ribes are usually small and either homogamous, proterandric or protogynous. Most Ribes have hermaphroditic flowers but two groups are dioecious: the female flowers of subg. Parilla produce poorly differentiated pollen which remains in a compact mass, and the male flowers produce abortive ovules in an externally normal ovary. Dioecy is further derived in subg. Berisia where the female flowers have sterile anthers without a clear sporogenous tissue, and the male flowers lack a differentiated ovary. Pollen sterility has been documented from a range of apparently hermaphroditic species in Ribes (Janczewski 1907), and this indicates that gynodioecy may be widespread in Ribes which would, in turn, render the independent evolution of dioecy in two unrelated groups more plausible. This may

also explain why fruit set is higher with crosspollination, despite the fact that some selfing does occur in species with hermaphroditic flowers (e.g. R. nigrum, R. rubrum, R. uva-crispa, Free 1993). Most species are entomogamous. Observations on flower visitors have been published for European species (Knuth 1898; Free 1993; Schweitzer 1996) and for a few North American species from cultivation in Europe (Knuth 1898); less detailed data are available on North American taxa in their natural habitats (Catling et al. 1998). There is broad congruence across the Atlantic and across a wide range of distantly related species; pollination seems to be largely unspecialized. Diptera and Hymenoptera predominate amongst flower visitors in typical, open Ribes flowers. All Ribes species are visited by honey bees and bumblebees (Hymenoptera: Apidae: Apis, Bombus, Nomada), and frequently various other bee groups (Hymenoptera: Andrenidae, Halictidae, Anthrophoridae). Blowflies (Diptera: Calliphoridae) are also often observed, and the flat and open flowers of many members of subg. Ribes are frequently visited by dung flies (Diptera: Scatophagidae) and hoverflies (Diptera: Syprhidae). Conclusive evidence for effective pollination has been presented only for honey bees. Some species in three groups of Ribes (subg. Parilla, Grossularia and Calobotrya) have progressed towards hummingbird pollination; they have mostly red, or red and green flowers with a long and tubular hyphanthium and/or porrect calyx lobes and/or petals, and stigmas and anthers usually exserted from the perianth. In (south-)western North America (subg. Grossularia and Calobotrya), numerous species are exclusively (R. speciosum) or mostly (R. lobbii, R. divaricatum, R. sanguineum) pollinated by hummingbirds (Pojar 1975). Fruit and Seed. Ribes is uniform in fruit morphology and all species have berries, which differ essentially in indumentum, size, shape, colour and seed number. The dry perianth and androecium persist on the developing berry. The exocarp is thinly membranaceous, often covered with a thin, white wax layer and more or less numerous trichomes, rarely with thin spines. Meso- and endocarp are soft and juicy in the mature fruit. Seed numbers vary between (3–)10 and 60; species with many seeds usually have small seeds (< 1 mm, R. ambiguum = sect. Microsperma) whereas those with few seeds have much larger ones (c. 4 mm long, R. nitidissimum). The seeds are covered with

Grossulariaceae

a mucilaginous outer testa (myxotesta) of 3–6 layers of large cells with thin cell walls, and a hard, inner testa of one layer of small cells containing calcium oxalate crystals with thick but not lignified cell walls and an innermost layer of narrow, longitudinally elongate, tanniniferous cells. The cells of the endosperm have walls of storage cellulose 5–10 µm thick and cell lumina filled with oil droplets. The embryo is weakly differentiated and very small. The fruits usually disarticulate at the point of prophyll attachment in most subgenera but remain firmly attached to the pedicel in subg. Grossularia. The fruits of Ribes are eaten by many mammals (incl. humans) and birds, and the seeds are endozoochorous. Phytochemistry. Phytochemistry of Ribes has been repeatedly studied and compiled (Hegnauer 1973, 1990; Bate-Smith 1976), but only R. nigrum has been screened for a wide range of compounds. Iridoids are absent; flavonoids and tannins (ellagitannins) are widespread. Flavonoids are abundant and varied, and are found both in the leaves and on their surfaces. Proanthocyanidins (prodelphinidin and procyanidin), quercetin, kaempferol and myricetin glycosides are nearly universally found, but more exotic compounds such as galangin, pinocembrin 7-methyl ether (Bohm 1993) and flavonoid acylglycosides (Gluchoff-Fiasson et al. 2001) have also been documented. Anthocyanins have been found in fruits (Le Lous et al. 1975). Ribes is usually weakly cyanogenic; nitrile-containing compounds such as nigrumin-5-p-coumarate (Lu 2002) have been identified. Volatile oils are widespread in the subg. Coreosma and Calobotrya and subg. Parilla sect. Parilla, all of which have essentially the same odour. R. nigrum (subg. Coreosma) yielded a complex mixture of monoand sesquiterpenes (i.a. ∆3 -carene, caryophyllene, geraniol) plus various other components (methyl salicylate, benzaldehyde, oct-1-en-3-ol). The volatile oils are secreted from the sessile yellow oil glands. The volatile components of the numerous odoriferous species in other groups (subg. Ribes sect. Berisia, subg. Parilla sect. Andina) have so far not been identified. A single report concerns a diterpenic acid, hardwickiic acid, identified in R. nigrum (George et al. 1974). The endosperm of Ribes seeds consists mainly of storage cellulose, proteins and c. 10–20% oil. The oil fraction of Ribes nigrum is very high in unsaturated fatty acids (47–49% linoleic acid, 12– 14% (α- & γ-) linolenic acid, 3–4% stearidonic acid, Artaud 1992).

173

Distribution and Ecology. Ribes is found in temperate regions of Eurasia, North America and Patagonia. In the Mediterranean region, Southeast Asia, Central and South America, the genus is restricted to montane and alpine habitats. Northtemperate, mesophilic species were evidently the starting point of the evolution of the xerotolerant and xerophilic species (Janczewski 1907). Morphologically, they are most similar to the closely related Saxifragaceae s.str. Occasionally, Ribes can be an important and even dominant element of scrub forests (evergreen, sclerophyllous species in Mediterranean climates, such as R. viburnifolium in Baja California and R. punctatum in Chile), but is more typically found in the undergrowth of broad-leaved and conifer forests. Pure stands of Ribes in the form of small forests are extremely rare (R. cuneifolium and R. viscosum in Peru) but are of crucial importance for the Andean avifauna. Some species are frost-hardy, and the genus is distributed far into the north of Siberia (R. fragrans) and also represents some of the highest-growing woody plants in the Andes (over 4,000 m). The major centres of species diversity (with approximately equal species numbers) are in the Himalayas, North America and the Andes. The South American subg. Parilla shows the widest range of habitats and growth habits, and displays extraordinary morphological diversification (leaf morphology, indumentum, inflorescence and floral characters), indicating a massive and relatively recent adaptive radiation. Parasites. The genus Ribes is subject to attack by a large number of pests both in nature and in cultivation. A co-evolution of some parasites with the plants is likely, since many pests are specific to the genus or certain subgroups. Breeding efforts aim at developing multiply resistant cultivars of Ribes. The economically most important pest is the white pine blister rust (Cronartium ribicola, Basidiomycetes), which has Ribes and certain Pinus species (subg. Strobus sect. Quinquaefoliae) as alternate hosts. White pine blister rust can destroy entire pine forests, and large-scale eradication programs of Ribes have been carried out in the USA to control this pest. Consequently, the cultivation of Ribes is banned in many federal states. Some Ribes are highly susceptible to Cronartium while other species or cultivars are largely or completely resistant; resistance follows no systematic pattern. Puccinia caricina (Basidiomycetes) is another specific rust of Ribes, with

174

M. Weigend

the alternate generation on Carex (Cyperaceae). There is also a whole range of highly host-specific invertebrate pests which attack only Ribes and are often restricted to gooseberries or currants, such as individual species of midges (Diptera, Cecidomyiidae: Dasyneura), sawflies (Diptera, Tenthredinidae: Nematus, Pteronidea), aphids (Homoptera, Aphididae: Aphidula, Cryptomyzus) and moths (Lepidoptera, Pyralididae: Zophodia; Incurviidae: Incuvaria). Subdivision. Ribes falls into a number of readily distinguished groups which have been variously treated as independent genera, subgenera or sections. The entities themselves have hardly changed in the past 200 years. They are retrieved by both morphological (Janczewski 1907) and molecular (Weigend et al. 2002) analyses. The only entity which has found wide acceptance at genus level outside Ribes are the gooseberries (Grossularia), but this group can be clearly shown to be a very derived lineage within Ribes linked to the morphologically more typical representatives via the spiny currants (subg. Grossularioides). The relationships between the readily defined subgroups have proved enigmatic but have been partially clarified by molecular data. Affinities. Grossulariaceae have been treated as a monogeneric family (Takhtajan 1997), as a family comprising some, or all woody Saxifrages (Cronquist 1981), or as part of the very broadly defined Saxifragaceae (Engler 1890). A presumed affinity of Ribes to other woody Saxifragales (Itea, Pterostemon, Tetracarpaea) found no support from, e.g. phytochemistry (phenolic compounds: Bate-Smith 1962, 1976; iridoids: Hegnauer 1973, 1990), serology (Grund and Jensen 1981) or embryology (Takhtajan 1996). All these lines of evidence more or less unequivocally pointed to the herbaceous Saxifragaceae as the closest relatives of Ribes. Striking similarities are found in floral structure, which is nearly indistinguishable between Ribes and most Saxifragaceae s.str. (Bensel and Palser 1975), and in vegetative morphology: the leaves of most Saxifragaceae s.str. and Ribes show a highly characteristic heteroblastic series from brown, chartaceous bud scales to leaves with membranaceous and laciniate stipules to apparently estipulate distal leaves (stipules reduced to fimbriate petiole margins, Fig. 56E–G). Mature leaves are similar in shape and structure (long-petiolate with cordate base, lamina membranaceous, with two dominant

lateral veins). The shoots of Saxifragaceae s.str. are differentiated into inflorescence-bearing short shoots (= leaf rosettes, with elongating internodes only in the inflorescence) and elongating branches, which are responsible for vegetative growth. This pattern is identical to that found in Ribes, with the only exception that most branches are here stiff and erect, while they are creeping and often rhizomatous in Saxifragaceae. The first internodes of Ribes seedlings are very short (atypical for woody plants; Janczewski 1907) and the seedlings are subrosulate and thus strongly reminiscent of seedlings and mature plants in Saxifragaceae s.str. The vegetative axes in both Saxifragaceae and Ribes are typically lignescent to ligneous. The inflorescences are simple racemes in most Saxifragaceae s.str. and in Ribes, with additional racemes appearing only very occasionally, the proximal internodes in both taxa being elongated. Pluriseriate, gland-tipped trichomes are present in the Saxifragaceae and are ontogenetically the first trichome type to be found on Ribes (Janczewski 1907). Growth patterns and mature leaf morphology of the other woody Saxifragales are all very different (petioles short, stipules absent or very different in shape and structure, lamina with pinnate venation without dominant pair of secondary veins, ovate in outline with rounded or mostly cuneate bases). The basic phytochemical inventory of Ribes (absence of iridoids, dominance of linoleic and linolenic acid in the seed oils, presence of flavonoids, proanthocyanidins, ellagic acid and tannins) is very similar to that of Saxifragaceae. A close and exclusive affinity of Ribes to Saxifragaceae s.str. has recently found additional support from molecular data (Soltis and Soltis 1997; Soltis et al. 2001). Economic Uses. Nearly all species of Ribes have edible fruits, some are used in the making of jams, preserves, ice cream, cakes, fruit juices, fermented drinks and liquors. The fruits are generally high in ascorbic acid (up to 0.15%) and other organic acids, but relatively low in sugar. Some species have insipid or mucilaginous, inedible fruits (esp. in subg. Parilla); very few species have bitter and possibly poisonous fruits. Tanaka (1976) and Moerman (1998) list over 60 edible species from Asia, Europe and North America, and additional edible species are known from South America (Rapoport et al. 1999). Fruits are often collected from wild plants and up to 11 edible Ribes species are reported from a single, medium-sized country (Dzhangaliev 2002). Ribes is cultivated primarily in the north-

Grossulariaceae

ern temperate zone, and world production of Ribes fruits amounts to over 500,000 tons, more than 3/4 of which is produced and consumed in Poland and Germany. The several thousand cultivars can be roughly subdivided into four groups: red currants (R. rubrum and hybrids with, e.g. R. petraeum, R. spicatum), black currants (Ribes nigrum), gooseberries (Ribes uva-crispa and hybrids with various North American species of subg. Grossularia) and currant-gooseberry hybrids (e.g. “Josta” – Ribes nigrum x R. hirtellum). North American native ethnic groups use leaves, roots, wood and bark of nearly all native Ribes species as condiments, for a wide range of medicinal and technical applications, and/or the fruits are eaten fresh and preserved, mainly by drying (Moermann 1998). The aromatic leaves of Ribes nigrum are used as tea mainly in Northeast Asia, and are attributed medicinal properties in the traditional Central European medicine. They form a rapidly expanding segment on the international tea market. In spite of the abundance of Ribes species in South America, their uses are very limited and restricted largely to the very high Andean species: these are a locally important source of firewood (R. cuneifolium, R. viscosum) and also provide good browsing to livestock (R. brachybotrys). Only one genus: Ribes L.

Figs. 55–58

Ribes L., Sp. Pl.: 200 (1753); Berger, New York Agric. Exp. Sta. Tech. Bull. 109:3–118 (1924), rev.; Lingdi & Alexander, Fl. China 8:428–452 (2001), reg. rev.; Pojarkova, Fl. U.S.S.R. 9 (English edn): 175–208 (1971), reg. rev.; Weigend & Binder, Bot. Jahrb. Syst. 123:111–134 (2001), reg. rev. Grossularia Mill. (1754).

Characters as for family. Seven subgenera are currently recognized (Weigend et al. 2002): subg. Ribes, including the hermaphroditic sect. Ribes (red currants) and sect. Heritiera (skunk currants) and the dioecious alpine currants (sect. Berisia); subg. Coreosma (black currants); subg. Calobotrya (ornamental currants, the paraphyletic sect. Calobotrya includes sect. Cerophyllum); subg. Symphocalyx (golden currants); subg. Grossularioides (spiny currants); subg. Grossularia (gooseberries); subg. Parilla (South American currants). The recognition of these well-defined groups at generic level is conceivable but seems unnecessary, given the overall morphological coherence of the genus.

175

Selected Bibliography Agababian, W.Sch. 1963. Pollen morphology of genus Ribes. Izvest. Akad. Nauk Armajanskoj S.S.R. 16:93–98. Andersson, J.P. 1943. Two notable plant hybrids from Alaska. Proc. Iowa Acad. Sci. 50:155–157. Artaud, J. 1992. Identification of α-linolenic acid-rich oils. Ann. Falsifications Expertise Chim. Toxic. 85/909:231–239. Bate-Smith, E.C. 1962. See general references. Bate-Smith, E.C. 1976. Chemistry and taxonomy of Ribes. Biochem. Syst. Ecol. 4:13–23. Bensel, C.R., Palser, B.F. 1975. Floral anatomy of Saxifragaceae s.l. II: Saxifragoideae and Iteoideae. Amer. J. Bot. 62:661–675. Berger, A. 1924. A taxonomic review of currants and gooseberries. New York Agric. Exp. Sta. Tech. Bull. 109:3–118. Bohm, B.A. 1993. External and vacuolar flavonoids of Ribes viscosissimum. Biochem. Syst. Evol. 21:745. Börner, K., Heinze, K., Kloft, W., Lüdicke, M., Schmutterer, H. 1957. Tierische Schädlinge an Nutzpflanzen 2, Homoptera 2. In: Appel, O., Blunck, H., Richter, H. (eds) Handbuch der Pflanzenkrankheiten V/4:1– 577. Britton, N.L., Brown, A. 1913. An illustrated flora of the northern United States and Canada 3:236–241. New York: Dover. Catling, P.M., Dumouchel, L., Brownell, V.R. 1998. Pollination of the Miccosukee Gooseberry (Ribes echinellum). Castanea 63:402–407. Cronquist, A. 1981. See general references. Davis, G.L. 1966. See general references. Döhler, W., Heddergott, H., Menhofer, H., Müller, F.P., Schmidt, G., Speyer, W., Weidner, H. 1953. Tierische Schädlinge an Nutzpflanzen 1. In: Appel, O., & Blunck, H., (eds.). Handbuch der Pflanzenkrankheiten IV/2:1–518. Dzhangaliev, D., Salova, T.N., Turekhanova, P.M. 2002. The wild fruit and nut plants of Kazachstan. In Janick, J. (ed.) Horticult. Rev. 29:305–371. Engler, A. 1890. Saxifragaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 2a:42–93. Leipzig: Engelmann. Francke-Grosmann, H., Gößwald, K., Hennig, W., Maercks H., Otten, E. 1953. Tierische Schädlinge an Nutzpflanzen 2. In: Appel, O., Blunck, H., Richter, H. (eds) Handbuch der Pflanzenkrankheiten V/1:1–311. Free, J.B. 1993. Insect pollination of crops, ed. 2. London: Academic Press. George, G., Candela, C., Quinet, M., Fellous, R. 1974. Identification of the diterpenic acid of Ribes nigrum buds. Helv. Chim. Acta 57:1247–1249. Gluchoff-Fiasson, K., Fenet, B., Leclerc, J.-C., Reynaud, J., Lussignol, M., Jay, M. 2001. Three new flavonol malonylrhamnosides from Ribes alpinum. Chem. Pharmceut. Bull. 49:768–70. Grund, C., Jensen, U. 1981. Systematic relationships of the Saxifragales revealed by serological characteristics of seed proteins. Pl. Syst. Evol. 137:1–22. Hassebrauk, K., Niemann, E., Schuhmann, G., Zycha, H. 1962. Basidiomycetes. In: Appel, O., Blunck, H., Rademacher, B., Richter, H. (eds) Handbuch der Pflanzenkrankheiten III/4:1–747. Hegnauer, R. 1973, 1990. See general references.

176

M. Weigend

Janczewski, E. 1907. Monographie de Groseillier. Mém. Soc. Phys. Genève 35/13:199–517. Keep, E. 1962. Interspecific hybridization in Ribes. Genetica 33:1–23. Knuth, P. 1898. Handbuch der Blütenbiologie, II, 1. Leipzig: Engelmann. Krach, J.E. 1977. Seed characters in and affinities among the Saxifraginae. In: Kubitzki, K. (ed.) Flowering plants evolution and classification at higher categories. Berlin Heidelberg New York: Springer, pp. 141–153. Le Lous, J., Majoie, B., Moriniere, J.L., Wulfert, E. 1975. Study of the flavonoids of Ribes nigrum. Ann. Pharmceut. Franç. 33:393–9. Lercker, G., Cocchi, M., Turchetto, E. 1988. Ribes nigrum seed oil. Rivista Italiana Sostanze Grasse 65, 1:1–6. Lingdi, L., Alexander, C. 2001. 29. Ribes. In: Wu, Zheng-yi, Raven, P.H. (eds) Flora of China 8:428–452. Beijing: Science Press. Lu, Y.R., Foo, L.Y., Wong, H. 2002. Nigrumin-5-p-coumarate and nigrumin-5-ferulate, two unusual nitrilecontaining metabolites from black currant (Ribes nigrum) seed. Phytochemistry 59:465–468. Mesler, M.R., Cole, J.C., Wilson, P. 1991. Natural hybridization in western gooseberries (Ribes subg. Grossularia, Grossulariaceae). Madroño 38:115–129. Metcalfe, C.R., Chalk, L. 1950. See general references. Meurman, O. 1928. Cytological studies in the genus Ribes. Hereditas 11:289–356. Moerman, D.E. 1998. Native American ethnobotany. Portland/OR: Timber Press. Pojar, J. 1975. Hummingbird flowers of British Columbia. Syesis 8:25–28. Pojarkova, A.I. 1971. Ribes. In: Komarov, V.L., Yuzepchuk, S.V. (eds) Flora of the U.S.S.R. 9 (English edn): 175–208. Springfield, VA: U.S. Department of Commerce.

Rapoport, E.H., Ladio, A.H., Sanz, E.H. 1999. Plants comestibles de la Patagonia andina. Bariloche: Imaginaria. Schweitzer, L. 1996. Zur Kenntnis der Wildbienen (Apoidea) im Landkreis Peine: ein naturnaher Garten in Vechelde. Beitr. Naturk. Niedersachsen 49:1–9. Sinnott, Q.P. 1985. A revision of Ribes L. subg. Grossularia (Mill.) Pers. sect. Grossularia (Mill.) Nutt. (Grossulariaceae) in North America. Rhodora 87:189–286. Soltis, D.E., Soltis, P.S. 1997. Phylogenetic relationships in Saxifragaceae sensu lato: a comparison of topologies based on 18S rDNA and rbcL sequences. Amer. J. Bot. 84:504–522. Soltis, D.E., Kuzoff, R.K., Mort, M.E., Zanis, M., Fishbein, M., Hufford, L., Koontz, J., Arroyo, M.K. 2001. Elucidating deep-level phylogenetic relationships in Saxifragaceae using sequences for six chloroplastic and nuclear DNA regions. Ann. Missouri Bot. Gard. 88:669– 693. Stern, W.L., Sweitzer, E.M., Philipps, R.E. 1970. Comparative anatomy and systematics of woody Saxifragaceae. Ribes. Bot. J. Linn. Soc. 63, suppl. 1:215–237. Takhtajan, A.L. 1996. See general references. Takhtajan, A. 1997. See general references. Tanaka, T. 1976. Tanaka’s cyclopedia of edible plants of the world (ed. S. Nakao). Tokyo: Keigaku. Verbeek-Reuvers, A.A.M.L. 1980. Grossulariaceae. In: Punt, W., Clarke, G.C.S. (eds) The northwest European pollen flora. New York: Elsevier, pp. 107–116. Weigend, M., Binder, M. 2001. A revision of the genus Ribes (Grossulariaceae) in Bolivia. Bot. Jahrb. Syst. 123:111– 134. Weigend, M., Motley, T., Mohr, O. 2002. Phylogeny and classification in the genus Ribes (Grossulariaceae) based on 5S-NTS sequences and morphological and anatomical data. Bot. Jahrb. Syst. 124:163–182.

Gunneraceae Gunneraceae Meissner, Pl. Vasc. Gen., tab. diagn.: 345, 346; Comm.: 257 (1842), nom. cons.

H.P. Wilkinson and L. Wanntorp

Perennial herbs, either with ascending or creeping pachycaulous stems, covered with large leaf scars, apically with large to gigantic, long-petioled leaves reaching up to c. 5 m in height (G. magnifica), and between these often covered with conspicuous bracts protecting the inflorescence and vegetative buds, or stoloniferous and mat-forming, with short, upright stem portions bearing leaf-rosettes, reaching from 4 cm to about 1 m in height, or in one case (G. herteri), diminutive annuals. Leaves alternate, crowded at stem tips; petioles short to very long; lamina oblong to reniform or peltate, dentate, crenate or palmately lobed, the crenations and lobes with protruding hydathodes; venation in large-leaved species palinactinodromous with veins very prominent and projecting as ribs on abaxial surface, in smaller-leaved species actinodromous or pinnate and less prominent. Sometimes with more or less conspicuous, simple to much divided scales between the leaf-bases, stolons with paired, or single ochrea-like, bracts apically. Inflorescences axillary or pseudoterminal, erect, simple or compound racemes, or spikes; lower flowers mostly pistillate, upper ones staminate, the middle ones sometimes perfect, or flowers all unisexual, in a few cases plants dioecious. Flowers small, bracteate or not, epigynous, sepals 2, anteri-posterior, valvate, sometimes obsolete, petals 2, transversal, mitre-shaped, slightly exceeding the sepals, caducous, in female flowers wanting; stamens 2(1), transversal, with short filaments; anthers dithecal and tetrasporangiate, opening by longitudinal slits; carpels 2, united to form an inferior, unilocular ovary; stylodia 2, transversal; stigmas dry, papillate; ovule solitary, pendulous from apex of locule. Fruit drupaceous, coriaceous to fleshy, oval to globose, green or bright red, rarely white or yellow. Seeds with a very small obcordate embryo embedded in copious, oily endosperm. Specialized organs containing endosymbiontic Nostoc cells are located in the stem between the leaf-bases of all species.

A monogeneric family with about 60 species, growing in cool and wet or damp habitats, from low altitudes to above 3,000 m, in South and Central America, Mexico, Hawaii, Africa, Madagascar, Tasmania, New Zealand, New Guinea and the Malayan archipelago Vegetative Morphology. Gunnera comprises a wide spectrum of growth forms from giant to dwarf herbs, usually perennial, with erect or creeping stems, often forming mats or clumps by stolons originating from leaf axils on the stems and bearing leaf-rosettes apically, or more rarely by branching of the stems themselves (Figs. 59, 63). The main stem of the dwarf G. herteri is interpreted as a chain of sympodial units each consisting of a leaf and an extra-axillary inflorescence (Rutishauser et al. 2004), a structural pattern which may also be valid for other species of Gunnera (see Skottsberg 1928). Stolons occur in subg. Pseudogunnera, Milligania and Misandra. In Pseudogunnera and Milligania, two bud scales at the tip of the stolons precede the foliage leaves on the erect stem. These cataphylls are regarded by Wanntorp et al. (2003) to be homologous with a cap-like “ochrea”, which in subg. Misandra occurs on the stolon as well as between the leaves of the upright stem. In subg. Panke, in which no stolons are formed, the stems are covered by numerous, large bract-like scales. Skottsberg (1928) and Wanntorp et al. (2003) consider also these scales to be cataphylls. Vegetative Anatomy. (Information mostly from Wilkinson 1998, 2000). Nodes are multilacunar and multitrace. Leaves are bifacial, hypostomatous or amphistomatous; stomata are anomocytic. The lower leaf surface has always a smooth wax cover; the cuticle is smooth or (in some species of subg. Milligania) finely striate. Marginal leaf hydathodes with an epithem are found in all subgenera (Fig. 59D), while laminar hydathodes are restricted to subg. Panke. The leaf axils of Gun-

178


nera herteri contain 2–5 inconspicuous glandular colleters (Rutishauser et al. 2004). Unicellular hairs are widespread and lacking only in G. herteri; other hair types including uniseriate and multiseriate, stalked and globular hairs are found in subg. Panke. Domes of raised silicified cells (“warts”) on the upper leaf surface and spine-like emergences on petioles and the larger veins of the lower leaf surface are characteristic of subg. Panke (Fig. 59C, E). The vascular systems of stems and petioles are typically polystelic. The bundles have the xylem surrounded by about six portions of phloem (amphicribal) and are sheathed by a well-defined endodermis with Casparian thickenings. In the stems of the pachycaulous, non-stoloniferous subg. Panke, the bundles may amount to several hundred per stem and in subg. Gunnera to about 60. Among the stoloniferous subgenera, the large-leaved subg. Pseudogunnera and the small-leaved subg. Milligania and Misandra have only few (3–5) larger and some smaller bundles, the latter to leaves and inflorescences. The vascular tissue of the stolons is not polystelic but siphonostelic (-modified); it consists of a single tube of xylem and phloem (G. densiflora), or of tubes of internal and external phloem separated by two tubes of xylem, and is surrounded by an endodermis. Vessel elements are usually very to moderately small; perforation plates in stolons and roots are mainly scalariform with few to many bars, and in the stems of large-leaved species simple perforation plates are more common. Cluster crystals (druses) are widespread in various tissues. Behnke (1986) found sieve element plastids containing protein crystals and starch grains (Pcs type).

Embryology. In Gunnera macrophylla and G. chilensis, the pollen grains are two-celled at anthesis. The ovule is anatropous, bitegmic and crassinucellate, and the micropyle is formed by the inner integument alone. The embryo sac is tetrasporic and 16-nucleate (Peperomia-type) and, apart from the egg and the synergids, contains six antipodal cells and a group of cells fusing to form the secondary embryo sac nucleus. Endosperm development is cellular; the suspensor forms no haustorium (Modilewski 1908). Pollen Morphology. Pollen of Gunnera is very distinctive, tricolpate, suboblate spheroidal (Fig. 60), and can be recognised by the fossaperturate shape with bulging mesocolpia and the microreticulate exine, usually 20–28 × 25–37 µm (Erdtman 1952; Praglowski 1970; Jarzen 1980; Wanntorp et al. 2004). Karyology. Beuzenberg and Hair (1963) reported 2n = 34 for Gunnera monoica, G. prorepens, G. densiflora, G. dentata and G. hamiltonii, and several hybrids (all in subg. Milligania); the same number was counted for various South American species by Dawson (1983) and Pacheco et al. (1993) Pollination. Gunnera perpensa shows all attributes of wind pollination (the general condition in the genus), such as high pollen/ovule ratio, strong protandry in the hermaphroditic flowers, and starch storage in pollen (Lowrey and Robinson 1988).

Flower Structure. The floral symmetry of Gunnera is most remarkable: the petals, stamens and carpels – at least the stylodia – are located in the transverse plane (Wantrop and Ronse De Graene 2005), reminiscent of the position of these floral organs in Sabiaceae and, to some degree, in Proteaceae.

Fruit and Seed. The fruit is drupaceous, greenish-reddish, dry and relatively small (1–2 mm long) in subg. Panke, Pseudogunnera and Gunnera, in subg. Misandra and Milligania larger (up to 8 mm long), and often brightly coloured; G. magellanica is called “frutilla del diablo”, devil’s strawberry. In the maturing seed, the integuments and nucellus disappear, with the exception of the outer epidermis of the outer integument which is made up of thin-walled cells filled with red sap; mechan-

Fig. 59. Gunneraceae. A–C Gunnera manicata growing in the Royal Horticultural Society’s garden at Wisley, Surrey, UK. A Whole plant. B One leaf measuring 94 in. (237.5 cm) in width and 77 in. (195.5 cm) in length. C An inflorescence (in spring) c. 2 ft. tall; note petiole with spine-like emergences to the right. D Marginal hydathodes

with terminal glandular tubes from a very young leaf of G. chilensis, scale bar = 1 mm. E “Warts” on the adaxial surface of a mature leaf of G. chilensis, scale bar = 0.25 mm. F Nostoc heterocysts in two large cells from a stem of G. lobata, scale bar = 50 µm. G Heterocysts from F at arrows, scale bar = 10 µm. (Orig. H. Wilkinson)

Gunneraceae

179

180


Fig. 61. Gunneraceae. Summary tree of Gunnera, based on Wanntorp et al. (2002, 2003).

Fig. 60. Gunneraceae, pollen grains. A, B, E, F Gunnera chilensis, SEM micrographs. C, D G. macrophylla, light micrographs. A Polar view. B, E Equatorial view. C, D Optical sections showing thickened exine at colpi margins (C) and poles (D). F Equatorial view of one colpus and reticulate ornamentation. A–E ×1,000; F ×51,500. (A, B, E, F Photographs H. Wilkinson; C, D photographs M.M. Harley)

ical protection of the seed is taken over by the pericarp. The endosperm is copious, its cells containing oil, starch and aleurone with crystalloids. The embryo is very small, heart-shaped and lies excentric (Netolitzky 1926). Phytochemistry. The leaves of Gunnera manicata contain high concentrations of an unidentified ellagitannin (Doyle and Scogin 1988); in G. chilensis, the tannin content of the rhizomes amounts to 9.3% (Hegnauer 1966). Pacheco et al. (1993) have studied the flavonoid variation of various South American species Relationships Within the Family. Cladistic analyses of Gunnera based on nuclear and plastid

gene regions by Wanntorp et al. (2002), and Wanntorp and Wanntorp (2003) resolved Gunnera as monophyletic and confirmed the sectional classification proposed by Schindler (1905). Moreover, subg. Ostenigunnera with the diminutive G. herteri was recovered as sister to all remaining sections, with subg. Gunnera subsequently sister to the remaining subclades. Figure 61 represents this topology with an indication of gains and losses of several characters. Gunnera herteri lacks the polystelic condition characteristic of the rest of the genus (the bundles are not sheathed by an endodermis; Wilkinson 2000); it is unique in being an annual, and possibly in the concaulescence of vegetative branches and inflorescences with the main axis for some distance above the axil. Affinities. Gunnera has traditionally been included in Haloragaceae but has often been elevated to family rank, although its affiliation has remained uncertain; Takhtajan (1997) included it in his Saxifraganae. Numerous molecular studies have now recovered Gunneraceae in close association with Myrothamnaceae in a clade at the base of the eudicots, more precisely as sister to all remaining core eudicots (Soltis et al. 2000, 2003). A comparison of the characters of Gunnera and Myrothamnus (Wilkinson 2000) shows that there exists very little agreement morphologically between the two genera. Distribution and Habitats. Gunnera is mostly southern hemispheric in distribution, but in South and Central America, the Hawaiian islands and Malesia it extends into low northern latitudes.

Gunneraceae

The species prefer wet or damp, cool places from low altitudes in cool climates to above 3,000 m in the tropics, mostly on mineral soil or peat, and are found on riverbanks, beside waterfalls, on steep slopes, in precipitous, small hanging valleys at the head of streams and in extremely rainy, wet regions, sometimes also in dense shade and mossy forests. Gunnera hamiltonii and G. dentata occur in damp sand hollows by the sea and G. herteri grows in seepages of emerging groundwater between coastal dunes (Wanntorp et al. 2003). Gunnera-Nostoc Symbiosis. All species have peculiar organs (often called “glands”) breaking through the epidermis immediately below very young developing leaves. These organs were identified by Miehe (1924) as arrested adventitious roots (Fig. 62). They produce copious mucilage through which cyanobacteria of the genus Nostoc

Fig. 62. Gunneraceae. Arrested roots infected with Nostoc algae (“phycorhizas”), occurring in groups of three below the leaf-bases on the axes of Gunnera macrophylla. (Miehe 1924)

181

gain entrance to the plant stem. Nostoc-infected tissue consists of isolated groups of larger and more rounded cells than those of the ordinary stem parenchyma surrounding them (Fig. 59F, G). In young stems, Nostoc colonies appear as bright blue-green structures. In slightly older parts of the stem, they take on a dark appearance and in even older parts appear as whitish, amorphous masses and are said to be “degenerate” (Bergman et al. 1992; Wilkinson 2000) Distributional History. Gunnera has an ample microfossil record in the southern hemisphere and parts of the northern hemisphere, dating nearly uninterruptedly back to the early Late Cretaceous (Jarzen 1980; Jarzen and Dettmann 1989; Wanntorp et al. 2004). During Upper Cretaceous and Early Tertiary times, the genus was more widely distributed than it is today. The earliest pollen record attributable to Gunnera (as Tricolpites reticulatus) is from the Turonian of South America; in the Campanian and Maastrichtian, the

Fig. 63. Gunnera magellanica. A Male plant. B Male flower. C Stamen. D Female plant. E Female flower. F Same, vertical section. G Infructescence. H Fruit, vertical section. I Fruit, transverse section. (Schindler 1905)

182


genus was represented in Antarctica, New Zealand, continental Australia (from where it is absent today), West Africa and, strangely enough, in North America. In the Palaeogene, the genus appeared additionally in southernmost South America, the Indian Ocean and the Indian Plate. In the Neogene, it retreated southwards in North America (where at present it is represented by a single species in Mexico) and appeared in New Guinea. Wanntorp and Wanntorp (2003) analysed the present distribution of Gunnera within the framework of a cladistic study and the fossil record. Most distributional facts are in agreement with viewing Gunnera as a Gondwana element, which obtained its present distribution mostly by vicariance. However, its widespread and abundant occurrence in North America from the Late Cretaceous to Eocene calls for an additional explanation. Wanntorp and Wanntorp (2003) propose a dispersal event out of South America before the Campanian as leading to the colonization of North America. From there, not only may the Hawaiian islands have been reached by long-distance dispersal but also South America may have been re-colonized by the lineage now corresponding to subg. Panke, where it met with subg. Misandra.

of single anther. One species, G. herteri Osten, coastal southern Brazil and Uruguay.

Uses. Species of subg. Panke are sometimes used as garden ornamentals; a few of the smaller species are grown in rock-gardens. Gunnera perpensa has been reported to have antifertility and antiabortifacient properties in rats by Mafatle and Joseph (1992). The stems and petioles of Gunnera chilensis are used by indigenous people on a small scale for tanning and dyeing, and petioles are eaten as salad (“nalca” or “rahuay”).

Subg. Milligania (J.D. Hook.) Schindler. Low stoloniferous, mat-forming herbs; leaves in rosettes on short upright stems, petiole 0.5–2 cm long, blade orbicular-reniform, subcordate, ovate or elliptic, 1–3.5(5) cm long. Plants monoecious, usually with staminate and pistillate flowers on separate racemes, except in G. monoica Raoul which has bisexual racemes with staminate flowers apically. Racemes 1–5 cm long, pistillate flowers with sepals only, staminate flowers with sepals and petals. About six species, one from Tasmania, all others from New Zealand.

Only one genus: Gunnera L.

Figs. 59–63

Gunnera L., Syst. Nat. ed. 12:587, 598 (Oct. 1767); Mant.: 16, 121 (Oct. 1767); Schindler in Engler, Pflanzenreich IV, 225:194–128 (1905); Mora-Osejo, Flora de Colombia 3:1– 178 (1984).

Description as for family; six subgenera: Subg. Ostenigunnera Mattfeld. Diminutive glabrous annual herb; leaf blades to 1.4 cm, flabelliform, with up to 20 lobes each ending in a hydathode; indumentum, bracts, stolons and rhizome 0. Inflorescences interaxillary, racemes, c. 1 cm long, pistillate flowers basally, without perianth, staminate flowers apically, often consisting

Subg. Gunnera (= subg. Perpensum [Burman] Schindler). Moderately large herb; rhizome horizontal, intermittently branching, 1–2 cm thick; bracts and stolons 0, leaves with long petiole, blade cordate or reniform, to 17 × 28 cm, densely dentate-crenate; young parts pubescent. Inflorescence thyrsoid, up to 40 cm long; flowers hermaphroditic. One species, G. perpensa L., South Africa to Ethiopia, Madagascar. Subg. Pseudogunnera (Oersted) Schindler. Moderately large-leaved, herb with long stolons; upright stems short, 1–2 cm diameter; leaves sheathlike at the base, petiole 0.3–1 m, blade reniform to cordate, irregularly lobed, acutely irregularly sphacelate-dentate and bullate, up to 50 cm wide, with strongly prominent reticulate venation beneath. Inflorescences up to 50 cm long, basal flowers pistillate with sepals only, apical flowers staminate with sepals and petals. One species, G. macrophylla Blume, Malayan archipelago (New Guinea, Solomon Islands, Sulawesi, Java, Sumatra, Borneo and Philippine islands).

Subg. Misandra (Comm.) Schindler. Low stoloniferous, dioecious herbs (Fig. 63); leaves from short upright stems with ochrea-like scales alternating with the leaves; petiole 2–25 cm long, blade, reniform or reniform-orbicular, to 11 cm wide indistinctly lobed. Inflorescences up to 15 cm, staminate as well as pistillate flowers without petals. Differing from subg. Milligania in the possession of ochrea-like scales on shoots. Two species, from Tierra del Fuego and Falkland Islands to Colombia. Subg. Panke (Molina) Schindler. Large to giant, pachycaulous perennials (Fig. 59A) with fleshy

Gunneraceae

stems, up to 3 m long and 40 cm thick, upright, with age often becoming decumbent, rarely branching; youngest parts of stem and terminal bud covered by numerous linear-lanceolate, ± laciniate or entire, often brightly orange-coloured bracts or scales up to 40 cm long, bearing mucilageproducing glands on the adaxial surface. Petioles up to 2.7 m long, blades mostly palmately lobed (Fig. 59B), from 25 cm up to 3 m in diameter. Inflorescences up to 0.5 m compound spikes or racemes (Fig. 59C). Pistillate flowers with sepals only, perfect and staminate flowers with sepals and petals. About 50 species, South and Central America, Mexico, the Juan Fernandez Islands and Hawaii; G. manicata Linden and G. chilensis Lam. often cultivated in gardens.

Selected Bibliography Behnke, H.-D. 1986. Contributions to the knowledge of sieve-element plastids in Gunneraceae and allied families. Pl. Syst. Evol. 151:215–222. Bergman, B., Johansson, C., Söderbäck, E. 1992. The NostocGunnera symbiosis. New Phytol. 122:379–400. Beuzenberg, E.J., Hair, J.B. 1963. Contributions to a chromosome atlas of the New Zealand Flora, 5. N. Z. J. Bot. 1:53–67. Boutique, R. 1968. Haloragaceae. In: Flore du Congo, du Rwanda et du Burundi. Meise: Jardin Botanique National de Belgique. Dawson, M.I. 1983. Chromosome numbers of three South American species of Gunnera (Gunneraceae). N. Z. J. Bot. 21:457–459. Doyle, M.F., Scogin, R. 1988. A comparative phytochemical profile of the Gunneraceae. N. Z. J. Bot. 26:493–496. Erdtman, G. 1952. See general references. Fuller, D.G., Hickey, L.T. 2005. Systematics and leaf architecture of the Gunneraceae. Bot. Rev. 7:295–353. Hegnauer, R. 1966. See general references. Jarzen, D.M. 1980. The occurrence of Gunnera pollen in the fossil record. Biotropica 12:117–123. Jarzen, D.M., Dettmann, M.E. 1989. Taxonomic revision of Tricolpites reticulatus Cookson ex Couper, 1953 with notes on the biogeography of Gunnera L. Pollen Spores 31:97–112. Johri, B.M. et al. 1992. See general references. Lowrey, T.K., Robinson, E.R. 1988. The interaction of gynomonoecy, dichogamy, and wind-pollination in Gunnera perpensa L. (Gunneraceae) in South Africa. Monogr. Syst. Bot. Missouri Bot. Gard. 25:237–246. Mafatle, T.J.P., Joseph, M.M. 1992. Antifertility and antiabortifacient properties of Gunnera perpensa. In: Abstract Volume South African Association of Botanists 18th Annual Congress, p. 33. Mattfeld, J. 1933. Weiteres zur Kenntniss der Gunnera herteri Osten. Montevideo: Ostenia (Coleccion de Trabajos Botanicos), pp. 102–118.

183

Miehe, H. 1924. Entwicklungsgeschichtliche Untersuchungen der Algensymbiose bei Gunnera macrophylla. Bl. Flora 117:1–15. Modilewski, J. 1908. Zur Embryobildung von Gunnera chilensis. Ber. Deutsch. Bot. Gesell. 26a: 550–556. Morgan, D.R., Soltis, D.E. 1993. Phylogenetic relationships among members of the Saxifragaceae sensu lato based on rbcL sequence data. Ann. Missouri Bot. Gard. 80:631–660. Netolitzky, F. 1926. Anatomie der Angiospermen-Samen. Berlin: Borntraeger. Pacheco, P., Crawford, D.J., Stuessy, T.F., Silva, O.M. 1993. Flavonoid chemistry and evolution of Gunnera (Gunneraceae) in the Juan Fernandez Islands, Chile. Gayana Bot. 50:17–28. Praglowski, J. 1970. The pollen morphology of the Haloragaceae with reference to taxonomy. Grana 10:159– 239. Rutishauser, R., Wanntorp, L., Pfeifer, E. 2004. Gunnera herteri – developmental morphology of a dwarf from Uruguay and S Brazil (Gunneraceae). Pl. Syst. Evol. 248:219–241. Schindler, A.K. 1905. Halorrhagaceae. In: Engler, A. (ed.) Das Pflanzenreich IV, 225. Leipzig: W. Engelmann, pp. 1–133. Skottsberg, C. 1928. Zur Organographie von Gunnera. Svensk Bot. Tidskr. 22:392–415. Soltis, D.E. et al. 2000. See general references. Soltis, D.E. et al. 2003. See general references. St. John, H. 1957. Gunnera magnifica, a new species from the Andes of Colombia. Svensk Bot. Tidsk. 51:521–528. Takhtajan, A. 1997. See general references. Van der Meijden, R., Caspers, N. 1971. Haloragaceae. Flora Malesiana I, 7:239–263. Leiden: Noordhoff. Wanntorp, L., Wanntorp, H.-E. 2003. The biogeography of Gunnera L.: vicariance and dispersal. J. Biogeogr. 30:979–987. Wanntorp, L., Wanntorp, H.-E., Källersjö, M. 2002. Phylogenetic relationships of Gunnera based on nuclear ribosomal DNA ITS region, rbcL and rps16 intron sequences. Syst. Bot. 27:512–521. Wanntorp, L., Wanntorp, H.-E., Rutishauser, R. 2003. On the homology of the scales in Gunnera (Gunneraceae). Bot. J. Linn. Soc. 142:301–308. Wanntorp, L., Dettmann, M.E., Jarzen, D.M. 2004. Tracking the Mesozoic distribution of Gunnera: comparsion with the fossil pollen species Tricolpites reticulatus Cookson. Rev. Palaeobot. Palyn. 132:163–174. Wanntorp, L., Praglowski, J., Grafström, E. 2004. New insight into the pollen morphology of Gunnera (Gunneraceae). Grana 43:15–21. Wanntorp, L., Ronse De Graene, L.P. 2005. The Gunnera flower: key to eudicot diversification or response to pollination mode? Intl. J. Plant Sci. 166:945–953. Wilkinson, H.P. 2000. A revision of the anatomy of Gunneraceae. In: Rudall, P.J., Gasson, P. (eds) Under the microscope: plant anatomy and systematics. Bot. J. Linn. Soc. 134:233–266. Wilkinson, H.P. 1998. Gunneraceae. In: Cutler, D.F., Gregory, M. (eds), Anatomy of the dicotyledons. 2nd edn, Vol. IV. Saxifragales. Oxford: Clarendon Press, 260– 272.

Haloragaceae Haloragaceae R. Br. in Flinders, Voy. Terra Austral. 2: 549 (1814), nom. cons.

K. Kubitzki

Small trees, shrubs, subshrubs, or perennial or annual terrestrial or aquatic herbs, glabrous or scabrous with simple uniseriate hairs; stems erect, ascending, procumbent or creeping, often rooting at lower nodes; nodes unilacunar. Leaves opposite, alternate or verticillate, sessile or petiolate, simple or deeply dissected, entire or toothed, estipulate, heterophyllous in Proserpinaca and Myriophyllum. Inflorescence thyrso-paniculate, thyrsoid or racemose, or flowers solitary; partial inflorescences usually dichasial; prophylls persistent or caducous. Flowers regular, hermaphroditic or unisexual-monoecious, epigynous, 4(–2)-merous; sepals valvate, persistent (0 in female flowers of Myriophyllum); petals imbricate, keeled, hooded, ± unguiculate, falling with the stamens (0 or rudimentary in Proserpinaca and female flowers of Myriophyllum and Laurembergia); stamens equal to or twice the number of sepals; filaments short, slender; anthers 4-sporangiate, dehiscing by slits; gynoecium 4(–2)-carpellate; stylodia free, clavate, from bulbous base; ovary 4(–1)-locular but septa sometimes weakly developed and present only at base and apex of ovary or reduced; ovules 2 or 1 per loculus (if 2, then one aborts at an early stage), anatropous or hemitropous, bitegmic, crassinucellar, with weakly developed funicular obturator. Fruit an indehiscent, 4–1-seeded nutlet, or indehiscent and comprising 4 pyrenes (Meziella), or splitting septicidally into (2–)4 mericarps (Myriophyllum), the exocarp often ornamented with tubercles, wings or ribs; seeds with straight, cylindrical embryo and usually with ± copious, fleshy endosperm. x = 7 (9, 21, 29). A subcosmopolitan family of 8 genera and c. 150 species, most south hemispheric, particularly Australian Morphology. In terrestrial forms, the primary root persists and builds a root system whereas, in the aquatic/amphibious genera Proserpinaca and Myriophyllum, it is replaced by adventitious roots which fasten the plant in the substrate, rather than

taking up water; they lack root hairs (Schindler 1905). In the northern hemisphere species of Myriophyllum, condensed vegetative shoots act as overwintering and dispersal units (turions). From most species of Myriophyllum, near the leaf axils and also in other positions, small filiform appendages are known which have been called hydathodes or pseudostipules, although nothing is known as to their function. The leaf blades are simple in terrestrial species but more or less deeply dissected in the aquatic genera; on aerial shoots of the latter, the degree of dissection is gradually diminished. The phenotypic plasticity of Proserpinaca and Myriophyllum, as expressed in changes of their shoot organisation, permits them to cope with, or anticipate, environmental changes such as desiccation of their aquatic habitats; in P. palustris, short photoperiods induce the submersed, and long photoperiods the aerial leaf form (Bowes 1987). Heterophylly may also be advantageous in giving direct access to gaseous CO2 from the air, and dissolved CO2 from the water. Anatomy (from Schindler 1905 and Orchard 1975). Hairs are simple and unicellular or multicellular. The leaves of the aquatic and helophytic species are amphistomatic and their mesophyll is little differentiated. Stomata are usually anomocytic. The primary cortex of the stems contains numerous air-cavities, which are particularly well developed in aquatic species. The vessels have simple perforations with narrow lumina and simple pits. Rays are heterogeneous to homogeneous. The wood is ring-porous with scanty or no wood parenchyma, bordered pits and both uniseriate and multiseriate homogeneous and heterogeneous wood rays. In Haloragis, the inner parts of the rays are uniseriate and homogeneous, and composed of vertically elongated cells. In Haloragodendron, the multiseriate rays are reduced in width and have lengthened uniseriate tails. In Glischrocaryon and Gonocarpus, multiseriate rays are entirely

Haloragaceae

lacking in the stems but retained in the roots. Sieve element plastids are of the S-type. Inflorescences. Their structure has been analysed by Schindler (1905) and more fully by Orchard (1975). Most genera have thyrsoids, i.e. determinate systems with usually multiflorous dichasia as lateral inflorescences. In the thyrses of Haloragis, the main axis lacks the terminal flower. Proserpinaca has thyrses similar in structure to those of Haloragis, and with hermaphroditic flowers. Laurembergia inflorescences are structured likewise but the flowers are unisexual and, in the dichasia, the distal positions are occupied mostly by male or hermaphrodite flowers, which stand out on a long pedicel from the almost sessile female flowers (Fig. 64B; Orchard 1975). In Gonocarpus, the individual dichasia are reduced to single flowers which, however, retain a pair of prophylls. Similarly, Myriophyllum has the bracteolate flowers in racemes, with females in the lower part of the inflorescence, and males in the upper. Flower Structure. The epigynous, 4-merous flowers with valvate sepals and imbricate petals, a diplostemonous androecium with 4-locular anthers, and a gynoecium provided with four stylodia represent the basic condition in the family. With or within several genera, various reductions have occurred, such as the complete or near loss of petals, the loss of the antepetalous or antesepalous stamen whorl and of part of the carpels, or the transition to unisexual flowers. Embryology (Corner 1976, and the literature cited in Orchard 1975 and Takhtajan 1997). In Laurembergia and probably in Haloragis, anther wall formation follows the Monocotyledonous type, in Myriophyllum the Dicotyledonous type. The tapetum is glandular, and pollen is shed in the 3-celled stage. The ovules are anatropous, bitegmic and crassinucellate; the raphe is dorsal. In Myriophyllum, the integuments are very short. Embryo sac development is of the Polygonum type; both cellular and nuclear endosperm development have been reported (Johri et al. 1992). Pollen Morphology. This section is based on the detailed, well-documented study by Praglowski (1970), which has been related to the modern classification of the family by Orchard (1975). Pollen of Haloragaceae is isopolar to slightly anisopolar, spheroidal to oblate, 4–6(–20)-colpate or -porate,

185

and usually radially symmetric; columellae are distinct, and the tectum is microperforate and provided with minute processes. Three main pollen types can be distinguished. 1. Glischrocaryon and Haloragodendron have isopolar, subspheroidal, 4–6-colpate pollen grains; the colpi are relatively long and usually tenuimarginate; the sexine is thicker than the nexine. 2. Among the remaining genera (Meziella excepted, of which the pollen is unknown), Haloragis, Gonocarpus, Lauremburgia, Proserpinaca and most Myriophyllum have usually shortly 4–6-colpate or -porate pollen grains which are isopolar to slightly anisopolar; the apertures are short colpi or, more rarely, pores and are crassimarginate and frequently protruding. 3. Two species of Myriophyllum, M. alterniflorum and M. muelleri, are peculiar in having comparatively large apertures, which are restricted to part of the circumference of the grain and thus make the pollen radially asymmetric. Karyology. Counts from several Myriophyllum species document a polyploid series based on x = 7, extending from the diploid to the hexaploid state. This agrees with the single count available for Haloragis (2n = 14) and a possibly octoploid Gonocarpus (2n = 56), although another Gonocarpus has been counted as having 2n = 12. Pollination. Haloragaceae are usually anemophilous, which to some degree correlates with the mostly small, inconspicuous, greenish petals and extensive papillosity of the stigmatic surfaces. Glischrocaryon species are exceptional in having showy, bright yellow or reddish flowers with plane petals and unilaterally papillose stigmas, which Schindler (1905) considered indicative of entomophily. Fruit and Seed. The inferior ovary of Haloragaceae is enclosed in a receptacle, which in the fruiting stage forms the often conspicuously ornamented or sometimes winged pericarp. Aircavities, which are found in the pericarp of wind(Glischrocaryon spp.) or water- (Laurembergia) dispersed fruits, develop early at flowering. In Haloragis, Haloragodendron and Gonocarpus, the ovaries initially have four locules each with one ovule; sometimes reduction to 3 or 2 locules occurs. In Haloragis, all four ovules can develop

186

K. Kubitzki

into seeds, and the septa and endocarp become woody, forming a single, indehiscent, 4-seeded fruit. Haloragodendron differs in that only a single seed is formed in the fruit, which crushes the septa to the side. In both genera, the endocarp becomes strongly woody, and the fruit increases in size after anthesis. In Gonocarpus, the septa are incomplete and are crushed by the single developing seed. The ovary wall becomes crustaceous in fruit, but hardly woody. In Laurembergia, the ovary is imperfectly 4-celled when young but later becomes 1-celled with a central columella; the 1-seeded fruit has a variable sculpture. Prosepinaca stands out in having trimerous flowers and ellipsoid anthers; the septa are solid and the fruit is 3-seeded (Schindler 1905; Orchard 1975). In Meziella, the ovary is 4-locular with welldefined septa and a single ovule in each locule, each of which can develop into a seed. The endocarp around each locule becomes woody but, in contrast to Haloragis where a single 4-locular woody mass is formed, in Meziella four separate woody, 1seeded pyrenes develop, which are held together by the spiny exocarp. This is similar to Myriophyllum where, however, the fruit disintegrates into normally four mericarpic pyrenes each surrounded by a portion of the exocarp which often is tuberculate, aculeate or spiny (Orchard and Keighery 1993). At the apex of the mericarp, the woody exocarp is replaced by an operculum, which is formed by tissue of the funiculus (Fauth 1903). The seeds are small, albuminous and exarillate. The seed coats are reduced to the tabular thinwalled cells of the exotesta, and the remains of the testa and tegmen are crushed. The endosperm is cellular or nuclear (Lauremburgia) and starchy; the embryo is straight and large (Corner 1976).

globular bodies, which turn red upon the addition of vanillin/HCl and contain a special derivative of leucoanthocyanin, myriophyllin. Further compounds recorded include saponins and cyanogenic glycosides, the latter apparently formed on the valin-isoleucin pathway. Calcium oxalate druses are widespread in the family, and hairs are often silicified (Hegnauer 1966, 1989). Affinities. The formerly considered relationship between Haloragaceae and Myrtales has now been discarded and, indeed, was untenable in view of the strong morphological differences between them (Takhtajan 1997: 268). The rbcL sequence data of Morgan and Soltis (1993) support a close rela-

Dispersal. The aptitude of the mericarps of Myriophyllum and the fruits of Proserpinaca for dispersal by fish or waterfowl, and of the winged propagules of Haloragodendron and Glischrocaryon by wind is obvious. Fauth (1903) observed that the pyrenes of Myriophyllum sink to the ground where they can overwinter, and also pointed to the possibility of their dispersal by ice floes. Phytochemistry. Haloragaceae contain large amounts of tannins diffusely distributed in various tissues; both proanthocyanins (‘leucoanthocyanins’) and ellagic acid have been reported. The trichomes of Myriophyllum contain refracting

Fig. 64. Haloragaceae. Laurembergia tetrandra. A Habit. B Detail of flowering branch. C Hermaphrodite flower. D Female flower. E Fruit from hermaphrodite flower. F Fruit from female flower. (Mendes 1978)

Haloragaceae

187

tionship between Haloragaceae and Saxifragales, in particular between Myriophyllum and Penthorum. This suggestion has now been put on a firm basis by the five-gene study of Fishbein et al. (2001), in which Haloragis and Myriophyllum are sequentially sister to Penthorum, Tetracarpaea (these two sometimes reversed), Aphanopetalum and Crassulaceae. The Angiosperm Phylogeny Group (APG II 2003) suggested the inclusion of Penthoraceae and Tetracarpaeaceae in Haloragaceae but this is not followed here because it would lead to the loss of the morphological profile of Haloragaceae, with the combination of epigyny and an essentially 4merous floral organisation. Distribution and Habitats. The almost cosmopolitan family has its centre of distribution in Australia, where six of the eight genera and 105 of the 150 species are found, with a high degree of endemism at the species level (Orchard 1990). The genera Haloragodendron and Glischrocaryon are entirely endemic to Australia, and so are most species of Haloragis, Gonocarpus and Myriophyllum which, above being restricted to Australia, there usually occupy only small distributional areas (see maps in Orchard 1990). The extra-Australian Myriophyllum and Proserpinaca, both aquatic, are distributed much more widely, the former from eastern South America through Africa to Southeast Asia, and the latter from western North America to the West Indies. Ecologically, genera such Haloragis, Haloragodendron and Gonocarpus have radiated into a wide variety of terrestrial habitats, preferably in warm-temperate to Mediterranean regions; Glischrocaryon is notable for recovering well after soil disturbance by fire and light (Orchard 1990). Little is known to me about the trophic preferences of the aquatic members of the family. In northern and central Europe, Myriophyllum alterniflorum is bound to oligotrophic freshwater habitats (Godwin 1975), and most of the Australian species of Myriophyllum and also Meziella trifida seem to be bound to seasonally moist, nutrient-poor, sandy habitats Palaeobotany. Fossil pollen attributable to Haloragaceae include ‘haloragoid’ pollen from the Upper Cretaceous of Europe, the Eocene of Burma, the Eocene and Palaeocene of Europa, and the Oligocene of New Zealand (see references in Praglowski 1970, and Gruas-Cavagnetto and Praglowski 1977). The oldest pollen find of Myrio-

Fig. 65. Haloragaceae. Myriophyllum balladoniense. A Habit. B Inflorescence. C Male flower, in situ. D Female flower, in situ. E Apex of female flower. F Fruit. (Orchard 1985)

phyllum-like pollen known to me is from the Upper Eocene of the southeast United States (Frederiksen 1980). Fruiting structures of a waterplant from the Upper Cretaceous (Maastrichtian/Campanian) of Mexico have also been attributed to the family; they are thought to combine characters of Haloragodendron, Meziella and Myriophyllum (Hernández-Castillo and Cevallos-Ferriz 1999). If correctly identified, this finding would be of high phytogeographical significance. Proserpinaca macrofossils are known from European beds up to the Pliocene (cf. references in Praglowski 1970).

Key to the Genera 1. Fruit an indehiscent 1–4-seeded nut not subdivided into 1-seeded pyrenes 2 – Fruit made up of 1-seeded pyrenes 7 2. All flowers with petals 3 – At least female flowers lacking petals (petals vestigial in Myriophyllum and Proserpinaca) 6

188

K. Kubitzki

3. Petals hooded; anthers non-apiculate; inflorescences indeterminate 4 – Petals navicular; anthers usually apiculate; inflorescences determinate 5 4. Fruits (2–)4-locular; pericarp woody with solid septa; flowers in (1)3–7-flowered dichasia in the axils of alternate bracts 1. Haloragis – Fruits 1-locular; pericarp crustaceous; septa 0 (crushed by single seed); flowers 1(–3) in the axils of opposite or alternate bracts 4. Gonocarpus 5. Leaves serrate; inflorescence narrow, spike-like; shrubs or small trees with 1–few woody stems/trunks 2. Halorgodendron – Leaves entire; inflorescence broad, umbelliform; subshrubs with numerous annual stems arising from a perennial rootstock 3. Glischrocaryon 6. Fruit 1-locular; flowers predominantly unisexual, in dichasia of up to about 11 flowers per axil, the terminal one in each dichasium usually male, the others female or rarely hermaphroditic; anthers linear-oblong 5. Laurembergia – Fruit 3-locular; flowers hermaphroditic, solitary or in dichasia of up to 3 flowers per axil; anthers ellipsoid 7. Proserpinaca 7. Fruit splitting at maturity into mericarps; sepals less than half length of petals (frequently 0), flat, lanceolate to ovate; flowers frequently unisexual 8. Myriophyllum – Fruit not splitting at maturity into mericarps; sepals almost equalling petals in length, subulate, developing into soft spines; flowers hermaphrodite 6. Meziella

Genera of Haloragaceae 1. Haloragis Forst. & G. Forst. Haloragis Forst. & G. Forst., Char. Gen.: 61, t. 31 (1775); Orchard, Bull. Auckland Inst. Mus. 10:64–150 (1975), rev., and Fl. Australia 18:6–27 (1990). Halorrhagis, orthogr. var.

Annual or perennial herbs or subshrubs from taproots or stolons, glabrous, scabrous or with simple hairs; stems ascending or creeping, some growing in water. Leaves usually opposite below and alternate above, petiolate or sessile, simple to pinnatifid, entire or serrate. Inflorescences indeterminate compounded of 3–7-flowered dichasia in axils of alternate bracts; flowers hermaphroditic, (2–)4-merous on short pedicels; sepals deltoid; petals hooded, ± unguiculate, keeled; usually diplostemonous, anthers linear, not apiculate; ovary 2–4-locular, each locule with 1(2) pendulous ovules; stylodia 2 or 4. Fruits smooth, ribbed or winged, and/or with protuberances opposite the sepals or on the entire fruit, or tuberculate between ribs or wings, with persistent sepals, (2–)4-locular with solid septa and woody endocarp and membranous or spongy exocarp, and with (1–)4 seeds. A genus of 28 species confined almost entirely to

Australia and New Zealand, with a few species on S Pacific Islands eastward to Juan Fernandez Islands, in a wide variety of terrestrial habitats, H. brownii (J.D. Hook.) Schindler an obligate aquatic. 2. Haloragodendron Orchard Haloragodendron Orchard, Auckland Inst. Mus. Bull. 10:140–150 (1970), and Fl. Australia 18:27–30 (1990).

Glabrous shrubs or small trees; branches strongly 4-angled, glabrous or glandular; leaves decussate, petiolate or almost sessile, juvenile leaves sometimes pinnatisect or pinnatifid, mature leaves linear or narrow-oblong to lanceolate, [bi]serrate. Inflorescence a narrow, spike-like thyrsoid with simple or compound dichasia. Flowers showy, sessile or shortly pedicellate, showy, cream or red; sepals deltoid; petals navicular or planar, not hooded; stamens 8, anthers apiculate; ovary longitudinally 4-ribbed or -angled, septa solid; 1 ovule per locule. Fruit 1-seeded, 4-ribbed or -angled, smooth between angles, pericarp ± spongy. Five species, all narrow endemics, Australia. 3. Glischrocaryon Endl. Glischrocaryon Endl., Ann. Wien. Mus. 2:209 (1839); Orchard, Bull. Auckland Inst. Mus. 10:150–163 (1975), rev., and Fl. Australia 18:30–34 (1990). Loudonia Lindl. (1840).

Glabrous perennial herbs from woody, branched rootstock. Leaves alternate, often deciduous, terete to narrow lanceolate or linear, sessile, entire. Inflorescence dense, terminated by a many-flowered compound dichasium with (2–)5 alternately arranged many-flowered dichasia below. Flowers yellow or cream, 2(3)–4-merous; sepals deltoid, decurrent in wings of ovary or free; petals 2 or 4, torsive, navicular or hooded; stamens 4 or 8; ovary ovoid to obpyriform, 2- or 4-winged, with a central columella and the body of the ovary swollen or not; the single locule with 4 pendulous ovules; septa 0. Fruit 2- or 4-winged or -ribbed, with pericarp between wings swollen or membranous, endocarp slightly woody; seed 1, occupying the entire locule. Four species, scattered throughout Australia. 4. Gonocarpus Thunb. Gonocarpus Thunb., Nov. Gen. 3:55 (1783); Orchard, Bull. Auckland Inst. Mus. 10:164–277 (1975), rev., and Fl. Australia 18:34–59 (1990).

Annual or perennial herbs or shrubs up to 4 m tall, often twiggy and multistemmed, glabrous,

Haloragaceae

scabrous, or with indumentum of simple hairs; leaves sessile or petiolate, opposite or rarely in whorls of 3(–5). Inflorescence an indeterminate raceme or spike in the axil of alternate, opposite or whorled primary bracts or from axils of upper leaves; pedicels with prophylls; flowers (3)4-merous, shortly pedicellate; sepals often with pronounced midrib and prominent median basal callus; petals hooded, ± unguiculate, keeled; stamens usually twice the number of petals; anthers 4-locular; ovary smooth or ribbed opposite sepals and/or petals, incompletely (3)4-locular, with 1(2) pendulous ovules per locule (the second aborting at an early stage); stylodia clavate, stigmas capitate. Fruit glabrous or scabrous with ± membranous pericarp and persistent sepals; septa ± 0, seed 1, occupying entire fruit. About 41 species, from Australia and New Zealand extending through New Guinea and Malesia to Borneo, the Philippines, Japan, Formosa and coastal south-eastern Asia; G. micranthus subsp. micranthus found almost throughout the range of the genus. Two sections: sect. Gonocarpus, styles clavate, not or only barely exceeding sepals; flowers all sessile; sect. Simplum Orchard (1977), stylodia subulate, greatly exceeding sepals, bisexual flowers sessile, male long-pedicellate. 5. Laurembergia Bergius

Fig. 64

Laurembergia Bergius, Descr. Pl. Cap.: 350 (1767); Schindler in Pflanzenreich IV, 225:61 (1905); A. Raynal, Webbia 19:683–695 (1965), African spp.; van der Meijden & Caspers, Fl. Males. I, 7:246–248 (1971). Serpicula L. (1767).

Perennial herbs from woody rhizome, some helophytic; stems ascending or prostrate. Leaves opposite or rarely (sub)verticillate or alternate, sessile or shortly petiolate, simple, entire or dentate. Inflorescences axillary 1–11-flowered fascicles, sometimes of 1–3 pedicellate hermaphrodite flowers and the others female and (sub)sessile, or 1 long-pedicellate male and the others female and (sub)sessile, or long-pedicellate male flowers in the axils of the upper leaves and female (sub)sessile flowers in the axils of lower leaves. Flowers with calyx-tube ellipsoid or urceolate, with longitudinal nerves and also longitudinal, often strongly mamillate ribs, sepals persistent, petals sometimes rudimentary or 0 in female flowers; stamens 4 or 8, anthers linear, not apiculate; ovary 4-locular, becoming 1-locular through dissolution of the septa; ovules 4; stylodia 4 or 0, stigmas plumose. Fruit 1-locular, a small, hard

189

indehiscent nut, ribbed or not; seed 1, pendulous. About four species, (sub)tropical Africa and Madagascar, tropical Asia from India to Java, and eastern South America, from 0 to 2,700 m a.s.l., L. tetrandra (Schott) Kanitz amphi-Atlantic, polymorphic. 6. Meziella Schindler Meziella Schindler in Engler, Pflanzenreich IV, 23:60 (1905); Orchard & Keighery, Nuytsia 9:111–117 (1993).

Glabrous annual or perennial semiaquatic herb; stems prostrate, rooting at nodes; leaves alternate, the lowermost entire, upper trifid with hydathodes on tips and in axils of lobes, lobes ± terete, with a short tooth in the angles between them. Inflorescence a spike; flowers with prophylls, bisexual, sepals and petals red, the latter hooded; stamens 4, antesepalous, apiculate; stylodia 4; ovary small, globular, with clusters of short subulate processes below the sepals. Fruit red, indehiscent, of 4 woody pyrenes contained within a dry, spiny exocarp. A single species, M. trifida (Nees) Schindler, in slightly submerged flats in Western Australia. 7. Proserpinaca L. Proserpinaca L., Sp. Pl. 1:88 (1753); Fernald in Gray’s Manual, 8th edn; Fasset, Commun. Inst. Trop. Invest. Ci. Univ. El Salvador 2:139–162 (1953).

Submerged, emergent or seasonally terrestrial rhizomatous perennials; stems ascending or prostrate, the lower parts branched and somewhat woody. Leaves alternate, subsessile, the submerged pinnatifid, the aerial occasionally simple but distinctly toothed. Flowers trimerous, hermaphrodite, sessile, solitary in leaf axils; calyx-tube triquetrous, petals rudimentary; stamens 3; anthers ellipsoidal; connectives apiculate; ovary tricarpellate. Fruit nut-like, 3-angled, 3-seeded. Two species, P. palustris L. strongly polymorphic, eastern North America from Canada to Florida and the West Indies, and Colombia, south-eastern Brazil. 8. Myriophyllum L.

Fig. 65

Myriophyllum L., Sp. Pl.: 992 (1753); van der Meijden & Caspers, Fl. Males. I, 7:239–263 (1971); Orchard, Brunonia 2:247–287 (1980), New Zealand spp.; ibid. 4:27–65 (1981), Amer. spp.; ibid. 8:173–291 (1985), Austral. spp. Vinkia van der Meijden (1975).

Perennial, rarely annual, aquatic or littoral herbs, free-floating or rhizomatous. Leaves basally sometimes with 1(–3) filiform to subulate deciduous

190

K. Kubitzki

stipule-like outgrowths (‘hydathodes’), usually in whorls of 3–6, sometimes opposite or alternate, usually dimorphic with pectinately divided submerged leaves and ± simple, entire emergent leaves, or, more rarely, leaves all similar, of one type or another. Inflorescences a simple, rarely branched spike with the flowers borne singly (occasionally in dichasia) in the axils of emergent leaves and provided with 2 prophylls; flowers rarely also in axils of submerged leaves, unisexual or rarely transitionally bisexual, plants monoecious or dioecious, in monoecious plants the upper flowers commonly male, the lower female; flowers (2–)4-merous, in males sepals and petals usually present, petals usually hooded, stamens (1–)4 or 8, ovary and stylodia vestigial or 0, in females sepals present or 0, petals vestigial or 0, stamens 0, ovary (2–)4-carpellate, stylodia 1 per carpel, clavate, rarely subulate, stigma usually capitate and fimbriate. Fruit dry, variously ornamented, splitting at maturity into 1seeded mericarps. Almost cosmopolitan, although absent from most of Africa, the Middle East and much of southern Asia and north-eastern South America; about 60 species, with centres in Australia (36 spp., 31 endemic), North America (13 spp., 7 endemic), and India/Indo-China (10 spp., 7 endemic); M. aquaticum (Vellozo) Verdc. native to South America and adventive throughout tropical and warm-temperate regions of the world.

Selected Bibliography APG II 2003. See general references. Bowes, G. 1987. Aquatic plant photosynthesis: strategies that enhance carbon gain. In: Crawford, R.M.M. (ed.) Plant life in aquatic and amphibic habitats. Oxford: Blackwell, pp. 79–98. Corner, E.J.H. 1976. See general references.

Fauth, A. 1903. Beiträge zur Anatomie und Biologie der Früchte und Samen einiger einheimischer Wasser- und Sumpfpflanzen. Beih. Bot. Centralbl. 14:327–373. Fishbein, M. et al. See general references. Frederiksen, N.O. 1980. The mid-Tertiary spores and pollen grains from Mississippi and Alabama. Tulane Stud. Geol. Palaeontol. 10:65–86. Godwin, H. 1975. The history of the British flora, 2nd edn. Cambridge: Cambridge University Press. Gruas-Cavagnetto, C., Praglowski, J. 1977. Pollen d’Haloragacées dans le Thanétien et le Cuisien du bassin de Paris. Pollen Spores 19:299–308. Hegnauer, R. 1966, 1989. See general references. Hernández-Castillo, G.R., Cevallos-Ferriz, S.R.G. 1999. Reproductive and vegetative organs with affinities to Haloragaceae from the Upper Cretaceous Huepac chert locality of Sonora, Mexico. Amer. J. Bot. 86:1717–1734. Johri, B.M. et al. 1992. See general references. Mendes, E.J. 1978. Haloragaceae. In: Launert, E. (ed.) Flora Zambesiaca 4:74–81. Royal Botanic Gardens, Kew. Moody, M.L., Les, D.H. 2000. Phylogenetic relationships in Myriophyllum (Haloragaceae). Amer. J. Bot. 87, 6:177. Morgan, D.R., Soltis, D.E. 1993. Phylogenetic relationships among members of Saxifragaceae sensu lato based on rbcL sequence data. Ann. Missouri Bot. Gard. 80:631– 660. Orchard, A.E. 1975. Taxonomic revisions in the family Haloragaceae. I. The genera Haloragis, Haloragodendron, Glischrocaryon, Meziella and Gonocarpus. Bull. Auckland Inst. Mus. 10:1–293. Orchard, A.E. 1985. Myriophyllum (Haloragaceae) in Australasia. II. The Australian species. Brunonia 8:173– 291. Orchard, A.E. 1990. Haloragaceae. In: Flora of Australia 18:5–85. Canberra: Australian Government Publishing Service. Orchard, A.E., Keighery, G.J. 1993. The status, ecology and relationships of Meziella (Haloragaceae). Nuytsia 9:111–117. Praglowski, J. 1970. The pollen morphology of the Haloragaceae with reference to taxonomy. Grana 10:159–239. Schindler, A.K. 1905. Haloragaceae. In: Engler, A., Pflanzenreich IV, 225. Leipzig: W. Engelmann. Takhtajan, A. 1997. See general references.

Huaceae Huaceae A. Chev., Rev. Intl Bot. Appl. Agric. Trop. 27:28 (1947).

C. Bayer

Trees, sometimes tall, or shrubs, with strong odour of garlic. Leaves alternate, simple, with few roundish glands, elliptic, tip acuminate to cuspidate, base cuneate to obtuse, margin entire; stipules caducous. Flowers hermaphroditic, actinomorphic, hypogynous, in dense or few-flowered axillary cymes or solitary; sepals 5, valvate in bud, free or partly united, with glands on adaxial surface; petals 5, free, induplicate-valvate, with long simple hairs on adaxial side; stamens (8)10, of equal length, all fertile, free, apparently arranged in one whorl; anthers basifixed, dithecal, inner pollen sacs smaller than outer ones, dehiscence lengthwise or by apical slits; gynoecium 5-carpellate with terminal style and entire stigma; ovary unilocular; ovules solitary (Hua) or 5–6, basal, anatropous. Fruit capsular or indehiscent, 1(2)-seeded; seeds large, with a basal hilum; embryo straight; surrounded by copious endosperm. A family of two quite distinct genera from tropical Central and West Africa. Vegetative Structures. Simple, branched, and/or stellate hairs and peltate scales occur mainly on young twigs, leaves and petioles. Minute circular or oval glands are frequent near the base of the leaf blade, and in Afrostyrax kamerunensis mainly along the margin. They are made up by epidermal palisade-like cells. Anatomical characteristics which indicate a close relationship between Hua and Afrostyrax include paracytic stomata, occurrence of cristarque cells in various tissues, complex petiole vasculature, wood with libriform fibres and confluent parenchyma, vessels with simple perforations, and dilating rays in the bark. In contrast to Malvales, mucilage is lacking and the bark is not stratified into fibrous and not-fibrous layers (Baas 1972). Reproductive Structures. In both genera, the inflorescences arise from the axils of foliage leaves on indeterminate shoots. The inflorescences

are dense cymose flower clusters with dichasial or monochasial ramifications. In Afrostyrax kamerunensis, these inflorescences are few- or even single-flowered. Floral ontogeny (pers. obs.) starts in both genera with a successive, not quincuncial development of sepal primordia. Subsequently, the primordia of the other pentamerous whorls appear in the following succession: petals, alternipetalous stamens, alternisepalous stamens, and alternisepalous carpels. Deviations from the pentamerous structure can frequently be observed, for instance, in the gynoecium of Afrostyrax. In both genera, circular to oval epithelial glands are present on the ventral surface of the sepals. The petals of Hua are clawed and have ventral hispid projections which close together at anthesis (Fig. 67A), leaving access to the stamens and stigma only between the petal claws. On the basis of the petal projections, which are lacking in Afrostyrax, a relationship between Hua and Malvaceae-Byttnerioideae has been constructed. The anthers of Hua are short and open only at the apex; they expose the pollen on their reflexed inner surface. In Afrostyrax, the anthers are much longer and the connective is prolonged by an apical appendage. Here, the thecae open by long lateral slits. The unilocular ovary of Hua has only a single basal ovule. At maturity, it shows no vestiges of a pentamerous origin, which is detectable only in early ontogenetic stages (pers. obs.). Depending on the number of carpels per flower, the ovary of Afrostyrax contains five to six ovules, of which usually only one or two develop into seeds. Embryology. Ovules are anatropous and bitegmic. In Hua, the seed coat is covered with simple unicellular hairs. The outer epidermis of the inner integument forms a lignified palisade layer. Endosperm is abundant and contains starch and oil droplets. The embryo is straight with flat cotyledons (Baas 1972).

192

C. Bayer

on the rest of the surface of the grains. The folds do not seem to open, and can be interpreted neither as colpi nor as artefacts but may be pseudocolpi. Phytochemistry. Beijersbergen’s (1972) tests for hydrolysable and condensed tannins were negative for both genera, more detailed data being unknown.

Fig. 66. Huaceae. Hua gaboni, pollen, SEM ×1,700. (Photograph C. Bayer)

Pollen Morphology. The pollen grains of both genera agree even in details. They are mediumsized, oblate to suboblate, rounded-triangular and anguloaperturate (Fig. 66). The three rounded to oval, crassimarginate pores are provided with opercula. Additionally, three folds are usually found on both polar sides. Oltmann (1971) interpreted these as colpi in Hua but Baas (1972), who observed similar structures in acetolysed grains, rejected this view. Critical point-dried, unacetolysed pollen grains show a more delicate micro-granulate sculpture along these folds than

Affinities. Hua was originally placed in Sterculiaceae, Afrostyrax in Styracaceae, each genus in a separate tribe or subfamily within the respective family to emphasize their isolated positions. Mildbraed (1913) was the first to propose a close relationship between the two genera, which formally were united as Huacaceae by Chevalier (1947a). Affinities with Malvales, Styracaceae, Olacaceae, Icacinaceae and Opiliaceae have been suggested; Cronquist (1981, 1983) included Huaceae in Violales. On the basis of a broad comparison of anatomical and other characters, Baas (1972) found most agreement between Huaceae and taxa now included in Malvaceae, whereas other members of Malvales as well as of Geraniales and Malpighiales showed fewer similarities. However, Huaceae differ from Malvaceae and other Malvales families in important characters such as the lack of palmate venation of the leaves – a negative result of the Halphen reaction, the absence of mucilage cavities, in inflorescence morphology, the type of glands, the structure of the androecium, and the

Fig. 67. Huaceae. A Hua gaboni, flower. B Afrostyrax lepidophyllum, flower, ×7. (Orig. C. Bayer)

Huaceae

unilocular gynoecium with basal placentation. Therefore, malvalean affinities are unlikely and the position of Huaceae remains obscure. Molecular studies (Soltis et al. 2000; Savolainen, Chase et al. 2000; Savolainen, Fay et al. 2000) indicated affinities with Celastraceae, albeit with low statistic support, and The Angiosperm Phylogeny Group (APG II 2003) left the family unassigned to order within the Eurosid I clade. More recently, Zhang and Simmons (2006) have provided some evidence for a possible sister relationship between Huaceae and Oxalidales. Distribution and Habitats. Both genera include trees and shrubs in forests and woodlands of Cameroon, Gabon, Congo, Zaire; Afrostyrax lepidophyllus extends to the Central African Republic and Ghana. Economic Importance and Conservation. For their garlic flavour and scent, the bark, leaves, roots and seeds of Huaceae are locally used as a spice and for medical purposes (Bouquet 1969; Hegnauer 1989). Like many other taxa of tropical Africa, the family is endangered by deforestation. Key to the Genera 1. Petioles densely covered with stellate or peltate scale hairs; ventral petal projection lacking; connective with apical appendage; ovary with 5–6 ovules; fruit indehiscent 1. Afrostyrax – Petioles glabrous or covered with few simple or stellate hairs; petals with ventral projections; connective without apical appendage; ovary with 1 ovule; fruit dehiscent 2. Hua

1. Afrostyrax Perkins & Gilg

Fig. 67B

Afrostyrax Perkins & Gilg, Bot. Jahrb. Syst. 43:216 (1909).

Calyx splitting in 3(–5) segments, each sepal with 1–2 central glands on adaxial surface; petals elliptical to oblong, abaxial side bearing peltate or stellate hairs; ovary containing 5–6 ovules; fruit 1(2)seeded, indehiscent. Two or three species, A. lepidophyllus Mildbr. and A. kamerunensis Perkins &

193

Gilg (probably including A. macranthus Mildbr.; Chevalier 1947b); tropical West and Central Africa. 2. Hua L. Pierre ex De Wild.

Figs. 66, 67A

Hua L. Pierre ex De Wild., Ann. Mus. Congo V, 1:287 (1906).

Sepals free, glands in a row near the margin; petals dark red, with ventral projections and simple hairs, apical part of petals bending outwards; ovary with 1 ovule; fruit dehiscent, opening with 5–6 valves. A single species, Hua gabonii L. Pierre ex De Wild., tropical West and Central Africa.

Selected Bibliography APG II 2003. See general references. Baas, P. 1972. Anatomical contributions to plant taxonomy, II. The affinities of Hua Pierre and Afrostyrax Perkins et Gilg. Blumea 20:161–192. Beijersbergen, A. 1972. Note on the chemotaxonomy of Huaceae. Blumea 20:160. Bouquet, A. 1969. Féticheurs et médicines traditionnelles du Congo (Brazzaville). Mém. O.R.S.T.O.M. 36. Chevalier, A. 1947a. La famille des Huacaceae et ses affinités. Rev. Intl Bot. Appl. Agric. Trop. 27:26–29. Chevalier, A. 1947b. Arbres à ail, Huacacées et Styrax à benjoin. Rev. Intl Bot. Appl. Agric. Trop. 27:401–407. Cronquist, A. 1981. See general references. Cronquist, A. 1983. Some realignments in the dicotyledons. Nordic J. Bot. 3:75–83. Germain, R. 1963. 89. Huaceae. In: Flore du Congo, du Rwanda et du Burundi 10:317–319. Meise: National Botanic Garden of Belgium. Hegnauer, R. 1989. See general references. Mildbraed, J. 1913: Über die Gattungen Afrostyrax Perk. et Gilg und Hua Pierre und die “Knoblauch-Rinden” Westafrikas. Bot. Jahrb. Syst. 49:552–559. Oltmann, O. 1971. Pollenmorphologisch-systematische Untersuchungen innerhalb der Geraniales. Diss. Bot. 11. Perkins, J. 1909. Eine neue Gattung der Styracaceae aus dem tropischen Afrika. Bot. Jahrb. Syst. 43:214–217. Robyns, A. 1976. Huaceae. In: Flore d’Afrique Centrale (Zaire–Rwanda–Burundi). Meise: National Botanic Garden of Belgium. Savolainen, V., Chase, M.W. et al. 2000. See general references. Savolainen, V., Fay, M.F. et al. 2000. See general references. Soltis, D.E. et al. 2000. See general references. Zhang, L.-B., Simmons, M.P. 2006. Phylogeny and delimitation of the Celastrales inferred from nuclear and plastid genes. Syst. Bot. 31:122–137.

Hypericaceae Hypericaceae Jussieu, Gen. Pl.: 254 (1789) (“Hyperica”).

P.F. Stevens

Evergreen or sometimes deciduous herbs, shrubs or trees; glands or canals in most parts of the plant; xanthones widespread; hairs uni- or multicellular, eglandular, colleters common; terminal bud scaly or naked; leaves opposite, occasionally whorled or alternate, entire, estipulate; inflorescences terminal, more or less cymose, rarely axillary or flowers single, flowers polysymmetric, perfect, usually with prophylls; sepals free, (2–)4–5; petals (3)4–5, free; stamens (9–)∞, free or variously fasciculate or connate, anthers < 1(–1.2) mm long, dithecate, extrose, opening by slits, connective often with glands, staminodes alternipetalous or 0; nectary absent; ovary superior, 3–5-locular, placentation axile to parietal, ovules 1–∞/carpel, anatropous, bitegmic, tenuinucellate; stylodia free or basally more or less fused or style single, stigmas more or less expanded, smooth and sticky or ± punctate and papillate; fruit baccate or capsular, rarely a drupe; seeds small, winged or not, exotegmen lignified, with sinuous anticlinal walls; embryo straight or rarely curved; endosperm initially nuclear, often absent at maturity; germination epigeal, phanerocotylar. A family with 9 genera and 540 species; ± worldwide. Vegetative Morphology. Hypericaceae are mostly shrubs to trees, but there are some annual herbs (Hypericum). Taxa growing in drier regions (Hypericum, Psorospermum [= Harungana]) tend to develop a lignotuber, from which they sprout after fire or drought; root suckering occurs in Hypericum (Hagemann 1989 and references therein; Hagemann and Meusel 1984) and Vismia. Architectural models within Vismia vary (Vester 1999). Roots of some Hypericeae inhabiting swamps (e.g., Triadenum, Hypericum) are swollen and with air spaces. The terminal bud may lack scales, but in many species of Harungana, Cratoxylum, etc., it has two or more pairs of scales; in Cratoxylum it may abort. Leaves are opposite, rarely more or

less irregularly spiral (e.g., Harungana [Psorospermum alternifolium]) or whorled. There are often colleters, but no stipules. Multicellular stellate hairs characterize Vismieae; Hypericeae may be glabrous, but unicellular hairs are found in some Hypericum. Buds in taxa that lack scales are sometimes covered with dense indumentum, as in Vismieae; colleters then appear to be lacking. The lamina is usually petiolate, although often sessile in Hypericum; the midrib is nearly always well-developed. Venation is commonly eucamptodromous or brochidodromous; it is close to parallelodromous or acrodromous in some species of Hypericum. The leaf margin is usually entire, but it may be crenate by glands (Harungana), or even lobate – and this can be true of the calyx as well – as in some species of Hypericum. Vegetative Anatomy. Metcalfe and Chalk (1950) summarize early literature; more recent studies include those of Spirlet (1959), Baas (1970), and Gibson (1980). There is a complex system of spherical to more or less elongated schizogenous glands and canals associated with the vascular tissue, and also found in both the cortex and pith. In the appendicular organs of the plant, these may be more or less independent of the vascular tissue (e.g., Cicarelli et al. 2001a). There are also reddish to black glands (as in Hypericum) containing hypericin and related compounds (Robson 1977; Cicarelli et al. 2001b; Onelli et al. 2002); these are clusters of cells that initially have meristematic features but that eventually become filled with black material. Variation in such glands, schizogenous structures and epidermal features in the leaves is of taxonomic interest (Lü and Hu 2001; Lü et al. 2001). Cotyledons, filaments and petals commonly have canals. The phellogen is always initiated in the deep-seated position in the pericycle (which may be lignified or not), both in stem and root. In

Hypericaceae

the stem, layers of cells, often with endodermal thickenings, are commonly interspersed with layers of unthickened cells in a polyderm (Mylius 1913); aerenchyma may develop (Schenck 1889). Hypericum has a clearly developed endodermis in the stem (cf. also some Bonnetiaceae). Nodes are single trace from a single gap. The petiole bundle varies from simple, commonly being arcuate in Hypericum, to more complex, annular, with additional vascular tissue inside the annulus, as in Vismia. Similarly, the midrib bundle varies from arcuate to more or less annular, with phloem toward the outside. The vascular bundles of even the higher-order veinlets vary from being more or less transcurrent, joined to at least one surface of the lamina by echlorophyllous and often lignified tissue, to embedded; the latter condition is common. Anticlinal epidermal cell walls are straight to sinuous. Leaves are nearly always hypostomatic, but amphistomatic in some Hypericum (e.g., Lü et al. 2001); stomates are usually paracytic, but in Hypericeae they may be anomocytic or even cyclocytic (Vestal 1937). In Harungana [Psorospermum membranaceum], stomata occur in small groups. Vessels are either single or in multiples, sometimes being in oblique lines. Perforation plates are usually simple, although they are sometimes scalariform. Pitting on tangential walls is generally alternate. Vasicentric tracheids have been recorded from a number of taxa. Wood parenchyma usually occurs, except perhaps in Hypericum. Septate fibers occur, either with or without nuclei, but their distribution is very sporadic. Inflorescence Structure. The inflorescence in most species is modified cymose or thyrsiform, and a terminal flower is nearly always present. Flowers have both bracts and prophylls. In Harungana, bracts are recaulescent, being borne on the pedicel where the lateral flowers of the cymose inflorescence diverge (the prophylls are in turn borne along the pedicels of the flowers they subtend); Vismia tends to show this behavior. In some Harungana from mainland Africa, the vegetative and floral parts of the stem are not clearly separated, and the relationship of branches to subtending leaves is very complex. Floral Structure. Sepals and petals are always present and free. Sepals are commonly five in number and quincuncial in aestivation, or four and decussate. When there are five petals, they are often

195

contorted. Indumentum on the corolla in particular is uncommon, but all Vismieae have dense, unicellular hairs on the adaxial surface of the corolla. The androecium is fasciculate, often with five antepetalous fascicles (Fig. 68), but there may be only three or four (Fig. 69; see below). Staminodes, representing the alternipetalous whorl of the androecium, are common (rare in Hypericum itself), and are either three or five in number. Filaments are slender, the anthers are extrose, < 1(–1.2) mm long, and often with simple anther glands at the apex between the thecae. There is no nectary at the base of the ovary, but the staminodes have been described as “nectariferous scales”, and their vascular supply lacks xylem elements, as would be expected for nectaries (Ronse Decraene and Smets 1991). There are usually three or five carpels; when there are as many carpels as perianth members, they are opposite the sepals. Placentation is basically axile, although the placentae may fail to meet in the middle, and it varies from axile to parietal within Hypericum. Stylodia are usually long and free (Figs. 68, 69), or are more or less fused to a single style (this varies infragenerically within Hypericum). The ovules are anatropous, tenuinucellate, and the micropyle is bitegmic; the inner integument may be up to seven cells thick, and there is an endothelium (Mourão and Beltrati 2001). In Hypericeae, the stigma is more or less punctate and the surface is papillate (Shivanna et al. 1989). In the rest of the family, the stigma is punctiform to more or less expanded, and the surface is more or less smooth. Floral Anatomy and Development. Little is known about floral development and anatomy, the study by Payer (1857) still being useful; see also Sattler (1973). The androecium is basically diplostemonous. The stamen fascicles are antepetalous, and may originate with the corolla as complex primordia, or separately, or separately and subsequently forming complex primordia; the anther primordia may coalesce to form a ring primordium (see Ronse Decraene and Smets 1991 for a summary). Stamen development is centrifugal on the fascicles in those few taxa in which this feature has been observed (e.g., Leins 1964; Ronse Decraene and Smets 1991). The fascicles are supplied by a single vascular bundle. In taxa with three fascicles, vascular evidence (and gross morphology) shows that two of the fascicles, slightly larger than the others, are a fused pair of fascicles of a basically 5-fasciculate androecium (Baas 1970; Robson 1972, 1974, 1981). Staminodes

196

P.F. Stevens

may develop opposite the sepals; whether they represent single stamens of a basically diplostemonous androecium or fascicles is unknown. Those of Hypericum differ from those in other Hypericaceae in that they lack a vascular connection (Robson 1977), and have been described as an example of “evolutionary recall” (Robson 1972). Robson’s work should be consulted for details of the vasculature of floral parts. Pollen Morphology. Knowledge of the palynology of Clusiaceae is largely based on a general survey by Seetharam (1985; see also Yi 1979; Seetharam and Maheshwari 1986). The pollen is in monads, triporate or tricolporate, there being some disagreement in the recording of this character. Costae colpi are usually present, and there is considerable variation in endaperture type and orientation; the endexine around the aperture may be markedly thinned, as in Vismieae, and the apertural membrane may have numerous granules. The pollen surface shows considerable variation, and there is also some variation in nexine thickness; in most taxa it is < 1 µm thick, but in the monotypic Eliea it is slightly thicker. Karyology. Within Hypericum, haploid numbers of 6–12, 14, 16, and 18–24 have been recorded (e.g., Robson and Adams 1968); Robson (1981) suggests that x = 12 is the primitive number, although in the absence of a phylogeny, this is somewhat speculative. Triadenum has n = 18, 19. Pollination and Reproductive Systems. Apospory is reported from Hypericum and Triadenum (Noack 1939; Myers 1964), and polyembryony from Hypericum (see Johri et al. 1992 for references). For information about hybridization in Hypericum, see Robson (1981). Little is known about pollination. Staminodes have been implicated in the opening of the flower (Hochreutiner 1918; Robson 1981). The predominant petal color is yellow, whereas white, pink, and red are less common; in European species of Hypericum, butterflies, flies, and bees are visitors. The flowers are usually perfect, and distyly appears to be quite common (Robson 1974); nothing further seems to be known about the latter. Anther glands are simple when they occur; dianthrones such as hypericin are found in the glands of Hypericum (Robson 1981). However, the flowers of many genera, perhaps even of those with glands, may offer predominantly pollen as a reward; the presence of

nectar remains to be demonstrated (but see Ronse Decraene and Smets 1991). Fruit and Seed. Fruits are commonly capsular, dehiscence being septicidal, loculicidal, or a mixture of both (Eliea). Hypericum (rarely) and Vismieae have several-seeded berries (see Mourão and Beltrati 2001 for their anatomy), while the endocarp is notably sclerified in Harungana madagascariense. The seed coat consists of a testa with a rather thin-walled epidermis that often contains tannins, as well as a low, lignified exotegmen with sinuous anticlinal walls (see also Corner 1976). There is a single chalazal vascular bundle. In some Harungana [Psorospermum] in particular, but also in Vismia, there are large, swollen, orange or black glands in the testa, and here the exotegmen may be inconspicuous in the mature seed. The endosperm often persists as a thin layer around the embryo. The embryo is usually white and straight, but in some Harungana it is green, and in others it may be curved. The embryo is 1–2 mm long, the cotyledons being about 25–40% the total length, but in some Madagascan species of Harungana the embryos are up to 6 mm long, the cotyledons being about 80% of their lengths. Germination is epigeal and phanerocotylar where known (e.g., Brandza 1908), although there are very few records. Dispersal. Taxa with capsules and small, dry seeds, and those with winged seeds, are probably wind-dispersed; the taxa with berries or drupes are probably animal-dispersed. Phytochemistry. Hypericaceae produce xanthones and anthraquinones. Xanthones such as mangiferin (e.g., Kitanov and Nedialkov 1998) have a wide distribution, but most others have narrower distributions. Prenylated xanthones are known from some, but not all, African species of Vismieae examined; only simple xanthones (and prenylated benzophenones) are known from American species (Habib et al. 1987). Emodin derivates, the naphto-dianthrones hypericin and pseudohypericin, show interesting distributions around and within Hypericum (Mathis and Ourisson 1963; Robson 1981). Anthrones, biemodyls, and related compounds occur in Vismieae, and the substitution patterns of prenylated anthranoids appear to help distinguish between African and American members of the

Hypericaceae

tribe (F. delle Monache, pers. comm.). There are distinctive coumarin derivates substituted at position 4 (Taylor and Brooker 1969). Relationships Within the Family. In the 19th century Clusiaceae and Hypericaceae were normally kept separate by, e.g., Planchon and Triana (1862, and references therein), Vesque (1893), and Engler (1925, see Robson 1981 for discussion). More recently, Clusiaceae have been included in Hypericaceae (the latter name is conserved, although Clusiaceae is generally the name that has been used: e.g., Robson 1978; Cronquist 1981); a variety of data can be interpreted to support this (e.g., Vestal 1937, who thought that Hypericaceae represented two separate lines derived from Clusiaceae). However, Hypericaceae are circumscribed narrowly here (Stevens on Clusiaceae-Guttiferae, this volume; see also Takhtajan 1997). Within the Hypericaceae, Vismieae are distinct; other groupings are less clear. Robson (1977, 1981) included Hypericum and Santomasia alone as Hypericeae. This tribe is circumscribed more broadly below (see Robson 2001), and includes all genera with papillate stigmas; generic limits need study. Cratoxyleae are the third tribe of the subfamily, and are phenetically distinct. Affinities. There is little doubt that Clusiaceae, Bonnetiaceae, and Hyperiaceae are closely related, but details are unclear (e.g., Gustafsson et al. 2002). They all produce distinctive xanthones (Kubitzki et al. 1978) and have similar, exotegmic seeds; for further details, see Clusiaceae-Guttiferae (this volume). What was unexpected was the association of Podostemaceae with Hypericaceae, perhaps in particular Hypericum (e.g., Chase et al. 2002; Gustafsson et al. 2002). Although at first sight there is little in common between the two (but this is true of practically any family with which Podostemaceae have been compared), Podostemaceae have cells that contain secretory products, tenuinucellate ovules, and papillate stigmas; xanthones are known to occur, and the pollen is sometimes tricolpate (see Podostemaceae, this volume, and Stevens 2005). A few Hypericeae are more or less aquatic plants. Distribution and Habitats. Hypericaceae are widely distributed. Hypericum itself includes shrubby to herbaceous plants, and grows both in more temperate regions and subalpine tropical habitats. Harungana in Africa grows in more

197

open and drier vegetation; Vismia, as well as some species of Harungana such as H. madagascariensis, flourish in secondary habitats; H. madagascariensis is apparently also sometimes lianescent. Pending a more detailed phylogeny, little can be said about the biogeography of the family. Vismieae are amphi-Atlantic, with Vismia in America, Harungana as here delimited in Africa–Madagascar (the one species of Harungana growing in Queensland is introduced). Hypericeae may have basal taxa endemic to Central America and east tropical Africa, while the Cratoxyleae are Madagascan-Malesian. Economic Importance. Several species of Hypericum are cultivated for their flowers. Several species are important in local pharmacopeias, while in western medicine anti-tumor activity has been detected in xanthones, benzophenones (Bennett and Lee 1989) and vismiones (Casinelli et al. 1986; see also Amonkar et al. 1981). A number of prenylated anthranoids show anti-feedant activity, especially in oliogophagous insects (e.g., Simmonds et al. 1985). Hypericin and pseudohypericin are involved in photosensitive reactions in animals, and species such as Hypericum perforatum are noxious weeds (attempts have been made to control this species with chrysomelid beetles in North America). At the same time, photoactivated hypericin is a potent anti-proliferative agent of potential value in medicine; Hypericum perforatum extract may alleviate depression, and there are many other potential applications of Hypericum in medicine (Onelli et al. 2002; see Ernst 2003 for references).

Classification of Hypericaceae I. Tribe Vismieae Choisy (1821). Genera 1–2 II. Tribe Hypericeae Choisy (1821). Genera 3–7 III. Tribe Cratoxyleae Bentham (1862). Genera 8–9

Key to the Genera 1. Indumentum on leaves and stem stellate; fruit baccate or drupaceous 2 – Plants usually glabrous, hairs simple; fruit capsular, rarely baccate 3 2. Bracts not (slightly) adnate to the pedicels; staminodes pubescent 1. Vismia – Bracts adnate to the pedicels (inflorescences capitate); staminodes glabrous 2. Harungana

198

P.F. Stevens

3. Petals often with adaxial scales; fruit dehiscing loculicidally (at least partly); seeds winged 4 – Petals usually lacking adaxial scales; fruit dehiscing septicidally; seeds barely or not winged 5 4. Fruit dehiscing septicidally and loculicidally; ovary loculi with inpushings 9. Eliea – Fruit dehiscing loculicidally; ovary loculi lacking inpushings 8. Cratoxylum 5. Petals yellow; stamens usually > 20/flower, staminodes very uncommon 6 – Petals pink or white; stamens < 18/flower, staminodes 3 7 6. Staminodes 5; petals subsymmetric 6. Santomasia – Staminodes 0(3); petals asymmetric or subsymmetric 3. Hypericum 7. Petals white; lamina with elongate glands abaxially; androecium with 10–18 stamens 4. Lianthus – Petals rose to flesh-colored, or pink and white; lamina lacking elongated glands abaxially; androecium with < 12 stamens 8 8. Rhizomatous herb of marshes; filaments in each fascicle 1/3–1/2 united 5. Triadenum – Evergreen shrub; filaments in each fascicle largely free 7. Thornea

H. Perr., Fl. Madag. Comores 135e & 136e fam., 10–50 (1951); Bamps, Bull. Jard. Bot. Bruxelles 36:440–453 (1966). Vismia Vand. subg. Afrovismia P. Bamps, Bull. Jard. Bot. Bruxelles 36:428–440 (1966).

Trees to very small shrubs, sometimes sprouting from basal burl; terminal bud rarely aborting, or with scales; bracts recaulescent; petals usually white; 1–∞ stamens/fascicle, staminodes glabrous; 1–8(-∞) ovules/carpel; testa often glandular; cotyledons 1/2–6/7 length of embryo. Perhaps 50 species, in seven groups, Africa, Madagascar (26 spp.); low alt. The genus needs revision.

Basic characters: Leaves opposite, entire, exstipulate, with glandular dots (short lines); inflorescence terminal, cymose; flowers polysymmetric, calyx and corolla free, androecium ± fasciculate, gynoecium superior. I. Tribe Vismieae Choisy (1821). Indumentum stellate; terminal bud lacking scales; flowers usually heterostylous, petals with hairs on the adaxial surface, contorted to cochleate, lacking scales; fascicles and staminodes 5; stigma expanded, smooth; fruits berries. 1. Vismia Vand. Vismia Vand., Fl. Lusit. Brasil. Spec.: 51, t. 3, f. 24 (1788); Ewan, Contr. U.S. Natl Herb. 35:293–377 (1962), rev.

Trees or shrubs; bracts not to hardly recaulescent; flowers homostylous or heterostylous; petals white to yellow or green; 3–∞ stamens/fascicle, staminodes hairy; 2–∞ ovules/carpel; testa rarely glandular; cotyledons 1/4–1/2(–3/5) length of the embryo. Circa 52 species, Central and South America; sea level to 2,800 m alt. 2. Harungana Lamarck

Fig. 68

Harungana Lamarck, Tab. Encycl. Méth., Bot. 2, 3: t. 645 (1796). Psorospermum Spach, Ann. Sci. Nat. Bot. II, 5:157 (1836);

Fig. 68. Hypericaceae. Harungana madagascariensis. A Flowering branch. B Flower. C The same, with a sepal and two petals removed. D Staminode. E Pistil. F Stamen fascicle. G Part of infructescence. H Drupe. I Coherent pyrenes. J The same, cut open to show seed. K Seed. (Milne-Readhead 1953)

Hypericaceae

II. Tribe Hypericeae Choisy, Prodr. Monogr. Hypéric.: 32 (1821). Plant usually glabrous, sometimes with unicellular or uniseriate hairs; terminal bud lacking scales; flowers usually homostylous, petals glabrous, yellow, sometimes white to red, contorted, lacking scales; fascicles 3, free or variously united, staminodes 0(3, 5); stigma usually not or only little expanded, with rounded papillae; fruit a septicidal capsule, rarely a berry; seeds usually unwinged. 3. Hypericum L. Hypericum L., Sp. Pl.: 783 (1753); Robson, Bull. Brit. Mus. Nat. Hist. (Bot.) 5:291–355 (1977), 8:55–226 (1981), 16:1–106 (1987), 12:163–325 (1985), 20:1–151 (1990), and Bull. Nat. Hist. Mus. (Bot.) 26:75–217 (1996), 31:37–88 (2001), 32:61–123 (2002). Ascyrum L., Sp. Pl.: 787 (1753). Androsaemum Duhamel du Monceau (1755).

Large shrubs or small trees to rhizomatous, sometimes annual herbs; inflorescences rarely umbellate, with 1–∞ flowers, these sometimes heterostylous; sepals 4 or 5, decussate or cochleate; petals 4, 5, yellow, sometimes red; fascicles sometimes 4, 5, or all united, 2–∞ stamens/fascicle, filaments free to connate, staminodes 0(3, 5); carpels 2–5, 2–∞ ovules/carpel, stylodia free to connate, stigmas punctate, sometimes expanded; cotyledons 1/4–1/2 length of embryo. Four hundred and twenty species, 32 sections: temperate regions generally (but few in Australia) and montane tropics. Scales on the petals are very rare. 4. Lianthus N. Robson Lianthus N. Robson, Bull. Nat. Hist. Mus. (Bot.) 31: 38 (2001).

Shrub, lamina with adaxial punctiform glands and abaxial linear glands; inflorescences with 5–7 flowers; petals white, ?aestivation; 3–6 stamens/fascicle, filaments united at base, staminodes 3; carpels 3, ∞ ovules/carpel, stylodia free; cotyledons unknown. One species, L. ellipticifolius (H.L. Li) N. Robson, China (Yunnan); 1,800–2,200 m alt. 5. Triadenum Raf. Triadenum Raf., Fl. Tellur. 3:78. 1837, non Triadenia Spach (1836).

Rhizomatous herbs; inflorescences also axillary; petals also cochleate, pink to purple or white; 3

199

stamens/fascicle, filaments fused, staminodes 3; carpels 3, ∞ ovules/carpel, stylodia free; cotyledons 1/4–1/2 length of embryo; n = 18, 19. Six species, Assam, East Asia, temperate North America; low alt. 6. Thornea Breedlove & McClintock Thornea Breedlove & McClintock, Madroño 23:369 (1976).

Shrubs; petals pink or pink and white; 3–4 stamens/fascicle, filaments at most basally united, anthers with glands or not; carpels 3, c. 15 ovules/carpel, stylodia free; cotyledons 1/4–1/2 length of embryo. Two species, southern Mexico (Chiapas) and northern Guatemala; montane. 7. Santomasia N. Robson Santomasia N. Robson, Bull. Brit. Mus. Nat. Hist. (Bot.) 8:61, Fig. 1 (1981).

Shrubs; flower single, rarely in small groups, terminal; petals yellow; fascicles 5, 7–∞ stamens/fascicle, filaments almost free, staminodes 5; carpels 5, ∞ ovules/carpel, stylodia free; cotyledons 1/2–2/3 length of embryo. One species, S. steyermarkii (Standley) N. Robson, Guatemala and Mexico; 2,500–2,700 m alt. III. Tribe Cratoxyleae Bentham & J.D. Hooker, Gen. Pl. 1:164 (1862). Plant woody, glabrous; terminal bud perulate; flowers homostylous or heterostylous; petals glabrous, rarely yellow, usually with scales; fascicles 3, staminodes 3; carpels 3, stigma slightly expanded, not papillate; fruit a more or less loculicidal capsule; seeds winged; cotyledons 1/2–2/3 length of embryo. 8. Cratoxylum Blume

Fig. 69

Cratoxylon Blume, Verh. Bat. Gen. 9:174 (1823); Gogelein, Blumea 15:453–475 (1967).

Tree to shrub; rarely pubescent and terminal bud aborting; flowers homostylous or heterostylous; petals cochleate, red, purple, pink to white, rarely green; rarely scales 0; ∞ stamens/fascicle; 3–∞ ovules/carpel; capsule loculicidal. Three sections, six species, northeastern India and southern China to western Malesia; low alt., occasionally submontane.

200

P.F. Stevens

Fig. 69. Hypericaceae. Cratoxylon arborescens. A Flowering branch. B Flower. C Petal, ventral side, with basal scale. D Stamen. E Androecium and gynoecium, one of the three stamen fascicles cut away, between them the staminodes. F Young fruit. G Dehisced capsule. H Seed. (Gogelein 1967)

9. Eliea Cambess. Eliea Cambess., Ann. Sci. Nat. I, 20:400, t. 13 (1830); H. Perr. in Fl. Madag. Comores 135e & 136e fam.: 8–10 (1951).

Tree; flowers heterostylous; petals contorted or cochlear, white; c. 15 stamens/fascicle; 2 ovules/ carpel, loculi almost completely subdivided; capsule septicidal and loculicidal. One species, E. articulata Cambess., Madagascar; low alt.

Selected Bibliography Amonkar, A., Chang, C.-J., Cassady, J.M. 1981. 6geranyloxy-3-methyl-1,8-dihydroxyanthrone, a novel anti-leukemic agent from Psorospermum febrifugum Sprach var. ferugineum (Hook. fil.) [sic]. Experienta 37:1138–1139.

Baas, P. 1970. Floral and vegetative anatomy of Eliaea from Madagascar and Cratoxylum from Indomalesia (Guttiferae). Blumea 18:369-391. Bennett, G.J., Lee, H.-H. 1989. Xanthones from Guttiferae. Phytochemistry 28:967–998. Brandza, G. 1908. Recherches anatomiques sur la germination des Hypéricacées et des Guttifères. Ann. Sci. Nat. Bot. IX, 8:221–300, pls 5–15. Cassinelli, G., Geroni, C., Botta, B., delle Monache, G., delle Monache, F. 1986. Cytotoxic and antitumor activity of vismiones isolated from Vismieae. J. Nat. Prod. 49:929– 931. Chase, M.W. et al. 2002. See general references. Cicarelli, D., Andreucci, A.C., Pagni, A.M. 2001a. Translucent glands and secretory canals in Hypericum perforatum L. (Hypericaceae): morphological, anatomical and histochemical studies during the course of ontogenesis. Ann. Bot. 88:637–644. Cicarelli, D., Andreucci, A.C., Pagni, A.M. 2001b. The black nodules of Hypericum perforatum L. ssp. perforatum: anatomical and histochemical studies during the course of ontogenesis. Israel J. Pl. Sci. 49:33–40. Corner, E.J.H. 1976. See general references. Cronquist, A. 1981. See general references. Engler, A. 1925. Guttiferae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 21. Engelmann, Leipzig, pp. 154–237. Ernst, E. (ed.) 2003. Hypericum: the genus Hypericum. New York: Taylor & Francis. Gibson, A. C. 1980. Wood anatomy of Thornea, including some comparisons with other Hypericaceae. I.A.W.A. Bull. n.s. 1:87–92. Gogelein, A.J.F. 1967. A revision of the genus Cratoxylum Bl. (Guttiferae). Blumea 15:453–475. Gustafsson, M.H.G., Bittrich, V., Stevens, P.F. 2002. Phylogeny of Clusiaceae based on rbcL sequences. Intl J. Pl. Sci. 163:1045–1054. Habib, A.M., Reddy, K.S., McCloud, T.G., Chang, C.-J., Cassady, J.M. 1987. New xanthones from Psorospermum febrifugum. J. Nat. Prod. 50:141–145. Hagemann, I. 1989. Wuchsformen einiger HypericumArten, ein Beitrag zum morphologischen und zum ökologischen Anliegen der Wuchsformen-Forschung. Flora 183:225–309. Hagemann, I., Meusel, H. 1984. Hypericum triquetrifolium Turra, ein Wurzelspross-geophyt: Wuchsform und Verbreitung. Flora 175:385–405. Hegnauer, R. 1966. See general references. Hochreutiner, B.P.G. 1918. La formation lodiculaire des corpuscles hypogynes chez les Guttifères. C. R. Soc. Phys. Hist. Nat. Genève 35:82–85. Johri, B.M. et al. See general references. Kitanov, G.M., Nedialkov, P.T. 1998. Mangiferin and isomangiferin in some Hypericum species. Biochem. Syst. Ecol. 26:647–653. Kubitzki, K., Mesquita, A.A.L., Gottlieb, O.R. 1978. Chemosystematic implications of xanthones in Bonnetia and Archytaea. Biochem. Syst. Ecol. 6:185–187. Leins, P. 1964. Die frühe Blütenentwicklung von Hypericum hookerianum Wight et Arn. und Hypericum aegyptiacum L. Ber. Deutsch. Bot. Gesell. 77:112– 123.

Hypericaceae Lü, H.-F., Hu, Z.-H. 2001. Comparative anatomy of secretory structures of leaves in Hypericum (in Chinese). Acta Phytotax. Sin. 39:393–404. Lü, H.-F., Chu, Q.-G., Hu, Z.-H. 2001. Comparative study on the epidermal micromorphology of Hypericum and Triadenum (in Chinese). Acta Bot. Bor.-Occ. Sin. 21:693–699. Mathis, C., Ourisson, G. 1963. Étude chimiotaxonomique du genre Hypericum, 1. Répartition de l’Hypéricine. Phytochemistry 2:157–171. Metcalfe, C.R., Chalk, L. 1950. See general references. Milne-Readhead, E. 1953. Hypericaceae. In: Turrill, W.B., Milne-Readhead, E. (eds) Flora of tropical East Africa. London: Crown Agents. Mourão, K.S.M., Beltrati, C.M. 2001. Morphology and anatomy of developing fruits and seeds of Vismia guianensis (Aubl.) Choisy (Clusiaceae). Revista Brasil. Biol. 61:147–158. Myers, O. 1964. Megasporogenesis, megagametophyte development and endosperm development in Hypericum virginicum. Amer. J. Bot. 51: 664 (Abstract). Mylius, G. 1913. Das Polyderm, eine vergleichende Untersuchung über die physiologischen Scheiden Polyderm, Periderm und Endodermis. Bibl. Bot. 18, 79:1–119, pls 1–4. Noack, K.L. 1939. Fortpflanzungsverhältnisse und Bastarde von Hypericum perforatum L. Zeitsch. Indukt. Abstamm. Vereb. 76:569–601. Onelli, E., Rivetta, A., Giorgi, A., Bignami, M., Cocucci, M., Patrignani, G. 2002. Ultrastructural studies on the developing secretory nodules of Hypericum perforatum. Flora 197:92–102. Payer, J.-B. 1857. Traité de organogénie comparée de la fleur. Paris: Masson. Planchon, J.E., Triana, J. 1862. Mémoire sur la famille des Guttifères. Ann. Sci. Nat. Bot. IV, 16:263–308. Robson, N.K.B. 1972. Evolutionary recall in Hypericum. Trans. Bot. Soc. Edinburgh 41:365–383. Robson, N.K.B. 1974. Hypericaceae. In: van Steenis, C.G.G.J. (ed.) Flora Malesiana I, 8:1–29. Leiden: Noordhoff. Robson, N.K.B. 1977. Studies in the genus Hypericum L. (Guttiferae) 1. Infrageneric classification. Bull. Brit. Mus. Nat. Hist. (Bot.) 5:291–355. Robson, N.K.B. 1978. Guttiferae. In: Heywood, V.H. (ed.) Flowering plants of the world. New York: Mayflower, pp. 85–87. Robson, N.K.B. 1981. Studies in the genus Hypericum L. (Guttiferae), 2. Characters of the genus. Bull. Brit. Mus. Nat. Hist. (Bot.) 8:55–226.

201

Robson, N.K.B. 2001. Studies in the genus Hypericum L. (Guttiferae), 4, 1. Sections 7. Roscyna to 9. Hypericum sensu lato (part 1). Bull. Nat. Hist. Mus. (Bot.) 31:37–88. Robson, N.K.B., Adams, W.P. 1968. Chromosome numbers in Hypericum and related genera. Brittonia 20:95–106. Ronse Decraene, L.P., Smets, E. 1991. Androecium and floral nectaries of Harungana madagascariensis (Clusiaceae). Pl. Syst. Evol. 178:179–194. Sattler, R. 1973. Organogenesis of flowers, a photographic text-atlas. Toronto: University of Toronto Press. Schenck, H. 1889. Ueber das Aërenchym, ein dem Kork homologes Gewebe bei Sumpfpflanzen. Jahrb. Wissensch. Bot. 20: 526-574, pls 23–28. Seetharam, Y.N. 1985. Clusiaceae: palynology and systematics. Pondichéry: Travaux de la Section Scientifique et Technique, Institut Français, t. 21. Seetharam, Y.N., Maheshwari, J.K. 1986. Scanning electron microscopic studies on the pollen of some Clusiaceae. Proc. Indian Acad. Sci. (Pl. Sci.) 96:217–226. Shivanna, K.R., Ciampolini, F., Cresti, M. 1989. The structure and cytochemistry of the pistil of Hypericum calycinum: the stigma. Ann. Bot. 63:613–620. Simmonds, M.S.J., Blaney, W.M., delle Monache, F., Marquina Mac-Quhae, M., Marini Bettolo, G.B. 1985. Insect antifeedant properties of anthranoids from the genus Vismia. J. Chem. Ecol. 11:1593–1599. Spirlet, M. 1959. Étude taxonomique des épidermes foliaires des Hypéricacées et des Guttiféracées du bassin du fleuve Congo. Bull. Inst. Franç. Afr. Noire 29:5–91. Stevens, P.F. 2005. See general references. Takhtajan, A. 1997. See general references. Taylor, H.L., Brooker, R.M. 1969. Isolation of Uliginosin A and Uliginosin B from Hypericum uliginosum. Lloydia 32:217–219. Vesque, J. 1893. Guttiferae. In: Candolle, A.C.P. de (ed.) Monographiae Phanerogamarum, vol. 8. Paris: Masson, pp.1–699. Vestal, P.A. 1937. The significance of comparative anatomy in establishing the relationship of the Hypericaceae to the Guttiferae and their allies. Philipp. J. Sci. 64:199– 256. Vester, H. 1999. Architectural diversification within the genus Vismia (Clusiaceae) in the Amazonian rainforest (Ararucuara, Colombia). In: Kurmann, M.H., Hemsley, A.R. (eds) The evolution of plant architecture. Royal Botanic Gardens, Kew, pp. 147–158. Yi, X.-Z. 1979. Pollen morphology of Guttiferae in China (in Chinese). Acta Bot. Sin. 21:36–41.

Iteaceae Iteaceae J. Agardh, Theoria Syst. Pl.: 151 (1858), nom. cons.

K. Kubitzki

Trees and shrubs, sometimes climbing; pith lamellate; axillary buds sometimes superposed. Leaves alternate, glandular-serrate (spiny-dentate in Itea ilicifolia) or rarely entire, pinnately veined; stipules minute, subulate, or 0. Inflorescences manyflowered terminal or axillary panicles or racemes, often superposed in groups of 2 or 3. Flowers small, regular, hermaphrodite or polygamous; sepals 5, basally connate into a short, turbinate or obconic tube adnate to base of ovary, lobes valvate or apert, persistent; petals 5, valvate, persistent; stamens 5, alternating with the petals, inserted at the margin of the annular nectary disk; anthers small, oblong to ovoid, dorsifixed, introrse, at the apex with a globular protrusion of the connective; gynoecium of 2 united carpels, ovary 2-locular, nearly superior to more than 3/4 inferior; style undivided (postgenitally united?) or more or less deeply divided into two stylodia but then, at anthesis, apically coherent with globular stigmas; stigmas capitate, cohering but separating in fruit; ovules numerous on axile placentas, bitegmic and crassinucellate. Fruit a capsule with persistent perianth, dehiscing septicidally; seeds with large, curved embryo surrounded by sparse, fleshy endosperm. n = 11. A single genus with about 27 species in Southeast Asia, one in Africa and one in North America. Morphology and Anatomy. Itea has simple, acutely pointed and glandular hairs, in contrast to the relatively complex trichomes present in other members of Saxifragales. The subulate stipules have been figured by Weberling (1976). Ovary position varies from nearly superior to more than 3/4 inferior. The carpels are connate through their entire length (Ge at al. 2002) or free from where the floral cup becomes free from the ovary wall (Bensel and Palser 1975). Nectariferous tissue (a disk) was found to be present in all species examined. Nodes are trilacunar–3-trace. Stomata are anomocytic. Leaf teeth are glandular. Druses are present in cortex and pith. Cork arises superficially. Vessel

elements have scalariform perforations with numerous slender bars; lateral pitting is scalariform. Rays are uniseriate, heterocellular. Embryology. In Itea virginica, Mauritzon (1939) found the ovules bitegmic and crassinucellate, and the embryo sac 8-nucleate. For Choristylis rhamnoides, the crassinucellate condition was also determined (Mauritzon 1933). Pollen Morphology. Pollen is bilateral/heteropolar and biporate, 14–23 × 20–33 µm; the exine is tectate (Erdtman 1952; Agababian 1960). Karyology. For Itea virginiana and four Asian species, 2n = 22 has been reported. Fruit and Seed. Seeds are narrowly fusiform or more or less ovoid, which Engler (1891) used to separate his sections of Itea, sect. Sempervirentes with evergreen leaves and fusiform seeds, and sect. Deciduae with deciduous leaves and ovoid seeds. The inclusion of I. rhamnoides, which is evergreen and has ± ovoid seeds, makes this distinction untenable. In Itea virginica and I. sinensis, the testa is strongly thickened and tanniniferous but apparently not lignified; all other tissues of the seed coat are crushed. The endosperm is moderately developed and contains fat and aleuron. The embryo has a length of about 3/4 of the seed (Krach 1976; Nemirovich-Danchenko 1994). Affinities. Formerly included in Escalloniaceae, Iteaceae differ from them in their peculiar diporate pollen grains, bitegmic and crassinucellate ovules, basic chromosome number, chambered pith and floral anatomy (Takhtajan 1997). The globular anther protrusion (Fig. 70D) may be compared with the apical nectaries on the anthers of Grossulariaceae. Molecular analyses place Itea and Choristylis into the Core Saxifragales sister to

Iteaceae

Pterostemon (Savolainen, Fay et al. 2000; Fishbein et al. 2001). Phytochemistry. Itea (3 spp. examined) lacks flavonols and consistently contains C-glycosyl flavones, an unusual feature in Saxifragales (Bohm et al. 1988). Distribution and Habitats. Itea occurs mainly in temperate and tropical South and Southeast Asia from the Himalayas to China, Japan, Java and the Philippines, mostly in colline and montane habitats, rarely ascending up to an altitude of 3,000 m; one species is found in East, Central and South Africa, where it grows in evergreen forest margins, riverine and valley forests, rock crevices and by streams at an altitude of 900–2,300 m; another species is known from eastern North America, where it occupies moist and wet sites preferably in the Coastal Plain.

203

Fossil Record. Fossil pollen referable to Itea has been reported from the Eocene through Pliocene in Europe, and the Oligocene and Pliocene in North America (see references in Hermsen et al. 2003). Uses. Itea ilicifolia, I. yunnanensis and the more hardy I. virginica are cultivated as garden ornamentals. Only one genus: 1. Itea L. Itea L., Sp. Pl.: 199 (1753). Choristylis Harv. in Hook., London J. Bot. 1:19 (1842); Verdcourt, Fl. Zambesiaca 7, 1:1–3 (1983).1

Description as for the family.

Selected Bibliography Agababian, V.S. 1960. On the palynosystematics of the family Iteaceae (in Russian). Bull. Armenian Acad. Sci., Biol. 13:99–102. Bensel, C.R., Palser, B.F. 1975. Floral anatomy in the Saxifragaceae sensu lato. II. Saxifragoideae and Iteoideae. Amer. J. Bot. 62:661–675. Bohm, B.A., Chalmers, G., Bhat, U.G. 1988. Flavonoids and the relationships of Itea to the Saxifragaceae. Phytochemistry 27:2651–2653. Cutler, D.F., Gregory, M. (eds) 1998. Anatomy of the dicotyledons, 2nd edn. IV. Saxifragales. Oxford: Clarendon Press. Elst, P. van der 1909. Beiträge zur Kenntnis der Samenanlage der Saxifragaceae. Ph.D. Dissertation, University of Utrecht. Engler, A. 1891. Saxifragaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 2a. Leipzig: W. Engelmann. pp. 41–93. Erdtman, G. 1952. See general references. Fishbein, M. et al. 2001. See general references. Ge, L.-P., Lu, A.-M., Pan, K.-Y. 2002. Floral ontogeny in Itea yunnanensis (Iteaceae). Acta Bot. Sin. 44:1261– 1267. Hermsen, E.J., Gandolfo, M.A., Nixon, K.C., Crepet, W.L. 2003. Divisestylus gen. nov. (aff. Iteaceae), a fossil saxifrage from the late Cretaceous of New Jersey, USA. Amer. J. Bot. 90:1373–1383.

Fig. 70. Iteaceae. Itea rhamnoides. A Habit. B Inflorescence. C Flower, opened out. D Stamen. E Vertical and transverse section of ovary. F Fruit, note the coherent stigmas. G Seed. (Drawn by E. Margaret Stones; Verdcourt 1973)

1 When Bentham (in Benth. & Hook., Gen. Pl. 1865) kept separate Itea and Choristylis, only two species of Itea were known. The addition of more than 20 species to Itea since then has greatly broadened its range of variation of characters, such as ovary position, the degree of fusion of the stylodia, and ramification of the inflorescences, and makes the maintenance of Choristylis virtually impossible. The pollen of the two genera is identical, and earlier claims of unitegmic ovules in Choristylis (still maintained in Cutler and Gregory 1998) are erroneous. Itea rhamnoides, comb. nov., based on Choristylis rhamnoides Harv. in Hook., London J. Bot. 1: 19 (1842).

204

K. Kubitzki

Hideux, M.J., Ferguson, I.K. 1976. See general references. Krach, J.E. 1976. Die Samen der Saxifragaceae. Bot. Jahrb. Syst. 97:1–60. Mauritzon, J. 1933. Studien über die Embryologie der Families Crassulaceae und Saxifragaceae. Ph.D. Thesis, University of Lund. Lund: H. Olssson. Mauritzon, J. 1939. Contributions to the embryology of the orders Rosales and Myrtales. Lunds Univ. Årsskr. N.F. 2, 35, 2. Lund: Gleerup, 121 p. Nemirovich-Danchenko, E.N. 1994. Morphology and anatomy of the seeds of Iteaceae (in Russian). Bot. Zhurn. (Moscow & Leningrad) 79:83–87. Petrov, S., Drazheva-Stamatova, T. 1973. Itea L. fossil pollen in Tertiary sediments of Europe and North America. C. R. Acad. Bulg. Sci. 26:811–814.

Rylova, T.B. 1994. Morphological features of pollen in some fossil and extant species of Itea (Iteaceae) (in Russian). Bot. Zhurn. (Moscow & Leningrad) 74:694–699. Savolainen, V., Fay, M.F. et al. 2000. See general references. Takhtajan, A. 1969. Flowering plants. Origin and dispersal. Edinburgh: Oliver and Boyd. Verdcourt, B. 1973. Escalloniaceae. In: Polhill, R.M. (ed.) Flora of Tropical East Africa. London: Crown Agents, pp. 1–3. Weberling, F. 1976. Weitere Untersuchungen zur Morphologie des Unterblattes bei den Dikotylen. IX, Saxifragaceae s.l., Brunelliaceae and Bruniaceae. Beitr. Biol. Pflanzen 52:163–181. Wolfe, J.A. 1970. Neogene floristic and vegetational history of the Pacific Northwest. Madroño 20:83–110.

Ixerbaceae Ixerbaceae Griseb., Grundr. Syst. Bot.: 122 (1854).

J.V. Schneider

Small, evergreen trees; unicellular lignified Tshaped trichomes present both on vegetative and floral parts. Leaves alternate, opposite or verticillate, simple, petiolate, estipulate, coriaceous, serrate, gland-tipped, venation pinnate-reticulate. Inflorescences terminal, few-flowered, corymbose panicles, the pedicels articulated. Flowers actinomorphic, perfect, the calyx tube short, adnate to base of ovary; sepals 5, persistent, imbricate, the outer ones shorter, the three inner ones enclosing the inner organs in bud; petals 5, imbricate, free, clawed, white, inserted on floral cup; stamens 5, free, antesepalous, alternating with disk lobes; anthers dorsifixed, sagittate, introrse, versatile, opening by longitudinal slits, with a hypogynous 5-lobed disk; gynoecium 5-carpellate; ovary superior to semi-inferior, syncarpous, 5-locular; style simple, apical, hollow; stigma punctiform; placentation axile, ovules 2 per carpel, pendant, collateral, bitegmic, crassinucellar, anatropous. Fruit a few-seeded, loculicidal capsule; seeds 1(2) per locule, large, shiny blackish with a red aril; embryo large, with thick cotyledons and small radicula; endosperm scanty. A single genus and species (Ixerba brexioides A. Cunn.), endemic to the North Island of New Zealand Vegetative Morphology. Ixerba is an evergreen tree up to 15 m in height. The leaves are pseudoverticillately arranged. The venation corresponds to the semicraspedodromous type; the intersecondaries are poorly defined (Gornall et al. 1998). Vegetative Anatomy. The leaf epidermis is one-layered. The stomata are anomocytic and restricted to the abaxial surface (Philipson 1967). The mesophyll consists of 1–3 layers of palisade parenchyma and is reported to contain crystal druses as well as simple crystals. The nodes are trilacunar

with three traces (Thouvenin 1890; Watari 1939; Hils 1985; Gornall et al. 1998). Cork arises in subepidermal layers. There are scattered groups of sclerenchymatous cells as well as simple crystals and druses in the cortex. The wood is hard, heavy, diffuse-porous, and vessels are solitary, rarely in multiples or clusters of 2–3. The vessel elements are up to 1,090 µm long. Perforation plates are scalariform and oblique. Intervessel pits are scanty, opposite and up to 39 µm in diameter. Helical thickenings are inconspicuous. Fibre-tracheids are eseptate, 8–35 mm in diameter, and have bordered pits on the tangential and radial walls. Wood parenchyma is sparse, apotracheal, rarely vasicentric. Rays are 1–5 cells wide (Watari 1939; Patel 1973; Meylan and Butterfield 1975; Gornall et al. 1998). Flower Structure. The flowers of Ixerba are large, bisexual and pentamerous. All organs are united into a cup. The five sepals are spirally arranged and the two outer sepals are smaller than the inner ones. Aestivation is imbricate but in petals may vary from quincuncial to cochlear or contort. There are five fertile antesepalous stamens which alternate with the five basal nectary lobes. The anthers show a connective protrusion. The gynoecium is syncarpous and consists of five antepetalous carpels. The ovary is superior to halfinferior and is characterised by five pronounced dorsal ridges and five less conspicuous ones in between. In the upper style, the five carpels are postgenitally united (Fig. 71C) and end in a single, punctiform stigmatic surface. The style is hollow. Placentation is axile and there are two collateral, antitropous ovules per carpel; some of the ovules may abort. Unicellular lignified, T-shaped hairs are present on the sepals and petals. Special mucilage cells are observed in the petals (Bensel and Palser 1975; Matthews and Endress 2005). The antepetalous staminodia of Ixerba reported by Takhtajan (1997) could not be verified.

206

J.V. Schneider

Embryology. Pollen grains are two-celled. Ovules are bitegmic, anatropous and crassinucellar. The embryo sac is of the Polygonum type (Kamelina 1992). Pollen. The pollen is 4–5-colporate and oblate to suboblate. The exine is thickened. The sexine is thinner than the nexine (Erdtman 1952; Pastre and Pons 1973). Fruit and Seed. The fruits are loculicidal capsules with few blackish seeds. The tips remain together while the bases are already separated (Fig. 71D). The seeds bear an incipient aril which contains fatty oils (Matthews and Endress 2005). Pollination and Dispersal. Ixerba is reported to be predominantly bird-pollinated. The diaspores are probably dispersed by birds and feral pigs (McEwen 1978; Thomson and Challies 1988). Phytochemistry. Proanthocyanidins are reported from the cortex. Urolic acid, a free triterpenic acid, occurs in the leaves (Hegnauer 1973). Affinities. Ixerba was often considered a member of Saxifragaceae or allied families. A close relationship with Brexia or Roussea, as suggested by Engler (1930) and others, is supported neither by molecular (e.g. Koontz and Soltis 1999) nor by detailed morphological/anatomical studies, since these genera differ markedly in floral vasculature, ovary position, number of ovules, disposition of sepals, embryology and/or wood and seed anatomy (Bensel and Palser 1975; Krach 1976; Kamelina 1992; Gornall et al. 1998), whereas their shared characters are few and probably plesiomorphic. According to the updated classification of the Angiosperm Phylogeny Group (APG II 2003), Ixerbaceae are included in Crossosomatales, which is supported by various molecular studies (Nandi et al. 1998; Savolainen, Fay et al. 2000; Soltis et al. 2000; Cameron 2003; Sosa and Chase 2003). Cameron (2003) emphasised the similarities in wood anatomy between Ixerbaceae and Strasburgeriaceae, and morphological and anatomical studies of the floral structure support the close relationship of Ixerbaceae and Strasburgeriaceae as well as that of Ixerbaceae, Strasburgeriaceae and Geissolomataceae (Cameron 2003; Matthews and Endress 2005). According to Matthews and

Fig. 71. Ixerbaceae. Ixerba brexioides. A Habit. B Flower. C Immature Fruit. D Dehiscing fruit. (Engler 1930)

Endress (2005), potential floral synapomorphies for both families may be the comparatively large flowers, stamens with long filaments and sagittate anthers, the pentamerous conical gynoecium with streamlined transition from ovary to style, the antitropous ovules, unicellular lignified T-shaped hairs on the perianth, and the presence of idioblasts with striate mucilaginous inner tangential walls in floral organs. Distribution and Habitats. Ixerba is endemic to New Zealand and occurs in mountainous forests (e.g. Podocarp-Tawa forests) of the North Island. Flowering is from September to December. Palaeobotany. Reports on fossil Ixerba from New Zealand date back to the Mid-Miocene (Lee et al. 2001). Economic Importance. Ixerba brexioides, locally called Tawari by the Maori, is economically not important, except for the honey produced from its flowers. Only one genus: Ixerba A. Cunn.

Fig. 71

Ixerba A. Cunn., Ann. Nat. Hist. 3:249 (1839).

Characters as for family. Ixerba brexioides A. Cunn. is the only species.

Ixerbaceae

Selected Bibliography APG II 2003. See general references. Bensel, C.R., Palser, B.F. 1975. Floral anatomy in the Saxifragaceae sensu lato. I. Introduction, Parnassioideae and Brexioideae. Amer. J. Bot. 62:176–185. Cameron, K.M. 2003. See general references. Engler, A. 1930. Brexioideae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 18a. Leipzig: W. Engelmann, pp. 185–187. Erdtman, G. 1952. See general references. Gornall, R.J., Al-Shammary, K.I.A., Gregory, M. 1998. Escalloniaceae. In: Cutler, D.F., Gregory, M. (eds) Anatomy of the dicotyledons, 2nd edn. IV. Saxifragales. Corby, UK: Oxford University Press. Hegnauer, R. 1973. See general references. Hils, M.H. 1985. Comparative anatomy and systematics of twelve woody Australasian genera of the Saxifragaceae. Ph.D. Thesis, University of Florida, FL. Kamelina, O.P. 1992. K embriologii roda Ixerba v svyazi s ego sistematicheskim polozheniem. (On the embryology of the genus Ixerba in relation to its systematic position). Bot. Zhurn. (Moscow & Leningrad) 77:112–117. Koontz, J.A., Soltis, D.E. 1999. DNA sequence data reveal polyphyly of Brexioideae (Brexiaceae; Saxifragaceae sensu lato). Pl. Syst. Evol. 219:199–208. Krach, J.E. 1976. Samenanatomie der Rosifloren, I. Die Samen der Saxifragaceae. Bot. Jahrb. Syst. 97:1–60. Lee, D.E., Lee, W.G., Mortimer, N. 2001. Where and why have all the flowers gone? Depletion and turnover in the New Zealand Cenozoic angiosperm flora in relation to

207

palaeogeography and climate. Austral. J. Bot. 49:341– 356. Matthews, M.L., Endress, P.K. 2005. See general references. McEwen, W.M. 1978. The food of the New Zealand Pigeon (Hemiphaga novaeseelandiae novaeseelandiae). N. Z. J. Ecol. 1:99–108. Meylan, B.A., Butterfield, B.G. 1975. Occurrence of simple, multiple, and combination perforation plates in the vessels of New Zealand woods. N. Z. J. Bot. 13:1– 18. Nandi, O.I. et al. 1998. See general references. Pastre, A., Pons, A. 1973. Quelques aspects de la systématique des Saxifragacées à la lumière des données de la palynologie. Pollen Spores 15:117–133. Patel, R.N. 1973. Wood anatomy of the dicotyledons indigenous to New Zealand. 2. Escalloniaceae. N. Z. J. Bot. 11:421–434. Philipson, W.R. 1967. Griselinia Forst. fil.: anomaly or link. N. Z. J. Bot. 5:134–165. Savolainen, V., Fay, M.F. et al. 2000. See general references. Soltis, D.E. et al. 2000. See general references. Sosa, V., Chase, M.W. 2003. See general references. Takhtajan, A. 1997. See general references. Thomson, C., Challies, C.N. 1988. Diet of feral pigs in the Podocarp-Tawa forests of the Urewera ranges. N. Z. J. Ecol. 11:73–88. Thouvenin, M. 1890. Recherches sur la structure des Saxifragacées. Ann. Sci. Nat., Bot. VII, 12:1–174. Watari, S. 1939. Anatomical studies on the leaves of some saxifragaceous plants, with special reference to the vascular system. J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 5:195– 316.

Krameriaceae Krameriaceae Dumort., Anal. Fam. Pl.: 20, 23 (1829), nom. cons.

B.B. Simpson

Rhizomatous shrubs, subshrubs, or perennial herbs semiparasitic on the roots of a wide array of flowering plants. Leaves alternate, simple or trifoliolate, estipulate, entire, variously vestitured. Flowers axillary and single or in botryoid panicles, bisexual, zygomorphic, hypogynous with 5(4) purple, pink, or yellow showy, imbricate sepals and 5(4) petals, the 2 abaxial of which are reduced to glandular, lipid-secreting structures and the remaining 3(2) small and forming a flag inserted adaxially above the ovary. Stamens 4(3), 4-locular, curved, with stout filaments usually united basally, and anthers dehiscing by terminal pores; ovary superior, unilocular; carpels 2 but appearing singular due to the early abortion of one carpel; style stout, curved; stigma recessed; ovules 2, pendulous from the top of the ovary, anatropous, bitegmic. Fruits globose, nut-like, spiny capsules with the thin pericarp splitting irregularly, 1-seeded; seed large, lacking endosperm; cotyledons orbicular, ventrally flattened. One genus with 18 species, primarily in warm arid and semiarid areas of North, Central, and South America, and sporadically in the West Indies. Vegetative Morphology. Krameria species range from small trees (to 6 m) to sprawling herbaceous perennials. The root system consists of the remnants of the original tap root, and a series of lateral, adventitious roots (Musselman 1975) that branch sparingly. Individual roots are flexible, covered with a thick, soft bark. The shoots of some shrubby species are stiff, forming thorns at the branch tips. In a few woody species, the stems can be lax. The herbaceous species are invariably prostrate, dying back to a woody caudex during the winter or in dry periods. Leaves are alternate, usually simple, and entire. They can be sessile or petiolate, range in shape from linear to ovate, and vary between 3 and 35 mm in length. One species has trifoliolate, petiolate leaves. Leaf surfaces in all species are vestitured with trichomes ranging from sparsely strigose to densely tomentose. Vestiture

is most pronounced on the young portions of the stems, with individual trichomes unicellular and thick-walled (Metcalfe and Chalk 1950). Some woody species loose their leaves during extremely dry periods. Vegetative Anatomy. All Krameria species examined to date are obligate semiparasites. Young woody stems have an epidermis with highly cutinized cell walls. The cork arises deep in the stem, sometimes even within the pericycle (Metcalfe and Chalk 1950). The phloem appears to lack lignified elements. The xylem forms a continuous cylinder with faint rays. Both the diameter of xylem elements and the amount of pith vary between species (Metcalfe and Chalk 1950). The seedlings do not produce root hairs (Cannon 1910), and haustorial attachment must occur within a few months of germination, or seedlings die (Simpson 1989). Haustoria are formed only by young, adventitious roots. Penetration of the haustoria appears to be shallow (Cannon 1910), with connections to the xylem only (Kuijt 1969). The vasculature of the haustoria consists of elongate, storied vessel elements (Musselman 1975). Stomates are present on both surfaces of the leaves. The outer epidermal walls and bases of the trichomes are cutinized. The leaves have three principal veins, each of which branches to form a network of veins supplying the entire leaf. The mesophyll includes scattered sclereids, and tanniferous material and crystals are common in unlignified cells. The xylem of the leaves lacks vessels and consists of tracheids overlain by a thin layer of poorly developed sieve tube elements (Sterling 1912; Metcalfe and Chalk 1950). Petiolar anatomy consists of a single, crescent-shaped (almost circular in some) vascular strand (Metcalfe and Chalk 1950). Inflorescence Structure. The flowers are borne singly in the axils of leaves, or in terminal racemes or panicles. Individual flowering stalks

Krameriaceae

consist of a combined peduncle-pedicel with a pair of transversal prophylls where the two join. The flowering stalk contains a single undissected vascular cylinder (Musselman 1975). The pedicel and bracts persist if the flower is shed. The lengths of the peduncle and pedicels vary between species. Flower Structure. Flowers are extremely modified, which led to almost 200 years of misunderstanding about the floral morphology and biology (Simpson 1982). It is now recognized that the flowers are not resupinate, and that the showy portions consist of the five (rarely four) free sepal lobes. The sepals have three principal veins, like the leaves. Only the upper surface, at least in K. lanceolata, bears stomata (Milby 1971). Two of the petals are modified into thick, orbicular to cuneate glands flanking, or slightly abaxial to, the ovary. Each of these small, fleshy structures is traversed by several veins (Milby 1971). The dorsal face of the glandular petals bears patches of secretory epidermal cells that secrete fatty oils under the cuticle. Once secreted, the oils are trapped until the cuticle is ruptured. The glandular cells can cover the dorsal petal surface or be restricted to the distal portion. The petaloid petals are small, strap-shaped or clawed, free or fused at the base, and form a flag inserted adaxially at the base the ovary. Each petal has a single vein (Milby 1971). All of the stamens are inserted on the base of the petaloid petals above the ovary. The veins of the sepals and petals are separated by a wide gap but, as suggested by the position of the stamens, those of the petals and stamens are close together (Milby 1971). In the common condition of four stamens, the stamens are didynamous, each supplied by a single vascular trace. The ovary is ovoid, densely vestitured and surmounted by a stout, glabrous style with a sunken stigma. The style and the stamens are curved and project outward from the plane of the flower. The flowers are nectar-less and fragrant. Fragrance appears to be concentrated in the glands, indicating that small amounts of volatile oils are dissolved in secreted lipids. The anthers have four locules that dehisce into a common, slightly conical terminal chamber through which the pollen is shed in a cylindrical mass. The ovary is bicarpellate, but early in ontogeny, the posterior carpel aborts. The abortive carpel has a vestigial locule, however, and a suture line demarks the boundary between the two, even in the mature ovary (Milby 1971). The fertile carpel bears two ovules, only one of which

209

ever forms a seed. The ovules are crassinucellate and bitegmic, with the micropyle formed by the inner integument alone (Verkerke 1985). Pollen Morphology. The pollen grains are shed as monads. Individual grains are isopolar, spheroidal, 26–38 µm in diameter, and striate with the striae perpendicular to the equatorial axis, tricolporate, triporate, or lalongate, or synorate (Fig. 72). The striae appear to be supported on stalks that penetrate a dense layer and then branch (Simpson and Skvarla 1981). The endexine is very thick. Karyology. Chromosome counts have been made for eight of the 18 species. All species have a haploid number of n = 6 (Turner 1958; Simpson 1989). Individual chromosomes are metacentric (Teppner 1984) and large, with those of K. secundiflora recorded to be 24.6 µm long (Lewis et al. 1962) and those of K. lappacea to be 10–14 µm long in metaphase (Teppner 1984). Pollination. All species of Krameria are pollinated by female solitary bees of the genus Centris (Apidae). These bees visit the flowers to collect oils secreted by the glandular petals. During oil collection, a female bee orients with the main axis of the flower, grasps the flag petals with her mandibles, straddles the stigma and anthers, and rubs her foreand midlegs over the glandular patches, rupturing

Fig. 72. Krameriaceae. Krameria lappacea, pollen grain, SEM ×2,400. (Photograph B.B. Simpson)

210

B.B. Simpson

the cuticle. The bee then backs off from the flower, and transfers the oil to dense patches of setae on the tarsi of the hind legs for transport to the nest. When landing on a flower, a female transfers pollen from a previously visited flower to the stigma, which is exerted slightly from the anthers. While collecting oils, pollen is extruded from the terminal pores and deposited on the ventral side of the bee’s head and at the juncture of the first pair of legs. Oils are used as a component of the larval food and may also be used in lining the walls of the individual nest cells. The bees do not actively collect Krameria pollen, but may carry combined loads of oils, Krameria pollen inadvertently collected, and pollen of other species to the nest. Sixteen species of Centris have been recorded visiting Krameria species, but there is no one-to-one specificity between Centris and Krameria, other than that resulting from limited geographical distribution of both partners. Likewise, Krameria-visiting Centris females can visit other genera for oil, nectar, and/or pollen. Non-oilcollecting species of bees have also been recorded visiting Krameria for pollen and for the collection of trichomes for nest materials (Simpson 1989). Fruit and Seed. Fruits are ovoid, 5–12 mm in diameter, and usually adorned with a mixture of spines and trichomes. The fruits are dry at maturity, the thin pericarp splitting irregularly and releasing the smooth, brown, slightly heart-shaped seed. The seed coat is formed by the inner and outer integuments, with a cuticular layer over the reduced inner integument (Verkerke 1985). The epidermal cells of the testa are rich in tannins. The mature seed consists of two large cotyledons and has no endosperm. There are four auricles at the junction of the cotyledons, which cover all but the tip of the radicle (Verkerke 1985). Many apparently mature fruits contain no seed. It is not clear whether this results from early abortion of a fertilized seed. Dispersal. Dispersal of Krameria fruits is by animals to which fruits adhere. Fruits of most species have spines with retrorse barbs that catch on feathers, fur, or clothing. If fruits are not pulled from the tree by a passing animal, they eventually fall to the ground. Over time, the pericarp splits and releases the seed, which can then be transported further by rain or wind. Reproductive Biology. The bisexual flowers of Krameria appear to be receptive while they are shedding pollen. Self-pollination is prevented to

some extent by the slight herkogamy. The extent of self-compatibility is unknown. One shrubby species (K. grayi) appears self-incompatible, and one herbaceous species (K. lanceolata) has been found to be self-compatible (Simpson 1989). Phytochemistry. There has been extensive work on the chemistry of Krameria because of its early use as a medicinal plant. The medicinally important compounds are tannins, principally those of the catechin type. In addition, N-methyl tyrosine and apiitol have been identified in leaf extracts (Simpson 1991). The former has been reported from Phorodendron and from rotting meat but otherwise appears uncommon in plants. In addition, neolignans and nor-neolignans have been documented in several species (Achenbach et al. 1987a, b, 1989). These compounds have been found to be effective in filtering ultraviolet radiation, prompting workers (Stahl and Ittel 1981) to suggest that the compounds might be effective in sun screen products. The floral oils of Krameria species have been shown to consist of free β-acetoxy fatty acids with carbon chain lengths of C16 to C20 (Simpson et al. 1977, 1978; Seigler et al. 1978). Affinities. Prior to 1960, Krameria was generally considered to be a member of Polygalaceae (de Candolle 1824; Bentham and Hooker 1862) or Fabaceae, placed in its own tribe (Taubert 1892). This latter placement, which prevailed during the first half of the 20th century, was based on the possession of trifoliolate leaves by one species of Krameria, and on the erroneous interpretation of the fruit as unicarpellate. However, cytological studies prompted Turner (1958) to re-segregate the genus into a monotypic family. Anatomical work by Milby (1971) strengthened this position. However, relationships of the family remained problematic. On the basis of serological studies (Busse-Jung 1979), Simpson (1989) suggested a relationship with Polygalaceae. By contrast, recent molecular data from rbcL sequences suggest that the sister group to Krameriaceae are Zyophyllaceae (Chase et al. 1993; Gadek et al. 1996; Savolainen, Fay et al. 2000), although this relationship does not appear to be close. Using three members of Zygophyllaceae (Guiaicum angustifolium, Kallostroemia parviflora, and Tribulus terrestris) as outgroups, Simpson et al. (2004) produced a phylogeny of the genus based on ITS DNA sequence data that

Krameriaceae

showed that there were two major clades in the genus, each with two subclades, all supported by one or more synapomorphies. One of the two major clades, characterized by rugose elaiophores, and fruits with spines that have one or two whorls of barbs at the tip, consists of two subclades. The first subclade contains two South American species and is defined by sepals borne perpendicular to the peduncle, tricolporate pollen, and spines of the fruit with two terminal whorls of barbs. The second subclade contains five North American species that share the characters of reflexed sepals, free, strap-shaped flag petals, triporate pollen with equatorially elongate pores, and fruits with spines that have a single apical whorl of barbs. The second major clade, characterized by connivent sepals and triporate pollen with broad, oval-shaped pores, also has two subclades. One of these subclades has five species in South America that share the character of elaiophores with striate dorsal surfaces. The second subclade contains six North American species characterized by elaiophores that have secretory areas restricted to the distal portion, and petaloid petals that are fused at the base and have cordate blades. Distribution and Habitats. Krameria species occur from Kansas in the USA southward across the USA southwest into Mexico, Central, and South America as far south as northern Chile and Argentina. One species also occurs sporadically in the West Indies. Eleven species occur in Mexico and four in eastern Brazil. Species are rarely sympatric, however, and if two co-occur, they generally differ in habit or blooming time. All species, except K. cytisoides and K. sonorae, are found in open grassy or arid habitats. Krameria cytisoides is found primarily in the short oak or oak-pine shrublands in the Sierra Madre Oriental of Mexico, but it also ranges into desert scrubland at lower elevations. Krameria sonorae occurs in the Sinoloan thornscrub and tropical deciduous forest of Sonora, Mexico. Most species occur at elevations below 1,500 m, but K. lappacea occurs in the Peruvian and Bolivian Andes at elevations up to 3,600 m above sea level. The phylogenetic study of Simpson et al. (2004) showed that each of the major clades contains a North American and a South American subclade. While it was not possible to determine on which continent the genus arose, it is obvious that two intercontinental dispersal events are required to explain the current distribution.

211

Fig. 73. Krameriaceae. Krameria grandiflora. A Habit. B Flowering branch. C Flower and flower buds. D Elaiophore. E Fruit. (Drawn by M.C. Ogorzaly; Simpson 1989)

Economic Importance. From the end of the 18th century until the beginning of the 20th century, Krameria was used medicinally in Europe and European North America externally as an astringent, eye wash, and oral styptic. Taken internally as a tea or decoction, it was used to induce menstruation, to cure excessive menstrual bleeding, as an abortifacient, for kidney problems, and to treat various cancers. Krameria species were used by traditional peoples of both North and South America, primarily for their styptic properties (Ruiz 1797) and as a dye (Felger and Moser 1985). Ruiz (1797), on the basis of a few experiments conducted in Peru, extolled the virtues of K. lappacea in Europe, which resulted in its incorporation into most European pharmacopoeias. During the 1970s, Krameria was suspected of causing esophageal cancer, which precipitated a series of studies by the U.S. National Institutes of Health (Dunham et al. 1974, O’Gara et al. 1974). Both its purported beneficial qualities and its presumed carcinogenic properties are now discounted. Its sole remaining uses are as a dye

212

B.B. Simpson

plant, and as an ingredient in dental and some cosmetic products (Simpson 1991). Only one genus: Krameria Loefling

Figs. 72, 73

Krameria Loefling, Iter hispanicum: 195 (1758).

Description as for family. Eighteen species, ranging across open habitats in the southwestern United States, Central America, tropical and subtropical South America, Hispaniola, and in the Greater and Lesser Antilles.

Selected Bibliography Achenbach, H., Gross, J, Dominguez, X.A., Cano, G., Star, J.V., Brussolo, L. d. C., Muñoz, F.S.G., López, L. 1987a. Lignans, neolignans, and nor-neolignans from Krameria cytisoides. Phytochemistry 26:1159–1166. Achenbach, H., Gross, J., Dominguez, X.A., Star, J.V., Salgado, F. 1987b. Ramosissin and other methoxylated nor-neolignans from Krameria ramosissima. Phytochemistry 26:2041–2043. Achenbach, H., Gross, J., Bauereiss, P., Dominguez, X.A., Vega, H.S., Star, J.V., Rombold, C. 1989. Nor-lignans and nor-neolignans from Krameria lanceolata. Phytochemistry 28:1959–1962. Bentham, G., Hooker, J.D. 1862. Polygaleae. Genera Plantarum 1, 1:134–140. London: Reeve. Busse-Jung, F. 1979. Phytoserologische Untersuchungen zur Frage der systematischen Stellung von Krameria triandra Ruiz et Pav. Dissertation, Christian-Albrechts University, Kiel, Germany. Candolle, A.P. de 1824. Krameria. Prodomus systematis naturalis regni vegetabilis 1:14. Paris: Treuttel and Würtz. Cannon, W.A. 1910. The root habits and parasitism of Krameria canescens Gray. Pages 5–24 in Macdougal, D.T., Cannon, W.A., The conditions of parasitism in plants. Publ. Carnegie Inst. Wash. 129:1–60. Chase, M.W. et al. 1993. See general references. Dunham, L.J., Sheets, R.H., Morton, J.F. 1974. Proliferation lesions in cheek pouch and esophagus of hamsters treated with plants from Curaçao. J. Natl Cancer Inst. 53:1259–1269. Felger, R.S., Moser, M.B. 1985. People of the desert and sea. Ethnobotany of the Seri Indians. Tucson: The University of Arizona Press. Gadek, P.A., Fernando, E.S., Quinn, C.J., Hoot, S.B., Terrazas T., Sheahan, M.C., Chase, M.W. 1996. Sapindales: molecular delimitation and infraordinal groups. Amer. J. Bot. 83:802–811. Kuijt, J. 1969. The biology of parasitic flowering plants. Berkeley, CA: University of California Press.

Lewis, W.H., Stripling, H.L., Ross, R.G. 1962. Chromosome numbers for some angiosperms of the southern United States and Mexico. Rhodora 64:147–161. Metcalfe, C.R., Chalk, L. 1950. See general references. Milby, T.H. 1971. Floral anatomy of Krameria lanceolata. Amer. J. Bot. 58:569–576. Musselman, L.J. 1975. Parasitism and haustorial structure in Krameria lanceolata (Krameriaceae). A preliminary study. Phytomorphology 25:416–422. O’Gara, R.W., Lee, C.W., Morton, J.F., Kapadia, G.J., Dunham, L.J. 1974. Sarcoma induced in rats by extracts of plants and by fractionated extracts of Krameria ixina. J. Natl Cancer Inst. 52:445–448. Ruiz, H. 1797. Memoria sobre la ratánhia. Acad. Nac. Med. (Madrid) 1:349–366. Savolainen, V., Fay, M.F. et al. 2000. See general references. Seigler, D., Simpson, B.B., Martin C., Neff, J.L. 1978. Free 3acetoxy fatty acids in floral glands of Krameria species. Phytochemistry 17:995–996. Simpson, B.B. 1982. Krameria (Krameriaceae) flowers: orientation and elaiophore morphology. Taxon 31:517– 528. Simpson, B.B. 1989. Krameriaceae. Flora Neotropica Monograph 49:1–109. New York Botanical Garden Press. Simpson, B.B. 1991. The past and present uses of rhatany (Krameria, Krameriaceae). Econ. Bot. 45:397–409. Simpson, B.B., Skvarla, J.J. 1981. Pollen morphology and ultrastructure of Krameria (Krameriaceae): utility in questions of intrafamilial and interfamilial classification. Amer. J. Bot. 68 277–294. Simpson, B.B., Neff, J.L., Seigler, D. 1977. Krameria, free fatty acids and oil-collecting bees. Nature 267:150–151. Simpson, B.B., Seigler, D.S., Neff, J.L. 1978. Lipids from the floral glands of Krameria. Biochem. Syst. Ecol. 7:193– 194. Simpson, B.B., Weeks, A., Helfgott, D.M., Larkin, L.L. 2004. Species relationships in Krameria (Krameriaceae) based on ITS sequences and morphology: implications for character utility and biogeography. Syst. Bot. 29:97–108. Stahl, E., Ittel, I. 1981. Neue lipophile Benzofuranderivate aus Ratanhiawurzeln. Pl. Med. 42:144–154. Sterling, C.M. 1912. Krameria canescens Gray. Kansas Univ. Sci. Bull. 6:363–372. Taubert, P. 1892. Leguminosae. II. 6. Caesalpinioideae-Kramerieae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, III, 3. Leipzig: W. Engelmann, pp. 166–168. Teppner, H. 1984. Karyologie von Krameria triandra (Krameriaceae). Mitteilungsbl. Kurzfassungen Beiträge, Botaniker-Tagung, 1–14 September, Wien, #0623. Turner, B.L. 1958. Chromosome numbers in the genus Krameria: evidence for familial status. Rhodora 60:101–106. Verkerke, W. 1985. Ovule ontogeny and seed coat development in Krameria Loefling (Krameriaceae). Beitr. Biol. Pflanzen 60:341–351.

Ledocarpaceae Ledocarpaceae Meyen, Reise 1:308 (1834). Vivianiaceae Klotzsch (1836). Rhynchothecaceae Endl. (1841).

M. Weigend

Shrubs, rarely subshrubs or perennial or annual herbs, 0.3–1.5(–4) m tall, stems erect or ascending, strongly branched, often differentiated into sometimes spinescent brachyblasts and dolichoblasts, stems tough, initially with white or brownish pith, terete, with greyish brown bark, underground stems occasionally present. Indumentum of simple, unicellular trichomes and uniseriate trichomes with a single-celled gland-tip, usually very dense on leaves, stems, calyx and ovary. Leaves evergreen or semi-deciduous, opposite or subopposite, rarely in whorls of three, shortly petiolate to sessile, petiole with clasping base, estipulate, lamina entire or pinnatifid to pinnate to trifoliolate, margin entire or serrate; interpetiolar line often present. Inflorescences terminal cymoids or pleiothyrsoids, with monochasial to asymmetrically dichasial paraclades, often reduced to 2–3 flowers, or a terminal flower only, frondose-bracteose, individual flowers of Balbisia subtended by prophylls. Flowers perfect, actinomorphic, pentamerous; sepals free or united in proximal half, imbricate with valvate tips, persistent in fruit; petals 5(4 or 0), free, with contort aestivation; stamens (4, 5, 4 + 4)5 + 5, usually obdiplostemonous and heterantherous, typically 5 long and 5 short; filaments sometimes with pair of basal appendages; gynoecium of 3–5 carpels; style single, very short, with 3–5 long stigmatic branches; ovary 3–5-lobed, with 1–20, pendulous, campylotropous ovules in each locule; placentation axile. Fruits septicidal or septifragous capsules with five 1–many-seeded locules; embryo straight or cochlear with spirally folded cotyledons; endosperm present, exotesta poorly developed or absent, occasionally mucilaginous. A family of four genera and about 18 species, mostly in Andean South America. Vegetative Morphology. Ledocarpaceae are exclusively or predominantly shrubby. The shoots are strongly branched, and the shrubs regenerate with long and relatively thick and large-leafed

dolichoblasts arising from the basal portion. In Rhynchotheca and some Viviania, some or most of the short lateral shoots turn into spines. In all shrubby species, the vegetative lateral axes have 1– several pairs of opposite, scale-like cataphylls, followed by progressively larger, regular foliage leaves. In Balbisia, most species have very short brachyblasts ( 20, connate at base; androgynophore subnul; stylodia 3–5, free; capsules 3-valved, oblong-ovoid. Two species, tropical West Africa. 17. Barteria Hook. f.

13. Paropsiopsis Engl. Paropsiopsis Engl., Bot. Jahrb. Syst. 14:391 (1891).

Fig. 97F

Smeathmannia Sol. ex R. Br., Trans. Linn. Soc. London 13:220 (1821).

Fig. 97G

Barteria Hook. f., J. Proc. Linn. Soc., Bot. 5:14; t. 2 (1860); Breteler, Adansonia III, 21:307–318 (1999), rev.

280

C. Feuillet and J.M. MacDougal

Shrubs or trees, in all but one species branches hollow and inhabited by black ants. Leaves alternate or subdistichous, subsessile or short-petiolate; stipules 0. Inflorescences axillary, sessile, 4–9-flowered, or flowers solitary; bracts numerous; flowers sessile; receptacle cupular; sepals 5; petals 5; corona in 2 series; nectar ring 0; stamens numerous, filaments connate at the base forming a tube around the ovary; androgynophore 0; style simple; fruit indehiscent, subglobose. Four species, Central Africa from Benin to Tanzania and Uganda, savanna, lowland and hill forest, and coastal region.

Selected Bibliography Ayensu, E.S., Stern, W.L. 1964. Systematic anatomy and ontogeny of the stem in Passifloraceae. Contr. U.S. Natl Herb. 34:45–73. Benson, W.W., Brown, K.S. Jr., Gilbert, L.E. 1976. Coevolution of plants and herbivores: passion flower butterflies. Evolution 29:659–680. Bernhard, A. 1999. Flower structure, development, and systematics in Passifloraceae and in Abatia (Flacourtiaceae). Intl J. Pl. Sci. 160:135–150. Cervi, A.C. 1997. Passifloraceae do Brasil. Estudo do gênero Passiflora L., subgênero Passiflora. Fontqueria 45:1–92. Chase, M.W. et al. 2002. See general references. Corner, E.J.H. 1976. See general references. Cusset, G. 1968. Les vrilles des Passifloracées. Bull. Soc. Bot. France 115:45–61. Dathan, A.S.R., Singh, D. 1973. Development and structure of seed in Tacsonia Juss. and Passiflora L. Proc. Indian Acad. Sci. B 77:5–18. Endress, P.K. 1994. Diversity and evolutionary biology of tropical flowers. Cambridge: Cambridge University Press. Escobar, L.K. 1988. 10: Passifloraceae. In: Pinto, P., Lozano, G. (eds) Flora de Colombia, 10. Bogotá: Universidad Nacional de Colombia, pp. 1–138. Feuillet, C. 2004. Passifloraceae. In: Smith, N.P., Mori, S.A., Henderson, A., Stevenson, D.W., Head, S.V. (eds) Flowering plants of the Neotropics. Princeton: Princeton University Press, pp. 286–287. Feuillet, C., MacDougal, J.M. 2004. A new infrageneric classification of Passiflora L. (Passifloraceae). Passiflora 13:34–38. García, M.T.A., Galati, B.G., Anton, A.M. 2002. Microsporogenesis, microgametogenesis and pollen morphology of Passiflora species (Passifloraceae). Bot. J. Linn. Soc. 139:383–394. Gilbert, L.E. 1971. Butterfly-plant coevolution: has Passiflora adenopoda won the selectional race with heliconiine butterflies? Science 172:585–586. Gilbert, L.E. 1975. Ecological consequences of a coevolved mutualism between butterflies and plants. In: Gilbert, L.E., Raven, P.H. (eds) Coevolution of animals and plants. Austin: University of Texas Press, pp. 210–240.

Hansen, A.K., Gilbert, L.E., Simpson, B.B., Downie, S.R., Cervi, A.C., Jansen, R.K. 2006. Phylogenetic relationships and chromosome number evolution in Passiflora. Syst. Bot. 31, 1:138–150. Harms, H. 1893. Über die Verwertung des anatomischen Baues für die Umgrenzung and Einteilung der Passifloraceae. Bot. Jahrb. Syst. 15:548–632, tab. 21. Harms, H. 1925. Passifloraceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 21. Leipzig: W. Engelmann, pp. 470–507. Hegnauer, R. 1969, 1990. See general references. Holm-Nielsen, L.B., Jørgensen, P.M., Lawesson, J.E. 1988. 126. Passifloraceae. In: Harling, G., Andersson, L. (eds) Flora of Ecuador 31. Copenhagen: Nordic J. Bot. Hutchinson, J. 1967. Passifloraceae. The genera of flowering plants, 2. Oxford: Clarendon Press, pp. 364–374. Huynh, K. 1972. Etude de l’arrangement du pollen dans la tétrade chez les angiospermes sur la base de données cytologiques. IV. Le genre Passiflora. Pollen Spores 14:51–60. Janzen, D.H. 1968. Reproductive behavior in the Passifloraceae and some of its pollinators in Central America. Behaviour 32:33–48. Johri, B.M. et al. 1002. See general references. Killip, E.P. 1938. The American species of Passifloraceae. Publ. Field Mus. Nat. Hist., Bot. 19:1–613. Kloos, A., Bouman, F. 1980. Case studies in aril development – Passiflora suberosa L. and Turnera ulmifolia L. Beitr. Biol. Pflanzen 55:49–66. Krosnick, S.E., Harris, E.M., Freudenstein, J.V. 2006. Patterns of anomalous floral development in the Asian Passiflora (subgenus Decaloba: supersection Disemma). Amer. J. Bot. 93:620–636. Lindman, C.A.M. 1906. Zur Kenntnis der Corona einiger Passifloren. In: Sernander, R., Svedelius, N., Norén, C.O. (eds) Botaniska Studier Tillägnade F.R. Kjellman. Uppsala: Almqvist & Wiksell, pp. 55–79. MacDougal, J.M. 1994. Revision of Passiflora subgenus Decaloba section Pseudodysosmia (Passifloraceae). Syst. Bot. Monogr. 41:1–146. Melo, N.F. de, Cervi, A.C., Guerra, M. 2001. Karyology and cytotaxonomy of the genus Passiflora L. (Passifloraceae). Pl. Syst. Evol. 226:69–84. Muschner, V.C., Lorenz, A.P., Cervi, A.C., Bonatto, S.L., Souza-Chies, T.T., Salzano, F.M., Freitas, L.B. 2003. A first phylogenetic analysis of Passiflora (Passifloraceae). Amer. J. Bot. 90:1229–1238. Pellegrin, F. 1952. Les Flacourtiacées du Gabon. Mém. Soc. Bot. France 1952:105–121. Perrier de La Bâthie, H. 1945. Flore de Madagascar et des Comores, Fam. 143, Passifloracées: 1–50. Paris: FirminDidot. Plisko, M.A. 1992. Passifloraceae. In: Takhtajan, A. (ed.) Anatomia seminum comparativa, tomus 4. Dicotyledones-Dilleniidae. St. Petersburg: Nauka, pp. 112–120. Presting, D. 1965. Zur Morphologie der Pollenkörner der Passifloraceen. Pollen Spores 7:193–247. Puri, V. 1947. Studies in floral anatomy. IV. Vascular anatomy of the flower of certain species of the Passifloraceae. Amer. J. Bot. 34:562–573. Puri, V. 1948. Studies in floral anatomy. V. On the structure and nature of the corona in certain species of the Passifloraceae. J. Indian Bot. Soc. 17:130–149.

Passifloraceae Sazima, M., Sazima, I. 1978. Bat pollination in the passion flower, Passiflora mucronata. Biotropica 10:100–109. Spencer, K.C. (ed.) 1988. Chemical mediation of evolution. San Diego: Academic Press. Spirlet, M. 1965. Utilisation taxonomique de grains de pollen de Passifloracées, I. Pollen Spores 7:249–301. Takhtajan, A. 1997. See general references. Thanikaimoni, G. 1986. Pollen apertures: form and function. In: Blackmore, S., Ferguson, I.K. (eds) Pollen and spores: form and function. London: Academic Press, pp. 119–136. Tillett, S.S. 1988. Passionis passifloris, II. Terminología. Ernstia 48:1–40. Ulmer, T., MacDougal, J.M. 2004. Passiflora: passionflowers of the world. Portland: Timber Press.

281

Wilde, W.J.J.O. de 1971a. A monograph of the genus Adenia Forssk. (Passifloraceae). Meded. Landbouwhogeschool Wageningen 71-18:1–281. Wilde, W.J.J.O. de 1971b. The systematic position of tribe Paropsieae, in particular the genus Ancistrothyrsus, and a key of the genera of Passifloraceae. Blumea 19:99– 104. Wilde, W.J.J.O. de 1972. The indigenous Old World passifloras. Blumea 20:227–250. Wilde, W.J.J.O. de 1973. Revision of Basananthe, formerly Tryphostemma (Passifloraceae). Blumea 21:327–356. Wilde, W.J.J.O. de 1974. The genera of tribe Passiflorae (Passifloraceae), with special reference to flower morphology. Blumea 22:37–50.

Penaeaceae Penaeaceae Guillemin, Dict. Class. Hist. Nat. 13:171 (1823). J. Schönenberger, E. Conti and F. Rutschmann1

Shrubs or shrublets (often ericoid), varying from procumbent to ascending or erect, sympodially branching at least in the adult stage; young branches glabrous, generally with 4 ridges ending in tooth- or peg-like processes on each side of the leaf bases. Leaves decussate, simple, entire (irregularly denticulate in Sonderothamnus), glabrous, linear to orbicular (subterete in Brachysiphon microphyllus), acuminate to retuse, sessile or shortly petiolate, more or less coriaceous and sclerophyllous; stipules rudimentary, more or less colleter-like. Inflorescences highly variable, indeterminate or determinate; terminal flowers preceded by two or more pairs of decussate bracts, the lateral flowers usually by transversal prophylls. Flowers sessile or pedicellate, bisexual, actinomorphic, 4-merous, obhaplostemonous, perigynos, apetalous; sepals free, petaloid, triangular to ovate, sometimes conspicuously carnose and reflexed at anthesis, simple-valvate or reduplicate-valvate (valvate with reflexed edges), persistent (together with hypanthium), inserted on the rim of a 5– 45 mm long, campanulate or broadly to narrowly cylindrical hypanthium; colour of hypanthium and calyx varying from white to yellow, pink, crimson or red; stamens as many as and alternating with sepals, free, inserted on the rim of the hypanthium, sometimes incurved in bud, basifixed, introrse, with longitudinal dehiscence; anthers bithecate, tetrasporangiate, with an expanded connective, sometimes versatile; thecae parallel or sometimes at an angle to each other; disc structures lacking but nectar secretion by epithelial and trichomatous glands; pistil 4-carpellate, syncarpous, superior, 4-locular with a single, terete, quadrangular or 4winged style; stigma terminal, capitate, and more or less 4-lobed or the stigmatic areas subapical and restricted to the angles formed by 4 sterile, commissural lobes or wings; locules with 2 or 4 ovules; when 2, ovules inserted more or less basally 1

Largely based on the work of the late Rolf Dahlgren.

and ascending; when 4, ovules insertion axile, 2 ascending and 2 pendant; or all 4 inserted more or less basally and ascending; ovules anatropous, bitegmic, crassinucellate. Fruit a loculicidal, smooth capsule; seeds ovoid, slightly compressed, dark brown to almost black when mature, with a glossy surface and a funicular, white elaiosome. A family with seven genera and 23 species, endemic to the southern and south-western parts of the Cape Province of South Africa. Vegetative Morphology. All species in this family are woody, evergreen perennials ranging from small, procumbent, much-branched shrublets to tall, erect, sparingly branched shrubs. The main stem is often thickened at its very base, sometimes forming a root-stock (ligno-tuber), as in Brachysiphon acutus. Branches are glabrous and have often distinct, paired ridges ending in short tips on each side of the leaf base. The leaves are opposite-decussate and often imbricate. Older branches are mostly leaf-less below, bearing numerous leaf-scars. The leaves are generally coriaceous, flat or longitudinally ridged, sometimes with thickened margins and more or less keeled abaxially. The leaf apex ranges from retuse to acuminate, bearing a tanniniferous gland (areola) in Sonderothamnus and sometimes in Saltera (Dahlgren 1968). On the leaf surface, only the midveins are distinct, sometimes poorly so, and only from the abaxial surface. The venation pattern is generally brochidodromus (Dickie and Gasson 1999). Stomata are anomocytic and the leaves are hypostomatous, amphistomatous, or sometimes intermediate. Epicuticular wax and hairs are usually absent or sparse. Stipules are minute, each divided into a row of subulate or hair-like multicellular, often reddish-brown, secretory structures (colleter-like) located in the leaf axil (Weberling 1963). Vegetative Anatomy. As in most Myrtales, Penaeaceae have internal phloem (bicollateral bun-

Penaeaceae

dles) and vestured pits. In most wood anatomical features reviewed by van Vliet and Baas (1984), Penaeaceae stand out as rather unspecialized, compared to other members of Myrtales (Dahlgren and Van Wyk 1988). According to Carlquist and Debuhr (1977), vessels are mostly solitary and relatively uniform in the family. Vessel-elements are not notably thick-walled and have simple, bordered perforation-plates. Exceptionally wide borders were observed on perforation-plates in the roots of Saltera sarcocolla. Lateral walls facing other vessels or tracheids bear alternate pits; when facing rays, the pits are likewise alternate or occasionally opposite. Pit vesturing is rather conspicuous in some species such as Brachysiphon acutus, less so in others, such as Penaea cneorum. Tracheids in the form of imperforate elements with pit apertures, which are fully bordered, are common in Penaeaceae. The only exception seems to be Endonema lateriflora, in which the pit apertures are slightly longer than the diameter of the pit cavity. These imperforate elements would therefore qualify as fibre-tracheids. Uniseriate rays predominate over multiseriate rays in Penaeaceae as a whole. In stems, multiseriate rays are rarely more than three cells in width, and biseriate rays are by far more common than multiseriate ones, which is well in accordance with what is known from other myrtalean families. In most species, there is a predominance of upright over procumbent cells. Axial parenchyma is scanty and diffuse in distribution in the family. In all examined species, axial parenchyma strands are composed of two to four, mostly three, cells. Growth rings are generally indistinct in Penaeaceae. Crystals in the wood are relatively rare in the family. The most notable ones are found in Brachysiphon acutus where a few axial parenchyma cells are subdivided into a row of at least ten cuboidal, crystal-bearing cells, each of which contains numerous crystals. These crystalliferous strands are wider than, but about as long as the tracheids. Dark-staining, amorphous deposits are present in all examined species. These may be infrequent, as in Stylapterus fruticulosus, or abundant, as in the root-stock of Saltera sarcocolla. Such deposits are primarily found in the ray cells and the axial parenchyma, but in some cases spread into the vessels and even into the tracheids. The nature of these deposits has to date not been identified. The periderm is formed by outer layers of the pericycle and is distinctly stratified (Supprian 1894), thick-walled and lignified. van Tieghem

283

(1893) found isodiametric, sclerotic parenchyma cells in the pith and cortex of Penaea acutifolia. Leaf anatomical characters are variable and homoplasious in Penaeaceae (Dahlgren 1968; Dickie and Gasson 1999). Epidermal cells are of similar size and shape on both surfaces, mostly more or less as tall as broad. A hypodermis is absent and the mesophyll is bifacial or isobilateral; the palisade is one- or two-layered. Veins are embedded, i.e. surrounded by parenchymatous bundle sheaths. The midrib bundle is circular or slightly flattened, and surrounded by thick-walled parenchyma and often by collenchyma. Along the leaf margin, the cuticle is relatively thick and epidermal cells tend to be somewhat papillate. Druses (crystal-clusters) are found frequently in subepidermal layers and in the mesophyll (Keating 1984). Idioblasts, in the form of branched, filiform sclereids and/or branched tracheoidal cells, are common (see also Rao 1965). Inflorescences. Inflorescences vary considerably in Penaeaceae (Dahlgren 1967a, b, c, 1968, 1971). Weberling (1988) considered a thyrsoid (a thyrse with terminal flower), as present in Sonderothamnus petraeus and S. speciosus, to be the basic pattern. In the majority of the taxa, the cymose, lateral paracladia (triads) are reduced to their terminal flower. The thyrsoid is thus converted to a stachyoid as, for instance, in Saltera sarcocolla. The inflorescences of Brachysiphon rupestris, B. mundii and B. microphyllus have a terminal flower whereas B. fucatus and B. acutus have indeterminate spikes, in which the apex ends in some scale-like leaves or as a dry tip respectively. In Penaea, the inflorescence is most often spicate. A terminal flower is, however, not uncommon in P. mucronata, P. cneorum and P. acutifolia. P. dahlgrenii is described to have a complex synflorescence, in which a terminal flower is always present (Rourke and McDonald 1989). In Stylapterus, the inflorescence is usually a spike-like raceme with a degenerated, dry tip. However, a terminal flower is often present in S. fruticulosus and S. ericifolius. In Glischrocolla, the inflorescence is a compact panicle or raceme which mostly bears a terminal flower, but this may drop at an early stage. A special case in the family is the genus Endonema. In both species, the flowers are borne laterally on young branches which continue vegetative growth, and each flower is subtended by two or three pairs of decussate bracts. Floral bracts are generally similar to, but often somewhat larger than foliage leaves. Prophylls

284

J. Schönenberger, E. Conti and F. Rutschmann

are often narrower than these and often are pale and more or less bracteose. Terminal flowers are usually subtended by two prophylls and one or two pairs of decussate bracts, whereas lateral flowers are subtended by a single pair of prophylls only (Fig. 99C). Floral Morphology and Anatomy. The interpretation of floral organization has been a matter of debate in the past (summarized in Schönenberger and Conti 2003). The perianth has been interpreted as either being apetalous, i.e. the flowers as being obhaplostemonous or as consisting of petals only, i.e. the flowers as being haplostemonous. In a combined phylogenetic and comparative morphological analysis including Penaeaceae and closely related Oliniaceae and Rhynchocalycaceae, Schönenberger and Conti (2003) were able to show that the flowers of Penaeaceae are most parsimoniously interpreted to have an obhaplostemonous organization, i.e. the perianth organs of Penaeaceae representing sepals rather than petals. The respective homology of the perianth organs among these three families could be further supported by congruent patterns of floral development and structural similarities at the anatomical and histological level. This interpretation also fits well with the generally small petals and sometimes even apetalous flowers of many other myrtalean taxa. Sepal aestivation is simple-valvate in Penaea and Stylapterus. The genus Brachysiphon is not uniform for this character; while B. microphyllus is simple-valvate, the other four species are reduplicative-valvate – a character-state they share with the remaining four genera. Another interesting feature in Penaeaceae and many other myrtalean families is whether the stamens are inflexed or erect in bud stage. Incurved stamens are found in both species of Endonema, and this feature has been regarded as synapomorphic for this genus. However, incurved stamens are also present in Brachysiphon acutus and B. mundii (J.S., pers. obs.). Endonema apparently is sister to all other Penaeaceae (see below) and, since incurved stamens are also present in Oliniaceae, Rhynchocalycaceae and Crypteroniaceae, it seems likely that inflexed stamens represent the ancestral condition in the family. The anther connective is usually much expanded and thickly laminar. The mostly wellseparated pollen sacs are positioned ventrally and open introrsely. In Penaea and Stylapterus, the pollen sacs are generally much shorter than the

Fig. 99. Penaeaceae. Penaea dahlgrenii. A Flowering branchlet. B Flower, side view. C Flower with subtending bracts, seen from above. D Stamen with short pollen sacs. E Gynoecium with winged style and with longitudinally sectioned ovary to show ascending ovules. F Seed with funicular elaiosome. (Rourke and McDonald 1989)

connective, and are located in the lower half of the anther (Fig. 99D). Style and stigma of Penaeaceae also display interesting morphological variations. In most genera, the style is slender and terete and the stigma is terminal and capitate, often weakly four-lobed. In Penaea and Stylapterus, however, the style is stout and bears four longitudinal, commissural wings (Penaea, Fig. 99E) or ridges (Stylapterus) running from the ovary to the truncate style apex. The stigma of these two genera is divided into four subapical stigmatic areas in the corners of the four stylar wings or ridges. In the intact flower, the wings/ridges interlock with the cleft between the two thecae of the stamens, which are positioned in the same radii, thereby forming four separate entrances to the floral centre. Flowers are often pro-

Penaeaceae

togynous, as in Brachysiphon rupestris, B. acutus and Sonderothamnus petraeus (Louw 1996). Most species of Penaeaceae have two (or four, in Saltera) ovules per carpel, and all ovules are inserted basally in the locule, i.e. the ovules are ascending. In Endonema and Glischrocolla (for the latter genus, see also Rao and Dahlgren 1968), however, there are two ascending and two pendant ovules, all of which are inserted in the middle part of the locule (axially). Such an ovule configuration seems occasionally also to be present in Brachysiphon rupestris (Phillips 1926, 1951). Information about the floral anatomy and histology of Penaeaceae is scarce. A description of the vascular anatomy of the flowers of Glischrocolla formosa is given by Rao and Dahlgren (1968), and Schönenberger and Conti (2003) reported the presence of oxalate druses in the flowers of Endonema retzioides. A floral feature which is currently not well understood and has to date not been studied is nectar production. General floral features clearly indicate insect pollination, and nectar is present in the hypanthium around the base of the ovary. Especially in large-flowered taxa such as Endonema and Saltera, nectar is often copious (J.S., pers. obs.). A nectary-disc is not present in any of the species. A preliminary comparative study of floral structure in Penaeaceae has revealed tightly packed glandular hairs and/or stomata, lining the lower part of the inner surface of the hypanthium, and transverse sections also show underlying secretory tissue. Hence, in Penaeaceae, nectar is apparently produced in the lower part of the hypanthium by epithelial and/or trichomatous nectary glands. Embryology. The pollen sac walls prior to maturation comprise five layers, i.e. an epidermis and endothecium, two middle layers, and a tapetum (investigated in Penaea mucronata and Saltera sarcocolla; Tobe and Raven 1984). The tapetum is glandular and its cells become two-nucleate before they degenerate. The two middle layers collapse, and the endothecium is ephemeral whereas the epidermis enlarges, its cells becoming papillate. No fibrous thickenings develop in the cells of the pollen sac walls. The septum between the two pollen sacs of a theca is completely disintegrated at maturity. Meiosis of the microspore mother cells is accompanied by simultaneous cytokinesis, and the resulting microspore tetrads are usually tetrahedral and occasionally decussate. Pollen grains are two-celled at the time of shedding.

285

According to Stephen’s classical study (1909), the ovules are anatropous, crassinucellate and bitegmic, each integument being two cell layers thick. The micropyle is formed by both integuments, the outer one being longer than the inner one. Neither integument is vascularized (Tobe and Raven 1984). The archesporium consists of a single cell (the megaspore mother cell). Meiosis and two subsequent nuclear divisions result in a tetrasporic embryo sac. The 16 nuclei are organized into four distinct groups of four, usually lying crosswise, with one nucleus each on the micropylar and on the chalazal ends, and the remaining two opposite on the sides. Within each group, three of the four nuclei become enclosed by cell walls and the free nuclei – one from each group – migrate to the centre of the embryo sac, where they gradually fuse to form the primary tetraploid endosperm nucleus. This unique tetrasporic 16-nucleate type of embryo sac formation is usually referred to as the Penaea type. The mature embryo sac contains four peripheral groups of cells, each group more or less resembling an egg-apparatus. Two cells corresponding to synergids in each egg-apparatus are irregular in form, and antipodal cells are not present (Tobe and Raven 1984). Fertilization and subsequent embryo-formation usually occur in the apical cell group. However, Stephens (1909) observed several cases in which embryos developed laterally in the embryo sac. After fertilization, the embryo sac enlarges at the expense of the nucellus, which is completely consumed during seed development. Endosperm formation is initially nuclear, and embryogeny conforms to the Onagrad type (Tobe and Raven 1984) and not to the Asterad type, as reported in earlier literature. Endosperm haustoria develop basally. The embryo is elongate, straight, with a massive hypocotyl and tiny cotyledons. A suspensor is not present in any stage of embryo development, i.e. the earliest stages of embryo development are spherical. Storage is restricted largely to the hypocotyl, which consumes most of the endosperm during seed maturation. The radicle of the embryo is thick and lacks a root cap (but see Tobe and Raven 1984). Pollen Structure. Erdtman (1952) and Patel et al. (1984) found a great variation in number and length of apertures, position of endoapertures, and surface structure. Pollen grains are tri-, tetra- or pentacolporate (Patel et al. 1984). Three apertures prevail in Endonema, Saltera, Sonderothamnus and Brachysiphon, while there

286


are mostly four or five in Stylapterus and Penaea, and generally five in Glischrocolla. Hexacolporate pollen was occasionally found in Saltera. Pollen is heterocolpate with isomerous pseudocolpi (named colpoid grooves by Erdtman 1952) or intercolpar concavities (in Saltera and Glischrocolla) alternating with the colpi. Such pseudocolpi are also characteristic of other families in Myrtales such as Lythraceae, Oliniaceae and Melastomataceae. Pollen grains are radially symmetrical, usually isopolar, prolate-spheroidal to subprolate in lateral view, and circular to hexagonal (or circular to octagonal in polar view). The surface is psilate (sometimes punctuate) or rugulate (in Endonema). Endoapertures are located either on the equator or on one polar face. In Penaea and Stylapterus, endoapertures are circular, while they are lalongate-elliptic with two lateral extensions in Endonema and Brachysiphon. In Sonderothamnus and Saltera, the endoapertures are slightly elliptic-lalongate. In Sonderothamnus petraeus, the colpus membrane often persists as a horizontal bar over the open endoapertures. Round opercula are present in Saltera, Stylapterus, Penaea cneorum and Brachysiphon fucatus. Approximate size of the pollen grains is 35–60 × 25–45 µm. The tectum between the colpi, or the pseudocolpi, is generally thick and without perforations in all taxa except for Glischrocolla, and a thin infratectal granular layer is present in all taxa other than Penaea. The foot-layer is also prominent, and usually is thicker than the tectum. Columellae are thick, short and irregular, and often surrounded by the infratectal granular layer. The endexine is thick and granular near the endoaperture. Towards the colpi and pseudocolpi, the endexine increases in thickness while the foot-layer and tectum decrease. Fruit and Seed. The fruit is a firm, often hard capsule, which remains enclosed by the persistent hypanthium. Capsule dehiscence is loculicidal, the carpel walls splitting in the upper half but remaining connate below. Often, only a single seed per locule develops (Gilg 1894). The seeds are longellipsoidal, generally dark brown to almost black, and lack endosperm. The seed surface is rather smooth and glossy, with a finely reticulate pattern. The mature seed coat consists of a two-layered testa as well as a two-layered tegmen (Tobe and Raven 1984, only Penaea mucronata and Saltera sarcocolla studied). Penaea mucronata has an exotestal seed, in which the exotesta is the principal component of the seed coat, whereas the endotesta is

more or less collapsed and represented primarily by a layer of crystals. In contrast, Saltera sarcocolla has endotestal seeds, in which the endotesta is the principal component of the seed coat and the exotesta becomes more or less crushed. The funiculus develops into a white elaiosome. The hilum is rounded, with a more or less prominent annular margin. The raphe is extrorse and forms a narrow ridge along the seed. Karyology. Chromosome numbers have been counted for Penaea mucronata, P. cneorum and Brachysiphon rupestris, all having 2n = 20, and for Saltera sarcocolla, which has 2n = ∼ 40 (Dahlgren 1968, 1971), suggesting a basic number of x = 10. Reproductive Biology, Pollination, and Dispersal. It is probable that allogamy is the normal mode of fertilization in the family, as there is sometimes great variation in the populations of, for example, Penaea and Saltera. However, in several species the populations apparently consist of only few individuals (e.g. Brachysiphon rupestris), and the appearance of the plants is so characteristic of a locality that the occurrence of autogamy should not be entirely excluded. Few reliable observations have been made on pollination in the family. Endonema and Glischrocolla share flowers which are relatively large, tubular and brightly coloured. E. retzioides has bright red flowers, whereas those of E. lateriflora are bright yellow and those of Glischrocolla formosa are described as “yellow flushed with carmine” (Dahlgren 1967b). Size, shape, colouring of the flowers of these three species suggest bird-pollination, but there are no observations to confirm this. Scott-Elliot (1890) observed that inflorescences of Saltera sarcocolla are often visited by sunbirds such as Nectarinia chalibea. Shape and size of the flowers of Saltera make bird-pollination likely but their colour – pink – argues against this. Marloth (1925) reported that Nectarinia olivacea (= Cinnyris olivaceus) visits S. sarcocolla but, considering the distribution of this bird species, this statement seems dubious. The relatively small-flowered members of Sonderothamnus, Brachysiphon and, in particular, Stylapterus and Penaea are most likely all insect-pollinated. Longproboscid flies were observed on Sonderothamnus petraeus (Whitehead et al. 1987) and Brachysiphon acutus (Louw 1996). Marloth (1925) reported a hairy beetle (Anisonyx lynx) to be a regular visitor of Penaea mucronata. Clearly, new studies on the pollination of Penaeaceae are needed.

Penaeaceae

Seeds of Penaeaceae possess elaiosomes, and ant-dispersal has been observed in the field in Brachysiphon (Louw 1996) as well as Endonema, Penaea and Saltera (Bond and Slingsby 1983), and is reported as likely to occur in Stylapterus (Bond and Slingsby 1983). Phytochemistry. In contrast to many other myrtalean families, aluminium accumulation was found to be absent in Penaeaceae, as is the case in Oliniaceae and Alzateaceae but not Rhynchocalycaceae (Jansen et al. 2002). Hegnauer (1969) reported the presence of tannins. Subdivisions and Relationships Within the Family. The latest taxonomic treatment of Penaeaceae recognized seven genera, without any further subdivision of the family (Dahlgren 1967a, b, c, 1968, 1971). Since Dahlgren’s work, two new species have been described, Penaea dahlgrenii (Rourke and McDonald 1989) and Brachysiphon microphyllus (Rourke 1995). The latter author stated that these new species are not easily assigned to any particular genus, emphasizing the lack of clear-cut boundaries between genera. It seems therefore not surprising that the results of a recent molecular phylogenetic study based on chloroplast sequences partially contradict earlier generic circumscriptions (Schönenberger and Conti 2003). This study suggests that at least some of Dahlgren’s genera, specifically Brachysiphon and Stylapterus, are not monophyletic. The genus Endonema appears to be sister to the rest of the family. The next split in the phylogeny is between a clade containing the monotypic genus Glischrocolla plus Brachysiphon rupestris and the remainder of the family. Sonderothamnus, Sarcocolla and Brachysiphon mundii form a well-supported clade but its exact position in the phylogeny remains unresolved. The same is true for the clade uniting Brachysiphon mundii and Stylapterus micranthus. The genus Penaea sensu Dahlgren (1971) appears monophyletic but its exact position in the family remains unknown. The more recently described Penaea dahlgrenii (Rourke and McDonald 1989) is resolved as sister to Stylapterus ericoides, but only with low support. Definitive taxonomic adjustments within the family will have to await results based on the analysis of additional molecular, preferably nuclear markers, as well as detailed studies of floral morphology. For the time being, we here follow Dahlgren’s taxonomic treatment (Dahlgren 1967a, b, c, 1968, 1971).

287

Affinities. In the past, Penaeaceae have been placed either in Myrtales or close to Thymelaeaceae (Gilg 1894; Supprian 1894), the latter sometimes also included in Myrtales (Cronquist 1981). Subsequently, authors agreed on the placement of Penaeaceae in Myrtales and the exclusion of Thymelaeaceae from this order (Dahlgren and Thorne 1984; Johnson and Briggs 1984; Takhtajan 1997). Recent molecular studies clearly support Penaeaceae as part of Myrtales (Conti et al. 1996; Savolainen, Fay et al. 2000). Within Myrtales, both non-molecular (Johnson and Briggs 1984) and molecular (Conti et al. 1997; Clausing and Renner 2001) analyses identified a clade comprising four families with a Western Gondwanan distribution: the South African Penaeaceae and Rhynchocalycaceae, the South and East African Oliniaceae, and the Central and South American Alzateaceae. Molecular phylogenetic analyses suggest that the monotypic New World Alzateaceae are sister to the three African families and, albeit with weak support, that the monotypic Rhynchocalycaceae are sister to Penaeaceae/Oliniaceae (Schönenberger and Conti 2003). This Western Gondwanan clade is strongly supported as sister to a fifth taxon, the Southeast Asian Crypteroniaceae (Clausing and Renner 2001; Conti et al. 2002; Rutschmann et al. 2004). Distribution and Habitats. Penaeaceae are restricted to the southern and south-western parts of the Cape Province in South Africa; they do not occur further east than Port Elizabeth (Penaea) and not beyond the Worcester District in the northwest (Stylapterus). The genera are confined to the Cape ‘fynbos’ or shrub macchia but, within this vegetation type, they occur in a wide range of habitats. Most species grow on mountain slopes, some in rock crevices (e.g. Sonderothamnus petraeus) or other rocky habitats. Penaea mucronata is a common constituent of normal, low, sandstone fynbos whereas Stylapterus fruticulosus grows in sand. Generally, the substrate is sand weathered from the Table Mountain Series. Brachysiphon mundii grows on limestone rocks and cliffs.

Key to the Genera 1. Stigma subapical, restricted to angles between extended commissural lobes; pollen sacs shorter than half of the total connective length 2

288


– Stigma terminal, capitate or slightly four-lobed; pollen sacs longer than half of the total connective length 3 2. Style with 4 prominent, longitudinal, commissural wings 7. Penaea – Style with 4 or 8 longitudinal ridges 6. Stylapterus 3. Ovules 4 in each locule, 2 ascending and 2 pendulous; floral tube 20–35 mm long 4 – Ovules 2 or 4 in each locule, all ascending (rarely, 2 ascending and 2 pendulous in Brachysiphon rupestris); floral tube less than 14 mm long (except for Saltera, where it is 19–45 mm) 5 4. Flowers in compact, terminal clusters; each flower subtended by a single pair of linear prophylls; pollen grains 5-colporate 2. Glischrocolla – Flowers solitary and lateral in leaf axils; each flower subtended by two prophylls and one or two pairs of circular to lanceolate empty bracts; pollen grains 3colporate 1. Endonema 5. Bracts and prophylls with entire, even margins without apical gland; bracts narrower than the vegetative leaves 5. Brachysiphon – Bracts and prophylls with margins partly denticulate to fimbriate, generally with apical gland; bracts broader than vegetative leaves 6 6. Free parts of filaments as long as the connective body; each locule with 4 ovules; vegetative leaves sometimes lacking apical gland 4. Saltera – Free parts of filaments much shorter than the connective body; each locule with 2 ovules; vegetative leaves always with apical gland 3. Sonderothamnus

2. Glischrocolla A. DC. Glischrocolla A. DC. in DC., Prodr. 14:490 (1856); Dahlgren, Bot. Notiser 120:57–68 (1967).

Shrubs or shrublets, erect or ascending; internodes of young branches 4-ridged. Leaves sessile, rhombic-ovate, with prominent midrib on lower surface and pale. Flowers in compact, terminal racemes; lower bracts foliaceous, upper narrow; prophylls lanceolate to linear; bracts and prophylls intensively purple or carmine; flowers relatively large with a distinct pedicel; hypanthium narrowly cylindrical, yellow in bud, carmine at anthesis; sepal lobes reduplicative-valvate, rather carnose, much shorter than hypanthium, cream to yellow, red at the base of the outer side; stamens erect in bud; anthers longer than filaments, exserted from the hypanthium at anthesis; thecae with membranous margin; pollen sacs almost as long as the connective body; ovary locules with 2 erect and 2 pendulous ovules; style terete, slender, as long as or longer than hypanthium; stigma terminal, capitate and obscurely 4-lobed. One very rare species, G. formosa (Thunb.) R. Dahlgren, in the northern part of the Hottentots Holland Mountains, Western Cape, at altitudes of 1,200 to 1,400 m.

Genera of Penaeaceae

3. Sonderothamnus R. Dahlgren

1. Endonema A. Juss.

Sonderothamnus R. Dahlgren, Opera Bot. 18:5–72 (1968). Sarcocolla Kunth (1830), in part. Brachysiphon A. Juss. (1846), in part.

Endonema A. Juss., Ann. Sci. Nat. Bot. III, 6:15–27 (1846); Dahlgren, Bot. Notiser 120:69–83 (1967).

Shrubs or shrublets, low and ascending or erect; internodes of young branches 4-ridged. Leaves sessile, coriaceous, rather closely set, ovate-elliptic in E. lateriflora Gilg, linear in E. retzioides Sond. Flowers solitary in axils of upper leaves, relatively large with a distinct pedicel, subtended by 2 prophylls and 1 or 2 pairs of decussate bracts; hypanthium tubular-cylindrical; sepal lobes reduplicative-valvate, carnose, much shorter than hypanthium, yellow (sometimes slightly reddish) in E. lateriflora, bright red in E. retzioides; stamens incurved in bud; filaments flattened with broad base; anthers about as long as filaments, versatile, and exserted from the tube at anthesis; pollen sacs almost as long as the connective body; ovary angled, with 2 erect and 2 pendulous ovules in each locule; style terete, as long as or longer than hypanthium tube; stigma terminal, capitate and obscurely 4-lobed. Two species in the Riversonderend Mountains, Western Cape.

Shrublets, erect or ascending, sparingly branched; branches thickened at internodes; internodes 4ridged. Leaves imbricate, obovate to elliptic, obtuse, entire or at least the upper ones minutely denticulate to fimbriate, with dark apical gland. Flowers in thyrsoids, with small lateral cymes; bracts and prophylls with partly fimbriate and hyaline margins, with apical gland; lower bracts larger than vegetative leaves; hypanthium narrowly cylindrical, 7–12 mm long, as the sepal lobes purple or partly rose; sepal lobes reduplicative-valvate, about half as long as hypanthium; stamens erect in bud; filaments much shorter than anthers; anthers only partly exserted from the hypanthium at anthesis; pollen sacs almost as long as the connective body; ovary locules each with 2 ascending ovules; style terete or slightly angular; stigma terminal, capitate, relatively large and slightly quadrangular. Two species, S. petraeus (Barker) R. Dahlgren, Hottentots Holland Mountains to Kleinmond; S. speciosus (Sond.) R. Dahlgren on Hermanus Mountain, the

Penaeaceae

Kleinrivier Mountains and Babilonstoring, Western Cape. 4. Saltera Bullock Saltera Bullock, Kew Bull. 13:109–110 (1959); Dahlgren, Opera Bot. 18:5–72 (1968). Penaea L. (1753), in part. Sarcocolla Kunth (1830), in part.

Erect or ascending, sparingly branched shrublet or shrub; internodes of young branches quadrangular, lowly 4-ridged; nodes with conical, glandular tooth on each side of leaf base. Leaves imbricate, entire, coriaceous, obovate, rhombic or circular, with or without apical gland. Flowers sessile, in a compact, head-like inflorescence with a terminal and 2–6 lateral flowers; lower bracts larger than vegetative leaves, with denticulate-fimbriate margins, with or without apical gland and more or less covered by a sticky secretion; lateral flowers with linear or spathulate prophylls with fimbriate margins; hypanthium tubular-cylindrical, 19–45 mm long, equally as sepals rose or purple, rarely white; sepal lobes about 1/3 as long as the tube; stamens erect in bud; filaments linear, as long as anthers; anthers exserted from the tube at anthesis; pollen sacs almost as long as the connective body; ovary with 4 ascending ovules in each locule; style slender; stigma terminal, relatively large, capitate, slightly quadrangular. x = 10. One species, S. sarcocolla (L.) Bullock, south-western parts of the Western Cape Province. 5. Brachysiphon A. Juss. Brachysiphon A. Juss., Ann. Sci. Nat. Bot. III, 6:15–27 (1846); Dahlgren, Opera Bot. 18:5–72 (1968); Rourke, Nordic J. Bot. 15:63–66 (1995).

Shrubs or shrublets, decumbent to erect; internodes of young branches sometimes minutely papillate and with 4-ridges ending in short indistinct tips. Leaves coriaceous, entire, oblanceolate, obovate or rhombic-elliptic (subterete in B. microphyllus J.P. Rourke), without apical gland. Flowers in thyrses or racemes; bracts foliaceous, as large as or more often smaller than vegetative leaves; prophylls usually narrow, often hyaline, with entire margin; hypanthium narrowly cylindrical to campanulate, 5–14 mm long and, similarly to the sepals, dark red, purple to pinkish white; sepal lobes reduplicative-valvate (simple-valvate in B. microphyllus); stamens incurved or erect in bud; pollen sacs almost as long as the connective

289

body; ovary with 2 ascending ovules in each locule (B. rupestris rarely with 2 ascending and 2 pendulous ovules); style terete or slightly angular; stigma relatively small, terminal, capitate, more or less distinctly quadrangular. x = 10. Five species, B. microphyllus in the arid mountain ranges of the central southern Cape, the other species in moister habitats of the south-western part of the Western Cape Province; B. mundii Sond. on limestone. 6. Stylapterus A. Juss. Stylapterus A. Juss., Ann. Sci. Nat. Bot. III, 6:15–27 (1846); Dahlgren, Opera Bot. 15:3–40 (1967).

Shrubs or shrublets, erect or occasionally procumbent to ascending; internodes of young branches often 4-angled and with 4 ridges ending sometimes in a short glandular tooth on each side of the leaf bases on the following node. Leaves sessile or sometimes shortly petiolate, entire, linear to ovate or oblanceolate, often reduced in size towards tips of branches. Flowers usually in spike-like racemes with degenerated and dry tip (terminal flower often present in S. fruticulosus A. Juss. and S. ericifolius (A. Juss.) R. Dahlgren); bract foliaceous. Flowers with a short, quadrangular or rectangular pedicel in cross-section; hypanthium campanulate or tubular-cylindrical, 3–6 mm long and, similarly to the sepals, almost white, yellow or pinkish, often becoming purplish after anthesis; sepal lobes simple-valvate, broadly triangular, often carnose at apex with keeled adaxial side; stamens erect in bud; anthers longer than filaments, only partly exserted from hypanthium; pollen sacs much shorter than connective body; ovary with 2 ascending ovules in each locule; style columnar, with 4 or 8 longitudinal ridges; stigmatic areas subapical, located between the 4 flat, commissural lobes present on the upper part of the style. Eight species, most of very limited distribution in the south-western part of the Western Cape Province, on rocky wet sandstone slopes, sandy flats and stream banks. 7. Penaea L.

Fig. 99

Penaea L., Sp. Pl.: 111 (1753); Dahlgren, Opera Bot. 29:5–58 (1971); Rourke & McDonald, S. African J. Bot. 55:400–404 (1989).

Erect shrubs or shrublets; internodes of young branches with 4 ridges ending in small, tooth-like tips on each side of the leaf base on following node. Leaves sessile, usually imbricate. Flowers lateral in foliaceous bracts, arranged in compact, erect head-

290


like spikes, sometimes with a terminal flower (consistently present in P. dahlgrenii J.P. Rourke); bracts usually much wider than vegetative leaves, red or purplish in P. mucronata L., white in P. dahlgrenii; terminal flowers with 1 or 2 pairs of decussate bracts; lateral flowers with prophylls. Flowers with short pedicel; hypanthium campanulate or tubular-cylindrical, 4–7 mm long and, similarly to the sepals, white and flushed-carmine (P. dahlgrenii) or yellow (all other species), sometimes turning purple after anthesis; sepal lobes with simple-valvate aestivation, broadly triangular, erect, shorter than hypanthium; stamens erect in bud; filaments very short, anthers only partly exserted from hypanthium; pollen sacs much shorter than the connective body; ovary with 2 ascending ovules in each locule; style with 4 prominent, longitudinal, commissural wings; stigmatic areas subapical, located between the commissural wings. x = 10. Four species, from the Cape Peninsula to Port Elisabeth in the east, on sandy soil in perennial and seasonal streams; P. mucronata is the most common and most widespread species in the family.

Selected Bibliography Bond, W.J., Slingsby, P. 1983. Seed dispersal by ants in shrub lands of the Cape Province and its evolutionary implications. S. African J. Sci. 79:231–233. Carlquist, S., Debuhr, L. 1977. Wood anatomy of Penaeaceae (Myrtales): comparative, phylogenetic, and ecological implications. Bot. J. Linn. Soc. 75:211–227. Clausing, G., Renner, S.S. 2001. Molecular phylogenetics of Melastomataceae and Memecylaceae: implications for character evolution. Amer. J. Bot. 88:486–498. Conti, E. et al. 1996. See general references. Conti, E. et al. 1997. See general references. Conti, E. et al. 2002. See general references. Cronquist, A. 1981. See general references. Dahlgren, R. 1967a. Studies in Penaeaceae. Part I. Systematics and gross morphology of the genus Stylapterus A. Juss. Opera Bot. 15:3–40. Dahlgren, R. 1967b. Studies on Penaeaceae III. The genus Glischrocolla. Bot. Notiser 120:57–68. Dahlgren, R. 1967c. Studies on Penaeaceae IV. The genus Endonema. Bot. Notiser 120:69–83. Dahlgren, R. 1968. Studies on Penaeaceae. Part II. The genera Brachysiphon, Sonderothamnus and Saltera. Opera Bot. 18:5–72. Dahlgren, R. 1971. Studies on Penaeaceae. VI. The genus Penaea L. Opera Bot. 29:5–58. Dahlgren, R., Thorne, R.F. 1984. The order Myrtales: circumscription, variation, and relationships. Ann. Missouri Bot. Gard. 71:633–699.

Dahlgren, R., Van Wyk, A.E. 1988. Structures and relationships of families endemic to or centered in Southern Africa. Monogr. Syst. Bot. Missouri Bot. Gard. 25:1– 94. Dickie, J.B., Gasson, P.E. 1999. Comparative leaf anatomy of the Penaeaceae and its ecological implications. Bot. J. Linn. Soc. 131:327–351. Erdtman, G. 1952. See general references. Gilg, E. 1894. Penaeaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 6. Leipzig: W. Engelmann, pp. 208–213. Hegnauer, R. 1969. See general references. Jansen, S., Watanabe, T., Smets, E. 2002. Aluminium accumulation in leaves of 127 species in Melastomataceae, with comments on the order Myrtales. Ann. Bot. 90:53– 64. Johnson, L.A.S., Briggs, B.G. 1984. Myrtales and Myrtaceae – a phylogenetic analysis. Ann. Missouri Bot. Gard. 71:700–756. Keating, R.C. 1984. Leaf histology and its contribution to relationships in the Myrtales. Ann. Missouri Bot. Gard. 71:801–823. Louw, N. 1996. A comparative study of the reproduction, autoecology and genetic diversity of Brachysiphon rupestris, B. acutus, and some other species of Penaeaceae. Ph.D. Thesis, University of Stellenbosch, South Africa. Marloth, R. 1925. Penaeaceae. The Flora of South Africa 2:208–111. Cape Town: Darter. Patel, V.C., Skvarla, J.J., Raven, P.H. 1984. Pollen characters in relation to the delimitation of Myrtales. Ann. Missouri Bot. Gard. 71:858–969. Phillips, E.P. 1926. The genera of South African flowering plants. Bot. Surv. S. Afr. 10:1–702. Phillips, E.P. 1951. The genera of South African flowering plants. Bot. Surv. Mem. 25:1–923. Rao, V.S. 1965. On foliar sclereids in Penaeaceae. Sci. Cult. 31:380. Rao, V.S., Dahlgren, R. 1968. Studies on Penaeaceae V. The vascular anatomy of the flower of Glischrocolla formosa. Bot. Notiser 121:259–268. Rourke, J.P. 1995. A new species of Brachysiphon (Penaeaceae) from the Southern Cape, South Africa. Nordic J. Bot. 15:63–66. Rourke, J.P., McDonald, D.J. 1989. A new species of Penaea (Penaeaceae), from the Langeberg range, southern Cape. S. African J. Bot. 55:400–404. Rutschmann, F., Eriksson, T., Schönenberger, J., Conti, E. 2004. Testing the out-of-India dispersal of Crypteroniaceae with molecular dating. Intl J. Pl. Sci. 165: S69–S83. Savolainen, V., Fay, M.F. et al. 2000. See general references. Schönenberger, J., Conti, E. 2003. Molecular phylogeny and floral evolution of Penaeaceae, Oliniaceae, Rhynchocalycaceae, and Alzateaceae (Myrtales). Amer. J. Bot. 90:293–309. Scott-Elliot, G.F. 1890. Ornithophilous flowers in South Africa. Ann. Bot. 4:265–280. Stephens, E.L. 1909. The embryo-sac and embryo in certain Penaeaceae. Ann. Bot. 23:363–376. Supprian, K. 1894. Beiträge zur Kenntnis der Thymelaeaceae und Penaeaceae. Bot. Jahrb. 18:306–353. Takhtajan, A. 1997. See general references.

Penaeaceae Tobe,H.,Raven,P.H.1984.Theembryologyandrelationships of Penaeaceae (Myrtales). Pl. Syst. Evol. 146:181–195. van Tieghem, P. 1893. Recherches sur la structure et les affinités des Thymelaeacées et des Pénaeacées. Ann. Sci. Nat., Bot., sér. 7, 17:185–294. van Vliet, G.J.C.M., Baas, P. 1984. Wood anatomy and classification of the Myrtales. Ann. Missouri Bot. Gard. 71:783–800. Weberling, F. 1963. Ein Beitrag zur systematischen Stellung der Geissolomataceae, Penaeaceae und Oliniaceae

291

sowie der Gattung Heteropyxis (Myrtaceae). Bot. Jahrb. 82:119–128. Weberling, F. 1988. The architecture of inflorescences in the Myrtales. Ann. Missouri Bot. Gard. 75:226–310. Whitehead, V.B., Giliomee, J.H., Rebelo, A.G. 1987. Insect pollination in the Cape Flora. In: Rebelo, A.G. (ed.) A preliminary synthesis of pollination biology in the Cape Flora. Pretoria: CSIR, S. African Nat. Sci. Prog. Rep. no. 141, pp. 52–82.

Penthoraceae Penthoraceae Rydb. ex Britton, Man. Fl. N. States: 475 (1901), nom. cons.

J. Thiede

Erect perennial rhizomatous herbs; nodes unilacunar, 1-trace; roots fibrous. Leaves alternate, serrulate, simple, shortly petiolate, estipulate; lamina elliptic to lanceolate, venation pinnate with prominent midvein, attenuate at base. Inflorescences terminal or axillary, secund, scorpioid (or corymblike) cymes; floral bracts lateral and perpendicular to the pedicels; flowers perfect, small, regular; 5(–8)-merous; tetra- or pentacyclic, slightly perigynous; perianth with distinct calyx and corolla, or only sepaline; calyx valvate, of 5(–8) unequal sepals, united below, regular, erect during anthesis, becoming reflexed in fruit, persistent; corolla absent or, when present, inconspicuous with 1–8 greenish or whitish, lanceolate, slightly clawed petals inserted on rim of hypanthium, usually shorter than calyx lobes; stamens free, 10(–16), inserted in 2 whorls on edge of hypanthium; filaments teretefiliform, tapering only slightly towards anthers; anthers oblong, 2-loculate, basifixed, latrorse, longitudinally dehiscent, and caducous; gynoecium 5(–8)-carpellate; ovary 5(–8)-locular, syncarpous in lower half and sunken in hypanthium below placental area, thus partly inferior at anthesis but wholly superior at maturity; stylodia short, submarginal, erect during anthesis; stigmas capitate; each carpel with a single, marginal, pendulous placenta in its distal, free part with 30–100 ovules; ovules anatropous, bitegmic, crassinucellate; fruiting carpels becoming obliquely oriented in fruit, dehiscing circumscissile above the syncarpous region of the gynoecium. Fruit many-seeded; seeds ellipsoid to obovoid, surface papillate (tuberculate to echinate); embryo large, straight, endosperm of the ab initio cellular type, scanty. A monogeneric family with 2 helophytic species, disjunct between eastern North America and East Asia. Vegetative Structure. The anatomy was studied in detail by Haskins and Hayden (1987). Both species are erect perennial herbs up to 1 m tall,

and multiply, spread and perennate by horizontal stolons or rhizomes produced from the rootstock towards the end of the growing season. The roots are fibrous. The cortex consists of an outer exodermis and a broad, inner aerenchymatous region. The endodermis frequently contains dark deposits and remains un- or only slightly sclerified with age. The primary xylem is pentarch to polyarch, the secondary xylem resembles that of the stem. Pith is absent. The primary stem exhibits an epidermis with dark deposits and a collenchyma beneath. The cortex is aerenchymatous. Cortical bundles are absent, druses are common. The primary vasculature is an eustele without primary medullary rays. The pith is circular and often contains darkly staining deposits and druses. Nodes are one-trace unilacunar, the leaf trace forming a continuous collateral arc of xylem and phloem. The petiole has a simple, arc-shaped collateral vascular bundle. The simple leaves are lanceolate and willow-like in P. chinense and (narrowly) elliptic in P. sedoides. The apex is acute and the base cuneate and shortly petiolate. The margin is serrate with glandular, irregularly spaced teeth which often have an apical hydathode. Trichomes, which are present in P. sedoides only, are multicellular, 3–4seriate, glandular, and distributed abaxially and commonly attached to the veins. The venation is pinnate-brochidodromous. Both epidermises are uniseriate with a thin cuticle, dark-stained deposits being common except near the primary vein. The leaves are amphistomatic with anomocytic stomates. The mesophyll is bifacial. Secondary thickening of the annual stems is absent or develops from a conventional cambial ring. The wood is without growth rings. Vessels are very numerous and evenly distributed, and exhibit exclusively scalariform perforation plates with many bars. Vessel elements are of medium length (480– 760 µm) and without spiral thickenings. Imperforate elements are intergrading fibre-tracheids and

Penthoraceae

293

vascular tracheids. Fibre-tracheids are non-septate and short to medium in length (310–1,300 µm). The numerous rays are homocellular and mostly uni-to biseriate. Axial xylem parenchyma is absent. Reproductive Morphology and Anatomy. The anthers are oblong, 2-loculate with a thick connective without ventral and dorsal furrows, basifixed without basal pit, latrorse, longitudinally dehiscent, and caducous (Endress and Stumpf 1991). For gynoecium structure, see Hayden and Lewandowski (1997). The gynoecium consists of a central/basal ovule-bearing syncarpous region and a separate lateral/distal plicate region which comprises lateral portions of the ovary walls and the separate stylodia and stigmas. The ventral sutures of early plicate distal primordia are continuous with the first evidence of locular spaces within the floral apex. The placentae are apical, pendulous and (in contrast to other reports) restricted to the central region. The carpels are vascularized by a dorsal bundle which ramifies through the distal region and one ventral bundle mostly supplying the placenta. The fruiting carpels are intensively reddish and dehisce by circumscissile abscission of each distal/plicate carpel region, thus exposing the relatively proximal seed masses. Variation in the number of sepals, petals and carpels is considerable, and may occur within flowers even of a single inflorescence. Flowers with more than 5 carpels occur at the base of the inflorescences. The seed coat consists of an exotesta only, consisting of protruding tannin-bearing cells with ± thickened outer walls. The tegmen is crushed and persists only in the micropylar region where it forms an endostomal micropylar operculum (Nemirovich-Danchenko 1994). The testa cells bear distinct papillae flattened along the longitudinal axis (Fig. 100), very similar to those of some Saxifragaceae (Boykinia) and Crassulaceae (Crassula) (Krach 1976; Knapp 1997). Embryology. The ovules are borne on long funiculi on a well-developed, pendulous, marginal placenta on the adaxial suture above the syncarpous region. The nucellus is weakly developed and multi-layered only in its chalazal part. The embryo sac mother cell develops into a normal tetrad. The embryo sac develops from the chalazal tetrad cell and is normal 8-celled. The basal suspensor cell gives rise to a well-developed micropylar haustorium. Pollen formation is simultaneous (Rocén 1928).

Fig. 100. Penthoraceae. Penthorum sedoides. Seed surface structure. Scale: 100 µm. (Knapp 1997)

Pollen Morphology. The pollen grains are subprolate, 14–16 µm long and 3-colporate (colporoidate). The sexine is as thick as the nexine and exhibits a psilate or finely reticulate pattern (Erdtman 1952; Wakabayashi 1970). Pollination and Dispersal. Flowering occurs more or less continuously throughout summer until frost. Pollinators of the hermaphroditic plants are unknown. Seeds are dispersed floating on the water surface, although many sink; the small seeds can certainly also be dispersed by wind (Ikeda and Itoh 2001). The buoyancy of the seeds can be attributed to an oil coating on the seed surface. After a moist-chilled pretreatment, seeds were found to germinate well in light at 10–25 ◦ C, but not in darkness. Seed germination does not differ between floating and sunken seeds (Ikeda and Itoh 2001), and only takes place at moderate depths of water up to 11 cm (Kimura et al. 1999, cited in Ikeda and Itoh 2001). Karyology. Chromosome numbers are based on n = 8 (Penthorum chinense), and n = 8 and 9 (P. sedoides) (Baldwin and Speese 1951; Fedorov 1969); this points to x = 8 as the base number of Penthoraceae, which has also been determined as basal in Crassulaceae (Mort et al. 2001) and occurs in some Haloragaceae, too. Phytochemistry. In their serological reactions of seed proteins, Penthorum is close neither to Saxifragaceae nor to Penthoraceae (Grund and Jensen 1981). In its flavonoid chemistry, Pentho-

294

J. Thiede

rum is characterised by a relatively simple array of quercetin and kaempferol mono- and diglucosides. The polyphenol chemistry is generally similar to that of Saxifragaceae and clearly different from Crassulaceae (Jay 1971). Numerous unidentified gallic acid-like phenolic compounds have been reported (Soltis and Bohm 1982). Ultrastructure. Penthorum exhibits the Ss type of sieve element plastids (without protein inclusions and containing starch), which is present also in most other Saxifragales including Saxifragaceae. Crassulaceae differ in exhibiting the S0 type (without protein inclusions and without starch), not found elsewhere in Saxifragales (Behnke 1991). Affinities. Most earlier authors treated Penthorum as a member of Saxifragaceae, following Baillon (1871) and Engler (1928) who established separate monotypic tribes and subfamilies respectively for the genus. Alternatively, Penthorum has been placed in Crassulaceae (de Candolle 1828; Torrey and Gray 1840; Schönland 1894; Hutchinson 1973) or in its own monogeneric family Penthoraceae (van Tieghem 1898; Takhtajan 1959; Airy Shaw 1973). Penthorum shares with Saxifragaceae the union of the sepals into a shallow hypanthium and the basally syncarpous gynoecium, but differs especially in the isomery of the gynoecium. The isomerous gynoecium relates Penthorum to Crassulaceae where it is particularly similar, in its flower morphology, to the genus Diamorpha, and in habit to some Phedimus species, but Penthorum differs clearly from Crassulaceae in its non-succulent leaves with anomocytic stomata, its vessel and fibre structure, its diplostemonous flowers, in having the follicles united almost to the middle, the lack of carpellary nectary scales, the presence of an operculum, and its chemistry (see Crassulaceae, this volume). Based on molecular data, Penthorum belongs to a distinct clade within Saxifragales, from which Crassulaceae, Aphanopetalaceae, Tetracarpaeaceae, Penthoraceae and Haloragaceae successively branch off; in turn, this clade is sister to a clade which includes Saxifragaceae, Grossulariaceae, Iteaceae and Altingiaceae (Savolainen, Chase et al. 2000; Savolainen, Fay et al. 2000; Soltis et al. 2000; Fishbein et al. 2001). Penthorum is thus classified as a distinct family within Saxifragales (APG 1998), and can be incorporated neither in Saxifragaceae nor in Crassulaceae. Penthoraceae differ from both families in having vessels with

Fig. 101. Penthoraceae. Penthorum sedoides. A Flowering shoot. B Flower with five-carpellate gynoecium. C Vertical section of flower, showing placenta on ventral suture of one carpel in the apocarpous region. D Fruit, beginning to dehisce. E Fruit with circumscissile beaks of several carpels. F Seed. (Spongberg 1972)

scalariform perforations and fibres with bordered pits (Takhtajan 1997), in their chemistry (Soltis and Bohm 1982), and especially in the presence of an operculum (Nemirovich-Danchenko 1994). Stevens (2005) lists a stem with endodermis, nodes 1:1 and the lack of stipules as putative morphological synapomorphies for the clade Crassulaceae + Aphanopetalaceae + Tetracarpaeaceae + Penthoraceae + Haloragaceae; synapomorphies for the subclades are still wanting. APG II (2003) suggests to merge the latter four families into a broadly circumscribed Haloragaceae, which is not followed here due to considerable morphological differences between them (see Haloragaceae, this volume).

Penthoraceae

Distribution and Habitats. Penthoraceae are holarctic. Penthorum sedoides occurs in wet, muddy soils of river flood plains, in swamps and low woodlands, along ditches (hence, the name “ditch stonecrop”), and in fallow fields in Atlantic North America from southern Ontario, Quebec and New Brunswick (Canada) southwards to Florida and westwards to Minnesota, Nebraska, Kansas, Oklahoma and eastern Texas. Penthorum chinense occurs in similar habitats from eastern Siberia (Russia) and Manchuria (China) through North and South Korea to adjacent China and Japan. Penthorum exhibits the classical disjunction between eastern North America and East Asia found in about 65 genera of seed plants. In this particular case, and based on molecular clock models, divergence was dated at 4.21 Ma (ITS sequences; Lee et al. 1996), 6.0–6.5 Ma (allozyme data; Lee et al. 1996) and 4.88 ± 2.46 Ma B.P. (rbcL sequences; Xiang et al. 2000). These and similar data for other genera are consistent with previous hypotheses supported by palaeontological evidence that the disjunct pattern resulted mainly from fragmentation, starting in the late Tertiary, of the mixed mesophytic forest once widespread in the northern hemisphere (Xiang et al. 2000). The origin of Penthoraceae was dated much earlier at 69–77 Ma B.P. (Wikström et al. 2001). Economic Importance. Penthorum may occasionally become a noxious weed which can compete with crop plants or foul irrigation ditches. It is used medicinally as a demulcent, adstringent, laxative and respiratory sedative. Only one genus: Penthorum L.

Figs. 100, 101

Penthorum L., Sp. Pl. 1:432 (1753).


Selected Bibliography Airy Shaw, H.K. 1973. A dictionary of the flowering plants and ferns, 8th edn. Cambridge: Cambridge University Press. APG 1998. See general references. APG II 2003. See general references. Baillon, H. 1871. Saxifragacées. Hist. Pl. 3:325–464. Paris: Hachette. Baldwin, J.T. Jr., Speese, B.M. 1951. Penthorum: its chromosomes. Rhodora 53:89–91.

295

Behnke, H.-D. 1991. Distribution and evolution of forms and types of sieve-element plastids in the dicotyledons. Aliso 13:167–182. Candolle, A.P. de 1828. Mémoire sur la famille des Crassulacées. Paris: Treuttel & Würtz. Endress, P.K., Stumpf, S. 1991. The diversity of stamen structures in ‘lower’ Rosidae (Rosales, Fabales, Proteales, Sapindales). Bot. J. Linn. Soc. 107:217–293. Engler, A. 1928. Saxifragaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 18a. Leipzig: W. Engelmann, pp. 74–226. Erdtman, G. 1952. See general references. Fedorov, A.A. 1969. See general references. Fishbein, M. et al. 2001. See general references. Grund, C., Jensen, U. 1981. Systematic relationships of the Saxifragales revealed by serological characteristics of seed proteins. Pl. Syst. Evol. 137:1–22. Haskins, M.L., Hayden, W.J. 1987. Anatomy and affinities of Penthorum. Amer. J. Bot. 74:164–177. Hayden, W.J., Lewandowski, J.D. 1997. Gynoecium structure in Penthorum. Amer. J. Bot. 84: 201. Hutchinson, J. 1973. The families of flowering plants, ed. 3. Oxford: Clarendon Press. Ikeda, H., Itoh, K. 2001. Germination and water dispersal of seeds from a threatened plant species Penthorum chinense. Ecol. Res. 16:99–106. Jay, M. 1971. Quelques problèmes taxinomiques et phylogénétiques des Saxifragacées vus à la lumière de la biochimie flavonique. Bull. Mus. Natl Hist. Nat., sér. 2, 42:754–775. Knapp, U. 1997. Samenoberfläche und Systematik der Saxifragaceae und Crassulaceae. Ph.D. Thesis, University of Kaiserslautern, pp. 1–234. Krach, J.E. 1976. Samenanatomie der Rosifloren. 1. Die Samen der Saxifragaceae. Bot. Jahrb. Syst. 97:1–60. Lee, N.S., Sang, T., Crawford, D.J., Yeau, S.H., Kim, S.-C. 1996. Molecular divergence between disjunct taxa in eastern Asia and eastern North America. Amer. J. Bot. 83:1373–1378. Mort, M.E., Soltis, D.E., Soltis, P.S., Francisco-Ortega, J., Santos-Guerra, A. 2001. Phylogenetic relationships and evolution of Crassulaceae inferred from matK sequence data. Amer. J. Bot. 88:76–91. Nemirovich-Danchenko, E.N. 1994. The seed structure of Penthorum sedoides and P. chinense (Penthoraceae). Bot. Zhurn. (Moscow & Leningrad) 79:64–69. Rocén, T. 1928. Beitrag zur Embryologie der Crassulaceen. Svensk Bot. Tidsskr. 22:368–376. Savolainen, V., Chase, M.W. et al. 2000. See general references. Savolainen, V., Fay, M.F. et al. 2000. See general references. Schönland, S. 1894. Crassulaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 2a. Leipzig: W. Engelmann, pp. 23–38. Soltis, D.E., Bohm, B.A. 1982. Flavonoids of Penthorum sedoides. Biochem. Syst. Ecol. 10:221–224. Soltis, D.E. et al. 2000. See general references. Spongberg, S.A. 1972. The genera of Saxifragaceae in the southeastern United States. J. Arnold Arb. 53:409–498. Stevens, P.F. 2005. See general references. Takhtajan, A.L. 1959. Die Evolution der Angiospermen. Jena: Gustav Fischer. Takhtajan, A. 1997. See general references.

296

J. Thiede

Tieghem, P. van 1898. Sur le genre Penthore considéré comme type d’une famille nouvelle, les Penthoracées. J. Bot. (Morot) 12:150–154. Torrey, J., Gray, A. 1840. A flora of North America, I. New York: Wiley & Putnam, pp. 1–711. Wakabayashi, M. 1970. On the affinity in Saxifragaceae s. lato with special reference to the pollen morphology (in Japanese with English summary). Acta Phytotax. Geobot. 24:128–145.

Wikström, N., Savolainen, V., Chase, M.W. 2001. Evolution of the angiosperms: calibrating the family tree. Proc. Roy. Soc. London, ser. B 268:2211–2219. Xiang, Q.-Y., Soltis, D.E., Soltis, P.S., Manchester, S.R., Crawford, D.J. 2000. Timing the eastern Asian-eastern North American floristic disjunction: molecular clock corroborates paleontological evidence. Mol. Phylog. Evol. 15: 462—472.

Peridiscaceae Peridiscaceae Kuhlm., Arq. Serv. Florest. 3:4 (1950), nom. cons.

C. Bayer

Trees, glabrous or with an indumentum of long simple hairs. Leaves alternate, simple, entire, basal veins prominent or (Soyauxia) not so; petiole present, pulvinate; stipules intrapetiolar, almost amplexicaul, enclosing vegetative buds, caducous or (Soyauxia) free. Flowers in axillary, elongated or condensed racemes, pedicellate, actinomorphic, hermaphroditic, hypogynous, scented; sepals 4–7, free, imbricate; petals 5 (Soyauxia), otherwise 0; corona short, entire (Soyauxia); stamens numerous, distinct or fused at the base; anthers bisporangiate or (Soyauxia) tetrasporangiate, opening by a longitudinal slit or lateral flaps; disk intrastaminal, in Peridiscus enclosing more than half of the ovary; gynoecium syncarpous, 3–4(5)-carpellate; ovary unilocular, free or partly sunken into the disk, glabrous or pubescent, in Soyauxia with a central column; stylodia distinct, ending in subulate stigmatic tips; ovules usually 6–8, pendulous from the top of the locule. Fruits drupaceous or (Soyauxia) capsular, 1-seeded; endosperm abundant, horny; embryo small. A tropical lowland family of three genera, one in West Africa, and two from tropical South America. Vegetative Structures. In the American genera, the intrapetiolar stipules are early caducous and leave oblique, almost amplexicaul scars. On the lower surface of the leaves, pits are found in the axils of the prominent basal veins and, more rarely, of other first-order lateral veins. These pits seem to be glandular and resemble domatia. The anatomy of the three genera was studied by Record (1941), Normand (1960), Metcalfe (1962) and Miller (1975). Some cells of leaves and stems contain calcium oxalate crystals. Stomata are anomocytic and restricted to the abaxial leaf surface. Two cylindrical vascular strands are present in the distal portion of the petiole. The cortex of the stem contains secretory cells and few fibres. The phloem is enclosed by a ring of sclereids and

fibres. The wood includes very long libriform fibres, tall, uniseriate-homocellular or (in Soyauxia) -heterocellular and (in Peridiscus and Whittonia) pluriseriate-heterocellular rays with elongate ends, and abundant, diffuse parenchyma. Vesselsegments have scalariform perforation-plates and scalariform to opposite lateral pitting; those of Soyauxia are exceptionally long (1,769–2,653 µm). Medullary bundles are present in Peridiscus but lacking in Whittonia and Soyauxia. Reproductive Structures. The inflorescences usually arise from the axils of persisting or fallen leaves on indeterminate shoots. In Peridiscus, the flowers are arranged in elongated, open racemes with persistent bracts; the pedicels are devoid of prophylls. Several racemes may be arranged in (cymose?) clusters. The inflorescences of Soyauxia are similar, whereas Whittonia has axillary clusters which might represent condensed racemes. A short, tubular corona with entire margin is present in Soyauxia, which therefore sometimes has been included in Paropsieae/Passifloraceae or Flacourtiaceae, but its homology with the corona in Passifloraceae is doubtful. The stamens of Whittonia are basally united to groups. The fused filament bases form an elevation on the receptacle, commonly interpreted as a disk. In Peridiscus, the disk is lobed and encloses the major portion of the ovary. The arrangement of the stamens does not exhibit any apparent order but the inner stamens are much shorter than the peripheral ones. Nevertheless, it is unknown if this difference is due to a centripetal development of the androecium. The junction between the flattened base of the anthers and the tapering tip of the filaments is somewhat flexible. In most stamens of Peridiscus and Whittonia, only two pollen sacs are visible, and their anthers are usually described as monothecal (e.g. Kuhlmann 1947; Sandwith 1962, but not Hutchinson 1967). It is not yet clear how these an-

298

C. Bayer

thers develop. Since single filaments with two bisporangiate “anthers” and pair-wise, partly fused filaments are occasionally found, it cannot be excluded that the bisporangiate stamens correspond to split tetrasporangiate ones. Fusion to various degrees between adjacent filaments occurs in many flowers of Peridiscus. The tetralocular anthers of Soyauxia, which dehisce by flaps, are distinct. According to the description given by Kuhlmann (1947), the mature fruit of Peridiscus contains a single seed, in which the minute, straight embryo is found in a cavity adjacent to the chalaza. The embryo is provided with membranous, ovate to lanceolate cotyledons and a short, thick radicle. The seeds of Soyauxia and Peridiscus share a distinctive seed coat of collapsed black cell walls and massively thickened, probably hemicellulosic endosperm cells (P.F. Stevens, pers. comm.). Pollen Morphology. The pollen grains are small and tricolporoidate (Sandwith 1962); those of Soyauxia are tricolpor(oid)ate/reticulate (Erdtman 1952; Brenan 1953).

Affinities. Peridiscus was originally described in Flacourtieae and subsequently was usually treated as a doubtful genus of Flacourtiaceae. By contrast, Hallier (1908) found most agreement between Peridiscus and Capparidaceae (Stixis, Forchhammeria). Metcalfe (1962) and Miller (1975) pointed to anatomical and morphological characters shared by Peridiscus and Whittonia, justifying their family rank distinct from Flacourtiaceae. Soyauxia, transferred from Passifloraceae to Medusandraceae by Brenan (1953: Medusandrales) but retained in Paropsieae-Passifloraceae by Takhtajan (1997), had also been allied to Peridiscus and Whittonia (Metcalfe 1962; Sandwith 1962). This suggestion is substantiated by morphological features common to the three genera, such as inflorescence type and position, the shape of stamens (tetrasporangiate in Soyauxia but otherwise similar), the three- or four-carpellate, unilocular ovary surrounded by a disk, the number and position of ovules, the distinct stylodia with subulate stigmas, the small embryos, and the occurrence of crystal idioblasts in the leaf epidermis.

Fig. 102. Peridiscaceae. Soyauxia floribunda. A Flowering branch. B Flower. C Same, petals and stamens removed. D Stamens, front and back, showing peltate 4-celled anther. E Ovary, vertical section. F Ovary, transverse sec-

tion. G Two dehisced fruits. H Dehisced fruit, showing persistent central column attached at base to ovary and at apex to left-hand valve. I Seed. (Hutchinson and Dalziel 1954)

Peridiscaceae

A placement of Peridiscaceae within Tiliales (Hutchinson 1959: 253), “for want of a better place”, was rejected by Hutchinson (1967) himself. Although the position of Peridiscaceae remained enigmatic until recently, the many vegetative, reproductive and anatomical traits shared between Peridiscus and Whittonia left little doubt that the family is monophyletic. Using rbcL sequence data, Savolainen, Fay et al. (2000) proposed a close relationship between Whittonia and Malpighiaceae; this has been discarded (Davis and Chase 2004) because it was evidently based on an artifact. Rather, the expansion of Peridiscaceae to include Soyauxia and its placement in Saxifragales are now strongly supported by the three-gene analysis of the sequences of Peridiscus and Soyauxia by Davis and Chase (2004). This finding is corroborated by the small saxifragalean embryo and the presence of a unique indel in the 18S rDNA gene found within dicots only in members of Saxifragales. The precise position of Peridiscaceae within this order remains to be explored; an association of Peridiscus with Paeonia was only moderately supported (Davis and Chase 2004), whereas Peridiscus plus Soyauxia come out with Daphniphyllum (M.W. Chase in litt., Nov. 2003). Distribution and Habitats. Peridiscus occurs in northern Brazil and Venezuela. Whittonia has been collected in Guyana. Both live in evergreen, sometimes riverine forests. The species of Soyauxia grow in the western African Guineo-Congolian rainforest belt (see Normand 1960). Key to the Genera 1. Petals 5; anthers tetrasporangiate, dehiscing by flaps; ovary with a central column; W Africa 3. Soyauxia – Petals 0; anthers bisporangiate, dehiscing by slits; ovary without a central column; South America 2 2. Leaves glabrous; flowers in elongated racemes; sepals 4–6; stamens inserted outside the lobulate disk; ovary glabrous, partly sunken in the disk 1. Peridiscus – Leaves with long simple hairs, especially on the main veins; flowers in condensed fascicles; sepals (6)7; stamens inserted on an annular elevated disk; ovary densely pubescent, not sunken in the disk 2. Whittonia

Genera of Peridiscaceae 1. Peridiscus Benth. Peridiscus Benth., Benth. & Hook. f., Gen. Pl. 1:127 (1862).

Trees, glabrous except for the stipules and inflorescences; stipules caducous. Flowers pale green to

299

yellowish or whitish; fruits subglobose, greenish; heartwood dull sulphur-yellowish, sapwood dark brown. A single species, P. lucidus Benth., from northern Brazil and Venezuela. 2. Whittonia Sandwith Whittonia Sandwith, Kew Bull. 15:468 (1962).

Small trees with long, golden-brownish hairs on young shoots, mature leaves and inflorescences; stipules caducous. Lower surface of leaves densely papillate; flowers yellowish; stamens very numerous (more than 100); heartwood brownish-yellowish, sapwood dull brick-red. A single species, W. guianensis Sandwith, from Guyana. 3. Soyauxia Oliv.

Fig. 102

Soyauxia Oliv. in Hook., Ic. Pl.: t. 1393 (1882); Hutch. & Dalz., Fl. W. Trop. Afr. ed. 2, 1:643 (1954), in Mesusandraceae.

Small trees or shrubs. Inflorescences axillary spikes or racemes, often paired; petals 5, free; anthers peltate, rounded-quadrate, 4-locellate, laterally dehiscing by flaps; ovary with a central column attached at base and apex; stylodia 3, filiform, persistent and accrescent in fruit. Fruit a loculicidal capsule splitting to the base; seed oblong, somewhat angular; testa shining. Nine species in West Africa.

Selected Bibliography Brenan, J.P.M. 1953. Soyauxia, a new genus of Medusandraceae. Kew Bull. 1953:507–511. Cronquist, A. 1981. See general references. Davis, C.C., Chase, M.W. 2004. Elatinaceae are sister to Malpighiaceae; Peridiscaceae belong to Saxifragales. Amer. J. Bot. 91:262–273. Erdtman, G. 1952. See general references. Hallier, H. 1908. Über Juliania, eine TerebinthaceenGattung mit Cupula, und die wahren Stammeltern der Kätzchenblütler. Beih. Bot. Centralbl. 23, 2. Abt.: 81–265. Hutchinson, J. 1959. The families of flowering plants, ed. 2, 2. Oxford: Clarendon Press. Hutchinson, J. 1967. The genera of flowering plants (Angiospermae), 2. Oxford: Clarendon Press. Hutchinson, J., Dalziel, J.M. 1954. Flora of western tropical Africa, vol. 1, 2nd edn, revised by Keay, R.W.J. London: Crown Agents. Kuhlmann, J.G. 1947. Peridiscaceae (Kuhlmann). Arq. Serv. Florestal 3:3–5, pl. Metcalfe, C.R. 1962. Notes on the systematic anatomy of Whittonia and Peridiscus. Kew Bull. 15:472–475.

300

C. Bayer

Miller, R.B. 1975. Systematic anatomy of the xylem and comments on the relationship of Flacourtiaceae. J. Arnold Arb. 56:20–102. Normand, D. 1960. Atlas des bois de la Côte d’Ivoire, 3. Nogent-sur-Marne: Centre Technique Forestier Tropical. Oliver, D. 1896. Peridiscus lucidus, Benth. Hooker’s Ic. Pl. IV, 25: pl. 2441.

Record, S.J. 1941. American woods of the family Flacourtiaceae. Trop. Woods 68:40–57. Sandwith, N.Y. 1962. Contributions to the flora of tropical America, LXIX. A new genus of Peridiscaceae. Kew Bull. 15:467–471. Savolainen, V., Fay, M.F. et al. 2000. See general references. Takhtajan, A. 1997. See general references.

Picramniaceae Picramniaceae (Engl.) Fernando & Quinn, Taxon 44:177 (1995).

K. Kubitzki

Dioecious trees or shrubs, rarely xylopodious. Leaves spiral, imparipinnate, estipulate; leaflets alternate or opposite, petioluled. Inflorescences long, slender, arching or pendulous, rarely erect thyrses or racemes, terminal or axillary. Flowers small, regular, unisexual, 3–5(6)-merous; sepals persistent, basally connate, the lobes imbricate or valvate; petals frail, sometimes 0 in male flowers, reduced and imbricate in female flowers; stamens as many as and alternate with sepals, sometimes on a column, wanting or reduced to staminodia in female flowers; gynoecium 2–3-carpellate, syncarpous, borne on small disk or gynophore, rudimentary or 0 in male flowers; ovary 1–3-locular; ovules 2 per locule, epitropous or apotropous, borne apically and pendulous, or basal, the ovules then erect; stylodia short, strongly recurved, ventrally papillose. Fruit a berry or a compressed samaroid capsule with persistent calyx and style branches; seed planoconvex to narrowly ellipsoidal; testa membranaceous; endosperm 0. A basically tropical family with two genera and c. 46 species distributed from Florida to northern Argentina. Vegetative Morphology. Usually, Picramniaceae are evergreen small trees or shrubs; Picramnia campestris and P. oreadica are xylopodiaceous halfshrubs. The indumentum consists of simple hairs. The number of leaflets varies from a few to 33 in Picramnia, and to more than 50 in Alvaradoa. Leaflets are typically alternate and only rarely opposite; in the latter case, the lowermost pair may appear as pseudostipules (Pirani 1990). Serial axillary buds, of which the uppermost is largest, are found in the axils of distal leaves of Picramnia pentandra (Tomlinson 1980). The rainforest species Picramnia magnifolia usually has hollow stems which are inhabited by ferocious ants (Pirani 1990). Vegetative Anatomy. Stomata are anomocytic. Cork is surficial. The wood is dominated by fibre

tracheids, which rarely are septate; the vessel members have simple perforations, and vascular tracheids are rather common in Alavaradoa but rare or lacking in Picramnia. Wood parenchyma is vasicentric in Alavaradoa but sparse or lacking in Picramnia. Rays are uni- and multiseriate (Webber 1936; Heimsch 1942). Inflorescence and Floral Structure. (Information mainly from Pirani 1993). The inflorescences are slender, arching or pendulous botrya (racemes) or thyrses, the botrya regularly occurring in Alavaradoa, the thyrses predominating in Picramnia. The main axis is always indeterminate and in the thyrses bears lateral cymes of condensed glomerules which may comprise up to about 30 flowers; less often, the dichasia are only 3- or 2-flowered. Whereas the bracts subtending the dichasia persist into the fruiting stage, the prophylls are usually caducous. The inflorescences are unbranched (monothyrses and monobotrya) but also may show various degrees of branching (dithyrses, pleiothyrses, etc.). The inflorescences often originate in terminal position but, through the development of an axillary subterminal vegetative shoot, shift into a lateral position. Less frequently, branch-borne and even stem-borne inflorescences are formed from resting buds. In connection with the pronounced dioecy of the family, it is noteworthy that male individuals have usually more flowers and more richly branched inflorescences than female individuals. Pirani (1993) reports that male-flowered inflorescences of South American tricarpellate Picramnia species are pleiothyrses whereas the female-flowered inflorescences are diplothyrses. Pollen Morphology. The pollen grains are 3colpor(oid)ate, prolate (Picramnia), or subprolate (Alvaradoa) and relatively small (to 17 µm long) (Erdtman 1952); the exine of A. subovata is tectate, echinate, microperforate and columellate, and has

302

K. Kubitzki

a basal layer which is especially well developed in the mesocolpia; the endexine is thin but thickened in the apertural region (Xifreda and Sanso 2000). Pollination. Alavaradoa is usually considered to be wind-pollinated (e.g. Thomas 2004), but direct observations seem to be lacking. Fruit and Seed. The pericarp anatomy has been studied by Fernando and Quinn (1992). In Picramnia, there is a broad and parenchymatous exocarp, a parenchymatous mesocarp containing a distinctive layer of sclereids immediately under the exocarp, and a thin layer of sclereids constituting the endocarp, which represents the lignified inner epidermis. In Alvaradoa, the lignified outer and inner epidermises constitute the main mechanical tissue; the thin-walled parenchymatous mesocarp is only 3–5 cells thick and is traversed by vascular bundles associated with some sclereids. Such pericarp structure is unknown in Simaroubaceae s.str. The seed coat of Picramnia is about six cells thick and vascularised; the cells are unlignified, or the two subepidermal layers are lignified, and the inner cell layers are crushed. The endosperm is copious and the embryo is minute. Alvaradoa has a resinousappearing exotesta and the endotesta seems to be represented by a resinous membrane. There is no endosperm, and the embryo has large cotyledons (Stevens 2005).

The molecular studies of Simaroubaceae by Fernando et al. (1995) revealed Picramnia and Alavarodoa as a robust grouping in an isolated position between the “rosid I” and “rosid II” clades as defined by Chase et al. (1993). No more precise position has been proposed by further molecular work, and the Angiosperm Phylogeny Group (APG II 2003) retains Picramniaceae as an unplaced rosid family. Distribution and Habitats. The species of both genera extend across the tropical zone from southern Florida through Mexico and Central America and the Caribbean to South America and

Phytochemistry. Simaroubaceae, to which Picramniaceae formerly were thought to belong, are characterised by bitter-tasting triterpene derivatives, the quassinoids (Simão et al. 1991). The bark of Picramniaceae is also bitter but does not contain these compounds, rather accumulating betulinic acid and similar triterpenes. Acetate-mevalonatederived anthraquinones and anthrocene derivatives are prominent in the leaves (Jacobs 2003). Tariri acid is the main fatty acid in the endosperm (Hegnauer 1973). Systematics and Affinities. Radlkofer (1891) recognised that Alavaradoa was misplaced in Sapindaceae but is close to Picramnia. Engler (1931) was aware of the aberrant position of the two genera within his Simaroubaceae but misinterpreted the petals of Alvaradoa as staminodes, placing it in a subfamily adjacent to but different from that for Picramnia. The close relationship between the two genera makes a distinction at subfamily level virtually pointless.

Fig. 103. Picramniaceae. Picramnia oreadica subsp. penduliflora. A Fruiting branch. B Female flower after fertilisation, 4-carpellate. C Vertical section of fertilised ovary; note trichomes at base of locules. D Transverse section of ovary. E Fertilised 3-carpellate flower, perianth bent back. F Male flower with disk and rudimentary pistil. (Pirani 1990)

Picramniaceae

303

into warm-temperate north-western Argentina. Most Alvaradoa species prefer rocky, open vegetation and dry forests whereas Picramnia is well represented in all kinds of vegetation, with a preference for evergreen moist forests; however, large forest trees are not found in the genus. In Mexico, it occurs both in the north in montane forests up to 2,500 m above sea level and in the southern lowland rainforest; in Brazil, it is well developed in the rainforest of Amazonia, Guyana and the Atlantic coast but also grows in coastal dune forests (restinga) and in savannas (Pirani 1990).

ovules (usually only one maturing); ovules basally attached; stylodia 3, the 2 longer corresponding to the sterile carpels. Fruit a samara or samaroid capsule, the fertile carpel sometimes winged similarly to the sterile ones, sometimes inconspicuous and partly surrounded by them. Five species, four in Mexico and Central America, Florida and the Caribbean, and one in southern South America (Bolivia, northern Argentina).

Uses. The economic value of the family is minimal; the fruits of some Picramnia are edible, the wood is used locally for carpentry and fuel, and the bark, leaves and roots of some species are reported to having uses in folk medicine (Thomas 2004).

APG II 2003. See general references. Chase, M.W. et al. 1993. See general references. Cronquist, A. 1944. Studies in the Simaroubaceae. IV. Resumé of the American genera. Brittonia 5:128–147. Engler, A. 1931. Simarubaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 19. Leipzig: W. Engelmann, pp. 359–405. Erdtman, G. 1952. See general references. Fernando, E.S., Quinn, C.J. 1992. Pericarp anatomy and sytematics of the Simaroubaceae sensu lato. Austral. J. Bot. 40:263–289. Fernando, E.S., Quinn, C.J. 1995. Picramniaceae, a new family, and a recircumscription of Simaroubaceae. Taxon 44:177–181. Hegnauer, R. 1973. See general references. Heimsch, C. 1942. Comparative anatomy of the secondary xylem of the ‘Gruinales’ and ‘Terebinthales’ of Wettstsein with reference to taxonomic grouping. Lilloa 8:83– 198. Jacobs, H. 2003. Comparative phytochemistry of Picramnia and Alvaradoa, genera of the newly established family Picramniaceae. Biochem. Syst. Ecol. 31:773–783. Pirani, J.R. 1990. As espécies de Picramnia Sw. (Simaroubaceae) do Brasil: uma sinopse. Bol. Bot. Univ. São Paulo 12:115–180. Pirani, J.R. 1993. Inflorescence morphology and evolution in the genus Picramnia (Simaroubaceae). Candollea 48:119–135. Radlkofer, L. 1891 (‘1890’). Über die Gliederung der Familie der Sapindaceen. Sitzungsber. math.-physik. Kl. Königl. Bayer. Akad. Wissensch. 20:105–379. Simão, S.M., Barreiros, E.L., da Silva, M.F. das G.F., Gottlieb, O.R. 1991. Chemogeographical evolution of quassinoids in Simaroubaceae. Phytochemistry 15:853–865. Stevens, P.F. 2005. See general references. Thomas, W.W. 1990. The American genera of Simaroubaceae and their distribution. Acta Bot. Brasil. 4:11–18. Thomas, W.W. 2004. Picramniaceae. In: Smith, N., Mori, S.A., Henderson, A., Stevenson, D.W., Heald, S.V. (eds) Flowering plants of the neotropics. Princeton: Princeton University Press, pp. 294–297. Tomlinson, P.B. 1980. The biology of trees native to tropical Florida. Allston, MA.: Harvard University Printing Office. Webber, I.A. 1936. Systematic anatomy of the woods of Simarubaceae. Amer. J. Bot. 23:577–587. Xifreda, C.C., Sanso, A.M. 2000. Adenda y precisiones sobre la morfología polínica en Alvaradoa subovata (Simaroubaceae) y Roupala brasiliensis (Proteaceae). Darwiniana 38:43–45.

Key to the Genera 1. Ovary regular, all locules fertile; ovules apically attached, pendulous; fruit a berry 1. Picramnia – Ovary flattened, only one locule fertile; ovules basal and erect; fruit a samara or samaroid capsule 2. Alvaradoa

1. Picramnia Swartz

Fig. 103

Picramnia Swartz, Prodr. Veg. Ind. Occ.: 27 (1788), nom. cons.; Thomas, Brittonia 40:89–105 (1988), Mexic. & C Amer. spp.; Pirani, Bol. Bot. Univ. São Paulo 12:115–180 (1990), Brazil. spp.

Small trees or shrubs. Inflorescences thyrses or racemes. Flowers 5–3-merous; sepals joined at the base, imbricate; petals narrow or 0; stamens 5–3, in female flowers reduced to staminodia; stamen filaments subulate, anthers introrse, nearly spheroidal, with thick connective; disk or gynophore small; ovary of 2 or 3 carpels, wanting or rudimentary in male flowers; ovules apically attached. Fruit 1–2(3)-locular with one seed per locule. About 45 species, Florida to northern Argentina. 2. Alvaradoa Liebm. Alvaradoa Liebm. in Kjöbenh. Vid. Meddel. 1853:100 (1854); Cronquist, Brittonia 5:132–137 (1944), rev.

Medium-sized trees to shrubs. Inflorescences of long, slender racemes. Flowers long-pedicellate, basally with 2 minute prophylls; sepals basally united and distally valvate in male flowers, distinct and imbricate in female; petals slender or 0; stamens inserted between lobes of disk; ovary 3-carpellate with 2 carpels sterile, the fertile with 2


Podostemaceae Podostemaceae L. Richard ex C. Agardh, Aphor. Bot.: 125 (1822), nom. cons. Tristichaceae J.C. Willis (1915).

C.D.K. Cook and R. Rutishauser

Annual or perennial, aquatic herbs, often bizarre in form, sometimes resembling lichens, bryophytes, seaweeds, or unlike any other plants; haptophytes, attached by adhesive hairs to rock or other hard objects in flowing freshwater, mostly in rapids and waterfalls; roots usually photosynthetic, creeping or partly floating, thread-like, ribbon-shaped, crustose (foliose), sometimes short-lived or absent. Shoots nearly always arising as endogenous buds from roots; stems reduced or elongate, simple or branched, sometimes dimorphic, occasionally only present when flowering. Photosynthesis takes place under water, flowers or even separate floral shoots develop as the water level drops, the vegetative shoots or leaves often shed as plants become exposed. Phyllotaxis variable, in Podostemoideae usually distichous. Leaves borne on elongate stems or arising from prostrate, often disk-like stems, extremely variable in size and shape, from scale-like to well developed and compound; sheaths single or, in many Podostemoideae, double; sheath lobes sometimes elongated into stipule-like appendages; leaf blades stalked or sessile, entire, lobed or dissected; blade lobes or segments often bearing photosynthetic filaments and/or additional hairs; ultimate leaf segments filiform, linear or spathulate. Flowers bisexual, actinomorphic or zygomorphic, solitary, in clusters or in racemeor cyme-like inflorescences; flower buds naked in Weddellinoideae and some Tristichoideae, surrounded by a cupula (a collar-like vascularised cup) in some Tristichoideae, or completely enclosed in a spathella (a tubular or sack-like cover) in Podostemoideae; spathellas mostly enclosing a single sessile or pedicellate flower; pedicels often elongating in fruit. Anthesis takes place in air or flowers cleistogamous under water. Perianth of 1 complete or incomplete whorl of tepals, often confined to one side of the flower; tepals in Tristichoideae and Weddellinoideae large, 5 or rarely 4 or 6, imbricate and sepal-like; tepals in Podostemoideae small, 2–20, linear or subulate, usually alternating with

stamens, in flowers with only 2 basally fused stamens occasionally an additional tepal borne at top of andropodium (common stalk); stamens 1–40, in 1 or 2 complete whorls, or in 1 incomplete whorl, or confined to one side of flower and consisting of 1–3 free stamens or a Y-shaped structure consisting of an andropodium carrying 2 stamens; filaments, when in whorls, mostly free or, in Tulasneantha, their bases united to form an androecial tube; anthers dehiscing longitudinally by slits, introrsely to latrorsely or rarely extrorsely; pollen shed in monads, dyads or (rarely) tetrads, tricolporate in Weddellinoideae, tricolpate to pentacolpate in Podostemoideae, pantoporate with up to 16 pores in Tristichoideae; ovary superior, 2- or 3-locular or 1-locular in some Podostemoideae; ovules axile, anatropous, bitegmic, tenuinucellate. Fruit a capsule, smooth or ribbed, with 2 or 3, equal or unequal valves, sometimes one or more persisting; stigmas 1–3, variable in shape and size. Seeds 2 to very numerous (over 2,000); seed coat usually mucilaginous and sticky; endosperm 0; embryo straight, with 2 cotyledons and a suspensor. The family consists of 49 genera, of which 26 (53%) are monotypic or nearly so (some have two doubtfully distinct species) and about 280 species. It is distributed worldwide in tropical and warm regions, extending into temperate eastern North America and temperate East Asia. Most of the species are endemic to small geographical areas; only one, Tristicha trifaria, is widespread and occurs in the Old and New Worlds. Vegetative Morphology. The interpretation of the vegetative body is controversial. Many Podostemaceae have a flattened photosynthetic body which adheres to a hard substrate. It has been called a ‘thallus’ because the conventional demarcation into stem, leaf and root is usually not obvious (Cario 1881; Willis 1902), and various botanists have denied or doubted the homology of this vegetative body with stems (caulomes),

Podostemaceae

leaves (phyllomes) and roots of other angiosperms (G. Cusset 1974; Cusset and Cusset 1988; C. Cusset 1992; Mohan Ram and Sehgal 1992, 2001; Schnell 1994, 1998; Khosla et al. 2000; Ota et al. 2001; Sehgal et al. 2002). These botanists consider the vegetative body of all (or most) Podostemaceae represents a unique architectural type. However, for convenience, we adopt the classical root-shoot model (CRS model) with its structural categories roots, shoots (including stems and leaves) as used by Warming (e.g. 1881), Goebel (1933), Rauh (1937), Troll (1941), Jäger-Zürn (e.g. 1970, 2000c), Rutishauser and Huber (1991) and Rutishauser (1997). We avoid the term ‘thallus’. We use the term ‘root’ for cylindrical to flattened photosynthetic structures when endogenous shoot buds are developed but no exogenous leaves. The term ‘stem’ is applied to a cylindrical or flattened photosynthetic body which develops exogenous leaves. For example, the prostrate and crustose body of Hydrobryum (Fig. 104C) and Zeylanidium olivaceum (Fig. 124D, F), which lacks exogenous leaves, is described as a root (Jäger-Zürn 2000b; Rutishauser and Moline 2005). The prostrate and often star-shaped body of Dalzellia zeylanica is described as a flattened stem or branch system because it bears exogenous scales which are often interpreted as leaves (Jäger-Zürn 1995; Imaichi et al. 2004). Podostemaceae show an amazing diversity of root types. Usually, the roots are persistent with long-lasting apical growth, bearing root-borne shoots and fixed to the hard substrate by adhesive hairs (Fig. 107A). They vary from thread-like (cylindrical) to ribbon-like and further to crustose (i.e. foliose, disk-like). The roots give rise to endogenous shoot buds, either from the flanks or in crustose roots also from the upper surface (Fig. 104C). Cylindrical to narrowly ribbon-like roots of Podostemaceae are normally provided with an asymmetric cap which resembles the calyptra of a typical root (Fig. 104A; Koi and Kato 2003). Broad ribbons and crustose (i.e. foliose, disk-like) roots often lack an obvious cap. Lateral roots of ribbon-like roots arise endogenously or exogenously (Fig. 104B), or show a mosaic pattern of endogenous and exogenous formation (e.g. Cladopus spp., Koi and Kato 2003). Crustose roots are found especially in Asian Podostemoideae (e.g. Hydrobryum, Zeylanidium olivaceum) and African Podostemoideae (e.g. Dicraeanthus, Ledermanniella spp.; Cusset 1984). The crustose root of Hydrobryum contains a network of nonvascular

305

strands (Ota et al. 2001). The crustose roots of Hydrobryum grow with a marginal meristem giving rise to exogenous lobes. The margin of these flat roots are fringed by a protective tissue which may be considered as a rudimentary cap (Suzuki et al. 2002). A progressive elaboration of the root is most obvious in Asian and Australian Podostemoideae where it is accompanied by gradual reduction of the cap (calyptra) and decrease in size of the root-borne leafy shoots (Willis 1902; Jäger-Zürn 2000a; Suzuki et al. 2002). Crustose roots have evolved at least three times in Podostemaceae, twice in Asian podostemoids and at least once in African members (Hiyama et al. 2002; Kita and Kato 2004b; Moline et al. 2007). In several genera the roots are insufficiently documented. There are a few species which lack obvious roots, e.g. Castelnavia princeps, Dalzellia zeylanica, Mourera fluviatilis and Rhyncholacis carinata, although other species in the same genera are clearly provided with roots (Warming 1899; Rutishauser and Grubert 1994; Mathew et al. 2001). Holdfasts (haptera in earlier literature) are clawlike organs superficially resembling the attachment organs of brown algae such as Fucus. They stick the plants to the solid substratum. They may be branched (e.g. Polypleurum spp.) or finger-like (e.g. Saxicolella submersa, Ameka et al. 2002). They arise as exogenous (e.g. Podostemum ceratophyllum) or endogenous outgrowths (e.g. Indotristicha ramosissima) of the root. Holdfasts may also arise as exogenous outgrowths from the base of leaves and shoots. All Podostemaceae investigated to date have dicotyledonous seedlings. The shoots of most arise as endogenous buds from hypocotyl-borne outgrowths (roots) which soon replace the short-lived seedling axis (Mohan Ram and Sehgal 1997; Sehgal et al. 2002). Seedling establishment by plumular activity seems to be the exception, rather than the rule; it is found in a few New World Podostemaceae such as Apinagia multibranchiata and Mourera fluviatilis (Grubert 1976; Rutishauser and Grubert 2000). More seedling features are described below under Seedlings and Life Cycle. Many African and American members of the Podostemoideae form elongate and branched shoots over 80 cm long (e.g. Ledermanniella bowlingii, Ameka et al. 2003), whereas a reduction in size of the root-borne shoots to 1 cm or less long and often unbranched is typical for most Podostemoideae in Asia. The longest shoots formed by Asian podostemads are those of Indotristicha

306


ramosissima which reach 60 cm. The shoots of several American genera are dorsiventral with respect to leaf orientation. Prostrate crustose shoots attached to the rock are found in, e.g. Dalzellia zeylanica (Tristichoideae, Imaichi et al. 2004) and Apinagia, Castelnavia and Marathrum (Podostemoideae, Rutishauser et al. 1999; JägerZürn 2005c). For additional features of crustose shoots (i.e. dorsiventrally flattened stems), see below the discussion of leaf sheaths. Axillary branches subtended by leaves or bracts are the exception, rather than the rule. They are found in Indotristicha ramosissima, if the ramuli (photosynthetic branchlets) are accepted as subtending compound ‘leaves’ (Rutishauser and Huber 1991). Axillary branching also occurs in African podostemoids, e.g. Saxicolella, Sphaerothylax and Stonesia spp. (Taylor 1953; Ameka et al. 2002). Most, however, have switched to alternative branching types. In several Podostemoideae, we find shoot bifurcation which is correlated with the presence of double-sheathed leaves (Figs. 104D, 116G). In Weddellina (subfam. Weddellinoideae), the vegetative shoots are often highly branched and up to 80 cm long, with scales and bunches of photosynthetic filaments. Branching appears to be extra-axillary, i.e. lateral shoots are not subtended by scale-like leaves (Fig. 104F). The leaf sheaths in American Podostemoideae such as Marathrum, Mourera and Oserya are inserted longitudinally due to leaf growth occurring in the median plane towards the abaxial side of the leaf (Rutishauser and Grubert 1994; Jäger-Zürn 2002b, 2005c). Lateral leaf insertion (as is typical

for most angiosperms) is found in Diamantina; the leaves of this genus are minute and lack any vascular tissue (Fig. 109G, H; Rutishauser et al. 2005). In many American Podostemoideae, the root-borne shoots initially produce leaves with a single sheath and subsequently leaves with two sheaths. The two sheaths of a double-sheathed leaf are opposite to each other or nearly so (Podostemum ceratophyllum, Fig. 104D): an inner one pointing towards the stem tip and an outer sheath pointing towards the stem base. These double-sheathed leaves have been called ‘dithecous’ by Warming (1881, 1882). They occur in several American and African Podostemoideae but are lacking in most Asian and Australian Podostemoideae, with the exception of Zeylanidium subulatum (Jäger-Zürn 1994, 1999; Imaichi et al. 2005). Double-sheathed leaves are an evolutionary novelty or key innovation of Podostemoideae and allow unique types of shoot construction (Jäger-Zürn 1994; Rutishauser and Grubert 1999; Rutishauser et al. 2003). The presence of these leaves is linked with the formation of prostrate and often disk-like stems with marginal leaves, especially in American Podostemoideae. For example, new leaves of the prostrate stems of Marathrum spp. may arise in both sheaths of the double-sheathed leaves. The leaf sheaths of species of Castelnavia, Lophogyne and Marathrum in particular appear to be congenitally fused into a widened and flattened body which is prostrate and lobed. This body, as in Castelnavia princeps, may be interpreted as the product of congenital fusion and dorsiventral flattening of various stem

Fig. 104. Podostemaceae. Scanning electron micrographs. A Podostemum ceratophyllum (eastern USA). Root tip with asymmetrical cap (Rc). Scale bar, 300 µm. B Zeylanidium subulatum (southern India). Distal region of exogenously branched root; Rh rhizoids along lower side of mother root, Rx exogenous daughter roots, Sn first leaf of endogenous shoot at the tip of mother root. Scale bar, 500 µm. C Hydrobryum floribundum (southern Japan). Marginal region of lobed crustose root, seen from above. Sn first leaves of endogenous shoot arising from the upper surface. Scale bar, 300 µm. D Podostemum ceratophyllum (eastern USA). Basal portion of double-sheathed mother leaf (Ly), with 2 lateral stipular sheaths (Ls), each ensheathing a daughter leaf (Ly+1). Scale bar, 100 µm. E Tristicha malayana (Malaysia). Distal portion of nearly mature ramulus (photosynthetic branchlet) with 3 rows of scales. Scale bar, 500 µm. F Weddellina squamulosa (Venezuela). Branching zone of vigorous vegetative shoot; large toothed scale (L) at level of shoot branching; arrows point to the 2 rows of photosynthetic fil-

aments which are restricted to 2 furrows along shoot axes. Scale bar, 500 µm. G Mourera fluviatilis (Venezuela). Early stage of flower development; stamen primordia (A) in 2 complete whorls surrounding ovary (G); T tepals, Fc remnant of removed spathella. Scale bar, 100 µm. H Marathrum schiedeanum (Mexico). Flower immediately prior to anthesis, with half-whorl of 4 stamens; T tepals. Note the 2 stigmas which are basally united. Scale bar, 1 mm. I Polypleurum stylosum (southern India). Flower in anthesis; Y-shaped androecium with andropodium (P) carrying 2 stamens; T tepal. Scale bar, 1 mm. J Tristicha trifaria (Nigeria). Flower in anthesis; with trimerous, basally tubular perianth (T), 1 stamen, 3 stigmas (arrow). Scale bar, 500 µm. K Mourera fluviatilis (Venezuela). Tricolpate spinulose pollen. Scale bar, 5 µm. L Farmeria indica (southern India). Dyad of pentacolpate pollen grains; 3 colpi per grain visible. Scale bar, 10 µm. M Weddellina squamulosa (Venezuela), 2 tricolporate pollen grains. Scale bar, 5 µm. (Adapted from Rutishauser 1997)

Podostemaceae

307

308


orders (Warming 1882; Matthiesen 1908; Engler 1928; Rutishauser et al. 1999; Jäger-Zürn 2005c). The coalescence of leaf sheaths and the supporting stem portion leads to pocket-like cavities in the prostrate body which become filled with new leaves or flower buds. Pocket formation due to congenital fusion of two adjacent leaf sheaths also occurs in taxa with elongate stems, as in Apinagia multibranchiata (Rutishauser and Grubert 2000). In many Podostemoideae, the leaf sheaths can be called ‘stipular’ because they have one or two lobes or teeth which extend beyond the leaf insertion area. Stipular sheaths (two per double-sheathed leaf) are found in several African and American podostemoid genera, e.g. Ledermanniella and Marathrum (Rutishauser et al. 1999; Ameka et al. 2003; Moline et al. 2006, 2007). Patterns unique with respect to position and number of stipular outgrowths are found in Podostemum spp. (Fig. 104D; Philbrick and Novelo 2004). In Ceratolacis pedunculatum, Crenias spp. and Podostemum muelleri with dorsiventral shoots, the leaf base is asymmetrical, with only one prominent stipule per leaf, restricted to the front side of the shoot (Tur 1997; Jäger-Zürn 2002a; Philbrick and Novelo 2004; Philbrick et al. 2004b). In Podostemoideae with digitate leaves (Cladopus, Diamantina), it is arbitrary whether one calls the lateral leaf lobes (teeth) stipular appendages or not (Rutishauser and Pfeifer 2002; Rutishauser et al. 2005). In Tristichoideae, a proper shoot apical meristem (SAM) is present, whereas a SAM is lacking or reduced to few meristematic cells in many Podostemoideae (Jäger-Zürn 2005b). In Asian podostemoids (e.g. Cladopus, Zeylanidium spp.) without a SAM, new leaves are formed endogenously on the adaxial side of a pre-existing leaf (Imaichi et al. 2005; Koi et al. 2005). Most taxa of Podostemoideae have distichous phyllotaxis. Leaf formation continues in the same median plane even when doublesheathed leaves or bracts are formed. There are, however, other phyllotactic patterns. For example, in reproductive shoots of Thawatchaia and Willisia the scale-like leaves are arranged around the stem in 4 (or even 6) rows, serving as exoskeleton. Ledermanniella subg. Phyllosoma is characterised by prominent compound leaves with distichous phyllotaxis and additional scales which are scattered irregularly (Cusset 1983). In Indotristicha ramosissima, the photosynthetic branchlets (ramuli) are arranged along a spiral which approaches the Fibonacci angle whereas additional scales along the stem are

intercalated without obvious order (Rutishauser and Huber 1991; Jäger-Zürn 1992). In Tristicha, the ramuli are arranged in two opposite rows along the often very short stems (Jäger-Zürn 1970; Imaichi et al. 1999). Each ramulus bears scales arranged in three rows in Tristicha (Fig. 104E) whereas they show spiral or irregular patterns in the ramuli of Indotristicha ramosissima. In Weddellina, stems are bunches of photosynthetic filaments which are arranged in two opposite rows whereas additional scales lack a regular phyllotactic pattern (Fig. 104F). The longest leaves of all Podostemaceae are found in Mourera fluviatilis, where they may reach 200 cm. Repeatedly forked blades are typical for many taxa, such as Oserya coulteriana and Podostemum ceratophyllum. In early development, the compound leaves of Marathrum and Rhyncholacis show a three-dimensional branching pattern (Rutishauser 1995, 1997; Rutishauser et al. 1999), and may be repeatedly branched until they terminate in filamentous nonvascular pinnae 0.02–0.4 mm wide, e.g. in Marathrum schiedeanum (Matthiesen 1908). Young leaves and their subunits (pinnae) in Mourera fluviatilis, Oserya spp. and other neotropical taxa are coiled or incurved during development. The side towards which they are coiled or curved may be called the ‘front side’ (upper side) because it is away from the surface of the prostrate shoot which faces the substratum. Ensiform (sword-like) blades are flattened in the median plane and usually provided with marginal pinnae. This median plane is identical to the plane of distichy, resembling leaves of Acorus, Iris and Xyris. Such ensiform and compound leaves are typical for species of Apinagia, Marathrum and Mourera (Jäger-Zürn 2002b, 2005a,c). Shoots of these genera may also be dorsiventral, with appendages (prickles, warts, hair tufts) restricted to the upper surfaces (front side) of the ensiform leaves, e.g. in Apinagia multibranchiata and Mourera fluviatilis (Rutishauser and Grubert 1994, 2000). The leaves of most Asian and Australian Podostemoideae are entire, subulate to filamentous (Fig. 104C). Some of the scale-like leaves of Willisia are provided with a filamentous blade, and in Zeylanidium subulatum these leaves may reach a length of 30 cm (Cusset 1992). Digitate leaves of Cladopus are borne in a seemingly scattered phyllotactic pattern. Similarly to many American Podostemoideae, the blades of several African taxa are repeatedly forked or pinnate but some

Podostemaceae

have entire, scale-like to filiform leaves, such as many Asian and a few American taxa. Anisophylly or heterophylly occur in some species of Ledermanniella subg. Phyllosoma: besides normally forked leaves, there are ± toothed, imbricate scales (Cusset 1983, 1987). In a few Ledermanniella spp. (e.g. L. letouzeyi, L. prasina), epiphyllous flowers arise from the cleft of forked leaves (Schenk and Thomas 2004; Rutishauser and Moline 2005). Tristichoideae have photosynthetic, 1–2 mm long scales which may be replaced by slightly longer filamentous appendages (Warming 1901; Cusset and Cusset 1988); Jäger-Zürn (1997a) considers them to be leaves. In Tristicha and Indotristicha, these scales are arranged along short-lived shootlets (called ramuli) up to 4 cm long (Fig. 104E). Scales and filamentous appendages are only one cell-layer thick, except for a weak prosenchymatic midrib which may be present or absent. Weddellina has bunches of photosynthetic filaments arising in two opposite sectors along the stem (Grubert 1976). These cylindrical filaments are thin and (in section) consist of four cells surrounding a central cavity; they may be interpreted as pinnae of three-dimensional compound leaves (Wächter 1897; Engler 1928); in addition, there are scales of various sizes along the main stems (Fig. 104F). Vegetative Anatomy. Intercellular lacunae such as gas canals and aerenchyma seldom occur, which is very unusual for aquatic vascular plants. The roots of most species, whether flattened or not, adhere to the rocky substratum by usually unicellular adhesive hairs which are called rhizoids by Engler (1928) and Ota et al. (2001). They are usually present on the lower side of the root where it is attached to the rock (Warming 1881). These hairs are reported to secrete a ‘super-glue’ from their tips. The ‘super-glue’ secreted from adhesive hairs and epidermal cells of roots and holdfasts in Griffithella hookeriana is a polysaccharide consisting mainly of arabinose and galactose (Vidyashankari 1988b). Jäger-Zürn and Grubert (2000) observed that this super-glue is associated with biofilm composed primarily of cyanobacteria. The vascular tissue often lacks clear differentiation into xylem and phloem (Schnell 1967, 1998). Typical phloem elements are difficult to find (Romano and Dwyer 1971; Ancibor 1990; Jäger-Zürn 2000c). Typical xylem elements are often absent, except for some annular-thickened tracheids in

309

stems and leaf midribs of Apinagia and Mourera (Rutishauser and Grubert 1994, 2000). Both xylem and phloem elements are lacking in the ‘nonvascular strands’ of Hydrobryum roots (Ota et al. 2001). The vascular pattern in flattened plant bodies (e.g. Dalzellia zeylanica) was used to support the hypothesis of ‘congenital fusion’ of several branch orders (Jäger-Zürn 1995, 1997a, 2000c). The basal portion of the cylindrical vegetative shoot axis of Weddellina and Apinagia spp. (e.g. A. multibranchiata) may become thickened following cell division in the cortex. Hair-like outgrowths are found along one sector in filiform leaf segments of many Podostemoideae. Certain American Podostemoideae (mainly species of Apinagia, Marathrum and Mourera) have broad leaf blades with fimbriate marginal lobes and a dissected tip. Laticiferous tubes embedded in parenchyma or sclerenchyma in various organs are an anatomical speciality of various neotropical Podostemoideae such as Apinagia, Castelnavia, Marathrum, Mourera, Rhyncholacis and Weddellina (Matthiesen 1908; Engler 1928; Schnell 1967; Rutishauser and Grubert 1994). Long-lived plant parts (roots, stems, occasionally also scales and leaf bases) of many Podostemaceae have a carapace of silica bodies in the epidermal and subepidermal layers. This may help in withstanding mechanical damage and also preventing the plant from collapsing during short periods of desiccation (Metcalfe and Chalk 1950). Like aquatic plants, Podostemaceae exhibit a great capacity for regeneration from wounded or ruptured portions of the plant body (Imaichi et al. 1999; Ota et al. 2001). Warming (1881) and Hammond (1936) illustrated roots and holdfasts of Podostemum ceratophyllum which had regenerated their tips; new roots and shoots may be also regenerated from injured stems. Inflorescence Structure. Inflorescences are not always easy to define in Podostemaceae because foliage leaves and flowers are often not clearly distinct. In Podostemoideae, fascicles, cyme-like and raceme-like inflorescences, and less clearly defined clusters are found. Except for the fascicles, the flowers are normally separated from each other by leaves with prominent blades or bracts with rudimentary blades. 1. Fascicles. In various New World Podostemoideae, there are two or more flowers arising as a fascicle in a sheath pocket (stem cavity)

310


next to the substrate. Such fascicles are typical for Rhyncholacis, Vanroyenella, Wettsteiniola and some species of Apinagia and Marathrum (Warming 1901; van Royen 1951; Tur 1997). In Rhyncholacis penicillata and Vanroyenella plumosa, such fascicles contain up to 25 and 11 flowers respectively; the flowers of each fascicle are initiated successively along a zigzag line resembling a condensed cymose inflorescence, although no subtending bracts are present (Rutishauser et al. 1999). 2. Cyme-like inflorescences. Various Apinagia spp. with stems (including A. multibranchiata) have repeated Y-shaped branching, construed as peculiar types of cymose inflorescences (Warming 1888; Rutishauser and Grubert 2000; Jäger-Zürn 2002b, 2005a, c). The first module of a root-borne shoot consists of few to several leaves and an apparently terminal flower. Then, all additional daughter modules consist of a leaf pair with a flower in between. These leaves are often double-sheathed, i.e. provided with an adaxial inner sheath and an abaxial outer sheath. In A. multibranchiata and allies, the two inner sheaths of a leaf pair form a tube protecting the young flower. When both outer sheaths of a leaf pair subtend a daughter module, reproductive shoots occur with repeated Y-shaped branching. Species such as Apinagia riedelii have reproductive modules of a solitary double-sheathed leaf and one flower only. A chain of such reduced modules was called drepanium (Sichelsympodium) by Engler (1928) and Jäger-Zürn (2005c) because the daughter modules are regularly borne on the same side. 3. Raceme-like inflorescences. Distinctive raceme-like inflorescences resembling swords are found in Mourera (Warming 1888). In M. fluviatilis, they are up to 64 cm long (including stalk), with about 40–90 flowers arranged along two flanks of the axis. The flowers along both rows are separated from each other by doublesheathed bracts which are initiated in basipetal order after the formation of a terminal doublesheathed leaf (Rutishauser and Grubert 1994, 1999). 4. Clusters. Various inflorescences of African Podostemoideae show dense groups of flowers which are here called ‘clusters’, for lack of a better term. In Dicraeanthus africanus, stalked flower clusters arise from endogenous buds of the stem cortex (Fig. 115H; Moline

et al. 2007). In Macropodiella macrothyrsa, similar candelabrum-like clusters of up to about 12 flowers are arranged as short shoots along the main shoots. These clusters have double-sheathed bracts between neighbouring flowers and were interpreted as cymose inflorescences by Cusset (1978). According to Jäger-Zürn (2000a, 2000c), the flower clusters of Sphaerothylax abyssinica are helicoid and scorpioid cymes with congenital fusion (syndesmy) of consecutive branch orders. In Tristichoideae, solitary flowers develop at the tip of short shoots which bear either scales only in Dalzellia, or scales as well as ramuli in Indotristicha and Tristicha (Cusset and Cusset 1988). Unbranched short shoots with a terminal flower arise directly from endogenous buds of the green, flattened plant body in Dalzellia zeylanica (Imaichi et al. 2004), or of the root, as in Tristicha, or they may be exogenous, arising from branches of vigorous and branched vegetative shoots, as in Indotristicha and Tristicha. In Indotristicha ramosissima, additional floral shoots may also arise as endogenous buds along the vegetative shoot axes (Rutishauser and Huber 1991). The root-borne shoots of Weddellina squamulosa are dimorphic. Floral shoots are unbranched and 2–12 cm long. They bear 2–10 scales which are often arranged in a helix which continues into the usually 5-merous perianth of the single terminal flower (Fig. 105C, D). Flower Structure. Podostemoideae are distinguishable from the two other subfamilies by the presence of a membranous, nonvascularised sacklike cover, the spathella, which encloses the young flower (Fig. 104G). Except for Macarenia, each spathella contains a single flower. In Marathrum foeniculaceum and Mourera fluviatilis, the young spathella is two-tipped, supporting the view that the spathella is formed by two fused bracts (Rutishauser and Grubert 1994; Jäger-Zürn 2005b). Diamantina has two different kinds of spathella on the one shoot; the spathella subtending the subterminal flower is scale-like and positionally homologous to a bract, whereas the spathella covering the terminal flower bud is tubular, as is usual for Podostemoideae (Rutishauser et al. 2005). In addition to a sheathing perianth, some Tristichoideae have a cover which encloses the young flower. This cup-like, vascularised cover, called a cupule, is found in Dalzellia zeylanica and Indo-

Podostemaceae

tristicha ramosissima. Unlike the spathella, the cupule carries scales and; in Indotristicha; also photosynthetic shootlets which are called ramuli (Rutishauser and Huber 1991; Jäger-Zürn and Mathew 2002). In most Podostemaceae (including Tristichoideae, Weddellinoideae), the pedicel (flower stalk) elongates as the fruit ripens. The pedicel in Podostemoideae develops within the spathella, but in a few members (e.g. Angolaea, Ceratolacis pedunculatum) the spathella is itself clearly stalked or pedunculate (Warming 1899; Philbrick et al. 2004b). The pedicel is lacking or very short prior to anthesis in Podostemoideae with erect flower buds, but some African taxa have an inverted and pedicellate flower bud inside the spathella, and in these taxa the pedicel elongates inside the young spathella prior to anthesis (Cusset 1987; Ameka et al. 2003). An intermediate condition with oblique flower buds inside the spathella occurs in Endocaulos, Thelethylax in part and Djinga (Moline et al. 2007). Pedicels more than 5 cm long are common in New World Podostemoideae with prostrate stems and pedicel insertion close to the substrate. A short and asymmetrically inflated pedicel is typical for Castelnavia. In Podostemoideae, the number of perianth segments varies from 2 to 25; the number of stamens per flower varies from 1 to 40. The perianth is reduced to linear, spathulate or tooth-like tepals (Fig. 104H, I) which, according to Khosla and Mohan Ram (1993), may be interpreted as staminodes because they are occasionally replaced by stamens. The flowers may be placed in five goups: 1. Various species of the American genera Apinagia, Marathrum and Rhyncholacis have a complete whorl of 6–12 stamens surrounding the dimerous gynoecium (Rutishauser 1997; Rutishauser et al. 1999). The number of stamens equals the number of tooth-like tepals; the tepals alternate with the stamens. 2. Polystemonous flowers with stamens outnumbering the tepals and arranged in up to 2 whorls are found in various species of Apinagia, Rhyncholacis and Mourera (Fig. 104G). In Apinagia multibranchiata, there are 6–29 stamens per flower (Went 1926; Rutishauser and Grubert 2000), while there are 4–40 stamens per flower in Marathrum squamosum (van Royen 1951) and 14–40 stamens in Mourera fluviatilis (Rutishauser and Grubert 1994, 1999). 3. In many New World Podostemoideae, the flowers become dorsiventral by loss of stamens

311

on one side. Marathrum schiedeanum, for example, has 4–8 stamens in a complete or incomplete whorl, although there may still be a complete whorl of rudimentary tepals (Fig. 104H; Rutishauser et al. 1999). In Castelnavia princeps and Vanroyenella, there are two or three stamens which may be free or slightly united below (forming an andropodium; Warming 1882). From the Old World Podostemoideae, only Angolaea is known to have three stamens, and these are free (Fig. 115C). 4. Many Podostemoideae, including most from the Old World, are characterised by flowers with two stamens having an andropodium at least 1 mm long. Thus, the androecium appears to be Y-shaped (Fig. 104I), and the family name ‘Podostemaceae’ (based on the genus Podostemum) refers to this distinctive feature. In all members with plagiotropous floriferous shoots (e.g. Castelnavia spp., Zeylanidium olivaceum, Fig. 124E), the andropodium is situated towards the substratum (Willis 1902; Jäger-Zürn 2000b). In Zeylanidium lichenoides, there are exceptional flowers with 3 or 4 stamens with 2 tepals inserted at different levels along the andropodium (Mathew and Satheesh 1997). Three stamens per andropodium occasionally occur in species of African genera such as Ledermanniella, Leiothylax, Macropodiella, Winklerella and Zehnderia (Engler 1928; Cusset 1987; Léonard 1993), while some populations of Podostemum ceratophyllum have a high percentage of flowers with 3–7 stamens per andropodium (Philbrick and Bogle 1988). On the other hand, there is sometimes only a single stamen in, e.g. Letestuella tisserantii and Oserya coulteri (Warming 1899; Taylor 1953; Cusset 1980, 1987). 5. In a few species, there is always only one stamen per flower associated with two lateral tepals, e.g. Polypleurum schmidtianum; the other species of Polypleurum usually have two stamens per flower and an andropodium (Cusset 1992). Three tepals, one on each side of the solitary stamen and one on the back of it, are found in Devillea (syn. Podostemum flagelliforme, Philbrick and Novelo 2004). In Tristichoideae, the perianth is in one whorl with three imbricate, sepal-like segments which protect the flower. The three tepals are basally fused or nearly free (Fig. 104J). The tristichoid flower usually has three stamens, except for the widespread

312


Tristicha trifaria which has one or, more rarely, two or three stamens (Cusset and Cusset 1989). The monotypic subfamily Weddellinoideae has 4–6 free, imbricate tepals. In contrast to the usually veinless scales along the floral shoots, tepal contains a minute vascular bundle. The flowers have 5–25 stamens (Fig. 105D; Jäger-Zürn 1997b; Rutishauser 1997). Podostemoideae with several stamens, such as species of Marathrum, Mourera and Rhyncholacis, tend to have elongate, 2–4 mm long anthers which are sagittate at their base (Fig. 104H), whereas the anthers of taxa with one or two stamens per flower are usually broader and shorter (Fig. 104I). The anthers mostly dehisce introrsely (to latrorsely), but the anthers of some species of the American genera Apinagia, Jenmaniella and Oserya are extrorse (van Royen 1951). The anthers of all tristichoid taxa are introrse and considerably flattened; they have a connective tip and a sagittate to cordate base (Fig. 104J; Cusset and Cusset 1988). The anthers of Weddellina are X-shaped, deeply emarginate at the top and cordate-sagittate at the base. Various Podostemoideae have a stalked ovary. Especially African taxa with an inverted flower in the unruptured spathella have a gynophore – a stalk-like structure which separates the ovary (capsule) from the insertion level of androecium and perianth. In Leiothylax and Zehnderia, the gynophore of mature capsules is up to 3 and 8 mm long respectively. A short gynophore is also found in a few American genera (Cipoia, Diamantina; Philbrick et al. 2004a). The ovary of many Podostemoideae is bicarpellate and usually bilocular, with a prominent central placenta and a thin septum. Bilocular ovaries represent the plesiomorphic condition in Podostemonoideae, occurring in most non-African members and some AfricanMadagascan taxa such as Endocaulos, Sphaerothylax, Thelethylax and Saxicolella in part (Jäger-Zürn 2000c; Ameka et al. 2002). Most African members have unilocular ovaries, occasionally with a rudimentary septum at the very base (Ameka et al. 2003). There are normally two free, linear stigmas (Fig. 104I). Some species, e.g. Hydrobryum griffithii, Zeylanidium lichenoides, are variable in stigma shape: in both taxa, . . . “every stage may be found from simple, narrow, subulate to broadly obcuneate with many teeth” (Willis 1902). The two stigmas of all Crenias spp., except one, are multilobed whereas the closely related Podostemum has two entire stigmas (Warming 1882; see also Philbrick and Novelo 2004 who incorporated Cre-

nias into Podostemum). A few taxa show stigmatic lobes which are united basally into a short stylar region (Marathrum schiedeanum, Fig. 104H). A single semi-globose stigma is found in Angolaea. Tristichoideae have three, simple, linear stigmas. The stigmas may be almost smooth (Tristicha trifaria) or hairy (Indotristicha ramosissima; Rutishauser and Huber 1991). The gynoecium of Weddellina (Weddellinoideae) consists of a bilocular ovary with a globular, papillose stigma. Weddellina shares the apical septum of the ovary with basal podostemoid genera such as Apinagia, Marathrum, Mourera and Rhyncholacis (Jäger-Zürn 1997b, 2003a, b). Embryology. Starting with Warming (1882), the embryology of various (especially Indian) members of Podostemaceae has been studied; summaries were given by Davis (1966), Kapil (1970), Battaglia (1987), Johri et al. (1992) and Mohan Ram and Sehgal (2001). Embryological data on African and American Podostemaceae, however, are scarce (Jäger-Zürn 1997b; Murguía-Sánchez et al. 2001, 2002). The ovules are anatropous, bitegmic and tenuinucellate. The inner integument is much shorter than the outer one, with the nucellus much exceeding the inner integument in all three subfamilies. Embryo sac development takes place in the nucellar region which projects beyond the inner integument. In all Podostemaceae investigated to date, the embryo sac deviates considerably from the usual pattern of angiosperms. A 4-celled embryo sac develops from four nuclei, the micropylar quartet, in the apical portion of the nucellus, whereas the basal nucellar region gives rise to a ‘nucellar plasmodium’, also called a ‘pseudo-embryo sac’. There are no antipodals. Embryo sac development of all Podostemaceae may be interpreted as following a reduced Allium type (Jäger-Zürn 1997b; MurguíaSanchez et al. 2001, 2002). Double fertilization has not been observed in Podostemaceae (observations in, e.g. Razi 1955, are doubtful). Thus, most, if not all Podostemaceae have single fertilization, the polar cell degenerating without being fertilized. Consequently, there is no endosperm, and its nutritive role is performed by the nucellar plasmodium. Embryogeny is always of the Solanad type (Engler 1928; Kapil 1970). Pollen Morphology. Pollen grain numbers per anther have been determined for a few Podostemaceae; for example, there are as few as 1,000

Podostemaceae

pollen grains per anther in Tristicha whereas there are up to more than 25,000 grains per anther in Apinagia longifolia and Mourera fluviatilis (Okada and Kato 2002). The pollen grains are relatively small: mean pollen diameter is 11–25 µm. The grains are typically spherical to ellipsoid, microechinate, with a tectate-granular sexine (ectexine) and a lamellar and/or granular nexine (endexine) in non-apertural regions. A tectate-columellate sexine, as is found elsewhere in most non-aquatic eudicots, is lacking in Podostemaceae. This granular exine architecture may be of adaptive significance for the aquatic habit (O’Neill et al. 1997; Osborn et al. 2000). Characters which vary among the taxa include the dispersal unit (grains may be dyads or tetrads), surface sculpture, infratectal granule size, and aperture morphology (Bezuidenhout 1964; O’Neill et al. 1997; Lobreau-Callen et al. 1998). In the presumably basal New World genera of Podostemoideae such as Apinagia, Marathrum, Mourera and Rhyncholacis, the pollen grains are shed in monads (Fig. 104K). In more derived Podostemoideae, including all Asian, Australian and many African taxa, they are in dyads (Fig. 104L; Bezuidenhout 1964; Jäger-Zürn 1967; Miyoshi and Kato 1982; Philbrick 1984; Vartak and Kumbhojkar 1984; Lobreau-Callen et al. 1998). Diamantina is the only genus which produces pollen in tetrads (Philbrick et al. 2004a). The grains of most Podostemoideae are echinate (spinulose) and tricolpate, but some species also have tetracolpate and even pentacolpate grains, e.g. Farmeria indica, Oserya coulteriana and Polypleurum stylosum (Fig. 104L; O’Neill et al. 1997). In Tristichoideae, the pollen is spherical and pantoporate with up to 16 pores which are often inconspicuous (Tristicha trifaria, Bezuidenhout 1964; O’Neill et al. 1997; Osborn et al. 2000). The grains of Weddellina squamulosa are ellipsoidal, tricolporate and rugulo-areolate (Fig. 104M; van Royen 1953; Lobreau-Callen et al. 1998). Occurrence of monads in Podostemaceae seems to be correlated with simultaneous microsporogenesis, whereas dyads are found in podostemoid taxa (e.g. Polypleurum, Zeylanidium) with successive microsporogenesis (Jäger-Zürn et al. 2005). Anthesis and Pollination. Anthesis of most Podostemaceae takes place in the air, or flowers developing under water may be cleistogamous (Philbrick 1984). The duration of anthesis is known for only a few species. Grubert (1974) observed that

313

it lasted 4–5 h in Weddellina and 1 day in Apinagia multibranchiata, Rhyncholacis penicillata and Mourera fluviatilis, whereas in Marathrum rubrum it was 3 or 4 days, according to Philbrick and Novelo (1998). Some American Podostemoideae (especially species of Apinagia, Mourera and Rhyncholacis) and Weddellina are polystemonous and pollinated by insects (e.g. Trigona bees), although additional wind pollination cannot be excluded (Gessner and Hammer 1962; Grubert 1974; Okada and Kato 2002). Wind pollination occurs in all Tristichoideae and those Podostemoideae which have less-conspicuous flowers, including all non-American Podostemoideae (Bezuidenhout 1964; Grubert 1974; Rutishauser and Huber 1991); normally, stamen number is reduced. In some oligostemonous Podostemoideae, self-pollination, including pre-anthesis cleistogamy within the unruptured spathella, may be more frequent than allogamy (e.g. in Griffithella, Hydrobryopsis, Leiothylax warmingii, Podostemum ceratophyllum, Polypleurum stylosum; Philbrick 1984; Khosla and Mohan-Ram 1993; Khosla et al. 2000, 2001). Okada and Kato (2002) found low pollen:ovule ratios in autogamous podostemads, while allogamous species have high values. Fruits and Seeds. The period from flowering to capsule maturation is up to 2 or 3 weeks in species of Apinagia, Mourera, Rhyncholacis and Weddellina (Grubert 1974). Philbrick and Novelo (1998) observed in Marathrum rubrum apparently mature capsules 9 days after anthesis; the capsules were brown, with prominent longitudinal ribs and a dark, hardened pedicel lacking outer parenchymatous tissue. In Marathrum and Vanroyenella, the seeds require at least an additional 2 weeks to develop within the capsule (Philbrick and Novelo 1995). The fruits of Polypleurum stylosum appear to mature in the incredibly short period of 4 or 5 days after pollination (Khosla et al. 2000). The fruits of most Podostemaceae are septicidal capsules. Farmeria metzgerioides seems to be the sole exception, in having indehiscent fruits with one or rarely two mature seeds (Willis 1902). Mature capsules are usually about the same size as the ovaries during anthesis; capsules can be 1–3 mm long in Zeylanidium, 3–6 mm long in Marathrum, or up to 13 mm long in Mourera fluviatilis. Capsule symmetry and the number of capsule ribs are used as convenient taxonomic characters in subfamily Podostemoideae. The ribs become more prominent once the capsule is mature and the epider-

314


mis and outer parenchymous cortex have been lost (Rutishauser and Pfeifer 2002; Ameka et al. 2003). The sutures are often marked by twin-ribs. In our generic descriptions, the number of ribs per valve ignores the sutures. Using a wider generic concept, genera such as Cladopus, Podostemum sensu lato and Zeylanidium all have species with both smooth and ribbed capsules (Philbrick and Novelo 2004). There are two valves which are either equal (isolobous, Fig. 123D) or unequal (anisolobous, Figs. 108F, 121E). The seeds of most Podostemaceae are nearly the same size as the ovules; they are very small (± 0.1–0.3 mm long) and probably dispersed by wind or water. Ornithochory is also possible; the sticky seed coat (myxospermy) suggests that the seeds could adhere to the feet of birds walking over exposed rocks (Philbrick 1984). In Polypleurum stylosum, there are 1,200,000 seeds per gram and in Griffithella hookeriana 700,000 seeds per gram (Vidyashankari 1988b; Khosla and Mohan Ram 1993). Podostemoideae vary considerably in seed number per capsule: 2,000–2,400 seeds per fruit have been counted in Mourera fluviatilis, 300–700 in Apinagia, Marathrum and Rhyncholacis, less than 300 in Asian taxa such as Cladopus and Polypleurum, ± 30 in Hydrobryum, 4–8 in Farmeria indica and only two in F. metzgerioides (Philbrick and Novelo 1997; Rutishauser 1997; Khosla et al. 2000). Ovule number, seed number and seed size in Central and North American species have been reviewed by Philbrick and Novelo (1997). Seeds can remain viable for up to 18 months when stored dry (Vidyashankari and Mohan Ram 1987; Vidyashankari 1988a; Philbrick and Novelo 1998). Seedlings and Life Cycle. Most species are annual but some are perennial as long as they remain submersed. Oserya spp., Podostemum ceratophyllum and some races of Tristicha trifaria are habitually perennial and tend to have fewer ovules than the annual species (Philbrick 1984; Philbrick and Novelo 1997). Germination is correlated with rainy seasons (Willis 1902; Mohan Ram and Sehgal 1992; Philbrick and Novelo 1995). The seeds become sticky when wet, due to expanding mucilage cells of the outer integument (Grubert 1970, 1976; Philbrick and Novelo 1997). Germination takes place at the beginning of the rainy season. The seedling has two cotyledons and a plumule which usually stops growth after some appendages develop (e.g. Indotristicha ramosissima; Schnell and

Cusset 1963; Vidyashankari 1988a; Mohan Ram and Sehgal 1997, 2001; Sehgal et al. 2002). However, no plumular activity was seen in Hydrobryum, according to Suzuki et al. (2002). Zeylanidium olivaceum seems to be the only Asian taxon with a persistent seedling axis (Jäger-Zürn 2003b) but, in New World taxa such as Apinagia spp., Mourera fluviatilis and Weddellina squamulosa, the plumule gives rise to vigorous shoots (Grubert 1976; Rutishauser and Grubert 1999). The radicular pole may rarely develop a rudimentary primary root, according to Kita and Kato (2005). In seedlings with short-lived plumules, development continues by lateral endogenous or exogenous outgrowths of the hypocotyledonary region which are usually called secondary roots or adventitious roots (Rauh 1937; Grubert 1970, 1976; Philbrick 1984; Sehgal et al. 2002; Suzuki et al. 2002). Karyology. Podostemaceae are cytologically poorly known. Oropeza et al. (1998, 2002) reviewed the existing literature and estimated that worldwide only 3.3% of the species have been cytologically investigated, none of them from Africa. Chromosome numbers are clearly very variable. The following numbers have been reported: n = 8, 10, 12, 14, 20; 2n = 20, 26, 28, 30, 34, 40. For example, Uniyal and Mohan Ram (1994) counted 2n = 34 in Polypleurum stylosum, 2n = 26 in Zeylanidium (syn. Hydrobryopsis) sessilis, and 2n = 30 in Dalzellia zeylanica (see also Mohan Ram and Sehgal 2001). Phytochemistry. Burkhardt et al. (1992, 1994) examined species of Mourera and Rhyncholacis; Romo Contreras et al. (1993) examined Marathrum, Oserya, Podostemum, Tristicha and Vanroyenella, all from the New World. Two xanthone aglycones with the following oxidation patterns were detected: 1,3,5-trihydroxylation in Mourera and 1,3,6,7-tetrahydroxylation in Marathrum, Oserya and Vanroyenella. Xanthones are also known in Weddellina (Weddellinoideae) but are not known from Tristichoideae (Kato et al. 2005). In Podostemum ceratophyllum, γ-mangostin and its 6-glucoside was found. Classification. The division of Podostemaceae into three subfamilies proposed by Engler (1928) is followed in this treatment. Tristichoideae and Weddellinoideae are clearly distinguishable from the large subfamily Podostemoideae. Tristichoideae, Weddellinoideae and then the New World Mourera,

Podostemaceae

Apinagia, Marathrum and Oserya within Podostemoideae are successive sister taxa (Les et al. 1997; Kita and Kato 2001; Kato et al. 2003). Basal members of Podostemaceae are (in ascending order) the Tristichoideae, Weddellinoideae and the New World genera Mourera, Apinagia, Marathrum and Oserya within Podostemoideae (Les et al. 1997; Kita and Kato 2001; Kato et al. 2003). All podostemoids studied from continental Africa form a clade which is sister to the Madagascan genera Endocaulos and Thelethylax. The sister of this African-Madagascan lineage is the American genus Podostemum and all Asian podostemoids (Moline et al. 2007). At present, considerable work is being devoted at the family and a reduction in the number of genera and species would be expected – the reverse is the case. As many as four new genera were described within the last years: Cipoia C.T. Philbrick, Novelo & Irgang, Diamantina Novelo, C.T. Philbrick & Irgang, Thawatchaia M. Kato, Koi & Y. Kita, and Vanroyenella Novelo & Philbrick. Using a rather wide genus concept, we have merged several small genera with closely related genera, e.g. Cladopus (incl. Torrenticola), Hydrobryum (incl. Synstylis), Tristicha (incl. Malaccotristicha and Terniopsis), Zeylanidium (incl. Hydrobryopsis). A few monotypic genera, however, are maintained, despite other botanists (Cheek et al. 2000; Philbrick and Novelo 2004) having merged these with larger genera, e.g. Butumia (not included in Saxicolella), Crenias and Devillea (not included in Podostemum). However, a complete resolution of the phylogeny of the family has not yet been achieved and we present the podostemoid genera in alphabetic sequence. Affinities. The relationships of Podostemaceae within the angiosperms remained unresolved for more than a century and a half, and quite divergent affinities have been hypothesized. Cusset and Cusset (1988) even proposed to place them in the class Podostemopsida coordinate with monocotyledons and dicotyledons. A closer relationship of Podostemaceae to eudicots, especially Saxifragales, and with Crassulaceae in particular was suggested by Mauritzon (1933), Kapil (1970), Les et al. (1997) and Ueda et al. (1997); the highly developed suspensor haustorium, and other embryological characters seemed to support this position. Hydrostachyaceae, also highly modified plants of river rapids in Africa (especially Madagascar), are probably not close to Podostemaceae, as molecular

315

evidence indicates that Hydrostachyaceae belong to Cornales, in the asterids (see Vol. VI of this series). Recent results based on analysis of rbcL, matK and 18S rDNA sequences indicate that Podostemaceae are members of eurosid I Malpighiales. Within Malpighiales, Clusiaceae/Hypericaceae and Bonnetiaceae appear to be most closely related (Soltis et al. 1999; Chase et al. 2000; Savolainen, Fay et al. 2000; Kita and Kato 2001; Gustafsson et al. 2002; Suzuki et al. 2002). From the shared common ancestor hypothesized for Hypericum and the two genera of Podostemaceae (Tristicha, Marathrum) included in the molecular analysis by Savolainen, Fay et al. (2000), the estimated branch length for Tristicha and Marathrum is twice that for Hypericum, which makes it appear as though rbcL is evolving twice as fast in Podostemaceae as in Hypericaceae (Chase et al. 2000). Non-molecular evidence that Podostemaceae are related to Clusiaceae includes the polystemonous and centrifugal androecium in both families (see, e.g. Mourera fluviatilis, Fig. 104G; Rutishauser and Grubert 1999), tenuinucellate ovules, resin cells and/or latex channels (Gustafsson et al. 2002). Distinctive xanthones are shared by some Podostemaceae, Clusiaceae and Bonnetiaceae (APG II 2003; Kato et al. 2005; Stevens 2005). Distribution and Habitats. Podostemaceae are cosmopolitan in tropical regions of the world, extending into warm-temperate eastern North America and East Asia (Engler 1928; Mathew and Satheesh 1997). They grow in flowing water and are therefore confined to hilly regions, being largely absent from the Amazon, Congo and Gangetic plains. Most of the species are restricted to small geographical areas; only one species, Tristicha trifaria, is widespread and occurs in the Old and New World (Kato et al. 2003). Kita and Kato (2004a) found that the American and West African T. trifaria are closely related, despite the great distance between their locations. The biogeographic history of the Asian genera Cladopus and Hydrobryum was explored by Kita and Kato (2004b) using molecular data. Their matK phylogeny revealed that the East Asian temperate species of both genera form monophyletic groups which are derived from tropical/subtropical species. Much has been published on the ecology of Podostemaceae; see especially Gessner and Hammer (1962), Grubert (1970, 1974, 1976, 1991), Léonard (1993) and Noro et al. (1994a, b). Podostemaceae

316


are haptophytes normally fixed to a hard substrate in rapids and waterfalls, usually in sunny places. In most species, flowering takes place when the water level drops. The substrate does not seem to be important as long as it is hard; C.D.K. Cook has seen Polypleurum stylosum growing on wood, concrete and a discarded bicycle in southern India. Most reports, e.g. Pannier (1960), Gessner and Hammer (1962), Quiroz et al. (1997) and OdinetzCollart et al. (2001), state that Podostemaceae grow in oligotrophic and oxygen-rich water. Endemism, Conservation Biology and Population Structure. Most species occupy rather small areas, often being confined to a single set of river-rapids or a single river. About half of all American species are very local endemics (van Royen 1951, 1953, 1954; Tur 1997; Cook 1999). The very high degree of endemism may well be a taxonomic artefact because few species have been sufficiently studied, and the related group of species of one taxonomist may be seen as environmental forms by others (see Novelo and Philbrick 1997). Various localities of endangered New and Old World taxa have already been lost due to industrial pollution, hydroelectric power plants and for other reasons (Grubert 1991; Mohan Ram and Sehgal 2001). A continuous and consistent effort is required to improve methods of ex situ and in situ conservation (Mohan Ram and Sehgal 2001). Ex situ culture and, thus, ex situ conservation of Podostemaceae were impossible until recently, but Mohan Ram and his school started to cultivate Podostemaceae using in vitro techniques. Polypleurum stylosum was the first podostemad grown in vitro until it flowered (Sehgal et al. 1993). Various podostemads have been cultivated in vitro since then (Uniyal and Mohan Ram 1996; Mohan Ram and Sehgal 1997, 2001; Imaichi et al. 2004; Kita and Kato 2005). Isozyme variation and population structure was studied by Philbrick and Crow (1992) in the perennial Podostemum ceratophyllum, which is the only northern temperate member of New World Podostemaceae. A population of this species even grows near the sea in a freshwater river under tidal influence, as described by Capers and Les (2001). Plant-Animal Interactions. According to Gessner and Hammer (1962), Mourera is an important food for fish. A fisherman on the Essequibo River in Guyana reported to C.D.K. Cook that some fish species are confined to stands of Podostemaceae. Connelly et al. (1999) describe

the riverweed darter (Etheostoma podostemonae), a small freshwater fish of the perch family, as being closely associated with the habitats of Podostemum ceratophyllum in North America. Hutchens et al. (2004) found a strong positive relationship between surface area of Podostemum ceratophyllum and macroinvertebrate abundance and biomass. Léonard and Dessart (1994) report that some species of the Torridincolidae (Myxophaga, Coleoptera) possibly have a symbiotic relationship with Ledermanniella, Leiothylax and Macropodiella in Central Africa. Palaeobotany. According to Collinson et al. (1993), the earliest fossil records are leaves, named Nitophyllites zaisanica, from the Upper Eocene from the Zaisan Basin in Russia. Leaves and flowers have been reported from the Pliocene in Poland and there are records from the Lower Miocene in Germany; Mai (1985) doubts that the material is correctly identified. Economic Importance. According to van Royen (1951), in Panama and Colombia Podostemaceae are used as forage in the dry season – cattle are driven into the river to graze. Cusset (1987) records that Dicraeanthus africanus, Macropodiella heteromorpha, Marathrum foeniculaceum and Thelethylax minutiflora are eaten as salad or vegetable. Leaves of Rhyncholacis sp. are dried and pulverized and used as a pepper-like seasoning (Philbrick and Novelo 1995, citing R. Schultes). Amerindians extract salt from the burnt leaves of Mourera fluviatilis and other large species. Salt can be also produced from Ledermanniella warmingiana, as described by Gilg (cited in Warming 1901). Marathrum utile is reported to be refreshing and febricidal (van Royen 1951). In parts of Mexico, species of Marathrum are evidently employed as a liver treatment (Philbrick and Novelo 1995). Rhynchonin A (a chromene newly found in Rhyncholacis penicillata) showed broad insecticidal, acaricidal and nematicidal potency, including strong biological activity against Heliothis zea (Burkhardt et al. 1994).

Keys to the Genera In the key and taxonomic treatment, genera are dealt with in three separate geographic groups – American, African (including Madagascan) and

Podostemaceae

Asian/Australian. Only the genera Tristicha and Cladopus (including Torrenticola) occur on more than one continent. Within the geographical groups, genera are presented alphabetically; the present state of knowledge does not permit to arrange them in a phylogenetically meaningful order. The number of ribs per valve ignores the lateral sutures but includes the midrib when it is rib-like. Key to the Genera of America 1. Tepals filamentous, subulate or scale-like, free, 2–20, not enclosing young flowers; young flowers totally enclosed in a spathella (a sack-like cover); ovary 2-locular 3 – Tepals broad and imbricate, oblanceolate to ovate, 3– 6, free or united below, enclosing the young flowers; young flowers may be enveloped by a few leaves but are never enclosed in a spathella; ovary 2- or 3-locular 2 2. Tepals 5 or rarely 4 or 6; stamens 5–25; capsule opening by 2 valves (Northern to central South America) 1. Weddellina – Tepals 3; stamens 1, 2 or rarely 3; capsule opening by 3 valves (America, also in Africa, Madagascar, Malaysia, Australia) 2. Tristicha 3. Spathellas containing 10–20 flowers (Colombia) 15. Macarenia – Spathellas containing a single flower 4 4. Flowers not in 2-sided, raceme-like inflorescences; leaves not rough, without wart-like and prickle-like processes on the upper surface 7 – Flowers in 2-sided, simple or branched, raceme-like inflorescences; leaves with (more rarely, without) warts and/or prickles on the upper surface 5 5. Stamen filaments united to halfway or slightly less, forming a tube below (Brazil) 21. Tulasneantha – Stamen filaments free or rarely some united at the very base, not forming a tube below, usually persisting in fruit 6 6. Stamen filaments flat, widened and wing-like, elliptic, membranous; stigmas flattened, crested (Brazil) 13. Lonchostephus – Stamen filaments linear, terete, not winged; stigmas linear or spathulate, not crested (widespread in South America) 17. Mourera 7. Capsules strongly asymmetrical when viewed laterally; upper capsule valve smaller and narrower than the lower and almost free from the pedicel, the lower valve saucer-shaped (central Brazil) 6. Castelnavia – Capsules symmetrical or asymmetrical when viewed laterally; upper and lower capsule valves distinctly attached to the pedicel, boat- or cup-shaped 8 8. Roots thread-like, cylindrical or sometimes somewhat flattened 9 – Roots usually distinctly flattened, ribbon-like 14 9. Shoots solitary, borne at irregular intervals along the root (SE Brazil) 10. Devillea – Shoots in ± opposite pairs, borne at almost regular intervals along the root 10 10. Leaves bearing 3–8 digitally arranged segments on expanded and sheathing bases (Minas Gerais, Brazil) 11. Diamantina

317

– Leaves simple or forked, never digitate 11 11. Capsules smooth; stigmas palmately lobed or (in Crenias glazioviana) simple (SE Brazil) 9. Crenias – Capsules ribbed; stigmas simple 12 12. Capsules with 2 subequal or unequal valves, the suture slightly acentric; stamens 2 or rarely 1 or 3 (Central and South America) 18. Oserya – Capsules with 2 equal or subequal valves, the suture centric or nearly so 13 13. Flowering stems sympodially branched, elongate, each module bearing 2 or rarely 1 leaf (widespread in South America) 5. Apinagia – Flowering stems simple and short, each one bearing several leaves (NE South America) 12. Jenmaniella 14. Ovary enclosed within the ruptured spathella during anthesis, only stigmas and stamens projecting; stamen 1 (Minas Gerais, Brazil) 8. Cipoia – Ovary emerging above the ruptured spathella during anthesis; stamens 2 or more, or rarely 1 in some flowers 15 15. Stamens 2 or more, free 19 – Stamens normally 2, united below or borne on an andropodium, occasional flowers with 1 stamen 16 16. Stigmas persisting in fruit, horn-like; midrib of each capsule valve running into the stigma (SE Brazil) 7. Ceratolacis – Stigmas withering after anthesis, simple or palmately branched, never horn-like; midrib of each capsule valve not running into the stigma 17 17. Capsules smooth, not ribbed, globose; stigmas palmately lobed or (in Crenias glazioviana) simple, with hair-like papillae (SE Brazil) 9. Crenias – Capsule valves each with 3 ribs, ovoid to spindleshaped; stigmas simple, with inconspicuous papillae 18 18. Capsules ellipsoidal, opening by 2 equal valves; pollen shed in monads (mainly NE South America) 12. Jenmaniella – Capsules ovoid, opening by 2 unequal valves, the larger usually persistent; pollen shed in dyads (tropical to temperate America) 19. Podostemum 19. Stigmas flattened, lobed or serrated at the apex, somewhat resembling a cock’s comb (C Brazil) 14. Lophogyne – Stigmas terete or flattened, when flattened, then entire or toothed but not resembling a cock’s comb 20 20. Capsules flattened; midrib of each capsule valve winged, the remaining ribs unwinged (N South America) 20. Rhyncholacis – Capsules terete; midrib of the capsule valves not winged or, if winged, then other ribs also winged 21 21. Pinnae and pinnules of the leaves with scale-like stipels; capsule valves each with 5 ribs (S Brazil) 23. Wettsteiniola – Pinnae and pinnules naked, without free stipels; capsule valves each with 1–7 ribs 22 22. Capsule valves each with 5 or 7 ribs (Central and South America) 5. Apinagia – Capsule valves each with 3 or less ribs or furrows 23 23. Stems elongate, frequently branched (Central and South America) 5. Apinagia – Stems very short, never branched 24 24. Capsule valves without ribs or each with 3 grooves or stripes 5. Apinagia

318


– Capsule valves each with 3 ribs 25 25. Capsule ribs winged (West Indies, Central and NW South America) 16. Marathrum – Capsule ribs not winged 26 26. Stigmas linear, not toothed (Central and South America) 5. Apinagia – Stigmas boat- or spoon-shaped, often toothed 27 27. Leaf blades repeatedly pinnate or forked; stamens 2– 40; stamen filaments deciduous after anthesis (West Indies, Central and NW South America) 16. Marathrum – Leaf blades plumose with the smallest segments forked and hair-like; stamens 2 or 3; stamen filaments persistent and indurate, remaining attached to the ribs of the capsule after anthesis (W Mexico) 22. Vanroyenella

Key to the Genera of Africa and Madagascar 1. Tepals 2 or occasionally 3 or 4, not imbricate, restricted to one side of the flower, linear to subulate; young flowers totally enclosed in a spathella (a sack-like cover); capsules opening by 2 valves 2 – Tepals 3, imbricate, surrounding the young flowers, ovate to oblong-obovate; young flowers not enclosed in a spathella; capsules opening by 3 valves (widespread in Africa and Madagascar) 2. Tristicha 2. Stigma 1, semi-globose; stamens 3 or rarely 4, united only at the base (Angola) 24. Angolaea – Stigmas 2, linear, horn-like, or flattened and lobed; stamens 1, 2 or rarely 3, when 2 or 3, then borne on an elongate andropodium 3 3. Flowers erect or rarely slightly inclined within the unruptured spathellas 13 – Flowers inverted or strongly inclined within the unruptured spathellas 4 4. Tepals 2, 1 each side of the andropodium base, without an appendage between the stamens 6 – Tepals 3, 1 each side of the andropodium base and 1 borne terminally on the andropodium between the stamens 5 5. Capsules broadly ellipsoidal; capsule valves each with 5 or 7 narrow ribs, those closest to the sutures not reaching the base and the apex (tropical W Africa) 36. Stonesia – Capsules obovoid; capsule valves each with 3 wide ribs, each extending from base to apex (Madagascar) 37. Thelethylax 6. Capsules smooth, globose or subglobose (Cameroon, D.R. Congo, Zambia) 30. Leiothylax – Capsules with longitudinal ribs or wings, laterally flattened or cylindrical to ellipsoidal or globose 7 7. Ovaries and capsules terete, not flattened; capsules without winged nerves 9 – Ovaries and capsules flattened; capsules with or without winged nerves 8 8. Capsules strongly flattened, with winged middle nerves; wings longer than the capsule and forming apical horns; stamens 2 (Cameroon) 38. Winklerella – Capsules slightly to strongly flattened, without wings or apical horns; stamens 1, 2 or 3 (tropical W Africa) 32. Macropodiella 9. Capsules ovoid-ellipsoidal or partly cylindrical 11

– Capsules globose or subglobose 10 10. Pedicels less than 5 mm long; capsules sessile or borne on minute gynophores; stamen 1 or perhaps sometimes 2; pollen shed in dyads (Madagascar, tropical and South Africa) 35. Sphaerothylax – Pedicels up to 15 mm long; capsules borne on up to 8 mm long gynophores; stamens 2 or rarely 3; pollen shed in monads (Cameroon) 39. Zehnderia 11. Flowers or flower clusters arranged in one row along the shoot; andropodium usually less than 1 mm long; stigmas conical, erect, rigid; capsules cylindrical to oblong (W and C Africa) 26. Dicraeanthus – Flowers or flower clusters arranged around the shoot, rarely in a row; andropodium usually much exceeding 1 mm long; stigmas linear, spreading or reflexed, flexible; capsules obovoid to ovoid or fusiform 12 12. Capsule valves each with 3 narrow or occasionally crest-like ribs; capsules ovoid to ellipsoidal or fusiform (species rich and widespread in tropical Africa) 29. Ledermanniella – Capsule valves each with 3 wide and flattened ribs; capsules obovoid (Madagascar) 37. Thelethylax 13. Capsule valves equal, usually both persistent; capsule sutures centric 15 – Capsule valves somewhat unequal, one valve caducous, the other persistent on pedicel or gynophore; capsule sutures acentric and oblique 14 14. Stamen 1; capsules globose or subglobose; capsule valves each with 3 wide ribs, each extending from base to apex (Cameroon) 27. Djinga – Stamens 2, borne on an andropodium; capsules asymmetrically ovoid and somewhat laterally flattened; capsule valves each with 7 narrow ribs, those closest to the sutures not reaching the base and the apex (Madagascar) 28. Endocaulos 15. Capsules globose or subglobose, smooth and shiny (W Africa from Namibia to Niger) 31. Letestuella – Capsules ovoid to ellipsoidal or fusiform, with longitudinal ribs 16 16. Flowering stems covered with at least 8 but usually many more, overlapping, scale-like leaves; stamens 2, borne on an andropodium (Madagascar) 33. Paleodicraeia – Flowering stems with elongate, simple or forked leaves or, if leaves scale-like, then rarely more than 4; stamen 1 17 17. Leaves below the flowers scale-like, shorter than the flowers; capsules ovoid, laterally flattened; stigmas unequal, flattened, elliptic to ovate in outline (Nigeria) 25. Butumia – Leaves below the flowers linear or divided into linear segments, longer than the flowers; capsules elliptic to fusiform, terete; stigmas equal, linear (tropical W Africa) 34. Saxicolella

Key to the Genera of Asia and Australia 1. Tepals 2 or occasionally 3 or 4, restricted to one side of the flower, linear to subulate, not imbricate; young flowers totally enclosed in a spathella (a sack-like cover); capsules opening by 2 valves or indehiscent; stamens 1

Podostemaceae

–

2. –

3.

–

4. – 5. – 6. – 7.

–

8. – 9. – 10.

–

11.

or 2, when 2, then borne on an andropodium; pollen shed as dyads 4 Tepals 3, surrounding the young flowers, ovate to oblong-obovate, imbricate; young flowers not enclosed in a spathella; capsules opening by 3 valves; stamens 1–3, free; pollen shed as monads 2 Stems at least partly elongate, bearing ramuli (mosslike branchlets with scale-like or linear appendages); roots elongate, thread-like or ribbon-like 3 Stems flattened, closely attached to substrate, crustose (foliose), without ramuli, often bearing photosynthetic scales above; roots absent or flattened and somewhat irregular in shape (S and SE Asia) 3. Dalzellia Flowers borne on slender pedicels without cup-like structures at the base; stems variable, often creeping, when free, then usually considerably less than 10 cm long; ramuli with scales arranged in 3 rows (China, Malaysia, Australia) 2. Tristicha Flowers arising from cup-like structures of united scales and ramuli; stems usually free, branched, up to 60 cm long; scales or linear appendages of ramuli arranged in many rows or irregularly scattered (S India) 4. Indotristicha Leaves or scales on flowering stems all entire 8 Leaves or scales on flowering stems with at least some divided into 2–8 simple lobes or lateral teeth 5 Leaves or scales on flowering stems arranged in 2 rows or appearing to be irregular 7 Leaves or scales of flowering stems arranged in 4 or 6 neat rows 6 Capsule valves unequal, the larger persisting; 2 of the rows of leaves or scales on flowering stems with filamentous tips (SW India) 48. Willisia Capsule valves equal; 2 of the rows of leaves or scales on flowering stems 2-lobed (N Thailand) 44. Hanseniella Capsule valves equal; spathellas thick, with 2 or 3 ridges; stamens mostly 2, borne on an andropodium; leaves or scales on flowering stems mostly 3-lobed (N Thailand) 47. Thawatchaia Capsule valves unequal; spathellas thin, without ridges; stamen mostly 1, simple; leaves or scales on flowering stems 2-to 8-lobed, rarely consistently 3-lobed (E and SE Asia, New Guinea, NE Australia) 40. Cladopus Capsule valves unequal, the smaller one caducous 11 Capsule valves equal, usually both persisting or sometimes both caducous 9 Capsule valves each with 9 fine ribs (excluding the lateral sutures); capsules laterally flattened (Vietnam, Laos) 41. Diplobryum Capsule valves each with 2–6 ribs (excluding the lateral sutures); capsules ± terete 10 Roots crustose, closely attached to substrate; flowers usually subsessile, scarcely raised above the spathella at anthesis (E Himalaya, S China, E and SE Asia) 45. Hydrobryum Roots elongate (ribbon- or thread-like), with the distal part usually free and floating; flowers pedicellate, held well above the spathella at anthesis (Sri Lanka, India, Thailand) 46. Polypleurum Flowers sessile or nearly so, usually remaining within the opened spathella or barely emerging above it; pedicels not more than 1 mm long; shoots confined to the margins of elongate roots; stamen 1 (consistently

–

12. – 13

–

319

so from flower to flower); stigmas unequal; capsules indehiscent or dehiscent; seeds 1–8(–18) (S India, Sri Lanka) 42. Farmeria Flowers stalked or subsessile, emerging above the opened spathella; pedicels usually more than 1 mm long; flowering shoots developing from the upper surface of crustose (foliose) roots or in the sinuses of lobed, ribbon- or thread-like roots; stamens 2, borne on an andropodium or rarely 1 (usually some flowers with 2); stigmas equal; capsules dehiscent; seeds 12 to numerous 12 Capsules with prominent, longitudinal ribs (Sri Lanka, S, W and NE India, Myanmar) 49. Zeylanidium Capsules smooth or obscurely ribbed 13 Spathellas erect, funnel-shaped, splitting into several rather irregular apical teeth; roots irregular in form, varying from star- to cup-shaped or ribbon-like but not regularly pinnate (S India) 43. Griffithella Spathellas prostrate, boat-shaped, splitting longitudinally; roots ± regularly, pinnately branched (S India) 49. Zeylanidium

Genera of Podostemaceae I. Subfam. Weddellinoideae (Warming) Engler (1928). Young flowers not enclosed in spathella or cupule; tepals (4)5(6), imbricate; stamens 5–25, free; pollen tricolporate, shed in monads; ovary 2-locular; capsule opening by 2 equal valves; valves with 1 rib-like midrib and 2 lateral ribs. Only one genus, Weddellina Tulasne, northern to central South America. 1. Weddellina Tulasne

Figs. 104F, M, 105A–D

Weddellina Tulasne, Ann. Sci. Nat., Bot. III, 11:90, 113 (1849).

Roots thread-like, laterally flattened, up to 2 mm wide, creeping, branched, with numerous disk-like holdfasts; stems arising laterally from the root; vegetative stems erect, up to 80 cm long, irregularly pinnately branched; branches thickly covered with entire or divided scale-like leaves and bunches of photosynthetic filaments; flowering stems unlike vegetative ones, unbranched, 2–12 cm long, bearing scale-like leaves and solitary terminal flowers. Flowers enveloped in scale-like leaves when young; scale-like leaves intergrading with tepals and usually spirally arranged; tepals oblanceolate, 3–6 mm long, free or slightly united at base, pink to lilac or white; stamen filaments terete. Capsules ellipsoidal to subglobose, 2.5–4 mm long; style linear, 0.5–1 mm long; stigma capitate; seeds ± 160. One species, W. squamulosa Tulasne, with two ‘formae’, northern to central South America.

320


Fig. 105. Podostemaceae-Weddellinoideae. Weddellina squamulosa. A Sterile shoot with photosynthetic filaments and scales (2 cm). B Sterile shoot with scales (1.5 cm). C Root with endogenous holdfasts and a fertile shoot with terminal capsule (1 cm). D Flower (2.5 mm). (Drawn by Cook)

muli moss-like, 2–4 cm long; scale-like appendages of ramuli entire or divided, arranged in 3 rows, usually 2 rows spreading and the third row smaller and appressed. Flowers solitary or sometimes in clusters, pedicellate; tepals 3, lanceolate to narrowly ovate, free or united at the base. Capsules ellipsoidal to ovoid; style short; stigmas linear, simple or rarely forked. Seeds up to ± 70. Probably only one, very polymorphic species, T. trifaria (Bory ex Willdenow) Sprengel, or up to 6 species, tropical America, Africa, Madagascar, Mascarene Islands, Malaysia, East China and north-eastern Australia. Terniopsis sessilis Chao, Tristicha australis C. Cusset & G. Cusset [= Malaccotristicha australis (C. Cusset & G. Cusset) M. Kato] and Malaccotristicha malayana (Dransfield & Whitmore) C. Cusset & G. Cusset seem to be no more than prostrate states of Tristicha trifaria. 3. Dalzellia R. Wight

II. Subfam. Tristichoideae (J.C. Willis) Engler (1928). Young flowers either exposed or, in Dalzellia and Indotristicha, enclosed in cupule (collar-like, vascularised cup); spathella 0; tepals 3, imbricate; stamens 1–3, free; pollen pantoporate with up to 16 pores, shed in monads; ovary 3-locular; stigmas 3; capsule opening by 3 equal valves; each valve with 1 rib-like midrib and 2 lateral ribs. Three genera (using a wide genus concept), tropical America, tropical and southern Africa, Madagascar, Mascarene Islands, South and Southeast Asia and northern Australia.

Fig. 106D–F

Dalzellia R. Wight, Ic.. Pl. Ind. Orient. 5, 2:34, t. 1919, 1920, 1919 (1852). Lawia Griffith ex Tulasne (1849), nom. illegit. Mnianthus Walpers (1852). Terniola Tulasne (1852). Tulasnea R. Wight (1852), nom. illegit.

2. Tristicha Du Petit-Thouars Figs. 104E, J, 106A–C Tristicha Du Petit-Thouars, Gen. Nova Madag. 3 (1806). Dufourea Bory (1810), nom. illegit. Philocrena Bongard (1837). Potamobryum Liebmann (1849). Tristichopsis A. Chevalier (1938), nom. illegit. Terniopsis H.C. Chao (dated 1948, publ. 1949). Heterotristicha Tobler (1953). Dalzellia non R. Wight, sensu Cusset & Cusset (1988). Malaccotristicha C. Cusset & G. Cusset (1988).

Roots creeping, ± cylindrical or laterally flattened and ribbon-like, 0.5–1 mm wide, branched, attached to rock by disk-like holdfasts; stems polymorphic, creeping or floating; floating stems simple or branched, up to 10 cm long, bearing scales and ramuli (photosynthetic branchlets); ra-

Fig. 106. Podostemaceae-Tristichoideae. A–C Tristicha trifaria. A Creeping root with ramuli (5 mm). B Flower (0.5 mm). C Fruiting shoot with three ramuli (2 mm). D–F Dalzellia zeylanica. D Fragment of crustose plant with exogenous scales and an endogenously formed rosette (1 cm). E Flower (1 mm). F Stalked capsule (1 mm). (Drawn by Cook)

Podostemaceae

Roots 0 or, in D. gracilis Mathew, Jäger-Zürn & Nileena, flattened and irregular in outline; plant body closely attached to rock, flattened, crustose, often ± star-shaped, up to 35 cm in diameter, the lobes usually rather irregular. Leaves numerous, simple, scale-like or linear, occurring on upper surface and along edges of plant body or in closely packed rosettes arising on older parts; ramuli (photosynthetic branchlets) 0; rosettes forming cupules (cup-like structures) of many scales which surround the individual flowers, cupules apparently lacking in D. gracilis. Flowers solitary, terminal, pedicellate; pedicel 2–3 mm long at anthesis, elongating in fruit to 10–20 mm long; tepals 3, narrowly ovate to ovate, united below; stamens 3(2). Capsules ellipsoidal to ovoid, remaining within tepals until dehiscence; stigmas 3, ovate to linear. Seeds 200– 300. Four or perhaps more species, in South and Southeast Asia. 4. Indotristicha P. Royen

321

lacking, not imbricate, linear, spathulate or subulate; stamens 1–40, often free; many genera with Y-shaped androecium, consisting of 2 stamens borne on an andropodium (a common stalk); pollen tricolpate or sometimes tetracolpate or pentacolpate, shed in monads or dyads (Diamantina in tetrads); ovary 2-locular or rarely, due to absence of a septum, 1-locular; capsule opening by 2 equal or unequal valves, or rarely indehiscent. Forty-five genera, tropical America to temperate eastern North America, tropical and subtropical Africa, Madagascar, tropical South and Southeast Asia to temperate East Asia and tropical Australia.

Fig. 107A–H

Indotristicha P. Royen, Acta Bot. Neerl. 8:475 (1959).

Roots thread-like, much branched, creeping, with finger- or disk-like holdfasts arising from same buds as shoots; vegetative stems totally submerged, becoming discarded as the water recedes, arising from the root, branched, up to 60 cm long, bearing photosynthetic scales and ramuli (photosynthetic branchlets); ramuli up to 4 cm long, with scale-like to filamentous appendages arranged spirally or irregularly but never in 3 rows; flowering stems short, each densely clothed in ramuli and scales; uppermost scales and ramuli united at their bases and forming a cupule (cup-like structure) of 5–7 scales and 1–3 ramuli at base of pedicel. Flowers solitary, terminal on short-shoots, pedicellate; tepals elliptic to ovate, united below; stamens 3; stigmas linear. Seeds ± 100 in I. ramosissima. Two species, I. ramosissima (P. Wight) P. Royen and the poorly known I. tirunelveliana Sharma, Karthikeyan & Shetty, both from southern India. Molecular data (Kato et al. 2003) indicate that Indotristicha ramossissima and Dalzellia zeylandica (Gardner) Wight are closely related. III. Subfam. Podostemoideae (Warming) Engler (1928). Young flowers enclosed in spathella (a membranous, nonvascularised cover); tepals 2–20, rarely

Fig. 107. Podostemaceae-Tristichoideae. A–D Indotristicha ramosissima. A Vegetative shoot with some branches and ramuli removed (2 cm). B Fertile branch (2 mm). C Capsule (1 mm). D Fragment of vegetative shoot with one ramulus (2 cm). E–H Indotristicha tirunelveliana. E Tip of a flowering shoot with two ramuli (1 mm). F Ramulus with scales (1 mm). G Capsule viewed from the side with three perianth segments attached (1 mm). H Capsule viewed from above (1 mm). (Drawn by Cook)

322


Podostemoid Genera of America 5. Apinagia Tulasne emend. P. Royen Fig. 108A–C Apinagia Tulasne, Ann. Sci. Nat., Bot. III, 11:97 (1849); van Royen, Med. Bot. Mus. Herb. Rijksuniv. Utrecht 107:25–69, 128–131 (1951), rev. Ligea Poiteau ex Tulasne (1849). Oenone Tulasne (1849). Monostylis Tulasne (1853). Neolacis Weddell (1873).

Roots ribbon-like to ± cylindrical and thread-like, branched; holdfasts, in most species, develop from basal portions of root-borne stems; stems arising along root margins, usually in opposite or subopposite pairs, either very short, disk-like and appearing stemless or elongate, when elongate, then simple or branched, when flowering, then each module with rarely 1 or mostly 2 leaves with a flower between them. Leaves in species with disk-like stems united at their bases and confluent with short stems which serve as holdfasts, in species with elongate stems, free; petioles present or 0; sheaths simple or double; leaf blades very variable in shape, lanceolate, lobed to pinnatisect with the tips and, rarely also the lobes, highly divided into filamentous segments, flat portions of blades often with tufts of filaments on upper surface; ultimate filamentous segments sometimes inrolled when young. Spathellas clubshaped to tubular. Flowers solitary, in cyme-like inflorescences or as fascicles in cavities of disklike stems; pedicels (0.5–)1–7(–12) cm long; tepals 2–16, free or united, whorled or confined to one side of flower; stamens 1–30, whorled or confined to one side of flower; anthers dehiscing introrsely or, in 2 species, extrorsely; pollen in monads. Capsules ovoid; each valve with 1–7 ribs, the ribs sometimes unequal in length, sometimes represented by grooves or stripes; stigmas cylindrical to linear. Seeds 20 to ± 600. About 50 species, probably much less when critically examined, northern and central South America. 6. Castelnavia Tulasne & Weddell

Fig. 108D–F

Castelnavia Tulasne & Weddell, Ann. Sci. Nat., Bot. III, 11:108 (1849).

Roots absent in C. princeps Tulasne & Weddell and perhaps also in other species; stems flattened, forked or lobed, firmly attached to rock. Leaves, unknown for some species, filiform and simple or forked, or lanceolate to fan-shaped and palmately lobed, the lobes ultimately divided into branched

Fig. 108. Podostemaceae-Podostemoideae. A–C Apinagia. A A. surumuensis. Vegetative shoot (2 cm). B A. batrachifolia. Flower (2 mm). C A. pygmaea. Flower (1 mm). D–F Castelnavia princeps. D Creeping crustose stem (1 cm). E Flower viewed from below (1 mm). F Capsule viewed from the side (1 mm). G–I Ceratolacis erythrolichen. G Creeping root with leafy shoots (2 cm). H Capsule (1 mm). I Flower (1 mm). (Drawn by Cook)

filaments. Spathellas ovoid, becoming ± tubular when open with several teeth at apex, ovary usually remaining within spathella. Flowers numerous, borne in cavities on upper side of flattened stem, distinctly zygomorphic, shortly pedicellate; pedicel inflated above and asymmetrical, not elongating in fruit; tepals 2 or 3 (rarely none), alternating with and sometimes united to stamens; stamens 1–3, free or united at the base; filaments membranous, cohering with base of ovary; anthers dehiscing introrsely; pollen in monads. Capsules often at right angles to pedicel; valves very unequal, the smaller almost free from pedicel, caducous, either smooth or with 3 or 5 ribs, with or without

Podostemaceae

323

papillae, the larger valve saucer-like, persistent, with 5, 7 or 9 ribs; stigmas linear, usually unequal in length, often longer than ovary at anthesis. Seeds relatively few. Nine species, central Brazil, most confined to the Araguaya and Tocantins. 7. Ceratolacis (Tulasne) Weddell

Fig. 108G–I

Ceratolacis (Tulasne) Weddell in A. de Candolle, Prodromus 17:66 (1873); van Royen, Acta Bot. Neerl. 3:224–228 (1954), rev.; Philbrick, Novelo & Irgang, Novon 14:108–113 (2004), rev.

Roots thread-like, cylindrical to semicylindrical, branched, rarely up to 5 mm wide, red or dark green; stems short and obscured by leaf bases, borne along lateral margins of roots, usually in opposite or subopposite pairs. Leaves 2–30 mm or more long, either entire and linear or a few times forked with linear segments, with 1 stipule on the dorsal side of the shoot, attached to the associate leaf. Spathellas club-shaped. Flowers up to 6 per shoot; pedicel in fruit either short or up to ±8 mm long, peduncle as additional stalk below spathella up to 8 mm long in C. pedunculatum; tepals 2 or 3, one each side of andropodium and one (when present) between the two filaments; stamens 2, borne on an andropodium; anthers dehiscing introrsely; pollen in dyads. Capsules spindle-shaped; valves equal, each with midrib running into stigmas and 2 faint lateral ribs; stigmas equal, persistent, horn-like, diverging. Seeds unknown. Two species, C. erythrolichen (Tulasne & Weddell) Weddell from Rio Tocantins, Brazil and C. pedunculatum C.T. Philbrick, Novelo & Irgang, from Minas Gerais, Brazil. 8. Cipoia C.T. Philbrick, Novelo & Irgang Fig. 109A–E Cipoia C.T. Philbrick, Novelo & Irgang, Syst. Bot. 29:113 (2004).

Roots thread-like and usually laterally flattened, branching; stems arising from lateral margins of root, usually in opposite or subopposite pairs, unbranched, (0.1–)2(–3.5) mm long, with hardened leaf remains below and a tuft of leaves at the tip. Leaves filamentous, (2)3 times forked or rarely simple, (3.8–)10(–20.4) mm long, ultimate segments linear to spathulate, stipule as boat-shaped extension of the leaf base. Spathellas club-shaped, (0.9–)1.7(–2.7) mm long, splitting irregularly from top. Flowers 1(–3) per shoot, remaining within spathella during anthesis; borne

Fig. 109. Podostemaceae-Podostemoideae. A–E Cipoia inserta. A Fragment of root bearing two subopposite shoots, each with an unopened spathella (5 mm). B Flower at anthesis, emerging from the spathella (2 mm). C Capsule showing suture and three ribs (5 mm). D Pre-anthesis flower with spathella removed (1 mm). E Two leaf bases with stipules (1 mm). F–K Diamantina lombardii. F Fragment of root bearing two subopposite shoots (5 mm). G Digitate leaf from immediately below a flower bud (1 mm). H Leaf with one elongate segment (4 mm). I Flower at anthesis (3 mm). J Unopened spathella (2 mm). K Detail showing tepals, stamens and gynophore. (Drawn by Cook)

on gynophore which elongates during anthesis and exceeds the pedicel; pedicels minute, shorter than spathella; tepals one each side of the stamen filament; stamen 1; filaments elongating during anthesis and projecting from ruptured spathella; anthers dehiscing introrsely; pollen in dyads. Capsules borne within spathella, ellipsoidal, each

324


3-ribbed, 2-locular, valves equal, the sutures thickened; stigmas equal, simple. Seeds unknown. One species, C. inserta C.T. Philbrick, Novelo & Irgang, Minas Gerais, Brazil. 9. Crenias A. Sprengel

Fig. 110A–C

Crenias A. Sprengel in K.P.J. Sprengel, Syst. Veg. 4, 2, Curae postoriores: 246 (1827); van Royen, Acta Bot. Neerl. 3:224– 228 (1954), rev. (under Mniopsis); Philbrick & Novelo, Syst. Bot. Monogr. 70:1–106 (2004), rev. (under Podostemum). Mniopsis Mart. (1823 or 1824), nom. illegit.

6 mm in fruit; tepals 3, lanceolate to triangular, ± 0.5 mm long, one each side of solitary stamen and one on back of it; anthers dehiscing introrsely; pollen in monads. Capsules ellipsoidal to globose, up to 1.2 mm long, smooth; valves unequal, the larger persisting, suture sometimes acentric; stigmas very short. Seeds unknown. One species, D. flagelliformis Tulasne & Weddell, Goiás, Brazil. Philbrick and Novelo (2004) incorporated this species into Podostemum.

Roots thread-like and usually laterally flattened, branching; stems arising from lateral margins of root, usually in opposite or subopposite pairs, simple or branched, usually with leaf remains below and a tuft of leaves at the tip. Leaves entire or a few times forked, with 1 stipule on front side of dorsiventral shoot, attached to or detached from associated leaf, the 2 dorsal rows of stipules accompanying the 2 lateral leaf rows. Spathellas bellor club-shaped, up to 3 mm long, splitting irregularly from top. Flowers few to numerous; pedicels hardly exceeding spathella; tepals 2 or 3, one each side of andropodium and one, when present, between or below filaments; stamens 2, borne on andropodium; anthers dehiscing introrsely; pollen in dyads. Capsules globose to ellipsoidal, smooth, 2locular, valves unequal, the larger persistent, the sutures oblique; stigmas equal, covered with hair-like papillae, usually palmately branched. One species, Crenias glazioviana, with simple stigmas. About five species, south-eastern Brazil. Phylogenetic analyses (Philbrick and Novelo 2004; Moline et al. 2006) place this genus within Podostemum. 10. Devillea Tulasne & Weddell

Fig. 110G, H

Devillea Tulasne & Weddell, Ann. Sci. Nat., Bot. III, 11: 107 (1849); van Royen, Acta Bot. Neerl. 3:223 (1954), rev.; Philbrick & Novelo, Syst. Bot. Monogr. 70:1–106 (2004), rev. (under Podostemum).

Roots thread-like, filamentous, branched; stems simple or few times branched, ±1 cm long, arranged irregularly but never in opposite or subopposite pairs. Leaves simple or repeatedly forked with filamentous segments, up to 2.5 cm long; leaf base sheathing and usually with a symmetrical, boat-shaped stipule. Spathellas bell-shaped, up to 3 mm long, when immature enveloped in the sheaths of the apical leaves. Flowers 1(2) per shoot; pedicels 0.5–1 mm long, elongating up to

Fig. 110. Podostemaceae-Podostemoideae. A–C Crenias weddelliana. A Fragment of creeping root with two subopposite shoots (1 cm). B Stigmas (0.5 mm). C Flower (1 mm). D–F Lonchostephus elegans. D Flowering shoot (1 cm). E Flower (2 mm). F Stigmas (1 mm). G, H Devillea flagelliformis. G Fragment of creeping root with leafy shoots (5 mm). H Flower (1 mm). I, J Jenmaniella tridactylifolia. I Fragment of creeping root with subopposite leafy shoots (5 mm). J Flower (0.5 mm). (Drawn by Cook)

Podostemaceae

11. Diamantina Novelo, Philbrick & Irgang Fig. 109F–K Diamantina Novelo, Philbrick & Irgang, Syst. Bot. 29:109 (2004); Rutishauser et al., Flora 200:245–255 (2005).

Roots thread-like or slightly flattened, branching; stems arising from lateral margins of root, usually in opposite or subopposite pairs with disk-like holdfasts, branched, erect, (3.5–)19.5(–40) mm long, with hardened leaf remains below and leaves above, their bases becoming broadened and disk-like when older. Leaves crowded, clothing the stem; first leaves thread-like, entire or with 2 or 3 segments; later leaves dimorphic, with expanded sheathing base bearing (2)3–7(8) digitally arranged segments lacking vascular tissue, segments variable in size and form; ‘short leaves’ with all segments alike, 0.5–1.5 mm long, rigid, tooth-like, borne towards base of stem or branch; ‘long leaves’ with 1 or 2 median segments longer than the lateral tooth-like laterals, median segments linear and flexible, up to 10 or more mm long, deciduous, borne towards tip of stem or branch. Spathellas dimorphic; that subtending the subterminal flower scale-like; that of terminal flower tubular, (1.5–)2.2(–2.9) mm long, splitting irregularly from top. Flowers 1 or 2 at tip of stem or branch, developing terminally or subterminally, borne on gynophore which elongates during anthesis to (0.5–)1.8(–2.5) mm long; pedicels (2.5–) 4.6(–7) mm long after anthesis; tepals (2)3(4), scale-like, alternating with stamens; stamens (1)2(3), free; filaments elongating during anthesis but never reaching length of ovary; anthers often rudimentary and sterile; if present, then dehiscing introrsely; pollen in tetrads. Capsules spherical or nearly so, with an apical cleft, opening by 2 equal valves, with thickened sutures; each valve 3- or rarely 4- or 5-ribbed; stigmas 2 or rarely 3, equal, simple, horn-like. Seeds unknown. One species, D. lombardii Novelo, Philbrick & Irgang, Minas Gerais, Brazil. 12. Jenmaniella Engler

325

forming a collar around each flower; leaf blades variable, usually a few times forked or pinnate with forked segments; ultimate segments linear, filiform to flattened, inrolled when young; sheaths simple or double, stipule-like on leaves subtending flowers. Spathellas club-shaped. Flowers solitary at end of root-borne stems; pedicels erect, up to 2.5 cm long; tepals 2–7, usually in an incomplete whorl, not all of them closely associated with base of stamens; stamens 1–7, free or sometimes 2 stamens united below, the number, shape and size of stamens often variable from flower to flower on the same plant; anthers dorsifixed, dehiscing introrsely in 4 species, extrorsely in 2 species; pollen in monads. Capsules borne on an up to 3-mm-long gynophore, ellipsoidal; valves equal, each with 3 or 5 ribs; stigmas simple, equal. Seven species, north-eastern South America, probably also Bolivia. 13. Lonchostephus Tulasne

Fig. 110D–F

Lonchostephus Tulasne, Arch. Mus. Hist. Nat. 6:198 (1852).

Roots insufficiently documented; holdfasts ±1 cm long, 0.2–0.5 cm wide; stems very short. Leaves in basal rosettes, very irregular in shape and size, 1–8 cm long, usually somewhat flabellate, blades smooth on both surfaces, repeatedly forked, ultimate segments capillary, narrowed below into short, flattened petiole. Spathellas 4–10 mm long, splitting radially. Flowers 3–6, alternating with bracts in a slightly flattened, 2-sided, simple, raceme-like inflorescence, borne on an up to 8 cm long naked peduncle; pedicels 0.5–2.5 cm long; bracts ±5 mm long, borne between 2 flowers, with double sheaths, double boat-shaped; tepals linear to lanceolate, ±0.5 cm long, free, reflexed; stamens 5–8, in one whorl; filaments free, flat, widened and wing-like, ellipsoidal, 3–5 mm long, membranous, persisting in fruit; anthers introrse. Capsules ovoid, 3–6 mm long; valves equal, each with 3 ribs; stigmas flattened, crested, persisting in fruit. One species, L. elegans Tulasne, upper Amazon, Brazil. This genus is close to Mourera and Tulasneantha.

Fig. 110I, J

Jenmaniella Engler, Bot. Jahrb. Syst. 61 Beibl. 138:7 (1927); van Royen, Med. Bot. Mus. Herb. Rijksuniv. Utrecht 107:119–127, 137 (1951), rev.

Roots thread-like or flattened, branched; stems closely adhering to rock, prostrate, flattened, short, represented by a holdfast, usually in opposite or subopposite pairs, at more or less regular intervals along the root. Leaf bases often united below and

14. Lophogyne Tulasne

Fig. 111A, B

Lophogyne Tulasne, Ann. Sci. Nat., Bot. III, 11:90, 99 (1849).

Roots closely attached to rock or partly floating, ribbon-like, up to 5 cm long; stems crustose, developing along edges of root, often hidden in leaf bases. Leaves with swollen bases which coalesce with stem; leaf blades finely dissected or repeatedly forked with capillary ultimate segments. Spathellas

326


club-shaped or apically 2-lipped, up to 7 mm long, embedded in leaf bases when young. Flowers solitary, arising in clefts in the crustose stems; pedicels up to 2 cm long; tepals 2–5, up to 2.5 mm long, in one complete or incomplete whorl, lanceolate to linear, acute; stamens 2–4, free; anthers sometimes spirally wound when dry; anthers dehiscing introrsely; pollen in monads. Capsules ellipsoidal to ovoid, up to 4.5 mm long, inserted subobliquely on pedicel; valves equal, each with 3 ribs; stigmas ±1 mm long, flattened with a serrate or lobed apex, resembling a cock’s comb, persisting in fruit. Two species, L. arculifera Tulasne & Weddell and L. helicandra Tulasne, eastern central Brazil. The two species often grow in the same cataract but are more or less ecologically distinct. 15. Macarenia P. Royen

terete or flattened; blades 1 or more times pinnate or entire in M. utile Tulasne. Spathellas club-like or tubular. Flowers solitary or in fascicles of up to 5, arising from sheath pockets on stem; pedicels (0.5–) 1–9 cm long; tepals scale-like to filiform, 2–25, as many as or 1 more than stamens, in 1 complete or incomplete whorl, alternating with and more or less fused to base of stamen filaments; stamens 3–40 or more, in 1 or 2 whorls or confined to one side of flower; filaments linear to linear-lanceolate or triangular, sometimes united at base; pollen in monads. Capsules ellipsoidal, opening by 2 equal or subequal valves; each valve with 3 ribs, the ribs

Fig. 111C–E

Macarenia P. Royen, Med. Bot. Mus. Herb. Rijksuniv. Utrecht 107:137 (1951), rev.

Roots unknown; stems absent or indistinct and represented by amorphous, somewhat corm-like base or holdfast, merging into leaves, ±7 mm wide. Leaves more or less in a basal rosette, up to 30 cm long; petiole terete, up to 10 cm long, provided at base with an up to 3 mm long, obtuse stipule; blades repeatedly forked, ultimate segments linear up to 15 mm long, each with a distinct nerve. Spathellas each containing 10–20 flowers, club-shaped, up to 12 cm long, solitary or 2 or 3 together, enveloped at base by 2 membranous bracts, individual flowers without a spathella occasionally found. Flowers 10–20, erect in a single spathella; peduncles terete, slightly winged, up to 3 cm long; tepals 2–5, lanceolate, ±0.8 mm long; stamens 2–4, up to 4 mm long; anthers dehiscing introrsely. Capsules ellipsoidal to obovoid, up to 4 mm long; valves equal, each with 3 ribs; stigmas simple. One species, M. clavigera P. Royen, Macarena Mountains, Colombia. 16. Marathrum Humboldt & Bonpland Figs. 104H, 111F, G Marathrum Humboldt & Bonpland, Pl. Aequin. 1:39. t. 11 (dated 1806, publ. 1808); van Royen, Meded. Bot. Mus. Herb. Rijksuniv. Utrecht 107:70–91, 131–133 (1951), rev.

Roots thread-like and slightly flattened, branched; stems prostrate, flattened, often short and disk-like. Leaves arranged along lateral margins of prostrate stems; sheaths simple or double, sometimes elongated into stipules; petioles long, short or absent,

Fig. 111. Podostemaceae-Podostemoideae. A, B Lophogyne helicandra. A Flowering shoot (1 mm). B Flower (0.5 mm). C–E Macarenia clavigera. C Spathella in longitudinal section (2 mm). D Flower (1 mm). E Flowering plant (1 mm). F, G Marathrum utile. F Elongate root with subopposite pairs of sterile shoots and one flowering shoot (1 cm). G Flower (1 mm). (Drawn by Cook)

Podostemaceae

sometimes winged; pedicel in fruit expanded and cup-like at tip in some species; stigmas 2, linear to boat- or spoon-shaped, joined at base, often toothed at tip. Seeds ± 200–1,500. About 25 species (probably less when critically examined), Mexico, Central America, West Indies and north-western South America. 17. Mourera Aublet

Figs. 104G, K, 112A,B

Mourera Aublet, Hist. Pl. Guiane 582 (1775).

Roots 0 in M. fluviatilis Aublet, thread-like in M. aspera (Bongard) Tulasne and M. schwackeana Warming, insufficiently documented in other species; stems creeping, simple, 1–20 cm long, 0.5–5 cm thick, merging with leaf bases; holdfasts developing from leaf bases, polymorphic, clawshaped to tendril-like, up to 4 cm long. Leaves in basal rosettes, very variable, 8–100(–200) cm long, elliptical or pinnately lobed with marginal fimbriae, or repeatedly forked into capillary segments, ultimate segments inrolled when young, with hairs along concave sector; upper surface in M. fluviatilis very coarse and provided with warts and rigid, conical, vascularised prickles, in 2 other species with warts only; lower surface in all species glabrous, sometimes with prominent palmate to net-like veins; leaf bases cuneate, merging with the holdfast; sheaths simple or double. Spathellas tubular, 10–15 mm long, splitting irregularly. Flowers alternating with bracts in a stalked, 2-sided, simple or forked, raceme-like inflorescence, with up to 90 flowers, or rarely reduced to 1 or 2 flowers, anthesis starting at distal end; pedicels pink to pale violet; bracts 5–13 mm long, borne between 2 flowers, occasionally with a leaf-like appendage, with double sheaths, appearing double boat-shaped, shorter than spathella; tepals free, 5–20; stamens 5–35(–40), in 1 or 2 whorls; filaments free or united in pairs or groups at base, linear, terete, pink to pale violet, persistent and indurate in fruit; anthers dehiscing extrorsely in inner whorl, introrsely in outer whorl. Capsules ovoid; valves equal, each with 2–13 ribs; stigmas linear or spathulate. Seeds up to 2,000 or more in each capsule. About six species, northern to central South America. 18. Oserya Tulasne & Weddell

Fig. 112C, D

Oserya Tulasne & Weddell, Ann. Sci. Nat., Bot. III, 11:105 (1849).

Roots thread-like, often becoming flattened when old, branched; stems short, developing at almost

327

regular intervals along sides of root, usually in opposite or subopposite pairs. Leaf sheaths simple or double; petioles cylindrical or flattened; blades simple or repeatedly forked with filamentous ultimate segments, inrolled when young. Spathellas club-shaped, slightly exceeding base, opening irregularly. Flowers solitary, terminating the stem or several in leaf axils; pedicels 0.1–0.8(1.4) cm long; tepals (2)3, when stamens 2, then one each side of the stamen and the third on back of the fork of filaments or rarely absent; stamens (1)2(3), when stamens 2, then usually united below into

Fig. 112. Podostemaceae-Podostemoideae. A, B Mourera fluviatilis. A Flowering shoot (3 cm). B Young capsule (1 mm). C, D Oserya minima. C Fragment of creeping root with one pair of opposite flowering shoots (5 mm). D Flower (1 mm). E–H Podostemum ceratophyllum. E Elongate stem arising from a creeping root (2 cm). F Persistent empty capsule valve (1 mm). G Flower at anthesis arising from ruptured spathella (3 mm). H Two short stems arising from a creeping root (3 mm). (Drawn by Cook)

328


short andropodium; anthers basifixed, introrse in Mexican species, or extrorse in South American species; pollen in monads. Capsules ovoid; valves equal (Mexico) or unequal (South America) with oblique and acentric sutures, the larger one persistent, with 3–13 ribs; stigmas very short. Seeds up to ± 80. Six species, Mexico, northern South America and central Brazil. 19. Podostemum A. Michaux Figs. 104A, D, 112E–H Podostemum A. Michaux, Fl. Bor.-Amer. 2:164 (1803), Podostemon orth. mut.; van Royen, Acta Bot. Neerl. 3:228–244 (1954); Philbrick & Novelo, Syst. Bot. Monogr. 70:1–106 (2004), rev.

Roots thread-like, usually flattened, branched, attached to rocks with finger-like holdfasts; stems distinct, arising from lateral margins of root, usually in opposite or subopposite pairs, simple or branched; flowering stems only in one species (P. comatum) distinct from vegetative ones, both borne along same root. Leaf sheaths simple or double; 1–3(–11) stipular lobes or teeth per sheath, attached to associated sheath in leaf axils, or in P. muelleri Warming stipule 1 per leaf borne on dorsal side of shoot; leaf blades simple or, more often, repeatedly forked into linear segments or, in P. distichum (Chamisso) Weddell and P. irgangii C.T. Philbrick & A. Novelo, leaf segments covered with triangular to subulate scales in half-whorls or whorls. Spathellas club-shaped, splitting irregularly from top. Flowers 1–several per stem; pedicels 0.1–0.5(–0.8) cm long; tepals 3, linear, 2 at each side of andropodium base, in P. muelleri Warming sometimes 0, and usually 1 on top of andropodium in fork between the two filaments (abnormal flowers with proliferation of tepals and stamens are uncommon); stamens usually 2, borne on an andropodium; anthers dehiscing introrsely and latrorsely; pollen in dyads. Capsules ovoid; valves unequal, the larger persistent; each valve with 3 ribs; style short; stigmas linear, equal or unequal. Seeds from ± 30 to ± 100 but P. rutifolium subsp. ricciiforme (Liebmann) A. Novelo & C.T. Philbrick rarely sets seed and, if so, then only 1 or 2 ripen. About seven species (17 recognised by van Royen), America, extending from northern Argentina to eastern North America. The Asian species are now placed in Zeylanidium and Polypleurum. Crenias (south-eastern Brazil) and Devillea (Goiás, Brazil) are closely related to Podostemum. Crenias and Devillea

are retained here as a distinct genera, although Philbrick and Novelo (2004) have incorporated them into Podostemum (see also Moline et al. 2006). 20. Rhyncholacis Tulasne

Fig. 113A, B

Rhyncholacis Tulasne, Ann. Sci. Nat., Bot. III, 11:95 (1849); van Royen, Med. Bot. Mus. Herb. Rijksuniv. Utrecht 107:133–138 (1951), rev.

Roots thread-like to slightly flattened, perhaps 0 in R. carinata P. Royen, simple or branched; stems prostrate, flattened, often disk-like, merging into root and leaves. Leaf sheaths simple or double; petioles terete or slightly flattened, sometimes shortly winged; blades usually pinnate with forked lobes or palmate with lobes divided into filiform segments at tips; ultimate segments filamentous. Spathellas club-shaped or tubular, rupturing at apex. Flowers solitary or up to 20 in fascicles, arising from sheath pockets which often form cavities in the stem; pedicels (0.5–)2–10(–20) cm long; tepals 2–20 in a complete whorl, an incomplete whorl, or at one side of flower, some occasionally reduced to small teeth; stamens 2–30, in 1 or 2 whorls; filaments sometimes flattened at base; pollen in monads; anthers introrse. Capsules ellipsoidal to ovoid, laterally compressed; valves equal, each with 2 lateral ribs and a winged midrib; stigmas beak-like or clavate. Seeds numerous, up to ± 720 in R. penicillata Matthiesen. About 26 species (probably less when critically examined), northern South America. 21. Tulasneantha P. Royen

Fig. 113C, D

Tulasneantha P. Royen, Acta Bot. Neerl. 2:16 (1953).

Root insufficiently documented; stems very short; holdfasts 1–5 cm long, 0.5–2 cm wide. Leaves in basal rosettes, 10–30 cm long; petioles slightly flattened, smooth, 5–16 cm long, 1–3 mm wide; leaf blades fan-shaped, repeatedly forked. Spathellas club-shaped, 0.5–1 cm long. Flowers alternating with bracts, in a 2-sided, compressed, unbranched, raceme-like, 8–30 cm long inflorescence; bracts with double-sided sheaths, double boat-shaped, 0.5–1 cm long; pedicels 1–3.5 cm long; tepals 6–10 or rarely rudimentary, lanceolate, ±0.5 mm long; stamens 6–10, in 1 whorl, 5–12.5 mm long; filaments terete, united halfway or slightly less into a tube below; pollen in monads; anthers introrse. Capsules ovoid to obovoid, 3.5–8 mm long; valves equal, each with 2 lateral ribs and a midrib slightly

Podostemaceae

329

filiform, persistent, indurate, remaining attached to ribs of capsule after anthesis; capsule valves each with 3 ribs; seeds up to 1,000 or more. One species, V. plumosa Novelo & C.T. Philbrick, Jalisco & Oaxaca, Mexico. 23. Wettsteiniola Suessenguth

Fig. 114E, F

Wettsteiniola Suessenguth, Repert. Spec. Nov. Regni Veg. 39:18 (1935).

Roots ribbon-like, up to 1 cm wide; stems disk-like and prostrate or represented by fused leaf bases. Leaves up to 30 cm long, either repeatedly pinnate or irregularly 2-pinnate with secondary pinnae repeatedly forked; ultimate segments filiform; bases of pinnae and pinnules with stipel-like appendages. Spathellas trumpet-shaped, up to 1 cm long. Flowers in fascicles of 2–8; pedicels up to 3.5 cm long; tepals linear to linear-lanceolate, (2–)3–6, in an incomplete whorl; stamens (1)2–4, in an incomplete whorl; filaments sometimes united in pairs at base; anthers dehiscing introrsely; pollen in monads. Capsules ellipsoidal to ovoid; valves equal, each

Fig. 113. Podostemaceae-Podostemoideae. A, B Rhyncholacis dentata. A Flowering shoot (1 cm). B Flower (1 mm). C, D Tulasneantha monodelpha. C Leaf with detached inflorescence (2 cm). D Flower (3 mm). (Drawn by Cook)

winged above; stigmas linear, persisting in fruit. Seeds unknown. One species, T. monadelpha (Bongard) P. Royen, western Brazil, which is close to Lonchostephus and Mourera. 22. Vanroyenella Novelo & C.T. Philbrick Fig. 114A–D Vanroyenella Novelo & C.T. Philbrick, Syst. Bot. 18:64 (1993).

Like Marathrum but leaf blades plumose with filamentous segments arising directly from rachis, ultimate divisions forked and hair-like; flowers in fascicles of up to 13; tepals 3 or 4; stamens 2(3), confined to one side of flower; stamen filaments

Fig. 114. Podostemaceae-Podostemoideae. A–D Vanroyenella plumosa. A Fragment of vegetative shoot (1 cm). B Filamentous leaf segments (1 mm). C Flower (0.5 mm). D Capsule with persistent filaments (0.5 mm). E, F Wettsteiniola pinnata. E Pinnate leaf (1 cm). F Capsule (1 mm). (Drawn by Cook)

330


with 5 ribs; stigmas linear. Three species, southern Brazil and northern Argentina. Podostemoid Genera of Africa and Madagascar 24. Angolaea Weddell

Fig. 115A–C

Angolaea Weddell in A. de Candolle, Prodromus 17:300 (1873).

Roots unknown; stems branched, floating, up to 50 cm long. Leaves repeatedly forked, segments filiform. Spathellas ellipsoidal, borne on 5–8 mm long stalks. Flowers erect in the spathella, borne in umbel-like clusters; tepals 2, small, one each side of stamens or andropodium base if present; stamens 3(4), free or united below, borne in a cluster on one side of flower; andropodium very short or apparently 0; pollen in dyads; ovaries 1- or 2-locular. Capsules ellipsoidal; valves equal, each with 3 ribs; style short, erect, bearing a semi-globose stigma. One species, A. fluitans Weddell, from the River Cuanza, Angola. 25. Butumia G. Taylor

ular distances along opposite sides of stem; blades linear or up to 3 times forked, often fan-like; ultimate segments linear. Spathellas elongate. Flowers inverted within unruptured spathella, solitary or 3–20 in sessile or pedunculate clusters, mostly appearing to be opposite leaves; pedicels up to 60 mm long in fruit; tepals 2, much shorter than ovary, one each side of andropodium; andropodium rarely exceeding 1 mm in length; stamens 2, about half as long as ovary; filaments half as long as anther; pollen in dyads; ovaries 1-locular. Capsules cylindrical to oblong, all ribs running entire length of capsule; valves equal, persistent, each with 3 ribs; stigmas conical, erect, persistent in fruit. Two spe-

Fig. 115D–F

Butumia G. Taylor, Bull. Brit. Mus. Nat. Hist., Bot. 1:55 (1953).

Roots ribbon-like, ±2 mm wide, branched, resembling a liverwort, sometimes connected by thread-like roots; stems arising endogenously along margins of root, very short, not branched. Leaves in rosettes, sessile, subulate; inner leaves subtending flowers with stipule-like teeth. Spathellas ovoid, apiculate, ±1 mm long. Flowers erect in spathella, terminal, solitary, subsessile; tepals 2, minute, 1 each side of stamen; stamen 1; filament ultimately 1–2 mm long; anther ±0.5 mm long; pollen in dyads; ovary 1-locular. Capsules ovoid, ±1 mm long; valves equal, each with 3 ribs; stigmas unequal, flattened, ovate to elliptic in outline, divergent, persisting in fruit. One species, B. marginalis G. Taylor, Cameroon and Nigeria. M. Cheek et al. (2000) transferred this monotypic genus to Saxicolella. 26. Dicraeanthus Engler

Fig. 115G–I

Dicraeanthus Engler, Bot. Jahrb. Syst. 38:94 (1905).

Roots usually ± star-shaped; stems arising from upper surface of roots, elongate, branched, floating, up to 1 m long, bearing leaves in 2 rows and, in a third row, flowers. Leaves arising at almost reg-

Fig. 115. Podostemaceae-Podostemoideae. A–C Angolaea fluitans. A Flowering shoot (1 cm). B Rupturing spathella. C Flower with spathella removed (2 mm). D–F Butumia marginalis. D Creeping root with flowering shoots (2 cm). E Spathella with leaves (0.5 mm). F Flower (5 mm). G–I Dicraeanthus africanus. G Young plant (10 cm). H Fragment of a flowering shoot (1 cm). I Flower emerging from spathella (2 mm). (Drawn by Cook)

Podostemaceae

cies, D. africanus Engler and D. zehnderi Hess, West and Central tropical Africa. 27. Djinga C. Cusset

Fig. 116A–C

Djinga C. Cusset, Fl. Cameroun 30:58 (1987).

Roots crustose or ribbon-like; stems arising endogenously along root margin, elongate, up to 12 cm or more long, irregularly branched, with long shoots or rosette-like short shoots. Leaves 0.5–1.5 cm long, subulate, entire or once forked. Spathellas ovoid to elliptic, arising in a rosette of linear or scale-like leaves. Flowers erect or inclined in spathella, solitary or 3 or 4 as part of dense short shoots; subsessile at anthesis; pedicels hardly elongating in fruit, up to 4 mm long; tepals 2, linear, much shorter than filament; stamen 1; filament 1.2–1.4 mm long; pollen in monads or in loose dyads; ovaries 1-locular. Capsules globose to subglobose, ± 1.2 mm long; valves unequal, each with 3 ribs; ribs somewhat flattened, wider than furrows; stigmas equal, linear to lanceolate and flattened, 0.7–0.8 mm long. One species, D. felicis C. Cusset, Cameroon. 28. Endocaulos C. Cusset

331

(1983), rev.; Cusset, op. cit., 6:249–278 (1984), rev. Sphaerothylax Bischoff ex Krauss (1844), pro parte. Inversodicraeia Engler ex R.E. Fries (1914). Monandriella Engler (1926).

Roots ribbon-like or crustose; stems rudimentary to well developed, erect, simple or branched, from very short to 1 m or more long. Leaves very variable, simple, lobed or forked, linear with thread-like segments, or scale-like, imbricate, with entire or toothed margins and sometimes with

Fig. 116D, E

Endocaulos C. Cusset, Adansonia II, 12:560 (dated 1972, publ. 1973).

Roots ribbon-like, 0.3–1 mm wide, infrequently branched, closely attached to rock or partly floating; stems arising along margins of root, very short, not branched. Leaves simple, elongate, 2–3 cm long, swollen at base; base sometimes with 2 stipule-like lobes; elongate portions of leaves become detached at flowering time. Spathellas ovoid, obtuse at tip, opening irregularly. Flowers somewhat inclined within spathella, solitary; pedicel in fruit 2–3 mm long; tepals 2, obovate, one each side of andropodium base; stamens 2, borne on an andropodium, somewhat exceeding ovary; pollen in dyads; ovaries 2-locular. Capsules asymmetrically ovoid, somewhat flattened laterally, held obliquely at tip of pedicel; valves unequal and persistent, each with 7 ribs, the ribs nearest the sutures shortest and not extending whole length of capsule; stigmas 2, elongate, equal. One species, E. mangorense (Perrier) C. Cusset, Madagascar. 29. Ledermanniella Engler

Fig. 116F–H

Ledermanniella Engler, Bot. Jahrb. Syst. 43:378 (1909); Cusset, Adansonia II, 14:271–275 (1974), rev.; Cusset, Bull. Mus. Natl Hist. Nat. Paris IV, B, Adansonia 5:361–390

Fig. 116. Podostemaceae-Podostemoideae. A–C Djinga felicis. A Plant with flower buds (1 cm). B Flower emerging from spathella (0.5 mm). C Capsule (0.5 mm). D, E Endocaulos mangorense. D Creeping root with sterile and flowering shoots (4 mm). E Two fertile shoots with one flower (1 mm). F–H Ledermanniella abbayesii. F Diagrammatic longitudinal section through a spathella (1 mm). G Fragment of a flowering shoot (5 mm). H Flower (2 mm). (Drawn by Cook)

332


apical teeth; imbricate scales and elongate leaves often develop on same stem in subg. Phyllosoma. Spathellas opening irregularly at tip. Flowers inverted within unruptured spathella, solitary or sometimes in sessile or stalked clusters; tepals 2, linear or filiform, one each side of solitary filament or andropodium base; stamens 1 or 2(3), either single or borne on an andropodium; andropodium usually more than 1 mm long, usually exceeding ovary at anthesis; pollen in monads or dyads. Ovaries 1-locular. Capsules ovoid to ellipsoidal or fusiform, with all ribs running entire length of capsule; valves unequal or rarely equal, each with 3 ribs; one or both valves persistent; stigmas linear, spreading or reflexed. About 46 species, tropical Africa, most in Central and West Africa. Molecular data indicate that this is not a natural genus (Moline et al. 2007); perhaps it should incorporate Dicraeanthus, Djinga and Macropodiella, or it should be split into smaller entities. 30. Leiothylax Warming

revolute teeth after rupturing. Flowers erect in spathella, 2 or 3 in irregular clusters, or rarely solitary, subsessile at anthesis; pedicels elongating to become ±1 cm long in fruit; tepals 2, very small, 1 each side of base of andropodium or filament; stamens (1)2, when 2, then borne on an andropodium with very short filaments; pollen in monads; ovaries 1-locular. Capsules borne on a 0.4–0.5 mm long gynophore, globose, smooth and shiny, papillate at tip; valves equal and quickly shed; stigmas

Fig. 117A, B

Leiothylax Warming, Overs. Kong. Danske Vidensk. Selsk. Skr. VI, 9:147 (1899); Cusset, Adansonia II, 20:199–209 (1980), rev. Leiocarpodicraeia (Engler) Engler (1905).

Roots crustose, entirely attached to rock or partly free and floating, stems branched, erect, up to 30 cm or more long. Leaves up to 4 cm long, linear or forked with linear segments. Spathellas ovoid or subglobose. Flowers inverted in unruptured spathella, solitary or in clusters; pedicels elongating after anthesis, becoming 1–2 cm long in fruit; tepals 2, one each side of andropodium base, much shorter than ovary or stamens, less than 0.4 mm long; stamens 2(3), borne on an andropodium; pollen in monads; ovaries 1-locular. Capsules borne on a gynophore up to 3 mm long, subglobose, smooth; valves equal, caducous; stigmas linear. Three species, Cameroon, D.R. Congo and Zambia. 31. Letestuella G. Taylor

Fig. 117C, D

Letestuella G. Taylor, Bull. Brit. Mus. Nat. Hist., Bot. 1:57 (1953); C. Cusset, Adansonia II, 20:199–209 (1980), rev.

Roots ribbon-like, branched; stems arising along margins of root, elongate, branched, up to 6 cm long. Leaves simple and linear or forked with linear segments, up to 4 cm long but usually less, often with stipule-like teeth at base. Spathellas oblongovoid, surface rough, becoming campanulate with

Fig. 117. Podostemaceae-Podostemoideae. A, B Leiothylax quangensis. A Distal part of a flowering shoot (2.5 mm). B Flower emerging from spathella (1 mm). C, D Letestuella tisserantii. C Distal part of shoot with spathellas (2.5 mm). D Flower (1 mm). E–G Macropodiella heteromorpha. E Fragment of shoot with leaves and unopened spathellas (10 cm). F Flower (1 mm). G Capsule viewed from the wide and from the narrow side (1 mm). (Drawn by Cook)

Podostemaceae

2, linear to clavate. One species, L. tisserantii G. Taylor, western Africa, from Namibia to Niger. 32. Macropodiella Engler

Fig. 117E–G

Macropodiella Engler, Bot. Jahrb. Syst. 60:466 (1926); Cusset, Adansonia II, 17:293–303 (1978), rev.

Roots crustose or ribbon-like; stems simple or branched, very short or in some species up to ±80 cm long. Leaves usually divided into linear or capillary segments, or scale-like. Flowers inverted within unruptured spathella, solitary or in clusters of up to ± 12, either terminal or borne on elongated stems in leaf axils but appearing opposite leaves; pedicel becoming up to 1.5 cm long in fruit; tepals 2, linear to filiform, borne one each side of andropodium base; stamens 1–3; pollen in monads; ovaries 1-locular. Capsules borne on an up to 2 mm long gynophore, ellipsoidal, laterally flattened; valves equal and caducous, each with 3 ribs; stigmas variable, simple and elongate or divided into linear lobes or cock’s comb-like with flattened and serrated margins. Six species, tropical West Africa. 33. Paleodicraeia C. Cusset

333

tened, simple or branched. Leaves simple and linear, or forked or laciniate; ultimate segments linear. Spathellas ovoid, opening irregularly at apex. Flowers erect in spathella, solitary or in loose clusters; pedicels elongating during anthesis, becoming up to 2 mm long; tepals 2, minute, one each side of filament base; stamen 1; pollen in dyads; ovaries 1- or 2-locular, depending on species. Capsules ellipsoidal to fusiform; valves equal and persistent, each valve with 3 or 5 narrow ribs; stigmas linear. About five species, in western tropical Africa, from Angola to Nigeria. 35. Sphaerothylax Bischoff ex Krauss Fig. 118E–G Sphaerothylax Bischoff ex Krauss, Flora 25:426 (1844). Anastrophea Weddell (1873).

Roots crustose, lobed with rounded lobes, resembling a liverwort, or ribbon-like and branched; stems arising from upper surface of root, either

Fig. 118A, B

Paleodicraeia C. Cusset, Adansonia II, 12:562 (dated 1972, publ. 1973).

Roots ribbon-like, branched, ±1 cm wide; stems arising along margins of root, up to ±2 cm long, branched and covered with at least 8 overlapping, scale-like leaves. Leaf bases persistent, 1.5–2 mm long, swollen and overlapping, shallowly 3-lobed; lateral lobes stipular; central lobe (or blade) linear and entire or bifid, caducous. Spathellas ovoid, splitting more or less regularly down one side. Flowers erect in spathella, subsessile, solitary, borne terminally; pedicel becoming up to 2 mm long in fruit; tepals 2, lanceolate, 0.5 mm long, 0.2 mm wide at base, one each side of andropodium base; stamens 2 borne on an andropodium; pollen unknown; ovaries 2-locular. Capsules ovoid; valves equal, each with 5 ribs; stigmas 2, linear and short. One species, P. imbricata (Tulasne) C. Cusset, Madagascar. 34. Saxicolella Engler

Fig. 118C, D

Saxicolella Engler, Bot. Jahrb. Syst. 60:456 (1926). Pohliella Engler (1926). Aulea C. Cusset ex Lebrun & Stork (1991), nom. illegit.

Roots crustose or ribbon-like; stems rudimentary or well developed, up to 20 cm long, somewhat flat-

Fig. 118. Podostemaceae-Podostemoideae. A, B Paleodicraeia imbricata. A Shoot with persistent capsule valve (1 mm). B Young capsule (0.5 mm). C, D Saxicolella nana. C Flowering shoot (5 mm). D Flower (2.5 mm). E–G Sphaerothylax abyssinica. E Crustose root bearing flowers and a flowering shoot (1 cm). F Capsule (0.5 mm). G Flower (0.5 mm). (Drawn by Cook)

334


very short and simple, or elongate and branched, up to 50 cm or more long. Leaves either scale-like or repeatedly forked with linear segments, up to 10 cm or more long. Spathellas globose, rupturing irregularly. Flowers inverted in unruptured spathella, arising from upper surface of root or on elongate stems, solitary or in clusters; tepals 2, one each side of filament base; stamen 1 or perhaps sometimes 2; filament often flattened; pollen in dyads; ovaries 2-locular. Capsules subsessile, globose to subglobose; valves nearly equal, the larger one persistent, each with 3 wide and flattened ribs; stigmas ±0.2 mm long, linear to ovate. Two or perhaps more species, Madagascar, northern tropical and southern Africa. 36. Stonesia G. Taylor

Fig. 119A–C

Stonesia G. Taylor, Bull. Brit. Mus. Nat. Hist., Bot. 1, 3:59 (1953); Cusset, Adansonia II, 13:307–312 (1973), rev.

Roots crustose; stems simple or branched, short or elongate and then 10–40 cm long. Leaves repeatedly forked into linear segments or scale-like, when scale-like, then often lobed, with 1 or 2 of the lobes prolonged into thread-like appendages. Spathellas subsessile, ±2 mm long, subtended by 2–6, usually lobed, scale-like leaves. Flowers inverted in unruptured spathella, either sessile on upper surface of creeping root, or along elongate stems, solitary or in clusters; pedicel 0.4–1 cm long in fruit; tepals 3, one each side of andropodium base, the third between the two filaments; stamens 2, borne on an andropodium; pollen in dyads; ovaries 2-locular. Capsules broadly ellipsoidal; valves equal and persistent, each with 5 or 7 ribs, the ribs nearest the sutures shorter than others and not reaching ends of valves; stigmas linear. Four species, West tropical Africa, confined to a small region in Guinea and Sierra Leone. 37. Thelethylax C. Cusset

Fig. 119D–F

Thelethylax C. Cusset, Adansonia II, 12:564 (1972).

Roots ribbon-like, up to 1 mm wide, branched, bearing shoots along margins; vegetative shoots and reproductive short-shoots of different shapes; vegetative stems bearing up to 20 simple leaves in a rosette, or up to 4 elongate and repeatedly forked leaves with linear ultimate segments, up to 1 m long; flowering stems bearing few-leaved rosettes, widened and overlapping at base, filamentous above. Spathellas obovoid, splitting irregularly. Flowers strongly inclined or inverted in un-

Fig. 119. Podostemaceae-Podostemoideae. A–C Stonesia gracilis. A Crustose root bearing flowers and two elongate shoots bearing flowers (1 cm). B Flower (1 mm). C Capsule. D–F Thelethylax minutiflora. D Vegetative shoot (1 cm). E Flower (1 mm). F Inverted flower removed from the spathella (1 mm). (Drawn by Cook)

ruptured spathella, terminal, solitary; tepals usually 3, one each side of andropodium base, the third between the two filaments, or rarely 2 one each side of andropodium base; stamens 2, borne on an andropodium; pollen in dyads; ovaries 2-locular. Capsules obovoid, ±1 mm long; valves equal or unequal, each with 3 wide ribs; stigmas linear. Two species, T. isalensis (Perrier) C. Cusset and T. minutiflora (Tulasne) C. Cusset, Madagascar. 38. Winklerella Engler

Fig. 120A–C

Winklerella Engler, Bot. Jahrb. Syst. 38:97 (1905).

Roots crustose or ribbon-like, 4–5 mm wide; stems simple or branched, 1–3 cm long. Leaves up to 6 mm long, once or twice forked into linear segments; ultimate segments filamentous. Spathellas obovoid. Flowers inverted in unruptured spathella,

Podostemaceae

335

solitary or in clusters; pedicel up to 1 cm long in fruit; tepals 2, very small, not more than 0.2 mm long, one each side of andropodium base; stamens 2(3); pollen in monads; ovaries 1-locular. Capsules ovate in outline, strongly flattened laterally with 2 lateral wings, each longer than capsule and forming 2 flattened, horn-like protuberances each side of stigmas; valves equal; stigmas linear. One species, W. dichotoma Engler, Edéa, Cameroon.

monads; ovaries 1-locular; gynophore up to 8 mm long. Capsules globose, 0.6–0.7 mm long; valves equal, each with 3 ribs; stigmas equal, linear, 0.7– 0.8 mm long. One species, Z. microgyna C. Cusset, Edéa, Cameroon, differing from Leiothylax in having a ribbed capsule.

39. Zehnderia C. Cusset

40. Cladopus H. Moeller

Fig. 120D–F

Zehnderia C. Cusset, Fl. Cameroun 30:56 (1987).

Podostemoid Genera of Asia and Australia Fig. 121A–E

Roots crustose; stems simple or branched, up to 3 cm long. Leaves ribbon-like, simple, 2–3 mm long, with stipules. Spathellas obovoid, ±1.5 mm long. Flowers inverted in unruptured spathella, arranged irregularly, either solitary or in clusters; pedicels up to 1.5 cm long in fruit; tepals 2, filiform, 0.2–0.3 mm long, one each side at base of andropodium; stamens 2 or rarely 3; anthers ±0.7 mm long; pollen in

Cladopus H. Moeller, Ann. Jard. Bot. Buitenzorg 16:115 (1899). Mniopsis Mart. pro parte (1823 or 1824), nom. illegit. Lawiella Koidzumi, in Y. Doi, Fl. Satsum. 1, 2:21 (1927); emend. Koidzumi, in Y. Doi, Fl. Satsum. 2:94 (1931). Hemidistichophyllum Koidzumi, in Y. Doi, Fl. Satsum. 1, 3:24 (1928), cum descr.; Koidzumi, Fl. Symb. Orient.-Asiat. 96 (1930), in syn. Lecomtea Koidzumi (1929). Torrenticola Domin ex Steenis (1949).

Fig. 120. Podostemaceae-Podostemoideae. A–C Winklerella dichotoma. A Distal part of flowering shoot (2.5 mm). B Flower (1 mm). C Transverse section of a capsule. D–F Zehnderia microgyna. D Flower (0.7 mm). E Flowering plant (4 mm). F Flower emerging from the spathella (0.7 mm). (Drawn by Cook)

Roots ribbon-like to almost cylindrical, irregularly lobed or branched, (0.5–)2–6 mm wide; stems erect, very short or up to 10 cm long, simple or rarely branched, arising along lateral margins of roots and on upper surface near sinuses of root lobes, some remaining embedded in root as rosettes with only the leaves emerging, others eventually emerging and bearing flowers. Leaves on young stems subulate, linear, with a few lateral teeth at base; leaves on older and flowering stems imbricate, scale-like, 2-lobed or palmately divided with 3–9 lobes or linear teeth, one or more median lobes sometimes with caducous, subulate to filamentous tips. Spathellas ovoid to globose, with an apical papilla, ±2 mm long, splitting at tip, ± circumscissile. Flowers solitary, terminal; pedicels very short to 1.25 mm long, sometimes elongating to ±3 mm long in fruit, the flowers barely emerging from spathella; tepals 2, minute, one each side of stamen or andropodium; stamens 1 or 2(3), when 2 or 3, then borne on an andropodium, when 1, then the anther halves separated by a broad connective; pollen in dyads. Capsules ovoid to almost globose, 1.25–1.75 mm long, borne on a short or a 1.5–3 mm long pedicel, obliquely 2-locular; valves unequal, each smooth or with 3 or 5 faint ribs, the larger valve persistent; stigmas linear or oblong-lanceolate. Seeds ± 100. About six species (more have been described), Southeast and East Asia, New Guinea, north-eastern Australia.

336


Cook and Rutishauser (2001) have incorporated Torrenticola into Cladopus (see morphological and molecular data in Rutishauser and Pfeifer 2002, and Kita and Kato 2004b). 41. Diplobryum C. Cusset

Fig. 121F, G

Diplobryum C. Cusset, Adansonia II, 12:279 (1972).

Roots crustose and closely attached to rock, or cylindrical to ribbon-like with lower part attached to rock and upper part floating; stems very short, simple, apparently arising on upper surface of root and in the sinuses of root branches. Leaves imbricate, scale-like, ovate-elliptic, up to 2 mm long, either obtuse at tip or with an elongated, caducous, linear tip. Spathellas with an apical beak, opening by a slit. Flowers solitary; pedicel very short, barely bearing the flower above the leaves; tepals 2, linear, 1 each side of andropodium; stamens 2, borne on an andropodium; pollen in dyads. Capsules ellipsoidal to fusiform, laterally flattened, 1–1.5 mm long; valves equal and persistent, each with 9 ribs; stigmas linear or globose. Seeds ± 40–70, elongate with fine, longitudinal ribs. Four species, Southeast Asia, closely related to Hydrobryum. 42. Farmeria Willis

Figs. 104L, 121H–K

Farmeria Willis ex J.D. Hooker in Trimen, Handb. Fl. Ceylon 5:386 (1900). Maferria C. Cusset (1992).

Roots thread-like, cylindrical or somewhat flattened, 1–2(–4) mm wide, up to 25 mm long, branched, forming entangled mats, closely attached to rocks by holdfasts associated with root-borne shoots; stems very short, simple, arising along lateral margins of roots, some remaining embedded in root with only the leaves emerging, the others barely emerging and bearing flowers. Leaves scattered in groups along edge of root or 1, 2 or rarely 3 pairs on flowering stems, linear, 2–5 mm long, with thread- or band-like, caducous tips. Spathellas ovoid, splitting at tip. Flowers sessile, remaining within opened spathella, only anthers and stigmas emerging; tepals 2, linear to subulate, borne one each side of stamen filament; stamen 1; filament slightly flattened laterally, exceeding ovary and stigmas; pollen in dyads. Capsules sessile or with stalk up to 1 mm long, obliquely ovoid or subglobose, ±0.7 mm long, valves smooth or each with 3 or 5 ribs, very unequal, in F. metzgerioides indehiscent, with 1 loculus aborting and the other with 1 or rarely 2 seeds, or in F. indica dehiscent

Fig. 121. Podostemaceae-Podostemoideae. A–E Cladopus nymani. A Ribbon-like root with shoot buds (2 mm). B Stem with unruptured spathella (1 mm). C Leaf (1 mm). D Flower (1 mm). E Persistent empty capsule valve (1 mm). F, G Diplobryum minutale. F Crustose root with six fertile shoots (1 mm). G Shoot with flower emerging from boat-shaped spathella (0.5 mm). H–K Farmeria indica. H Creeping root with vegetative shoots (5 mm). I Flowering shoot (1 mm). J Flower removed from spathella (1 mm). K Capsule (1 mm). (Drawn by Cook)

or indehiscent, with (4–)8(–18) seeds; stigmas linear, unequal. Two species, F. indica Willis, south-western India and F. metzgerioides (Trimen) Willis, Sri Lanka, southern India. 43. Griffithella (Tulasne) Warming Fig. 122A–D Griffithella (Tulasne) Warming, Overs. Kong. Danske Vidensk. Selsk. Skr. VI, 11(1):13, 65 (1901).

Roots variable, star-shaped or ribbon-like, when ribbon-like, then up to 1 cm wide, green to red, usually closely attached to the rocks but sometimes cup-like and then attached only by central part; stems simple, short, arising endogenously along lateral margins or from upper surface of

Podostemaceae

root, with 2–6 leaves. Leaves imbricate, scale-like, 3–4 mm long, often caducous; leaf bases ± hooded, overlapping. Spathella broadly funnel-shaped, 2–3 mm long, splitting irregularly at tip into several teeth, the torn parts appearing fimbriate. Flowers solitary; pedicel ±3 mm long at anthesis, 4 mm or more long in fruit; tepals 2, one on each side of andropodium; stamens 2; andropodium 1.5–2 mm long, as long or longer than ovary; filaments 0.5–0.7 mm long; pollen in dyads. Capsules narrowly ovoid, 2.5 mm long, smooth; valves unequal, the larger persistent; stigmas linear. Seeds ±250, ±0.2 mm long. One species, G. hookeriana (Tulasne) Warming, southern India.

44. Hanseniella C. Cusset

337

Fig. 122E–K

Hanseniella C. Cusset, Bull. Mus. Natl Hist. Nat. Paris IV, 14, B, Adansonia 1:36 (1992); M. Kato, Acta Phytotax. Geobot. 55:133–165 (2004), rev.

Roots crustose, green, irregularly lobed or branched, lobes ± 4 mm long; stems short, simple, scattered on upper surface of root. Leaves on juvenile or submerged stems linear, simple in irregular rosettes; leaves on flowering or emergent stems imbricate, scale-like, of two kinds, arranged in 4 rows; 2 rows scale-like and entire, ±1.5 mm long; remaining 2 rows 2-lobed, 1.25–1.75 mm long, with the sinus half or more as long as leaf, the lobes ± equal and bluntly rounded. Spathellas ellipsoidal, thick, with 2 or 3 ridges, rupturing irregularly at tip. Flowers solitary; pedicel 2–3 mm long, barely holding flowers above spathella; tepals 2, 1 each side of andropodium, linear-triangular, almost reaching top of ovary; stamens 2, borne on an andropodium, much exceeding ovary; pollen in dyads. Capsules ellipsoidal, somewhat flattened, borne on a ± 0.8 mm long gynophore; valves equal, each with 3 main ribs, in H. heterophylla sometimes with up to 3 fainter additional ribs; stigmas linear. Seeds 8–12, relatively large, 0.6–0.9 mm long. Two species, H. heterophylla C. Cusset and H. smitinandii M. Kato, both from northern Thailand. Molecular data of Kita and Kato (2004b) indicate a close relationship with Hydrobryum. 45. Hydrobryum Endlicher

Figs. 104C, 123A–D

Hydrobryum Endlicher, Gen. Pl. 1375 (1841), M. Kato, Acta Phytotax. Geobot. 55:133–165 (2004), rev. Polypleurella Engler (1927), pro parte. Euhydrobryum Koidzumi (1931). Hydroanzia Koidzumi (1935). Synstylis C. Cusset (1992).

Fig. 122. Podostemaceae-Podostemoideae. A–D Griffithella hookeriana. A Creeping root with two fruiting shoots (2 mm). B Flowering shoot (1 mm). C Young cup-shaped root (2 mm). D Persistent empty capsule valve (1 mm). E–K Hanseniella heterophylla. E Shoot with unopened spathella (1 mm). F Fragment of root bearing tufts of juvenile leaves (3 mm). G Shoot with capsule (1 mm). H Rosette of juvenile leaves (1 mm). I Two-lobed ‘ventral’ leaf (1 mm). J Flower (1 mm). K Placenta with seeds (0.5 mm). (Drawn by Cook)

Roots crustose, irregularly lobed, 1–10(–30) cm in diameter; stems scattered on upper surface of root; vegetative shoots very short, rosette-like; flowering stems simple, very short. Leaves of vegetative stems 2–8, tufted, in 2 rows, linear, up to 12 mm long; leaves of flowering stems imbricate, scale-like, 2–8, in 2 rows, overlapping, enlarged at base, tips linear and caducous or lacking. Spathellas boat-shaped, opening irregularly at tip or splitting down one side, thin, smooth. Flowers solitary, terminal, subsessile, remaining within the leaves; tepals 2 (rarely 1, 3 or 4), linear, 1–1.5 mm long; stamens 1 or 2(3), borne on andropodium at least as long

338


as filaments; pollen in dyads. Capsules shortly pedicelled, ± ellipsoidal, sometimes laterally flattened; valves equal, each with 5 or 6(–9) ribs; styles short or 0; stigmas linear to cuneate, entire, toothed or lobed. Seeds 8–60, elliptic-patelliform, surface granular. About 12 species, north-eastern India, Nepal, Bhutan, southern Central China, North Vietnam, Thailand and southern Japan, ten species in Thailand. The genus Synstylis was based on Polypleurella micranthera Engler; we are convinced it belongs to the genus Hydrobryum. Diplobryum is also very close to Hydrobryum. 46. Polypleurum Warming

fertile stems appressed to or sometimes strongly oblique to root surface or rarely ascending, 2–3 mm long. Leaves on juvenile (submerged) stems linear, 2–5, in 2 ranks, in small rosettes, sheathed at base; leaves of flowering stems imbricate, scale-like, arranged in 4 rows; 4–6 per row, upper ones 3-lobed or uppermost one sometimes 2-lobed with a lateral lobe reduced, 1.5–3 mm long; lobes acute, the median usually somewhat longer than the later-

Figs. 104I, 123E, F

Polypleurum Warming, Overs. Kong. Danske Vidensk. Selsk. Skr. VI, 11(1):464 (1901). Podostemum auctt. Ind., non A. Michaux (1803).

Roots usually ribbon-like or sometimes threadlike, usually lower part closely attached to rock with upper part free, or sometimes entirely attached to rock; free parts usually repeatedly forked, up to 50 cm long, rather tough, sometimes resembling Fucus; holdfasts often branched; stems short, developed endogenously at sometimes almost regular intervals along or near margin of root, bearing 2–8 or rarely more leaves; vegetative stems 0; flowering stems unbranched, less than 5 mm long. Leaves imbricate, scale-like, entire or lobed, with or without a caducous, elongate apical appendage. Spathellas sessile, ovoid to clubshaped, opening irregularly at tip. Flowers solitary, pedicellate; pedicel up to 1 cm long in fruit; tepals 2, 1 each side of andropodium or stamen, flattened, subulate; stamens 2(1), when 2, then borne on an andropodium; pollen in dyads. Capsules ellipsoidal, 2–3 mm long, sometimes laterally somewhat flattened; valves equal and persistent, each with 3, 5 or 7 ribs; style short or 0; stigmas linear or subconical. Seeds up to 200 or more. About eight species, Sri Lanka, India and Thailand. Podostemum munnarense (Nagendran & Arekal) Mathew & Satheesh belongs to Polypleurum. 47. Thawatchaia M. Kato, Koi & Y. Kita Fig. 123G–K Thawatchaia M. Kato, Koi & Y. Kita, Acta Phytotax. Geobot. 55:66 (2004).

Roots crustose, green, irregularly lobed; stems very short, simple, scattered on upper surface of root;

Fig. 123. Podostemaceae-Podostemoideae. A–D Hydrobryum japonicum. A Fragment of a crustose root with juvenile-leaved shoots (1 mm). B Tuft of juvenile leaves (3 mm). C Flowering shoot (1 mm). D Capsule with two equal valves (1 mm). E, F Polypleurum stylosum. E Seaweed-like root with marginal flowering shoots (1 cm). F Flowering shoot (2 mm). G–K Thawatchaia trilobata. G Fragment of crustose root bearing juvenile-leaved shoots (3 mm). H Three-lobed leaf (1 mm). I Shoot with spathella splitting (1 mm). J Flower emerging from spathella (1 mm). K Young capsule (1 mm). (Drawn by Cook)

Podostemaceae

als. Spathellas ellipsoidal, thin, not ridged, rupturing irregularly at tip. Flowers solitary; pedicel 2–2.5 mm long, barely holding flowers above spathella; tepals 2, 1 each side of andropodium, linear-triangular, almost reaching top of ovary; stamens 2, borne on andropodium, exceeding ovary; pollen in dyads. Capsules ellipsoidal, somewhat flattened; valves equal, each with 3 or 4 ribs; stigmas linear. Seeds 14–18(–22). One species, T. trilobata M. Kato, Koi & Y. Kita, northern Thailand. 48. Willisia Warming

Fig. 124A–C

Willisia Warming, Overs. Kong. Danske Vidensk. Selsk. Skr. VI, 11(1):58 (1901). Mniopsis Mart. (1823 or 1824) pro parte, nom. illegit.

339

or in the sinuses of root lobes; erect structures, up to 3 cm long, stalked below and terminating in photosynthetic filaments may also arise from upper surface of root; flowering stems erect or rather prostrate, with scale-like leaves. Leaves of vegetative stems thread-like, (0.5–)2–5(–30) cm long; leaves of flowering stems imbricate, scale-like, those at base terminating in a caducous, threadlike tip, those below flowers rounded. Spathellas ovoid or boat-like, with an apical beak, opening at tip or by a longitudinal slit, remaining embedded in surrounding leaves or carried well above leaves. Flowers subsessile or pedicellate; tepals 2, one each side of andropodium or stamen; stamens 2 or rarely 1, when 2, then borne on an andropodium; pollen in dyads. Capsules ellipsoidal to subglo-

Roots usually ribbon-like or crustose and sometimes irregularly lobed or branched, 2–3 cm in diameter; stems arising along or near root margin, dimorphic; vegetative shoots caducous as the water level falls, simple or rarely branched, up to 50 cm long, almost leafless below, above with numerous, up to 8 cm long, filamentous leaves; flowering stems densely crowded, simple, rigid, erect, 2–10 cm long, closely covered with leaves. Leaves of flowering stems in 4 or 6 distinct rows, imbricate, scale-like, some entire, 2 rows with 2 scale-like, lateral teeth and a hair-like but caducous tip. Spathellas urn-shaped, forked at tip into 2 stiff teeth, distal part may fall off as a cap or it may persist in cleistogamous flowers until seeds are ripe. Flowers solitary, terminal, sessile; tepals 2, 1 each side of andropodium; stamens 2, borne on andropodium; pollen in dyads. Capsules smooth or middle nerve of each valve forming a rib; the larger valve persistent; stigmas linear. Seeds ± 80. Two doubtfully distinct species, W. arekaliana Shivamurthy & Sadanand, W. selaginoides (Beddome) Warming ex Willis, both south-western India. 49. Zeylanidium (Tulasne) Engler Figs. 104B, 124D–H Zeylanidium (Tulasne) Engler in Engler & Prantl, Nat. Pflanzenfam. ed. 2, 18a:61 (1928); sensu C. Cusset, Bull. Mus. Natl Hist. Nat. Paris IV, 14, B, Adansonia 1:28 (1992). Podostemum auctt. Ind., non A. Michaux (1803). Hydrobryopsis Engler (1928).

Roots thread-like, subcylindrical and forked, or ribbon-like and pinnately lobed, lobes sometimes overlapping or foliose, 1–10(–30) cm diameter and irregularly lobed; stems simple, short or somewhat elongate, simple, scattered on upper surface of root

Fig. 124. Podostemaceae-Podostemoideae. A–C Willisia selaginoides. A Crustose root with one vegetative and two young fertile shoots (2 cm). B Flowering shoot (1 mm). C Persistent empty capsule valve (1 mm). D–H Zeylanidium. D–F Z. olivaceum. D Crustose root with six fruiting shoots (5 mm). E Flowering shoot (2 mm). F Crustose root with vegetative shoots (5 mm). G, H Z. lichenoides. G Ribbon-like root with young fertile shoots (5 mm). H Spathella emerging from leaves (2 mm). (Drawn by Cook)

340


bose, 2–5 mm long; valves unequal, the larger one persistent; each valve smooth or with 3 ribs; stigmas slightly unequal, conical to linear, sometimes slightly flattened and fan-like. Seeds ± 40 in Z. sessilis (Willis) C.D.K. Cook & R. Rutishauser. Five or six species, Sri Lanka, southern, western and north-eastern India, Myanmar.

Selected Bibliography Ameka, G.K., Pfeifer, E., Rutishauser, R. 2002. Developmental morphology of Saxicolella amicorum and S. submersa (Podostemaceae: Podostemoideae) from Ghana. Bot. J. Linn. Soc. 139:255–273. Ameka, K.G., Clerk, C.G., Pfeifer, E., Rutishauser, R. 2003. Developmental morphology of Ledermanniella bowlingii (Podostemaceae) from Ghana. Pl. Syst. Evol. 237:165–183. Ancibor, E. 1990. Anatomia de las especies Argentinas de Podostemum Michaux (Podostemaceae). Parodiana 6:31–47. APG II. 2003. See general references. Battaglia, E. 1987. Embryological questions. 11. Has the debated case of Podostemaceae been resolved? Annali Bot. (Roma) 45:37–64. Bezuidenhout, A. 1964. The pollen of the African Podostemaceae. Pollen Spores 6:463–478. Burkhardt, G., Schild, W., Becker, H., Grubert, M. 1992. Biphenyls and xanthones from the Podostemaceae. Phytochemistry 31:543–548. Burkhardt, G., Becker, H., Grubert, M., Thomas, J., Eicher, T. 1994. Bioactive chromenes from Rhyncholacis penicillata. Phytochemistry 37:1593–1597. Capers, R.S., Les, D.H. 2001. An unusual population of Podostemum ceratophyllum (Podostemaceae) in a tidal Connecticut river. Rhodora 103:219–223. Cario, R. 1881. Anatomische Untersuchung von Tristicha hypnoides Spreng. Bot. Zeitung 39:25–33, 41–48, 57– 64, 73–82, pl. I. Chase, M.W., Fay, M.F., Savolainen, V. 2000. Higher-level classification in the angiosperms: new insights from perspective of DNA sequence data. Taxon 49:685–704. Cheek, M. 2003. A new species of Ledermanniella (Podostemaceae) from western Cameroon. Kew Bull. 58:733–739. Cheek, M., Onana, J., Pollard, P. 2000. The plants of Mount Oku and the Ijim Ridge. Royal Botanic Gardens, Kew. Collinson, M.E., Boulter, M.C., Holmes, P.L. 1993. Magnoliophyta (Angiospermae). In: Benton, M.J. (ed.) The fossil record, 2. London: Chapman and Hall. Connelly, W.J., Orth, D.J., Smith, R.K. 1999. Habitat of the riverweed darter, Etheostoma podostemonae Jordan, and the decline of riverweed, Podostemum ceratophyllum, in the tributaries of the Roanoke River, Virginia. J. Freshwater Ecol. 14:93–102. Cook, C.D.K. 1996a. Aquatic plant book, 2nd revised edn. The Hague: SPB Academic. Cook, C.D.K. 1996b. Aquatic and wetland plants of India. Oxford: Oxford University Press.

Cook, C.D.K. 1999. The number and kinds of embryobearing plants which have become aquatic: a survey. Perspectives Pl. Ecol. Evol. Syst. 2:79–102. Cook, C.D.K., Rutishauser, R. 2001. Name changes in the Podostemaceae. Taxon 50:1163–1167. Cusset, G. 1974. Quelques traits remarquables de l’organisation du Thelethylax minutiflora C. Cusset (Podostémacée). In: Actes 99ème Congrès National des Sociétés Savantes, Besançon, 1974, Sciences, fasc. 2, pp. 177– 188. Cusset, C. 1978. Contribution à l’étude des Podostemaceae. 5. Le genre Macropodiella Engl. Adansonia II, 17:293– 303. Cusset, C. 1980. Contribution à l’étude des Podostemaceae. 6. Les genres Leiothylax, et Letestuella. Adansonia II, 20:199–207. Cusset, C. 1983 (publ. 1984). Contribution à l’étude des Podostemaceae. 7. Ledermanniella Engl. sous-genre Phyllosoma C. Cusset. Bull. Mus. Natl Hist. Nat. Paris V, B, Adansonia 4:361–390. Cusset, C. 1984. Contribution à l’étude des Podostemaceae. 8. Ledermanniella Engl. sous-genre Ledermanniella. Bull. Mus. Natl Hist. Nat. Paris VI, B, Adansonia 3:249– 278. Cusset, C. 1987. Podostemaceae et Tristichaceae. In: Satabié, B., Morat, Ph. (eds) Flore du Cameroun 30:51–99. Cusset, C. 1992. Contribution à l’étude des Podostemaceae. 12. Les genres asiatiques. Bull. Mus. Natl Hist. Nat. Paris IV, B, Adansonia 14:13–54. Cusset, G., Cusset, C. 1988. Etude sur les Podostemales. 10. Structures florales et végétatives des Tristichaceae. Bull. Mus. Natl Hist. Nat. Paris IV, B, Adansonia 10:179– 218. Cusset, G., Cusset, C. 1989. Biogéographie évolutive de Tristicha trifaria (Bory ex Willd.) Sprengel. Bull. Mus. Natl Hist. Nat. Paris IV, B, Adansonia 11:39–70. Davis, G.L. 1966. See general references. Engler, A. 1928. Reihe Podostemales. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 18a. Leipzig: W. Engelmann, pp. 1–68, 483–484. [published as one volume in 1930] Gessner, F., Hammer, L. 1962. Ökologisch-physiologische Untersuchungen an den Podostemonaceen des Caroni. Intl Rev. Gesell. Hydrobiol. 47:497–541. Goebel, K. 1933. Organographie der Pflanzen, 3. Samenpflanzen, ed. 3. Jena: G. Fischer. Grubert, M. 1970. Untersuchungen über die Verankerung der Samen von Podostemonaceen. Intl Rev. Gesell. Hydrobiol. 55:83–114. Grubert, M. 1974. Podostemaceen-Studien. Teil 1. Zur Oekologie einiger venezolanischer Podostemaceen. Beitr. Biol. Pflanzen 50:321–391. Grubert, M. 1976. Podostemaceen-Studien. Teil 2. Untersuchungen über die Keimung. Bot. Jahrb. Syst. 95:455– 477. Grubert, M. 1991. Ecologia de fanerógamas de saltos tropicales adaptadas en forma extrema. Natúra (Caracas) 91:54–61. Gustafsson, M.H.G., Bittrich, V., Stevens, P.F. 2002. Phylogeny of Clusiaceae based on rbcL sequences. Intl J. Pl. Sci. 163:1045–1054. Hammond, B.L. 1936. Regeneration of Podostemon ceratophyllum Michx. Bot. Gaz. 97:834–845.

Podostemaceae Hiyama, Y., Tsukamoto, I., Imaichi, R., Kato, M. 2002. Developmental anatomy and branching of roots of four Zeylanidium species (Podostemaceae), with implications for evolution of foliose roots. Annals Bot. 90:735–744. Hutchens, J.J., Wallace, J.B., Romaniszyn, E.D. 2004. Role of Podostemum ceratophyllum Michx. in structuring benthic macroinvertebrate assemblages in a southern Appalachian river. J. N. Amer. Benthol. Soc. 23:713–727. Imaichi, R., Ichiba, T., Kato, M. 1999. Developmental morphology and anatomy of the vegetative organs in Malaccotristicha malayana (Podostemaceae). Intl J. Pl. Sci. 160:253–259. Imaichi, R., Maeda, R., Suzuki, K., Kato, M. 2004. Developmental morphology of foliose shoots and seedlings of Dalzellia zeylanica (Podostemaceae) with special reference to their meristems. Bot. J. Linn. Soc. 144:289–302. Imaichi, R., Hiyama, Y., Kato, M. 2005. Leaf development in absence of a shoot apical meristem in Zeylanidium subulatum (Podostemaceae): evolutionary implications. Ann. Bot. 96:51–58. Jäger-Zürn, I. 1967. Embryologische Untersuchungen an vier Podostemaceen. Oesterr. Bot. Z. 114:20–45. Jäger-Zürn, I. 1970. Morphologie der Podostemaceae. I. Tristicha trifaria (Bory ex Willd.) Spreng. Beitr. Biol. Pflanzen 47:11–52. Jäger-Zürn, I. 1992. Morphologie der Podostemaceae. II. Indotristicha ramosissima (Wight) van Royen (Tristichoideae). Trop.-subtrop. Pflanzenwelt 80:1–48. Mainz: F. Steiner. Jäger-Zürn, I. 1994. Morphologie der Podostemaceae. IV. Zur Kenntnis der dithekischen Blätter bei Podostemum subulatum Gard. (Podostemoideae). Beitr. Biol. Pflanzen 68:391–419. Jäger-Zürn, I. 1995. Morphologie der Podostemaceae. III. Dalzellia ceylanica (Gard.) Wight (Tristichoideae). Trop.-subtrop. Pflanzenwelt 92:1–77. Mainz: F. Steiner. Jäger-Zürn, I. 1997a. Comparative morphology of the vegetative structures of Tristicha trifaria, Indotristicha ramosissima and Dalzellia ceylanica. Aquat. Bot. 57:71–96. Jäger-Zürn, I. 1997b. Embryological and floral studies in Weddellina squamulosa Tul. (Podostemaceae, Tristichoideae). Aquat. Bot. 57:151–182. Jäger-Zürn, I. 1999. Developmental morphology of the shoot system of Podostemum subulatum (Podostemaceae–Podostemoideae). Beitr. Biol. Pflanzen 71:281–334. Jäger-Zürn, I. 2000a. Developmental morphology of roots and root-born shoots of Podostemum subulatum as compared with Zeylanidium olivaceum (Podostemaceae–Podostemoideae). Pl. Syst. Evol. 220:55–67. Jäger-Zürn, I. 2000b. Crustose root and root-borne shoots of Zeylanidium olivaceum (Podostemaceae– Podostemoideae). Flora 195:61–82. Jäger-Zürn, I. 2000c. The unusual ramification mode of Sphaerothylax abyssinica (Wedd.) Warm. (Podostemaceae–Podostemoideae). Flora 195:200–227. Jäger-Zürn, I. 2002a. Comparative studies in the morphology of Crenias weddelliana and Maferria indica with reference to Sphaerothylax abyssinica (Podostemaceae). Bot. J. Linn. Soc. 137:63–84. Jäger-Zürn, I. 2002b. Morphology and morphogenesis of ensiform leaves in Apinagia multibranchi-

341

ata and Mourera fluviatilis (Podostemaceae– Podostemoideae). Flora 197:394–407. Jäger-Zürn, I. 2003a. The occurrence of apical septum in ovaries of Rhyncholacis, Apinagia, Marathrum and Mourera (Podostemoideae–Podostemaceae): taxonomic implications. Bot. Jahrb. Syst. 124:303–324. Jäger-Zürn, I. 2003b. The architecture of Zeylanidium olivaceum (Podostemaceae) inferred from the structure of the primary shoots. Pl. Syst. Evol. 241:103–114. Jäger-Zürn, I. 2005a. Structural analysis of the dissected ensiform leaves and shoot morphology of Marathrum foeniculaceum (Podostemaceae). Flora 200:229–244. Jäger-Zürn, I. 2005b. Shoot apex and spathella: two problematical structures of PodostemaceaePodostemoideae. Pl. Syst. Evol. 253:209–218. Jäger-Zürn, I. 2005c. Morphology and morphogenesis of ensiform leaves, syndesmy of shoots and an understanding of the thalloid plant body in species of Apinagia, Mourera and Marathrum (Podostemaceae). Bot. J. Linn. Soc. 147:47–71. Jäger-Zürn, I., Grubert, M. 2000. Podostemaceae depend on sticky biofilms with respect to attachment to rocks in waterfalls. Intl J. Pl. Sci. 161:599–607. Jäger-Zürn, I., Mathew, C.J. 2002. Cupula structure of Dalzellia ceylanica and Indotristicha ramosissima (Podostemaceae). Aquat. Bot. 72:79–91. Jäger-Zürn, I., Novelo, R.A., Philbrick, C.T. 2005. Microspore development in Podostemaceae-Podostemoideae, with implications on the characterization of the subfamilies. Pl. Syst. Evol. 256:209–216. Johri, B.M. et al. 1992. See general references. Kapil, R.N. 1970. Podostemaceae. In: Proc. Symp. Comparative Embryology of Angiosperms. Bull. Indian Natl Sci. Acad. 41:104–109. Kato, M., Kita, Y., Koi, S. 2003. Molecular phylogeny, taxonomy and biogeography of Malaccotristicha australis comb. nov. (syn. Tristicha australis) (Podostemaceae). Austral. Syst. Bot. 16:177–183. Kato, M., Koi, S., Kita, Y. 2004. A new foliose-rooted genus of Podostemaceae from Thailand with a note on root evolution. Acta Phytotax. Geobot. 55:65–73. Kato, L., de Oliveira, C.M.A., Bittrich, V., Amaral, M.C.E. 2005. Xanthones from Weddellina squamulosa Tul. (Podostemaceae). Biochem. Syst. Ecol. 33:331–334. Khosla, Ch., Mohan Ram, H.Y. 1993. Morphology of flower, fruit and seed in Polypleurum stylosum. Aquat. Bot. 46:255–262. Khosla, C., Shivanna, K.R., Mohan Ram, H.Y. 2000. Reproductive biology of Polypleurum stylosum (Podostemaceae). Aquat. Bot. 67:143–154. Khosla, C., Shivanna, K.R., Mohan Ram, H.Y. 2001. Cleistogamy in Griffithella hookeriana (Podostemaceae). S. African J. Bot. 67:320–324. Kita, Y., Kato, M. 2001. Infrafamilial phylogeny of the aquatic angiosperm Podostemaceae inferred from the nucleotide sequence of the matK gene. Pl. Biol. 3:156–163. Kita, Y., Kato, M. 2004a. Phylogenetic relationships between disjunctly occurring groups of Tristicha trifaria (Podostemaceae). J. Biogeogr. 31:1605–1612. Kita, Y., Kato, M. 2004b. Molecular phylogeny of Cladopus and Hydrobryum (Podostemaceae, Podostemoideae) with implications for their biogeography in East Asia. Syst. Bot. 29:921–932.

342


Kita, Y., Kato, M. 2005. Seedling developmental anatomy of an undescribed Malaccotristicha species Podostemaceae, (subfamily Tristichoideae) with implications for body plan evolution. Pl. Syst. Evol. 254:221–232. Koi, S., Kato, M. 2003. Comparative developmental anatomy of the root in three species of Cladopus (Podostemaceae). Ann. Bot. 91:927–933. Koi, S., Imaichi, R., Kato, M. 2005. Endogenous leaf initiation in the apical-meristemless shoot of Cladopus queenslandicus (Podostemaceae) and implications for evolution of shoot morphology. Intl J. Pl. Sci. 166:199–206. Koi, S., Fujnami, R., Kubo, N., Tsukamato, J., Imaichi, R., Kato, M. 2006. Comparative anatomy of root meristem and root cap in some species of Podostemaceae and the evolution of root dorsiventrality. Amer. J. Bot. 93:682–692. Léonard, J. 1993. Etude phytosociologique des chutes de la Tshopo (Kisangani–Zaïre). Bull. Jard. Bot. Natl Belgique 62:283–347. Léonard, J., Dessart, P. 1994. Avis de recherche: Torridincolidés (Coleoptera) vivant en symbiose avec Podostémacées (Podostémales). Bull. Ann. Soc. Roy. Belge Entomol. 130:71–76. Les, D.H., Philbrick, C.T., Novelo, R.A. 1997. The phylogenetic position of river-weeds (Podostemaceae): insights from rbcL sequence data. Aquat. Bot. 57:5–27. Lobreau-Callen, D., LeThomas, A., Suarez-Cervera, M. 1998. Ultrastructural characters of the pollen of some Podostemales. Affinities with advanced Rosidae (in French). C. R. Acad. Sci. Paris III, 321:335–345. Mai, D.H. 1985. Entwicklung der Wasser- und Sumpfpflanzen-Gesellschaften Europas von der Kreide bis ins Quartär. Flora 176:449–511. Mathew, C.J., Satheesh, V.K. 1997. Taxonomy and distribution of the Podostemaceae in Kerala, India. Aquat. Bot. 57:243–274. Mathew, C.J., Jäger-Zürn, I., Nileena, C.B. 2001. Dalzellia gracilis – a new species of Podostemaceae (Tristichoideae) from Kerala, India. Intl J. Pl. Sci. 162:899– 909. Mathew, C.J., Nileena, C.B., Jäger-Zürn, I. 2003. Morphology and ecology of two new species of Polypleurum (Podostemaceae) from Kerala, India. Pl. Syst. Evol. 237:209–217. Matthiesen, F. 1908. Beiträge zur Kenntnis der Podostemaceen. Bibl. Bot. 1908:1–55, 9 pls. Mauritzon, J. 1933. Über die systematische Stellung der Familien Hydrostachyaceae and Podostemonaceae. Bot. Notiser 1933:172–180. Metcalfe, C.R., Chalk, L. 1950. See general references. Miyoshi, N., Kato, H. 1982. Pollen morphology by means of scanning electron microscope. 5. Angiospermae (Piperales, Podostemonales). Jap. J. Palynol. 28:7–11. Mohan Ram, H.Y., Sehgal, A. 1992. Podostemaceae – the strange family of aquatic angiosperms. Palaeobotanist 41:192–197. Mohan Ram, H.Y., Sehgal, A. 1997. In vitro studies on developmental morphology of Indian Podostemaceae. Aquat. Bot. 57:97–132. Mohan Ram, H.Y., Sehgal, A. 2001. Biology of Indian Podostemaceae. In: Rangaswamy, N.S. (ed.) Phytomorphology (Recent trends in plant sciences) Golden Ju-

bilee Issue 2001. Delhi: International Society of Plant Morphologists, pp. 365–391. Moline, P., Les, D., Philbrick, C.D., Novelo, A.R., Pfeifer, E., Rutishauser, R. 2006. Comparative morphology and molecular systematics of Podostemum (including Grenias) – Amercan river-weeds (Podostemonaceae). Bot. Jahrb. Syst. 126:427–476. Moline, P., Thiv, M., Ameka, G.K., Ghogue, J.-P., Pfeifer, E., Rutishauser, R. 2007. Comparative morphology and molecular systematics of African Podostemaceae – Podostemoideae, with emphasis on Dicraeanthus and Ledermanniella from Cameroon. Intl J. Pl. Sci. (in press). Murguía-Sánchez, G., Novelo, R.A., Philbrick, C.T., Márquez Guzmán, G.J. 2001. Desarrollo de los verticilos sexuales de Vanroyenella plumosa Novelo & Philbrick. Acta Bot. Mex. 57:37–50. Murguía-Sánchez, G., Novelo, R.A., Philbrick, C.T., Márquez Guzmán, G.J. 2002. Embryo sac development in Vanroyenella plumosa, Podostemaceae. Aquat. Bot. 73:201–210. Noro, T., Suzuki, H., Kanayama, T. 1994a. Phenology and distribution of Hydrobryum japonicum Imamura (Podostemaceae) in the Kaminkawa River, Kagoshima, Japan (in Japanese). J. Jap. Bot. 69:162–166. Noro, T., Suzuki, H., Kanayama, T. 1994b. Water quality at the habitat of Hydrobryum japonicum Imamura (Podostemaceae) in Japan (in Japanese). J. Jap. Bot. 69:167–175. Novelo, R.A., Philbrick, C.T. 1997. Taxonomy of Mexican Podostemaceae. Aquat. Bot. 57:275–303. Odinetz-Collart, O., Tavares, A.S., Enriconi, A. 2001. Response of Podostemaceae aquatic biocenosis to environmental perturbations in central Amazonian waterfalls. Verh. Intl Verein. Limnol. 27:4063–4068. Okada, H., Kato, M. 2002. Pollination systems inferred from pollen-ovule ratio of some species of Podostemaceae. Acta Phytotax. Geobot. 53:51–61. O’Neill, S.P., Osborn, J.M., Philbrick, C.T. 1997. Comparative pollen morphology of five New World genera of Podostemaceae. Aquat. Bot. 57:133–150. Oropeza, N., Mercado-Ruaro, P., Novelo, R.A., Philbrick, C.T. 1998. Karyomorphological studies of Mexican species of Marathrum (Podostemaceae). Aquat. Bot. 62:207–211. Oropeza, N., Palomino, G., Novelo, R.A., Philbrick, C.T. 2002. Karyomorphological studies in Oserya, Vanroyenella and Tristicha (Podostemaceae sensu lato). Aquat. Bot. 73:163–171. Osborn, J.M., O’Neill, S.P., El-Ghazaly, G. 2000. Pollen morphology and ultrastructure of Marathrum schiedeanum (Podostemaceae). Grana 39:221–225. Ota, M., Imaichi, R., Kato, M. 2001. Developmental morphology of the thalloid Hydrobryum japonicum (Podostemaceae). Amer. J. Bot. 88:382–390. Pannier, F. 1960. Physiological responses of Podostemaceae in their natural habitat. Intl Rev. Gesell. Hydrobiol. 45:347–354. Philbrick, C.T. 1984. Aspects of floral biology, breeding system, and seed and seedling biology in Podostemum ceratophyllum (Podostemaceae). Syst. Bot. 9:166–174. Philbrick, C.T., Bogle, A.L. 1988. A survey of floral variation in five populations of Podostemum ceratophyllum Michx. (Podostemaceae). Rhodora 90:113–121.

Podostemaceae Philbrick, C.T., Crow, G.E. 1992. Isozyme variation and population structure in Podostemum ceratophyllum Michx. (Podostemaceae): implications for colonization of glaciated North America. Aquat. Bot. 43:311–325. Philbrick, C.T., Novelo, R.A. 1993. A fascinating family of aquatic flowering plants. Aquaphyte 13:1–7. Philbrick, C.T., Novelo, R.A. 1995. New World Podostemaceae: ecological and evolutionary enigmas. Brittonia 47:210–222. Philbrick, C.T., Novelo, R.A. 1997. Ovule number, seed number and seed size in Mexican and North American species of Podostemaceae. Aquat. Bot. 57:183–200. Philbrick, C.T., Novelo, R.A. 1998. Flowering phenology, pollen flow, and seed production in Marathrum rubrum (Podostemaceae). Aquat. Bot. 62:199–206. Philbrick, C.T., Novelo, R.A. 2004. Monograph of Podostemum (Podostemaceae). Syst. Bot. Monogr. 70:1–106. Philbrick, C.T., Novelo, R.A., Irgang, B.E. 2004a. Two new genera of Podostemaceae from the state of Minas Gerais, Brazil. Syst. Bot. 29:109–117. Philbrick, C.T., Novelo, R.A., Irgang, B.E. 2004b. A new species of Ceratolacis (Podostemaceae) from the state of Minas Gerais, Brazil. Novon 14:108–113. Quiroz, F., Novelo, R.A., Philbrick, C.T. 1997. Water chemistry and the distribution of Mexican Podostemaceae: a preliminary evaluation. Aquat. Bot. 57:201–212. Rauh, W. 1937. Die Bildung von Hypokotyl- und Wurzelsprossen und ihre Bedeutung für die Wuchsformen der Pflanzen. Nova Acta Leopoldiana, n.s. 4:396–553. Razi, B.A. 1955. Some aspects of the embryology of Zeylanidium olivaceum and Lawia zeylanica. Bull. Bot. Soc. Bengal 9:36–41. Romano, G.R., Dwyer, J.D. 1971. A demonstration of phloem in the Podostemaceae. Bull. Torrey Bot. Club 98:46–53. Romo Contreras, V., Scogin, R., Philbrick, C.T., Novelo, R.A. 1993. A phytochemical study of selected Podostemaceae: systematic implications. Aliso 13:513–520. Royen, P. van 1951. The Podostemaceae of the New World. I. Proefschrift, P. Harte, Bergen op Zoom, pp. 1–151, 16 pls., Reissued in Med. Bot. Mus. Herb. Rijksuniv. Utrecht 107:1–151, 16 pls. Royen, P. van 1953. The Podostemaceae of the New World. II. Acta Bot. Neerl. 2:1–21. Royen, P. van 1954. The Podostemaceae of the New World. Part III. Acta Bot. Neerl. 3:215–263. Rutishauser, R. 1995. Developmental patterns of leaves in Podostemaceae compared with more typical flowering plants: saltational evolution and fuzzy morphology. Canad. J. Bot. 73:1305–1317. Rutishauser, R. 1997. Structural and developmental diversity in Podostemaceae (river-weeds). Aquat. Bot. 57:29–70. Rutishauser, R., Grubert, M. 1994. The architecture of Mourera fluviatilis (Podostemaceae). Bot. Helv. 104:179– 194. Rutishauser, R., Grubert, M. 1999. The architecture of Mourera fluviatilis (Podostemaceae). Developmental morphology of inflorescences, flowers and seedlings. Amer. J. Bot. 86:907–922. Rutishauser, R., Grubert, M. 2000. Developmental morphology of Apinagia multibranchiata (Podostemaceae) from the Venezuelan Guyanas. Bot. J. Linn. Soc. 132:299–323.

343

Rutishauser, R., Huber, K.A. 1991. The developmental morphology of Indotristicha ramosissima (Podostemaceae, Tristichoideae). Pl. Syst. Evol. 178:195–223. Rutishauser, R., Moline, P. 2005. Evo-devo and the search for homology (“sameness”) in biological systems. In: Evolutionary developmental biology – new challenges to the homology concept? Theory Biosci. 124, 2:213– 241. Rutishauser, R., Pfeifer, E. 2002. Comparative morphology of Cladopus (including Torrenticola, Podostemaceae) from East Asia to north-eastern Australia. Austral. J. Bot. 50:725–739. Rutishauser, R., Novelo, R.A., Philbrick, C.T. 1999. Developmental morphology of New World Podostemaceae: Marathrum and Vanroyenella. Intl J. Pl. Sci. 160:29– 45. Rutishauser, R., Pfeifer, E., Moline, P., Philbrick, C.T. 2003. Developmental morphology of roots and shoots of Podostemum ceratophyllum (Podostemaceae– Podostemoideae). Rhodora 105:337–353. Rutishauser, R., Pfeifer, E., Novelo, R.A., Philbrick, C.T. 2005. Diamantina lombardii – an odd Brazilian member of the Podostemaceae. Flora 200:245–255. Savolainen, V., Fay, M.F. et al. 2000. See general references. Schenk, J.J., Thomas, D.W. 2004. A new species of Ledermanniella (Podostemaceae) from Cameroon. Novon 14:227–232. Schnell, R. 1967. Etudes sur l’anatomie et la morphologie des Podostémacées. Candollea 22:157–225. Schnell, R. 1994. Les stratégies végétales. Essai de morphologie évolutive. Paris: Masson. Schnell, R. 1998. Anatomie des Podostémacées. In: Carlquist, S., Cutler, D.F., Fink, S., Ozenda, P., Roth, I., Ziegler, H. (eds) Encyclopedia of plant anatomy: extreme adaptations in angiospermous hydrophytes. Berlin: Borntraeger, pp. 197–283. Schnell, R., Cusset, G. 1963. Remarques sur la structure des plantules de Podostemonaceae. Adansonia II, 3:358– 369. Sculthorpe, C.D. 1967. The biology of aquatic vascular plants. London: Edward Arnold. Sehgal, A., Mohan Ram, H.Y., Bhatt, J.R. 1993. In vitro germination, growth, morphogenesis and flowering of an aquatic angiosperm, Polypleurum stylosum (Podostemaceae). Aquat. Bot. 45:269– 283. Sehgal, A., Sethi, M., Mohan Ram, H.Y. 2002. Origin, structure, and interpretation of the thallus in Hydrobryopsis sessilis (Podostemaceae). Intl J. Pl. Sci. 163:891–905. Soltis, D.E., Mort, M.E., Soltis, P.S., Hibsch-Jetter, C., Zimmer, E.A., Morgan, D. 1999. Phylogenetic relationships of the enigmatic angiosperm family Podostemaceae inferred from 18S rDNA and rbcL sequence data. Mol. Phylog. Evol. 11:261–272. Stevens, P.F. 2005. See general references. Suzuki, K., Kita, Y., Kato, M. 2002. Comparative developmental anatomy of seedling in nine species of Podostemaceae (subfamily Podostemoideae). Ann. Bot. 89:755–765. Taylor, G. 1953. Notes on Podostemaceae for the revision of the Flora of West Tropical Africa. Bull. Brit. Mus. Nat. Hist., Bot. 1:53–79. Troll, W. 1941. Vergleichende Morphologie der höheren Pflanzen, vol. 1/3, pp. 2007–2736. Berlin: Borntraeger.

344


Tur, N.M. 1997. Taxonomy of Podostemaceae in Argentina. Aquat. Bot. 57:213–241. Ueda, K., Hanyuda, T., Nakano, A., Shiuchi, T., Seo, A., Okubo, H., Hotta, M. 1997. Molecular phylogenetic position of Podostemaceae, a marvellous aquatic flowering plant family. J. Pl. Res. 110:87–92. Uniyal, P.L., Mohan Ram, H.Y. 1994. Karyological studies in some members of Podostemaceae. Aquat. Bot. 47:85– 90. Uniyal, P.L., Mohan Ram, H.Y. 1996. In vitro germination and seedling morphology of Dalzellia zeylanica (Gardner) Wight (Podostemaceae). Aquat. Bot. 54:59–71. Vartak, V.D., Kumbhojkar, M.S. 1984. Palynological study of the family Podostemaceae from Western India. Biovigyanam 10:89–92. Vidyashankari, B. 1988a. Seed germination and seedling morphology in Indotristicha ramosissima (Podostemaceae) grown in vitro. Curr. Sci. 57:369–373. Vidyashankari, B. 1988b. Developmental biology of Griffithella hookeriana. Ph.D. Thesis, University of Delhi, Delhi. Vidyashankari, B., Mohan Ram, H.Y. 1987. In vitro germination and origin of thallus in Griffithella hookeriana (Podostemaceae). Aquat. Bot. 28:161–169. Wächter, W. 1897. Beiträge zur Kenntniss einiger Wasserpflanzen. Flora 83:381–397.

Warming, E. 1881. Familien Podostemaceae, I. Kong. Danske Vidensk. Selsk. Nat. Math. Afd. 2:1–34, pls I–VI. Warming, E. 1882. Familien Podostemaceae, II. Kong. Danske Vidensk. Selsk. Nat. Math. Afd. 2:77–130, pls VII–XIV. Warming, E. 1888. Familien Podostemaceae, III. Kong. Danske Vidensk. Selsk. Nat. Math. Afd. 4:443–514. Warming, E. 1899. Familien Podostemaceae, V. Kong. Danske Vidensk. Selsk. Nat. Math. Afd. 9:105–154. Warming, E. 1901. Familien Podostemaceae, VI. Kong. Danske Vidensk. Selsk. Nat. Math. Afd. 11:1–67. Went, F.A.F.C. 1912. Untersuchungen über die Podostemaceen, II. Verhandl. Konink. Akad. Wetensch. Amsterdam 17:1–19. Went, F.A.F.C. 1926. Untersuchungen über die Podostemaceen, III. Verhandl. Konink. Akad. Wetensch. Amsterdam 25:1–59, 11 pls. Willis, J.C. 1902. Studies in the morphology and ecology of the Podostemaceae of Ceylon and India. Ann. Roy. Bot. Gard. Peradeniya 1:267–465.

Websites http://www.systbot.unizh.ch/podostemaceae http://people.wcsu.edu/philbrickt/Podostemaceae %20front%20page.htm

Polygalaceae Polygalaceae Hoffmanns. & Link, Fl. Portug. 1:62 (1809), nom. cons.

B. Eriksen and C. Persson

Trees, lianas, shrubs, subshrubs, or perennial as well as annual herbs. Indumentum, if present, consisting of simple, unicellular or sometimes uniseriate hairs with a smooth or verrucate surface. Stems mostly terete, occasionally angular or winged; branches sometimes spine-tipped. Leaves usually alternate, sometimes opposite or verticillate, sessile or petiolate, simple, estipulate; nectariferous glands sometimes present at the base of the petiole or on the leaf blade. Inflorescences terminal or axillary, simple or compound racemes, panicles, or rarely flowers solitary. Flowers bisexual or allegedly functionally unisexual (Balgoya), hypogynous, ± actinomorphic to zygomorphic, subtended by a bract and two prophylls which are often early caducous. Calyx pentamerous, the sepals subequal to strongly unequal (in Polygaleae, the lateral ones are very large and petaloid), free, partly connate, or fused into a tube, caducous or persistent. Corolla pentamerous or trimerous, the petals free from each other, subequal to strongly irregular, the abaxial one often boat-shaped or developed into a carina (keel), which may be trilobed at apex or provided with a crest. Flowers white, yellow, pink, purple or blue, the abaxial petal (carina) often of contrasting colour. Stamens (2–)5–8(–10); filaments free, adnate to corolla lobes and/or fused into a sheath; anthers 2–4-sporangiate. Nectary absent or present, tending to be annular in genera with bilocular fruits and unilateral in those with unilocular fruits. Ovary 2–8-carpellate, syncarpous, usually with as many locules as carpels, occasionally unilocular (Xanthophyllum and pseudomonomerous genera), each locule with a single pendulous, epitropous ovule, except Xanthophyllum with 4–40 ovules in its single locule. Style straight or curved to geniculate, sometimes laterally compressed, distally undivided or bilobed with 1–2 stigmatic areas. Fruits capsules, sometimes dry and indehiscent, and occasionally winged (samaras), drupes or berries. Seeds glabrous or hairy, those of capsules and some berries often crowned

by a ± prominent exostome aril (caruncle), or possessing other types of arillar outgrowths. A cosmopolitan family of 21 genera and 800– 1,000 species having its centre of diversity in tropical and subtropical areas. Vegetative Morphology. Polygalaceae show a wide variety of life-forms, comprising annual and perennial herbs, subshrubs, shrubs, lianas and trees. The tallest trees may reach 50 m (Xanthophyllum), whereas lianas attain a length of up to 30 m (e.g. Balgoya). The longevity of perennials is poorly known, but two species of Muraltia are reported to obtain an age of more than 50 years whereas Polygala bracteolata lives for only 8 years (van Wilgen and Forsyth 1992). Some herbs are achlorophyllous and myco-heterotrophic (Epirixanthes). Hairs, if present, are simple and unicellular, or sometimes uniseriate in Bredemeyera and Xanthophyllum (Metcalfe and Chalk 1950). Presence of verrucae on the hairs has been reported in Balgoya, Monnina, Pteromonnina and Securidaca (Marques 1989, 1996; Verkerke 1991; Eriksen, unpubl. data). Anomalous growth of the stem is typical of Moutabeae and some Polygaleae, especially among lianas. Polygalaceae are usually unarmed. However, spine-tipped branches are present in Hualania, Muraltia, Securidaca, Bredemeyera microphylla, several species of Acanthocladus, and in a few Polygala. In addition, Moutabea typically has short spines on the twigs. The leaves are simple with an entire margin, sometimes needle-like, reduced to scales, or absent (e.g. Hualania colletioides). Venation is mostly brochidodromous. The insertion of the leaves is usually alternate, rarely opposite or verticillate (as in some Polygala). Stipules are absent but several genera are equipped with stalked or sessile glands (extrafloral nectaries) at the leaf and inflorescence nodes. These have in older literature incorrectly been referred to as stipules. Glands may also oc-

346


cur on various parts of the leaves (Weberling 1974; Eriksen 1993a). Vegetative Anatomy. Wood and leaf anatomy of Xanthophyllum were described in detail by Bridgewater and Baas (1982) and Dickison (1973) respectively, and Styer (1977) examined Moutabeae. An account of the leaf anatomy in Balgoya was given by Baas (1991) and of the wood anatomy by Détienne (1991). Other records are extracted from Metcalfe and Chalk (1950). The vessels of the wood are predominantly solitary, 60–150 µm in diam., sometimes up to 500 µm in Xanthophyllum. The perforation plates are usually simple, transverse and slightly oblique, but rounded in Moutabeae. Tyloses can be found in Moutabeae and in some Xanthophyllum. Intervascular pitting is alternate in Moutabeae but rare in genera with solitary vessels. Rays are usually uniseriate, sometimes biseriate or multiseriate. In Polygaleae, wood parenchyma is mostly paratracheal whereas Xanthophyllum has apotracheal as well as paratracheal parenchyma. The axial parenchyma of Moutabeae has been variously described due to the irregular configuration of the wood caused by included phloem. In order to provide a consistent terminology, Styer (1977) divides the parenchyma into three groups: (1) diffuse and tangential apotracheal, (2) diffuse paratracheal with wings and (3) aliform (vasicentric) paratracheal. The last type is only found in small amounts. The fibres are equipped with distinctly bordered pits and are present in both radial and tangential walls. The pith contains both lignified and unlignified cells in which, in some species, stone cells have been recorded (Solereder 1908). Included phloem of the “concentric” type is present in climbers. The mesophyll of leaves with a broad lamina is usually dorsiventral, although Carpolobia is known to have uniform tissue. Among narrow-leaved species, Comesperma, Polygala and some species of Muraltia have centric tissue whereas other species of Muraltia (those formerly assigned to Nylandtia) have uniform tissue. Cells on the abaxial side are often provided with knob-like papillae. The outer walls of the epidermal cells are occasionally strongly thickened. Lysigenous secretory ducts have been found in leaves and stems of several species of Polygala (Holm 1929). Stomata may be present on both the adaxial and the abaxial side, or be confined to the lower side. The stomata are usually paracytic or anomocytic, rarely anisocytic

(Xanthophyllum) or cyclocytic (Balgoya). Stomata are absent in the achlorophyllous genus Epirixanthes. The nodal anatomy of Xanthophyllum is unilacunar with a broad trace departing from the cauline stele (Dickison 1973). Sieve-tube plastids of the S type have been recorded in Polygalaceae (Behnke 1981). Inflorescence Structure. The inflorescences may be axillary or terminal. They are usually racemose (Saint-Hilaire and Moquin-Tandon 1828), a character shared with Fabaceae (Prenner 2004). The pedicels may be very short, making the raceme spike-like. In Bredemeyera and Barnhartia, the inflorescences are usually branched and form panicles. Panicles also occur in Polygala, Xantho-

Fig. 125. Polygalaceae, flowers. A Xanthophyllum papuanum ×4. B Diclidanthera penduliflora ×3. C Moutabea aculeata ×4. D Xanthophyllum ramiflorum ×4. E Acanthocladus guayaquilensis ×4. F Bredemeyera floribunda ×4. G Monnina reticulata ×4. H Salomonia cantoniensis ×17. I Polygala boliviensis ×6. J Muraltia heisteria ×4. (A, D Eriksen, redrawn from van der Meijden 1982; C, E, G, I from Tind in Eriksen et al. 2000; B, F, H, J orig. Eriksen)

Polygalaceae

phyllum and Securidaca. Krüger and Robbertse (1988) observed undeveloped axillary buds in the axils of small bracts at the base of peduncles in Securidaca longepedunculata, suggesting that racemose inflorescences have potential to become panicles. In Monnina, the inflorescences are also usually branched but, in this case, several racemes originate from a short portion of the main stem, resulting in a broom-like appearance. These structures are referred to as compound

Fig. 126. Polygalaceae-Polygaleae. Securidaca diversifolia. A Flowering branch. B Fruiting branch. C–G Dissected flower showing pedicel and outer calyx whorl (C), enlarged lateral sepal (D), carina (E), lateral corolla lobes and stamens (F), and pistil (G). (From Tind in Eriksen et al. 2000)

347

racemes. Concaulescence (fusion of axes) resulting in anaphysis (irregular order of flower opening in the inflorescence) is reported to occur in Atroxima and Carpolobia (Breteler and Smissaert-Houwing 1977). Floral Structure and Anatomy. The flowers of Polygalaceae are hypogynous and zygomorphic, to a greater or lesser extent (Fig. 125). Even when there is symmetry in the number of flower parts, differences in size, shape and position of the parts create zygomorphism. There are always five sepals, which may be free, partly connate or united into a tube. The sepals are usually somewhat unequal or, as in large parts of Polygaleae, the lateral ones are clearly differentiated, large and petaloid. These are often called wings, although they are not homologous to the wings of the papilionaceous flower of Fabaceae (Westerkamp and Weber 1999). However, there are a number of floral developmental features which support the close relationship between the two families (Prenner 2004). There are five petals in Xanthophylleae, Moutabeae and Carpolobieae but only three in Polygaleae. The abaxial petal is often distinct, boat-shaped or differentiated into a keel (carina) which is sometimes provided with a ± fimbriate crest at the apex (Fig. 126E); the lateral petals are rudimentary or absent in Polygaleae. Usually, there is no evidence of vestigial traces representing missing floral elements (Milby 1976; Eriksen 1993b), and there is no evidence of vascular fusion to indicate that the keel is a compound structure (as suggested by Dube 1962). In Polygala dalmaisiana, Westerkamp and Weber (1997, 1999) found that the carina is provided with a V-shaped hinge consisting of thinner tissue between the claw and the blade. This particular construction makes the carina movable, which is important for the pollination mechanism. The petals are often adnate to other flower parts. The colour of the petals and the petaloid sepals ranges from white and yellow to various shades of pink, purple and blue. The keel is often contrasting. Some species of Xanthophyllum, Carpolobia and Hualania have spotted petals. An overview of the variation in the androecium is given by Eriksen (1993b). The number of stamens varies from two to ten. Ten stamens are found in Eriandra as well as in some species of Xanthophyllum and Diclidanthera. In most genera, however, a vascular trace is never formed for the adaxial stamen, and further reductions are the rule. Most gen-

348


era have eight stamens. Among the genera in Polygaleae with eight stamens, the development of the eighth stamen is due to a split of the vascular trace in the abaxial position. As a result, the stamens are laterally displaced and no stamen occurs opposite the keel. However, in Muraltia which has seven stamens, the vascular trace does not split and a stamen is present in the adaxial position. Only five stamens develop in Carpolobieae, and five or less stamens are also the rule in Salomonia and Epirixanthes. The anthers are basifixed and basically tetrasporangiate. The prevailing bisporangiate condition in certain genera is the result of suppression of the two ventral sporangia (Jauch 1918; Venkatesh 1956; Milby 1976). The filaments are often adnate to the corolla lobes and/or connate to each other, forming a tube or a sheath. In most genera of Polygaleae, the filament sheath is adnate to the margins of the adaxial petals (Fig. 126F). The ovary consists of 2–8 carpels. According to Chodat (1891) and Leinfellner (1972), bicarpellate ovaries is the plesiomorphic state whereas higher numbers are advanced. Bicarpellate taxa are certainly, by number, the most common in the family but comparison with sister taxa (Surianaceae, Quillajaceae) suggests that the basal number of carpels may have been five. In Polygalaceae, the ovaries of Diclidanthera and some Moutabea are pentacarpellate. In Xanthophylleae, the ovaries are bicarpellate, forming unilocular or incompletely bilocular fruits. In Moutabeae, there are 2–8 carpels and locules, in Carpolobieae always three. The ovaries of Polygaleae are bicarpellate and bilocular, or sometimes one carpel is reduced, resulting in pseudomonomerous fruits. In Securidaca longepedunculata as well as other pseudomonomerous genera such as Monnina and Pteromonnina, only the abaxial carpel enlarges (Krüger and Robbertse 1988; Eriksen, pers. obs.). There is a single ovule in each locule, except in Xanthophyllum where there are two to many. Placentation in Xanthophyllum is parietal. In the remaining tribes, the ovules are attached to the roof of the ovary wall where the septum and the wall converge. On the basis of vascular anatomy, placentation is best understood as parietal, since vascular strands descend from the ovary wall to the ovules from above (Jauch 1918; Milby 1976). The style is straight in ± regular flowers, curved or geniculate in zygomorphic ones. Apically, the curved and geniculate styles of Polygaleae are often bifurcated. The stigmatic surface may consist

of two localised groups of unicellular papillae, as in Acanthocladus, Badiera, Bredemeyera and some Polygala and Securidaca (Venkatesh 1956; Krüger and Robbertse 1988; Krüger et al. 1988), or the abaxial branch may be sterile and variously shaped. In Securidaca longepedunculata and Polygala virgata var. decora, there is a single stylar canal, which is open to the surface in Securidaca but covered by a cuticular membrane in Polygala (Krüger et al. 1988). The nectary varies in shape from an entire disc to a unilateral gland or may be completely missing (Jauch 1918). It has been observed that the flowers are occasionally heavily parasitised by insects (Securidaca longepedunculata, Krüger and Robbertse 1988; Monnina spp. and Pteromonnina spp., Eriksen, pers. obs.). Embryology. At anthesis, the pollen grains are binucleate in Securidaca longepedunculata (Coetzee and Robbertse 1985) and Polygala fruticosa (Paiva and Santos Dias 1990), whereas they are stated to be trinucleate by the time of dispersal in Salomonia (Rao 1964). The ovule is epitropous, bitegmic and crassinucellate (Rodrigue 1893; Wirz 1910; Verkerke 1984, 1985). In Epirixanthes (Wirz 1910) and Salomonia (Rao 1964), the megasporocyte forms a linear tetrad of which the lowermost megaspore develops into an 8-nucleate megagametophyte. It is plausible that megagametophyte development in the family in general is of Polygonum type. The endosperm is formed by free nuclear division.

Fig. 127. Polygalaceae. Pollen grain of Monnina denticulata. ×1,200. (Photograph by T. Bergqvist, Göteborg University)

Polygalaceae

Pollen Morphology. Pollen grains are suboblate to subprolate, isopolar and polycolporate (Fig. 127). There are 7–28 colpi, and the equatorial pores form a prominent girdle. This gives the pollen its characteristic “Chinese lantern” shape. Ornamentation is faint; the grains are psilate or ± foveolate in the apocolpial field. Pollen is generally medium-sized, the longest axis measuring 25– 62 µm (Erdtman 1952). With few exceptions, low numbers of colpi seem to be common in the tribes Xanthophylleae, Moutabeae and Carpolobieae, higher numbers in Polygaleae (Erdtman 1944; Eriksen 1993a). Polygala pollen is polymorphic with regard to colpus number (Chodat 1891; Erdtman 1952; Heubl 1984; Arreguín-Sánchez et al. 1988; Furness and Stafford 1995). In Mexican members of Polygala sect. Polygala, the number is 8–10, in European members 8–14, and in African 21–28. In Polygala sect. Hebeclada and P. sect. Chamaebuxus, the number of colpi is 14–24. Securidaca longepedunculata has pollen grains with 8–12 colpi (Coetzee and Robbertse 1985). Fossil pollen, agreeing in morphology to present-day Polygalaceae pollen, was described from the lower Eocene in India as Polygalacidites clarus by Sah and Dutta (1966). Karyology. Although chromosome numbers have been recorded only for ten out of 21 genera in Polygalaceae, a broad variation of different numbers have been found. Most counts are from Polygaleae; no counts are available for Xanthophylleae and only a single count is reported from Moutabeae (Eriandra 2n = 28; Oginuma et al. 1998). In Carpolobieae, the chromosome numbers seem to vary among species within genera; Arends and van der Laan (1979) reported 2n = 22 for both genera, whereas Mangenot and Mangenot (1957) counted 2n = 18 and 2n = 20 for Atroxima and Carpolobia respectively. In Polygaleae, most genera seem to have a single or a few basic numbers, although for Polygala the entire variation is encompassed within the genus. Records from the sections Hebeclada (Polygala grandiflora) and Pseudosemeiocardium (P. triphylla) show that both have 2n = 28. Based on pollen size and ploidy level, the basic number in Polygala sect. Chamaebuxus is hypothesised to be x = 7, and P. chamaebuxus, having 2n = 44, is interpreted as a hyper-hexaploid (Merxmüller and Heubl 1983). Variation of chromosome numbers within Polygala sect. Polygala seems to correlate with geographical distribution (Lewis and Davis

349

1962); most European species display a basic number of x = 17 whereas African species are reported to have x = 19 (Larsen 1959). North American species, on the other hand, exhibit a wide array of basic numbers (x = 6, 7, 8, 9, 10, 17, 23; Lewis and Davis 1962; Paiva 1988). The monotypic genus Hualania is characterised by having 2n = 14 (Darlington and Wylie 1961), the only count in Securidaca (the African species S. longepedunculata, Johnson 1987) shows 2n = 32, and Epirixanthes has 2n = 24 (Wirz 1910; Miège 1960). In Monnina, most species are diploids with 2n = 20 (Larsen 1964; Eriksen et al. 2000), but triploids as well as tetraploids are also reported. Available counts for Pteromonnina, 2n = 18, 20 and 40, indicate the existence of both aneuploidy and polyploidy (Larsen 1967). In Badiera, the variation in chromosome number is broader, including x = 8, 15, 17, and x = 28–30 (Lewis and Davis 1962). Polyploidy as well as aneuploidy has obviously played an important role in the evolution of Polygala, and the effects are seen in both P. sect. Polygala and P. sect. Chamaebuxus. Lewis and Davis (1962) give an account of the chromosome numbers, in which the ploidy level ranges from 2× to 16×, with several levels in between. Intraspecific ploidy level variation is reported to occur in P. vulgaris, which includes diploids as well as tetraploids. Whether the polyploids are of allo- or autoploid origin is unknown. Records of chromosome data are taken from the Index to Plant Chromosomes Numbers (various editors), if not stated otherwise. Pollination and Reproductive Systems. Bees and bumblebees are the main pollinators of papilionaceous flowers in Polygaleae (Brantjes 1982; Lack and Kay 1987; Eriksen, pers. obs.). One case of bird-visitation is known from Costa Rica where the Peg-billed Finch, Acanthidops bairdii, was seen probing for nectar in the relatively large flowers of Monnina pittieri (Eriksen, pers. obs). Floral scent is known to occur in Eriandra (van Royen and van Steenis 1952), Bredemeyera (Marques 1980) and in some species of Monnina (Eriksen, pers. obs.). Visual attraction is mostly due to the two enlarged petaloid sepals of the zygomorphic flowers. The two upper petals form the abutment required for depression of the keel by an insect. These overlapping petals also roof the filament furrow and form a tongue guide. Nectar is secreted by a disc of variable shape and accumulates in a nectar chamber shielded by the touching edges of the filament furrow. The lowermost petal forms

350


the keel, concealing the pollen (Westerkamp and Weber 1999). Pollen is released from the anthers below the stigma in the unvisited flower (secondary pollen presentation). At the first visit, the stigma is clean and may receive pollen from other individuals. Subsequent visits allow self-pollination, when pollen is squeezed out of the rostrum of the carina in front of the stigma by a piston mechanism (tertiary pollen presentation, Westerkamp and Weber 1997). Different style morphologies, including various types of brushes and spoons, are associated with the pollen presentation mechanisms by which pollen is brushed or pumped out of the carina (Brantjes and van der Pijl 1980). The sticky substance produced by the stigma glues the pollen to the insect visitors’ body parts (Brantjes 1982). Precise pollen deposition on insect visitors results in reproductive isolation between sympatric species. Some species of Monnina are known to set seed in isolation, but most species are visited by insects in their natural environment (Eriksen, pers. obs.). Most likely, facultative autogamous to strictly xenogamous mating systems are common among species with larger flowers. In contrast, many small-flowered species are self-pollinated. Autogamy is reported for Epirixanthes (Wirz 1910), Salomonia (Rao 1964), Polygala (Venkatesh 1956) and Muraltia (Miller 1971). Often, pollen is deposited directly on the stigma, which is sometimes covered by a glutinous secretion, or the pollen grains germinate in the open anther and the pollen tubes penetrate the adjacent stigma. Each of the five anthers of Epirixanthes contains up to 32 pollen grains (Wirz 1910), making the pollen:ovule ratio equal to 80, which is well within the range of strictly autogamous species (Cruden 1977). Chasmogamous and cleistogamous flowers are produced in Polygala paucifolia (Ferrara and Quinn 1985) and Pteromonnina wrightii (Eriksen 1993c). In the latter species, the flowers of the main inflorescence are chasmogamous, whereas those of the branches are usually cleistogamous. Fruits and seeds from chasmogamous flowers in Polygala paucifolia are larger than those from cleistogamous flowers (Ferrara and Quinn 1985). Flowers of Xanthophyllum are brightly coloured, contain nectar, and have good pollen production but, despite apparent adaptations to cross-pollination by insects, cleistogamy is also considered to be an important means of reproduction (van der Meijden 1982). Muraltia heisteria is self-compatible and largely selfpollinating (Levyns 1954), and the same is true for Polygala vulgaris (Lack and Kay 1987). A mean

Fig. 128. Polygalaceae, fruits. A Polygala vulgaris, capsule ×10. B Acanthocladus guayaquilensis, capsule ×0.7. C Bredemeyera myrtifolia, capsule ×4. D Muraltia heisteria, capsule ×4. E Salomonia cantoniensis, ± indehiscent capsule provided with hooks at the margins of the capsule halves ×17. F Pteromonnina herbacea, samara ×5.5. G Securidaca fragilis, samara ×0.7. H Monnina reticulata, drupe ×4. I Moutabea aculeata, berry ×0.7. (A, C–E orig. Eriksen; B, F–I from Tind in Eriksen et al. 2000)

Polygalaceae

seed:ovule ratio of 0.65 has been calculated for P. vulgaris, which is well within the range of perennial inbreeders (Norderhaug 1995). Morat and van der Meijden (1991) found no open anthers and no pollen grains in flowers of Balgoya, leading them to conclude that the specimens examined all came from female plants, the reproductive system consequently being dioecy or apogamy. Fruit and Seed. The fruits of Polygalaceae have one to eight locules, each carrying a single or,

Fig. 129. Polygalaceae-Polygaleae. Seeds of capsular fruits. A Bredemeyera myrtifolia, seed with a caruncle and long hairs attached near hilum ×6. B Polygala vulgaris, seed with a helmet-shaped caruncle ×13. C Comesperma ericinum, seed with funicular and chalazal outgrowths and long hairs attached in the lower part of the seed ×13. D Salomonia cantoniensis, seed with funicular outgrowth ×13. E Muraltia heisteria, seed with a hood-shaped caruncle ×13. (Orig. Eriksen)

351

more rarely, many ovules (Fig. 128). The tribe Polygaleae is characterised by having bicarpellate or sometimes pseudomonomerous fruits. The dominating fruit type is the capsule with a membranaceous (Comesperma, Muraltia, Polygala, Salomonia) or fleshy (Bredemeyera, Epirixanthes) pericarp (Verkerke 1985). In Ancylotropis, Pteromonnina and Securidaca, fruits have become indehiscent with a hard pericarp (Verkerke 1985; Eriksen 1997). Many of the dry, indehiscent fruits are unilaterally or bilaterally winged. Krüger et al. (1988) observed that the radicle grows through a thinner part of the pericarp at germination in Securidaca longepedunculata. The fruits of Monnina and the species of Muraltia formerly included in Nylandtia are drupes with fleshy mesocarp and hard endocarp (Verkerke 1985). Pseudomonomery is common among species with indehiscent fruits. The fruits of the tribes Moutabeae and Carpolobieae are berries which often turn orange as they ripen (Verkerke 1985, 1991). The mesocarp is leathery in Balgoya, Diclidanthera and Eriandra, crustaceous in Moutabea and some species of Atroxima, and fleshy in Carpolobia and the rest of Atroxima. Berries also prevail in Xanthophyllum (van der Meijden 1982; Verkerke 1985); a single species is reported to have a capsular fruit. To promote dispersal, species with relatively dry berries seem to compensate the lack of juiciness of the fruit tissue, either by a large aril surrounding each haircovered seed or by juicy seed hairs. The seeds of dehiscing fruits are usually provided with an exostome aril (caruncle) or other types of outgrowths (Fig. 129), and have well-differentiated seed coats (Rodrigue 1893; Verkerke 1984, 1985). Polygala, Comesperma, Muraltia, Salomonia and Epirixanthes have an endotestal palisade of elongated cells. In contrast, Acanthocladus, Badiera (including Polygala sect. Hebecarpa) and Bredemeyera (including B. papuana) have short, ± isodiametric endotesta cells. According to Rodrigue (1893), some Comesperma species have elongated cells in the endotestal palisade, whereas others have short cells. Presence or absence of a proper coma is another polymorphic character associated with the seeds in Comesperma. These characters indicate that the genus may not be monophyletic. The presence of an endotestal palisade of elongated cells is often linked with a black seed colour; seed of species with short palisade cells are usually brown. The seed surface is smooth and shiny and often covered by unicellular, acicular trichomes

352


(Isaacs et al. 1993). The extremely long hairs (the coma) attached near the hilum in the seeds of Bredemeyera and Hualania or throughout large parts of the seed surface of some Comesperma have been considered to support a close relationship among these three genera (Fig. 129). However, molecular data suggest that a coma has arisen at least three times within the family. The amount of endosperm present in the mature seed varies among genera (Wirz 1910; Rao 1964; Verkerke 1985). Usually, the endosperm is completely absorbed by the seedling, but scanty to copious amounts may remain. Seeds of Polygala generally lose their vitality soon after ripening (Holm 1929), but seeds of P. lutea and P. ambigua (P. sect. Polygala) have been found to survive in natural seed banks for several years. A study from the fynbos of South Africa reports seed dormancy in Polygala bracteolata lasting more than 42 years (van Wilgen and Forsyth 1992). Dispersal. Myrmecochory is a dispersal mode found in, e.g. Polygala vulgaris. The species has capsular fruits and black seeds provided with an exostome aril, or elaiosome, which is attractive to ants (Oostermeijer 1989). Juvenile and adult plants have a patchy spatial distribution correlated with the nests of the ants. In the case of P. vulgaris, ants of the species Lasius niger carry the seeds to their nests for maximum distances of 2 m. Such limited gene flow allows local differentiation within each population, since the small isolated subpopulations are subject to inbreeding and genetic drift (Lack and Kay 1987). Birds are presumed to be responsible for dispersal of seeds of certain Asian species of Polygala sect. Chamaebuxus with large, bright orange, red or scarlet arils (Ridley 1930; Paiva 1998). They also appear to be very fond of fruits of certain Xanthophyllum species (van der Meijden 1982) and, likewise, the drupes of Monnina and Muraltia may be adapted to dispersal by birds or perhaps small mammals. The seeds of Salomonia are inappendiculate and offer no reward for dispersal agents. Rather, long hooked spines on the capsules indicate that the fruits may be dispersed epizooically. Spider monkeys (Ateles) disperse the berries of Moutabea guianensis. As the red exocarp deteriorates, it contrasts with the yellowish, scented mesocarp and monkeys are attracted. They crack the fruit and suck the aril; the curled, firm hairs on the seeds prevent them from chewing (Verkerke 1985). Samaras are presumably wind-dispersed.

Phytochemistry. A number of different chemical compounds have been found in Polygalaceae (Hegnauer 1969, 1990). Apart from triterpenoid saponins, which occur in the majority of the genera (Kassau 1931; Eriksen 1993a), several common phenolic compounds have been isolated from the family, but leucoanthocyans and tannins are lacking. Minute amounts of alkaloids have been reported for Bredemeyera and Polygala. Starch seems to be absent from many Polygalaceae and is generally replaced by sugar or polygalite (1,5anhydrosorbit). Calcium oxalate occurs as single crystals or druses. Aluminium accumulation is characteristic for Moutabeae and Xanthophylleae (Chenery 1948; Eriksen 1993a) but scattered occurrences are also present in Polygaleae (B. Eriksen, unpubl. data). Subdivision and Relationships Within the Family. The traditional subdivision of Polygalaceae into three tribes, Xanthophylleae, Polygaleae and Moutabeae (Chodat 1893), was recently changed when Eriksen (1993a) added a fourth tribe, Carpolobieae. The monotypic Xanthophylleae differ from the other tribes in having more or less unilocular ovaries and 4–40 ovules. Some authors consider these differences sufficient to place Xanthophylleae in a separate family (e.g. Cronquist 1981). However, both morphological and DNA-based cladistic analyses unambiguously suggest a close relationship of Xanthophylleae to Polygalaceae, although the precise placement differs between the two types of analyses. While plastid DNA data from the trnL-F region alone, or in conjunction with rbcL (Forest et al., pers. comm.), place Xanthophylleae as sister to the rest of Polygalaceae (Persson 2001), morphological data indicate a sister-group relationship to Moutabeae (Eriksen 1993a). In contrast to other Polygalaceae, Moutabeae show a great range of morphological variation and are disjunct between South America and the Pacific. Their flowers vary from almost actinomorphic to zygomorphic and the ovaries have 2–8 locules. Because of their deviant morphology, Moutabea and Diclidanthera have formerly been placed in other families but their placement in Polygalaceae is now accepted. Whereas the monophyly of the tribe was not supported by trnL-F data alone (Persson 2001), both morphological data (Eriksen 1993a) and sequence data from trnL-F and rbcL together (Forest et al., pers. comm.) support a single origin of Moutabeae.

Polygalaceae

Likewise, although Carpolobieae were poorly supported in the analysis by Persson (2001), both the morphological analysis by Eriksen (1993a) and the molecular analysis by Forest et al. (pers. comm.) indicate a monophyletic origin. Morphologically, Carpolobieae are distinguished by having pentamerous flowers and trilocular ovaries (Breteler and Smissaert-Houwing 1977). The monophyly of Polygaleae is supported by morphological and molecular data, but phylogenetic relationships within the tribe are partly unclear. The tribe is well known for its papilionaceous flowers, which mainly consist of the three petals and usually two large petaloid sepals. In addition, the typical Polygaleae flowers have bilocular ovaries and eight monadelphous stamens. DNA sequences indicate the tribe consists of two major clades. The first clade is entirely resolved and comprises Bredemeyera s.str. as sister to Acanthocladus and Badiera, which have often been assigned to Polygala. Further, Bredemeyera microphylla appears as sister to Badiera. The second clade is basally unresolved, comprising six Polygala clades in addition to Hualania, Comesperma, Muraltia (including Nylandtia), Securidaca, Salomonia and Monnina s.l. (including Pteromonnina and Ancylotropis). The close relationship of Muraltia and Nylandtia has previously been put forward by Levyns (1949) and is also supported by morphological data (Eriksen 1993a). New evidence from a molecular study focusing on the relationship between the two genera shows that Nylandtia is derived from Muraltia and is nested within subg. Psiloclada (Forest and Manning 2006). Hence, Nylandtia is put into synonomy. The monophyly of Monnina s.l. is reflected in older classifications but was disputed in Eriksen’s morphological cladistic analysis (1993a), which indicated a polyphyletic origin of the group. The circumscription of Polygala constitutes a major problem in Polygaleae. Molecular data suggest that the characters used for defining Polygala (capsule, 8 stamens, and absence of long hairs on the seed) are plesiomorphic. Interestingly, the clades representing Polygala tend to group by geographical distribution, rather than after sectional affiliation. For example, the monotypic section Brachytropis is internested among other European species of the section Polygala, and members of the section Chamaebuxus occurring on different continents appear in two different clades. The recently resurrected genus Heterosamara (Paiva 1998) accommodates both South East Asian and southern African species and is here treated under Polygala,

353

awaiting a more detailed phylogenetic study. As Polygala is circumscribed by plesiomorphic characters and tends to group after geographical distribution, several “Polygala” groups may have their closest relatives among other genera. Thus, African species of Polygala may be closely related to Muraltia whereas Asian species may have their closest relatives in Salomonia. In contrast to Polygala, DNA data indicate that the characters used for circumscribing Bredemeyera s.l. are homoplasious. For example, long hairs on the seeds, the most important character for merging several lineages into Bredemeyera, seems to have arisen at least three times. Furthermore, the spiny shrubs Hualania colletioides and Bredemeyera microphylla, both of which have been placed in the section Hualania, seem to be distantly related. Affinities. The traditional placement of Polygalaceae in Polygalales or Malphigiales (Hutchinson 1967; Cronquist 1981; Goldberg 1986; Thorne 1992) has recently been rejected by plastid DNA studies. Rather, a close relationship to Fabaceae, Surianaceae and Quillajaceae is suggested (Chase et al. 1993; Fernando et al. 1993; Morgan et al. 1994; Crayn et al. 1995; Doyle et al. 1997; Källersjö et al. 1998; Savolainen, Chase et al. 2000; Savolainen, Fay et al. 2000; Persson 2001), and Polygalaceae are placed by the Angiosperm Phylogeny Group (APG 1998; APG II 2003) in the expanded Fabales. Apart from the superficial resemblance of the flowers of Polygalaceae to those of subfamily Papilionoideae of Fabaceae, few characters, let alone synapomorphies, support Fabales. Judd et al. (1999) mention vestured pits with single perforations and large green embryos as possible common characters for the group. While the inclusion of Polygalaceae in Fabales is supported by several datasets, its sister group remains unclear. Results from rbcL indicate that either Surianaceae or Quillajaceae are sister to Polygalaceae, whereas trnL-F sequences suggest that Fabaceae, Surianaceae and Quillajaceae together form its sister group. As all interfamilial support in Fabales is poor, more data are needed to resolve their exact relationship. Distribution and Habitats. By far the most widespread genus of Polygalaceae is Polygala. It is cosmopolitan, except for the Arctic, Antarctica and New Zealand. Xanthophyllum and Salomonia occur in tropical and subtropical Asia with extensions to Australia, and Securidaca spans the tropical zone of the American as well as the African and Asian

354


continents. Bredemeyera, in a strict sense, is confined to tropical South America but the genus is disjunct when the New Guinean B. papuana is included. Other strictly American genera are Diclidanthera, Moutabea, Acanthocladus, Badiera, Ancylotropis, Monnina and Pteromonnina, as well as the monotypic Barnhartia and Hualania. The genera confined to Africa are Atroxima and Carpolobia in the central part, and Muraltia in the south. Epirixanthes is found in the subtropical and tropical zones of Asia, whereas the monotypic Balgoya and Eriandra are confined to New Caledonia, and New Guinea and the Solomon Islands respectively. Comesperma in its present circumscription is confined to Australia. Xanthophylleae, Moutabeae and Carpolobieae are mostly restricted to wet tropical rainforests. Small trees, shrubs and lianas prevail but some forest-trees occur as well. Most species seem to have a preference for high-light environments such as secondary vegetation and forest edges along rivers. Shrubs and lianas also occasionally occur in dry, semi-deciduous forests. Polygaleae comprise woody as well as herbaceous members. Some of them are forest elements (Acanthocladus, Badiera, Bredemeyera, Polygala and Securidaca) in humid or semi-dry habitats. A couple of herbaceous genera are bound to wet tropical forests. These are either myco-heterotrophs among litter on the forest floor (Epirixanthes) or grow in open land such as flood plains (Salomonia). Otherwise, herbs, subshrubs and shrubs, such as Ancylotropis, Comesperma, Muraltia, Polygala and Pteromonnina, prefer grassland and semi-deserts. The semi-desert species have often evolved into spiny and sometimes leafless shrubs such as Bredemeyera microphylla and Hualania colletioides in Argentina, Muraltia spinosa in the fynbos of South Africa, and several species of Acanthocladus and Polygala. Polygala has also by far the widest ecological amplitude in the family. The genus Monnina is confined to mountain forests and grassland in the Andes from 500 to 3,500 m alt. A few other genera are reported to occur at higher altitudes (Salomonia, up to 1,500 m; Muraltia, up to 2,750 m; Polygala and Pteromonnina, up to 2,500 m). Economic Importance. Polygalaceae are generally of little economic importance but are often used locally in herbal medicine. The North American Polygala senega, snakeroot, is one of the most famous examples and has been used as a stimulating expectorant, diuretic and diaphoretic. It was

also used by the Seneca Indians for treating snake bites. The African Securidaca longepedunculata is said to have up to 100 medical properties and has been used in traditional medicine for a variety of purposes. For example, it has been used as an anodyne, purgative, venereal remedy and vermifuge. More recent studies also show that S. longepedunculata has a selective inhibition on HIV replication (Mahmood et al. 1993). Polygala costaricensis (of the former P. sect. Hebecarpa, to be recombined with Badiera), is used as substitute for Ipecacuanha (Psychotria ipecacuanha, Rubiaceae) as expectorant. Infusions of root extracts are taken as diuretics (Bredemeyera floribunda, Polygala paniculata), pectorals or emetics (Polygala angustifolia), or are used for treating venereal diseases (Securidaca diversifolia). Roots of Polygala sibirica, together with liquorice, are used to treat depression, irritability and insomnia in modern Chinese herbalism. Because of a high saponin content and antifungal properties, several species of Monnina have often been used as anti-dandruff shampoo in tropical America. Polygalaceae are rarely used for food or for beverage. However, the so-called beni-seeds of Polygala butyracea are used to produce malukang butter; Securidaca longepedunculata is an important soup vegetable for the dry season in Burkina Faso, and the fruits of Carpolobia and drupaceous Muraltia are sometimes eaten. In Nepal, the roots of Polygala arillata are fermented for alcoholic drinks. Fibres of the African Polygala butyracea are used in sacking, and twigs of Securidaca longepedunculata are the source of a fibre (buaze) which is used in fishing nets. The fruits of Monnina and Polygala are used for dyeing. Polygalaceae are of little horticultural value but several Polygala, e.g. P. chamaebuxus, P. myrtifolia and P. dalmaisiana, are grown as ornamentals. Conservation. Many species have a restricted distribution, which is reflected in the fact that 96 species in six genera of Polygalaceae are listed in the 1997 IUCN Red List of Threatened Plants (Walter and Gillett 1998). Many more species may be endangered due to habitat loss, but data on distribution and frequency are mostly lacking. Key to the Genera 1. Corolla pentamerous – Corolla trimerous. Tribe Polygaleae 2. Sepals free

2 9 3

Polygalaceae – 3. – 4. – 5. – 6. – 7. – 8. – 9. – 10. – 11. – 12. – 13. – 14. –

15. – 16. – 17. – 18. – 19.

Sepals connate 7 Stamens 5. Tribe Carpolobieae 4 Stamens (6–)8–10 5 Lianas or lianescent shrubs, glabrous in their vegetative parts; seeds with juicy hairs and without endosperm 7. Atroxima Shrubs, treelets, or trees, at least partly hairy in their vegetative parts; seeds, at least partly, with ordinary hairs, and with copious endosperm 8. Carpolobia Four petals pairwise connate at base, the fifth petal distinct; ovary usually 2-locular 4. Barnhartia All petals free; ovary not 2-locular 6 Liana; filaments completely fused into a tube; ovary 3(4)-locular with 1 ovule per locule 2. Balgoya Trees or shrubs; filaments free or connate at base; ovary 1-locular (rarely semi-bilocular) with a total of 4–40 ovules 1. Xanthophyllum Flower distinctly zygomorphic; ovary usually 4-locular 6. Moutabea Flowers actinomorphic or only slightly zygomorphic; ovary 5–8-locular 8 Nodal glands present; corolla 8–27 mm long, the petals connate for 3/4 of their length into a narrow tube; ovary usually 5-locular 5. Diclidanthera Nodal glands absent; corolla 5–6 mm long, the petals connate for 1/2 of their length into a wide tube; ovary 7–8-locular 3. Eriandra Fruit dehiscent (capsule) 10 Fruit indehiscent (drupe, samara, etc.) 17 Stamens < 8; calyx slightly irregular 11 Stamens 8; calyx distinctly irregular with enlarged lateral sepals (wings) 12 Stamens 4–6; capsule with a fringed margin 20. Salomonia Stamens 7; capsule with 4 horns or teeth at apex 17. Muraltia Seeds usually provided with a coma (hairs often as long as the seed), if not, then plant leafless or leaves reduced to minute scales 13 Seeds glabrous or provided with short hairs 15 Shrub leafless with spine-tipped branches; seeds with coma 15. Hualania Plants usually with leaves, if leaves reduced to scales, then seeds without coma 14 Leaves small, < 1 cm wide; inflorescence racemose; Australia 13. Comesperma Leaves larger, ≥ 1 cm wide (except B. microphylla, a spiny shrub from Argentina); inflorescence usually paniculate, rarely racemose, fasciculate or flowers solitary; South America and New Guinea 11. Bredemeyera Calyx persistent or, if caducous, then the keel equipped with a crest or a beak 18. Polygala Calyx caducous; crest or beak on keel absent 16 Leaves opposite, subopposite or alternate; branches often spine-tipped; capsule woody, the locules subglobose 9. Acanthocladus Leaves alternate, branches lacking spines; capsule subcoriaceous, laterally compressed 10. Badiera Fruit fleshy 18 Fruit dry, sometimes winged 19 Calyx persistent; keel crested; stamens 7 17. Muraltia Calyx caducous; keel unappendaged; stamens 8 16. Monnina Lianas or shrubs; fruit a unilaterally winged samara 21. Securidaca

355

– Herbs; fruit unwinged or bilaterally winged 20 20. Achlorophyllous herbs; calyx slightly irregular, persistent; stamens 2–5 14. Epirixanthes – Autotrophic herbs; calyx distinctly irregular, caducous; stamens (4–)6–8 21 21. Keel apically deeply incised; style curved, apically entire with a tuft of hairs; nectary absent 12. Ancylotropis – Keel apically emarginate; style geniculate, apically bifid without hairs; nectary unilateral 19. Pteromonnina

Tribes and Genera of Polygalaceae I. Tribe Xanthophylleae Chodat (1896). Woody plants. Leaves alternate, very rarely decussate. Flowers zygomorphic or almost actinomorphic, subtended by one bract and two prophylls. Calyx and usually also corolla 5-merous. Anthers opening by short, introrse slits. Ovary bicarpellate, unilocular or sometimes incompletely bilocular with few to many ovules per locule. Nectary annular. Fruit a berry or rarely an irregularly dehiscent capsule. 1. Xanthophyllum Roxb.

Fig. 125A, D

Xanthophyllum Roxb., Pl. Coromandel 3:81 (1820) (“1819”), nom. cons.; van der Meijden, Systematics and evolution of Xanthophyllum (Polygalaceae): 1–159 (1982), rev.

Shrubs or trees. Glands usually present at nodes. Inflorescences usually axillary, the flowers solitary or in few- to many-flowered panicles or racemes on the branches. Flowers zygomorphic. Calyx consisting of an adaxial and two abaxial small sepals and two lateral ones, twice as large, the sepals free, usually caducous. Corolla usually white, sometimes yellow, pink or purple, the petals free from each other, the abaxial petal usually boat-shaped, clawed at base, unappendaged at apex. Stamens (7)8(–10), the filaments free or fused at base, rarely up to half of their length. Ovary with a total of 4–20(–40) ovules; style slightly curved, usually bifid with two stigmatic areas, sometimes capitate. Fruit globular. The genus comprises about 90 species, most in Malesia but extending to Australia and southern India, occurring usually in lowland tropical rainforests. II. Tribe Moutabeae Chodat (1896). Woody plants. Leaves alternate. Flowers zygomorphic or actinomorphic, subtended by one bract and two prophylls. Calyx and corolla 5-merous. Anthers

356


opening along the margin or rarely by long, introrse slits. Ovary usually multicarpellate, multilocular with a single ovule in each locule. Nectary annular when present. Fruit a berry. 2. Balgoya Morat & Meijden Balgoya Morat & Meijden, Bull. Mus. Natl Hist. Nat., B, Adansonia 13:3–8 (1991).

Liana. Glands present on leaves. Inflorescences axillary, racemose. Flowers almost actinomorphic. Calyx caducous, the sepals free. Corolla yellowish white, the petals free from each other. Stamens (6–)8, filaments completely fused into tube, adnate to the petals basally; anthers free, opening by marginal slits. Ovary 3(4)-locular; style straight; stigma capitate. Nectary annular. Berry ± globose, orange at maturity; seeds hairy, completely surrounded by a fleshy aril. Only one species, B. pacifica Morat & Meijden, endemic to New Caledonia, in humid dense forests. 3. Eriandra P. Royen & Steenis Eriandra P. Royen & Steenis, J. Arnold Arb. 33:94 (1952).

Tree. Glands present on leaves. Inflorescences axillary, few-flowered fascicles. Flowers actinomorphic or nearly so, white. Calyx 5(4)-merous, the sepals basally connate, caducous. Corolla pentamerous (tetramerous), the petals connate for 3/4 of their length, at base adnate to the sepals. Stamens (8–)10, the filaments fused into a tube which is adnate to the corolla; anthers opening by marginal slits. Ovary 7– 8-locular; style straight; stigma capitate to discoid. Nectary annular. Berry globular, orange at maturity. 2n = 28. Only one species, E. fragrans P. Royen & Steenis, New Guinea and Solomon Islands, primary and secondary rainforest. 4. Barnhartia Gleason Barnhartia Gleason, Bull. Torrey Bot. Club 53:297 (1926).

Small tree or shrub, sometimes scandent. Glands present on leaves. Inflorescences terminal or axillary, simple or compound racemes or panicles. Flowers actinomorphic. Calyx caducous, the sepals free. Corolla orange, four of the petals connate basally in two pairs, the fifth distinct. Stamens 7–8, free from each other but adnate to the petals; anthers opening by marginal slits. Ovary 2–3-locular; style straight; stigma capitate. Nectary absent. Only one species, B. floribunda Gleason, the Guianas and Brazil.

5. Diclidanthera Mart.

Fig. 125B

Diclidanthera Mart., Nov. Gen. Sp. Pl. 2:139 (1827) (“1826”).

Small trees, erect or scandent shrubs, or lianas. Glands present on leaves and at nodes. Inflorescences terminal or axillary, simple or compound racemes. Flowers actinomorphic or nearly so. Calyx caducous, the sepals basally connate. Corolla yellowish brown to white, the petals connate to above the middle. Stamens (8–)10, the filaments fused into a tube which is adnate to the corolla, anthers introrse opening by long slits. Ovary 5(–7)-locular; style straight; stigma capitate. Nectary absent. Four species, Brazil, Guyana and Peru, inundated forests, river margins. 6. Moutabea Aubl.

Figs. 125C, 128I

Moutabea Aubl., Hist. Pl. Guiane: 679 (1775).

Small trees, or erect or scandent shrubs; branches often equipped with spines. Glands present on leaves and at nodes. Inflorescences axillary, short racemes. Flowers zygomorphic. Calyx caducous, the sepals connate, the tube halfway cleft on the dorsal side. Corolla white or yellow, the petals connate, the tube distally cleft on the dorsal side, adnate to the calyx, the abaxial petal slightly boat-shaped. Stamens 8, the filaments fused into a sheath which is adnate to the petals; anthers opening by marginal slits. Ovary (2–)4(5)-locular; style slightly curved; stigma capitate or slightly undulate. Nectary annular. Berry globose. Eight species, Brazil, Costa Rica, Ecuador, French Guiana, Guyana, Panama and Peru, primary and secondary rainforest. III. Tribe Carpolobieae Eriksen (1993). Woody plants. Leaves alternate. Flowers zygomorphic, subtended by one bract and two prophylls. Calyx and corolla 5-merous. Anthers introrse opening by short slits. Ovary tricarpellate, trilocular with a single ovule per locule. Nectary annular with a lateral process. Fruit a berry. 7. Atroxima Stapf Atroxima Stapf, J. Linn. Soc., Bot. 37:85 (1905); Breteler & Smissaert-Houwing, Meded. Landbouwhogesch. Wageningen 77-18:1–45 (1977), rev.

Lianas or clambering shrubs. Glands absent or present at nodes. Inflorescences axillary, simple or compound racemes. Sepals free, caducous, the lat-

Polygalaceae

eral ones slightly larger than the rest. Corolla lobes slightly unequal, the abaxial petal concave, clawed, colour unknown. Stamens 5, the filaments fused for most or all of their length into a U-shaped staminal sheath which is adnate to the basal part of all petals. Style slightly curved; stigma capitate. Berry orange or brown at maturity; seeds coated by juicy hairs. 2n = 18 or 22. Two species, West and Central Africa, in rainforests and semi-deciduous forests. 8. Carpolobia G. Don Carpolobia G. Don, Gen. Hist. 1:370 (1831); Breteler & Smissaert-Houwing, Meded. Landbouwhogesch. Wageningen 77-18:1–45 (1977), rev.

Shrubs, treelets or trees. Glands absent or present at nodes. Inflorescences axillary, simple or compound and partly concaulescent racemes. Sepals free, caducous, the lateral ones slightly larger than the rest. Corolla lobes slightly unequal, the abaxial petal concave to carinate, clawed, white to yellow, often striated or streaked with red. Stamens 5(4), the filaments fused for half or three quarters of their length into a U-shaped staminal sheath which is adnate to the basal part of all petals; staminodes 0–3. Style slightly curved; stigma capitate. Berry yellow to orange at maturity; seeds glabrous or partly or entirely coated by long, non-juicy hairs. 2n = 20 or 22. Four species, tropical Africa, rainforests and semi-deciduous forests. IV. Tribe Polygaleae Chodat (1896). Herbaceous or woody plants. Leaves alternate, occasionally opposite or whorled. Flowers zygomorphic, usually subtended by one bract and two prophylls. Calyx 5-merous. Corolla 3-merous. Anthers introrse opening by short, or rarely long, slits. Ovary bicarpellate, bilocular with a single ovule in each locule, sometimes pseudomonomerous. Nectary annular, semi-annular, annular with a lateral process, unilateral, or absent. Fruit a capsule (sometimes indehiscent), drupe or samara.

357

opposite. Inflorescences axillary, few-flowered racemes. Calyx consisting of an adaxial and two abaxial small sepals and two large, lateral and petaloid ones (wings), the sepals free, caducous. Corolla lobes free from each other, the abaxial petal (keel) carinate, clawed at base and slightly emarginate but unappendaged at apex. Flowers white, yellow or bluish. Stamens 8, the filaments fused for most of their length into a U-shaped staminal sheath which is adnate to the lateral margins of the adaxial petals. Style often geniculate and bifid with two stigmatic areas. Nectary annular. Fruit a compressed bilocular capsule with woody pericarp; seeds glabrous or pubescent, surmounted by a caruncle. About six species, Brazil, Ecuador and Peru, in primary and secondary rainforests and savannas. 10. Badiera DC. Badiera DC., Prodr. 1:334 (1824). Polygala L. sect. Hebecarpa Chodat (1893).

Unarmed subshrubs, shrubs, treelets or perennial herbs. Glands absent. Inflorescences axillary or terminal short racemes, sometimes corymb-like or fascicled. Calyx consisting of an adaxial and two abaxial small sepals and two larger (ca. one-third longer), lateral and petaloid ones (wings), the sepals free, caducous. Corolla lobes free from each other, the abaxial petal (keel) carinate, sometimes clawed at base, sometimes three-lobed, but unappendaged at apex. Flowers usually purplish, sometimes yellow-green or whitish. Stamens 8, the filaments fused for most of their length into a U-shaped staminal sheath which is adnate to the lateral margins of the adaxial petals. Style geniculate, bifid with 2 stigmatic areas. Nectary annular. Fruit a compressed, bilocular capsule (or one cell aborted), subcoriaceous; seeds glabrous to densely pubescent, surmounted by a caruncle. Species number varying among treatments from c. 25 to 70. West Indies, Central America and northern South America, in thickets and woodlands. The species traditionally placed in Polygala sect. Hebecarpa are here included in Badiera.

9. Acanthocladus Klotzsch ex Hassk. Figs. 125E, 128B

11. Bredemeyera Willd.

Acanthocladus Klotzsch ex Hassk., Ann. Mus. Bot. Lugduno-Batavum 1:184 (1864); Marques, Rodriguésia 36:3–10 (1984), reg. rev. of Brazil. spp.

Bredemeyera Willd., Gesell. Naturf. Freunde Berlin N. S. 3:412 (1801); Marques, Rodriguésia 32:269–321 (1980), rev. Brazil. spp.

Trees or shrubs, branches often spine-tipped. Glands absent. Leaves alternate, subopposite or

Erect or scandent shrubs, rarely small-leaved with chlorophyllous and spine-tipped branches,

Figs. 125F, 128C, 129A

358


or lianas. Glands absent. Inflorescences terminal, usually paniculate, rarely fasciculate or flowers solitary. Calyx consisting of an adaxial and two abaxial small sepals and two larger, lateral and petaloid ones (wings), the sepals free, caducous. Corolla lobes free from each other, the abaxial petal (keel) carinate, clawed or hooded at base, sometimes slightly three-lobed but unappendaged at apex. Flowers white or yellowish, sometimes with green sepals. Stamens 8, the filaments fused for more than two thirds of their length into a Ushaped staminal sheath. Style curved or geniculate, bifid with 2 stigmatic areas. Nectary on filaments. Fruit a compressed oblong-cuneate, spatulate or obcordate, bilocular, coriaceous or membranous to subcarnose capsule; seeds glabrous or pilose, surmounted by a caruncle, and with long hairs attached at hilum. About 15 species, mostly in tropical America from southern Mexico to Paraguay but reaching into temperate Argentina, in primary and secondary forest vegetation, rarely in semideserts. This description includes Bredemeyera microphylla. Recent phylogenetic studies indicate, however, that B. microphylla forms the sister group to Badiera s.l. and may merit recognition at the generic level. Bredemeyera papuana also keys out here, although there is some doubt as to where this New Guinean species actually belongs. It differs from the description given here by having a persistent calyx, an axillary inflorescence and purple wings (as in B. microphylla). 12. Ancylotropis B. Eriksen Ancylotropis B. Eriksen, Pl. Syst. Evol. 186:48 (1993). Monnina subg. Monninopsis Chodat (1896).

Annual herbs. Glands absent. Inflorescences terminal, simple racemes. Flowers zygomorphic. Calyx consisting of an adaxial and two abaxial small sepals and two large, lateral and petaloid ones (wings), the sepals free, caducous. Corolla white to pink, the petals free from each other, the abaxial petal (keel) carinate, sessile, profoundly tripartite but unappendaged at apex. Stamens 8, the filaments fused for all their length into a U-shaped staminal sheath which is adnate to the lateral margins of the adaxial petals. Style geniculate, at apex entire, hirsute and with a single stigmatic area. Nectary absent. Fruit an indehiscent capsule or a samara. Two species, eastern Brazil, in dry grassland. The generic status of this taxon is challenged and the question should be further investigated.

13. Comesperma Labill.

Fig. 129C

Comesperma Labill., Nov. Holl. pl. 2:21 (1806); Pedley, Austrobaileya 2:7–14 (1984), rev. of Queensland spp.

Shrubs, subshrubs or erect or twining herbs. Glands absent. Inflorescences terminal, racemose. Calyx consisting of an adaxial and two abaxial small sepals and two larger, lateral and petaloid ones (wings), the sepals free, caducous. Corolla lobes free from each other, the abaxial petal (keel) carinate, usually unappendaged at apex but rarely with horn-like appendages. Flowers purple, pink, blue, yellow or white. Stamens 8, the filaments fused for more than half of their length into a U-shaped staminal sheath, which is basally adnate to the adaxial petals. Style curved, apex bifid with a single stigmatic area and a sterile lobe. Nectary annular. Fruit a compressed, cuneate to orbicular capsule, coriaceous or nearly membranous; seeds pubescent, without caruncle but often with a membranous appendage along funiculus or at the chalazal end, and usually with long hairs (coma) from the testa. About 40 species, endemic to Australia, often on sandy soils. 14. Epirixanthes Blume Epirixanthes Blume, Catalogus: 25 (1823); van der Meijden, Fl. Males. I, 10:488–492 (1988), rev.

Achlorophyllous herbs. Glands absent. Leaves small and scale-like. Inflorescences terminal, spike-like racemes; prophylls present or absent. Calyx lobes unequal, smaller than the corolla, free or connate at base, persistent. Corolla lobes unequal, the abaxial petal concave at apex and connate to the upper petal lobes in its lower half. Stamens 2–5, the filaments fused for some or all of their length into a staminal sheath which is halfway adnate to the corolla; anthers opening by long slits. Style straight, bifid at apex, with one large stigmatic area and one small sterile lobe. Nectary semi-annular. Fruit an indehiscent capsule with a fleshy pericarp; seeds glabrous, with funicular aril. 2n = 24. Five species, eastern India to China and throughout Malesia as far as the Solomon Islands, myco-heterotroph among rainforest litter. 15. Hualania Phil. Hualania Phil., Anales Univ. Chile 21:390 (1862).

Leafless shrubs, young branches chlorophyllous and spine-tipped. No information available regarding glands. Inflorescences axillary, the flowers

Polygalaceae

solitary or in few to many-flowered fascicles on the branches. Calyx consisting of an adaxial and two abaxial small sepals and two somewhat larger, lateral and petaloid ones (wings), the sepals free, persistent in fruit. Corolla lobes free from each other, the abaxial petal (keel) carinate, unappendaged at apex; keel yellowish white, the upper petals with violet dots. Stamens 8, the filaments fused into a U-shaped staminal sheath which is probably adnate to the corolla, although this has not been explicitly stated. Style geniculate, bifid with two stigmatic areas. Nectary absent. Fruit a compressed, cuneate or spatulate, bilocular, coriaceous capsule; seeds with long hairs attached at hilum; no information available regarding the presence or absence of an aril. 2n = 14. Only one species, H. colletioides Phil., central Argentina, semi-deserts. 16. Monnina Ruiz & Pav.

Figs. 125G, 127, 128H

Monnina Ruiz & Pav., Syst. Veg. Fl. Peruv. Chil. 1:169 (1798); Ferreyra, J. Arnold Arb. 27:123–167 (1946), rev. Peruv. spp.; Ferreyra, Smithsonian Misc. Collect. 121:1–59 (1953), rev. Columb. spp.; Ferreyra, Brittonia 9:9–18 (1957), rev. Venez. spp.; Taylor, Rhodora 87:159–188 (1985), rev. C. Amer. spp.; Eriksen, Ståhl & Persson, Fl. Ecuador 65:1–132 (2000).

Shrubs and treelets, erect or clambering. Glands absent or present at nodes. Inflorescences terminal, simple or compound racemes. Calyx consisting of an adaxial and two abaxial small sepals and two large, lateral, blue to purple petaloid ones (wings), free or the two abaxial ones connate, caducous. Corolla lobes free from each other, the abaxial petal (keel) carinate, sessile, plicate and emarginate but unappendaged at apex, mostly yellow. Stamens 8, the filaments fused for most of their length into a U-shaped staminal sheath which is adnate to the lateral margins of the adaxial petals. Ovary pseudomonomerous; style geniculate, apex bifid with a single stigmatic area and a sterile lobe. Nectary unilateral. Fruit a drupe, blue or black at maturity. 2n = 20, 30 or 40. About 150 species, from Mexico to Bolivia, mountain forests and grassland, 500– 3,500 m alt. Taxa of Monnina with nodal glands and species of Pteromonnina appear in a wellsupported clade separate from the rest of Monnina in a molecular analysis based on ITS sequences (Eriksen and Persson, unpubl. data). Since this monophyletic entity is difficult to circumscribe and distinguish morphologically from Monnina s.str., the genus Pteromonnina will most likely be put into synonomy.

17. Muraltia DC.

359

Figs. 125J, 128D, 129E

Muraltia DC., Prodr. 1:335 (1824), nom. et orth. cons.; Levyns, J. S. African Bot. suppl. 2:1–247 (1954), rev. Nylandtia Dumort., Comment. Bot. 31 (1822); Johnson & Weitz, S. African J. Bot. 57:229–233 (1991), rev.

Shrubs and subshrubs, the branches sometimes spine-tipped. Glands absent. Inflorescences axillary, at base with three or four persistent bracts, 1– 2-flowered. Calyx lobes subequal or the calyx consisting of an adaxial and two abaxial small sepals and two large, lateral, white to purple petaloid ones (wings), the sepals free, persistent. Corolla white to purple, the abaxial petal (keel) carinate, clawed, apically with a bilobed or fimbriate crest, and in its lower half connate to the adaxial petal lobes. Stamens 7, fused for all of their length into a staminal sheath which is halfway adnate to the corolla; anthers opening by long slits. Style straight, apex bifid with a single stigmatic area and a sterile lobe. Nectary annular or absent. Fruit a capsule or a drupe; capsule 2-locular, bearing four horns or teeth at apex; drupe fleshy or more or less leathery, red to yellow. Seeds 1–2, glabrous or hairy, in capsular fruits surmounted by a caruncle. One hundred and fifteen species accepted by Levyns (1954), emended to 119 by Forest and Manning (2006). South Africa, especially the Cape region, in dry to moist places on open, sandy or stony soils or in grassland from sea level up to 2,750 m alt. 18. Polygala L.

Figs. 125I, 128A, 129B

Polygala L., Sp. Pl.: 701 (1753); Chodat, Mém. Soc. Phys. Genève 31:1–500 (1893), rev.; Blake, Contr. Gray Herb. 47:1–122 (1916), rev. N. Amer. spp.; van der Meijden, Fl. Males. I, 10:459–482 (1988); Marques, Rodriguésia 36:31–34 (1984), rev. Brazil. spp. (sect. Gymnospora); Marques, Arq. Jard. Bot. Rio de Janeiro 29:1–114 (1989), rev. Brazil. spp. (sect. Polygala); Bernardi, Cavanillesia Altera 1:1–456 (2000), rev. of selected American spp.; Eriksen, Ståhl & Persson, Fl. Ecuador 65:1–132 (2000). Polygaloides Haller (1768). Brachytropis Rchb. (1828). Chamaebuxus (Tourn.) Spach (1839). Phlebotaenia Griseb. (1861). Heterosamara Kuntze (1891). Monrosia Grondona (1949).

Small trees, erect or clambering shrubs, annual or perennial herbs. Glands absent or present at nodes. Leaves alternate, (sub-)opposite, or whorled. Inflorescences terminal or axillary, simple racemes or rarely paniculate. Calyx irregular, consisting

360


of an adaxial and two abaxial small sepals and two large, lateral, white to purple or sometimes yellow petaloid ones (wings), free or the two abaxial ones connate, persistent or caducous (sect. Chamaebuxus). Corolla irregular, the abaxial petal (keel) carinate, clawed, unappendaged or apically with a ± fimbriate crest, white, blue to purple or yellow. Stamens 8, the filaments fused for most or all of their length into a U-shaped staminal sheath, which is adnate to the lateral margins of the adaxial petals. Style curved, at apex bifid, with one or two stigmatic areas. Nectary annular, sometimes with a unilateral process (sect. Chamaebuxus and Ligustrina) or absent. Fruit a capsule, occasionally narrowly winged along the margin; seeds glabrous or hairy, usually surmounted by a caruncle. The sections Chamaebuxus, Pseudosemeiocardium, and Hebeclada include species with the basic number x = 7 whereas in sect. Polygala the basic numbers x = 17 (Europe and North America), x = 19 (Africa) or x = 6–10 and 23 (North America) in diploids to octaploid constellations are known. The infrageneric subdivision of Polygala seems artificial in its present form, and the limits towards related genera such as Comesperma, Muraltia, Salomonia and Ancylotropis are not clear. Although several sections within Polygala are now recognised at the generic level, morphological and molecular analyses (Jauch 1918; Persson 2001; Forest et al., pers. comm.) indicate that Polygala as well as several of its sections are still strongly polyphyletic. Therefore, one of the main tasks of future research is to unravel the relationships among species and sections of Polygala and its close allies. About 300–350 species, cosmopolitan except for the Arctic, Antarctica and New Zeeland, with an extensive ecological range. 19. Pteromonnina B. Eriksen

Fig. 128F

Pteromonnina B. Eriksen, Pl. Syst. Evol. 186:49 (1993); Eriksen, Ann. Missouri Bot. Gard. 80:191–207 (1993), reg. rev. (as Monnina subg. Pterocarya); Marques, Rodriguésia 67:3–33 (1989), rev. Brazil. spp. (as Monnina); Eriksen, Ståhl & Persson, Fl. Ecuador 65:1–132 (2000). Monnina subg. Pterocarya (DC.) Chodat (1896).

Annual or perennial herbs. Glands absent or present at nodes. Inflorescences terminal, simple racemes. Calyx consisting of an adaxial and two abaxial small sepals and two large, lateral, blue to purple and petaloid ones (wings), the sepals usually free, caducous. Corolla mostly yellow, the abaxial petal (keel) carinate, sessile, plicate and

emarginate but unappendaged at apex. Stamens 4–8, the filaments fused for most or all of their length into a U-shaped staminal sheath, which is adnate to the lateral margins of the adaxial petals. Ovary 2-locular, occasionally pseudomonomerous; style geniculate, at apex bifid with a single stigmatic area and a glabrous or hairy sterile lobe. Nectary unilateral. Fruit an indehiscent capsule with hard pericarp, or a samara. 2n = 18, 20, or 40. About 30 species, South America from central Ecuador to central Chile along the west coast, and from north-eastern Brazil to Argentina in the east; possible anthropogenic dispersal to Mexico, in dry grassland and semi-deserts. Taxa of Pteromonnina appear in a wellsupported clade together with species of Monnina having nodal glands in a molecular analysis based on ITS sequences (Eriksen and Persson, unpubl. data). Since this monophyletic entity is difficult to circumscribe and distinguish morphologically from Monnina s.str., the genus Pteromonnina will most likely be put into synonomy. 20. Salomonia Lour.

Figs. 125H, 128E, 129D

Salomonia Lour., Fl. Cochinch. 1:14 (1790), nom. cons.; van der Meijden, Fl. Males. I, 10:486–488 (1988); Koyama, Bull. Natl Sci. Mus. Tokyo, Ser. B 21:1–12 (1995), rev.

Annual herbs. Glands absent. Inflorescences terminal, rarely axillary, spike-like racemes; prophylls absent (present, Sumithraarachchi 1987). Calyx lobes unequal, smaller than the corolla, connate at base, persistent. Corolla cream with a pinkish tinge, the abaxial petal concave at apex and connate to the upper petal lobes in its lower half. Stamens 4–6, fused for most of their length into a staminal sheath which is halfway adnate to the corolla. Style strongly curved, bifid at apex; no information available regarding the number of stigmatic areas. Nectary absent. Fruit a capsule with teeth or spines along the margin; seeds glabrous, inappendiculate. Six species, tropical and subtropical Asia and Australia, 0–1,500 m alt., open land on wet soil or forest floors. 21. Securidaca L.

Figs. 126, 128G

Securidaca L., Syst. Nat. ed. 10:1151, 1155 (1759), nom. cons.; Marques, Arq. Jard. Bot. Rio de Janeiro 34:7–144 (1996), rev. Brazil. spp.; Eriksen, Ståhl & Persson, Fl. Ecuador 65:1–132 (2000).

Lianas or rarely shrubs or small trees. Glands absent or present at nodes. Inflorescences terminal or

Polygalaceae

axillary, simple racemes or few- to many-flowered panicles. Calyx consisting of an adaxial and two abaxial small sepals and two large, lateral, white to purple and petaloid ones (wings), the sepals free, caducous. Corolla pink to purple, sometimes yellowish at base, the abaxial petal (keel) carinate, clawed, unappendaged or apically with a ± fimbriate crest. Stamens 8, the filaments fused for most or all of their length into a U-shaped staminal sheath which is adnate to the lateral margins of the adaxial petals. Ovary pseudomonomerous; style curved, at apex bifid, with one or two stigmatic areas. Nectary annular, often with a unilateral projection. Fruit a unilaterally winged samara. 2n = 32 (S. longepedunculata, Africa). About 80 species, pantropical, the majority in America, absent in Australia, in dry and humid forests. The genus has never been monographed and its taxonomy is still in a state of flux.

Selected Bibliography APG 1998. Angiosperm Phylogeny Group. See general references. APG II 2003. Angiosperm Phylogeny Group. See general references. Arends, J.C., van der Laan, F.M. 1979. [Miscellaneous chromosome counts]. In: Löve, Á. (ed.) IOPB Chromosome number reports LXV. Taxon 28:635–636. Arreguín-Sánchez, M.L., Palacios-Chávez, R., QuirozGarcía, D.L., Ramos-Zamora, D. 1988. Morfología de los granos de polen de la familia Polygalaceae del Valle de Mexico. Acta Bot. Mex. 4:21–27. Baas, P. 1991. Leaf anatomy of Balgoya pacifica (Polygalaceae) from New Caledonia. Bull. Mus. Natl Hist. Nat., B, Adansonia 13:13–15. Behnke, H.-D. 1981. Sieve-element characters. Nordic J. Bot. 1:381–400. Brantjes, N.B.M. 1982. Pollen placement and reproductive isolation between two Brazilian Polygala species (Polygalaceae). Pl. Syst. Evol. 141:41–52. Brantjes, N.B.M., van der Pijl, L. 1980. Pollination mechanisms in Polygalaceae. Acta Bot. Neerl. 29:56–57. Breteler, F.J., Smissaert-Houwing, A.A.S. 1977. Revision of Atroxima Stapf and Carpolobia G. Don (Polygalaceae). Meded. Landbouwhogesch. Wageningen 77-18:1–45. Bridgewater, S., Baas, P. 1982. Wood anatomy of Xanthophyllum Roxb. I.A.W.A. Bull. n.s. 3:115–125. Chase, M.W. et al. 1993. See general references. Chenery, E.M. 1948. Aluminium in the plant world. Kew Bull. 2:173–183. Chodat, R. 1891. Monographia polygalacearum, part 1. Mém. Soc. Phys. Genève suppl. 1890, 7:1–143. Chodat, R. 1893. Monographia polygalacearum, part 2. Mém. Soc. Phys. Genève 31:1–500. Chodat, R. 1896. Polygalaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 4. Leipzig: W. Engelmann, pp. 323–345.

361

Coetzee, H., Robbertse, P.J. 1985. Pollen and tapetal development in Securidaca longipedunculata. S. African J. Bot. 51:111–124. Crayn, D.M., Fernando, E.S., Gadek, P.A., Quinn, C.J. 1995. A reassessment of the familial affinity of the Mexican genus Recchia Moçiño and Sessé ex DC. Brittonia 47:397–402. Cronquist, A. 1981. See general references. Cruden, R.W. 1977. Pollen-ovule ratios: a conservative indicator of breeding systems in flowering plants. Evolution 31:32–46. Darlington, C.D., Wylie, A.P. 1961. Chromosome atlas of flowering plants, 2nd edn. Aberdeen: University Press. Détienne, P. 1991. Anatomie du bois de Balgoya pacifica (Polygalaceae) de Nouvelle-Calédonie. Bull. Mus. Natl Hist. Nat., B, Adansonia 13:17–20. Dickison, W.C. 1973. Nodal and leaf anatomy of Xanthophyllum (Polygalaceae). Bot. J. Linn. Soc. 67:103–115. Doyle, J.J., Doyle, J.L., Ballenger, J.A., Dickson, E.E., Kajita, T., Ohashi, H. 1997. A phylogeny of the chloroplast gene rbcL in the Leguminosae: taxonomic correlations and insights into the evolution of nodulation. Amer. J. Bot. 84:541–554. Dube, V.P. 1962. Morphological and anatomical studies in Polygalaceae and its allied families. Agra Univ. J. Res., Sci. 11:109–112. Erdtman, G. 1944. The systematic position of the genus Diclidanthera Mart. Bot. Notiser 97:80–84. Erdtman, G. 1952. See general references. Eriksen, B. 1993a. Phylogeny of the Polygalaceae and its taxonomic implications. Pl. Syst. Evol. 186:33–55. Eriksen, B. 1993b. Floral anatomy and morphology in the Polygalaceae. Pl. Syst. Evol. 186:17–32. Eriksen, B. 1993c. A revision of Monnina subg. Pterocarya (Polygalaceae) in northwestern South America. Ann. Missouri Bot. Gard. 80:191–207. Eriksen, B. 1997. Heterogeneity in Monnina sect. Stipulatae – evidence from fruit anatomy and morphology. BioLlania ed. esp. no. 6:311–323. Eriksen, B., Ståhl, B., Persson, C. 2000. Polygalaceae. In: Harling, G., Andersson, L. (eds) Flora of Ecuador 65:1–132. Göteborg: Botanical Institute, Göteborg University. Fernando, E.S., Gadek, P.A., Crayn, D.M., Quinn, C.J. 1993. Rosid affinities of Surianaceae: molecular evidence. Mol. Phylog. Evol. 2:344–350. Ferrara, L.S., Quinn, J.A. 1985. Cleistogamous and chasmogamous flower and fruit production in New Jersey populations of Polygala paucifolia Willd. Amer. J. Bot. 72:851–852. Forest, F., Manning, J.C. 2006. Evidence for inclusion of South African endemic Nylandtia in Muraltia (Polygalaceae). Syst. Bot. 31:525–532. Furness, S.H., Stafford, P.J. 1995. The Northwest European Pollen Flora. 55. Polygalaceae. Rev. Palaeobot. Palynol. 88:61–82. Goldberg, A. 1986. Classification, evolution, and phylogeny, of the families of the dicotyledons. Smithsonian Contr. Bot. 58:1–314. Hegnauer, R. 1969, 1990. See general references. Heubl, G.R. 1984. Systematische Untersuchungen an mitteleuropäischen Polygala-Arten. Mitt. Bot. Staatssamml. München 20:205–428. Holm, T. 1929. Morphology of North American species of Polygala. Bot. Gaz. 88:167–185.

362


Hutchinson, J. 1967. The genera of flowering plants (Angiospermae), vol. II. Oxford: Clarendon Press. Isaacs, M.J.H., Weitz, F.M., Johnson, C.T. 1993. Seed-coat characteristics of selected southern African species of Polygala L. (Polygalaceae). S. African J. Bot. 59:592– 596. Jauch, B. 1918. Quelque points de l’anatomie et de la biologie des Polygalacées. Bull. Soc. Bot. Genève 10:47–84. Johnson, C.T. 1987. Taxonomy of the African species of Securidaca (Polygalaceae). S. African J. Bot. 53:5–11. Judd, W.S., Campell, C.S., Kellogg, E.A., Stevens, P.F. 1999. Plant systematics (a phylogenetic approach). Sunderland, MA: Sinauer. Källersjö, M., Farris, J.S., Chase, M.W., Bremer, B., Fay, M.F., Humphries, C.J., Petersen, G., Seberg, O., Bremer, K. 1998. Simultaneous parsimony jackknife analysis of 2538 rbcL sequences reveals support for major clades of green plants, land plants, seed plants and flowering plants. Pl. Syst. Evol. 213:259–287. Kassau, E. 1931. Beiträge zur Systematik einiger Polygalaceen-Gattungen unter Berücksichtigung des Vorkommens von Saponin. Inaugural-Dissertation, Friedrich-Wilhelms Universität, Berlin. Berlin: Doktordruck, pp. 1–40. Krüger, H., Robbertse, P.J. 1988. Floral ontogeny of Securidaca longepedunculata Fresen. (Polygalaceae), including inflorescence morphology. In: Leins, P., Tucker, S.C., Endress, P.K. (eds) Aspects of floral development. Berlin: J. Cramer, pp. 159–167. Krüger, H., van der Merwe, M.J., Robbertse, P.J. 1988. Floral organogenesis in Securidaca longepedunculata and Polygala virgata var. decora (Polygalaceae). S. African J. Sci. 84:308–313. Lack, A.J., Kay, Q.O.N. 1987. Genetic structure, gene flow and reproductive ecology in sand-dune populations of Polygala vulgaris. J. Ecol. 75:259–276. Larsen, K. 1959. On the cytological pattern of the genus Polygala. Bot. Notiser 112:369–371. Larsen, K. 1964. The chromosomes of Monnina xalapensis. Phyton (Buenos Aires) 21:45–46. Larsen, K. 1967. Cytological studies on Monnina. Feddes Repert. 75:43–46. Leinfellner, W. 1972. Zur Morphologie des Gynözeums der Polygalaceen. Oesterr. Bot. Z. 120:51–76. Levyns, M.R. 1949. The floral morphology of some South African members of Polygalaceae. J. S. African Bot. 15:79–92. Levyns, M.R. 1954. The genus Muraltia. J. S. African Bot. suppl. 2:1–247. Lewis, W.H., Davis, S.A. 1962. Cytological observations of Polygala in eastern North America. Rhodora 64:102– 113. Mahmood, N., Moore, P.S., De Tommasi, N., De Simone, F., Colman, S., Hay, A.J., Pizza, C. 1993. Inhibition of HIVinfection by Caffeoylquinic acid derivatives. Antiviral Chem. Chemotherapy 4:235–240. Mangenot, S., Mangenot, G. 1957. Nombres chromosomiques nouveaux chez diverses dicotylédones et monocotylédones d’Afrique occidentale. Bull. Jard. Bot. État 27:639. Marques, M.C.M. 1980. Revisão das espécies do gênero Bredemeyera Willd. (Polygalaceae) do Brasil. Rodriguésia 32:269–321.

Marques, M.C.M. 1989. Monnina Ruiz et Pavón (Polygalaceae) no Brasil. Rodriguésia 67:3–33. Marques, M.C.M. 1996. Securidaca, L. (Polygalaceae) do Brasil. Arch. Jard. Bot. Rio de Janeiro 34:7–144. Meijden, R. van der 1982. Systematics and evolution of Xanthophyllum (Polygalaceae). Leiden Bot. Ser. 7:1–157. Merxmüller, H., Heubl, G.R. 1983. Karyologische und palynologische Studien zur Verwandtschaft der Polygala chamaebuxus L. Bot. Helv. 93:133–144. Metcalfe, C.R., Chalk, L. 1950. See general references. Miège, J. 1960. Nombres chromosomiques de plantes d’Afrique Occidentale. Rev. Cytol. Biol. Vég. 21:373–380. Milby, T.H. 1976. Studies in the floral anatomy of Polygala (Polygalaceae). Amer. J. Bot. 63(10):1319–1326. Miller, N.G. 1971. The Polygalaceae in the Southeastern United States. J. Arnold Arb. 52:267–284. Morgan, D.R., Soltis, D.E., Robertson, K.R. 1994. Systematic and evolutionary implications of rbcL sequence variation in Rosaceae. Amer. J. Bot. 81:890–903. Morat, P., Meijden, R. van der 1991. Balgoya (Polygalaceae trib. Moutabeae), a new genus from New Caledonia. Bull. Mus. Natl Hist. Nat., B, Adansonia 13:3–8. Norderhaug, A. 1995. Mating system in three meadow plant species. Nordic J. Bot. 15:243–250. Oginuma, K., Kiaptranis, R., Damas, K., Tobe, H. 1998. A cytological study of some plants from Papua New Guinea. Acta Phytotax. Geobot. 49:105–114. Oostermeijer, J.G.B. 1989. Myrmecochory in Polygala vulgaris L., Luzula campestris (L.) DC., and Viola curtisii Forster in a Dutch dune area. Oecologia 78:302–311. Paiva, J. 1988. El género Polygala (Polygalaceae) en el Mediterráneo Occidental. Collect. Bot. (Barcelona) 17:191–203. Paiva, J.A.R. 1998. A revision of the African and Malagasy species of the genus Polygala L. (Polygalaceae), and a synopsis of the genus Heterosamara Kuntze, segregated from the former and extending throughout Africa and Asia. Fontqueria 50:117–136. Paiva, J., Santos Dias, J.D. 1990. The pollen grain of Polygala fruticosa Berg. (Polygalaceae). Anales Jard. Bot. Madrid 47:377–385. Persson, C. 2001. Phylogenetic relationships in Polygalaceae based on plastid DNA sequences from the trnL-F region. Taxon 50:763–779. Prenner, G. 2004. Floral development in Polygala myrtifolia (Polygalaceae) and its similarities with Leguminosae. Pl. Syst. Evol. 249:67–76. Rao, A.N. 1964. An embryological study of Salomonia cantoniensis Lour. New Phytol. 63:281–288. Ridley, H.N. 1930. The dispersal of plants throughout the world. Ashford, Kent: L. Reeve. Rodrigue, A. 1893. Structure du tégument séminal des Polygalacées. Bull. Herb. Boissier 1:450–463, 513–541, 571– 583. Royen, P. van, Steenis, C.G.G.J. van 1952. Eriandra, a new genus of Polygalaceae from New Guinea. J. Arnold Arb. 33:91–96. Sah, S.C.D., Dutta, S.K. 1966. Palyno-stratigraphy of the sedimentary formations of Assam. 1. Stratigraphical position of the Cherra formation. Palaeobotanist 15:72–86. Saint-Hilaire, A.F.C.P., Moquin-Tandon, A. 1828. Premier mémoire sur la famille des Polygalacées. Mém. Mus. Hist. Nat. 17:313–375.

Polygalaceae Savolainen, V., Chase, M.W. et al. 2000. See general references. Savolainen, V., Fay, M.F. et al. 2000. See general references. Solereder, H. 1908. Systematic anatomy of the dicotyledons. Oxford: Clarendon Press. Styer, C.H. 1977. Comparative anatomy and systematics of Moutabeae (Polygalaceae). J. Arnold Arb. 58:109–145. Sumithraarachchi, D.B. 1987. Polygalaceae. In: Dassanayake, M.D., Fosberg, F.R. (eds) A Revised Handbook to the Flora of Ceylon, vol. 6. New Delhi: Balkema, pp. 301–317. Thorne, R.F. 1992. An updated phylogenetic classification of flowering plants. Aliso 13:365–389. Venkatesh, C.S. 1956. The special mode of dehiscence of anthers of Polygala and its significance in autogamy. Bull. Torrey Bot. Club 83:19–26. Verkerke, W. 1984. Ovule and seed of Xanthophyllum (Polygalaceae). Blumea 29:409–421. Verkerke, W. 1985. Ovules and seeds of the Polygalaceae. J. Arnold Arb. 66:353–394. Verkerke, W. 1991. Fruits and seeds of Balgoya pacifica (Polygalaceae) from New Caledonia. Bull. Mus. Natl Hist. Nat., B, Adansonia 13:9–12. Walter, K.S., Gillett, H.J. (eds) 1998. 1997 IUCN Red List of Threatened Plants. World Conservation Monitoring

363

Centre, International Union for the Conservation of Nature, Gland, Switzerland and Cambridge, UK, lxiv + 862 pp. Weberling, F. 1974. Weitere Untersuchungen zur Morphologie des Unterblattes bei den Dikotylen. VII. Polygalales. VIII. Koeberlinia Zucc. Beitr. Biol. Pflanzen 50:277–289. Westerkamp, C., Weber, A. 1997. Secondary and tertiary pollen presentation in Polygala myrtifolia and allies (Polygalaceae, South Africa). S. African J. Bot. 63:254–258. Westerkamp, C., Weber, A. 1999. Keel flowers of the Polygalaceae and Fabaceae: a functional comparison. Bot. J. Linn. Soc. 129:207–221. Wilgen, B.W. van, Forsyth, G.G. 1992. Regeneration strategies in fynbos plants and their influence on the stability of community boundaries after fire. In: Wilgen, B.W. van, Richardson, D.M., Kruger, F.J., Hensbergen, H.J. van (eds) Fire in South African mountain fynbos. Ecological Studies 93, chap. 4. Berlin Heidelberg New York: Springer, pp. 54–80. Wirz, H. 1910. Beiträge zur Entwicklungsgeschichte von Sciaphila spec. und von Epirrhizanthes elongata Bl. Flora 101:395–446.

Proteaceae Proteaceae Juss., Gen. Pl.: 78 (1789).

P.H. Weston

Perennial shrubs or trees; plants usually completely bisexual but sometimes dioecious or andromonoecious; clusters of short lateral roots (‘proteoid roots’) often produced. Leaves alternate or less commonly opposite or whorled, simple or pinnately to bipinnately or rarely palmately compound, entire or pinnately to tripinnately or rarely dichotomously dissected, often with marginal teeth, estipulate, petiolate or sessile; venation pinnate or occasionally parallel or palmate, or reduced to a single vein; stomates brachyparacytic or rarely laterocytic (in Bellendena); trichomes usually 3-celled, occasionally also glandular, rarely plants glabrous. Inflorescence simple or compound, axillary or terminal, with flowers borne laterally either singly or in pairs, rarely also with a terminal flower, racemose or raceme-like or paniculate or condensed. Flowers usually bisexual, actinomorphic or zygomorphic, hypogynous; perianth of 4 (3 in Grevillea donaldiana and 5 in a minority of flowers of Eidothea hardeniana) valvate, free or variously united tepals; stamens (3)4(5), opposite tepals, usually all fertile or sometimes 1 or more sterile; filaments partly or wholly adnate to tepals or rarely free; anthers basifixed, usually bilocular and tetrasporangiate but occasionally the lateral anthers unilocular and bisporangiate; 1–4 hypogynous glands usually present, scale-like or fleshy, free or fused into a crescentic or annular nectary; gynoecium of 1 carpel (sometimes 2, free carpels in Grevillea banksii); ovary superior, sessile or stipitate, with variously positioned marginal placentae; style usually distinct, often with apex functioning as a pollen presenter; stigma small or sometimes relatively large and plate-like, terminal or subterminal; ovules 1 to many, anatropous to orthotropous, bitegmic, crassinucellate. Fruit dehiscent or indehiscent, a follicle, achene, drupe or drupe-like. Seeds 1 to many, sometimes winged; endosperm present or absent at maturity. A family comprising 80 genera and about 1,700 species, distributed mainly in the southern hemi-

sphere, where it is almost completely restricted to Gondwanic continental blocks and fragments (Fig. 130). It is most diverse in Australia, followed by southern Africa, South America, New Caledonia, New Guinea, Malesia, South and East Asia, tropical Africa, Central America, Madagascar, New Zealand, Fiji, southern India, Sri Lanka, Vanuatu and Micronesia. Nota bene: Statements as to apomorphy and plesiomorphy of character states are made in the context of published phylogenetic classifications and analyses, the topology of the tree shown in Fig. 131, and knowledge that the immediate outgroups to Proteaceae are, successively, Platanaceae and Nelumbonaceae. Vegetative Morphology. Proteaceae are woody plants, ranging from almost herbaceous subshrubs to trees over 40 m tall, but mostly shrubs or small trees. They are evergreen, although alpine populations of the temperate South American Embothrium coccineum are facultatively deciduous. The family is probably ancestrally arborescent (Johnson and Briggs 1975). All Proteaceae, except subfam. Persoonioideae and Symphionematoideae (Lee 1978), produce proteoid roots (Dinkelaker et al. 1995 and references therein), small lateral roots of determinate growth which form dense clusters on otherwise ‘ordinary’ secondary roots close to the soil surface, under conditions of low phosphate availability. They are produced in seasonal flushes and remain physiologically active for only 2–3 months. They enhance nutrient uptake from the soil because their narrow diameter and densely set root hairs greatly increase the root surface area, and they exude organic acids, particularly citrate and malate, into the rhizosphere in intense bursts lasting 2–3 days, resulting in the mobilization of phosphate and possibly other nutrients. Proteoid roots probably evolved in the family’s stem lineage and were secondarily lost in both Persoonioideae and Symphionematoideae.

Proteaceae

365

Fig. 130. Distribution of Proteaceae. (Drawn by L. Elkan)

They are not homologous with the cluster roots of Casuarinaceae, Fabaceae and Myricaceae, contrary to the assertion of Dinkelaker et al. (1995). Leaf morphology is very variable in Proteaceae but most species have leathery leaves with brochidodromous venation. They may be compound, deeply dissected or lobed, up to a fourth order of dissection, toothed, lobed and toothed, or simple and entire. The degree to which leaf shape varies between different stages in development is a striking feature of many rainforest taxa in particular. Some species (e.g. Alloxylon flammeum) produce trilobed leaves as the first pair of seedling leaves, followed by a phase of simple, unlobed seedling leaves, then lobed juvenile leaves and finally, simple, unlobed leaves as adults (stages as f0 to f3 respectively; Johnson and Briggs 1975). In some taxa, leaves in the f2 stage are pinnatisect (e.g. Alloxylon pinnatum) or compound (e.g. Carnarvonia araliifolia, Fig. 137B), rather than lobed. Ontogenetic variation in leaf toothing is also often overlaid over this sequence, with entire adult leaves often following toothed seedling and juvenile leaves (e.g. Roupala montana, Fig. 138A–D). In many other taxa, the f0 stage is absent (e.g. Placospermum coriaceum, Fig. 133A, B, Roupala montana, Fig. 138A–D), the f0 and f1 stages are absent (e.g. Stenocarpus sinuatus) or the f3 stage is absent (e.g. Carnarvonia araliifolia, Fig. 137). Other taxa produce only simple, entire leaves (e.g. Alloxylon wickhamii, Persoonia, Fig. 134, Protea, Fig. 136) or lobed leaves (e.g. Bellendena

montana, Fig. 132) or pinnatisect leaves (e.g. Symphionema montana, Fig. 135, Grevillea robusta, Fig. 139). Variation in leaf form sometimes provides synapomorphies above generic level (e.g. tribe Persoonieae versus Placospermum, see taxonomic treatment and Weston 1994) but is more often informative at lower taxonomic levels. The ability to resprout from a lignotuber and/or epicormic shoots following major disturbances such as fire varies even between very closely related species, but is of great ecological significance. Lignotuberous species are known in many genera of fire-prone environments, especially in Australia and Africa but also in America and New Caledonia. Sprouting from epicormic shoots is much rarer and is restricted to shrubs and trees with thick, protective bark. Vegetative Anatomy. Proteaceous wood usually has small to medium-sized vessels, with simple perforation plates, associated with abundant axial parenchyma in curved, adaxially concave, tangential bands which span from ray to ray. The rays are commonly of two distinct kinds, large multiseriate rays and small uniseriate ones (hence, the common name ‘silky oak’, by comparison with the wood of Quercus). Libriform fibres with simple or indistinctly bordered pits form the ground mass of the wood. However, a minority of taxa have scattered large vessels, or some multiple perforation plates, or sparse parenchyma, or abaxially concave tangential bands of parenchyma, or apotra-

366

P.H. Weston

cheal parenchyma, or large or small homogeneous rays. Wood characters seem to be highly homoplasious but some genera (e.g. Alloxylon) and higher taxa (e.g. subtribe Banksiinae) are characterised by wood synapomorphies. Johnson and Briggs (1975) concluded that small, homogeneous rays, vessels isolated or in small groups, and the absence of tangential bands of parenchyma between rays were likely to represent ancestral character states in the family. Lanyon (1979) described the wood anatomy of three monotypic genera which occupy phylogenetically pivotal positions in Johnson and Briggs’ classification, and interpreted their rather atypical features as consistent with those authors’ evolutionary hypotheses. However, Platanaceae and Proteaceae share wide, high rays, a condition which seems likely to be a shared, ancestral homology, contrary to Johnson and Briggs’ opinion. Indeed, some woodworkers had already noticed the superficial similarity of ‘silky oak’ and Platanus woods (R. Gifkin, pers. comm.). In other respects, Johnson and Briggs (1975) were probably correct in their polarization of wood character states. Stevens (2005) judges the wood anatomy of Platanaceae and Proteaceae to be “very different”. Qualitative differences include alternate intervascular pitting and absence of tyloses in Proteaceae but opposite pitting and presence of tyloses in Platanus. More qualitative differences include the rarity of scalariform perforation plates and presence of uniseriate rays (usually in combination with wide rays) in Proteaceae but the predominance of scalariform perforation plates and the rarity or absence of uniseriate rays in Platanus. Leaf anatomy is remarkably diverse, especially in the range of scleromorphic structures (Dillon 2002, and in Jordan et al. 2005). There are six kinds of lignified hypodermes, five kinds of isolated sclereids, three kinds of sclereid associated with vein endings, diverse patterns of bundle sheath extension and midrib architecture, several kinds of stomatal encryption, lignified leaf margins, lignified steles in terete leaves and diverse cuticular architecture. Of these scleromorphic structures, only bundle sheath extensions are found in the outgroup, Platanus, so they have evolved mostly within the Proteaceae. In subfamily Proteoideae, especially the African taxa, exists surprisingly low leaf anatomical diversity, contrasting markedly with Grevilleoideae which include most of the variation. The small Australian and South American genus Orites is especially notable, showing as much anatomical diversity as large grevilleoid

genera such as Grevillea and Banksia and far more than large proteoid genera such as Protea and Leucadendron. The extreme ecological range of Orites, from tropical rainforests to alpine heathlands, seems the most likely explanation for this. Jordan et al. (2005) found that most leaf anatomical characters were highly homoplasious. Employing a combination of anatomical data and phylogenetic information, they found significant associations between scleromorphic structures of the upper leaf surface and open vegetation but not with dry habitats. These results support the hypothesis that at least some scleromorphic structures are adaptations protecting photosynthetic tissues from excess light. Proteaceae are characterised by a distinctive kind of trichome, which is found in all but the very few, completely glabrous species. This is uniseriate, the simplest variant being 3-celled, with a single basal cell in the epidermis, bearing a (usually short) stalk cell, above which is a (usually elongated and acute) simple terminal cell. Variations on this structural plan include the terminal cell being equally or unequally bifid in Hakeinae, Sphalmium, Floydia and some species of Heliciinae and Stenocarpinae (Johnson and Briggs 1975); basal cells being two or more (up to 20); and the stalk cell being thickened and cylindrical in Banksieae (Carpenter 1994; Carpenter and Jordan 1997). Immature leaves are usually liberally covered in hairs, the terminal cells of which are sloughed off as the leaf matures, leaving characteristic, rounded scars on the cuticle surface; similar trichome bases are found also in Platanaceae (Carpenter et al. 2005). Cuticles of all Proteaceae, except Bellendena, can be distinguished from those of other Proteales by their brachyparacytic stomates, in contrast to the laterocytic, anomocytic, sometimes paracytic stomates of Platanus and the laterocytic stomates of Bellendena (Carpenter et al. 2005). Inflorescence Structure. Inflorescence form varies spectacularly in Proteaceae but this can be interpreted as variation on two basic ‘structural plans’: racemiform, simple or compound inflorescences, and racemiform conflorescences of flower pairs (subfam. Grevilleoideae). Comparative analysis shows that the latter kind of inflorescence evolved from the former but the detailed transformational homology of grevilleoid flower pairs is not understood. Johnson and Briggs (1975) distinguished between the unit inflorescence or uniflorescence (the

Proteaceae

smallest unit of organisation above flower-pedicelbract in the inflorescence) and the conflorescence (a unit of inflorescence organisation above the uniflorescence and qualitatively different from it). In all subfamilies excepting Grevilleoideae, the uniflorescence is racemose (often highly modified) and may be grouped into branching inflorescences or conflorescences. Variants of this structural plan include: – Obsolescence of pedicels (Symphionematoideae, most Proteoideae and a few Persoonioideae); – Loss of bracts (Bellendena, Fig. 132A); – The ability of the apical bud to grow on into a leafy shoot, auxotely (Persoonia, Fig. 134A); – Modification of flower-subtending bracts from scale-leaves to leaves (many Persoonia, Fig. 134A); – Compaction of the uniflorescence axis (Protea, Fig. 136A, Petrophileae and Leucadendreae); – Reduction in flower number to one (Adenanthos, a few Spatalla and Persoonia); – Thickening and sclerification of floral bracts to form a cone-like inflorescence (Petrophile, Isopogon and Leucadendron); – Extreme modification and sterilisation of lateral inflorescence branches to form an involucre of bract-like structures surrounding the female inflorescence (Aulax); – Differentiation in form of the uniflorescences from the primary inflorescence axis to form a conflorescence (Spatalla, Sorocephalus, Paranomus, some Serruria and Vexatorella); – Synorganisation of bracts and flowers to form highly regular uniflorescences (Spatalla and some Mimetes); – Synorganisation of inflorescences and brightly coloured, overtopping, inflorescencesubtending leaves to form an auxotelic conflorescence (some Mimetes); and – Enlargement and colouring of subtending bracts to form showy involucres (Protea, Fig. 136A, Orothamnus, Diastella and some Leucadendron, Serruria and Mimetes). All but a handful of species of Grevilleoideae are characterised by conflorescences in which the uniflorescence is a pair of flowers. The flowers may each be pedicellate, subtended by a floral bract, and with a common peduncle, subtended on the conflorescence axis by a common bract. The ‘grevilleoid conflorescence’ is a raceme or racemiform panicle of flower pairs (see Figs. 138A, 139A, 140B). Most authors (e.g. Haber 1960, 1961, 1966;

367

Johnson and Briggs 1963, 1975; Venkata Rao 1971) have interpreted the flower pair as a synorganised, reduced, lateral branch but an equally plausible transformation is the amplification of a first-order meristem homologous with the floral meristems of non-grevilleoid inflorescences (Douglas and Tucker 1996a). Variants on the structural plan of the grevilleoid conflorescence parallel those in other subfamilies to some extent and include: – Obsolescence of pedicels (Banksieae, most taxa of Gevuininae, some Helicieae, etc.); – Obsolescence of common peduncles, correlated with loss of floral bracts (Embothrieae, Macadamiinae, some Helicieae, Gevuininae and Dryandra) or without loss of floral bracts (most Banksiinae), assuming the transformational homologies of the flower pair suggested by Johnson and Briggs (1975); – Obsolescence of both the common peduncle and pedicels; – Compaction of the conflorescence rachis to form pseudo-umbels (Stenocarpinae); – Reduction in flower number to one (some Lambertia, Strangea and Grevillea); – Thickening and sclerification of the conflorescence axis to form a cone-like inflorescence (Banksiinae); – Shortening and broadening of the conflorescence axis to form a capitate conflorescence (Dryandra); – Enlargement and colouring of subtending bracts to form showy involucres (Telopea, Lambertia, Eucarpha and some Grevillea); – Development of the apical meristem of the conflorescence into a terminal flower (Lambertia); and – Synorganisation of multiple, strongly asymmetrical conflorescences to form superconflorescences (some Alloxylon). Two grevilleoid genera, Carnarvonia and Sphalmium, are particularly notable in having racemiform compound and simple inflorescences respectively, both lacking any vestiges of flower pairs (see, for example, Douglas 1996). However, their precise relationships and, hence, the evolutionary origin/status of these flower pairs are unclear. Flower Structure and Anatomy. Proteaceaous flowers have a single whorl of (usually 4) valvate tepals, each supplied by 1–5 vascular bundles which emerge from a gap in the floral stele. The homology of the tepals is unclear. Proteaceae

368

P.H. Weston

may be primitively monochlamydeous, having diverged from other angiosperms prior to the origin of differentiated sepals and petals. However, the male flower of Platanaceae, often interpreted as dichlamydeous (Boothroyd 1930; Cronquist 1981), suggests the possibility that the stem lineage of Proteaceae might also have been dichlamydeous. It has also been suggested that the four hypogynous nectary glands, adaxial to and alternating with the tepals, found in many Proteaceae are reduced petals (Haber 1960, 1961, 1966) but this is unlikely (Venkata Rao 1971; Douglas 1995b). Another possibility is that Proteaceae are primitively dichlamydeous and dimerous, similarly to many other basal eudicots (Soltis et al. 2003), and this suggestion is consistent with the decussate pattern of tepal initiation commonly observed (Douglas 1996; Douglas and Tucker 1996b, c). However, flowers with an actinomorphic, 5-merous perianth and androecium are found occasionally in a number of taxa with actinomorphic perianths (Venkata Rao 1971) and regularly in Eidothea hardeniana. The tepals are usually free from one another but may remain basally or largely coherent, held together by interlocking, marginal papillae. In a number of taxa (mostly in subfam. Proteoideae), however, the tepals are basally connate, forming a tube or, in the African genera Leucospermum, Protea and Faurea, a bilabiate perianth of one tepal free (or almost so) from the others and three basally to completely connate ones. Immediately inside each tepal is a stamen, with a vascular supply consisting of one or two basal vascular bundles. In species where there are two traces, these fuse to form one bundle below the anther. In Bellendena (Fig. 132B, F), each stamen is free of its subtending tepal and in Eidothea, Cenarrhenes and Dilobeia is at most minutely adnate to it. In all other Proteaceae, the filament is at least basally adnate to the subtending tepal (Figs. 135E, F, 140E) and in most species is completely so (e.g. Figs. 133C, 134H, I, 137E, F). Introrse anthers are probably primitive but all points on the continuum between introrse and fully latrorse anthers are found. The anther connective extends beyond the locules as an apiculum in many taxa (e.g. Figs. 133C, 137E, 140E), a state which is probably plesiomorphous in the family relative to the absence of an apiculum (Figs. 134H, 135D, F, 139H). Inside and alternating with the whorls of tepals and stamens in most taxa are four hypogynous nectary glands (e.g. Figs. 133D, 134G, 136I), a condition which is probably an apomorphy of

the family (Johnson and Briggs 1975). However, many taxa have fewer than four nectary glands, apparently resulting from the suppression and/or connation of individual glands. For example, the solitary, C-shaped nectary of Grevillea robusta (Fig. 139F) may result from the suppression of the posterior gland and fusion of anterior and lateral glands, and the annular nectary of Brabejum stellatifolium (Fig. 140G) from the fusion of all four equal glands. A few taxa have no nectary glands at all (e.g. Figs. 132G, 135D, 137D). There is a single (two in some plants of Grevillea banksii) carpel which develops terminally or laterally after the differentiation of the perianth and androecium (Douglas and Tucker 1996b) and is supplied by the ring of vascular bundles which emerges from the apical residuum of the floral stele (Haber 1960, 1961, 1966). One to many ovules are vascularised by branches from the two ventral bundles. In a few taxa the ovary is sessile, but more often is borne on a basal stalk (gynophore) which is usually quite short (probably the most primitive state) or more conspicuously elongated. In most taxa, the style is elongated and conspicuously exserted (Figs. 132, 133–140), with the tip of the style usually modified as a ‘pollen presenter’. This, as its name suggests, ‘presents’ the pollen to pollinators (insects or birds for most species). In the flower bud, this structure is adjacent to the anthers, which dehisce and shed their pollen onto it before anthesis. The pollen presenter surrounds the minute stigma and varies considerably in morphology between different taxa. It may be morphologically undifferentiated from the rest of the style (Fig. 138E), slightly swollen, more or less radially symmetrical and elongated (e.g. Fig. 137D), more or less radially symmetrical and shortly conical (e.g. Fig. 139D, E) or oblique to lateral and flattened (e.g. some species of Embothrieae, Gevuininae). In some taxa, specialised cells grow from the stigma or style tip and prevent pollen from falling off the style or onto the stigma (Ladd et al. 1998). A number of taxa lack a pollen presenter, presenting the pollen in the anthers, as in most other flowering plants (e.g. Figs. 132E, 133C, 134H, 135F). The stigma terminates the style (e.g. Figs. 132G, I, 134E) but appears to be lateral in flowers with an extremely oblique style tip (e.g. Figs. 133E, 135D). Since they have only one carpel, no Proteacea has strictly actinomorphic flowers but, in a substantial minority of taxa, the receptacle, perianth, androecium and nectary(s) (if present) are all radially symmetrical and the carpel is straight. Such

Proteaceae

actinomorphy is most likely to be plesiomorphous in the family. Zygomorphy of one or more of these whorls (e.g. Figs. 133, 135, 136, 139) has evolved independently in multiple lineages and in many different ways. The receptacle may be oblique (e.g. Fig. 139), the tepals may be curved (e.g. Figs. 133, 139), bent, or differentially saccate or widened, the anthers and/or anther loculi may be differentially sterilised or sized, the nectary glands may be differentially suppressed and/or fused (e.g. Fig. 139F), and the carpel may be curved (e.g. Figs. 133E, 139C, D) or bent (e.g. Fig. 135D). The direction of curvature of the carpel in Grevilleoideae is always towards its ventral surface. In a number of taxa, the style elongates so much before anthesis that a looped part of it protrudes between a pair of tepals and, in such taxa which have antero-posterior flowers (e.g. Stenocarpus, Buckinghamia), the flowers may be truly asymmetrical. The orientation of the perianth is anteroposterior in all Proteaceae, the line between the uninflorescence axis and the floral bract (or bract primordium) passing through anterior and posterior tepals (Douglas and Tucker 1996b). Carpel orientation is usually also antero-posterior, with the ventral side facing the axis (dorsiventral: Douglas and Tucker 1996b). However, the orientation of carpel and nectary glands is much more complex in Grevilleoideae, with at least three different kinds of both antero-posterior (dorsiventral, lateri-axial, ventral-dorsal) and diagonal orientation (adaxial-lateral, abaxiallateral, distal abaxial lateral; Douglas and Tucker 1996b). Interestingly, carpel orientation in some grevilleoid taxa is developmentally unstable, with mixed orientations in the same inflorescence, as in both Macadamia integrifolia and M. tetraphylla, where approximately 60% of flowers have adaxiallateral carpels and 40% have lateri-axial carpels. Such variants are potentially useful character states for phylogenetic analysis but are difficult to distinguish in mature flowers of taxa with straight carpels. In my taxonomic descriptions, I have recorded carpel orientation only for zygomorphic flowers in which it can be readily observed. Embryology. Pollen development is unusual, the plesiomorphous condition in the family being shown by taxa with triaperturate grains in which development proceeds according to ‘Garside’s Rule’ (see Blackmore and Barnes 1995; otherwise known only in some Olacaceae). The apertures form in groups of three at four points within

369

the tetrahedral tetrad, unlike those of all other triaperturate eudicots, in which apertures form in pairs at six points in the tetrad (‘Fischer’s Rule’). Development of biporate grains in Embothrium and Banksieae results from a change from simultaneous to successive cytokinesis and tetrahedral to decussate or tetragonal arrangement of microspores (Blackmore and Barnes 1995). Proteaceous ovules are bitegmic, crassinucellar, and vary in form from anatropous to orthotropous, although the majority of taxa have hemitropous ovules. They are borne on marginal placentae from subapical to sub-basal positions in the locule. In most taxa, the micropyle faces directly towards the base of the ovary and in all taxa it points at least obliquely downwards. The embryo sac is 8-nucleate and of the Polygonum type, and there is significant variation in endosperm and embryo development (Venkata Rao 1971). The endosperm is at first nuclear and remains so in a few taxa such as Cenarrhenes but in most it becomes partially or wholly cellular. In non-Grevilleoid taxa, the nucellar cells are digested gradually and the endosperm is not haustorial. In Grevilleoideae, nucellar cells around the embryo sac are digested quickly and, in most taxa, the endosperm develops haustoria. In all taxa excepting Bellendena and Persoonia (and probably other Persoonioideae), the endosperm is resorbed at seed maturity. Proteaceous cotyledons show systematically useful variation. Toronia and most species of Persoonia are readily distinguished by having three or more cotyledons; some species of Persoonia have up to nine. Other taxa with radially symmetrical embryos (e.g. species of Hicksbeachia and Isopogon) also produce a small minority of embryos with three cotyledons. All Grevilleoideae have basally auriculate cotyledons (well illustrated in George’s revision of Banksia) or further transformed states of this condition. Thus, in Panopsis cinnamomea the auricles are fused, rendering the hemispherical cotyledons peltate. In Cardwellia sublimis, which has large, exceptionally wide cotyledons, the auricles are relatively tiny, basal teeth superficially unlike the auricles of other taxa. In the fleshy cotyledons of Hollandaea, the auricles seem to have been secondarily lost altogether. Pollen Morphology. Dettmann and Jarzen (1998) reviewed the fragmented literature on the morphology of proteaceous pollen, but from a palaeontological, not a cladistic perspective. Johnson and Briggs (1975) considered that pro-

370

P.H. Weston

teaceous pollen is primitively triporate, triangular in polar view, isopolar, with the pores aligned in the equatorial plane. The most notable transformations from this putatively ancestral state include the colpoidate apertures found in Beauprea, the biporate grains of tribe Banksieae and Embothrium, the spherical grains of Aulax and Franklandia and the grossly anisopolar grains of some species of Persoonia (see also Dettmann and Jarzen 1998). Variation in exine structure, especially that of the apertures and sculpturing of the tectum and supratectal elements, is extensive but is probably moderately to highly homoplasious. Detailed studies of variation in exine characters within particular clades (e.g. Feuer 1990) have shown that it may be phylogenetically informative below, at and above generic level and, in some cases, provides synapomorphies characterising subtribes. Karyology. Variation in chromosome number and morphology has been surveyed almost comprehensively at generic level (see Stace et al. 1998 for a review). Haploid numbers of n = 5, 7, 10, 11, 12, 13, 14, 26 and 28 are known. Chromosome size tends to be fairly homogeneous within species and varies from tiny (e.g. a mean length of 1.0 µm in Brabejum stellatifolium) to very large (e.g. a mean length of 14.4 µm in Placospermum coriaceum). Chromosomes are mostly metacentric to submetacentric but some taxa have a minority of subtelocentrics. Stace et al. (1998) proposed a model of chromosome evolution involving no polyploid events other than autapomorphic doublings in a few tetraploid species, but a combination of dysploid increases and decreases from an ancestral karyotype of x = 12. This hypothesis accounts, to some extent, for variation in chromosome size as well as number in Proteaceae and their sister group, Platanus. These authors also argue that hypotheses invoking palaeopolyploidy (see Venkata Rao 1971; Johnson and Briggs 1975) predict the frequent occurrence of paralogous nuclear genes (e.g. isoenzymes) in supposedly palaeopolyploid taxa and note that this prediction has so far not been borne out in studies of allozyme variation. Pollination. Known pollinators in Proteaceae include insects such as bees, beetles, flies, butterflies and moths, birds such as honeyeaters, sunbirds, sugarbirds and hummingbirds, and mammals, including rodents, small marsupials,

elephant shrews and bats, as in Banksia and Protea (see Collins and Rebelo 1987 on Australian and African Proteaceae; Maynard 1995 especially on Australian insect-pollinated clades). Taxa which are either known to be bird- or mammal-pollinated or have flower morphology consistent with vertebrate pollination are nested relatively well within the phylogenetic tree in Fig. 131, so entomophily is probably plesiomorphous, with vertebrate pollination arising independently in a number of different lineages (Johnson and Briggs 1975). Reproductive Systems. Goldingay and Carthew (1998) review the literature on breeding and mating systems, which emphasizes a few shrubby or economically important genera, particularly Banksia. The anthers dehisce at or before anthesis. The stigma may vary from ‘wet’ to ‘dry’ even within genera, and may be receptive at anthesis or attain maximum receptivity up to 48 h later. Four genera are dioecious (Dilobeia, Aulax, Leucadendron, Heliciopsis) and a further 11 genera are either overtly andromonoecious (Placospermum, Eidothea, Stirlingia, Sphalmium, Musgravea, Austromuellera) or include at least some cryptically andromonoecious species (Xylomelum, Helicia, Banksia, Dryandra, Hakea). A few rare species are sterile, persisting entirely through vegetative spread (e.g. Lomatia tasmanica, Hakea pulvinifera). The remaining taxa appear to be bisexual. Species vary from fully to partially self-compatible to fully self-incompatible, and such variation occurs between closely related species in several genera and even within some species of Banksia. Some partially self-compatible species appear to outcross preferentially. Selfincompatibility involves rejection of self-pollen at the stigma in some taxa but in the lower style in others; it would be interesting to know if different mechanisms are involved. Early-acting inbreeding depression may also be responsible for the failure of self-pollinated flowers to set fruit. Percentage fruit set is low in many taxa, especially in those which have both many-flowered inflorescences and large fruits and, in some of these, selective fruit abortion has been demonstrated. Fruit and Seed. All fruits of Proteaceae develop from a solitary carpel, but are morphologically diverse. Those of Bellendena, Symphionemoideae and most Proteoideae are dry, indehiscent and one-seeded. These are usually described as nuts or achenes, although neither term is strictly correct.

Proteaceae

Other Proteoideae and tribe Persoonieae have succulent fruits which, at least in the latter, are drupes, in the strict sense of the term, with a bony endocarp developed from the inner epidermis of the ovary wall. Placospermum and most Grevilleoideae have dehiscent fruits which are true follicles but other grevilleoids have indehiscent fruits variously termed ‘drupes’ (but lignified tissues are derived from the inner mesocarp) or ‘achenes’, depending on whether or not the mesocarp includes a fleshy layer. The endocarp of Persoonia develops from the inner epidermis of the ovary whereas the seemingly similar woody tissue in Hicksbeachia develops from the inner mesocarp (Johnson and Briggs 1975; Strohschen 1986a, b, c). Seeds may be winged or wingless, flattened to globular, variously shaped, and sometimes separated from each other by dissepiments developed from the ovary wall or the integuments. There is some variation in cotyledon number (see above). Strohschen (1986a, b, c) confirmed earlier reports that the seed coats of Proteaceae develop from the chalaza and outer integument. More significantly, she also noted (as reported by Netolitzky 1926) that the inner epidermis of the outer integument forms a distinctive layer of cells containing calcium oxalate crystals. Manning and Brits (1993) also found a homologous crystalliferous testal layer in their study of seed development in Leucospermum cordifolium, and drew attention to the earlier, neglected work of Piet Jordaan in which the development of this layer had been accurately described in several species of Leucospermum and Leucadendron. Since this crystal layer fuses to the ovary wall in many Proteoideae, some (Venkata Rao 1971; Johnson and Briggs 1975) erroneously concluded that their fruits possessed a crystalliferous endocarp. Since the crystalliferous testal layer is widespread in the family, Manning and Brits (1993) concluded that it is plesiomorphic there, and so its absence must be secondary. Johnson and Briggs (1975) argued that Proteaceae primitively possessed follicular fruits with numerous winged seeds. However, the small, oneseeded indehiscent fruits of Platanus are similar to those of Symphionematoideae and most Proteoideae, and so are probably plesiomorphous in Proteaceae. Hence, the follicle of Placospermum is likely to have evolved independently of those of Grevilleoideae, which is not surprising, given their structural dissimilarity. Manning and Brits’ (1993: 147) conclusion that “complete re-evaluation

371

of published accounts of the nature of the fruit and seed covering structures in Proteaceae is required before any meaningful phylogenetic discussions can be entertained” is a reasonable assessment of our understanding of character phylogeny of these structures. Serotiny, the accumulation of seeds by a plant in its canopy, has evolved independently in several different lineages of Proteaceae and this phenomenon has spawned an impressive literature. Serotinous plants all live in fire-prone environments, and release their seeds after the death of the fruit-bearing shoot or whole plant, although in some taxa a succession of wet/dry cycles is also required. Serotiny is usually interpreted as an adaptation for both protecting seeds from fire and subsequently releasing them onto a relatively fertile, vacant substrate. Six serotinous Australian genera of Grevilleoideae produce fire-resistant, woody fruits (see Lamont and Groom 1998). The African Proteoideae Aulax, Protea and Leucadendron include serotinous species which protect their thin-walled fruits behind woody bracts or analogous structures (for the ecology of these structures, see Bond 1985). The Australian proteoid genera Isopogon and Petrophile are also serotinous. Dispersal. A number of authors have speculated on the means of dispersal of proteaceous fruits and seeds (see, for example, Weston and Crisp 1996; Rourke 1998), although there are few empirical studies and this literature is scattered. Elaiosomes attached to seeds or fruits which are dispersed by ants occur in some Leucadendron and Grevillea, and in all Leucospermum, Mimetes, and Orothamnus (see, for example, Bond and Breytenbach 1985; Auld and Denham 1999). Light, plumose indehiscent fruits as well as winged seeds released from follicular fruits have obvious aerodynamic properties and some of these are predominantly winddispersed (see, for example, Bond 1988; Hammill et al. 1998). Succulent fruits in Proteaceae vary greatly in size, from the tiny drupes of Beaupreopsis to the almost mango-like fruits of some species of Heliciopsis. Flying and non-flying mammals and birds have all been suggested as potential dispersers of these but, so far, only flying birds have been implicated in the few published empirical studies (e.g. Buchanan 1989). The fruits or seeds of many Proteaceae are gathered by rodents in Australia and Africa. These granivores accumulate caches of edible seeds and, although most are probably eaten, a small minority probably ‘escape’ and germinate.

372

P.H. Weston

Phytochemistry. Johnson and Briggs (1975) briefly reviewed the variation in phenolic compounds, fatty acids of seed oils, free amino acids and aluminium accumulation, and concluded that “available data are insufficient for a critical assessment of relationships within the family”. Subsequent surveys of cyanogenesis (Swenson et al. 1989), phenolic spiro-bislactones, nectar sugars (Nicolson and Van Wyk 1998) and polyol variation (Bieleski and Briggs 2005) do not inspire optimism in micromolecular data as a viable source of independent phylogenetic characters. However, a well-corroborated phylogeny might help illuminate the functional aspects of micromolecular variation in the family. Some compounds do provide synapomorphies for known clades. For example, the sister genera Protea and Faurea (tribe Proteeae) are the only taxa known to produce xylose as a major nectar sugar (Nicolson and Van Wyk 1998) and are also characterised by unusually high concentrations of polygalactol, a polyol sugar (Bieleski and Briggs 2005). Subdivision and Relationships Within the Family. Until the 1960s, suprageneric taxa recognised in Proteaceae tended to be monothetic, the classifications resembling identification keys more than phylogenetic systems. For example, the primary division which Robert Brown (1810) used in his key to genera, separating taxa on the basis of their possession of dehiscent or indehiscent fruits, was reflected in all infrafamilial classifications prior to Johnson and Briggs’ (1963) first phylogenetic monograph of the family. The suprageneric classification adopted in this treatment (Fig. 131) is novel, reflecting the results of recently conducted molecular systematic analyses (Hoot and Douglas 1998; Barker et al. 2002; Weston and Barker 2006). Of previously published, morphology-based classifications, it most closely resembles that of Douglas (1995a) but there are significant differences even from that system, and few of its higher taxa are characterised by unique morphological character states. Johnson and Briggs (1963) recognised two polythetic subfamilies, the circumscription of which was close to those of earlier classifications. Their Grevilleoideae are monophyletic, with a circumscription essentially identical to that adopted here, but molecular data suggest that their Proteoideae are polyphyletic. Of the seven polytypic tribes which they recognised, four appear to be monophyletic. Venkata Rao’s (1971)

two subfamilies are almost identical to those of Johnson and Briggs (1963), differing only in the inclusion of Placospermum (treated as a genus incertae sedis by Johnson and Briggs) in his paraphyletic subfamily Proteoideae. Venkata Rao also proposed a radically modified tribal-subtribal classification but this has largely been ignored (see also Johnson and Briggs 1975). Of Venkata Rao’s eight polytypic tribes and three polytypic subtribes, only three seem to be monophyletic. Johnson and Briggs’ (1975) widely accepted classification was much more highly resolved than its predecessors, with five subfamilies, 11 tribes and 28 subtribes; of its 30 polytypic suprageneric taxa, 12 have been corroborated by molecular evidence as monophyletic. Douglas’ (1995a) classification differs from that of Johnson and Briggs (1975) only in having two, new, monotypic subfamilies. Affinities. Prior to 1993, the affinities of Proteaceae were poorly understood, and the family was placed in a diverse range of taxa in different classification systems. However, molecular phylogenetic analyses published over the past 15 years have resolved their relationships. The family is sister group of Platanaceae, and these sister to Nelumbonaceae (Soltis et al. 2000), the three families constituting the order Proteales (APG II 2003 and references therein). Proteales are one of several eudicot lineages which branch below the core eudicots. Platanaceae and Nelumbonaceae have similar trichome bases (Carpenter et al. 2005), although platanaceous trichomes are compound candelabriform hairs, unlike the three-celled hairs of Proteaceae. The Angiosperm Phylogeny Group (APG II 2003) suggests that Platanaceae could be included in Proteaceae because Platanaceae consist of only one extant genus and are therefore a redundant grouping. However, morphological variation between the Proteaceae sensu stricto and Platanaceae is much greater than that within either family, and combining Platanaceae with Proteaceae would render the resulting family very difficult to characterise morphologically. For this reason, I recommend that the traditional circumscription of Proteaceae be retained. Distribution and Habitats. Proteaceae are a classic Gondwanic family. Perhaps the most interesting aspect of the family’s distribution is the pattern of repeated disjunctions, linking isolated Gondwanic landmasses, shown by at least 12 dif-

Proteaceae

373

Fig. 131. Proteaceae. Supertree of genera of Proteaceae produced by Weston and Barker (2006), synthesising the results of published and unpublished molecular phylogenetic analyses of the Proteaceae (Hoot and Douglas 1998; Mast and Givnish 2002; Barker et al. 2002; Weston, Barker and Downs, unpubl. data). Numbered rectangles on the righthand side refer to higher taxa recognised in this treatment, signified by the Roman numerals used for subfamilies, digits for tribes and lowercase letters for subtribes. For example, the rectangle to the right of Bellendena, I, refers to subfamily I, Bellendenoideae. Similarly, the three rectangles to the right of Roupala, V, V.1 and V.1.a, refer respectively to subfamily V, Grevilleoideae, tribe 1, Roupaleae, subtribe a, Roupalinae

374

P.H. Weston

ferent taxa (Johnson and Briggs 1975; Weston and Crisp 1996). For example, two of the eight South American genera (Lomatia and Orites) occur also in Australia and the other six are all closely related to genera which occur elsewhere in the southern hemisphere. Similarly, the African taxa Aulax, subtribe Leucadendrinae and Brabejum are sister to the Australian Petrophile, Adenanthos and the neotropical genus Panopsis. These distributional patterns are consistent with a history of diversification prior to the major phase of Gondwanic fragmentation during the Cretaceous, starting over 100 million years ago. Although fossil evidence of the family is not quite that old, it has been broadly accepted, since the triumph of plate tectonics in geology, that Proteaceae were well diversified by the time that Africa, Madagascar and India rifted from the rest of Gondwana (Johnson and Briggs 1975; Weston and Crisp 1996). However, detailed cladistic biogeographic support for a causal role for continental drift in the vicariant history of the family exists only for Lomatia and subtribe Embothriinae (Weston and Crisp 1996 and references therein). The vicariant model has recently been challenged by palaeontologists (e.g. Hill et al. 1995 and references therein) and very recently by the results of molecular dating analyses, which suggest that the African Proteaceae are too young to have evolved in situ (Austin Mast, Frank Rutschman and Nigel Barker, pers. comm.), implicating trans-oceanic dispersal in their biogeographic history. Proteaceae occur in a variety of habitats, ranging from open, shrubby or grassy communities to tropical rainforests. Most species occur in fire-prone, sclerophyllous heathlands, woodlands or forests, reflecting the high species diversity of clades which appear to have radiated prolifically in response to the drying of Australia and southern Africa during the late Tertiary. Although Johnson and Briggs (1975) thought that the ancestral Proteaceae were rainforest trees, the only published mapping of habit and habitat features onto a molecular phylogeny (Jordan et al. 2005) is weakly inconsistent with this idea. Most Proteaceae prefer acidic, moderately to well-watered but well-drained soils which tend to be deficient in nutrients, particularly phosphorous. Soils derived from plutonic igneous rocks and sandstones and metasediments derived from these often support diverse proteaceous communities. They occur from sea level to over 3,800 m altitude. A number of species from south-eastern Australia

(including Tasmania) and the southern Andes thrive in subalpine communities where they are buried under snow for considerable periods during the winter. Parasites. A diverse range of arthropods, nematodes, fungi, oomycetes and bacteria parasitize Proteaceae. Among the several mistletoes in the family Loranthaceae growing on Proteaceae, some specialise on Proteaceous hosts; for example, Amyema gibberulum is found only on species of Hakea and Grevillea. The most destructive pathogen of both cultivated and wild Proteaceae is the oomycete Phytophthora cinnamomi, which causes fatal root rot in many, but not all species (for Protea, Leucadendron and Leucospermum, and more briefly, other genera, see Crous et al. 2004). This pathogen has a wide host range and has proved to be particularly virulent where it has been introduced into areas which have Mediterranean climates. It is listed under the Australian Environment Protection and Biodiversity Conservation Act 1999 as a “key threatening process” not only to native vegetation but also to some native animals which are dependent on Phytophthora-sensitive plants as sources of food and shelter. South-western Australia, which has no native pathogenic species of Phytophthora, has many species of Proteaceae which are highly susceptible to attack by P. cinnamomi, and some areas have been almost denuded of native Proteaceae (and other woody plants) by this pathogen. Crous et al. (2004) consider the anamorphic hyphomycete Fusarium oxysporum to be the second most destructive pathogen of cultivated Proteaceae in southern Africa. This fungus causes ‘Fusarium wilt’ of the shoot system, resulting from the destruction of vascular tissue in the root system. The forma specialis of Fusarium oxysporum which parasitizes Proteaceae has not been recorded as an environmental problem, nor has it been found outside of southern Africa but is an economically damaging pathogen of cut-flower orchards there. Crous et al. (2004) describe numerous other species of Ascomycetes which parasitize Proteaceae, most of which are judged to be of little or no economic (and presumably ecological) importance. However, species of several genera, including Botryosphaeria (leaf spot, stem canker), Botrytis (stem canker), Calonectria (leaf spot, root rot), Coleroa (leaf spot), the form genus Colletotrichum (stem canker, shoot dieback, leaf spot), Drechslera (leaf, stem and flower blight), Elsinoë (scab disease), Lep-

Proteaceae

tosphaeria (leaf spot) and Mycosphaerella (leaf spot) cause economically damaging, sometimes catastrophic diseases of cultivated Proteaceae. Most of these have wide host ranges and geographic distributions but only Botryosphaeria is known to cause serious environmental problems, and this only in south-western Australia. Some basidiomycetes, especially species of Armillaria and the form genus Rhizoctonia, are also responsible for root rotting diseases. Armillaria luteobubalina, an Australian native, is mainly responsible for damage to commercial crops there, while species native to the northern hemisphere are responsible for cases of Armillaria root rot in South Africa. Palaeobotany. Proteaceae have a rich fossil record but the interpretation of this record has presented several challenges. Firstly, few distinctive, family-level synapomorphies are commonly fossilised. Evidence of tetrad formation according to ‘Garside’s Rule’, the only palynological feature which is almost unique to Proteaceae as a whole (see Embryology above), is, unfortunately, rarely preserved. Distinguishing fossil proteaceacous pollen from the superficially similar grains of some Amaranthaceae, Caryophyllaceae, Santalaceae, Sapindaceae and Symplocaceae has relied only on detailed assessment of overall similarity with the pollen of particular extant taxa. The combination of brachyparacytic stomata and characteristic trichome bases (see Vegetative Anatomy above) is diagnostic for the family (excluding the basal, or near basal genus Bellendena), and this has at least enabled the recognition of proteaceous macrofossils in which these details have been preserved (Carpenter and Jordan 1997). Secondly, the absence of a detailed, explicit, morphology-based phylogenetic framework for the whole family has also been a major impediment. Most identifications below family level have been made by matching fossils with comparable structures of the most similar, extant taxa, an approach which is vulnerable to being misled by both symplesiomorphy and convergence (see, for example, Weston and Crisp 1996). Exceptions include leaf fossils which can be assigned to Banksieae (e.g. Carpenter and Jordan 1997), based on having two features (stomata in areoles and a specialised trichome type) which are unique within the family. Similarly, some leaf fossils from the Oligocene in Tasmania have, in addition to venation and cuticular anatomy consistent with a subclade of Orites, hypodermal

375

structures which are synapomorphic for that clade (Jordan et al. 1998, 2005). Proteaceous fossils have been found on all major Gondwanic landmasses, and the proteaceous palaeofloras of Australia, New Zealand and temperate South America and the Antarctic Peninsula have all been recently reviewed (Hill et al. 1995; Pole 1998; Askin and Baldoni 1998). The record of putatively proteaceous fossil pollen is diverse by the late Cretaceous and remains variably so throughout the Cenozoic. The mid-Cretaceous (Cenomanian-Turonian) pollen grains of Triorites africaensis from northern Africa and Peru are the oldest fossils attributed to the family (Ward and Doyle 1994). Some proteaceous palynomorphs are relatively abundant during the late Cretaceous to early Oligocene in south-eastern Australia and during the Eocene in Western Australia; at some sites, proteaceous grains make up 35–40% of the fossil pollen flora (Dettman and Jarzen 1998). This contrasts with the very low percentages in surface samples from modern sites at which Proteaceae now predominate. The macrofossil record, however, is nonexistent until the late Palaeocene, some 20 million years younger than the first pollen records, and Proteaceae make up only a small proportion of the fossil leaves in fossil macrofloras, despite often being among the best preserved. It has been suggested that these fossil grains, relatively small, were produced by wind-pollinated Proteaceaceae which are now extinct (Hill et al. 1995). Yet another anomaly is that pollen attributed to several extant taxa appears for the first time in the late Cretaceous but is absent from Palaeocene deposits. If correctly identified, these palynomorphs must have survived through the Palaeocene in areas distant from sites of fossil preservation. Some problems to which the proteaceous fossil record has been applied include estimating the timing of diversification in the family, reconstructing centres of origin and dispersal routes, testing hypotheses for the evolution of scleromorphy, reconstructing palaeoenvironments and, very recently, calibrating molecular phylogenetic dating analyses. According to Dettmann and Jarzen (1998 and references therein), many of the groups now recognised as tribes and subtribes and even a few extant genera had differentiated by the late Cretaceous. Outside of northern Gondwana, the oldest records of putatively proteaceous fossils are of Turonian age in south-eastern Australia, Campanian in New Zealand and Antarctica, Maastrichtian in Western Australia and Palaeocene in temper-

376

P.H. Weston

ate South America and north-eastern Australia (Askin and Baldoni 1998; Dettmann and Jarzen 1998; Pole 1998). Proteaceous diversity peaked in south-eastern Australia during the Maastrichtian, according to the palynological record, then suffered a series of dramatic declines in the Palaeocene and Oligocene, interspersed with gradual increases through the Eocene and Miocene (Dettmann and Jarzen 1998). Diversity was greatest at later times in other places: during the Eocene in New Zealand, Miocene in north-eastern Australia, and Oligocene in Western Australia (Pole 1998; Dettmann and Jarzen 1998). Whether these patterns accurately reflect historical processes depends partly on the assumption that the fossil record of sampled areas is unbiased. However, there is little doubt that some areas, such as New Zealand and Tasmania, had much higher proteaceous diversity in the past (e.g. Jordan et al. 1998) and that the distributions of many taxa have changed dramatically over time. Dettmann and Jarzen (1998 and references therein) used the fossil pollen record to ‘trace’ dispersal routes, from a centre of origin in northern Gondwana through northern Australia to south-eastern Australia, the postulated ‘centre of diversification’, and thence to other parts of Gondwana. Weaknesses of this narrative include the evident falsity of a central assumption (virtual completeness of the fossil record) and the dubious identity of some key fossils, most notably Triorites. A number of authors have incorporated data on proteaceous fossils in palaeoecological studies. For example, Carpenter and Jordan (1997) found a diverse array of proteaceous taxa, along with members of Podocarpaceae, Araucariaceae, Casuarinaceae, Lauraceae, Nothofagaceae and Cunoniaceae, in a Tasmanian Oligocene palaeoflora. They used variation in leaf morphology amongst the proteaceous fossils to infer that the palaeoenvironment was an ecologically complex landscape with great variations in incident sunlight, but with relatively low variation in temperature and consistently high rainfall and humidity (Carpenter and Jordan 1997:560). Ecological interpretation of fossil proteaceous palynofloras is more difficult because ecological characteristics can rarely be inferred directly from pollen morphology. Such inference requires the assumption that a particular fossil palynomorph be produced by an ecologically uniform plant group. Although it might seem reasonable to make this assumption for subgenera of Nothofagus, it would be misleading if applied to ecologically variable taxa such as Orites, Stenocarpus or Grevil-

lea, particularly considering the apparently high levels of extinction within the family during the Cenozoic. The Eocene palynofloras of southern Australia, in which Petrophile and Xylomelum co-occur with Nothofagus, suggest that these sites were either ecological mosaics even more heterogeneous than that described by Carpenter and Jordan, or that the assumption of ecological uniformity for genera such as Petrophile is false. Economic Importance. Proteaceae have long been used by various indigenous groups of people as sources of food, medicine, tannins and other dyes, firewood and timber (Sleumer 1955; Vogts 1982; Orchard 1995; Prance et al. 2006). The succulent mesocarps of Persoonia fruits were eaten by Australian Aborigines and the seeds of some species of Brabejum, Finschia, Gevuina, Floydia, Hakea, Hicksbeachia, Macadamia and Panopsis were and, in some cases, still are eaten by indigenous people, some after being detoxified. Young shoots of Helicia serrata and H. robusta are reported to be eaten by people in Java. The inflorescences of several Australian genera were used as sources of nectar by Aborigines. Traditional medicinal uses have been reported for some species of Banksia, Faurea, Grevillea, Hakea, Helicia, Heliciopsis, Oreocallis, Persoonia, Protea, Roupala and Xylomelum. Most commonly, infusions are prepared from roots, bark, leaves or flowers. Depending on the species, these are used externally as a topical application for skin complaints or internally as a tonic, aphrodisiac or lactogenic or to treat a variety of ailments including headaches, coughs, dysentery, diarrhoea, indigestion, stomach ulcers and kidney problems. The woods of many arborescent species are attractively figured, durable and readily worked, and have been put to traditional uses too numerous to list. Commercial use of Proteaceae probably commenced in the late 18th century in South Africa, where Protea nitida was logged for timber and Leucadendron plantations were established to supply firewood and tanning bark. In the early 19th century, commercial logging of large, arborescent species such as Grevillea robusta commenced. Logging of native forests in which such species grow was suspended in South Africa in 1939 and ceased in Australia in the 1980s and in New Zealand in 2002, but continues in parts of South America, Southeast Asia and the south-western Pacific. Although a number of proteaceous species show silvicultural potential,

Proteaceae

only Grevillea robusta is grown in plantations, in montane tropical Asia, Africa and America, for its wood (for timber and fuel) and also as shade trees in tea and coffee plantations. The commercial significance of Proteaceae is now dominated by trade in macadamia nuts and, to a much lesser extent, the sale of cut flowers and potted plants. World production of macadamia nuts (from Macadamia integrifolia, M. tetraphylla and their hybrids) in 2001/2002 was estimated at 106,800 tonnes (United States Department of Agriculture 2004), a 15-fold increase over the corresponding value for 1987 (Orchard 1995). Australian growers, who account for 30% of world production, received US$ 1.21 per kg for their product, amounting to US$ 130 million in sales. Reliable data on the total economic value of the proteaceous cut-flower industry are lacking but the total area planted with these crops in 2002 has been estimated to be 10,000 hectares (Crous et al. 2004). The wholesale value of production from Australian plantings, which amounted to about 10% of world production in 2002, was projected to reach US$ 12 million in 2000 (Karingal Consultants 1997). Conservation. The already outdated 1997 IUCN Red List of Threatened Plants (Walter and Gillett 1998) lists 371 threatened taxa of Proteaceae (including four monotypic genera), of which five are considered extinct, 77 endangered, 94 vulnerable, 190 rare, and five insufficiently known. Application of assessment criteria is inconsistent, and thus Prance et al. (2006) consider that 31, rather than three, neotropical species are threatened. In contrast, none of the 58 Papua New Guinean species is even listed as rare, but this may not reflect the real situation. Recovery plans have been published for only a small minority of threatened taxa but these give a good indication of the range of processes which could cause the decline of rare Proteaceae. Such processes include habitat destruction or fragmentation caused by land clearing for urban or agricultural development, inappropriate fire regimes, diseases (see Parasites above), competition with naturalized plants, soil degradation caused by compaction, salinization or pollution, selective harvesting, trampling by people and other animals, grazing by herbivores, drought, inbreeding depression and vandalism. To these should be added the spectre of climate change, which could threaten even many of the common species.

377

Key to the Genera 1. Leaves opposite or whorled or pseudo-whorled 2 – Leaves alternate 12 2. Fruit falling at maturity, either indehiscent or a tardily dehiscent, leathery, globose follicle 3 – Fruit persistent on plant for several to many years, follicular, woody or cartilaginous 10 3. Inflorescence a dense axillary capitulum or short raceme or a leafy raceme which grows on into a vegetative shoot; flowers not paired; style tip not swollen, not functioning as a pollen presenter 4 – Inflorescence a raceme of flower pairs; style tip swollen, functioning as a pollen presenter 5 4. Inflorescence a raceme which may or may not grow on into a vegetative shoot; staminal filaments largely or wholly adnate to tepals; hypogynous glands 4; fruit a drupe; shrubs and small trees, mostly of sclerophyllous communities; Australia 6. Persoonia – Inflorescence a dense axillary capitulum; staminal filaments free or adnate to tepals at their very base; hypogynous glands absent; fruit a drupe with prominent longitudinal ridges on the inner surface of the endocarp; rainforest trees; E Australia 9. Eidothea 5. Perianth strongly zygomorphic; hypogynous glands free, 4 or 2; pericarp fleshy; E Australia 39. Triunia – Perianth slightly zygomorphic or actinomorphic; hypogynous glands connate, forming a ring around ovary; pericarp leathery to woody 6 6. Flower pairs pedunculate; flowers pedicellate (‘pedicels basally connate’) 45. Helicia – Flower pairs sessile; flowers pedicellate (‘pedicels free’) 7 7. Fruit ellipsoidal, densely ferruginous-pubescent; bracts of flower pairs obovate, conspicuous in bud, caducous before anthesis; South Africa 67. Brabejum – Fruit ± globose, glabrous or minutely tomentose; bracts of flower pairs ovate to oblong to triangular, inconspicuous 8 8. Testa bony, extremely hard, 0.8–10 mm thick; intermediate (and sometimes adult) leaves with toothed margins; Australia 65. Macadamia – Testa brittle or leathery, 1–2 mm thick; leaves with entire margins 9 9. Adult leaves mostly in whorls of 5 or 6; Australia, Sulawesi 65. Macadamia – Adult leaves opposite or in whorls of 4; South and Central America 66. Panopsis 10. Inflorescence a seven-flowered head, or reduced to a single flower, surrounded by a conspicuous involucre; fruit beaked, often bearing conspicuous horns and spines; Australia 43. Lambertia – Inflorescence not consistently one- or seven-flowered, lacking an involucre; fruit not beaked nor horned nor spiny 11 11. Inflorescence raceme-like, with a non-woody axis; follicle symmetrical, ellipsoid to pear-shaped; Australia 44. Xylomelum – Inflorescence cone-like, with a woody axis; follicle asymmetrical, laterally compressed; Australia 51. Banksia 12. Leaves palmately compound with 5 radiating segments, some or all of the segments often themselves

378

– 13. – 14. – 15. – 16. – 17. – 18.

– 19.

–

20. –

21. – 22.

–

23.

P.H. Weston pinnately compound or trifoliolate; NE Australia 35. Carnarvonia Leaves simple or pinnately or bipinnately or dichotomously compound 13 Leaves dichotomously dissected or compound 14 Leaves either entire or with dentate margins or 1–3pinnately compound or divided 21 Leaves prominently dotted with glands; SW Australia 14. Franklandia Leaves lacking glands 15 Fruit a persistent, woody follicle; hypogynous gland solitary, anterior, crescentic 62. Hakea Fruit falling at maturity, an achene or drupe; hypogynous glands 4 or absent 16 Dioecious trees; female flowers with vestigial style; fruit a puberulous drupe; Madagascar 12. Dilobeia Bisexual or andromonoecious shrubs; bisexual flowers with well-developed style; fruit an achene 17 Perianth strongly zygomorphic; adaxial anther sterile; lateral anthers 1-locular; SW Australia 17. Synaphea Perianth actinomorphic or the adaxial tepal shorter than the others; anthers all fertile, 2-locular 18 Plants morphologically andromonoecious; bisexual flowers with style tip broadly cupular or vestigial, not functioning as a pollen presenter; SW Australia 15. Stirlingia Plants and flowers morphologically bisexual; style tip swollen but not cupular, functioning as a pollen presenter 19 Inflorescence compound, a spike-like conflorescence of lateral, mostly 4-flowered uniflorescences, with flowers subtended by leathery but not conspicuously imbricate bracts; hypognynous glands present; South Africa 26. Paranomus Inflorescence a simple capitulum, the bases of the flowers buried in a cone-like structure formed by the imbricate, fleshy floral bracts; hypogynous glands absent 20 Cone scales falling with the fruits; achene villous, not compressed; Australia 22. Isopogon Cone scales firmly adhering to the inflorescence axis and opening to release the fruits; achene usually basally or marginally long-haired, compressed; Australia 18. Petrophile Adult leaves paripinnate 22 Adult leaves simple or imparipinnate or bipinnate or tripinnate 23 Ovules 10–14; fruit a woody follicle, containing 10–14 winged seeds; inflorescence a richly branched panicle of flower pairs; leaflets entire; NE Australia 73. Cardwellia Ovules 2; fruit drupaceous, with pericarp differentiated into bony inner layer and succulent outer layer, containing 1(–2) unwinged seeds; inflorescence a pseudo-raceme or 2–3-branched panicle of flower pairs; leaflets toothed or entire; South America 75. Euplassa Flowers not borne in pairs on the inflorescence axis (most easily observed in bud); inflorescence either simple or compound: if simple, the inflorescence a raceme (sometimes leafy) or spike (sometimes cone-like) or umbel, or capitulum, or reduced to one or two flowers; if compound, then the inflorescence a panicle (sometimes with lateral branches bearing

–

24. – 25. – 26. – 27. – 28.

– 29. – 30. – 31. – 32. –

33. – 34.

– 35.

sterile flowers) or with flowers borne in lateral clusters of 3–9 along the inflorescence axis, or singly in lateral ‘involucres’ 24 Flowers borne in sessile or pedunculate pairs on the inflorescence axis (most easily observed in bud); inflorescence a pseudo-raceme or pseudo-spike or pseudoumbel of flower pairs or a panicle of such inflorescences 68 Perianth zygomorphic 25 Perianth actinomorphic 40 Pedicels absent; ovule 1 26 Pedicels present; ovules > 1 35 Involucral bracts conspicuous, relatively large, usually colourful 27 Involucral bracts inconspicuous or absent 29 Inflorescence a subterminal conflorescence, composed of aggregated, axillary uniflorescences; South Africa 31. Mimetes Inflorescence a simple, axillary or terminal capitulum, not aggregated; South Africa 28 Claws of three adaxial perianth segments fused to form a sheath; inflorescence 2–30 cm in diameter; achene densely (covered?) in long straight hairs; Africa 20. Protea Claws of perianth segments free except at their bases; inflorescence 1–2 cm in diameter; achene glabrous or puberulous; South Africa 32. Diastella One anther and two half anthers abortive, the loculi of adjacent anthers coherent in bud, each half-anther apparently 1-locular; hypogynous glands absent 30 Anthers not as above, either all developed and fully 4-locular or 1 infertile; hypogynous glands present 31 Lower anther abortive; perianth white, blue, grey or pink; leaves entire; Australia 16. Conospermum Upper anther abortive; perianth yellow; leaves usually dissected; SW Australia 17. Synaphea Inflorescence simple, a spike, a capitulum or reduced to a single flower 32 Inflorescence compound, a conflorescence of 1–4flowered uniflorescences 34 Inflorescence reduced to a single flower; all four perianth claws fused for most of their length to form a slit tube; Australia 23. Adenanthos Inflorescence multi-flowered; three adaxial perianth claws fused to form a sheath, the abaxial perianth claw separated from the adaxial sheath for most of its length 33 Inflorescence a spike; leaves entire, lacking glands; Africa or Madagascar 21. Faurea Inflorescence a capitulum; leaves entire or lobed, with conspicuous glands on the tips; Africa 30. Leucospermum Leaves monomorphic and dissected, or dimorphic with dissected intermediate leaves and entire, spathulate adult leaves; uniflorescences mostly 4-flowered; achenes glabrous with a ring of hairs around the base; South Africa 26. Paranomus Leaves monomorphic, entire; uniflorescences 1- or 3-flowered; achenes pubescent; South Africa 29. Spatalla Upper stamen fertile, the other 3 reduced to staminodes; plant andromonoecious, most flowers lacking a carpel; fruit a follicle in which the numerous winged

Proteaceae

–

36.

– 37.

– 38. – 39.

–

40. – 41.

–

42.

–

43. –

44.

seeds are oriented transversely; large rainforest trees; NE Australia 2. Placospermum All stamens fertile, or rarely 1 or all stamens infertile; all flowers usually bisexual; fruit either not follicular or follicular but with longitudinally oriented seeds or with 2 transversely oriented seeds; shrubs or trees 36 Carpel about half length of perianth, hooked so that tip sits in pouch of ventral tepal below ventral anther; style tip not functioning as a pollen presenter; fruit a drupe; Australia 6. Persoonia Carpel about as long as perianth or longer, exserted; style tip functioning as a pollen presenter; fruit a follicle 37 Flower orientation antero-posterior (axis of symmetry of carpel passing through anterior and posterior tepals); seed enclosed within a membranous envelope 38 Flower orientation diagonal (axis of symmetry of carpel passing between tepals); seed not enclosed within a membranous envelope 39 Ovules, seeds > 2; follicle leathery or cartilaginous 58. Stenocarpus Ovules 2, seeds 1 or 2; follicle woody 59. Strangea Fruit dehiscing down from both sides of style base, along ventral suture and dorsal midline, with secondary woody thickening (which is distinctly paler in colour than primary sclerified tissue) usually persistent on plant for several to many years 62. Hakea Fruit dehiscing down from only the ventral side of style base, along ventral suture, lacking secondary woody thickening, usually not persisting on the plant for more than a year 63. Grevillea Plants dioecious 41 Plants bisexual or andromonoecious 42 Flowers pedicellate, lacking hypogynous glands; female inflorescence cupule-like, a central racemose column surrounded by an inner involucre of incurved, feathery, partly or wholly sterilised lateral inflorescences and an outer involucre of narrow, leaf-like or coloured bracts; male inflorescence lacking an involucre of coloured leaves; South Africa 19. Aulax Flowers sessile, with 4 hypogynous glands; female inflorescence a globose, ovoid or cylindrical cone-like structure formed by the imbricate, leathery floral bracts, either lacking an involucre or surrounded by an involucre of coloured leaves; South Africa 24. Leucadendron Bases of the flowers buried in a globose, ovoid or cylindrical cone-like structure formed by the imbricate, leathery floral bracts (‘cone scales’); inflorescence a simple capitulum 43 Bases of the flowers either exposed or somewhat obscured by floral bracts or floral bracts absent; floral bracts scale-like or leafy or leathery but not conspicuously imbricate, not forming a distinct ‘cone’; inflorescence racemose, spicate, capitate or paniculate 44 Cone scales falling with the fruits; achene villous, not compressed; Australia 22. Isopogon Cone scales firmly adhering to the inflorescence axis and opening to release the fruits; achene usually basally or marginally long-haired, compressed; Australia 18. Petrophile Hypogynous nectar gland(s) present 45

379

– Hypogynous nectar glands absent 62 45. Style tip functioning as a pollen presenter, often swollen; fruit dry 46 – Style tip not functioning as a pollen presenter, rarely swollen; fruit a drupe 55 46. Flowers pedicellate; fruit a follicle; Australia 59. Strangea – Flowers sessile; fruit an achene 47 47. Pinnately to tripinnately dissected leaves present 48 – Dissected leaves absent 49 48. Entire leaves absent; segments of dissected leaves terete; South Africa 25. Serruria – Entire leaves sometimes present and then distal to dissected leaves; segments of dissected leaves channelled above; South Africa 26. Paranomus 49. Involucral bracts large, conspicuous, often brightly coloured 50 – Involucral bracts small, inconspicuous, not brightly coloured 52 50. Uniflorescences axillary, aggregated into a subterminal conflorescence, which grows on into a leafy shoot; South Africa 31. Mimetes – Uniflorescences axillary or terminal, not aggregated into a conflorescence 51 51. Involucral bracts spreading, not concealing the flowers; inflorescence, 1–2 cm in diameter; South Africa 32. Diastella – Involucral bracts campanulate, almost concealing flowers; inflorescence 4–6 cm in diameter; South Africa 33. Orothamnus 52. Inflorescence a simple terminal capitulum or sometimes a panicle of 2–6 simple capitula 53 – Inflorescence a conflorescence of 4–9-flowered uniflorescences 54 53. Leaves terete; South Africa 28. Sorocephalus – Leaves flat; South Africa 27. Vexatorella 54. Leaves spathulate to ovate or orbicular; South Africa 26. Paranomus – Leaves linear or lanceolate; South Africa 28. Sorocephalus 55. Ovule > 1 56 – Ovule 1 59 56. Ovules 3–8; New Caledonia 4. Garnieria – Ovules 2 57 57. Anthers and anther appendage gently incurved; SW Australia 5. Acidonia – Anthers straight or recurved to revolute; anther appendage straight to recurved or absent 58 58. Endocarp smooth; carpel as long, or longer than stamens; Australia 6. Persoonia – Endocarp obliquely ribbed; carpel shorter than stamens; New Zealand 3. Toronia 59. Posterior anther terminated by a much longer appendage than the lateral and anterior anthers; Australia (Tasmania) 13. Cenarrhenes – Anthers similar, with or without appendages 60 60. Flowers sessile; drupe < 2 mm long; New Caledonia 11. Beaupreopsis – Flowers pedicellate; drupe 5–25 mm long 61 61. Perianth white to pink or purplish; inflorescences usually paniculate (rarely simple), with flowers subtended by scale leaves, never growing on into a leafy shoot; leaves often toothed or dissected; New Caledonia 10. Beauprea

380

P.H. Weston

– Perianth yellow, occasionally with reddish markings or rarely white (but then with most flowers subtended by leaves); inflorescences simple, often growing on into a leafy shoot; flowers often subtended by leaves; leaves simple, entire; Australia 6. Persoonia 62. Flowers mostly ebracteate; Australia (Tasmania) 1. Bellendena – Flowers each borne in the axil of a scale leaf 63 63. Inflorescence a capitulum, surrounded by colourful involucral bracts; South Africa 32. Diastella – Inflorescence a spike, raceme, panicle, umbel, compound capitulum, or reduced to a single flower, lacking colourful involucral bracts 64 64. Flowers pedicellate; fruit a follicle 65 – Flowers sessile; fruit indehiscent 66 65. Inflorescences racemose; intermediate leaves pinnate; some flowers lacking a carpel; large trees; Australia 34. Sphalmium – Inflorescences umbellate or reduced to one or two flowers; leaves simple, entire; flowers all bisexual; shrubs; Australia 59. Strangea 66. Leaves pinnatisect 8. Symphionema – Leaves entire 67 67. Perianth tubular at base; inflorescence usually compound; fruit not winged; Australia 16. Conospermum – Perianth segments free from base; inflorescence simple; fruit prominently 3-winged; Australia (Tasmania) 7. Agastachys 68. Flowers sessile, in dense, cone-like to capitate inflorescences; fruit a persistent woody follicle 69 – Flowers pedicellate to sessile, but not in cone-like inflorescences; fruit leathery, woody or succulent, often falling at maturity, sometimes indehiscent 70 69. Inflorescences usually globose to cylindrical with a woody, cylindrical to spherical axis, or rarely reduced and head-like; involucral bracts inconspicuous, narrow, often falling by anthesis; Australia or New Guinea 51. Banksia – Inflorescences capitate, the axis a concave, flat or convex receptacle; involucral bracts usually conspicuous, imbricate, persistent; SW Australia 52. Dryandra 70. Perianth zygomorphic 71 – Perianth actinomorphic 89 71. Flowers 3-merous; Australia 63. Grevillea – Flowers 4-merous 72 72. Hypogynous nectary glands 2–4, free 73 – Hypogynous nectary gland absent or solitary, sometimes annular and surrounding the carpel, sometimes lobed 77 73. Flower pairs sessile; flowers pedicellate (‘pedicels free’); fruit follicular 74 – Flower pairs pedunculate; flowers sessile (‘pedicels connate’); fruit drupaceous 75 74. Hypogynous nectary glands 3, alternating with tepals; ovules and seeds > 2; Australia, South America 53. Lomatia – Hypogynous nectary glands 4, opposite tepals; ovules and seeds 2; Australia 63. Grevillea 75. Adult leaves simple, entire; hypogynous nectary glands 4; New Caledonia 74. Sleumerodendron – Adult leaves mostly pinnate, the leaflets with serrate to dentate margins 76 76. Rachis of compound leaves prominently winged; margins of simple leaves and leaflets of compound

– 77. – 78. – 79. – 80.

–

81. – 82.

–

83.

–

84. – 85.

– 86.

leaves serrate; ovary sparsely hairy; New Guinea 77. Bleasdalea Rachis of compound leaves not winged; margins of simple leaves and leaflets of compound leaves dentate; ovary densely hairy; Chile, Argentina 76. Gevuina Flower pairs pedunculate; flowers sessile (‘pedicels connate’) 78 Flower pairs sessile; flowers pedicellate (‘pedicels free’) 80 Ovary densely hairy; New Caledonia 79. Kermadecia Ovary (and rest of carpel) glabrous 79 Rachis of compound leaves usually winged; fruit globose; NE Australia 77. Bleasdalea Rachis of compound leaves not winged; fruit laterally compressed, inequilaterally obovoid; Vanuatu, Fiji 80. Turrillia Perianth straight, asymmetrical only at base, falling almost immediately after anthesis; adult leaves simple, entire, distinctly petiolate; fruit drupaceous, with bony inner mesocarp distinctly quadrangular in cross-section; rainforest trees; New Caledonia 79. Kermadecia Perianth recurved, at least at tip, usually persistent for one or more days; adult leaves often toothed, dissected or compound, often sessile or obscurely petiolate; fruit follicular or drupaceous, but then with bony inner mesocarp not quadrangular in cross-section; shrubs or trees 81 Ovules 2; seeds 1 or 2; biramous hairs usually present on branchlets and immature leaves 82 Ovules > 2; seeds > 2; biramous hairs absent 84 Fruit dehiscing down from both sides of style base, along ventral suture and dorsal midline, with secondary woody thickening (which is distinctly paler in colour than primary sclerified tissue) often persistent on plant for several to many years; Australia 62. Hakea Fruit dehiscing down from only the ventral side of style base, along ventral suture, or indehiscent, lacking secondary woody thickening, usually not persisting on the plant for more than a year 83 Fruit dry, a crustaceous to bony follicle or rarely an achene; adult leaves simple and entire to deeply divided to compound; shrubs or trees; Australia, New Guinea, Sulawesi, New Caledonia 63. Grevillea Fruit drupaceous, with fleshy outer mesocarp and bony, inner mesocarp; adult leaves simple, entire; large rainforest trees; Palau Island to Vanuatu, including New Guinea 64. Finschia Flower orientation antero-posterior (axis of floral symmetry passing through anterior and posterior tepals), perianth white to cream, 3–20 mm long 85 Flower orientation diagonal (axis of floral symmetry passing between tepals), perianth red or sometimes white or yellow but then usually > 20 mm long 86 Lower surface of leaves densely covered in persistent, appressed, shining hairs; intermediate leaves pinnate; perianth c. 3 mm long; hypogynous gland bifid; NE Australia 60. Opisthiolepis Lower surface of leaves glabrous; intermediate leaves pinnatisect; perianth 7–20 mm long; hypogynous gland crenulate; NE Australia 61. Buckinghamia Pollen presenter ellipsoidal, almost radially symmetrical; tepal claws cohering in a slit tube in their lower

Proteaceae

– 87. – 88. – 89. – 90. – 91. – 92.

– 93.

– 94. – 95.

–

96. – 97.

1/2 to 2/3 but becoming free in the upper 1/2 to 1/3; Chile, Argentina 54. Embothrium Pollen presenter strongly oblique, apparently lateral; tepal claws cohering in a slit tube to their tips or free to their bases 87 Involucral bracts present, conspicuous, sometimes brightly coloured; perianth strongly curved; SE Australia, including Tasmania 57. Telopea Involucral bracts absent; perianth gently curved 88 Follicle canoe-shaped after dehiscence; wood with vessels not conspicuously aggregated; Australia, New Guinea 56. Alloxylon Follicle splayed nearly flat after dehiscence; wood with vessels aggregated into conspicuous tangential bands between rays; Peru, Ecuador 55. Oreocallis Plants dioecious; SE Asia 72. Heliciopsis Plants bisexual or andromonoecious 90 Hypogynous nectary glands absent or fused to form a single annular or horseshoe-shaped nectary, sometimes 4-lobed or irregularly lobed 91 Hypogynous nectary glands 3 or 4, free 96 Flower pair with a distinct common peduncle (‘pedicels fused’) 92 Flower pair lacking a common peduncle (‘pedicels free’) 94 Bracts subtending flower pairs conspicuous, red, longer than the flowers, enclosing unopened buds, caducous before anthesis; budding inflorescence enclosed by imbricate, red involucral bracts which are caducous before anthesis; ovules 4; New Caledonia 38. Eucarpha Bracts subtending flower pairs inconspicuous, scale-like, persistent; involucral bracts absent; ovules 2 93 Ovules orthotropous; fruit drupe-like; seed 1, not winged; pericarp differentiated into inner woody layer and outer, soft fleshy layer; New Caledonia 70. Virotia Ovules hemitropous; fruit follicular; seeds 2, winged; pericarp leathery; NE Australia 36. Megahertzia Staminal filaments adnate to tepals only at their bases; fruit a massive, globose to fusiform achene; tropical South and Central America 66. Panopsis Staminal filaments completely adnate to tepals; fruit a follicle 95 Fruit dehiscing down from both sides of style base, along ventral suture and dorsal midline, with secondary woody thickening (which is distinctly paler in colour than primary sclerified tissue) usually persistent on plant for several to many years; Australia 62. Hakea Fruit dehiscing down from only the ventral side of style base, along ventral suture, lacking secondary woody thickening, usually not persisting on the plant for more than a year; Australia 63. Grevillea Hypogynous glands 3; pollen grains biporate, curvedellipsoidal 97 Hypogynous glands 4; pollen grains triporate, triangular 98 Mature, hardened leaves glabrous; inflorescence pendulous, lateral, ramiflorous; perianth 14–25 mm long; intermediate leaves pinnate; NE Australia 50. Austromuellera

381

– Mature, hardened leaves densely and finely tomentose underneath; inflorescence ascending to erect, terminal or axillary; perianth 4–5 mm long; intermediate leaves simple although sometimes deeply lobed; NE Australia 49. Musgravea 98. Ovules > 2; seeds 2 or more 99 – Ovules 2; seeds 1 or 2 103 99. Tepals with truncate tips, not differentiated into basal claw and wider terminal limb, 4.5–6 mm long; style not functioning as a pollen presenter; NE Australia 41. Neorites – Tepals with acute tips, differentiated into basal claw and wider terminal limb, 15–33 mm long; style tip functioning as a pollen presenter 100 100. Bracts subtending flower pairs conspicuous, red, longer than the flowers, enclosing unopened buds, caducous before anthesis; budding inflorescence enclosed by imbricate, red involucral bracts which are caducous before anthesis; New Caledonia 38. Eucarpha – Bracts subtending flower pairs inconspicuous, or large but not brightly coloured, much shorter than flower buds, caducous or persistent; involucral bracts absent or present but dull-coloured 101 101. Flowers white to cream; intermediate leaves pinnately lobed; adult leaves entire; NE Australia 47. Darlingia – Flowers red to purplish; intermediate leaves with toothed margins; adult leaves entire or with toothed margins 102 102. Inflorescence axes pendulous, 15–40 cm long; seeds not winged; NE Australia 46. Hollandaea – Inflorescence axes spreading to erect, 2–10 cm long; seeds winged; New Zealand 37. Knightia 103. Adult leaves pinnate or pinnatifid to pinnately lobed 104 – Adult leaves simple, entire or with toothed margins 106 104. Fruit follicular, grey to brown, with 2 winged seeds; tropical South and Central America 40. Roupala – Fruit drupaceous, with 1 (rarely 2), unwinged seed 105 105. Adult leaves pinnate to deeply pinnatisect; flowers bluish mauve to deep maroon; fruit bright red when mature; E Australia 78. Hicksbeachia – Adult leaves pinnately lobed (usually mixed with unlobed leaves); flowers cream; fruit pink to deep blue when mature; NE Australia 71. Athertonia 106. Flower pair sessile on inflorescence rachis (‘pedicels free’); individual floral bracts absent 107 – Flower pair borne on a common peduncle (‘pedicels partly connate’); individual floral bracts absent or present and decurrent on pedicels 109 107. Fruit indehiscent, enclosing one wingless seed; Asia, Melanesia and Australia 45. Helicia – Fruit dehiscent, enclosing two winged seeds 108 108. Style tip not swollen, only sometimes functioning as a pollen presenter; ovules hemitropous; Australia, Chile, Bolivia 42. Orites – Style tip swollen, functioning as a pollen presenter; ovules orthotropous; tropical South and Central America 40. Roupala 109. Fruit a follicle; seeds 2, winged; NE Australia 36. Megahertzia – Fruit indehiscent; seed solitary, not winged 110

382

P.H. Weston

110. Ovules anatropous; Asia, Melanesia and Australia 45. Helicia – Ovules orthotropous 111 111. Plant completely glabrous; tepals pink to red; NE Australia 69. Catalepidia – Plant with young stems and pedicels sparsely to densely hairy, sometimes immature leaves and tepals also hairy; tepals cream to pale yellow 112 112. Intermediate leaves pinnately lobed with serrate margins; adult leaves with toothed or entire margins; branchlets densely tomentose; NE Australia 71. Athertonia – Intermediate and adult leaves entire; branchlets sparsely pubescent or pilose 113 113. Tepals 4–5 mm long; ovary glabrous; fruit drupaceous; Madagascar 68. Malagasia – Tepals 12–17 mm long; ovary minutely pubescent; fruit a massive achene; E Australia 48. Floydia

II.1. Tribe Placospermeae C.T. White & W.D. Francis (1924). Plants andromonoecious. Cotyledons obreniform, shortly stalked, flat. Carpel sessile. Fruit a follicle;

Subfamilies, Tribes and Genera of Proteaceae I. Subfam. Bellendenoideae P.H. Weston (1995). Cluster roots present. Cotyledons not known. Staminal filaments free. Pollen grains triporate. Carpel shortly stipitate; ovules 2, orthotropous; style tip not functioning as a pollen presenter. Fruit dry, 2-winged, indehiscent. Chromosome mean length 6.7 µm. 1. Bellendena R. Br.

Fig. 132

Bellendena R. Br., Trans. Linn. Soc. London 10:166 (1810); Weston, Fl. Australia 16:125–127 (1995).

Shrubs. Plants bisexual. Leaves alternate, simple, entire or shallowly imparipinnately to bipinnately lobed in distal half. Inflorescence terminal or lateral, racemose. Floral bracts usually absent or present and decurrent on pedicel. Flowers pedicellate. Perianth actinomorphic; tepals free. Stamens equal, free; anthers inapiculate. Hypogynous glands absent. Style straight; stigma terminal. 2n = 10. One species, B. montana R. Br., usually alpine to subalpine shrublands, Tasmania. II. Subfam. Persoonioideae L.A.S. Johnson & B.G. Briggs (1975). Cluster roots absent. Cotyledons not auriculate. Leaves simple. Staminal filaments largely or completely adnate to tepals. Pollen grains triporate. Ovules 1–22, orthotropous; style tip not functioning as a pollen presenter. Chromosome mean length 9.1–14.4 µm.

Fig. 132. Proteaceae. Bellendena montana. A Inflorescence. B Flower. C Flowering branch. D Tepal. E Stamen. F Tepal plus stamen. G Pistil with receptacle. H Pistil, vertical section. I Stigma. J Fruit, ventral view. K Fruit, lateral view. L Fruit opened, showing seed. (Drawn by L. Elkan)

Proteaceae

383

endocarp woody, not extending between the seeds. Seeds flat, winged on both sides. 2. Placospermum C.T. White & W.D. Francis Fig. 133 Placospermum C.T. White & W.D. Francis, Proc. Roy. Soc. Queensland 35:79 (1924); Weston, Fl. Australia 16:47–49 (1995).

Trees. Leaves alternate; seedling and adult leaves entire; juvenile leaves usually pinnatifid. Inflorescence terminal or lateral, a raceme or panicle of racemes. Floral bracts scale-like. Flowers pedicellate. Perianth zygomorphic, curved to anterior; tepals not connate. Stamens dimorphic; filaments adnate to tepals; posterior stamen fertile; anther free, prominently apiculate; lateral and anterior stamens sterile. Hypogynous glands 4, free. Carpel curved to anterior; ovules 15–22; style curved to anterior; stigma strongly oblique, adaxial. 2n = 14. One species, P. coriaceum C.T. White & W.D. Francis, rainforest, north-eastern Australia. II.2. Tribe Persoonieae Reichb. (1828). Plants bisexual. Cotyledons elliptic to linear, sessile, semicircular to triangular in cross-section. Leaves entire. Carpel shortly stipitate. Fruit a drupe; endocarp woody, penetrating between the seeds. Seeds ovoid, not winged. 3. Toronia L.A.S. Johnson & B.G. Briggs Toronia L.A.S. Johnson & B.G. Briggs, Bot. J. Linn. Soc. 70:174 (1975).

Shrubs or small trees. Cotyledons usually 3 (rarely 2 or 4). Leaves alternate. Inflorescence lateral, anauxotelic. Floral bracts scale-like. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Stamens equal; filaments adnate to tepals except at tips; anthers free, inapiculate. Hypogynous glands 4, free. Ovules 2. Style straight, recurved to posterior at tip; stigma terminal. 2n = 28. One species, T. toru (A. Cunn.) L.A.S. Johnson & B.G. Briggs, shrubland to rainforest, North Island, New Zealand. 4. Garnieria Brongn. & Gris Garnieria Brongn. & Gris, Bull. Soc. Bot. France 18:189 (1871); Virot, Fl. Nouv.-Caléd. Dépend. 2:74–78 (1968).

Shrubs or small trees. Cotyledons 2. Leaves alternate. Inflorescence lateral, anauxotelic. Floral

Fig. 133. Proteaceae. Placospermum coriaceum. A Flowering branch. B Juvenile leaf. C Male flower with the single fertile stamen and three staminodes. D Bisexual flower with lateral tepal removed, showing pistil and hypogynous glands. E Pistil with hypogynous glands, vertically sectioned, containing transversely oriented ovules. F Fruit. G Seed, lateral view. H Seed, surface view. (Drawn by C. Wardrop)

384

P.H. Weston

bracts scale-like. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Stamens equal; filaments adnate to tepals; anthers free, inapiculate. Hypogynous glands 4, free. Ovules 3–7. Style straight; stigma terminal. 2n = 14. One species, G. spathulifolia (Brongn. & Gris) Brongn. & Gris, shrubland on ultrabasic soils, New Caledonia. 5. Acidonia L.A.S. Johnson & B.G. Briggs Acidonia L.A.S. Johnson & B.G. Briggs, Bot. J. Linn. Soc. 70:175 (1975); Weston, Telopea 6:51–165 (1994).

Shrubs. Cotyledons 2. Leaves alternate. Inflorescence lateral, anauxotelic. Floral bracts scale-like. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Stamens equal; filaments adnate to tepals; anthers free, incurved-apiculate. Hypogynous glands 4, free. Ovules 2. Style straight but recurved to posterior at tip; stigma posterolateral. One species, A. microcarpa (R. Br.) L.A.S. Johnson & B.G. Briggs, swampy shrubland, south-western Australia. 6. Persoonia Sm.

Fig. 134

Persoonia Sm., Trans. Linn. Soc. London 4:215 (1798); Weston, Fl. Australia 16:50–124 (1995).

Shrubs or trees. Cotyledons 2–9. Leaves usually alternate or occasionally opposite-decussate or whorled, simple, entire. Inflorescence terminal or lateral, auxotelic or anauxotelic. Floral bracts scale-like or leafy. Flowers usually pedicellate. Perianth actinomorphic or zygomorphic with a pouch in the anterior tepal; tepals not connate. Stamens equal, or rarely anterior stamen sterile and entirely adnate to anterior tepal; filaments adnate to tepals; anthers free, apiculate or inapiculate. Hypogynous glands 4 or 2, anterior, free. Ovules 1 or 2. Style straight or curved to anterior or variously sinuous; stigma terminal or anterolateral. 2n = 14. One hundred species, mostly shrublands and eucalypt forests, widespread in Australia, including Tasmania. Persoonia appears to be polyphyletic, with Toronia, Garnieria and Acidonia nested amongst its basal subclades (Weston and Porter, unpubl. data). III. Subfam. Symphionematoideae P.H. Weston & N.P. Barker (2006). Plants bisexual. Cluster roots absent. Cotyledons not known. Leaves alternate. Flowers sessile. An-

Fig. 134. Proteaceae. Persoonia lanceolata. A Flowering branch. B Flower. C Same, one tepal removed. D Pistil. E Stigma. F Ovary, vertical section. G Ovary with hypogynous glands. H Tepal plus stamen, front view. I Same, side view. J Fruit. K Fruit, vertical section, showing pyrene. (Drawn by L. Elkan)

Proteaceae

385

thers free, inapiculate. Hypogynous glands absent. Carpel sessile to very shortly stipitate. Style tip not functioning as a pollen presenter. Fruit dry, indehiscent, 1-seeded. Chromosome mean length 3.1 µm (Agastachys). 7. Agastachys R. Br. Agastachys R. Br., Trans. Linn. Soc. London 10:158 (1810); Telford, Fl. Australia 16:131 (1995).

Shrubs or small trees. Leaves entire. Inflorescence lateral, spicate. Floral bracts scale-like. Perianth actinomorphic; tepals not connate. Stamens equal; filaments adnate to tepals except towards tips. Ovary 3-winged; ovule 1, hemitropous; style straight; stigma oblique. Fruit with 2 lateral wings and a narrower, abaxial wing. 2n = 26. One species, A. odorata R. Br., shrublands to rainforest, Tasmania. 8. Symphionema R. Br.

Fig. 135

Symphionema R. Br., Trans. Linn. Soc. London 10:157 (1810); Telford, Fl. Australia 16:133–135 (1995).

Shrubs. Leaves pinnately to tripinnately dissected. Inflorescence terminal or lateral, a spike or panicle of spikes. Floral bracts scale-like. Perianth actinomorphic; tepals not connate. Stamens equal; filaments basally adnate to tepals, cohering with adjacent filaments at their geniculate tips. Ovary not winged; ovules 2 (one much larger than the other), orthotropous; style tip recurved; stigma terminal. Fruit ellipsoidal. 2n = 20. Two species, shrublands to eucalypt forests, south-eastern Australia. IV. Subfam. Proteoideae Eaton (1836) (‘Proteeae’). Cluster roots present. Cotyledons not auriculate. Leaves simple. Staminal filaments adnate to tepals or rarely free. Pollen grains triporate. Carpel sessile to very shortly stipitate. Fruit indehiscent, dry or drupaceous, 1-seeded. Chromosome mean length 1.2–3.4 µm. Genera incertae sedis 9. Eidothea A.W. Douglas & B. Hyland Eidothea A.W. Douglas & B. Hyland, Fl. Australia 16:472 (1995); P.H. Weston & R.M. Kooyman, Telopea 9:821–832 (2002).

Fig. 135. Proteaceae. Symphionema montanum. A Flowering branch. B Inflorescence. C Flower. D Same, one tepal and stamen removed. E Tepal plus stamen, side view. F Same, seen from inside. G Pistil. H Ovary, vertical section. I Fruit with bract. (Drawn by L. Elkan)

386

P.H. Weston

Trees. Plants andromonoecious. Leaves pseudoverticillate, entire or dentate. Inflorescence lateral, a capitulum; bisexual flower solitary, near the centre of the capitulum, or lacking, the other flowers being male. Floral bracts scale-like, vestigial in more central flowers. Flowers sessile. Perianth actinomorphic; tepals basally connate, with free lobes. Stamens equal; filaments free or basally adnate to tepals; anthers free, inapiculate. Hypogynous glands absent. Ovule 1, orthotropous. Style straight, tip not functioning as pollen presenter; stigma terminal. Fruit drupaceous. Two species, rainforest, eastern Australia.

Trees. Plants dioecious. Leaves alternate, dichotomously lobed. Inflorescences lateral. Floral bracts scale-like. Perianth actinomorphic; tepals not connate. Hypogynous glands absent. Male inflorescence a panicle of spikes. Male flowers sessile. Stamens equal; filaments vestigially adnate at the base to the tepals; anthers free, apiculate. Female inflorescence lateral, racemose or rarely a panicle of racemes. Female flowers pedicellate. Ovule 1, orthotropous. Style vestigial, not functioning as pollen presenter; stigma terminal, prominently 2-lobed. Fruit drupaceous. 2n = 52. Two species, forests, eastern Madagascar.

10. Beauprea Brongn. & Gris

13. Cenarrhenes Labill.

Beauprea Brongn. & Gris, Bull. Soc. Bot. France 18:243 (1871); Virot, Fl. Nouv.-Caléd. Dépend. 2:20–74 (1968).

Cenarrhenes Labill., Nov. Holl. Pl. 1:36, t. 50 (1805); Telford, Fl. Australia 16:131–133 (1995).

Shrubs or trees. Plants bisexual. Leaves alternate, entire or imparipinnately to tripinnately lobed or dissected, with or without marginal teeth. Inflorescence terminal or occasionally lateral, a raceme or panicle of racemes. Floral bracts scale-like. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Stamens equal; filaments basally adnate to tepals; anthers free, apiculate. Hypogynous glands 4, free. Ovule 1, hemitropous to anatropous. Style straight, tip sometimes thickened but not functioning as pollen presenter; stigma terminal. Fruit drupaceous. 2n = 22. Thirteen species, shrublands to rainforests, New Caledonia.

Shrubs or small trees. Plants bisexual. Leaves alternate, with dentate margins. Inflorescence lateral, a spike. Floral bracts scale-like. Flowers sessile. Perianth actinomorphic; tepals not connate. Stamens dimorphic; Filaments vestigially adnate at the base to the tepals; anthers 4-locular, apiculate, posterior anther subulately so. Hypogynous glands 4, free. Ovule 1, orthotropous. Style straight, tip not functioning as pollen presenter; stigma terminal. Fruit drupaceous. 2n = 26. One species, C. nitida Labill., shrublands, eucalypt forests and rainforest, Tasmania.

11. Beaupreopsis Virot Beaupreopsis Virot, Fl. Nouv.-Caléd. Dépend. 2:14–19 (1968).

Shrubs. Plants bisexual. Leaves alternate, entire or shallowly lobed in distal half. Inflorescence terminal, a panicle of spikes. Floral bracts scale-like. Flowers sessile. Perianth actinomorphic; tepals not connate. Stamens equal; filaments basally adnate to tepals; anthers free, subulate-apiculate. Hypogynous glands 4, free. Ovule 1, hemitropous. Style straight, tip not functioning as pollen presenter; stigma terminal. Fruit minutely drupaceous. 2n = 22. One species, B. paniculata (Brongn. & Gris) Virot, shrubland on ultrabasic soils, New Caledonia.

14. Franklandia R. Br. Franklandia R. Br., Trans. Linn. Soc. London 10:157 (1810); George, Fl. Australia 16:316–317 (1995).

Shrubs. Plants bisexual. Leaves alternate, dichotomously dissected, with glandular cavities. Inflorescence terminal, racemose. Floral bracts scale-like. Flowers pedicellate. Perianth actinomorphic; tepals basally connate, forming a tube with free lobes. Stamens equal; filaments adnate to tepals; anthers adnate to tepals except at tips, apiculate. Hypogynous glands 4, basally connate and adnate to perianth tube. Ovule 1, orthotropous. Style straight, tip not functioning as pollen presenter; stigma terminal. Fruit dry, indehiscent. 2n = 28, 56. Two species, shrublands, south-western Australia.

12. Dilobeia Thou.

IV.1. Tribe Conospermeae Endl. (1837).

Dilobeia Thou., Gen. Nov. Madag. 7 (1806); Bosser & Rabevohitra, Fl. Madag. Comores, famille 57. Protéacées: 49–58 (1991).

Leaves alternate. Floral bracts scale-like. Flowers sessile. Tepals basally connate. Staminal filaments adnate to tepals except at tips; anthers inapiculate;

Proteaceae

loculi coherent to fertile loculi of adjacent anthers. Hypogynous glands absent. Ovule 1. Style tip not functioning as pollen presenter; stigma terminal. Fruit dry, indehiscent. IV.1.a. Subtribe Stirlingiinae L.A.S. Johnson & B.G. Briggs (1975). Plants andromonoecious.

387

adaxial lobe longest and widest, hooded; lateral lobes falcate; abaxial lobe smallest. Stamens trimorphic; posterior anther sterile; lateral anthers 1-locular; anterior anther 2-locular, coherent with adjacent, fertile locules of lateral anthers. Ovule hemitropous. Style basally straight but adaxially bent near the tip; stigma posteriolateral, plate-like or 2-lobed. 2n = 22. Fifty species, shrublands and eucalypt woodlands and forests, south-western Australia.

15. Stirlingia Endl. Stirlingia Endl., Gen. Pl., 339 (1837); George, Fl. Australia 16:136–140 (1995).

IV.2. Tribe Petrophileae P.H. Weston & N.P. Barker (2006).

Shrubs. Leaves dichotomously dissected. Inflorescence terminal, a pedunculate capitulum or panicle of capitula. Perianth actinomorphic. Stamens equal; anthers coherent with adjacent anthers. Ovule anatropous. Style straight; stigma terminal, capitate. 2n = 26. Seven species, shrublands to eucalypt forests, south-western Australia.

Shrubs. Leaves alternate. Perianth actinomorphic; tepals basally connate. Anthers free. Fruit dry, indehiscent.

IV.1.b. Subtribe Conosperminae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. 16. Conospermum Sm. Conospermum Sm., Trans. Linn. Soc. London 4:213 (1798); Bennett, Fl. Australia 16:224–271 (1995).

Shrubs or small trees. Leaves entire. Inflorescence terminal or lateral, a dense spike or panicle of dense spikes. Perianth actinomorphic or more frequently zygomorphic and bilabiate, with adaxial lip of one broad lobe, abaxial lip 3-lobed. Stamens trimorphic; adaxial anther 2-locular, coherent with adjacent, fertile locules of lateral anthers; lateral anthers 1-locular; abaxial stamen sterile. Ovule orthotropous. Style basally straight but abaxially bent near the tip; stigma terminal, capitate. 2n = 22. Fifty-three species, shrublands and eucalypt woodlands and forests, South Australia including Tasmania. 17. Synaphea R. Br. Synaphea R. Br., Trans. Linn. Soc. London 10:155 (1810); George, Fl. Australia 16:271–315 (1995).

Shrubs. Leaves entire or dentate or imparipinnately to tripinnately or dichotomously lobed or dissected. Inflorescence terminal or lateral, a spike or panicle of spikes. Perianth zygomorphic;

18. Petrophile R. Br. ex Knight Petrophile R. Br. ex Knight, Cult. Prot. 92 (1809); Foreman, Fl. Australia 16:149–193 (1995).

Plants bisexual. Leaves entire or imparipinnately to tripinnately dissected. Inflorescence terminal or lateral, a cone-like capitulum or spike, usually subtended by an involucre of imbricate bracts. Floral bracts (‘cone scales’) conspicuous, imbricate, hardening, persistent. Flowers sessile. Stamens equal; filaments adnate to tepals; anthers apiculate. Hypogynous glands absent. Ovule 1 or rarely 2, hemitropous. Style straight, tip swollen, fusiform or clavate, functioning as pollen presenter; stigma terminal. 2n = 26. Fifty-three species, shrublands and eucalypt woodlands and forests, South Australia. 19. Aulax Berg. Aulax Berg., Descriptiones Plantarum ex Capite Bonae Spei: 33 (1767); Rourke, S.-Afr. Tydskr. Plantk. 53:464–480 (1987).

Plants dioecious. Leaves entire. Inflorescences terminal. Floral bracts scale-like. Flowers pedicellate. Male inflorescence a raceme or panicle of racemes. Stamens equal; filaments adnate to tepals except towards tips; anthers inapiculate. Female inflorescence a cupule-like structure consisting of a central racemose column enclosed by incurved foliaceous fascicles of modified side branches, the side branches occasionally bearing male or male and female flowers. Ovule 1, orthotropous to anatropous. Style slightly curved, tip not functioning as pollen presenter; stigma oblique. 2n = 22. Three species, shrublands, Cape region of South Africa.

388

P.H. Weston

IV.3. Tribe Proteeae Dumort. (1829). Plants bisexual. Leaves alternate, entire; tip not glandular. Floral bracts scale-like. Flowers sessile. Perianth zygomorphic, adaxially curved; adaxial and lateral tepals connate, forming a sheath. Staminal filaments adnate to tepals; Anthers free, apiculate. Hypogynous glands 4, free. Ovule 1, hemitropous. Style tip functioning as pollen presenter, not swollen. Fruit dry, indehiscent. 20. Protea L.

Fig. 136

Protea L., Mant. 187, 194, 328 (1771); Rourke, The proteas of southern Africa (1980); Beard, The proteas of tropical Africa (1992); Brummitt & Marner, Fl. Trop. E. Afr., Proteaceae (1993).

Shrubs or trees. Inflorescence terminal or lateral, a dense simple capitulum, subtended by an involucre of large, usually colourful bracts. Anterior tepal free. Anthers equal or dimorphic, the anterior anther sometimes sterile. Style straight or gently adaxially curved; stigma ventral. 2n = 24. One hundred and three species (according to Brummitt & Marner) or 114 species (according to Beard), grasslands, shrublands and savannas, widespread, sub-Saharan Africa. 21. Faurea Harvey Faurea Harvey, London J. Bot. 6:373, t 15 (1847).

Trees. Inflorescence terminal, spicate. Anterior tepal basally connate to other tepals. anthers equal, free, apiculate. Style straight or gently adaxially curved; stigma terminal. 2n = 24. About 15 species, savannah, gallery forests and montane rainforests, widespread, sub-Saharan Africa and Madagascar. IV.4. Tribe Leucadendreae P.H. Weston & N.P. Barker (2006). Leaves alternate. Inflorescence or uniflorescence (in taxa with conflorescences) subtended by an involucre of bracts or leaves (except in some species of Isopogon and Leucadendron). Staminal filaments adnate to tepals; anthers free, apiculate. Fruit dry, indehiscent. IV.4.a. Subtribe Isopogoninae P.H. Weston & N.P. Barker (2006). Floral bracts (‘cone scales’) conspicuous, imbricate, caducous after flowering or shed with fruit.

Fig. 136. Proteaceae. Protea cynaroides. A Flowering branch. B Tepals with anthers. C Single tepal with anther. D Stigma with pollen presenter. E Flower bud. F Opened flower. G Bracts at perianth base. H A single bract from perianth base. I Nectaries. J Fruit. K Ovary, vertical section. (Drawn by C. Wardrop)

Proteaceae

22. Isopogon R. Br. ex Knight Isopogon R. Br. ex Knight, Cult. Prot. 93 (1809); Foreman, Fl. Australia 16:194–223 (1995).

Shrubs or small trees. Plants bisexual. Leaves entire or imparipinnately to tripinnately or dichotomously lobed or dissected; tips not glandular. Inflorescence terminal or lateral, a cone-like capitulum, usually subtended by an involucre of imbricate bracts. Floral bracts (‘cone scales’) conspicuous, imbricate, caducous after flowering or shed with fruit. Perianth actinomorphic; tepals basally connate. Anthers equal. Hypogynous glands absent. Ovules 1 or rarely 2, orthotropous. Style straight; pollen presenter swollen, clavate; stigma terminal. 2n = 26. Thirty-five species, shrublands and eucalypt woodlands and forests, South Australia.

389

Shrubs or trees. Plants dioecious. Leaves entire; tip usually glandular. Inflorescence terminal, a spike or capitulum; involucral bracts, leafy, often brightly coloured. Perianth ± actinomorphic. Hypogynous glands 4 or absent. Male floral bracts scale-like. Pistillode tip usually functioning as pollen presenter. Female inflorescence cone-like due to large, fleshy floral bracts. Style straight; stigma terminal or ventral. 2n = 26. Eighty species, shrublands and savannas, Cape region, South Africa. 25. Serruria Salisb. Serruria J. Burman ex Salisb., Parad. Lond. ad t. 66 (1807).

23. Adenanthos Labill.

Shrubs. Plants bisexual. Leaves pinnately to bipinnately dissected or rarely entire; tips not glandular. Inflorescence terminal or lateral, a capitulum or panicle of capitula, each capitulum subtended by an involucre of sometimes large, colourful bracts. Floral bracts scale-like. Perianth ± actinomorphic or zygomorphic and curved to the posterior. Hypogynous glands 4. Style straight or gently to strongly curved to anterior; pollen presenter slightly swollen or not, clavate; stigma terminal. 2n = 24. Fifty-one species (Rebelo 1995), shrublands, Southwest Cape region of South Africa.

Adenanthos Labill., Nov. Holl. Pl. 1:28 (1805); Nelson, Brunonia 1:303–406 (1978).

26. Paranomus Salisb.

IV.4.b. Subtribe Adenanthinae L.A.S. Johnson & B.G. Briggs (1975). Anthers equal or dimorphic with posterior anther sterile. Hypogynous glands 4, basally adnate to perianth.

Shrubs or small trees. Plants bisexual. Leaves entire or pinnately to tripinnately or dichotomously lobed or dissected; tips glandular or leaf covered in scattered glands. Inflorescence terminal or lateral, single-flowered; involucral bracts scale-like. Perianth zygomorphic, gently to strongly curved to anterior; tepals basally connate. Hypogynous glands 4, basally adnate to perianth. Ovule 1, hemitropous. Style gently to strongly curved to anterior or posterior; pollen presenter flattened and elliptical or slightly swollen, conical; stigmatic groove ventral. 2n = 26. Thirty-three species, shrublands and eucalypt woodlands and forests, South Australia.

Paranomus Salisb., Parad. Lond. ad t. 66 (1807); Levyns, Contr. Bolus Herb. 2:3–48 (1970).

Shrubs. Plants bisexual. Leaves entire or pinnately to dichotomously dissected; tips often glandular. Conflorescence terminal or lateral, a spike of capitula, each of 4 (or sometimes fewer) flowers, each flower subtended by a free, scale-like bract. Perianth ± actinomorphic. Hypogynous glands 4. Style straight or gently curved to anterior; pollen presenter slightly swollen, clavate, or not swollen; stigma terminal. 2n = 24. Eighteen (+1) species (Rebelo 1995), shrublands, Cape region of South Africa. 27. Vexatorella Rourke

IV.4.c. Subtribe Leucadendrinae P.H. Weston & N.P. Barker (2006).

Vexatorella Rourke, J. S. African Bot. 50:377 (1984); Rourke, J. S. African Bot. 50:373–391 (1984).

Anthers equal. Hypogynous glands (if present) free. Ovule 1, hemitropous.

Shrubs. Plants bisexual. Leaves entire; tip glandular. Conflorescence terminal, a capitulum or panicle of capitula, sometimes subtended by an involucre of bracts. Floral bracts scale-like, enlarging and becoming woody in fruit. Perianth actinomorphic. Hypogynous glands 4. Style straight; pollen pre-

24. Leucadendron R. Br. Leucadendron R. Br., Trans. Linn. Soc. London 10:50 (1810); Williams, Contr. Bolus Herb. 3:1–425 (1972).

390

P.H. Weston

senter swollen, clavate; stigma terminal. Four species, shrublands, Southwest Cape region of South Africa. 28. Sorocephalus R. Br. Sorocephalus R. Br., Trans. Linn. Soc. London 10:139 (1810); Rourke, J. S. African Bot. suppl. 7:1–124 (1969).

Shrubs. Plants bisexual. Leaves entire; tip not glandular. Conflorescence terminal, a raceme of capitula, each subtended by an involucre of free, scale-like bracts, each of 4–9 flowers. Floral bracts scale-like. Perianth actinomorphic. Hypogynous glands 4. Style straight; pollen presenter swollen, clavate; stigma terminal. Eleven species, shrublands, Southwest Cape region of South Africa. 29. Spatalla Salisb. Spatalla Salisb., Parad. Lond. ad t. 66 (1807); Rourke, J. S. African Bot. suppl. 7:1–124 (1969).

Shrubs. Plants bisexual. Leaves entire; tip not glandular. Conflorescence terminal, a raceme of capitula, each subtended by an involucre of 4 free or basally connate, scale-like bracts, each capitulum of 1–3 flowers. Floral bracts scale-like. Perianth zygomorphic, curved to the anterior, the posterior tepal longer and wider than the others. Hypogynous glands 4. Style curved to anterior at tip; pollen presenter swollen, oblique; stigma terminal or ventral. 2n = 24. Twenty species, shrublands, Southwest Cape region of South Africa. 30. Leucospermum R. Br. Leucospermum R. Br., Trans. Linn. Soc. London 10:95 (1810); Rourke, J. S. African Bot. suppl. 8:1–194 (1972).

Shrubs or small trees. Plants bisexual. Leaves entire or with 1–16 subapical teeth; tip and teeth glandular. Inflorescence lateral, a capitulum, subtended by an involucre of imbricate bracts. Floral bracts scale-like. Perianth zygomorphic, straight or curved to posterior; posterior and lateral tepals connate for most of their length, forming a sheath; anterior tepal distally free. Hypogynous glands 4. Style straight or curved to posterior; pollen presenter usually swollen; often oblique, stigma terminal or ventral. 2n = 24. Forty-eight species (Rebelo 1995), shrublands, Cape region of South Africa, northeast to the Chimanimani Mountains, Zimbabwe.

31. Mimetes Salisb. Mimetes Salisb., Parad. Lond. ad t. 67 (1807); Rourke, J. S. African Bot. 50:171–236 (1984).

Shrubs or small trees. Plants bisexual. Leaves entire or with 1–2 subapical teeth; tip and teeth glandular. Inflorescence lateral, a capitulum, subtended by an involucre of small and woody or large, colourful bracts, overtopped in some species by a brightly coloured leaf, all of the inflorescences of a shoot collectively forming a conflorescence. Floral bracts scale-like or linear. Perianth ± actinomorphic although sometimes bent in bud. Hypogynous glands 4. Style straight; pollen presenter swollen or not; stigma terminal. 2n = 24. Thirteen species (Rebelo 1995), shrublands, Cape region of South Africa. Mimetes appears to be polyphyletic, including both Diastella and Orothamnus as subclades (Barker et al. 2002). 32. Diastella Salisb. Diastella Salisb. in Knight, Cult. Prot. 61 (1809); Rourke, J. S. African Bot. 42:185–210 (1976).

Shrubs. Plants bisexual. Leaves entire or with 1 or 2 subapical teeth; tip and teeth glandular. Inflorescence terminal or lateral, a simple capitulum, subtended by an involucre of large, colourful bracts. Floral bracts linear to filiform. Perianth ± actinomorphic or the anterior tepal slightly longer than the others; tepals not connate or basally connate. Hypogynous glands 4 or absent. Style straight; pollen presenter not swollen; stigma terminal. Seven species (Rebelo 1995), shrublands, Southwest Cape region of South Africa. 33. Orothamnus Pappe ex Hook. Orothamnus Pappe ex Hook., Bot. Mag. 4357 (1848).

Shrubs. Plants bisexual. Leaves entire; tip glandular. Inflorescence terminal or lateral, a simple capitulum; involucral bracts large, red, almost enclosing the inflorescence. Perianth ± actinomorphic. Hypogynous glands 4. Style gently curved; pollen presenter not swollen; stigma terminal. One species, O. zeyheri, shrublands, Cape region of South Africa. V. Subfam. Grevilleoideae Engl. (1892). Cluster roots present. Cotyledons auriculate (auricles obscure in a few genera due to thickening or widening of the cotyledons or connation). Chromosome mean length 1.0–2.6 µm.

Proteaceae

391

Genera incertae sedis 34. Sphalmium B.G. Briggs, B. Hyland & L.A.S. Johnson Sphalmium B.G. Briggs, B. Hyland & L.A.S. Johnson, Austral. J. Bot. 23:165 (1975); Hewson, Fl. Australia 16:342–343 (1995).

Trees. Plants andromonoecious. Leaves alternate, simple and entire or imparipinnately lobed to compound. Inflorescence lateral, a raceme, the flowers not in pairs. Floral bracts scale-like. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Stamens equal; filaments basally adnate to tepals; anthers free, apiculate to inapiculate; pollen grains triporate. Hypogynous glands absent. Carpel shortly stipitate; ovules 2, anatropous; style straight; tip not functioning as pollen presenter; stigma terminal. Fruit follicular; seeds winged. 2n = 24. One species, S. racemosum (C.T. White) B.G. Briggs, B. Hyland & L.A.S. Johnson, rainforest, north-eastern Australia. 35. Carnarvonia F. Muell.

Fig. 137

Carnarvonia F. Muell., Fragm. 6:80 (1867); Hyland, Fl. Australia 16:343–345 (1995).

Trees. Plants bisexual. Leaves alternate, compound, trifoliolate or palmate with 5 leaflets or the 1–3 central segments 1–2-imparipinnate. Inflorescence terminal or lateral, a raceme or irregularly branched panicle, the flowers not in pairs. Floral bracts scale-like. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Stamens equal; filaments adnate to tepals; anthers free, apiculate; pollen grains triporate. Hypogynous glands absent. Carpel shortly stipitate; ovules 2, hemitropous; style straight; tip not functioning as pollen presenter; stigma terminal. Fruit follicular; seeds winged. 2n = 28. One species, C. araliifolia F. Muell., with two varieties, rainforest, north-eastern Australia. V.1. Tribe Roupaleae Meisn. (1841). Anthers equal, free. Pollen grains triporate. Genera incertae sedis 36. Megahertzia A.S. George & B. Hyland Megahertzia A.S. George & B. Hyland, Fl. Australia 16:497 (1995); George & Hyland, Fl. Australia 16:355 (1995).

Trees. Plants bisexual. Adult leaves alternate, simple, entire. Conflorescence terminal or lateral, a raceme of flower pairs. Flower pair subtended

Fig. 137. Proteaceae. Carnarvonia araliifolia var. araliifolia. A Flowering branch. B Juvenile leaf. C Seedling leaf. D Flower. E Tepal plus stamen, inside view. F Same, lateral view. G Pistil, front view. H Pistil, back view. I Ovary, vertical section. J Seed. K Fruit. (Drawn by L. Elkan)

392

P.H. Weston

by a scale-like bract; common peduncle present. Floral bracts scale-like, decurrent on pedicels. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Staminal filaments adnate to tepals; anthers apiculate. Hypogynous glands free or irregularly connate. Carpel sessile; ovules 2, hemitropous; style straight; pollen presenter slightly swollen; stigma subterminal. Fruit follicular; seeds winged. One species, M. amplexicaulis A.S. George & B. Hyland, rainforest, north-eastern Australia. 37. Knightia R. Br.

cence terminal, a raceme of flower pairs, the whole subtended by an involucre of imbricate bracts. Flower pair subtended by a scale-like bract; common peduncle absent. Floral bracts absent. Flowers pedicellate. Perianth zygomorphic, posterior and lateral tepals connate for c. half their length; anterior tepal free. Staminal filaments adnate to tepals; anthers apiculate. Hypogynous glands 2, adaxial, or rarely 4, free. Carpel sessile; ovules 2, hemitropous; style gently curved; pollen presenter swollen; stigma subterminal. Fruit drupaceous; seeds not winged. 2n = 28. Four species, rainforest, eastern Australia.

Knightia R. Br., Trans. Linn. Soc. London 10:193 (1810).

Trees. Plants bisexual. Leaves alternate, simple, with serrate margins. Conflorescence lateral, a raceme of flower pairs. Flower pair subtended by a scale-like, caducous bract; common peduncle present. Floral bracts absent. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Staminal filaments adnate to tepals; anthers apiculate. Hypogynous glands 4, free. Carpel sessile; ovules 4, hemitropous; style straight; pollen presenter swollen; stigma terminal. Fruit follicular; seeds winged. One species, K. excelsa R. Br., rainforest, New Zealand. 38. Eucarpha (R. Br.) Spach Eucarpha (R. Br.) Spach, Hist. Nat. Veg. Phan. 10:402 (1841); Virot, Fl. Nouv.-Caléd. Dépend. 2:236–246 (1968), as Knightia.

Shrubs or trees. Plants bisexual. Leaves alternate, simple, dentate or entire. Conflorescence terminal or lateral, a dense raceme of flower pairs, the whole subtended by an involucre of large, colourful, imbricate, caducous bracts. Flower pair subtended by a large, colourful, caducous bract; common peduncle present. Floral bracts absent. Flowers pedicellate. Perianth actinomorphic; tepals not connate. Staminal filaments adnate to tepals; anthers apiculate. Hypogynous glands 4, free or basally connate. Carpel sessile; ovules 4, hemitropous; style straight; pollen presenter swollen; stigma subterminal. Fruit follicular; seeds winged. Two species, shrubland to rainforest, New Caledonia. 39. Triunia L.A.S. Johnson & B.G. Briggs Triunia L.A.S. Johnson & B.G. Briggs, Bot. J. Linn. Soc. 70:175 (1975); Foreman, Fl. Australia 16:404–407 (1995).

Shrubs or trees. Plants bisexual. Leaves pseudoverticillate, simple, dentate or entire. Conflores-

V.1.a. Subtribe Roupalinae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. Adult leaves alternate. Conflorescence a raceme or panicle of flower pairs; common peduncle absent. Floral bracts absent. Perianth actinomorphic; tepals not connate. Hypogynous glands 4. Carpel sessile; style straight. Fruit follicular; seeds winged. 40. Roupala Aubl.

Fig. 138

Roupala Aubl., Hist. Pl. Guiane: 83 (1775); Sleumer, Bot. Jahrb. 76:139–211 (1954).

Shrubs or trees. Leaves simple and entire to imparipinnately lobed or dissected or compound, usually with dentate margins. Conflorescence lateral. Flower pair subtended by a scale-like, sometimes caducous bract. Flowers pedicellate or sessile. Staminal filaments adnate to tepals; anthers apiculate. Hypogynous glands free. Ovules 2, orthotropous. Style tip swollen, functioning as a pollen presenter; stigma subterminal. 2n = 28. Thirty-three species (Prance et al. 2006), shrublands, savannas and rainforests, widespread, tropical South and Central America. 41. Neorites L.S. Sm. Neorites L.S. Sm., Contr. Queensland Herb. 6:15 (1969); Hewson, Fl. Australia 16:352–353 (1995).

Trees. Adult leaves dentate, occasionally pinnatisect, otherwise entire. Conflorescence lateral, a panicle of spikes of flower pairs. Flower pair subtended by an ovate, caducous bract. Flowers sessile. Staminal filaments adnate to tepals except towards tips; anthers inapiculate. Hypogynous glands free. Ovules 6–8, hemitropous. Style tip slightly swollen but not functioning as pollen

Proteaceae

393

presenter; stigma strongly oblique. 2n = 28. One species, N. kevediana L.S. Sm., rainforest, north-eastern Australia. 42. Orites R. Br. Orites R. Br., Trans. Linn. Soc. London 10:189 (1810); George, Fl. Australia 16:346–352 (1995).

Shrubs or trees. Adult leaves simple, entire or with toothed margins, sometimes also pinnately lobed. Conflorescence terminal or lateral, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by an ovate to linear, caducous bract. Flowers pedicellate or subsessile. Staminal filaments basally to almost completely adnate to tepals; anthers inapiculate or apiculate. Hypogynous glands free or basally connate. Ovules 2, hemitropous. Style tip sometimes functioning as pollen presenter, slightly swollen or not; stigma terminal. 2n = 28. Eight species, alpine shrubland to rainforest, eastern Australia including Tasmania, Chile and Argentina. V.1.b. Subtribe Lambertiinae (Venkata Rao) L.A.S. Johnson & B.G. Briggs (1975). Leaves simple. Anthers free; pollen grains triporate. Carpel sessile; ovules 2. Style tip functioning as pollen presenter; stigma terminal. Fruit a woody follicle; seeds winged. 43. Lambertia Sm. Lambertia Sm., Trans. Linn. Soc. London 4:214, 223 (1798); Hnatiuk, Fl. Australia 16:425–436 (1995).

Fig. 138. Proteaceae. Roupala montana. A Flowering branch. B Dentate leaf. C Deeply lobed leaf. D Compound leaf. E Flower. F Tepal with anther. G Ovary, vertical section, with hypogynous glands. H Fruit. I Seed. (Drawn by C. Wardrop)

Shrubs or small trees. Plants bisexual. Leaves in whorls of 3 or opposite-decussate, entire or with dentate margins. Conflorescence terminal, a capitulum of 1–19 flowers (most commonly of 3 lateral flower pairs surrounding a central terminal flower), the whole subtended by an involucre of large, imbricate, often colourful bracts. Flower pair subtended by a large, often colourful bract; common peduncle absent. Floral bracts absent. Flowers sessile. Perianth actinomorphic or zygomorphic and curving to anterior or posterior; tepals basally connate, forming a tube with free lobes. Staminal filaments adnate to tepals; anthers equal, apiculate or inapiculate. Hypogynous glands 4(–2), connate or free, or absent. Ovules orthotropous. Style straight or gently curved; pollen presenter slightly swollen; stigma terminal. 2n = 28. Ten species, shrubland to eucalypt forest, south-western and south-eastern Australia.

394

P.H. Weston

44. Xylomelum Sm. Xylomelum Sm., Trans. Linn. Soc. London 4:214 (1798); Foreman, Fl. Australia 16:399–403 (1995).

Shrubs or trees. Plants andromonecious. Leaves opposite-decussate, entire or with dentate margins. Conflorescence lateral or terminal, a spike of flower pairs, or a panicle of such spikes. Flower pair subtended by a scale-like, often caducous bract; common peduncle absent. Floral bracts absent. Flowers sessile or shortly pedicellate. Perianth actinomorphic; tepals not connate. Staminal filaments adnate to tepals; anthers apiculate. Hypogynous glands 4, free. Ovules anatropous. Style straight; pollen presenter swollen; stigma terminal. 2n = 28. Six species, shrubland to eucalypt forest, south-western and eastern Australia. V.1.c. Subtribe Heliciinae L.A.S. Johnson & B.G. Briggs (1975). Leaves simple. Conflorescence a raceme of flower pairs. Perianth actinomorphic; tepals not connate. Staminal filaments adnate to tepals; anthers apiculate; pollen grains triporate. Carpel sessile; ovules anatropous; style straight, tip swollen, functioning as pollen presenter; stigma terminal. Seeds not winged. 45. Helicia Lour. Helicia Lour., Fl. Cochinch. 1:83 (1790); Sleumer, Blumea 8:2–95 (1955); Foreman, Handb. Fl. Papua New Guinea 3:234–268 (1995); Pham, Fl. Cambodge Laos Vietnam 26:86–109 (1992); Foreman, Fl. Australia 16:393–399 (1995).

Shrubs or trees. Plants bisexual or andromonoecious. Leaves alternate or rarely opposite, entire or dentate. Conflorescence lateral or rarely terminal. Flower pair subtended by a scale-like, usually caducous bract; common peduncle present or absent. Floral bracts scale-like, often decurrent on pedicels, or absent. Flowers pedicellate. Hypogynous glands 4, free or connate. Ovules 2. Fruit indehiscent, drupaceous or dry. 2n = 28. One hundred species, rainforests, southern India, Sri Lanka, China and Japan to southeastern Australia, with centre of diversity in New Guinea.

Shrubs or trees. Plants bisexual. Leaves alternate, dentate or entire. Conflorescence lateral. Flower pair subtended by a scale-like bract; common peduncle usually present. Floral bracts scale-like. Flowers pedicellate or sessile on common peduncle. Hypogynous glands 4, free. Ovules 4–14. Fruit follicular. 2n = 28. Two species, rainforest, north-eastern Australia. V.1.d. Subtribe Floydiinae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. Leaves alternate. Conflorescence lateral. Flowers paired. Floral bracts absent. Perianth actinomorphic; tepals not connate. Anthers apiculate; pollen grains triporate. Hypogynous glands 4, free. Ovary sessile; style straight, tip functioning as pollen presenter; stigma terminal. 47. Darlingia F. Muell. Darlingia F. Muell., Fragm. 5:152 (1866); Hyland, Fl. Australia 16:356–357 (1995).

Trees. Leaves simple, entire or pinnately lobed. Conflorescence a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a broad, caducous bract; common peduncle vestigial. Flowers shortly pedicellate. Staminal filaments adnate to tepals, sometimes free at tips; Ovules 4, hemitropous. Fruit follicular; seeds winged. 2n = 28. Two species, rainforest, north-eastern Australia. 48. Floydia L.A.S. Johnson & B.G. Briggs Floydia L.A.S. Johnson & B.G. Briggs, Bot. J. Linn. Soc. 70:175 (1975); Foreman, Fl. Australia 16:417–419 (1995).

Trees. Leaves simple, entire. Conflorescence a raceme of flower pairs. Flower pair subtended by a scale-like bract; common peduncle present. Flowers shortly pedicellate. Staminal filaments adnate to tepals except at tips; Ovules 2, orthotropous. Fruit dry, indehiscent; seed not winged. 2n = 28. One species, F. praealta (F. Muell.) L.A.S. Johnson & B.G. Briggs, rainforest, eastern Australia. V.2. Tribe Banksieae Reichb. (1828).

46. Hollandaea F. Muell. Hollandaea F. Muell., Chem. & Druggist Australasia 2:173 (1887); Hyland, Fl. Australia 16:391–393 (1995).

Flowers paired, each pair subtended by a scale-like bract. Staminal filaments adnate to tepals except at tips; anthers free, apiculate. Pollen grains bipo-

Proteaceae

rate. Carpel sessile; style tip functioning as pollen presenter. Fruit follicular. V.2.a. Subtribe Musgraveinae L.A.S. Johnson & B.G. Briggs (1975). Trees. Plants andromonoecious. Leaves alternate. Common peduncle of flower pair present. Floral bracts scale-like. Perianth actinomorphic; tepals not connate. Stamens equal. Hypogynous glands 3, anterior and lateral, free. Ovules hemitropous. Stigma apparently terminal. False dissepiment scarcely formed between seeds; seeds winged. 49. Musgravea F. Muell. Musgravea F. Muell., Proc. Linn. Soc. New South Wales ser. 2, 5:186 (1890); Hyland, Fl. Australia 17B:170–172 (1999).

Leaves simple, entire or pinnately lobed. Conflorescence terminal or lateral, a raceme of flower pairs, or a panicle of such racemes. Flowers sessile on common peduncle. Ovules 1 or 2. Pollen presenter swollen or not. 2n = 28. Two species, rainforest, north-eastern Australia. 50. Austromuellera C.T. White Austromuellera C.T. White, Bull. Misc. Inform. Kew 1930:234 (1930); Hyland, Fl. Australia 17B:173–175 (1999).

Leaves simple, entire or imparipinnately dissected or compound. Conflorescence lateral, a raceme of flower pairs. Flowers shortly pedicellate. Ovules 1 or 2. Pollen presenter slightly swollen. 2n = 28. Two species, rainforest, north-eastern Australia. V.2.b. Subtribe Banksiinae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. Leaves simple. Flowers sessile. Tepals basally connate. Anthers equal. Hypogynous glands 4, free. Ovules 2, Ovules hemitropous to anatropous. 51. Banksia L. f. Banksia L. f., Suppl. Pl. 15 (1782); George, Fl. Australia 17B:175–251 (1999).

Shrubs or trees. Leaves alternate or whorled, pinnately lobed or dissected or with dentate to entire margins. Conflorescence terminal (often on a short lateral shoot), a dense, cylindrical to hemispherical, spike or capitulm of flower pairs, the whole

395

subtended by an involucre of scale-like bracts. Floral bracts scale-like. Perianth actinomorphic or zygomorphic. Style straight or hooked; pollen presenter swollen or not; stigma terminal, oblique or ventral. False dissepiment formed between seeds; seeds winged. 2n = 28. Seventy-six species, shrublands, savannas, woodlands and sclerophyll forests, widespread in Australia including Tasmania, one species extending to southern New Guinea. Banksia is paraphyletic, including Dryandra as a subclade (Mast and Givnish 2002). 52. Dryandra R. Br. Dryandra R. Br., Trans. Linn. Soc. London 10:211 (1810); George, Fl. Australia 17B:251–363 (1999).

Shrubs or trees. Leaves alternate, entire or serrate to pinnately or bipinnately lobed or dissected. Conflorescence terminal or lateral, a hemispherical capitulum of flower pairs, the whole subtended by an involucre of imbricate bracts. Floral bracts scalelike or absent. Perianth actinomorphic or zygomorphic. Style straight or curved; pollen presenter swollen or not; stigma oblique. False dissepiment formed between seeds or absent; seed wing present or absent. 2n = 28. Ninety-three species, shrublands, woodlands and sclerophyll forests, southwestern Australia. V.3. Tribe Embothrieae Reichb. (1828). Common peduncle of flower pairs absent. Floral bracts absent. Staminal filaments adnate to tepals; anthers equal, free, minutely apiculate to inapiculate. Style tip functioning as pollen presenter, swollen. Ovules hemitropous. V.3.a. Subtribe Lomatiinae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. Flower pair subtended by a scale-like bract. Flowers pedicellate. Perianth zygomorphic. Pollen grains triporate. Hypogynous glands 3, anterior and lateral, free. Carpel diagonally oriented, prominently stipitate; ovules numerous; style abruptly ventrally bent immediately above base, curved to tip; pollen presenter swollen, oblique; stigma ventral. Fruit follicular; seeds winged. 53. Lomatia R. Br. Lomatia R. Br., Trans. Linn. Soc. London 10:199 (1810); Wilson, Hewson & Mowatt, Fl. Australia 16:374–382 (1995).

396

P.H. Weston

Shrubs or trees. Leaves alternate or opposite, simple or imparipinnately to tripinnately lobed or compound, often with toothed margins. Conflorescence terminal or lateral, a raceme of flower pairs, or a panicle of such racemes. Tepals not connate. 2n = 22. Twelve species, shrublands to rainforests, eastern Australia including Tasmania, Chile, Argentina, Peru and Ecuador. V.3.b. Subtribe Embothriinae Endl. (1837). Plants bisexual. Adult leaves alternate. Conflorescence a raceme of flower pairs. Flower pair subtended by a scale-like bract. Flowers pedicellate. Perianth zygomorphic. Hypogynous gland solitary, anterior, crescentic to horseshoe-shaped. Carpel diagonally oriented, prominently stipitate; ovules numerous; style gently ventrally curved; pollen presenter swollen. Fruit follicular; seeds winged.

by an involucre of bracts. Tepals connate almost to tips except between posterior tepals. Pollen grains triporate. Pollen presenter strongly oblique; stigma ventral. 2n = 22. Four species, rainforests, eastern Australia, southern New Guinea and Aru Island. 57. Telopea R. Br. Telopea R. Br., Trans. Linn. Soc. London 10:197 (1810); Crisp & Weston, Fl. Australia 16:386–390 (1995).

Shrubs or trees. Adult leaves simple, entire or with dentate margins or occasionally imparipinnately lobed. Conflorescence terminal, subtended by an involucre of large, imbricate, often colourful bracts. Tepals free from each other or connate almost to tips except between posterior tepals. Pollen grains triporate. Pollen presenter strongly oblique; stigma ventral. 2n = 22. Five species, shrublands to rainforests, south-eastern Australia including Tasmania.

54. Embothrium J.R. Forst. & G. Forst. Embothrium J.R. Forst. & G. Forst., Charact. Gen. 15 (1776); Sleumer, Bot. Jahrb. Syst. 76:139–211 (1954).

Shrubs or trees. Leaves simple, entire. Conflorescence terminal or lateral, not subtended by an involucre of bracts. Tepals connate in basal half except between posterior tepals. Pollen grains biporate. Pollen presenter fusiform; stigma terminal. 2n = 22. One species, E. coccineum R. Forst. & G. Forst., alpine shrublands to rainforests, Chile, Argentina.

V.3.c. Subtribe Stenocarpinae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. Adult leaves alternate. Floral bracts absent. Flowers pedicellate. Tepals not connate. Pollen grains triporate. Carpel with antero-posterior orientation, prominently stipitate; style ventrally curved, tip functioning as pollen presenter, swollen; pollen presenter strongly oblique; stigma ventral. Fruit follicular; seed winged.

55. Oreocallis R. Br. Oreocallis R. Br., Trans. Linn. Soc. London 10:196 (1810); Sleumer, Bot. Jahrb. Syst. 76:139–211 (1954).

Shrubs or trees. Leaves simple, entire. Conflorescence terminal or lateral, not subtended by an involucre of bracts. Tepals connate almost to tips except between posterior tepals. Pollen grains triporate. Pollen presenter strongly oblique; stigma ventral. 2n = 22. One or two species, montane shrublands to rainforests, Peru and Ecuador. 56. Alloxylon P.H. Weston & Crisp Alloxylon P.H. Weston & Crisp, Telopea 4:498 (1991); Weston & Crisp, Telopea 4:497–507 (1991).

Trees. Adult leaves simple and entire or imparipinnately lobed or imparipinnately compound. Conflorescence terminal or lateral, not subtended

58. Stenocarpus R. Br. Stenocarpus R. Br., Trans. Linn. Soc. London 10:201 (1810); Virot, Fl. Nouv.-Caléd. Dépend. 2:176–236 (1968), Foreman, Fl. Australia 16:363–369 (1995).

Shrubs or trees. Leaves simple and entire to pinnately to tripinnately lobed or compound. Conflorescence terminal or lateral, an umbel of flower pairs, or a panicle of such umbels. Flower pair ebracteate or subtended by a scale-like bract. Perianth zygomorphic. Anthers minutely apiculate or inapiculate. Hypogynous gland solitary, anterior, oblong to horseshoe-shaped. Ovules numerous. 2n = 22. Twenty-one species, shrublands to rainforests, northern and eastern Australia, New Guinea, Aru Island, New Caledonia. Stenocarpus is probably paraphyletic, including Strangea as a subclade.

Proteaceae

59. Strangea Meisn. Strangea Meisn., Hooker’s J. Bot. Kew Gard. Misc. 7:66 (1855); Hnatiuk, Fl. Australia 16:360–363 (1995).

Shrubs. Leaves simple, entire or rarely trilobed. Conflorescence lateral or terminal, an umbel of flower pairs, a panicle of such umbels, or reduced to 1 or 2 flowers. Flower pair subtended by a scale-like bract. Perianth zygomorphic to almost actinomorphic. Anthers inapiculate. Hypogynous glands absent. Ovules 1–2. 2n = 22. Three species, shrublands, south-western and eastern Australia. V.3.d. Subtribe Hakeinae Endl. (1837). Adult leaves alternate. Pollen grains triporate. Style tip functioning as pollen presenter, swollen. 60. Opisthiolepis L.S. Sm. Opisthiolepis L.S. Sm., Proc. Roy. Soc. Queensland 62:79 (1952); Foreman, Fl. Australia 16:373–374 (1995).

Trees. Plants bisexual. Adult leaves usually simple and entire or sparsely dentate but sometimes imparipinnately lobed or compound. Conflorescence lateral, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a caducous, scale-like bract. Flowers pedicellate. Perianth zygomorphic; tepals not connate. Hypogynous gland solitary, anterior, 2-lobed. Carpel with antero-posterior orientation, shortly stipitate; ovules 10–12; style abruptly bent immediately above ovary; pollen presenter disc-like, oblique; stigma ventral. Fruit follicular; seeds winged. 2n = 22. One species, O. heterophylla L.S. Sm., rainforest, north-eastern Australia. 61. Buckinghamia F. Muell. Buckinghamia F. Muell., Fragm. 6:248 (1868); Foreman & Hyland, Fl. Australia 16:371–373 (1995).

Trees. Plants bisexual. Adult leaves simple, entire. Conflorescence terminal or lateral, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a scale-like bract. Flowers pedicellate. Perianth zygomorphic; posterior tepal free, anterior and lateral tepals basally connate. Hypogynous gland solitary, anterior, horseshoe-shaped. Carpel with antero-posterior orientation, stipitate; ovules 4; style strongly curved; pollen presenter disc-like, oblique; stigma ventral. Fruit follicular;

397

seeds winged. 2n = 22. Two species, rainforests, north-eastern Australia. 62. Hakea Schrad. & J.C. Wendl. Hakea Schrad. & J.C. Wendl, Sert. Hannov. 27 (1797); Barker, Haegi & Barker, Fl. Australia 17B:1–170 (1999).

Shrubs or trees. Plants bisexual or cryptically monoecious or dioecious or rarely sterile. Adult leaves simple and entire or dentate or imparipinnately dissected or compound. Conflorescence lateral or terminal, usually a raceme or umbel of flower pairs, the whole usually subtended by an involucre of imbricate bracts but occasionally reduced to a single flower. Flower pair ebraceate or subtended by minute, caducous, scale-like bract. Flowers pedicellate. Perianth actinomorphic or zygomorphic; tepals not connate or fused almost to tips except between posterior tepals. Hypogynous gland solitary, anterior, crescentic. Carpel diagonally oriented, stipitate or subsessile; ovules 2; style straight to curved, hooked, sinuous or bent; pollen presenter ± radially symmetrical to strongly oblique; stigma terminal or ventral. Fruit a woody follicle; seeds winged. 2n = 20. One hundred and forty-nine species, shrublands, savannas, woodlands and sclerophyll forests, widespread in Australia including Tasmania. 63. Grevillea R. Br. ex Knight

Fig. 139

Grevillea R. Br. ex Knight, Cult. Prot. xvii, 120 (1809); McGillivray & Makinson, Grevillea (Proteaeae) – a taxonomic revision (1993); Olde & Marriott, Grevillea Book 1 (1994), 2–3 (1995); Makinson, Fl. Australia 17A:1–524 (2000).

Shrubs or trees. Plants bisexual. Adult leaves simple, entire or dentate or imparipinnately to tripinnately dissected. Conflorescence terminal or lateral, a raceme, umbel or capitulum of flower pairs, or a panicle of such structures, or rarely reduced to a single flower or flower pair. Flower pair subtended by a scale-like bract. Flowers pedicellate or sessile. Perianth actinomorphic or zygomorphic; tepals variously connate or not. Hypogynous gland solitary, anterior, oblong to horseshoe-shaped or annular, rarely 4-lobed or absent. Carpel diagonally oriented, sessile to prominently stipitate; Ovules 2; style straight to curved, hooked, sinuous or bent; pollen presenter ± radially symmetrical to strongly oblique; stigma terminal or ventral. Fruit follicular or rarely an achene; seeds winged or rarely wingless. 2n = 20.

398

P.H. Weston

Three hundred and sixty-two species, shrublands, savannas, woodlands, sclerophyll forests and rainforests, widespread in Australia including Tasmania, New Caledonia, New Guinea and Sulawesi. Grevillea is probably polyphyletic, including both Hakea and Finschia as subclades (Weston and Porter, unpubl. data). 64. Finschia Warb. Finschia Warb., Bot. Jahrb. 13:297 (1891); Foreman, Handb. Fl. Papua New Guinea 3:228–232 (1995).

Trees. Plants bisexual. Leaves alternate, simple, entire. Conflorescence lateral, a raceme of flower pairs. Flower pair subtended by a scale-like, usually caducous bract or ebracteate; Flowers pedicellate. Perianth zygomorphic, diagonally oriented; tepals not connate. Hypogynous gland solitary, anterior, horseshoe-shaped. Carpel prominently stipitate; ovules 2; style strongly ventrally bent; pollen presenter swollen, conical; stigma terminal. Fruit drupaceous; seeds hemispherical, wingless. 2n = 20. Four species, rainforests, New Guinea, with one species extending northwest to Palau Island and southeast to Vanuatu. V.4. Tribe Macadamieae C. Venkata Rao (1968). Flowers paired. Tepals not connate. Anthers equal, free, apiculate. Pollen grains triporate. Ovary sessile; style tip functioning as pollen presenter. V.4.a. Subtribe Macadamiinae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. Leaves simple. Common peduncle absent. Floral bracts absent. Flowers pedicellate. Stamens equal. Hypogynous gland solitary, cylindrical to cup-like, surrounding base of ovary. Ovules 2, orthotropous. Seed not winged. 65. Macadamia F. Muell. Macadamia F. Muell., Trans. Proc. Philos. Inst. Victoria 2:72 (1857); Gross, Fl. Australia 16:419–425 (1995). Fig. 139. Proteaceae. Grevillea robusta. A Flowering branch. B Leaf. C Unopened Flower. D Open flower. E Pollen presenter and stigma. F Ovary with gynophore and nectary. G Ovary, vertical section. H Tepals with anthers. I Fruit, back view. J Fruit, side view. K Seed, side view (below) and top view (above). (Drawn by L. Elkan)

Trees. Leaves whorled, entire or dentate. Conflorescence terminal or lateral, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a scale-like bract. Perianth actinomorphic or slightly zygomorphic. Staminal filaments basally adnate to tepals or free only towards tips.

Proteaceae

399

Style straight, curved or geniculate; pollen presenter slightly swollen or not; stigma terminal. Fruit dry, indehiscent or follicular. 2n = 28. Nine species, rainforests, eastern Australia, Sulawesi. Macadamia appears to be paraphyletic, including both Panopsis and Brabejum as subclades (Weston and Downs, unpubl. data). 66. Panopsis Salisb. Panopsis Salisb. in Knight, Cult. Prot. 104 (1809); Sleumer, Bot. Jahrb. Syst. 76:139–211 (1954).

Shrubs or trees. Leaves alternate, oppositedecussate or 4-whorled, entire. Conflorescence terminal or lateral, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a scale-like bract. Perianth actinomorphic. Staminal filaments basally adnate to tepals. Style straight; pollen presenter not to slightly swollen; stigma terminal. Fruit dry, indehiscent. Twenty-five species (Prance et al. 2006), shrublands, savannas, xerophytic woodlands, riparian forests and lowland to montane rainforests, widespread in tropical South and Central America. 67. Brabejum L.

Fig. 140

Brabejum L., Sp. Pl. 121 (1753).

Shrubs or trees. Leaves whorled, dentate. Conflorescence lateral, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a scale-like bract. Perianth actinomorphic. Stamens equal; filaments basally adnate to tepals. Style straight; pollen presenter slightly swollen; stigma terminal. Fruit dry, indehiscent. 2n = 28. One species, B. stellatifolium L., riparian shrublands, Southwest Cape region of South Africa. V.4.b. Subtribe Malagasiinae P.H. Weston & N.P. Barker (2006). Trees. Plants bisexual. Leaves alternate, simple, entire. Conflorescence lateral, a raceme of flower pairs. Flower pair subtended by a scale-like bract; common peduncle present. Floral bracts scale-like. Flowers pedicellate. Perianth actinomorphic. Stamens equal; filaments adnate to tepals except at tips. Hypogynous glands 4, free. Ovules 2, orthotropous. Stigma terminal. Fruit drupaceous; woody inner mesocarp smooth.

Fig. 140. Proteaceae. Brabejum stellatifolium. A Flowering branch. B Inflorescence. C Juvenile leaves. D Flower. E Tepal with stamen, adaxial view. F Same, abaxial view. G Flower, tepals removed. H Pollen presenter and stigma. I Ovary, nectaries and receptacle, vertical section. J Detail of inflorescence showing bracts and flower pairs. K Bract. L Fruit. M Same, vertical section. (Drawn by L. Elkan)

400

P.H. Weston

68. Malagasia L.A.S. Johnson & B.G. Briggs Malagasia L.A.S. Johnson & B.G. Briggs, Bot. J. Linn. Soc. 70:175 (1975); Bosser & Rabevohitra, Fl. Madag. Comores, famille 57. Protéacées: 64–67 (1991).

Floral bracts decurrent on pedicels. Staminal filaments adnate to tepals except at tips. Style straight but with a slight kink above the middle; pollen presenter slightly swollen. One species, M. alticola (Capuron) L.A.S. Johnson & B.G. Briggs, remnant forests, Madagascar. 69. Catalepidia P.H. Weston Catalepidia P.H. Weston, Fl. Australia 16:499 (1995); Weston, Fl. Australia 16:415–416 (1995).

Floral bracts basal or decurrent on pedicels. Staminal filaments adnate to tepals. Style straight; pollen presenter prominently swollen. One species, C. heyana (F.M. Bailey) P.H. Weston, montane rainforests, north-eastern Australia. V.4.c. Subtribe Virotiinae P.H. Weston & N.P. Barker (2006). Adult leaves alternate, simple. Flower pair subtended by a scale-like bract. Flowers pedicellate. Perianth actinomorphic. Stamens equal; filaments adnate to tepals. Ovules 2, orthotropous. Style straight; stigma terminal. Fruit drupaceous; woody inner mesocarp with pitted to reticulate sculpturing. 70. Virotia L.A.S. Johnson & B.G. Briggs

terminal or lateral, a raceme of flower pairs. Flower pair subtended by a scale-like bract; common peduncle present. Floral bracts scale-like. Hypogynous glands 4, free. Pollen presenter swollen. One species, A. diversifolia (C.T. White) L.A.S. Johnson & B.G. Briggs, montane rainforests, north-eastern Australia. 72. Heliciopsis Sleumer Heliciopsis Sleumer, Blumea 8:79 (1955); Sleumer, Blumea 8:79–86 (1955); Pham, Fl. Cambodge Laos Vietnam 26:109–112 (1992).

Trees. Plants dioecious. Adult leaves imparipinnately lobed to entire. Conflorescence lateral, a raceme of flower pairs. Common peduncle present or absent. Floral bracts scale-like, decurrent on pedicels. Anthers of female flowers lacking pollen. Hypogynous glands 4, free. Ovules absent in male flowers. Pollen presenter slightly swollen. Fourteen species, rainforests, Burma and southeastern China to Malesia, west of Wallace’s Line. V.4.d. Subtribe Gevuininae L.A.S. Johnson & B.G. Briggs (1975). Plants bisexual. Adult leaves alternate. Flower pair subtended by a scale-like bract. Floral bracts absent. Staminal filaments adnate to tepals. 73. Cardwellia F. Muell. Cardwellia F. Muell., Fragm. 5:23 (1865); Hyland, Fl. Australia 16:358–359 (1995).

Shrubs or trees. Plants bisexual. Adult leaves entire or imparipinnately lobed. Conflorescence terminal or lateral, a raceme of flower pairs. Common peduncle present. Floral bracts scale-like, sometimes decurrent on pedicels. Hypogynous gland solitary, annular, 4-lobed or minutely dentate. Pollen presenter swollen or not. 2n = 26. Six species, shrublands to rainforests, New Caledonia.

Trees. Adult leaves paripinnate, with entire leaflets. Conflorescence terminal, a panicle of racemes of flower pairs. Flower pair subtended by a scale-like, caducous bract; common peduncle present. Flowers sessile on common peduncle. Perianth zygomorphic. Hypogynous glands 4, free. Carpel orientation antero-posterior; ovules 10–14, hemitropous; style strongly curved; pollen presenter swollen, strongly oblique; stigma lateral. Fruit follicular; seeds winged. 2n = 28. One species, C. sublimis F. Muell., rainforests, north-eastern Australia.

71. Athertonia L.A.S. Johnson & B.G. Briggs

74. Sleumerodendron Virot

Athertonia L.A.S. Johnson & B.G. Briggs, Bot. J. Linn. Soc. 70:176 (1975); Weston, Fl. Australia 16:413–415 (1995).

Sleumerodendron Virot, Fl. Nouv.-Caléd. Dépend. 2:101– 109 (1968).

Trees. Plants bisexual. Adult leaves with serrate or entire margins, usually unlobed. Conflorescence

Trees. Adult leaves simple, entire. Conflorescence terminal or lateral, a raceme of flower pairs. Flower

Virotia L.A.S. Johnson & B.G. Briggs, Bot. J. Linn. Soc. 70:176 (1975); Virot, Fl. Nouv.-Caléd. Dépend. 2:109–140 (1968), treatment of Macadamia.

Proteaceae

pair subtended by a scale-like bract; common peduncle present. Flowers sessile on common peduncle. Perianth zygomorphic. Hypogynous glands 4, free. Carpel orientation antero-posterior; ovules 2, orthotropous; style strongly curved; pollen presenter swollen, strongly oblique; stigma lateral. Fruit drupaceous; seed not winged. One species, S. austrocaledonium (Brongn. & Gris) Virot, rainforests, New Caledonia. 75. Euplassa Salisb. Euplassa Salisb. in Knight, Cult. Prot. 101 (1809); Sleumer, Bot. Jahrb. Syst. 76:139–211 (1954).

Shrubs or trees. Adult leaves paripinnate, the leaflets with dentate or entire margins. Conflorescence lateral or rarely terminal, a raceme of flower pairs, or rarely a panicle of such racemes. Flower pair subtended by a scale-like bract; common peduncle present or absent. Flowers pedicellate or sessile on common peduncle. Perianth zygomorphic. Hypogynous glands 4, free or basally connate. Carpel orientation antero-posterior; ovules 2, orthotropous; style strongly curved; pollen presenter swollen, strongly oblique; stigma lateral. Fruit drupaceous; seed not winged. Twenty species (Prance et al. 2006), savannas to rainforests, widespread in tropical South America. 76. Gevuina Molina Gevuina Molina, Sag, Stor. Nat. Chili 184, 353 (1782); Sleumer, Bot. Jahrb. Syst. 76:139–211 (1954).

Trees. Adult leaves imparipinnate to tripinnate, the leaflets with serrate margins and the terminal leaflet often 3-lobed. Conflorescence lateral, a raceme of flower pairs. Flower pair subtended by a scale-like bract; common peduncle present. Flowers shortly pedicellate or sessile on common peduncle. Perianth zygomorphic. Hypogynous glands 2, anterior, free. Carpel orientation antero-posterior; ovules 2, orthotropous; style strongly curved; pollen presenter swollen, strongly oblique; stigma lateral. Fruit drupaceous; seed not winged. 2n = 26. One species, G. avellana Molina, rainforests and disturbed sites, Chile and Argentina. 77. Bleasdalea F. Muell. Bleasdalea F. Muell., Fragm. 5:91 (1865); Smith & Haas, Amer. J. Bot. 62:133–147 (1975), including species treated here as Turrillia.

401

Trees. Adult leaves imparipinnate or sometimes simple with dentate margins. Conflorescence lateral or terminal, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a scale-like bract; common peduncle present. Flowers sessile on common peduncle. Perianth zygomorphic. Hypogynous glands 1 or 2, free. Carpel orientation antero-posterior; ovules 2, orthotropous; style strongly curved; pollen presenter swollen, strongly oblique; stigma lateral. Fruit drupaceous; seed not winged. 2n = 26. Two species, rainforests, north-eastern Australia and New Guinea. Recent floristic treatments have placed these two Australasian species in a variety of genera, including Turrillia (Smith 1985) and Gevuina (Weston 1995). On the basis of morphology, they seem to be closely related sister species. So far, it has not been possible to obtain DNA of B. papuana but molecular systematic analyses (Weston, Barker and Downs, unpubl. data) of B. bleasdalei do not strongly resolve its relationship to other genera of Gevuininae. 78. Hicksbeachia F. Muell. Hicksbeachia F. Muell., S. Si. Rec. 3:33 (1883); Weston, Telopea 3:231–239 (1988).

Trees. Adult leaves imparipinnately lobed to compound, the leaflets with dentate margins, the terminal leaflet usually pinnately lobed, and the rachis usually prominently winged. Conflorescence lateral, a raceme of flower pairs. Flower pair subtended by a scale-like bract; common peduncle present. Flowers shortly pedicellate or sessile on common peduncle. Perianth actinomorphic. Hypogynous glands 4, free. Carpel straight; ovules 2, orthotropous; style straight; pollen presenter swollen, ovoid; stigma terminal. Fruit drupaceous; seed not winged. 2n = 26. Two species, rainforests and moist eucalypt forests, eastern Australia. 79. Kermadecia Brongn. & Gris Kermadecia Brongn. & Gris, Bull. Soc. Bot. France 10:228 (1863); Virot, Fl. Nouv.-Caléd. Dépend. 2:78–101 (1968).

Trees. Adult leaves simple, entire. Conflorescence lateral or terminal, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a scale-like bract; common peduncle present or absent. Flowers pedicellate or sessile on common peduncle. Perianth slightly to strongly zygomorphic. Hypogynous gland

402

P.H. Weston

solitary, anterior, crescentic or bilobed-oblong. Carpel orientation antero-posterior or diagonal; ovules 2, orthotropous; style straight or strongly curved; pollen presenter slightly swollen, fusiform or strongly oblique; stigma terminal or ventral. Fruit drupaceous; seed not winged. 2n = 28. Four species, rainforests, New Caledonia. Weston and Crisp (1996) asserted, on the basis of floral morphology, that K. pronyensis is misplaced in Kermadecia. However, molecular systematic analyses (Weston, Barker and Downs, unpubl. data) strongly group it with other species of Kermadecia. 80. Turrillia A.C. Sm. Turrillia A.C. Sm., Fl. Vitiensis Nova 3:753 (1985); Smith & Haas, Amer. J. Bot. 62:133–147 (1975), as Bleasdalea, including species treated here in that genus.

Trees. Adult leaves imparipinnate or simple with entire margins. Conflorescence lateral or terminal, a raceme of flower pairs, or a panicle of such racemes. Flower pair subtended by a scale-like bract; common peduncle present. Flowers sessile on common peduncle. Perianth slightly to strongly zygomorphic. Hypogynous gland solitary, anterior. Carpel orientation antero-posterior; ovules 2, orthotropous; style straight or strongly curved; pollen presenter slightly swollen, conical or strongly oblique; stigma terminal or lateral. Fruit drupaceous; seed not winged. Three species, rainforests, Vanuatu, Fiji. Recent taxonomic and floristic treatments have placed these three species in a variety of genera, including Bleasdalea (Smith & Haas 1975). On the basis of morphology they seem to form a clade of closely related species. So far, it has been possible to obtain DNA of only T. lutea from Vanuatu and molecular systematic analyses (Weston, Barker and Downs, unpubl. data) weakly group it with Kermadecia.

Selected Bibliography APG II 2003. See general references. Askin, R.A., Baldoni, A.M. 1998. The Santonian through Paleogene record of Proteaceae in the southern South America-Antarctic Peminsula region. Austral. Syst. Bot. 11:373–390. Auld, T.D., Denham, A.J. 1999. The role of ants and mammals in dispersal and post-dispersal seed predation of the shrubs Grevillea (Proteaceae). Pl. Ecol. 144:201–213. Barker, N.P., Weston, P.H., Rourke, J.P., Reeves, G. 2002. The relationships of the southern African Proteaceae as elucidated by internal transcribed spacer (ITS) DNA sequence data. Kew Bull. 57:867–883.

Bieleski, R.L., Briggs, B.G. 2005. Taxonomic patterns in the distribution of polyols within the Proteaceae. Austral. J. Bot. 53:205–217. Blackmore, S., Barnes, S.H. 1995. Garsides rule and the microspore tetrads of Grevillea rosmarinifolia A. Cunnigham and Dryandra polycephala Bentham (Proteaceae). Rev. Palaeobot. Palynol. 85:111–121. Bond, W.J. 1985. Canopy-stored seed reserves (serotiny) in Cape Proteaceae. S. African J. Bot. 51:181–186. Bond, W.J. 1988. Proteas as ‘tumbleseeds’: wind dispersal through the air and over soil. S. African J. Bot. 54:455– 460. Bond, W.J., Breytenbach, G.J. 1985. Ants, rodents and seed predation in Proteaceae. S. African J. Zool. 20:150–154. Boothroyd, L.E. 1930. The morphology and anatomy of the inflorescence and flower of the Platanaceae. Amer. J. Bot. 17:678–693. Brown, R. 1810. On the Proteaceae of Jussieu. Trans. Linn. Soc. 10:15–226. Buchanan, R.A. 1989. Pied currawongs (Strepera graculina): their diet and role in seed dispersal in suburban Sydney, New South Wales. Proc. Linn. Soc. New South Wales 111:241–255. Carpenter, R.J. 1994. Cuticular morphology and aspects of the ecology and fossil history of North Queensland rainforest Proteaceae. Bot. J. Linn. Soc. 116:249–303. Carpenter, R.J., Jordan, G.J. 1997. Early Tertiary macrofossils of Proteaceae from Tasmania. Austral. Syst. Bot. 10:533–563. Carpenter, R.J., Hill, R.S., Jordan, G.J. 2005. Leaf cuticular morphology links Platanaceae and Proteaceae. Intl J. Pl. Sci. 166:843–855. Chattaway, M.M. 1948. The wood anatomy of the Proteaceae. Austral. J. Sci. Res. B, 1:279–302. Collins, B.G., Rebelo, T. 1987. Pollination biology of the Proteaceae in Australia and southern Africa. Austral. J. Ecol. 12:387–422. Cronquist, A. 1981. See general references. Crous, P.W., Denman, S., Taylor, J.E., Swart, L., Palm, M.E. 2004. Cultivation and diseases of Proteaceae: Leucadendron, Leucospermum and Protea. Utrecht: Centraalbureau voor Schimmelcultures. Dettmann, M.E., Jarzen, D.M. 1998. The early history of the Proteaceae in Australia: the pollen record. Austral. Syst. Bot. 11:401–438. Dillon, R.J. 2002. The diversity of scleromorphic structures in leaves of Proteaceae. Honours Thesis, University of Tasmania, Hobart, Australia. Dinkelaker, B., Hengeler, C., Marschner, H. 1995. Distribution and function of proteoid roots and other root clusters. Bot. Acta 108:183–200. Douglas, A.W. 1995a. Affinities. Flora of Australia 16:6–14. Collingwood: CSIRO. Douglas, A.W. 1995b. Morphological features. Flora of Australia 16:14–20. Collingwood: CSIRO. Douglas, A.W. 1996. Inflorescence and floral development of Carnarvonia (Proteaceae). Telopea 6:749–774. Douglas, A.W., Tucker, S.C. 1996a. Inflorescence ontogeny and floral organogenesis in Grevilleoideae (Proteaceae), with emphasis on the nature of the flower pairs. Intl J. Pl. Sci. 157:341–372. Douglas, A.W., Tucker, S.C. 1996b. The developmental basis of diverse carpel orientations in Grevilleoideae (Proteaceae). Intl J. Pl. Sci. 157:373–397.

Proteaceae Douglas, A.W., Tucker, S.C. 1996c. Comparative floral ontogenies among Persoonioideae including Bellendena (Proteaceae) Amer. J. Bot. 83:1528–1555. Feuer, S. 1990. Pollen morphology of the Embothrieae (Proteaceae) II. Embothriinae (Embothrium, Oreocallis, Telopea). Grana 29:19–36. Goldingay, R.L., Carthew, S.M. 1998. Breeding and mating systems of Australian Proteaceae. Austral. J. Bot. 46:421–437. Haber, J.M. 1960. The comparative anatomy and morphology of the flowers and inflorescences of the Proteaceae. I. Some Australian taxa. Phytomorphology 9:325–358. Haber, J.M. 1961. The comparative anatomy and morphology of the flowers and inflorescences of the Proteaceae. II. Some American taxa. Phytomorphology 11:1–16. Haber, J.M. 1966. The comparative anatomy and morphology of the flowers and inflorescences of the Proteaceae. III. Some African taxa. Phytomorphology 16:490–527. Hammill, K.A., Bradstock, R.A., Allaway, W.G. 1998. Postfire seed dispersal and species re-establishment in proteaceous heath. Austral. J. Bot. 46:407–419. Hill, R.S., Scriven, L.J., Jordan, G.J. 1995. The fossil record of Australian Proteaceae. Flora of Australia 16:21–30. Collingwood: CSIRO. Hoot, S.B., Douglas, A.W. 1998. Phylogeny of the Proteaceae based on atpB and atpB-rbcL intergenic spacer region sequences. Austral. Syst. Bot. 11:301–320. Johnson, L.A.S., Briggs, B.G. 1963. Evolution in the Proteaceae. Austral. J. Bot. 11:21–61. Johnson, L.A.S., Briggs, B.G. 1975. On the Proteaceae – the evolution and classification of a southern family. Bot. J. Linn. Soc. 70:83–182. Jordan, G.J., Carpenter, R.J., Hill, R.S. 1998. Macrofossil evidence of past diversity of Proteaceae in Tasmania, including nine new species. Austral. Syst. Bot. 11:465– 501. Jordan, G.J., Dillon, R.A., Weston, P.H. 2005. Solar radiation as a factor in the evolution of scleromorphic leaf anatomy in Proteaceae. Amer. J. Bot. 92:789–796. Karingal Consultants 1997. The Australian Wildflower Industry, a Review, 2nd edn. Melbourne: Rural Industries Research & Development Corporation, Res. Pap. no. 97/64. Ladd, P.G., Nanni, I., Thomson, G.J. 1998. Unique stigmatic structure in three genera of Proteaceae. Austral. J. Bot. 46:479–488. Lamont, B.B., Groom, P.K. 1998. Seed and seedling biology of the woody-fruited Proteaceae. Austral. J. Bot. 46:387–406. Lanyon, J.W. 1979. The wood anatomy of three proteaceous timbers Placospermum coriaceum, Dilobuia thouarsii and Garnieria spathulaefolia. IAWA Bull. 1979, 2/3:27– 33. Lee, H.M. 1978. Studies of the family Proteaceae II. Further observations on the root morphology of some Australian genera. Proc. Roy. Soc. Victoria 90:251–256. Manning, J.C., Brits, G.J. 1993. Seed coat development in Leucospermum cordifolium (Knight) Fourcade (Proteaceae) and a clarification of the seed covering structures in Proteaceae. Bot. J. Linn. Soc. 112:139–148. Mast, A.R., Givnish, T.J. 2002. Historical biogeography and the origin of stomatal distributions in Banksia and Dryandra (Proteaceae) based on their cpDNA phylogeny. Amer. J. Bot. 89:1311–1323.

403

Maynard, G.V. 1995. Pollinators of Australian Proteaceae. Flora of Australia 16:30–36. Collingwood: CSIRO. Metcalfe, C.R., Chalk, L. 1950. Anatomy of the Dicotyledons, 2. Clarendon Press: Oxford. Netolitzky, F. 1926. Anatomie der Angiospermen-Samen. In: Linsbauer, K. (ed.) Handbuch der Pflanzenanatomie, X, 4. Berlin: Bornträger. Nicolson, S.W., Van Wyk, B.-E. 1998. Nectar sugars in Proteaceae: patterns and process. Austral. J. Bot. 46:489– 504. Orchard, A.E. 1995. Utilisation. Flora of Australia 16:37–41. Collingwood: CSIRO. Pole, M. 1998. The Proteaceae record in New Zealand. Austral. Syst. Bot. 11:343–372. Prance, G.T., Plana, V., Edwards, K.S., Pennington, R.T. 2006. Proteaceae. Flora Neotropica (in press). New York Botanical Garden Press. Rebelo, T. 1995. Sasol Proteas: a field guide to the proteas of southern Africa. Vlaeberg: Fernwood Press. Rourke, J.P. 1998. A review of the systematics and phylogeny of the African Proteaceae. Austral. Syst. Bot. 11:267– 285. Sleumer, H. 1955. Proteaceae. Flora Malesiana ser. I, 5(2):147–206. Leiden: Noordhoff. Smith, A.C. 1985. Flora Vitiensis Nova: A New Flora of Fiji (Spermatophytes only). Lawai: Pacific Tropical Botanical Garden. Smith, A.C., Haas, J.E. 1975. Studies of Pacific island plants XXIX. Bleasdalea and related genera of Proteaceae. Amer. J. Bot. 62:133–147. Soltis, D.E. et al. 2000. See general references. Soltis, D.E. et al. 2003. See general references. Stace, H.M., Douglas, A.W., Sampson, J.F. 1998. Did ‘paleopolyploidy’ really occur in Proteaceae? Austral. Syst. Bot. 11:613–629. Stevens, P.F. 2005. See general references. Strohschen, B. 1986a. Contributions to the biology of useful plants 4. Anatomical studies of fruit development and fruit classification of the macadamia nut (Macadamia integrifolia Maiden and Betche.) Angew. Bot. 60:239– 247. Strohschen, B. 1986b. Contributions to the biology of useful plants, 5. Anatomical studies of fruit development and fruit classification of the monkey nut (Hicksbeachia pinnatifolia F. Muell.) Angew. Bot. 60:249–256. Strohschen, B. 1986c. Contributions to the biology of useful plants, 6. Anatomical studies of fruit development and fruit classification of Persoonia pinifolia R. Br. Angew. Bot. 60:257–265. Swenson, W.K., Dunn, J.E., Conn, E.E. 1989. Cyanogenesis in the Proteaceae. Phytochemistry 28:821–823. United States Department of Agriculture 2004. Situation and outlook for macadamias. http://www.fas.usda.gov/ htp/Hort_Circular/2001/01-03/MacfeatTOC.htm Venkata Rao, C. 1971. Proteaceae. New Delhi: Council of Scientific & Industrial Research. Vogts, M. 1982. South Africa’s Proteaceae, know them and grow them. Cape Town: C. Struik. Walter, K.S., Gillett, H.J. (eds) 1998. 1997 IUCN Red List of Threatened Plants. Gland, Switzerland and Cambridge, UK: IUCN, The World Conservation Union. Ward, J.V., Doyle, J.A. 1994. Ultrastructure and relationships of mid-Cretaceous polyforate and triporate pollen from northern Gondwana. In: Kurmann, M.H.,

404

P.H. Weston

Doyle, J.A. (eds) Ultrastructure of fossil spores and pollen. Royal Botanic Gardens, Kew, pp. 161–172. Weston, P.H. 1994. The Western Australian species of subtribe Persooniinae (Proteaceae: Persoonioideae: Persoonieae). Telopea 6:51–165. Weston, P.H. 1995. Gevuina. Flora of Australia 16:409–410. Collingwood: CSIRO.

Weston, P.H., Barker, N.P. 2006. A new suprageneric classification of the Proteaceae, with an annotated checklist of genera. Telopea 11 (in press). Weston, P.H., Crisp, M.D. 1996. Trans-Pacific biogeographic patterns in the Proteaceae. In: Keast, A., Miller, S.E. (eds) The origin and evolution of Pacific island biotas, New Guinea to eastern Polynesia: patterns and processes. Amsterdam: SPB Academic, pp. 215–232.

Pterostemonaceae Pterostemonaceae Small, N. Amer. Fl. 22, 2:183 (1905).

K. Kubitzki

Shrubs with much-branched stems and dichasial branches; nodes trilacunar. Leaves alternate, crowded at the ends of branchlets, shortly petioled; blades simple, leathery, glandular and glutinousresinous above, finely toothed; stipules minute. Inflorescences few-flowered corymb-like cymes. Flowers regular, perfect, epigynous, 5-merous; calyx tube turbinate, adnate to ovary; sepals triangular, erect, valvate, persistent, surmounting the hypanthium; petals clawed, imbricate, persistent, ultimately reflexed; stamens antesepalous, with broad filaments denticulate at apex, with ovoid, dorsifixed, introrse anthers; staminodia antepetalous, narrower than stamens; carpels 5, united to form an inferior, 5-celled ovary; ovules 4–6 per locule, axile, ascending; style shortly 5-lobed with short and radiate stigmas. Fruit capsular, 5-valved, septicidal, woody, surmounted by the erect sepals and reflexed petals. Seeds with cartilaginous testa, attenuated at either end; embryo elongate, surrounded by fleshy endosperm. A single genus with two species in Mexico.

in the narrow, fibriform vessels, which have long, overlapping tails. Tracheids are rare and grade into fibre-tracheids and thick-walled, pitted fibres. Axial parenchyma is diffuse and sparse; the rays are 1–4 cells wide. (All data from Wilkinson 1994.) Pollen Morphology. Pollen of P. mexicanus is tricolporate, subprolate, 27 × 23 µm, the tectum unsculptured and transitional between complete and perforate, the endoaperture complex (Erdtman 1952; Hideux and Ferguson 1976). Phytochemistry. In both species of Pterostemon, 3-O-glycosides of quercetin and C-glycosyl flavones were found (Bohm et al. 1999). With regard to the latter compounds, Pterostemon agrees with Itea which, however, lacks flavonols, these otherwise being ubiquitous in Saxifragales. Affinities. Formerly associated with Escalloniaceae and Hydrangeaceae, Pterostemon differs from them i.a. in having bitegmic and crassinu-

Morphology. Both species are much-branched shrubs, of which P. mexicanus is up to 4 m tall, and P. rotundifolius 1 m. Pocket domatia are present in the angles of the lateral veins with the midrib. The leaf bases are accompanied by small stipules (Weberling 1976). Anatomy. The upper leaf surface is covered by a glossy film of varnish. Simple/unicellular and glandular/multicellular hairs are found on both leaf surfaces, the latter obviously secreting lacquer; they are particularly frequent over the hydathodes on the leaf teeth and crenations. Stomata are anomocytic; druses occur around the leaf veins and in the mesophyll. The cortex is lenticellate and cork develops surficially. The xylem is diffuse porous with usually solitary vessels; perforation plates range from simple in the widest vessels to scalariform with at least 6 bars

Fig. 141. Pterostemonaceae. Pterostemon mexicanus. A Flowering branch. B Flower. C Same, vertical section. D Ovary, vertical section. (Engler 1930)

406

K. Kubitzki

cellate ovules. The five-gene analysis of Fishbein et al. (2001) provides strong support for the former “woody Saxifragaceae” Iteaceae + Pterostemon and Ribes as subsequently sister to Saxifragaceae s.str. Pterostemon differs, however, from Iteaceae in the possession of anomocytic stomata, imbricate petals, 2 stamen whorls, 3-colporate pollen and a 5-locular, inferior ovary, among other features (Takhtajan 1997), and from Ribes in the large embryo. Distribution and Ecology. The two species grow in low, deciduous thorn forest and matorral vegetation on calcareous bluffs and ledges in Oaxaca, Mexico at an altitude from 1,520 to 2,650 m (Rzedowski 1978). Only one genus: Pterostemon Schauer

Fig. 141

Pterostemon Schauer, Linnaea 20:736 (1847).

Description as for family. Two species, P. mexicanus Schauer and P. rotundifolius Ramírez.

Selected Bibliography Bohm, B.A., Yang, J.Y., Page, J.E., Soltis, D.S. 1999. Flavonoids, DNA and relationships of Itea and Pterostemon. Biochem. Syst. Ecol. 27:79–83. Engler, A. 1930. Saxifragaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 18a. Leipzig: W. Engelmann, pp. 74–226. Erdtman, G. 1952. See general references. Fishbein, M. et al. 2001. See general references. Hideux, M.J., Ferguson, I.K. 1976. See general references. Jay, M. 1970. Quelques problèmes taxinomiques et phylogénétiques des Saxifragacées vus à la lumière de la biochimie flavonique. Bull. Mus. Hist. Nat. Paris II, 42:754–775. Mauritzon, J. 1933. Studien über die Embryologie der Familien Crassulaceae und Saxifragaceae. Doctoral Diss., University of Lund. Rzedowski, J. 1978. Vegetación de México. Mexico: Editorial Limusa. Takhtajan, A. 1997. See general references. Weberling, F. 1976. Weitere Untersuchungen zur Morphologie des Unterblattes bei den Dikotylen. IX, Saxifragaceae s.l., Brunelliaceae and Bruniaceae. Beitr. Biol. Pflanzen 52:163–181. Wilkinson, H.P. 1994. Leaf and twig anatomy of the Pterostemonaceae (Engl.) Small: ecological and systematic features. Bot. J. Linn. Soc. 115:115–131.

Quillajaceae Quillajaceae D. Don, Edinburgh New Philos. J. 10:299 (1831).

K. Kubitzki

Evergreen glabrous trees with saponaceous bark; nodes unilacunar. Leaves alternate, simple, penninerved, leathery, serrate, shortly petioled; stipules small, caducous. Inflorescences terminal and axillary few-flowered botryoids, terminal flower hermaphroditic, lateral ones staminate. Flowers 5-merous, rather large, tomentose, pedicels with prophylls; sepals valvate; petals spathulate, white or cream-coloured; disk thick, fleshy, lining the receptacle and produced into 5 lobes adnate with the sepals; stamens 10, the antesepalous 5 inserted near the apex of the disk-lobes some way up the sepals and the antepetalous near the base of the ovary; filaments subulate; anthers bithecate, introrse; carpels 5, cohering by their bases; stylodia terminal, with decurrent stigmas; ovules numerous, 2-seriate, ± horizontal, pleurotropous. Follicles spreading star-like, dehiscing ventrally and dorsally with 2 coriaceous valves. Seeds many, exotestal, with long wing at apex; endosperm thin; cotyledons convolute. 2n = 28. A single genus with two species from warm-temperate South America. Vegetative Structures. Quillaja saponaria is reported as growing in the coastal areas of Chile as

a shrub but, in the lower parts of the valleys of the Andes, as a tree up to 10 and more m high and 1 m thick (Reiche 1898). In young axes, cork is initiated subepidermally, and the rhytidome is scaly. An endodermis is lacking, and the secondary phloem dilates diffusely. In all these features, Quillaja differs from Rosaceae (Lotova and Timonin 1999). Rays are heterogeneous, and the vessels of the secondary xylem have simple and scalariform perforations with many bars, in contrast to all Rosaceae (except Neillia), in which Quillaja formerly had been included. Reproductive Structures. The fleshy disk lining the receptacle and extending into five lobes is a very peculiar structure hardly found elsewhere. Carpel morphology has been studied within the context of the former Quillajeae/Rosaceae by Sterling (1966). The ovule is bitegmic, more details remaining unknown (Péchoutre 1902). The seeds are winged, and the seed coat has a testa of three hardly thickened cell layers and a disintegrated tegmen; the endosperm is but one cell layer thick, and the cotyledons are concolute (Péchoutre 1902). Pollen Morphology. Pollen grains are tricolporate and prolate/angulaperturate; the exine is striate (Fig. 142). Karyology. The chromosome number 2n = 28 has been determined for both species (Goldblatt 1976); tetraploidy is excluded; this number sets the genus apart from all putative relatives in Rosaceae. Phytochemistry. The bark of Quillaja saponaria has a saponin content of 8.5–16.4%. Proanthodelphinidin was recorded from the leaves (Bate-Smith 1965).

Fig. 142. Quillajaceae. Quillaja saponaria, pollen grain, equatorial view, SEM ×3,800. (Photograph B. Herber)

Uses. The wood of Quillaja saponaria is valued for its hardness and has been used for props in mines and still serves today for making stirrups.

408

K. Kubitzki

The inner bark of Q. saponaria is a source of an emulsifying agent used in fire-extinguishers and as a mild soap. Affinities. The relationships of Quillaja have been the subject of much discussion but, until recently, its inclusion in Rosaceae has rarely been questioned. Commonly accommodated in tribe Quillajeae, Quillaja shares many important features particularly with Kageneckia, including follicular fruits with numerous ovules which mature into winged seeds, and the South American distribution. In the rbcL analysis of Morgan et al. (1994), however, Quillaja appeared in a clade together with Surianaceae, Polygalaceae and Leguminosae. This position has been confirmed by subsequent studies (e.g. Savolainen, Fay et al. 2000). The non-molecular evidence distinguishing Quillaja from Rosaceae includes the base chromosome number x = 14, which does not exist in Rosaceae, vessels with scalariform perforation plates, and the trihydroxy-substituted proanthodelphinidin, which is extremely rare there.

Distribution and Habitats. Quillaja is a southern warm-temperate genus reflecting the well-known disjunction between the southern Andes and south-eastern Brazil (“Araucaria type”; Rambo 1956). The Chilean Q. saponaria grows in the winter-rain region from 31 to 38◦ S, from sea level up to 2,000 m altitude, and in the valleys once formed dense forests which have largely been replaced by pastures (Hueck 1966). Quillaja brasiliensis is a tree of mixed mesophytic forests and extends from São Paulo, Brazil, to Uruguay and Misiones, Argentine. It is also reported from Peru (Depto. Cuzco) but it is questionable whether it is indigenous there. A single genus: Quillaja Molina

Figs. 142, 143

Quillaja Molina, Saggio Chili: 354 (1781).

Two species in South America (Chile, Brazil to northern Argentine).


Fig. 143. Quillajaceae. Quillaja saponaria. A Flowering branch. B Flower. C Fruiting branchlet with dehiscing follicles. (Takhtajan 1981)

Bate-Smith, E.C. 1965. Investigation of the chemistry and taxonomy of subtribe Quillajeae of the Rosaceae using comparisons of fresh and herbarium material. Phytochemistry 4:535–539. Goldblatt, P. 1976. Cytotaxonomic studies in the tribe Quillajeae (Rosaceae). Ann. Missouri Bot. Gard. 63:200– 206. Hegnauer 1973, 1990. Chemotaxonomie der Pflanzen, vol. 6, vol. 9. Basel: Birkhäuser. Hooker, J.D. 1897. Quillaja saponaria. Curtis’s Bot. Mag. III, 53, t. 7568. Hueck, K. 1966. Die Wälder Südamerikas. Stuttgart: G. Fischer. Lovota, K.I., Timonin, A.C. 1999. Anatomy of cortex and secondary phloem in Rosaceae. III. Quillajoideae. Bot. Zhurn. (Moscow & Leningrad) 84:34–41. Morgan, D.R., Soltis, D.E., Robertson, K.R. 1994. Systematic and evolutionary implications of rbcL sequence variation in Rosaceae. Amer. J. Bot. 81:890–903. Péchoutre, F. 1902. Contribution à l’étude du développement de l’ovule et des graines des Rosacées. Ann. Sci. Nat. VIII, Bot. 16:1–158. Rambo, B. 1956. Der Regenwald am oberen Uruguay. Sellowia 7/8:183–233. Reiche, C. 1898. Flora de Chile, 2. Santiago: Cervantes. Savolainen, V., Fay, M.F. et al. 2000. See general references. Sterling, C. 1966. Comparative morphology of the carpel in the Rosaceae. IX. Spiraeoideae: Quillajeae, Sorbarieae. Amer. J. Bot. 53:951–960. Takhtajan, A. 1981. See general references.

Rhynchocalycaceae Rhynchocalycaceae L.A.S. Johnson & B.G. Briggs, Ann. Missouri Bot. Gard. 71:732 (1984).

J. Schönenberger

Tree up to 12 m high; young shoots terete or slightly oval in transversal section, glabrous. Leaves opposite, decussate, simple, entire, coriaceous, more or less sessile when young, later shortly petiolate, elliptic to oblong; stipules rudimentary, marcescent. Inflorescence a multifloral, anthotelic panicle, mainly terminal. Flowers small, bisexual, actinomorphic, usually hexamerous, obhaplostemonous, with short hypanthium, slightly perigynous; sepals valvate, broad-based, triangular, and recurved at anthesis, persistent; petals white, distinct, narrowly clawed, with sub-orbicular lacerate lamina, thin, caducous, in bud hood-like, covering the anthers; stamens antepetalous, arising immediately below the petals on inner rim of hypanthium, incurved in bud; filaments more or less terete, longer than anthers; anthers sub-basifixed, versatile, tetrasporangiate, introrse, longitudinally dehiscent; connective elliptical; disc 0; ovary superior, 2(–3)-carpellate, 2(–3)-locular, dorsiventrally compressed; style stout, shorter than ovary, basal part persistent; stigma capitate, papillate; ovules 15–20 per locule, bitegmic, anatropous, crassinucellate, superposed in a single vertical series per locule; placentation axile. Fruit a dorsiventrally compressed capsule, loculicidal at apex, reddish brown. Seeds depressedovoid, narrowly winged; seed coat thin and papery, rather smooth, brownish; embryo more or less flattened; cotyledons folded; endosperm 0. The only species, Rhynchocalyx lawsonioides Oliv., is a rare tree in moist forests in southern KwaZulu-Natal and Pondoland (Eastern Cape) in South Africa. Vegetative Morphology and Anatomy. Rhynchocalix lawsonioides is an evergreen, midsized tree with a straight stem. The bark is grey with a pink slash, rough but not deeply fissured and with tiny flaking scales (Strey and Leistner 1968). The upper branchlets are opposite or in whorls of three to five. The foliage leaves of Rhynchocalyx are

provided with two minute, rudimentary stipules situated on either side of the leaf axil at the base of the petiole (Graham 1984). Rudimentary stipules are present in a number of other myrtalean families, including the closely related Crypteroniaceae, Alzateaceae, Oliniaceae and Penaeaceae (Dahlgren and Thorne 1984; Weberling 1968). The midvein of the leaf lamina of Rhynchocalyx terminates in a minute glandular tip. Such glandular leaf apices are also present in Oliniaceae and at least some Penaeaceae (Dahlgren and Van Wyk 1988). The upper surface of the leaf blade is dark green, somewhat shiny and with a prominent midrib and secondary veins. The lower surface is greyish-green. Leaves are glabrous. Stomata are confined to the abaxial epidermis and are intermediate between anomocytic and cyclocytic. The mesophyll is composed of two layers of palisade cells and unlignified spongy tissue. The midrib is adaxially flattened, abaxially prominently raised. Vascular bundles of the primary and most minor veins are bicollateral, with a collenchymatous to parenchymatous unlignified bundle sheath extending to the upper and lower epidermis. Foliar sclereids are unbranched and restricted to the petioles (Rao and Das 1979). Nodes are unilacunar with a single trace. Secondary phloem consists of sieve tubes, companion cells, chambered parenchyma cells, and infrequent thick-walled sclereids. Crystals are present in the form of druses in the ground tissue of leaf lamina and the petiole as well as in the pith and the cortex of twigs. (Information on vegetative anatomy mostly from van Vliet and Baas 1975 and Keating 1984.) Wood anatomy is characterized by crystalliferous, chambered fibres and heterogeneous narrow rays as well as scanty paratracheal to vasicentric parenchyma surrounded by thin-walled fibres (van Vliet 1975; Baas and Zweypfenning 1979). Floral Morphology and Anatomy. Flowers are arranged in many-flowered, terminal and/or

410

J. Schönenberger

axillary, anthotelic panicles (Fig. 144A). Individual flowers are small and inconspicuous. The flowers are bisexual, actinomorphic and obhaplostemonous. Most often they are hexamerous, but penta- and heptamery occur as well. Aspects of floral development and structure were described by Schönenberger and Conti (2003). The sepals are inserted on the rim of a short hypanthium and each sepal is served by three vascular bundles. The petals alternate with the sepals and are inserted on the adaxial side of the hypanthium rim (Fig. 144C). Their development is retarded relative to the sepals in young buds. Each petal is served by a single vascular bundle. Stamens are produced opposite or, more precisely, immediately below the petals on the adaxial side of the hypanthium rim. Stamens are strongly incurved in bud, with their pollen sacs directed towards the hypanthium. The apex of the two-carpellate ovary tapers into a short style with a terminal stigma. Scattered cells with oxalate

druses are present in all floral organs, except for the petals. Embryology. Embryology was studied by Tobe and Raven (1984). Anthers are tetrasporangiate. The developing anther wall is five cell layers thick. The endothecium and two middle layers are ephemeral. The tapetum is glandular and its cells become two-nucleate before degeneration. At the time of dehiscence, the mature anther wall is composed only of the persistent epidermis. The septum between the two pollen sacs of each theca remains intact even at the time of dehiscence, which is a rather unusual feature among angiosperms. Meiosis in microspore mother cells is accompanied by simultaneous cytokinesis. The shape of the resulting tetrads is usually tetrahedral and often decussate. Pollen grains are two-celled when they are shed. Ovules are bitegmic, anatropous and crassinucellate. The micropyle is formed by the inner integument. The embryo sac is eight-nucleate and corresponds to the Polygonum type. Endosperm formation is Nuclear. Endosperm is scanty throughout seed development and literally absent in mature seeds. Embryogenesis conforms to the Onagrad type. In mature seeds the embryo is more or less flattened; its cotyledons are folded inside. Pollen Structure. Pollen has been described by Patel et al. (1984) as tricolporate, heterocolpate with three subsidiary colpi (pseudocolpi), radially symmetrical and isopolar, spheroidal in lateral view and triangular-hexogonal in polar view. The surface is coarse, with many punctae and irregular channels. The foot-layer is well developed in the mesocolpial areas. Columellae are numerous, erect and branched distally, often forming an infratectal granular layer (Muller 1975). The tectum is thick, perforate, with an undulating upper margin which is locally discontinuous. The endexine is very thin in mesocolpial areas but thick at the colpi and subsidiary colpi, and granular in the region of the endoaperture.

Fig. 144. Rhynchocalycaceae. Rhynchocalyx lawsonioides. A Part of branch and inflorescence. B Flower bud. C Anthetic flower. D Clawed petal. E Mature fruit. F Seed. (A–D Oliver 1894; E, F Strey and Leistner 1968)

Fruit and Seed. The fruit is described as a two(or sometimes three-)locular, dorsiventrally compressed capsule which is partially loculicidal at the apex (Fig. 144E; Strey and Leistner 1968). The 15– 20 seeds in each locule are tightly packed in a more or less distinct vertical row on an axile placenta. As described by Tobe and Raven (1984), the mature seed is depressed-ovoid in shape with a flat mem-

Rhynchocalycaceae

branous wing on the micropylar side (Fig. 144F). The wing is formed by divisions and elongation of cells of the funiculus. The seed coat is derived from the two-layered testa as well as from the two-layered tegmen. The outer surface of the outer epidermis of the testa is conspicuously lignified. The winged seeds indicate wind-dispersal. Karyology. Goldblatt (1976) reported a chromosome number of 2n = 20. Phytochemistry. Aluminium is accumulated in Rhynchocalyx whereas it was not found in its closest relatives Oliniaceae, Penaeaceae and Alzateaceae (Dahlgren and Van Wyk 1988; Jansen et al. 2002). The composition of flavonoids of Rhynchocalyx has been found to agree well with the general profile for many other myrtalean families (Averett and Graham 1984). Noteworthy is the absence of myricetin, which is frequently found in the Myrtales but is lacking also in Alzateaceae (Graham and Averett 1984). Affinities. Rhynchocalyx was first described in Lythraceae (Oliver 1894) but was later included in an expanded Crypteroniaceae (van BeusekomOsinga and van Beusekom 1975). However, the distinctive embryology of Rhynchocalyx prompted its elevation to family rank (Johnson and Briggs 1984; Tobe and Raven 1984). Recent molecular studies clearly support Rhynchocalycaceae as part of Myrtales (e.g. Conti et al. 1996). Phylogenetic relationships among myrtalean families have been addressed based on both non-molecular (Johnson and Briggs 1984) and molecular data (Conti et al. 1997; Clausing and Renner 2001). All analyses identified a clade comprising four families with a Western Gondwanan distribution: the South African Rhynchocalycaceae and Penaeaceae, the South and East African Oliniaceae, and the Central and South American Alzateaceae. This Western Gondwanan clade is strongly supported as sister to the Southeast Asian Crypteroniaceae (Clausing and Renner 2001; Conti et al. 2002). Molecular phylogenetic analyses further suggest that the monotypic New World Alzateaceae are sister to the three African families and, although with weak support, that Rhynchocalycaceae are sister to Penaeaceae/Oliniaceae (Schönenberger and Conti 2003). Distribution and Habitat. The single species of Rhynchocalycaceae is known from a few localities in the sandstone region of Southern

411

KwaZulu-Natal and Pondoland (Eastern Cape) in South Africa. It is restricted to the forest margins of sheltered, moist ravines and often grows near water courses. First collected in 1884, it was rediscovered only in 1966 (Strey and Leistner 1968). Only one genus: Rhynchocalyx Oliv.

Fig. 144

Rhynchocalyx Oliv., Hook. Ic. Pl. IV, 24: t. 2348 (1894).

Monotypic, see above.

Selected Bibliography Averett, J.E., Graham, S.A. 1984. Flavonoids of Rhynchocalycaceae (Myrtales). Ann. Missouri Bot. Gard. 71:853– 854. Baas, P., Zweypfennig, R.C.V.J. 1979. Wood anatomy of the Lythraceae. Acta Bot. Neerl. 28:117–155. Clausing, G., Renner, S.S. 2001. Molecular phylogenetics of Melastomataceae and Memecylaceae: implications for character evolution. Amer. J. Bot. 88:486–498. Conti, E. et al. 1996. See general references. Conti, E. et al. 1997. See general references. Conti, E. et al. 2002. See general references. Dahlgren, R., Thorne, R.F. 1984. The order Myrtales: circumscription, variation, and relationships. Ann. Missouri Bot. Gard. 71:633–699. Dahlgren, R., Van Wyk, A.E. 1988. Structures and relationships of families endemic to or centered in Southern Africa. Monogr. Syst. Bot. Missouri Bot. Gard. 25:1–94. Goldblatt, P. 1976. New or noteworthy chromosome records in the angiosperms. Ann. Missouri Bot. Gard. 63:889– 895. Graham, S.A. 1984. Alzateaceae, a new family of Myrtales in the American tropics. Ann. Missouri Bot. Gard. 71:757–779. Graham, S.A., Averett, J.A. 1984. Flavonoids of Alzateaceae (Myrtales). Ann. Missouri Bot. Gard. 71:855–857. Jansen, S., Watanabe, T., Smets, E. 2002. Aluminium accumulation in leaves of 127 species in Melastomataceae, with comments on the order Myrtales. Ann. Bot. 90:53– 64. Johnson, L.A.S., Briggs, B.G. 1984. Myrtales and Myrtaceae – a phylogenetic analysis. Ann. Missouri Bot. Gard. 71:700–756. Keating, R.C. 1984. Leaf histology and its contribution to relationships in the Myrtales. Ann. Missouri Bot. Gard. 71:801–823. Muller, J. 1975. Note on the pollen morphology of Crypteroniaceae s.l. Blumea 22:275–294. Oliver, D. 1894. Rhynchocalyx lawsonioides. In: Hooker’s Ic. Pl. IV, 24: t. 2348. Patel, V.C., Skvarla, J.J., Raven, P.H. 1984. Pollen characters in relation to the delimitation of Myrtales. Ann. Missouri Bot. Gard. 71:858–969. Rao, T.A., Das, S. 1979. Leaf sclereids – occurrence and distribution in the angiosperms. Bot. Notiser 132:319– 324.

412

J. Schönenberger

Schönenberger, J., Conti, E. 2003. Molecular phylogeny and floral evolution of Penaeaceae, Oliniaceae, Rhynchocalycaceae, and Alzateaceae (Myrtales). Amer. J. Bot. 90:293–309. Strey, R.G., Leistner, O.A. 1968. The rediscovery of Rhynchocalyx lawsonioides Oliv. J. S. African Bot. 34:9–13. Tobe, H., Raven, P.H. 1984. The embryology and relationships of Rhynchocalyx Oliv. (Rhynchocalycaceae). Ann. Missouri Bot. Gard. 71:836–843. van Beusekom-Osinga, R.J., van Beusekom, C.F. 1975. Delimitation and subdivision of the Crypteroniaceae (Myrtales). Blumea 22:255–266.

van Vliet, G.J.C.M. 1975. Wood anatomy of Crypteroniaceae sensu lato. J. Microscopy 104:65–82. van Vliet, G.J.C.M., Baas, P. 1975. Comparative anatomy of the Crypteroniaceae sensu lato. Blumea 22:175– 195. Weberling, F. 1968. Bemerkungen über das Vorkommen rudimentärer Stipeln. I. Cyrillaceae und die Gattung Cyrillopsis Kuhlm. II. Alzatea Ruiz & Pav. (Lythraceae) und Tristania R. Br. Acta Bot. Neerl. 17:282–287.

Sabiaceae Sabiaceae Blume, Mus. Bot. 1:368 (1851), nom. cons. Meliosmaceae Endl. (1841), nom. rej.

K. Kubitzki

Evergreen, rarely deciduous trees, scandent shrubs or woody climbers, glabrous or pubescent, very rarely armed with short spines (Sabia japonica). Leaves spirally arranged, penninerved, simple or imparipinnate, with dentate or entire margins, sometimes heteromorphic, often on subwoody petiole bases, estipulate, the leaflets often on pulvini. Flowers small, hermaphroditic, actinomorphic or zygomorphic, in terminal or axillary panicles, these often reduced to solitary axillary flowers; the pedicels often very short, provided with 0–numerous minute bracts; sepals, petals and stamens opposite to each other; sepals (4)5, imbricate, free or ± connate at the base, equal or the inner 2 much smaller; petals (4)5, the innermost 2 often much smaller; stamens and staminodes 5; stamens all polliniferous (Sabia), or only the 2 opposite the inner petals polliniferous and the 3 other staminodial; thecae unilocellate; filament below the anther often swollen or bearing a collar-like extension (the latter perhaps formed by connective); nectary disk thin, annular, surrounding the base of the ovary, its lobes and ribs, if present, alternating with the stamens; ovary syncarpous of 2(3) carpels, either (all Ophiocaryon, very rarely in Sabia) the carpels free in the apical part and ending in 2 short stylodia with capitate stigmas, or (Meliosma, nearly all Sabia) the carpels apically united into a short, cylindric or conical style with a capitate stigma; cells 2(3), each with (1)2 pendulous or horizontal, axile, hemitropous, unitegmic, crassinucellar ovules. Fruit 1-celled or rarely 2-coccous, asymmetric, drupaceous or dry, indehiscent, developing a single seed; endocarp osseous or crustaceous. Endosperm scanty or wanting; embryo with an elongated, curved hypocotyl and 2 flat, folded or coiled cotyledons. A neotropical and Indo-Malesian family of three genera and c. 52 species, or 15–20 more if in Asian Meliosma a narrower species concept is applied.

Vegetative Morphology. Sabia has simple leaves whereas, in Ophiocaryon and Meliosma, these vary from imparipinnate to simple (or unifoliolate?), often in groups of closely related species. Particularly in Ophiocaryon leaves can be very large, and pinnae up to 4 dm are reported. Leaf dimorphism is found in many Ophiocaryon and some Meliosma, sterile shoots often bearing pinnate leaves whereas those of flowering branches are either simple or 1–3-foliolate. In Meliosma, saplings and sterile shoots develop a much stronger leaf serration than do mature or reproductive shoots. Vegetative Anatomy. Salient features are given by Metcalfe and Chalk (1950); notable is the lack of secretory cavities. Hairs are simple-multicellular and sometimes have 2-celled heads. The most recent study of the wood anatomy is by Carlquist et al. (1993). Despite the small size of the family and its restriction to mesic sites, these authors report considerable variation of wood anatomical characters (long scalariform, multiperforate and simple perforation plates; heterocellular to homocellular multiseriate rays; tracheids, fibre tracheids, or libriform fibres as imperforate tracheary elements; presence or absence of silica bodies and calcium oxalate in rays; presence or absence of growth rings of various types; and variations in vessel diameter, vessel density and vessel element length). From the wood anatomical point of view, the authors considered the family fitting best in Rutales (presumably mainly because they found nothing contradicting this traditional placement). Inflorescences. In Sabia, the flowers are arranged in many- to few-flowered axillary panicles or are solitary. Ophiocaryon and Meliosma have usually many-flowered, large terminal or axillary panicles, in which the flowers are often subsessile. Flowers. Urban (1895, 1900) has demonstrated that the three genera basically agree in flower

414

K. Kubitzki

structure, which is 5-merous and in which sepals, petals and stamens are arranged in opposite whorls (Fig. 145C, D), i.e. they lie on five radii. The differences in androecium and gynoecium structure do not justify the separation of the genera into two families, an aspect discussed by many authors up to the present (e.g. Cronquist 1981). The floral organs are disposed in a continuous 2/5 spiral. Meliosma has the most complicated structure. The three outer petals are slightly imbricate and completely enclose the stamens and gynoecium (Fig. 146). The two inner petals

are strongly reduced and the only two functional stamens are adnate to them. (This has prompted several authors to postulate a trimerous floral structure.) The stamen filaments of Meliosma have a collar-like configuration below the anther (perhaps formed by the connective). In bud, the anthers are sharply bent downwards and inwards by a fold of the filament, and the anther cells fit into the cavities of the adjacent staminodes. This complex of fertile stamens and staminodes envelops the pistil, and the staminodes are often somewhat connate at the top and leave a pore through which the tip of the style protrudes. The anther cells burst when the flowers are still in bud but the pollen cannot be released as long as the anther cells are locked in the cavities of the staminodes. At maturity, the bud explodes at the slightest touch, and the stamens snap backwards and fling a puff of pollen into the air. Because anthesis is so short-lived, almost only buds and old flowers are found. This mechanism, reported by van Beusekom (1971), seems to have been observed first by Blume. With regard to floral morphology, Ophiocaryon is intermediate between Sabia and Meliosma: functional stamens are two but the petals are not strongly dimorphic, the filaments are thickened beneath the anther, and the two carpels do not form a common style. Among early-diverging eudicots, nectary disks elsewhere are found only in Buxaceae and Proteaceae. Karyology. Chromosome counts are available for several Meliosma spp. with 2n = 32, and for Sabia japonica with 2n = 24 (Fedorov 1969). Pollen Morphology. Pollen (only Sabia and Meliosma spp. studied) is tricolporate with lalongate ora, (sub-)prolate, and relatively small (up to 34 µm long); the exine is semitectate and more or less distinctly reticulate (Erdtman 1952; Mondal 1990).

Fig. 145. Sabiaceae. Sabia limoniacea. A, B Habit. C Anthetic flower. D Petal and, opposite, stamen. E Disk and pistil. F Fruit. G Embryo. (Drawing by Ruth van Crevel; van Beusekom and van de Water 1989)

Embryology. In Meliosma and Sabia, the pollen grains are two-celled when shed, and the ovules are much alike in both genera: apotropous, unitegmic and crassinucellar. A parietal cell is cut off from the archesporial cell, and the embryo sac develops according to the Polygonum type. Endosperm development is of the Helobial type (Mauritzon 1936; Davis 1966). Seeds and Fruits. In Sabia, each locule of the two-paired ovary can develop into a drupelet

Sabiaceae

415

Fig. 146. Sabiaceae, Meliosma. A Semi-diagrammatic sketch of flower (subg. Meliosma) with opened outer petals but stamens still in bud position. B Semi-diagrammatic vertical section of bud (subg. Meliosma). C Diagram (subg. Kings-

boroughia and subg. Meliosma) showing a sepals, b outer petals, c inner petals, d fertile stamens, e staminodes, f disk, g style. (Drawing by Ruth van Crevel; van Beusekom 1971)

with a thin pulpy mesocarp and a crustaceous endocarp. The two drupelets have persistent stylodia and are connected with each other at the base. In the ovaries of Ophiocaryon and Meliosma, usually only one of the four ovules develops into a seed. The fruit is a drupe with a pulpy mesocarp or completely dry, the endocarp is stony to crustaceous. van Beusekom (1971) has studied the endocarp diversity of Recent and fossil Meliosma stones, in which the position and degree of enclosure of the vascular bundle connecting the pedicel and seed provide important data for an infrageneric classification. In mature seeds, the endosperm is largely reduced and the embryo has developed cotyledons on an extended, curled hypocotyl; hence, the name “snake nut” for Ophiocaryon paradoxum R.H. Schomb.

early-diverging eudicots (Nandi et al. 1998). The morphological gap between the probably dimerous flowers of Proteaceae and the pentamerous flowers of Sabiaceae appears considerable, although various models argue for an “easy” transition from dimery to pentamery (see discussion in Soltis et al. 2003: 468). Nevertheless, it is clear that in Sabiaceae pentamery has been achieved on a unique pathway within eudicots, as is evidenced by the superposition of the floral organs, which do not obey Hofmeister’s rule.

Phytochemistry. The absence of cyanolipids (Hegnauer 1973) is in line with the rejected affinity with Sapindaceae. Systematics and Phylogeny. Although doubts about the homogeneity of the family have repeatedly been raised, Urban (1895, 1900) had argued that the genera of Sabiaceae form a coherent group. In molecular studies, the family appears among the early-diverging eudicots often in close proximity to Proteaceae, either basal to them, or Proteaceae basal to Sabiaceae, or perhaps both as a clade (see, e.g. Savolainen, Fay et al. 2000; Soltis et al. 2000, 2003; Hilu et al. 2003). Sabiaceae and Proteaceae have in common a wedge-shaped phloem and a nectary disk, both rare attributes in

Distribution, Fossils and Distributional History. Presently, Ophiocaryon is restricted to northern South America whereas Meliosma is disjunct between Indo-Malesia and the neotropics (southern Mexico, Central America, and Andean and lowland South America southwards to Peru and Brazil); Sabia has the same Indo-Malesian distribution as Meliosma. A fossil genus, Insitiocarpus, dates back to the Cenomanian, whereas Sabia and Meliosma are known from the Turonian and Maastrichtian onward, respectively (Knobloch and Mai 1986; Mai 1995). Van Beusekom (1971) gave a detailed analysis of the distributional history of Meliosma; the four sections he distinguished were recognisable as early as the Lower Eocene. Subgenus Kingsboroughia, represented by two extant species in China (the only deciduous members of the family), of which one is found also in Mexico, in Europe and Asia has a fossil record from the Oligocene through the Pliocene. The fossil distribution of subg. Meliosma includes North

416

K. Kubitzki

America (Oligocene, Miocene), Europe (Eocene through Miocene), and East Asia (Pliocene). As explanation, van Beusekom considered westward dispersal of Meliosma during the climatic optimum in the Eocene from East Asia to Europe along the northern shores of the Sea of Tethys, and contended repeated eastward migrations via Beringia in order to account for the New World representation of the genus. Alternatively, the primary centre of the family may be sought in the Caribbean, from where the family dispersed into North and South America and, following the northern shore of the Sea of Tethys, to East Asia, which thereby became a secondary centre. Key to the Genera 1. Lianas or scandent shrubs. Flowers usually in fewflowered axillary panicles, sometimes reduced to single axillary flowers. Fertile stamens 5, equal. Leaves simple, entire or subentire 1. Sabia – Trees. Flowers in usually large, terminal or axillary panicles. Fertile stamens 2, opposite the inner petals; the other 3 androecial elements abortive and reduced to scales. Leaves imparipinnate and/or simple, entire or toothed 2 2. Petals subequal; staminodes lacking lateral cavities; carpels ending in free stylodia 2. Ophiocaryon – Petals strongly unequal, the 2 inner ones much reduced; staminodes near the top with lateral holes into which fit the anther cells of the fertile stamens; carpel tips united into a common style (very rarely, stylodia present) 3. Meliosma

Genera of Sabiaceae 1. Sabia Colebr.

Fig. 145

Sabia Colebr., Trans. Linn. Soc. London 12:355 (1818); van de Water, Blumea 26:1–64 (1980), rev.

Evergreen or deciduous lianas or scandent shrubs; leaves simple, (sub)entire. Flowers in usually few-flowered subumbellate panicles or solitary; sepals 5(–7); petals 5(–7); stamens 5, all fertile. Disk mostly crown-shaped, lobes and ribs, if present, alternating with stamens. Pistil 2-celled with a simple style or, very rarely, carpels ending in stylodia. Drupelets 1(2)-seeded, laterally compressed; mesocarp pulpy, endocarp crustaceous. Seed solitary, endosperm a thin layer. Embryo with flat or folded cotyledons and a rootlet curving to the hilum. 2n = 24 (S. purpurea). About 19 species, from the Deccan Peninsula along the Himalayas through Myanmar and China to southern Japan,

and throughout Malesia to the Solomon Islands. From the lowlands up to 2,000 m altitude. 2. Ophiocaryon R.H. Schomb. ex Endl. Ophiocaryon R.H. Schomb. ex Endl., Gen. Suppl. 1:1425 (1841); Barneby, Mem. New York Bot. Gard. 23:114–120 (1972), rev. Phoxanthus Benth. (1857).

Evergreen small trees; leaves simple and/or imparipinnate, often very large. Inflorescences pyramid shaped, much-branched, the flowers nearly sessile, small. Sepals (4)5. Petals (4)5, narrowly ovate or linear, subequal; fertile stamens 2, opposite the inner petals; filaments below anther incrassate; staminodes (2)3, lacking lateral cavities; disk 5-dentate. Carpels fused, with the exception of free stylodia. Seven species in the Guayana lowlands and adjacent Amazon lowlands of Brazil and Peru; one species in the Guayana Highland; along rivers and in moist forest on terra firme. 3. Meliosma Bl.

Fig. 146

Meliosma Bl., Cat.: 32 (1823); van Beusekom, Blumea 19:355–529 (1971), rev. Old World spp.

Trees, evergreen or rarely deciduous. Leaves simple or imparipinnate, entire or dentate, with or without hairy domatia. Inflorescence terminal, or sometimes axillary, a pyramidal panicle, poor to usually profuse, up to 4 times ramified, often very large. Flowers sessile or short-pedicelled; sepals (3–4)5; petals 5, the 3 outer ones large, the 2 inner very much reduced, the latter sometimes bifid; fertile stamens 2, opposite and adnate to the inner reduced petals; filaments below the anther with a collar-like configuration; staminodes 3, near the top with lateral holes into which fit the anthers of the adjacent stamens; disk usually present; ovary 2(–3)-locular, with 1(–2) ovules per cell. Drupe with 1 stone; seed exalbuminous; embryo with long, 2–3 times folded radicle (or hypocotyl?) and ± folded cotyledons. About 25 species, if broadly construed (van Beusekom, but many more recognised, particularly in the New World), 15 in Asia/Malesia, and about 10 (or more) in Mexico, southern Central America, Antilles, in South America mainly in the Andes southwards to Peru, and south-eastern Brazil. In humid lowland, hill and mountain forests under tropical to warm-temperate conditions; the deciduous M. alba Walp. in China and Mexico.

Sabiaceae

Selected Bibliography Beusekom, C.F. van 1971. Revision of Meliosma (Sabiaceae), sect. Lorenzanea excepted, living and fossil, geography and phylogeny. Blumea 19:355–529. Carlquist, S., Morrell, P.L., Manchester, S.R. 1993. Wood anatomy of Sabiaceae (s.l.); ecological and systematic implications. Aliso 13:521–549. Chen, L. 1943. A revision of the genus Sabia Colebrooke. Sargentia 3:1–75. Cronquist, A. 1981. See general references. Davis, G.L. 1966. See general references. Erdtman, G. 1952. See general references. Fedorov, A.A. 1969. See general references. Hegnauer, R. 1973. See general references. Hilu, K.W. et al. 2003. See general references. Knobloch, E., Mai, D.H. 1986. See general references. Mai, D.H. 1995. Tertiäre Vegetationsgeschichte Europas. Jena: G. Fischer.

417

Mauritzon, J. 1936. Zur Embryologie und systematischen Abgrenzung der Reihen Terebinthales und Celastrales. Bot. Notiser 1936:161–212. Metcalfe, C.R., Chalk, L. 1950. See general references. Mondal, M.S. 1990. Pollen morphology and systematic relationships of families Sabiaceae (s.l.) and Connaraceae. Adv. Pollen Spore Res. 17. New Delhi: Today & Tomorrow’s, 137 p. Nandi, O.I. et al. 1998. See general references. Raju, M.V.S. 1952. Embryology of Sabiaceae. Curr. Sci. 21:107–108. Savolainen, V., Fay, M.F. et al. 2000. See general references. Soltis, D.E. et al. 2000. See general references. Soltis, D.E. et al. 2003. See general references. Urban, I. 1895. Über die Sabiaceengattung Meliosma. Ber. Deutsch. Bot. Gesell. 13:211–222, t. XIX. Urban, I. 1900. Sabiaceae. In: Symbolae Antillanae, I. Berlin: Borntraeger, pp. 498–518. van Beusekom, C.F., van de Water, Th.P.M. 1989. Sabiaceae. In: van Steenis, C.G.G.J., de Wilde, W.J.J.O. (eds) Flora Malesiana I, 10:679–715. Dordrecht: Kluwer.

Saxifragaceae Saxifragaceae Juss., Gen. Pl.: 308 (1789), ‘Saxifragae’, nom. cons.

D.E. Soltis

Perennial herbs, rarely annual or biennial, often rhizomatous. Leaves rosulate, alternate, on the inflorescence axis rarely opposite, simple or less often pinnately or palmately compound or decompound, margin various, from entire to lobed, crenate, or toothed; leaf base often sheathing, leaves on inflorescence often stipulate. Inflorescences cymose to racemose. Flowers perfect or sometimes some or all unisexual, regular to less often irregular, perigynous to often partly or wholly epigynous, homostylous (heterostylous in Jepsonia); hypanthium free from or variously adnate to base of ovary; calyx lobes (3–)5(–10); petals generally (4)5(6), sometimes 0, clawed or rarely cleft or dissected, well-developed or less often relatively small and inconspicuous; stamens usually 5 or 10, anthers basifixed in basal pit, tetrasporangiate and dithecal, opening by longitudinal slits, bisporangiate and opening terminally in Leptarrhena and Tanakaea; gynoecium of 2(3) carpels, these connate at least at very base and distally free to form hollow or solid stylodia terminated by capitate, rarely decurrent stigmas; ovules numerous and anatropous, usually bitegmic (unitegmic in Micranthes and Darmera), crassinucellate, on axile or parietal placentae. Fruit capsular or follicular; seeds typically numerous, small; endosperm present. A family of 33 genera and approximately 500 species, nearly worldwide in distribution but preferably in temperate, often mountainous parts of the Northern Hemisphere, with the greatest number of genera occurring in western North America. Plants generally flower in spring to early summer; Jepsonia is distinctive in flowering in fall. Vegetative Morphology. Plants are typically herbaceous perennials from a rhizome that varies from short and slender to large, thick and scaly. The leaves are generally basal, usually simple and pinnately or often palmately veined, rarely pinnately or palmately compound or decompound. Leaves on the inflorescence axis (when present) are alternate

or less often opposite. Sheathing leaf bases are welldeveloped in the basal and lower cauline leaves of genera such as Boykinia, Heuchera, Peltoboykinia, Bolandra, Tolmiea, Mitella, Tellima, Suksdorfia, Hieronymusia, and Lithophragma. In many species of these genera, the upper leaves have distinct, usually foliaceous stipules adnate to the cauline leaves (Weberling 1975; Bensel and Palser 1975; Wells 1984; Gornall and Bohm 1985). Vegetative Anatomy. Multicellular glandular hairs are common; in Bergenia they are immersed. Tanniniferous secretory cells containing proanthocyanidins and/or ellagitannins are widespread; idioblasts with cyanogenic compounds or containing crystal druses are uncommon; crystals of calcium oxalate are known from species of Micranthes, Saxifraga, and Bergenia (Engler 1930; Gornall 1987a). Stem bundles occur in a more or less continuous cylinder, sometimes accompanied by cortical and/or medullary bundles; cork arises usually in the outermost layer of the pericycle or subepidermally. Vessel-segments have simple or, in some primary (?) tissue, scalariform perforations with 6–11 bars; imperforate tracheary elements, when present, are small, with bordered pits (Bensel and Palser 1975). Nodes are most commonly trilacunar, but sometimes multilacunar (as in Astilbe), and unilacunar, 1-trace in Chrysosplenium, and unilacunar, 2-trace in Micranthes. Rays in secondary tissue are difficult to distinguish. The leaves often have hydathodes, which sometimes function as chalk-glands (Webb and Gornall 1989); stomates are most commonly anomocytic (Moreau 1984), but sometimes are anisocytic or diacytic. Inflorescence Structure. Flowers appear in various cymose or racemose inflorescences; rarely, they are solitary. Members of the Heuchera group have indeterminate (polytelic) inflorescences, whereas other members of the family have de-

Saxifragaceae

terminate (monotelic) inflorescences (Rosendahl et al. 1936; Wells 1984; Troll and Weberling 1989; Soltis et al. 1993). The thyrsoids of Rodgersia and Bergenia have scorpioid cymes void of prophylls; Bergenia is bractless. Flower Structure and Anatomy. The pollenconducting tissue of the stylodia does not seem to merge (Rabe and Soltis 1999); in other words, a compitum is lacking. The complete range of ovary positions, from superior to inferior, has been reported for the family, as well as for individual genera (e.g., Lithophragma, Saxifraga). Recent developmental studies demonstrate, however, that those ovaries referred to as ‘superior’ in the family may be technically inferior. Most species reported to have superior ovaries actually have developmentally epigynous flowers in which the ovary has a small portion below the insertion of the perianth and androecium. Such ovaries of epigynous flowers that mimic superior ovaries are termed pseudosuperior (Kuzoff et al. 2001; Soltis and Hufford 2002). Apparent differences in ovary position in the family may be the result of allometric shifts in the growth proportions of the superior vs. inferior regions of the ovary (Kuzoff et al. 2001). Embryology. Placentation is variously axile or parietal; ovules are several to usually numerous on each placenta, anatropous, bitegmic or sometimes unitegmic (as in Micranthes and Darmera; Webb and Gornall 1989), and crassinucellulate; embryo sac development follows the Polygonum or Allium type; endosperm development is cellular, helobial, or nuclear (Davis 1966; Johri et al. 1992). Hybridization. Hybridization has occurred both within and between genera of Saxifragaceae, with certain groups more prone to hybridization than others. Members of the Heuchera group of genera seem particularly prone to hybridization, with naturally occurring intergeneric hybrids reported between Conimitella and Mitella, Tellima and Tolmiea, Mitella and Tiarella, and Heuchera and Tiarella (reviewed in Soltis et al. 1991a). Most of these proposed examples have been documented with molecular markers. Within genera, hybridization appears to be fairly common in Heuchera (Rosendahl et al. 1936; Wells 1984; Soltis and Kuzoff 1995) and in Saxifraga (Webb and Gornall 1989). Molecular studies have also revealed a number of unexpected examples of hybridization, both within genera (e.g., distantly

419

related species of Heuchera) and between genera (e.g., Tellima × Mitella; Soltis et al. 1991a, b). For example, molecular data reveal that some populations of the monotypic Tellima have in the past hybridized with, and captured the chloroplast genome of a species of Mitella (Soltis et al. 1991b). Also of interest are stepping-stone chloroplast capture events in Heuchera in which one species has hybridized with a second species and the second species with a third species, ultimately transferring the cpDNA genome of the first species to the third species (Soltis et al. 1991a). Karyology. Most members of the family have x = 7. Karyotypic studies have been conducted on many of those taxa having x = 7. These data further support some of the well-marked clades, such as the Boykinia and Heuchera groups; these two groups differ in their basic karyotypes. In some species having 2n = 14, tetraploids with 2n = 28 also occur, and genetic studies have revealed that several of these tetraploids are autopolyploids (reviewed in Soltis and Soltis 1993). A base number of x = 11 is found in Peltoboykinia, and x = 11 and 12 are found in Chrysosplenium. These cytological data support a close relationship between these two genera, in agreement with recent phylogenetic hypotheses (Soltis, Kuzoff et al. 2001). Members of the Darmera group are also united by base chromosome number as well as the karyotype; most genera have x = 17, others having x = 15 and x = 18 (Fedorov 1969; Soltis 1986); this well-marked clade is presumed to be of polyploid origin. In contrast to other genera, Saxifraga and Micranthes are cytologically complex. A large range of numbers is found in both genera; in Micranthes, 2n = 10–120; in Saxifraga, 2n = 12–approx. 220. Because these two clades are well-separated phylogenetically, multiple events of aneuploid and polyploid increase have evidently occurred in the family. Pollen Morphology. Most taxa are 2–3colporoidate or -colpate with predominantly diffuse or simple endoaperatures; they exhibit a wide range of tectum structures, with a reticulate pattern common (Hideux and Ferguson 1976). The details of exine sculpturing are of considerable help in defining the sections of the genus Saxifraga (in the broad sense); four main types can be recognized (Ferguson and Webb 1970). These palynological differences also support the segregation of Micranthes from Saxifraga s. str. (Soltis et al. 1996b).

420

D.E. Soltis

Pollination. A surprisingly diverse array of pollinators has been suggested for Saxifragaceae, including Diptera (e.g., Chironomideae, Calliphoridae, Muscidae, Syriphidae), Hymenoptera (e.g., Cephidae, Ichneumonidae, Formicidae, Eumenidae, Halictidae, Apidae), Coleoptera (e.g., Dermestidae, Nitidulidae, Curculionidae), Lepidoptera, and Trichoptera (Ornduff 1971; Spongberg 1972; Savile 1975). Okuyama et al. (2004) studied the pollination of four streamside species of Mitella in Japan, the principal pollinators of which are fungus gnats (Mycetophilidae). In spite of very few visits by the pollinators, fruit set is high, which suggests that these animals can be highly efficient pollinators. In most instances, however, pollination has not been well-studied (but see Segraves and Thompson 1999); additional research is encouraged. In many species, nectar is secreted from a disc of tissue that surrounds the base of the ovary, or (in the case of inferior or partially inferior ovaries) the base of the stylodia. Diverse floral visitors have been observed, including Syrphidae and unspecialized Hymenoptera for species of Saxifraga (Holdregger 1996), ovary parasitic Greya moths for species of Lithophragma (Thompson 1994), and Lasioglossum, bombyliid flies, and Greya moths for species of Heuchera (Segraves and Thompson 1999). Tolmiea is bumblebee-pollinated, and Tellima has a mixed-mating system possibly facilitated by rove-beetles (Weiblen and Brehm 1996). Savile (1975) hypothesized that pollination in Chrysosplenium was facilitated, at least in part, by a splash mechanism involving water drops from the canopy. In Lithophragma, diversity in ovary position may be related to coevolutionary interactions between the flowers and the assemblage of pollinators visiting them (Thompson 1994). Importantly, considering the variable ovary position in the family (Kuzoff et al. 2001; Soltis and Hufford 2002), ovary position may have evolved in consonance with pollinator preferences (e.g., Thompson and Pellmyr 1992; Thompson 1994; Segraves and Thompson 1999). Fruit and Seed. The fruit is dry, dehiscent, most often dehiscent along the ventral sutures of the carpels above their level of union; seeds are generally numerous, small, with a small embryo embedded in copious endosperm. The seed is winged in several genera (Sullivantia and Leptarrhena); the surface texture is various, ranging from smooth to warty or spinulose. The seed coat is exotestal(–endotegmic), the testa often reduced to the tanniniferous outer epi-

dermis with often thickened cell walls, and the tegmen usually crushed, but sometimes, as in Astilbe, Rodgersia, Heuchera, provided with a thickened inner epidermis (Corner 1976; Takhtajan 1996). Dispersal. Morphological adaptations to seed dispersal supply many generic characters in Saxifragaceae; there is marked variation in seed dispersal mechanisms. Chrysosplenium, occupying moist forest floors and stream banks, has a flaring, erect capsule, which functions as a splash-cup (Fig. 148F): seeds are thrown out by the rebound of a falling water drop (Savile 1975). Some species of Mitella occurring in moist forests also have a splash-cup (Fig. 151C), independently evolved from that in Chrysosplenium. Tiarella has a horizontal capsule with a long lower valve, and the seeds are ejected by a springboard mechanism that also relies on falling water drops (Savile 1975). In many species of Heuchera, dispersal is thought to be by a censer mechanism, with flexible inflorescence stems swung by wind or passing animals; in other Heucheras, a more rigid inflorescence stem is present in which high wind speed induces vibration, bouncing seeds out. Censer or vibrator mechanisms also appear to be present in Saxifraga, Conimitella, Suksdorfia, Tellima, Telesonix, and Lithophragma (Savile 1975). Some taxa, such as Tolmiea menziesii and several species of Heuchera, have bristly seeds that may be spread by birds or mammals. Leptarrhena and Sullivantia have small seeds with a loose, strongly bitailed (or winged) coat that facilitates aerial and aquatic transport. There is evidence for long-distance dispersal in Chrysosplenium and other genera in the family, from Asia to South America and also from North America to South America (Soltis, Tago-Nakazawa et al. 2001). Phytochemistry. Saxifragaceae are characterized by high contents of tannins, amounting to 20% in Bergenia and Heuchera, and comprising both condensed and hydrolysable tannins, the former based on procyanidin and prodelphinidin, the latter containing ellagic and gallic acids. Bergenin, a C-glycoside of gallic acid, is known from several genera; some members of the family are weakly cyanogenic (Hegnauer 1973, 1990). Saxifragaceae may be one of the best studied groups of flowering plants for flavonoid compounds (e.g., Bohm and Wilkins 1976, 1978; Bohm et al. 1977, 1986, 1988; Bohm 1979; Bohm and Collins 1979; Bohm

Saxifragaceae

and Bhat 1985). The major flavonoids of Saxifragaceae are kaempferol, quercetin, and myricetin, all of which occur as 3-O-mono-, 3-O-di-, 3-O-triand 3,7-O-triglycosides; flavones typically constitute a small proportion of the total flavonoid chemistry of members of the family. 6-oxygenation and O-methylation are uncommon structural features that have clearly evolved several times in the family (Soltis et al. 1993). Gallyated flavonoid glycosides also appear in some members of the family. Although most members of the family have a rich array of flavonoid glycosides, several taxa have extremely simple profiles; phylogenetic data suggest that these are examples of flavonoid reduction. Family Circumscription. Saxifragaceae have been variously defined. Engler (1930) took a very broad view of the family, in which he included 15 highly diverse subfamilies, and included not only herbaceous genera, but also woody genera now segregated into other families such as Hydrangeaceae, Grossulariaceae, and Escalloniaceae. Other authors, starting with Hutchinson (1924), found the Englerian concept too broad to be useful, and therefore defined the family more narrowly. A series of molecular systematic studies (Soltis et al. 1993, 2000; Soltis and Soltis 1997; Hoot et al. 1999; Savolainen, Chase et al. 2000) revealed a well-defined and strongly supported family Saxifragaceae s. str. that corresponds to the Saxifragoideae of Engler, and is identical to the family circumscriptions of Takhtajan (1987, 1997) and Thorne (1992). Molecular phylogenetic studies also demonstrated that groups considered part of a broadly defined family Saxifragaceae such as hydrangeoids, escallonioids, Penthorum, Parnassia, Lepuropetalon, Francoa, Vahlia, and Eremosyne are only distantly related to core Saxifragaceae. Subdivision and Relationships Within the Family. Engler (1930) considered Saxifragaceae s. str. (his tribe Saxifrageae, which was part of the very broadly defined Saxifragaceae s. l.) to consist of four subtribes: Astilbinae, Leptarrheninae, Saxifraginae, and Vahliinae. Later, Schulze-Menz (1964) recognized three tribes: Astilbeae, Leptarrheneae, and Saxifrageae. Klopfer (1973), in contrast, recognized two large groups, one centered around Heuchera having parietal placentation, another centered around Saxifraga having axile placentation. Data from diverse sources, including morphology, cytology, flavonoid chemistry, as well as molecular phylogenetic studies (reviewed in

421

Soltis et al. 1993; Soltis, Kuzoff et al. 2001) indicate clearly that these groups are not monophyletic. Phylogenetic and systematic studies rather suggest the presence of six well-marked clades, which are informally recognized as the Boykinia, Heuchera, Darmera, Chrysosplenium, Astilbe, and Leptarrhena groups. Relationships within some of them, such as the Boykinia and Heuchera groups, have also been studied in detail from a molecular phylogenetic standpoint (e.g., Soltis and Kuzoff 1995; Soltis et al. 1997). Molecular phylogenetic studies also demonstrate that the genus Saxifraga comprises two well-separated lineages: Saxifraga s. str., and Micranthes (Soltis et al. 1996b). Phylogenetic relationships within other genera have been studied, too, including Chrysosplenium (Soltis, Tago-Nagazawa et al. 2001), Micranthes (Mort and Soltis 1999), Saxifraga (Conti et al. 1999; Vargas et al. 1999), and Lithophragma (Kuzoff et al. 1999). Other studies have focused on the Boykinia and Heuchera groups (Soltis and Kuzoff 1995; Soltis et al. 1996a). Soltis, Kuzoff et al. (2001) demonstrated that Saxifragaceae comprise two major lineages, one with Saxifraga s. str. (including Saxifragella), and another with all remaining genera of the family (the heucheroids). This major split is accompanied by general biogeographical and morphological differences. Whereas Saxifraga is largely arctic to alpine in occurrence, the heucheroid clade is largely temperate in distribution. Saxifraga has a relatively uniform floral morphology (generally actinomorphic; 5 sepals, 5 petals, 10 stamens, 2 carpels), whereas the heucheroid clade encompasses actinomorphic and zygomorphic forms, as well as variation in the number of sepals, petals, stamens, and carpels. The affinities of two monotypic genera (Saxifragella and Saxifragodes) endemic to Tierra de Fuego were also elucidated using DNA sequence data. Saxifragella is an early branching member of the primarily north temperate genus Saxifraga s. str.; Saxifragodes is sister to Cascadia, a genus endemic to Oregon and Washington. Long-distance dispersal from East Asia or western North America to South America may have played an important role in forming these and other similar disjunctions in the family involving North America and South America. Although relationships among genera within the family are generally well-known, the relationships of two genera that are rare and/or restricted to remote locations are still unclear (i.e., Hieronymusia, and in particular, Saniculiphyllum).

422

D.E. Soltis

Affinities. Saxifragaceae are part of a wellsupported Saxifragales clade (sensu Soltis and Soltis 1997). The immediate sister group of Saxifragaceae is Ribes, followed by a clade of Itea and Pterostemon (Soltis et al. 1996b; Soltis and Soltis 1997; Fishbein et al. 2001). Other members of Saxifragales include Crassulaceae, Haloragaceae, Tetracarpaeaceae, Hamamelidaceae, and Cercidiphyllaceae. However, the position of Saxifragales within the eudicots remains unclear. In some multigene analyses, Saxifragales are sister to the rosids; other analyses place Saxifragales following Gunnerales as sister to all other core eudicots. However, no placement of Saxifragales receives strong bootstrap support (Soltis et al. 2000). Distribution and Habitats. The family is nearly cosmopolitan in distribution, but with limited representation in the tropics in Africa and Australia, and in New Zealand. The vast majority of genera and species is found in the Northern Hemisphere, particularly in mountainous areas, with centers of diversity in western North America, eastern Asia and the Himalayas, and Europe. The greatest number of genera occurs in North America, especially the western Cordillera. Habitats are variable, but include moist woodlands, damp meadows and bogs, alpine areas, wet to extremely dry cliffs and rocky slopes, and grasslands. Parasites. Savile (1954, 1975) has studied the taxonomy of a group of microcyclic rusts of the genus Puccinia that uses the leaves of several genera of Saxifragaceae as host (these include Mitella, Tiarella, Bergenia, Saxifraga, Chrysosplenium, Heuchera, Tolmiea, and Tellima). Savile suggests that the rusts are “mostly of a single evolutionary group” that probably originated in the Himalayan region and there parasitized an underived saxifragaceous host-complex. The angiosperm genus Orobanche (Orobanchaceae) parasitizes the roots of several Saxifragaceae in western North America, including Suksdorfia and Lithophragma (Taylor 1965). Paleobotany. The early fossil history of Saxifragaceae is unsatisfactorily documented. Muller (1981) did not adduce any pollen record of the family, and two fossil flowers from the Upper Cretaceous of, the one Sweden and the other North America (see Friis and Skarby 1982; Gandolfo et al. 1995, 1998) also show similarities with Hydrangeaceae or other families now excluded

from Saxifragaceae s. str., so that they cannot provide a precise starting point of the fossil history of the family. Economic Importance. Species of Astilbe, Bergenia, and Heuchera (e.g., H. sanguinea, coral bells) are frequently cultivated as gardenornamentals. Many of the species of Saxifraga are considered choice ornamentals, particularly in Europe, and are often grown in rock gardens. Other garden-ornamentals include Tiarella cordifolia, as well as an intergeneric hybrid known as Heucherella involving Tiarella cordifolia and a species of Heuchera. Tolmiea menziesii (the piggyback plant) and Saxifraga stolonifera are common house plants. Leaves of Chrysosplenium have been used as salad greens; leaves of Astilbe were used in the Philippines for smoking; species of Boykinia, Tiarella, and Heuchera were of medicinal value to native peoples. Rhizomes of Astilboides contain tannin and starch, and can be used to make tannin extract and wine.

Key to the Genera 1. – 2. – 3. – 4. – 5. – 6. – 7.

–

8.

Placentation parietal 2 Placentation axile 12 Petals 0; sepals 4; stamens 4 or 8 5. Chrysosplenium Petals +; sepals 5; stamens 5 or 10, rarely 3 3 Fruit consisting of 2 very unequal dehiscent parts (carpels); stamens 10; petals entire, linear 20. Tiarella Fruit consisting of 2 or 3 essentially equal parts; stamens 3, 5, or 10; petals entire to laciniate 4 Stylodia 3; petals white or pink, laciniate, sometimes entire; plants bearing bulbils in leaf axils or on the underground parts 13. Lithophragma Stylodia 2; petals variously colored, petals entire or three-lobed to pinnately divided; plants not bulbilbearing 5 Petals entire 6 Petals trifid to pectinately or pinnately lobed 10 Inflorescence paniculate, spicate, or thyrsoid; seeds finely echinulate in longitudinal rows; stamens 5; calyx never narrowly turbinate 15. Heuchera Inflorescence racemose; seeds rarely echinulate, but if so, then the calyx narrowly turbinate; stamens 3, 5, or 10 7 Stamens 3; calyx greenish-purple to reddish-brown, split much more deeply on one side than between the rest of the lobes; petals linear-subulate, reddish-purple 18. Tolmiea Stamens 5 or 10; calyx typically green, not split much more deeply on one side than between the rest of the lobes, usually saucer-shaped to campanulateturbinate; petals not linear-subulate, white to green 8 Flowers and fruit elongate; racemes loosely 5–12flowered; leaf margins ciliate 16. Conimitella

Saxifragaceae – Flowers and fruit saucer-shaped; racemes closely 10–45-flowered; leaf margins not ciliate 9 9. Flowers slightly irregular 14. Bensoniella – Flowers regular 19. Mitella 10. Calyx (including that portion adnate to the ovary) usually only 2–4 mm long, in one species up to 4–6 mm long but then the petals trilobed; stylodia less than 1 mm 19. Mitella – Calyx (including the adnate portion) (6)7–10 mm long; stylodia over 1 mm long 11 11. Stamens 10 12. Tellima – Stamens 5 17. Elmera 12. Leaves compound, sometimes unifoliate 13 – Leaves simple, entire to lobed but not compound 14 13. Rhizome slender; basal leaves often twice or three times ternately divided; petals usually present, 1–5 28. Astilbe – Rhizome large, thick; basal leaves pinnately or palmately compound; petals often 0 or occasionally 1, 2, or 5 8. Rodgersia 14. Sepals and petals 4 or 5; stamens 8 7. Astilboides – Sepals and petals usually 5, rarely 0; stamens usually 5 or 10 15 15. Stamens generally 10 16 – Stamens 5(–7) 28 16. Perennial from thick, well-developed rhizome or corm, generally 1 cm or more in diameter 17 – Perennial from slender rhizome, much less that 1 cm in diameter 21 17. Petals 0 10. Oresitrophe – Petals + 18 18. Leaf blades not peltate 19 – Leaf blades peltate, nearly orbicular 20 19. Plants from thick, creeping rhizome; flowers homostylous; flowering in spring 11. Bergenia – Plants from fleshy corm; flowers heterostylous; flowering in fall 22. Jepsonia 20. Inflorescence axis naked; petals white 6. Darmera – Inflorescence axis bearing a single leaf; petals pale yellow 4. Peltoboykinia 21. Stems slender, weak, prostrate 22 – Stems erect 23 22. Ovary not much longer than wide, nearly completely inferior; petals not much longer than sepals, and with pink to purple specks 2. Saxifragodes – Ovary elongate, 1/2–2/3 inferior; petals distinctly longer than sepals, without pink to purple specks 1. Cascadia 23. Carpels distinct almost to the base, adnate to the calyx for less than 1/5 their length; leaves leathery; anthers bisporangiate, dehiscing terminally by broad opening 24 – Carpels usually fused or adnate to the calyx for at least 1/5 their length; leaves not leathery; anthers tetrasporangiate, opening by longitudinal slits 25 24. Leaves slightly crenate; flowers apetalous 30. Leptarrhena – Leaves serrate; flowers with petals 31. Tanakaea 25. Leaf blade jointed to and falling before petiole 29. Saxifragopsis – Leaf blade not jointed to or falling before petiole 26 26. Plants glandular pubescent; stylodia partially connate; petals pink to deep red or purple; calyx campanulate, usually reddish, (5)6–10 mm long; leaves alternate, petiolate 21. Telesonix

423

– Plants usually not glandular pubescent; stylodia free above the ovuliferous portion of the ovary; petals usually white, but if (rarely) pink or red (to purple), then either the calyx not immediately campanulate, red, nor as long as 6 mm, or the leaves sessile and opposite 27 27. Flowering stem leafless, sometimes with large bracts (all leaves arranged in basal rosette); pollen surface reticulate; ovules unitegmic; leaf crystals present 3. Micranthes – Flowering stem generally leafy; pollen surface granular or striate, never reticulate; ovules bitegmic; leaf crystals generally 0 32. Saxifraga 28. Leaves all basal (scape leafless); carpels 2–3 29 – Leaves basal and cauline; carpels 2 30 29. Carpels 2; bracts and disc 0 9. Mukdenia – Carpels 2–3; bracts and disc + 33. Saniculiphyllum 30. Calyx campanulate, the sepals lanceolate-acuminate; ovary appearing nearly superior 23. Bolandra – Calyx not campanulate, various as to size and shape, the sepals not lanceolate-acuminate; ovary with an obvious inferior region 31 31. Plants bulbiferous at the root stock, neither stoloniferous nor conspicuously rhizomatous; flowering stems rarely over 2 dm tall; upper cauline leaves conspicuously stipulate; petals white, rose, or violet 25. Suksdorfia (see also 26. Hieronymusia) – Plants not bulbiferous at the root stock, usually either stoloniferous or with evident rhizomes; flowering stems either well over 3 dm tall or else the upper cauline leaves without conspicuous stipules; petals white 32 32. Petals 1.5–2.5 mm long, withering persistent; calyx mostly 2.5–3.5 mm long; stems rarely 25 cm tall 24. Sullivantia – Petals mostly 4–7 mm long, deciduous; calyx rarely less than 4 mm long; stems (15)20–80(100) cm tall 27. Boykinia

Genera of Saxifragaceae I. Heucheroids I.1. Cascadia Group Perennials with slender, prostrate stems. Leaves alternately inserted along the length of the stem. Flowers borne at tips of stems on short peduncles; calyx lobes 5; petals 5; stamens 10; carpels 2; placentation axile. 1. Cascadia A.M. Johnson Cascadia A.M. Johnson, Amer. J. Bot. 14:38 (1927).

Stems weak, frequently branching from below the middle. Leaves petiolate, alternate, ovatelanceolate to lanceolate, leaves of inflorescence branches reduced to bracts. Flowers with welldeveloped hypanthium; petals distinctly longer than sepals; ovary elongate, 1/2–2/3 inferior; seeds spiny. One species, C. nuttallii A.M. Johnson, from a small area of western Oregon and Washington.

424

D.E. Soltis

2. Saxifragodes D.M. Moore Saxifragodes D.M. Moore, Bot. Notiser 122:324 (1969).

Stems slender, branched at base. Leaves suborbicular to ovate-elliptical, entire or three-lobed; petals 5, varying from slightly shorter than to slightly longer than the sepals, elliptic to oblanceolate, white with pink to purple flecks; fertile stamens 6; ovary nearly completely inferior. Capsule ovoid, compressed, deeply bifid; seeds tuberculate, brown. One poorly understood species, S. albowiana D.M. Moore, from Tierra del Fuego. I.2. Micranthes Group 3. Micranthes Haworth

Fig. 147

Micranthes Haworth, Syn. Pl. Succ.: 320 (1812). Saxifraga sects. Micrantha and Merkianae, Engler & Irmscher, Pflanzenreich IV, 117:1–448 (1916).

Herbaceous perennial. Leaves primarily or exclusively basal, entire, toothed, or lobed, petiolate to sessile, glabrous to glandular-hairy, with calcium oxalate crystals. Inflorescence cymose, leafless (sometimes with conspicuous bracts). Flowers regular, perfect, calyx saucer-shaped to conic or campanulate; calyx lobes 5; petals commonly 5, white to greenish, yellow; stamens 10, inserted with the petals on or at the top of the hypanthium (if any); carpels 2(3), ranging from only basally fused to connate well above the ovuliferous portion; ovary nearly superior to more than half inferior; placentation axile; ovules unitegmic. Fruit capsular and dehiscent for at least half its length; seeds numerous, smooth to variously wrinkled, winged, crested, muricate, or tuberculate. 2n = 10–120. About 70 species, primarily of north temperate to Arctic regions. See comment under Saxifraga. I.3. Peltoboykinia Group Perennials. Leaves basal and cauline (cauline leaves few and alternate). Flowers regular; carpels 2; fruit capsular; x = 11. 4. Peltoboykinia (Engler) H. Hara Peltoboykinia (Engler) H. Hara, Bot. Mag. (Tokyo) 51:251 (1937); Gornall & Bohm, Bot. J. Linn. Soc. 90:1–71 (1985), rev.

Large, erect herb from short, thick, creeping rhizome. Leaves chiefly basal, long-petioled, large, peltate, palmately lobed, stipules membranous. Inflorescence a few-leaved, terminal cyme;

Fig. 147. Saxifragaceae. Micranthes nivalis. A Habit. B Flower, vertically sectioned. C Dehiscing tricarpellate fruit. D Seed. (Engler 1930)

calyx-tube shallowly campanulate, adnate to the ovary on lower half, lobes 5; petals 5, pale yellow, toothed, glandular-dotted, ascending, deciduous; stamens 10; ovary nearly superior but with a short inferior region; placentation axile. Capsules enclosed in the somewhat inflated calyx-tube; seeds numerous, longitudinally tuberculate. 2n = 22. One species, P. tellimoides (Maxim.) H. Hara, Japan. 5. Chrysosplenium L.

Fig. 148

Chrysosplenium L., Sp. Pl.: 398 (1753); Hara, J. Fac. Sci. Univ. Tokyo, Bot. 7:1–90 (1957), rev.

Plants stoloniferous. Leaves glabrous to pilose, small, opposite or alternate, petiolate, crenate, estipulate. Inflorescence a few-flowered terminal or apparently axillary cyme, or flowers solitary. Flowers greenish, yellow, or white, often inconspicuous; calyx adnate to the lower half of the ovary, broadly campanulate, the lobes 4, spreading; petals 0; stamens 4 or 8, alternating with small,

Saxifragaceae

425

Large herb, rhizome scaly, typically submerged. Leaves only basal, large, peltate, developing later than inflorescence. Inflorescence large, leafless. Flowers showy; calyx adnate to the base of the ovary, deeply 5-lobed; petals 5, white to bright pink, entire; stamens 10; carpels 2, free above the point of adnation with the calyx; ovary nearly superior, but with short inferior region; seeds cellular-rugulose; 2n = 34. One species, D. peltata (Torr.) A. Voss, occurring along fast-flowing streams in northern California and southern Oregon. 7. Astilboides Engler Astilboides Engler in Nat. Pflanzenfam., ed. 2, 18a:116 (1930); Jintang et al., Fl. China 8:269–452 (2001). Fig. 148. Saxifragaceae. Chrysosplenium biondianum. A Flowering plant. B Inflorescence. C Male flower. D Female flower. E Pistil. F Fruit. G Seed. (Wu and Raven 2003)

fleshy glands forming a minute disc-like margin around the ovary; ovary slightly to more than half inferior, the 2 short stylodia protruding through the disc; placentation parietal. Capsule 2-lobed and dehiscent throughout the superior portion; seeds small, several to numerous, smooth; the most common chromosome numbers are 2n = 22 and 24, other numbers include 2n = 8, 14, 16, 18, and 42. Approximately 55 species, in moist areas of temperate to arctic North America and Eurasia, several in South America; most species occur in Asia. Molecular data (Nakazawa et al. 1997; Soltis, Tago-Nakazawa et al. 2001) support the traditional division of the genus into opposite- and alternateleaved species (see Franchet 1890; Hara 1957). I.4. Darmera Group Perennials from large, thick, sometimes scaly, horizontal rhizome. Leaves sometimes only basal, or with few, alternate, cauline leaves much smaller than basal leaves. Inflorescence sometimes leafless, cymose. Flowers numerous, regular; carpels generally 2; placentation axile. Fruit follicular, opening between the stylodia; 2n = 30 or higher, generally 2n = 34. 6. Darmera (Torrey) A. Voss Darmera (Torrey) A. Voss, Gart. Zentral-Bl. 1:625 (1899). Peltiphyllum Engler (1890).

Large herb, rhizome scaly. Leaves primarily basal, large, nearly round or ovate, with short and stiff hairs on both surfaces, shallowly palmately lobed, stem leaf one, similar to the basal leaf, but smaller. Inflorescence with one leaf similar to the basal leaf, but smaller. Flowers numerous, small, white; calyx bell-shaped, 4–5-lobed, the lobes broad ovate; petals 4–5, obovate-oblong; stamens 8; carpels 2; ovary with short inferior region; seeds winged; 2n = 34, 36. One species, A. tabularis (Hemsl.) Engler, northeastern China (provinces Liao-ning and Ji-ling) and Korea, in mountain forests and along valley streams. 8. Rodgersia A. Gray Rodgersia A. Gray, Mem. Amer. Acad. Arts II, 6:389 (1858).

Large herb with short, stout, scaly rhizome. Leaves primarily basal, palmately or pinnately compound, long-petiolate; leaflets 3–9(10), toothed. Inflorescence large and few-leaved, the ultimate branches scorpoid-cymose. Flowers numerous, white, small; calyx-tube shallow, short, the lobes (4)5(–7), spreading, white at anthesis; petals narrowly linear, small, often 0 or occasionally 1, 2, or 5; stamens usually 10(–14); carpels 2(3); ovary nearly superior but with a short inferior region. 2n = 30, 60 (Fedorov 1969). Five species, from the Himalayas to East Asia (Japan), in mountain forests. 9. Mukdenia Koidzumi Mukdenia Koidzumi, Acta Phytax. Geobot. 4:120 (1935). Aceriphyllum Engl. (1890).

Herbs from large rhizome. Leaves basal, palmately 5-lobed. Inflorescence scapose, partial inflorescences cincinnate. Flowers showy; calyx

426

D.E. Soltis

adnate to the base of the ovary, deeply 5–6-lobed, white, longer than the petals; petals white, 5–6(7); stamens 5–6(7); carpels 2, basally connate; ovary nearly superior but with a short inferior region. Fruit a capsule. 2n = 34. One species, M. rossii (Oliver) Koidzumi, from northern China and Korea, on rocky slopes and in ravines. 10. Oresitrophe Bunge Oresitrophe Bunge, Enum. Pl. China Bor. 31 (1833).

Herbs from short, thick, rhizome. Leaves 2–3, basal, petiolate, blade ovate to cordate, dentate, nearly glabrous. Inflorescence cymose with dense glandular hairs. Flowers small, hypanthium bowlshaped; calyx lobes 5–7, oblong-ovate, pink and petaloid; petals 0; stamens 10–14, with thin, threadlike filaments and purple anthers; carpels 2; ovary with a short inferior region, nearly superior, coneshaped. One poorly known species, O. rupifraga Bunge, from mountains near Beijing, China. 11. Bergenia Moench

Fig. 149

Bergenia Moench, Methodus: 664 (1794); Yeo, Kew Bull. 26:113–148 (1966), rev.

Herbs from large, scaly rhizome, forming dense clumps or colonies. Leaves basal, with immersed glands, thick, waxy, simple, persistent, entire, toothed, or crenate. Inflorescence large, bractless. Flowers showy; calyx 5-lobed, green, not fused with ovary; petals 5, entire, white, pink, red, or purple; stamens 10 with pointed filaments and short ovate anthers opening to the side; carpels 2(3), connate at base; ovary with a short inferior region, nearly superior; seeds dark brown. 2n = 34. Ten species from the Himalayas, northern Mongolia, Siberia, and China. I.5. Heuchera Group Perennials. Leaves basal and cauline (cauline leaves few, sometimes 0), alternate, rarely opposite or 0, simple, long-petiolate, reniform, palmately veined, stipules small, membranous; calyx lobes 5; petals 5(4, 0); stamens 3, 5, or 10; carpels 2(3); placentation parietal; x = 7. 12. Tellima R. Br. Tellima R. Br. in Franklin, Narrat. J. Polar Sea app.: 765 (1823).

Plants from short, stout rhizome, coarsely hirsute. Leaves cordate-ovate, slightly lobed. Inflorescence

Fig. 149. Saxifragaceae. Bergenia purpurascens. A Habit. B Inflorescence. C Sepal, adaxial view. D Petal. E Stamen and pistil. F Glandular hair. G Gynoecium, vertically sectioned. (Wu and Raven 2003)

an elongate, minutely bracteate raceme. Flowers showy, hypanthium well-developed, campanulatetubular; petals 5, short-clawed, the blade pinnately divided, white; stamens 10; carpels 2; ovary about 1/4 inferior. Capsule dehiscent along the sutures of the beaks, seeds brown, ellipsoid-ovoid. 2n = 14. One species, T. grandiflora R. Br. from northern California to southeastern Alaska. 13. Lithophragma Nutt. Lithophragma Nutt., J. Acad. Philadelphia 7:26 (1834); Taylor, Univ. Calif. Publ. Bot. 37:1–122 (1965), rev.

Plants from slender rhizome bearing numerous bulblets. Leaves orbicular-reniform to reniform, palmately parted or cleft, the petioles slender, cauline leaves 1–several, reduced, sometimes ses-

Saxifragaceae

sile. Inflorescence a terminal raceme, sometimes with bulblets in the axils of the cauline leaves and the bracts. Flowers showy, rarely replaced by bulblets, hypanthium narrowly cyathiform-obconic to campanulate or cup-shaped; petals 5, white or pink or purplish-tinged, narrowly clawed and with a large, expanded, usually digitately, rarely pinnately cleft or divided to shallowly lobed or sometimes entire blade; stamens 10; carpels 3; ovary position ranging from very slightly inferior [appearing superior] to nearly fully inferior. Capsule 3-valved, seeds slightly wrinkled but otherwise smooth to irregularly reticulate, verrucose, or muricate. 2n = 14, 28, 35, 42. Ten species of temperate western North America.

427

14. Bensoniella Morton Bensoniella Morton, Leafl. W. Bot. 10:181 (1965).

Plants with long, slender, branching rhizome. Leaves cordate, petioles slender with long brown hairs. Inflorescence a scapiform raceme. Flowers slightly irregular, hypanthium campanulate; petals 5, filiform, entire, whitish; stamens 5, antesepalous; carpels 2, connate for half their length, subcompressed; ovary slightly inferior. Capsule widely dehiscing between the stylodia. 2n = 14. One species, B. oregona Morton, western USA. 15. Heuchera L.

Fig. 150

Heuchera L., Sp. Pl. 1:226 (1753); Rosendahl, Butter & Lakela, Monogr. of Heuchera (1936); Wells, Syst. Bot. Monogr. 3:45–121 (1984), rev. eastern N. Amer. spp.

Plants usually with thick, scaly rootstocks and erect, naked to bracteate flowering stems, glandular to sometimes glabrous. Leaves primarily basal, palmately lobed and usually deeply once or twice crenate-dentate. Inflorescence with or without leaves, paniculate, spicate, or thyrsoid. Flowers regular, rarely slightly irregular, usually complete, hypanthium greenish, yellowish, or red, from shallowly saucer-shaped to conic or tubular-campanulate, adnate to the ovary; petals 5, sometimes fewer, rarely 0, white to greenishyellow, or red, mostly distinctly clawed and with an ovate to spatulate or linear, entire blade; stamens 5; carpels 2; ovary from about half to nearly completely inferior, stylodia well-developed to almost 0. Capsule dehiscent along the beaks; seeds spinulose in longitudinal rows, sometimes nearly smooth. 2n = 14, 28. About 35 species of North America, ranging from southern Mexico to the Arctic, with most species in western USA. 16. Conimitella Rydb. Conimitella Rydb., N. Amer. Fl. 22:2, 96 (1905).

Fig. 150. Saxifragaceae. Heuchera rubescens. A Habit. B Flower. C Same, vertically sectioned. D Fruit. (Drawing B. Angell; Cronquist et al. 1997)

Plants from short rhizome. Leaves basal, reniform, ciliate. Inflorescence a terminal, inconspicuously bracteate raceme; flowers regular, complete, elongate; calyx turbinate-obconic, adnate to the ovary for about 1/2–1/3 its length, the hypanthium tubular; petals 5, white, with an entire blade and slender claw; stamens 5, antesepalous; carpels 2(3); ovary almost completely inferior, with short stylodia. Capsule dehiscing from small stylar region. 2n = 14. One species, C. williamsii Rydb., western USA.

428

D.E. Soltis

17. Elmera Rydb. Elmera Rydb., N. Amer. Fl. 22:2, 97 (1905).

Plants with slender rhizome. Leaves primarily basal, reniform, palmately lobed and once or twice crenate, strongly pubscent, glandular above. Inflorescence a minutely bracteate, simple, terminal raceme. Flowers showy, regular; calyx cup-shaped, adnate to the ovary at the base; petals 5, white, short-clawed, blade 3–7-cleft or entire; stamens 5, opposite to, and shorter than, the calyx lobes; carpels 2; ovary 1/4 inferior. Fruit an ovoid capsule dehiscent on the beaklike upper portion. 2n = 14. One species, E. racemosa Rydb., Pacific Northwest of the USA.

almost circumscissile; seeds generally black. 2n = 14, 28. This broadly defined genus comprises 20 species as traditionally circumscribed; these are mostly of the western USA, Japan, and eastern Asia. The genus is clearly polyphyletic, comprising perhaps four or more distinct lineages most of which ultimately should be recognized as distinct genera (Soltis and Kuzoff 1995).

18. Tolmiea (Pursh) Torr. & Gray Tolmiea (Pursh) Torr. & Gray, Fl. N. Am. 1:582 (1840).

Plants from slender rhizome. Leaves primarily basal, often with prominent plantlet at base of blade. Inflorescence a sparingly leafy raceme. Flowers showy, irregular; calyx free of the ovary, greenish-purple to reddish-brown, with a tubular, oblique-based hypanthium; petals 4, linearsubulate, reddish-purple; stamens 3; carpels 2; ovary appearing nearly superior but with a very short inferior region. Fruit a capsule dehiscent along the divergent beaks; seeds dark brown to black, smooth, ovoid. 2n = 14, 28. Two species, Tolmiea menziesii (Pursh) Torr. & Gray, from northern California to southeastern Alaska. 19. Mitella L.

Fig. 151

Mitella L., Sp. Pl. 1:406 (1753); Rosendahl, Bot. Jahrb. Syst. 50, suppl.: 375–397 (1914), rev.

Plants rhizomatous, rarely stoloniferous, glandular-puberulent and often somewhat hirsute with leafless or 1–3-foliate flowering stems. Leaves cordate or ovate to reniform cordate. Inflorescence an elongate, bracteate, simple raceme. Flowers regular; calyx saucer-shaped to turbinate-campanulate, adnate to the ovary; petals 5, borne with the stamens at, or near the top of, the hypanthium, greenish, white, or pinkish-to purple-tinged, slenderly clawed and with a usually filiformly dissected to trilobed, rarely entire blade; stamens 10, or 5 and then either opposite or alternate with the calyx lobes; carpels 2; ovary from less than half to nearly completely inferior. Fruit a capsule, dehiscent by adaxial, rarely ventral sutures on the free, lobed portion, the dehiscent fruit appearing

Fig. 151. Saxifragaceae. Mitella stauropetala. A Habit. B Flower. C Dehisced splash-cup capsule. (Cronquist et al. 1997)

Saxifragaceae

20. Tiarella L. Tiarella L., Sp. Pl. 1:405 (1753); Lakela, Amer. J. Bot. 24:344–351 (1937), rev.

Plants from slender (sometimes spreading) rhizome. Leaves primarily basal, cordate and palmately lobed to 3-foliolate, variously toothed to cleft, leaves on infloresence 2–3-foliate. Inflorescence an elongate raceme. Flowers showy, slightly irregular; calyx irregular, hypanthium campanulate, free or nearly so of the ovary; petals 5, white, linear to subulate, very similar to the filaments; stamens 10; carpels 2, unequal at anthesis; ovary appearing nearly superior but with a very short inferior region. Fruit dehiscent along the unequal sterile valves above the fertile basal portion; seeds nearly black, shining and almost smooth. 2n = 14. Three species, one each in Asia, and western and eastern North America, the western North American species, T. trifoliata L., comprising three varieties sometimes treated as three distinct species. I.6. Boykinia Group Perennials. Leaves basal and cauline (cauline leaves few, alternate, usually much smaller than basal leaves), simple, reniform, palmately veined, and long-petiolate with small, membranous stipules. Inflorescence cymose. Flowers perfect, regular; calyx lobes 5; petals 5; carpels 2; placentation axile; fruit a loculidal capsule. x = 7. 21. Telesonix Raf. Telesonix Raf., Fl. Tell. 2:69 (1836).

Plants glandular-pubescent, from short, thick rootstocks. Leaves reniform, doubly crenate; inflorescence compact, terminal, few-flowered, bracteate. Flowers showy; calyx turbinate-campanulate, adnate to the lower part of the ovary, with a somewhat expanded, tubular, free hypanthium, the lobes ovate-lanceolate; petals pink to deep red or purple, ovate to spatulate; stamens 10, inserted at the top of hypanthium, from barely as long to nearly twice as long as the calyx lobes; ovary about half inferior, tapered above into the somewhat beaklike stylodia. 2n = 14. Two species, western USA. 22. Jepsonia Small Jepsonia Small, Bull. Torrey Bot. Club 23:18 (1896); Ornduff, Brittonia 21:286–298 (1969), rev.

Plants from distinctive, fleshy corm. Leaves basal, long-petiolate, round-cordate, lobed and toothed.

429

Inflorescence appearing in the fall (basal leaves not present at that time), with multiple inflorescences developing. Flowers heterostylous, hypanthium campanulate, not fused with the ovary; calyx lobes yellow green to pink, short, triangular; petals lanceolate, white with tan or purple veins; stamens 10; ovary with a small inferior region. Capsule thin-walled, opening between the stylodia. 2n = 14, 28. Three closely related species from southern California, Channel Islands, and Baja California. 23. Bolandra Gray Bolandra Gray, Proc. Amer. Acad. Arts Sci. 7:341, 342 (1867); Gornall & Bohm, Bot. J. Linn. Soc. 90:1–71 (1985), rev.

Plants with short, bulbiferous rhizome. Leaves primarily basal, reniform, palmately veined and longpetiolate, the upper cauline leaves reduced but their stipules becoming larger. Inflorescence terminal, few-flowered, open, conspicuously bracteate; calyx tubular-campanulate, with lanceolate, spreading lobes, greenish and purplish-tinged; petals linear, nearly erect or only slightly spreading, reddishpurple, exceeding the stamens; stamens 5, opposite the sepals; carpels fused only 1/4–1/5 their length, free of the calyx; ovary appearing nearly superior. 2n = 14. Two species, western USA. 24. Sullivantia Torrey & Gray ex Gray Sullivantia Torrey & Gray ex Gray, Amer. J. Sci. 42:22 (1842); Soltis, Brittonia 43:27–53 (1991), rev.

Plants moderately glandular-pubescent, one species stoloniferous. Leaves cordate-reniform, incised-lobed and sharply toothed. Inflorescence of usually numerous flowers in a modified compound cyme; calyx turbinate, the lobes triangular, about as long (at anthesis) as the lower adnate portion; petals white, persistent; stamens 5, opposite the calyx lobes; ovary 1/2–3/4 inferior. Capsule dehiscent along the ventral suture of the sterile portion of the 2 carpels; seeds linear-fusiform, narrowly wing-margined. 2n = 14. Three species, USA. 25. Suksdorfia Gray Suksdorfia Gray, Proc. Amer. Acad. Arts Sci. 15:41, 42 (1879); Gornall & Bohm, Bot. J. Linn. Soc. 90:1–71 (1985), rev.

Plants with very short, sparsely to copiously bulbiferous rootstock. Leaves crenate to deeply divided, cordate to reniform, cauline leaves strongly stipulate, glandular-pubescent at least in the inflores-

430

D.E. Soltis

cence. Inflorescence few- to many-flowered; calyx lobes erect to spreading; petals white, rose, or violet, erect to spreading, entire, spatulate to oval; stamens 5, antesepalous; ovary slightly more than half to nearly completely inferior. Capsule dehiscent along the ventral sutures of the beaks; seeds somewhat prismatic, faintly to prominently warty. 2n = 14. Two species, Pacific Northwest of North America. 26. Hieronymusia Engler

Fig. 152

Hieronymusia Engler, Notizbl. Bot. Gart. Mus. BerlinDahlem 7:265–267 (1918).

Plants from a slender rhizome. Leaves roundcordate, shallowly lobed and serrate. Inflorescence with distal 3–5-flowered partial inflorescences subtended by leafy bracts with spatulate, toothed stipules; calyx lobes erect, prolonged above into a nearly companulate hypanthium, fused with ovary; petals ovate, sessile with broad base, smaller than sepals; stamens 5; ovary completely inferior. One poorly known species, H. alchemilloides (Griseb.) Engl., placed in Suksdorfia by Gornall and Bohm (1985); Sierra de Tucuman in Argentina and in Bolivia on damp, shady humus and damp rock cliffs at 3,000–4,000 m.

Fig. 152. Saxifragaceae. Hieronymusia alchemilloides. A Habit. B Flower, longitudinally sectioned. C Sepal. D Petal. E Anther. F Nearly mature fruit. G Seed. H Embryo. (Engler 1930)

27. Boykinia Nutt.

much smaller than the basal leaves), compound, rarely unifoliolate; stipules scarious; leaflets lanceolate to ovate-orbicular, basally cuneate, toothed. Inflorescence a bracteate panicle. Flowers numerous, regular, small; calyx lobes and petals generally 5; carpels 2, connate at the base; ovary appearing nearly superior, but with a short inferior region; placentation axile. Fruit follicular, dehiscing between the stylodia; x = 7.

Boykinia Nutt., J. Acad. Nat. Sci. Philadelphia 7:113 (1834), nom. cons.; Gornall & Bohm, Bot. J. Linn. Soc. 90:1–71 (1985), rev.

Astilbe Buch.-Ham. ex D. Don, Prodr. Fl. Nepal.: 210 (1825).

Plants glandular-pubescent and often brownishpilose, from slender to thick, scaly rhizomes. Leaves cordate to reniform, several times shallowly cleft and toothed; stipules varying from well-developed and leaf-like to bristle-like. Inflorescence terminal or subterminal; calyx turbinate to campanulate, green, prolonged above ovary as a tubular hypanthium, the lobes equal, lanceolate; petals white, spatulate or obovate to oblong-ovate, short-clawed, caducous; stamens 5, inserted with the petals at the top of the hypanthium opposite the calyx segments; ovary 1/3 to 3/4 inferior; seeds minutely tuberculate. 2n = 12, 14, 26, 28, 36, 84. Six species, four from western North America, one in eastern North America, and one in Japan. I.7. Astilbe Group Perennials from slender, woody rhizome. Leaves basal and cauline (cauline leaves few, alternate, and

28. Astilbe Buch.-Ham. Leaves ternately compound, rarely unifoliolate. Flowers white or rose purple, bisexual or unisexual, plants sometimes dioecious; calyx-tube short, adnate to base of ovary, lobes 5(7–11); petals persistent, linear, (0)1–5; stamens 5, 8, or 10. 2n = 14, 28. About 25 species, one or perhaps two endemic to the southern Appalachians in North America, and about 23 in eastern Asia from Japan through China into the Himalayan region and extending southward into New Guinea. 29. Saxifragopsis Small Saxifragopsis Small, Bull. Torrey Bot. Club 23:19 (1896).

Leaves unifoliolate, blade jointed to and falling before petiole. Flowers bisexual, showy; hypanthium campanulate, partly fused with the base of the ovary; calyx lobes 5, ovate to ovate-lanceolate, recurved; petals 5, white; spatulate, pointed, 1.5 times longer than the sepals, recurved; stamens 10, with

Saxifragaceae

431

pointed, basally winged filaments. 2n = 14. One species, S. fragaroides (Greene) Small, in northern California and southern Oregon. Sometimes erroneously placed in Saxifraga; it is, in fact, the sister group to Astilbe. I.8. Leptarrhena Group Perennials; strongly rhizomatous. Leaves leathery, persistent or evergreen, short-petiolate, estipulate, primarily basal, cauline leaves few, much smaller than basal leaves. Inflorescence paniculate. Flowers numerous, regular; calyx lobes typically 5; stamens 10; anthers bisporangiate, dehiscing terminally; carpels 2, fused only at the base; ovary only slightly inferior; placentation axile. Capsule ventrally dehiscent. 2n = 14. 30. Leptarrhena R. Br. Leptarrhena R. Br., Chlor. Melvill.: 15 (1823).

Leaves persistent but not evergreen. Inflorescence sparsely leafy, slightly glandular-pubescent. Flowers numerous, tightly aggregated; hypanthium deeply saucer-shaped; calyx lobes 5, erect; petals 5, white, small, persistent. One species, L. pyrolifolia R. Br., Pacific Northwest of USA to Alaska. 31. Tanakaea Franchet & Savat. Tanakaea Franchet & Savat., Enum. Pl. Jap. 2:352 (1878).

Fig. 153. Saxifragaceae. Saxifraga media Gouan. A Habit. B Flower. (Engler and Irmscher 1919)

Plants stoloniferous. Leaves primarily basal, oblong, irregularly serrate, evergreen. Inflorescence with small linear bracts; flowers white, functionally unisexual and plants dioecious; calyx-tube short, shallow, the lobes (4)5(–7); petals 0. One species, T. radicans Franchet & Savat., in China and Japan. II. Saxifragoids 32. Saxifraga L.

Figs. 153, 154, 155

Saxifraga L., Sp. Pl. 1:398 (1753), excl. sects. Micranthes and Merkiana, Engler & Irmscher in Pflanzenreich IV, 117 (1919). Zahlbrucknera Reichb. (1832). Saxifragella Engler (1890).

Perennials or more rarely delicate annuals or biennials. Leaves entire to toothed, lobed, or pinnatifid, simple, alternate, rarely opposite, petiolate to sessile, glabrous to usually glandular-hairy, sometimes with bulbils in the leaf axils or in the inflorescence, generally without calcium oxalate crystals

Fig. 154. Saxifragaceae. Saxifraga imbricata Royle. A Cushion. B Flowering branch. (Engler and Irmscher 1919)

432

D.E. Soltis

any, or on the calyx around the ovary; pollen surface granular or striate, not reticulate; carpels 2, rarely 3, 4, or even 5, from distinct and joined at base to connate well above the ovuliferous portion; ovary ranging from nearly superior in appearance to completely inferior; placentation axile. Fruit from plainly capsular and dehiscent across the top by the ventral sutures of the stylar beaks to follicular and dehiscent the full length; seeds numerous, with two integuments, from smooth to variously wrinkled, muricate, or tuberculate. 2n = 10 to more than 200. Micranthes has been considered part of a broadly defined Saxifraga, but the former is clearly a distinct lineage that should be recognized as a distinct genus. Saxifraga in the narrow sense is a morphologically diverse genus that comprises about 370 species, widely distributed but primarily of temperate or Arctic regions of the Northern Hemisphere; many of the species are circumboreal.

Placement unknown 33. Saniculiphyllum C.Y. Wu & T.C. Ku Saniculiphyllum C.Y. Wu & T.C. Ku, Acta Phytotax. Sin. 30: 194 (1992).

Fig. 155. Saxifragaceae. Saxifraga granulata. A Habit. B Flower. C Fruit. D Bulbils. E Bulbil vertically sectioned. (Engler and Irmscher 1919)

(these present in section Irregulares). Inflorescence cymose, generally leafy. Flowers generally regular but conspicuously irregular in section Irregulares, usually perfect; calyx lobes 5, saucer-shaped to conic or campanulate; petals commonly 5, white [spotted or flecked with yellow or reddish-purple] to greenish, yellow, or violet-purple, usually alike, clawless or with a distinct and often slender claw, deciduous or persistent; stamens 10, inserted with the petals on or at the top of the hypanthium, if

Perennial from long, horizontal, thick rhizome. Leaves all basal, palmately deeply lobed, petiolate, stipules 0. Inflorescence cymose; flowers small, green; sepals 5, imbricate with round tips; petals 5, ovate-triangular, entire, imbricate; stamens 5, antesepalous, on thick disc, filaments short; carpels 3(2); ovary inferior with short stylar beaks. One poorly known species, S. guangxiense Y.C. Wu & T.C. Ku, from southeastern Yunnan and northwestern Guangxi, China. The thick rhizomes and palmately lobed leaves suggest that the genus belongs in the Darmera group, but until the single species (known from one collection) is examined more closely, it is appropriate to consider the placement of this taxon as unknown.

Selected Bibliography Bensel, C.R., Palser, B.F. 1975. Floral anatomy in the Saxifragaceae sensu lato. II. Saxifragoideae and Iteoideae. Amer. J. Bot. 62:661–675. Bohm, B.A. 1979. Flavonoids of Tolmiea menziesii. Phytochemistry 18:1079–1080.

Saxifragaceae Bohm, B.A., Bhat, U.G. 1985. Flavonoids of Astilbe and Rodgersia compared to Aruncus. Biochem. Syst. Ecol. 13:437–440. Bohm, B.A., Collins, F.W. 1979. Flavonoids of some species of Chrysosplenium. Biochem. Syst. Ecol. 7:195–201. Bohm, B.A., Ornduff, R. 1978. Chemotaxonomic studies in the Saxifragaceae s.l., 9. Flavonoids of Jepsonia. Madroño 52:39–43. Bohm, B.A., Wilkins, C.K. 1976. Flavonoids and gallic acid derivatives from Peltiphyllum peltatum. Phytochemistry 15:2012–2013. Bohm, B.A., Wilkins, C.K. 1978. Chemosystematic studies in the Saxifragaceae s.l., 8. The flavonoids of Elmera racemosa (Watson) Rydberg. Brittonia 30:327–333. Bohm, B.A., Collins, F.W., Bose, R. 1977. Flavonoids of Chrysosplenium tetrandrum. Phytochemistry 16:1205– 1209. Bohm, B.A., Donevan, L.S., Bhat, U.G. 1986. Flavonoids of some species of Bergenia, Francoa, Parnassia, and Lepuropetalon. Biochem. Syst. Ecol. 14:75–77. Bohm, B.A., Chalmers, G., Bhat, U.G. 1988. Flavonoids and the relationships of Itea to the Saxifragaceae. Phytochemistry 27:2651–2653. Conradi, R. 1960. Astilbe. Norsk. Hagetid. 76:192–193. Conti, E., Soltis, D.E., Hardig, T.M., Schneider, J. 1999. Phylogenetic relationships of the Silver Saxifrages (Saxifraga, sect. Ligulatae Haworth): implications for the evolution of substrate specificity, life histories, and biogeography. Mol. Phylog. Evol. 13:536–555. Corner, E.J.H. 1976. See general references. Cronquist, A. 1981. An integrated system of classification of flowering plants. New York, NY: Columbia University Press. Cronquist, A., Holmgren, N.A., Holmgren, P.K. (eds) (1997) Intermountain Flora, vol. 3A. Bronx: New York Botanical Garden. Davis, G.L. 1966. See general references. Elvander, P.E. 1984. The taxonomy of Saxifraga (Saxifragaceae) section Boraphila subsection Integrifoliae in western North America. Syst. Bot. Monogr. 3:1–44. Engler, A. 1930. Saxifragaceae. In: Engler, K., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 18a. Leipzig: W. Engelmann, pp. 74–226. Engler, A., Irmscher, E. 1919. Saxifragaceae-Saxifraga. Pflanzenreich IV, 117. Leipzig: W. Engelmann. Fedorov, A.A. (ed.) 1969. See general references. Ferguson, I.K., Webb, D.A. 1970. Pollen morphology in the genus Saxifraga and its taxonomic significance. Bot. J. Linn. Soc. 63:295–311. Fishbein, M. et al. 2001. See general references. Franchet, A. R. 1890. Monographie du genre Chrysosplenium Tournefort. Nouv. Arch. Mus. Hist. Nat. publiées par les professeurs-administrateurs de cet établissement (Paris) III, 2:87–114. Friis, E.M., Skarby, A. 1982. Scandianthus gen. nov., angiosperm flowers of saxifragalean affinity from the Upper Cretaceous of southern Sweden. Ann. Bot. II, 50:569–583. Gandolfo, M.A., Nixon, K.C., Crepet, W.L. 1995. Fossil flowers with hydrangeacean affinity from the Late Cretaceous of New Jersey. Amer. J. Bot. 82, suppl.: 85. Gandolfo, M.A., Nixon, K.C., Crepet, W.L. 1998. Tylerianthus crossmanensis gen. et sp. nov. (aff. Hydrangeaceae)

433

from the Upper Cretaceous of New Jersey. Amer. J. Bot. 85:376–386. Gornall, R.J. 1987a. Foliar crystals in Saxifraga and segregate genera (Saxifragaceae). Nordic J. Bot. 7:233–238. Gornall, R.J. 1987b. An outline of a revised classification of Saxifraga L. Bot. J. Linn. Soc. 95:273–292. Gornall, R.J., Bohm, B.A. 1985. A monograph of Boykinia, Peltoboykinia, Bolandra, and Suksdorfia (Saxifragaceae). Bot. J. Linn. Soc. 90:1–71. Hara, H. 1957. Synopsis of the genus Chrysosplenium L. (Saxifragaceae). J. Fac. Sci. Univ. Tokyo, Bot. 7:1–90. Hegnauer, R. 1973, 1990. See general references. Hideux, M.J., Ferguson, I.K. 1976. See general references. Holderegger, R. 1996. Reproduction of the rare monocarpic species Saxifraga mutata L. Bot. J. Linn. Soc. 122:301– 313. Hoot, S.B., Magallon, S., Crane, P.R. 1999. Phylogeny of basal eudicots based on three molecular datasets: atpB, rbcL, and 18S nuclear ribosomal DNA sequences. Ann. Missouri Bot. Gard. 86:1–32. Hutchinson, J. 1924. Contributions towards a phylogenetic classification of flowering plants: IV. Kew Bull. 1924:114–134. Jintang, P., Cuizhi, G., Shumei, H., Chaofen, W., Shuying, J., Lingdi, L., Ohba, H., Gornall, R.J., Soltis, D., Cullen, J., Hultgård, U.-M., Akiyama, S., Bartholomew, B., Alexander, C. 2001. Saxifragaceae. In: Wu, Z., Raven, P.H. (eds) Flora of China, vol. 8, pp. 269–452 (Brassicaceae–Saxifragaceae). Beijing: Science Press & St. Louis: Missouri Botanical Garden. Johnson, A.M. 1923. A revision of the North American species of the section Boraphila Engler of the genus Saxifraga (Tourn.) L. Univ. Minnesota Stud. Biol. Sci. 4:1– 109. Johnson, A.M. 1927. The status of Saxifraga nuttallii. Amer. J. Bot. 14:38–43. Johri, B.M. et al. 1992. See general references. Kern, P. The genus Tiarella in western North America. Madroño 18:152–160. Klopfer, K. 1973. Florale Morphogenese und Taxonomie der Saxifragaceae sensu lato. Feddes Repert. 84:475–516 Kuzoff, R.K., Soltis, D.E., Hufford, L., Soltis, P.S. 1999. Phylogenetic relationships within Lithophragma (Saxifragaceae): hybridization, allopolyploidy, and ovary diversification. Syst. Bot. 24:598–615. Kuzoff, R.K., Hufford, L., Soltis, D.E. 2001. Structural homology and developmental transformations associated with ovary diversification in Lithophragma (Saxifragaceae). Amer. J. Bot. 88:196–205. Lakela, O. 1937. A monograph of the genus Tiarella L. in North America. Amer. J. Bot. 24:344–351. Magallón-Puebla, S., Crane, P.R. Herendeen, P.S. 1999. Phylogenetic pattern, diversity, and diversification of eudicots. Ann. Missouri Bot. Gard. 86:297–372. Moreau, F. 1984. Contribution phytodermatologique à la systématique des Saxifragacées sensu stricto et des Crassulacées. Rev. Cytol. Biol. Vég. 7:31–92. Morgan, D.R., Soltis, D.E. 1993. Phylogenetic relationships among Saxifragaceae sensu lato based on rbcL sequence data. Ann. Missouri Bot. Gard. 80:631–660. Mort, M.E., Soltis, D.E. 1999. Phylogenetic relationships and the evolution of ovary position in Saxifraga section Micranthes. Syst. Bot. 24:139–147. Muller, J. 1981. See general references.

434

D.E. Soltis

Nakazawa, M., Wakabayashi, M., Ono, M., Murata, J. 1997. Molecular phylogenetic analysis of Chrysosplenium (Saxifragaceae) in Japan. J. Pl. Res. 110:265–274. Okuyama, Y., Kato, M., Murakami, N. 2004. Pollination by fungus gnats in four species of the genus Mitella (Saxifragaceae). Bot. J. Linn. Soc. 144:449–460. Ornduff, R.O. 1969. Ecology, morphology, and systematics of Jepsonia (Saxifragaceae). Brittonia 21:286–298. Ornduff, R.O. 1971. The reproductive system of Jepsonia heterandra. Evolution 25:300–311. Rabe, A.J., Soltis, D.E. 1999. Pollen tube growth and selfincompatibility in Heuchera micrantha var. diversifolia (Saxifragaceae). Intl J. Pl. Sci. 160:1157–1162. Rosendahl, C.O. 1914. A revision of the genus Mitella with a discussion of geographical distribution and relationships. Bot. Jahrb. Syst., suppl. 50:375–397. Rosendahl, C.O., Butters, F.K., Lakela, O. 1936. A monograph on the genus Heuchera. Minneapolis: University of Minnesota Press. Savile, D.B.O. 1954. Taxonomy, phylogeny, host relationship and phytogeography of the microcyclic rusts of Saxifragaceae. Canad. J. Bot. 32:400–425. Savile, D.B.O. 1975. Evolution and biogeography of Saxifragaceae with guidance from their rust parasites. Ann. Missouri Bot. Gard. 62:354–361. Savolainen, V., Chase, M.W. et al. 2000. See general references. Schulze-Menz, G.K. 1964. Saxifragaceae. In: Melchior, H. (ed.) A. Engler’s Syllabus der Pflanzenfamilien. Berlin: Borntraeger, pp. 201–206. Segraves, K.A., Thompson, J.N. 1999. Plant polyploidy and pollination: floral traits and insect visits to diploid and tetraploid Heuchera grossulariifolia. Evolution 53:1114–1121. Soltis, D.E. 1980a. Flavonoids of Sullivantia: taxonomic implications at the genetic level within the Saxifraginae. Biochem. Syst. Ecol. 8:149–151. Soltis, D.E. 1980b. Karyotypic relationships among species of Boykinia, Heuchera, Mitella, Sullivantia, Tiarella, and Tolmiea (Saxifragaceae). Syst. Bot. 5:17–19. Soltis, D.E. 1981. Heterochromatin banding in Boykinia, Heuchera, Mitella, Sullivantia, Tiarella and Tolmiea (Saxifragaceae). Amer. J. Bot. 69:108–115. Soltis, D.E. 1984. Karyotypes of Leptarrhena and Tanakaea (Saxifragaceae). Canad. J. Bot. 62:671–673. Soltis, D.E. 1986. Karyotypic relationships among Astilboides, Bergenia, Darmera, and Mukdenia and their implications for subtribal boundaries in Saxifrageae (Saxifragaceae). Canad. J. Bot. 64:586–588. Soltis, D.E. 1987. Karyotypes and relationships among Bolandra, Boykinia, Peltoboykinia, and Suksdorfia (Saxifragaceae: Saxifrageae). Syst. Bot. 12:14–20. Soltis, D.E. 1988. Karyotypes of Bensoniella, Conimitella, Lithophragma, and Mitella, and relationships in Saxifrageae (Saxifragaceae). Syst. Bot. 13:64–72. Soltis, D.E. 1991. A revision of Sullivantia (Saxifragaceae). Brittonia 43:27–53. Soltis, D.E., Hufford, L. 2002. Ovary position diversity in Saxifragaceae: clarifying the homology of epigyny. Intl J. Pl. Sci. 163:277–293. Soltis, D.E., Kuzoff, R.K. 1995. Discordance between molecular and chloroplast phylogenies in the Heuchera group (Saxifragaceae). Evolution 49:727–742.

Soltis, D.E., Soltis, P.S. 1986. Intergeneric hybridization between Conimitella williamsii and Mitella stauropetala (Saxifragaceae). Syst. Bot. 11:293–297. Soltis, D.E., Soltis, P.S. 1993. Molecular data and the dynamic nature of polyploidy. Crit. Rev. Pl. Sci. 12:243–273. Soltis, D.E., Soltis, P.S. 1997. Phylogenetic relationships in Saxifragaceae s.l.: a comparison of topologies based on 18S rDNA and rbcL sequences. Amer. J. Bot. 84:504– 522. Soltis, D.E., Soltis, P.S., Collier, T.G., Edgerton, M.L. 1991a. Chloroplast DNA variation within and among genera of the Heuchera group (Saxifragaceae): evidence for chloroplast transfer and paraphyly. Amer. J. Bot. 78:1091–1112. Soltis, D.E., Mayer, M.S., Soltis, P.S., Edgerton, M.L. 1991b. Chloroplast-DNA variation in Tellima grandiflora (Saxifragaceae). Amer. J. Bot. 78:1379–1390. Soltis, D.E., Morgan, D.R., Grable, A., Soltis, P.S., Kuzoff, R.K. 1993. Molecular systematics of Saxifragaceae sensu stricto. Amer. J. Bot. 80:1056–1081. Soltis, D.E., Johnson, L.A., Looney, C. 1996a. Discordance between ITS and chloroplast topologies in the Boykinia group. Syst. Bot. 21:169–185. Soltis, D.E., Kuzoff, R. K., Gornall, R., Ferguson, K. 1996b. matK and rbcL gene sequence data indicate that Saxifraga (Saxifragaceae) is polyphyletic. Amer. J. Bot. 83:371–182. Soltis, D.E. et al. 1997. See general references. Soltis, D.E. et al. 2000. See general references. Soltis, D.E., Kuzoff, R.K., Mort, M.E., Zanis, M., Fishbein, M., Hufford, L., Koontz, J., Arroyo, M.K. 2001. Elucidating deep-level phylogenetic relationships in Saxifragaceae using sequences for six chloroplastic and nuclear DNA regions. Ann. Missouri Bot. Gard. 88:669–693. Soltis, D.E., Tago-Nakazawa, M., Xiang, Q.-Y., Kawano, S., Murat, J., Wakabayashi, M. 2001. Phylogenetic relationships and evolution in Chrysosplenium (Saxifragaceae) based on matK sequence data. Amer. J. Bot. 88:883–893. Spongberg, S.A. 1972. The genera of Saxifragaceae in the southeastern United States. J. Arnold Arb. 53:409–498. Taylor, R.L. 1965. The genus Lithophragma (Saxifragaceae). Univ. Calif. Publ. Bot. 37:1–122. Takhtajan, A. 1987. See general references. Takhtajan, A.L. 1996. See general references. Takhtajan, A. 1997. See general references. Thompson, J.N. 1994. The coevolutionary process. Chicago: University of Chicago Press. Thompson, J.N., Pellmyr, O. 1992. Mutualism with pollinating seed parasites amid co-pollinators: constraints on specialization. Ecology 73:1780–1791. Thorne, R.F. 1992. An updated phylogenetic classification of the flowering plants. Aliso 13:365–389. Troll, W., Weberling, F. 1989. Infloreszenzuntersuchungen an monotelen Familien. Stuttgart: G. Fischer. Vargas, P., Morton, C.M., Jury, S.L. 1999. Biogeographic patterns in Mediterranean and Macaronesian species of Saxifraga (Saxifragaceae) inferred from phylogenetic analyses of ITS sequences. Amer. J. Bot. 86:724–734. Webb, D.A., Gornall, R.J. 1989. A manual of saxifragas and their cultivation. Portland: Timber Press. Weberling, F. 1975. Über die Beziehungen zwischen Scheidenlappen und Stipeln. Bot. Jahrb. Syst. 96:471–491.

Saxifragaceae Weiblen, G.D., Brehm, B.G. 1996. Reproductive strategies and barriers to hybridization between Tellima grandiflora and Tolmiea menziesii (Saxifragaceae). Amer. J. Bot. 83:910–918. Wells, E.F. 1984. A revision of the genus Heuchera (Saxifragaceae) in eastern North America. Syst. Bot. Monogr. 3:45–121.

435

Wu, C.-Y., Ku, T.-C. 1992. A new tribe with a new monotypic genus of Saxifragaceae (s. l.) from China. Acta Phytotax. Sin. 30:193–196. Wu, Zhengyi, Raven, P.H. (eds) 2003. Flora of China, Illustrations, vol. 8. Beijing: Science Press. Yeo, P.F. 1966. A revision of the genus Bergenia Moench (Saxifragaceae). Kew Bull. 26:113–148.

Stachyuraceae Stachyuraceae J. Agardh, Theoria Syst. Pl.: 152 (1858), nom. cons.

J.V. Schneider

Small trees or shrubs, sometimes climbing, deciduous or evergreen, the branchlets with large pith, the winter buds small, with 2–4 outer scales. Leaves involute, alternate, simple, petiolate, membranaceous to coriaceous, glabrous or pubescent, serrate to serrulate; venation pinnate-reticulate; stipules small, caducous. Inflorescences axillary or terminal, racemes or spikes, erect or pendulous, few- to many-flowered, with each flower subtended by a bract; pedicel articulated or inconspicuous, apically with two basally united prophylls. Flowers bisexual or functionally unisexual and then plants dioecious, pedicellate or sessile; sepals 2 + 2, decussate, imbricate, the outer two smaller; petals 4, free, imbricate, yellow, greenish, pinkish or white; stamens 4 + 4, diplostemonous, distinct; anthers tetrasporangiate, deeply sagittate, opening by longitudinal slits, dorsifixed, introrse, versatile; nectary at base of gynoecium well developed on sepaline radii; carpels 4; ovary syncarpous, superior, incompletely 4-locular due to intrusion of parietal placentae, sometimes pubescent; style simple, short, apical, stigma wet, capitate; placentation parietal (in upper part of ovary) to axile (in basal part), ovules numerous, arranged in two alternating rows in each carpel, anatropous, crassinucellate, bitegmic. Fruit berry-like, with leathery pericarp and deciduous calyx; seeds numerous, small, with soft funicular aril and sclerotic testa; endosperm copious, fleshy, oily and albuminous, not starchy, perisperm 0; embryo straight, small, with short, fleshy funicle; cotyledons elliptic, flat, radicles short. n = 12. A single genus with 16 species, temperate (to subtropical) eastern Asia from the Himalayas to Taiwan and Japan. Vegetative Morphology. Stachyuraceae are shrubs or small trees generally not exceeding 5 m in height. Leaves are simple and serrate to inconspicuously serrulate. The leaf veins generally protrude into teeth. Leaf venation is pinnate-reticulate and

corresponds to the brochidodromous or eucamptodromous type (Yu and Chen 1990; Klucking 1992). Stipules are present but early caducous. Epicuticular waxes of tubular or scaly shape, sometimes arranged as a rosette, were found on leaves or petioles (Ditsch and Barthlott 1994). Vegetative Anatomy. The leaves are bifacial, the anomocytic stomata confined to the abaxial side. Nodes are trilacunar and the petioles have an arch-shaped strand accompanied by two smaller ones. Cluster crystals and tanniniferous cells are present in the parenchymatous tissue. Stem sections reveal that cork originates in the epidermis. The wood is diffuse-porous with distinct growth rings. Vessels are solitary or, less frequently, in radial multiples of 2–3 or in clusters. Vessel elements are 650–1,200 µm long with oblique end walls. The perforation plates are scalariform with 30–50 bars. Intervessel pits are scanty and helical thickenings are indistinct. Fibre-tracheids are 8–35 µm in diameter, the pits distinctly bordered, circular, 7–8 µm in diameter, with oblique slit-like apertures. Wood parenchyma is fairly abundant, predominantly apotracheal, diffuse and diffuse-inaggregates. Rays are uniseriate to multiseriate, the latter 2–6 cells wide and up to 2,700 µm tall. Rayvessel pits are usually opposite, circular or slightly elongated in horizontal direction, 4–6 µm in horizontal diameter. Crystals are absent (van Tieghem 1900; Metcalfe and Chalk 1950; Suzuki et al. 1991). Inflorescences. The inflorescences are erect or pendulous racemes or spikes which usually appear on the branches of the preceding year (Li 1943). Each flower is subtended by a bract. The pedicels bear apically two prophylls which are united at the base. In distinctly pedicellate flowers, the pedicels are generally articulated. Flower Structure. Most species (all?) of Stachyuraceae have bisexual flowers but are func-

Stachyuraceae

tionally dioecious, with female flowers bearing staminodes and male flowers having a reduced pistil (Tang et al. 1983). The flowers are actinomorphic, tetramerous, and petal aestivation is irregularly imbricate. The androecieum is diplostemonous and the anthers are tetrasporangiate, introrse, dorsifixed, opening by longitudinal slits. A connective protrusion is present but short. The superior, syncarpous, 4-carpellate ovary is elevated on a short stalk. The tips of the carpels are postgenitally united into a capitate stigma with a single surface. The ovary is incompletely 4-locular, since the carpel partitions are centrally not united in the middle and upper parts. A nectary is present at the base of the ovary (Matthews and Endress 2005). A detailed analysis of the floral morphology was given by Matthews and Endress (2005). Embryology. The anthers consist of five to six cell layers: an epidermis, an endothecium, two to three middle layers and a tapetum. The formation of the wall corresponds to the Basic type. The tapetum is glandular and predominantly two-nucleate. Meiosis of the microspore mother cells results in tetrads of tetrahedral shape. Pollen grains are two-celled at the time of shedding (Kimoto and Tokuoka 1999). Placentation is axile at the base of the ovary, parietal in the upper parts, due to the different degree of intrusion of the placentae. The ovules are anatropous, bitegmic, crassinucellate and syntropous. Meiosis of the megaspore mother cell results in a linear or T-shaped tetrad. The development of the embryo sac corresponds to the Polygonum type and embryogeny follows the Solanad type. Polyembryony is due to cleavage of the zygotic proembryo, or simultaneous development of zygotic and synergid embryos (Mathew and Chaphekar 1977). An obturator is not formed but a weakly differentiated hypostase can be observed in older ovules (Kimoto and Tokuoka 1999). The two integuments are not vascularized and both contribute to the micropylar canal. Fertilization is porogamous. Endosperm formation is of the Nuclear type (Mauritzon 1936; Satô 1976; Mathew and Chaphekar 1977; Kimoto and Tokuoka 1999). Pollen Morphology. The pollen is tricolporate or tricolporoidate, subprolate to prolate. The sexine is slightly thicker than the nexine and ± finely reticulate, with lalongate ora, about 24 µm long (Erdtman 1952; Tang et al. 1983).

437

Karyology. Karyological analyses of five taxa showed a chromosome number of 2n = 24 (Kurosawa 1971; Tang et al. 1983). Pollination. Reports of field observations are unknown but Stachyuraceae are most likely pollinated by insects. Fruit and Seed. The fruits are berry-like and contain numerous seeds. The seeds are small, ellipsoidal, arillate and albuminous. The aril develops from the apical region of the funicle and grows towards the chalazal end of the ovule, eventually covering the entire seed from the micropyle to the chalaza. The testa comprises four to five cell layers and is completely sclerotic. The mechanically most specialized tissue of the mature seed are the cells of the exotesta, which consists of radially elongated cells of the outer epidermis, and thick-walled mesotesta and endotesta cells which are tangentially elongated. The inner integument disappears during seed ripening, except for the cells of the exotegmen which only loose their living content. According to Pritzel (1897), the endosperm is fleshy and oily but not starchy, and contains small proteinaceous particles. The embryo is straight, has flat cotyledons and a short radicle (Mathew and Chaphekar 1977; Kimoto and Tokuoka 1999). Phytochemistry. Apart from trivial flavonols, proanthocyanidins and ellagitannins are known from Stachyurus. Particularly the latter group of compounds is strongly diversified, and more than ten different ellagitannins, based partly on different methylated derivatives of hexahydroxydiphenic acid, have been characterised. The cortex of Stachyurus is also known for one of the erratic occurrences of ecdysone in angiosperms (Hegnauer 1973, 1986, 1989, 1990 where references to original papers can be found; Han et al. 1995). Affinities. Originally, Stachyurus was included in Pittosporaceae but Gilg (1893) preferred to have it as a distinct family, which often was considered to be close to Flacourtiaceae or Ternstroemiaceae. Most more recent classifications (Dahlgren 1980; Thorne 1992; Takhtajan 1997) placed Stachyuraceae in Theales, except for Cronquist (1981) who included them in Violales. According to the APG II (2003), Stachyuraceae are assigned to Crossosomatales. Molecular studies based on rbcL

438

J.V. Schneider

and/or atpB and 18S sequences (Soltis et al. 2000; Cameron 2003; Sosa and Chase 2003) revealed Stachyuraceae being sister to Crossosomataceae, both in turn sister to Staphyleaceae. A close relationship of Stachyuraceae and Crossosomataceae is further supported by embryological data: the non-vascularized outer integument, albuminous mature seeds, thin mesotesta, and a testa of highly sclerotic cells are shared with Crossosomataceae and Staphyleaceae whereas a persistent anther epidermis, the 4–5-layered testa, the sclerotic endotestal cells, and the aril links the family particularly with Crossosomataceae (Kimoto and Tokuoka 1999). Distribution and Habitats. Stachyuraceae are confined to temperate (and subtropical) eastern Asia, ranging from the Himalayas to Taiwan and Japan. Most of them grow in mountainous thickets or forests ranging from 500 to 3,500 m altitude but some species are found also in thickets at sea level. Economic Importance. Some species are cultivated as horticultural plants (e.g. Li 1943).

Fig. 156. Stachyuraceae. Stachyurus praecox. A Flowering branch. B Flower, opened out. C Fruiting branch. D Fruit, transverse section. (Takhtajan 1981)

Only one genus: 34. Stachyurus Siebold & Zucc.

Fig. 156

Stachyurus Siebold & Zucc., Fl. Jap. 1:42, pl. 18 (1836); Li, Bull. Torrey Bot. Club 70:615–628 (1943), rev.; Chen, Acta Bot. Yunn. 2:125–137 (1981), rev., in Chinese.

Characters as for family.

Selected Bibliography APG II 2003. See general references. Cameron, K.M. 2003. See general references. Cronquist, A. 1981. See general references. Dahlgren, R.M.T. 1980. A revised system of classification of the angiosperms. Bot. J. Linn. Soc. 80:91–124. Ditsch, F., Barthlott, W. 1994. Mikromorphologie der Epicuticularwachse und die Systematik der Dilleniales, Lecythidales, Malvales und Theales. Trop.-subtrop. Pflanzenwelt 88:1–74. Erdtman, G. 1952. See general references. Gilg, E. 1893. Stachyuraceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 6. Leipzig: W. Engelmann, pp. 192–193. Gilg, E. 1925. Stachyuraceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 21. Leipzig: Engelmann, pp. 457–459. Han, L., Hatano, T., Okuda, T., Yoshida, T. 1995. Tannins of Stachyurus species. 3. Stachyuranins A, B and C, three new complex tannins from Stachyurus praecox leaves. Chem. Pharmacol. Bull. (Tokyo) 43:2109–2114. Hegnauer, R. 1973, 1986, 1989, 1990. See general references. Kimoto, Y., Tokuoka, T. 1999. Embryology and relationships of Stachyurus (Stachyuraceae). Acta Phytotax. Geobot. 50:187–200. Klucking, E.P. 1992. Leaf venation patterns, 6. Flacourtiaceae. Berlin: J. Cramer. Kurosawa, S. 1971. Cytological studies on some Eastern Himalayan plants and their related species. In: Hara, H., Hohashi, H. (eds) Flora of Eastern Himalaya, second report. Tokyo: University of Tokyo Press, pp. 355– 364. Li, H.-L. 1943. The genus Stachyurus. Bull. Torrey Bot. Club 70:615–628. Mathew, C.J., Chaphekar, M. 1977. Development of female gametophyte and embryogeny in Stachyurus chinensis. Phytomorphology 27:68–78. Matthews, M.L., Endress, P.K. 2005. See general references. Mauritzon, J. 1936. Zur Embryologie einiger ParietalesFamilien. Svensk Bot. Tidskr. 30:79–113. Metcalfe, C.R., Chalk, L. 1950. See general references. Pritzel, E. 1897. Der systematische Wert der Samenanatomie, insbesondere des Endosperms, bei den Parietales. Bot. Jahrb. Syst. 24:348–394. Satô, Y. 1976. Embryological studies on Stachyurus praecox and its variety. Sci. Rep. Tohoku Univ. IV, Biol. 37:131– 138. Soltis, D.E. et al. 2000. See general references. Sosa, V., Chase, M.W. 2003. Phylogenetics of Crossosomataceae based on rbcL sequence data. Syst. Bot. 28:96– 105.

Stachyuraceae Suzuki, M., Noshiro, S., Takahashi, A., Yoda, K., Joshi, L. 1991. Wood structure of Himalayan plants, II. In: Ohba, H., Malla, S.B. (eds) The Himalayan plants, II. Tokyo: University of Tokyo Press. Takhtajan, A. 1981. See general references. Takhtajan, A. 1997. See general references. Tang, Y.-C., Cao, Y.-L., Xi, Y.-Z., He, J. 1983. Systematic studies of Chinese Stachyuraceae, 1. Phytogeograph-

439

ical, cytological, palynological. Acta Phytotax. Sin. 21:236–253. Thorne, R.F. 1992. Classification and geography of the flowering plants. Bot. Rev. 58:225–348. van Tieghem, P. 1900. Sur les Stachyuracées et les Koeberliniacées. J. Bot. (Morot) 14:1–12. Yu, C.H., Chen, Z.L. 1990. Leaf architecture of the woody dicotyledons from tropical and subtropical China. Oxford: Pergamon Press.

Staphyleaceae Staphyleaceae Martynov, Teckno-Bot. Slovar: 598 (1820), nom. cons.

S.L. Simmons

Trees or shrubs, evergreen or deciduous. Leaves opposite, petiolate, pinnately compound, rarely unifoliolate, serrate, stipulate; stipels usually present but sometimes reduced to glands or absent. Inflorescences terminal or axillary in upper leaves, paniculate. Flowers perfect, hermaphroditic, actinomorphic; sepals 5, distinct or united, unequal, imbricate; petals 5, free, fused for part of their length or fused to form a short floral cup, unequal, imbricate in bud, often inserted on or below a crenate or lobed disk; stamens 5, arising outside of or between the lobes of the disk, alternate with the petals; filaments complanate; anthers 2-celled, dorsifixed, introrse, dehiscing longitudinally; ovary superior to partially inferior, 2–3(4)carpellate, the carpels nearly free or united, sessile, the stylodia at least partially free but distally fused to form a capitate, wet stigma; placentation axile, ovules few–many in 2 series on ventral suture. Fruit a berry, a membranous inflated capsule, or a multifollicle; seeds with a straight, green embryo and copious or rarely scanty fleshy endosperm. Two genera with 45–50 species, distributed widely in the Northern Hemisphere of both the Old World and the New, but extending beyond the equator in Ecuador, Peru, Bolivia, and Southeast Asia to Papua New Guinea. Vegetative Morphology. All Staphyleaceae are woody, ranging from small stoloniferous shrubs (2 m) and small trees reaching 15 m (Staphylea) to upper canopy trees of 25–30 m (Dalrympelea). Stump sprouting of saplings and adult trees has been observed in tropical Staphylea. Buttressing is common in the larger tropical trees (Dalrympelea). Bark in Staphylea is gray to black and somewhat mottled, with or without lenticels. Bark in Dalrympelea ranges from creamy yellow and flaky (“Dalrympelea” [Turpinia] calciphila)1 to smooth 1

Generic names for which the new combinations now becoming necessary (see section on Classification) do not yet exist are placed within quotation marks.

gray (“D.” [Turpinia] grandis). The branches of “Staphylea” [Euscaphis] japonica are glabrous. Members of Staphyleaceae have opposite, decussate, and trifoliate or imparipinnately compound (rarely unifoliolate) leaves. The rachis is green, sometimes tinged with red (“S.” japonica), and glabrous to pubescent. Leaf margins are glandular and dentate, serrate, or crenate. Leaves are deciduous in temperate taxa, evergreen in tropical ones. Stipules are well developed and usually caducous. In most species of Staphylea, each leaf has a pair of free, multi-veined stipules. In Dalrympelea, the stipules of opposed leaves fuse, sometimes becoming bifid at the apex, often having colleters. Trichomes, when they occur, are of the simple, uniseriate and predominantly unicellular types. Vegetative Anatomy. The wood anatomy of Staphyleaceae has been examined most recently by Carlquist and Hoekman (1985). Characters that unite the family are: vessels mostly solitary; vessel elements long with scalariform perforation plates; scalariform, alternate or opposite lateral wall pitting; and fiber tracheids with fully bordered pits. The woods of tropical members lack growth rings prominent in temperate taxa. Rhomboidal crystals, tyloses and dark-staining deposits are found in the wood of some, but not all, species. The leaf cuticle is thin on both surfaces. Both the upper and lower epidermal layers are uniseriate; some species have a hypodermis on the adaxial surface. Stomata are confined to the abaxial surface, with both genera having anisocytic stomata (Metcalfe and Chalk 1950). Leaf venation with fibers is prevalent in most taxa, whereas fibers are notably absent in “Staphylea” [Euscaphis] japonica. Crystals are present in the leaves of both genera. Inflorescence Structure. The many flowers are borne in terminal or axillary panicles or thyrses, held erect above the foliage, or drooping. Panicles range from 5 to 30 cm in length, can contain from

Staphyleaceae

a few (< 20 in some Staphylea) to many (> 100 in some Dalrympelea) flowers, and can be either compact or lax. Floral Structure and Anatomy. The descriptions of “Dalrympelea” [Turpinia] formosana and “D.” [Turpinia] ternata (Nakai 1924) specified dioecy, but later treatments described perfect flowers (Ka 1965; Li 1993). Floral morphology and anatomy of Staphyleaceae have been treated in detail by Dickison (1986). The calyx has (4)5 sepals, which are distinct or show various degrees of connation along their length, and are alternately positioned with an equal number of petals. Petals have a quincuncial aestivation, and are either essentially distinct or fused in a short floral tube, and are usually cream-white, or cream tinged with green, pink, or yellow. Stamens are borne opposite the sepals outside a lobed nectary disk; the filaments can arise either outside of, or between the lobes of the disk. The filaments are campanulate, and typically vary from pubescent to glabrous. Anthers are 2-lobed, 4-locular and dorsifixed, dehiscing with longitudinal slits. The gynoecia are embedded in the nectary disk and consist of 2–3(4) carpels. The ovaries are more or less syncarpous, but in S. japonica the carpels are free from each other but adnate along their dorsal surface to the surrounding floral cup. The stylodia are largely free for most of their length, uniting distally to form a single blunt, often lobed, stigma. Each carpel has one locule containing 2–several ovules arranged in two rows, with axile placentation. Transmitting tissue leads from the stigma separately through the stylodia to the ovarian portions of the carpels. In most Staphylea, the ovules are covered with papillate transmitting tissue. Druses and frothy mucilage cells are widespread in Dalrympelea (Dickison 1986). The sequence from apocarpous to more or less syncarpous ovaries was interpreted by Dickison (1986) as a progressive fusion. The peculiar fusion of the stigmas, and the occurrence of more or less free stylodia and carpels suggest, however, that apocarpy may be evolutionarily secondary. In such gynoecia, the stigma enhances selection of pollen tubes during their growth to the ovules (Ramp 1987). Thus, the gynoecium structure of Dalrympelea would appear pleisiomorphic, rather than derived. This may correlate with the fact that the vessels of Dalrympelea have the largest number of bars per perforation plate (Carlquist and Hoekman 1985).

441

Embryology. The embryology of “Dalrympelea” [Turpinia] nepalensis was studied by Narayana (1960). Meiosis in the pollen mother-cell is normal, and cytokinesis takes place by furrowing. Pollen tetrads are tetrahedral, and pollen grains are binucleate when shed. For Staphyleaceae in general, ovules are crassinucellate, bitegmic, and anatropous. The micropyle is formed by both integuments. Development of the embryo sac is of the Polygonum type (Johri et al. 1992). Pollen Morphology. Pollen is tricolporate, circular to triangular in outline in polar view, and mostly spheroidal. Ectoapertures are long, recessed, and granular. The exine is stratified into tectum, columellae, foot layer, and endexine. The exine surface varies from foveolate to reticulate (Erdtman 1952; Lobreau 1969; Dickison 1987b). Karyology. Chromosome counts have been reported for six species of Staphylea and three species of Dalrympelea. It has been proposed that the family has a base chromosome number of x = 13, with “S.” [Turpinia] cochinchinensis, n = 13; “D.” [Turpinia] formosana, n = 11; “D.” [Turpinia] nepalensis, n = 13, 14; “D.” [Turpinia] pomifera, n = 13; S. bolanderi, n = 13; S. bumalda, 2n = 26 (Hsu 1968; Mehra and Khosla 1969; Mehra 1976; Gill et al. 1984). Putative polyploids include S. colchica, 2n = 52; S. pinnata, 2n = 24, 26; and S. trifolia, 2n = 78 (Winge 1917; Foster 1933; Pogan et al. 1983). Foster (1933) observed secondary pairing in meiotic figures from pollen mother-cells of S. trifolia. Pollination and Reproduction. Staphylea exhibit some vegetative reproduction via stolons, and often grow in groves of clones (Dore 1962; pers. obs.). Root suckering in S. trifolia is common (Garwood and Horvitz 1985). Staphylea trifolia is self-incompatible (Garwood and Horvitz 1985), and the remainder of the family is thought to be so, too. Flowers are protogynous, and bloom in the spring as the leaves are expanding in temperate Staphylea, and at the end of the tropical rainy season in tropical members. Twenty insect species have been reported to visit Staphylea trifolia, including species of short-tongued bees, long-tongued bees, and Diptera (Robertson 1889). Fruit and Seed. The two genera of Staphyleaceae are most easily distinguished by fruit type. Staphylea fruits are either: inflated, membranous,

442

S.L. Simmons

bladder-like capsules, dehiscent or indehiscent, olive-brown to red-brown when dry; non-inflated, indehiscent berries with a papery pericarp adherent to the seeds, yellow to green; or multifollicles, dehiscing along the ventral suture, slightly reddish at maturity. Staphylea carpels usually separate from each other at the apex before maturity. Dalrympelea fruits are berries, with the exocarp ranging from thick and fleshy to woody, usually green to purple in color. For Staphylea trifolia, it has been demonstrated that only a small number of fruits mature, in comparison to the number of flowers initially produced (29%; Garwood and Horvitz 1985). The seeds of Staphyleaceae are round to angular, brown, red-brown or black; in “S.” [Euscaphis] japonica, the epidermis of the testa is pulpy, whereas the mesophyll cell layers are thick-walled and lignified. The seed coat is exomesotestal (Corner 1976). Endosperm is scanty (“S.” japonica) to fleshy, and the embryos are straight and have a short radicle and plano-convex cotyledons. Dispersal, Germination and Seedlings. The capsules of temperate Staphylea remain on the shrubs after the leaves have fallen. However, both the capsules and the seeds are buoyant, suggesting water-dispersal. Ridley (1930) also suggested that the fruits were light enough to be wind-dispersed, and the bladder fruits may be blown into streams along which they sail with the current. Dalrympelea berries may be dispersed by birds and other animals (Pereira 1995). “Staphylea” [Euscaphis] japonica follicles dehisce on the branch, exposing shiny, black seeds that are likely bird-dispersed. Seeds of S. trifolia have been germinated after scarification and freezing (Dore 1962). Phytochemistry. The common phenolics and other substances known from the family seem to be of little systematic relevance (Hegnauer 1973, 1990). Classification. The treatment of the family by Bentham and Hooker (1867) included five genera (Staphylea, Turpinia, Euscaphis, Tapiscia, and Huertea), placed within the order Sapindales. Pax (1893) was the first to suggest a formal separation of Tapiscia and Huertea from the other three genera. He placed these in a separate subfamily distinct from his Staphyleoideae, Tapiscioideae, which was elevated to family status by Takhtajan (1980). Tapisciaceae are now recognized as closely related

to Capparales, and have been treated in Volume V of this series (Kubitzki 2003). Among the remaining genera, the members of Staphylea (this name being derived from the Greek staphylodendron, meaning bladdernut) have been traditionally identified by the conspicuous, inflated, bladder-type fruits. Other diagnostic features, less often emphasized, are a shrubby habit and relatively small inflorescences within the family. The genus Turpinia was described to separate the taxa of Staphyleaceae with fruits not inflated, and which are evergreen trees, rather than shrubs. The concept of Turpinia was later expanded to include Asian members of the family that also lack the conspicuous bladder fruit. In addition, a third genus, Euscaphis, identified a third fruit type, dehiscent follicles. The relationship among the genera now placed in Staphyleaceae and their circumscription has been recently clarified using nuclear and chloroplast markers (Simmons, in prep.). This work shows that neither Staphylea nor Turpinia is monophyletic. Rather, the family is divided into two large clades, one of which includes all species of Staphylea, the New World species of the former Turpinia, the monotypic Euscaphis, and the Asian Turpinia cochinchinensis. To date, morphological evidence that would unite the taxa included under a broadened concept of Staphylea is limited. The second clade, for which the generic name Dalrympelea is adopted, contains all other Old World species of what was formerly Turpinia. Dalrympelea had been erected by Roxburgh (1819) for D. pomifera, a species of western and southwestern Asia. When the genus Turpinia, originally described for the New World species, was expanded to include all Asian members of the family, Dalrympelea became a synonym of Turpinia. However, the type of Turpinia falls within our broadened concept of Staphylea. Thus, Dalrympelea, the oldest available name for the Asian species, is resurrected as the correct name for the Old World species of Turpinia, except for T. cochinchinensis. Affinities. Until recently, the systematic position of Staphyleaceae has been contentious. On the basis of detailed morphological analyses (Carlquist and Hoekman 1985; Dickison 1986, 1987a, b), affinities of Staphyleaceae with Celastrales, Cunoniales or Saxifragales have been suggested. In contrast, molecular (rbcL) sequence data from two representatives of the family, Staphylea

Staphyleaceae

and Turpinia (Gadek et al. 1996), indicated an affinity of Staphyleaceae with Crossosoma (Crossosomataceae) and Geraniaceae within Geraniales, but not with Sapindales nor Cunoniales. A more inclusive rbcL study (Simmons, in prep.) places Staphyleaceae sister to a clade containing Stachyurus (Stachyuraceae) and Crossosoma. Distribution and Habitats. Staphyleaceae, as circumscribed here, are distributed across both the Old and New World, primarily in the Northern Hemisphere. Staphylea occurs in western North America (California), and eastern North America from Canada to South America, as well as in Europe and Asia. Dalrympelea is distributed in the Old World from China, Japan and Taiwan through Malaysia and Indonesia south to Papua New Guinea, southern India and Sri Lanka. The family as a whole is found at mesic sites: shady valleys, cloud forests, along river bottoms or streams, and in the understory of tropical rainforest, at elevations ranging from sea level (“Dalrympelea” [Turpinia] pentandra in Papua New Guinea; Barker 1981) to 3,300 m (“Staphylea” [Turpinia] cochinchinensis in China; Krause 1960). The present distribution of the family is similar to the distribution of taxa such as Acer, Illicium, Liquidambar, and Quercus, all identified as belonging to the Arcto-Tertiary Flora (Li 1971; Hoey and Parks 1991). Paleobotany. Seeds of the extant “Staphylea” [Euscaphis] japonica have been found in Pliocene and Pleistocene deposits in Japan, and the related extinct species Euscaphis rugosa and E. staphyleoides occupied present-day Moldavia (in southern Russia) in the Miocene (Tiffney 1979). The fossil records of Staphylea closely correspond to its present distribution; nine extinct and four extant taxa have been identified in Tertiary deposits, including S. rackowii in Germany (Oligocene), S. rugosa in Russia (Oligocene) and S. bumalda in Japan (Pliocene). The fossil distributions of S. rotundata, S. bessarabica (Miocene), and S. splendens (Eocene) correspond to the distribution of the contemporary S. trifolia. In addition, S. acuminata from the Florissant beds of Colorado closely resembles S. trifolia (Brown 1944). Fossil wood data indicate that an extinct taxon related to Staphylea, Staphyleoxylon kickapooense, inhabited what is now Mississippi, and Tertiary fossil wood identified as Turpinia has been found as far north as Wyoming (Blackwell 1983).

443

Economic Importance. Several species of Staphylea are cultivated ornamentally in North America, Asia, and Europe. In the Caucasus Mountains, the flower buds of S. colchica are fermented and eaten, and the seed oil of this species is used as a purgative (Weaver 1980). Old World bladdernuts (Staphylea) are reportedly edible, and are similar to pistachios (Fernald and Kinsey 1943). The leaves of “Dalrympelea” [Turpinia] pentandra, when eaten with the leaves of Zingiber, are reported to prevent conception. Although the wood of Dalrympelea is not durable (Barker 1981), it is used in Malaysia for timber. In addition, some Dalrympelea species grow rapidly on eroded mountain slopes, and are used for reforestation in central Java (Pereira 1995). Key to the Genera 1. Fruit an indehiscent berry with thickened pericarp; leaves coriaceous; stipules fused, at least at the base; evergreen trees 1. Dalrympelea – Fruit an inflated, lobed capsule, dehiscent multifollicle or berry with thin, often papery pericarp; stipules free; mostly deciduous trees and shrubs 2. Staphylea

1. Dalrympelea Roxb.

Fig. 157

Dalrympelea Roxb., Hort. Beng.: 17 (1814), type D. pomifera Roxb. Ochranthe Lindl. (1836). Kaernbachia Schltr. (1914). Turpinia auct. (excl. type).

Evergreen shrubs to large trees. Leaves (1- or 3-) 5–15-foliolate; stipules of opposite leaves basally connate to fused along their length. Inflorescences terminal or axillary panicles, with >100 flowers per inflorescence; sepals free, shorter than the pink, cream, yellow, or green-white petals; stamens arising between the lobes of the nectary disk; ovary sometimes partially embedded in the disk, more or less syncarpous, with 2–8 ovules per locule. Fruit an indehiscent, ellipsoidal, nearly globose or trilobed berry, fleshy or leathery; seeds 1–6 per fruit. Twenty to 25 species, Japan south to Papua New Guinea, west to India. 2. Staphylea L. Staphylea L., Sp. Pl. 1:270 (1753), type S. pinnata L. (designated by N.L. Britton in A. Brown, Ill. Fl. N. U.S. ed. 2, 2:493 (1913)). Triceros Lour. (1790), non Griff. Turpinia Vent. (1807), type T. paniculata Vent. Euscaphis Sieb. & Zucc. (1835).

444

S.L. Simmons


Fig. 157. Staphyleaceae. A–F “Dalrympelea” [illustration published as Turpinia] borneensis. A Flowering branch. B Flower. C Same, vertical section. D Stamen. E Fruit. F Same, transverse section. G “Dalrympelea” [Turpinia] stipulacea, defoliated part of twig showing persistent fused stipules. (Drawn by R. Crevel; van der Linden 1960)

Deciduous shrubs or small trees. Leaves (3–)7– 11-foliolate, with or without stipule-like glands at the insertion of the petiolules; stipules of opposite leaves free along entire length. Inflorescences terminal or axillary panicles, up to >50-flowered; sepals partially fused at the base, slightly shorter than or as long as petals; petals pink-, cream-, or green-white; stamens inserted outside or below the nectary disk; ovary partially embedded in the disk, superior to partially inferior, 2–3-carpellate; carpels partially free or united in the ovarian region; ovules 2–33 per locule. Fruit dehiscent or indehiscent, either inflated or with the pericarp adherent to the seeds, a capsule, berry or fruit of 1–3 spreading follicles with carpels separating at the apex before maturation; seeds 1–2(–15) per fruit, brown to black. Twenty-three species, temperate regions of the Northern Hemisphere, Japan, eastern China, Taiwan and islands south to Hainan, Himalayas west to Europe, United States, Mexico, Central and South America.

APG II 2003. See general references. Barker, W.R. 1981. Staphyleaceae. Handbooks of the Flora of Papua New Guinea, II. Melbourne: E.E. Henty, Melbourne University Press. Bentham, G., Hooker, J.D. 1867. Genera Plantarum, I, 1. London: A. Black. Blackwell, W.H. 1983. Fossil wood from “Sand Hill”, western central Mississippi. Bull. Torrey Bot. Club 110:63– 69. Brown, R.W. 1944. Temperate species in the Eocene flora of the southeastern United States. J. Wash. Acad. Sci. 34:349–351. Carlquist, S.A., Hoekman, D.A. 1985. Wood anatomy of Staphyleaceae: ecology, statistical correlations, and systematics. Flora 177:195–216. Corner, E.J.H. 1976. See general references. Cronquist, A. 1981. See general references. Dickison, W.C. 1986. Floral morphology and anatomy of Staphyleaceae. Bot. Gaz. 147:312–326. Dickison, W.C. 1987a. Leaf and nodal anatomy and systematics of Staphyleaceae. Bot. Gaz. 148:475–489. Dickison, W.C. 1987b. A palynological study of the Staphyleaceae. Grana 26:11–24. Dore, W.G. 1962. The bladdernut shrub at Ottowa. Canad. Field-Naturalist 76:100–103. Erdtman, G. 1952. See general references. Fernald, M.L., Kinsey, A.C. 1943. Edible wild plants of eastern North America. Cornwall-on-the-Hudson: Idlewild Press. Foster, R.C. 1933. Chromosome number in Acer and Staphylea. J. Arnold Arb. 14:386–393. Gadek, P.A., Fernando, E.S., Quinn, C.J., Hoot, B.S., Terrazas, T., Sheahan, M.C., Chase, M.W. 1996. Sapindales: molecular delimitation and infraordinal groups. Amer. J. Bot. 83:802–811. Garwood, N.C., Horvitz, C.C. 1985. Factors limiting fruit and seed production of a temperate shrub, Staphylea trifolia L. (Staphyleaceae). Amer. J. Bot. 72:453–466. Gill, B.S., Bir, S.S., Singhal, V.K. 1984. Chromosome number reports LXXXIV. Taxon 33:536–539. Hegnauer, R. 1973, 1990. See general references. Hoey, M.T., Parks, C.R. 1991. Isozyme divergence between eastern Asian, North American and Turkish species of Liquidambar (Hamamelidaceae). Amer. J. Bot. 78:938– 947. Hsu, C.-C. 1968. Preliminary chromosome studies on the vascular plants of Taiwan II. Taiwania 14:11–27. Johri, B.M. et al. 1992. See general references. Ka, M.-U. (1965). Staphyleaceae. Flora of Japan. Washington, DC: Smithsonian Institution. Krause, J. 1960. Staphyleaceae. In Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 20b. Berlin: Duncker & Humblot, pp. 255–321. Kubitzki, K. 2003. Tapisciaceae. In: Kubitzki, K., Bayer, C. (eds) Flowering plants. Dicotyledons. The Families and Genera of Vascular Plants, V. Berlin Heidelberg New York: Springer, pp. 369–370. Li, H.-L. 1971. Floristic relationships between eastern Asia and eastern North America. Philadelphia: The Morris Arboretum. Li, H.-L. 1993. Staphyleaceae. Woody flora of Taiwan. Narbeth, PA: Livingston Publ.

Staphyleaceae Linden, B.L. van der 1960. Staphyleaceae. In: Flora Malesiana I, 6. Leiden: Noordhoff, pp. 49–59. Lobreau, D. 1969. Les limites de l‘ordre des Celastrales d’après le pollen. Pollen Spores 11:499–555. Mehra, P.N. 1976. Cytology of Himalayan Hardwoods. Calcutta: Sree Saraswaty Press. Mehra, P.N., Khosla, P.K. 1969. IOPB chromosome number reports XX. Taxon 18:213–221. Metcalfe, C.R., Chalk, L. 1950. See general references. Nakai, T. 1924. Some new and noteworthy ligneous plants of eastern Asia. J. Arnold Arb. 5: 80. Narayana, L.L. 1960. Embryology of Staphyleaceae. Curr. Sci. 10:403–404. Pax, F. 1893. Staphyleaceae. In Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 5. Leipzig: W. Engelmann, pp. 258–262. Pereira, J.T. 1995. Staphyleaceae. In: Soepadmo, E., Wong, K.M. (eds) Tree flora of Sabah and Sarawak, 1. Sabah: Forest Research Institute of Malaysia. Pogan, E., Jzmalow, R. et al. 1983. Further studies in chromosome numbers of Polish angiosperms, Part XVI. Acta Biol. Cracov., Ser. Bot. 24:159–189.

445

Ramp, E. 1987. Funktionelle Anatomie des Gynoeciums bei Staphylea. Bot. Helv. 97:89–98. Ridley, H.N. 1930. The dispersal of plants throughout the world. Ashford, Kent: L. Reeve. Robertson, C. 1889. Flowers and insects, III. Bot. Gaz. 14: 302. Roxburgh, W. 1819. Plants of the coast of Coromandel, selected from drawings and descriptions presented to the hon. court of directors of the East India company. London: W. Bulmer. Takhtajan, A.L. 1980. Outline of the classification of flowering plants (Magnoliophyta). Bot. Rev. 46:225–359. Thorne, R.F. 1992. Classification and geography of the flowering plants. Bot. Rev. 58:225–348. Tiffney, B.H. 1979. Fruits and seeds of the Brandon Lignite III. Turpinia (Staphyleaceae). Brittonia 31:39–51. Watson, S. 1890. Contributions to American botany. Proc. Amer. Acad. Arts Sci. 25: 146. Weaver, R.E. 1980. The bladdernuts. Arnoldia 40:76–93. Winge, O. 1917. The chromosomes. Their numbers and general importance. C. R. Trav. Lab. Carlsberg 13:131– 275.

Strasburgeriaceae Strasburgeriaceae van Tieghem, J. Bot. (Morot) 17:204 (1903). W.C. Dickison1

Small to medium-sized tree. Leaves spiral, leathery, large, simple, obovate; blade entire with widely spaced serrulations; petioles with narrow, lateral wings; stipules united on the adaxial side of petiole to form a distally toothed, intrapetiolar structure. Flowers large, solitary, axillary, pentamerous, hypogynous and bisexual; sepals 8–10, imbricate, gradually increasing in size from outer to inner; petals 5(6), imbricate; stamens 5 + 5; filaments thick; anthers dorsifixed, tetrasporangiate, thecae separate in the lower third of anther, latrorse, opening by slits; disk intrastaminal, thickened, lobed; carpels 4–7, laterally united throughout with the stylar portions congenitally into a single, twisted style with a slightly lobed stigma; ovules anatropous, bitegmic, crassinucellate, pendant on lateral placenta, usually 1 per locule; endosperm cellular. Fruit indehiscent, fibrous, with persistent style and calyx; seeds with a rudimentary aril on funicle, a thin layer of endosperm and a straight, dicotyledonous embryo. A single genus and species, endemic to New Caledonia where it occurs at mid- to high elevations. Vegetative Morphology. Strasburgeria grows to about 10 m in height. The thick, glabrous leaves are essentially entire and about 20–22 × 7–8 cm in size. Vegetative and reproductive parts show an abundance of large, cream-colored mucilaginous idioblasts, especially on dried organs. Vegetative Anatomy. The morphology and anatomy of Strasburgeria have been described by van Tieghem (1903) and Dickison (1981). The leaves are coriaceous with a brochidodromous venation. Leaf blades contain numerous epidermal and mesophyll cells filled with a frothy mucilaginous substance. Major veins are ensheathed with fibres. Stomata are anomocytic. Nodal anatomy is trilacunar, 3-trace, the stipules vascularized by traces originating from the lateral leaf traces. The 1

With updates by K. Kubitzki.

early departure of lateral leaf traces forms what have been described as “cortical bundles” in the stem. Calcium oxalate crystals in the form of druses and small, irregularly shaped clusters are widely scattered throughout the leaf and young stem. The wood anatomy is characterized by a suite of primitive features, including mostly solitary vessel elements with many-barred (18–28), scalariform perforation plates in nearly vertical end walls, heterogeneous rays, tracheids, and diffuse and diffuse-in-aggregates wood parenchyma, also paratracheal scanty. The wood of Strasburgeria shares several plesiomorphic features with that of Ixerba (Cameron 2003). Floral Structure. The large, solitary, bisexual flowers of Strasburgeria arise in the axillary position as figured by Carlquist (1965). The persistent, free sepals are concave, spirally arranged and leathery. They are covered internally with unicellular, unbranched trichomes. The free petals extend well beyond the calyx and vary in form from inner to outer. The imbricate perianth parts are thick and covered with a well-developed cuticle. Internally, enlarged mucilage cells are common throughout the mesophyll of sepals, less so in petals. What has been described as a two-cycled androecium is, in fact, composed of 10 stamens borne in a single cycle. Filaments are conspicuously broad and thick. A thickened, lobed, crystalliferous, vascularized disk is associated with the androecium. The superior gynoecium consists of 4–7 laterally united carpels which are also adnate with a central core of tissue. Each carpel contains a single, rather small locule. Mucilaginous cells occur throughout the style. The floral structure was described by Dickison (1981) and Matthews and Endress (2005). Of particular note is an extremely rich and complex gynoecial wall vasculature. Karyology. Strasburgeria was found to be very highly polyploid: 2n = c. 500 (Oginuma et al. 2005).

Strasburgeriaceae

Embryology. The anther wall contains a conspicuous sub-epidermal endothecial layer distinguished by lignified, fibrous thickenings. A single-layered tapetum is present in mature anthers. Each large, pendulous, epitropous, bitegmic, anatropous ovule is borne on an axile placenta. The more massive, outer ovular integument is 7–8 layers thick and the inner integument is composed of 3–4 layers; the micropyle is “zigzag”. Ovules are crassinucellate with an extensive, 8–10-layered nucellus. Embryo sac and embryo development are unknown. Pollen Morphology. Pollen grains are 3-colporate, distinctly brevicolpate, and have lalongate endoapertures. They are triangular (angulaperturate), oblate, tectate, and psilate to psilate-granular (Dickison 1981, see also Jarzen and Pocknall 1993).

447

Fruit and Seed. The distinctive fruit of Strasburgeria is a large, globose, indehiscent, multiloculate capsule, about the size of a small apple. The style and sepals are persistent. After the fruit falls from the tree, the gradual disintegration of ground tissue results in appearance of numerous, fibrous vascular bundles forming an extensive vascular “skeleton”. Seeds are large and wingless, exarillate, and somewhat flattened. The hilum extends over the entire chalaza end. At maturity, the seed coat is very hard and the exotesta is composed of multiple layers of crystalliferous sclereids. The external seed surface is punctate. The seeds have a thin layer of oily endosperm; the embryo is straight. Affinities. Strasburgeria has often been regarded as an evolutionary island relict, the systematic position of which has been difficult to establish. It had been placed in “Theales” or an equivalent group, either next to, or in Ochnaceae. The distinctly primitive vegetative anatomy but specialized vegetative features and particularly the peculiar pollen morphology of Strasburgeria led Dickison to propose its recognition as an independent family (Dickison 1981), in that following van Tieghem (1903). Since Dickison wrote this account, molecular data have placed Strasburgeria as sister to the New Zealand genus Ixerba in the recently recognised Crossosomatales (Savolainen, Fay et al. 2000; Cameron 2003). The two genera share several features, including trilacunar nodes, acicular crystals, flattened filaments, and a conspicuous, persistent style. Distribution and Habitats. Strasburgeria robusta is restricted to the island of New Caledonia where it occurs in moist mountainous forests. The classic locality is the summit of Mt. Mou at about 1,150 m altitude on nickel-rich rock. Strasburgeria has an ample pollen record in Tertiary beds (Palaeocene through Pliocene) of western and southern Australia, Tasmania and New Zealand (Jarzen and Pocknall 1993; Hill 1994). Only one genus:

Fig. 158. Strasburgeriaceae. Strasburgeria robusta. A Flowering branch. B Two nodes of young stem with leaf bases and intrapetiolar stipules. C Stipule. D Flower bud. E Flower with part of perianth and androecium removed. F Anther, side view. G Anther, dorsal view. H Fruit. I Seed. J Ovule, transversal section showing vascularization (ovt). (A–C, H Orig., rest Dickison 1981)

Strasburgeria Baillon

Fig. 158

Strasburgeria Baillon, Adansonia 11:372 (1876).

Characters as for family. The only species, S. robusta (Vieill. ex Panch. & Seb.) Guillaumin, is endemic to New Caledonia.

448

W.C. Dickison

Selected Bibliography Cameron, K.M. 2003. See general references. Carlquist, S. 1965. Island life. A natural history of the islands of the world. New York: Natural History Press, Garden City. Dickison, W.C. 1981. Contributions to the morphology and anatomy of Strasburgeria and a discussion of the taxonomic position of the Strasburgeriaceae. Brittonia 33:564–580. Engler, A. 1925. Strasburgeriaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 21. Leipzig: W. Engelmann, pp. 87–89. Hill, R.S. (ed.) 1994. History of Australian vegetation: Cretaceous to Recent. Cambridge: Cambridge University Press.

Jarzen, D.M., Pocknall, D.T. 1993. Tertiary Bluffopollis scabratus (Couper) Pocknall & Mildenhall, 1984, and modern Strasburgeria pollen: A botanical comparison. N. Z. J. Bot. 31:185–192. Matthews, M.L., Endress, P.K. 2005. See general references. Oginuma, K., Munzinger, J., Tobe, H. 2005. Strasburgeria robusta (Strasburgeriaceae) survives as a high-polyploid species in New Caledonia. In: Abstract Volume XVII International Botanical Congress, 12–16 July, University of Vienna, Austria, Abstract P0668. Savolainen, V., Fay, M.F. et al. 2000. See general references. Tieghem, P. van 1903. Sur le genre Strasburgeria considéré comme type d’une famille nouvelle, les Strasburgeriacées. J. Bot. (Morot) 17:198–204.

Surianaceae Surianaceae Arn. in Wight & Arn., Prodr. Fl. Ind. Orient. 1:360 (1834), nom. cons. Stylobasiaceae J. Agardh (1858).

J.V. Schneider

Trees or shrubs; trichomes simple or glandular, or plants glabrous. Leaves alternate, simple or compound and with alate rachis, petiolate or almost sessile, subcoriaceous to fleshy, rarely with nectaries on petiole or midrib (Cadellia); venation pinnate-reticulate; stipules present or not. Inflorescences axillary or terminal, sometimes borne on the branches, few- to many-flowered panicles or cymes, or flowers solitary in leaf axils; bracts and prophylls generally present; pedicels articulated or not. Flowers actinomorphic, perfect or polygamous; sepals 5(–7), quincuncially imbricate, distinct or united at base, generally persistent; petals 5 or (Stylobasium) 0, imbricate, unguiculate or not, yellow, orange, cream or white, caducous; stamens obdiplostemonous, 10 or 5 + 5 staminodes, the staminodial whorl often reduced in number; filaments free, the antesepalous ones generally longer than the antepetalous ones, sometimes articulated, caducous or persistent, glabrous or basally pilose; anthers tetrasporangiate, basifixed or dorsifixed, versatile, introrse (rarely latrorse), opening by longitudinal slits; ovary superior, apocarpous, carpels 1–5, inserting on the ± flat receptacle or on a gynophore (Recchia), glabrous or pilose; placentation basal, ovules 2 per carpel, collateral; stylodia gynobasic; stigmas capitate or peltate. Fruit a berry, drupe or nutlet, 1-seeded, mesocarp hard or fleshy (and sometimes fibrous), endocarp usually hard, bony; endosperm 0 or rarely (Stylobasium) sparse; embryo curved, conduplicate, transversally induplicate or globose, cotyledons fleshy (thin in Cadellia), oily or starchy. Five genera with eight species, Cadellia, Guilfoylia, Stylobasium endemic to Australia, Recchia from humid and dry forests of Mexico, and Suriana pantropical along sea coasts, except in West Africa. Vegetative Morphology. Surianaceae are medium-sized trees (occasionally to 28 m high) to small shrubs with acrotonic or basitonic

branching. The vegetative shoots of Suriana show monopodial growth whereas the generative parts have a sympodial structure (Gutzwiller 1961). The leaves are simple, except in two species of Recchia which have compound leaves with an alate rachis. Leaf disposition is alternate and generally distichous but Suriana has a 2/5 phyllotaxis. Leaves of Suriana appear apically crowded, leaving conspicuous scars after shedding. Leaf succulence is apparent in Suriana, whereas the leaves of the other genera are ± coriaceous. The venation is pinnate-reticulate. Stipules are present in Cadellia, Guilfoylia, Recchia and Stylobasium (Weberling et al. 1980). The indumentum may be conspicuous, with simple and glandular trichomes covering most of the vegetative and generative parts, as in Suriana, or the plants are glabrous; in Stylobasium, only the youngest plants exhibit trichomes (Prance 1965). Extrafloral nectaries are known only from the petiole or midrib of Cadellia (Gutzwiller 1961). Vegetative Anatomy. The leaves are bifacial, with the stomata confined to the abaxial surface (Cadellia, Guilfoylia, Recchia), or aequifacial (Stylobasium, Suriana), with the stomata equally distributed on both surfaces. The stomata are anomocytic or anisocytic (Jadin 1901; Gutzwiller 1961; Nooteboom 1966). The epidermis of Suriana contains mucilage. The palisade parenchyma consists of 1 or 3 layers beneath the adaxial epidermis or, in Suriana, beneath both epidermal layers (Jadin 1901). Spongy tissue is found in the centre and near the veins (Prance 1965). In Stylobasium, the lateral veins are not surrounded by a ring of sclerenchyma (Prance 1965). Crystals of calcium oxalate (solitary or druses) are abundant in the mesophyll (Cadellia, Recchia, Suriana) and the epidermis (Guilfoylia, Recchia) but are lacking in Stylobasium (Loesener and Solereder 1905; Prance 1965). The epicuticular sculpture is mostly bare of crystalloids but sometimes wax scales are observed (Fehrenbach and Barthlott 1988). The simple trichomes are uni-

450

J.V. Schneider

cellular, the glands consisting of a uniseriate stalk of 5–7 cells and a head of 15–20 cells (Gutzwiller 1961). The nodes are unilacunar (Suriana; Jadin 1901) or trilacunar (Cadellia, Stylobasium). The stem anatomy of Surianaceae is uniform. The cortex shows a more or less continuous ring of sclerenchyma or single groups of fibres. Solitary crystals and druses are common in the cortex of Cadellia and Recchia (Loesener and Solereder 1905; Weberling et al. 1980). Cork develops in the inner part of the primary cortex or in a subepidermial layer (Loesener and Solereder 1905). The wood exhibits growth rings, sometimes poorly defined. Pores are moderately present to very numerous (16–66 m2 ), mostly somewhat angular and in multiples of 2–9 and clusters of 3–5, some solitary and elliptic, mostly small to very small (diameter 14–89 µm) but sometimes rather large (in Recchia, to 240 µm; Loesener and Solereder 1905). Vessel elements are cylindrical to irregular in shape, very short to long (58–685 µm), often containing reddish to brownish gum. Perforation plates are horizontal or oblique, the perforations simple. Intervascular pit-pairs are bordered with included apertures, the pitting is alternate. Ray-vessel and parenchyma-vessel pitting is half-bordered or, in Guilfoylia, often unilaterally compound. Vestured pits are present in Recchia (Loesener and Solereder 1905), absent in Suriana (Jansen et al. 2001). Rays are uniseriate, rarely biseriate, and frequently storied. Uniseriate rays are extremely low (1–36 cells), extremely fine to very fine (8–20 µm wide), the cells mostly upright, moderately thick-walled, often filled with reddish gum. The wood parenchyma is generally scanty, vasicentric or paratracheal, diffuse, and crystalliferous strands are observed in all genera except for Stylobasium (Jadin 1901; Loesener and Solereder 1905; Webber 1936; Chattaway 1956; Prance 1965; Weberling et al. 1980; Carlquist 1985). Libriform wood fibres and fibre tracheids are cylindrical and in a central position, tapering gradually or abruptly at first to smooth or occasionally forked or saw-toothed ends, 400– 1,140 µm long, 8–38 µm in diameter, or sometimes wide-lumened in Recchia (Loesener and Solereder 1905), sometimes septate in Recchia, Stylobasium and Suriana. The walls show few to rather numerous minute pits, the pits oblique, those of the fibre tracheids with vestigial borders. Usually, they are filled with gummy contents (Webber 1936; Prance 1965). The sieve-element plastids are of the P-type (Stylobasium) or S-type (Suriana) (Behnke et al. 1996).

Inflorescences. Inflorescences are terminal or axillary. The general type is a few- to manyflowered panicle but single flowers in leaf axils are also observed. Gutzwiller (1961) describes the inflorescence of Suriana as clearly separated from the vegetative parts, and as a panicle with terminal dichasia of scorpioid shape. For Cadellia and Guilfoylia, accessory buds are reported (Gutzwiller 1961). Bracts and a pair of prophylls are present but often early caducous. The pedicel is articulated in Cadellia and Guilfoylia (Stylobasium?). Flower. The flowers are basically actinomorphic, pentamerous and perfect. However, Stylobasium is polygamous with some perfect flowers, and functionally male and female flowers with abortive ovaries and staminodes respectively. The sepals and petals are quincuncial. The sepals are distinct or basally united; the petals are generally early caducous or even wanting, and in Suriana and Recchia they are unguiculate. The epidermis of the petals of Suriana is rugose to smooth and longitudinally striate, and the abaxial pattern is tabular (see the classification of Christensen and Hansen 1998). The androecium is obdiplostemonous; the outer whorl may be staminodial and reduced in number (Tschunko and Nickerson 1976). The anthers have a papillate epidermis, and the dehiscence line extends over the lower and upper shoulders of a theca. A single vascular bundle serves each anther (Endress and Stumpf 1991). In bud, the sepals and the inner whorl of stamens originate before the petals and the outer staminal whorl (Suriana; Gutzwiller 1961). The gynoecium is apocarpous with 1–5 carpels, each with a ventrobasal stylodium (Fig. 159F). Guilfoylia has usually a single carpel, the second being rudimentary or wanting. In Recchia, the carpels are borne on a short gynophore but, in the other genera, they are inserted centrally or marginally on the more or less flat receptacle. The carpels are basally ascidiate whereas the stylodia form the plicate zone. The multilayered transmission tissue is of the closed type (Ramp 1988). The cavity of the ovary is entirely filled with mucilage (Suriana; Gutzwiller 1961), which may mediate between the transmission tissue and the micropyle (Ramp 1988). The ventral margins of the carpels are free in bud but later shortly fused and leaving an inner channel (Suriana). In Suriana and Cadellia, the carpels approach each other at a geniculate part of the stylodia. They may agglutinate, although there is apparently no

Surianaceae

451

compitum, and apocarpy in Surianaceae may be primary (Ramp 1988). However, the positioning of the family in a group of principally syncarpous taxa (see below) calls for further investigation concerning the nature of apocarpy. Embryology. The anthers are tetrasporangiate and the wall consists of 5–6 cell layers: an epidermis, an endothecium, 2–3 middle layers, and a tapetum. The wall formation conforms with the Basic Type. During maturation, the middle layers collapse while the endothecium develops fibrous thickenings. The tapetum is glandular and its cells become 2-nucleate. Mature pollen is two-celled at the time of shedding (Endress and Stumpf 1991; Heo and Tobe 1994). Placentation is (supra)basal. The two collateral ovules of Suriana are anatropous or campylotropous, unitegmic and crassinucellate; ovule and seed are pachychalazal (Heo and Tobe 1994). A hypostase is present and a nucellar cap is formed. The embryo sac is of the Polygonum type, and there are no starch grains. An unbranched chalazal haustorium develops, and endosperm formation is of the Nuclear type. Pollen. Pollen of Surianaceae is tricolpor(oid)ate, suboblate, oblate-spheroidal or spheroidal to subprolate. The exine is usually thin and verrucate to reticulate, the sexine about as thick as the nexine or slightly thicker (Erdtman 1952; Prance 1965; Weberling et al. 1980). Karyology. There are no data available. Pollination. There is little information on the pollination biology of the family. However, the small apetalous flowers of Stylobasium, with large stamens which produce copious pollen and an expanded stigmatic surface, can be associated with wind pollination (Prance 1965).

Fig. 159. Surianaceae. Suriana maritima. A Flower, two sepals and four petals removed. B Stamen. C Staminodes. D Young infructescence. E Fruit. F Mericarp with stylodium. G Seed. H Fruiting branch. (Drawn by Manuel Escamilla; Juárez S. 1988)

Fruit and Seed. The fruits are single-seeded drupes, nuts or berries. The sepals are generally persistent in fruit. The general pattern of pericarp anatomy includes a parenchymatous mesocarp bounded with a crystalliferous cell layer against a palisade of strongly lignified sclereids forming the outer endocarp. In Stylobasium, the mesocarp is fleshy and the endocarp palisade is particularly well developed whereas the pericarp of the berrylike fruits of Guilfoylia lacks any sclerified tissue (Fernando and Quinn 1992).

452

J.V. Schneider

The seed coat of Suriana is constructed by four cell layers: an exotesta, two layers of mesotesta, and an endotesta. At maturity, the seed coat comprises largely only the thick-walled, tanniniferous exotesta, the remaining layers having collapsed (Heo and Tobe 1994). On germination, the fruit is split into two equal halves in Stylobasium and germination is epigeal (Prance 1965). The mature seed lacks endosperm and typically has a curved embryo. The embryo is notorhizal (Recchia, Suriana). The cotyledons are thick (except in Cadellia) and contain abundant starch or oil (Loesener and Solereder 1905; Gutzwiller 1961; Johri et al. 1992). Dispersal. There is little information on dispersal mechanisms of the family. The diaspore is the single carpel. Suriana maritima is dispersed by ocean currents, as inferred from its coastal distribution pattern and the presence of a cavity in the fruit which facilitates floating (Nooteboom 1962). Phytochemistry. Reports on chemical components are scarce and refer to Suriana only. In S. maritima, surianol, a triterpenoid diol, has been detected. Surianol belongs to a stereochemical series different from the triterpenes from which the lactones of Simaroubaceae are probably derived, a fact which supports the exclusion of Suriana from Simaroubaceae (Nooteboom 1966; Mitchell and Geissman 1971). Subdivision and Relationships Within the Family. Surianaceae underwent several rearrangements since their erection by Arnott. Loesener and Solereder (1905) divided “Surianoideae” into two tribes, Surianeae and Rigiostachy[d]eae, the former having simple leaves and few-flowered inflorescences or single flowers, the latter with compound leaves and many-flowered inflorescences. Surianeae comprised the genera Cadellia, Guilfoylia and Suriana, Rigiostachyeae the single genus Rigiostachys (= Recchia). Recchia does indeed have the largest inflorescences but the discovery of a species with simple leaves (Wendt and Lott 1985) weakened the concept of Loesener and Solereder (1905); Stylobasium was not yet considered a member of Surianaceae. Later, Gutzwiller (1961) proposed informally to erect the tribe Cadellieae including Cadellia and Guilfoylia, and to place it together with the Rigiostachyeae in a subfamily Rigiostachyoideae (within Simaroubaceae). Guilfoylia, sometimes assigned to Cadellia, is maintained as a distinct

genus, based on anatomical characteristics including the berry-like fruit with a different endocarp, the monocarpous gynoecium, and the absence of an obturator (Loesener and Solereder 1905; Weberling et al. 1980). The position of Stylobasium was unclear, and Prance (1965) argued in favour of a separate family, Stylobasiaceae. According to Behnke et al. (1996), the very distinctive Pf sieve-element plastids may also suggest that Stylobasium be kept separate. However, molecular studies based on rbcL data (Crayn et al. 1995) provide strong evidence for including all five genera into Surianaceae: Recchia is sister of Cadellia, and both are sister to the remaining genera of Surianaceae, with Suriana being sister to Guilfoylia and Stylobasium. Affinities. The placement of Surianaceae remained controversial for a long time. In the classifications of Takhtajan (1987) and Thorne (1992), the family was placed in Rutales, in Cronquist (1983) in Rosales. In most classifications, Surianaceae were assigned to Simaroubaceae or to Chrysobalanaceae, but numerous characters in combination (e.g. chemistry, presence of stipules, ventrobasal stylodia, absence of a nectary disk [not in Recchia], collateral ovules on a basalmarginal placenta, and different embryology and anatomy) raised doubts concerning these assignments. Molecular analyses based on 18S rDNA, rbcL and/or atpB sequences revealed a clade comprising Surianaceae, Polygalaceae, and Quillajaceae along with Fabaceae (e.g. Fernando et al. 1993; Crayn et al. 1995; Soltis et al. 2000). Accordingly, Surianaceae are included in Fabales within the eurosids I (APG II 2003). Unfortunately, relationships within Fabales are unclear, although in view of the apocarpous nature of the gynoecium in Surianaceae, it is noteworthy that Fabaceae have a single, rarely two or more free carpels. Distribution and Habitats. The monotypic Suriana has a scattered distribution along tropical or subtropical coasts, with the exception of West Africa. It generally grows on shallow sandy, loamy or stony beaches, just above the high-water mark. Recchia is a genus confined to rainforests or deciduous forests of southern Mexico, R. simplicifolia being particularly common on limestone substrates (Wendt and Lott 1985). The two species of Stylobasium grow on sandy soils in dry areas of northern and western Australia (Prance 1965). The other two Australian endemics, Cadellia

Surianaceae

and Guilfoylia, occur in xerophytic shrub or forest vegetation. Palaeobotany. There is a single fossil record of Suriana known from the Eocene of North America (Kruse 1954). Economic Importance. None of the species is economically important, although Standley (1923) describes Recchia mexicana as a potentially valuable timber. The wood of Suriana is hard, heavy, probably durable and may be, in larger plants, suitable for turning (Record and Hess 1943). Juárez S. (1988) reports some medicinal properties of Suriana maritima: roots and shoots are used for stimulating blood circulation, and against inflammations and epilepsy. In Cuba, the leaves and the cortex are used against rheumatism and oral ulcers. Thomas (2004) cites Suriana as being further used to combat diarrhoea, rectal bleeding and mouth sores. Conservation. The Australian Cadellia pentastylis is a threatened species of semiarid forests (Fletcher 2002). Key to the Genera 1. Carpels borne on a short gynophore; leaves compound or simple 3. Recchia – Carpels borne on a flat or inconspicuously elevated receptacle; leaves simple 2 2. Plants densely pubescent, with simple and glandular trichomes (also on perianth, carpels, fruits, and basally on filaments) 5. Suriana – Plants glabrous or with scattered trichomes principally confined to the vegetative parts; glandular trichomes lacking or very few, filaments and fruits glabrous 3 3. Flowers apetalous, polygamous; leaves with stomata on both surfaces 4. Stylobasium – Flowers with petals (sometimes early caducous), generally hermaphroditic; stomata confined to abaxial surface of the leaves 4 4. Fruit nut-like; petals white; nectar glands present on petiole or midrib 1. Cadellia – Fruit a berry; petals yellow; nectar glands wanting 2. Guilfoylia

Genera of Surianaceae 1. Cadellia F. Muell. Cadellia F. Muell., Fragm. 2:25 (1860).

Tree to 28 m high; indumentum of scattered simple hairs. Leaves simple, entire, subcoriaceous, with nectaries on petiole or midrib; venation pinnate-reticulate; stipules caducous. Inflores-

453

cences axillary or terminal panicles, few-flowered, with accessory buds; bracts present; pedicels articulated. Flowers hermaphroditic; sepals 5(–7), basally fused, persistent; petals 5, not unguiculate, white; stamens 9–10, fertile ones 5, the second whorl with 4 or 5 staminodes; filaments glabrous, anthers basifixed, introrse; carpels 1–5; stigma peltate; placentation suprabasal; ovules with obturator. Fruit nut-like, glabrous. One species, C. pentastylis F. Muell., endemic to Australia. 2. Guilfoylia F. Muell. Guilfoylia F. Muell., Fragm. 8:33 (1873).

Tree to 20 m, with simple trichomes. Leaves simple, subcoriaceous; stipules caducous. Inflorescence axillary or terminal, paniculate, with accessory buds; pedicels articulated. Flowers hermaphroditic; sepals 5, basally united, persistent; petals 5, not unguiculate, yellow, caducous; stamens 10, the inner whorl fertile, the outer one staminodial, caducous; filaments glabrous; anthers basifixed, introse; carpels 1(2); stigma capitate; placentation basal; ovules without appendix. Fruit a berry, glabrous. One species, G. monostylis (Benth.) F. Muell., endemic to Australia. 3. Recchia Moç. & Sessé ex DC. Recchia Moç. & Sessé ex DC., Syst. Nat. 1:411 (1818); Loesener & Solereder, Verh. Bot. Verein. Prov. Brandenburg 47:35–62 (1905), rev. Rigiostachys Planch. (1847).

Trees or shrubs, glabrous or with simple and glandular trichomes. Leaves simple or imparipinnately compound and with an alate rachis, with 5–11 leaflets, subcoriaceous; venation pinnatereticulate; stipules persistent. Inflorescence a terminal or axillary panicle or borne on the trunk; bracts and prophylls present; pedicels articulated or not. Flowers hermaphroditic, small, sometimes fragrant; sepals 5, free or inconspicuously united at the base; petals 5, inconspicuously unguiculate, yellow, orange or cream, persistent or caducous; stamens 10, all fertile or 5 staminodial, filaments free, articulated, the antesepalous ones longer than the antepetalous ones; anthers dorsifixed, introrse; carpels 2(3), borne on a short gynophore; stylodia nearly basally attached; stigma capitate or peltate; ovules suborthotropous. Fruit of 1–3 drupes, glabrous, bright orange-red, mesocarp fleshy; embryo globose, cotyledons fleshy, starchy. Three species endemic to Mexico.

454

J.V. Schneider

4. Stylobasium Desf. Stylobasium Desf., Mém. Mus. Hist. Nat. 5:37, t. 2 (1819); Prance, Bull. Jard. Bot. Etat, Bruxelles 35:435–448 (1965).

Shrubs, glabrous, only the seedling with scattered trichomes. Leaves simple, entire; stipules minute or 0. Inflorescences terminal, short, few-flowered, racemiform or flowers solitary in leaf axils. Flowers mostly polygamous, the female ones with long staminodes, the male ones with a small abortive ovary, some flowers appear to be hermaphroditic; sepals persistent in fruit; petals wanting; stamens 10, staminodial in female flowers; filaments persistent in male flowers; carpel 1, abortive in male flowers, glabrous; stigma peltate; ovules erect, the micropyle facing towards the style. Fruit a one-seeded drupe, glabrous, the mesocarp thin, fleshy, the endocarp thick, bony; seed with little endosperm, the radicle pointing downwards, cotyledons thick, transversally induplicate. Two species, endemic to Australia (Western Australia, Northern Territory), in dry, sandy habitats. 5. Suriana L.

Fig. 159

Suriana L., Sp. Pl.: 284 (1753); Gutzwiller, Bot. Jahrb. Syst. 81:1–49 (1961).

Shrub or small tree to 8 m high, densely pubescent, with simple and glandular trichomes. Leaves simple, estipulate, apically crowded, arranged in a 2/5 spiral, fleshy, almost sessile, leaving prominent scars. Flowers solitary or in few-flowered axillary or terminal cymes or panicles; bracts and prophylls at the point of articulation of the pedicel. Flowers hermaphroditic; sepals 5, united at base, persistent in fruit; petals 5, persistent or caducous, (weakly) unguiculate, yellow; stamens 10 (sometimes reduced in number) or 5 plus 5 (inner) staminodes; anthers dorsifixed, introrse (latrorse?), filaments pilose at base; carpels generally 5(6), pilose; stigma capitate; ovules anatropous or campylotropous. Fruit nut-like, epicarp thin, endocarp crustaceous; embryo curved; cotyledons fleshy, oily. One species, S. maritima L., from tropical or subtropical sea coasts, except for the west coast of Africa.

Selected Bibliography APG II 2003. See general references. Behnke, H.D., Kiritsis, U., Patrick, S.J., Kenneally, K.F. 1996. Form-Pfs plastids, stem anatomy and systematic affi-

nities of Stylobasium Desf. (Stylobasiaceae). A contribution to the knowledge of sieve-element plastids in the Rutales and Sapindales. Bot. Acta 109:346–359. Carlquist, S. 1985. Vasicentric tracheids as a drought survival mechanism in the woody flora of southern California and similar regions: review of vasicentric tracheids. Aliso 11:37–68. Chattaway, M.M. 1956. Crystals in woody tissues, part II. Trop. Woods 104:100–124. Christensen, K.I., Hansen, H.V. 1998. SEM-studies of epidermal patterns of petals in the angiosperms. Opera Bot. 135:1–91. Crayn, D.M., Fernando, E.S., Gadek, P.A., Quinn, C.J. 1995. A reassessment of the familial affinity of the Mexican genus Recchia Moçiño and Sessé ex DC. Brittonia 47:397–402. Cronquist, A. 1983. Some realignments in the dicotyledons. Nordic J. Bot. 3:75–83. Endress, P.K., Stumpf, S. 1991. The diversity of stamen structure in “lower” Rosidae (Rosales, Fabales, Proteales, Sapindales). Bot. J. Linn. Soc. 107:217–293. Erdtman, G. 1952. See general references. Fehrenbach, S., Barthlott, W. 1988. Mikromorphologie der Epicuticular-Wachse der Rosales s.l. und deren systematische Gliederung. Bot. Jahrb. Syst. 109:407–428. Fernando, E.S., Quinn, C.J. 1992. Pericarp anatomy and systematics of the Simaroubaceae sensu lato. Austral. J. Bot. 40:263–289. Fernando, E.S., Gadek, P.A., Crayn, D.M., Quinn, C.J. 1993. Rosid affinities of Surianaceae: molecular evidence. Mol. Phylog. Evol. 2:344–350. Fletcher, R. 2002. Ooline Cadellia pentastylis F. Muell.: a survivor. Victorian Naturalist Blackburn 119:235–236. Gutzwiller, M.A. 1961. Die phylogenetische Stellung von Suriana maritima L. Bot. Jahrb. Syst. 81:1–49. Heo, K., Tobe, H. 1994. Embryology and relationships of Suriana maritima L. (Surianaceae). J. Pl. Res. 107:29– 37. Jadin, F. 1901. Contribution à l’étude des Simarubacées. Ann. Sci. Nat. Bot. VIII, 13:201–304. Jansen, S., Baas, P., Smets, E. 2001. Vestured pits: their occurrence and systematic importance in eudicots. Taxon 50:135–167. Johri, B.M. et al. 1992. See general references. Juárez, S.C. 1988. Flora de Veracruz. Surianaceae. Fasciculo 58. Xalapa: Instituto Nacional de Investigaciones sobre Recursos Bióticos. Kruse, H.O. 1954. Some Eocene dicotyledonous wood from Eden Valley, Wyoming. Ohio J. Sci. 54:243–268. Loesener, T., Solereder, H. 1905. Über die bisher wenig bekannte südmexikanische Gattung Rigiostachys. Verh. Bot. Verein. Prov. Brandenburg 47:35–62. Mitchell, R.E., Geissman, T.A. 1971. Constituents of Suriana maritima: a triterpene diol of novel structure and a new flavonol glycoside. Phytochemistry 10:1559–1567. Nooteboom, H.P. 1962. Simaroubaceae. In: van Steenis, C.G.G.J. (ed.) Flora Malesiana I, 6:193–226. Leiden: Noordhoff. Nooteboom, H.P. 1966. Flavonols, leuco-anthocyanins, cinnamic acids and alkaloids in dried leaves of some Asian and Malesian Simaroubaceae. Blumea 14:309–315. Prance, G.T. 1965. The systematic position of Stylobasium Desf. Bull. Jard. Bot. Etat, Bruxelles 35:435–448.

Surianaceae Ramp, E. 1988. Struktur, Funktion und systematische Bedeutung des Gynoeciums bei den Rutaceae und Simaroubaceae. Dissertation, Universität Zürich. Record, S.J., Hess, R.W. 1943. Timbers of the New World. New Haven: Yale School of Forestry. Soltis, D.E. et al. 2000. See general references. Standley, P.C. 1923. Trees and shrubs of Mexico. Contr. U.S. Natl Herb. 23, 3:1–1721. Takhtajan, A. 1987. Systema Magnoliophytorum. Leningrad: Nauka. Thomas, W.W. 2004. Surianaceae. In: Smith, N.P., Mori, S.A., Henderson, A., Stevenson, D.W., Heald, S.V. (eds) Flowering plants of the Neotropics. New Jersey: Princeton University Press.

455

Thorne, R.F. 1992. Classification and geography of the flowering plants. Bot. Rev. 58:225–348. Tschunko, A.H., Nickerson, N.H. 1976. The androecium of Suriana maritima. Rhodora 78:162–164. Webber, I.E. 1936. Systematic anatomy of the woods of the Simarubaceae. Amer. J. Bot. 23:577–587. Weberling, F., Lörcher, H., Böhnke, F. 1980. Die Stipeln der Irvingioideae und Recchiodeae und ihre systematische Wertung nebst Bemerkungen zur Holzanatomie und Palynologie. Pl. Syst. Evol. 133:261–283. Wendt, T., Lott, E.J. 1985. A new simple-leaved species of Recchia (Simaroubaceae) from southeastern Mexico. Brittonia 37:219–225.

Tetracarpaeaceae Tetracarpaeaceae Nakai (1943).

K. Kubitzki

Low erect bushy shrub, quite glabrous. Nodes unilacunar and one-trace. Leaves petiolate, estipulate, alternate, small, simple, crenate or serrate, with rounded to acute teeth, pinnately veined with conspicuous secondary veins terminating near the leaf margin. Inflorescences erect bracteate racemes. Flowers essentially 4-merous, small, regular, hermaphrodite; sepals 4, essentially free, imbricate, persistent; petals 4, free, spreading, spatulate, clawed, slightly imbricate(?), caducous; stamens 4 or 8, borne apparently in a single whorl, although one or more members of the whorl may be missing; filaments free, filiform; anthers elliptic-oblong, basifixed, latrorse; carpels 4(5), fusiform, prominently stipitate, erect, free for most of their length; stigmas subsessile, small, lobed; ovules bitegmic, crassinucellate, numerous, borne on branched submarginal placentae. Fruits multifollicles; follicles erect, stipitate, coriaceous, many-seeded; seeds very small, obovoid-subulate, testa membranous, slightly prolonged at each end, with narrow wings extended along their entire length and parallel ridges on the surface; embryo minute, at the base of fleshy copious endosperm. A single genus and species, Tetracarpaea tasmannica Hook. f., in the mountains of Tasmania. Anatomy. Both epidermal layers of the leaves are uniseriate and are covered by a very thick cuticle; stomata are anomocytic. Marginal leaf teeth are apparently non-glandular; the medial vein does not reach the margin. The secondary xylem is diffuse porous. Vessel elements are of medium length (213–455 µm); perforation plates are scalariform with 5–18 bars, which are completely bordered. Imperforate vessel elements are exclusively tracheids, which are thickwalled, pitted and shorter than the vessel elements. Axial parenchyma is sparse, apotracheal. Rays are uniseriate of upright cells and homocellular or uniand biseriate heterocellular (all data from Hils et al. 1988).

Flower Structure. Hils et al. (1988) were unable to confirm the imbricate condition often ascribed to the calyx and corolla of Tetracarpaea. The stamens appear in a single whorl; if there are only 4 stamens present, then they stand on the sepaline radii. The carpels are alternisepalous. Developing carpels have an open ventral suture extending over their entire length, which later is closed. The narrow, marginal placentae bear single, double or triple rows of numerous ovules. Embryology. The anther wall lacks a fibrous hypodermal layer (Hils et al. 1988). The ovules are bitegmic and crassinucellate, with a straight, exostomal micropyle (Mauritzon 1933). Pollen Morphology. Pollen grains are very small (17 × 13 µm), 3-colporate, tectate-perforate, not sculptured (Hideux and Ferguson 1976). Fruit and Seed. Hils et al. (1988) studied the anatomy of the follicles and seeds. The seeds are about 0.5 mm long. The seed coat becomes extended at both the chalazal and micropylar ends, and the seed body has one or two longitudinal wings. The seed coat is covered by a prominent cuticle but otherwise is undifferentiated; it consists usually of four layers of cells (Krach 1976 found only two but probably studied more-mature seeds) but a distinction between testa and tegmen is not evident because the inner layers often are crushed in the mature seed. Cellular endosperm is abundant; the embryo is small. Affinities. The position of Tetracarpaea has long remained contentious, and placements in Cunoniaceae and later in Saxifragaceae and Escalloniaceae have been proposed. Hils et al. (1988) adduced a number of morphological features which are in favour of a position close to the core Saxifragaceae, among which the bitegmic/crassinucellate ovules exclude the formerly purported

Tetracarpaeaceae

457

affinity with Escalloniaceae. Molecular analyses agree in placing Tetracarpaea in Saxifragales and, in the five-gene analysis of Fishbein et al. (2001), it is resolved as member of their “Haloragaceae alliance”, which comprises also Aphanopetalum and Penthorum and is moderately supported as sister to Crassulaceae. Distribution and Habitats. Tetracapaea is endemic to Tasmania and occurs in subalpine habitats throughout most of the island, being absent only from the east and northwest sectors. Only one genus: Tetracarpaea Hook. f.

Fig. 160

Tetracarpaea Hook. f. in Hooker, Ic. Pl.: t. 264 (1840).



Fig. 160. Tetracarpaeaceae. Tetracarpaea tasmanica. A Flowering shoot. B Flower. C Gynoecium, carpel opened. (Engler 1930)

Engler, A. 1930. Saxifragaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 18a. Leipzig: W. Engelmann, pp. 74–226. Fishbein, M. et al. 2001. See general references. Hideux, M.J., Ferguson, I.K. 1976. See general references. Hils, M.H., Dickison, W.C., Lucansky, T.W., Stern, W.L. 1988. Comparative anatomy and systematics of woody Saxifragaceae: Tetracarpaea. Amer. J. Bot. 75:1687–1700. Krach, J.E. 1976. Die Samen der Saxifragaceae. Bot. Jahrb. Syst. 97:1–60. Mauritzon, J. 1933. Studien über die Embryologie der Families Crassulaceae und Saxifragaceae. Ph.D. Thesis, University of Lund. Lund: H. Olsson.

Turneraceae Turneraceae Kunth ex DC., Prodr. 3:345 (1828), nom. cons.

M.M. Arbo

Herbs, shrubs or rarely trees, erect or decumbent, frequently with serial axillary buds; hairs usually present, simple in most genera, sometimes stellate, forward directed-stellate in Piriqueta, often glandular. Leaves alternate, simple, entire, crenate or toothed, sometimes pinnatifid or revolute-ericoid, rarely very narrow, sessile or petiolate, pinnately veined, sometimes glandular-punctate, often with extrafloral nectaries; stipules usually small or 0, well-developed in Erblichia and some Turnera. Flowers mostly solitary, occasionally epiphyllous, sometimes in monochasial or dichasial inflorescences or in capitula or racemes. Flowers homostylous or heterostylous, regular, perfect, tetracyclic, generally upright, the pedicels provided with 2 prophylls; sepals 5, frequently connate, lobes quincuncial; petals 5, unguiculate, contorted, sometimes ligulate, free or the claw adnate to the calyx and then forming a 10- to pluriveined, cylindric, campanulate or funnel-shaped floral tube, the floral tube sometimes with fringed corona or 5 glands or lobes between corona and androecium; stamens 5, antesepalous, sometimes exserted, the filaments free or partially adnate to the calyx or floral tube; anthers tetrasporangiate, commonly dorsifixed but nearly basifixed in Erblichia and Turnera series Turnera, dehiscing longitudinally; gynoecium 3-carpellate, ovary superior or slightly half-inferior, 1-locular; ovules anatropous, crassinucellate, 1–numerous on parietal placentae, rarely (Stapfiella) 1 basal ovule; stylodia 3, distinct, filiform, connivent or divergent at the base; stigmas generally brush-like. Fruits 3-valved loculicidal capsules, sometimes dressed with the persistent torn perianth, dehiscence generally from apex. Seeds 1–many, obovoid, straight or curved; seed coat crustaceous and dark brown or blackish when ripe; aril plump, membranous when dry; endosperm fleshy; embryo straight. A family of ten genera and about 200 species, distributed from North to South America and in Africa, including Madagascar and the Mascarene Islands.

Vegetative Anatomy. The indumentum is made up of simple, stellate and glandular hairs. The simple hairs are unicellular in Erblichia, Mathurina, Stapfiella and most Turnera, usually with thick walls, sometimes with ornamented cuticule. There are also microhairs in some species of Turnera (Arbo 2004), simple multicelullar hairs in Hyalocalyx, Streptopetalum, Tricliceras (Berger 1919) and in some species of Piriqueta, Turnera and Erblichia (in the latter, they are restricted to leaf axils). The stellate hairs are multicellular, tufted in Adenoa and a few Turnera, with a bulging foot in Loewia and some Piriqueta. The glandular hairs are stipitate-capitate in Turnera series Papilliferae and sessile-capitate in most Turnera series Annulares, Microphyllae and some Leiocarpae; microcapitate hairs are frequent in Piriqueta and several series of Turnera; clavate hairs are found in some species of Piriqueta and Turnera series Turnera; Piriqueta, Stapfiella, Streptopetalum, Tricliceras and Turnera collotricha have setiform glandular emergences/hairs with distinct swollen basis and very small head (Gonzalez and Arbo 2004). Leaf epidermis is uniseriate; in surface view, the cells may be polygonal or irregular with undulating walls, frequently containing tannins in Erblichia, Piriqueta and Turnera; stomata are often present on both surfaces or sometimes confined to the abaxial surface (Mathurina, Turnera spp.), and are anomocytic in Piriqueta and Turnera, paracytic in Streptopetalum and Tricliceras, and sometimes anisocytic. Mucilage cells are occasionally present. The mesophyll is generally dorsiventral, often with druses, isobilateral in some species of Turnera and Streptopetalum. Sieve-element plastids belong to the Ss type, containing only starch (Behnke 1991). The extrafloral nectaries are localised at the margins of the petiole or blade basis or, more rarely, on the lower leaf surface; they are discoid or cup-shaped and vascularized. The secretory tissue

Turneraceae

is a glandular parenchyma covered by a biseriate palisade epidermis; nectar secretion is transcuticular; in Turnera series Turnera, there is a secretory device which externally looks like a pore (Gonzalez 1996). Colleters are common; four types are recognized in Turnera and Piriqueta, based on their morphology (Gonzalez 1998). The glands along the margin of Adenoa petals seemingly are colleters. The primary stem is usually pilose and circular in cross section, exceptionally it is costate (Turnera trigona). The cortex consists of collenchyma, parenchyma, and sometimes fibre strands; its width varies considerably. The vascular bundles are collateral, open, and the interfascicular parenchyma is usually very narrow. The phloem strands usually have fibre caps, the sieve tubes have simple plates. The vessels are small, their perforations mostly simple. Sometimes there are vascular bundles in the cortex, leaf traces running upwards through the cortex. The pith is generally parenchymatous, sometimes containing sclereids. Crystals and tannin cells occur frequently, especially in the cortex and pith. Secondary growth develops from an annular vascular cambium, the cork cambium being more or less superficial (Berger 1919; Gonzalez 2000). Wood structure is known only in Erblichia, Piriqueta and Turnera. The vessels are very small to medium-sized, solitary or in 2–6-multiples, with spiral thickening or pitted and simple perforations. Parenchyma is apotracheal, sometimes scanty. Rays are heterogeneous and abundant. Libriform fibres have thick walls and minute bordered pits. Occasionally, crystals and starch grains are seen in parenchyma cells (Record and Hess 1943; Gonzalez 2000). Inflorescences and Flowers. Inflorescences are axillary or terminal; they are cymose in Stapfiella, Streptopetalum, Tricliceras and some species of Piriqueta and Turnera series Salicifoliae, and racemose in Turnera series Anomalae, Capitatae and some species of Leiocarpae; solitary flowers occur in Adenoa, Erblichia, Hyalocalyx, Loewia, Mathurina and most species of Piriqueta and Turnera. Epiphyllous flowers are found in Turnera series Turnera and Leiocarpae. The flowers are ephemeral and frequently showy. The sepals are nearly free in Erblichia and Mathurina, but connate into a tube in all other genera. The petals are clawed; the blade is yellow, sometimes red, orange, pink or white, now and

459

then with a basal purple spot, ligulate in Tricliceras. They are free in Erblichia and Mathurina, whereas the claw is adnate to the calyx and forms a short or lengthy floral tube in the other genera. In Hyalocalyx, the main bundles of the petals are connected with the lateral ones of the sepals. A corona is variously present, free in Mathurina and Erblichia, narrow, fringed and attached to the floral tube at the throat in Piriqueta (Fig. 161C). The staminal filaments are inserted at the base of the calyx or floral tube (Adenoa, Erblichia, Hyalocalyx, Piriqueta, Tricliceras and several series of Turnera: flowers hypogynous), or the filaments are adnate to the floral tube (Turnera series Turnera and Anomalae: flowers perigynous). These latter taxa have five nectariferous pockets, or the nectaries may be borne on the sepals (Mathurina and Stapfiella), on the floral tube (Streptopetalum, Tricliceras, Piriqueta and Turnera) or on the staminal filaments (Turnera). Floral Anatomy. A detailed study of the floral anatomy of Piriqueta and Turnera has been undertaken by Gonzalez (1993, 2000, 2001). The lateral bundles of the sepal lobes branch off the main bundles of the petals. There are also distinctive, common sepal-stamen traces. The corona of Piriqueta and the ligule on the petals of some species of Turnera are of similar structure, lacking vascularization. The glandular tissue of the nectaries includes the epidermis and the underlying parenchyma; nectar is secreted through anomocytic stomata. The anther wall is made up of epidermis, endothecium, middle layers and glandular tapetum. The gynoecium has a transmission tissue on the inner surface of the ovary and placentae, ascending within the stylodia and on the smooth stigmata. Reproductive Systems. Most species bloom in the morning and the flowers survive only a few hours. Adenoa, Erblichia and Mathurina are homostylous, the other genera mainly heterostylous. Most species have long- and short-styled flowers but some, for instance, Piriqueta morongii, Turnera macrophylla, T. sidoides, have long-, short- and homostylous flowers. Usually, homostyly is linked with self-compatibility and heterostyly with selfincompatibility (Shore and Barrett 1985). Some species of Loewia, Streptopetalum and Tricliceras, besides being heterostylous, have three long and two short stamens in the one flower, and sometimes in Streptopetalum there are stylodia of different length. Unfortunately, there is no information about compatibility in these genera.

460

M.M. Arbo

Embryology. This topic has been studied only in Turnera ulmifolia (Raju 1956) and T. subulata (Vijayaraghavan and Kaur 1967). Cytokinesis of microspore mother cells is of the simultaneous type, and tetrads are tetrahedral or decussate. Mature pollen grains are binucleate. The ovules are bitegmic, crassinucellar, and the micropyle is produced by both integuments and is zigzag. Embryo sac development is of the Polygonum type; polar nuclei are fused before fertilization; and the three antipodal cells are ephemeral. Endosperm development is Nuclear, and centripetal wall formation starts after the proembryo reaches the octant stage. Proembryo development follows the Onagrad type, and the embryo is straight. Pollen Morphology. Pollen is released in monads. The grains are isopolar, tricolporate, of medium size (23–53 µm), semitectate, reticulate, and NPC = 345 (Erdtman 1952; Melhem et al. 1971; Arbo 1979, 1995, 2004). In heterostylous species, the short-styled morph has the larger pollen grains. A reticulum with very small brochi is found in Piriqueta and Mathurina, and with wide brochi and free bacula in Erblichia. Both types are found in Turnera. Karyology. Only Piriqueta and Turnera are known cytologically. The former has the base number x = 7, while in Turnera there are three base numbers: x = 7, 5 and 13; ser. Salicifoliae, ser. Stenodictyae, ser. Microphyllae and ser. Leiocarpae have x = 7; the only species known with x = 13 is one of two members of ser. Papilliferae, while ser. Turnera (= Canaligerae) has x = 5 (Barrett 1978; Fernández 1987; Solís Neffa and Fernández 2000). There is no information about the other series. Polyploidy has played an important role in the evolution of both genera, in which there are diploid and polyploid taxa; some species have two or more cytotypes. The highest ploidy level recorded in Piriqueta is 6×, while in Turnera it is 10×. The latter genus includes autopolyploids (4×, 8×) and segmental allopolyploids with ploidy levels between 4× and 8×. Pollination. Pollination is mainly by bees, butterflies and wasps. Hummingbirds pollinate Erblichia odorata, and have been recorded also in Turnera panamensis (Augspurger 1983). Protomeliturga turnerae (Hymenoptera, Andrenidae) is a specialist bee, endemic to north-eastern Brazil,

which collects pollen and mates only in Turnera subulata (Medeiros and Schlindwein 2003). In the homostylous self-compatible species of Turnera ser. Turnera, self-pollination occurs when the flower withers and the petals curl and shrink together, pushing the anthers into full contact with the stigmas. Fruit and Seed. Capsules are usually globose or ovoid (linear in Tricliceras) and have a smooth, verrucose or tuberculate outer face; they are 3-valved with linear placentae up to the middle. Dehiscence is loculicidal and begins at the apex, except in Tricliceras where it starts laterally, below the beak. In Adenoa and some species of Turnera, the perianth is persistent and splits as the fruit ripens. One to 60 seeds are formed; they are straight in Mathurina and Tricliceras, and slightly or notably curved in the other genera. An exostome is usually distinct, the raphe is wide in Adenoa and Erblichia, filiform in the other genera, and the chalaza is obtuse, sometimes prominent and navel-like. The seed coat is striate in Adenoa, Erblichia, Mathurina and some Turnera, and is usually reticulate; the areoles have 0–2 pores, and the epidermis is smooth or papillose. An aril is always present; it is fleshy when fresh, membranous when dry, glabrous as a rule, exceptionally hairy (Turnera marmorata), and generally inserted around the hilum, on the basal segment of the raphe in T. blanchetiana (Gonzalez 2000) and Erblichia odorata. The aril of Mathurina penduliflora is unique – it is divided into very long and thin filaments. Some seeds are so distinctive that they allow the recognition of the species. Thus, the seeds of Piriqueta racemosa with conical knobs and punctiform depressions, the curved, reticulate seeds of Turnera pumila with their prominent chalaza, and the crested seeds of T. sidoides are unique. Seed coat anatomy in Streptopetalum, Tricliceras, Erblichia, Piriqueta and Turnera was studied by Berger (1919), and many species of the last two genera were thoroughly analyzed by Gonzalez (2000). Both integuments participate in the composition of the seed coat, and they are not multiplicative. Sclereids in the outer layer of the inner integument provide mechanical strength (exotegmic seeds). In most species, the seed coat pattern is determined by the relative size and arrangement of the exotegmen sclereids and the endotesta cells. In the crested seeds of Turnera sidoides, the seed coat pattern is developed by the exotesta. Germination is phanerocotylar.

Turneraceae

Dispersal and Biotic Interactions. The seeds of Mathurina are wind-dispersed; the flying device is the aril, which is not fleshy but split up into slender long filaments. The nectar secreted by the extrafloral nectaries of Turnera attracts ants of several genera which, in turn, aid in seed dispersal. Ants carry the seeds to their nests, where they eat the arils. Species of Turneraceae are the main hosts of larvae –caterpillars – of several genera of Nymphalidae butterflies. In Africa, many species of Acraea feed preferentially on Tricliceras, some Passifloraceae and Salicaceae (Clausen et al. 2002); certain species feed also on other plants, but the main host of Acraea asema is Tricliceras; in America, Eueides procula feeds on Erblichia odorata (Robinson et al. 2004). In Mexico and the Antilles, Euptoieta hegesia, the ‘Mexican fritillary’, uses Turnera velutina and T. ulmifolia as main hosts, and some species of Passiflora and Hybanthus as secondary host plants. Predation by ants on eggs or larvae of E. hegesia has not been observed, but ant-attended plants show a decrease in herbivory and have higher reproductive fitness; wasps (Polistes and Polybia) also have a positive effect on reproductive success (Schappert and Shore 1995, 2000; Cuautle and Rico-Gray 2003). There is also a synergistic interaction between ant defence and cyanogenesis: plants which are highly cyanogenic and ant-defended have higher reproductive fitness (Pratt and Schappert 2004). Some Curculionid beetles deposit their eggs in the ovary of several species of Turnera, in which the larva feeds on the developing seeds, the adult emerging when the fruit dehisces. Phytochemistry. Cyanogenesis has been detected in all genera except Hyalocalyx, and Adenoa which has not been tested; major cyclopentenoid cyanogenic glycosides found are cyclopentenilglycine, deidaclin, epitetraphyllin B, epivolkenin, linamarin, taraktophyllin, tetraphyllin A and B, and volkenin (Spencer et al. 1985; Olafsdottir et al. 1990; Shore and Obrist 1992; Wellendorph et al. 2001). Cyanogenic glycosides are considered as a plant defence system against some herbivores. Cyanogenesis in T. ulmifolia is strongly heteromorphic (Schappert and Shore 1995, 2000). Nymphalid butterflies are not inhibited by cyanogenesis but rather seem to be attracted (Clausen et al. 2002). Euptoieta hegesia apparently sequesters the cyanogenic glycoside for its own chemical defence against its predator, the lizard Anolis (Schappert and Shore 1999). Among the essential oils of

461

Turnera diffusa, 54 components have been characterized and identified, the most abundant being 1,8-cineol (11.4%), opoplenone (10.3%), cadalene (5.1%), and epi-cubenol (4.1%; Bicchi et al. 2003). A few species of Piriqueta, Turnera and Tricliceras have been tested for flavonoids, and luteolin, quercetin and unidentified flavonols found (Harborne 1975). Affinities. The genera of Turneraceae are welldifferentiated and there is little doubt about their delimitation. Turneraceae, placed in Violales by Cronquist (1988) and Dahlgren (1980), have long been recognized as close relatives of Passifloraceae and Malesherbiaceae, and these share many morphological and anatomical traits such as a palisade exotegmen, a tube formed by the calyx and corolla, and the transmission of plastids by the male gametes (the latter, however, not known from Malesherbiaceae). More recently, the presence of secondary metabolites has underlined the connections with other families such as Salicaceae. However, Hutchinson (1973) included Turneraceae in Loasales (now in asterids). Based on numerous recent gene sequence analyses (e.g. Chase et al. 2002), the close relationship among Turneraceae, Malesherbiaceae and Passifloraceae has been confirmed. These families form the Passifloraceae clade, which is now placed in Malpighiales (APG II 2003). Distribution and Ecology. Loewia, Stapfiella, Streptopetalum and Tricliceras are confined to Africa, Hyalocalyx occurs in Africa and Madagascar, and Mathurina is endemic to Rodrigues Island (Mascarenes). Erblichia has one New World species, E. odorata, and four in Madagascar. Adenoa is endemic to Cuba where it grows in serpentine soils. Piriqueta has 44 species in America and one in Africa. Turnera has around 120 species in America and two in Africa. Brazil holds the top number of species, the highest number of endemics being found in the mountains of the states of Bahia, Goiás and Minas Gerais. Even though the majority of species are found in the tropics between sea level and 2,600 m elevation, Piriqueta cistoides subsp. caroliniana extends close to 33◦ N in the United States and P. taubatensis and Turnera sidoides reach 40◦ S in temperate Argentina. Both in Africa and America, Turneraceae dwell in a variety of habitats, from grasslands and dry sandy places to open woodlands and tropical rain-

462

M.M. Arbo

forest. Erblichia odorata and the Amazonian species of Turnera live in lowland forest, while the latter genus is particularly well-diversified in Brazilian ‘cerrado’ and ‘caatinga’ and at higher elevations in ‘campo rupestre’ and ‘campos gerais’. Economic Importance and Applications. Turnera subulata, a common tropical weed, is used as an ornamental in southern Brazil. There are species, such as Turnera panamensis and Turnera bahiensis with showy, abundant flowers, which would merit usage in tropical horticulture. Erblichia odorata is a beautiful tree sometimes cultivated in Mesoamerica as an ornamental; its wood has been used for railroad sleepers and in general construction. An infusion made with the leaves of Turnera diffusa is widely used in the traditional Mexican medicine as an anti-cough, diuretic and aphrodisiac agent; it has antibacterial activity against the most common gastrointestinal diseases afflicting local populations (Hernández et al. 2003). Anti-ulcerogenic properties and antiinflammatory activity have been demonstrated in species of the Turnera ulmifolia complex (Gracioso et al. 2002; Okoli et al. 2003).

Key to the Genera 1. Sepals free or almost so; petals free; corona present (except in Erblichia odorata with ligulate petals) 2 – Lower part of the sepals coherent into a calyx tube; petal claws adnate to the calyx developing a floral tube; corona absent except in Piriqueta 3 2. Flowers erect; aril fleshy; zoochorous 2. Erblichia – Flowers pendulous; aril divided in filiform filaments; anemochorous 1. Mathurina 3. Flowers small (2–7 mm long), arranged in axillary or terminal thyrses; fruit one-seeded; Africa 3. Stapfiella – Flowers small to large, solitary or arranged in other inflorescences; fruit usually several-seeded; America or Africa 4 4. Calyx tube with more than 10 veins; Africa 5 – Calyx tube 10-veined; mostly America 8 5. Shrubs or trees; flowers 2.5 cm long, solitary; fruit several-seeded 4. Loewia – Herbs 6 6. Flowers small, 4–5 mm long, solitary; leaves up to 4 cm long 6. Hyalocalyx – Flowers 1–4 cm long, usually arranged in racemiform cymes (cincinni); leaves up to 20 cm long 7 7. Petals ligulate; fruit linear or narrowly ellipsoid (siliquiform); dehiscence loculicidal, not starting at apex; seeds straight, in linear arrangement 5. Tricliceras – Petals eligulate; fruit ovoid, short, dehiscing from apex downwards; seeds curved, not in linear arrangement 7. Streptopetalum

8. Hairs stellate; petals provided with minute glands all along the margin 8. Adenoa – Hairs porrect-stellate or simple (stellate in some Turnera); petals without glands along the margin 9 9. Peduncle of inflorescence free; corona present; hairs porrect-stellate (except P. capensis with simple hairs, and some glabrous specimens of P. cistoides); leaves very seldom with nectarines 9. Piriqueta – Peduncle free or adnate to the petiole (flowers epiphyllous); corona 0, exceptionally petals ligulate; hairs simple, sometimes stellate; leaves often with nectarines 10. Turnera

Genera of Turneraceae 1. Mathurina Balf. f. Mathurina Balf. f., J. Linn. Soc., Bot. 15:159 (1876); Urban, Jahrb. Königl. Bot. Gart. Berlin 2:80–81 (1883).

Tree 4–12 m high, heterophyllous; hairs simple. Leaves almost glabrous; petiole with extrafloral nectaries; juvenile blade linear, crenulato-serrate, adult blade angusti-obovate, apex acute; stipules subulate, deciduous. Flowers pendent, homostylous, in 3-flowered cymes or solitary; peduncle with 2 elliptic prophylls, pedicel articulated; calyx 2–2.8 cm long; sepals free, 3-veined, mucronate, with a prominent inner basal nectary; petals white, acuminate; stamen filaments adnate at base to nectaries; anthers basifixed, obtuse; stylodia filiform, divergent at base; stigmas faintly lobate. Fruit pendent, dehiscent to base. Seeds straight, chalaza rounded, not prominent, episperm striate; aril dissected in slender filaments much longer than seed, anemochorous. Only one species, M. penduliflora Balf. f., Mascarenes (Rodrigues Island). 2. Erblichia Seem. Erblichia Seem., Bot. Voy. Herald t. 27 (1853); id.: 130 (1854); Arbo, Adansonia II, 18:459–482 (1979), rev.

Shrubs or trees to 27 m high; hairs simple, unicellular, in leaf axils also multicellular. Leaves usually petiolate, obovate or elliptic, glabrous or scattered pilose, with extrafloral nectaries on the margin; stipules sometimes up to 3-pinnate. Flowers solitary, homostylous; peduncle1 free, prophylls 2; pedicel articulate; calyx 0.5–6 cm long, sepals almost free; petals yellow to red-orange; corona annular, lacking in E. odorata which has 1

M.M. Arbo prefers, in the tradition of Urban (1883), to denominate the portion of the pedicel beneath the prohylls (the hypopodium) as ‘peduncle’ and restricting the term ‘pedicel’ to the portion above the prophylls (the epipodium), which is followed here in order to facilitate the usage of Arbo’s revisions. K. Kubitzki.

Turneraceae

ligulate petals; staminal filaments free; anthers basifixed, apiculate except in E. integrifolia; stylodia ± divergent at base; stigmas faintly lobate-penicillate. Fruit upright, usually granulate; seeds slightly curved, chalaza rounded; episperm striate-scrobiculate; aril unilateral or surrounding the seed, membranous when dry, oily and orange in E. odorata. Five species, four in Madagascar, E. odorata Seem. in Mesoamerica. 3. Stapfiella Gilg Stapfiella Gilg, Deutsche Zentral-Afrika Exped. Wissensch. Ergebn. 1907–1908, 2 (Bot.): 571 (1913); Lewis, Kew Bull.: 282 (1953).

Shrubs to 3 m high; hairs simple, sometimes glandular with swollen bases. Leaves petiolate, elliptic, pubescent, often glandular-punctate, with extrafloral nectaries on the basal teeth; stipules very short. Flowers in axillary or terminal thyrses; peduncle free; prophylls reduced and alternate; pedicel articulate; calyx 2–5 mm long; sepals briefly coherent, each with a distinct basal nectary; petals 2–7 mm long, white or yellow, claw adnate to the calyx tube; staminal filaments briefly adnate to nectaries; anthers basifixed; stylodia connivent; stigmas faintly lobate. Fruit dehiscing from apex. Seed 1(2), straight, concave, chalaza somewhat prominent; episperm striate-reticulate, areoles minute, trans-rectangular; aril short, of smooth cells, membranous when dry. Six species, tropical Africa. 4. Loewia Urb. Loewia Urb., Ann. Reale Ist. Bot. Roma 6:189 (1897); Rotti Michelozzi G., Webbia 23:365–378 (1969).

Shrubs with serial buds; hairs simple, unicellular and stellate. Leaves usually petiolate, without extrafloral nectaries, glabrous or pubescent, often glandular-punctate; stipules very small. Flowers solitary, heterostylous; peduncle free or 0; prophylls 2, pedicel very short or 0; calyx 12–20 mm long; sepals coherent beyond the middle; petals yellow or orange, the claw adnate to calyx, up to throat forming a pluriveined floral tube; nectaries usually 0; staminal filaments briefly adnate to floral tube, all equal or 3 longer and 2 shorter; anthers basifixed; stylodia connivent; stigmas faintly lobate. Fruit smooth or slightly verrucose. Seeds numerous, somewhat curved; chalaza rather prominent, concave; episperm reticulate, areoles with 2 pores; aril short, made of papillose cells, membra-

463

nous when dry. Three species, East Africa: Ethiopia, Kenya and Somalia. 5. Tricliceras Thonn. ex DC. Tricliceras Thonn. ex DC., Pl. Rar. Jard. Bot. Genève: 56 (1826); Fernandes, Bol. Soc. Brot. II, 49:13–27 (1975). Wormskioldia Thonn. in Schumach. & Thonn. (1827).

Annual or perennial herbs, sometimes acaulescent, with serial buds; hairs simple and pluricellularglandular-setiform with swollen base. Leaves petiolate or sessile, sometimes heteromorphic, occasionally pinnatilobed to bi-pinnatisect, margin bi– tri-serrate, rarely with nectaries; stipules reduced or 0. Flowers homostylous or heterostylous, in axillary cincinni; peduncles often longer than subtending leaves; prophylls 2(1); pedicels often accrescent and reflexed in fruit; calyx 1–2 cm long; sepals coherent beyond the middle, petals yellow to scarlet, rarely white, with a small ligule at the main vein base, claw adnate to calyx, forming a 15veined floral tube with nectaries above stamen insertion; stamens usually 3 long, 2 short; anthers basifixed; stylodia connivent, equally long; stigmas faintly lobed. Fruit siliquiform, obtuse rostrate, sometimes constricted; seeds numerous, in one string, obovoid, usually straight; chalaza prominent and concave; episperm reticulate, areoles 2porate; aril unilateral, cells smooth. Sixteen species, central and southern Africa. 6. Hyalocalyx Rolfe Hyalocalyx Rolfe, J. Linn. Soc., Bot. 21:257–258 (1884); Fernandes in Fl. Zambes. 4:353–354 (1978).

Annual herb up to 30 cm; hairs simple, pluricellular; stem branched, rarely simple. Leaves petiolate, without nectaries; blade distally serrate; stipules reduced. Flowers solitary, heterostylous; peduncle 0.5–1.5 mm long, setose; prophylls 2, 0.3 mm long; pedicel short, setose; sepals 2–2.5 mm long., connate beyond the middle, apically setose, forming a 15-veined calyx tube; petals yellow, claw adnate to calyx base (0.2 mm); staminal filaments adnate to floral tube, 0.1 mm; anthers very short; stylodia connivent; stigmas penicillate. Fruit subgloboseellipsoid, smooth, 3–10-seeded, pendent; pedicel accrescent and reflexed. Seeds obovoid, curved, 1–1.5 mm long, blackish; chalaza rounded; episperm reticulate, areoles 2-porate; aril unilateral, cells smooth, membranous when dry. One species, H. setiferus Rolfe, Madagascar and south-eastern Africa.

464

M.M. Arbo

7. Streptopetalum Hochst. Streptopetalum Hochst., Flora 24:665 (1841); Lewis, Turneraceae in Fl. Trop. E. Afr.: 1–19 (1954); Fernandes in Fl. Zambes. 4:365–368 (1978).

Annual or perennial herbs, with serial buds, simple hairs and glandular setiform emergences/hairs with swollen base; stems 1–many. Leaves petiolate or sessile, sometimes heteromorphic, without nectaries, entire, serrate, pinnatifid or pinnatilobed; stipules reduced. Axillary cincinni. Flowers homostylous or heterostylous; peduncles usually longer than subtending leaves; prophylls 2(–0), small, alternate; pedicels sometimes accrescent; calyx 1–2 cm long; sepals 3-veined, coherent beyond the middle; petals yellow or orange, the claws adnate to calyx up to throat, together forming the floral tube; stamens with the basal portion adnate to floral tube, with nectaries at the insertion, equally long or two shorter; anthers nearly basifixed; stylodia connivent, equally long or one shorter; stigma faintly lobed. Fruit obtuse rostrate, setiferous. Seeds numerous, curved, chalaza prominent and concave, exostome distinct; episperm reticulate, areoles 2-porate; aril unilateral, cells papillose. Six species, east tropical and southern Africa.

glandular-setiform with swollen basis. Leaves petiolate or sessile, rarely with nectaries; stipules reduced or 0. Flowers mostly heterostylous, axillary and solitary, sometimes in cincinni, rarely in a terminal raceme; peduncle free; prophylls inconspicuous; pedicel articulate; calyx 4–28 mm long; sepals 20–50% connate; petals yellow, salmon or pink, rarely red-orange or white, sometimes with a basal purple spot, the claw adnate to calyx which forms a 10-veined floral tube; corona annular, fimbriate-lacerate, inserted at the throat on sepals and petals; stamens shortly adnate to floral

8. Adenoa Arbo Adenoa Arbo, Hickenia 1, 16:89 (1977).

Shrub to 3 m high, velvety ferruginous; hairs stellate. Leaves petiolate, coriaceous, above with scattered hairs, beneath velvety with prominent reticulate venation; stipules 0. Flowers axillary, solitary, homostylous; peduncle free, prophylls 2, pedicel short; calyx 2–3 cm long, sepals 1/3 connate; calyx tube 10-veined; petals white, elliptic, with minute glands (seemingly colleters) all along the margin; stamens free, filiform, glabrous; anthers dorsifixed; stylodia filiform, slightly divergent at base; stigmas faintly lobate. Fruit dressed with persistent, tearing perianth. Seeds slightly curved, chalaza rounded, not prominent; episperm striate; aril unilateral, short, membranous when dry. Only one species, A. cubensis (Britton & Wilson) Arbo, restricted to southeast Cuba and known as a nickel hyperaccumulator (Reeves et al. 1999). 9. Piriqueta Aubl.

Fig. 161

Piriqueta Aubl., Hist. Pl. Guiane 1:298, pl. 117 (1775); Arbo, Fl. Neotrop. Monogr. 67 (1995).

Herbs, subshrubs or shrubs, sometimes with serial buds; hairs porrect-stellate and simple and often

Fig. 161. Turneraceae. Piriqueta sidifolia var. multiflora. A Habit. B Two calyx lobes with stellate trichomes. C Petals, corona, scars of removed stamens (cross-hatched) and, partly covered, sepals. D Stamens. E Ovary with stylodia. F Arillate seed. (Arbo 1995)

Turneraceae

tube, often with nectaries; anthers dorsifixed; stylodia connivent; stigma usually penicillate. Fruit granulate/tuberculate, sometimes smooth. Seeds numerous, curved, occasionally straight; chalaza obtuse (except in P. capensis); episperm reticulate (knotty in P. racemosa), areoles 0–1(–2)-porate; aril seldom surrounding, cells smooth or papillose. Forty-four species in America and one, P. capensis (Harv.) Urb., in South Africa. 10. Turnera L. Turnera L., Sp. Pl. 1:271 (1753); Arbo, Bonplandia 9:151–208 (1997), 10:1–82 (2000), rev.

Perennial herbs or shrubs, rarely trees, often with serial buds; hairs simple, rarely stellate; glandular hairs frequent. Leaves usually petiolate, often with nectaries, rarely pinnatisect; stipules very small or well-developed, sometimes adnate to foliar base. Inflorescences axillary cincinni or dichasia, or sometimes racemes, but mostly reduced to solitary flowers. Flowers mostly heterostylous; peduncle free or flowers epiphyllous; prophylls persistent, sometimes foliaceous; pedicel mostly 0; calyx 2–39 mm long, sepals more or less connate; petals yellow, white, salmon, pink, orange or red, often with a dark basal spot, exceptionally ligulate, the claw adnate to calyx forming a 10-veined floral tube; stamens shortly attached at base or adnate along margins to floral tube beyond its middle forming nectar-pockets; anthers dorsifixed or basifixed; stylodia connivent; stigmas usually penicillate. Fruit smooth, granulate or tuberculate. Seeds usually numerous and curved; chalaza obtuse or prominent and concave; episperm striate or reticulate, areoles 0–1-porate; aril with smooth or papillate cells, inserted around hilum (along basis of raphe in T. blanchetiana). About 120 species in America and two in Africa, T. thomasii (Kenya) and T. oculata (Angola and Namibia). Urban (1883) divided Turnera into nine series; I am referring to these entities until my revision of the genus, now underway (Arbo 1997, 2000, 2004), is completed, which may lead to a novel classification. Our phylogenetic studies of the genus (Arbo 2004; Truyens et al. 2005) indicate that the genus is monophyletic.

Selected Bibliography APG II 2003. See general references.

465

Arbo, M.M. 1979. Revisión del género Erblichia (Turneraceae). Adansonia II, 18:459–482. Arbo, M.M. 1995. Turneraceae Parte I. Piriqueta. Flora Neotropica Monogr. 67. New York: New York Botanical Garden. Arbo, M.M. 1997. Estudios sistemáticos en Turnera (Turneraceae). I. Series Salicifoliae y Stenodictyae. Bonplandia 9:151–208. Arbo, M.M. 2000. Estudios sistemáticos en Turnera (Turneraceae). II. Series Annulares, Capitatae, Microphyllae y Papilliferae. Bonplandia 10:1–82. Arbo, M.M. 2004. Revisión taxonómica de las especies de Turnera de las series Anomalae y Turnera. Tesis Doctoral, Universidad Nacional del Nordeste, Corrientes, Argentina. Augspurger, C.K. 1983. Phenology, flowering synchrony and fruit set of six neotropical shrubs. Biotropica 15:257– 267. Barrett, S.C.H. 1978. Heterostyly in a tropical weed: the reproductive biology of the Turnera ulmifolia complex (Turneraceae). Canad. J. Bot. 56:1713–1725. Behnke, H.-D. 1991. See general references. Berger, M.G. 1919. Étude organographique, anatomique et pharmacologique de la famille des Turneracées. Thèse, Faculté de Médécine et de Pharmacie, Université de Lille. Bicchi, C., Rubiolo, P., Camargo, E.E.S., Vilegas, W., Gracioso, J. de, S., Brito, A.R.M.S. 2003. Components of Turnera diffusa Willd. var. afrodisiaca (Ward) Urb. essential oil. Flavours Fragrances J. 18:59–61. Chase, M.W. et al. 2002. See general references. Clausen, V., Frydenvang, K., Koopmann, R., Jørgensen, L.B., Abbiw, D.K., Ekpe, P., Jaroszewski, J.W. 2002. Plant analysis by butterflies: occurrence of cyclopentenylglycines in Passifloraceae, Flacourtiaceae and Turneraceae and discovery of the novel nonproteinogenic amino acid 2-(3 -cyclopentenyl)glycine in Rinorea. J. Nat. Prod. 65:542–547. Cronquist, A. 1988. See general references. Cuautle, M., Rico-Gray, V. 2003. The effects of wasps and ants on the reproductive success of the floral nectaried plant Turnera ulmifolia (Turneraceae). Funct. Ecol. 17:417– 423. Dahlgren, R.M.T. 1980. A revised sytem of classification of the angiosperms. Bot. J. Linn. Soc. 80:91–124. Erdtman, G. 1952. See general references. Fernández, A. 1987. Estudios cromosómicos en Turnera y Piriqueta (Turneraceae). Bonplandia 6:1–21. Gonzalez, A.M. 1993. Anatomía y vascularización floral de Piriqueta racemosa, Turnera hassleriana y Turnera joelii (Turneraceae). Bonplandia 7:143–184. Gonzalez, A.M. 1996. Nectarios extraflorales en Turnera, series Canaligerae y Leiocarpae. Bonplandia 9:129–143. Gonzalez, A.M. 1998. Colleters in Turnera and Piriqueta. Bot. J. Linn. Soc. 128:215–228. Gonzalez, A.M. 2000. Estudios anatómicos en los géneros Piriqueta y Turnera (Turneraceae). Tesis Doctoral, Universidad Nacional de Córdoba, Argentina. Gonzalez, A.M. 2001. Nectarios y vascularización floral de Piriqueta y Turnera (Turneraceae). Bol. Soc. Argent. Bot. 36:47–68. Gonzalez, A.M., Arbo, M.M. 2004. Trichome complement of Turnera and Piriqueta (Turneraceae). Bot. J. Linn. Soc. 144:85–97.

466

M.M. Arbo

Gracioso, J. de, S., Vilegas, W., Hiruma-Lima, C.A., Souza Brito, A.R.M. 2002. Effects of tea from Turnera ulmifolia L. on mouse gastric mucosa support the Turneraceae as a new source of antiulcerogenic drugs. Biol. Pharmceut. Bull. 25:487–491. Harborne, J.B. 1975. Flavonoid bisulphates and their cooccurrences with ellagic acid in the Bixaceae, Frankeniaceae and related families. Phytochemistry 14:1331– 1117. Hernández, T., Canales, M., Avila, J.G., Duran, A., Caballero, J., Romo de Vivar, A., Lira, R. 2003. Ethnobotany and antibacterial activity of some plants used in traditional medicine of Zapotitlán de las Salinas, Puebla (México). J. Ethnopharmacol. 88:181–188. Hutchinson, J. 1973. The families of flowering plants, 3rd edn. Oxford: Clarendon Press. Kloos, A., Bouman, F. 1980. Case studies in aril development. Passiflora suberosa L. and Turnera ulmifolia L. Beitr. Biol. Pflanzen 55:49–66. Medeiros, P.C.R. de, Schlindwein, C. 2003. Territórios de machos, acasalamento, distribuição e relação com plantas em Protomeliturga turnerae (Ducke, 1907) (Hymenoptera, Andrenidae). Revista Brasil. Entomol. 47:589–596. Melhem, T.S., Moura, C.A.F., Lieu, J. 1971. Pollen grains of plants of the “Cerrado” – Styracaceae and Turneraceae. Hoehnea 1:153–178. Obermeyer, A.A. 1976. Turneraceae. In: Ross, J.H. (ed.) Flora of Southern Africa 22:93–103. Pretoria: Botanical Research Institute. Okoli, C.O., Akah, P.A., Nwafor, S.V. 2003. Anti-inflammatory activity of plants. J. Nat. Remedies 3:1–30. Olafsdottir, E.S., Jaroszewski, J.W., Arbo, M.M. 1990. Cyanohydrin glucosides of Turneraceae. Biochem. Syst. Ecol. 18:435–438. Pratt, S., Schappert, P.J. 2004. Ant defense of Turnera ulmifolia. In: Abstract Volume 55th Annual Meeting of the Lepidopterists’ Society, 15–18 July 2004, University of Maryland, College Park, MD. Raju, M.V.S. 1956. Development of embryo and seed coat in Turnera ulmifolia L. var. angustifolia Willd. Bot. Notiser 109:308–312. Record, S.J., Hess, R.W. 1943. Timbers of the New World. New Haven: Yale University Press. Reeves, R.D., Baker, A.J.M., Borhidi, A., Berazaín, R. 1999. Nickel hyperaccumulation in the serpentine flora of Cuba. Ann. Bot. (London) 83:29–38.

Robinson, G.S., Ackery, P.R., Kitching, I.J., Beccaloni, G.W., Hernández, L.M. 2004. Hosts – a database of the hostplants of the world’s Lepidoptera. http://www.nhm.ac.uk/entomology/hostplants/ Schappert, P.J., Shore, J.S. 1995. Cyanogenesis in Turnera ulmifolia L. (Turneraceae). I. Phenotypic distribution and genetic variation for cyanogenesis on Jamaica. Heredity 74:392–404. Schappert, P.J., Shore, J.S. 1999. Effects of cyanogenesis polymorphism in Turnera ulmifolia on Euptoieta hegesia and potential Anolis predators. J. Chem. Ecol. 25:1455–1479. Schappert, P.J., Shore, J.S. 2000. Cyanogenesis in Turnera ulmifolia L. (Turneraceae): II. Developmental expression, heritability and cost of cyanogenesis. Evol. Ecol. Res. 2:337–352. Shore, J.S., Barrett, S.C.H. 1985. Morphological differentiation and crossability among populations of the Turnera ulmifolia complex (Turneraceae). Syst. Bot. 10:308–321. Shore, J.S., Obrist, C.M. 1992. Variation in cyanogenesis within and among populations and species of Turnera series Canaligerae (Turneraceae). Biochem. Syst. Ecol. 20:9–18. Shore, J.M., McQueen, K.L., Little, S.L. 1994. Inhertitance of plastid DNA in the Turnera ulmifolia complex. Amer. J. Bot. 81:1636–1639. Solís Neffa, V.G., Fernández, A. 2000. Chromosome studies in Turnera (Turneraceae). Gen. Mol. Biol. 23:925– 930. Spencer, K.C., Seigler, D.S., Fraley, S.W. 1985. Cyanogenic glycosides of the Turneraceae. Biochem. Syst. Ecol. 13:433–435. Truyens, S., Arbo, M.M., Shore, J.S. 2005. Phylogenetic relationships, chromosome and breeding system evolution in Turnera (Turneraceae): inferences from ITS sequence data. Amer. J. Bot. 92:1749–1758. Urban, I. 1883. Monographie der Familie der Turneraceen. Jahrb. Königl. Bot. Gart. Berlin 2:1–152. Vijayaraghavan, M.R., Kaur, D. 1967. Morphology and embryology of Turnera ulmifolia L. and affinities of the family Turneraceae. Phytomorphology 16:539–553. Wellendorph, P., Clausen, V., Jørgensen, L.B., Jaroszewski, J.W. 2001. Cyclopentanoids of Mathurina penduliflora. Biochem. Syst. Ecol. 29:649–651.

Vitaceae Vitaceae Juss., Gen. Pl.: 267 (1789), nom. cons.

J. Wen

Hermaphroditic or polygamo-monoecious to polygamo-dioecious woody climbers or vines, rarely small succulent trees; stems unarmed, with conspicuous lenticels, or the bark sometimes shredding (in most species of Vitis), branches often swollen at the 3–7-lacunar nodes, pith continuous or interrupted by diaphragms at nodes; tendrils simple, bifid, or 2–3-, or 4–12-branched (in Parthenocissus), usually leaf-opposite, rarely tendrils 0; raphide sacs present in the parenchymatous tissues. Leaves simple, lobed or unlobed, digitately or pedately compound to 1–3-pinnately compound, alternate, distichous, variously toothed, commonly with multicellular, stalked, caducous spherical structures known as “pearl” glands; stipules 2 or rarely 0, often caducous. Inflorescences in panicles, corymbs, or rarely spikes, often leaf-opposed, pseudo-terminal, or axillary (in Cayratia and Tetrastigma). Flowers small, pedicellate, with prophylls, actinomorphic, hypogynous, 4–5(–7)-merous; calyx of 4–5(–7) small teeth or lobes or a continuous ring; petals valvate, 4–5(–7), free or basally connate, or distally connate to form a calyptra (e.g., in Vitis); stamens 4–5(–7), antepetalous, anthers tetrasporangiate or rarely bisporangiate, introrse, dehiscing longitudinally; floral disk intrastaminal, ring-shaped, cupular, or gland-shaped; ovary superior, 2-locular, with a simple style, the stigma discoid or capitate, rarely (Tetrastigma) 4-lobed, non-papillate; ovules 2 per locule, axile, appearing nearly basal, apotropous or anatropous, bitegmic and crassinucellar. Fruit a berry, 1–4-seeded; seeds endotestal with an abaxial chalazal knot and an adaxial raphe with 2 furrows one on each side; the embryo small and straight; endosperm oily and proteinaceous, copious, ruminate. A pantropical family of 14 genera and about 750 species, with a few members in north temperate regions; nine genera in East and Southeast Asia. Vegetative Morphology. Vitaceae are usually woody climbers or herbaceous vines (often in

Cayratia), or small succulent trees (e.g., in some Cissus and Cyphostemma). They have generally leaf-opposite tendrils, which are considered to be modified shoots or inflorescences (Tucker and Hoefert 1968; Gerrath et al. 2001). In Parthenocissus and Vitis, a portion of the primordium may be induced to form flowers, with the remainder developing as a tendril arm (Millington 1966; Boss and Thomas 2002). Tendrils sometimes bear adhesive suckers (as in Parthenocissus, some young vegetative Cissus, and Tetrastigma obtectum), enabling the plants to climb up tree trunks, rocks, and cliffs. The branching patterns of the tendrils vary greatly from 2-furcate or 2–3branched to 4–12-branched (as in Parthenocissus) or unbranched. Most species of the family have an interrupted tendril pattern, in which tendrils are at two nodes in a three-node sequence. Cissus alata exhibits tendrils at each node. The distribution of the various tendril patterns in Vitaceae needs to be examined. The phyllotaxis of Vitaceae is unusual because the shoot apex produces both leaf primordia and “uncommitted” primordia (Lacroix and Posluszny 1989a). The latter may develop into either tendrils or inflorescences, but at initiation of the uncommitted primordia there is no structural evidence on their fate (Posluszny and Gerrath 1986). Stem growth is monopodial (e.g., in Ampelopsis brevipedunculata, Tetrastigma voinerianum) or sympodial, or sometimes appearing dichasial (e.g., in Rhoicissus rhomboidea; Suessenguth 1953a). The sympodial condition was considered to be the basal character state of the family (Gerrath et al. 1998). Gerrath et al. (2001) proposed five basic patterns in shoot architecture (Fig. 162). Pattern 1 is characterized by spiral phyllotaxis, a lack of tendrils, and presence of terminal inflorescences (e.g., some Cyphostemma that are not lianas). Patterns 2–5 are found in lianas, and have distichous phyllotaxis. Pattern 2 has interrupted tendrils and axillary buds at the one tendril-less node in the three-node se-

468

J. Wen

Posluszny 1989b; Gerrath et al. 1998). Domatia are sometimes present as tufts of hairs or pits.

Fig. 162. Vitaceae. Shoot architectural patterns. (Gerrath et al. 2001)

quence (e.g., Cissus antactica and Parthenocissus trifoliata). Pattern 3 has interrupted tendrils and axillary buds at two of three nodes, the upper tendril node and tendril-less node (e.g., Parthenocissus inserta). Pattern 4 is characterized by interrupted tendrils and continuous axillary buds (e.g., Vitis riparia and V. vinifera). Pattern 5 has continuous tendrils and continuous axillary buds (e.g., Cissus alata). Leaf form varies greatly in the family, with simple or compound leaves. Compound leaves can be palmate, 1–3-pinnate, or ternate. Simple leaves are often palmately divided. Both palmate (usually) and pinnate venations occur in the family. Heterophylly is common in many taxa (Critchfield 1970; Gerrath and Posluszny 1989a; Gerrath et al. 2004). The KNOTTEDI-like homeobox (KNOXI) genes regulate the development of the leaf from the shoot apical meristem, and may regulate leaf architecture. In Vitis, simple leaves are developed from complex primordia through secondary morphogenesis. This developmental pattern is similar to that in Cissus congestum, which has trifoliate leaves (Bharathan et al. 2002). The simple leaves in Vitaceae may thus well represent a derived character state, although the evolution of leaf form in Vitaceae is still poorly understood. In several members, the stipules develop before the associated leaf blade and function as protective structures enclosing the rest of the shoot tip (Shah 1959; Lacroix and

Vegetative Anatomy. Leaves in Vitaceae commonly bear “pearl” glands. These glands are usually spherical structures, each with a short stalk. Inside the gland are large polygonal cells surrounded by epidermal cells with a stoma usually situated opposite the stalk. Walter (1921) found evidence for the appearance of pearl glands in Vitis and Parthenocissus under increased cell sap concentration. The mesophyll contains calcium oxalate crystals and mucilage cells, often with raphides in bundles of several hundreds per cell (Metcalfe and Chalk 1950; Arnott and Webb 2000). Raphide sacs usually have mucilage as well as crystals. Raphides also give fruits of many Vitaceae species an acrid and stinging taste, and can be irritating to tongue and mouth. Sometimes mucilage cells are present. Vitaceae usually have 5–7 leaf traces, although variability (e.g., 3, 4 and 8) has been documented. Leaf epidermal characters have been studied by Ren et al. (2003). They found anomocytic stomata in Ampelocissus, Ampelopsis, Parthenocissus, Vitis, and Yua, whereas Cayratia, Cissus, Rhoicissus, and Tetrastigma possess staurocytic, hemiparacytic or cyclocytic stomata. Yua is distinguished from other genera by its papillate leaf cuticle, whereas the pattern in other genera is striate, scaly or granular. Wood of Vitaceae has exclusively simple perforation plates, large rays, vessel-ray parenchyma pits with reduced borders, storied imperforate elements, scanty paratracheal parenchyma, and septate fibers (Adkinson 1913; Wheeler and LaPasha 1994; Poole and Wilkinson 2000). Vessels are large in comparison with those in the close relatives in Leeaceae. Genera of Vitaceae can differ in vessel size and arrangement, vessel pitting (scalariform or alternate), crystal type (prismatic, druses, or raphides) and location (in chambered parenchyma or ray parenchyma), and cambial variants (present or 0). The secondary phloem develops from the cambial ring or sometimes via concentric cambia (e.g., in Tetrastigma). It is stratified into hard (fibrous) and soft (parenchymatous) zones, or not stratified (Esau 1948). Sieve-tube plastids in Vitaceae are unusual in having starch and protein inclusions (P-type I (b); Behnke 1991). Inflorescence and Floral Structure and Development. The thorough analysis by Troll (1969) has shown that the inflorescences of Vita-

Vitaceae

ceae are typically paniculate systems. They are not cymose, and the characterization as “dichasial cymes” often applied to them is inappropriate. Vitis vinifera and V. davidii have elongate panicles, and especially the panicle of the latter has strongly developed basal branches. In the corymbs of Parthenocissus, the basal-most branch is as strongly developed as the remaining portion of the synflorescence, so the inflorescence appears furcate. This kind of corymb is the most frequent inflorescence form in the family. Further complications result from the contraction of paracladia, and from the transformation of basal branches of the panicle into tendrils (Troll, l.c.). Flowers of Vitaceae are relatively uniform in morphology at maturity, and not particularly informative in systematic studies. Developmental studies of flowers of Vitaceae have been systematically carried out by Posluszny, Gerrath and their collaborators (e.g., Posluszny and Gerrath 1986; Gerrath and Posluszny 1988a, b, c, 1989a, b, c; Gerrath et al. 2004). Thus, sepal initiation is spiral; petals and stamens develop from a common primordium, and the bicarpellate gynoecium arises as a ring primordium usually. However, the gynoecium in Vitis cv. “Ventura” is initiated as five primordia. Two previously reported growing centers of the gynoecial ring were interpreted to be the likely result of the inward growth of the septae, which then subdivide the ovary (Gerrath and Posluszny 1989a, b). In Ampelopsis, however, the gynoecium appears to be bicarpellate even before the septa have begun to initiate (Gerrath and Posluszny 1989c). The disk is highly variable in Vitaceae (see Table 1 in Gerrath et al. 2004). It is a typical nectariferous saucer-like structure in Ampelopsis. In Vitis, the disk is morphologically evident at maturity, but does not produce nectar. In Parthenocissus, it is not morphologically recognizable but there is some nectar production. The disk is initiated from the base of the ovary. Embryology. The initial microspore tetrads are tetrahedral, or isobilateral, or decussate. Embryo-sac development is of the Polygonum type. Polar nuclei fuse prior to fertilization. There are three antipodal cells. Synergids are hooked, and endosperm formation is Nuclear. Embryogeny is Asterad. Pollen Morphology. Pollen grains in Vitaceae are tricolporate, and vary from oblate to prolate

469

in shape. The sexine is reticulate and of about the same thickness as the nexine (Erdtman 1952; Reille 1967). Karyology. There is extensive variation in chromosome numbers (Shetty 1959; Lavie 1970, 1979; Kumbhojkar and Jadhav 1980). Ampelocissus, Ampelopsis, Clematicissus, and Parthenocissus generally have 2n = 40, except that Ampelocissus araneosa was reported to have 2n = 80 (Shetty 1959; Lavie 1970). Counts were made for two species of Rhoicissus (R. rhomboidea and R. tridentata), with 2n = 40 as well. Within Vitis, sect. Vitis (e.g., V. vinifera) has n = 19 and sect. Muscadinia (e.g., V. rotundifolia) has n = 20 (Sax 1930). The diploid number of Cissus is mostly 24 and sometimes 48, or occasionally 26, 28, 32, 40, 50 to even c. 85 and c. 95. There is considerable chromosomal variation in Cyphostemma (2n = 20, 22, 40, 44, c. 46, 54; Lavie 1979). Chromosomal information is available for only a few species of Cayratia and Tetrastigma. The diploid numbers of Cayratia vary greatly, e.g., 30, 40, 60, and 80. Tetrastigma mostly has 2n = 22 or 44, although 52 was also reported (Lavie 1970). Reproductive Systems. Plants of Vitaceae are hermaphrodite, monoecious, polygamomonoecious, or functionally dioecious (Kevan et al. 1985, 1988; Gerrath et al. 2004). Dioecy is often accompanied by pollen dimorphy, as in Vitis (Kevan et al. 1985, 1988), and in the female flowers of the functionally dioecious Vitis riparia, the pollen was found to be inaperturate (Gerrath and Posluszny 1988b, c). Fruit and Seed. Fruits in Vitaceae are fleshy, 1– 4-seeded berries, varying in color depending upon species: blue (common in Ampelopsis), dark blue, black, orange, white, purple, or green. Some are edible, but most are astringent, acrid and stinging due to the presence of raphides and tannins in the parenchyma tissue. Seeds of Vitaceae are albuminous with oily-albuminous, ruminate endosperm (Periasamy 1962); the embryo is dicotyledonous and straight. The endosperm rumination is highly complex in Vitaceae. In cross section, it is most commonly M-shaped (Fig. 163M), and also T- or U-shaped (Fig. 164). Suessenguth (1953a) hypothesized an evolutionary pathway of endosperm rumination, with the simple T-shaped endosperm as in Cayratia subg. Discypharia as the basal condition. Evolution of endosperm needs to be further tested within a phylogenetic framework of Vi-

470

J. Wen

Fig. 164. Vitaceae. Different forms of ruminate endosperm in Vitaceae and its close relative Leeaceae. A Leea. B Cissus. C Vitis. D Tetrastigma. E Ampelocissus. F Cayratia. (Periasamy 1962)

a chalazal knot (a depressed to raised region) is on the abaxial surface (Fig. 163K, L). The seeds have a thin sarcotesta, a lignifid endotesta and a compact, thin, persistent tracheidal tegmen (Corner 1976). Seed Dispersal. Species of Vitaceae are dispersed by animals, especially birds (McAtee 1906; Harvey 1915; Ridley 1930; Tiffney and Barghoorn 1976; Gorchov 1987). Mammals and turtles also have acted as dispersing agents (Ridley 1930; Klimstra and Newsome 1960). Martin et al. (1961) noted 63 species of birds feeding on Vitis, and 27 species on Parthenocissus. Harvey (1915) reported that seeds of Parthenocissus voided by Passer domesticus sprouted and grew rapidly.

Fig. 163. Vitaceae. A–L Cissus erosa. A Leaf (left) and part of stem with branching tendril (right). B Stem with leaves and inflorescence. C Detail of inflorescence. D Lateral view of bud. E Calyptrally dehiscent corolla. F Lateral view of flower, showing antepetalous stamens. G Medial section of flower with petals removed. H Abaxial (right) and adaxial (left) views of anthers. I Developing ovary with floral disk. J Infructescence. K Seed, abaxial view showing the chalazal knot. L Seed, adaxial view showing the raphe and two grooves. M Vitis rotundifolia. Seed in transverse section showing three-lobed endosperm, M-shaped. (A–L Mori et al. 2002, M Judd et al. 2002)

Phytochemistry. (Information summarized from Hegnauer 1973, 1990). Presence of gallic and ellagic acids, proanthocyanins and catechin in the grape (but also in other Vitaceae) are indicative of the presence of hydrolysable and condensed tannins, which are essential for the savor of wine. In seeds and stalks of the fruits of grapevine, tannins amount to 7.3%. Other widespread compounds include prodelphinidin, caffeic and chlorogenic acids, and tartaric acid, accompanied by malic and oxalic acids. The fungitoxic stilbene resveratrol is induced in the leaves as a phytoalexin, but is regularly present in the wood.

taceae. Externally, the seeds are unusual in comparison with those of other angiosperms in that they have a cordlike raphe on the adaxial surface, extending from the hilum to the seed apex and continuing onto the abaxial surface. A groove is commonly present on both sides of the raphe, and

Subdivisions and Relationships Within the Family. The Linnaean concept of Cissus encompasses three presently recognized genera: Cissus, Cayratia, and Cyphostemma. Planchon (1887) treated Cayratia as a section of Cissus. Cissus is characterized by its inflorescence as a compound

Vitaceae

cyme opposite a leaf, its 4-merous flowers, and a continuous cupular floral disk, but was recently shown to be polyphyletic (Rossetto et al. 2001a, 2002). Our chloroplast trnL-F sequence data (A. Soejima and J. Wen, unpubl. data) support several relationships: (1) a clade of Cayratia and Tetrastigma, (2) Cyphostemma forming a monophyletic group with Cayratia plus Tetrastigma, (3) a clade of Nothocissus plus Ampelocissus, (4) a clade of eastern Asian-neotropical Cissus, (5) the South American Cissus striata being phylogenetically isolated from other taxa of Cissus, (6) Vitis forming a clade (only Asian and North and Central American species sampled), (7) Asian Parthenocissus forming a clade, but distinct from the North American P. quinquefolius and P. inserta, (8) Ampelopsis from Asia and eastern North America constituting a monophyletic group, and (9) little resolution in the backbone of the phylogeny. Acareosperma and Cayratia appear closely related on account of their shared pedate leaf architecture. Yua has many characters in common with Parthenocissus, as is discussed under Yua below. Our trnL-F data suggest Ampelocissus and Nothocissus as a clade. I consider the tendrils on the inflorescence of Pterisanthes as evidence for its close relationship to the Ampelocissus-Nothocissus group. These hypothesized relationships need to be further tested. Affinities. The phylogenetic position of Vitaceae within the eudicots has been controversial. Vitaceae are clearly most closely related to the monogeneric Leeaceae, and they share several important characters including the presence of “pearl” glands and raphides. Most workers have now excluded Leea from Vitaceae, and recognized the family Leeaceae (e.g., Planchon 1887; Suessenguth 1953b; Ridsdale 1974; Shetty and Singh 2000; Latiff 2001a; Ren et al. 2003), although APG (1998) and APG II (2003) placed Leea in Vitaceae. Traditionally, Vitaceae were placed in the order Rhamnales along with Rhamnaceae (e.g., Kirchheimer 1939; Cronquist 1981, 1988). Takhtajan (1997) recognized the order Vitales as consisting of Vitaceae and Leeaceae, and considered the Vitales as highly isolated and as a sole member of the Superorder Vitanae in Rosidae. Based on rbcL sequence data, Chase et al. (1993) identified the Vitaceae-Leeaceae clade as sister to Dilleniaceae. The three-gene (atpB, rbcL, and 18S) analysis of Soltis et al. (2000) placed Vitaceae sister to the

471

rest of the rosids, but did not confirm a close relationship between Vitaceae and Dilleniaceae. APG II (2003) added Vitaceae (s.l.) to the rosids, but left it unplaced to order. Distribution and Habitats. The family is mostly pantropical in Asia, Africa, Australia, the neotropics, and the Pacific islands, with a few genera in temperate regions (Vitis, Parthenocissus, and Ampelopsis). Ampelopsis and Parthenocissus are disjunctly distributed in eastern Asia and eastern North America, extending to Mexico. Most species in Vitaceae are forest plants, although some Cissus and Cyphostemma are savanna dwellers. Many species of Ampelocissus, Nothocissus, Cissus, and Pterisanthes prefer lowland tropical forests. Parthenocissus, Ampelopsis, and Vitis are found primarily in the mountainous regions in temperate zones, with some species in montane forests at mid-altitudes in subtropical to tropical regions. Tetrastigma is well developed in lowland forests, but many species are montane and some also occupy limestone habitats. Host-Parasite Relationships. The holoparasitic Rafflesia, Sapria, and Rhizanthes of Rafflesiaceae have been reported to be parasitic on stems of various species of Tetrastigma in southeastern Asia (Latiff 1983; Barkman et al. 2004). The parasites live their entire vegetative life inside the Tetrastigma stems. Recent mitochondrial nad1B-C sequence data (Davis and Wurdack 2004) suggest that part of the mitochondrial genome of the parasitic Rafflesiaceae originated from the Tetrastigma hosts, and was horizontally transferred to these obligate parasites. Horizontal gene transfer may be an important mechanism for the parasites to assemble their genetic architecture, and this phenomenon needs to be further examined with the Tetrastigma and Rafflesiaceae model. Evolutionarily, Rafflesiaceae are only distantly related to Vitaceae, but are placed with Malpighiales (Barkman et al. 2004). Paleobotany. Vitaceae have a rich fossil record throughout the Tertiary (Reid and Chandler 1933; Kirchheimer 1939; Miki 1956; Dorofeev 1957, 1963; Chandler 1961, 1962, 1963, 1964; Tiffney and Barghoorn 1976; Cevallos-Ferriz and Stockey 1990; Wheeler and LaPasha 1994). More than 120 reports of vitaceous seeds are available from sediments from the early Eocene to the Pleistocene (Tiffney and Barghoorn 1976; Cevallos-Ferriz and

472

J. Wen

Stockey 1990), including those of various genera: Ampelocissus, Ampelopsis, Cayratia, Parthenocissus, Tetrastigma, and Vitis. Fossil wood of Vitaceae dates back to the early Eocene from the London Clay flora of southeast England, and this oldest fossil twig was suggested to be related to the African genus Rhoicissus (Poole and Wilkinson 2000). Economic Importance. The family is highly important for grapes, wine, and raisins (especially Vitis vinifera, as well as several other species and hybrids of Vitis). There are a few ornamental climbers from Ampelopsis, Cissus, Parthenocissus, Rhoicissus, and Tetrastigma. Boston-ivy (Parthenocissus tricuspidata) of China and Japan, and Virginia creeper (P. quinquefolia) of eastern North America are widely cultivated (Rehder 1908; Brizicky 1965; Li 1998). Leaves of a few species of Ampelopsis and Vitis have been used as traditional medicines by native Americans and Asians for diarrhea and stomachaches. Bai Lian (Ampelopsis japonica Radix) is a medicine in China for aches. The leaves of the Old World tropical species, Cissus quadrangularis, are used as food and traditional medicine (Latiff 2001a). The West African Cissus populnea was shown to have antibacterial activity (Koné et al. 2004).

Key to the Genera 1. Fruit 1-seeded; seeds with 14 radially arranged prolongations, somewhat curved at the top, the shortest 6 surrounding the dorsal or chalazal scar, the 8 others grouped around the ventral face or rapheale 12. Acareosperma – Fruit 1–4-seeded; seeds smooth or with some barely visible projections 2 2. Stigma of bisexual flowers 4-lobed or 4-parted, enlarged, wider than the tip of style, style very short; petals 4, frequently corniculate, with small hornlike appendages at the tips 13. Tetrastigma – Stigma not 4-parted or 4-lobed, usually never wider than the end of style; petals 4–5, not corniculate 3 3. Inflorescence axis highly enlarged into a wide, ribbonshaped structure with an entire or ribbed margin, often with a tendril at the base; fertile flowers imbedded on both sides of this structure; long pedicellate sterile flowers often present along the margins of the inflorescence 5. Pterisanthes – Inflorescence a panicle or corymb, occasionally aggregated into a roundish structure by reduction of the axes (some Ampelocissus spp.), never ribbon-shaped 4 4. Petals united into a cap-like structure (calyptra) which drops off as a unit at anthesis; bark on older twigs usually loose, pealing off in stripes 8. Vitis – Petals not forming a calyptra; bark intact, not peeling off in stripes 5

5. Inflorescence with a tendril at the base 6 – Inflorescence without a tendril at the base, tendrils normally leaf-opposite 7 6. Berry dry, two-parted with 2–4 seeds; seeds of various shapes, the ventral infolds relatively deep and narrow; endosperm N-shaped in cross section 10. Clematicissus – Berry usually fleshy; with 2–3 seeds; seeds convexcarinate, the ventral infolds shallow and wide; endosperm T-shaped in cross section, often triangular-ovate but then without indentations 3. Ampelocissus 7. Petals 4 8 – Petals 5 or to 7 11 8. Inflorescences usually leaf-opposed; floral disk cupular even when 4-lobed, raised above the ovary 9. Cissus – Inflorescences usually axillary or sometimes seemingly terminal; floral disk not cupular 9 9. Floral buds flask-shaped; floral disk of 4 free glands 14. Cyphostemma – Floral buds globose or oblong; floral disk entire and adnate to the base of ovary 10 10. Dorsal side of seeds convex, smooth or with 4–5 elevated lateral ridges, ventral side carinate; endosperm T- or N-shaped in cross section 11. Cayratia – Dorsal side of seeds laterally furrowed, ventral side with narrow and parallel infolds; endosperm M-shaped in cross section 4. Nothocissus 11. Style elongated; floral disk significantly cup-shaped, connected with the base of the ovary, far protruding at the top, 5- or 4-lobed, forming a basal ring below the fruit 1. Ampelopsis – Style usually rather short; floral disk without free diskseam, adnate to the ovary and covering its lower part 12 12. Tendrils on stem with 4–12 branches, tip with suckers 6. Parthenocissus – Tendrils with 1–2 branches without suckers 13 13. Inflorescences small corymbs; floral disk without an edge; petals 5, not fleshy; eastern Asia 7. Yua – Inflorescences loose panicles; floral disk ring-shaped with an irregular edge, adnate to the base of the ovary, recognizable even in the ripe fruit as a weak basal ring; petals 5–7, fleshy and firm, at least at the tip portion; tropical and South Africa 2. Rhoicissus

Genera of Vitaceae 1. Ampelopsis Michx. Ampelopsis Michx., Fl. Bor.-Amer. 1:159 (1803); Li, Fl. Reip. Pop. Sin. 48:32–53 (1998); Lombardi, Fl. Neotrop. Monogr. 80:24–27 (2000); Shetty & Singh, Fl. India 5:262–266 (2000).

Deciduous woody climbers; hermaphrodite; tendrils usually few and scattered, bifurcate, without adhesive disks. Leaves simple, variously lobed, bipinnate, or trifoliate. Inflorescence a loose corymb, few to many flowered, leaf-opposite, often repeatedly branched, rarely elongate and racemose, sometimes showing transitions to tendrils, with the peduncle or a branch coiled, functioning as a tendril for climbing (in A. cordata), adhesive

Vitaceae

disks 0. Flowers 5-merous; calyx small, saucer-like; corolla spreading at anthesis; stamens erect; floral disk cupular, lower part adnate to the ovary, slightly lobed; style slender, stigma small, simple. Fruit subglobose to obovoid, blue, black or green, 1–4-seeded; seeds obovate to broadly so, convex on abaxial side, angular on adaxial side, chalazal knot spatulate, raphe narrowly linear, 2 adaxial grooves oblanceolate, present in the lower half of the seed; endosperm T-shaped in cross section. 2n = 40. Approximately 25 species disjunct between temperate to subtropical Asia (c. 23 spp.) and North and Central America (three spp. including two in eastern North America, and one in Mexico and Guatemala). 2. Rhoicissus Planchon Rhoicissus Planchon in A. DC., Monogr. Phanerog. 5:320 (1887); Gilg & Brandt, Bot. Jahrb. 46:436–442 (1911).

Woody climbers, scramblers or shrubs, hermaphrodite; tendrils leaf-opposite, bifurcate, adhesive disks 0. Leaves 3(5)-foliolate or simple, often rusty; stipules present or 0; leaflets entire or variously toothed. Inflorescence a panicle, leaf-opposite. Flowers (4)5–7-merous; calyx cup-shaped, more or less entire; petals fleshy and firm, recurved at anthesis; anthers bending over the ovary; floral disk ring-shaped without longitudinal furrows and adnate to the base of the ovary, forming a basal ring on the mature fruit; style short and cylindrical, stigma undivided, not broader than style. Fruit globose, 1–2-seeded; seeds ovoid, rugose or smooth, with a longitudinal furrow; endosperm ruminate. 2n = 40. About 12 species in forest areas in tropical and South Africa. Gerrath et al. (2004) support a close relationship between Rhoicissus and Ampelopsis. 3. Ampelocissus Planchon Ampelocissus Planchon, Vigne Amér. Vitic. Eur. 8:371 (1884), nom. cons.; Li, Fl. Reip. Pop. Sin. 48:131–136 (1998), Chinese spp.; Lombardi, Fl. Neotrop. Monogr. 80:15–24 (2000); Shetty & Singh, Fl. India 5:247–262 (2000).

Woody climbers; polygamo-monoecious; tendrils borne on the inflorescences, adhesive disks 0. Leaves simple or lobed to digitately and pedately compound with 3–9 leaflets; stipules deltate, inconspicuous, caducous. Inflorescence a leafopposed, paniculate spike with a basal tendril. Flowers 5-merous; calyx cupular or saucer-shaped, entire or with 5 obscure teeth; petals oblong to

473

ovate-oblong, spreading or recurved at anthesis; stamen filaments slender; floral disk annular, erect, often vertically 5–10-furrowed; ovary more or less embraced in the disk, style short, conical, often 10 furrowed, stigma small in staminate flowers, discoid in hermaphrodite flowers. Fruit 1–4-seeded; seeds oblong to obovoid, abaxial surface convex, adaxial surface 2-furrowed, with a broad raphe, often crenately cleft at the margin; endosperm T-shaped in cross section. 2n = 40, 80. About 95 species, mostly in Africa, tropical Asia, and Australia, with only four species in the New World (Central America and the Caribbean). Based on inflorescence structure, leaf and seed morphology, Planchon (1887) recognized four sections: sect. Ampelocissus (Africa, Asia and the Americas), sect. Nothocissus (Malesia), sect. Kalocissus (c. 15 spp. in Malesia), and sect. Eremocissus (only one species from St. Domingue, A. robinsonii Planchon). Section Nothocissus has been elevated to generic rank (Latiff 1982). 4. Nothocissus (Miq.) Latiff Nothocissus (Miq.) Latiff, Feder. Mus. J. 27:70 (1982), and Folia Malay. 2:179–189 (2001). Vitis L. sect. Nothocissus Miq. (1863). Ampelocissus Planchon sect. Nothocissus (Miq.) Planchon (1887).

Moderate woody climbers, stems reaching 4 cm in diameter; tendrils leaf-opposite in the middle part of the long trailing stem, simple, adhesive disks 0. Leaves simple to 3–5-lobed, appearing 3–5-foliolate or palmately 3–5-foliolate, sometimes heterophyllous; stipules caducous. Inflorescence axillary or seemingly terminal, rarely leaf-opposite, a simple or compound raceme, or a branched panicle; in N. spicifera (Griff.) A. Latiff, the racemes with pedicellate as well as subsessile flowers fascicled on the axes. Flowers 4-merous; calyx cup-shaped, lobed; corolla elliptic, truncate to corniculate; stamens with filiform filaments and orbicular anthers; floral disk adnate to the base of the ovary; style short, stigma large, entire. Fruit globose to ellipsoid, 1–2seeded; seeds oblong, the dorsal side laterally furrowed, the chalazal knot oblong, the ventral infolds narrow and parallel; endosperm M-shaped in cross section. Five species from peninsular Malaysia, Sumatra, Bangka, Borneo, and Papua New Guinea. 5. Pterisanthes Blume Pterisanthes Blume, Bijdr.: 192 (1825); Latiff, Feder. Mus. J. 27:42–68 (1982), and Malay. Nat. J. 55:29–42 (2001).

474

J. Wen

Scandant wiry climbers with small stems seldom exceeding 4 mm in diameter; polygamo-monoecious; tendrils as modified inflorescence branches, rather than vegetative stems, adhesive disks 0. Leaves simple or palmately (2)3–7-foliolate, some species heterophyllous (e.g., P. cissoides with simple or 2–5-foliolate leaves). Inflorescence a leafopposed applanate or lamellate panicle, fleshy and foliaceous, with branched tendrils on the peduncle; lamellae rectangular, horseshoe-like, rayfish-like, triangular, or very narrow, sometimes a tail present, with entire, undulate or dentate margin. Flowers in sect. Pterisanthes lamellate and pedicellate, in sect. Paginiflora only lamellate; lamellate flowers hermaphrodite, 4–5-merous, lacking pedicels and partially embedded in the fleshy lamellae, except those in P. hirtiflora; pedicellate flowers 4-merous; calyx obscure in lamellate flowers, cupuliform in pedicellate flowers; corolla ovate-triangular; ovary 2-locular. Fruit pinkishred to dark purple, situated on the lamellae; seeds curved outward, wrinkled. Twenty species, Malay Peninsula, Borneo, Sumatra, Java, Philippines, and peninsular Thailand. Two sections, see above. 6. Parthenocissus Planchon Parthenocissus Planchon in A. DC., Monogr. Phanerog. 5:447 (1887); Li, Fl. Reip. Pop. Sin. 48:12–27 (1998); Shetty & Singh, Fl. India 5:302–306 (2000).

Deciduous woody climbers; hermaphrodite; tendrils leaf-opposed, monochasially 3–12-branched, rarely 0, usually with an adhesive disk at the tip of each branch. Leaves simple, lobed or palmately (rarely pedately) 5–7-foliolate; leaflets coarsely toothed to serrate. Inflorescence a many-flowered panicle or a branched corymb lacking tendrils, leaf-opposed or terminal. Flowers 5-merous; calyx cupular, 5-dentate; petals spreading or occasionally calyptrate; floral disk inconspicuous, fused with the base of the ovary; style short, conical, stigma capitate, small. Fruit subglobose, dark blue to black, often glaucous, 1–4-seeded, inedible; seeds globose to obovate, smooth, convex on the abaxial surface, chalazal knot round to short spatulate, the 2 grooves on adaxial surface extending from the apex to the base of the seed; endosperm M-shaped in cross section. 2n = 40. Approximately 15 species, about 12 in East Asia with one species extending into the western Ghats, India, and three in North America. Galet (1967) proposed three series within Parthenocissus, primarily based on leaf forms. Li

(1998), based on tendril morphology, leaf form, and inflorescence structure, divided the genus into three sections: Parthenocissus, Margaritaceae, and Tuberculiformes. 7. Yua C.L. Li Yua C.L. Li, Acta Bot. Yunnan. 12:2 (1990), and Fl. Reip. Pop. Sin. 48:27–32 (1998).

Deciduous woody climbers; lenticels conspicuous on stems, pith white; hermaphroditic; tendrils leaf-opposed, 2-furcate, without adhesive disks. Leaves palmately 5-foliolate. Inflorescence a branched corymb lacking tendrils. Flowers usually 5-merous; calyx cupular, entire or wavy at the margin; petals initially calyptrate, spreading at anthesis; disk inconspicuous, fused with the base of the ovary; style short and stout, stigma subcapitate, small. Fruit globose, 1–4-seeded, sweet and sour in taste; seeds pyriform, rostrate at base, chalazal knot extending 2/3 of the seed length from the base; endosperm M-shaped in cross section. 2n = c. 40. Three species, subtropical China, India (Assam) and central Nepal. The species now included in Yua were previously placed in Parthenocissus (Planchon 1887; Rehder 1905, 1945) or Cayratia (Suessenguth 1953a). Li (1990) argued that these species differed in their tendril and inflorescence morphology, and established his new genus Yua. The digitate leaf form, the fall color changes from green to red, the 5merous flower, and the inconspicuous floral disks of Yua support a close connection with Parthenocissus. 8. Vitis L.

Fig. 164M

Vitis L., Sp. Pl. 2:230 (1753); Comeaux et al., Castanea 52:197–215 (1987), N. Carolina spp.; Moore, Rhodora 89:75–91 (1987), SE U.S. spp.; Li, Fl. Reip. Pop. Sin. 48:136– 178 (1998); Shetty & Singh, Fl. India 5:320–324 (2000). Muscadinia (Planchon) Small (1903).

Deciduous woody climbers, polygamodioecious, usually with shreddy bark on old stems; lenticels 0 or inconspicuous (subg. Vitis) or prominent (subg. Muscadinia); pith brown, interrupted by diaphragms within the nodes (subg. Vitis) or continuous through nodes (subg. Muscadinia); tendrils leaf-opposed, 2–3-furcate (subg. Vitis) or simple (subg. Muscadinia), present usually on two consecutive nodes or less commonly on three or more consecutive nodes, without adhesive disks. Leaves simple, often lobed, dentate to serrate,

Vitaceae

palmately veined; stipules caducous. Inflorescence a panicle, present opposite only two consecutive nodes or at three to many consecutive nodes, sometimes with a tendril at the apex of the peduncle. Flowers 5-merous, morphologically bisexual and unisexual but functionally unisexual; calyx minute with 5 teeth to entire; petals (3–)5(–9), forming a calyptra at anthesis; stamens usually 5, erect in male and bisexual flowers, reflexed or occasionally 0 in female flowers; disk of 5 glands alternating with stamens; gynoecium rudimentary in male flowers; in female flowers, style conical and short and stigma small, capitate. Fruit pulpy, globose, purple to black, rarely whitish or greenish, often glaucous, 1–4-seeded; seeds obovoid to pyriform, the adaxial surface with two longitudinal grooves on either side of the raphe, the abaxial surface with a round to elliptic chalazal knot, extending to c. 1/3 of the seed length from base; endosperm M-shaped. 2n = 38, 40. About 60 species, mostly temperate regions of the northern hemisphere, one species extending into South America. Subg. Muscadinia consists of 2–3 species from the USA, the West Indies and Mexico (Brizicky 1965), whereas subg. Vitis has a wide distribution in the northern hemisphere. 9. Cissus L.

Fig. 163A–L

Cissus L., Sp. Pl. 1:117 (1753); Gilg & Brandt, Bot. Jahrb. 46:442–547 (1911); Lombardi, Fl. Neotrop. Monogr. 80:27–219 (2000); Shetty & Singh, Fl. India 5:277–297 (2000). Pterocissus Urban & Ekman (1926).

Woody or herbaceous climbing or scrambling lianas, or sometimes erect shrubs, hermaphroditic to polygamo-monoecious; stems terete, winged or striated, often succulent; sometimes tuberous roots present; tendrils leaf-opposed, ramified or unbranched, occasionally with adhesive disks at the tip, especially when young. Leaves simple or palmately 3–5(–7)-foliolate to (bi)pinnately compound; stipules caducous. Inflorescence a corymb or a compound corymb, leaf-opposed. Flowers 4-merous; calyx cupular, minute; petals adhering by interlocked epidermal cells in bud, reflexed at anthesis, deltoid in shape; floral disk adnate to the base of the ovary, conspicuous, cupular to 4-lobed; style conical or cylindrical, stigma entire. Fruit 1(–4)-seeded, inedible; seeds ovoid, obtusely 3-cornered to pyriform, with an encircling raphe, smooth or faceted or pitted on either side, the testa crustaceous; endosperm

475

with 3 vertical lobes, M-shaped in cross section; cotyledons reniform, sometimes 3, radicle large. 2n = 24, 26, 28, 32, c. 36, 40, c. 45, 48, 50, c. 85, c. 95. About 350 species, widely distributed in all tropical regions, a few extending into the temperate zone. The genus has been shown to be polyphyletic (Rossetto et al. 2002). 10. Clematicissus Planchon Clematicissus Planchon in A. DC., Monogr. Phanerog. 5:422 (1887); Jackes, Austrobaileya 3:11–19 (1989).

Deciduous climbers or spawling shrubs to 2 m tall, hermaphrodite; stems striate, glabrous; tendrils leaf-opposite, usually bifurcate, adhesive disks 0. Leaves palmately (3–)5(–7)-foliolate, glabrous, entire to dentate; stipules rounded and membranaceous. Inflorescence leaf-opposed, congested heads terminating one or both branches of the tendril. Flowers 5-merous; calyx shortly lobed; petals reflexed after anthesis, caducous; filaments erect, flattened; disk adnate to and entirely surrounding the base of the ovary; style conical, stigma capitate, undivided. Fruit globose to nearly so, 1–2(–4)-seeded; seeds pyriform, convex on the back, perichalaza c. 2/3 to nearly the entire length of the dorsal surface; endosperm U-shaped in cross section. One species, C. angustissima (F. Muell.) Planchon, endemic in the Irwin District of Western Australia (Jackes 1989a). 11. Cayratia Juss. Cayratia Juss. in Dict. Hist. Nat. Sci. 10:103 (1818), nom. cons.; Jackes, Austrobaileya 2:365–379 (1987), Austral. spp.; C.-L. Li, Fl. Reip. Pop. Sin. 48:68–85 (1998). Cissus sect. Cayratia (Juss.) Planchon (1887).

Climbing shrubs and herbs sometimes with tuberous roots; hermaphrodite; tendrils opposite to leaves, usually 2–3-furcate, adhesive disks 0. Leaves alternate, pedately or pinnately 3–7-foliolate; leaflets serrate at margin; stipules caducous. Inflorescence a branched corymb, axillary or pseudo-axillary by the abortion of lateral axis, or sometimes opposite to leaves. Flowers 4merous; calyx cup-shaped; petals cohering in bud by interlocked epidermal cells; stamen filaments erect; disk adnate to and entirely surrounding the ovary, 4-lobed; style conical, stigma minute. Fruit 2–4-seeded, usually dry; seeds hemispheric pyriform to oblong, obcordate, smooth or angular, convex on the back, with 1–2 ventral cavities;

476

J. Wen

endosperm in transverse section T- or U-shaped; cotyledons small, ovate, radicle small. 2n = 30, 40, c. 66, c. 72, 80, c. 98. Sixty three species, tropical and subtropical Asia, Africa, Australia and the Pacific Islands (Galet 1967). 12. Acareosperma Gagnepain Acareosperma Gagnepain, Bull. Mus. Hist. Nat. 25:131 (1919), and Fl. Gén. Indo-Chine, Ampélidacées, suppl. 7:914–915 (1950).

Stem terete, longitudinally striated, spreading; tendrils opposite the leaves, slender and trifurcate but not verticillate, branches unequal and spreading, without adhesive disks. Leaves compound, unequally triternate, glabrous but appearing granular because of crystals; first-order petioles 3, terminal ones unifoliolate, basal ones with 3–5 leaflets, pedately arranged with unequal petiolules; leaflets lanceolate-acuminate, 5-dentate on each side; lateral veins 5–6 pairs, parallel, curving near the margin. Inflorescence glabrous, axillary or terminal with short axillary branches, loosely branched-corymbose with spreading branches. Flowers unknown. Fruit ovately oblong, compressed (?), with small dots, somewhat fleshy; pericarp thin, with netlike veins inside, 1-seeded; seeds large, dorsiventrally compressed, with 14 appendages arranged in two rows; endosperm copious, dorsally excavate, with four folds, which dissect the endosperm into 5 lobes; embryo small, basal. One poorly known species, A. spireanum Gagnepain, from Laos. It differs from Cissus in the five-lobed endosperm. 13. Tetrastigma (Miq.) Planchon Tetrastigma (Miq.) Planchon in A. DC., Monogr. Phanerog. 5:423 (1887); Jackes, Austrobaileya 3:149–158 (1989); Li, Fl. Reip. Pop. Sin. 48:86–131 (1998); Shetty & Singh, Fl. India 5:306–320 (2000). Vitis sect. Tetrastigma Miq. (1863).

Climbers, mostly evergreen, polygamo-dioecious; stems striate, initially terete, often becoming flattened with age; tendrils leaf-opposed, simple or branched, branches subtended by a bract, without adhesive disks. Leaves pedately 5–11-foliolate or sometimes palmately 1–2-, 3- or 5–7-foliolate, or occasionally 1-foliolate; stipules caducous. Inflorescence usually axillary, an umbellate, bi- or multibranched corymb. Flowers 4-merous; calyx cupular, entire or slightly lobed; petals reflexed at anthesis, caducous; stamens in pistillate flowers

reduced to staminodes; floral disk inconspicuous, almost completely embracing the reduced ovary in staminate flowers, adnate to and entirely surrounding the base of the ovary in pistillate flowers; style short, stigma large, 4-lobed in pistillate flowers, capitate and undivided in staminate flowers. Fruit pyriform (sect. Carinata), globose to ellipsoid (sect. Tetrastigma), 1–4-seeded; seeds ovoid, globose or pyriform, convex on the back, perichalaza c. 2/3 to nearly the entire length of the dorsal surface; endosperm T- or M-shaped in cross section. 2n = 22 or 44, rarely 52. About 95 species, primarily in tropical and subtropical Asia, with five species in Australia. Latiff (1983) recognized two sections: sect. Tetrastigma (with globose to ellipsoid, 1–2-seeded berries, seeds globose or plano-convex with smooth testa, chalazal knot extending 3/4 of the length of the seeds, and endosperm M- to T-shaped in transverse section), and sect. Carinata (with pyriform, 3- or 4-seeded berries, seeds cainate ventrally with tuberculate testa, the chalaza extending 1/2 along the length of the seeds, and endosperm T-shaped in cross section) (also see Jackes 1989b; Latiff 1991). 14. Cyphostemma (Planchon) Alston Cyphostemma (Planchon) Alston in Trimen, Handb. Fl. Ceylon suppl. 6:53 (1931); Mabberley in Dassanayake, Rev. Handb. Fl. Ceylon 9:460–462 (1995); Shetty & Singh, Fl. India 5:246–324 (2000). Cissus subg. Cyphostemma Planchon (1887).

Erect, prostrate or climbing shrubs and herbs, sometimes with fleshy stems; hermaphrodite; tendrils leaf-opposed or 0, without adhesive disks. Leaves palmately 3–9-foliolate, rarely simple; stipules conspicuous, caducous; leaflets variously toothed at margin. Inflorescences axillary or pseudo-terminal, corymbose cymes. Flowers 4-merous, buds flask-shaped, more or less constricted near the middle; calyx truncate or 4-lobed; petals oblong, hooded at apex, deflexed after anthesis; filaments erect, not bending over the ovary; floral disk of 4 fleshy, truncate or conical glands, adnate to ovary but free from each other; style subulate, stigma slightly bifid or subentire or subcapitate. Fruit globose, usually 1-seeded; seeds ovoid and rugose with a dorsal crest; endosperm M-shaped in cross section. 2n = 20, 22, 24, 40, 44, c. 46, 54. About 150 species, mainly in Africa and Madagascar, with a few species in India and Sri Lanka, extending into Thailand.

Vitaceae

Selected Bibliography Adkinson, J. 1913. Some factors of the anatomy of the Vitaceae. Ann. Bot. 27:133–139. Alston, A.H.G. 1931. A handbook to the Flora of Ceylon, part 6, suppl. London: Dulau. APG 1998. See general references. APG II 2003. See general references. Arnott, H.J., Webb, M.A. 2000. Twined raphides of calcium oxalate in grape (Vitis): implications for crystal stability and function. Intl J. Pl. Sci. 161:133–142. Baker, J.G. 1871. Ampelideae. In: Martius, C.F.P. von (ed.) Flora Brasiliensis 14, 2. Leipzig: F. Fleischer, pp. 197– 220. Barkman, T.J., Lim, S.-H., Salleh, K.M., Nais, J. 2004. Mitochondrial DNA sequences reveal the photosynthetic relatives of Rafflesia, the world’s largest flower. Proc. Natl Acad. Sci. U.S.A. 101:787–792. Beck, C.B., Schmid, R., Rothwell, G.W. 1982. Stelar morphology and the primary vascular system of seed plants. Bot. Rev. 48:681–815. Behnke, H.-D. 1991. See general references. Bharathan, G., Goliber, T.E., Moore, C., Kessler, S., Pham, T., Sinha, N.R. 2002. Homologies in leaf form inferred from KNOXI gene expression during development. Science 296:1858–1860. Boss, P.K., Thomas, M.R. 2002. Association of dwarfism and floral induction with a grape ‘green revolution’ mutation. Nature 416:847–850. Brizicky, G.K. 1965. The genera of Vitaceae in the southeastern United States. J. Arnold Arb. 46:48–67. Cevallos-Ferriz, S.R.S., Stockey, R.A. 1990. Permineralized fruits and seeds from the Princeton chert (Middle Eocene) of British Columbia: Vitaceae. Canad. J. Bot. 68:288–295. Chandler, M.E.J. 1961. The Lower Tertiary floras of southern England. I. Paleocene floras, London Clay Flora (suppl.). London: British Museum (Natural History). Chandler, M.E.J. 1962. The Lower Tertiary floras of southern England. II. Flora of the Pipe-clay series of Dorset (Lower Bagshot). London: British Museum (Natural History). Chandler, M.E.J. 1963. The Lower Tertiary floras of southern England. III. Flora of the Bournemouths Beds, the Boscombe, and the Highcliffe Sands. London: British Museum (Natural History). Chandler, M.E.J. 1964. The Lower Tertiary floras of southern England. IV. A summary and survey of findings in light of recent botanical observations. London: British Museum (Natural History). Chase, M.W. et al. 1993. See general references. Comeaux, B.L., Nesbitt, W.B., Fantz, P.R. 1987. Taxonomy of the native grapes of North Carolina. Castanea 52:197– 215. Corner, E.J.H. 1976. See general references. Critchfield, W.B. 1970. Shoot growth and leaf dimorphism in Boston ivy Parthenocissus tricuspidata. Amer. J. Bot. 57:535–542. Cronquist, A. 1981. See general references. Cronquist, A. 1988. The evolution and classification of flowering plants, 2nd edn. Bronx: New York Botanical Garden.

477

Davis, C.C., Wurdack, K.J. 2004. Host-to-parasite gene transfer in flowering plants: phylogenetic evidence from Malpighiales. Science 305:676–678. Decoings, B. 1960. Un genre méconnu de Vitacées: compréhension et distinction des genres Cissus L. et Cyphostemma (Planch.) Alston. Notulae Syst. 16:113–125. Dorofeev, P.I. 1957. Seeds of Ampelopsis from the Tertiary deposits of the territory of USSR. Bot. Zhurn. (Moscow & Leningrad) 42:643–648. Dorofeev, P.I. 1963. Tretichnye flory zapadoni Sibiri. Izdat Nauka, Leningrad: V.L. Komarov Bot. Inst. Erdtman, G. 1952. See general references. Esau, K. 1948. Phloem structure in the grapevine, and its seasonal changes. Hilgardia 18:217–296. Gagnepain, F. 1911. Classification des Cissus et Cayratia. Notulae Syst. 1:339–343. Gagnepain, F. 1919. Acareosperma, un genre nouveau d’Ampélidacées. Bull. Mus. Natl Hist. Nat. 25:131–132. Gagnepain, F. 1950. Ampélidacées. Flore générale de l’IndoChine, suppl. 7. Paris: Masson, pp. 855–915. Galet, P. 1967. Recherches sur les méthodes d’identification et de classification des Vitacées tempérées. II Thèse, Faculté des Sciences de Montpellier, Université de Montpellier, France. Gerrath, J.M., Posluszny, U. 1988a. Morphological and anatomical development in the Vitaceae. I. Vegetative development in Vitis riparia. Canad. J. Bot. 66:209–224. Gerrath, J.M., Posluszny, U. 1988b. Morphological and anatomical development in the Vitaceae. II. Flora development in Vitis riparia. Canad. J. Bot. 66:1334–1351. Gerrath, J.M., Posluszny, U. 1988c. Comparative floral development in some members of the Vitaceae. In: Leins, P., Tucker, S.C., Endress, P.K. (eds) Aspects of floral development. Berlin: J. Cramer, pp. 121–131. Gerrath, J.M., Posluszny, U. 1989a. Morphological and anatomical development in the Vitaceae. III. Vegetative development in Parthenocissus inserta. Canad. J. Bot. 67:803–816. Gerrath, J.M., Posluszny, U. 1989b. Morphological and anatomical development in the Vitaceae. IV. Floral development in Parthenocissus inserta. Canad. J. Bot. 67:1356–1365. Gerrath, J.M., Posluszny, U. 1989c. Morphological and anatomical development in the Vitaceae. V. Vegetative and floral development in Ampelopsis brevipedunculata. Canad. J. Bot. 67:2371–2386. Gerrath, J.M., Lacroix, C.R., Posluszny, U. 1998. Phyllotaxis in the Vitaceae. In: Jean, R.V., Barabé, D. (eds) Symmetry in plants. Singapore: World Scientific Press, pp. 89–107. Gerrath, J.M., Posluszny, U., Dengler, N.G. 2001. Primary vascular patterns in the Vitaceae. Intl J. Pl. Sci. 162:729– 745. Gerrath, J.M., Wilson, T., Posluszny, U. 2004. Morphological and anatomical development in the Vitaceae. VII. Floral development in Rhoicissus digitata with respect to other genera in the family. Canad. J. Bot. 82:198– 206. Gilg, E. 1896. Vitaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien III, 5. Leipzig: W. Engelmann, pp. 427–456.

478

J. Wen

Gilg, E., Brandt, M. 1911. Vitaceae Africanae. Bot. Jahrb. 46:415–557. Gorchov, D.L. 1987. Sequence of fruit ripening in birddispersed plants: consistency among years. Ecology 68:223–225. Harvey, B.T. 1915. The dissemination of Virginia creeper seeds by English sparrows. Pl. World 18:217–219. Hegnauer, R. 1973, 1990. See general references. Hooker, J.D. 1862. Ampelideae. In: Bentham, G., Hooker, J.D., Genera plantarum. London: Reeve, pp. 386–388. Ingrouille, M.J., Chase, M.W., Fay, M.F., Bowman, D., van der Bank, M., Bruijn, A.D.E. 2002. Systematics of Vitaceae from the viewpoint of plastid rbcL sequence data. Bot. J. Linn. Soc. 138:421–432. Jackes, B.R. 1987. Revision of the Australian Vitaceae, 2. Cayratia Juss. Austrobaileya 2:365–379. Jackes, B.R. 1988. Revision of the Australian Vitaceae, 3. Cissus L. Austrobaileya 2:481–505. Jackes, B.R. 1989a. Revision of the Australian Vitaceae, 4. Clematicissus Planch. Austrobaileya 3:11–19. Jackes, B.R. 1989b. Revision of the Australian Vitaceae, 5. Tetrastigma (Miq.) Planchon. Austrobaileya 3:149– 158. Judd, W.S., Campbell, C.S., Kellogg, E.A., Stevens, P.F., Donoghue, M.J. 2002. Plant systematics: a phylogenetic approach, 2nd edn. Sunderland, MA: Sinauer. Kevan, P.G., Longair, R.W., Gadawski, R.M. 1985. Dioecy and pollen dimorphism in Vitis riparia (Vitiaceae). Canad. J. Bot. 63:2263–2267. Kevan, P.G., Blades, D.C.A., Posluszny, U., Ambrose, J.D. 1988. Pollen dimorphism and dioecy in Vitis aestivalis. Vitis 27:143–146. Kirchheimer, F. 1939. Rhamnales I: Vitaceae. In: Fossil. Catal. vol. II, 24, pp. 1–174. Klimstra, W.D., Newsome, F. 1960. Some observations on the food coactions of the common box turtle (Terrapene c. caroline). Ecology 41:637–647. Koné, W.M., Kamanzi, K.A., Terreaux, C., Hostettmann, K., Traoré, D., Dosso, M. 2004. Traditional medicine in North Côte-d’Ivoire: screening of 50 medicinal plants for antibacterial activity. J. Ethnopharmacol. 93:43– 49. Kumbhojkar, M.S., Jadhav, A.S. 1980. Chromosome numbers in the family Vitaceae. Curr. Sci. 49:37–38. Lacroix, C.R., Posluszny, U. 1989a. Phyllotactic patterns in some members of the Vitaceae. Bot. Gaz. 150:303–313. Lacroix, C.R., Posluszny, U. 1989b. Stipules in some members of the Vitaceae: relating process of development to the mature structure. Amer. J. Bot. 76:1203–1215. Latiff, A. 1982. Studies in Malesian Vitaceae, I–IV. Federation Museums J. 27:46–93. Latiff, A. 1983. Studies in Malesian Vitaceae, VII. The genus Tetrastigma in the Malay Peninsula. Gard. Bull. Singapore 36:213–228. Latiff, A. 1991. Studies in Malesian Vitaceae, X. Two new species of Tetrastigma from Borneo. Blumea 35:559– 564. Latiff, A. 2001a. Diversity of the Vitaceae in the Malay Archipelago. Malay. Nat. J. 55(1&2):29–42. Latiff, A. 2001b. Studies in Malesian Vitaceae, XII: Taxonomic notes on Cissus, Ampelocissus, Nothocissus and Tetrastigma and other genera. Folia Malay. 2:179–189.

Lavie, P. 1970. Contribution à l’étude caryosystématique des Vitacées. Thèse, Faculté des Sciences, Université de Montpellier, France, 292 pp. Lavie, P. 1979. Caryosystématique des Vitaceae: 1. Cissus L., Cyphostemma (Planch.) Alst., Rhoicissus Planch. Adansonia II, 19:175–198. Lawson, M.A. 1875. Ampelideae. In: Hooker, J.D. (ed.) Flora of British India, vol. 1. London: L. Reeve, pp. 644–668. Li, C.L. 1990. Yua C.L. Li – a new genus of Vitaceae. Acta Bot. Yunnan. 12:1–10. Li, C.L. 1998. Vitaceae. In: Flora Reipublicae Popularis Sinicae, vol. 48, 2. Beijing: Science Press, pp. 1–177. Linnaeus, C. 1753. Species plantarum. Stockholm: L. Salvii. Lombardi, J.A. 1997. Types of names in Ampelocissus and Cissus (Vitaceae) referring to taxa in the Caribbean, Central and N. America. Taxon 46:423–432. Lombardi, J.A. 2000. Vitaceae – gêneros Ampelocissus, Ampelopsis e Cissus. Flora Neotropica Monograph 80. Bronx, NY: New York Botanical Garden. Mabberley, D.J. 1995. Vitaceae. In: Dassanayake, M.D. (ed.) A Revised Handbook to the Flora of Ceylon, vol. 9. New Delhi: Amerind, pp. 446–482. Martin, A.C., Zim, H.S., Nelson, A.L. 1961. American wildlife and plants: a guide to wildlife food habits. New York: Dover. McAtee, W.L. 1906. Virginia creeper as a winter food for birds. Auk 23:346–347. Metcalfe, C.R., Chalk, L. 1950. See general references. Miki, S. 1956. Seed remains of Vitaceae in Japan. J. Inst. Polytech. Osaka City Univ. Ser. D 7:247–271. Millington, W.F. 1966. The tendril of Parthenocissus inserta: determination and development. Amer. J. Bot. 53:74– 81. Moore, M.O. 1987. A study of selected taxa of Vitis (Vitaceae) in the southeastern United States. Rhodora 89:75–91. Moore, M.O. 1991. Classification and systematics of eastern North American Vitis L. (Vitaceae) North of México. Sida 14:339–367. Mori, S.A., Cremers, G., Gracie, C., de Granville, J.-J., Heald, S.V. 2002. Guide to the vascular plants of central French Guiana. Part 2. Dicotyledons. Mem. New York Bot. Gard. 76, 2:1–900. Periasamy, K. 1962. Studies on seeds with ruminate endosperm: 2. Development of rumination in the Vitaceae. Proc. Indian Acad. Sci. B 56:13–26. Planchon, J.E. 1887. Monographie des Ampélidées vrais. In: Candolle, A.F.P.P. de, Candolle, C. de (eds) Monographiae Phanaerogamarum 5, 2. Paris: Masson, pp. 305–654. Poole, I., Wilkinson, H.P. 2000. Two early Eocene vines from south-east England. Bot. J. Linn. Soc. 133:1–26. Posluzny, U., Gerrath, J.M. 1986. The vegetative and floral development of the hybrid grape cultivar ‘Ventura’. Canad. J. Bot. 64:1620–1631. Rehder, A.A. 1905. Die amerikanischen Arten der Gattung Parthenocissus. Mitt. Deutsch. Dendrol. Gesell. 14:129– 136. Rehder, A. 1908. The New England species of Psedera. Rhodora 10:24–27. Rehder, A.A. 1945. Moraceae, Hippocastanaceae et Vitaceae, nomina conservanda. J. Arnold Arb. 26:277–279. Reid, E.M., Chandler, M.E.J. 1933. The London Clay Flora. London: British Museum (Natural History).

Vitaceae Reille, M. 1967. Contribution à l’étude palynologique de la famille des Vitacées. Pollen Spores 9:279–303. Ren, H., Pan, K.-Y., Chen, Z.-D., Wang, R.-Q. 2003. Structural characters of leaf epidermis and their systematic significance in Vitaceae. Acta Phytotax. Sin. 41:531–544. Ridley, H.N. 1930. The dispersal of plants throughout the world. Kent: L. Reeve. Ridsdale, C.E. 1974. A revision of the family Leeaceae. Blumea 22:57–100. Rossetto, M., McNally, J., Henry, R.J. 2001a. Evaluating the potential of SSR flanking regions for examining taxonomic relationships in Vitaceae. Theoret. Appl. Genet. 103:61–66. Rossetto, M., Jackes, B.R., Scott, K.D., Henry, R.J. 2001b. Intergeneric relationships in the Australian Vitaceae: new evidence from cpDNA analysis. Genet. Resources Crop Evol. 48:307–314. Rossetto, M., Jackes, B.R., Scott, K.D., Henry, R.J. 2002. Is the genus Cissus (Vitaceae) monophyletic? Evidence from plastid and nuclear ribosomal DNA. Syst. Bot. 27:522–533. Sax, K. 1930. Chromosome counts in Vitis and related genera. Proc. Amer. Soc. Hort. Sci. 26:32–33. Shah, J.J. 1959. Studies on the stipules of six species of Vitaceae. J. Arnold Arb. 40:398–412. Shah, J.J., Dave, Y.S. 1966. Are tendrils of Vitaceae axillary? Curr. Sci. 22:559–561. Shetty, B.V. 1959. Cytotaxonomical studies in Vitaceae. Bibliogr. Genet. 18:167–272.

479

Shetty, B.V., Singh, P. 2000. Vitaceae. In: Singh, N.P., Vohra, J.N., Hajra, P.K., Singh, D.K. (eds) Flora of India, vol. 5. Calcutta: Botanical Survey of India, pp. 246–324. Small, J.K. 1903. Flora of the southeastern United States. New York: published by the author on a press of The New Era Printing Company, Lancaster, PA. Soltis, D.E. et al. 2000. See general references. Suessenguth, K. 1953a. Vitaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 20d. Berlin: Duncker & Humblot, pp. 174–333. Suessenguth, K. 1953b. Leeaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 20d. Berlin: Duncker & Humblot, pp. 372–390. Takhtajan, A. 1997. See general references. Tiffney, B.H., Barghoorn, E.S. 1976. Fruits and seeds of the Brandon Lignite. I. Vitaceae. Rev. Palaeobot. Palynol. 22:169–191. Troll, W. 1969. Die Infloreszenzen, vol. 2, 1. Stuttgart: G. Fischer. Tucker, S.C., Hoefert, L.L. 1968. Ontogeny of the tendril in Vitis vinifera. Amer. J. Bot. 55:1110–1119. Urban, I. 1926. Plantae Haitienses novae vel rariores II. Arkiv Bot. 20A, 5:1–65, with 3 pls. Viala, P. 1910. Ampélographie générale. In: Viala, P., Vermorel, V. (eds) Ampélographie, vol. 1. Paris: Masson, pp. 3–108. Walter, H. 1921. Über Perldrüsenbildung bei Ampelideen. Flora 13:187–231. Wheeler, E.A., LaPasha, C.A. 1994. Woods of the Vitaceae – fossil and modern. Rev. Palaeobot. Palynol. 80:175–207.

Vochysiaceae Vochysiaceae A. St.-Hil., Mém. Mus. Natl Hist. Nat. 6, 4:253–270 (1820) (Vochisieae).

M.L. Kawasaki

Tall trees to shrubs, Al-accumulating; hairs, when present, simple or stellate. Leaves opposite or verticillate, simple, entire; venation brochidodromous or eucamptodromous; stipules usually present, often modified into glands or associated with extrafloral nectaries. Inflorescences thyrses (panicles of cincinni), cincinni, or racemes, terminal or axillary. Flowers with prophylls, bisexual, strongly zygomorphic, hypogynous or epigynous; calyx 5-merous, connate at base, often unequal, the largest one usually spurred; petals 1, 3, or 5, rarely 0, free, clawed, white, yellow, pink, or purple, caducous; stamen 1, anther dorsifixed or basifixed, commonly sagittate, longitudinally dehiscent; staminodes 0–4; ovary 1- or 3-locular; style simple; stigma terminal or lateral; ovules 1– many per locule; placentation axile or apical. Fruit a loculicidal capsule or samaroid, 4–5-winged by the unequally enlarged and persistent calyx-lobes. Seeds 1–several, exalbuminous, often winged and hairy; testa chartaceous; embryo straight. A family comprising about 200 species in seven genera, five of which are neotropical; two genera in West Africa. Vegetative Morphology. Vochysiaceae are shrubs or trees, often very large. Species of Qualea, Vochysia, and especially Erisma are some of the tallest trees of the Amazon basin, reaching c. 50 m high; many have well-developed buttresses. The indumentum, when present, is usually composed of simple hairs. Stellate hairs are observed only in Erisma. Leaves of Vochysiaceae are always simple and entire, opposite and secondarily distichous in Callisthene, opposite in Erismadelphus, Korupodendron, and Qualea, opposite or verticillate in Vochysia, or usually opposite in Erisma. The venation is brochidodromous or eucamptodromous. Stipules are usually present (e.g., Fig. 166A); in Qualea, they are often modified into glands or associated with extrafloral nectaries (Fig. 167A). Cataphylls are commonly observed at the base

of branchlets and inflorescences in Callisthene (Fig. 168A), and less often in Qualea. Vegetative Anatomy. The epidermis commonly has mucilaginous cells; crystals of calcium oxalate are solitary or in clusters. The leaves are usually dorsiventral; the stomates are anomocytic (Erisma, Salvertia, and Vochysia) or paracytic (Callisthene and Qualea) (Metcalfe and Chalk 1950; Sajo and Rundall 2002). Cork is pericyclic. The wood is characterized by the presence of vestured vessel pitting, only libriform fibers, banded axial parenchyma (apotracheal in Callisthene, Erisma, Erismadelphus; paratracheal in Qualea, Salvertia, Vochysia), and intercellular canals. Rays are homocellular (Qualea and Salvertia) or heterocellular (Callisthene, Erisma, Erismadelphus, Vochysia); they are all uniseriate in Erismadelphus, predominantly multiseriate in Callisthene and Qualea, and often predominantly uniseriate in Salvertia, Vochysia, and Erisma (Quirk 1980). Included phloem is present only in Erisma and Erismadelphus. Flower Structure and Anatomy. In Vochysiaceae, the basic element of the inflorescence is a one- to several-flowered cincinnus that is usually arranged in racemes, panicles, or thyrses. The flowers are bisexual and strongly zygomorphic, hypogynous (tribe Vochysieae), or epigynous (tribe Erismeae). The calyx is formed by 5 subequal or unequal lobes connate at the base; the largest one is commonly spurred, deciduous in Erisma. The spur develops from the floral axis (Kopka and Weberling 1984), and its morphology is taxonomically useful at the species level. There are five white petals in Erismadelphus, Korupodendron, and Salvertia, usually three yellow petals (rarely absent) in Vochysia, or one white, yellow, pink, or purple petal in Callisthene, Erisma, and Qualea. The stamen is characteristically solitary, standing in the plane of symmetry, in front of

Vochysiaceae

Fig. 165. Vochysiaceae. Salvertia convallariodora. A Habit. B Flower bud. C Anthetic flower. D Stamen. E Transverse section of ovary. F Longitudinal section of ovary. G Fruit. H Seed. (Orig.)

the spurred calyx-lobe in Erismadelphus, Salvertia, and Vochysia, or outside the plane of symmetry in Callisthene, Erisma, and Qualea. The usually sagittate anther is dorsifixed or basifixed; in the species of Qualea sect. Trichanthera (recognized at generic rank as Ruizterania by Marcano-Berti 1969), the anther is conspicuously barbate. Two staminodes are commonly present. In tribe Vochysieae, the ovary is trilocular, with two (Salvertia and Vochysia) to several (Callisthene and Qualea) axile ovules per locule. Erismeae have unilocular ovaries with one (Erismadelphus and Korupodendron) or two (Erisma) ovules. Embryology. Information on the embryology of Vochysiaceae is incomplete. In species of Qualea and Vochysia (Davis 1966; Boesewinkel and Venturelli 1987), the ovules are hemitropous, crassinucellate, and bitegmic. The ovule primordium is trizonate. The inner and outer integuments are initiated from dermal cells; both integuments form the micropyle.

481

Fig. 166. Vochysiaceae. Vochysia guianensis. A Habit, a node enlarged to show stipules. B Flower bud. C Anthetic flower. D Transverse section of ovary. E Longitudinal section of ovary. F Stamen. G Fruit. H Seed. (Orig.)

The nuclear endosperm is absent in the mature seed. The embryo is straight with two convolute (Vochysieae) or planoconvex (Erismeae) cotyledons. Pollen Morphology. Pollen grains are tricolporate, angulaperturate, with equatorially elongate endoapertures and columellate, reticulate or striate exine (Erdtman 1952; Makino-Watanabe 1995). The pollen of the northernmost species, Vochysia guatemalensis, is quite variable and is sometimes syncolpate (Ludlow-Wiechers 1980). Karyology. The few chromosome number counts reported for the family have indicated x = 11 or 12 (Cronquist 1981; Berry 1987). Pollination and Reproductive Systems. The numerous but ephemeral flowers with a single stamen often appear in the dry season, or at the transition between the dry and rainy season. This flowering pattern is common in neotropical plants,

482

M.L. Kawasaki

the flowers opening when potential pollinators are more likely to be available. The data on pollination biology of Vochysiaceae are incomplete. The markedly zygomorphic flowers, which have white, yellow, pink, or purple petals with adequate landing surface and often nectar guides, weak odor, and a single stamen, are characteristic of bee-pollination (Faegri and van der Pijl 1979). Bees have been observed visiting flowers of Vochysiaceae (Fischer and Gordo 1993), and they are probably rewarded by nectar accumulated in the spur. Pollination also by moths has been reported in Qualea grandiflora Mart. (Silberbauer-Gottsberger and Gottsberger 1975). Secondary pollen presentation occurs in Vochysia, when the pollen is initially deposited on the style and eventually transferred to pollinators (Yeo 1993). Fruit and Seed. The fruits of Vochysieae are loculicidal capsules with winged seeds. In Callisthene the capsule has a thick, central column and the exocarp is fragile, easily broken and separating from

the endocarp; an outgrowth of the testa surrounds the seed, forming the wing. The seed is unilaterally winged in Qualea, Salvertia, and Vochysia; in these genera, the wing is composed of hairs of the testa. The capsules have three (Salvertia and Vochysia) to several (Callisthene and Qualea) seeds. Erismeae comprise genera with samaroid fruits (pseudosamaras). The wings are represented by the accrescent, unequal, and persistent calyx-lobes that enclose the single seed; there are five wings in Erismadelphus and Korupodendron, and four wings in Erisma. Erisma calcaratum (Link) Warm. has oneseeded, wingless and nut-like fruits. The seed coat of Qualea is well differentiated: it has an endotestal crystal layer and a fibrous exotegmen underlain by tanniniferous cells. Callisthene is similar but the cell walls of the exotegmen do not thicken to any appreciable extent. In Vochysia, the inner integument and the inner, crystalliferous layer of the outer integument are resorbed during seed coat development, and the mature seed coat is derived from the outer integument alone. Erismeae have indehiscent fruits and the seed coat is relatively undifferentiated, being made up of a multilayered, compressed testa traversed by vascular bundles (Boesewinkel and Venturelli 1987). Dispersal. The species of Vochysiaceae are basically adapted for wind-dispersal; the fruits are either loculicidal capsules with winged seeds or samaroid. Nevertheless, with a few exceptions, most species have restricted distributions. The floating, nut-like fruits of Erisma calcaratum are adapted to water-dispersal, and apparently the seeds are effectively dispersed, since the species is widely distributed in the Amazon basin. Phytochemistry. There is no complete information on the phytochemistry of Vochysiaceae. The species of this family often have tanniniferous cells and accumulate aluminum (Metcalfe and Chalk 1950; Quirk 1980). No alkaloids, iridoid compounds, nor other chemical compounds of taxonomic significance have been reported (Dahlgren 1980).

Fig. 167. Vochysiaceae. Qualea rosea. A Habit, enlarged a ramified node with extrafloral nectaries. B Flower bud. C Anthetic flower. D Petal. E Transverse section of ovary. F Flower with petal removed, the ovary longitudinally sectioned. G Fruit. H Seed. (Orig.)

Subdivision and Relationships Within the Family. Vochysiaceae are traditionally divided into two tribes: Vochysieae and Erismeae. However, molecular studies do not support the traditional tribes and phylogenetic relationships among the genera (Litt 1996). Vochysieae, which may not be monophyletic, comprise Callisthene, Qualea,

Vochysiaceae

483

not in the plane of symmetry, and a deciduous spurred calyx-lobe, can be considered the most derived genus of the family. Affinities. In the traditional systems of classification (Tahktajan 1980, 1997; Cronquist 1981, 1988), Vochysiaceae have been related to Trigoniaceae, Polygalaceae, and Malpighiaceae. More recent, molecular studies (Chase et al. 1993; Conti et al. 1996), however, place the family in Myrtales. The bicollateral vascular bundles in the primary stem, and the vestured pitting in the secondary xylem (both absent from Polygalales) link Vochysiaceae with Myrtales, together with other characters from anatomy and embryology, while within Myrtales, Vochysiaceae are sister to Myrtaceae. Distribution and Habitats. The three African species of Vochysiaceae (Erismadelphus and Korupodendron) are found in the forests of Nigeria, Cameroon, Congo, and Gabon in

Fig. 168. Vochysiaceae. Callisthene major. A Habit, enlarged lateral shoot base with cataphylls. B Flower bud. C Anthetic flower. D Petal. E Transverse section of ovary. F Longitudinal section of ovary. G Fruits. H Seed. (Orig.)

Salvertia, and Vochysia. They are characterized by hypogynous flowers, a trilocular ovary, two to several ovules per locule, and loculicidal capsules with three to several winged seeds. Salvertia and Vochysia have in common the stamen in the plane of symmetry, two ovules per locule, and capsules with three, unilaterally winged seeds. The monotypic Salvertia, with five petals, would be less advanced than species of Vochysia, which usually have three petals. Qualea and Callisthene appear more advanced than Vochysia on the basis of having a single petal, the stamen standing outside the plane of symmetry, and the presence of specialized structures such as glands or extrafloral nectaries (Qualea), and capsules with a central column (Callisthene). Erismeae are likely to be monophyletic; they include Erisma, Erismadelphus, and Korupodendron. All have the derived features of epigynous flowers, a unilocular ovary, one or two ovules per locule, and samaroid fruits with a single seed. Erisma, comprising species with a single petal, the stamen

Fig. 169. Vochysiaceae. Erisma floribundum. A Habit, enlarged the stellate hairs. B External bract. C Floral bud. D Anthetic flower. E Spurred calyx-lobe. F Petal. G Longitudinal section of flower, showing the two apical ovules. H Unilocular ovary in transverse section. I Fruit. (Reprinted, with permission, from Kawasaki 1998)

484

M.L. Kawasaki

West Africa. All the other species of the family are neotropical. Salvertia convallariodora is distributed from Bolivia to southeastern, central and northern Brazil and Surinam, and typically grows in cerrado vegetation and at the transition between cerrado and forest. Species of Vochysia and Qualea, the largest genera of the family, are mainly South American and occur especially in the rainforests of the Amazon region, but also in Andean highland forests, lowland moist forests of eastern Brazil, and savannalike vegetation (llanos of Venezuela and Colombia; cerrados and campos rupestres of central and southeastern Brazil); few species of these genera are found in Central America. Most species of Erisma are found in tropical rainforests of the Amazon basin and the Guyanas. The geographic range of the genus has been extended to Central America and southeastern Brazil, with collections of Erisma blancoa in Panama and of E. arietinum in coastal forests of the state of Espírito Santo, Brazil. Except for E. calcaratum, which

grows in inundated forests, all the other species occur in non-flooded areas. The few species of Callisthene occur especially in cerrado vegetation of central, southeastern and northeastern Brazil, Bolivia, and Paraguay. Sytsma et al. (2004) argue for a dispersal event in order to account for the African lineage of the family, because the nesting of the three African species within the American taxa is strongly supported by both molecular and morphological data. Economic Importance. Although many species of Vochysiaceae are potentially significant as ornamental trees, none of them is known for its economic value. The wood is usually of low quality and mostly employed locally for the making of boards, boxes, or for other minor uses in carpentry. Seeds of Erisma calcaratum are used in the manufacturing of soaps and candles sold at local markets. The use of the resin of the bark and seeds as a source of food (e.g., Erisma japura) has been reported in ethnobotanical studies. Conservation. Species of Vochysiaceae are found mostly in the Amazonian forests and in the cerrados and campos rupestres of central and eastern Brazil. These types of vegetation, characterized by high endemism, are severely in need of preservation. Many species, especially those from Amazonia, have not been collected recently and several species are known only from a few collections (e.g., Erisma lanceolatum, Qualea elegans, Qualea macropetala, Vochysia catingae, Vochysia parviflora). Some species (e.g., Erisma arietinum, Qualea macrocarpa, Qualea magna, Vochysia glazioviana) are restricted to the moist, coastal forests of southeastern Brazil, widely known as one of the most endangered regions of the world.

Key to the Genera

Fig. 170. Vochysiaceae. Erismadelphus exsul. A Habit, node with stipules enlarged. B Floral bud. C Anthetic flower. D Longitudinal section of ovary. E Transverse section of ovary. F Stamen. G Fruit. (Orig.)

1. Hairs simple. Flowers hypogynous; ovary 3-locular. Fruit a loculicidal capsule; seeds 3 to several, winged 2 – Hairs usually stellate. Flowers epigynous; ovary 1-locular. Fruit samaroid by the accrescent and persistent calyx-lobes, or nut-like; seed 1, without wings 5 2. Petals usually 3, less frequently 5; ovules 2 per locule 3 – Petal 1; ovules several per locule 4 3. Petals 5, white; style incrassate, stigma lateral 1. Salvertia

Vochysiaceae – Petals usually 3, yellow; style cylindric, not incrassate, stigma terminal or lateral 2. Vochysia 4. Stipules transformed into glands or associated with extrafloral nectaries. Capsule without a distinctive central column; exocarp thick, attached to endocarp 3. Qualea – Stipules obsolete, not transformed into glands nor associated with extrafloral nectaries. Capsule with a distinctive central column; exocarp thin, not attached to endocarp 4. Callisthene 5. Spurred calyx-lobe deciduous; petal 1; ovules 2 per locule. Fruit with 4 wings or nut-like. Neotropical 5. Erisma – Spurred calyx-lobe persistent; petals 5; ovule 1 per locule. Fruit with 5 wings. African 6 6. Calyx-lobes subequal 6. Erismadelphus – Calyx-lobes unequal, three larger and petaloid 7. Korupodendron

Genera of Vochysiaceae I. Tribe Vochysieae Dumort. (1829). Hairs simple. Flowers hypogynous; ovary 3locular; ovules 2–several per locule, axile. Fruit a loculicidal capsule; seeds 3–several, winged. 1. Salvertia A. St.-Hil.

Fig. 165

Salvertia A. St.-Hil., Mém. Mus. Natl Hist. Nat. 6, 4:259 (1820); Stafleu, Recueil Trav. Bot. Néerl. 41:398–540 (1948).

Trees or shrubs. Leaves verticillate, in whorls of 4 to several; stipules very small, deciduous. Inflorescences panicles of cincinni or thyrses, terminal; spurred calyx-lobe persistent; petals 5, white; stamen in the plane of symmetry; stigma lateral; ovules 2 per locule. Seeds 3, unilaterally winged. A single species, S. convallariodora A. St.-Hil., in Brazil, Bolivia, and Surinam. 2. Vochysia Aubl.

Fig. 166

Vochysia Aubl., Hist. Pl. Guiane 18 (1775); Stafleu, Recueil Trav. Bot. Néerl. 41:398–540 (1948).

Large trees to shrubs. Leaves opposite or verticillate, in whorls of 3 or 4; stipules present, often deciduous. Inflorescences thyrses or racemes, usually terminal; spurred calyx-lobe persistent; petals usually 3, yellow, rarely absent; stamen in the plane of symmetry; stigma terminal or lateral; ovules 2 per locule. Seeds 3, unilaterally winged. About 100 species, from Central to South America. The genus is divided into three sections (Stafleu 1948): sect. Vochysiella, sect. Ciliantha, and sect. Pachyantha.

3. Qualea Aubl.

485

Fig. 167

Qualea Aubl., Hist. Pl. Guiane 5 (1775); Stafleu, Acta Bot. Neerl. 2:144–217 (1953). Ruizterania Marcano-Berti (1969).

Large trees to shrubs. Leaves opposite; stipules present, often replaced by glands or associated with extrafloral nectaries. Inflorescences cincinni or panicles of cincinni, terminal or axillary; largest calyx-lobe usually spurred, persistent; petal 1, in front of spurred calyx-lobe, white, yellow, pink, or purple; stamen outside the plane of symmetry; stigma terminal; ovules several per locule. Seeds several, unilaterally winged. Circa 60 species, from Central to South America. Stafleu (1953) recognized two subgenera: subg. Qualea with four sections (Trichanthera, Qualea, Costatifolium, Polytrias) and subg. Amphilochia (Mart.) Stafleu. Section Trichanthera was recognized as a separate genus, Ruizterania, by Marcano-Berti (1969). 4. Callisthene Mart.

Fig. 168

Callisthene Mart. in Mart. & Zucc., Nov. Gen. Sp. Pl. 1:123 (1824); Warming, Fl. Brasil. 13, 2:21–29 (1875); Stafleu, Acta Bot. Neerl. 1:222–242 (1952).

Trees or shrubs; cataphylls often present at the base of branchlets and inflorescences. Leaves opposite, distichous; stipules obsolete. Inflorescences axillary cincinni; spurred calyx-lobe persistent; petal 1, in front of spurred calyx-lobe, white to yellow; stamen outside the plane of symmetry; stigma terminal; ovules several per locule. Fruit with a thick, central column, the exocarp separating from the endocarp; seeds 3–several, circularly winged. About 10 species in central and eastern Brazil, Paraguay, and Bolivia. Two sections were recognized by Stafleu (1952): Callisthene and Cathaphyllantha. II. Tribe Erismeae Dumort. (1829). Hairs usually stellate. Flowers epigynous; ovary 1locular, 1–2 ovules per locule, apical or lateral. Fruit samaroid by the accrescent and persistent calyxlobes, or nut-like; seed 1, without wings. 5. Erisma Rudge

Fig. 169

Erisma Rudge, Pl. Guianae 1:7 (1805); Warming, Fl. Brasil. 13, 2:106–114 (1875); Stafleu, Acta Bot. Neerl. 3:459–480 (1954); Kawasaki, Mem. New York Bot. Gard. 81:1–40 (1998).

486

M.L. Kawasaki

Emergent or canopy trees. Hairs stellate. Leaves opposite, rarely in tetramerous whorls; stipules present or absent. Inflorescences panicles of cincinni, usually terminal; spurred calyx-lobe obcordate, convolute, the outer side sepal-like, the inner side petal-like, deciduous; petal 1, in front of spurred calyx-lobe, white to yellow, or purple; stamen outside the plane of symmetry; stigma terminal, capitate; ovules 2. Fruit indehiscent, samaroid, 4-winged (fruit wingless and nut-like only in E. calcaratum (Link) Warm.). Sixteen species in Central and South America, mostly in Brazilian Amazon. 6. Erismadelphus Mildbr.

Fig. 170

Erismadelphus Mildbr., Bot. Jahrb. Syst. 49:549 (1913); Keay & Stafleu, Acta Bot. Neerl. 1:594–599 (1953).

Trees. Hairs simple. Leaves opposite; stipules present. Inflorescences panicles of cincinni, usually terminal; spurred calyx-lobe persistent; petals 5, white; stamen in the plane of symmetry; stigma terminal, capitate; ovule 1. Fruit indehiscent, samaroid, 5-winged. Two species, E. exsul Mildbr. and E. sessilis Keay & Stafleu in West Africa. 7. Korupodendron Litt & Cheek Korupodendron Litt & Cheek, Brittonia 54:13–17 (2002).

Trees. Hairs simple. Leaves opposite. Inflorescences racemes; calyx-lobes unequal, three larger and petaloid; spurred calyx-lobe persistent; petals 5, white; stigma lateral; ovule 1. Fruit indehiscent, samaroid, 5-winged. A single species, K. songweanum Litt & Cheek in West Africa.

Selected Bibliography Berry, P. 1987. Chromosome number reports. XCV. Vochysiaceae. Taxon 36:493. Boesewinkel, F.D., Venturelli, M. 1987. Ovule and seed structure in Vochysiaceae. Bot. Jahrb. Syst. 108:547–566. Chase, M.W. et al. 1993. See general references. Conti, E., Litt, A., Sytsma, K.J. 1996. Circumscription of Myrtales and their relationships to other rosids: evidence from rbcL sequence data. Amer. J. Bot. 83:221–233. Cronquist, A. 1981. See general references. Cronquist, A. 1988. The evolution and classification of flowering plants, ed. 2. Bronx: New York Botanical Garden. Dahlgren, R.M.T. 1980. A revised system of classification of angiosperms. Bot. J. Linn. Soc. 80:91–124.

Davis, G.L. 1966. See general references. Dumortier, B.C. 1829. Analyse des familles des plantes avec l‘indication des principaux genres qui s’y rattachent. Vochysiaceae. Tournay: J. Casterman. Erdtman, G. 1952. See general references. Faegri, K., Pijl, L. van der 1979. The principles of pollination ecology, 3rd edn. New York: Pergamon Press. Fischer, E.A., Gordo, M. 1993. Qualea cordata, pollination by the territorial bee Centris tarsata in the “campos rupestres”, Brazil. Ci. Cult. 45:144–146. Hilaire, A. de St. 1820. Mémoire sur la nouvelle famille des Vochysiées. Mém. Mus. Natl Hist. Nat. 6, 4:253–270. Kawasaki, M.L. 1998. Systematics of Erisma (Vochysiaceae). Mem. New York Bot. Gard. 81:1–40. Keay, R.W.J., Stafleu, F.A. 1952. Erismadelphus. Acta Bot. Neerl. 1:594–599. Kopka, S., Weberling, F. 1984. Zur Morphologie und Morphogenese der Blüte von Vochysia acuminata Bong. subsp. laurifolia (Warm.) Stafleu (Vochysiaceae). Beitr. Biol. Pflanzen 59:273–302. Litt, A. 1996. Phylogeny of the Vochysiaceae: implications of molecular data for floral evolution. Amer. J. Bot. 83 (abstracts): 175. Litt, A., Cheek, M. 2002. Korupodendron songweanum, a new genus and species of Vochysiaceae from West-Central Africa. Brittonia 54:13–17. Litt, A., Stevenson, D.W. 2003a. Floral development and morphology of Vochysiaceae. I. The structure of the gynoecium. Amer. J. Bot. 90:1533–1547. Litt, A., Stevenson, D.W. 2003b. Floral development and morphology of Vochysiaceae. II. The position of the single fertile stamen. Amer. J. Bot. 90:1548–1559. Ludlow-Wiechers, B. 1980. Catálogo palinológico para la flora de Veracruz, no. 3. Biota 5:181–190. Makino-Watanabe, H. 1995. Flora polínica da reserva do parque estadual das Fontes do Ipiranga (São Paulo, Brasil). Hoehnea 22:141–146. Marcano-Berti, L. 1969. Un nuevo género de las Vochysiaceae. Pittieria 2:3–27. Metcalfe, C.R., Chalk, L. 1950. See general references. Mildbraed, J. 1913. Erismadelphus exsul Mildbr. n. gen. et spec. eine Vochysiacee aus Kamerun. Bot. Jahrb. Syst. 49:547–551. Quirk, J.T. 1980. Wood anatomy of the Vochysiaceae. IAWA Bull. 1, 4:172–179. Sajo, M.G., Rudall, P. 2002. Leaf and stem anatomy of Vochysiaceae in relation to subfamilial and suprafamilial systematics. Bot. J. Linn. Soc. 138:339–364. Silberbauer-Gottsberger, I., Gottsberger, G. 1975. Über spingophile Angiospermen Brasiliens. Pl. Syst. Evol. 123:157–184. Stafleu, F.A. 1948. A monograph of the Vochysiaceae. I. Salvertia and Vochysia. Recueil Trav. Bot. Néerl. 41:398–540. Stafleu, F.A. 1951. Vochysiaceae. In: Pulle, A. (ed.) Flora of Suriname 3, 2:178–199. Amsterdam: Koninklijke Vereeniging Indisch Instituut. Stafleu, F.A. 1952. A monograph of the Vochysiaceae. II. Callisthene. Acta Bot. Neerl. 1:222–242. Stafleu, F.A. 1953. A monograph of the Vochysiaceae. III. Qualea. Acta Bot. Neerl. 2:144–217.

Vochysiaceae Stafleu, F.A. 1954. A monograph of the Vochysiaceae. IV. Erisma. Acta Bot. Neerl. 3:459–480. Sytsma, K.J., Litt, A., Zjhra, M.L., Pires, J.C., Nepokroeff, M., Conti, E., Walker, J., Wilson, P.G. 2004. Clades, clocks, and continents: historical and biogeographical analysis of Myrtaceae, Vochysiaceae, and relatives in the southern hemisphere. Intl J. Pl. Sci. 165 suppl. 4:S85– S105.

487

Takhtajan, A.L. 1980. Outline of the classification of flowering plants (Magnoliophyta). Bot. Rev. 46:225–359. Takhtajan, A. 1997. See general references. Warming, E. 1875. Vochysiaceae. In: Martius, C.F.P. von (ed.) Flora Brasiliensis 13, 2:17–116, t. 2–21. Munich: R. Oldenburg. Yeo, P.F. 1993. Secondary pollen presentation: form, function, and evolution. Pl. Syst. Evol. suppl. 6:94–95.

Zygophyllaceae Zygophyllaceae R. Br., Flind. Voy. Bot. app. 3:545 (1814). Balanitaceae Endl. (1841).

M.C. Sheahan

Trees, shrubs, subshrubs or annual or perennial herbs, often with jointed branches and swollen at the nodes; axillary or stipular thorns sometimes present. Leaves stipulate, opposite or less often alternate, bi- or trifoliolate or pinnately multifoliolate, rarely simple; usually petiolate, rarely with glandular dots, sometimes unequal; leaf(let) lamina entire, often asymmetric, flattened, fleshy or terete. Flowers solitary, paired or in few-flowered cymes, axillary or terminal, bisexual, actinomorphic or rarely slightly zygomorphic; sepals 4–6, ± free, rarely connate at base, usually imbricate, valvate in Seetzenia; petals free, often clawed, mostly as many as sepals, rarely 0; disc often present; stamens (5)8–12 as many as or twice the number of petals and then obdiplostemonous; filaments sometimes with basal scales or appendages; anthers introrse, dorsifixed, 4-sporangiate, with longitudinal dehiscence; ovary syncarpous, superior, sessile or shortly stipitate, angular, ribbed or winged, (2–)4–5(–12)-locular; style filiform or subulate; stigma capitate, clavate or slightly lobed or ridged; ovules 1 to many per locule, bitegmic, pendulous, usually with axile placentation. Fruit a loculicidal or septicidal capsule, or splitting into mericarps which may be winged, lobed or angled, spiny or tuberculate; rarely a 1-seeded drupe (Balanites). Seeds with or without endosperm; embryo straight or slightly curved. Comprising 22 genera and 230–240 species in hot dry regions of Europe, Asia, Australia, Africa and the Americas. Vegetative Morphology. Leaves are opposite in subfamilies Zygophylloideae, Larreoideae and Seetzenioideae, and alternate in Morkillioideae. In Tribuloideae, Tribulopis, Neoluederitzia and Balanites have alternate leaves; in Tribulus and Kallstroemia, they are opposite but unequal and are sometimes apparently alternate by abortion of the smaller leaf of a pair; in Kelleronia and Sisyndite, the lower leaves are predominantly alternate but

the upper leaves may be opposite. In genera with opposite leaves, often only one branch develops at each node, so branching may appear alternate (e.g. in Guaiacum, Porlieria, Zygophyllum). The leaves may be bi- or trifoliolate or pinnately compound, and are only rarely simple. Hunziker et al. (1977) regard multifoliolate as the more primitive condition, with the bifoliolate species representing a reductional trend in response to aridity. Other adaptations to the often extreme habitats where many members of the family are found include a similar pattern of reduction of leaf area. In some species such as Zygophyllum dumosum and Sisyndite spartea, the leaflets fall, leaving only the photosynthesing petiole or rachis. Simple leaves, as in Zygophyllum simplex, may have evolved as an extreme expression of this tendency. As many species lose all their stems and branches under arid conditions, they are sometimes referred to as perennial herbs (e.g. by Borisova 1974). When a persistent woody base remains, however, it is more accurate to call the plants suffrutescent shrubs or, in Raunkiaer’s classification, chamaephytes. Nyctinasty is reported in some genera with pinnate leaves, notably Porlieria. Vegetative Anatomy. The two main types of leaf anatomy represent different adaptations to often extreme habitats. Leaves may be succulent with a thin cuticle, shallow epidermis, slender veins, abundant water-storage and scanty mechanical tissue, as in many Zygophyllum, or have small leaves, small stomata and a high proportion of palisade tissue, as in Larrea. The main types of mesophyll arrangement are dorsiventral, more or less isolateral, and centric (in cylindrical leaves, with central water-storage tissue). In leaves and leaflets with a flat lamina, venation is pinnate, reticulate, camptodromousbrochidodromous, with more or less straight primary veins, randomly ordered higher-order veins,

Zygophyllaceae

and incomplete or imperfect areoles (terminology from Hickey 1973); cylindrical leaves have one or two central veins with a peripheral network of smaller veins. There are sometimes abundant, dilated tracheoids associated with veinlet endings. Stomata are usually anomocytic, sometimes paracytic or weakly actinocytic. Trichomes are usually unicellular and either one- or two-armed; however, Fagonia has glandular trichomes with a unicellular head on a multicellular stalk (Fahn and Shimony 1996), and lobed, peltate trichomes were seen in two central Asian species, Zygophyllum eurypterum and Z. darvasicum (Sheahan and Cutler 1993). In stems, there are commonly separate strands of thick-walled fibres and stone cells in the cortex. Phloem sieve elements are usually small (diam. 5– 8 µm), with compound sieve plates. Sieve-element plastids are reported to be mainly S-type but P-type, with two different-sized protein crystals, have been seen in Larrea divaricata (Behnke 1988). There is much storeying of elements of the secondary xylem. The wood is characterised by short, frequently solitary xylem vessels with simple perforations, small alternate intervascular pitting and horizontal to oblique end walls. Other tracheary elements are narrow (< 25 µm) and short (80–160 µm); fibre-tracheids, libriform fibres and gradations between the two may be present; in several species there are also vasicentric tracheids. Rays are usually short and homocellular, mostly 1–2 (rarely 3–4) cells wide. Axial parenchyma is mainly apotracheal, occasionally paratracheal, diffuse or sometimes sub-reticulate; cells are fusiform, sometimes with cross-walls. Balanites is reportedly different from other members of the family in having taller, wider rays (up to 35 cells wide) and vestured intervascular pits, although vesturing has also been observed in several other members of the family (Parameswaran and Conrad 1982; Jansen et al. 2001). Nodes are typically trilacunar; the three traces entering the base of the leaf are derived as a median and two ‘split laterals’ which depart at the lateral gaps and divide to girdle the stem towards each of the opposite leaves (Howard 1970). Zygophyllaceae are one of about 18 families in which the C4 photosynthetic pathway is found. All Tribulus so far examined have shown the C4 pathway. However, Kallstroemia and Zygophyllum are among the few dicot genera reported to have both C3 and C4 species: all species of Kallstroemia except one, K. perennans (Smith and Robbins 1974), are C4 plants but, in Zygophyllum, only Z. simplex

489

has so far been categorised as C4 (Welkie and Caldwell 1970; Sheahan and Cutler 1993). All C4 species exhibit typical Kranz anatomy, except Z. simplex which has centric leaves, and the Kranz cells form an incomplete sheath around only the outer part of the vein. Flower Structure. The flowers are insectpollinated. They are most often axillary, sometimes terminal or leaf-opposed, and may be solitary or aggregated into few-flowered cymes. The calyx is uniseriate, sometimes unequal; where present, the petals are of the same number as the sepals and may be white, pink, purple, blue or yellowish (absent in Seetzenia and Zygophyllum portulacoides). A hypogynous disc is often present, although sometimes inconspicuous, and may be (4)5- or 10-angled or -lobed; nectariferous glands are also sometimes present (Fig. 173C). Neoluederitzia has a structure formed from scales enclosing the ovary which apparently arise from the disc, although according to Engler (1931), they are formed from the stamens. Stamens are usually twice the number of sepals, in two whorls; in Tribulus, Tribulopis and Kallstroemia, the antesepalous whorl may be sterile or absent. The anthers sometimes have winged filaments. Fringed or divided scale-like appendages occur in many taxa at the base of the filament; the presence or absence of these has sometimes been used to distinguish taxa but, in combined molecular and morphological analyses, this character appears to be useful only within individual genera. Carpels are usually of the same number as the sepals, but are double the number in Augea and Kallstroemia. The locules contain one to several ovules, although often only one matures. Embryology. Information is summarised by Davis (1966) and Johri et al. (1992). Pollen tetrads are tetrahedral and decussate. Pollen grains are 2-celled when shed in Zygophyllum and Seetzenia, 3-celled in Fagonia and Balanites. Ovules are anatropous, bitegmic and crassinucellate; a single embryo sac develops, of the Polygonum type. Endosperm formation is nuclear, with wall formation beginning at the micropylar end. Embryogeny is mostly of the Solanad type, but Tribulus terrestris and Zygophyllum fabago are reported to be of the Caryophyllad type. Pollen Morphology. Data on pollen morphology are mainly from Erdtman (1952); later studies include Mathur and Bhandari (1983), Lahham and

490

M.C. Sheahan

Al-Eisawi (1986), Praglowski (1987), Yi and Zhou (1992) and Singh and Kaur (1998); however, not all genera have been examined. The pollen is eurypalynous and is heterogeneous, even at subfamily level. In most of the family, pollen grains are tricolpate, tricolporate or tricolporoidate, rarely 6rugorate. Exine thickness varies in the range 1– 8 µm; the sexine is usually of the same thickness as the nexine but may be thicker, e.g. in Seetzenia. Exine ornamentation is mainly reticulate, occasionally also described as rugulate, baculate and retipilate. The grains vary in shape from prolate to oblatespheroidal; they also vary in size, the longest axis from 10 to 67 µm. However, Tribulus, Kallstroemia and Kelleronia are distinct from the rest of the family in having reticulate polyporate spheroidal pollen. They differ in this even from other members of the same subfamily, e.g. Neoluederitzia, Sisyndite and Balanites. Karyology. Many different base numbers have been recorded in the family, from 6 to 15; x = 13 predominates in Larreoideae. Chromosome sizes are small, and therefore it may be necessary to treat some of the reports with circumspection. There are some clearly defined polyploid series: e.g. 2×, 4× and 6× in Larrea tridentata (x = 13) and 2×, 4×, 6× and 8× in Tribulus terrestris (x = 6). In Zygophyllum, base numbers of 8, 9, 10 and 11 have been reported – further evidence of the heterogeneity of this genus. Poggio et al. (1989) reported that in the South American genera Larrea, Bulnesia and Pintoa, an increase in DNA content was found in species which inhabit the most arid environments, derived from an increase either in ploidy level (Larrea) or in intrachromosomal DNA (Bulnesia and Pintoa). Poggio et al. (1992) also drew attention to variations in both chromosome morphology and DNA content in Zygophyllaceae. Fruit and Seed. The commonest form of fruit is a capsule, which may be loculicidally dehiscent, or separate septicidally into dehiscent or indehiscent mericarps. There is much variation in the shape and surface features of the capsule, which may be lobed, winged or spiny, and the surface smooth, warty, pubescent or sericeous. In some genera, e.g. Fagonia, Seetzenia and Tribulus, a persistent central column remains. Balanites is unusual in the family in having a drupe with bony endocarp (Fig. 174). Seed coat structure is degraded in genera with indehiscent fruits or endocarp cocci and, in

the capsular genera, both the endotesta and/or endotegmen may be lignified or not (Corner 1976). Dispersal. The diverse fruit morphology is related to different methods of dispersal. Seeds from loculicidally dehiscent capsules are shaken out by wind; winged schizocarps, as in Bulnesia (Fig. 171B), can be dispersed by wind, and fruits with very long hairs, such as in Neoluederitzia and Sisyndite, may also be adapted for wind-blown dispersal across the desert. Some species of Tribulus have become widespread weeds because their spiny fruits (Fig. 173D) can become attached to the feet and skin of animals (and sometimes also become embedded in car tyres). Kallstroemia fruits lack such projections, and Porter (1969) conjectures that they may be eaten by animals and pass through unharmed. The capsules of Guaiacum open to expose colourful arillate seeds (Fig. 172E), which are probably dispersed by birds or perhaps insects; some Zygophyllum also have arillate seeds. The seed coat of many species becomes mucilaginous when wet and sticks to birds’ feet, e.g. in Augea and many species of Zygophyllum. According to Boesewinkel (1994), dispersal of Balanites seeds can be by elephants. Phytochemistry. (Information taken mainly from Hegnauer 1973, 1990.) Phenolic compounds including methylated flavonoids and lignans are frequent in the family. Lignans and neolignans abound both in terms of different compounds and quantity, and the wood of Guaiacum contains 15–20% resin, mainly constituted of lignans. The neolignan nordihydroguaiaretic acid (NDGA) is known from Bulnesia, Guaiacum, Porlieria and Larrea. In Larrea, the leaves are covered by wax and appear “varnished” (Volkens 1890); the wax is a complex mixture containing much NDGA (up to 10% of the dry weight of the leaves of L. tridentata) and various methylated flavonoid aglycones. The high reactivity of NDGA to oxygen and especially the reactivity of the oxidised NDGA to hydroxyl and amino groups probably account for its effectiveness as a defence substance against herbivores (Mabry et al. 1977b). Zygophyllaceae are among the relatively few families which produce steroid and triterpenoid saponins. According to Hegnauer (1990), these may also be responsible for the observed resistance to herbivore activity. The family also produces the quinazoline alkaloids harman (e.g. in Fagonia cret-

Zygophyllaceae

ica and Tribulus terrestris), harmin and harmol (in Zygophyllum fabago). Mucilages have been found in the leaf epidermis of Augea and are reported in the epidermis of Plectrocarpa (Castro 1981); they may also be abundant in seeds, for example, in Augea and species of Zygophyllum. Calcium oxalate crystals are frequent, sometimes very abundant; these are mostly druses but styloid, prismatic and acicular crystals occur, too. Subdivision and Relationships within the Family. Systematic relationships within the family have long been the subject of disagreement. Even when Nitraria, Peganum, Malacocarpus and Tetradiclis are excluded (see Affinities below), Zygophyllaceae remain a heterogeneous family. Balanites has often been thought of as a separate family Balanitaceae, and in the past it has also been suggested that some other genera (e.g. Tetraena, Seetzenia, and members of the tribuloid group) should be segregated into separate families. Engler (1896a, 1931) divided the family into seven subfamilies (as well as a number of tribes and subtribes), three of which (Nitrarioideae, Peganoideae and Tetradiclidoideae) are now excluded. The remaining four were Morkillioideae (as Chitonioideae), Balanitoideae, Zygophylloideae and Augeoideae (although subsequently Engler had second thoughts about Augeoideae, considering that its sole representative Augea should be included in Zygophylloideae; Engler 1896b). Recent molecular work has led to a review of the taxonomy of the family (Sheahan and Chase 1996, 2000). According to these studies, the inclusion of Augea in Zygophylloideae has been confirmed, as has the monophyly of Engler’s Morkillioideae (Morkillia, Viscainoa, Sericodes). Balanites, the sole member of Engler’s Balanitoideae, appears embedded within the tribuloid group, in spite of many morphological and anatomical autapomorphies, and this relationship is supported by chemical similarities (Maksoud and El-Hadidi 1988; Narayana et al. 1990). It has also been proposed that Engler’s Zygophylloideae should be divided into four well-supported monophyletic subfamilies: Seetzenioideae, Larreoideae, Tribuloideae and Zygophylloideae sensu stricto (Sheahan and Chase 1996, 2000). Seetzenia was previously thought to be related to Fagonia, chiefly on account of its three-foliolate leaves, but palynological and chemical evidence (Erdtman 1952; Lahham and

491

Al-Eisawi 1986) as well as molecular data support its isolated position in a separate subfamily. Subfamily Larreoideae contains the New World genera Larrea, Bulnesia, Porlieria and Guaiacum. According to Lia et al. (2001), Plectrocarpa belongs in this subfamily and, by implication, also Metharme. Tribulus, Tribulopis, Kallstroemia and Kelleronia form a natural group characterised by opposite, even-pinnate leaves, indehiscent mericarps, polyporate pollen and non-endospermic seeds. Neoluederitzia and Sisyndite appear, with Balanites, in a clade sister to these four genera; however, the exact relationships between members of this subfamily need further clarification. The remaining genera of the restricted Zygophylloideae are Zygophyllum, Augea, Fagonia and Tetraena. A substantial revision of this subfamily has recently been made, using both molecular and morphological characters, by Beier et al. (2003) who have made promising suggestions for new genera and combinations. They found six monophyletic (albeit not always well supported) groups within the subfamily: Fagonia and Augea retain their generic status; Tetraena appear embedded within one clearly defined section of Zygophyllum growing mainly in Arabia and Africa, to which the name Tetraena is transferred; the Zygophyllum species from Australia and southern Africa are assigned to a new genus Roepera; and two distinctive species of Zygophyllum found only in eastern Africa are assigned to a new genus Melocarpum. The remaining species of Zygophyllum sensu stricto, found mainly in Asia, are retained in Zygophyllum. Affinities. In past taxonomic accounts, Peganum, Malacocarpus, Tetradiclis and Nitraria have often been included in the family, sometimes in separate subfamilies (see Sheahan and Cutler 1993 for an overview of earlier taxonomic treatments). More recent molecular studies, in which these genera were analysed in an rbcL matrix including other members of Zygophyllaceae as well as a large number of representatives from other eurosid families (Gadek et al. 1996; Sheahan and Chase 1996; Savolainen, Fay et al. 2000), have indicated that they have affinities to other families in Sapindales, within the eurosid II group sensu APG (1998). They are therefore not considered to be close to Zygophyllaceae and will be dealt with elsewhere in this series. Earlier studies associated Zygophyllaceae sensu lato with a number of different orders, e.g.

492

M.C. Sheahan

Malpighiales, Sapindales, Rutales, Polygalales and Linales, but most commonly with Geraniales. With the removal of the four genera above, and the use of molecular evidence from a number of different genes (Savolainen, Fay et al. 2000; Soltis et al. 2000), it appears that the remaining genera of Zygophyllaceae form an isolated monophyletic clade together with Krameriaceae, a monogeneric family of hemi-parasitic shrubs and herbs from the arid and semiarid neotropics, although the two families share few morphological similarities. Soltis et al. (2000) propose placement of these two families together in their own order Zygophyllales, within the eurosid I group, and this position is confirmed in APG II (2003). Distribution and Habitats. Zygophyllaceae are an ancient family found in arid, semiarid and saline deserts throughout the world; some genera (e.g. Augea, Sisyndite) flourish in the driest habitats in which plant growth is possible. Several genera show disjunct distributions, four of them discussed in detail by Porter (1974). The case of Larrea is well known and is often quoted as an example of a disjunct distribution between North and South America, but Porlieria and Fagonia show a similar disjunction: although most species of Fagonia grow in the Old World, there are also species in both North and South America; in addition, Porlieria has five species in South America and one (P. angustifolia) in northern Mexico and Texas. Bulnesia is disjunct between the north and south of South America, with two species in Venezuela and Colombia, north of the equator, and the rest over 2,000 km distant in Bolivia, Paraguay, Argentina, Peru and Chile. A further example is Seetzenia, which is found in southwest Africa as well as northern Africa, the Middle East and India. Economic Importance. Some of the South American species have been used for their timber, notably Guaiacum which has extremely strong, hard, resinous wood. The resin of G. sanctum (known as Lignum vitae) was also used as a treatment for rheumatism, gout and liver disorders as well as syphilis. The timber of the related genera Bulnesia and Porlieria has also been of economic importance, and polishing waxes are made from Bulnesia resins. The resin on Larrea leaves is a powerful antioxidant and has been used as a source of antiseptic, although excessive internal use can lead to liver damage.

Many members of the family are poisonous to livestock, but Augea seeds are reported to have a high protein content and are eaten by sheep. The bark of Balanites was used medicinally; the fruits have a high nutritional value and are also used for soap. The buds of some species of Zygophyllum and Larrea have been used as a caper substitute, hence the name ‘bean caper’ which is sometimes applied to the family. Tribulus terrestris is a noxious weed which spreads widely by means of its spiny mericarps; these can penetrate and damage the feet of animals and even the tyres of cars; in addition, it is reported to be a fatal poison to sheep.

Key to the Genera 1. Fruit a large, fleshy, oval 1-seeded drupe up to 3 cm, with bony endocarp 19. Balanites – Fruit a loculicidal capsule, or separating into mericarps 2 2. Leaves paripinnate with 2–12 pairs of leaflets; flowers 5-merous with 10 stamens in 2 unequal rows; filament appendages lacking; fruits separating into 5 or 10 indehiscent mericarps; seeds without endosperm; pollen polyforate 3 – Plants lacking the above combination of characters 6 3. Upright woody shrubs or subshrubs to 1.5 m 16. Kelleronia – Prostrate to ascending herbs, rarely woody at base 4 4. Ovary and stigma 10-lobed; fruit breaking into 10 mericarps, leaving persistent central axis 15. Kallstroemia – Ovary and stigma 5-lobed; fruit breaking into 5 mericarps, leaving no central axis 5 5. Leaves opposite; leaflets becoming smaller towards leaf apex; ovules usually 2–5 per locule 14. Tribulus – Leaves usually alternate; leaflets becoming larger towards leaf apex; ovules 1 per locule 13. Tribulopis 6. Upright glabrous spartioid shrubs with terete branches; leaflets very small, widely spaced, caducous; petiole/rachis strongly resembling branches 17. Sisyndite – Not as above 7 7. Leaves alternate, sometimes growing in clusters from short shoots (rarely singly) 8 – Leaves opposite, rarely fasciculate 11 8. Fruit separating into mericarps 9 – Fruit a septicidally dehiscent capsule 10 9. Robust, stiff, upright shrubs with multipinnate leaves 18. Neoluederitzia – Low woody shrubs with small, simple linear leaves 22. Sericodes 10. Flowers 4-merous, solitary or in pairs, violet or pink 20. Morkillia – Flowers 5-merous, in few-flowered clusters, pale or bright yellow 21. Viscainoa 11. Leaves simple, ± cylindrical, fleshy, united at base by a stipular rim; ovary and capsule 10-merous 3. Augea

Zygophyllaceae – Leaves compound, 2–multifoliolate (sometimes reduced to unifoliolate by abortion of lateral leaflets); ovary and capsule 4–5-merous 12 12. Leaves usually digitately trifoliolate, rarely reduced to unifoliolate by abortion of lateral leaflets 13 – Leaves bifoliolate or pinnately compound 14 13. Diffusely branched small shrubs, often with spinescent stipules; petals present 2. Fagonia – Low, creeping annual herbs, rarely woody at base; petals absent 12. Seetzenia 14. Leaves black gland-dotted below; fruit with several seeds per locule 9. Pintoa – Leaves not black gland-dotted below; fruit mostly with 1 seed per locule 15 15. Old World shrubs, subshrubs and herbs 16 – New World shrubs and trees, often with hard, resinous wood 17 16. Ovary with 4 carpels divided almost to the base; fruit of 4(3) falcate-oblong mericarps united at base; a rare endemic from the Gobi Desert in Inner Mongolia 4. Tetraena – Fruit an angled, lobed or winged loculicidal or septicidal capsule, or separating into mericarps; a widespread genus 1. Zygophyllum 17. Fruits broadly winged or angular, or with dorsal spur 18 – Fruits not winged nor angular 20 18. Shrubs and trees with 3–5 stout spines radiating at nodes; fruit with dorsal spur 10. Plectrocarpa – Shrubs and trees without spines; fruit broadly winged or angular; filaments without basal scale 19 19. Flowers yellow; filaments with lacerate basal scale; capsule separating into ventrally dehiscent mericarps 5. Bulnesia – Flowers blue, red or purple; filaments lacking basal scale; capsule septicidally dehiscent 6. Guaiacum 20. Aromatic shrubs with resin-covered leaves and glandular sepals; ovary shortly stipitate 8. Larrea – Shrubs lacking resins and glands; ovary sessile 21 21. Leaflets very small (2–3 mm long); fruit covered in long silky hairs 11. Metharme – Leaflets 10–15 mm long; fruit ± glabrous 7. Porlieria

Genera of Zygophyllaceae I. Subfam. Zygophylloideae (R. Br.) Arn. (1832) (as Zygophylleae). 1. Zygophyllum L. Zygophyllum L., Sp. Pl. 1:385 (1753); Beier et al., Pl. Syst. Evol. 240:11–39 (2003); Barker, Adelaide Bot. Gard. 17:161–172 (1996), Austral. spp.; Schreiber, Prodr. Fl. Südwestafrika, Zygophyllac.: 1 (1966); Borisova, Fl. U.S.S.R. 14:117–149 (1974), English edn.

Glabrous or pubescent spreading shrubs, subshrubs and herbs, rarely annuals, with fleshy articulate stems; stipules sometimes spinescent. Leaves opposite, sessile or petiolate, usually bifoliolate, rarely simple or multifoliolate, with

493

cylindrical, fleshy or somewhat flattened lamina. Flowers yellow, cream or white, often with reddish basal spot, axillary or terminal, solitary or in pairs or few-flowered cymes; sepals 4–5, imbricate; petals (3)4–5, imbricate, clawed, rarely absent; disc fleshy, angled or cup-shaped; stamens (6)8–10, mostly with basal appendages; ovary 4–5-locular, with 2 or more ovules per locule; style simple. Fruit a (3)4–5-angled, -lobed or -winged, loculicidal capsule, or separating septicidally into 4–5 mericarps. Seeds 1 or more per locule, pendulous, with scanty endosperm. 2n = 16, 18, 20, 22, 44. Up to 100 species, growing in warm dry regions of Africa, Asia and Australia. Further studies will probably lead to subdivision of this genus. 2. Fagonia L. Fagonia L., Sp. Pl. 1:386 (1753), Beier, Syst. Biodiv. 3:221–263 (2005), rev.

Diffusely branched small shrubs, subshrubs or herbs to 80 cm high, glabrous, pubescent or glandular, often with spinose stipules. Leaves opposite, mostly digitately 3-foliolate, occasionally unifoliolate by abortion of lateral leaflets. Flowers pink to purple, rarely whitish, solitary, axillary; sepals and petals 5; disc inconspicuous; stamens 10, without appendages; stigma simple to minutely lobed; ovary sessile, 5-angled, 5-locular with two or more ovules per locule; style subulate, 5-sided. Fruit a deeply 5-angled or -lobed capsule with persistent style; each carpel ventrally dehiscent. Seeds ellipsoid, pendulous, with bony endosperm, mucilaginous. 2n = 18, 20, 22. About 30–40 species in dry regions of Africa, Asia, the Mediterranean basin and North America. 3. Augea Thunb. Augea Thunb., Prodr. Pl. Cap.: 80 (1794); Nov. Gen. 133 (1798).

Glabrous succulent annual or perennial, to 60 cm, with thick jointed stems. Leaves simple, opposite, ± cylindrical, united at base with a stipular rim; short pointed stipules present on young shoots. Flowers white, 1–3(4), axillary; sepals 5, united at base, imbricate; petals 5, with 3 narrow lobes; disc cup-shaped with 10 teeth; stamens 10; filaments with 2 lateral toothed appendages; ovary sessile, more or less enclosed by the disc, 10-locular with 2–3 ovules per locule; style short, stigma capitate. Fruit a 10-ribbed oblong schizocarp, with 1–2 seeds

494

M.C. Sheahan

per mericarp. Seeds flattened; endosperm 0. Only one species, A. capensis Thunb., endemic to South Africa and Namibia. 4. Tetraena Maxim. Tetraena Maxim., Enum. Fl. Mongol. 1:129 (1889).

Twisted, straggling much-branched low shrub to 1 m. Leaves bifoliolate, opposite or fasciculate on short shoots; stipules membranous; leaflets thick, fleshy, pubescent, apiculate. Flowers white, solitary, axillary, shortly pedicellate. Sepals 4, thickly pubescent abaxially, imbricate; petals 4, valvate; stamens 8, in two whorls, with toothed appendages. Ovary silky-pubescent with 4 carpels united only at the base, 4-locular with 3–4 ovules in each locule; style subgynobasic. Fruit pubescent with 4(3) falcate-oblong, 1-seeded mericarps. Endosperm 0. 2n = 14. Only one species, T. mongolica Maxim., from the eastern edge of the Central Asian desert region, endemic to Inner Mongolia. II. Subfam. Larreoideae Sheahan & M.W. Chase (1996). 5. Bulnesia Gay

Fig. 171

Bulnesia Gay, Fl. Chil. I: 474, t. 15 (1846); Palacios & Hunziker, Darwiniana 25:299–320 (1984), rev.

Shrubs and long-lived trees with very hard wood. Leaves opposite, pinnately compound, with 1 to several pairs of sub-opposite leaflets. Flowers yellow, axillary, solitary or in few-flowered cymes, actinomorphic or slightly zygomorphic; sepals 5, unequal; petals 5, clawed, imbricate; disc thick, 10-angled; stamens 10, filaments with toothed or laciniate appendages; ovary sometimes stipitate, 5locular with numerous ovules in 2 rows in each locule; style simple. Fruit a winged capsule separating into 3–5 ventrally dehiscent mericarps, each 1-seeded by abortion. Embryo with or without endosperm. 2n = 26, 52. Eight species, mostly in dry areas of South America. 6. Guaiacum L.

Fig. 172

Guaiacum L., Sp. Pl. 1:381 (1753).

Shrubs or small bushy trees to 10 m high, with hard resinous wood. Leaves opposite but often only 1 branch develops at each node. Leaves pinnately compound with 1–14 pairs of sessile leaflets. Flowers blue, red or purple, rarely white, 1 to many, axillary; sepals 4–5, unequal, free or united

Fig. 171. Zygophyllaceae. A Bulnesia retama-dominated vegetation at the end of summer, Basin of Andalgalá, Catamarca, Argentina. B Bulnesia retama, young fruits. (Photographs K. Kubitzki)

at base, imbricate; petals 4–5, imbricate, clawed; disc inconspicuous; stamens 8–10, filaments sometimes slightly winged, without appendages; ovary shortly stipitate, 2–5-locular with 8–10 ovules per locule; style slender, pointed, with a simple or lobed stigma. Fruit an angled or winged capsule, septicidally dehiscent, each locule 1-seeded by abortion; embryo with or without endosperm. 2n = 26. Six species in tropical Americas and West Indies. 7. Porlieria Ruiz and Pav. Porlieria Ruiz and Pav., Fl. Peruv. Chil. Prodr.: 55, t. 9 (1794).

Small stiff shrubs with stout woody branches. Leaves opposite, paripinnate with 5–20 pairs of small sub-opposite leaflets, showing nyctinastic movements; stipules small, often spinescent. Flowers whitish to pale yellow, sub-actinomorphic, mostly solitary (sometimes 2–3) in axils; sepals 4(5) ± unequal, imbricate; petals 4(5), clawed; disc small; stamens 8–10; filaments with toothed

Zygophyllaceae

495

basal scales; ovary ± globose, shortly stipitate, 5(6)-lobed, 5(6)-locular with 5–9 ovules per locule; style simple. Fruit a tomentose capsule, splitting into 5(6) 1-seeded mericarps. Seeds with bony endosperm. 2n = 26, 52, 78. Six species, 5 in Peru and Argentina, 1 in hot deserts of North America. 9. Pintoa Gay Pintoa Gay, Fl. Chil. I:479 (1846).

A rigid, much-branched tomentose shrub with swollen nodes and broad membranous stipules. Leaves opposite, paripinnate with 4–6 pairs of leaflets; rachis ending in terminal point 1–2 mm long. Leaflets asymmetric, thickly pubescent, densely black-dotted below. Flowers solitary, yellow, axillary; sepals and petals 5; disc thick, angled; stamens 10, unequal, with broad lacerate basal scale; ovary sessile, sericeous, 5-locular; ovules numerous; style tapering, stigma simple. Fruit a 5-lobed capsule, globose-oblong, pilose, septicidal, with several seeds in each locule. Seeds flattened, angular, with fleshy endosperm. 2n = 20. Only one species, P. chilensis Gay, endemic to the Atacama province of Chile. Fig. 172. Zygophyllaceae. Guaiacum sanctum. A Flowering branch. B Flower. C Same, vertically sectioned. D Pistil. E Fruits, closed and dehisced from side and above. (Correll and Correll 1982)

or lacerate scales; ovary ± sessile, lobed, 2–5locular with 2–4 ovules per locule; style simple; fruit a lobed capsule formed of 3–5 ± globose, 1-seeded, ventrally dehiscent mericarps. Seed with fleshy endosperm; embryo straight. 2n = 52. Six species, 5 in South America and 1 in northern Mexico and Texas. 8. Larrea Cav. Larrea Cav., Anal. Hist. Nat. 2:119, t. 18, 19 (1800); Descole et al., Lilloa 5:257–343 (1940), rev. Arg spp. Covillea Vail (1895).

Much-branched aromatic shrubs with swollen nodes, short internodes and slender branches; inner surface of stipules covered with resinous glands. Leaves evergreen, opposite, stipulate, bifoliolate (often with connate leaflets) or imparipinnate with up to 17 sessile leaflets. Flowers solitary, axillary with 5 sepals pubescent beneath, and 5 yellow clawed petals; disc small, 5-lobed, nectariferous; stamens 10 with 2-lobed or -toothed

10. Plectrocarpa Gillies Plectrocarpa Gillies in Hook., Bot. Misc. III:166 (1833).

Much-branched woody shrubs and trees, greyfelted when young; 3–5 stout spines extending radially at nodes. Leaves opposite, paripinnate, pubescent, growing in clusters, with 3–7 pairs subopposite to alternate, asymmetric leaflets; on horizontal branches, leaves grow from the upper part. Flowers solitary among the leaves; sepals 5, unequal, imbricate, densely villous; petals 5, clawed, yellow; disc inconspicuous; stamens 10 with a divided appendage at the base which occasionally extends almost the length of the filament; ovary sessile, densely villous, 5-locular with 2 ovules per locule; stigma small, simple. Fruit villous, pointed, splitting into 5 1-seeded mericarps each with a dorsal spur. Seeds compressed; endosperm thin, fleshy. Two or 3 species, endemic to northwest Argentina. 11. Metharme Phil. ex Engl. Metharme Phil. ex Engl. in Engler & Prantl, Nat. Pflanzenfam. III, 4:86 (1896).

Small perennial or shrub. Leaves opposite, small, paripinnate, thickly sericeous, with 15–18 pairs of very small (1–2 mm) linear leaflets. Flowers termi-

496

M.C. Sheahan

nal or axillary; sepals 5, persistent; petals 5, yellow, long-clawed; stamens 10, the 5 antesepalous with deeply bifid appendage at base; ovary sessile, covered in long silky hairs, deeply 5-lobed, 5-locular with 1 ovule per locule; stigmas 5. Fruit splitting into 5 1-seeded sericeous mericarps. Seeds with endosperm. One little-known species, M. lanata Phil., endemic to Tarapacá in northern Chile.

III. Subfam. Seetzenioideae Sheahan & M.W. Chase (1996). 12. Seetzenia R. Br. Seetzenia R. Br. in Denham and Clapperton, Trav., app.: 231 (1826).

Low, creeping annual or perennial herb branching from a woody base, with lax, brittle, jointed branches and pubescent nodes. Leaves small, opposite, succulent, 3-foliolate, petiolate with apiculate leaflets. Flowers solitary, axillary, pedicellate; sepals 5, somewhat fleshy, valvate; petals absent; disc inconspicuous, 5-lobed; stamens normally 5, without appendages; ovary sessile, oblong-clavate, 5-locular with 1 ovule per locule; styles normally 5, stigmas capitate. Fruit a 5-lobed septicidal capsule separating into 5 1-seeded mericarps from a 5angled central axis. Seeds compressed, with scanty endosperm. One species, S. lanata R. Br., found in sandy and saline deserts, disjunct in North and South Africa, also in the Middle East and Asia.

ported in some species (Keighery 1982). Six to 10 species, endemic to Australia. 14. Tribulus L.

Fig. 173

Tribulus L., Sp. Pl. 1:386 (1735); Barker, Nuytsia 12:9–35 (1998), rev. Austral. spp.

Mostly prostrate, sometimes ascending, muchbranched annual herbs, rarely woody at base, often bristly or pubescent. Leaves opposite, unequal in size, sometimes apparently alternate by abortion of smaller leaf, paripinnate with up to 12 pairs of asymmetric leaflets. Flowers solitary or in scorpioid cymes, in axil of smaller leaflet of a pair; sepals 5, pubescent, often caducous; petals 5, yellow, orange or white, clawed, spreading; disc present, sometimes cup-shaped, lobed; stamens (5)10, in 2 unequal whorls, filaments without appendages, those opposite the sepals with glands at base; ovary sessile, covered with long erect hairs, 5-lobed, 5-locular, with 3–10 superposed ovules per locule; style stout, caducous, stigma 5-lobed. Fruit separating into (4)5 indehiscent, ± triangu-

IV. Subfam. Tribuloideae (Rchb.) D.M. Porter (1969). 13. Tribulopis R. Br. Tribulopis R. Br. in Sturt, Exped. Centr. Austral. II, app.: 70 (1849); Barker, J. Adelaide Bot. Gard. 18:77–93 (1998), preliminary rev.

Prostrate, usually pubescent annual, rarely perennial, herbs. Leaves usually alternate, paripinnate, with 2–6 pairs leaflets. Flowers solitary; sepals 5; petals 5, yellow, sometimes orange or red at base; disc 5-lobed with 5 episepalous glands; stamens (5)10, sometimes with sterile anthers; filament appendages absent; ovary 5-locular with 1 ovule per locule; style short, conical, persistent; stigma 5ridged. Fruit ovoid to pyramidal, splitting into 1–5 indehiscent, 1-seeded mericarps, sometimes spiny, winged or tuberculate; endosperm 0. Geocarpy re-

Fig. 173. Zygophyllaceae. Tribulus zeyheri. A Flowering shoot. B Flower. C Pistil and intrastaminal glands, with hairs partly removed from ovary. D Schizocarps. (Launert 1963)

Zygophyllaceae

lar, spiny or winged (rarely tuberculate) mericarps with up to 5 seeds in each, leaving no central axis; seeds separated by cross-walls. Endosperm 0; embryo straight. 2n = 12, 24, 30, 36, 48. About 25 species in warm regions worldwide, mainly Mediterranean, North and South Africa and southwest Asia, and introduced into the New World. At least T. terrestris a highly troublesome weed. All species examined are reported to have the C4 photosynthetic pathway. 15. Kallstroemia Scop. Kallstroemia Scop., Introd. Hist. Nat.: 212 (1777); Porter, Contr. Gray Herb. 198:41–153 (1969), rev.

Much-branched annual, rarely perennial, prostrate or decumbent herbs, rarely woody at base, often pubescent. Leaves opposite, unequal, paripinnate, with 2–6(10) pairs of asymmetric leaflets. Flowers solitary, growing in axil of smaller leaf; sepals 5(6), pubescent, usually persistent; petals 5(6), orange, yellow or white, caducous; disc fleshy, 10(12)-lobed; stamens 10(12) in 2 unequal whorls, antesepalous stamens subtended by small bilobed gland; filaments rarely winged, without appendages; ovary sessile, 10(12)-lobed, 10(12)-locular with 1–2 ovules per locule; stigmas sub-clavate, 10-lobed, persistent. Fruits ovoid or pyramidal, separating into 10(12) indehiscent, bony 1(2)-seeded mericarps, ± tuberculate dorsally, with persistent central axis. Endosperm absent; embryo straight. 2n = 32, 36. The largest New World genus of the family, with about 17 species, found in warm dry regions from Illinois to Argentina. Kallstroemia is sometimes reported to occur in Australia because some workers, notably Engler (1896b, 1931), included Tribulopis (as Tribulopsis) in Kallstroemia. 16. Kelleronia Schinz Kelleronia Schinz in Bull. Herb. Boiss. III:400 (1895); Thulin, Fl. Somalia, I:179–186 (1993).

Small slender shrubs to 1.5 m, young branches pubescent; leaves alternate (or the upper may be opposite and unequal), paripinnate, with 3–5 pairs asymmetric leaflets. Flowers showy, yellow, copper-coloured or red, solitary, leaf-opposed or sub-terminal. Sepals and petals 5; disc lobed, nectariferous; stamens 10, lacking appendages; ovary sessile, pilose or pubescent, 5-lobed, 5-locular, with 2 ovules per locule; stigma ± capitate with 5 stigmatic ridges. Fruit densely sericeous, 5-angled,

497

splitting into 5 keeled, 2-seeded indehiscent mericarps. Seeds without endosperm. A genus formerly considered to have up to 9 or 10 species, more recently reduced to 3, found on gypsum soils and dry rocky regions in tropical East Africa and southern Arabia. 17. Sisyndite E. Mey. ex Sond. Sisyndite E. Mey. ex Sond., Fl. Cap. I:354 (1860).

Upright, glabrous, glaucous spartioid shrub; branches rigid, terete, with long internodes. Leaves sub-opposite to alternate, often opposite above, long, paripinnate. Leaflets up to 5 pairs attached to adaxial surface of rachis, small, widely spaced, sub-opposite, soon caducous, leaving only the petiole-rachis which resembles the branches; in severe drought this also falls. Flowers 1(–3) in the forks of the branches; sepals 5, lanate within and at margins; petals 5, bright yellow; disc 5-lobed; stamens 10, filaments with fringed appendages; ovary sessile, densely villous, 5-locular with 1 ovule per locule; style simple, stigmatic area ridged. Fruit a 5-lobed capsule covered in long, yellowish silky hairs, splitting into 5 1-seeded, ventrally dehiscent mericarps. Seeds compressed; endosperm absent. 2n = 20. One species, S. spartea E. Mey. ex Sond., in Namaqualand/southwest Africa, growing in the most arid areas. 18. Neoluederitzia Schinz Neoluederitzia Schinz in Bull. Herb. Boiss. II:190 (1894).

Robust, stiff pubescent shrub with stout, straight branches, short internodes and axillary thorns. Leaves pubescent, alternate, imparipinnate with 5–11 sub-opposite leaflets, growing singly or in clusters from short shoots. Flowers axillary, solitary, large; sepals 5, silky-tomentose, persistent; petals 5, pale yellow or white, densely villous at base; disc with membranous scales enclosing ovary; stamens 10, caducous, the 5 antepetalous filaments with deeply lobed, villous basal appendages; ovary 5-loculed, densely sericeous, enveloped in hood-like scales or disc-lobes; style persistent, stigma ribbed. Fruit a capsule, covered in long yellowish, silky hairs, separating from the central column into 5 1-seeded, ventrally dehiscent mericarps. Endosperm absent. One species, N. sericeocarpa Schinz, endemic to Great Namaqualand in southwest Africa. The flowers were described by Schinz as being of separate sexes, although he admits he did not ob-

498

M.C. Sheahan

serve male flowers; the confusion may have arisen because the stamens fall early.

except in the northwest, also in India, Burma and the Middle East.

19. Balanites Delile

V. Subfam. Morkillioideae (Engl.) Rose & J.H. Painter (1907).

Fig. 174

Balanites Delile in Mem. Egypte III:326 (1801, 1802); Sands, Kew Bull. 56:1–128 (2001), rev.

Shrubs or small trees, often with axillary or supra-axillary simple or forked spines. Leaves alternate or spirally arranged, bifoliolate; stipules minute, caducous. Flowers yellowish-green, in short axillary cymes, rarely solitary; sepals (4)5, silky-hairy within, deciduous; petals (4)5, spreading; disc fleshy, 10-grooved, surrounding base of ovary; stamens 8–10, without appendages; ovary villous, embedded in disc, 4–5-locular with 1 elongated ovule per locule; style short, stigma small, simple. Fruit a large, fleshy, 1-seeded oily drupe with leathery exocarp and woody endocarp. Endosperm absent. Up to 28 species reported in the past (e.g. Phillips 1951; Boesewinkel 1994), reduced to 9 by Sands (2001); throughout Africa

20. Morkillia Rose & J.H. Painter Morkillia Rose & J.H. Painter, Smithsonian Misc. Collect. 50:33 (1907). Chitonia Moç. & Sessé ex DC. (1824).

Much-branched shrubs or small trees. Leaves alternate, imparipinnate with 5–15 short-stalked, opposite (rarely alternate) leaflets; thickly felted with trichomes, giving grey-green appearance. Flowers terminal, single or paired; sepals 4; petals 4, large, showy, violet or pink; disc absent; stamens 8, without basal appendages; ovary 4-locular with several ovules in each locule; stigma 4-lobed. Fruit a large, 4-lobed, 4-winged, septicidally dehiscent pubescent capsule with 2 or more seeds in each locule. Endosperm bony; seeds ovate, black with red fleshy aril. A genus of 2 species, endemic to Mexico. 21. Viscainoa Greene Viscainoa Greene, Pittonia 1:163 (1888).

Stout, woody evergreen shrub with pubescent leaves and young stems. Leaves alternate, simple, or rarely imparipinnate with 3–5 leaflets. Flowers in few-flowered clusters opposite leaves; sepals 5, tomentose, caducous; petals 5, pale or bright yellow, veined; disc inconspicuous; stamens 10(8–12), without basal scale; ovary 3–5-locular with 2 ovules per locule, pilose, stipitate, with 3–5 persistent styles united into lobed clavate beak. Fruit a pendulous, somewhat inflated, 3–5-lobed, beaked, septicidally dehiscent capsule. Seeds 2(1) in each locule, sticky, black. Endosperm bony. One species, V. geniculata Greene, in Mexico, mainly on Baja California. 22. Sericodes A. Gray Sericodes A. Gray, Pl. Wright 1:28 in Smithsonian Contr. III (1852).

Fig. 174. Zygophyllaceae. Balanites angolensis. A Branch with stout floriferous spines. B Petiole and stipule. C Fascicle of flowers. D Flower with perianth removed, showing bract, pedicel, stamens, disc and pistil. E Fruit. (Drawn by M. Tebbs; Sands 2001)

Low woody shrub with short internodes; stout woody branches ending in a spine. Leaves ± linear, small, sessile, simple, growing in alternate clusters on short shoots, with fine pointed stipules. Flowers yellow, 1–3 among leaf clusters; sepals and petals 5; disc absent; stamens 10, the 5 antesepalous with

Zygophyllaceae

a bifid scale at base; ovary densely villous, sessile, 5-locular with 1 ovule in each locule; style 5-angled above, clavate. Fruit villous, breaking into five 1-seeded, indehiscent mericarps, leaving central column. Endosperm 0. One species, S. greggii A. Gray, endemic to north-eastern Mexico.

Selected Bibliography APG 1998. See general references. APG II 2003. See general references. Barker, R.J. 1996. New taxa, new combinations, keys and comments on generic concepts of Zygophyllum and a new species of Tribulus (Zygophyllaceae) in the manuscripts of the late H.J. Eichler. J. Adelaide Bot. Gard. 17:161–172. Barker, R.J. 1998a. Notes on the genus Tribulopis (Zygophyllaceae) in Australia. J. Adelaide Bot. Gard. 18:77–93. Barker, R.J. 1998b. A trial key and notes on Tribulus (Zygophyllaceae) in Australia, including one new species and validation of Tribulus suberosus. Nuytsia 12:9– 35. Behnke, H.-D. 1988. Sieve-element plastids and systematic relationships of Rhizophoraceae, Anisophylleaceae and allied groups. Ann. Missouri Bot. Gard. 75:1387–1409. Beier, B.-A. 2005. A revision of the desert shrub Fagonia (Zygophyllaceae). Syst. Biodiv. 3:221–263. Beier, B.-A., Chase, M.W., Thulin, M. 2003. Phylogenetic relationships and taxonomy of subfamily Zygophylloideae (Zygophyllaceae) based on molecular and morphological data. Pl. Syst. Evol. 240:11–39. Bobrov, E.G. 1974. Zygophyllaceae. In: Shishkin, B.K., Bobrov, E.G. (eds), Flora of the U.S.S.R. vol. 4 (translation of the 1949 Russian edn). Jerusalem: Israel program for scientific translations. Boesewinkel, F.D. 1994. Ovule and seed characters of Balanites aegyptiaca and the classification of the Linales-Geraniales-Polygalales assembly. Acta Bot. Neerl. 43:15–25. Borisova, A.G. 1974. Zygophyllum. In: Shishkin, B.K., Bobrov, E.G. (eds) Flora of the U.S.S.R., vol. 14 (translation of the 1949 Russian edition). Jerusalem: Israel Program for Scientific Translations. Castro, M.A. 1981. Anatomia foliar del género Plectrocarpa 35:137–147. Correll, D.S., Correll, H.B. 1982. Flora of the Bahama Archipelago. Vaduz: J. Cramer. Corner, E.J.H. 1976. See general references. Davis, G.L. 1966. See general references. Descole, H.R., O’Donell, C.A., Lourteig, A. (1940). Revisión de las Zygofiláceas argentinas. Lilloa 5:257–343. Engler, A. 1896a. Zygophyllaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, III, 4. Leipzig: Engelmann, pp. 74–93, 353–357. Engler, A. 1896b. Über die geographische Verbreitung der Zygophyllaceen. Berlin: Königliche Akademie der Wissenschaften. Engler, A. 1931. Zygophyllaceae. In: Engler, A., Prantl, K., Die natürlichen Pflanzenfamilien, ed. 2, 19a, 2. Leipzig: Engelmann, pp. 144–184.

499

Erdtman, G. 1952. See general references. Fahn, A., Shimony, C. 1996. Glandular trichomes of Fagonia L. (Zygophyllaceae) species: structure, development and secreted materials. Ann. Bot. 77:25–34. Gadek, P., Fernando, E.S., Quinn, C.J., Hoot, S.B., Terrazas, T., Sheahan, M.C., Chase, M.W. 1996. Sapindales: molecular delimitation and infraordinal groups. Amer. J. Bot. 83:802–811. Hegnauer, R. 1973, 1990. See general references. Hickey, L.J. 1973. A classification of the architecture of dicotyledonous leaves. Amer. J. Bot. 20:17–33. Howard, R.A. 1970. Some observations on the nodes of woody plants with special reference to the problem of the ‘split-lateral’ versus the ‘common gap’. In: Robson, N.K., Cutler, D.F., Gregory, M. (eds) New research in plant anatomy. London: Academic Press, pp. 195–214. Hunziker, J.H., Palacios, R.A., Poggio, L., Naranjo, C.A., Yang, T.W. 1977. Geographic distribution, morphology, hybridization, cytogenetics, and evolution. In: Mabry, T.J., Hunziker, J.H., DiFeo, D.R. Jr. (eds) Creosote bush: biology and chemistry of Larrea in New World deserts. Stroudsburg, PA: Dowden, Hutchinson and Ross, pp. 10–47. Jansen, S., Baas, P., Smets, E. 2001. Vestured pits: their occurrence and systematic importance in eudicots. Taxon 50:135–167. Johri, B.M. at al. 1992. See general references. Keighery, G.J. 1982. Geocarpy in Tribulopsis R. Br. (Zygophyllaceae). Flora 172:329–333. Lahham, J.N., Al-Eisawi, D. 1986. Pollen morphology of Jordanian Zygophyllaceae. Candollea 41:325–328. Launert, E. 1963. Zygophyllaceae. In: Exell, A.W., Fernandes, A., Wild, H. (eds) Fl. Zambesiaca 2, 1:125–130. London: Crown Agents. Lia, V.V., Confalonieri, V.A., Comas, C.I., Hunziker, J.H. 2001. Molecular phylogeny of Larrea and its allies (Zygophyllaceae): reticulate evolution and the probable time of Creosote Bush arrival to North America. Mol. Phylog. Evol. 21:309–320. Mabry, T.J., Hunziker, J.H., DiFeo, D.R. Jr. (eds) 1977a. Creosote bush: biology and chemistry of Larrea in New World deserts. Stroudsburg, PA: Dowden, Hutchinson & Ross. Mabry, T.J., DiFeo, D.R. Jr., Sakakibara, M., Bohnstedt, C.F. Jr., Seigler, D. 1977b. The natural products of Larrea. In: Mabry, T.J., Hunziker, J.H., DiFeo, D.R. Jr. (eds) Creosote bush: biology and chemistry of Larrea in New World deserts. Stroudsburg, PA: Dowden, Hutchinson & Ross, pp. 115–134. Maksoud, S.A., El-Hadidi, M.N. 1988. The flavonoids of Balanites aegyptiaca from Egypt. Pl. Syst. Evol. 160:153– 158. Mathur, A., Bhandari, M.M. 1983. Studies on pollen grains of Fagonia and Seetzenia species. J. Econ. Tax. Bot. 4:331–334. Narayana, L.L., Satyanarayana, P., Radhakrishnaiah, H. 1990. Systematic position of Balanitaceae. In: Bilgrami, K., Dogra, J. (eds) Phytochemistry and plant taxonomy. Delhi: C.B.S. Publications, pp. 157–164. Palacios, R.A., Hunziker, J.H. 1984. Revisión taxonómica del género Bulnesia (Zygophyllaceae). Darwiniana 25:299–320.

500

M.C. Sheahan

Parameswaran, N., Conrad, H. 1982. Wood and bark anatomy of Balanites aegyptiaca in relation to ecology and taxonomy. IAWA Bull. N.S. 3:75–88. Phillips, E.P. 1951. The genera of South African flowering plants, 2nd edn. Pretoria: Department of Agriculture. Poggio, L., Burghardt, A.D., Hunziker, J.H. 1989. Nuclear DNA variation in diploid and polyploid taxa of Larrea (Zygophyllaceae). Heredity 63:321–328. Poggio, L., Hunziker, J.H., Wulff, A.F. 1992. Cariotipo y contenido de ADN nuclear de Pintoa chilensis y Sisyndite spartea (Zygophyllaceae). Darwiniana 31:11–15. Porter, D. 1969. The genus Kallstroemia (Zygophyllaceae). Contr. Gray Herb. 198:41–153. Porter, D. 1974. Disjunct distributions in the new world Zygophyllaceae. Taxon 23:339–346. Praglowski, J. 1987. Pollen morphology of Tribulaceae. Grana 26:193–211. Sands, M.J.S. 2001. The desert date and its relatives: a revision of the genus Balanites. Kew Bull. 56:1–128. Savolainen, V., Fay, M.F. et al. 2000. See general references. Sheahan, M.C., Chase, M.W. 1996. A phylogenetic analysis of Zygophyllaceae R. Br. based on morphological, anatomical and rbcL DNA sequence data. Bot. J. Linn. Soc. 122:279–300. Sheahan, M.C., Chase, M.W. 2000. Phylogenetic relationships within Zygophyllaceae based on DNA sequences of three plastid regions, with special emphasis on Zygophylloideae. Syst. Bot. 25:371–384.

Sheahan, M.C., Cutler, D.C. 1993. Contribution of vegetative anatomy to the systematics of the Zygophyllaceae R. Br. Bot. J. Linn. Soc. 113:227–262. Singh, B.P., Kaur, I. 1998. Systematic position of the genus Peganum. J. Econ. Tax. Bot. 22:705–708. Smith, W.K., Robbins, M.J. 1974. Evolution of C4 photosynthesis: an assessment based on 13 C/12 C ratios and Kranz anatomy. In: Avron, M. (ed.) Proc. 3rd International Congress on Photosynthesis. Amsterdam: Elsevier. Soltis, D.E. et al. 2000. See general references. Thulin, M. 1993. Zygophyllaceae. Flora of Somalia, vol. I. Royal Botanic Gardens, Kew. Van Huyssteen, D.C. 1937. Morphologisch-systematische Studien über die Gattung Zygophyllum. Dissertation, Mathematisch-Naturwissenschaftlichen Fakultät, Friedrich-Wilhelms Universität Berlin. Volkens, G. 1890. Über Pflanzen mit lackierten Blättern. Ber. Deutsch. Bot. Gesell. 8:120–140. Welkie, G.W., Caldwell, M. 1970. Leaf anatomy of species in some dicotyledon families as related to the C3 and C4 pathways of carbon fixation. Canad. J. Bot. 48:2135–2146. Yi, Y., Zhou, S. 1992. A contribution to the pollen morphology of Tetraena and Malpighiaceae with a discussion of the affinity and taxonomic position of Tetraena. Chinese J. Bot. 4:6–12.

Additions and Corrections to Volumes II–VI

Vol. II

p. 271, 3. Camassia: this genus is also in South America.

p. 414, left column, the correct name is: 14. Dioscoreophyllum Engl.

p. 273, the reference to 12. Adamanthopsis is: Phyton (Austria) 38:74 (1998). The genus has two species.

p. 418, right column, insert: 16a. Pachygone Miers Pachygone Miers, Ann. Mag. Nat. Hist. II, 7:37 (1851); Forman, Kew Bull. 43:400 (1988) and Fl. Males. I, 10:217 (1986).

Woody climbers; leaves simple, base 3–5-nerved. Inflorescences pseudo-racemose. Male flowers: sepals 6(–12), inner larger, imbricate; petals 6, basal auricles clasping the opposite stamens; stamens 6. Female flowers: sepals similar to male; petals ± flat, auricles less developed; staminodes 6 or 0; carpels 3; style reflexed, stigma entire. Drupe curved with style-scar near base, subcompressedobovoid; endocarp rather smooth, with dorsal median groove and on each lateral face a small central sublunate perforation leading to the central hollow condyle. Seed curved; endosperm 0; cotyledons large, thick. About 10 spp., China, SE Asia, Malesia, Australia and Polynesia; used for stupefying fish and crocodile.

Vol. III. p. 24, left column, line 17 from bottom. The references given in parenthesis should read: (Aristolochiaceae: Behnke and Dahlgren 1976; Behnke 1981, 1995). p. 25, caption to Fig. 18: the magnification is 20,000. p. 32, left column, line 4: replace “Behnke, H.-D. (1976)” by “Behnke, H.-D., Dahlgren, R. (1976)”. p. 104, left column, line 4 from bottom: replace “12. Tribe. . . ” by “11. Tribe Eucharidae. . .”, and reduce the numeration of tribes on pp. 105–107 correspondingly.

p. 278, the reference to 34. Avonsera is: Phyton (Austria) 38: 95 (1998). p. 280, the reference to 46. Barnardia is: Phyton (Austria) 38:96 (1998). The reference to 47. Autonoe is: Phyton (Austria) 38:93 (1998). p. 480, right column, line 15–13 from bottom. The note in parenthesis should read: “(absent from Talbotia: Menezes et al. 1994)”.

Vol. IV p. 418, in caption to Fig. 99: replace “Rapatea celiae” by “Stegolepis celiae”. p. 420, in caption to Fig. 100: replace “Stegolepis angustata” by “Stegolepis ptaritepuiensis”.

Vol. V p. 258. My combination of Pityranthe trichosperma (Merr.) Kubitzki lacks reference to author and place of publication of the basionym. This is remedied here. Pityranthe trichosperma (Merr.) Kubitzki, nov. comb. Basionym: Hainania trichosperma Merr., Lingnan Sci. J. 14:36 (1935). The editor is most grateful to Drs. HansDietmar Behnke, Paul Berry, Laurence Dorr and Mr. Walter Erhardt for directing his attention to these errors.

Index to Scientific Names References to main entries in bold-faced print, to illustrations in italics.

Acanthocladus 357 A. guayaquilensis 346, 350 Acareosperma 476 Aceriphyllum 425 Acidonia 384 Acopanea 39 Acre clade 107 Acrotrema 150 A. lanceolatum 151 A. thwaitesii 151 Adenanthinae 389 Adenanthos 389 Adenaria 236 Adenia 271, 275 A. sect. Adenia 276 A. sect. Blepharanthes 276 A. sect. Erythrocarpus 276 A. fasciculata 271 A. firingalavensis 272 A. glauca 272 A. globosa 271 A. hondala 276 A. sect. Microblepharis 276 A. sect. Ophiocaulon 276 A. sect. Paschanthus 276 A. racemosa 271 A. venenata 271 Adenoa 464 Adrastaea 147 Adromischus 110 Aeonieae 104 Aeonium 104 A. tabulaeforme 105 Aextoxicaceae 1, 23 Aextoxicon 25 A. punctatum 23, 24 Afrostyrax 193 A. lepidophyllum 192 Afrovivella 106 Agastachys 385 Aichryson 104 Aizopsis 103 Allanblackia 62 Alloxylon 396 Altamiranoa 108 Altingiaceae 15, 16 Alvaradoa 303 Alzatea 28 A. verticillata 27 Alzateaceae 8, 9, 26

Amerosedum 108 Ammannia 236 A. latifolia 231 Ampelocissus 473 A. sect. Nothocissus 473 A. sp. 470 Ampelopsis 472 Anastrophea 333 Ancistrothyrsus 277 Ancylotropis 358 Androsaemum 199 Androsiphonia 271, 279 Angolaea 330 A. fluitans 330 Anogeissus 78 A. sect. Finetia 79 Apacheria 121 Aphanopetalaceae 15, 16, 29 Aphanopetalum 30 A. resinosum 30 Aphloia 32 A. theiformis 31 Aphloiaceae 4, 31 Apinagia 322 A. batrachifolia 322 A. pygmaea 322 A. surumuensis 322 Araeoandra 220 Archytaea 38 Ascyrum 199 Asterids 1 Asterosedum 103 Astilbe 430 A. group 430 Astilboides 425 Athertonia 400 Atroxima 356 Augea 493 Aulax 387 Aulea 333 Austromuellera 395 Axinandra 125 A. coriacea 124 Badiera 357 Balanitaceae 488 Balanites 498 B. angolensis 498 Balbisia 219 B. gracilis 218

B. peduncularis 218 Balboa 61 Balgoya 356 Banksia 395 Banksieae 394 Banksiinae 395 Barnhartia 356 Barteria 271, 279 B. nigritana 272 Basananthe 276 B. triloba 272 Beauprea 386 Beaupreopsis 386 Bellendena 382 B. montana 382 Bellendenoideae 382 Bensoniella 427 Berberidopsidaceae 1, 33 Berberidopsidales 1, 1 Berberidopsis 34 B. corallina 34 Bergenia 426 B. purpurascens 426 Bersama 256 Bleasdalea 401 Bolandra 429 Bonnetia 39 B. ahogadoi 38 Bonnetiaceae 3, 36 Boykinia 430 B. group 429 Brabejum 399 B. stellatifolium 399 Brachysiphon 288, 289 Brachytropis 359 Bredemeyera 357 B. floribunda 346 B. myrtifolia 350, 351 Breitungia 108 Bryophyllum 111 Buchenavia 78 Bucida 78 Buckinghamia 397 Bulnesia 494 B. retama 494 Butumia 330 B. marginalis 330 Buxaceae 2, 40 Buxales 1, 2 Buxus 45

504 B. arborea 42 B. benguellensis 42 B. cochinchinensis 42 B. moctezumae 45 Byrnesia 109 Cacoucia 79 Cadellia 453 Caesarea 220 Callisthene 485 C. major 483 Calophylleae 57 Calophyllum 59 C. trachycaule 60 Calopyxis 79 Calycopterideae 79 Calycopteris 79 Candollea 147 Capuronia 236 Caraipa 58 Cardwellia 400 Carnarvonia 391 C. araliifolia 391 Carpolobia 357 Carpolobieae 356 Caryophyllales 1 Cascadia 423 C. group 423 Castelnavia 322 C. princeps 322 Catalepidia 400 Cayratia 475 C. sp. 470 Cenarrhenes 386 Ceratolacis 323 C. erythrolichen 322 Cercidiphyllaceae 15, 16 Chamaebuxus 359 Chiastophyllum 102 Chitonia 498 Choristylis 203 Chrysochlamys 61 Chrysosplenium 424 C. biondianum 425 Cipoia 323 C. inserta 323 Cissabryon 220 Cissus 475 C. sect. Cayratia 475 C. sect. Cyphostemma 476 C. erosa 470 C. sp. 470 Cladopus 335 C. nymani 336 Clausenellia 108 Clematicissus 475 Clementsia 102 Clusia 60 C. sp. 61 Clusiaceae-Guttiferae 3, 48 C. alliance 3 Clusieae 60 Clusiella 58 Clusioideae 60

Index to Scientific Names Combretaceae 7, 9, 67 Combreteae 77 Combretinae 79 Combretoideae 76 Combretum 79 C. subg. Apetalanthum 79 C. bongense 80 C. subg. Cacoucia 79 C. subg. Combretum 79 C. poggei 80 Comesperma 358 C. ericinum 351 Conimitella 427 Conocarpus 79 C. sect. Anogeissus 78 C. erectus 68 Conospermeae 386 Conosperminae 387 Conospermum 387 Cotyledon 111 Covillea 495 Crassula 112 C. columnaris 112 C. streyi 90 Crassulaceae 15, 16, 83 Crassuloideae 111 Cratoxyleae 199 Cratoxylum 199 C. arborescens 200 Cremnophila 108 Crenea 236 Crenias 324 C. weddelliana 324 Crossosoma 121 C. californica 120 Crossosomataceae 3, 119 Crossosomatales 3 Crossostemma 277 C. laurifolium 272 Crypteronia 126 Crypteroniaceae 8, 9, 123 Cuphea 237 C. nitidula 229 C. teleandra 237 Curatella 146 C. americana 134 Cyphostemma 476 Dactylocladus 125 Dalrympelea 443 D. borneensis 444 D. stipulacea 444 Dalzellia 320, 320 D. zeylanica 320 Dansiea 77 Daphniphyllaceae 15, 16, 127 Daphniphyllum 128 D. himalayense 128 D. macropodum 128 Darlingia 394 Darmera 425 D. group 425 Davilla 145 D. sect. Davilla 146

D. flexuosa 146 D. sect. Homalochlaena 146 Decaphalangium 60 D. peruvianum 60 Decodon 237 D. verticillatus 237 Deidamia 276 Delimoideae 142, 145 Devillea 324 D. flagelliformis 324 Diamantina 325 D. lombardii 323 Diamorpha 108 Diastella 390 Diclidanthera 356 D. penduliflora 346 Dicraeanthus 330 D. africanus 330 Didesmandra 150 Didiplis 237 Didymelaceae 2, 129 Didymeles 131 D. integrifolia 131 D. madagascariensis 130 Dilkea 271, 277 Dilleneae 132 Dillenia 151 D. excelsa 151 D. indica 151 Dilleniaceae 1, 19, 132 Dillenioideae 142, 149 Dilobeia 386 Diplerisma 255 Diplobryum 336 D. minutale 336 Diplusodon 237 Djinga 331 D. felicis 331 Doliocarpoideae 142, 145 Doliocarpus 146 D. sect. Calinea 147 D. sect. Doliocarpus 147 Dryandra 395 Duabanga 238 D. grandiflora 238 Dudleya 107 Dufourea 320 Dystovomita 60 Echeveria 110 Efulensia 277 Eidothea 385 Eliaea 200 Elmera 428 Embothrieae 395 Embothriinae 396 Embothrium 396 Endocaulos 331 E. mangorense 331 Endodesmia 60 Endodesmieae 60 Endonema 288 Epirixanthes 358 Erblichia 462

Index to Scientific Names Eriandra 356 Erisma 485 E. floribundum 483 Erismadelphus 486 E. exsul 484 Erismeae 485 Erodium 164 Etiosedum 108 Eucarpha 392 Euhydrobryum 337 Euplassa 401 Euscaphis 443 Fabales 5 Fagonia 493 Farmeria 336 F. indica 305, 336 Faurea 388 Finetia 79 Finschia 398 Floydia 394 Floydiinae 394 Forsellesia 121 Francoa 256 Franklandia 386 Galpinia 238 Garcinia 62 G. hunsteinii 62 Garcinieae 62 Garnieria 383 Geissoloma 156 G. marginatum 156 Geissolomataceae 4, 155 Geraniaceae 5, 157 Geraniales 5 Geranium 163 G. maculatum 163 Getonia 79 Gevuina 401 Gevuininae 400 Ginoria 238 Glischrocaryon 188 Glischrocolla 288 Glossopetalon 121 G. spinescens 121 Gonocarpus 188 Granadilla 278 Graptopetalum 109 Greenovia 104 Grevillea 397 G. robusta 398 Grevilleoideae 390 Greyia 256 G. sutherlandii 256 Greyiaceae 250 Griffithella 336 G. hookeriana 337 Grossularia 175 Grossulariaceae 15, 16, 168 Guaiacum 494 G. sanctum 495 Guiera 80 Guilfoylia 453

Gunnera 180, 182 G. chilensis 179 G. subg. Gunnera 182 G. lobata 179 G. macrophylla 179, 181 G. magellanica 181 G. manicata 179 G. subg. Milligania 182 G. subg. Misandra 182 G. subg. Ostenigunnera 182 G. subg. Panke 182 G. subg. Perpensum 182 G. subg. Pseudogunnera 182 Gunneraceae 7, 177 Gunnerales 1, 7 Guttiferae 48 Gynopleura 249 Haitia 238 Hakea 397 Hakeinae 397 Haloragaceae 15, 16, 184 Haloragis 188 Haloragodendron 188 Halorrhagis 188 Hamamelidaceae 15, 16 Hanseniella 337 H. heterophylla 337 Haploclathra 58 Harungana 198 H. madagascariensis 198 Hasseanthus 107 Havetia 60 Havetiopsis 60 Heimia 239 Helicia 394 Heliciinae 394 Heliciopsis 400 Hemidistichophyllum 335 Hemistema 147 Heteropyxidaceae 9 Heterosamara 359 Heterotristicha 320 Heuchera 427 H. group 426 H. rubescens 427 Heucheroids 423 Hibbertia 147 H. subg. Adrastaea 149 H. baudouini 149 H. complanatum 148 H. dilatatum 148 H. subg. Hemistema 148 H. subg. Hibbertia 149 H. junceum 148 H. subg. Pachynema 148 H. scandens 149 Hibbertioideae 142, 147 Hicksbeachia 401 Hieronymusia 430 H. alchemilloides 430 Hionanthera 239 Hjaltalinia 108 Hollandaea 394

505 Hollrungia 278 Hua 193 H. gaboni 192 Huaceae 20, 191 Hualania 358 Hyalocalyx 463 Hydroanzia 337 Hydrobryopsis 339 Hydrobryum 337 H. floribundum 305 H. japonicum 338 Hylotelephium 101 H. telephium 101 Hypagophytum 112 Hypericaceae 3, 194 Hypericeae 199 Hypericum 199 Hypseocharis 163 H. tridentata 162 Hypseocharitaceae 157 Indotristicha 321 I. ramosissima 321 I. tirunelveliana 321 Inversodicraeia 331 Isopogon 389 Isopogoninae 388 Itea 203 I. rhamnoides 203 Iteaceae 15, 16, 202 Ixerba 206 I. brexioides 206 Ixerbaceae 3, 205 Jenmaniella 325 J. tridactylifolia 324 Jepsonia 429 Jovibarba 103 Kaernbachia 443 Kalanchoe 111 K. brachyloba 90 K. grandiflora 101 Kalanchoideae 110 Kallstroemia 497 Kayea 59 Kelleronia 497 Kermadecia 401 Kielmeyera 58 Kielmeyeroideae 57 Kitchingia 111 Knightia 392 Koehneria 239 Korupodendron 486 Krameria 212 K. grandiflora 211 K. lappacea 209 Krameriaceae 19, 208 Kungia 100 Lafoensia 240 L. punicifolia 239 Lagerstroemia 240 L. speciosa 240

506 Laguncularia 76 L. racemosa 77 Laguncularieae 76 Lambertia 393 Lambertiinae 393 Larrea 495 Larreoideae 494 Laurembergia 188 L. tetrandra 186 Lawia 320 Lawiella 335 Lawsonia 240 Lebrunia 60 Lecomtea 335 Ledermanniella 331 L. abbayesii 331 Ledocarpaceae 5, 213 Ledocarpon 219 Leea 224 L. acuminatissima 222 L. compactiflora 222 L. coryphantha 222 L. guineensis 223 L. indica 222, 223 L. magnifolia 222, 223 L. simplicifolia 223 L. sp. 470 Leeaceae 18, 221 Leguminosae-Fabaceae s.l. 5 Leiocarpodicraeia 332 Leiothylax 332 L. quangensis 332 Lenophyllum 109 Leptarrhena 431 L. group 431 Letestuella 332 L. tisserantii 332 Leucadendreae 388 Leucadendrinae 389 Leucadendron 389 Leucosedum clade 105 Leucospermum 390 Lianthus 199 Ligea 322 Lithophragma 426 Loewia 463 Lomatia 395 Lomatiinae 395 Lonchostephus 325 L. elegans 324 Lophogyne 325 L. helicandra 326 Lorostemon 63 L. bombaciflorum 63 Loudonia 188 Lourtella 240 Lumnitzera 77 Lythraceae 8, 9, 9, 226, 234 Lythrum 241 L. rotundifolium 229 Macadamia 398 Macadamieae 398 Macadmaiinae 398

Index to Scientific Names Macarenia 326 M. clavigera 326 Macrobia 104 Macropodiella 333 M. heteromorpha 332 Macropteranthes 77 Maferria 336 Mahurea 58 Malaccotristicha 320 Malagasia 400 Malagasiinae 399 Malesherbia 249 M. sect. Albitomenta 249 M. sect. Cyanpetala 249 M. humilis 248 M. sect. Malesherbia 249 M. paniculata 248 M. sect. Parvistella 249 M. weberbaueri 248 M. sect. Xeromontana 249 Malesherbiaceae 12, 247 Malpighiales 3, 12 Mammea 59 Marathrum 326 M. schiedeanum 305 M. utile 326 Marila 57 Mathurina 462 Megahertzia 391 Megalonium 104 Meiostemon 79 Melastomaceae 9, 9 Melianthaceae 5, 250 Melianthus 255 M. comosus 255 Meliosma 416 M. sp. 415 Meliosmaceae 413 Memecylaceae 9, 9 Mesua 59 Meterostachys 100 Metharme 495 Meziella 188 Micrandra M. nivalis 424 Micranthes 424 M. group 424 Mimetes 390 Mitella 428 M. stauropetala 428 Mitostemma 277 Mnianthus 320 Mniopsis 324, 335, 339 Monandriella 331 Monanthes 104 Monnina 359 M. denticulata 347 M. subg. Monninopsis 358 M. subg. Pterocarya 360 M. reticulata 346, 350 Monostylis 322 Monrosia 359 Monsonia 164 M. patersonii 164

Montrouziera 63 Morkillia 498 Morkillioideae 498 Moronobea 62 Mourera 327 M. fluviatilis 305, 327 Moutabea 356 M. aculeata 346, 350 Moutabeae 355 Mucizonia 108 Mukdenia 425 Muraltia 359 M. heisteria 346, 350, 351 Muscadinia 474 Musgravea 395 Musgraveinae 395 Myriophyllum 188 M. balladoniense 187 Myrothamnaceae 7 Myrtaceae 9 Myrtaceae-Myrtoideae 8 Myrtaceae-Psiloxyloideae 8 Myrtales 7 Natalia 256 Neblinaria 39 Nelumbonaceae 12 Neodillenia 147 Neogleasonia 39 Neolacis 322 Neoluederitzia 497 Neorites 392 Neotatea 57 Nesaea 241 Nothocissus 473 Notobuxus 45 Nylandtia 359 Ochranthe 443 Ochrocarpos 62 Oedomatopus 60 Oenone 322 Ohbaea 108 Olinia 263 O. aequipetala 261 Oliniaceae 8, 9, 260 Oliveranthus 110 Oliverella 110 Onagraceae 8, 9 Ophiocaryon 416 Opisthiolepis 397 Oreocallis 396 Oreosedum 108 Oresitrophe 426 Orias 240 Orites 393 Orostachys 101 O. sect. Schoenlandia 100 Orothamnus 390 Oserya 327 O. minima 327 Pachynema 147 Pachyphytum 110

Index to Scientific Names Pachysandra 46 Paeonia 268 P. anomala 266 P. delavayi 267 P. intermedia 267 P. lactiflora 265 P. sect. Moutan 268 P. sect. Onaepia 268 P. sect. Paeon 268 P. sect. Paeonia 268 P. suffruticosa 266 Paeoniaceae 15, 16, 265 Paleodicraeia 333 P. imbricata 333 Panopsis 399 Paramammea 59 Paranomus 389 Paropsia 271, 279 P. guineensis 271 Paropsiopsis 271, 279 Parthenocissus 474 Parvisedum 107 Passiflora 271, 278 P. arborea 271 P. subg. Astrophea 278 P. subg. Decaloba 279 P. subg. Deidamioides 278 P. ovalis 271 P. subg. Passiflora 278 P. racemosa 271, 272 P. spicata 271 Passifloraceae 12, 270 P. alliance 12 "Passiflorales" 12 Passifloreae 270 Pehria 241 Pelargonium 164 P. bowkeri 159 P. fulgidum 159 P. grossularioides 159 P. laxum 159 P. lobatum 159 P. longiflorum 159 P. magenteum 159 P. multicaule 159 P. rapaceum 159 P. scabrum 159 P. squamulosum 165 P. ternifolium 159 P. triandrum 159 Peltiphyllum 425 Peltoboykinia 424 P. group 424 Pemphis 241 Penaea 289, 289 P. dahlgrenii 284 Penaeaceae 8, 9, 282 Pentadesma 62 Pentaphalangium 62 Penthoraceae 15, 16, 292 Penthorum 295 P. sedoides 293, 294 Peplis 241 Peridiscaceae 15, 16, 297

Peridiscus 299 Perrierosedum 101 Persoonia 384 P. lanceolata 384 Persoonieae 383 Persoonioideae 382 Petrophile 387 Petrophileae 387 Petrophyes 104 Petrosedum 103 Phedimus 103 Philocrena 320 Phlebotaenia 359 Phoxanthus 416 Physocalymma 241 Picramnia 303 P. oreadica 302 Picramniaceae 20, 301 Pilosperma 60 Pintoa 495 Pinzona 146 Piriqueta 464 P. sidifolia 464 Pistorinia 106 Placospermeae 382 Placospermum 383 P. coriaceum 383 Platanaceae 12 Platonia 63 P. insignis 63 Plectrocarpa 495 Pleurandra 147 Pleurophora 242 Ploiarium 38 Podostemaceae 3, 304 Podostemoideae 321 Podostemum 328, 338, 339 P. ceratophyllum 305, 327 Poeciloneuron 59 Pohliella 333 Poivrea 79 Polygala 359 P. boliviensis 346 P. sect. Hebecarpa 357 P. vulgaris 350, 351 Polygalaceae 5, 345 Polygaleae 357 Polygaloides 359 Polypleurella 337 Polypleurum 338 P. stylosum 305, 338 Porlieria 494 Potamobryum 320 Prometheum 106 Proserpinaca 188 Protea 388 P. cynaroides 388 Proteaceae 12, 364 Proteales 1, 12 Proteeae 388 Proteoideae 385 Psiloxylaceae 9 Pseudorosularia 106 Pseudosedum 102

507 Psorospermum 198 Pteleopsidinae 77 Pteleopsis 78 Pterisanthes 473 Pterocissus 475 Pteromonnina 360 P. herbacea 350 Pterostemon 406 P. mexicanus 405 Pterostemonaceae 15, 16, 405 Punica 242 Qualea 485 Q. rosea 482 Quapoya 60 Quillaja 408 Q. saponaria 407, 408 Quillajaceae 5, 407 Quisqualis 79 Ramatuellea 78 Ranunculales 1 Recchia 453 Renggeria 60 Rheedia 62 Rhodiola 102 Rhoicissus 473 Rhynchocalycaceae 8, 9, 409 Rhynchocalyx 411 R. lawsonioides 410 Rhyncholacis 328 R. dentata 329 Rhynchotheca 220 R. speciosa 219 Rhynchothecaceae 213 Ribes 175 R. sect. Berisia 175 R. sect. Calobotrya 175 R. subg. Calobotrya 175 R. sect. Cerophyllum 175 R. subg. Coreosma 175 R. subg. Grossularia 175 R. subg. Grossularioides 175 R. sect. Heritiera 175 R. incarnatum 170 R. multiflorum 171 R. subg. Parilla 175 R. sect. Ribes 175 R. subg. Ribes 175 R. roezlii 170 R. sanguineum 170 R. speciosum 170 R. subg. Symphocalyx 175 R. triste 170 R. viburnifolium 169 Rigiostachys 453 Rochea 112 Rodgersia 425 Rosids 1 Rosularia 106 R. sect. Chrysanthae 106 R. sect. Sempervivella 108 Rotala 242 R. juniperina 242

508 Roupala 392 R. montana 393 Roupaleae 391 Roupalinae 392 Ruizterania 485 Sabia 416 S. limoniacea 414 Sabiaceae 1, 20, 413 Salomonia 360 S. cantoniensis 346, 350, 351 Saltera 289 Salvertia 485 S. convallariodora 481 Saniculiphyllum 432 Santalales 1 Santomasia 199 Sarcocaulon 164 Sarcococca 46 S. wallichii 42 Sarcocolla 288, 289 Saxicolella 333 S. nana 333 Saxifraga 431 S. granulata 432 S. imbricata 431 S. media 431 S. sect. Merkianae 424 S. sect. Micrantha 424 Saxifragaceae 15, 16, 418 Saxifragales 1, 15 Saxifragella 431 Saxifragodes 424 Saxifragoids 431 Saxifragopsis 430 Schlechterina 277 Schumacheria 150 S. castaneifolia 150 Securidaca 360 S. diversifolia 347 S. fragilis 350 Sedeae 105 Sedella 107 Sedum 108 S. acre 107 S. ser. Rupestria 103 S. sedoides 105 S. wrightii 90 Seetzenia 496 Seetzenioideae 496 Semperviveae 103 Sempervivella 108 Sempervivoideae 100 Sempervivum 103 Septogarcinia 62 Sericodes 498 Serpicula 188 Serruria 389 Sinocrassula 100 Sisyndite 497 Sleumerodendron 400 Smeathmannia 271, 279 S. pubescens 272 Sonderothamnus 288

Index to Scientific Names Sonneratia 243 S. alba 227 Sorocephalus 390 Soyauxia 299 S. floribunda 298 Spatalla 390 Spathulata 103 Sphaerothylax 331, 333 S. abyssinica 333 Sphalmium 391 Stachyuraceae 3, 436 Stachyurus 438 S. praecox 438 Stapfiella 463 Staphylea 443 Staphyleaceae 3, 440 Stenocarpinae 396 Stenocarpus 396 Stirlingia 387 Stirlingiinae 387 Stonesia 334 S. gracilis 334 Strangea 397 Strasburgeria 447 S. robusta 447 Strasburgeriaceae 3, 446 Strephonema 76 S. sericea 76 Strephonematoideae 76 Streptopetalum 464 Streptothamnus 35 Stylapterus 289 Stylobasiaceae 449 Stylobasium 454 Styloceras 46 Stylophyllum 107 Suksdorfia 429 Sullivantia 429 Suriana 454 S. maritima 451 Surianaceae 5, 449 Symphionema 385 S. montanum 385 Symphionematoideae 384 Symphonia 64 S. globulifera 64 Symphonieae 62 Synaphea 387 Synstylis 337 Tacitus 109 Tanakaea 431 Telephieae 100 Telesonix 429 Tellima 426 Telopea 396 Terminalia 78 T. brownii 78 Terminaliopsis 78 Terminaliinae 77 Terniola 321 Terniopsis 320 Tetilla 257 Tetracarpaea 457

T. tasmanica 457 Tetracarpaeaceae 15, 16, 456 Tetracera 145 T. sect. Akara 145 T. biviniana 145 T. sect. Tetracera 145 Tetradia 243 Tetraena 494 Tetrapathaea 278 Tetrastigma 476 T. sp. 470 Tetrastylis 278 Tetrataxis 243 Thawatchaia 338 T. trilobata 338 Thelethylax 334 T. minutiflora 334 Thiloa 79 Thompsonella 109 Thornea 199 Thysanostemon 63 Tiarella 429 Tillaea 112 Tolmiea 428 Toronia 383 Torrenticola 335 Tovomita 61 T. brasiliensis 61 Tovomitidium 61 Tovomitopsis 61 Trapa 243 T. natans 243 Triadenum 199 Tribuloideae 496 Tribulopsis 496 Tribulus 496 T. zeyheri 496 Triceros 443 Tricliceras 463 Tripetalum 62 Trisema 147 Tristicha 320 T. malayana 305 T. trifaria 305, 320 Tristichaceae 304 Tristichoideae 320 Tristichopsis 320 Triunia 392 Trochodendrales 1 Tryphostemma 276 Tulasnea 321 Tulasneantha 328 T. monodelpha 329 Turnera 465 Turneraceae 12, 458 Turpinia 443 T. borneensis 444 T. stipulacea 444 Turrillia 402 Tylecodon 111 Umbiliceae 102 Umbilicus 102 U. horizontalis 90

Index to Scientific Names Urbinia 110 Vanroyenella 329 V. plumosa 329 Velascoa 121 Vexatorella 389 Villadia 108 Vinkia 188 Viridivia 279 Virotia 400 Virotiinae 400 Viscainoa 498 Vismia 198 V. subg. Afrovismia 198 Vismieae 198 Vitaceae 16, 18, 467 Vitales 18 Vitis 474 V. sect. Nothocissus 473 V. rotundifolia 470 V. sp. 470

509

V. sect. Tetrastigma 476 Viviania 220 V. marifolia 219 Vivianiaceae 213 Vochysia 485 V. guianensis 481 Vochysiaceae 8, 9, 480 Vochysieae 480, 485

Wormskioldia 463 Xanthophylleae 355 Xanthophyllum 355 X. papuanum 346 X. ramiflorum 346 Xylomelum 394

Weddellina 320 W. squamulosa 305, 310 Weddellinoideae 319 Wendtia 219 Wettsteiniola 329 W. pinnata 329 Whittonia 299 Willisia 339 W. selaginoides 339 Winklerella 334 W. dichotoma 335 Woodfordia 244

Zahlbrucknera 431 Zehnderia 335 Z. microgyna 335 Zeylanidium 339 Z. lichenoides 339 Z. olivaceum 339 Z. subulatum 305 Zygophyllaceae 19, 488 Zygophyllales 19 Zygophylleae 493 Zygophylloideae 493 Zygophyllum 493

Yua 474

Flowering Plants. Eudicots: Berberidopsidales, Buxales, Crossosomatales, Fabales p.p... (The Families and Genera of Vascular Plants, Volume 9)

Flowering Plants. Eudicots: Sapindales, Cucurbitales, Myrtaceae (The Families and Genera of Vascular Plants, Volume 10)

Flowering Plants. Eudicots