Scala Millettiearum. A survey of the generaof the Millettieae (Legum.-Pap.) with methodological considerations BY Robert Geesink Rijksherbarium, Leiden E. J. BRILL / LEIDEN UNIVERSITY PRESS LEIDEN 1984 This book can be cited as: GEESINK, R. 1984. Scala Millettiearum. E. J. Brill / Leiden University Press. BotanicalSeries, vol. 8, viii + 131 5 18 5 (Leiden pp., plates, tables, figs.) be of In the LeidenBotanicalSeries will published papers a monographic nature from the entire field of botany (including its history, bibliography, and which their biography) by length (100 printed pages or more) are unsuitable for in publication journals. Information can be obtained from the editors, Rijksherbarium, Schelpenkade 6, Leiden, The Netherlands. World distributor for publications of the UniversitairePers, Leiden: E. J. Brill, Postbus 9000, 2300 PA Leiden, The Netherlands. Drawings: Jan van Os, Jan Jaap Vermeulen, and Joop Wessendorp Cover: Joop Wessendorp ISBN 90 04 07498 8 Copyright 1984 by E. J. Brill, Leiden, The Netherlands reserved. No this book be All rights part of may reproducedor translated in any form, by print, photoprint, microfilm, microfiche orany other means without written permission from the publisher. PRINTED IN THE NETHERLANDS BY E. J. BRILL In commemorationof the centenary of George Bentham (22. ix. 1800 —10. ix. 1884) Contents Summary VII Acknowledgements VIII 1. Why this revision? 1 2. Development of the concept of the tribeMillettieae 2 3. Delimitationof the Millettieaeand related tribes 3 4. Characters for generic delimitation 8 —Inflorescence 8 9 —Flower structure with notes on flower biology —Pollen 14 —Fruit 14 —Chemistry 16 —Vegetative anatomy 18 —Chromosomenumbers 18 5. 19 Natural classification, a desire for the impossible? 6. Derris, Millettia, and Lonchocarpus: the problem of the complex genus 35 the decisions delimitation 48 7. Character compatibility and on generic 8. Geographical distributions 58 9. Taxonomic part 59 —Glossary 59 —Abbreviationsof the references 60 -Millettieae 61 —Plates I—V 63 to the 68 —Key genera —Genera (in alphabetical order) 76 Literature 123 Indices 127 Summary In the present revision the tribeMillettieaecomprises 43 genera,4 ofwhich are either former new, or subgenera or sections here raised to generic rank: Austrosteenisia, Endosamara, Imbralyx, and Paraderris. The generaBrachypterum, Callerya, Deguelia, and not for 50 have been Philenoptera, Sarcodum, generally accepted years or longer, reinstated. The and Millettiareceived restricted genera Derris, Lonchocarpus, a more than circumscription usual. Ostryocarpus includes also the commonly accepted genera Aganope and Xeroderris.The rather common and rather widespread genera Muellera and Pongamia have been reduced to Lonchocarpus and Millettiarespectively. New combinationson specific rank are limited to the type-species of new or hitherto untypified genera, viz. Austrosteenisia blackii, Callerya nitida, Endosamara racemosa, Imbralyx albiflorus, Paraderris cuneifolia. One more combination, Afgekia filipes, not a type-species, is made. All here conceived defined monothetic of genera as are by a set characters, most have also characters. The Derris, genera unique generaApurimacia, Craspedolobium, Lonchocarpus, Margaritolobium, Millettia, Paraderris, Philenoptera, Platycyamus, and Requienia lack unique characters. A key is presented, also containing genera that are likely to be mistaken for members of the Millettieae. The genera are presented in alphabetical order as no unambiguous subdivision of the tribe couldbe made. Two different (but complementary) numero-cladistic methods have been applied (chapters 5, 6, and 7). Zandee’sthree-taxon-statements-permutation method resulted in selection numerous possible cladograms with many parallels. With a more restricted of characters it did into not result a fully resolved cladogram. Meacham’s compatibility analysis, slightly modified, resulted in three different meagre cliques of mutually compatible characters, therewith exactly indicating the cause of the complexity already intuitively recognized. The tribe is paraphyletic and, in order to obtain a more satisfactory picture of its natural structure (if attainable at all in this tribe), similar treatments will have to be made of the “surrounding” tribes Dalbergieae, Bossiaeeae, Brongniartieae, Robinieae, Phaseoleae (at least its subtribe Glycininae s.l.), and Abreae. Also more (new) characters have to be found and considered, as the characters used in this study have insufficient mutualcompatibilities. Acknowledgements This is study mainly based upon material from the Rijksherbarium, Leiden, and the Herbarium, Royal Botanic Gardens, Kew. Material was also borrowed from the following herbaria, from most even for a considerable time: A, AAU, BKF, BM, BO, C, E, K, KYO, MEXU, P, SAN, SAR, SING, U, US, WAG. The pleasant cooperation with Dr. M. Zandee (Leiden) resulted into substantialcontributionsto the theoretical chapters 5, 6, and 7. His critical remarks are much appreciated. Mrs. Diedel Kornet introduced me into the jungle of philosophical literature; she demonstratedthat there in it. I will are trails, even ways, never forget our regular misunderstandings. Dr. H. O. Sleumer corrected the Latin diagnoses. I want to express my appreciation to Dr. R. M. Polhill (Royal Botanic Gardens, Kew) and to Dr. D. J. Mabberley (Forest Herbarium, Oxford) for the stimulating correspondence and the discussions. The latter also polished the text of the earliest stages of the theoretical chapters; all mistakes have thus later been made. I feel much obliged to Mrs. Willy Dessing, who voluntarily retyped and cleaned the manuscript, and much when never complained too the theoretical chapters appeared to be "improved" again. 1. WHY THIS REVISION? than Slightly more ten years ago I started a revision ofthe S. E. Asiatic species of the genus Millettia. The distinctionof the described species did not seem too difficult and after a few years I couldrecognize most of themon sight. Morealarming was a growing of material that could of Millettia "pile" flowering represent either unknown species or of other species genera. The latterappeared to be the case, but the genera to which the material belonged were, in flowering stage, not or hardly distinguishable from Millettia. these that still in different tribes. I tried Moreover, genera were (at time) placed to the in order obtain with rearrange existing supraspecific taxa to genera differentiating characters. I submitted these proposed initialchanges to Dr. R. M. Polhill, who reacted with little enthusiasm, to put it mildly; he warned me that I was touching a world-wide problem that could not be satisfactorily solved on the basis of a regional S. E. Asiatic revision He either wider maintenanceof the only. suggested a scope, or (then) present generic circumscription. I plumped for the first suggestion, and presented on the first InternationalLegume Conference(Kew, 1978) a key to the genera. It appeared that the generic relations in this tribe (then called “Tephrosieae”) were about as complex as those in the Mimosoideae-Ingeae and in the Papilionoideae-Phaseoleae, and Dr. B. Verdcourt assured his he doubted if me that, according to experience, a satisfactory solution was possible at all. As this study (see chapters 6 & 7) demonstrates, he was correct. During the elaborationof the tribal treatment in the framework ofthe Proceedings of this Legume I found and unsolved Conference, more more (or unsolvable) problems. After the treatment was written I decided to continue the project for some time, were it alone for a more precise description of the complexity observed. A revision of the tribe based on species revisions would have been the best 'attack', but this would inhibittoo much the planned contributions to the treatment of the Papilionoideae for the Flora Malesiana, the Floraof Thailand, and the "Flore du Cambodge, du Laos, et du Viet-Nam". A compromise between moderately heavy leaning on existing literature randomly checked with herbarium material and what can be considered a "selective search for difficulties" be in the It considered appeared to possible, resulting present revision. was to be "completed" after smaller groupings with monothetic sets of characters (see chapter 5) were obtained and after two supplementary numero-cladistic approaches had failed to result into one, unambiguous grouping of these smaller groups. The next to obtain "better" and classification thereof will be step necessary genera a species revisions of the 'genera' here distinguished, and to start the whole comparison of "all with all" all over again. I hope that within the frameworks of the larger floras now in progress a new and better generic arrangement can be achievedafter a few decades. 1 2. DEVELOPMENT OF THE CONCEPT OF THE TRIBE MILLETTIEAE The history of the tribe Millettieaecan be summarized as the history of three groups and of some "nomadic" genera. The history of the 'nomadic' genera (e. g. Disynstemon, Sarcodum, Hesperothamnus, Craspedolobium) cannot be generalized, and is in the nomenclatural and taxonomic notes underthese in the presented genera taxonomic part. The three groups are: 1. The genera 'around Tephrosia’. These comprise subshrubs or herbs with woody base of the stem (Mundulea, Chadsia, Requienia, Ptycholobium, Lupinophyllum, and Caulocarpus). 2. The genera 'around Millettia’. These comprise woody plants with dehiscent pods (e. g. Callerya, Wisteria, Afgekia, Fordia, Dewevrea, Craibia, Schefflerodendron, Platysepalum).