PACHYPODIUM (APOCYNACEAE) PROMOTOR Dr
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PACHYPODIUM (APOCYNACEAE) PROMOTOR Dr. Ir.L.J.G . van der Maesen - Hoogleraar ind e Plantentaxonomie CO-PROMOTOR DrA.J.M . Leeuwenberg- Universitair hoofd-docent, vakgroep Plantentaxonomie OKto&Xol , £6S^ Pachypodium (Apocynaceae) S.HJ.V. Rapanarivo PROEFSCHRIFT terverkrijgin g vand egraa dva ndocto r opgeza gva nd eRecto r Magnificus vand eWageninge n Universiteit, dr.CM .Karssen , inhe topenbaa rt everdedige n opwoensda g 27oktobe r 1999 desnamiddag st ehal f tweei nd eAula . A.A.BALKEM A/ ROTTERDAM/ BROOKFIELD/199 9 € a -c ')>1 )}^ ' ~I am afemm e ame sdeu x filles 'Jededi ec etravail ' Photographs made by W. Rdosli 1-13, 15-32, 34-46, 48-68, 72, 74, 79-80; by J.J.Lavrano s 69-70, 73, 75,78; by M.Kroenlei n 71; by A.J.M. Leeuwenberg 33,47; by D.Supthu t 14;b yJ .d e Koning 76-77. Proefschrift: ISBN 90 5410 4848 Handelseditie: ISBN 90 5410 485 6 © 1999A.A.Balkema , Rotterdam K/JV5 o&zcV/Z-fcSS Propositions — Stellingen 1. At present 23 species of Pachypodium are recognized, 18 in Madagascar and 5 in the African continent, indicating that the genus originated during a period prior to the separation (some 165 MA ago) of Madagascar from the African continent. 2. The opinion of G.D. Rowley that Pachypodium inopinatum, P. bicolor and P. eburneum do not deserve specific rank is incorrect. Rowley, G.D., 1999. The Cactus File Handbook 5, Pachypodium & Adenium. 3. The location Horombe Plateau for Pachypodium densiflorum as indicated by Allorge is incorrect. This species has never been collected there. Allorge, L., 1993. Pachypode. Succulentes 3: 24. 4. Pachypodium geayi, P. lamerei, P. rosulatum and P. rutenbergianum grow in Leeuwenberg's model, but P. brevicaule probably not, as it does not form branchlets. Halle, F., Oldeman, R.A.A. & Tomlinson, P.B., 1978. Tropical Trees and Forests. 5. If the present Nature Reserves in Madagascar would be well preserved, the species of Pachypodium are protected simultaneously. 6. CITES protects Pachypodium. However, in practice the regulations have hampered scientific exchange and did not sufficiently prevent illegal commercial exploitation. 7. The inclusion of the genus Macoubea in the tribe Tabernaemontaneae (Apocynaceae) by Boiteau leads to erroneous conclusions in cladistic studies. Boiteau, P. & Satre, C, 197S. Sur l'arille des Macoubea et la classification des Tabemaemontanoi'dees (Apocynacees). Adansonia ser. 2, 15:239-250 . Endress, M.E., Sennblad, B., Nilsson, S., Civeyrel, L., Chase, M.W., Huysmans, S., Grafstrom, E. & Bremer, B. 1996. A Phylogenetic analysis of Apocynaceae s. str. and some related taxa in Gentianales: a multidisciplinary approach. Opera Bot. Belg. 7: 59-102. 8. To sink Geissospermum into Aspidosperma (Apocynaceae) was proposed in a cladistic study based on flowers alone, ignoring fruits, seeds and architecture of the trees, which characters point to a separate position. Potgieter, K. 1997. Abstracts, Congress of North American Botany, Montreal. 9. The seeds of friendship are planted by the moment, but its fruits are harvested during a lifetime. 10. Despite the advanced satellite facilities to pinpoint the exact location of a plant by co- ordonates, in the case of endangered plants their whereabouts should be reported with restraint. 11. A good plant taxonomist needs both theoretical knowledge and ample field experien ce. Stellingen behorende bij het proefschrift, Pachypodium (Apocynaceae). S.H.J.V. Rapanarivo, 27 October 1999. Tableo f contents FOREWORD VII CURRICULUM VITAE VIII 1 TAXONOMIC REVISION OFPACHYPODIUM SERIES OF REVISIONS OF APOCYNEAE XLVIII 1 Introduction 1 History of the genus 1 Geographical distribution 2 Morphology 3 Relationship with other genera 5 Genus description of Pachypodium 6 Key to the species of Pachypodium 7 Key to the species of Pachypodium endemic to Madagascar 7 Key toth e species of Pachypodium confined to the African continent 9 Treatment of the species 10 1.Pachypodium ambongense Poiss. 10 2.Pachypodium baronii Costanti n &Boi s 12 3. Pachypodium bicolor Lavranos & Rapanarivo 14 4.Pachypodium brevicaule Bake r 17 5.Pachypodium cactipes K.Schum . 20 6.Pachypodium decaryi Poiss. 24 7. Pachypodiumdensiflorum Baker 26 8.Pachypodium eburneum Lavranos & Rapanarivo 30 9. Pachypodium geayi Costantin & Bois 33 10.Pachypodium gracilius (H.Perrier ) Rapanarivo 35 11.Pachypodium horombense Poiss. 39 12.Pachypodium inopinatum Lavranos 42 13.Pachypodium lamerei Drake 44 14.Pachypodium meridionale (H .Perrier )Picho n 49 15.Pachypodium rosulatum Baker 51 16.Pachypodium rutenbergianum Vatke 54 17.Pachypodium sofiense (Poiss.) H. Perrier 59 18.Pachypodium windsorii Poiss . 60 19.Pachypodium bispinosum (L.f.) A.DC. 63 20. Pachypodiumlealii Welw . 67 21. Pachypodium namaquanum (Wyley ex Harv.) Welw. 70 VI Tableof contents 22. Pachypodium saundersiiN.E.Br . 72 23. Pachypodium succulentum (L.f.) A.DC. 76 Excluded species 81 References 81 2 THE HABITATS OFPACHYPODIUM SPECIES 83 Introduction 83 Study area, material and methods 83 Results 87 Discussion and conclusions 96 Acknowledgements 101 References 102 3 CULTIVATION OFPA CHYPODIUM 105 Species list with information 105 Pachypodium ambongense Poiss. 105 Pachypodium baronii Costantin &Boi s 106 Pachypodium bicolor Lavranos & Rapanarivo 106 Pachypodiumbrevicaule Baker 106 Pachypodiumcactipes K. Schum. 107 Pachypodium decaryi Poiss. 107 Pachypodium densiflorum Baker 107 Pachypodium eburneum Lavranos & Rapanarivo 108 Pachypodium geayi Costantin & Bois 108 Pachypodium gracilius (H. Perrier) Rapanarivo 108 Pachypodiumhorombense Poiss. 109 Pachypodiuminopinatum Lavranos 109 Pachypodiumlamerei Drak e 109 Pachypodium meridionale(H .Perrier ) Pichon 110 Pachypodiumrosulatum Baker 110 Pachypodiumrutenbergianum Vatke 110 Pachypodium sofiense (Poiss.) H. Perrier 111 Pachypodiumwindsorii Poiss . Ill INDEX OF EXSICCATAE 113 INDEX OF SCIENTIFIC NAMES 117 VII Foreword The present publication incorporates a taxonomic monograph of the genus Pachypo- diunt based on herbarium material and living plants of all species,a detaile d studyo f the habitats and ecological preferences of most species and a chapter on cultivation. The latter describes the successes of artificial propagation, as the ecological condi tionshav ebee nsimulate dcarefull y for thepurpose . The monograph hasbee n written byRapanarivo , whogo tessentia l inputsfro m the plant explorer Lavranos and the taxonomist Leeuwenberg, world specialist of the Apocynaceaefamily . Thetaxonom y isa moder n andcompletel y revised updateo fth e publications of Codd (1963) on the continental African species and that of Markgraf (1976) on the Madagascan species, describing 23 species as presently distinguished. All have ornamental value and most can be classified as threatened in the wild, but sustained exploitation is possible through multiplication by seeds.Thi s enables trade withoutfurthe r damaging thenatura lpopulations . Thehabitat s have been studied by Rapanarivo, whotravelle d to many localitieso f Pachypodium in Madagascar. He could not visit continental Africa, and ecological inputswer econtribute d for hisstud yb yLavranos . Theautho ro f thechapte r oncultivatio n isRoosli ,wh ogrow sal l species inhi spri vate greenhouses from seeds he collected in the wild. He showed all of his living plants to the monographer, which was of great interest for detailed observations,es pecially for the species not seen by him in the wild. Lavranos and Roosli also made mosto fth eexcellen tphotographs . L.J.G.va nde rMaese n VIII Curriculum vitae Solo Hery Jean Victor Rapanarivo was born on 25Ma y 1954.H ejoine d the Univer sity of Antananarivo (en Filidre Sciences Naturelles) in 1979,wher e he obtained the certificates 'Licence d'Enseignement en Sciences Naturelles' and 'Maitrise de Re cherche option Biologie Vegetale' in 1988 and 'Diplome D'Etude Approfondie op tion Ecologie Veg6tale' in 1992. He started to work at the Pare Botanique et Zo- ologique de Tsimbazaza (Botanical and Zoological Park of Tsimbazaza) in Antananarivo inMarc h 1992.H ei sresponsabl e for theherbariu m and is Head of the Flora Departement. Between November 1995 and February 1998, he was affiliated with theDepartemen t of Plant Taxonomy,Wageninge n Agricultural University, fora Ph.D. study, madepossibl e by a sandwich grant. Hei s currently working at thePar e Botanique etZoologiqu e deTsimbazaz a in Antananarivo. Hemad ecollection s inth e field with various colleagues in Madagascar, among whom his copromotor. He is married andha stw odaughters . CHAPTER 1 Taxonomic revision ofPachypodium Serieso f revisions of ApocynaceaeXLVII I S.H.J.V. Rapanarivo & A.J.M. Leeuwenberg ABSTRACT: The genus Pachypodium (Apocynaceae) comprises 23 species. Eight een are endemic to Madagascar and five occur in continental African (Angola, Bots wana, Mozambique, South Africa, Swaziland and Zimbabwe). The study is based on herbarium material and living plants. The varieties P. baronii var. windsorii and P. rosulatum var. gracilius are raised to the rank of species and P. cactipes, cited as synonym of P. rosulatum by Markgraf (1976), is reinstated as a distinct species. Re cently three new species have been described: P. bicolor, P. eburneum and P. inopi- natum and these have been maintained. The key consists of an introductory part, keying out the most conspicuous life forms, and leading to the regional keys for Madagascar and for continental Southern Africa. INTRODUCTION The present paper is a monographic revision of the genus Pachypodium Lindl. The study is based on herbarium material and on living plants in the