Volume 83Number 31996Annalsof theMissouriBotanicalGardenA REVISION OF CYNANCHUM Sigrid Liede2(ASCLEPIADACEAE) INAFRICA'ABSTRACT Based on the study of dried specimens and living material, a taxonomic revision of Cynanchum in mainland Africais presented. Cynanchum here comprises 31 species (about half the number found in Madagascar), 6 of them new. Onenew combination is proposed and two species are neotypified. An artificial key to ail taxa is presented; ail species arefully described, and taxa not previously illustrated are provided with illustrations. Names for African Cynanchum placedinto synonymy under other genera are listed with their current placement. Since the works of Schlechter (1895) and Brown(1902-1903, 1908), the African species of Cynan-chum have not been revised. Asclepiadaceae havenot been treated to date in most African Flora pro-jects, with exception of Bullock (1963) for West Af-rica and Huber (1967) for Namibia. Therefore, evenregional treatments of Cynanchum are lacking formost of the continent. The present account is thefirst one covering ail of mainland Africa. Vincetoxicum is understood as being separatefrom Cynanchum and is not considered here. Thereare only a very few species of Vincetoxicum in theextreme north and northeast of the African conti-nent. The separation of Vincetoxicum renders irrel-evant the question of whether Blyttia Arnold shouldbe maintained for the treatment of Cynanchum, be-cause Blyttia could possibly be subsumed underVincetoxicum, but certainly not under Cynanchum.A more detailed account on the Cynanchum/Vin-cetoxicum problem is in preparation (Liede, inpress). To date, there is no valid infrageneric classifi-cation for Cynanchum. The present author recog-nizes only some East Asian members as sufficiently ' The continued support of my Asclepiad work by the Deutsche Forschungsgemeinschaft is gratefully acknowledged(grants LI 496/1-4). F. Weberling, G. K. Gottsberger (Ulm), and F. Albers (Mtinster) provided working space and supportat their departments. For long-term loans of rather large numbers of specimens I owe gratitude to the directors of theherbaria listed in materials and methods. Gina Douglas took the trouble to provide information from the Linnean library. I am deeply indebted to the artists, Jim Conrad, Graziela Hintze, and Ulrich Meve, for their patience in workingwith sometimes rather bad material and a very critical author. U. Meve, Mtnster, in addition, is taking care of theliving material; he provided chromosome counts and supportive criticism at ail stages of the work. The cheerful companyof N. E. Newton, Kenyatta University, Kenya, during fieldwork in East Africa deserves particular mention. Helpfulcomments from W. D. Stevens and M. G. Gilbert, Missouri Botanical Garden, on an earlier draft of this manuscript aregratefully acknowledged. 2 Abtlg. Spezielle Botanik (Biologie V), Universit�t Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany. ANN. MISSOURI BOT. GARD. 83: 283-345. 1996.
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