XVI International Botanical Congess

Hymenoptera (mainly bees and wasps) and Diptera (flies) dominate as pollinators in the Apocynaceae-Asclepiadoideae since their extremities and mouth tools are most appropiate for pollinaria transfer. Most flowers are polyphilic, and especially in the species-rich tribes Asclepiadeae and Stapelieae comparatively generalistic pollination systems have been developed instead of specialized, co-evolved monophilic ones. In consequence, similar to identical floral morphological structures and colours have evolved independently several times in both, closely and distantly related groups. This widespread occurrence of such parallel evolution was responsible for many systematic misunderstandings in Asclepiadoideae and served for long-standing taxonomic errors. Four examples, where similar corolla and corona structures led to erroneous classifications, are presented. Two show Hymenoptera pollinated Asclepiadinae species of the genera Philibertia and Platykeleba, Sarcostemma and Funastrum. Another two show fly pollinated Stapelieae species of the genera Riocreuxia and Ceropegia, Huernia and Duvalia. Ulrich Meve