A revised classification of the Apocynaceae s.l.

The Asclepiadaceae, as traditionally defined, have repeatedly been shown to be an apomorphic derivative of the Apocynaceae. It has often been recommended that the Asclepiadaceae be subsumed within the Apocynaceae in order to make the latter monophyletic. To date, however, no comprehensive, unified classification has been established. Here we provide a unified classification for the Apocynaceae, which consists of 424 genera distributed among five subfamilies: Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae, and Asclepiadoideae. Keys to the subfamilies and tribes are provided, with lists of genera that (as far as we have been able to ascertain) are recognized in each tribe.