The taxonomy and systematics of Apocynaceae: where we stand in 2012

In their most recent classification of Apocynaceae in 2000, Endress and Bruyns recognized five subfamilies of Apocynaceae (Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae and Asclepiadoideae). Subsequently, through various studies using molecular data, it has been shown that most tribes and subtribes of Rauvolfioideae were not monophyletic, and new tribes and subtribes have been erected to reflect improved phylogenetic understanding of the family: Aspidospermeae in Rauvolfioideae; Nerieae, Odontadenieae and Baisseeae in Apocynoideae; Fockeeae in Asclepiadoideae; and Orthosiinae in Asclepiadeae. Several genera in Rauvolfioideae have been reassigned to different tribes in order to improve the monophyly of these tribes. The sister group of Asclepiadoideae plus Secamonoideae is not Periplocoideae, as formerly assumed, but tribe Baisseeae. Periplocoideae are nested in Apocynoideae. However, tribal composition remains unclear in some parts of the family. Clade structure in Apocynaceae is now generally well understood. The principal challenges now lie in identifying characters that can reflect and articulate these clades in a formal classification. Species‐rich, recent radiations such as core Asclepiadinae in Africa and the Metastematinae in Latin America present particular problems in this regard. © 2013 The Linnean Society of London