A Taxonomic Account of Mucuna (Leguminosae–Papilionoideae) in Africa, Madagascar, and the Indian Ocean Islands, with Comments on Its Biogeographic History

Abstract

A taxonomic account of the papilionoid legume genus Mucuna Adans. in Africa, Madagascar, and the Indian Ocean islands is presented. Fifteen large herbaria that host representative collections of African specimens were visited and online databases consulted. A new phylogenetic analysis is also presented. Nineteen taxa are described and mapped. Twelve species and six infraspecific taxa (including autonyms, thus 15 terminal taxa) of Mucuna are present on the African mainland, where three species are representatives of Mucuna subg. Mucuna and the other nine are members of Mucuna subg. Stizolobium (P. Browne) Baker. In the Madagascar and Indian Ocean islands biodiversity hotspot, Mucuna is represented by six species, two of which (M. gigantea (Willd.) DC. and M. pruriens (L.) DC.) also occur on the African mainland. The other four species are endemic to Madagascar or adjacent islands and are representatives of Mucuna subg. Mucuna. The only representative of Mucuna subg. Stizolobium in Madagascar is M. pruriens. Our study suggests that the African mainland is the center of origin of Mucuna subg. Stizolobium. It is also revealed as the world’s most species-rich region in representatives of this subgenus, whereas on the other continents, subgenus Mucuna is the most diverse.