Re-circumscription of the mimosoid genus Entada including new combinations for all species of the phylogenetically nested Elephantorrhiza (Leguminosae, Caesalpinioideae, mimosoid clade).

Abstract

• Recent phylogenomic analyses of 997 nuclear genes support the long-held view that the genus is congeneric with . is resolved as monophyletic only if the genus is subsumed within it. The two genera were distinguished solely by relatively minor differences in the mode of dehiscence of the fruits (a craspedium separating into one-seeded endocarp segments in versus a craspedium with the whole fruit valve breaking away from the persistent replum in ) and the craspedial fruit type itself provides a shared synapomorphy for the re-circumscribed . Here, we provide a synopsis of , including 11 new combinations in total, for the eight species, one subspecies and one variety previously placed in , as well as a new combination for a subspecies of Spreng. not previously dealt with when DC. was placed in synonymy. These new combinations are: (Benth.) S.A. O’Donnell & G.P. Lewis, ; (Burch.) S.A. O’Donnell & G.P. Lewis, ; (Harms) S.A. O’Donnell & G.P. Lewis, ; Entada goetzei subsp. lata (Brenan & Brummitt) S.A. O’Donnell & G.P. Lewis, ; (Burtt Davy) S.A. O’Donnell & G.P. Lewis, ; (J.H. Ross) S.A. O’Donnell & G.P. Lewis, ; (Harms) S.A. O’Donnell & G.P. Lewis, ; Entada rheedei subsp. sinohimalensis (Grierson & D.G. Long) S.A. O’Donnell & G.P. Lewis, ; (Dinter) S.A. O’Donnell & G.P. Lewis, ; (E. Phillips) S.A. O’Donnell & G.P. Lewis, ; and Entada woodii var. pubescens (E. Phillips) S.A. O’Donnell & G.P. Lewis, We provide a revised circumscription of the genus which now comprises 40 species distributed pantropically, with the greatest diversity of species in tropical Africa. We present a complete taxonomic synopsis, including a map showing the global distribution of the genus and photographs showing variation amongst species in habit, foliage, flowers and fruits. A short discussion about extrafloral nectaries, mainly observed in the Madagascan species, is presented.