Studies in Neotropical Araliaceae. III. Resurrection of the New World genus Didymopanax Decne. & Planch., previously included in Schefflera (Araliaceae)

Didymopanax had been recognized for at least a century as the only genus of Araliaceae in the Americas with bicarpellate ovaries, but in recent decades, it had been treated in synonymy under Schefflera , where it has been recognized as an informal group. During this time, several new species belonging to the group were described under Schefflera , but there has been a growing understanding over the past 15 years that this broadly defined genus is polyphyletic, comprising five non-sister clades. The Neotropical species form a monophyletic group, but its five major subclades are both morphologically and geographically coherent, and are therefore being recognized as distinct genera. As a result, Crepinella Marchal and Sciodaphyllum P. Browne have been reinstated (but with new circumscriptions), and the remaining subclades will be accommodated in two new genera. Here we resurrect Didymopanax , transferring the 37 species out of Schefflera . As now defined, Didymopanax includes species with bicarpellate as well as a few with 5–6-carpellate ovaries, mostly from the rainforests and open savannic vegetations of Brazil. Twenty-one new combinations are proposed for taxa originally described under Panax L. (1), Schefflera (19), or Sciodaphyllum (1).