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

摘要

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).