Over the past 30 years, the pantropical genus Schefflera has been greatly expanded to include all members of Araliaceae with palmately compound leaves, unarticulated pedicels, and unarmed vegetative parts. Using this broad definition, the genus has swelled to over 650 species, representing greater than half of species diversity found in the family and including many genera that were once treated as distinct (e.g., Brassaia, Didymopanax, Dizygotheca, Octotheca, Plerandra, Sciadophyllum, and Tupidanthus, inter alia). Phylogenetic analyses based on a nuclear (ITS) and chloroplast (trnL-trnF) sequences agree in suggesting that Schefflera, as currcently circumscribed, represents a polyphyletic group of no fewer than four distinct and unrelated clades within Araliaceae, each of which comprises a biogeographically coherent group, with two clades of Pacific Island taxa, one of African/Malagasy taxa, and another of SE Asian taxa, to which the neotropical Scheffleras appear to be allied. Although our current sample is non-exhaustive, it includes representatives from nearly all major segregate groups (sections of Schefflera and formerly recognized genera) and all geographic regions. Despite the finding of polyphyly, many of the generic realigments suggested over past decades are strongly supported. For example, the Asian clade comprises species once referred to Schefflera, Agalma, Brassaia, and Tupidanthus, and one of the Pacific clades includes taxa referred to Dizygotheca plus two informal groups of Schefflera ("Canacoschefflera" and "Gabriellae"). The second Pacific Island clade represents the type section (Schefflera sect. Schefflera), but this lineage shows no close relationship to any of the other clades of Schefflera. Overall, these results indicate the need for massive taxonomic revision, but also hold out the hope that smaller and more workable groups can be identified for future, more intensive studies.

Key words: Araliaceae, ITS, molecular phylogenetics, Schefflera, trnL-trnF