The circumscription of the genus has varied greatly. Phylogenetic studies have shown that the widely used broad circumscription was polyphyletic, so most of its hundreds of species have been reassigned to other genera.[6][7] Molecular analyses have recovered five polyphyletic clades of Schefflera, all of which are geographically isolated from one another yet share similar traits indicating parallel evolution.[8] These clades have been split into separate genera, primarily along geographical lines, with Schefflera now consisting of thirteen species restricted to New Zealand and some Pacific islands.[9][10][11] The houseplant popularly known as "Schefflera" is now Heptapleurum arboricola.
The old Didymopanax Decne. & Planch., 1854 genus was resurrected in 2020 to welcome the 37 American species of Schefflera J.R. et G. Forst..[12]
The genus has had a turbulent taxonomic history; the list of former synonyms includes:
^G. M. Plunkett; Porter P. Lowry II; D. G. Frodin & Jun Wen (2005). "Phylogeny and geography of Schefflera: pervasive polyphyly in the largest genus of Araliaceae". Annals of the Missouri Botanical Garden. 92 (2): 202–224. JSTOR3298514.
^Pedro Fiaschi & Gregory M. Plunkett (2011). "Monophyly and phylogenetic relationships of Neotropical Schefflera (Araliaceae) based on plastid and nuclear markers". Systematic Botany. 36 (3): 806–817. doi:10.1600/036364411X583754. S2CID85944746.
^Plunkett, Gregory M; Lowry, Porter P; Frodin, David G; Wen, Jun (2005). "Phylogeny and geography of Schefflera: Pervasive polyphyly in the largest genus of Araliaceae". Annals of the Missouri Botanical Garden. 92 (2): 202–224.
^Łańcucka-Środoniowa M.: Macroscopic plant remains from the freshwater Miocene of the Nowy Sącz Basin (West Carpathians, Poland) [Szczątki makroskopowe roślin z miocenu słodkowodnego Kotliny Sądeckiej (Karpaty Zachodnie, Polska)]. Acta Palaeobotanica 1979 20 (1): 3–117.