The African-Malagasy genus Protorhus and the African-Malagasy species of Rhus s.l. have been suggested to be polyphyletic, but definitive evidence has been lacking. We investigated a clade of Anacardiaceae subfamily Anacardioideae in order to clarify evolutionary relationships of the African-Malagasy members of these two genera. Phylogenetic analysis of sequence data from cpDNA trnL–trnF, and nrDNA ETS and ITS provide strong statistical support for the 1) polyphyly of Protorhus; 2) monophyly of Malagasy Protorhus species; 3) polyphyly of Rhus section Baronia (Malagasy Rhus). These results support the need for new circumscriptions of these groups. Two new combinations are proposed, Searsia erosa and Searsia pendulina.