The genus Protorhus (Anacardiaceae) consists of one African species and fifteen Malagasy species. The morphological features that distinguish these two geographically segregated groups of taxa are so striking that many botanists have questioned their placement within the same genus. They differ mainly in style and fruit characteristics. In this study, morphological data as well as DNA sequence data from both the chloroplast and nuclear genomes (trnL, trnL-trnF spacer, ITS, ETS) were used to investigate the generic affinities of the species currently recognized in Protorhus. The data indicate that P. longifolia (Bern.) Engl., the African species, is far removed from the Malagasy species clade, which is sister to the genus Ozoroa Del. Because P. longifolia is the type species for Protorhus, we propose erecting a new genus, Abrahamia, for the Malagasy taxa. In addition to the fifteen transferred species, we recognize five new species of Abrahamia in Madagascar.

Key words: Abrahamia, Anacardiaceae, ETS, ITS, Protorhus, trnL