Taxonomy and ethnobotanical overview of ikhathazo: The Alepidea amatymbica group (Saniculeae, Apioideae, Apiaceae)

A taxonomic revision of the Alepidea amatymbica group is presented. The species in this group are readily distinguished by the predominantly glabrous fruit and the well-developed rhizomes. It is these well-developed rhizomes which are known and traded under the local isiZulu name ‘ikhathazo’ and reported to be one of the most frequently utilized medicinal plants in southern Africa. Three species are recognised, A. amatymbica Eckl. and Zeyh., A. cordifolia B.-E.van Wyk and A. macowanii Dümmer. Two taxa, A. amatymbica var. aquatica and A. amatymbica var. microbracteata, are reduced into synonymy with A. amatymbica. The repeated misconception that A. amatymbica is the most widely utilized medicinal species within the genus is exposed in the ethnobotanical overview and refuted. Rather, A. cordifolia is clarified as the more extensively utilized species, validated by its much wider geographical range. A key to the species, updated nomenclature, typifications, complete descriptions, illustrations and the known geographical distributions for all three species are presented. Lectotypes are designated for four names (A. amatymbica, A. amatymbica var. microbracteata, A. aquatica and A. macowanii).