Achyranthemum N.G.Bergh, a new genus segregated from Syncarpha DC. (Asteraceae, Gnaphalieae)

Abstract The genus Syncarpha from the Cape region of South Africa has been shown to comprise two separate lineages based on phylogenetic analysis of plastid and nuclear DNA sequence data. The lineage that does not house the type of Syncarpha corresponds to the ‘Helichrysum paniculatum group’ of species. Here we erect a new genus, Achyranthemum, to house these species, make the necessary nomenclatural changes, and present a taxonomic revision with key, descriptions and distribution maps based on verified records. Achyranthemum comprises seven species confined to the Cape Floristic Region and with the highest concentration of species in the Port Elizabeth region. Species are distinguished by leaf shape and orientation, leaf and peduncle indumentum, colour of the involucral bracts, and capitulum arrangement, as well as other features including differences in edaphic habitat. Nomenclatural and taxonomic investigations indicate that Syncarpha chlorochrysum is a synonym of Syncarpha mucronatum, and that there are two species present in the taxon currently known as Syncarpha argentea.