Tetradenia (Lamiaceae) in Africa: new species and new combinations

The taxonomy of the African representatives of the Afro-Malagasy genus Tetradenia Benth. is reviewed. In a previous treatment of the genus, a single species, T. riparia (Hochst.) Codd, was taken to encompass almost all of the variation of the genus in tropical Africa: however, this interpretation has proved unsatisfactory. We recognise 10 species in Africa, of which two are described here as new, and we provide four new nomenclatural combinations for species originally described either in the genus Moschosma Rchb. or in Iboza N.E.Br. The two new species comprise: T. discolor, characterised by its discolorous leaves with woolly indument on the abaxial surface of densely matted, long white eglandular trichomes and shorter glandular trichomes, combined with relatively large flowers and hispid stems; and T. tanganyikae, characterised by its dense spikes of male flowers, relatively large flowers and short, generally sparse indument.