Systematics and biology of the African genus <i>Ferraria</i> (Iridaceae: Irideae)

Following field and herbarium investigation of the subequatorial African and mainly western southern African Ferraria Burm. ex Mill. (Iridaceae: Iridoideae), a genus of cormous geophytes, we recognize 18 species, eight more than were included in the 1979 account of the genus by M.P. de Vos. One of these, F. ovata, based on Moraea ovata Thunb. (1800), was only discovered to be a species of Ferraria in 2001, and three more are the result of our different view of De Vos’s taxonomy. In tropical Africa, F. glutinosa is recircumscribed to include only mid- to late summer-flowering plants, usually with a single basal leaf and with purple to brown flowers often marked with yellow. A second summer-flowering species, F. candelabrum, includes taller plants with several basal leaves. Spring and early summer-flowering plants lacking foliage leaves and with yellow flowers from central Africa are referred to F. spithamea or F. welwitschii respectively