Leistner, O.A. (2005) Seed plants of southern tropical Africa: families and genera SABONET Report No. 26 SABONET, Pretoria
Description of the genus
Herbaceous perennial. Rootstock tuberous. Leaves opposite, subsessile. Inflorescence of terminal and lateral umbels. Corolla deeply 5-lobed. Corona 5-lobed, petal-like, more conspicuous than the corolla, with 2-3 lobes in the claw. Follicles in pairs, fusiform, beaked, pubescent.
Worldwide: 1 species in tropical Africa with 8 subspecies.