This species is characterized by its small to medium-sized habit, inflorescences enclosed by well developed, involucrate bracts, white corollas, and blue to purple or purple-black fruits. It is widespread across tropical Africa.

Verdcourt (1976) separated three subspecies, based on leaf shape, calyx lobe length and shape, and corolla size, and Figueiredo later recognized a fourth. The subspecies are generally all allopatric. The plants of Madagascar have not been evaluated as to their infraspecific identity.