Greek koleon—sheath, cephalocereus, referring to the structure of the flowering area.
Shrubby plants if branching then from the base. Stems narrowly cylindrical. Ribs few to many. Flowering areoles woolly or bristly and fused together to form a distinctive head (cephalium). Flowers nocturnal or diurnal, shape variable. Pericarpel and flower tube naked. Fruit red, fleshy.
Here taken to include Buiningia Buxb. The 2 most widely cultivated species are keyed out below.
Inner perianth segments wheel-like; fruit red; fertile region forming a cephalium, sometimes in a sunken groove.
About 10 species from E Brazil.
Source: (1997). Cactaceae. In: . Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.