Body tree-like, columnar to 12 m or so tall in nature few branches. Ribs mostly 12-30. Areoles with flowers generally more woolly than those without. Flowers nocturnal, funnel- to bell-shaped. Pericarpel and flower tube with small scales, sometimes with hair in the axils. Stamens at base of flower arising from a rim at the top of the nectar chamber. Fruit ovoid with numerous small scales and persistent remnants of the perianth.
Known largely through the popular hairy C. senilis (Haw.) K. Schum., Old Man Cactus, from C Mexico which is grown for its long hair, sometimes given additional marketing appeal by being decorated with artificial eyes, glasses etc.; it has 12-30 rounded ribs (fewer at first), flowers more or less creamy white with a dark midrib and red fruit. The cephalium develops only on mature plants.
Most species formerly in Cephalocereus are now placed in Pilocereus.
Woolly areoles.
A genus of 2-3 species from Mexico.
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.
