Homalocephala

A grey-green cactus with sharp ribs, strong recurved spines and yellow flowers with a reddish base. Seed and tissue culture studies reveal successive developmental stages, from seed-coat opening and the first areole to obtaining a rooted plant.

A cactus forming clumps of heavily armed stems. Yellow flowers open among the spines, and dry, hairy fruits release seeds through an opening at the base. Variation in spine, scale and seed surfaces helps distinguish the two accepted subspecies.

A low cactus with a broad stem often almost level with the ground surface. Pink flowers and red, fleshy fruits clearly distinguish it from the two yellow-flowered Homalocephala species. Its structure formed the basis for describing this genus as early as 1922.