The species of the genus
Haageocereus grow like a shrub to tree-like, with outstretched and creeping, lengthwise, ascending or upright shoots. The shoots usually consist of many ribs, with closely spaced
areoles from which numerous thorns arise. Areoles from which flowers arise often have additional bristles. The tubular to bell-shaped flowers are white to pink or red, open at night and remain open until the next day. The flower tube is strong and fleshy. The flower cup and the flower tube are covered with numerous scales and few to many hairs. The stamens are in a single circle. The fleshy, spherical fruits are green to red and have a few scales and hairs. The rest of the flowers are perennial. The egg-shaped seeds are shiny black and irregularly pitted. == Species ==