About Corryocactus melanotrichus (K.Schum.) Britton & Rose
Corryocactus melanotrichus is a highly branched, shrubby cactus that grows up to 4 meters tall. It has vertical yellowish-green stems that can reach up to 6 cm in diameter. Stems have 7 to 9 ribs that bear areoles. The areoles produce unequal, awl-shaped spines that start light yellow to brown and turn gray as they age. These spines measure 0.7 to 2 cm in length, and occasionally may reach up to 3 cm. Central and radial spines are not distinctly separate in this species. This cactus produces slightly purple flowers that grow up to 5 cm long and 6 cm across. Its fruits are spherical, soft, spiny, and can reach up to 6 cm in diameter. Corryocactus melanotrichus is native to Bolivia, where it occurs in the departments of La Paz, Chuquisaca, Cochabamba, Oruro, and Tarija. It grows in desert or dry scrub biomes on slopes, at elevations between 2100 and 3600 meters.