About Thelocactus setispinus (Engelm.) E.F.Anderson
Thelocactus setispinus (Engelm.) E.F.Anderson is a globe-shaped to short cylindrical cactus. It grows 20 cm (8 inches) to 30 cm (12 inches) wide, and reaches up to 60 centimetres (24 inches) in height. It has 12 to 15 needle-shaped radial spines, which are bright, brown or white, and grow up to 10 centimetres (4 inches) long. It also has 1 to 3 central spines, which are longer and sturdier, straight, and hooked at the tip. Its flowers are orange, dark yellow, magenta, or violet with a red center, and measure around 18 centimetres (7 inches) long. This cactus flowers from late spring to summer. Its fruits are red, round or elliptical, slightly scaly, and range from 8 millimetres (0.31 inches) to 10 millimetres (0.39 inches) in size. This species is widespread across southern United States (the state of Texas) and the Mexican states of Coahuila, Nuevo León and Tamaulipas. It has been spread around the world as an ornamental plant. Its natural habitat is arid deserts, where it is widely distributed but occurs in scattered populations. It typically grows in black or clay soils on coastal lowlands beneath mesquite scrub, at elevations between 0 and 550 metres (0 to 1,804 ft) above sea level. It can be found growing alongside Astrophytum asterias, Mammillaria heyderi, Echinocereus stramineus, Echinocereus poselgeri and Homalocephala texensis.
