About Thelocactus conothelos (Regel & E.Klein bis) F.M.Knuth
Thelocactus conothelos is a solitary, spherical cactus that reaches 7 to 18 cm (2.8 to 7.1 inches) in both height and diameter. It has indistinct ribs that bear squared, conical warts which are light green at the base. Its areoles are woolly, measuring approximately 3 mm (0.12 inches) wide. This cactus produces 7 to 20 glassy radial spines that range in color from ocher yellow to grayish, and grow 8 to 12 mm (0.31 to 0.47 inches) long. It also has 4 central spines that grow 1 to 9 cm (0.39 to 3.54 inches) long. The large, spreading flowers are 4.5 to 6 cm (1.8 to 2.4 inches) wide, and their color varies from white to magenta. The fruits are 12 mm (0.47 inches) long and 7 mm (0.28 inches) in diameter, and hold dark reddish to black seeds. This species is native to Tamaulipas, Nuevo León, and San Luis Potosí, Mexico. It grows at elevations between 1200 and 2200 meters, in shrubland and on limestone slopes. It can be found growing alongside Mammillaria candida, Mammillaria picta, Mammillaria formosa subsp. formosa, Mammillaria winterae, Turbinicarpus schmiedickeanus subsp. gracilis, Thelocactus bicolor, Astrophytum myriostigma and Echinocactus platyacanthus.
