This sub-tribe consists of low spiny plants, mostly globular, but sometimes cylindrical. They have numerous tubercles and these are usually arranged spirally. Themay be large or small according to the species.
THELOCACTUS. The genus includes 25 species of globular plants, sometimes very spiny.
Thelocactus bicolor. S. Texas to Central Mexico.
Theis usually solitary, globular to oval, but sometimes cylindrical, with 8 ribs. Radial spines number 9 to 18, central spines 4; the flowers are large and violet-red.
Thelocactus wagnerianus. W. Mexico. The stem is cylindrical, with 13 ribs. Radial spines number about 20, spreading comb-like, with only 1 central spine. The spines are red, or yellow and red. This species sometimes produces young plants at the base.
Thelocactus giehdorfianus. Mexico. The greyish-green stem is solitary, globular to oval, with the ribs divided into broad angular warts. The areoles bear 6 to 7 spreading spines. The plant is free flowering, with white flowers.
Thelocactus nidulans. Mexico. The stem is solitary with about 20 ribs divided into acute warts. The spines number about 15, and are so grouped and arranged that they look like a bird s nest. This is a fine species with pale yellow flowers.