Body to 15 cm tall and 20 cm wide, compressed spherical. Ribs indistinct or up to 30. Tubercles with areoles mostly more than 2 cm apart and without nectaries. Central spines 0-4, up to 6 cm long. Radial spines 0-5 and mostly up to about 3.5 cm long. Flower white to pink or occasionally yellowish or magenta and sometimes with a dark midvein. Fruit greenish, slightly fleshy, opening by basal pore. [T. nidulans (Quehl) Britton & Rose, T. phymatothelos (Ruempl.) Britton & Rose]

NE Mexico

Source: Thompson, A, ; Forbes, S.; Spencer, R. (1997). Cactaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.