Solitary or clustering with large tubercles having a distinctive woolly groove above with a flower-bearing areole on the outer surface. Flowers magenta.
E Mexico, SW North America
This species is rather different from others in the genus and may eventually be placed in Turbinicarpus (Backeb.) Buxb.
Source: (1997). Cactaceae. In: . 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.
