Plants flat-topped and usually flush with soil surface, or at most, above-ground portion low, dome-shaped. Stems shiny, sparsely speckled by bright white extra-areolar hair tufts 0.5-1 mm diam.; ribs usually 8, straight, very low, nearly flat or rounded; areoles 3-5 mm diam., with yellow or gray wool. Flowers opening widely, externally long woolly; inner tepals lanceolate, acuminate. 2n = 22.
|Star-peyote, star cactus, sea-urchin cactus|