1. Astrophytum asterias (Zuccarini) Lemaire, Cactées. 50. 1868.
Star-peyote, star cactus, sea-urchin cactus
Echinocactus asterias Zuccarini, Abh. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. 4(2): 13. 1845
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.
Flowering Mar-May and sporadically after summer rainfall. Grasslands, shrublands, Tamaulipan thorn scrub, gravelly slopes and deep soil of flats; of conservation concern; 20-100 m; Tex.; Mexico (Nuevo León, Tamaulipas).
The vernacular name of Astrophytum asterias, star-peyote, reflects its superficial similarity to peyote, Lophophora williamsii, which has very soft, uniformly pale blue-green stems quite unlike the hard, speckled, almost shiny, green stem surface in A. asterias. Astrophytum asterias is extremely rare and localized north of Mexico, presently known only from Starr County, Texas.