STEMS: solitary or rarely 2-4(12), subglobose to obovoid, 3.2-6.2 cm long, 2.6-4 cm in diameter, the stem apex at or to 3 cm above soil level; tubercles 3-4 mm long, 5-7 mm in diameter; areoles elliptic, white or yellow-villous

Leaves: SPINES dense, obscuring the stem; central spines mostly 0; radial spines mostly (7-)13-16(-18), 3-5 mm long, about 0.8 mm in width, white or yellowish-tan, tips spread downward and taper from bulbous bases

Flowers: mostly 2 cm long, 1.5 cm in diameter; outer tepals straw-yellow, inner tepals paler, 1-1.5 cm long, about 3 mm broad, oblanceolate

Fruit: green, turning reddish-brown, 7-10 mm long, 10 mm in diameter, smooth, top-shaped and basally constricted, the apex slightly convex, dehiscing by a vertical slit. SEEDS brownish-black, papillae and rugose, up to 2.8 mm long, 1.7-2 mm wide

Misc: Desertscrub; 1050-1200m (3400-4000 ft); Mar-Apr

REFERENCES: Heil, Kenneth D., and Mark J. Porter. 2001. Cactaceae. J. Ariz. - Nev. Acad. Sci. Volume 33(1)