Shrubs, forming mats, to 50 cm, in series of usually 2-4 stem segments. Roots diffuse. Stem segments curved and narrowed at base, 10-15 × 2.5-4 cm; tubercles prominent, 20-30 mm, narrow, 4-6 times longer than wide, obscured by interlacing spines; areoles 5-6 mm in diam.; wool gray-white. Spines 17-27 per areole, ± uniformly distributed along stems; major 4-6 abaxial spines deflexed, tan with whitish margins, strongly flattened, longest to 4.5 cm; major 4-5 adaxial spines divergent, tan to reddish tan, angled at base, longest subterete, to 5 cm. Glochids few in adaxial portion of areole, yellow, 5-6 mm. Flowers: inner tepals yellow to pale yellow-green, to 15-20 mm; filaments white; style light green to white; stigma lobes white. Fruits sometimes proliferating, lemon yellow to yellow, 40-75 × 15-40 mm, fleshy, very spiny, glochidiate; spines (4-)6-17 per areole, straw yellow to brown, 12-20 mm, retrorsely barbed; areoles (40-)45-70. Seeds yellowish white, 4-5 × 3.5-4.5 mm, smooth. 2n = 44. Flowering spring (Apr-Jun). Sonoran Desert, silty, sandy, or gravelly flats and hills; 200-600 m; Ariz.; Mexico (Baja California, Sonora).

Plant: Mat-forming shrub, much-branched, to 50 cm tall; STEM segments, curved and narrowed at base, 10-15 cm long, 2.5-4 cm in diam.; tubercles prominent, 2-3 cm long. AREOLES gray-white-felty, subcircular, ca. 5-6 mm in diam Leaves: SPINES well distributed along stems, obscuring them, 17-27 per areole; major 4-5 apical spines tan to reddish tan, divergent, angled at base, the largest subterete, to 5 cm long; major 4-6 basal spines tan with whitish margins, strongly flattened, deflexed, the largest to 4.5 cm long. GLOCHIDS yellow, few in apical part of areole, 5-6 mm long Flowers: inner tepals yellow to pale yellow-green, to 1.5-2 cm long; filaments white; anthers yellow; style light green to white; stigmas white Fruit: lemon-yellow to yellow, fleshy, sometimes proliferating, 4-7.5 cm long, 1.5-4 cm in diam.; glochidiate and spiny, the spines straw-yellow to brown, (4-)6-17 per areole, 12-20 mm long; areoles (40-)45-70. SEEDS yellowish-white, smooth, 4-5 mm long, 3.5-4.5 mm wide Misc: Sonoran Desert, silty, sandy to gravelly flats and hills; 200-600 m (700-1900 ft); Apr-Jun REFERENCES: Pinkava, Donald J. 1999. Cactaceae. Ariz. – Nev. Acad. Sci. 32(1).