Shrubs, forming mats, 10-20 cm in series of usually 1-2 stem segments. Roots diffuse. Stem segments clavate, 5-9 × 2-3 cm; tubercles prominent, 15-25 mm, narrow, 4-6 times longer than wide, obscured by interlacing spines; areoles 5 mm in diam.; wool grayish white. Spines 14-17(-22) per areole, mostly in distal areoles or ± uniformly distributed, white to brownish, tipped yellow; major 5-6 abaxial spines strongly deflexed, flattened, longest white margined, 25-45(-58) mm; central spine brown or white, long tapered; major ca. 5 adaxial spines divergent, blackish or brown to tan, subterete, angular-flattened at base, longest to 42 mm. Glochids adaxial in areoles, yellow, 5-8 mm. Flowers: inner tepals pale yellow with narrow reddish midstripes, 15-22 mm; filaments pinkish or greenish to pale yellow; style whitish to pale yellow or dull pinkish; stigma lobes white, greenish white or pale yellow. Fruits yellow, 35-55 × 15-20 mm, fleshy, spineless, densely yellow glochidiate; areoles 35-52. Seeds yellowish white, 4-4.5 × 3.5-4.5 mm, smooth. 2n = 22. Flowering late spring-early summer (May-Jul). Mojave and Sonoran deserts, silty, sandy, or gravelly flats, dunelets, hills; 300-900 m; Ariz., Calif., Nev. L. D. Benson (1969) segregated plants of the southern Arizona populations, which are less robust than the others, as 'Opuntia stanlyi var. peeblesiana;' unfortunately he included with its type other specimens that belong to Grusonia kunzei. Diploid plants of G. parishii have spineless (but glochidate) fruits; tetraploid plants of G. kunzei have spiny and glochidate fruits.

Plant: Mat-forming shrub, low, much-branched, 10-20 cm tall; STEM segments clavate, 5-9 cm long, 2-3 cm in diam.; tubercles prominent, 1.5-2.5 cm long. AREOLES grayish white-felty, sub-circular, ca. 5 mm in diam Leaves: SPINES mostly in distal areoles to well distributed, white to brownish, yellow-tipped, 14-17(-22) per areole; major apical spines ca. 5, brownish, divergent, subterete, angular-flattened at base, the largest to 4.2 cm long; major 5-6 basal spines whitish, pinkish or tan-centered, strongly deflexed, flattened, the largest white-margined, 2.5-4.5(-5.8) cm long. GLOCHIDS yellow, distal in areole, 5-8 mm long Flowers: inner tepals pale yellow with narrow reddish center line, 1.5-2.2 cm long; filaments pinkish or greenish to pale yellow, the anthers pale yellow to yellow; style whitish to pale yellow or dull pinkish; stigmas white, greenish-white to pale yellow Fruit: yellow, fleshy, 3.5-5.5 cm long, 1.5-2 cm in diam., spineless but densely yellow-glochidiate; 35-52. SEEDS yellowish-white, smooth, 4-4.5 mm long, 3.5-4.5 mm wide Misc: deserts, silty, sandy to gravelly flats, dunelets and hills; 350-900 m (1200-2900 ft); May-Jul REFERENCES: Pinkava, Donald J. 1999. Cactaceae. Ariz. – Nev. Acad. Sci. 32(1).