Shrubs, low, forming mats, 2-10 cm. Stem segments easily detached when terminal, dark green, subspheric to subcylindric, to flattened and elliptic obovate, (1.5-)2-5.5 × (1-)1.5-3 cm, low tuberculate (pronounced when dried), glabrous; areoles 3-5 per diagonal row across midstem segment, oval, 3 × 2.5 mm; wool white. Spines 3-8 per areole, in most areoles spreading, gray with brown tips, straight, ± acicular, terete, the longest 8-24 mm; depressed spines at base of areoles 0-3, 1-3 mm. Glochids in crescent at adaxial margin of areole, tan to brown, inconspicuous, to 3 mm. Flowers: inner tepals yellow, sometimes basally red, 20-26 mm; filaments white or red; anthers yellow; style white; stigma lobes green. Fruits tan, 10-30 × 8-15 mm, dry, glabrous; areoles 12-22, distal areoles bearing 1-6 short spines. Seeds tan to gray, flattened, warped, oblong to subcircular, 5-6 mm diam.; girdle protruding 1-1.5 mm. 2n = 66. Flowering summer (late Jun-early Jul). Barren areas in grasslands, woodlands, sandy or gravelly soils, on outcrops of granite, limestone, or quartzite; 0-2400 m; Alta., B.C., Man., Ont., Sask.; Ariz., Calif., Colo., Idaho, Ill., Iowa, Kans., Mich. , Minn., Mont., Nebr., N.Mex., N.Dak., Okla., Oreg., S.Dak., Tex., Utah, Wash., Wis., Wyo. Opuntia fragilis is a widespread, though inconspicuous, species; in many places, it flowers infrequently, if at all. Its easily detached stem segments are dispersed by animals and possibly water.

Plant: low, mat-forming shrub, 2-10 cm tall. PADS dark green, glabrous, the terminal ones easily detached, subspheric to cyclindric, to flattened and elliptic obovate, low-tuberculate (becoming pronounced when dried), (1.5-)2-5.5 cm long, (1-)1.5-3 cm broad; AREOLES 3-5 in a row diagonal across midpad, oval, 3 mm long, 2.5 mm wide; wool white Leaves: SPINES in most areoles, gray with brown tips, terete, straight, spreading, 3-8 per areole, the largest to 3.5 cm long. GLOCHIDS inconspicuous, tan to brown, in apical crescent in areole Flowers: inner tepals yellow, sometimes basally red, 2-2.6 cm long; filaments white or red; style white; fresh stigmas green Fruit: FRUITS tan, dry, 1-3 cm long, 0.8-1.5 cm in diameter; areoles 19-21, the uppermost ones bearing 1-6 short spines. SEEDS 5-6 mm in diameter; girdle protruding 1-1.5 mm. Misc: Sandy or gravelly soils or on outcrops of granite or quartzite, barren areas in grasslands, woodlands, forests; 1500-2400 m (4900-7900 ft); May-Jul REFERENCES: Pinkava, Donald J. Cactaceae. 2003. J. Ariz. – Nev. Acad. Sci. Volume 35(2).