Trees or shrubs, erect, 2-2.5 m, with spiny, well-defined trunk to 30 cm diam. Stem segments not disarticulating, blue-green, flattened, obovate to circular, 13-21 × 11.5-19 cm, nearly smooth, glabrous; areoles 7-10 per diagonal row across midstem segment, subcircular to elliptic, with basal ridge, 3-6 × 2.5-4 mm; wool tan, aging grayish white. Spines absent or usually in distal areoles to evenly distributed over entire stem segment, yellow, aging red-brown to blackish, straight or weakly curved, ± acicular, deflexed, or some erect in marginal areoles; larger spines 0-7 per areole, terete or basally flattened, 25-45 mm, usually accompanied by few straight to wavy bristle-spines. Glochids crowded in narrow crescent along adaxial margins, longer toward base of areole margins, subapical tuft absent or poorly developed, yellow, aging reddish brown, to 14 mm. Flowers: inner tepals yellow (sometimes with reddish blush near base), abaxially reddish streaked along midveins, broadly spatulate-apiculate, 18-30 mm; filaments white to yellow; anthers; style and stigma lobes white, yellowish, or pale green. Fruits red, barrel-shaped, 30-60 × 18-40 mm, fleshy (often mummifying), glabrous, spineless; umbilicus 6-9 mm deep; areoles 40-68. Seeds yellowish, 3.5-4 × 3-3.5 mm, 1.5-1.8 mm thick, reniform to subcircular, flattened, often warped; girdle protruding 0.1-0.5 mm. 2n = 22. Flowering spring-summer (Apr-Jul). Desert grasslands, woodlands, chaparral, desert flats, rocky ledges, hills, canyons; 600-2400 m; Ariz., Calif., Nev., N.Mex., Utah; Mexico (Baja California, Baja California Sur, Sonora). Opuntia chlorotica hybridizes with O. santa-rita in southeastern Arizona and with the hexaploid O. phaeacantha forming the tetraploid O. ×curvispina in areas of Arizona, California, and Nevada.

Plant: tree or shrub 2-2.5 m tall, with spiny trunks to 30 cm long. PADS blue-green, obovate to circular, glabrous, 13-21 cm long, 11.5-19 cm broad. AREOLES 7-10 in a row diagonal across midpad, subcircular to elliptic with a basal ridge, 3-6 mm long, 2.5-4 mm wide; wool tan, aging grayish white Leaves: SPINES absent or mostly in distal areoles to well distributed over entire pad, yellow, aging red-brown to blackish, straight or weakly curved, acicular, deflexed except some erect in pads' marginal areoles; larger spines (0-)1-8+ per areole, terete or basally flattened, 2.5-4.5 cm long, usually accompanied by few straight to wavy bristle-spines. GLOCHIDS crowded in narrow marginal apical crescent, increasing in length toward base of areole, the subapical tuft absent or poorly developed, yellow, aging reddish brown, to 14 mm long Flowers: inner tepals yellow (sometimes with reddish blush at base), broadly spatulate-apiculate, 1.8-3 cm; filaments white to yellow; style and fresh stigmas white to yellowish or very pale green Fruit: FRUITS red, barrel-shaped, fleshy (often mummifying), glabrous, spineless, 3-5 cm long, 2-4 cm in diameter, the umbilicus 6-9 mm deep; areoles 40-68. SEEDS yellowish, reniform to subcircular, flattened but often warped, 3.5-4 mm long, 3-3.5 mm wide, 1.5-1.8 mm thick; girdle protruding 0.1-0.5 mm. Misc: Rocky ledges, hills, canyons, or uncommonly desert flats, desert grasslands, woodlands and chaparral; 600-2400 m (1900-7900 ft); Apr-Jul REFERENCES: Pinkava, Donald J. Cactaceae. 2003. J. Ariz. – Nev. Acad. Sci. Volume 35(2). REFERENCES: Pinkava, Donald J. Cactaceae. 2003. J. Ariz. – Nev. Acad. Sci. Volume 35(2).