Opuntia polyacantha var. hystricina

Stem segments obovate, 8-10 × 5-8 cm; areoles (6-)8-10 per diagonal row across midstem segment, 10-17 mm apart. Spines in most areoles, grading in size and orientation; longer spines (1-)2-6 per areole, slightly descending porrect, ascending near apex, (yellow-gray to) brown to black, (40-)50-80 mm; smaller spines 4-6 per areole, reflexed, gray-white. Fruits stout; areoles 11-21, bearing 4-8 spines, 4-18 mm. 2n = 44, 66.

Flowering late spring. Grasslands, pinyon-juniper woodlands, clay or limestone soils; 1300-1900(-2400) m; Ariz., Calif., Colo., Nev., N.Mex., Utah.

PADS: obovate, 8-10 cm long, 5-8 cm broad. AREOLES: ca. 10-17 mm apart, (6-)8-10 in a row diagonal across midpad. SPINES: in most areoles, the major ones grading in size and orientation, the longest (yellow-gray to) brown to black, slightly descending porrect, ascending near apex, (4-)5-8 cm long, (1-)2-6 per areole, the minor ones shorter, gray-white, reflexed, 4-6 per areole. FRUITS: stout; areoles 11-21, most bearing 4-8 spines 4-18 mm long. 2n = 44, 66. NOTES: See also parent taxon. Clay or limestone soils, grasslands to pinyon-juniper woodlands, Apache, Coconino, Navajo cos.; 1350-1850(-2400) m (4400-6000[-7900] ft); late spring; CA, CO, NV, NM, UT. REFERENCES: Pinkava, Donald J. 2003. Cactaceae. J. Ariz. - Nev. Acad. Sci. Volume 35(2).