Opuntia phaeacantha Engelmann var. flavispina L. D. Benson, Cact. Succ. J. (Los Angeles) 46: 79. 1974

Stem segments obovate, 15-23 × 14-18 cm, to 1.5 times longer than wide. Spines (0-)1-7 per areole, evenly distributed on stem segments, arching downward, yellow with extreme reddish brown basal portions, aging deep red to black, often twisted, the longest 65-75 mm, smaller ones depressed, whitish. 2n = 66.

Flowering spring (Apr-May). Sonoran Desert, sandy bajadas; 500-800 m; Ariz.; Mexico (Sonora).