Stem segments narrowly to broadly obovate, 10-27 × 7-18 cm; areoles 8-11 per diagonal row across midstem segment, 12-30 mm apart. Spines in most areoles, of 2 kinds: major spines 1-5 per areole, down curved, ascending near stem segment apex, pink-gray or basal 2/3 brown to black, the longest 45-150 mm; minor spines 3-8 per areole, deflexed, white to gray, 60-220 cm (spine clusters easily detached in preparing specimens). Fruits stout; areoles 18-24, most bearing 3-12 spines, 8-17 mm. 2n = 66.
Flowering spring. Barren areas with saltbush and ephedra, limestone or red, sandy soils; 1200-1300 m; Ariz., Utah.
PADS: narrowly to broadly obovate, 10-27 cm long, 7-18 cm broad.
AREOLES: ca. 12-30 mm apart, 8-11 in a row diagonal across midpad.
SPINES: in most areoles, of two kinds: major spines pink-gray or basal two-thirds brown to black, down-curved, ascending near pad apex, 1-5 per areole, the largest 4.5-15 cm long; minor spines 3-8 per areole, white to gray, deflexed, 6-22 cm long; spine cluster easily detached in preparing specimens.
FRUITS: stout; areoles 18-24, most bearing 3-12 spines, 8-17 mm long. 2n = 66.
NOTES: See also parent taxon. Red sandy soil or on limestone chips, barren areas with saltbush and ephedra, Coconino Co.; 1190-1300 m (3900-4300 ft); spring; above Colorado River at AZ-UT border.
REFERENCES: Pinkava, Donald J. Cactaceae. 2003. J. Ariz. - Nev. Acad. Sci. Volume 35(2).
