SPINES: lower central spine hooked, 1.7-5.9 cm long, 0.5-1 mm diameter, white, dark brown, purplish-pink or black; upper central spine 1.9-5.7 cm long, mostly 1.5-2 mm wide, mostly white, rarely purple to pink, mostly angled, rarely flat or rhombic in cross-section. FLOWERS: inner tepals purple, rose, pink or rarely white. 2n = 22. NOTES: See also parent taxon. Blackbrush communities and pinyon-juniper woodlands: Apache, Coconino, Mohave, Navajo cos; mostly at mid elevations, 1350-2000 m (4500-6500 ft); May-Jun; CO, NM, UT. REFERENCES: Heil, Kenneth D., and Mark J. Porter. 2001. Cactaceae. J. Ariz. – Nev. Acad. Sci. Volume 33(1).