Stem segments appearing spineless or nearly so from afar, exposing strongly mammillate tubercles beneath. Spines of stems not or little interlaced with spines of adjacent areoles, longest usually 1-2 cm; sheaths tightly fitting. 2n = 22. Flowering spring-fall (Apr-Aug, Oct). Sonoran desert scrub, sandy flats, rocky slopes, rolling hills; 200-1100 m; Ariz.; Mexico (Baja California, Sinaloa, Sonora). A morphotype with crested stems from south-central Arizona is commonly cultivated as the boxing-glove cactus.

SPINES: of stems not or but little interlaced, the largest spines usually 1-2 cm, their sheaths tight-fitting. STEM: segments appearing spineless or nearly so from afar, obviously exposing the strongly mammillate tubercles. 2n = 22. NOTES: See also parent taxon. Sandy desert flats to rocky slopes, rolling hills; Gila, Maricopa, Pima, Pinal cos.; 200-1100 m (600-3600 ft); Apr-Aug, Oct; Sin., Son., ne Gulf of CA islands in Mex. A crested morph from Pinal Co. is commonly cultivated as the Boxing-glove Cholla. REFERENCES: Pinkava, Donald J. 1999. Cactaceae. Ariz. – Nev. Acad. Sci. 32(1).