Ferocactus hamatacanthus var. crassispinus (Engelmann) L. D. Benson

Stems ovoid or ovoid-cylindric, 10-63 × 7.5-30 cm; ribs 13-17, undulate or crenate. Spines 12-16(-28) per areole; central spines 4(-8) per areole, principal central spine terete or angled, 60-165 × (0.5-)1-1.5(-2.5) mm, hard. Flowers 5.5-8(-10) × 6.5-9.5 cm; stigma lobes 11-14. Fruits green to greenish brown or dull brownish purple, 30-50 × 25-30 mm. Seeds 1.4-1.6 mm. 2n = 22.

Flowering summer. Chihuahuan desert scrub, prairies, semidesert grasslands, oak-juniper savannas, pine-oak woodlands, stony hills, bluffs, and flats, igneous and calcareous substrates; 500-2300 m; N.Mex., Tex.; Mexico (Chihuahua, Coahuila, Durango, San Luis Potosí, Zacatecas).

In Mexico, plants of Ferocactus hamatacanthus var. hamatacanthus grow much larger; our measurements pertain only to northern specimens.