Plants 1-3 m; young thorns densely puberulent; mature thorns 20-60 mm, 2-3.4 mm at base (15 or less times longer than base width). Flowers: petals ca. 3 mm; style 0.4-0.7 mm, straight (sometimes slightly curved when dry); gynophore (stipe) 0.3-0.5 mm.

Flowering Jun-Jul. Desert flats, hillsides, arroyos; 100-2100; Ariz., N.Mex., Tex.; Mexico (Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Sonora, Zacatecas).

Variety wivaggii is primarily a taxon of the Chihuahuan Desert, occurring in a region between the more easterly var. spinosa and the more westerly var. tenuispina.