Plants biennial or perennial. Stems 4-8 dm, sparingly to copiously prickly, prickles long, patent. Leaf blades: abaxial surface prickly on main veins, adaxial surface less prickly to almost unarmed on veins. Inflorescences: buds broadly ellipsoid, body 15-20 × 11-15 mm, prickly, prickles patent; sepal horns terete or angular in cross section, 7-12 mm, basally prickly. Flowers 7-10 cm broad, usually closely subtended by 1-2 foliaceous bracts; petals white or pale lavender; stamens 150 or more; filaments pale lemon yellow or red; pistil 3-4-carpellate. Capsules narrowly ellipsoid-lanceoloid to ellipsoid-ovoid, 30-45 × 8-13 mm (including stigma and excluding prickles), prickly, surface clearly visible; longest prickles scattered, to 10 mm, interspersed with a few shorter ones. Seeds 1.8-2.2 mm.
Flowering and fruiting spring-fall. Arid plains and mountains; 900-2000 m; Tex.; Mexico (Chihuahua and Coahuila).