Mem. Torrey Bot. Club 21: 50. 1958. 1958
Plants annual or short-lived perennial. Stems 3-8 dm, prickly. Leaf blades: abaxial surface prickly on veins, adaxial surface unarmed or sparingly prickly on veins; proximal lobed 3/4-5/6 distance to midrib. Inflorescences: buds ellipsoid-oblong, body 15-20 × 13-16 mm, prickly; sepal horns terete, 7-12 mm, unarmed or with a few basal prickles. Flowers 7-12 cm broad, often subtended by 1-2 foliaceous bracts; petals bright yellow to golden or bronze; stamens ca. 150; filaments red or purplish; pistil 4-5-carpellate. Capsules narrowly ellipsoid-oblong, 25-35 × 12-16 mm (including stigma and excluding prickles), coarsely prickly, surface clearly visible, prickles very unequal, longest ca. 8 mm. Seeds 1.5-1.7 mm. 2n = 28.
Phenology: Flowering and fruiting early spring–summer.
Habitat: Dry plains and low hills, road and field margins
Elevation: 0-1500 m
Tex., Mexico (Coahuila, Nuevo León, and Tamaulipas).