Plants perennial. Stems 4-12(-18) dm, moderately prickly throughout, prickles patent, longest 7-10 mm. Leaf blades: abaxial surface prickly on main veins, adaxial surface unarmed or sparingly prickly on midrib; basal blades shallowly to often deeply lobed; distal not clasping. Inflorescences: buds subglobose to oblong, body 15-18 × 12-15 mm, sparingly prickly, prickles patent; sepal horns usually slender, terete, (5-)8-12(-14) mm, unarmed or with 1-2 prickles near base. Flowers 6-9 cm broad; petals white; stamens about 150; filaments pale yellow; pistil 3-4-carpellate. Capsules narrowly ellipsoid to narrowly ellipsoid-ovoid, 30-45 × 8-14 mm (including stigma and excluding prickles), scattered-prickly, surface clearly visible, longest prickles 6-8(-10) mm. Seeds to 2 mm. 2 n = 28. Flowering spring; fruiting spring-summer. Washes and outwash plains, deserts; 0-900 m (s to n); Ariz.; Mexico (Sonora and Baja California).

Plant: shrub or herb; STEMS glaucous green, with 5-25 perpendicular or declinate prickles per square cm of surface, the largest 7-10 mm long Leaves: prickly on the veins, about 3-15 prickles per square cm of surface below, 0-5 prickles per square cm above; lower and middle cauline leaves lobed one-fourth to four-fifths to the midrib, the lobes one or two times as long as wide, the margin angular at the apex, the sinuses and lobes subequal in width; uppermost leaves shallowly lobed or dentate, half-clasping INFLORESCENCE: cymose Flowers: buds subspherical before anthesis; calyx with 10-30 mostly ascending prickles per sepal, the sepal horn 7-12 mm long, with 0-4 prickles near its base, typically terete when fresh, the apical prickle usually not basally flattened or enlarged; petals white; stamens 150 or more Fruit: CAPSULES narrowly elliptic, with 20-50 prickles per square cm of surface, the largest prickles 5-10 mm long; SEEDS numerous, pitted Misc: Deserts and foothills; 50-1050 m (100-3500 ft); Mar REFERENCES: Ownbey, Gerald B., Jeffrey W. Brasher, and Curtis Clark. 1998 Papaveraceae. J. Ariz. – Nev. Acad. Sci. 30(2): 120.