A Prickly glabrous annual herb, 30-125 cm tall, branched. Leaves alternate, elliptic-oblong, pinnatifid, semiamplexicaul, sinuate-lobulated; variegated green and white, 5-20 cm long, 2-8 cm broad, ultimate segments, dentate, prickly on the margin, midrib and the veins beneath; Flowers sessile, 3-8 cm in diam., subtended by 2-3 foliaceous bracts. Sepals 8-12 mm long, 5-7 mm broad, with an acute, terete horn below the apex, very sparsely prickly outside, concave, imbricate caducous. Petals 4-6, obovate, 2.5-3.5 cm long, (1.5-)2-2.5 cm broad, narrowed below, bright yellow, imbricate, more or less crumpled in bud. Stamens indefinite, 8-12 mm long; anther c. 2 mm long, curved after flowering. Ovary ovate, 8-10 mm long, 3-5 mm broad covered with long soft spines; stigma red, 3-6 lobed; lobes usually broad. Capsule, oblong or elliptic-oblong, 2.5-4 cm long, 1.2-2 cm broad, with rounded ribs, covered with sharp erect prickles; valves 3-6. Seeds many, blackish brown to brown, ± rounded, 1.5-2 mm in diam, with fine, con¬spicuous tuberculae.