Annual herb. Stems ± stout, decumbent to erect, sparsely spiny or sometimes without spines, 20-60 cm tall. Rosette lvs few, withering and falling early; cauline lvs persistent. All lvs sessile, glaucous, pale near veins, tapering gradually to base; lamina ovate to obovate, pinnatifid, 7-15 × 2-5 cm, coarsely toothed; each tooth tipped with a long yellowish spine. Fls solitary or in lax leafy cymes, closely subtended by 2-3 leaflike bracts. Sepals entire, spiny, but without lateral spines, glaucous, with a spine-tipped horn near apex. Petals 2-3 cm long, narrow-ovate, cream. Style 2-3 mm long; stigma magenta. Capsule ellipsoid, spiny, 1.5-3 × 0.7-1.5 cm, dehiscing by 4-(6) valves in distal ⅓. Seeds globose, reticulate, very dark brown, c. 1.5 mm long.