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