Endangered
Robust, herbaceous perennial, with 3-12 branching stems, 0.5-1.5 m tall; leaves blue-green, 10-15 cm long, divided, the sinuses broad and square, margins, midribs, and veins armored with stout yellow spines; stem and leaf latex white; flowers large a...
Diminutive, tufted, strigulose perennial forming clumps up to 3 dm across; stems up to 1 cm long; leaves crowded, up to 4 cm long, odd-pinnate, leaflets 7-11, oblong-elliptic, 0.7-2.0 mm long, petiole and rachis forming persistent spines after fall o...
Annual herb with 1 or few erect stems, 2-5 dm tall with long-villose, non-glandular hairs mixed with shorter gland-tipped hairs; leaves oblong to lanceolate, unlobed, 3-nerved, 2-4 cm long, with strongly wavy margins and bases clasping the stem; flor...
Stems solitary or few in a cluster, more or less conical, 10-15 cm tall, 7-10 cm wide; ribs 7-12, tubercled; spines usually 3-7 per areole, thick, to over 1 mm near swollen base, often angular in cross section, usually white to pale gray, sometimes b...
Stems growing in clumps, or commonly branched to form small dense clusters, the individual stems mostly 1-2 cm thick and to 10 cm tall; tubercles on mature stems with upper surface grooved; spines slender, spreading to erect in any one areole, mostly...
Rhizomatous, perennial herb, the rhizomes slender and unbranched; stems several, unbranched, clustered, somewhat woody at the base, 10-20 cm tall; leaves opposite, 8-15 mm long, 2.5-5.0 mm wide, sessile, oblong-lanceolate, tip rounded to acute, margi...
Biennial to short-lived monocarpic perennial, erect, 3-8 dm tall; stems mostly solitary, occasionally branched from the base; basal leaves in a rosette, senescent at flowering; basal leaves ovate in outline, 3-5 cm long, pinnatifid in 9-15 linear div...
Stems 1.0-2.5 cm in diameter, solitary or a few in a cluster, barely protruding above ground level; tubercles not grooved; spines about 20 per areole, all radials, radiating from areole and appressed to the plant, 1-2 mm long, usually whitish, pinkis...