Imperiled
Perennial herb arising from a thick taproot with numerous, short (1-3 cm), ascending-erect caudex branches, the upper portion of these with persistent old leaf bases; stems erect, 5-8 cm tall, unbranched, green, sparsely short-strigose with white, st...
Annuals; stems erect-spreading, 1.0-3.5 dm tall; basal leaf blades broadly elliptic, 1.5-2.5 cm long, glabrous and green on both surfaces except for scattered villous hairs along the margins and midvein; stem leaves similar to basal leaves, but more ...
Perennial herb forming a flat mat or cushion-like mound up to 3.5 dm across from an intricately branching caudex; leaves all basal, short-petioled, the blade narrowly elliptic, 4-12 mm long, 1.5-3.5 mm wide, silky tomentose, the margins revolute; inf...
Tufted perennial herb forming mats up to 5 dm across; leaves broadly elliptic, 3-5 cm long, 1.5-3.0 cm wide, margins entire, green above, white tomentose below; inflorescences branched 3-5 times, 2-5 dm tall; bracts leaflike, those of the first node ...
Stems solitary, growing in clumps, or commonly branched to form small dense clusters, the individual stems mostly 2-4 cm thick and to 15 cm long; tubercles on mature stems with upper surface bearing a groove; spines with a yellowish cast often reddis...
Stems solitary, few in a clump, or commonly branched to form small dense clusters of 20 or more stems, the individual stems mostly 2-4 cm thick, to 15 cm tall; tubercles on mature stems with upper surface grooved; spines about 20-60 per areole, sprea...
Stems forming small dense clusters, the individual stems mostly 1-2 cm thick and to 8 cm tall; tubercles on mature stems with upper surface grooved; spines about 30-90 per areole, typically white often brown at tip, fading to gray, slender and bristl...
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...
Stems solitary, growing in clumps, or commonly branched to form small dense clusters, the individual stems mostly 2-4 cm thick and to 15 cm long; tubercles on mature stems with upper surface bearing a groove; spines about 20-50 per areole, majority s...