Winter annuals or biennials (perennial?); taproots enlarged above; stems 1 to several, usually with several branches 1.5-3.5 dm long, pubescent at base with simple trichomes, glabrous above ;leaves mostly in flat basal rosettes, denticulate to dentat...
Perennial; caudex multicipital; branches prostrate, slender and usually matted; basal leaves tufted, linear-oblanceolate to obovate, entire to denticulate, 0.5-1.3(-2.5) cm long; stem leaves 3-8, slightly smaller; plants including pedicels cinereous ...
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...
Densely tufted, sparsely hairy perennial herbs; stems from many crowded, short branches, 5-16 cm tall; basal leaves lance-shaped to elliptic, broader above the middle, to 7 cm long and 7 mm wide, usually smaller, blades about one-half the length of t...
Herbaceous perennial with creeping rhizomes; stems 2.5-4.5 dm tall, sparsely branching from near the base, growing in clumps to about 3 dm in diameter; leaves alternate, oblong, about 1.0 cm long, glabrous except for occasional ciliate hairs on the m...
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...
Tufted, herbaceous, perennial, growing from a woody base; leaves basal, dark green, thick, glabrous above, sparsely hairy beneath, blade ovate to reniform, 1.0-2.0 cm long, 1.5-2.5 cm wide, petiole often longer than the blade; inflorescence an open l...
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...
Perennial herb forming hemispheric mounds up to 3 dm across from an intricately branching caudex; leaves all basal, short-petiolate, the blade narrowly elliptic, 4-12 mm long, 1.5-4 mm wide, silky-tomentose below, green and strigose above, the margin...
Herbaceous perennial with a basal rosette of leaves and a scapose stem to 1.5 m tall; basal leaves linear, up to 1 m long, entire or rarely with one or two spinose teeth; cauline leaves few and reduced; inflorescence a compound umbel with compact hea...