On the Rare Plant Technical Council List
Matted perennial from woody rootstocks; stems to 5 cm high; sparsely pubescent with ascending or loosely appressed hairs, terminated by a solitary flower head; basal rosettelike leaves clustered, spatulate or lance shaped, spiny at the tip, 1.5-6 mm ...
Biennial; stems up to 2 m tall, sparingly branched, hairy; leaves about 40 cm long, pointed at the tip, lobed, the lobes toothed, teeth tipped with slender spines, upper surface of the leaves hairy, lower surface without hairs; the base of the stem l...
Biennial; stems to 1 m tall, unbranched below the middle, with few ascending branches above, densely cobwebby and finely hairy at first, becoming sparsely hairy to nearly naked as it ages; leaves lance-shaped to nearly linear in outline, to 20 cm, gl...
Stout rhizomatous biennial with a robust basal rosette; stem 1.0-1.8 m tall, with many ascending, brown-purple branches; basal leaves green, glabrous, 3-5 dm long, up to 2 dm wide, ragged-edged, divided nearly to the midrib, the divisions tipped with...
Robust biennial or monocarpic perennial; stem strict, 1-2.5 m tall; basal leaves ample, succulent, 30 cm or more long, sinuate or pinnatifid, weakly prickly with short black spines, nearly glabrous, the thin weblike wool tardily deciduous; stem leave...
Annual; stems slender, erect, up to 60 cm tall; leaves sessile or with short stalks, palmately compound, leaflets 3, elliptic, slender, folded, 2 mm wide or less; flowers in axils of stem leaves, petals pink or white, 4-7 mm long; pods elongate, up t...
Stems succulent, hemispheric, tubercled, up to 15 cm in diameter and tall, or exceptionally taller, usually single but sometimes a few in a cluster; tubercles to 7 mm long, conical, somewhat dorsiventrally flattened, with a felted groove running the ...
Small tree or shrub to 3 m tall; branches thorny, the thorns purplish brown, 3-4 cm in length; leaves simple, alternate and rhombic in outline, margins with 3-4 broad lobes on each side of the upper two-thirds of the leaf, these lobes with fine margi...
Twining, tangled, yellow threadlike annual with stems 0.5 mm or less in diameter; inflorescence a glomerule of subsessile flowers on glabrous pedicels; flowers 5-merous, 2.1-4 mm long, slightly fleshy; calyx campanulate-cupulate, about 1/2 the coroll...