Perennial herb; stems several with numerous branches (bushy appearance), slender, 3-5 dm tall, white, glabrous to above the middle, puberulent near the top; basal leaves absent; lower stem leaves narrowly lanceolate to linear, up to 4 cm long, entir...
Stem consisting of loosely attached flattened joints up to 8 cm in length by 2-3 cm in width, the joints highly varied in size and shape, bearing areoles with dense clumps of yellowish glochids; rhizomes and often larger roots also often bearing gloc...
Diminutive, tufted perennial, 3-5 cm tall, forming clumps up to 2 dm across, covered with white, felty or woolly tomentum; basal leaves linear, 1-2 cm long, 1-2 mm wide, margins rolled inwards; stem leaves reduced to small scales; flower stems taller...
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...
Root large, fleshy, round at the top, tapering; stems 2 m long, pale gray-green, slender, 1-2.5 cm in diameter, strongly angled by the 4-6 low, broad ribs; areoles narrowly oval about 4 mm long, white to gray woolly, bearing approximately 12 gray to ...
Tufted perennial from a woody base; stems to 30 cm tall; leaves opposite in lower portion, becoming alternate above, the blades 15-25 mm long, 8-20mm wide, thickened and leathery, broadly triangular to kidney-shaped, somewhat toothed to very shallowl...
Plants robust annuals to about 8 dm tall; stems to 2 cm thick, pubescent and glandular throughout; stem leaves broadly lanceolate, 4-10 cm long, 1.5-5 cm wide, irregularly crenate-dentate or lobed, lower and basal leaves deeply lobed to pinnatifid; i...
Annual; herbage strongly glandular and sticky; stems 1-3.4 dm tall, erect, simple or branched at base, with simple setose, hirsute and multicellular glandular hairs; leaves lanceolate, serrate, dentate to shallowly lobed, 1-4 cm long, 0.5-2 cm wide, ...
Succulent perennial herb; taproot tuberous, roughly globose to broadly napiform, up to 5 cm in diameter (usually less); stems short, usually not extending above the ground surface, terminated by a leafy rosette 5-15 cm in diameter; leaves terete, 3-1...
Erect shrub 1-2 m tall; leaves opposite, ovate, ovate-lanceolate or narrowly elliptic, margins entire, 10-35 mm long, 4-17 mm wide, glabrous or glabrescent above, sparsely villous hairy below, petiole about 2 mm long; flowers usually solitary (rarely...