Annuals, 5-60 cm. Stems 1-5+, ± erect, branched distally, sparsely leafy, glabrous. Cauline leaves: proximal obovate, pinnately lobed (lobes 3-5+ pairs, triangular to oblong or linear), not fleshy, ultimate margins entire or dentate, faces glabrous; distal reduced (usually with 2 lobes near bases). Calyculi of 5-8+, ovate to lanceolate bractlets, hyaline margins 0.05-0.2 mm. Involucres ± campanulate, 7-10 × 3-6 mm. Phyllaries 16-20+ in 2-3 series, lanceolate to lance-linear, hyaline margins 0.05-0.1 mm wide, faces glabrous. Receptacles not bristly. Florets 19-70; corollas usually yellow, sometimes white, 6-7 mm; outer ligules exserted 1-2 mm. Cypselae ± cylindro-fusiform, 1.7-2.3 mm, ribs extending to ca. 0.1-0.2 mm short of apices (minutely hirtellous or muriculate), ± equal (distal 0.1-0.2 mm of cypselae smooth); pappi persistent, of 8-15+, needlelike teeth plus 1(-2) bristles. Pollen 70-100% 4-porate. 2n = 28. Flowering Mar-Jun. Gravelly soils beneath shrubs, along ditches, near streams, in sagebrush steppes, creosote bush scrublands; 300-1300 m; Ariz., Calif., Nev., N.Mex.; Mexico (Sonora). Malacothrix stebbinsii grows in the Mojave Desert (Borrego area, California) and the Sonoran Desert (Santa Catalina, Mazatzal, Baboquivari, and Santa Rita mountains, and elsewhere in Arizona).

Plant: Annual forb <30 cm; herbage with milky sap Leaves: leaves most basal, entire to coarsely toothed Flowers: flowers all ligulate, yellow; achenes columnar but short; pappus bristles white.