Annuals, 4-36 cm. Stems 1-5, erect or ascending, branched mostly distally, glabrous. Cauline leaves: proximal oblanceolate to lance-linear, sometimes pinnately lobed, not fleshy, ultimate margins usually dentate, faces glabrous; distal reduced (margins 2-4-dentate near bases or entire). Calyculi of 5-12, lance-deltate to lanceolate bractlets, hyaline margins 0.05-0.2 mm. Involucres narrowly campanulate, 4-8+ × 2-4+ mm. Phyllaries 8-15+ in 2+ series, lance-linear to linear, ± equal, hyaline margins 0.05-0.3 mm wide, abaxial faces glabrous. Receptacles not bristly. Florets 19-67); corollas pale yellow, 4-7.4 mm; outer ligules exserted 1-3 mm. Cypselae fusiform or prismatic, 1.2-1.8 mm, ribs extending to apices, 5 more prominent than others; persistent pappi of 15-24+, needlelike teeth plus 1 bristle. Pollen 70-100% 3-porate, mean 25 µm. 2n = 14. Flowering Mar-Jun. Cleared areas (burns, slides), usually chaparral, rarely margins of creosote bush shrub; 20-1500 m; Calif.; Mexico (Baja California); introduced, South America (Argentina, Chile). Malacothrix clevelandii grows in northwestern California, Sierra Nevada foothills, San Joaquin Valley, central western California, and northern Channel Islands (Santa Rosa Island).
Plant: Annual 4-36 cm, glabrous; sap milky Leaves: basal not fleshy, generally (ob)lanceolate, teeth or short lobes ± equal, well spaced; cauline much reduced, alternate, sessile, upper 2-4-toothed at base INFLORESCENCE: primary inflorescence a head, each resembling a flower; heads ligulate, 2.5-3.5 mm diam; involucre 5-8.7 mm; outer phyllaries ± 1/2 inner, generally lanceolate Flowers: corollas 4.6-7.7 mm, pale yellow, readily withering, outer corollas exserted 1-3 mm; ligules yellow or white, generally ± purple-striped below Fruit: achenes, 1.2-1.8 mm, fusiform, ± light brown; veins ± equal, extending to very tip; outer pappus teeth needle-like, bristle 1 Misc: Cleared areas (burns, slides), generally chaparral; < 2100 m.