Annuals, 5-44 cm. Stems 1-4, erect to ascending, usually branched proximally and distally, glabrous (usually glaucous). Cauline leaves: proximal obovate, usually pinnately lobed (lobes 3-8 pairs, ± equal, bases white-hairy), ± fleshy, ultimate margins dentate, faces glabrous; distal reduced (sometimes 2-4-dentate near bases). Calyculi of 8-12+, ovate to lanceolate bractlets, hyaline margins 0.05-0.3 mm wide. Involucres ± campanulate, 5-8 × 2-6 mm. Phyllaries 18-22+ in 2-3 series, oblong or lanceolate to linear, hyaline margins 0.05-0.2 mm wide, faces glabrous. Receptacles not bristly. Florets 30-65; corollas white, 5-8 mm; outer ligules exserted 1-3 mm. Cypselae ± cylindro-funnelform or weakly prismatic, 1.2-2 mm, ribs extending to apices, ± equal or 5 more prominent than others; pappi 0 or crenate crowns (0.01-0.1 mm). Pollen 70-100% 3-porate. 2. = 14.

Flowering Apr-Jun. Diatomaceous shale, open chaparral burns, slides, openings in Bishop pine-Douglas fir woodlands; 100-1400 m; Calif.

Malacothrix phaeocarpa grows in Monterey County (near Jolon above Boucher´s Gap), San Luis Obispo County (Santa Lucia Mountains), Santa Barbara County (Purissima Hills and Santa Inez Mountains), and Santa Clara County (Santa Cruz Mountains).