Annuals, (5-)10-40+ cm. Stems (1-)3-5+, ascending to erect, usually branched proximally and distally, glabrous or sparsely arachno-puberulent near bases (sometimes glaucous). Cauline leaves: proximal usually pinnately lobed (lobes 3-6+ pairs, usually filiform, subequal to unequal, apices acute), ultimate margins entire, faces glabrous or ± hairy (then usually glabrescent); distal reduced (usually pinnately lobed). Calyculi of 12-20+, lanceolate to linear bractlets, hyaline margins 0.05-0.2 mm wide (abaxial faces often ± densely white-hairy). Involucres campanulate to hemispheric, 9-17 × 4-7 mm. Phyllaries 20-25+ in 2-3 series, lance-linear to linear, hyaline margins 0.05-0.3 mm wide, faces usually glabrous, abaxial sometimes ± white-hairy. Receptacles bristly. Florets 31-139; corollas usually pale yellow, sometimes white, 15-23+ mm; outer ligules exserted 9-15+ mm. Cypselae ± cylindro-fusiform (sometimes weakly 5-angled), 2-3.3 mm, ribs extending to apices, usually ± equal; persistent pappi of 0-12+, blunt to acute teeth plus 1-2(-5) bristles. Pollen 70-100% 3-porate. 2n = 14.

Flowering Mar-Jul. Coarse soils in open areas, or among shrubs, creosote bush scrublands, Amsinckia, Artemisia, and Atriplex-Larrea associations, Joshua tree woodlands; 0-1800 m; Ariz., Calif., Idaho, Nev., N.Mex., Oreg., Utah; Mexico (Baja California, Sonora).

Malacothrix glabrata grows in the Mojave, Great Basin, and Sonoran deserts in California and the Intermountain region in Arizona, Nevada, Oregon, and Utah.

Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Ascending, moderately branched, wholly glabrous plant except slightly pubescent on youngest leaves in some plants, and on smallest outer involucral bracts, stems 10-40 cm tall.

Leaves: Leaves 1-2 x pinnatifid, cauline near base, usually with 2-3 or rarely only 1 large head at tips of upper branches; basal leaves oblong-oblanceolate, 2-8 cm long, sinuately lobed to remotely pinnatifid into linear segments, glabrous.

Flowers: Involucres 5-12 mm high, glabrous or lowest bracts sparsely arachnoid-pubescent; ligules yellow, often tinged with purple or lavender on lower surface.

Fruits: Cypselae cylindric, 1.6-2 mm long, finely and evenly 15-ribbed or nerved, glabrous, truncate and with a low ring of tissue at apex, bearing a white-scarious, denticulate ring inside that tissue; pappus bristles white, 5-6 mm long.

Ecology: Found on sandy and gravelly plains, rocky hillsides and mesas below 7,000 ft (2134 m); flowers March-June.

Distribution: s OR, s ID, CA, NV, UT, AZ, s NM; south into Baja MEX.

Notes: Distinguished by the annual life form, mostly basal, divided leaves with linear, filiform, terete lobes; white-yellow ligulate flowers tinged with purple on undersides; and phyllarees ranging from glabrate to densely hairy.

Ethnobotany: The roots were used by the Apache as a blood medicine.

Etymology: Malacothrix is from malakos, soft and thrix, hair, while glabrata means somewhat glabrous.

Synonyms: Malacothrix californica var. glabrata

Editor: SBuckley, 2010