83. Physaria tenella (A. Nelson) O’Kane & Al-Shehbaz, Novon. 12: 328. 2002.
Lesquerella tenella A. Nelson, Bot. Gaz. 47: 426. 1909; L. gordonii (A. Gray) S. Watson var. sessilis S. Watson
Annuals or, rarely, biennials; with a taproot; densely pubescent, trichomes (simple or stellate, sessile or short-stalked), 4-7-rayed, rays usually furcate, rarely bifurcate, (nearly smooth to finely tuberculate). Stems several from base, decumbent to erect, (several-branched, frequently stout), 1.5-6 dm. Basal leaves: blade elliptic, (1.5-)3-6.5 cm, margins entire, repand, or shallowly dentate. Cauline leaves: (proximal shortly petiolate, distal sessile); blade linear to elliptic or obovate, (0.5-)1-3.5(-4.5) cm, margins entire or repand. Racemes loose. Fruiting pedicels (recurved, sigmoid), 5-15 mm. Flowers: sepals oblong, lanceolate, or elliptic, (3-)3.5-6(-7.5) mm, (lateral pair subsaccate, median pair thickened apically, cucullate); petals (yellow to orange), suborbicular or obovate, (5-)6.5-8(-11) mm, (narrowing gradually to broad claw, usually widened at base). Fruits (sessile or shortly stipitate), orbicular or obovoid, often slightly compressed, (3.5-)4-6 mm; valves sparsely pubescent, trichomes sessile and stellate, densely pubescent inside, trichomes simple or branched; ovules 4-12 per ovary; style 2-4.5 mm. Seeds flattened. 2n = 10, 20.
Flowering Feb-May. Sandy soils, gravel, clayey loam, loose rocky slopes, washes, desert slopes and plains, lava hills, frequently in or near bushes; (0-)600-1900 m; Ariz., Calif., Nev., Utah; Mexico (Sonora).