Physaria tenella (A. Nelson) O'Kane & Al-Shehbaz
Family: Brassicaceae
Moapa Bladderpod
[Lesquerella tenella A. Nels.]
Physaria tenella image

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).

Wiggins 1964, Felger 2000, Kearney and Peebles 1969, FNA 2008

Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Annual, sparsely to densely stellate pubescent with some simple hairs, finely glandular; stems slender 15-60 cm tall, decumbent to erect, often branched in larger plants; clambers through small shrubs.

Leaves: Narrowly elliptic to obovate, entire to wavy, or shallowly or sometimes coarsely toothed; other stems leaves elliptic to linear, entire and sessile above.

Flowers: Racemes 9-20 cm, flowers widely spaced, bright yellow, showy, 9-10 mm wide; petals 8-10 mm.

Fruits: Fruiting pedicels S-shaped, often 15-18 mm; globose fruit 3.5-4.8 mm wide.

Ecology: Found on sandy and rocky soils in washes and on slopes below 4,000 ft (1219 m); flowers February-March.

Distribution: CA, s NV, UT; south to nw MEX.

Notes: L. tenella is told apart from L. gordonii by the stellate hairs of the ovary and fruits, and by the margined seeds.

Ethnobotany: Unknown

Etymology: Physaria is from Greek phusa or physa or bellows, while tenella is Latin for quite delicate, dainty.

Synonyms: Lesquerella tenella

Editor: SBuckley, 2010