61. Physaria oregona S. Watson, Proc. Amer. Acad. Arts. 17: 363. 1882.
Coulterina oregona (S. Watson) Kuntze; Lesquerella oregona (S. Watson) G. A. Mulligan
Perennials; caudex simple, (cespitose); (silvery) pubescent throughout, trichomes (stalked), few-rayed, rays furcate or imperfectly so, (tuberculate throughout). Stems several from base, erect or somewhat decumbent, (unbranched), 1-3.5 dm. Basal leaves: (petiole slender, usually incised or with broad teeth along petiole); blade obovate, 4-6 cm, margins entire. Cauline leaves: blade oblanceolate or broader, 1.5-2.5 cm, margins entire or sparsely dentate, (apex acute). Racemes somewhat loose, (5-15 cm). Fruiting pedicels (spreading or ascending, curved, fruits not pendent), 10-20 mm. Flowers: sepals oblong, 5-7 mm; petals (lemon yellow), spatulate, 9-12 mm. Fruits didymous, obreniform, moderately inflated, angustispetate, (8-)10-12(-15) × 10-14(-16) mm, (papery, not keeled, basal sinus absent, apical sinus broad and open); valves (retaining seeds after dehiscence, rounded or irregular), loosely pubescent, trichomes spreading; replum broadly lanceolate, as wide as or wider than fruit, apex acute; ovules 8 per ovary; style 1-2 mm. Seeds flattened. 2n = 8.
Flowering Apr-Jun. Gravelly banks, stream shores, rocky slopes, dry hillsides, serpentine soils; 900-1900 m; Idaho, Oreg., Wash.