PLANTS: Perennials. STEMS: to 45 cm tall, producing branches along their entire length. LEAVES: to 13 cm long, to 3 cm wide, sessile, obovate or oblanceolate to elliptic and broadly lanceolate; margins toothed to lobed, or entire if plants are not rapidly growing; upper leaves tapering to slightly broadened or sometimes slightly clasping bases, often also with clasping basal lobes. FLOWERS: pedicillate, subtended by 1 linear-lanceolate, entire or few-toothed bract; petals yellow, (6-)8-15 mm long, (2-)4-6 mm wide, with trichomes at apex only; staminodia 0-5, slightly to definitely smaller than petals; stamens with broad filaments common in 2-3 whorls; style 4-10 mm long; stigmatic papillae forming a slight tuft. CAPSULES: cylindric, sometimes broadly so, 6-12 mm long. SEEDS: horizontal, winged, oval to obovate, flattened; testa cells with straight to slightly wavy adjoining walls, the surface walls with ca. 5-10 bumps. 2n = 20. NOTES: Commonly on rock outcrops, talus of canyon walls (Map 4B): La Paz (-), Maricopa, Mohave, Pima, Pinal, Yuma cos.; 100-1100 m (400-3600 ft); Mar-Oct (-Dec); s CA, s NV; Baja C, Mex. These plants become broadly hemispheric in age and when growing rapidly have broad leaves with relatively short internodes, giving the plant a very leafy appearance. REFERENCES: Christy, Charlotte M. 1998. Loasaceae. J. Ariz. - Nev. Acad. Sci. 30(2): 96.