Leaf blades narrowly lanceolate, 5–8 mm wide. Flowers: corolla rotate, petals purplish to pale pink, broadly fan-shaped, length not greater than 1.5 times width, deeply 2-lobed, lobes usually 1/5–1/2 petal length. 2n = 16.

Flowering May–Aug. Foothill woodlands; 0–1000 m; Calif.

Subspecies biloba is known from the central and northern Sierra Nevada Foothills, especially in Calaveras, El Dorado, and Tuolumne counties, and from the eastern San Francisco Bay area in Contra Costa County.