Leaves: petiole glabrous or long stipitate-glandular; blade orbic-ulate to pentagonal, shallowly lobed. Inflorescences glabrous or sparsely short to medium stipitate-glandular. Flowers: hypanthium obconic, 1.4-4.5 × 1-3.7 mm, short to long stipitate-glandular; sepals 0.6-1.2 mm, apex rounded to acute; petals 0.2-0.7 mm wide; styles 1.6-3.1 mm. 2n = 28.

Flowering May-Jun. Evergreen coniferous forests on basalt, schistose shale, metavolcanic, ultra basic, or serpentine-derived soils; 10-1900 m; Calif., Idaho, Oreg., Wash.

Variety micrantha occurs in the Coast Range, Cascade Range, Blue and Klamath mountains, northern Sierra Nevada, and the Columbia River gorge, and on wooded banks of the Columbia and its tributaries.