Distribution: Occurring west of the Cascades crest in southwestern Washington; southwestern Washington to adjacent northwestern Oregon.
Habitat: Moist woods at middle elevations in the mountains.
Conservation Status: Sensitive in Washington (WANHP)
Herbaceous perennial from a woody rhizome, the stems often hollow, 8-15 dm. tall, sparsely puberulent.
Leaves alternate, nearly tri-ternate, the leaflets broadly lanceolate, acute to rounded at the base, coarsely serrate-dentate and irregularly lobed.
Inflorescence large, paniculate, loosely flowered; pedicles 2-10 mm. long, often exceeding the flowers; sepals 5, 4-5 mm. long, pale, early-deciduous; petals often present, 5 mm. long, cream-colored, acutely bi-lobed; stamens numerous, cream-colored, the outer 5 often broad and petaloid; pistils 3-5.
Follicles 10-14 mm. long, narrowed to a stipe 4-6 mm. long