Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska south to California.
Habitat: Moist woods, low to mid-elevations in the mountains.
Conservation Status: Not of concern
Dioecious, rhizomatous, perennial herbs, the several glabrous stems 1-2 m. tall.
Leaves numerous, mostly cauline, long-petiolate, reduced upward from imperfectly triternate-pinnatifid below to ternate-pinnatifid above; leaflets ovate to oblong-lanceolate, pointed, up to 15 cm. long and 8 cm. broad, sharply twice-serrate.
Inflorescence a large terminal panicle of numerous spike-like, racemose branches; calyx 1.5-2 mm. broad, the 5 triangular lobes spreading; petal 5, white, about 1 mm. long in the pistillate flowers; staminate flowers with 15-20 stamens.
Ovary superior; pistils 3, distinct; follicles 3 mm. long.