Plants , 2-4 dm. Leaves: petiole 1-3 cm. Central leaflet blade 4-11 × 4-8 cm, proximal margins entire, distal margins (1-)3-4(-8)-lobed. Inflorescences 2.5-5 cm excluding peduncle. Flowers: stamens 3-4 mm; ovaries 1-1.5 mm. Follicles red-purple, 3-4.5 mm. 2 n = 12.

Flowering spring-summer (Apr-Jul). Mountain regions in Cascade Range and Coast Range of California in coniferous forests; 0-1500 m; B.C.; Calif., Oreg., Wash.

Medicinally, Native Americans used preparations of the leaves of Achlys triphylla to treat tuberculosis, for a hair wash, and as an emetic (D. E. Moermann 1986).