Perennials; usually glabrous, rarely sparsely pubescent basally. Rhizomes cylindrical, slender (rarely slightly thickened at stem base), 1-3(-4) mm diam. Stems erect or decumbent basally, unbranched or branched, (0.6-)1.5-6(-7) dm. Rhizomal leaves absent. Cauline leaves 3-8(-11), 3 or 5-foliolate (rarely only terminal leaflet present), petiolate, leaflets petiolulate or subsessile; petiole (0.7-)1-4(-6) cm, base not auriculate; lateral leaflets (when present) subsessile or petiolulate (to 0.4 cm), blade similar to terminal, often much smaller and narrower than terminal; terminal leaflet (petiolule 0.4-1.6 cm), blade usually ovate to orbicular, rarely subcordate, 1.5-4(-5) cm × 15-35(-50) mm, base truncate, rounded, or cordate, margins crenate, dentate, sinuate, or to 11-lobed. Racemes ebracteate. Fruiting pedicels ascending to divaricate-ascending, (7-)10-20 mm. Flowers: sepals oblong, 2-3(-3.8) × 1-1.5 mm, lateral pair not saccate basally; petals white, oblanceolate, 3.5-6(-7) × 1.5-2.5(-3) mm (not clawed, apex rounded or ± emarginate); filaments: median pairs 2.5-3.5 mm, lateral pair 2-2.5 mm; anthers oblong, 0.7-1 mm. Fruits linear, 1.5-3.5 cm × 1-1.5 mm; ovules 14-28 per ovary; style 0.2-1.5(-2.5) mm. Seeds brown, oblong, 1-1.6 × 0.9-1.1 mm. Flowering Jun-Jul. Stream banks, seepage, lakeshores, creeks, wet meadows, swamps, ponds; 1200-3000 m; B.C.; Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.