Distribution: Occurring on the Olympic Peninsula in Washington; Washington south along the coast to central Oregon.
Habitat: Moist woods, meadows, streambanks, roadside ditches.
Conservation Status: Not of concern
Glandular-pubescent, herbaceous perennial from stolons or rhizomes, the stem 3-7 dm. tall.
Lower leaves long-petioled, with brownish, membranous stipules, the petioles becoming much shorter and the stipules more pronounced upward; blades reniform, up to 20 cm. broad, unequally 3- to 7-lobed halfway to the base and again 2-3 times toothed.
Inflorescence a many-flowered, open, pyramidal panicle; hypanthium campanulate; sepals 2-3 mm. long; petals 5, white, 3-7 × 1-3 mm. long, spatulate to ovate, tapered to base; stamens 5, opposite the calyx lobes; ovary half inferior.
Carpels 2; seeds ellipsoid, 0.7 mm. long, black.
Differs from Boykinia major s.s., which does not occur in Washington, by its stoloniferous habit, more slender stems, pyramidal inflorescences (vs. flat-topped), smaller stipules, campanulate hypanthium (vs. saucer-shaped), and petals tapered to base (vs. strongly clawed).