Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, east to the Atlantic Coast.
Habitat: Wet ground.
Origin: Both native and introduced from eastern North America
Growth Duration: Annual
Conservation Status: Sensitive in Washington (WANHP)
Pollination: Bumblebees, bees, flies, wasps
Perennial from short, leafy rhizomes, the stems upright, 1-5 dm. tall, simple or branched above.
Leaves opposite, sessile, lanceolate to oblong, rounded, 1-3.5 cm. long, 5- to 7-nerved.
Inflorescence of terminal cymes with small, linear bracts; sepals 5, lanceolate, 4-7 mm. long; petals 5, yellow, about equal to the sepals; stamens 15-35, the filaments almost capillary, distinct; styles 3, short.