Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Stream banks, pond and lake edges, and other wet places at low elevations.
Flowers: July-September
Origin: Native
Growth Duration: Annual
Conservation Status: Not of concern
Pollination: Bees, flies, beetles, wasps
Annual, nearly glabrous throughout, 1-10 dm. tall.
Leaves sessile, simple, lance-linear to lance-ovate, serrate to sub-entire, 4-20 cm. long and 5-45 mm. wide.
Heads hemispheric, the disk 12-25 mm. wide, nodding in age; outer involucral bracts 5-8, lance-linear, leafy and spreading, inner bracts yellowish above; rays 6-8, yellow, up to 1.5 cm. long, or rarely wanting
Achenes narrowly triangular, compressed-quadrangular, 5-8 mm. long, with persistent pappus of four retrorsly-barbed awns.
The undivided leaves and large flowering heads with prominent ray flowers readily separates Bidens cernua from the other species of Bidens.
PNW Herbaria: Specimen records of Bidens cernua in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Bidens cernua checklist entry
OregonFlora: Bidens cernua information
E-Flora BC: Bidens cernua atlas page
CalPhotos: Bidens cernua photos