Distribution: Widely distributed throughout much of Washington; widely distributed throughout North America except Alaska and northernmost Canada.
Habitat: Wet areas at low elevations.
Conservation Status: Not of concern
Annual, nearly glabrous throughout, 2-12 dm. tall.
Leaves with petioles 1-6 cm. long, pinnately compound, with 3-5 lanceolate, pointed, serrate leaflets up to 10 cm. long and 3 cm. wide.
Heads without rays, the disk about 1 cm. wide; outer involucral bracts 5-8, green and leafy, surpassing the orange disk.
Achenes flat, narrowly wedge-shaped, dark brown, 5-10 mm. long, with persistant pappus of 2 barbed awns.
The leaves of Bidens frondosa have long, slim petioles, while the similar B. tripartita has leaves with winged petioles.