Page authors: Don Knoke, David Giblin
Bidens tripartita
three-lobed beggar-ticks

Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast where native.

Habitat: Wet places, often where disturbed, primarily at low elevations.

Flowers: August-October

Origin: Introduced from Eurasia and eastern North America

Growth Duration: Annual

Conservation Status: Not of concern

Pollination: Bumblebees


Annual, nearly glabrous throughout, 1-20 dm. tall.


Leaves simple (but appearing trifoliate), sharply serrate, usually deeply divided into 3 narrow lobes, the center one larger and wider, 3-15 cm. long.


Heads erect, rayless, or occasionally with rays up to 4 mm. long; outer involucral bracts 4-9, herbaceous, enlarged and leafy.


Achenes wedge-shaped, flat or compressed-quadrangular, brown or blackish to purplish, with persistent pappus of 2-4 awns.

Identification Notes:

The winged petioles of Bidens tripartita should separate it from the very similar B. frondosa.

Accepted Name:
Bidens tripartita L.
Publication: Sp. Pl. 2: 831. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Bidens tripartita in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Bidens tripartita checklist entry

OregonFlora: Bidens tripartita information

E-Flora BC: Bidens tripartita atlas page

CalPhotos: Bidens tripartita photos

13 photographs:
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