Burke: Bidens laevis vs. Bidens tripartita

	Bidens laevis	Bidens tripartita
		three-lobed beggar-ticks
Habit		Annual, nearly glabrous throughout, 1-20 dm. tall.
Leaves		Leaves simple (but appearing trifoliate), sharply serrate, usually deeply divided into 3 narrow lobes, the center one larger and wider, 3-15 cm. long.
Flowers		Heads erect, rayless, or occasionally with rays up to 4 mm. long; outer involucral bracts 4-9, herbaceous, enlarged and leafy.
Fruits		Achenes wedge-shaped, flat or compressed-quadrangular, brown or blackish to purplish, with persistent pappus of 2-4 awns.

	Bidens laevis	Bidens tripartita
Identification notes		The winged petioles of Bidens tripartita should separate it from the very similar B. frondosa.
Flowering time		August-October
Habitat		Wet places, often where disturbed, primarily at low elevations.
Distribution	[WildflowerSearch map] [BONAP county map]	Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast where native. [WildflowerSearch map] [BONAP county map]
Origin		Introduced from Eurasia and eastern North America
Conservation status		Not of concern
Sibling taxa	B. amplissima, B. beckii, B. cernua, B. connata, B. frondosa, B. tripartita, B. vulgata	B. amplissima, B. beckii, B. cernua, B. connata, B. frondosa, B. vulgata
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Bidens laevis

Bidens tripartita

three-lobed beggar-ticks

Habit

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

Leaves

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

Flowers

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

Fruits

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