Distribution: Occurring west of the Cascades crest in the northern Puget Trough area in Washington; southwestern British Columbia to King County, Washington.
Habitat: Wetlands, estuaries, pond and stream margins.
Flowers: July-October
Origin: Native
Growth Duration: Perennial
Conservation Status: Review Group 1 in Washington (WANHP)
Pollination: Bees, flies, beetles, wasps
Glabrous annual, the stem 5-10 dm. tall.
Leaves opposite, simple, sessile, or the lower with a short, winged petiole, 8-20 cm. long, the middle and lower leaves deeply three-parted, the divisions deeply toothed or incised.
Heads few and large, the involucre bracts in two series, the outer bracts 8-10, spreading, enlarged and leafy; rays yellow, 8-11, 4-8 mm. long; disk flowers perfect; receptacle flat, chaffy; pappus usually of two awns.
Achenes wedge-shaped, 5-7 mm. long.
Publication: Pittonia. 4: 268. 1901.
Bidens elata (Torr. & A. Gray) Sherff
PNW Herbaria: Specimen records of Bidens amplissima in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Bidens amplissima checklist entry
OregonFlora: Bidens amplissima information
E-Flora BC: Bidens amplissima atlas page
CalPhotos: Bidens amplissima photos
