Distribution: Occurring chiefly east of the Cascades in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other open areas, often where disturbed, at low to middle elevations.
Flowers: June-September
Origin: Native and introduced populations in Washington
Growth Duration: Annual
Conservation Status: Not of concern
Pollination: Bumblebees, bees, butterflies, wasps
Coarse annual, 4-20 dm. tall, the herbage rough-hairy.
Leaves chiefly alternate, long-petiolate, mostly toothed, ovate or broader, the lower often cordate.
Heads large, reddish-brown disk over 2 cm. wide; involucral bracts ovate, sub-equal, green, tapered to a point, covered with short, stiff hairs, with longer hairs on the margins; ray flowers large, yellow and neutral; receptacle chaffy throughout; pappus of 2 readily deciduous awns.
Achenes clasped by the inner involucral bracts.
PNW Herbaria: Specimen records of Helianthus annuus in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Helianthus annuus checklist entry
OregonFlora: Helianthus annuus information
E-Flora BC: Helianthus annuus atlas page
CalPhotos: Helianthus annuus photos