August - October. This Bidens species is one without ray flowers The yellowish "blossom" is created from August through October by many small flowers crowded together into a tubular head, forming a disk, without ray flowers present. Each head is subtended by five to eight leafy, ciliate bracts. Stems are erect and smooth, reaching up to four feet tall. Leaves are opposite, pinnately divided into three to seven segments, with each segment smooth and up to four inches long and two inches wide. Occurs naturally in ditches, along pond margins and streambanks, and road or railroad rights-of-way.