An annual, with erect or partially prostrate stems, smooth or hispid and usually much branched, from a few inches to 3 feet high. Leaves sessile, opposite, usually somewhat united around the stem. Lanceolate to oblong-lanceolate in shape, coarsely and sharply toothed, smooth, long pointed, 3 to 6 inches long, one-fourth to 1 inch wide. Heads numerous, at least on vigorous plants, globose, short-stalked, one-half to 1 inch broad, nodding after or during flowering, consisting of six to ten short, yellow ray flowers, one-fourth to one-half of an inch long, surrounding the globose, yellow or brownish-yellow disk. Very often the ray flowers are absent. Bracts of the involucre in two series, the outer green and leaflike and much larger than the membranaceous, yellowish-margined inner bracts. Seed a wedge-shaped achene, about one-sixth of an inch long, retrorsely hispid on the margins, and with usually four downwardly barbed awns at the summit.
In wet soil and swamps, Nova Scotia to Hudson bay and British Columbia south to North Carolina, Missouri and California. Also found in Europe. Flowering from July to October. Dwarf forms are frequent.
Memoir 15 N. Y. State Museum
Small Or Nodding Bur Marigold - Bideas cernua