Plants (30-)100-200+ cm (perennating bases ± erect or horizontal rhizomes, internodes winged, at least proximal). Leaves all or mostly alternate (proximal sometimes opposite); blades lance-elliptic or lanceolate to lance-linear, 10-25+ × 2-8+ cm, bases narrowly cuneate, margins coarsely toothed to subentire, apices attenuate, faces scabrellous. Heads (3-)8-25(-50+) in corymbiform to paniculiform arrays. Involucres ± saucerlike, 10-12+ mm diam. Phyllaries 8-12+ in 1(-2) series, ± spreading to reflexed, spatulate or lance-linear to linear, 3-8+ mm. Ray florets (2-)6-8+; laminae 15-25+ mm. Disc florets 40-60+; corollas yellow. Cypselae dark brown to black, oblanceolate to ± orbiculate, 4.5-5 mm, faces sparsely hirtellous to glabrate; pappi 1.5-2 mm. 2n = 68.
Perennial 1-3 m, the stem leafy, spreading-hirsute to subglabrous, usually ±winged; lvs alternate, lanceolate or lance-elliptic to occasionally ovate, usually gradually narrowed to a petiolar base, sharply serrate or subentire, 10-25 נ2-8 cm, scabrous-hirsute, especially above; heads 10-100+ in an open infl; disk 1-1.5 cm wide in fl; invol bracts few, glabrous or subglabrous, rather small, narrow, soon deflexed, the disk-fls loosely spreading even before anthesis; rays 2-10, neutral, yellow, 1-3 cm; achenes broadly winged or sometimes wingless, spreading in all directions, forming a globose head 8-15 mm thick; 2n=68. Thickets, woods, and bottomlands; N.Y. and s. Ont. to e. Neb., s. to Fla., La., and Okla., rarely adventive elsewhere. Aug.-Oct. (Actinomeris a.; Ridan a.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Infrequent to frequent or locally common throughout the state, although there are no reports from the northwestern counties. It is a coarse weed preferring moist situations, and found usually in alluvial soil along streams in open woodland and pastures.