Helenium flexuosum Raf.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Fibrous-rooted perennial 2–10 dm, ± puberulent or villous- puberulent at least on the stem, the lower part of the stem generally spreading-villous; lvs decurrent but smaller, fewer, and more erect than in no. 1 [Helenium autumnale L.], entire or subentire, the lowermost ones oblanceolate, commonly deciduous, the others oblong or lanceolate to lance-linear, sessile, generally not much reduced upwards, 3–12 × 0.5–2 cm; heads in well developed plants numerous in an open, corymbiform, leafy-bracteate infl, the disk subglobose or ovoid-globose, 6–15 mm wide, red-brown or purplish; rays ca 8 to ca 13, neutral, sometimes purplish at base, (0.5–)1–2 cm (rarely wanting); disk-fls predominantly 4-merous; pappus- scales 5(–8), ovate or lanceolate, shortly awn-tipped, ca (0.5–)1 mm overall; 2n=28. Moist ground and waste places; Mass. and N.H. to Fla., w. to Wis., Ill., Mo. and Tex., apparently only intr. northward. June–Oct. (H. nudiflorum; H. polyphyllum)