Helianthus pauciflorus Nutt.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Perennial with long rhizomes; stems scabrous or hispid to subglabrous, ± naked above, the heads long-pedunculate; lvs nearly all opposite, to 15 pairs below the infl, scabrous to shortly hispid on both sides, mostly (2–)2.5–8 times as long as wide, mostly trinerved, toothed or entire, tapering to a short petiole or petiolar base, the middle ones seldom much smaller than the lowest ones present at anthesis; disk red-purple, 1.5–2.5(–3) cm wide; invol bracts evidently imbricate, broad, firm, appressed, mostly ovate or broadly lanceolate, sharply acute to obtuse, conspicuously ciliolate, otherwise generally glabrous; rays 10–21, 1.5–3(–3.5) cm; pappus nearly always with some short scales in addition to the 2 longer awns; 2n=102. Prairies and roadsides; Mich. and Ind. to Alta., N.M., and Tex., and e. occasionally to Mass. and N.B. Aug., Sept.