Plants (30-)50-150 cm. Cauline leaves: largest proximal to mid stems; blades usually 3- or 5-nerved, elliptic or ovate-lanceolate to lanceolate, 10-50 cm, faces sparsely hirsute or glabrous. Heads usually borne singly, ± nodding. Involucres hemispheric or broader, (25-)40-50 mm diam. Phyllaries (outer sometimes ± foliaceous) ovate to lanceolate (subequal to unequal, margins ciliate). Paleae scarious, relatively soft. Ray florets (13-)21; (corollas bright yellow) laminae 25-30(-40) mm. Disc corollas yellow. Cypselae strongly compressed, narrowly obovate (margins ciliate, faces strigose); pappi of 2 ± subulate scales plus 2-4+ shorter scales. Flowering Jun-Aug(-Oct). Moist meadows, aspen glades; 1400-3600 m; Ariz., Colo., Idaho, Mont., Nev., N.Mex., Oreg., S.Dak., Wyo.; Mexico (Chihuahua, Nuevo León). Helianthella quinquenervis grows primarily in the Rocky Mountains, Great Basin ranges, and Black Hills.