Aspen Sunflower

Helianthella quinquenervis grows primarily in the Rocky Mountains, Great Basin ranges, and Black Hills.

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.

Helianthus quinquenervis Hooker, London J. Bot. 6: 247. 1847