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.

Duration: Perennial

Nativity: Native

Lifeform: Forb/Herb

General: Herbaceous, coarse perennials, to 150 cm tall, stout, simply or few branching, herbage sparsely hirsute to glabrous, with a taproot, sometimes with a woody caudex.

Leaves: Basal leaves opposite, glabrous or sparsely hirsute, lanceolate, acute, or acuminate, 3-5 nerved, acute or acuminate at the tips, sessile or borne on short petioles, cauline leaves similar, in 3-4 pairs, the largest leaves usually lower to midway up the stems. Stems usually not very leafy distally.

Flowers: Heads large, showy, radiate, rays yellow, 25-30 mm long, disk flowers yellow, the disk 2-3 cm wide, receptacle pales soft and scarious, involucres 2 cm high and 4-5 cm wide, broad to hemispheric, phyllaries unequal, ciliate, lanceolate, with acute or acuminate tips, heads long-peduncled, often nodding, heads borne solitary or sometimes with a few reduced lateral heads.

Fruits: Achenes 8-10 mm long, appressed pubescent on the faces, ciliate on the margins. Pappus awns slender, half as long as the achenes.

Ecology: Found in mountain meadows, aspen glades, and woods, from 5,000-10,000 ft (1524-3048 m); flowering July-October.

Distribution: South Dakota to Idaho, south to New Mexico, Arizona, and Mexico.

Notes: The large, showy heads, yellow rays, and thin leaves are good identifiers for this species.

Ethnobotany: Unknown

Etymology: Helianthella is a diminutive of Helianthus, while quinquenervis means having five nerves.

Synonyms: Helianthus quinuenervis

Editor: LCrumbacher 2011