A. Gray, Amer. Naturalist. 8: 213. 1874.
Parry's arnica, nodding arnica
A. Gray, Proc. Acad. Nat. Sci. Philadelphia 15: 68. 1864;
A. Gray subsp.
simple or branched among heads.
(2—)3—4 pairs, basal and cauline (basal usually withered by flowering, petiolate or subsessile, blades ovate or nearly round to oblong-ovate, much smaller than cauline; sterile rosettes often present, proximal cauline often crowded toward stems bases); petiolate; blades broadly to narrowly lanceolate, oblong-ovate, ovate-lanceolate, or round, 4—22 × 1—6 cm, (bases obtuse or cuneate to truncate) margins usually entire, sometimes sparsely denticulate, faces scantily to moderately pilose (hairs white), adaxial sparsely stipitate-glandular (distal cauline leaves sessile, extremely reduced, nearly linear to narrowly elliptic-lanceolate).
(1—)3—9(—14; often nodding in bud).
turbinate to narrowly campanulate.
8—20, linear to narrowly lanceolate.
usually 0 (sometimes peripheral florets pistillate; corollas yellow, laminae rudimentary).
20—50; corollas yellow (1 or more lobes sometimes expanded, giving appearance of laminae); anthers yellow.
brown to black, 4—7 mm, glabrous or sparsely stipitate-glandular to densely hirsute;
usually stramineous, rarely tawny, bristles barbellate to ± subplumose.
= 38, 57, 76.
Flowering May—Sep. Open conifer forests to alpine meadows; 500—3800 m; Alta., B.C., Yukon; Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.