Arnica latifolia

Plants 10-50 cm. Stems usually simple, sometimes branched distally. Leaves 2-4(-6) pairs, cauline (basal leaves often persistent on sterile rosettes), petiolate (proximal, petioles relatively short, broadly winged) or sessile (mid and distal); blades lance-elliptic to ovate, 2-10 × 1-6 cm, margins serrate to dentate, apices obtuse to acute, faces glabrous or sparsely villous. Heads 1 or 3-5(-9). Involucres narrowly turbinate. Phyllaries 8-20, lanceolate to oblanceolate. Ray florets 8-15; corollas yellow. Disc florets 20-90; corollas yellow; anthers yellow. Cypselae dark brown, 5-9 mm, sparsely villous; pappi white, bristles barbellate. 2n = 38, 76.

Flowering Jul-Aug. Relatively moist, montane conifer forests to subalpine meadows; 500-3300 m; Alta., B.C., N.W.T., Yukon; Alaska, Calif., Colo., Idaho, Mont., Oreg., Utah, Wash., Wyo.