Arnica cordifolia
Fl. Bor.-Amer. 1: 331. 1834.
Plants 10–40 (–70) cm. Stems usually simple, sometimes branched. Leaves 2–4 (–6) pairs, mostly cauline (basal often persistent on sterile rosettes); petiolate; blades cordate or subcordate to ovate, 3–10 × 2–10 cm, margins dentate to coarsely dentate, apices acute to rounded, faces puberulent to sparsely villous, sometimes stipitate-glandular (especially adaxial). Heads 1, or 3–5 (–10). Involucres broadly campanulate. Phyllaries 10–20, narrowly ovate to lanceolate. Ray-florets 6–13; corollas yellow. Disc-florets: corollas yellow; anthers yellow. Cypselae dark gray, 5–10 mm, sparsely to densely hirsute (hairs duplex), sometimes stipitate-glandular as well; pappi white, bristles barbellate. 2n = 38, 57, 76, 95, 114.
Phenology: Flowering May–Jul.
Habitat: Conifer forests to subalpine meadows
Elevation: 500–3000 m
Distribution
Alta., B.C., Man., N.W.T., Ont., Sask., Yukon, Ariz., Calif., Colo., Idaho, Mich., Mont., Nev., N.Mex., Oreg., S.Dak., Utah, Wash., Wyo.
Discussion
Selected References
None.