Arnica chamissonis

Plants 20–80 (–150) cm. Stems usually branched from mid heights or distally. Leaves 4–10 pairs, mostly cauline (evenly distributed; basal leaves often withered by flowering, 1–2 pairs, subsessile to short-petiolate); sessile (proximalmost with membranous connate-sheathing bases); blades lance-elliptic, broadly oblanceolate, or oblong, 5–20 × 2–6 (–8) cm, margins entire or remotely denticulate to prominently dentate, apices acute, faces nearly glabrous or puberulent to sparsely or densely white-tomentose-pilose. Heads (1–) 3–10 (–16). Involucres campanulate (rarely hemispheric). Phyllaries 8–23, nearly linear to narrowly lanceolate (apices each with conspicuous tuft of white hairs). Ray-florets 8–20; corollas yellow. Disc-florets: corollas yellow; anthers yellow. Cypselae gray to brown, 3–8 mm, subglabrous to sparsely hirsutulous, stipitate-glandular; pappi stramineous, bristles barbellate to subplumose. 2n = 38, 57, 76.

Phenology: Flowering Apr–Sep.
Habitat: Moist meadows and conifer forests, stream banks, late snow-melt areas, often montane to subalpine
Elevation: 0–3500 m

Alta., B.C., Man., N.W.T., Ont., Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo.

Discussion

Selected References

None.

Lower Taxa