Arnica lanceolata subsp. prima
Novon 16: 2006.
Leaves: basal commonly withered by flowering, sessile or subsessile to petiolate, blades usually oblong to narrowly lanceolate or oblanceolate, rarely ovate, margins subentire to prominently dentate-serrate; cauline sessile (bases sometimes partly connate-sheathing), blades narrowly to broadly lance-elliptic or ovate, margins subentire to serrate-dentate, faces sparsely to densely pilose. Phyllaries narrowly lanceolate. 2n = 38, 57, 76.
Phenology: Flowering May–Sep.
Habitat: Moist areas, along stream banks, snow-melt areas, montane to alpine meadows
Elevation: 0–3000 m
Alta., B.C., N.W.T., Yukon, Alaska, Calif., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.
The name Arnica amplexifolia Rydberg (1900c) was a superfluous (illegitimate) substitution for A. amplexicaulis Nuttall (1841).