Lanceleaf arnica, arnica à aigrettes brunes

Arnica mollis Hooker var. petiolaris Fernald

Leaves: basal petiolate, blades elliptic-lanceolate or oblanceolate, margins subentire, denticulate, or dentate-serrate; cauline mostly sessile (proximalmost pair petio-late), blades lanceolate to elliptic-lanceolate or oblanceolate, margins subentire, irregularly denticulate, or serrate, faces glabrate to scantily pilose. Phyllaries narrowly to broadly lanceolate. 2n = 76.

Flowering Jun–Sep. Moist areas, stream banks, gravel bars, to subalpine meadows; 0–1000 m; N.B., Que.; Maine, N.H.