Narrowleaf arnica

Arnica alpina subsp. angustifolia (Vahl) Maguire; A. alpina (Linnaeus) Olin & Ladau var. angustifolia (Vahl) Fernald

Plants 5–40 cm. Stems usually simple, rarely branched. Leaves 1–5 pairs, mostly cauline; petio-late (petioles broadly to narrowly winged, shorter than blades); blades broadly lanceolate to linear, 2–20 × 0.3–4 cm, margins entire or irregularly denticulate or dentate, apices acute or acuminate, faces glabrous or densely woolly-villous and stipitate-glandular. Heads 1–3(–5; erect). Involucres hemispheric. Phyllaries 9–22, usually narrowly to broadly lanceolate, sometimes oblanceolate. Ray florets 6–16; corollas yellow. Disc florets: corollas yellow; anthers yellow. Cypselae brown, 3–8 mm, densely hirsute, rarely glandular; pappi white, bristles barbellate.

Subspecies 2 (2 in the flora): North America; Europe; Asia.