Broadleaf Arnica

Plants 10–50 cm. Stems usually simple, sometimes branched distally. Leaves 2–4(–6) pairs, cauline (basal leaves often persistent on sterile rosettes), petiolate (proximal, petioles relatively short, broadly winged) or sessile (mid and distal); blades lance-elliptic to ovate, 2–10 × 1–6 cm, margins serrate to dentate, apices obtuse to acute, faces glabrous or sparsely villous. Heads 1 or 3–5(–9). Involucres narrowly turbinate. Phyllaries 8–20, lanceolate to oblanceolate. Ray florets 8–15; corollas yellow. Disc florets 20–90; corollas yellow; anthers yellow. Cypselae dark brown, 5–9 mm, sparsely villous; pappi white, bristles barbellate. 2n = 38, 76.

Arnica menziesii Hook. Fl. Bor. Am. 1: 331. 1834
Rootstock horizontal; stem 4-6 dm. high, striate, more or less villous and glandular, especially in the inflorescence; leave* of the offsets long-petioled, the petioles 5-15 cm. long; blades cordate or ovate, coarsely dentate, 4-8 cm. long, puberulent on both sides; stem-Ii 3 or 4 pairs, the lower short petioled, with usually rounded -cordate blades, the upper]
sessile ..irply dentate, 3 6 cm. long; head, i 5, cymose; involucre broadly turbinate
itiulatc, al»out 12 mm. high and 15-1 Ij villous and glandular put
brad 12 IS, oblanceolate, acuminate, raj flowei 10 i -', the ligules 13—20 mm, long,
about 4 mm. wide, 2-4-toothed; d. 7 mm long; a. In lie , (. mm long, (Daringly
ly towards the apex; pappi 6 nun long, white, barbellate
Tm locality Roekj Mountains.
v • now Hook i'i Boi Am pi. III.

Arnica latifolia Bong. Mem. Acad. St. Petersb VI. 2: 147. 1833.
Arnica Menziezii Hook. Fl. Bor. Am. 1: 331, in part. 1834. Arnica intermedia Howell, Ms.
Rootstock horizontal; stem 3-6 dm. high, sparingly villous and puberulent, densely shortvillous, almost velutinous in the inflorescence; leaves of the offsets long-petioled, the petioles 5-10 cm. long; blades thin, oval or ovate or those of the earlier ones cordate, crenate-dentate, with mucronulate teeth, 2-8 cm. long, puberulent above, paler and glabrous or sparingly pubescent on the veins beneath; stem-leaves 3-5 pairs, the lower short-petioled, the upper sessile; blades crenate-dentate, ovate, 3-S cm. long; heads 1-5, cymose; involucre broadly turbinate, 12-15 mm. high, 12-15 mm. broad, finely and rather densely villous; bracts 12-15, oblanceolate or rarely linear-oblanceolate, acuminate; ray-flowers 8-12, the ligules 15-20 mm. long, 3-4 mm. wide; disk-corollas 7 mm. long; achenes striate, 6 mm. long, from glabrous to glandular-granuliferous, often with a few hairs near the apex; pappus-bristles white, 6 mm. long, barbellate.
Type locality: Sitka. Alaska. Distribution : Alaska to Oregon.

Arnica latifolia is a species of arnica in the sunflower family, known by the common names broadleaf arnica, broad leaved arnica, mountain arnica, and daffodil leopardbane. It is native to western North America from Alaska east to Northwest Territories and south to Mono County, California, and Taos County, New Mexico. It grows in mountain habitat such as forest and meadows.

Arnica latifolia is a perennial herb growing from a long rhizome and producing a hairy, mostly naked stem 10 to 50 centimeters tall. It has a cluster of leaves around its base and usually a few pairs along the lower part of the stem. The leaves are lance-shaped to broad and nearly heart-shaped, and are usually toothed.

The inflorescence contains one or more daisy-like flower heads lined in glandular phyllaries. Each has a center of yellow disc florets and several yellow ray florets up to 3 centimeters long. The fruit is an achene with a white pappus.

The plant was first described in 1832 by German-Russian botanist Gustav Heinrich von Bongard, based on material collected near Sitka, now in Alaska (then called Russian America).

The species could be confused with the similar Arnica cordifolia, from which it can be distinguished by the leaves.