Arnica lanceolata subsp. lanceolata

Arnica petiolaris (Fernald) Rydberg, sp. nov
Arnica mollis Tott. Fl. N. Y. 1: 403. 1843. Not A. mollis Hook. 1834. Arnica Ckamissonis f. A. Gray, Syn. Fl. N. Am. I 2 : 382. 1884. Arnica mollis Femad, Rhodora 7: 149. in part. 1905. Arnica mollis petiolaris Fernald, Rhodora 7: 150. 1905.
Rootstock branched; stem slender, 2-4 dm. high, sparingly hairy, more or less glandularpuberulent in the inflorescence; leaves of the offsets long-petioled, the petioles 4-7 cm. long, the blades narrowly oblanceolate, sinuate-denticulate, 5-10 cm. long, 1-2 cm. wide, acute at the apex, attenuate at the base, ciliolate on the margins, otherwise glabrate, or rarely with a few scattered hairs; stem-leaves 3-5 pairs, the lowest like those of the offsets, the middle linear or linear-oblanceolate, usually short-petioled, the uppermost sessile, narrowly lanceolate, acuminate, more pubescent and glandular-granuliferous; heads 1-3; peduncles 4-8 cm. long; involucre rounded-turbinate, 10-12 mm. high, 12-15 mm. broad, densely hirsute and glandularpuberulent; bracts about 15, linear-lanceolate, acuminate; ray-flowers 10-15, the ligules 15-18 mm. long, 4-5 mm. wide, irregularly and deeply 2or 3-toothed; disk-corollas 6 mm. long; achenes sparingly hirsute, 4 mm. long; pappus-bristles yellowish, short-plumose, 6 mm. long.
Type locality: Moxie Falls, Sommerset County. Maine. Distribution: Maine to Quebec and northern New York.