Arnica amplifolia

Arnica amplifolia Rydberg, sp. nov
Rootstock branched; stem about 3 dm. high, sulcate, short-hirsute with crisp hairs and glandular-puberulent ; leaves of the offsets short-petioled, oblanceolate, 6-8 cm. long, shorthispid; stem-leaves about 4 pairs, the lower ones oblanceolate, tapering at the base or shortpetioled, the upper two pairs sessile, ovate or the uppermost broadly lanceolate, the one next below 6-7 cm. long, 3-4 cm. wide, rough-hispidulous and glandular-granuliferous; heads mostly 3; peduncles 6-10 cm. long, hispidulous; involucre 8 mm. high, about 10 mm. broad, glandularhispid; bracts about 15, lanceolate, acuminate; ray-flowers about 10, the ligules orange, about 10 mm. long, 3 mm. wide; achenes hispid; pappus-bristles 5-6 mm. long, brown, shortplumose.
Type collected at the head of Bear Creek, Bitter Root Forest Reserve, Idaho, August 26, 1897, J. B. Leiberg 2934 (herb. N. Y. Bot. Card.). »