Arnica humilis

Arnica humilis Rydberg, sp. nov
Arnica pumila Rydb. Fl. Rocky Mts. 978, in small part. 1917.
Rootstock branched; stem 1.5-2 dm. high, glandular-granuliferous, occasionally with a few hairs, striate ; leaves of the offsets unknown ; stem-leaves 2 or 3 pairs; lower leaves petioled, the petioles 2-3 cm. long; blades ovate, mostly truncate at the base, usually entire, 3-4 cm. long, about 2 cm. wide, puberulent and glandular-granuliferous on both sides, the uppermost pair lanceolate, subsessile; heads solitary or sometimes several; peduncle 3-6 cm. long; involucre turbinate, about 15 mm. high, 15-18 mm. broad, glandular-puberulent, and only slightly villous; bracts 12-14, lance-linear, acute; ray-flowers 10-12, the ligules 15-18 mm. long, 4—6 mm. wide, acute or acutely 2or 3-toothed; disk-corollas 8 mm. long; achenes 6-7 mm. long, hirsute; pappus-bristles white, 7 mm. long, barbellate.
Type collected on the "Saddle," Lake Louise, Alberta, July 20, 1904, John Macoun (Geol. Surv. Can. no.) 6SS04 herb. N. Y. Bot. Gard.).
Distribution: Rocky Mountains of Alberta.