Chamisso Arnica

Arnica foliosa Nutt. Trans. Am. Phil. Soe. II. 7: 407. 1841
Arnica ocreata A. Nels. Bot. Gaz. 30: 201. 1900. Arnica exigua A. Nels. Bot. Gaz. 30: 202. 1900. Arnica stricta A. Nels. Bot. Gaz. 31: 407. 1901.
Rootstock long, horizontal; stem 2-6 dm. high, striate, more or less shortvillous, or glabrate below; stem-leaves 5-10 pairs, the lower petioled, with the bases of the petioles connate-sheathing, the upper sessile; blades of the lower leaves linear-oblanceolate to narrowly lanceolate, entire or remotely denticulate, usually densely and finely canescent and slightly glandular-puberulent, sometimes almost glabrous, 5-12 cm. long, 1-2 cm., rarely 2.5 cm. wide, the upper stem-leaves linear, sessile, acute; heads usually several; peduncles 3-10 cm. long; involucre broadly turbinate, 8-10 mm. high, 15-20 mm. broad, whitevillous; bracts about 15, linear or linear-lanceolate, obtusish or acute; ray-flowers about 15, the ligules 10-12 mm. long, 4 mm. wide; disk-corollas 7 mm. long; achenes 4-5 mm. long, sparingly pilose and somewhat glandular-granuliferous; pappus-bristles straw-colored, 6-7 mm. long, barbellate. (A. exigua A. Nels. is a depauperate form scarcely 2 dm. high.)
Type locality: Alluvial flats of the Colorado of the West [Green River), "particularly near Bear River of the Lake Timpanagos."
I ii>tribi tion: Western Ontario to Mackenzie, British Columbia, Oregon, and Colorado.

Arnica chamissonis Less. Linnaea 6: 238. 1831
Arnica monlana Hook. Fl. Bor. Am. 1: 330, in part. 1834.
Arnica columbiana Greene, Pittonia 4: 159. D 1900. Not .4. Columbiana A. Nels. S 1900.
Arnica Greenei A. Nels. Bot. Gaz. 31: 406. 1901.
Rootstock long, horizontal; stem 3-7 dm. high, sulcate, rather sparingly villous, with white flat hairs; stem-leaves 5-10 pairs; blades of the lower ones lanceolate or oblanceolate, acute or acuminate at the apex, tapering below into the petiole, more or less denticulate, 5-7ribbed, green, puberulent, and somewhat glandular-granuliferous above, somewhat paler and long-villous beneath, especially along the ribs, 7— IS cm. long, 2-3 cm. wide, the petioles somewhat connate and sheathing at the base, the upper leaves lanceolate, sessile, usually acuminate; heads 5-20; peduncles 5-10 cm. long; involucre broadly turbinate, about 12 mm. high and 2 cm. broad, whitevillous, especially at the base; bracts about 15, linear-lanceolate, acute; ray-flowers 12-15, the ligules 12-15 mm. long, 4 mm. wide; disk-corollas 7 mm. long; achenes
5 mm. long, sparingly hispidulous; pappus-bristles straw-colored, strongly barbellate.
Type locality: Unalaska.
Distribution: Saskatchewan to Montana, British Columbia, and Alaska.