GENUS 97. THISTLE FAMILY. 
wn 
oO 
LSP) 
97- ARNICA L. Sp. PI. S84.) 1753. 
Erect, simple or little branched herbs, with opposite leaves, or the upper rarely alternate. 
and large, long-peduncled heads of both tubular and radiate. yellow flowers, or rays wanting 
in some species. Involucre turbinate or campanulate, its bracts im I or 2 series, narrow, 
nearly equal. Receptacle flat, naked. fimbnillate or villous. Ray-flowers pistillate, fertile. the 
rays spreading, enure, ar 2>3-teothed. Disk-flowers perfect, fertile, the corolla 5-lobed, the 
style with slender branches. Anthers entire or minutely 2-auriculate at the base. Achenes 
linear, 5-10-ribbed. more or less pubescent. 
rigid, slender bristles. 
Pappus a single series of rough or barbellate, 
[Derivation uncertain, perhaps from Ptarmica.] 
About 45 species, natives of the northern hemisphere. Besides the following, many others 
occur in the western parts of North America. Type species: 
Arnica montana L. 
Basal leaves ovate or oval, sessile ; southern. . 1. -t. acauiss. 
Basal leaves oblong, lanceolate, or cordate-ovate. petioled. : 
Basal leaves cordate-ovate. 2. A. cerdifolia 
Basal leaves not cordate, tapering to the petiole. 
Leaves dentate. 
Pappus brownish, plumose. 3. Al. mollis. 
Pappus white, barbellate. 4. A. chionopappe. 
Leaves entire or nearly so. 3. i. alpina. 
. Arnica acatilis (Walt.) B.S.P. 
Leopard’s-bane. Fig. 4599. 
Doronicum acaule Walt. Fl. Car. 205. 1 
Arnica Claytoni Pursh, Fl. Am. Sept. 
Arnica nudicaulis Nutt. Gen. 2: 164. 
airnica acaulis B.S.P. Prel. Cat. N. Y. 30. 1838. 
a 
Glandular-hirsute; stem 1°-3° high, bearing 
several slender-peduncled heads at the sum- 
mit. Basal leaves tufted. ovate or oval, obtuse, 
narrowed to a ses ssile base. denticulate or en- 
tire, 2’-5’ long, 13-3’ wide: stem leaves I-3 
pairs, and some alternate. very small ones 
above: heads 1-13" broad; bracts of the invo- 
Iucre hnear-lanceolate, acute or acutish: rays 
I2I5, commonly 3-toothed at the truncate 
apex: achenes pubescent when young, glabrous 
or nearly so when mature. 
aM ond ada ges) b bse sen 
In low woods, Delaware and southern Pennsyl- 
yvania to Florida. April-May. 
2. Arnica cordifélia Hook. Heart- 
leaf Arnica. Fig. 4600. 
arnica cordifolia Hook. Fl. Bor. Am. 1: 331. 
Villous or pubescent; stem simple or 
sparingly branched, glandular above. 1°-2° 
high. Basal and lower leaves ovate to 
nearly orbicular, obtuse or acute. deeply 
cordate at the base, dentate. 1~3" long. 
with slender sometimes margined petioles: 
stem leaves I-3 pairs, ovate to oblong, ses- 
sile or short-petioled. much smaller; heads 
1-8, 2-3’ broad: bracts of the involucre 
acute or acuminate, villous, 6-10” long: 
rays 1216, toothed at the apex: achenes 
hirsute-pubescent, or glabrous at the base: 
pappus barbellate, white. 
Lake Superior to North Dakota. Seniouas 
Montana. New Mexico and California. Re 
corded from western Nebraska. May-July. 
