Arnica. COMPOSITE. 381 



Gray, 1. c. A. Claytoni, Pursh, Fl. ii. 527. Doronicum acaule, Walt. Car. 205. D. nudicwde, 

 Michx. Fl. ii. 121. Piue barreus, &c., Penn. to Florida. 



* * Radical leaves mostly cordate at base, on slender or sometimes winged petioles: rootstocks 

 slender and creeping. Pacific and Rocky Mountain species. 



-I Rays wanting or rarely some rudiments: cnnline leaves sometimes by disjunction alternate, 

 some of them petioled, irregularly dentate: heads rather numerous, paniculate. 



A. parvifiora, GHAY. A foot high, slender, pubescent, even the peduncles but slightly 

 glandular : leaves narrowly deltoid or oblong, truncate or abrupt at base, an inch or two 

 loug: involucre 4 or 5 lines high, about 20-flowered ; its linear bracts sparsely pubescent : 

 akeues not pubescent, minutely glandular. 1'roc. Am. A cad. vii. 3(5.3, & Rot. Calif, i. 415. 

 California, in Humboldt Co., Bvlander. Also at some station north of San Francisco 

 Bay, G. R. Vase//. 



A. discoidea, BEXTI-I. A foot or two high, stouter, more or less villous and viscid : radi- 

 cal and lowest cauline leaves from ovate with truncate or abruptly cuneate base to cordate, 

 not rarely wing-petioled : involucre half-inch high, 30-50-flowered, usually very villous and 

 glandular; its bracts lanceolate or linear : akeues pubescent. PI. Ilartw. 319; Gray, Bot. 

 Calif. 1. c., with a part of A. cordifolia. Wooded hills iu the coast ranges of California, from 

 San Luis Obispo Co. northward to Washington Terr. ; first coll. by Hnrtweg. Northwardly 

 seems to pass into A. cordifolia. 



H H Rays conspicuous and elongated, rarely wanting: cauline leaves all opposite, in one or 

 two or at most three pairs, broad, usually membranaceous, dentate or denticulate. 



A. cordifolia, HOOK. A foot or two, or when alpine a span or two high, pubescent, or the 

 steins hirsute and peduncles villous : lower cauline as well as radical leaves long-petioled, 

 deeply cordate, yet sometimes only ovate ; upper cauline small, sessile : heads few, in smaller 

 plants solitary : involucre two-thirds inch long, pubescent or villous : rays commonly inch 

 long: akenes more or less hirsute. Fl. i. 331 ; Torr. & Gray, Fl. ii. 450. A. macrophylla, 

 Nutt. Trans. Am. Phil. Soc. 1. c. 407. Senccio Citminyii, Klatt in Abh. Nat. Hist. Gesellsc-h. 

 xv. 9, is either this or the next. Woods and high mountains, Brit. ( 'olumbia, and mountains 

 near Saskatchewan, to those of Colorado, Utah, Nevada, and eastern borders of the Sierra 

 Nevada, California. 



Var. eradiata is an ambiguous form; with smaller and rayless heads, and oblong- 

 ovate at most subeordate leaves. E. Oregon, Montana, &c. Transition to A. Parri/i. 



A. latifolia, BONG. Minutely pubescent or commonly glabrous, with smaller heads than 

 the preceding : only radical leaves cordate or subcordate and petioled ; cauline 2 or 3 pairs, 

 equal, ovate or oval, usually sharply dentate, closely sessile by a broad base, or lowest with 

 contracted base: akenes commonly glabrate or glabrous. Veg. Sitch. 147; Torr. & Gray, 

 I.e. A. Menziesii, Hook. Fl. i. 331, t. 111. Pine woods, Alaska and Brit. Columbia to 

 Oregon, and Rocky Mountains to Colorado and Utah ; first coll. by Mcnzies. 



Var. viscidula. Viscidly pubescent : cauline leaves less broad at base : heads rather 

 larger : akenes pubescent. High Sierra Nevada, California, Greene, Prinyle. And a very 

 similar plant from Sitka. 



* * * No cordate leaves; radical leaves petioled, tapering or sometimes abrupt at base: root- 

 stocks usually creeping and slender. Western and Northern species. 



4- Leafy to the top: cauline leaves very seldom less than 4 pairs, and the upper not conspicuously 



diminished: heads several or few, or in smaller plants solitary. 

 w- Heads all with rays half-inch or more long: plants a foot or two high: the species continent. 



A. amplexicaulis, NUTT. Slightly pubescent or almost glabrous: leaves from ovate to 

 lanceolate-oblong, acute or acuminate, all the cauline sessile by a half-clasping base, saliently 

 and very acutely dentate: akenes hirsute-pubescent. Trans. Am. Phil. Soc. vii. 408; Torr. 

 & Gray, 1. c. Woods and shaded rocks, Oregon to Brit. Columbia, Nuttull, Li/all, Wallace. 

 &c. Broad-leaved forms much resembling the preceding, except in more leafy stems and 

 want of cordate radical leaves : narrower-leaved forms nearly pass into the succeeding. 



A. Chamissonis, LESS. From tomentulose- or villous-pubescent to nearly glabrous : 

 leaves oblong or oblong-lanceolate, denticulate or dentate, acute or obtuse ; lowest tapering 

 into a margined petiole, upper broad at base (sometimes ovate-lanceolate) .and somewhat 

 clasping: akeues hirsute-pubescent. Less, in Linn. vi. 238; DC. Prodr. vi. 317; Torr. & 



