Arnica. COMPOSIT.E. 381 



Gray, 1. c. A. Claytoni, Pursh, Fl. ii. 527. Doronicnm ncnnJe, Walt. Car. 205. D. nudicaule, 

 Miclix. n. ii. 121. — Fiue barreus, &c., Peuu. to Florida. 



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

 slender and creeping. Pacific and Rocky Mountain species. 



-)— Rays wanting or rarely some rudiments: cauline leaves sometimes bj' disjunction alternate, 

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



A. parviflora, Gray. A foot high, slender, pube.scent, even the peduncles bnt .slightly 

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

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

 akenes not pubescent, minutely glandular. — Proc. Am. Acad. vii. 36.3, & Bot. Calif, i. 415. 

 — California, in Humboldt Co., Bu/ander. Also at some station north of San Francisco 

 Bay, G. R. Vusen. 



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

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

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

 glandular; its bracts lanceolate or linear : akenes pubescent. — PI. Hartw. 319; Gray, Bot. 

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

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

 seems to pass into A. cordifolia. 



-)— -(— Rays conspicuous and elongated, rarely wanting: cauline leaves all opposite, in one or 

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



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

 stems 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 : invcjlucre two-tliirds inch long, pubescent or villous : rays commonly inch 

 long: akenes more or less hirsute. — Fl. i. 331 ; Torr. & Gray, Fl. ii. 450. A. macrop/iylla, 

 Nutt. Trans. Am. Phil. Soc. 1. c. 407. Senecio Cumimjil, Klatt in Abh. Nat. Hist. Gesellsch. 

 XV. 9, is either this or the next. — Woods and high mountains, Brit. Columbia, and mountains 

 near Saskatchewan, to those of Colorado, Utali, 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 subcordate leaves. — E. Oregtm, 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 sharpl}' dentate, closely sessile by a broad base, or lowest with 

 contracted base: akenes commonly glabrate or glabrous. — Veg. Sitch. 147; Torr. & Gi-ay, 

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

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



Var. viscidula. Viscidly pubescent: cauline leaves less broad at base: lieads ratlier 

 larger: akenes pubescent. — High Sierra Nevada, California) Greene, Prinr/le. And a very 

 siniilar plant fn^n Sitka. 



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

 stocks usually creeping and slender. Western and Northern species. 



-1— 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 ])lants solitary. 



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



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

 lanceulate-oblong, acute or acuminate, all the cauline sessile by a half-clasping base, salieutly 

 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, Nuttall, Li/all, Wallace, 

 &c. Broad-leaved forms niuch resembling tlie preceding, except in more leaf}' 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 ol)l(>ng or olilong-lanceolate, denticulate or dentate, acute or obtuse; loM-est tapering 

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

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



