Arnica. COMPOSITE. 



A genus of few species, of difficult discrimination. One, the officinal Arnica montana, is 

 peculiar to Europe ; another, found in high northern regions all round the world, but sparingly in 

 Europe, extends southward along the mountains of the western part of our continent as far as 

 California ; the others are indigenous to similar regions in this country, except that one is con- 

 fined to the somewhat Southern Atlantic States. 



* Radical and lower cauline leaves cordate or truncate at base and long-petioled. 

 +- Some or most of the leaves alternate : heads several in a naked panicle, rayless. 



1. A. parviflora, Gray. A foot or so in height : leaves mainly at or near the 

 base of the slender stem, deltoid-lanceolate or ovate-lanceolate, seldom cordate at 

 hase, unequally dentate ; the upper ones small ; all petioled and commonly alter- 

 nate : heads small (only half an inch long) : akenes not pubescent but minutely 

 glandular. Proc. Am. Acad. vii. 363. 



Chaparral, Humboldt Co., Bolcmder. Leaves an inch or two long, on petioles of at least equal 

 length. 



2. A. discoidea, Benth. About two feet high, stouter and more hairy : leaves 

 ovate or oblong, coarsely and irregularly dentate, either cordate or truncate or rarely 

 somewhat cuneate at base ; the upper small and sessile, often alternate : heads 7 to 

 9 lines long : involucre villous and glandular : akeues sparsely pubescent, becoming 

 glabrate, not glandular. PI. Hartw. 319. 



In woods, not rare from Monterey northward. Lower leaves 2 or 3 inches long, on petioles of 

 equal length. 



-{- -t- Leaves all opposite : heads solitary or few, usually with long rays. 



3. A. cordifolia, Hook. A foot or two (or in alpine forms a span or so) high, 

 sparsely more or less hairy : lower leaves ovate or roundish and deeply cordate, 

 mostly coarsely toothed, commonly only 2 pairs on the stem ; the upper pair sessile 

 or nearly so, small, and often narrowed at base : head an inch long : akenes hirsute : 

 rays usually about 12 and an inch long, rarely wanting. 



Sierra Nevada, near Sierra Valley (Lemmori) and Carson (Anderson) ; thence east to the Rocky 

 Mountains and northward through Oregon. Mt. Hamilton in the Contra Costa Range, Brewer : 

 a rayless form ; the same collected also in Sierra Valley by Lemmon, along with an ordinary 

 form. 



* * Radical leaves rounded or someivhat cordate at base and slender-petioled ; the 



cauline mostly closely sessile by a broad base. 



4. A. latifolia, Bongard. A foot or so high, sparsely pubescent or almost 

 glabrous, bearing solitary or few heads : cauline leaves 2 to 4 pairs, ovate or deltoid- 

 ovate, sharply and usually coarsely serrate, all alike, or the uppermost smaller and 

 narrower : head half to three fourths of an inch long : akenes slightly pubescent or 

 at length glabrous. A. Menziesii, Hook. Fl. t. 111. 



Sierra Nevada, from Nevada Co. (Lemmon, Greene) ; thence north through Oregon to Alaska, 

 and east to the Rocky Mountains. 



* * * Radical and lower cauline leaves never cordate or truncate at base, but often 

 tapering into petioles, the lowermost pairs of petioles commonly sheathing at base. 



These species are exceedingly difficult, and apparently pass into each other throughout the whole 

 series. The akenes vary too greatly in the character and amount or absence of the pubescence to 

 furnish distinctions. 



5. A. mollis, Hook. A foot or two high, somewhat hairy with either soft or 

 slightly harsh pubescence, leafy to the top, bearing solitary or 3 rather large broad 

 heads : leaves thin, oblong or the upper and closely sessile ones ovate-lanceolate with 

 a broad base, mostly serrate or denticulate : rays pretty large, deep yellow : pappus 

 so densely and strongly barbellate as to be almost plumose. 



Yosemite Valley or near it, and near Mount Dana (Brewer) : north to British Columbia and 

 eastward to Lake Superior, the White Mountains of New Hampshire, &c. Leaves 3 to 5 inches 



