Arnica. COMrOSITyK . 4-15 



A genus of few spcdcs, of difnrult (lisnrimination. One, tlic ofTicinnl yirnka monlann, is 

 ppciiliar to Europe ; nnotlicr, found in higli northern regions all round tlic world, l)ut sparingly in 

 lin rope, 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, excejit that one is con- 

 fined to the somewhat Southern Atlantic States. 



* liadical and Imrer caiiline leaves cordate or truncate at bajie and longpetioled. 

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



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

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

 base, unc(|ually dentate ; the upper ones small ; all petiolcd and commonly alter- 

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

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



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

 length. 



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

 (ivnte or oblong, coarHcJy and irregularly ilentntt^, eitlier c.ordaln or truncate or nirely 

 Romcwliivt cuiioato at base ; tlin upper HUiall and sossile, oIltMi allernate : Jieads 7 to 

 \) liiit\s long: involucre villous and glandular: akenes sparsely i)ube3ccnt, beconiing 

 glabrate, not glandular. — PI. llartw. 319. 



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

 equal length. 



-f- -f- Leaves all opposite : heads solitary or few, usually luitli. lonr) rays. 



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

 sparsely more or less hairy : lower leaves ovate or roundish an<l deeply cordate, 

 mostly coarsely toothed, connuoidy only 2 pairs on the stem ; the upper i)air 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 Avanting. 



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

 Mountains and northward through Oregon. Mt. Hamilton in the Contra Costa Range, J^rciwr; 

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

 form. 



Ki « Nadicnl leaves rounded or sonietiihat cordate at hnse and slender-petioled; the 

 cavline mostly closely sessile hi/ a broad hnse. 



4. A. latifolla, Bongard. A foot or so bigli, sparsely pul)oscont or almost 

 glabrous, bearing solitary or few heads : caulii\o 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. Memiesii, Hook. Fl. t. 111. 



Sierra Nevada, from Nevada C^. {Lcmmon, 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 

 tapei'ing into petioles, the lomer most pairs of j^etioles commonly sheathing at ba.se. 



These species are exceedingly difficult, ami apparently pass into each otlier 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 liairy wit.li either soft or 

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

 heads : loaves thin, oblong or the upp(>r ajid closely sessile ones oviite-lanceolato with 

 a broad base, mostly serrate or dentiodate : rays pretty large, deep yellow : iiapj)us 

 so densely and strongly barbellate as to be almost plumose. 



Vosemite Valley or near it, and near Mount Dana (Hirim) : UDrlh ti> Briti-^h Colnmbin and 

 eastward to Lake Supeiioi', the White Monntnins of New Ihinipshin-. kr. l,i;ivcs '.\ ti> .1 imhrs 



