arnica COMPOSITE 373 



A. spathulata Greene Pitt. iii. 103. "A foot high or more, stoutish, 

 somewhat vi=cidly hirsute and tomentulose, very leafy below and florif- 

 erous from about midway of the stem : lowest leaves 3 to 5 inches long, 

 broadly lanceolate-spatulate, doubly toothed, the two or more pairs of 

 lower cauline more narrowly spatulate but dilated just above the inser- 

 tion : peduncles 6 to 10, the lowest with a pair of ovate-acuminate sessile 

 bracts in the middle : heads campanulate, % inch high ; involucre densely 

 woolly-hirsute and viscidulous; rays none; disk-corollas orchroleucous, 

 the tube hirsute, the teeth with a tuft of pilose hairs at tip: achenes 

 glabrous, minutely resinous-dotted; pappus white, barbellulate-scabrous. 

 Oregon." 



** ♦♦ Rays conspicuous and elongated, rarely wanting: cauline 



leaves all opposite, in 1-3 pairs, broad and usually membranaceous, 



dentate or denticulate. 



A. cordifolia Hook. Fl. i, S31. Pubescent or the stems hirsute and 

 the peduncles villous: stems 1-2 feet Irgh, or in alpine forms 4-8 inches 

 high : lower cauline and radical leaves long-petioled, deeply cordate, or 

 sometimes onlv ovate; upper cauline small, sessile: heads few, in smaller 

 plants solitary: involucre 8 lines high, pubescent or villous : rays usually 

 an inch long: achenes more or less hirsute. Woods and high mountains, 

 Brit. Columbia to California and the Rocky Mountains. 



var. eradiata Gray Syn. Fl. i, pt. 2, 381. Heads smaller, without 

 rays: leaves oblong-ovate, at most subcordate. Eastern Oregon to Mont. 



A. latifolia Bong. Yeg. Sitch. 147. Glabrous or minutely pubescent: 

 stems rather slender, 6-18 inches high: radical leaves cordate or subcor- 

 date and petioled, cauline 2-3 pairs equal ovate, or oval, usually sharply 

 dentate, closely sessile by a broad base, or lowest with contracted base : 

 heads one to several, on slender peduncles in the axils of the upper leaves ; 

 bracts of the involucre oblanceolate with a broad base and long accumi- 

 nate apex; achenes usually glabrate or glabrous. In mountainous districts 

 Alaska to Oregon and the Rocky Mountains of Colorado 



A. cernuua Howell Glabrous or minutely pubescent; t- terns slender, 

 usually solitary, 4-12 inches high, bearing a single head on a curved pe- 

 duncle : leaves all more or less petioled, entire or coarsely dentate, ovate 

 and subcordate, or the upper lanceolate with a broad cuneate base, usu- 

 ally not more than 15 lines long : involucre 8-10 lines long, of lanceolate 

 but not acuminate bracts : achenes short -pubescent. On the serpentine 

 formation of the Coast range, near Waldo, Oregon 



* * No cordate leaves : radical leaves petioled tapering or some- 

 times abrupt at base : root-stock usually creeping and slender 



■*- Leafy to the top : cauline leaves very seldom less than 4 pairs 

 and the upper not conspicuously diminished : heads several or few, 

 in small plants solitary. 



A. amplexicaulis Xutt. Trans. Am. Phil. Soc. vii, 480. Glabrous or 

 sometimes pubescent : 1-2 feet high: many-stemmed from matted root 

 stocks, rather stout, leaves from ovate to lanceolate-oblong, acute or acu- 

 minate, all the cauline sessile by half-clasping base, saliently and very 

 acutely dentate ; achenes hirsute-pubescent. Along small streams and on 

 waterfalls never where it becomes dry. Oregon to Brit. Columbia. 



A. Chamissonis Less, in Linn, vi, 238. Few-stemmed from short 

 running root stocks; from tomentulose or villous pubescent to nearly glab- 

 rous, 1-2 feet high, rather slender: leaves oblong or oblong-lanceolate, 

 denticulate or dentate, lowest tapering into a marginal petiole, upper broad 

 at base and somewhat clasping: achenes hirsute-pubescent. In the high 

 mountains, Alaska to California, Utah, Colorado, Lake Superior and 

 Washington. 



