34 COMPOSITAE. 



row of deciduous equal white barbed bristles, but none in the 

 ray-flowers. 



Crocidium multicaule Hook. Woolly when young but soon glabrate; 

 stems numerous, tufted, 5-25 cm. high; radical leaves in a basal tuft, obovate 

 or spatulate, few-toothed, sessile or short-petioled; cauline leaves small, 

 linear; heads slender-peduncled, small but showy; tegules oblong-ovate. 



In open ground, Vancouver Island to California. First found at Fort 

 Vancouver, Washington, by Douglas. 



538. ARNICA. 



Perennial herbs; stems mostly simple, from creeping rootstocks 

 or a corm-like base; leaves all or some of them opposite, simple, 

 entire, or merely toothed; heads rather large, solitary or few, 

 usually long-peduncled, many-flowered; flowers yellow, all fertile; 

 ray-flowers elongated, pistillate, or sometimes none; involucre 

 broadly campanulate, the tegules in 1-2 rows; receptacle naked, 

 flat; pappus a single series of rather rigid strongly scabrous or 

 barbellate capillary bristles; akenes linear, 5 -angled or 510- 

 ribbed, somewhat hirsute or nearly glabrous. 



The species of this genus are of very unsatisfactory definition. 



Basal leaves cordate, long-petioled. 



Herbage pubescent, the stems hirsute or villous. A. cordifolia. 



Herbage glabrous. 



Akenes atomiferous-glandular; leaves often simi- 

 larly glandular on both sides. A, gracilis. 

 Akenes glabrous or nearly so. 



Leaves large, usually dentate, thin. A. latifolia. 



Leaves small, crenate-dentate, firm. A. betonicaefolia. 



Basal leaves not cordate, short-petioled. 



Heads rayless. A. eradiata. 



Heads radiate. 



Pappus whitish, barbellate. 



Herbage viscid-glandular; upper leaves much re- 

 duced. A.fulgens. 

 Herbage atomiferous-glandular or glandless; 



upper leaves but little reduced. A. aurantiaca. 



Pappus fuscous, subplumose. 



Upper surface of leaves glabrous, sticky. 



Stem leaves ovate or ovate-oblong. A. amplexicaulis. 



Stem leaves lanceolate or lance-oblong. A . macounii. 



Upper surface of leaves pubescent. 



Pubescence sparse, pilose. A. aspera. 



Pubescence dense, short. A. mollis. 



* Arnica cordifolia Hook. Erect from horizontal rootstocks, 2(MK) cm. high, 

 sparsely pubescent; basal leaves ovate or orbicular, deeply cordate, dentate, 

 acute or obtuse, 5-10 cm. long, on petioles about as long; cauline usually 2 

 , pairs, less broad, the short petioles margined; heads long-peduncled; involucres 

 turbinate-campanulate, 15-20 mm. high, viscid-pubescent, the linear-lanceolate 

 tegules acute; ray-flowers 8-12, yellow, 2-3 cm. long; akenes pubescent. 

 i L^U. In the mountains at low altitudes, rare in our limits, but common east of 

 the Cascade Mountains; upper Nisqually Valley, Allen. 



