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COMPOSITiE 143 



1. C. villdsa, Nutt. 



Whitish-pubescent throughout; stems much branched and somewhat 

 spreading; leaves narrowly oblong; heads terminating the short branches; 

 achene villous. Dry prairies, Man.-Alta., July-Sept. 



2. C. hispida, (Hook.) Nutt. 



More sparsely and coarsely hairy than the preceding, sometimes sticky; 

 stem erect and simple, or tufted and decumbent, seldom more than 1 ft. 

 high ; leaves oblanceolate to spatulate, the basal tapering into petioles ; 

 heads smaller than in the preceding, rather numerous, arranged in a spread- 

 ing corymb; acheues hairy. Dry gravelly soil, Sask. 



12. ARNICA 



Heads many-flowered, radiate; rays pistillate, spreading; in- 

 volucre of 1 or 2 rows of equal bracts; receptacle flat, not chaffy; 

 pappus a single row of rigid rough bristles. Perennial herbs with 

 simple stems, opposite leaves, and solitary or clustered heads of 

 showy yellow flowers. 



1. A. cordifdlia, Hook. 



Stem 1-2. ft. high, somewhat hairy; root leaves orbicular or. nearly so, 

 cordate at the base, petioled; stem leaves 1-3 pairs, oblong, sessile or nearly 

 so; heads 1-8 on slender peduncles; rays 12-16. Eastern slope of Rocky 

 Mts. 



2. A. latifolia, Bongard. 



Slender, 8-16 in. high, villous or nearly glabrous; lower leaves ovate, 

 more or less dentate, on short petioles; heads large and showy; bracts and 

 achenes usually pubescent. Rocky Mts. 



3. A. foliosa, Nutt. 



Stem slender, 1-3 ft. high, erect, leafy, somewhat glandular-pubescent, 

 from a creeping rootstock; leaves 6-10 pairs, ascending, lanceolate, entire 

 or nearly so, the lower petioled ; petioles slender, uniting Jind sheathing the 

 stem at the base; heads 1-several, if the latter, arranged in a sort of raceme, 

 the lateral heads smaller. Thickets and damp prairies, Sask. and Alta. 



4. A. ffllgens, Pursh. 



Stem simple, erect, 8-16 in. high, slightly hairy towards the top; leaves 

 rather thick, the basal spatulate, the upper linear, mostly entire, 3-nerved, 

 the bases of the stem leaves sometimes uniting around the stem; heads 

 conspicuous, solitary or few, mostly on long peduncles; achenes mostly 

 pubescent. {A. pedunculata, Rydb.) {A. alpina, Murr.) Prairies, Man.- 

 Alta., and far northward. 



