COMPOSITE 



153 



7. H. pamUus, Nutt. 



Stem simple, 1-2 ft. high; leaves lanceolate to ovate, in 5-7 pairs on 

 short, margined petioles; the whole plant rough and hairy; heads few, on 

 peduncles; bracts of the involucre in about 3 rows, sharp, whitish. Rooky 

 Mts. and adjacent plains and river valleys. ' 



29. COREOPSIS. 



Heads many-flowered, radiate; rays 5-8, neutral, 3-toothed; 

 involucre double, the bracts of the outer row mostly shorter than 

 those of the inner; receptacle flat and chaffy. Annual or perennial 

 herbs with mostly opposite leaves and large showy heads on long 

 peduncles. 



1. C. tinctdria, Nutt. 



Annual, glabrous, 1-2 J ft. high; leaves once or twice pinnately divided; 

 rays yellow, brown at the base, or more rarely all brown. Damp places, 

 W. Sask. and Alta. , 



30. BIDENS. Bub-Mariqold. 



Heads many-flowered, 

 usually radiate ; rays few or 

 absent, neutral; involucre 

 double, the outer row of 

 bracts large and often leaf- 

 like; receptacle chaffy, the 

 chaff falling with the 

 achenes; pappus of 2-6 per- 

 sistent barbed awns. An- 

 nual or perennial herbs with 

 .opposite leaves and yeUow 

 flowers. 



1. B. fronddsa, L. 



Annual; stem erect, 1-3 ft. 

 high, almost glabrous, fre- 

 quently tinged with purple; 

 leaves thin, at least the lower 

 pinnately 3-S-parted; leaflets 

 lanceolate to oblong, sharply 

 serrate, usually pubescent be- 

 neath; heads numerous, with 

 very inconspicuous rays or 

 none; corollas of the disk- 



' Fig. 88. — Bidens f rondosa. 



