164 SELECTED WESTERN FLORA 



flowers orange-yellow; outer bracts of the involucre leaf-like and much 

 larger than the narrow inner bracts ; awns of the achene slender and barbed 

 downwardly. Moist places, Man.-Alta. 



2. B. vulgata, Greene. 



Resembling the preceding but usually much taller; rays generally pres- 

 ent, yellow; outer bracts of the involucre linear or spatulate, ciliate, the 

 inner short^er andrather broad. Moist places, Man.-Alta. 



3. B. cernua, L. 



Annual, glabrous, mostly erect; leaves oblong to lanceolate, sessile, 

 coarsely serrate; heads numerous, globular, nodd^ng; rays 6-10 or none, 

 short; outer bracts ciliate, often large and leaf -like; pappus usually 4 

 barbed awns. Marshy places, N. Man.-Alta. 



31. ACHILLEA. Yaeeow. 



Heads small, many-flowered, radiate; ray-flowers few, pistillate; 

 involucre of 2 or 3 series of narrow appressed bracts with thin dry 

 margins, the outer row shorter; receptacle chaffy; pappus none. 

 Perennial herbs with finely divided leaves and numerous heads of 

 white or pink flowers in flat-topped clusters ending the stems. 



1. A. Millefolium, L. Common Yabrow. 



Stem usually simple, very leafy; leaves finely dissected; flower clusters 

 large; flowers white or rarely pink. Dry prairies, common. 



32. GAlLLARDIA. 



Heads many-flowered, radiate; rays toothed, neutral, or rarely 

 pistillate; receptacle convex, usually bristly; involucre in 2 or 3 

 rows, the tips of the bracts spreading : achenes top-shaped, hairy at 

 the base; pappus 5-10 scales tipped with awns. Coarse perennial 

 herbs with showy heads of yellow flowers on long peduncles. 



1. G. aristata, Pursh. 



Perennial, hairy, sometimes woolly near the flowers; leaves firm, pubes- 

 cent, varying in shape, and either entire or pinnatifld; rays yellow, often 

 with a darker tinge at the base; disk purple or brown. A variable species, 

 dry prairies, Man.-Alta. 



33. HELENIUM. Sneeze Weed. 



Heads radiate ; the ray-flowers fertile or neutral, 3-5-lobed; disk- 

 flowers perfect, their tubes 4 or 5-toothed; achenes top-shaped, 

 ribbed; pappus of 5-8 scales. Erect branching herbs with alter- 



