ASTER 259 



y. Involucres and peduncles not glar-dular- 



hairy 

 (x) Outer bracts as long or longer than 



the inner, often leaf-like A. folidceus 



(y) Outer bracts shorter than the inner, 



not leaf-like 

 m. Bracts more or less hairy on the 



back 



(m) Stems 2-6 in. high; leaves 

 bristly ciliate, less than 1 

 cm. long ; heads single at the 

 end of each branch, 1-1.5 

 cm. wide; rays white, 12-15 A.ericoides 

 (n) Stems 1-4 ft. high, leaves 

 somewhat ciliate, 1-5 cm. 

 long ; heads not single on the 

 branches 



r. Bracts pointed with a short 

 white bristle; heads usually 

 many in a panicle; invol- 

 ucre 4-8 mm. high; rays 

 mostly white, sometimes 

 bluish A. multiftorus 



s. Bracts not bristle-pointed; 

 heads few in a cyme-like 

 cluster; rays violet A. griseus 



n. Bracts smooth on the back 



(m) Stems and peduncles smooth 

 r. Rays white; leaves linear or 

 lance-linear; stems 1-2 ft. 

 high 



(r) Heads few-several in a 

 flat-topped cluster ; stems 

 simple A. ptarmicoides 



(s) Heads many in a panicle; 



stems much branched A. Porteri 

 s. Rays lilac to blue-purple; 

 leaves lance-oblong to spatu- 

 late or ovate, upper with 

 clasping base; stems 1-5 ft. 

 high A. levis 



