121 



89a. Leaves decurrent on the stem Cudweed, Gnaphalium decurrens. 

 89b. Leaves not decurrent on the stem 



Cudweed, Gnaphalium polycephalum. 



90a. Twining vine (flowers white, summer) 



Hemp Weed, Mikania scandens. 



90b. Not twining or climbing 91. 



91a. Involucral bracts deeply fringed at the tip (flowers purple, blue, 



or rarely white, summer; 36 dm. high) 92. 

 91b. Involucral bracts entire or nearly so 93. 



92a. Upper leaves linear or narrowly lanceolate 



Corn Flower, Centaurea cyanus, 

 92b. Upper leaves oblong or oblong-lanceolate 



Knapweed, Centaurea nigra. 



93a. Pappus none or a short ring or crown (5 10 dm. high; flowers 

 yellow, summer) 



Costmary, Chrysanthemum balsamita var. tanacetoides. 

 93b. Pappus of 24 stiff awns (215 dm. high; flowers yellow, late 



summer) (Bur Marigold) 130. 

 93c. Pappus of hairs or bristles 94. 



94a. Leaves linear or narrowly lanceolate, entire; heads never 



in a large flat-topped cluster 95. 

 94b. Leaves not linear 99. 



95a. Heads showy, purple, in a long spike or raceme (late summer) 



(Blazing Star) 96. 

 95b. Heads not showy, in a loose panicle or raceme ,240b. 



96a. Involucral bracts rounded at the tip, appressed (5 15 dm. 



high) 97. 

 98b. Involucral bracts pointed (36 dm. high) 98. 



97a. Heads 8 12-flowered Blazing Star, Liatris spicata. 



&7b. Heads with 25 flowers or more Blazing 1 Star, Liatris scariosa, 



98a. Involucral bracts long-acuminate, spreading 



Blazing* Star, Liatris squarrosa, 

 98b. Involucral bracts mucronate, appressed 



Blazing* Star, Liatris cylindracea. 



99a. Flowers yellow (28 dm. high) 172b. 



99b. Flowers bright-red or purple, in flat-topped clusters (8 20 dm. 

 high; late summer) (Ironweed) 100. 



99c. Flowers blue (3 8 dm. high; late summer) 



Mist Flower, Eupatorium ccelestinum. 



99d. Flowers flesh-color, pink, cream-color, or white (flowers in sum- 

 mer) 103. 



lOOa. Leaves glabrous beneath or minutely pubescent; heads 



15 30-flowered 101. 

 lOOb. Leaves tomentose beneath; heads 30 50-flowered 102. 



