134 



248a. Stems in clusters; leaves rigid, linear, with 1 vein; flowers 

 blue Aster, Aster linariifolius. 



248b. Stem solitary; leaves not rigid; flowers rose-pink 



Aster, Aster nemoralis. 



249a. Heads solitary at the end of minutely leafy branchlets; leaves 

 linear Aster, Aster dnmosus. 



249b. Heads in flat-topped clusters; leaves lanceolate or broader 

 250. 



249c. Heads in more or less one-sided racemes 251. 



249d. Heads in panicles or irregular clusters 253. 



250a. Leaves rigid, linear-lanceolate Aster, Aster ptarmicoides. 

 250b. Leaves not rigid, lanceolate Aster, Aster umbellatus. 

 251a. Leaves lanceolate, sharply serrate 252. 



251b. Leaves linear or narrowly linear-lanceolate, only the larger 

 ones with a few teeth near the middle Aster, Aster yimineus. 

 252a. Stem glabrous or somewhat pubescent 



Aster, Aster lateriflorus. 

 252b. Stem woolly with long hairs 



Aster, Aster lateriflorus Tar. hirsuticaulis. 

 253a. Bracts narrow,, approximately equal in length 



Aster, Aster longifolins. 

 253b. Bracts of several lengths, the outer successively shorter 254. 



254a. Heads 10 15 mm. wide, including the rays 



Aster, Aster tradescanti. 



254b. Heads 15 25 mm. wide, including the rays 255, 



255a. Bracts with conspicuous dilated or subrhombic tips 



Aster, Aster salicifolius. 



255b. Bracts without conspicuous green tips 256. 



256a. Rays purple or rose; bog plant with linear leaves 



Aster, Aster jimceus. 



256b. Rays white, or slightly tinged with blue; leaves oblong to 

 narrowly lanceolate -. Aster, Aster paniculatns. 



