ANALYTICAL KEY TO GENERA OF COMPOSITAE* 1 043 



PAGE 



h Leaves very large, reniform or orbicular, basal Petasites 1021 



hh Leaves smaller, cauline, and basal. 

 i Heads 6-35 mm. broad; rays mostly longer than the diameter of 



the disk Erigeron 966 



ii Heads 4 mm. broad; rays not longer than diameter of disk. 



Leptilon (in Erigeron) 969 

 ggg Involucral bracts in 3-5 series. 

 h Involucral bracts firm; rays few, white; leaves spatulate, linear, or 



obovate, nearly or quite entire Sericocarpus 945 



hh Involucral bracts membranous. 



i Pappus distinctly double; inner bristles long, outer shorter. 

 j Leaves lanceolate, ovate or obovate; rays white. 



Doellingeria (in Aster) 970 



jj Leaves narrowly linear; rays violet lonactls (in Aster) 971 



U Pappus single. 



j Disk-flowers turning red r purple, or brown Aster 946 



jj Disk-flowers permanently white; leaves subulate-spatulate, 



crowded, rigid Leucelene 965 



