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NEW YORK STATE MUSEUM 



Sinus broad and shallow 



Broader leaves orbicular-cordate, their teeth and the 

 inflorescence-leaves inconspicuous . .12 A. i a n t h i n u s 

 Broader leaves reniform, sharply incised ; some inflorescence- 

 leaves conspicuous 13 A. v i o 1 a r i s 



Sinus rather deep and narrow; broader leaves ovate-cordate, 



sharply serrate 14 A. m u 1 1 i f o r m i s 



Rays blue or purple; plants not glandular; bracts of the involucre appressed 

 or nearly so; rays eight to twenty 

 Leaves all entire, or nearly so, thick and finn, rough-puberulent on 



both sides, the upper bractlike 1 5 A. a z u r e u s 



Leaves nearh' all sharply serrate and thin 



Heads 2 to 3 Hues high, numerous; bracts obtuse or bluntish 



Leaves rough; petioles not wing-margined; bracts appressed, . 



16 A. c o r d i f o 1 i u s 



Leaves smooth, or nearly so; petioles, or some of them 



wing-margined 1 7 A. 1 o w r 1 e a n u s 



Heads 4 to 5 lines high, usually few; bracts acute or acuminate. . . . 



18 A. 1 i n d 1 e y a n u s 

 Heads 3 to 5 lines high, mmierous; bracts acute or acuminate; 



stems glabrous or nearly so ; bract-tips spreading 



19 A. s a g i 1 1 i f o 1 i u s 

 B No cordate and petioled leaves; those of the stem, or some of them, with more or less 

 cordate or auricled clasping bases (only slightly auricled in A. t a r d i- 

 floras and sometimes in A. 1 a e v i s) 

 Stem rough, or hirsute-pubescent 



Leaves, at least the lower, sen-ate; stem hispid-pubescent; bracts glabrous 



or ciHate 20 A. p u n i c e u s 



Leaves entire, oblong, linear or lanceolate 



Heads one-half to i inch broad, the linear to linear-lanceolate leaves 

 but slightly clasping; bracts hispid or ciliate 



21 A. a m e t h y s t i n u s 

 Heads i to 2 inches broad; leaves sessile and strongly clasping 



Stems hirsute; leaves lanceolate; involucre hemispheric; bracts 

 yiscid 22A. novae-angliae 



