302 NEW YORK STATE MUSEUM 



Sinus broad and shallow- 

 Broader leaves orbicular-cordate, their teeth and the 

 inflorescence-leaves inconspicuous. .12 A. ianthinus 

 Broader leaves reniform, sharply incised ; some inflorescence- 

 leaves conspicuous 13 A. violaris 



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



sharply serrate 14 A. multiformis 



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 firm, rough-puberulent on 



both sides, the upper bractlike 15 A. azureus 



Leaves nearly all sharply serrate and thin 



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



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



16 A. cordifolius 

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



wing-margined 17 A. 1 o w r i e a n u s 



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



18 A. 1 i n die y anus 

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



stems glabrous or nearly so ; bract-tips spreading 



19 A. sagittifolius 

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

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

 f 1 o r u s and sometimes in A. 1 a e v i s) 

 Stem rough, or hirsute-pubescent 



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



or ciliate 20 A. puniceus 



Leaves entire, oblong, linear or lanceolate 



Heads one-half to 1 inch broad, the linear to linear-lanceolate leaves 

 but slightly clasping; bracts hispid or ciliate 



21 A. amethystinus 

 Heads 1 to 2 inches broad ; leaves sessile and strongly clasping 



Stems hirsute; leaves lanceolate; involucre hemispheric; bracts 

 viscid 22 A.novae-angliae 



