238 coMrosiTE family. 



X X Leaves with few or many prominent teeth. 

 + Leaf base distinctly clasping. 



A. prenanthoides, Muhl. l°-3°, hairy above in lines ; leaves ovate- 

 lanceolate, rou,t;h above and smooth beneath, narrowed into a long entire 

 portion which is suddenly dilated into an auriclcd base ; heads ou short 

 divergent peduncles, pale violet or whitish. Along streams, N. 



A. puniceus, Linn. Tall and stout, y°-7°, rough-hairy all over (or in 

 some forms smoothish below) ; leaves oblong-lanceolate and but little 

 narrowed at the base ; heads subsessile, in a panicle or thyrse ; flowers 

 large, purple to white. Variable. N. ; S. to Ga. 



+ + Leaf base icing-petiole-like, not auriculate. 



A. pdtulua. Lam. Glabrous or nearly so, l°-4° ; leaves ovate or 

 oblong- lanceolate, serrate in middle, narrowed at both ends, the lower 

 ones into a winged petiole ; heads loosely panicled, violet or white ; scales 

 unequal. N. Eng. 



A. EUidttii, Torr. & Gray. Stem (2"-3°) minutely pubescent ; leaves 

 thickisli, oblong-lanceolate, appressed-toothed, tapering into a narrow, 

 petiole-like contraction ; heads numerous, corymbose-paniculate, purple ; 

 scales nearly equal. S. C. to Fla. 



o o Leaves {mostly narrower) not cordate-clasping., nor icith wing-sessile 



bases. 



X Livohtcre and branchlets viscid or glandidar. 



+ Leaves rigid and obtuse. 



A. grandifl6rus, Nutt. Slendei", hispid, l°-3° ; leaves very small, 

 linear; rays violet, long. Handsome. Va., S. 



+ + Leaves soft and acute. 



A. oblongif61ius, Nutt. Minutely glandular-puberulent, l°-2° ; leaves 

 narrow-oblong or lanceolate, mucronate, somewhat clasping; flowers 

 rather small, purple. Banks, N. 



A. spectabilis, Ait. Koughish, stout, l°-2°, leaves oblong-lanceolate 

 or spatulate-oblong, mostly entire ; heads few, large and showy (purple), 

 the scales with the upper half herbaceous and spreading. Near the coast, 

 Mass. to Del. 



X X Xot viscid or glandular {except, perhaps, in A. surcidosus). 



+ Badical leaves tapering into margined petioles. 



- Leaves entire or obscurely serrate. 



A. surculdsus, Michx. Low (1° or less), with filiform rootstocks; 

 leaves linear or lanceolate, rigid ; heads medium-sized, few or solitary, 

 light purple. Near coast, N. J., S. 



A. gracilis, Nutt. Leaves oblong-lanceolate and small ; scales coria- 

 ceous and whitish, with short-ovate green tips ; heads few. Pine barrens, 

 N. J., S. and W. _ _ ^^^^^^ sharply serrate. 



A. rddula. Ait. Smooth or lightly hairy, leafy, l°-3° ; leaves oblong- 

 lanceolate, pointed, rugose, rough both sides, very closely sessile ; scales 

 with short, spreading green tips ; flowers light-violet. N. Eng. to Del. 



-f -I- Badical leaves not with margined jietioles. 



— Involncral scales squarrose or with prominently spreading green tips; 

 leaves small, linear and entire ; heads small and racemose. 



A. amethystinus, Nutt. Tall and erect, 2°-5°, somewhat hirsute, 

 branchy ; loaves lax ; scales with only the tips spreading ; rays light blue. 

 Mass. to la. 



