238 COMPOSITE FAMILY. 



XX Leaves with feio or many prominent teeth. 

 + Leaf base distinctly clasping. 



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

 lanceolate, rough above and smooth beneath, narrowed into a long entire 

 portion which is suddenly dilated into an auricied base ; heads on short 

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



A. puniceus, Linn. Tall and stout, 3°-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 wing-petiole-like, not auriculate. 



A. pdtiilus, Lam. Glabrous or nearly so, \°-AP ; 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. X. Eng. 



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

 thickish, 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 (rnostly narrower) not cordate-clasping, nor with wing-sessile 



bases. 



X Involucre and branchlets viscid or glandular. 



+ Leaves rigid and obtuse. 



A. grandifl6ru8, Nutt. Slender, hispid, l°-3°; leaves very small, 

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



+ -I- 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. spectdbilis, Ait. Roughish, stout, l°-2°, leaves oblong-lanceolate 

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

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

 Mass. to Del. 



X X Not viscid or glandular {except, perhaps, in A. surculosus). 



+ Badical leaves tapering into margined petioles. 



— Leaves entire or obscurely serrate. 



A. surcul6su8, Michx. Low (1° or less), with filiform rootstocks; 

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

 light purple. Near coa.st, N. J., S. 



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

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



N. J., S. and W. , , , 



' — Leaves 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. 



+ + Badical leaves not with margined petioles. 



- Involucral scales squarrose or with prominently spreading green tips ; 

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



A. ametbystinus, Xutt. Tall and erect, 2°-5°, somewhat hirsute, 

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

 Mass. to la. 



