164 COMPOSITE. 



f Leaves of different forms. 



11. A. cordifolius Linn.: stem often flexuous, hairy, racemose, panicu- 

 late at the summit ; lower leaves petiolate, cordate, acuminate, sharply ser- 

 rate, hairy beneath ; upper becoming gradually smaller ; heads in divari- 

 cate panicles; scales of the involucre closely imbricate. A. paniculate 

 Ait. A. heterophyllus WiUd. 



Woods. Can. to Geor. Aug. Oct. %.. Stem. 2 4 feet high, often hairy 

 or roughish above. Leaves varying from broad- to narrow-ovate, the upper 

 small. Heads small, crowded on the spreading branches ; rays pale purple or 

 whitish ; disk yellowish, changing to purple. Heart-leaved Aster. 



12. A. sagittifolius Willd. : stem smooth, racemose-compound above ; 

 leaves ovate-lanceolate, acuminate, slightly ciliate; lower cordate-sagit- 

 tate, on slender narrowly winged petioles, serrate ; upper linear-lanceolate, 

 acuminate at each end, sessile and usually entire ; heads in dense com- 

 pound racemes, on short peduncles ; scales of the involucre closely imbri- 

 cate, linear-subulate. A. paniculatus MuJd. not of Ait. 



Dry woods. Yates county, N. Y. Dr. Sartwell. S. to Geor. W. to Miss. 

 Aug. Oct. QJ-. Stem 2 4 feet high, with numerous erect and rigid branches 

 above. Heads small, in crowded racemes ; rays pale purple ; disk yellow. 



Arrow-leaved Aster. 



13. A. undulatus Linn. : stem grayish-pubescent ; leaves ovate or ovate- 

 lanceolate, rough above, somewhat woolly -pubescent beneath, acute, the 

 margins undulate or crenate- serrate ; lower cordate and on slightly mar- 

 gined and often dilated petioles ; uppermost smaller, cordate, clasping ; scales 

 closely imbricate. A. diversifolius Mich. 



Dry woods. Nearly throughout the U. S. Torr. $ Gr. Sept., Oct. r l\.. 

 Stem 2 3 feet high, pyramidally branched at the summit. Heads middle sized, 

 the branches and pedicels pubescent ; rays violet-blue ; disk yellow, at length 

 purple. Wave-leaved Aster. 



j-f Leaves all nearly of a similar form. 



14. A. prenanthoides Muhl. : stem and branches hairy in lines, corym- 

 bose-paniculate at the summit ; leaves spatulate-lanceolate or oval-lanceo- 

 late, incisely serrate in the middle, acuminate, cordate or auriculate-clasp- 

 ing at base, scabrous above, smooth beneath ; scales of the involucre linear, 

 squarrose-spreading at the apex. 



Moist woods. Western N. Y. and Penn. W. to Ken. Sept., Oct. 7|_. Stem 

 1 4 feet high, sparingly branched. Heads above middle size, rather few. clus- 

 tered towards the end of the branches ; rays violet or lilac, sometimes nearly 

 white. Prenanthes-like Aster. 



15. A. puniccus Linn. : stem hispid, paniculate above ; leaves oblong- 

 lanceolate, clasping-auriculate at base, acuminate, coarsely serrate in the 

 middle, scabrous above, smoothish beneath ; scales of the involucre loosely 

 imbricate, linear-subulate, nearly equal. 



Wet grounds. Can. and N. S. Sept. Nov. %..Stem 36 feet high, hispid 

 with strong prickly hairs, mostly purple. Leaves often rough on both sides and 

 sparingly serrate. Heads above the middle size, on nearly naked pedicels ; rays 

 violet purple, sometimes pale. Red-stalked Aster. 



16. A. astivus Ait. : stem branching from near the base, erect, hispid ; 

 branches lax, hairy, with a head at the extremity of each : leaves lanceo- 



