COMPOSITE. 165 



.ttte, ciliate, subclasping; radical, appressed-serrate ; cauline entire ; involu' 

 ere narrow, obconic ; inner scales subulate. 



Dry woods. N. Y. and Penn. Pursh. July— Sept. %.—Stem 2 feet high. 

 Heads middle-sized ; rays blue. A doubtful speeies. Summer Aster. 



17. A. Novi-Belgii Lmn. : stem terete, smooth, often somewhat glau- 

 ecus ; branches rigid, racemose or corymbose ; leaves lanceolate, sub- 

 clasping, acute, scabrous on the margin ; lower serrate in the middle ; 

 involucre loosely imbricate ; scales linear-lanceolate, acuminate. A. Novi- 

 Belgii a.iid Jloribundus Willd. 



Moist grounds. N. S. ? S. to Geor. W. to Miss. Aug.— Oct. %.—Stem 1-A 

 feet high. Flowers middle-sized ; rays pale purple. Glaucous Aster. 



18. A. simplex Willd. : stem smooth, racemose-decompound ; branches 

 subcorymbose at the summit ; leaves lanceolate, acuminate, very smooth, 

 scabrous on the margin; the lower serrate; involucre loosely imbricate, 

 the scales linear-subulate. 



Margins of swamps. Can. and throughout the U. S. Aug. — Oct. %. — Stem 

 from 2 — 6 feet high, pubescent in lines. Leaves sessile or a little clasping. 

 Heads middle-sized, loosely racemose or a little crowded on the short branch- 

 lets ; rays pale purple ; disk yellowish, at length purple-brown. A very varia- 

 ble species. Simple A§ier. 



19. A. laxus Willd. : stem smooth, racemose-compound or decompound, 

 the branches loose and subcorymbose at the top, the branchlets elongated ; 

 leaves narrow-lanceolate, acuminate, rough an the margin ; the lower ser- 

 rate ; those of the branches Unear, obliquely spreading ; scales of the in- 

 volucre loose, linear, reflexed at the tips. 



Sandy soils. Mass. and N. Y. Sept., Oct. %. — Stem about 3 — 4 feet high, 

 with numerous rigid branches, purplish. Heads loosely corymbose ; rays very 

 numerous, purplish-blue. Loose Aster. 



20. A. praaltus Poir : stem somewhat hairy, racemose-paniculate or co- 

 rymbose at the summit ; leaves lanceolate, somewhat clasping, acute, nearly 

 entire, rough on the margin, smooth and somewhat shining above ; lower 

 narrowed at base ; scales of the involucre loosely imbricate, linear-lanceo- 

 late, acute, often with spreading tips. A. salicifolius Pursh. 7 



Moist woods. N. H. to Penn. Aug.— Oct. %.—Stem 1—5 or 6 feet high, 

 branched near the summit. Heads large and showy ; rays reddish-blue ; disk 

 changing to purple. Tall Aster. 



21. .4. TradescantiLinn.: stem smoothish, racemose-compound ; branches 

 virgate, the branchlets*. often unilateral ; leaves sessile, smooth, v^dth rough 

 margins ; cauline linear-lanceolate, acuminate, remotely and coarsely ser- 

 rate ; those of the branches becoming smaller, entire, spreading and mucro- 

 nate ; scales of the involucre imbricated in 3 — 4 series, narrow-hnear, acute. 



var. fragilis Torr. <f« Gr. : cauline leaves, except the lowermost, mi- 

 nutely appressed, serrulate or entire, usually shorter ; ho^ids more scattered 

 on the branchlets. A. fragilis Willd. A. tenuif alius Ell. not of Linn. 



Fields and dry swamps. Mass. to Ala. and Louis. Aug. — Oct. %. — Stem 

 2 — 4 feet high, bushy, with numerous branches, at length widely spreading. 

 Heads small, numerous, on branchlets disposed in a racemose manner; rays 

 pale purple, almost white ; disk becoming purplish. TradescanVs Aster.' 



22. A. dumosus Linn. : stem smooth or slightly scabrous, racemosely 



