194 COMPOSITE. (COMPOSITE FAMILY.) 



***** Leaves none of them heart-shaped ; those of the sterr* tappnw/ at 

 sessile; involucre imbricated ; the scales of unequal length, ivith sliorl and narrow 

 appressed or rather loose greenish tips : heads small or middle-sized : rays white or 

 pale bluish-purple. 



- Heads small. (Involucre \' - % long.) 



18. A. dlimosilS, L. Smooth or nearly so, raccmoscly compound, the 

 Kattered heads mostly solitary at the end of the tpreuding branchlets ; leaves linear 

 or the upper oblong, crowded, entire or slightly serrate, with rough margins ; 

 scales of the closely imbricated involucre linear-spatulate, obtuse, in 4-6 rows. 

 Thickets, in dry or moist soil; common. A variable species, l-3 high, 

 loosely branched, with small leaves, especially the upper, and an inversely con- 

 ical or bell-shaped involucre, with more abrupt green tips than any of the sue 

 cecding. Kays pale purple or blue, larger than in the next. Runs into several 

 peculiar forms. 



19. A Trsiclcscitnti, L. Smooth or smooth ish ; the numerous heads dosdy 

 racemcd along one side of the erect-spreading or diverging branches ; loaves 

 lanceolate-linear, elongated, the larger ones remotely serrate in the middle with 

 fine sharp teeth; scales of the involucre narrowly linear, acute or acutish, imbricated 

 in 3 or 4 rows. Var. FRAoiLis has the leaves entire or nearly so, except the 

 lowest, and the heads more scattered. Moist banks, &c., very common. 

 Stems 2 -4 high, bushy: heads very numerous, smaller than in the last. 

 Rays white or nearly so. 



20. A. miser, L., Ait. More or less hairy, much branched; the branches 

 usually diverging, bearing racemose often scattered heads; leaves lanceolate or ob- 

 long-lanceolate, tapering or pointed at each end, sharply su-nitc in the middle; 

 ft d'es of the involucre linear, acute or rather obtuse, imbricated in 3 or 4 rows. 

 Thickets, fields, &c., very common, and extensively variable. Leaves larger 

 than in cither of the preceding (2' 5') ; the involucre intermediate between them, 

 us to the form of the scales. Rays mostly short, pale bluish-purple or white. 



- Heads middle-sized. (Involucre y~ ' lomj.) 



21. A. Simplex, Willd. Smooth or nearly so (3 -6 high), much 

 branched; the branches and scattered heads somewhat corymbose at the summit; 

 It a rex lanceolate, pointed, the lower serrate ; scales of the /;?roA '/>< linear-awl-shaped, 

 loosely and sparingly imbricated. Shady moist banks, common. Pi ay* pale. 

 Approaches in its different forms the preceding and the two following. 



22. A. tenilifoliffS, L. Nearly smooth ; stem much branched (2 -3 

 high) ; the heads somewhat paniclcd or racemcd ; lea res narroirly lanceolate, 

 taperiny into a lon<j slender point (2' -6' long), with rough margins, tin- l<><r<r xuinc- 

 what serrate in the middle ; scales of the hemispherical involucre linear-un-1-slic.ind, 

 ivry slender-pointed, numerous, closely imbricated. Low grounds, New York to 

 Wisconsin, and southward. Rays short and narrow, pale purple or whitish. 



23. A. cdrncus, Nees. Smooth, or the branches rougher pubescent; 

 lanceolate, somewhat pointed, or the upper short and partly clasping; 



heads racemose along the ascending leafy branches ; scn/<* <>f d- obovate moo* 

 lucre, lauctuldti , abruptly ai.nte, <7o.sWy imbricatttd, Moist soil ; common. Leaven 

 firm in texture, smooth, or rough above. Rays rather large, bluish, purplish 



