202 COMPOSITE., (composite family.) 



*- ■<- Lowest leaves conspicuouslij serrate : heads small. 



23. A. COrdifolius, L. Stem commonly smooth, raccmose-paniclcd above; 

 leaves smootli, or ruuyli above and pul)escent beneath, all cordate, serrate, and 

 slender-pctioled, or the uppermost on short winged petioles, or sessile and entire ; 

 heads very numerous in panicled racemes ; scales of the obconical involucre loose- 

 ly imbricated, with obtuse or slightly pointed green tips. — Open woods, in the 

 upper districts. — Stem l°-3° high. Leaves commonly thin. Rays pale violet. 



24. A. sagittifolius, WlUd. Stem nearly smooth, racemose-branched 

 above ; leaves ovate-lanceolate, acuminate, pubescent ; the lowest cordate, on 

 long and mostly margined petioles ; the upper abruptly contracted into a winged 

 petiole ; those of the branches lanceolate, acute at botli ends, entire ; heads in 

 dense compound racemes ; scales of the oblong involucre rather loosely imbri- 

 cated, linear-subulate, the tips green and spreading. (A. paniculatus, JE^/Z.) — 

 Rich woods, Florida and northward. — Stem 2° -3° high. Heads more crowded 

 than tliose of the preceding. Rays purple. 



***** Leaves linear or lanceolate, entire, sessile ; radical ones spatulate-lanceo- 

 late, serrate: heads small and numerous, racemed: scales of the involucre in several 

 rows, rigid, with spreading or recurved green tips. 



25. A. ericoides, L. Smooth ; stem much branched ; leaves linear-lance- 

 olate, acute at each end ; those of the branches subulate ; heads racemose, mostly 

 on one side of the spreading branches ; scales of the involucre broadest at the base, 

 with acute or subulate tips. — Var. a'ILLOSus. Stem and broader leaves rouj^h- 

 liairy, and the smaller heads in shorter and more dense racemes. — Var. i'i.aty- 

 riiYLLLS. Stem (3° -4°) and larger leaves clothed with soft white hairs ; lu-ads 

 larger. — Dry soil, Florida, and northward. — Stem 1° - 2° high. Rays white 

 or pale blue. 



26. A. mvdtiflorus, Ait. Whitish-pulicscent; stem very leafy, and much 

 branched ; leaves linear, obtuse at each end, often bristlc-])ointed, spreading or 

 recurved, the upper ones sessile or somewhat clasping; heads densely racemose 

 on the short and very leafy branches, or sometimes solitary at their summits ; 

 scales of tlie involucre broadest at tlie apex, obtuse or short-pointed. — Dry 

 sterile soil, in the upper districts. — Stem l°-2° high. Leaves about 1' long. 

 Rays white. 



****** Leaves linear, lanceolate, or ohlong, sessile, usually narrowed at the 

 hasfi. : heads small or middle-sized : scales of the involucre membranaceous, with aj>- 

 jjressed or slightlg spreading tips : rays pale purple or while. 



-t- Heads small. 



27. A. racemosus, Ell. Rough-pubescent ; stem much branched, bear- 

 ing the small heads in a spiked raceme near the summit of the slender erect 

 branches ; leaves linear, sessile, rigid ; scales of involucre smooth, linear-subu- 

 late; the inner ones as long as tiic disk; rays very short. — Damp rich soil, 

 Paris Island, Soiilh Carolina. — Stem 2° high. Rays pale ]>urple. 



28. A. Baldwinii, Torr. & Cray. Rough-pubescent ; Htcm slindcr, pnni- 

 rled above, hearing the solitary or loosely racemose heads on the slciulcr branch- 

 lets; leaves very r()ii;'li, entire ; the lowest ovate, on slender margined petioles, 



