202 C'o.Mi't).srr.F.. (coMrosiTK ia.milv.) 



•*- ■*- f.owest hares coiispicuousli/ aerrale : heads small. 



23. A. COrdifolius, I^. Sam commonlv smooth, raccmose-panicltdnhovc; 

 loaves smooth, or luugli above and pubescent beneath, all cordate, serrate, and 

 slender-petioled, or the uppermost on short winged ])ctioles, or sessile and entire; 

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

 ly imbricated, with obtuse or sligiitly pointed green ti|)S. — Open woods, in the 

 upper distiicts. — Stem 1 ° - 3° high. Leaves commonly thin. ■ Kays pale violet. 



24. A. sagittifolius, Willd. 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 both 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, /?//.) — 

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

 than those of t!ic preceding. Rays jjurple. 



***** Jifavcs linear or lanceolate, entire, sessile ; radical ones spatidate-lancro- 

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

 rows, rigid, with s]>reading or recurved green tips. 

 23. A. ericoides, L. Smootli ; stem much branched ; leaves lincar-lance- 

 olatc, 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. villosus. Stem and broader leaves rough- 

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

 PHYLLUS. Stem (3° -4°) and larger leaves clothed with soft white hairs ; heads 

 larger. — Dry soil, Florida, and northward. — Stcni l°-2° high. Rays white 

 or pale blue. 



26. A. multiflorus, Ait. "Wliitish-pubescent ; stem very leafy, and nnicli 

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

 rccuncd, the upper ones sessile or somewhat clasping ; heads densely i-acemose 

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

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

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

 Rays white. 



****** Leaves linear, lanceolate, or ohlong, sessile, itsualli/ narrowed at the 

 base: heads small or middle-sized : scales of the involucre membranaceous, with op- 

 pressed or sliyhtlif spreading tips: rays pale purple or white. 



t- Heads small. 



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

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

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

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

 Paris Island, South Carolina. — Stem 2° high. Rays pale purple. 



28. A. Baldwinii, Torr. & Gray. Rough-pubescent; stem slender, pani- 

 cled above, bearing the solitary or loosely racemose heads on the slender branch- 

 lets ; leaves very rough, entire ; the lowest ovate, on slender margined petioles, 



