202 coMPOsiTiE. (composite family.) 



■I- -1- Lowest leaves conspicuousli] serrate : heads small. 



23. A. cordifolius, L. Stem commonly smooth, racemose-paniclcd above; 

 leaves smooth, or rough above and pubescent beneath, all cordate, serrate, and 

 slender-petioled, or the uppennost on shoi1||ivinged 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 vifoods, in the 

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



24. A. sagittifolius, Wiild. 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. Ell.) — 

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

 than those of the preceding. Kays purple. 



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

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

 rows, rigid, with spii'eading 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. villosus. Stem and broader leaves rough- 

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

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

 larger. — Dry soil, Florida, and northward. — Stem l°-2° high. Eays white 

 or pale blue. 



26. A. multiflorus, Ait. Whitish-pubescent; stem very leafy, and mucli 

 branched ; leaves linear, obtuse at each end, often bristle-pointed, 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 the involucre broadest at the 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 

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

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

 -I- 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 the disk ; rays very short. — Damp rich soil, 

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



28. A. Baldwiuii, Toit. & Gray. Rough-pubescent ; stem slender, pani- 

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

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



