200 composiTjE. (composite family.) 



very ; scales of the involucre leafy and spreading ; achenia smooth. — A Western 

 species, a form of which, with narrower and less silvery leaves and scales, grows 

 on the mountains of North Carolina. — Stem 10'-20' high. Leaves J'-l' 

 long. Heads showy. 



11. A. eoncolor, L. Stem mostly simple, slender, bearing towards the 

 summit, the middle-sized heads in a long often compound raceme ; leaves lance- 

 olatd, silky when young ; the lowest ones oblong ; scales of the obovoid involu- 

 cre lanceolate, appressed, the subulate tips spreading ; achenia silky. — Dry 

 sandy soil, Florida and northward. — Root sometimes tuberous. Stem l°-3° 

 high. Leaves erect ^' - 1 ' long. 



* * Leaves rough, all sessile or clasping and entire : heads chiefly solitary, terminat- 

 ing the hranchlets : scales of the ohovoid or bell-shaped involucre imbricated in several 

 rows, coriaceous, with herbaceous slightly spreading tips : rays purplish-blue : achenia 

 hairy. 



■t- Leaves very small, sessile : heads small: scales of the involucre spatnlate. 



12. A. squarrosus, Walt. Stem slender, diffuse ; leaves oblong or tri- 

 angular-ovate, refiexcd, very rough, sessile ; the lowest spatulate. — Dry soil, 

 Florida to North Carolina. — Stem l°-2° high. Lowest leaves J' long, the 

 others 2" - 3" long. 



13. A. adnatus, Nutt. Stem with the slender branches erect ; leaves ob- 

 long, very rough, the midrib partly adnate to the stem, free at the apex; the 

 lowest wedge-obovate, free. ■ — Sandy barrens, Florida and Alabama. — Stem 

 l°-2° high. Heads smaller than in the preceding. 



H- +- Leaves all clasping and auricled at the base ; heads large ; scales of the invo- 

 lucre linear. 



14. A. patens, Ait. Stem pubescent, loosely paniclcd above; leaves 

 ovate-oblong, with very rough and wavy margins ; those on the slender and 

 spreading branchlets very small. — Var. PHLOGiroLrtjs. Leaves larger, thinner, 

 and less roughened, contracted below the middle ; heads often racemose on the 

 short lateral branches. — Dry soil, chiefly in the upper districts. — Stem l°-3° 

 high. Leaves l'-2' (in the var. 3'-6') long. Heads show}-. 



* * * Leaves {and stems) smooth : the lowest tapering into a petiole, the others 



sessile or clasping: heads middle-sized, showy: scales of the obovoid involucre 

 whitish, the short green tips scarcely spreading : rays bright blue : achenia mostly 

 smooth. 



15. A. Isevis, L. Very smooth and often glaucous; stem rigid, panicled 

 above, bearing the showy heads on short rigid branchlets ; leaves oblong or lan- 

 ceolate, coriaceous, mostly entire and rough on the margins ; the upper ones 

 sessile or clasping ; scales of the involucre rigid, appressed, with abruptly pointed 

 herbaceous tips. — Open woods in the upper districts. — Stem 2° -3° high. 



16. A. graeilentUS, Torr. & Gray. Very smooth; stem slender, loosely 

 panicled above, bearing the heads at the end of slender leafy branchlets ; leaves 

 linear, elongated; the lower ones coarsely toothed above the middle, the upper 

 slightly clasping and entire ; scales of the involucre much shorter than the disk, 



