220 coMPOSiT-E. (composite family.) 



14. A. adnatus, Nutt. Stem with the slender hraiichcs erect; leavea 

 oblong, very mugli, tlie midrib partly adnate to the stem, free at tlie apex; 

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

 Stem l°-2° liigli. Heads smaller than in the preceding. 



■>- -t- Lravcs (ill clasjiiii(/ and auriclid at the bast: heads lanjc : scales of the 

 inculucre linear. 



1j. a. pateus, Ait. Stem ])ube.scent, loosely paniiled abo\e; leaves 

 ovate-oblung, witii very rough and wavy margins; those on the slender spread- 

 ing branchlets very small. — Var. I'liLouii-oi.ius. Leaves larger, tiiinner, 

 and less rougiiened, contracted below the middle ; heads often racemo?ie on 

 the sliort lateral branches. — Dry soil, chiefly in the upper districts. — Stem 

 l°-3° high. Leaves V-2' (in the var. 3'-6') long. Heads showy. 

 ♦ 3. Leaves (and stems) smooth : the lowest tapering into a petiole, the others 



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



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



moxtly smooth. 



If). A. Isevis, L. Very .smooth and often glaucous ; stem rigid, pauicled 

 above, bearing the showy heads on short rigid branclilets ; leaves oblong or 

 lanceolate, coriaceous, mostly entire and rough on the margins ; the ujiper 

 cues sessile or clasping ; scales of the involucre rigid, api)ressed, witii aljruptly 

 pointed herbaceous tips. — Open woods in the upper di.stricts. — Stem 2° -3° 

 high. 



17. A. virgatUS, Kll. Stem very smooth, straight, simple or brandling; 

 heads racemose ; leaves linear-lanceolate, entire, rough on tlie margins, partly 

 clasping, the lowest broader and narrowed at the base; scales of the involucre 

 lanceolate, acuminate, the outer ones spreading. — Upper districts of Georgia, 

 and westward. — Stem 3° -4° high. Lower leaves 3' -6' long; those of the 

 branches small and numerous. 



18. A. COncinnus, Willd. Stem nearly smooth, somewhat loo.sely cor- 

 3'ml)ose ; tlie branches virgate, dichotomous-paniculate ; leaves lanceolate, 

 partlv chisping, remotely and sharply serrate, with scabrous margins, those 

 of the branchlets oblong, entire ; scales of the involucre linear, acute, closely 

 imbricated. (A. cyaneus? Ell.) — Nortii Carolina ( Schweinitz). — Stem 2° - 3° 

 high. Achenia pubescent. 



» 4. Lower leaves large, cordate, on long petioles : heads middle-sized or small, 

 racemed or panicled : scales of the involucre somewhat membranaceous, with 

 short green tips : rays blue or violet. 



•*- Leaves entire, or nearly so. 



19. A. azureus, Lindl. Stem roughish, rigid, racemose-compound at 

 the summit, tiie branches slender ; leaves rigid, rough ; the lowe.st ovate-lanceo- 

 late or oblong ; the upper lanceolate or linear, sessile ; those of the branches 

 subulate, appressed ; scales of the obconical involucre closely imbricated, 

 abruptly acute. — Dry soil in the upper districts of Georgia, and northward. 

 — Stem 2° -3° high. Rays bright blue. 



20. A. Shortii, Hook. Stem smoothish, slender, racemose-panicled at 

 the summit; leaves nearly smooth, ovate-lanceolate, acute; those of the stem 



