220 COMPOSITE. (COMPOSITE FAMILY.) 



14. A. adnatUS, Kutt. Stem with the slender branches erect; leaves 

 oblong, 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. 



- -i- Leaves all clasping and attricled at the base: heads large: scales of the 



involucre linear. 



15. A. patens, Ait. Stem pubescent, loosely pauicled above; leaves 

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

 ing brauchlets very small. Var. PHLOGIFOLIUS. 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 showy. 



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



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

 whitish, the short green tips scarcely spreading : rai/s bright blue : achenia 

 mostly smooth. 



16. A. laevis, L. Very smooth and often glaucous ; stem rigid, panicled 

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

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

 ones sessile or clasping ; scales of the involucre rigid, appressed, with abrupt! v 

 pointed herbaceous tips. Open woods in the upper districts. Stem 2-3 

 high. 



17. A. virgatus, Ell. Stem very smooth, straight, simple or branching; 

 heads racemose; leaves linear-lanceolate, entire, rough on the margins, parti v 

 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 loosely cor- 

 ymbose ; the branches virgate, dichotomous-pauiculate ; leaves lanceolate, 

 partly clasping, remotely and sharply serrate, with scabrous margins, those 

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

 imbricated. (A. cyaneus? Ell.) North Carolina ( Schu-einitz) . 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. 



-t- Leaves entire, or nearly so. 



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

 the summit, the branches slender ; leaves rigid, rough ; the lowest 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-pan icled at 

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



