192 COMPOSITE. (composite family.) 



* * Lower leaves not heart-shaped ; the upper all sessile and more or less clasping by 

 a heart-shaped or auricled base : heads showy : scales of the inversely conical or bell- 

 shaped involucre regularly imbricated in several rows, the outer siwcessively shorter, 

 oppressed, coriaceous, whitish, with short herbaceous tips : rays large, purple or blue. 



8. A. pateilS, Ait. Rough- pubescent ; stem loosely panielcd above (1°- 3° 

 high), with widely spreading branches, the heads mostly solitary, terminating 

 the slender branchlets ; leaves oblong-lanceolate or ovate-oblong, often contracted 

 below the middle, all clasping by a deep auriclcd-heart-shaped base, rough, especially 

 above and on the margins, entire ; scales of the minutely roughish involucre 

 with spreading pointed tips; achenia silky. — Var. phlogif6lius is a form 

 which the plant assumes in shady moist places, with larger and elongated thin 

 scarcely rough leaves, downy underneath, sometimes a little toothed above, 

 mostly much contracted below the middle. — Dry ground, common, especially 

 southward. Heads |' broad, and with showy deep blue-purple rays. 



9. A. IjfeviS, L. Very smooth throughoid ; heads in a close panicle; leaves 

 thickish, lanceolate or ovate-lanceolate, chiefly entire, the upper more or less 

 clasping by an auricled or heart-shaped base ; scales of the short-obovoid or hemi- 

 spherical involucre with apprcssed green points ; rays sky-blue ; achenia smooth. A 

 variable species, of which the two best-marked forms arc : — 



Var. lu;Yig;\tli§. Scarcely if at all glaucous ; leaves lanceolate or ob- 

 long; involucre nearly hemispherical; the scales lanceolate or linear, with nar- 

 row and acute green tips tapering down on the midncrve. (A. laevis, L. A. 

 laevigatus, Willd.) — Dry woodlands; rather common. 



Var. cyaiiews. Very smooth, but pale or glaucous; leaves thicker; the 

 upper often oblong or ovate-lanceolate, clasping by a heart-shaped base ; invo- 

 lucre nairowed at the base, of broader and more coriaceous scales with shorter 

 and abrupt tips. (A. cyaneus, Hoffm., <j-c.) —Border of woodlands; common, 

 especially northward. — A very elegant species, with showy flowers. 



10. A. {wrbinellMS, Lindl. Very smooth ,- stem slender, paniculatcly 

 branched ; leaves lanceolate, tapering to each end, entire, with rough margins ; in- 

 volucre elongated-obconical or almost club-shaped (|' long) ; the scales linear, with 

 very short and blunt green tips ; rays violet-blue ; achenia nearly smooth. — Dry 

 hills, &c, Illinois and southwestward. 



* # * Lower leaves all heart-shaped and petiolcd, the upper sessile or pelioled: invo- 

 lucre imbricated much as in the last division, but the heads smaller, very numerous. 

 racemose or panicled. 



+- Leaves entire or slightly serrate : heads middle-sized : rays bright-blue. 



11. A. azfas-eias, Lindl. Stem rather rough, erect, racemose-compound 

 at the summit, the branches slender and rigid ; leaves rough ; the lower ovate-lance- 

 olate or oblong, heart-shaped, on long often hairy petioles ; the others lanceolate or lin- 

 ear, sessile, on the branches awl-shaped ; involucre, inversely conical. — Copses 

 and prairies, Ohio to Wisconsin and southward. — A handsome species ; the in- 

 volucre much as in No. 9, but much smaller, and slightly pubescent ; the rays 

 bright blue. 



12. A. Shdrtii, Boott. Stem slender, spreading, nearly smooth, bearing 

 very numerous heads in racemose panicles ; leaves smooth above, minutely pubescent 



