192 COMPOSITE. (COMPOSITE FAMILY.) 



# # Luir,',- it arts not itmrt-sltapfd ; the njiper all sessile and more or less clasping by 

 a In art-shaj.-eif <>r attrirled l>use : In ads shon-y : scales of the run rst /// conical or bell- 

 shiipid in ml urn: rn/ii'arty imbricated in iv-reral rotrs, the outer sin-cessivfly shorter, 

 app. ' ons, u-hitith, with short ' >'ps : rays large, purple or blue. 



8. A. pattiiis, Ait. Rough-pubescent; stem loosely panicled above (1- 8 

 high), with widely spreading hranchos, tlic heads mostly solitary, terminating 

 the slender branehlets ; hi res oblong-lanceolate or ovate-oblong, often contracted 

 below the middle, all clasping by a deep awrieledJeart-ihaped base, rough, especially 

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

 with spreading pointed tips; achcnia silky. Var. riiLooiFm.irs is a form 

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

 se;ireely 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. lifevis, L. Very smooth throughout ; 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 shoti-ohoroid or hemi- 

 s])heriatl involucre with oppressed green points ; rays sky-blue ; adierJa smooth. A 

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



Var. laevigfltUS. 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 midnerve. (A. la:vi.s, L. A. 

 bjevigatus, Wilid.) Dry woodlands ; rather common. 



Var. cyiineilS. Very smooth, but pale or glaucous; leaves thicker; tho 

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

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

 and abrupt tips. (A. cyaneus, Iloffm., frc.) Border of woodlands ; common, 

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



10. A. tlirbilll!il$, Lindl. Very smooth ; stem slender, paniculately 

 branched ; lea MS Inncculut, , tapering to each end, entire, with rough margins ; in- 

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

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

 bills, &c., Illinois and southwestward. 



* * * Lower Ixins till lu'drt-shapid and pctiohd, the upper sessile or petioltd : invo- 

 lucre inilin'rul'd nincli as in die last division, but the hauls smaller, rcry niii.- 

 racemose, or pa/iicled. 



*- Li arts ml, re or slit/lttly serrate: heads middle-sized : rays bright-Hue. 



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

 at the summit, the branches slender and rigid; haws rough; the loicer ovate-lance., 

 date or olilon;/, heart-shaped, on long often hairy pitiuhs; the others lanceolate or lin- 

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



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. Slioi'tii, Boott. Stem slender, spreading, nearly smooth, bearing 

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



