COMPOSIT.E. (COMPOSITK FAMILY.) 2i')9 



Aos^, or directly sessile by a heart-shapeil hiuie ; involucre ohovoid, the scales 



less rigid. — Dry copses; coniinon. 



++ ++ Leaves conspicuous! // serrate ; heads small ; rays pale blue or nearly white. 



21. A. COrdifdlius, L. Stem imich branched above, ^/jc .s/)r<-ar//n7 or ^/Z- 

 i-iercjinrj branches bcarinrj very numerous panicled heads; lower leaves all lieart- 

 shaped, on slender and mostly naked ciliate petioles; scales of the inverseh/ 

 conical involucre all appressed and tipped with very short green points, obtuse or 

 acutish. — Woodlands ; very common. — Heads profuse, l)ut (juite small. Vai ies 

 with the stem and leaves either smooth, rouf^hish, or sometimes hairy, also 

 with the leaves all narrower. Apparent hybrids with n. 'i.T also occur. 



22. A. sagittifolius, Willd. Stem rigid, erect, witii ascendiny branches 

 bearing numerous racemose heads; leaves ovate-lanceolate, pointed ; the lower 

 heart-shaped at base, on margined petioles; the upper lanceolate or linear, 

 pointed at both ends; scales of the oblong involucre linear, tapering into aivl- 

 shapecl slender and loose tips. — Dry ground, N. Y. and Penn. to Ky., and north- 

 ward. — Green, but usually more or less hairy or downy; the heads rather 

 larger than in the last, almost sessile. 



2-3. A. Drummondii, Lindl. Pale with fine gray pubescence ; leaves 

 cordate to cordate-lanceolate, mostly on margined petioles, the uppermost lan- 

 ceolate and sessile; scales acute or acutish. — Passing into the last. Open 

 ground, etc.. 111. to Minn, and Kan. 



24. A. Lindleyanus, Torr. & Gray. Rather stout, 1 -2° high, sparsely 

 pubescent or nearly glabrous ; radical and lowest leaves ovate, moderately or 

 obscurely cordate, the uppermost sessile and pointed at both ends ; heads larger, 

 rather few in a loose tliyrse or panicle, the linear-attenuate scales looser and less 

 imbricated; rays pale violet. — Lab. to L. Superior; Lisbon, N. H. (C. E. 

 Faxon), and Mt, Desert {Rand}. 



* 6. Without heart-shaped petioled leaves, the radical and lower all acute or 

 attenuate at base ; not glandular nor viscid, nor silky-canescent. 



"t- Stnooth and glabrous throughout (or nearly so,except forms of n. 30), and usu- 

 ally pale and glaucous ; involucral scales closely imbricated, Jirm and whitish- 

 coriaceous below, green-tipped ; leaves firm, usually entire. 



•*•*■ Rays violet or blue; scales j-ather abruptly green-tipped ; leaves on the branch- 

 lets reduced to rigid snbidate bracts. 



2.5. A. turbinellus, Lindl. Stem slender, 3° high, paniculately branched ; 

 leaves oblong to narrowly lanceolate, taj)oring to each end, with rough margins ; 

 involucre elongated-obamical or almost club-shaj)ed {\' long) ; the scales linear, 

 with very short and blunt green tips; rays violet-blue ; achencs nearly smooth. 

 — Dry hills, etc., 111., Mo., and southwestward. — Well-marked anil handsome. 



2fj. A. laevis, L. Stouter, 2-4° high; heads in a close panicle; leaves 

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

 clasping by an auricled or heart-shaj)ed ba.se; scales of the short-obovnid or 

 hemispherical involucre with short abrupt green tips; rays sky-blue; achenes 

 smooth. — Borders of woodlands ; common. A variable and elegant species. 



27. A. virg^tUS, Ell. Slender, strict and simple, with few or several 

 racemose or terminal /learfs, like those of the last; leaves lanceolate or linear, 

 the lower usually long and narrow. — S. W. Va., and southward. 



