COMFOSITiE. (composite FAMILY.) 195 



Violet-purple, or almost white. — On a thorough revision of the genus, older 

 names will be found and verified for this and No. 21, which here cover a mul- 

 titude of forms. A. mutabilis, L., is probably one of them. 

 ****** Stem-leaves sessile, the upper more or less clasping : scales of the hem- 

 ispherical involucre loosely more or less imbricated, somewhat equal, with herbaceous 

 tips, or the outer often entirdy herbaceous: heads middle-sized or large: rays blue 

 or purple. (The species of this group are still perplexing.) 



24. A. sestivns, Ait. Stem slender, rough, bushy-branched; leaves nar- 

 rowly lanceolate-linear, elongated, taper-pointed, entire, with rough margins ; heads 

 corymbose, loose ; scales of the involucre linear, hose ; rays lai-ge, apparently light 

 blue. (A. laxifolius, Nees.) — Var. L^TirL6Kus has veiy slender branches 

 and leaves, and the scales of the involucre unequal and more apprcsscd. — 

 Moist shady places, Ohio to Wisconsin and northward. Heads about as large 

 as in A. puniceus, in some forms appealing more like A. camous. Leaves 

 4' -7' long, i' to ^' wide. 



25. A. Novi-Belgii; L. Nearly smooth; stem stout; leaves oblong-lanceo- 

 late, pale, or somewhat glaucous, serrate in the middle, acute, tapering to each end ; 

 scales of the involucre rather closely imbricated, with broadish acute herbaceous tips ; 

 rays pals blue or purplish. — Low grounds, not clearly known in a wild state. 

 The plant here in view is intermediate between No. 23 and No. 26. — Heads 

 smaller and less showy than in the next. 



26. A. longifolins, Lam. Smooth or nearly so ; stem branched, corym- 

 bose-panicled at the summit; leaves lanceolate or linear, or the lower ovate-lance- 

 olate, entire or sparingly serrate in the middle, taper-pointed, shining above; scales 

 of the involucre imbricated in 3-5 rows, linear, with acute or awl-shaped spreading of 

 recurved green tips ; rays large and numerous, bright purplish-blue. — Moist 

 places, along streams, &c., common eastward. — Plant l°-5° high, with large 

 and showy heads ; very variable in the foliage, involucre, &c. ; its multifoiin 

 varieties including A. thyrsiflorus, Hoffm., A. laxus, WUld. (a form with more 

 leafy involucres), A. prsealtus. Pair., A. elides, Torr. 4r Gr., &c. 



27. A. puniceus, L. Stem tall and stout, rough-hairy all over or in lines, 

 usually purple below, panicled above ; leaves oblong-lanceolate, clasping by an auri- 

 ded base, sparingly serrate in the middle with appressed teeth, rough above, nearly 

 smooth underneath, pointed ; scales of the involucre nairowly linear, acute, loose, 

 equal, in about 2 rows ; rays long and showy (lilac-blue, paler or whitish in 

 shade). — Low thickets and swamps, very common. — Stems 3° -6° high, in 

 open grounds rough with rigid bristly hau'S. 



Var. Viminens (A. vimineus, Willd.) is a variety nearly smooth through- 

 out ; growing in shade. 



28. A. prenanthoides, Muhl. Stem low (l°-3° high), corymbose- 

 panicled, hairy above in lines ; leaves rough above, very smooth undemeatJi, ovate-lan- 

 ceolate, sharply cut-toothed in the middle, conspicuously taper-pointed, and tapering 

 hdow in u, long contracted entire portion, which is abruptly dilated into an auricled- 

 heart-sliaped clasping base ; scales of the involucre narrowly linear, with recuiTed- 

 spreading tips ; rays light blue. — Borders of rich woods, W. New York and 

 Penu. to Wisconsin. 



