COMPOSITE. (COMPOSITE FAMILY 194 



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. mutahilis, L., is probably one of them. 

 * * * % -s/f * Stem-leaves sessile, the upper more or less clasping : scales of the Jiem- 

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

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

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



24. A. SBStlVUS, Ait. Stem slender, rouyh, bushy-branched ; leaves nar- 

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

 corymbose, loose; scales of the involucre linear, loose; rays large, apparently light 

 blue. (A. laxifolius, Nees.) Var. L2ETIFL6RUS has very slender branches 

 and leaves, and the scales 'of the involucre unequal and more appressed. 

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

 as in A. puniceus, in some forms appearing more like A. carneus. Leaves 

 4' -7' long, \> 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 tij)s , 

 rays pale 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. loiigifolillS, 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, ivith acute or aid-shaped spreading or 

 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 multiform 

 varieties including A. thyrsiflorus, Iloffm., A. laxus, Willd. (a form with more 

 leafy involucres), A. praraltus, Poir., A. clodes, Torr. $* Gr., c. 



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

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

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

 smooth underneath, pointed ; scales of the involucre narrowly 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, ir 

 open grounds rough with rigid bristly hairs. 



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

 out ; growing in shade. 



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

 paniclcd., hairy above in lines ; leaves rough above, very smooth underneath, ovate-lan- 

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

 below in a long contracted entire portion, which is abruptly dilated into an auricled- 

 heart-shaped clasping base; scales of the involucre narrowly linear, with recurved- 

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

 Penn. to Wisconsin. 



