190 COMPOSITE. (COMPOSITE FAMILY.) 



in dose clusters, few-flowered; pappus white. Thickets, S. New England to 

 Virginia, near the coast. July. 



2. S. conyzoides, Nees. Somewhat pubescent; leaves oblong-lanceolate 

 or the lower spatulate, mostly serrate towards the apex, ciliate, veiny ; heads rather 

 loosely corymbed, obconical (4" - 6" long) ; pappus rusty-color. Dry ground ; 

 common. July. 



3. S. tortifolillS, Nees. Hoary-pubescent ; leaves obovate or oblong-spatu- 

 late, short ('-!' long), turned edgewise, both sides alike, nearly veinless; heads 

 rather loosely corymbed, obovoid (4" -5" long) ; pappus white. Pine woods, 

 Virginia and southward. Aug. 



GALAT^LLA HYSSOPiF6LiA, Nees, is omitted, because it has not been found 

 in our district, and probably is not an American plant. 



13. ASTER, L. STARWORT. ASTER. 



Heads many-flowered, radiate ; the ray-flowers in a single series, fertile. 

 Scales of the involucre more or less imbricated, usually with herbaceous or leaf- 

 like tips. Receptacle flat, alveolate. Achenia generally more or less flattened. 

 Pappus simple, of capillary bristles. Perennial herbs (or annual in 6), with 

 corymbed, panicled, or racemose heads. Kays white, purple, or blue : the disk 

 yellow, often changing to purple. (Name dorqp, a star, from the appearance 

 of the radiate heads of flowers.) 



$ 1. BlOTIA, DC. Involucre obovoid-bell-shaped ; the scales regularly imbricated 

 in several rows, oppressed, nearly destitute of herbaceous tips: rays 6-15 (white or 

 nearly so) : achenia slender : lower leaves large, heart-shaped, petioled, coarsely ser- 

 rate : heads in open corymbs. 



1. A. COrymbosilS, Ait. Stem slender, somewhat zigzag; leaves thin, 

 smoothish, coarsely and unequally serrate with sharp spreading teeth, sharp-pointed, 

 ovate or ovate-lanceolate, all but the uppermost heart-shaped at the base and on 

 slender naked petioles; rays 6-9. Woodlands; common, especially north- 

 ward. July -Aug. Plant 1- 2 high, with smaller heads, looser corymbs, 

 rounder and less rigid exterior involucral scales, and thinner leaves, than the 

 next ; not rough, but sometimes pubescent. 



2. A. macropliyllus, L. Stem stout and rigid (2 -3 high); leaves 

 thickish, rough, closely serrate, somewhat pointed ; the lower heart-shaped (4' -10' 

 long, 3' -6' wide), long-petioled ; the upper ovate or oblong, sessile or on mar- 

 gined petioles ; heads in ample rigid corymbs ; rays 12-25 (white or bluish). 

 Moist woods ; common northward, and southward along the mountains. Aug., 

 Sept. Involucre ' broad; the outer scales rigid, oblong or ovate-oblong, the 

 innermost much larger and thinner. 



2. CALLlASTRUM, Torr. & Gr. Scales of the involucre imbricated in several 

 rows, coriaceous, with herbaceous spreading tips: rays 12-30, violet: achenia nar- 

 row (smoothish) : pappus of rigid bristles of unequal thickness : stem-leaves all 

 sessile; lower ones not heart-shaped: heads few, large and showy. (Allied to 

 1, and to Sericocarpus.) 



