228 COMPOSITE, (composite family.) 



equal, in a single row. Achenia elongated at maturity, club-shaped, beset with 

 stalked glands above. Pappus none. — Slender perennials^ with the alternate 

 thin and petioled leaves smooth and green above, white woolly beneath, and few 

 small (whitish) heads in a loose panicle, beset with glands (whence the name, 

 from dSrjU, a gland, and KavKos, a stem). 



1 . A. taicolor, Hook. Leaves triangular, rather heart-shaped, with angu- 

 lar-toothed margins ; petioles margined. — Moist woods, shore of Lake Supe- 

 rior, and westward. 



12-. SERICOCAEPUS, Nees. White-topped Aster. 



Heads 12-15-flowered, radiate; the rays about 5, fertile (white). Involucre 

 somewhat cylindrical or club-shaped; the scales closely imbricated in several 

 rows, cartilaginous and whitish, appressed, with short and abrapt often spread- 

 ing green tips. Receptacle alveolate-toothed. Achenia short, inversely pyram- 

 idal, very silky. Pappus simple, of numerous capillary bristles. — Perennial 

 tufted herbs (I°-2° high), with sessile somewhat 3-nerved leaves, and small 

 heads mostly in little clusters, disposed in a flat corymb. Disk-flowers pale 

 yellow. (Name from arjpiKos, sUhy, and Kapiros, fruit.) 



1. S. solidagineus, Nees. Smooth, slender; leaves linear, rigid, obtuse, 

 entire, with rough mafljins, tapering to the base ; heads narrow (3" long), in dose 

 clusters, few-flowered; pappus white. — Thickets, S. New England to Virginia, 

 near the coast. July. 



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

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

 loosely coryrabed, obconical (4" -6" long); pappus rttsty-color. — Biy ground: 

 common. July. 



3. S. tortif61ius, Nees. Hoary-pubescent; leaves obovate or oblong-spatu- 

 late, short, H'-V long), turned edgewise, both sides aUke, nearly veinless ; heads, 

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

 Virginia and southward. Aug. 



13. ASTER, L. Starwobt. Astek. 



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 more or less flattened. Pappus 

 simple, of capillary bristles. — Perennial herbs (or annual only in § 6), ivith co-- 

 rymbed, panicled, or racemose heads ; flowering in autumn. Rays white, pui^ple, 

 or blue: the disk yellow, often changing to purple. (Name aori,/), a star, from 

 the appearance of the radiate heads of flowers.) 



§ 1. BIOTIA, DC. Involucre obovoid-bell-shaped ; the scales regularly imbricated in 



several rows, appressed, nearly destitute of herbaceous tips : rays 6-15 {white or 



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



serrate : heads in open corymbs. 



1. A. C0rymb6sus, Ait. Stem slender, somewhat zigzag; leaves thin, 



smoothish, coarsely and mequalty serrate with sharp spreading teeth, sharp^pointed, 



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



