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 d&j^i/, a gland, and /cauXds, a stem). 



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

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

 rior, and westward. 



12. SERICOCARPUS, 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 abrupt often spread- 

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

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

 tufted herbs (l-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 o-npiKos, silky, and Kaprros, fruit. ) 



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

 entire, with rough margins, tapering to the base ; heads narrow (3" long), inclose 

 dusters, 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. tortif61ius, 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. 



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 more or less flattened. Pappus 

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

 rymbed, panicled, or racemose heads ; flowering in autumn. Rays white, purple, 

 or blue : the disk yellow, often changing to purple. (Name doT^p, a star, from 

 the appearance of the radiate heads of flowers.) 



1. BI6TIA, 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. eorymbbsilS, 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 



