COMPOSITAE. 



VOL. III. 



2. Sericocarpus bifoliatus (Walt.) Porter. 



Rough White-topped or Silk-seed- 



Aster. Fig. 4280. 



Conyza bifoliata Walt. Fl. Car. 204. 1788. 



Aster tortifolius Michx. Fl. Bor. Am. 2: 109. 1803. 



.9. tortifolius Nees, Gen. & Sp. Ast. 151. 1832. 



S. bifoliatus Porter, Mem. Torr. Club 5: 322. 1894. 



Densely puberulent or scabrous, about 2 high, 

 the stem terete, or slightly angled. Leaves ses- 

 sile, obscurely veined, obovate or broadly spatu- 

 late, thick, obtuse, ascending or erect by a twist 

 at the base, i'-i' long, 4"-8" wide, entire, mu- 

 cronulate, densely appressed-puberulent on both 

 sides, the upper mostly oblong, much smaller; 

 heads 4"-s" high, cymose-paniculate ; involucre 

 narrowly campanulate, its bracts oblong or the 

 inner linear, pubescent, their tips somewhat 

 spreading; rays short; pappus white. 



In dry soil, Virginia to Florida and Louisiana, 

 mainly near the coast. Rattlesnake-master. July-Sept. 



3. Sericocarpus asteroides (L.) B.S.P. 

 Toothed White-topped Aster. Fig 4281. 



Conyza asteroides L. Sp. PI. 861. 1753. 



S. conyzoides Nees, Gen. & Sp. Ast. 150. 1832. 



S. asteroides B.S.P. Prel. Cat. N. Y. 26. 1888. 



Stem pubescent, or glabrate, slightly angled, 

 i-2 high. Leaves thin, pubescent or glabrous, 

 ciliate, pinnately veined and faintly 3-nerved, the 

 basal and lower ones obovate or spatulate, den- 

 tate or rarely entire, 2'-4' long, i'-iJ' wide, nar- 

 rowed into margined petioles ; upper leaves ob- 

 long or oblong-lanceolate, entire or dentate, acute 

 or obtuse, smaller ; heads s"-6" high, densely clus- 

 tered ; involucre campanulate, its bracts oblong, 

 ciliate or pubescent, the outer with green reflexed 

 tips; pappus brown or white. 



In dry woods, Maine to Florida, west to Ohio, 

 Kentucky and Alabama. July-Sept. 



31. ASTER L. Sp. PI. 872. 1753.* 



Perennial or rarely annual, mostly branching herbs, with alternate leaves, and corymbose 

 or paniculate (rarely racemose or solitary) heads of both tubular and radiate flowers. Invo- 

 lucre hemispheric, campanulate or turbinate, its bracts various, imbricated in several series, 

 the exterior ones usually smaller and shorter. Receptacle flat or convex, generally foveolate. 

 Ray-flowers white, pink, purple, blue, or violet (very rarely yellowish), pistillate. Disk- 

 flowers tubular, perfect, their corollas 5-lobed, usually yellow and changing to red, brown, 

 or purple. Anthers obtuse and entire at the base. Style-branches flattened, their appendages 

 subulate, lanceolate or ovate, acute. Pappus-bristles slender, numerous, scabrous or denticu- 

 late, usually in I series, sometimes in 2 series. Achenes mostly flattened and nerved. [Greek, 

 star.] 



A genus of not less than 250 species, most abundant in North America, where, in addition to 

 the following, many others occur beyond our limits. A large number of the species apparently con- 

 sist of many slightly differing races, and hybridism is also suspected. Known as Asters or Star- 

 worts. Type species : Aster amellus L. 



A. Basal and lower leaves, or some of them, cordate and slender-petioled. (See No. 50.) 



i. None of the stem leaves cordate-clasping. 

 * Rays white, violet, or rose. 



Rays white, or rarely rose, usually 2-toothed ; plants not glandular, 

 t Involucre ovoid, campanulate or turbinate, its bracts mostly obtuse or rounded ; basal leaves few 



and small, or commonly none (except in No. 5). 

 (a) Leaves membranous or thin, smooth, or nearly so. 



Heads short-peduncled, g" broad or less, the disk turning crimson ; leaves acute or short-acuminate. 

 __ i. A. carmesinus. 



* Text prepared for our first edition with the assistance of Prof. EDWARD S. BURGESS, 

 here somewhat revised. 



