198 COMPOSITE, (composite family.) 



3. S. tortifolius, Nces. Closely pubescent ; leaves short, obovate, rarely 

 serrate, vertical ; involucre top-shaped ; the scales oblong and slightly spreading 

 at the tips; pappus copious, white. (Aster tortifoHus, Michx.) — Sandy pine 

 barrens, Florida to North Carolina, and westward. August. — Stem l°-2° 

 high. Leaves 1 ' long. 



16. ASTER, Tourn. Aster. Star wort. 



Heads many-flowered ; the rays (white, blue, or purple) in a single series, pls- 

 tillaie. Scales of the involucre more or less imbricated, mostly with herbaceous 

 or leafy tips. Receptacle flat, pitted. Achenia usually compressed. Pappus a 

 single row of numerous rough capillary bristles. — Perennial (rarely annual) 

 herbs. Leaves alternate. Disk-flowers yellow, often changing to purple. 

 § 1. BioTiA. — Involucre olovate-beU-shaped ; the scales (pale) closely imbricated, 

 and nearlij destitute of herbaceous tips: achenia somewhat 3-anyled; bristles of the 

 pappus ritjid : leaves large ; the lower ones cordate : heads corymbed. 



1 . A. eorymbosus, Ait. Stem slender, smooth ; leaves on slender peti- 

 oles, thin, coarsely sei-rate, acuminate; the lower ones cordate, the upper oblong; 

 involucre shorter than the disk, the scales obtuse ; rays 6-9, white. — Shady 

 woods in the upper districts, Georgia and northward. Sept. and Oct. — Stem 

 ] o _ 9o high. Leaves 2' - 4' long. Corymbs loose. 



2. A. maerophyllus, L. Stem stout, rough-pubescent ; leaves large, 

 rather thick, rough, mucronate-serrate, acute ; the lowest broadly cordate, on 

 slender naked petioles ; the upper ovate, on short and winged petioles ; invo- 

 lucre nearly as long as the disk ; the exterior scales rigid, with spreading fringed 

 tips; rays about 10, pale purple. — Low shady woods, in the upper districts of 

 Georgia, and along the mountains, northward. Sept. — Stem l^°-2° high. 

 Leaves 4'- 6' long, 2' -4' wide. 



§ 2. Cai^liastrum. — Scales of the involucre imbricated in several rows, coriaceous, 

 usualli/ with herbaceous spreading tips : rays 1 2 or more : achenia nearly smooth : 

 pappus of unequal rather rigid bristles, somewhat thic/cened upward: leaves rigid, 

 none of them cordate : heads large and showy. 



3. A. nairabilis, Torr. & Gray. Rough-pubescent ; stem corymbosely 

 branched above ; leaves ovate, mucronate-serrate, sessile ; the lowest abruptly 

 narrowed into a petiole ; involucre hemispherical ; the scales oblong-linear, ob- 

 tuse and recurved at the summit ; achenia nearly smooth, striate. — Columbia, 

 South Carolina, Prof. Oibbes. Sept. — Stem 1°- 2° high. — Stem-leaves l'-3' 

 long. Rays about 20, blue or violet, elongated. 



4. A. spectabilis, Ait. Stem corymbose and glandular-pubescent above ; 

 leaves oblong-lanceolate, rough on the upper surface, sessile and entire; the 

 lowest tapering into a petiole, and sparingly seixate ; heads not numerous, single, 

 terminating the branches ; involucre nearly hemispherical, as long as the disk ; 

 the scales linear-oblong, with obtuse and spreading glandular tips. (A. surcu- 

 losus 1 Ell., with obovate-oblong, mostly serrate leaves, and broader scales of the 

 involucre.) — Pine barrens, Florida and northward. Sept. and Oct. — Rhizoma 

 slender. Stem 1 ° - 2° high. Leaves 2'-4' long. Heads ^' in diameter. Rays 

 about 20, 1 ' long, deep violet. 



