198 co-AirosiT^. (composite family.) 



3. S. tortifolius, Necs. Closely pubescent ; leaves short, ohovate, rarelv 

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

 at the tips; pappus copious, white. (Aster tortifolius, Afkhx.) — Sandy pine 

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

 high. Leaves 1 ' long. 



16. ASTER, Toum. Aster. Starwout. 



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

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

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

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

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



§ 1. BiOTlA. — Involucre ohovute-heU-shajxd ; the scales (pale) closely imbricated, 

 and neurlj destitute of herbaceous tips: achenia somewhat ^-angled: bristles of the 

 pappus rigid : leaves large ; the loiver ones cordate : heads cor ymbed. 



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

 oles, thin, coarsely serrate, 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 

 l°-2°high. Leaves 2' -4' long. Corymbs loose. 



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

 rather thick, rough, nuu ronate-scrrate, acute ; the lowest broadly cordate, on 

 slender naked ])etioles; 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. C.^r.LiASTRUM. — Scales of the involucre imbricated in several rows, coriaceous, 

 usually with herliacroiis spreading tips ; 7'ays \2 or more : achenia nearly smooth : 

 pappus of unerpud rather rigid bristles, somewhat thickened upward: leaves rigid, 

 none of them cordate : heads large and showy. 



3. A. mirabilis, Ton-. & Gray. Rough-pubescent ; stem cor^mbosely 

 branched above ; leaves ovate, mucronatc-scrrate, sessile ; the lowest abruptly 

 narrowed into a petiole ; involucre hemispherical ; the scales oldong-lincar, ob- 

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

 South Carolina, Prof. Gihbes. Sept. — Stem 1 ° - 2° high. — Stem-leaves 1 ' - 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 serrate ; 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 ? 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. 



