Oedbb 10.— composite. 421 



§ 1. BIOTIA, DC. CoKTMBED Asters. 



1 A. corymbosua Ait. St. oorymbous-fastigiate, nearly smooth, brauoliea pu- 

 bescent ; Ivs. thin, ovate-acuminate, serrate, with sharp spreading teeth, the lower 

 cordate, peliolate, the petioles wingless ; invoL oblong, 6 to 9-rayed, imbricate 

 with close-pressed, acute scales. — Common in dry woods, N. and Mid. States. 

 St. 2f high, often reddish, more or less flexuous. Lvs. large, mostly smooth, the 

 upper becoming lanceolate, sessile. Hds. 4" long, in a broad, flat, open corymb, 

 with about 6 oblong, white or roseate rays. Aug. (Burybia corymbosa Cass.) 



2 A. maoroph;^llaB Willd. St. rough-pubescent, widely branched ; fos. ovate, 

 petiolate, serrate with short, depressed teeth, rough, the upper ovate-lanceolate, 

 sessile, lower cordate, petiolate, petioles somewhat winged ; inVoL eyliudric, closely 

 imbricate with oblong, acute scales; rays 8 to 15. — Woods N. States and Can. 

 St. furrowed, 1 to 2f high. Lvs. often very large (6 to 10' by 3 to 6''). Eaya 

 white or pale blue. Hds. 6" long. Sept. (Eurybia corymbosa Cass.) 



§ 2. CALLIASTRUM, Torr. & Gr. Violet-Flowered Asters. 



3 A. mirabilis Torr. & Gr. Scabrous, simple below; lvs. ovate, serrate, the 

 lowest petiolate, the others sessile, t?io$e of the ^tranches roundish, small ; iuvol. 

 hemispherical, shorter than the disk, scales imbricated, in 4 or 5 series succes- 

 sively shorter, with obtuse, green, recurved tips ; rays about 20. — Columbia, S. Car. 

 (Prof. Gibbs in N. Am. Flora II., 165). We have not met with, this species. 



4 A. rddula Ait. Erect, simple below, angular; lvs. lanceolate, acuminate, nar- 

 rowed to the sessile base, shmply serrate, rugous and rough ; invol. Imbricate, 

 squarrous with the short spreading green tips of the scales. — Moist groves and 

 hedges. Me. to Penn. Height 1 to 3f, remarkable for its straight, smooth stem, 

 stiff, sharply serrate lvs. Branches nearly leafless, simple, each bearing a single 

 large head, rarely more, with 20 pale violet rays spreading Ij'. Aug., Sept. 



5 A. spect^bilis Ait. Erect, rough-puberulent above; lvs. roughish, oblong- 

 lanceolate, sessUe, entire, the lower obscurely serrate ; branches corymbed ; invol. 

 hemispherical, with squarrous, spreading, ciliate scales. — A low, handsome Aster, 

 of pine baiTens, Mass. to N. J. and Ky. St. 1 to 2f high, branching above into a 

 nearly simple corymb of 10 — 15 large and show^ heads, each with about 20 long 

 violet blue rays. Sept. — Nov. 



6 A. surculosus Mx. Sts. arising from a knotted creeping rhiwme, low, slender, 

 simple or corymbous at top; lvs. linear-lamceolate, entire or subserrate, upper 

 linear, clasping ; hds. 1 to 5 ; scales linear-oblong, ciliate, inner obtuse, outer with 

 green spreading tips ; rays about 20. — "Wet pine barrens, U. J. to N. Car. and 

 Tenn. Sts. smoothish, 12 to 18' high. Rt.-lvs. spatulate, 4 to 6' long. Hds. 

 large, oboonic, with violet-purple rays. Sept. 



j8. GRACILIS Gray. Hds. smaller and more numerous (8 to 12), with the invol- 

 ucre more close, and the rays about 12 (A. gracilis Nutt). 



7 A paludosus L. Slender, glabrous ; lvs. long, linear, rigid, margins scarcely 

 rough, clasping at base; hds. 1 to 6, hemispherical; scales green, lance-linear, 

 somewhat spreading; rays about 30, longer than the (6") involucre. — Swamps in 

 pine barrens, N. Car. to Fla. and La. Sts. 2 to 3f high. Hds. yery large, with 

 violet-blue rays spreading IJ to 2'. Pappus tawny. Aug. — Oct. 



§ 3. ASTER PROPER. True Asters. 



8 A. oordifolius L. St. paniculate, smoothish; lower lvs. cordate, hairy 

 beneath, sharply serrate, acuminate, petiolate; petioles winged; invol. closely 

 imbricate, the scales with short, green tips. — Common in rocky woods, N. and W. 

 States. Stem with a handsome panicle of racemes at top of numerous, rather 

 small flowers. Rays 10 — 15, pale blue varying to white. Lower leaves large. 

 Petioles more or less winged, hairy. Above, the leaves are gradually reduced 

 to small or minute bracts. Sepi 



9 A. sagittifoliuB Willd. Arrow-leaved Aster. St. ijdth racemous branches 

 above, smooth; lvs. oblong-lanceolate, acuminate, sessile, serrate in the middle, 

 radical ones ovate, oblong, cordate-sagittate, serrate, petiolate; invol. loosely 

 imbricate, scales linear-subulate. — Low woods, N. and W. States and Can. Stem 



