§ Biotia, DC. Scales closely imbricated, slightly tipped with green. Hds, corymbous.

rays 6 to 15 ,white or roseate.Lvs. cordate, petiolate, serrat,large...................

.....Nos. 1,2

§ Calliastrum, T. & G. Scales loosely imbricated, with green spreading tips. Heads

corymbous or few, large, rays 12 to 30, violet. Leaves never cordate, rigid ; pappus

unequal, rigid, the inner slightly club-shaped. - Leaves all or the lower seriate.......................

.....Nos. 3 - 5

-Leaves entire ..................................

......Nos 6,7

§ Aster proper. Scales (variously) imbricated, with green tips or wholly green.

paniculate or racemous. Pappus soft, equal (none club-shaped), (a)

a Leaves clasping with a cordate or auriculate base, (b)

a Leaves sessile or petiolate, none of them cordate or auriculate. (c)

a Leaves petiolate, the lower cordate,-evidently serrate.................................

....Nos. 8,9

- entire, or obscurely serrate...........

. Nos. 10 - 12

b Leaves entire,-very small (1 to 3"long),erect or reflexed..................

....Nos. 13,14

-middle size (1 to 3" long),-Achenia silky.................

Nos. 15-17

-Achenia smoth.............

Nos. 20, 35

b Leaves serrate (more or less). spreading, equal, in 2 rows. ......

......No. 18

- Scales imbicated, in 3 to 5 rows....................................

Nos. 19 - 21

C Leaves silky on both sides alike. Pappus tawny................................................................

..Nos. 22, 23

C Leaves not silky. - Involucre closely imbricated, (d)

- Involucre squarrous, the scales spreading, (e)

d Leaves all entire.- scales of the involucre obtuse......................................................

....nos. 24,25

- scales acute or mucronate...............................................................

Nos. 26 - 28

d Leaves (lower) sharply serrate. - Heads larger (4 to 6" long)-----

..Nos. 29, 30

-Heads small (2 to 3" long).....

e Scales obtuse, in several rows, unequal. Leaves also obtuse

.. Nos. 33, 34

e Scales acute, in several rows, unequal- Pappus tawny.....

Nos. 35 - 37

- Pappus bright.....

.Nos. 38 - 40

e Scales acute, in one row. equal. Leaves linear. Heads solitary

-No. 41

§ Scariosae. Scales (variously) imbricated, with scarious margins and destitute of

green tips, (f)

f leaves Ianceolate broadly or narrowly. scales rather obtuse..........................

Nos. 42 - 44

Leaves subulate or linear. Scales very acute.-Heads large large, few..............

. Nos. 45, 46

-Heads small, many...........................................

...Nos 47,48

§ 1. BIOTIA, DC. Corymbed Asters.

1 A. corymbdsus Ait. St. corymbous-fastigiate, nearly smooth, branchea pubescent ; lus. 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. (Eurybia corymbosa Cass.)

2 A. macrophyllus Willd. St. rough-pubescent, widely branched; lvs. ovate, petiolate, serrate with short, depressed teeth, rough, the upper ovate-lanceolate, sessile, lower cordate, petiolate, petioles somewhat winged; invol. cylindric, 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'). Rays 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, those of the branches roundish, small; invoL hemispherical, shorter than the disk, scales imbricated, in 4 or 5 series successively shorter, with obtuse, green, recurved tips; rays about 20. - Columbia, S. Car. (Prof. Gibbs in N. Am. Flora II., 1G5). We have not met with this species.

4 A. radula Ait. Erect, simple below, angular; lvs. lanceolate, acuminate, narrowed to the sessile base, sharply 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 1 1/2'. Aug., Sept.

5 A. spectabilis Ait. Erect, rough-puberulent above; lvs. roughish, oblong-lanceolate, sessile, entire, the lower obscurely serrate; branches corymbed; invol. hemispherical, with squarrous, spreading, ciliate scales. - A low, handsome Aster, of pine barrens, Mass. to N. J. and Ky. St. 1 to 2f high, branching abovo into a nearly simple corymb of 10 - 15 large and showy heads, each with about 20 long violet blue rays. Sept. - Nov.

6 A. surculosus Mx. Sts. arising from a knotted creeping rhizome, low, slender, simple or corymbous at top; lvs. linear-lanceolate, 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, N. J. to X. Car. and Tenn. Sts. smoothish, 12 to 18' high. Rt.-lvs. spatulate, 4 to 6' long. Hds. large, obconie, with violet-purple rays. Sept.

. gracilis Gray. Hds. smaller and more numerous (8 to 12), with the involucre 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. very large, with violet-blue rays spreading 1 1/2 to 2'. Pappus tawny. Aug. - Oct.

§ 3. ASTER proper. Panicled Asters.

8 A cordifolius 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, palo blue varying to white. Lower leaves large. Petioles more or less winged, hairy-. Above, the leaves are gradually reduced to small or minute bracts. Sept.

9 A. sagittifolius Willd. Arrow-leaved Aster. St. with 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

2 - 4f high, dividing into many ascending, rigid branches, with numerous and crowded heads, forming a compound panicle of leafy racemes. Heads small, each with about 12 rays, which are white or with various shades of blue. Leaves becoming smaller above, lanceolate and even linear. Sept.

10 A. undulatus L. St. paniculate, puberulent; branches bracted, 1 (or few)-flowered; lvs. oblong-cordate, amplexicaul, entire, hairy, somewhat undulate or crenate-serrate, lower ones ovate, cordate, subserrate, with winged petioles; invol. closely imbricate. - Dry woods, U. S. Plant rough, about 2f high, with slender branches. Lower lvs. on winged petioles, cordate, acuminate, upper ones becoming narrow-ovate and clasping. Fls. pale blue, solitary or somewhat clustered, forming a loose, racemous panicle. Aug., Sept.

. diversifolius. Very slender; lvs. shorter in proportion, ovate and oblong; branches slender, 1-flowered. - South (Pond.) (A diversifolius, Mx.)

11 A. azureus Lindl. Scabrous; stand racemous-paniculate branches slender but rigid; lvs. lance-ovate, cordate, slightly serrate, on slender petioles, middle and upper ones lanceolate and linear, acute at each end, sessile, entire, highest subulate; hds. broadly obconic; scales oblong-linear, acute, appressed. - Woods and prairies, W. States. St. about 2f high. Lvs. of several forms between the lowest cordate ' to the small, subulate, numerous, floral ones of the slender branches. Rac. pani-cled, with middle sized heads, sometimes reduced to a single raceme or head

111/2 A. anomalus Eng. Lvs. as in No. 11. Invol. with loose recurved scales.- Limestone cliffs. I11. (J. Wolf), Iowa (Dr. Cousins), and Mo. Hds. large, handsome.