This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Aster paniculatus Lam. Encycl. 1: 306. 1783.
Aster tenuifolius var. bellidiflorus T. & G. Fl. N. A.
2: 132. 1841.
Stem glabrous or nearly so, or sometimes pubescent, paniculately much branched, 20-8° high. Leaves lanceolate to oblong-lanceolate or linear, acuminate at the apex, narrowed to a sessile or slightly clasping base, glabrous, usually thin, roughish-margined, those of the stem sparingly serrate, or sometimes entire, 3'-6' long, 3"-o wide, the upper and those of the branches gradually smaller; heads numerous, 8"-10" broad; involucre 3"-4" high, its bracts narrowly linear-lanceolate, acuminate, appressed, green-tipped, imbricated in 4 or 5 series; rays numerous, white, or faintly tinged with violet, 3"-4" long; pappus white or nearly so; achenes minutely pubescent.
In moist soil, New Brunswick to western Ontario and Montana, south to New Jersey, Virginia, Kentucky, Louisiana and Missouri. Consists of many races, differing in leaf-form, leaf-serration, size of heads, color of rays, and pubescence. Aug.-Oct.
Aster missouriensis Britton, in Britt. & Brown, 111. Fl. 3: 378. 1898.
Stem densely puberulent or pubescent, at least above, much branched, 2° high or more. Leaves thin, oblong-lanceolate to oblanceolate, acute or acuminate at the apex, sharply serrate above the middle, gradually tapering to an entire sessile or slightly clasping base, or the lower petioled, puberulent above, finely pubescent beneath, the larger 3'-4' long, the upper much smaller, entire; heads 6"-8" broad, pan-icled, short-peduncled, or terminating short leafy branchlets, sometimes somewhat secund; involucre 2"-3" high, its linear acute bracts well imbricated, ciliate or pubescent; rays white.
In moist soil, Kansas, Missouri and Iowa. Sept.-Oct.
Aster Tradescanti L. Sp. Pl. 876. 1753.
Stem slender, paniculately branched, 2°-5° high, the branches usually ascending and often pubescent in lines. Stem leaves linear-lanceolate or lanceolate, acuminate at the apex, narrowed to a sessile base, 3'-6' long, 1 1/2"-6" wide, glabrous or nearly so on both sides, commonly thin, sharply serrate in the middle with low teeth, or sometimes entire; heads very numerous, racemose but not secund on the branches, 5"-8" broad; involucre hemispheric to broadly turbinate, 2"-3" high, its bracts linear, acute, appressed, green-tipped, imbricated in 4 or 5 series; rays white or nearly so, numerous, 2"-3" long; pappus white; achenes minutely pubescent.
In fields and swamps, Maine to Virginia, Ontario, Illinois and Missouri. Aug.-Oct.
Aster saxatilis (Fernald) Blanchard, of rocky situations in New England, appears to be a low race of this species, rather than of A. vimineus.