Plants 7-200+ cm. Stems usually sparsely to ± densely hirsute, often glabrescent, sometimes glabrate proximally, sometimes entirely so (hirsute in lines in arrays). Leaves: abaxial faces paler than adaxial, with a dark, distinct reticulum, adaxial without impressed main veins; array leaves usually equal to mid cauline. 2n = 16, 32.

Flowering Aug-Oct. Wet soils, often peaty, open to moderately shaded, margins of alluvial deciduous woods and alder thickets, swamp margins, edges of bogs, stream and lake shores, marshes, wet meadows, early-melting coastal or riparian snowbeds with boreal forbs (northern alpine and subarctic regions), roadside and drainage ditches; 0-2000 m; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Sask.; Ala., Conn., Del., Ga., Ill., Ind., Iowa, Maine, Md., Mich., Minn., Mo., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., W.Va., Wis.; introduced in Europe.

The following forms that pertain to var. puniceum are not recognized here: Aster puniceus forma blandus (Pursh) Lepage, forma candidus Fernald, forma colbyi Shinners, forma demissus (Lindley) Fernald, forma etiamalbus Venard, and forma rufescens Fassett. Variety calderi is a dwarf morphotype at the northern limit of the range that does not deserve taxonomic recognition. Hybrids of var. puniceum with the following species have been reported: Symphyotrichum lanceolatum (probably A. tardiflorus Linnaeus var. lancifolius Fernald), S. lateriflorum, S. urophyllum, and S. cordifolium.

From Flora of Indiana (1940) by Charles C. Deam

Frequent in the northern part of the state, becoming infrequent to very rare in the southern part. It is an inhabitant of springy places along streams and about lakes and swamps. It rarely forms large colonies and sometimes grows to great height. In Noble County, I measured a specimen that was 9 feet high. [Variety compactus] is a form with subrhomboidal leaves that are usually as long as or longer than the branches. I have it from only Parke County where I found it in the remnant of Nigger Legs Prairie about a mile east of Rosedale. [Variety demissus] has elongate-lanceolate leaves that are usually as long as or longer than the branches. Peattie reported it from La Porte County and I have it from Grant, Lagrange, and Owen Counties. Buhl (Bull. Chicago Acad. Sci. 5: 9. 1934) was in error in reporting Peattie's collection as from Porter County. Peattie's report was from Trail Creek, Michigan City, which is in La Porte County.

……

Indiana Coefficient of Conservatism: C = 7

Wetland Indicator Status: OBL