Leaves: abaxial faces moderately to densely hairy. 2n = 32.

Flowering Aug-Oct. Often shaded, usually moist, alluvial soils, alluvial stream or lake shores, floodplain deciduous forests or thickets, bogs, marshes, edges of fields, roadsides; 10-300+ m; Ont., Que.; Ala. , Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Miss., Mo., Nebr., N.Y., N.C., Okla., Pa., S.Dak., Tenn., Tex., Vt., Wis.

A. G. Jones (1989) suggested that var. ontarionis hybridizes with Symphyotrichum lanceolatum, S. lateriflorum, and S. racemosum. Existence of such hybrids needs confirmation.

Probably infrequent in Indiana. My specimens are from low woodland bordering streams. My specimen no. 26479 from the Kankakee River in Porter County is provisionally referred to [variety thyrsoides, a plant with more densely racemose heads].