Herbage sparsely to moderately relatively soft -hairy. Distal cauline leaf blades lanceolate to elliptic, not much reduced distally. Heads in compact to lax pyramidal arrays, branches divergent and recurved arrays, proximal branches sometimes much elongated. Rays florets 4-13. 2n = 18, 36. Flowering Aug-Oct. A range of soils, fields, woods and usually wet grounds, along water courses; 0-1200+ m; St. Pierre and Miquelon; N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Miss., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis. Typical var. rugosa is a generally more northern race of the species but occurs infrequently scattered across the southern United States. Although var. villosa has often been recognized (e.g., H. A. Gleason and A. Cronquist 1991), it grades completely into var. rugosa. Single clones include shoots with long-branched arrays and others with short-branched ones not exceeding the subtending leaves. The variety is diploid throughout its range, with a few scattered tetraploids.
Subspecies 2 (2 in the flora): e United States; Mexico.
From Flora of Indiana (1940) by Charles C. Deam
Infrequent in the lake area and local south of it. In the northern part of the state it is found mostly on the wet or moist borders of lakes, bogs, and marshes. In the southern part it grows in wet woodland. It is to be noted that Indiana plants differ from that shown in plate 426 of Rhodora, 1938. The leaves of our plants are not oblanceolate but are of a lanceolate, ovate, or elliptic type and the surface is more or less rugose both above and beneath. The pubescence of the upper surface of the leaves is sparse and consists of simple, short, stout, colorless, conical hairs, arising from a papillose base and is usually more or less appressed. The pubescence of plants I have seen from New England consists of multicellular, flattened trichomes similar to those of Solidago ulmifolia and the surface of the leaves is not conspicuously rugose. The trichomes of the New England plants arise mostly from veinlets while ours arise mostly from the spaces enclosed by the veinlets. The blades of Indiana plants are usually thick while those of New England plants are thin.