This taxon is known from rocky river banks in the Appalachian Plateaus of Tenn. and Ky., especially the upper Cumberland Rv. plus its tributaries, and the Obed-Emory Rv. It also occurs in W.Va. along the New Rv. and perhaps elsewhere (W.Va. Univ. herbarium). These riparian plants differ from var. coridifolium in their relatively large heads, usually white rays (versus usually bluish), generally shorter flowering branches, more ascending leaves that remain relatively wide on flowering branches, and relatively short rhizomes. In these characters they generally resemble var. strictior (and were perhaps confused by Sm); both taxa appear to be tetraploids (2n = 32; J.C. Semple, pers. comm.). However, their heads are distinctly larger, with involucres ca. 5-7 mm long (versus 3-5 mm). Moreover, they are disjunct from the largely midwestern var. strictior. Their riparian habitat is similar to that of S. tradescanti (L.) Nesom, a northeastern diploid (2n = 16) that may be closely related. Similar biogeographic patterns occur in Eurybia (saxicastellii versus radula), Solidago Sect. Maritimae (austrina versus uliginosa), and Solidago Sect. Humiles (arenicola versus racemosa).