The taxon seems to merit more than forma status, as treated in F. It occurs across most of the range of the species, but with less southern extension. Although locally distinct in Appalachian Ky., intermediates are known in other states (e.g. colls. at DOV). A. Reznicek, R. Naczi (pers. comm.) and others doubt the taxonomic significance of congestion versus extension within the inflorescences of scoparia (as in tribuloides).