Although often treated as a species (F, W), this relatively southern taxon may be weakly separated from the more widespread, less robust marginatus, and these are sometimes combined (e.g. FNA 22). Several colls. from Ky. appear intermediate and further analysis is required. Sorrie & Knapp (in W) have emphasized the larger vegetative dimensions of biflorus, especially blade width (the widest 3.1-4.5 mm versus 1.6-2.6 mm), but earlier treatments have emphasized number of glomerules and other characters of the inflorescence (F). Reportedly, biflorus ranges as far south as Argentina, and it extends into more seasonally drying sites, such as pine savannas (W).