R. fulgida has been defined in a narrow sense (Sm, F), as adopted here, or a much broader (Cr, FNA 21) sense. Typical fulgida is widespread in southeastern states on medium-acid soils, and it is scattered across Ky. on non-calcareous soils. A few Ky. colls. have been tentatively segregated here as var. spathulata; see notes under that name. There has also been much confusion with tenax, umbrosa and other species. R. fulgida may intergrade with tenax, especially along roadsides and other disturbed area; the use of limestone gravel on sandy uplands may enhance the intergradation. R. acuminata C.L. Boynt. & Beadle, based on colls. from e. Tenn., may just represent a robust form of typical R. fulgida, but it has suggested a distinct variant or transition to other taxa (such as tenax or umbrosa). It has unusually broad, darker leaves up to 3-4 cm wide.