Carex molestiformis, described in 1997 as an endemic to the Ozark and Ouachita Mountain regions, is newly collected from Georgia, Mississippi, and Ohio. Herbarium records also have confirmed this species from North Carolina, Virginia, and West Virginia bringing the overall range of this species to 11 states. A morphological comparison of C. molestiformis from east of the Mississippi River with western populations did not reveal regional differences. Some eastern populations occupied ruderal habitat, namely drier grassy roadsides and hay meadows rather than the river bottom openings typical of western populations. New chromosome counts for this species from the eastern portion of its range confirmed existing reports of n  =  37 and also found agmatoploidy with n  =  35.