This southeastern species is unknown in Ky. but it is likely to occur, since there are several records from the Cumberland Plateau in Tenn., north to within 30 miles of the state line (Ch). It is in the distinctive series Tenuissimae, with achenes white or very pale grey (versus yellowish, brown or olive in series Eleocharis). E. microcarpa also has largely annual habit, sometimes mat-forming via proliferating and arching inflorescences (stoloniferous), sometimes entirely vegetative (FNA 23; W).