The frequently used subspecific name Eleocharis palustris subsp. vulgaris Walters (1949) is a later homonym of E. palustris var. vulgaris Čelak. (1867), so a replacement name, E. palustris subsp. waltersii, is proposed here. Eleocharis palustris var. vulgaris Čelak. is neotypified here with a modern specimen with 2n = 38, making it a taxonomic synonym of E. palustris subsp. waltersii or E. vulgaris “(Walters) Á. Löve et D. Löve”.