| Eleocharis rostellata (Torr.) Torr., 1843 |
| Eleocharis rostellata var. congdonii Jeps., 1922 |
| Eleocharis rostellata var. occidentalis S. Watson, 1880 |
| Eleocharis rothiana Boeckeler, 1860 |
| Eleocharis rzedowskii S. González, 1985 |
| Eleocharis scariosa Steud., 1854 |
| Eleocharis schaffneri Boeckeler, 1886 |
| Eleocharis schottiana (Nees) Steud., 1854 |
| Eleocharis sellowiana Kunth, 1837 |
| Eleocharis sellowiana var. sellowiana Kunth, 1837 |
| Eleocharis septata Miq., 1843 |
| Eleocharis setacea R. Br., 1810 |
| Eleocharis sintenisii Boeckeler, 1888 |
| Eleocharis spiralis Boeckeler, 1870 |
| Eleocharis stolonifera (Nees) Boeckeler, 1870 |
| Eleocharis subcancellata C.B. Clarke, 1908 |
| Eleocharis sulcata Nees, 1834 |
| Eleocharis svensoniana S. González, 1985 |
| Eleocharis tenarum S. González & M. González, 2009 |
| Eleocharis tenuissima Boeckeler, 1870 |