| Eleocharis parishii Britton, 1889 |
| Eleocharis parvula (Roem. & Schult.) Link ex Bluff, Nees & Schauer, 1836 |
| Eleocharis parvula var. anachaeta (Torr.) Svenson, 1934 |
| Eleocharis parvula var. coloradoensis (Britton) Beetle, 1938 |
| Eleocharis parvula var. parvula (Roem. & Schult.) Link ex Bluff, Nees & Schauer, 1836 |
| Eleocharis pauciflora (Lightf.) Link, 1827 |
| Eleocharis pauciflora var. bernardina (Munz & I.M. Johnst.) Svenson, 1929 |
| Eleocharis pittieri Boeckeler, 1896 |
| Eleocharis plantaginea (Sw.) Boeckeler, 1870 |
| Eleocharis plicarhachis (Griseb.) Svenson, 1929 |
| Eleocharis purpureo-vaginata Boeckeler, 1896 |
| Eleocharis pygmaea Torr., 1836 |
| Eleocharis pygmaea var. anachaeta Torr., 1836 |
| Eleocharis quadrangulata (Michx.) Roem. & Schult., 1817 |
| Eleocharis quinqueflora (Hartmann) O. Schwarz, 1949 |
| Eleocharis quinqueflora var. bernardina (Munz & I.M. Johnst.) S. González & P.M. Peterson, 1996 |
| Eleocharis radicans (A. Dietr.) Kunth, 1837 |
| Eleocharis ravenelii Britton, 1903 |
| Eleocharis retroflexa (Poir.) Urb., 1900 |
| Eleocharis retroflexa subsp. retroflexa (Poir.) Urb., 1900 |