| Paspalum orbiculatum Poir., 1804 |
| Paspalum orbiculatum subsp. potarense Chase, 1922 |
| Paspalum orbiculatum var. lanuginosum Henrard, 1942 |
| Paspalum oricolum Millsp. & Chase, 1903 |
| Paspalum oriziformis Steud., 1855 |
| Paspalum orthos Schult. ex Kunth, 1833 |
| Paspalum oryziformis Steud. ex Döll, 1877 |
| Paspalum ovatum Nees ex Trin., 1826 |
| Paspalum ovatum var. grandiflorum Nees, 1829 |
| Paspalum oxyanthum Steud., 1855 |
| Paspalum palmeri Chase, 1929 |
| Paspalum paniculatum L., 1759 |
| Paspalum papillosum Spreng., 1819 |
| Paspalum paspalodes (Michx.) Scribn., 1894 |
| Paspalum paspaloides (Michx.) Scribn., 1894 |
| Paspalum paucispicatum Vasey, 1893 |
| Paspalum pauperculum E. Fourn., 1886 |
| Paspalum pauperculum var. altius E. Fourn., 1886 |
| Paspalum pectinatum Nees ex Trin., 1828 |
| Paspalum pectinatum Nees, 1829 |