| Panicum ovinum Scribn. & J.G. Sm., 1899 |
| Panicum owenae E.P. Bicknell, 1908 |
| Panicum pacificum Hitchc. & Chase, 1910 |
| Panicum pallens Sw., 1788 |
| Panicum pallens var. angustifolium Rupr., 1842 |
| Panicum pallens var. majus Nees, 1829 |
| Panicum pallens var. swartzii Nees, 1829 |
| Panicum palmaefolium J. Koenig, 1788 |
| Panicum palmeri Vasey, 1893 |
| Panicum palmifolia J. Koenig, 1788 |
| Panicum paludicola Miq., 1857 |
| Panicum paludivagum Hitchc. & Chase, 1910 |
| Panicum pampinosum Hitchc. & Chase, 1910 |
| Panicum panicoides (P. Beauv.) Hitchc., 1919 |
| Panicum paniculatum (L.) Kuntze, 1898 |
| Panicum paniculiferum Steud., 1853 |
| Panicum paraguayense Steud. ex Döll, 1877 |
| Panicum parciflorum Steud., 1853 |
| Panicum parcum Hitchc. & Chase, 1910 |
| Panicum parvifolium Lam., 1791 |