| 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 |
| Panicum parviglume Hack., 1901 |
| Panicum parvipaniculatum Ashe, 1900 |
| Panicum parvispiculum Nash, 1897 |
| Panicum paspaliforme J. Presl, 1830 |
| Panicum paspaloides Pers., 1805 |
| Panicum patagonicum Hieron., 1881 |
| Panicum patentifolium Nash, 1899 |
| Panicum patentissimum Desv. ex Poir., 1816 |