| Panicum manatense Nash, 1897 |
| Panicum marginellum Schrad., 1838 |
| Panicum martianum Nees, 1829 |
| Panicum martinicense Griseb., 1864 |
| Panicum maximum Jacq., 1781 |
| Panicum maximum var. bulbosum (Kunth) Vasey, 1878 |
| Panicum maximum var. gongylodes (Jacq.) Döll, 1877 |
| Panicum maximum var. maximum Jacq., 1781 |
| Panicum maximum var. trichoglume Robyns, 1932 |
| Panicum maynense Trin., 1836 |
| Panicum medium Muhl. ex Elliott, 1816 |
| Panicum megacarpum Steud. ex Griseb., 1864 |
| Panicum megapotamicum Spreng., 1827 |
| Panicum megastachyum J. Presl, 1830 |
| Panicum megiston Schult., 1824 |
| Panicum melicoides Poir., 1816 |
| Panicum melinis Trin., 1834 |
| Panicum melinis var. inerme Döll, 1877 |
| Panicum meridionale Ashe, 1898 |
| Panicum meridionale var. albemarlense (Ashe) Fernald, 1934 |