| Pooideae Benth., 1861 |
| Poranthera Raf., 1830 |
| Poranthera ciliata (Elliott) Raf. ex B.D. Jacks., 1894 |
| Poranthera nutans Raf. ex B.D. Jacks., 1894 |
| Porroteranthe Steud., 1854 |
| Preissia Opiz, 1852 |
| Pringleochloa Scribn., 1896 |
| Pringleochloa stolonifera (E. Fourn.) Scribn., 1896 |
| Procerae Ohwi, 1942 |
| Prosphysis Dulac, 1867 |
| Psammophila Schult., 1822 |
| Psammopyrum Á. Löve, 1986 |
| Pseudechinolaena Stapf, 1919 |
| Pseudechinolaena polystachya (Kunth) Stapf, 1919 |
| Pseudobrachiaria Launert, 1970 |
| Pseudobromus K. Schum., 1895 |
| Pseudoechinolaena Hook. f., 1896 |
| Pseudoeriocoma Romasch., P.M. Peterson & Soreng, 2019 |
| Pseudoeriocoma acuta (Swallen) Romasch., 2019 |
| Pseudoeriocoma constricta (Hitchc.) Romasch., 2019 |