| Muhlenbergia polypogonoides Hack., 1902 |
| Muhlenbergia porteri Scribn., 1896 |
| Muhlenbergia presliana Hitchc., 1935 |
| Muhlenbergia pringlei (Scribn.) Scribn., 1892 |
| Muhlenbergia pubescens (Kunth) Hitchc., 1935 |
| Muhlenbergia pubigluma Swallen, 1943 |
| Muhlenbergia pulcherrima Scribn. ex Beal, 1896 |
| Muhlenbergia purpurea Nutt., 1848 |
| Muhlenbergia purpusii Mez, 1921 |
| Muhlenbergia pusilla Steud., 1854 |
| Muhlenbergia quadridentata (Kunth) Kunth, 1829 |
| Muhlenbergia quadridentata (Kunth) Trin., 1824 |
| Muhlenbergia quitensis (Kunth) Hitchc., 1913 |
| Muhlenbergia racemosa (Michx.) Britton, Sterns & Poggenb., 1888 |
| Muhlenbergia ramosissima Vasey, 1886 |
| Muhlenbergia ramulosa (Kunth) Swallen, 1947 |
| Muhlenbergia reederorum Soderstr., 1967 |
| Muhlenbergia repens (J. Presl) Hitchc., 1912 |
| Muhlenbergia reverchonii Vasey & Scribn., 1892 |
| Muhlenbergia richardsonis (Trin.) Rydb., 1905 |