| Muhlenbergia asperifolia (Nees & Meyen ex Trin.) Parodi, 1928 |
| Muhlenbergia berlandieri Trin., 1841 |
| Muhlenbergia berteroniana (Schult.) Kunth, 1829 |
| Muhlenbergia beyrichiana Kunth, 1833 |
| Muhlenbergia biloba Hitchc., 1913 |
| Muhlenbergia botteri E. Fourn., 1886 |
| Muhlenbergia bourgeaei E. Fourn., 1885 |
| Muhlenbergia brandegeei C. Reeder, 1956 |
| Muhlenbergia brasiliensis Steud., 1854 |
| Muhlenbergia brevifolia Scribn. ex Beal, 1896 |
| Muhlenbergia brevifolia var. richardsonis (Trin.) M.E. Jones, 1912 |
| Muhlenbergia brevigluma (Scribn.) Columbus, 2010 |
| Muhlenbergia breviligula Hitchc., 1937 |
| Muhlenbergia brevis C.O. Goodd., 1941 |
| Muhlenbergia breviseta Griseb. ex E. Fourn., 1886 |
| Muhlenbergia brevivaginata Swallen, 1958 |
| Muhlenbergia buckleyana Scribn., 1890 |
| Muhlenbergia caespitosa Chapm., 1878 |
| Muhlenbergia calamagrostidea Kunth, 1829 |
| Muhlenbergia capillaris (Lam.) Trin., 1824 |