| Talasium Spreng., 1827 |
| Tema Adans., 1763 |
| Terrellia Lunell, 1915 |
| Terrellia canadensis (L.) Lunell, 1915 |
| Terrellia canadensis var. glaucifolia (Willd.) Lunell ex Hitchc., 1935 |
| Terrellia diversiglumis (Scribn. & C.R. Ball) Lunell, 1915 |
| Terrellia glauca (Buckley) Lunell, 1915 |
| Tetragonocalamus Nakai, 1933 |
| Tetrapogon Desf., 1800 |
| Tetrapogon brandegeei (Vasey) P.M. Peterson, 2015 |
| Tetrapogon chlorideus (J. Presl) P.M. Peterson, 2015 |
| Thalysia Kuntze, 1891 |
| Thellungia Stapf, 1920 |
| Themeda Forssk., 1775 |
| Themeda foliosa (Kunth) Balansa, 1890 |
| Themeda quadrivalvis (L.) Kuntze, 1891 |
| Thinopyrum Á. Löve, 1980 |
| Thinopyrum intermedium (Host) Barkworth & D.R. Dewey, 1985 |
| Thinopyrum pycnanthum (Godr.) Barkworth, 1998 |
| Thrasya Kunth, 1815 |