| Tetrachyron brandegeei (Greenm.) Wussow & Urbatsch, 1980 |
| Tetrachyron chimalapanum B.L. Turner, 2006 |
| Tetrachyron discolor (A. Gray) Wussow & Urbatsch, 1980 |
| Tetrachyron grayi (Klatt) Wussow & Urbatsch, 1980 |
| Tetrachyron manicatum Schltdl., 1847 |
| Tetrachyron oaxacana B.L. Turner, 1986 |
| Tetrachyron omissum Rzed. & Calderón, 2008 |
| Tetrachyron orizabaensis (Klatt) Wussow & Urbatsch, 1980 |
| Tetrachyron orizabaensis var. orizabaensis (Klatt) Wussow & Urbatsch, 1980 |
| Tetrachyron orizabaensis var. websteri (Wussow & Urbatsch) Wussow & Urbatsch, 1980 |
| Tetrachyron paneroi B.L. Turner, 2016 |
| Tetrachyron torresii B.L. Turner, 1985 |
| Tetrachyron websteri (Wussow & Urbatsch) B.L. Turner, 1988 |
| Tetradymia DC., 1838 |
| Tetradymia comosa A. Gray, 1877 |
| Tetragonotheca L., 1753 |
| Tetragonotheca texana A. Gray & Engl., 1846 |
| Tetraneuris Greene, 1898 |
| Tetraneuris linearifolia (Hook.) Greene, 1898 |
| Tetraneuris linearifolia var. linearifolia (Hook.) Greene, 1898 |