| Trixis pringlei var. oligantha (B.L. Rob. & Greenm.) C.E. Anderson, 1971 |
| Trixis pringlei var. pringlei B.L. Rob. & Greenm., 1904 |
| Trixis pterocaulis B.L. Rob. & Greenm., 1904 |
| Trixis radialis (L.) Kuntze, 1891 |
| Trixis rosmarinifolia Nees, 1847 |
| Trixis rugulosa B.L. Rob. & Greenm., 1904 |
| Trixis seemannii (A. Gray) Sch. Bip., 1856 |
| Trixis silvatica B.L. Rob. & Greenm., 1904 |
| Trixis suffruticosa S. Watson, 1880 |
| Trixis turbinata (La Llave & Lex.) Sch. Bip., 1856 |
| Trixis wrightii B.L. Rob. & Greenm., 1904 |
| Troximon Gaertn., 1791 |
| Troximon heterophyllum (Nutt.) Greene, 1883 |
| Tuckermannia Nutt., 1841 |
| Tuckermannia maritima Nutt., 1841 |
| Turpinia Lex., 1824 |
| Turpinia tomentosa Lex., 1824 |
| Tussilagininae Dumort., 1827 |
| Tussilago L., 1753 |
| Tussilago nutans L., 1759 |