| Wenderothia acuminata (Rose) Piper, 1925 |
| Wenderothia glabra M. Martens & Galeotti, 1843 |
| Wenderothia pilosa M. Martens & Galeotti, 1843 |
| Wenderothia villosa (Benth.) Piper, 1925 |
| Willardia Rose, 1891 |
| Willardia argyrotricha (Harms) F.J. Herm., 1947 |
| Willardia eriophylla (Benth.) Standl., 1922 |
| Willardia mexicana (S. Watson) Rose, 1891 |
| Willardia parviflora Rose, 1905 |
| Willardia schiedeana (Schltdl.) F.J. Herm., 1947 |
| Wisteria Nutt., 1818 |
| Wisteria sinensis (Sims) Sweet, 1826 |
| Wisteria villosa Rehder, 1926 |
| Xerocassia Britton & Rose, 1930 |
| Xerocassia armata (S. Watson) Britton & Rose, 1930 |
| Xiphocarpus C. Presl, 1830 |
| Xiphocarpus martinicensis C. Presl, 1830 |
| Xylophacos Rydb., 1903 |
| Xylophacos amphioxys (A. Gray) Rydb., 1906 |
| Xylophacos aragalloides Rydb., 1907 |