| Senna tomentosa Batka, 1854 |
| Senna tonduzii (Standl.) H.S. Irwin & Barneby, 1982 |
| Senna toroides Roxb., 1832 |
| Senna undulata (Benth.) H.S. Irwin & Barneby, 1982 |
| Senna uniflora (Mill.) H.S. Irwin & Barneby, 1982 |
| Senna unijuga (Rose) H.S. Irwin & Barneby, 1982 |
| Senna villosa (Mill.) H.S. Irwin & Barneby, 1982 |
| Senna wislizeni (A. Gray) H.S. Irwin & Barneby, 1979 |
| Senna wislizeni var. painteri (Britton) H.S. Irwin & Barneby, 1979 |
| Senna wislizeni var. pringlei (Rose) H.S. Irwin & Barneby, 1982 |
| Senna wislizeni var. villosa (Britton) H.S. Irwin & Barneby, 1979 |
| Senna wislizeni var. wislizeni (A. Gray) H.S. Irwin & Barneby, 1979 |
| Senna x floribunda (Cav.) H.S. Irwin & Barneby, 1982 |
| Septentrionales E.R. Souza & L.P. Queiroz, 2013 |
| Sesbania Adans., 1763 |
| Sesbania Scop., 1777 |
| Sesbania cavanillesii S. Watson, 1882 |
| Sesbania drummondii (Rydb.) Cory, 1936 |
| Sesbania emerus (Aubl.) Urb., 1919 |
| Sesbania exaltata (Raf.) Rydb., 1924 |