| Schrankia distachya DC., 1825 |
| Schrankia heterocarpa Standl., 1940 |
| Schrankia latidens (Small) K. Schum., 1903 |
| Schrankia leptocarpa DC., 1825 |
| Schrankia quadrivalvis (L.) Merr., 1910 |
| Schrankia subinermis S. Watson, 1882 |
| Sciacassia Britton, 1930 |
| Sciacassia siamea (Lam.) Britton ex Britton & Rose, 1930 |
| Scytalis E. Mey., 1835 |
| Securigera DC., 1805 |
| Securigera varia (L.) Lassen, 1989 |
| Selerothamnus Harms, 1921 |
| Selerothamnus ehrenbergii Harms, 1921 |
| Selerothamnus purpusii Harms, 1921 |
| Senegalia Raf., 1838 |
| Senegalia acanthophylla Britton & Rose, 1928 |
| Senegalia acapulcensis Britton & Rose, 1928 |
| Senegalia acatlensis (Benth.) Britton & Rose, 1928 |
| Senegalia anisophylla (S. Watson) Britton & Rose, 1928 |
| Senegalia aristeguietana (L. Cárdenas) Seigler & Ebinger, 2012 |