| Steyermarkina R.M. King & H. Rob., 1971 |
| Steyermarkina naiguatensis V.M. Badillo, 1976 |
| Stramentopappus H. Rob. & V.A. Funk, 1987 |
| Stramentopappus congestiflorus Redonda-Mart. & Villaseñor, 2014 |
| Stramentopappus pooleae (B.L. Turner) H. Rob. & V.A. Funk, 1987 |
| Strongylosperma Less., 1832 |
| Strongylosperma australe (Siebert ex Spreng.) Less., 1832 |
| Strotheria B.L. Turner, 1972 |
| Strotheria gypsophila B.L. Turner, 1972 |
| Struchium P. Browne, 1756 |
| Struchium africanum P. Beauv., 1804 |
| Struchium americanum Poir., 1806 |
| Struchium herbaceum P. Browne ex J. St. -Hil., 1805 |
| Struchium sparganophorum (L.) Kuntze, 1891 |
| Stuessya B.L. Turner & F.G. Davies, 1980 |
| Stuessya apiculata (S.F. Blake) B.L. Turner & F.G. Davies, 1980 |
| Stuessya michoacana B.L. Turner & F.G. Davies, 1980 |
| Stuessya perennans B.L. Turner & F.G. Davies, 1980 |
| Stylimnus Raf., 1819 |
| Stylocline Nutt., 1840 |