| Sphaerocardamum macropetalum (Rollins) Rollins, 1984 |
| Sphaerocardamum macrum (Standl.) Rollins, 1984 |
| Sphaerocardamum nesliiforme S. Schauer, 1847 |
| Sphaerocardamum ramosum Rollins, 1984 |
| Sphaerocardamum stellatum (S. Watson) Rollins, 1984 |
| Sphaerotorrhiza (O.E. Schulz) A.P. Khokhr., 1985 |
| Sprengeria Greene, 1906 |
| Sprengeria flava (Torr.) Greene, 1906 |
| Sprengeria minuscula Greene, 1906 |
| Sprengeria watsoniana Greene, 1906 |
| Stanfordia S. Watson, 1880 |
| Stanfordia californica S. Watson, 1880 |
| Stanleya Nutt., 1818 |
| Stanleya pinnata (Pursh) Britton, 1889 |
| Stanleyella Rydb., 1907 |
| Stenonema Hook., 1862 |
| Streptanthella Rydb., 1917 |
| Streptanthella longirostris (S. Watson) Rydb., 1917 |
| Streptanthus Nutt., 1825 |
| Streptanthus arizonicus S. Watson, 1890 |