| Scleropogon longisetus Beetle, 1981 |
| Scleropogoninae Pilg., 1956 |
| Sclerostachya (Andersson ex Hack.) A. Camus, 1922 |
| Scolochloa Mert. & W.D.J. Koch, 1823 |
| Scolochloa arundinacea (P. Beauv.) Mert. & Koch, 1823 |
| Scolochloa donax (L.) Gaudin, 1828 |
| Scoparia Hitchc. & Chase, 1910 |
| Secale L., 1753 |
| Secale cereale L., 1753 |
| Secale turkestanicum Bensin, 1933 |
| Semeiostachys Drobow, 1941 |
| Senisetum Honda, 1932 |
| Senites Adans., 1763 |
| Senites capillaris Hitchc., 1913 |
| Senites hartwegii (E. Fourn.) Arthur, 1919 |
| Senites latifolia (E. Fourn.) Hitchc., 1913 |
| Senites latifolia subsp. pringlei (Hack.) Hitchc., 1913 |
| Senites mexicana (Kunth) Hitchc., 1913 |
| Senites pringlei (Scribn.) Hitchc., 1913 |
| Senites smilacifolia (Scribn.) Hitchc., 1913 |