| Eragrostis rigida (Vasey) Scribn., 1891 |
| Eragrostis robusta Stent, 1927 |
| Eragrostis rufescens Schrad. ex Schult., 1824 |
| Eragrostis rufescens var. mesoamericana Davidse, 1992 |
| Eragrostis salzmannii Steud., 1854 |
| Eragrostis scabra Phil., 1860 |
| Eragrostis scribneriana Hitchc., 1913 |
| Eragrostis secundiflora J. Presl, 1830 |
| Eragrostis secundiflora subsp. oxylepis (Torr.) S.D. Koch, 1978 |
| Eragrostis secundiflora subsp. secundiflora J. Presl, 1830 |
| Eragrostis secundiflora var. capitata (E. Fourn.) Beetle, 1983 |
| Eragrostis sessilispica Buckley, 1862 |
| Eragrostis silveana Swallen, 1932 |
| Eragrostis simpliciflora (J. Presl) Steud., 1854 |
| Eragrostis soratensis Jedwabn., 1924 |
| Eragrostis spectabilis (Pursh) Steud., 1840 |
| Eragrostis spectabilis var. spectabilis (Pursh) Steud., 1840 |
| Eragrostis spicata Vasey, 1891 |
| Eragrostis sporoboloides J.G. Sm. & Bush, 1895 |
| Eragrostis squarrosa E. Fourn., 1886 |