| Carex ehrenbergiana Boeckeler, 1877 |
| Carex emmonsii Dewey ex Torr., 1836 |
| Carex emmonsii var. australis (L.H. Bailey) Rettig, 1989 |
| Carex emoryi Dewey, 1859 |
| Carex endlichii Kük., 1910 |
| Carex erinacea Muhl., 1806 |
| Carex eurycarpa Holm, 1905 |
| Carex eurycarpa var. oxycarpa (Holm) Kük., 1909 |
| Carex evadens S. González & Reznicek, 1997 |
| Carex felipensis C.B. Clarke, 1908 |
| Carex festivelloides Reznicek, 1993 |
| Carex filifolia Nutt., 1818 |
| Carex filifolia var. filifolia Nutt., 1818 |
| Carex filifolia var. valida Olney ex L.H. Bailey, 1885 |
| Carex firmula (Kük.) J.R. Starr, 2015 |
| Carex flexirostris Reznicek, 1986 |
| Carex foenea Muhl., 1817 |
| Carex fracta Mack., 1922 |
| Carex fructus Reznicek, 1990 |
| Carex fuscolutea Boeckeler, 1886 |