| Carex cooleyi Dewey, 1845 |
| Carex cortesii Liebm., 1850 |
| Carex coulteri Boott ex Hemsl., 1885 |
| Carex curviculmis Reznicek, 1993 |
| Carex densa (L.H. Bailey) L.H. Bailey, 1889 |
| Carex dentata Reznicek & S. González, 2021 |
| Carex diandra Schrank, 1781 |
| Carex diehlii M.E. Jones ex F.J. Herm., 1954 |
| Carex distentiformis F.J. Herm., 1971 |
| Carex donnell-smithii L.H. Bailey, 1889 |
| Carex douglasii Boott, 1839 |
| Carex durandii Boeckeler, 1896 |
| Carex durangensis Reznicek & S. González, 1995 |
| Carex eburnea Boott, 1839 |
| Carex echinata Murray, 1770 |
| Carex echinata subsp. echinata Murray, 1770 |
| Carex echinata subsp. townsendii (Mack.) Reznicek, 1987 |
| Carex echinata var. angustata (J. Carey) L.H. Bailey, 1889 |
| Carex egglestonii Mack., 1915 |
| Carex egglestonii var. festivelliformis F.J. Herm., 1960 |