| Capriola dactylon var. maritima (Kunth) Hitchc., 1920 |
| Caryochloa Trin., 1826 |
| Caryochloa stipodes (Trin. & Rupr.) Kuntze, 1891 |
| Caryophyllea Opiz, 1852 |
| Caryophyllea airoides Opiz, 1852 |
| Catabrosa P. Beauv., 1812 |
| Catabrosa nervata (Willd.) Link, 1844 |
| Catabrosa pumila (Pursh) Roem. & Schult., 1817 |
| Catapodium Link, 1827 |
| Catapodium rigidum (L.) C.E. Hubb., 1953 |
| Catatherophora Steud., 1829 |
| Cathestecum J. Presl, 1830 |
| Cathestecum annuum Swallen, 1937 |
| Cathestecum brevifolium Swallen, 1937 |
| Cathestecum erectum Vasey & Hack., 1884 |
| Cathestecum multifidum Griffiths, 1912 |
| Cathestecum prostratum J. Presl, 1830 |
| Cathestecum stoloniferum (E. Fourn.) Griffiths, 1912 |
| Cathestecum varium Swallen, 1937 |
| Cenchrinae Dumort., 1829 |