| Croton wilburii McVaugh, 1961 |
| Croton wilsonii Griseb., 1859 |
| Croton xalapensis Kunth, 1817 |
| Croton yecorensis V.W. Steinm. & Felger, 1998 |
| Croton ynesae Croizat, 1940 |
| Croton yucatanensis Lundell, 1940 |
| Croton zavaletae Conz.ex Rzed., 1988 |
| Crotoneae Dumort, 1829 |
| Crotonoideae Pax, 1884 |
| Crotonopsis Michx., 1803 |
| Ctenomeria Harv., 1842 |
| Cupameni Adans., 1763 |
| Cupamenis Raf., 1838 |
| Cyathophora Raf., 1838 |
| Cyathophora ciliata Raf., 1838 |
| Cyathophora heterophylla (L.) Raf., 1838 |
| Cyathophora picta Raf., 1838 |
| Cyclostigma Hochst. ex Endl., 1842 |
| Cyclostigma denticulatum Klotzsch, 1853 |
| Cyclostigma panamense Klotzsch, 1853 |