| Ctenodon simulans (Rose) A. Delgado, 2020 |
| Ctenodon sousae (Rudd ex A. Delgado & Sotuyo) A. Delgado, 2020 |
| Ctenodon standleyi (Ant. Molina) A. Delgado, 2020 |
| Ctenodon vigil (Brandegee) A. Delgado, 2020 |
| Ctenodon viscidulus (Michx.) D.B.O.S. Cardoso & A. Delgado, 2020 |
| Cylipogon Raf., 1819 |
| Cylipogon capitatum Raf., 1819 |
| Cymbosema Benth., 1840 |
| Cymbosema roseum Benth., 1840 |
| Cynometra L., 1753 |
| Cynometra colimensis Britton & Rose, 1930 |
| Cynometra hemitomophylla (Donn. Sm.) Britton & Rose, 1930 |
| Cynometra oaxacana Brandegee, 1915 |
| Cynometra retusa Britton & Rose, 1926 |
| Cystium (Steven) Steven, 1856 |
| Cystium agninum (Jeps.) Rydb., 1929 |
| Cystium coulteri (Benth.) Rydb., 1913 |
| Cystium ineptum (A. Gray) Rydb., 1906 |
| Cystopora Lunell, 1916 |
| Cystopora lotiflora (Hook.) Lunell, 1916 |