| Cotula pygmaea (Kunth) Benth. & Hook. f. ex Hemsl., 1881 |
| Cotula spilanthes L., 1767 |
| Cotula viscosa L., 1753 |
| Cotulinae Kitt., 1853 |
| Coulterella Vasey & Rose, 1890 |
| Coulterella capitata Vasey & Rose, 1890 |
| Coulterellinae H. Rob., 1978 |
| Crassina Scepin, 1758 |
| Crassina elegans (Jacq.) Kuntze, 1891 |
| Crepidinae Cass. ex Dumort., 1827 |
| Crepis L., 1753 |
| Crepis barberi Greenm., 1904 |
| Crepis capillaris (L.) Wallr., 1840 |
| Crepis japonica (L.) Benth., 1861 |
| Crepis runcinata (L.E. James) Torr. & A. Gray, 1843 |
| Crepis runcinata subsp. barberi (Greenm.) Babc. & Stebbins, 1938 |
| Crepis runcinata var. barberi (Greenm.) B.L. Turner, 1990 |
| Crepis runcinata var. runcinata (L.E. James) Torr. & A. Gray, 1843 |
| Critonia P. Browne, 1756 |
| Critonia aromatisans (DC.) R.M. King & H. Rob., 1971 |