| Cryptostegia madagascariensis Bojer ex Decne., 1844 |
| Cynanchum L., 1753 |
| Cynanchum (Mellichampia) (A. Gray) Woodson, 1941 |
| Cynanchum angustifolium Pers., 1805 |
| Cynanchum apocynellum (Gleason & Moldenke) Spellman, 1973 |
| Cynanchum astephanoides (A. Gray ex S. Watson) Standl., 1924 |
| Cynanchum barbigerum (Scheele) Shinners, 1951 |
| Cynanchum bonplandianum Schult., 1820 |
| Cynanchum californicum (Benth.) Moran, 1989 |
| Cynanchum chiapense (A. Gray) Standl. & Steyerm., 1947 |
| Cynanchum clausum Jacq., 1763 |
| Cynanchum cubense (A. Rich.) Woodson, 1941 |
| Cynanchum cyathiforme (Sundell) W.D. Stevens, 2000 |
| Cynanchum eulaxiflorum Lundell, 1977 |
| Cynanchum foetidum (Cav.) Kunth, 1819 |
| Cynanchum glaberrimum (Woodson) L.O. Williams, 1968 |
| Cynanchum grandiflorum Cav., 1791 |
| Cynanchum jaliscanum (Vail) Woodson, 1941 |
| Cynanchum kunthii (Decne.) Standl., 1924 |
| Cynanchum ligulatum (Benth.) Woodson, 1941 |