| Revealia stevioides R.M. King & H. Rob., 1976 |
| Rhaponticum Ludw., 1757 |
| Rhaponticum repens (L.) Hidalgo, 2006 |
| Rhodoseris Turcz., 1851 |
| Rhodoseris conspicua Turcz., 1851 |
| Rhysolepis S.F. Blake, 1917 |
| Rhysolepis kingii H. Rob., 1972 |
| Rhysolepis morelensis (Greenm.) S.F. Blake, 1917 |
| Rhysolepis palmeri (A. Gray) S.F. Blake, 1917 |
| Ridan Adans., 1763 |
| Riddellia Nutt., 1841 |
| Riddellia cooperi A. Gray, 1868 |
| Riddellia tagetina Nutt., 1841 |
| Robinsonecio T.M. Barkley & J.P. Janovec, 1996 |
| Robinsonecio gerberifolius (Sch. Bip. ex Hemsl.) T.M. Barkley & Janovec, 1996 |
| Robinsonecio porphyresthes (T.M. Barkley) T.M. Barkley & Janovec, 1996 |
| Rockhausenia D.J.N. Hind, 2022 |
| Rockhausenia nubigena (Kunth) D.J.N. Hind, 2022 |
| Rojasianthe Standl. & Steyerm., 1940 |
| Rojasianthe superba Standl. & Steyerm., 1940 |