| Rhabdadenia Müll. Arg., 1860 |
| Rhabdadenia biflora (Jacq.) Müll. Arg., 1860 |
| Rhabdadenia cordata (Mill.) Miers, 1878 |
| Rhabdadenia paludosa (Vahl) Miers, 1878 |
| Rhabdadenieae Pichon ex M.E. Endress, 2014 |
| Rothrockia A. Gray, 1885 |
| Rothrockia cordifolia A. Gray, 1885 |
| Rotundanthus Morillo, 2015 |
| Rotundanthus fulvidus (F. Ballard) Morillo, 2015 |
| Ruehssia H. Karst., 1849 |
| Ruehssia astephanoides (A. Gray) L.O. Alvarado, 2021 |
| Ruehssia bourgaeana (Baill.) L.O. Alvarado, 2021 |
| Ruehssia callichicola (Carnevali & Juárez-Jaimes) L.O. Alvarado, 2021 |
| Ruehssia callosa (Juárez-Jaimes & W.D. Stevens) L.O. Alvarado, 2021 |
| Ruehssia carterae (W.D. Stevens & Juárez-Jaimes) L.O. Alvarado, 2021 |
| Ruehssia coulteri (Hemsl.) L.O. Alvarado, 2021 |
| Ruehssia cuixmalensis (Juárez-Jaimes & L.O. Alvarado) L.O. Alvarado, 2021 |
| Ruehssia edulis (S. Watson) L.O. Alvarado, 2021 |
| Ruehssia gallardoae (Lozada-Pérez) Lozada-Pérez, 2021 |
| Ruehssia gualanensis (Donn. Sm.) L.O. Alvarado, 2021 |