| Rhaphis zizanioides (L.) Roberty, 1954 |
| Rhipidocladum McClure, 1973 |
| Rhipidocladum barbinode Ruiz-Sanchez, C.D. Tyrrell & Vigosa, 2021 |
| Rhipidocladum bartlettii (McClure) McClure, 1973 |
| Rhipidocladum martinezii Davidse & R.W. Pohl, 1992 |
| Rhipidocladum pittieri (Hack.) McClure, 1973 |
| Rhipidocladum racemiflorum (Steud.) McClure, 1973 |
| Rhipidocladum zoqueorum Ruiz-Sanchez & C.D. Tyrrell & Sosa, 2019 |
| Rhombolytrum Link, 1833 |
| Rhombolytrum albescens (Vasey) Nash, 1901 |
| Rhynchelytrum Nees, 1836 |
| Rhynchelytrum repens (Willd.) C.E. Hubb., 1934 |
| Rhynchelytrum roseum (Nees) Stapf & C.E. Hubb., 1930 |
| Rhynchelytrum tonsum (Nees) Lanza & Mattei, 1910 |
| Rhytachne Desv. ex Ham., 1825 |
| Rhytachne guianensis (Hitchc.) Clayton, 1966 |
| Rhytachne rottboellioides Desv., 1825 |
| Rhytachne subgibbosa (Winkl. ex Hack.) Clayton, 1966 |
| Riedelia Kunth, 1833 |
| Riedelia mikanii Trin. ex Kunth, 1830 |