| Panicum rudgei Roem. & Schult., 1817 |
| Panicum rudgei var. brasiliense Raddi, 1823 |
| Panicum rugelii Griseb., 1866 |
| Panicum rugulosum Trin., 1826 |
| Panicum rugulosum f. effusum Hack., 1909 |
| Panicum rugulosum var. condensatum Hack., 1909 |
| Panicum rugulosum var. glabrescens Döll, 1877 |
| Panicum rugulosum var. hirtiglume Griseb., 1866 |
| Panicum rugulosum var. lasianthum (Trin.) Hack., 1906 |
| Panicum rugulosum var. pubescens Döll, 1877 |
| Panicum rugulosum var. subvelutinum Döll, 1877 |
| Panicum ruprechtii E. Fourn., 1886 |
| Panicum ruscifolium Kunth, 1815 |
| Panicum ruscifolium var. ruscifolium Kunth, 1815 |
| Panicum sabulicola Nees, 1829 |
| Panicum sabulorum Lam., 1798 |
| Panicum sabulorum var. patulum (Scribn. & Merr.) C.F. Reed, 1989 |
| Panicum sabulorum var. thinium (Hitchc. & Chase) C.F. Reed, 1989 |
| Panicum saccharatum Buckley, 1866 |
| Panicum sacchariferum (L.) Salisb., 1796 |