| Panicum lagostis Trin., 1834 |
| Panicum lanatum Sw., 1788 |
| Panicum lanatum var. sorghoideum (Desv. ex Ham.) Griseb., 1864 |
| Panicum lancearium Trin., 1826 |
| Panicum lancearium var. lancearium Trin., 1826 |
| Panicum lancearium var. patulum (Scribn. & Merr.) Fernald, 1934 |
| Panicum langei E. Fourn., 1886 |
| Panicum languidum Hitchc. & Chase, 1910 |
| Panicum lanuginosum Elliott, 1816 |
| Panicum lanuginosum var. huachucae (Ashe) Hitchc., 1906 |
| Panicum lanuginosum var. implicatum (Scribn.) Fernald, 1934 |
| Panicum lanuginosum var. lindheimeri (Nash) Fernald, 1934 |
| Panicum lanuginosum var. papillosum (Schmoll) B. Boivin, 1979 |
| Panicum lanuginosum var. praecocius (Hitchc. & Chase) Dore, 1976 |
| Panicum lanuginosum var. septentrionale (Fernald) Fernald, 1934 |
| Panicum lanuginosum var. siccanum Hitchc. & Chase, 1906 |
| Panicum lanuginosum var. tennesseense (Ashe) Gleason, 1952 |
| Panicum lappaceum Willd. ex Spreng., 1825 |
| Panicum lasianthum Trin., 1830 |
| Panicum lassenianum Schmoll, 1939 |