| 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 |
| Panicum latifolium L., 1753 |
| Panicum laxiflorum Lam., 1798 |
| Panicum laxiflorum var. pubescens Vasey, 1892 |
| Panicum laxiflorum var. strictirameum (Hitchc. & Chase) Fernald, 1934 |
| Panicum laxum Sw., 1788 |
| Panicum laxum var. amplissimum Hack., 1909 |
| Panicum laxum var. pubescens Döll, 1877 |
| Panicum laxum var. vestitum L.B. Sm. & Wassh., 1978 |
| Panicum leandrii Trin., 1835 |
| Panicum leiogonum Sieber ex Link, 1827 |
| Panicum leiophyllum E. Fourn., 1886 |
| Panicum lepidulum Hitchc. & Chase, 1910 |