| Lichenodiplis lecanorae (Vouaux) Dyko & D. Hawksw., 1979 |
| Lineolata Kohlm. & Volkm.-Kohlm., 1990 |
| Lineolata rhizophorae (Kohlm. & E. Kohlm.) Kohlm. & Volkm.-Kohlm., 1990 |
| Listeromyces Penz. & Sacc., 1902 |
| Listeromyces insignis Penz. & Sacc., 1902 |
| Lobocolax M. Howe, 1914 |
| Lobocolax deformans M. Howe, 1914 |
| Lodderomyces Van del Walt, 1966 |
| Lodderomyces elongisporus (Recca & Mrak) Van del Walt, 1971 |
| Lychnagalma Haeckel, 1888 |
| Lychnagalma utricularia (Claus, 1879) |
| Lymnorea Péron & Lesueur, 1810 |
| Lymnorea borealis Mayer, 1900 |
| Macrovalsaria Petr., 1962 |
| Macrovalsaria megalospora (Mont.) Sivan., 1975 |
| Manoharachariella Bagyan., N. K. Rao & Kunwar, 2009 |
| Manoharachariella lignicola Bagyan., N. K. Rao & Kunwar, 2009 |
| Marrus Totton, 1954 |
| Marrus orthocannoides Totton, 1954 |
| Masoniomyces J. L. Crane & Dumont, 1975 |