| Lesquerella sinuosa Rollins, 1984 |
| Lesquerella wyndii Rollins & E.A. Shaw, 1973 |
| Leucosinapis (DC.) Spach, 1838 |
| Lexarzanthe Diego & Calderón, 2004 |
| Lexarzanthe mexicana (Iltis & Al-Shehbaz) Diego & Calderón, 2004 |
| Linostrophum Schrank, 1792 |
| Lobularia Desv., 1815 |
| Lobularia maritima (L.) Desv., 1815 |
| Lomaspora (DC.) Steud., 1841 |
| Lonchophora Durieu, 1847 |
| Loxostemon Hook. f. & Thomson, 1861 |
| Lunaria L., 1753 |
| Lunaria annua L., 1753 |
| Lycocarpus O.E. Schulz, 1924 |
| Lyrocarpa Hook. & Harv., 1845 |
| Lyrocarpa coulteri Hook. & Harv., 1845 |
| Lyrocarpa coulteri var. apiculata Rollins, 1941 |
| Lyrocarpa coulteri var. coulteri Hook. & Harv., 1845 |
| Lyrocarpa coulteri var. palmeri (S. Watson) Rollins, 1941 |
| Lyrocarpa linearifolia Rollins, 1949 |