| Lesquerella palmeri S. Watson, 1888 |
| Lesquerella peninsularis Wiggins, 1933 |
| Lesquerella pueblensis Payson, 1922 |
| Lesquerella purpurea (A. Gray) S. Watson, 1888 |
| Lesquerella purpurea subsp. foliosa (Rollins) Rollins & E.A. Shaw, 1973 |
| Lesquerella rosei Rollins, 1984 |
| Lesquerella rosei var. perotensis Rollins, 1984 |
| Lesquerella schaffneri S. Watson, 1888 |
| 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 |