| Astragalus jaliscensis (Rydb.) Barneby, 1964 |
| Astragalus julianus M.E. Jones, 1895 |
| Astragalus lagunensis M.E. Jones, 1898 |
| Astragalus legionensis Barneby, 1964 |
| Astragalus lentiginosus Douglas ex Hook., 1831 |
| Astragalus lentiginosus var. australis Barneby, 1945 |
| Astragalus lentiginosus var. borreganus M.E. Jones, 1898 |
| Astragalus lentiginosus var. ineptus (A. Gray) M.E. Jones, 1923 |
| Astragalus lentiginosus var. lentiginosus Douglas ex Hook., 1831 |
| Astragalus leptocarpoides (M.E. Jones) Cory, 1936 |
| Astragalus leptocarpus Torr. & A. Gray, 1838 |
| Astragalus leucopsis (Torr. & A. Gray) Torr., 1859 |
| Astragalus leucopsis var. lonchus M.E. Jones, 1923 |
| Astragalus longissimus (M.E. Jones) Barneby, 1964 |
| Astragalus lotiflorus Hook., 1831 |
| Astragalus lozani (M.E. Jones) Rose ex M.E. Jones, 1923 |
| Astragalus lyonnetii Barneby, 1964 |
| Astragalus macgregorii (Rydb.) Tidestr., 1937 |
| Astragalus madrensis M.E. Jones, 1923 |
| Astragalus magdalenae Greene, 1888 |