| Astragalus militaris M.E. Jones, 1923 |
| Astragalus miserandus Greene, 1895 |
| Astragalus mollissimus Torr., 1827 |
| Astragalus mollissimus var. bigelovii (A. Gray) Barneby, 1964 |
| Astragalus mollissimus var. earlei (Greene ex Rydb.) Tidestr., 1935 |
| Astragalus mollissimus var. irolanus (M.E. Jones) Barneby, 1964 |
| Astragalus mollissimus var. nitens Barneby, 1964 |
| Astragalus moranii Barneby, 1976 |
| Astragalus nigrescens Pall., 1800 |
| Astragalus niquiriciaefolius Sessé & Moc., 1894 |
| Astragalus niveus (Rydb.) Barneby, 1944 |
| Astragalus nothoxys A. Gray, 1864 |
| Astragalus nuttallianus DC., 1825 |
| Astragalus nuttallianus var. austrinus (Small) Barneby, 1964 |
| Astragalus nuttallianus var. cedrosensis M.E. Jones, 1923 |
| Astragalus nuttallianus var. imperfectus (Rydb.) Barneby, 1942 |
| Astragalus nuttallianus var. zapatanus Barneby, 1956 |
| Astragalus oocarpus A. Gray, 1864 |
| Astragalus orcuttianus S. Watson, 1885 |
| Astragalus orizabae Seaton, 1893 |