| Astragalus peonis (M.E. Jones) James, 1951 |
| Astragalus pervelutinus Rydb., 1929 |
| Astragalus pilosior Spellenb. E.& W. Anderson, 2019 |
| Astragalus piscinus (M.E. Jones) Barneby, 1964 |
| Astragalus playanus M.E. Jones, 1898 |
| Astragalus pomonensis M.E. Jones, 1902 |
| Astragalus pomphocalyx Villarreal & M.A. Carranza, 1994 |
| Astragalus potosinus Barneby, 1964 |
| Astragalus pringlei S. Watson, 1886 |
| Astragalus prorifer M.E. Jones, 1893 |
| Astragalus pueblae M.A. Jones, 1912 |
| Astragalus purpusii M.E. Jones, 1912 |
| Astragalus purpusii var. coccineus Parry, 1890 |
| Astragalus quinqueflorus S. Watson, 1886 |
| Astragalus racemosus Pursh, 1814 |
| Astragalus racemosus var. brevisetus M.E. Jones, 1895 |
| Astragalus racemosus var. racemosus Pursh, 1814 |
| Astragalus racemosus var. treleasei Ch. Porter, 1945 |
| Astragalus racemosus var. typicus Ch. Porter, 1945 |
| Astragalus radicans Hornem., 1815 |