Gucker, C.L.; Shaw, N.L. 2023. Purple milkvetch (Astragalus agrestis Douglas ex G. Don). In: Gucker, C.L.; Shaw, N.L., eds. Western forbs: Biology, ecology, and use in restoration. Reno, NV: Great Basin Fire Science Exchange. https://westernforbs.org/species/purple-milkvetch-astragalus-agrestis/