Astragalus oxyphysus is a species of milkvetch known by the common name Mt. Diablo milkvetch or Stanislaus milk-vetch. It is endemic to central California, where it grows in dry grassland and scrub habitat in the Central Valley and the adjacent Inner Coast Ranges and Sierra Nevada foothills.[1]
Astragalus oxyphysus is a robust perennial herb forming clumps of erect, leafy stems up to 80 centimeters tall. Leaves are up to 17 centimeters long and are made up of many lance-shaped leaflets. The plant flowers in large inflorescences of up to 65 flowers each.
The individual flower is cream-colored and at least 2 centimeters long. The fruit is a hanging legume pod up to 4 centimeters long. It is inflated but narrow and dries to a thin, almost transparent papery texture.