Astragalus crassicarpus Nutt.
other common names: buffalo apple, buffalo pea, buffalo plum, milk vetch, buffalo bean
Astragalus: ancient Greek name for a leguminous plant. It actually means “star” and “milk.” (This is one of the largest genera of flowering plants in North America.)
Crassicarpus: from Latin and Greek, meaning “thick pod,” which aptly describes the thick, rounded fruit pods of this species
Legume family: Fabaceae (Leguminosae)
Photograph by Thomas Rosburg, Wildflowers of the Tallgrass Prairie: The Upper Midwest, Second Edition