Astragalus monoensis is a rare species of milkvetch known by the common name Mono milkvetch. It is endemic to the open pumice plains of central Mono County, California.
Astragalus monoensis is a rhizomatous perennial herb with stems growing partly underground and emerging to lie flat on the sand. The leaves are up to long and are made up of several tiny oval-shaped leaflets. Stem and leaflets are hairy.
The inflorescence is a cluster of 6 to 12 very pale pink to yellowish flowers, each around a centimeter long. The fruit is a legume pod, curved to bent in shape and drying to a papery, hairy texture. It is in length and contains around 18 to 20 seeds in its two chambers.