Sandbar Milkvetch (Astragalus endopterus)  

The Sandbar Milkvetch is known exclusively from the type material that had been collected in 1947 near Cameron in Coconino County, Arizona, USA, where the plant grew a gravelly washes and sandbars of summer-dry streams at elevations of 1110-1200 m. 

This species was never found again and is believed to be extinct.

*********************

edited: 19.09.2019