This member of the legume family is known only from fresh to slightly brackish tidal marshes of the mid-Atlantic seaboard.
Due to its very low numbers and highly restricted worldwide distribution, the Sensitive Joint-Vetch has been federally listed as "Threatened" by the US Fish & Wildlife Service. The world's second largest known population of this species is found growing along the Mattaponi River, less than 200 feet from the proposed intake site for Newport News' planned King William reservoir project.