A taxonomic review of the Astragalus lentiginosus complex in Utah indicates that the epithet var. albiflorus, antecedes and therefore should replace var. diphysus. The range of var. vitreus has been extended to include Kane and Garfield cos., Utah, and var. fremontii has now been identified from the state.
Schoener, Carol S.
"Notes on three varieties of Astragalus lentiginosus (Leguminosae),"
Great Basin Naturalist: Vol. 34
, Article 2.
Available at: http://scholarsarchive.byu.edu/gbn/vol34/iss3/2