The following is a very brief listing of the milkvetches of the american southwest:
Halfmoon Milkvetch: Astragalus allochrous var. allochrous
Halfmoon Milkvetch: Astragalus allochrous var. playanus
Torrey's Milkvetch: Astragalus calycosus var. calycosus (Synonym: Astragalus calycosus var. mancus)
Torrey's Milkvetch: Astragalus calycosus var. scaposus
Salton Milkvetch, Salton Milk Vetch: Astragalus crotalariae
Groundcover Milkvetch, Villous Groundcover Milkvetch, Locoweed: Astragalus humistratus (Synonyms: Astragalus datilensis, Batidophaca humistrata, Pisophaca datilensis, Tium humistratum, Tragacantha humistrata)
Borrego Milkvetch, Borrego Milk-vetch: Astragalus lentiginosus var. borreganus (Synonym: Astragalus lentiginosus var. coulteri)
Palmer's Locoweed, Palmer's Milkvetch, Palmer's Milk Vetch: Astragalus palmeri (Synonym: Astragalus vaseyi)
Ashen Milkvetch, Silverline Locoweed: Astragalus tephrodes var. brachylobus (Synonym: Astragalus arrectus var. pephragmenus)