[Wikipedia] Rarity: Astragalus anxius is a rare species of milkvetch known by the common names troubled milkvetch and Ash Valley milkvetch. It is endemic to northern Lassen County, California, where it is critically imperiled.[1] It was formally described in 1992. (link added by Mary Ann Machi)
Calflora:
Information on California plants for education, research and conservation,
with data contributed by
public and private institutions and individuals.
[web application]. 2025.The Calflora Database
[a non-profit organization].Available:
https://www.calflora.org/(Accessed: 04/01/2025).