Level slope, dry sandy gravelly loam, dry swale. Widely distributed, common. Bunton reported losses from loco(ca) vesslunk, and a number of cases of loco in 1927. Peruvian triflorus (DC.) A. Gray (1853) is based on Phaca triflora DC. (18__), a Peruvian plant. By most modern American authors "Astragalus triflorus A. Gray" is regarded as an aggregate, comprising A. wootoni Sheld. (Mexico & SW US), an annual with small reddish flowers and A. allochorous A. Gray which "is a short-lived perennial and a larger plant with larger bluish-purple flowers and somewhat larger pods.".