Astragalus trichopodus is a species of legume known by the common name Santa Barbara milk vetch. It is native to southern California and Baja California, where it grows in several types of open habitat, including in the Transverse Ranges and Mojave Desert.
This is a robust perennial herb producing a branching stem up to about a meter in maximum height. The hairy stem is lined with many leaves each up to 20 cm (7.9 in) long which are made up of several pairs of widely spaced lance-shaped leaflets each up to 2.5 cm (0.98 in) in length. The inflorescence is a raceme of up to 50 flowers which are cream colored and sometimes tinted with light purple. Each flower is 2 to 3 cm (0.79 to 1.18 in) long including its tubular base of sepals.
The fruit is a laterally compressed, slightly inflated legume pod up to 4 to 5 cm (1.6 to 2.0 in) long which dries to a papery texture. The fruits hang in bunches where they develop from the inflorescence. Each pod contains many seeds.