Astragalus aquilonius, the Lemhi milkvetch, is a species of milkvetch in the family Fabaceae.[1] [2] It is native to Idaho.[3]
The flowers color can be white, green, purple, or violet. The bloom period is May, June, and July. The leaf arrangement is alternate. The fruit type is legume. The long stipules are purplish in color, but start out as brownish. There are 4 flat leaflets. The lanceolate is commonly purplish in color. The pedicels are very slender. The fruit is usually straight and divaricate. The pods loosely spread.[4]
It has a global rank of G3, which means it is vulnerable. It has the same rank in Idaho. It is found around the upper Salmon River and the lower Lemhi River, it is found in Lemhi, Custer, and Butte counties. 39 places are known where it is found.[5]