Hairy vetch is an annual weed with slender stems 30-100 cm long which recline along the ground or climb up through other foliage. The stems are strongly angled in cross-section and are glabrous to sparsely pubescent, as are the leaves. The pinnately compound leaves have 6-9 pairs of narrowly oblong to linear leaflets with squared off tips which measure 10-18 mm long (Note the photo above.). The stipules at the base of each leaf are small and cut into slender lobes.
The racemes are 3-10 flowered and found in the upper leaf axils. The peduncles are much shorter than the leaves and the corollas are turned to one side of the inflorescence. The pubescent calyx is 3 mm long with narrow awl-shaped calyx lobes about equal in length. The minute corollas are white to pale bluish in color and at most 4 mm long. The flattened pods (in cross-section) are 8-10 mm long and covered with minute hairs (Note photo at right.). They contain 2 seeds.
Hairy vetch may be found along roadsides, in waste areas, and in disturbed meadows or grazed areas.
Native to Europe, hairy vetch may be found west of the Cascade Mts. and into the Columbia River Gorge in Washington and Oregon.
In the Columbia River Gorge, it may be found between the elevations of 100'-1800' from near Crown Point eastward to the Klickitat River.