Field milk-vetch is a weak-stemmed, loosely arranged perennial, which may grow as much as 5-25 cm high. The pinnately compound leaves range from 2-10 cm long, with 13-21 leaflets, each of which might be 4-18 mm long. The individual leaflets are elliptic to oblong-elliptic in shape. The leaflets often ascend sharply upwards from the rachis or mid-leaf vein (See leaf photos on this page.).
The flower stems are erect or incurved and measure from 1.5-11 cm long. The racemes are densely 5-15 flowered, with the shape of the raceme being ovoid or globose. Typically the flowers are erect or ascending ( See photos.). The bell-shaped to cylindrical calyx is 5 -12.5 mm long. The flowers are purple or lilac. The banner, which is only slightly recurved away from the keel measures 15-22 mm long, the wing petals 1-3 mm shorter than the banner, and the keel being 11-14 mm long. The pods are erect, ovoid or oblong-ellipsoid in shape, and 7-10 mm long by 3-4.5 mm wide. The pods are densely covered with long, silky hairs that are shiny, straight or curly, and measure from 1-2 mm long.
Field milk-vetch is found in moist valley and mountain meadows, typically along streambanks, lake shores, ditches and near springs from low to mid-elevation in the mountains.
Field milk-vetch is widely found from northern temperate Asia to the Yukon, south to central New Mexico and east across the prairies to northern Manitoba, Minnesota, and northern Iowa. It is found southward in the United States to southern Utah and central Nevada, and westward to the eastern base of the Cascades and into northwestern California.
- -Field milkvetch as seen in moist meadows along the headwaters of the south branch of Little Cottonwood Creek where the Arizona Creek Road reaches a pass in the Pueblo Mountains of southeastern Oregon........June 1, 2012.
The photo above shows a close-up of the raceme of field milk-vetch from Malheur National Wildlife Refuge...........June 22, 1999. Note the fine, long, spreading hairs on the calyx.
The photo above shows part of field milk-vetch, including the inflorescence and stem leaves, as seen several miles north of the P Ranch at Malheur National Wildlife Refuge..........June 22, 1999.
Field milk-vetch from Malheur NWR.............June 22, 1999.