[Milk-vetches: The Genus Astragalus in the Columbia River Gorge of Oregon and Washington]

Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch

Astragalus succumbens

Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

The photo above shows Columbia milk-vetch along Columbia River shores near Crow Butte State Park..........April 28, 2006.
Inflorescence of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbensThe photo at right shows a close-up of the flowers of Columbia milk-vetch along Columbia River shores near Crow Butte State Park.........April 28, 2006.
Characteristics:

Columbia milk-vetch is a grayish, microscopic haired perennial. The erect to decumbent main stem may reach a length between 10 and 50 cm. The compound pinnate leaves are somewhat fleshy, 3 to 10 cm in length. the 13 to 19 leaflets are mostly oblong to oblong-obovate inshape, each being 5 to 15 mm long.

The racemes are densely flowered, with 10 to 60 flowers. Individual flowers are pinkish, with a purple-tipped keel and deep pink penciling on the banner. Each flower is 18 to 26 mm in length. The wings are nearly straight and are oblong in shape. They are about equal in length compared to the banner, and may even be as much as 4 mm longer. The edges of the banner are only slightly reflexed. The calyx is tubular, 9 to 15 mm long, with linear-lanceolate teeth which are 1/2 to 2/3 as long as the tube.

The seed pods are erect, sessile and 3 to 4 cm long., and 5 to 8 mm wide. The surface is glabrous. The seed pods are straight to slightly arched, with strongly compressed bodies that are narrowly heart-shaped in cross-section.

Habitat:

Columbia milk-vetch is found in sandy places and into the rockier sagegrush desert, from the Columbia River to the lower foothills.

Range:

Columbia milk-vetch is found along the Columbia River in Klickitat and Grant counties in Washington, and in Umatilla and Gilliam counties in Oregon.

In the Columbia River Gorge, Columbia Milk-vetch may be found between the elevations of 300'-700' from near Wishram, WA and eastward to the far eastern gorge near Umatilla, OR.

Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

Columbia milk-vetch as seen on ashy soils along Alderdale Road near the junction with Washington Highway 14........April 23, 2013.

Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens - Inflorescence of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens - Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

Columbia milk-vetch blooming along Washington Highway 14 above Wishram, WA.......April 20, 2018.

Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

The photo above shows a close-up of the raceme of Columbia milk-vetch.

Maturing fruits of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens - Maturing fruits of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

The photo above shows the narrow pods of Columbia milk-vetch. Note how the pod folds inward at the lower suture.

Stem leaf of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

Columbia milk-vetch along Columbia River shores near Crow Butte State Park.........May 1, 1998.
Paul Slichter