[Milkvetches: The Genus Astragalus East of the Cascade Mountains 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.
Close-up of the 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. Click the photo to see an enlarged view.
Characteristics:

Columbia milk-vetch is a grayish, microscopic haired perennial. Generally a single , branched stem ascends between 10 and 50 cm high. The pinnately compound leaves are somewhat fleshy, 3 to 10 cm in length. The 13 to 19 leaflets are mostly oblong to oblong-obovate in shape, each being 5 to 15 mm long.

The flower stems generally are not as high as the leaves. 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 and each is 18 to 26 mm in length. The wings are nearly straight and oblong in shape. They are about equal in length compared to the banner, and may be up to 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 measure 3-4 cm long and 5-8 mm wide. The pod surface is glabrous and they are straight to slightly arched, with strongly compressed bodies that are narrowly heart-shaped in cross-section (See photos.). As evidenced by the photos of the pods below, the ventral surface of the pods is noticeably grooved.

Habitat:

Columbia milk-vetch is found in sandy places in the lowlands and into the rockier sagebrush desert, from along 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.

Close-up sideview of the corolla and calyx of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

The photo above shows a close-up sideview of the calyx and corolla of Columbia milk-vetch as seen along Washington Highway 243 just south of Schwana, WA........April 30, 2007.

Frontal view of the flower of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

This photo shows a close-up frontal view of the keel and banner of Columbia milk-vetch as seen along the Alderdale Road in the eastern Columbia River Gorge.......June 2, 2008.

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

The photo above shows the leaf of Columbia milk-vetch as seen along Washington Highway 243 just south of Schwana, WA.........April 30, 2007.

Arched pod of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens - Pods of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

These 2 photos show close-ups of the erect fruits or seed pods of Columbia milk-vetch as seen along the Alderdale Road in the eastern Columbia River Gorge........June 2, 2008. Note that the pods are grooved or folded inwards at the ventral margin.

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

Close-up of the inflorescence of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens - Close-up sideview of a flower of Columbia Milkvetch, Columbia Milk-vetch, Crouching Milk-vetch, Sprawling Milk-vetch: Astragalus succumbens

Additional close-up images of Columbia milkvetch as seen atop the Horse Heaven Hills about 2 miles southwest of Benton City, Washington...........May 3, 2012.

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

Columbia milkvetch as seen on gravell beds and sand dunes at White Bluffs North, Hanford Reach National Monument...........April 26, 2014.
Paul Slichter