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

Bent Milkvetch, Hairy Milk-vetch

Astragalus inflexus

Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

Hairy milk-vetch along the Columbia River near Crow Butte State Park, WA..........April 28, 2006.

Inflorescence of Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus The photo at right shows a close-up of the banner of hairy milk-vetch along the Columbia River near Crow Butte State Park, WA..........April 28, 2006.
Characteristics:

Hairy milk-vetch is a fairly attractive perennial wildflower with freely branched stems ascending or widely spreading from 10-40 cm long from a woody base. The stems and leaves are densely covered with grayish or white, long, tangled hairs throughout. The pinnately compound leaves bear from 15-29 elliptic-lanceolate, oblong or obovate leaflets which are rounded or tapered to a point at the tip. Individual leaflets measure from 8-14 mm long.

The flower stems are as long as or longer than the upper leaves and capped by a short, compact raceme of 6-19 flowers subtended by awl-shaped bracts. The racemes measure 1-3 cm long in bloom and from 6-8 cm long in fruit. The cylindrical calyx is 11-15 mm long, fairly densely haired (See photo at right.) with narrow teeth from 3-7 mm long. The purple corolla is 18-22 mm long with a white blotch on the banner with purplish veins. The narrow wings are slightly longer than the keel but shorter than the banner. The banner is also hairy on the back (barely visible on the photo at right.). The spreading, densely woolly pods measure from 15-30 mm long and are abruptly curved or arched above the middle.


Similar Species:

Hairy Milk-vetch: Astragalus inflexus - Foliage densely whitish pubescent. Ascending stems from 10-40 cm long. Purplish corolla 18-22 mm long. Found from both shores of the Columbia River to the east of Rock Creek and north into central Washington and east to western Montana.

Newberry's Milk-vetch: Astragalus newberryi - Foliage densely silvery pubescent or with satiny, appressed hairs. Leaflets broadly obovate. Whitish, yellowish, or commonly pink or purplish corolla 20-25 mm long. In our area, found from Crook County in central Oregon south to southeastern Oregon, Nevada and California.

Pursh's Milk-vetch: Astragalus purshii - Foliage densely whitish pubescent. Depressed stems from 0-10 cm long. Purplish corolla 25-30 mm long. Found across much of central and eastern Washington and Oregon.


Habitat:

Hairy milk-vetch is found among sagebrush in the basin valleys and hillsides.


Range:

Hairy milk-vetch is found from central Washington south to northern oregon and east to the Snake River Canyon of southeastern Washington and northeastern Oregon and hence east to western Montana.

In the Columbia River Gorge, it may be found near the elevations of 200'-300' east of Roosevelt, WA and near Arlington, Or and eastward towards Umatilla, OR.


Flowers of Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

Hairy milk-vetch along the Columbia River near Crow Butte State Park, WA...........April 28, 2006.

Woolly pod of Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

The photo above shows the distinctly arched, hairy pod of Astragalus inflexus along the Columbia River near Crow Butte State Park, WA...........May 2, 2008.

Inflorescence and upper stem leaves of Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

Hairy milk-vetch along the Columbia River near Crow Butte State Park, WA..........April 28, 2006. The similar woolly milk-vetch (Astragalus purshii) would generally be much more compact or smaller in size.

Pinnately compound leaf of Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

A stem leaf of hairy milk-vetch.

Woolly pods of Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

The photo above shows a cluster of the arched, hairy pods of hairy milk-vetch along the Columbia River near Crow Butte State Park, WA...........May 2, 2008. The pods measure from 1-2.5 cm in length.

Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus - Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

Additional views of hairy milkvetch as seen on gravelly flats along Washington Highway SR14 just east of Roosevelt, WA...........April 18, 2010.

Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus - Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

Hairy milkvetch as seen on gravelly flats along Washington Highway SR14 about one mile east of Roosevelt, Washington............May 2, 2019.

Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

Hairy milkvetch as seen on gravelly flats along Washington Highway SR14 about one mile east of Roosevelt, Washington............May 3, 2012.

Bent Milkvetch, Hairy Milk-vetch: Astragalus inflexus

Hairy milkvetch as seen in the ditch along Washington Highway SR14 about one mile east of Roosevelt, Washington..........April 23, 2013.

Paul Slichter