Also known as Pursh's milk-vetch, woolly-pod milk-vetch is an attractive perennial wildflower both in flower and in fruit. It is a loosely to densely matted plant with very short stems, or often lacking stems all together. The foliage is densely covered with many whitish, woolly to cottony hairs. When present, the prostrate stems range from 0-10 cm long. The pinnately compound leaves are 1-12 cm long and bear from 5-17 leaflets. Individual leaflets are rounded to obovate or even narrowly elliptic or oblanceolate and measure from 2-14 mm long.
The flower stems are incurved and ascending in bloom, later becoming prostrate in fruit (See photo above.). They measure from 0.5-10 cm long and are tipped with 2-12 ascending flowers in a short raceme. The calyx is a long bell or tubular in shape and measures 6-17 mm long. The calyx teeth range from lance to awl shaped, or may be broadly triangular and range from 1-6 mm long. The outer surface of the calyx is covered with white to grayish-brown hairs. The corolla measures 20-25 mm long and varies from white to yellowish, pale pink or "hot" pink-purple. The banner measures 9-25 mm long and is gently recurved from the axis of the tube and bears a whitish central spot with pink to purple venation. The wings are 1-3 mm shorter than the banner while the keel is 8-21 mm long. The distinctive fruits are densely covered by long, whitish, woolly hairs from 1.5-5 mm long. They are ovoid to lance-ellipsoid in shape, slightly curved in profile and depressed above, and measure 7-27 mm long and 3.5-11 mm wide.
variety glareosus: Petals pink or pink-purple. Flowers 20-25 mm long. Pods somewhat incurved, measuring 15-30 mm long. Found across eastern Washington, and in the northern half of Oregon south to the southern edge of the Blue Mts and east across the Snake River Plains to northwestern Utah.
variety lagopinus: Petals pink or pink-purple. Flowers 10-16 mm long. Pods 7-17 mm long, strongly incurved, often through a half circle or further. In Oregon, found from Deschutes County south to the California border and east to southeastern Oregon.
variety ophiogenes: Petals pink or pink-purple. Pods 8-13 mm long, strongly incurved, often nearly forming a complete spiral. Found from the Owhyee Canyon of southeastern Oregon into southwestern Idaho.
variety purshii: Petals, except for tip of keel, whitish or creamy. Flowers 20-30 mm long. Pods 13-27 mm long, not ventrally depressed or only slightly incurved. Found scattered across much of eastern Oregon and Washington.
variety tinctus: Petals pink or pink-purple. Flowers 20-25 mm long. Pods 13-27 mm long, not ventrally depressed or only slightly incurved. Found across south-central to southeastern Oregon.
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 2-2.5 cm 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 2.5-3 cm long. Found across much of central and eastern Washington and Oregon.
Open grassy to rocky, open slopes in the eastern Columbia River Gorge.
Woolly-pod Milk-vetch is distributed east of the Cascade Mountain range from southern British Columbia south to northern California, and eastwart in Canada to Alberta, and south through the Dakotas into Utah, Nevada, and New Mexico.In the Columbia River Gorge, it may be found between the elevations of 100'-2600' from east of Bingen, WA east at least to near both Roosevelt, WA and Arlington, OR.