[The Milk-vetch East of the Cascade Mts.]

Newberry's Milk-vetch

Astragalus newberryi var. castoreus

Newberry's milk-vetch from Domingo Pass Rd, Pueblo Mts......June 25, 1999.

Characteristics:

Newberry's Milk-vetch is a low growing perennial, relatively small in size, with the foliage with many silky, silvery hairs (See photos.). The base of the plant is covered with the remains of old leaf bases from previous years. The leaves are many, crowded on the root-crown, with 7-11 obovate , obtuse, rhombic-elliptic, or oblanceolate leaflets. Individual leaflets are 5-16 mm in length, while the leaves as a whole are 2-13 cm long (See photos).

The inflorescence is a raceme, with 3-8 flowers atop the stout flower stem which is equal to or shorter than the leaves. The flowers are ascending, with vivid pink-purple, pink, or whitish petals. The corolla is 2.5-3 cm long while the calyx is about 12 mm long with thin, awl-shaped teeth up to 6 mm long. The banner is 17-32 mm long and held fairly closely above the keel and wings. The keel measures 17-26 mm long and is shorter than the narrow wings which are up to 30 mm long. The pod is up to 17-28 X 7-13 mm, broadly rounded at the base, and incurved or backward hooked with a pointed tip. The pod's surface as seen from the photos is covered with a dense coat of whitish hairs (See photo above and at right.).


Habitat:

Newberry's milk-vetch is found in sagebrush and pinyon-juniper woodlands in the plains, foothills, bluffs and badlands.


Range:

Newberry's milk-vetch is found from southern Oregon (east of the Cascades) south into the eastern Mojave Desert, east to New Mexico, and north again into eastern Utah. Variety castoreus is the variety found in the Pacific Northwest, and is found from the headwaters of the Deschutes River, south through southeastern Oregon to Twin Falls County, Idaho, and then southward through the southern portion of the Bonneville Basin in Utah, most of Nevada, and to the northern and eastern Mojave Desert in California.


Leaf from Newberry's milk-vetch (Astragalus newberryi var. castoreus), Pueblo Mts........6/25/99.

Paul Slichter