[Milkvetches: The Genus Astragalus East of the Cascade Mountains of Oregon and Washington]

Alvord Milkvetch

Astragalus alvordensis

Close-up of the flowers of Alvord Milkvetch: Astragalus alvordensis

The photo above shows a close-up view of the calyx and corollas of Alvord milk-vetch as seen in the Alvord Basin about 2 miles east of Pueblo Mt. along the Whitehorse Rd in southeastern Oregon.........May 28, 2000. Note the shaggy whitish hairs on the calyx and that the calyx teeth are much broader and shallower above than below.

Close-up of the banner and wings of Alvord Milkvetch: Astragalus alvordensisThe photo at right shows a close-up of the banner and wings of Alvord milk-vetch as seen in the Alvord Basin about 2 miles east of Pueblo Mt. along the Whitehorse Rd.........May 28, 2000.
Characteristics:

Alvord milk-vetch is a perennial with freely branched stems spreading from the base. The slender stems range from 15-50 cm long and are woolly-haired throughout with short, curved hairs. The pinnately compound leaves are 3-4 cm long with 9-21 obovate leaflets, each measuring from 3-6 mm long.

The flowering stems measure 1-3.5 cm long and are equal to or longer than the leaves and are topped with very short racemes. The racemes are loosely 5-15 flowered. The calyx is 2.3-3.3 mm long with short triangular to ovate lobes up to 0.7 mm long. The whitish to lilac corolla is 6-10 mm long with the banner marked with purplish veins. The moderately recurved banner measures 5.5-7.2 mm long and the incurved wings are nearly as long. The keel measures 3.7-5.3 mm long. The pendulous pods measure 12-18 mm long and 4 mm wide and are pubescent and sometimes mottled. They are strongly compressed laterally and make one-half to one and a half turns of a spiral with the spiral 7-10 mm in diameter.


Habitat:

Alvord milk-vetch may be found in sandy soils in the basins and lower foothills between the elevations of 1050-1350 meters.


Range:

Alvord milk-vetch may be found in southern Harney and Malheur Counties of southeastern Oregon and northern Humboldt County in Nevada.


Close-up frontal view of a flower of Alvord Milkvetch: Astragalus alvordensis - Close-up frontal view of a flower of Alvord Milkvetch: Astragalus alvordensis - Close-up sideview of a flower of Alvord Milkvetch: Astragalus alvordensis

Curled pod of Alvord Milkvetch: Astragalus alvordensis - Curled pod of Alvord Milkvetch: Astragalus alvordensis - Alvord Milkvetch: Astragalus alvordensis

Alvord Milkvetch: Astragalus alvordensis - Alvord Milkvetch: Astragalus alvordensis

Alvord Milkvetch: Astragalus alvordensis - Alvord Milkvetch: Astragalus alvordensis

Additional close-up images of Alvord milkvetch as seen in sandy soils along Whitehorse Ranch Road in the southern Alvord Desert, southeastern Oregon........June 1, 2012.

Curled pods of Alvord Milkvetch: Astragalus alvordensis

The photo above shows the pubescent pods of Alvord milk-vetch as seen in the Alvord Basin about 2 miles east of Pueblo Mt. along the Whitehorse Rd..........May 28, 2000. Note that the pods shown here have formed a complete spiral.

Alvord Milkvetch: Astragalus alvordensis

The photo above shows the short inflorescence and upper stem leaves of Alvord milk-vetch as seen in the Alvord Basin about 2 miles east of Pueblo Mt. along the Whitehorse Rd.........May 28, 2000. Note that the leaflets are covered with whitish or silvery hairs on both surfaces and that the tips of the leaflets are blunt or slightly notched.

Alvord Milkvetch: Astragalus alvordensis

The photo above displays the form of Alvord milk-vetch, consisting of one to several sprawling to slightly ascending, branched stems arising from sandy or alkaline soils. Photographed near Borax lake in the Alvord Basin of southeastern Oregon.........May 28, 2000.

Paul Slichter