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

Alpine Milkvetch, Alpine Milk-vetch

Astragalus alpinus var. alpinus

Synonyms: Astragalus alpiniformis, Astragalus alpinus ssp. alaskanus, Astragalus alpinus ssp. arcticus, Astragalus astragalinus

Sideview of a flower of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

The photo above shows a close-up ofthe calyx and corolla of alpine milk-vetch as seen in open woods near Irondyke Campground along the Lostine River in the Wallowa-Whitman N.F.........July 8, 2007. Note the dark hairs on the pedicel and clayx, the long awl-shaped calyx teeth that are slightly shorter than the calyx tube and the white corolla with the tip of the keel and banner tinged with lavender.
Frontal view of a flower of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)The photo at right shows a close-up frontal view of the flower of alpine milk-vetch as seen in open woods near Irondyke Campground along the Lostine River in the Wallowa-Whitman N.F.........July 8, 2007.
Characteristics:

Also known as Wallowa milk-vetch , alpine milk-vetch is a weak perennial wildflower with spreading stems from 5-30 cm long. The pinnately compound leaves are 2.5-11 cm long with 13-25 lanceolate to elliptic or obovate leaflets from 7-14 mm long The thin and soft leaflets are covered with long, soft, straight hairs on their ventral surface.

The erect flower stems are generally longer than the leaves and are topped by closely flowered racemes of 7-20 spreading flowers. The bell-shaped calyx is covered with black hairs and is 3-4 mm long with awl-shaped teeth up to 2 mm long. The corolla is white with the tips of the banner and keel tinged with lavender while the narrow wings are solidly white (Note photo above.). The banner and keel are about 7.5-13 mm long and the wings are shorter than the keel. The keel is abruptly incurved from 75-90¾ at the tip. The pendulous pods are obliquely ellipsoid, straight, or slightly incurved and measure 7-14 mm long and 2.5-4 mm wide. The pods appear heart-shaped in cross-section and are covered with numerous black or black and white hairs.

Habitat:

Alpine milk-vetch may be found on lake shores, streambanks, cool open woodlands or mountain meadows. It is found near sea level in the Arctic and up to 3400 meters in the Rocky Mts.

Range:

Alpine milk-vetch may be found over much of boreal North America. It is found in the Wallowa Mts. of northeastern Oregon and eastward to the mountains of southeastern Idaho and into South Dakota. It is found south through the Rocky Mts. to New Mexico. It is also found in Elko County Nevada, Grand County, Utah and in the Wasatch Mts. in Salt Lake County, Utah.

Pods of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis) - Pods of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

The two photos above shows the dark, hairy, pendant pods of alpine milk-vetch as seen in open woods near Irondyke Campground along the Lostine River in the Wallowa-Whitman N.F.........July 8, 2007. The pods are generally closely appressed to the flower stem. This species has also seen at the summit of the pass for the Frances Lake Trail above 7500 feet.

Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

The photo above shows a close-up of alpine milk-vetch as seen in open woods near Irondyke Campground along the Lostine River in the Wallowa-Whitman N.F.........July 8, 2007.

Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

These flatbed scans of alpine milk-vetch were all taken of material from along the Lostine River. The photo above shows the pods and flowers as well as the branched stem and pinnately compound leaves of this species. The leaflets are greenish and vary from nearly linear to obovate in outline.

Inflorescence of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis) - Inflorescence of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

Upper leaf surface of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis) - Lower leaf surface of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

Pods of Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

What appears to be alpine milkvetch as seen on slopes just east of Lost Lake Fen, Okanogan National Forest.........July 12, 2015.

Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis) - Alpine Milkvetch, Alpine Milk-vetch: Astragalus alpinus var. alpinus (Synonym: Astragalus alpiniformis)

The above photos show close-up views of the pendant, blackish pods and purple-tinged flowers of alpine milk-vetch. Sampled from the Lostine River of the Wallowa Mts. of northeastern Oregon.........July 24, 1997.
Paul Slichter