Astragalus cusickii var. cusickii
The photo above shows the attractive form of Cusick's milkvetch (variety cusickii) as seen along Oregon Highway 3 near the Oregon-Washington Border...................July 7, 2008.
Also known as barren milk-vetch or Packard's milk-vetch, Cusick's milk-vetch is a slender, sparsely leafy perennial, with clustered stems from 10-70 cm tall. Plants range from glabrous to sparsely haired with short, appressed hairs. The slender stems are stiff and ascending to erect. The leaves vary from 3-12 cm in length, with 7-17 narrowly linear, linear-oblong, or linear-elliptic leaflets from 10-25 mm long (See photo below.). Individual leaflets are usually scattered widely on the leaf and have margins that are rolled upwards.
The flower stems typically are longer than the uppermost leaves. The racemes are loosely flowered, with from 2-14 white or creamy-white flowers (often tinged with pinkish-purple) with the corollas from 12-15 mm long. the banner is slightly reflexed away from the keel and measures from 8-15 mm long while the wings are 1-2 mm shorter and the keel from 8-12 mm long. The bell-shaped is 5-6 mm long with broadly triangular teeth. The pods are pendulous and either symmetrically or obliquely obovoid or ellipsoid in shape (See photos). The pods become like inflated bladders as they dry, with varying amounts of reddish mottling on the smooth surfaces. The pods range from 20-48 mm long and 7-16 mm wide.
variety cusickii: Plants with stems not arising from elongated, running rootstocks. Pods slightly mottled to lacking mottling (See photo at right above.). Leaflets from 5-18 mm long. Found on rocky hillsides, canyon terraces and cliff ledges from 400-900 meters in elevation from southeastern Washington (south of the Snake River) south to the lower Malheur River, Willow Creek and Snake River valley of northern Malheur County and east to Washington County in Idaho.
variety sterilis: Plants with stems arising from elongated, running rootstocks. Pods brightly red-mottled. Leaflets from 2-5 mm long. Found in ashy soils on bluffs, talus slopes and on open hilltops of the Owyhee Desert from Malheur county in southeastern Oregon east into Owyhee County in Idaho.
Cusick's Milk-vetch is found below 4600 feet on rocky hillsides, talus-slopes, and barren hilltops.
Cusick's Milk-vetch is found from southeastern Washington south through eastern Oregon, and east through the Salmon and Snake River canyons of Idaho.