Balloon Milk-vetch, Balloonpod Milkvetch, Balloon-pod Milk-vetch, Whitney's Balloon Milkvetch

Also known as balloon pod milk-vetch, balloon milk-vetch is a perennial with with several to many branched stems that are spreading and clustered close to the ground. Plants range from 10-20 cm high and the foliage ranges from green to covered with silvery hairs. The compound-pinnate leaves are tufted close to the ground, measure 2.5-4 cm long, and bear 9-21 leaflets. Individual leaflets are narrowly oblong to obovate in shape 6-10 mm long. The upper surface of the leaflets ranges from glabrous to sparsely haired while the lower surface is covered with appressed hairs.

The flower stems are longer than the upper leaves and topped by a short, dense raceme of 5-20 flowers up to 1.5 cm long, and not elongating much in fruit. The tubular, bell-shaped calyx 4-5 mm long with triangular, awl-shaped teeth up to 2 mm long. The corolla is pinkish, lavender-purple, or yellowish and measures up to 1 cm long. The pod is greatly inflated, somewhat pear-shaped, clear with reddish or purple blotches over the surface. The pods measure 2.5-3 cm long and are very thin-walled and sparsely covered with minute, appressed hairs (See photos.).

Additional photos of balloon milk-vetch

Balloon milk-vetch is found on rocky outcrops and mountain crests at higher elevations, frequently on serpentine rock (especially in the Siskiyous). It is typically found between the elevations of 1300-3600 meters.

Balloon milk-vetch is widely distributed east of the Cascade Mts, from central Washington south to northeastern California, east to Nevada and southwest Idaho.