Alpine Sweet-vetch

This plant is a perennial herb producing several erect stems from its caudex. It grows to 70 centimetres (28 inches) in height. The taproot is thick and woody, and it has rhizomes which can produce new stems. The leaves are each divided into a number of leaflets up to 3.5 centimetres (1.4 inches) long. The inflorescence is a dense raceme of flowers. The flowers are pink or pale purple and up to 1.5 centimetres (0.59 inches) long. The flowers are pollinated by insects such as the bumblebee and honeybee. The fruit is a flat legume pod which is narrowed between the seeds, with as many as 9 segments.

This plant generally grows in the boreal and northern temperate climates. It occurs in tundra and taiga habitat types, in floodplains, grasslands, and dry forests. It is well adapted to calcareous soils. It is usually not a dominant species but it is considered dominant in several river deltas and plains in Alaska. It is a pioneer species on floodplains that have been recently scoured by water and ice. It grows with willows and birches along waterways and in forests dominated by spruces. It grows on grasslands with grass species such as little bluestem (Schizachyrium scoparium), Canada bluegrass (Poa compressa), and American dunegrass (Leymus mollis).

Alpine sweetvetch is an important source of food for many types of animals, including black bears, grizzly bears, American bison, moose, Dall's sheep, and caribou. Bears are adept at digging up the nutritious roots, and patches of exposed dirt may be found around where the plants grow. The roots are a primary food for grizzly bears in some areas, such as Banff National Park. In parts of Alaska this plant is a primary food for Dall's sheep, caribou, and muskoxen. Many small mammals, such as voles and short-tailed weasels eat it, and a variety of birds nest in alpine sweetvetch habitat.