Tall Milkvetch

Astragalus altus, commonly known as Tall Milkvetch, is a perennial herbaceous plant belonging to the legume family, Fabaceae. This species is native to the western United States, particularly found in the mountainous regions of the Rocky Mountains, extending from Montana to New Mexico. Tall Milkvetch typically grows in well-drained soils and is often found in open grasslands, meadows, and disturbed areas, where it can thrive in full sun to partial shade.

The growth habit of Astragalus altus is characterized by its erect form, reaching heights of 30 to 90 centimeters (approximately 12 to 35 inches). The plant features compound leaves that are pinnately divided, typically consisting of 9 to 15 leaflets that are oval to lanceolate in shape. These leaves are often covered with fine hairs, giving them a slightly fuzzy appearance. The flowers of Tall Milkvetch are notable for their distinctive morphology, forming clusters of purple to violet blooms that are typical of the genus. Each flower has a characteristic banner, wings, and keel, which are adaptations for attracting pollinators. The fruit is a flattened pod that contains several seeds, which are dispersed when the pod dehisces.

Tall Milkvetch plays an important ecological role in its native habitat, contributing to soil stabilization and nitrogen fixation due to its leguminous nature. This ability to fix atmospheric nitrogen makes it beneficial for improving soil fertility, which can enhance the growth of surrounding plant species. In addition to its ecological significance, Astragalus altus has been utilized in traditional medicine by Indigenous peoples for its potential health benefits. The plant’s adaptations, including its deep root system, allow it to access water and nutrients in arid conditions, making it well-suited for survival in its native environments.