milkvetches

Milkvetches are plants belonging to the genus Astragalus, a large group within the legume family (Fabaceae). The term milkvetch refers to many species, most of them perennials, native to temperate regions of North America, Europe, and Asia. Common examples include Canadian milkvetch (Astragalus canadensis) and numerous other Astragalus species that occur in meadows, prairies, and woodlands. Because the genus is vast—hundreds to thousands of species—characteristics vary, but milkvetches typically are herbaceous with pinnate leaves and pea-like flowers arranged in racemes, followed by pods.

Leaves are pinnate with numerous small leaflets; flowers are typically white, pink, or purple; fruit is a flat pod. Milkvetches are nitrogen-fixing legumes, forming nodules with soil bacteria, contributing to soil fertility and sometimes used in erosion control and rangeland restoration.

Agricultural and ecological significance: Some milkvetch species are important forage plants in native ranges, but many also contain toxins or swainsonine-producing alkaloids that can cause locoism in livestock if ingested in sufficient quantities. Grazing management and species choice influence risk, and toxicity varies by species and region. Some milkvetches are also cultivated as ornamentals or for soil stabilization.

Taxonomy and diversity: Astragalus is one of the largest plant genera, and common usage of milkvetch can refer to multiple taxa; in some contexts, related Oxytropis species are grouped under the broader locoweed category.