Freckled Milkvetch (Astragalus lentiginosus)

Freckled Milkvetch (Astragalus lentiginosus)

Astragalus lentiginosus is a species of legume known by the common names spotted locoweed and freckled milkvetch. It is native to western North America, where it grows in many habitat types. There are a great number of wild varieties of this species, and they vary in appearance. The flower and the fruit of a given individual are generally needed to identify it down to the variety.

As a species, Astragalus lentiginosus is distributed throughout the Great Basin of North America, west from the Rocky Mountains to the California Coast Ranges, south to Mexico, and north to British Columbia. The varieties are largely limited to marginal habitats such as disturbed sites in the arid regions of the continent. The group also contains a number of edaphic specialists which occur at desert seeps, which frequently exhibit high levels of calcium carbonate.

Astragalus lentiginosus is a perennial or occasionally annual herb with leaves up to 15 centimetres (5.9 inches) long divided into many pairs of small leaflets. The plant is prostrate to erect in form and quite woolly to nearly hairless. The inflorescence holds up to 50 pea-like flowers which may be purplish or whitish or a mix of both. A unifying character among most of the varieties is an inflated, beaked legume pod with a groove along the side. The pod dries to a papery texture and dehisces starting at the beak to release the seeds. The epithet lentiginosus refers to the red mottling commonly found on the pods which resemble freckles.


About the author

Jim Mattern

Jim is a scapegoat for the NPS, an author, adventurer, photographer, radio personality, guide, and location scout. His interests lie in Native American and cultural sites, ghost towns, mines, and natural wonders in the American Deserts.