Woollypod Milkvetch

astragalus purshii

The Woollypod Milkvetch (Astragalus purshii) is a fascinating, low-growing perennial plant native to the arid and semi-arid regions of western North America. Resembling a soft, silver cushion hugging the dusty earth, this resilient wildflower is celebrated for its remarkable adaptation to harsh, dry environments. It is a member of the Fabaceae (pea) family, and it immediately captures the eye with its extremely fuzzy, wool-covered seed pods that look like tiny tufts of cotton or sheep's wool scattered across the desert floor. Throughout spring, it produces beautiful clusters of pea-like flowers ranging in color from cream and pale yellow to vibrant purple, providing vital nourishment for native pollinators.

Habitat: Typically found in open, arid environments such as sagebrush steppes, grasslands, and rocky slopes of western North America.

Appearance

Woollypod Milkvetch forms low, dense mats or tufts that rarely exceed 15 centimeters in height. The entire plant is heavily blanketed in dense, soft, white or grayish hairs, giving it a distinct velvety, silver-green appearance. The leaves are pinnately compound, divided into small, oval leaflets. The flowers are classic pea-like blossoms, typically cream, yellowish, or violet-purple, arranged in tight clusters. The most striking visual identifier is the seed pod: a short, plump, curved legume that is so densely covered in thick, woolly white hairs that it resembles a miniature cotton ball.

KingdomPlantaePhylumTracheophytaClassMagnoliopsidaOrderFabalesFamilyFabaceaeGenusAstragalus

Woollypod Milkvetch

Interesting facts

Indigenous peoples of the Great Basin historically used infusions of various milkvetch species for medicinal purposes, though many Astragalus species can accumulate toxic levels of selenium.

The incredibly fluffy white seed pods of the Woollypod Milkvetch look so much like miniature sheep that some locals refer to them as 'ground-kittens' or 'lambs-wool'.

The thick coat of wool on its seed pods functions like insulation, protecting the developing seeds from late-spring frosts and the scorching desert heat.

Special abilities

The dense coating of white hairs reflecting intense sunlight and reducing moisture loss from drying desert winds.

Partners with symbiotic rhizobia bacteria in its root system to convert atmospheric nitrogen into usable soil nutrients.

Enters a dormant state during extremely hot, dry summer months to conserve water and survive severe droughts.

Measurements & details

Length: 5-15 cm
Lifespan: 3-10 years

Diet & Feeding

As a photoautotrophic plant, the Woollypod Milkvetch synthesizes its own organic compounds using sunlight, carbon dioxide, and water through photosynthesis.

Primary Foods

Sunlight
Carbon Dioxide
Water
Soil Nitrogen
Minerals

Ecological connections

mutualism

Hunt's Bumblebee

Bombus huntii

Provides nectar and pollen to native bumblebees, which act as primary pollinators.

host plant

Melissa Blue

Plebejus melissa

Serves as a larval host plant for caterpillars of the Melissa Blue butterfly.

eaten by

Northern Pocket Gopher

Thomomys talpoides

Roots and seed pods are sometimes consumed by foraging pocket gophers.

Traits

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Also known as

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Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How to identify Woollypod Milkvetch?

The easiest way to identify Woollypod Milkvetch is to use the Snappit nature identifier app.

How long is Woollypod Milkvetch?

5-15 cm

How long does Woollypod Milkvetch live?

3-10 years

What does Woollypod Milkvetch eat?

As a photoautotrophic plant, the Woollypod Milkvetch synthesizes its own organic compounds using sunlight, carbon dioxide, and water through photosynthesis.

Where is Woollypod Milkvetch usually found?

Typically found in open, arid environments such as sagebrush steppes, grasslands, and rocky slopes of western North America.