Bloomipedia
Woollypod milkvetch (Astragalus purshii)
Photo: Deniz Wilson via iNaturalist · CC0 · resized

Flower profile

Woollypod milkvetch

Astragalus purshii

Woollypod milkvetch (Astragalus purshii) is a flowering plant in the Fabaceae family, native in the lower 48 states, blooming mostly March–May across the U.S.

Native in the lower 48

Woollypod milkvetch is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 2 states, and across the U.S. it's most often seen in bloom in March–May.

11states where USDA records it
2Bloomipedia state lists include it
4,519U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Idaho, Nevada

Quick look

Astragalus purshii is a species of milkvetch known by the common names woollypod milkvetch and Pursh's milkvetch.

  • It belongs to the Fabaceae family. iNaturalist
  • USDA PLANTS describes it as an herb (forb) with a perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as native in the lower 48 states and records it in 11 states. USDA PLANTS
  • NatureServe lists it as native to Idaho and Nevada. NatureServe
  • USDA PLANTS lists its flower color as white. USDA PLANTS
  • USDA PLANTS gives its bloom period as mid spring. USDA PLANTS
  • USDA PLANTS lists a mature height of about 0.6 ft. USDA PLANTS
  • iNaturalist has 771 research-grade sightings of it in Idaho, ranking #33 among the 143 flowers on our Idaho list. iNaturalist
  • iNaturalist has 570 research-grade sightings of it in Nevada, ranking #68 among the 132 flowers on our Nevada list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (462 records)
Bloom time in the 2 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
IdahoNativefew records (33)771
NevadaNativefew records (20)570

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
G5 Secure worldwide. NatureServe
Idaho
No list Idaho has no state law listing endangered or threatened plants, so we show NatureServe's Idaho ranks instead. NatureServe: S5, secure in Idaho.
Nevada
Not listed Not on Nevada fully protected plants, critically endangered (NAC 527.010). NatureServe: S4, apparently secure in Nevada. NAC 527.010
Rare elsewhere
No other U.S. state ranks it S1, S2, SH or SX.

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleToxic (slight, per USDA)

USDA PLANTS rates its toxicity as “slight.” (USDA's rating covers people and livestock and doesn't say which parts.) NC State Extension has no page for it. USDA PLANTS

For petsToxic to horses

ASPCA's entry “Loco Weed (Astragalus spp.)” (Astragalus spp), which covers the whole genus, lists it as toxic to horses. Signs include: Incoordination, depression, inability to eat and drink, fetal death and birth defects Credit: Image Courtesy of Gary Coffman, PBase.com Gallery… ASPCA

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records woollypod milkvetch in 11 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington, Wyoming.

Idaho counties with USDA records: Ada, Adams, Bannock, Bear Lake, Bingham, Blaine, Boise, Butte, Canyon, Caribou, Cassia, Clark, Custer, Elmore, Franklin, Fremont, Gem, Gooding, Idaho, Kootenai, Lemhi, Lincoln, Nez Perce, Owyhee, Payette, Power, Twin Falls, Washington.

Nevada counties with USDA records: Carson City, Churchill, Clark, Douglas, Elko, Esmeralda, Eureka, Humboldt, Lander, Lincoln, Lyon, Mineral, Nye, Pershing, Storey, Washoe, White Pine.

Growing conditions

USDA PLANTS gives Woollypod milkvetch a high shade tolerance, high drought tolerance and low moisture use. It is rated for soil pH 5.6 to 7.5 and winter lows down to -33 °F.

Shade tolerance
High
Drought tolerance
High
Moisture use
Low
Soil textures it is adapted to
coarse, medium
Soil pH range
5.6 to 7.5
Minimum temperature tolerated
-33 °F
Frost-free days needed (minimum)
80
Annual precipitation range
10 to 20 inches
Minimum root depth
10 inches
Salinity tolerance
Low
Fertility requirement
Low
Growth rate
Moderate
Lifespan
Moderate
Active growth period
Spring and Summer
Fruit or seed
Black · Spring to Summer
Can be propagated by
seed
Commercial availability
No Known Source

From the USDA PLANTS characteristics data for ASPU9. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

Native status by region (USDA PLANTS): Canada: Native; Lower 48 states: Native.

County records: USDA PLANTS lists it in 183 counties across 11 states; the most are in Montana (37), Idaho (28), California (25).

Other Astragalus on Bloomipedia (12): Ground-plum, Woolly locoweed, Drummond's milkvetch, Laxmann's milkvetch, Early purple milkvetch, Alpine milkvetch, Utah milkvetch, Timber milkvetch, Browse milkvetch, Tufted milkvetch.

More from the Fabaceae family (114 on Bloomipedia; most observed first): Lupines, White clover, Red clover, Eastern redbud, Purple crownvetch, Bird's-foot trefoil, Partridge pea, White sweetclover.

More Idaho flowers

Red clover (Trifolium pratense)

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★ VT state flowerIntroduced

🌼 Few flowering records in ID
Yellow sweetclover (Melilotus officinalis)

Yellow sweetclover

Melilotus officinalis

Introduced

🌼 Few flowering records in ID
White clover (Trifolium repens)

White clover

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Introduced

🌼 Few flowering records in ID

Sources