Flower profile

Early purple milkvetch

Astragalus shortianus

Early purple milkvetch (Astragalus shortianus) is a flowering plant in the Fabaceae family, native in the lower 48 states, blooming mostly April–May across the U.S.

Native to Colorado

Early purple milkvetch is a wildflower that USDA PLANTS lists as native in the lower 48 states. In Colorado it's most often seen in bloom in April–May.

4states where USDA records it

1,788CO sightings*

1,865U.S. sightings*

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

On our lists for: Colorado

Quick look

Astragalus shortianus, the early purple milkvetch, is a species of flowering plant in the family Fabaceae. It is native to the west-central United States; Wyoming, Colorado, Nebraska, and New Mexico. A perennial flowering from April through July, it is found growing in dry, rocky soils at elevations from 5,200 to 9,000 ft.
From Wikipedia's article Astragalus shortianus, CC BY-SA 4.0.

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 4 states. ^{USDA PLANTS}
NatureServe lists it as native to Colorado. ^NatureServe
In Colorado, most iNaturalist sightings of it in flower come in April–May. ^iNaturalist
iNaturalist has 1,788 research-grade sightings of it in Colorado, ranking #92 among the 160 flowers on our Colorado list. ^iNaturalist

When does it bloom?

In Colorado, most flowering sightings come in April–May.

Flowering records by month in Colorado (iNaturalist research-grade observations marked “Flowering”) (195 records)

Conservation status

Federal (U.S. ESA): Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. ^{USFWS ECOS}
NatureServe global: G4 Apparently secure worldwide. ^NatureServe
Colorado: No list Colorado has no state law listing endangered or threatened plants, so we show NatureServe's Colorado ranks instead. NatureServe: S4, apparently secure in Colorado.
Rare elsewhere: Other states where NatureServe ranks it rare or missing: NE (S1). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

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

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

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 early purple milkvetch in 4 states.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Colorado, Nebraska, New Mexico, Wyoming.

Colorado counties with USDA records: Boulder, Delta, Douglas, El Paso, Elbert, Gilpin, Grand, Jefferson, Larimer, Las Animas, Otero, Park.

Names, range and relatives

County records: USDA PLANTS lists it in 22 counties across 4 states; the most are in Colorado (12), Wyoming (6), Nebraska (2).

Other Astragalus on Bloomipedia (12): Woollypod milkvetch, Ground-plum, Woolly locoweed, Drummond's milkvetch, Laxmann's 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 Colorado flowers

Lambert's locoweed

Oxytropis lambertii

Native

🌼 Blooms in CO: May–July

Yellow sweetclover

Melilotus officinalis

Introduced

🌼 Blooms in CO: May–August

Red clover

Trifolium pratense

★ VT state flowerIntroduced

🌼 Blooms in CO: June–September

Sources

USDA, NRCS. PLANTS Database, profile ASSH3.
iNaturalist, Astragalus shortianus: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Astragalus shortianus (lead quoted under CC BY-SA 4.0).
Colorado: Colorado noxious weed lists A, B and C (8 CCR 1206-2, eff. May 15, 2025).
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Astragalus shortianus (global and state ranks).
Edibility and toxicity: ASPCA.
Photo: Anders Hastings via iNaturalist · CC BY 4.0 · resized.