North America Native Plant

Plains Milkvetch

Botanical name: Astragalus gilviflorus var. purpureus

USDA symbol: ASGIP

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Orophaca triphylla Isely var. purpurea (Dorn) Isely (ORTRP)   

Plains Milkvetch: A Hidden Gem for Wyoming Native Plant Gardens If you’re looking to add authentic Wyoming character to your native plant garden, meet the plains milkvetch (Astragalus gilviflorus var. purpureus). This perennial wildflower might not be the showiest plant in the garden center, but it’s got something special that ...

Rare plant alert!

Region: Conservation status by state

Status: S5T2: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Plains Milkvetch: A Hidden Gem for Wyoming Native Plant Gardens

If you’re looking to add authentic Wyoming character to your native plant garden, meet the plains milkvetch (Astragalus gilviflorus var. purpureus). This perennial wildflower might not be the showiest plant in the garden center, but it’s got something special that makes it worth considering for dedicated native plant enthusiasts.

What Makes Plains Milkvetch Special?

Plains milkvetch belongs to the legume family, which means it has a secret superpower: it can actually improve your soil by fixing nitrogen from the air. Think of it as nature’s fertilizer factory, working quietly underground while adding authentic prairie character to your landscape.

This native perennial is exclusively found in Wyoming, making it a true regional treasure. If you live in the Cowboy State and want to create a garden that truly reflects your local ecosystem, this is exactly the kind of plant that belongs in your native plant palette.

A Word of Caution: Rarity Considerations

Here’s something important to know: plains milkvetch has a conservation status that suggests it’s not particularly common in the wild. This means if you decide to grow it, you’ll want to source your plants or seeds responsibly from reputable native plant nurseries rather than collecting from wild populations. Think of yourself as a conservation gardener, helping to preserve this unique Wyoming native for future generations.

Is Plains Milkvetch Right for Your Garden?

This plant is best suited for gardeners who are passionate about authentic native landscaping and don’t mind working with species that require a bit more patience and care. It’s perfect for:

  • Prairie restoration projects
  • Authentic Wyoming native plant gardens
  • Naturalized areas where you want true local character
  • Gardeners interested in supporting local ecosystems

Growing Plains Milkvetch Successfully

Since specific growing information for this variety is limited, your best bet is to mimic the conditions where it naturally thrives in Wyoming’s landscapes. As a native prairie plant, it likely prefers:

  • Well-draining soils (most prairie plants hate wet feet)
  • Full sun conditions
  • Low to moderate water once established
  • Minimal soil amendments (native plants often prefer lean soils)

Finding Plains Milkvetch

Because this is a regionally specific and somewhat uncommon variety, you’ll need to do some detective work to find it. Contact Wyoming native plant societies, university extension programs, or specialized native plant nurseries. Don’t be surprised if it takes some patience to locate – the best native plants often do!

The Bottom Line

Plains milkvetch isn’t for every gardener, but it’s perfect for those who want to create truly authentic Wyoming landscapes while supporting plant conservation efforts. If you’re the type of gardener who gets excited about growing something genuinely local and meaningful, this little legume might just become one of your favorite discoveries.

Remember, when you plant natives like plains milkvetch, you’re not just gardening – you’re participating in preserving your region’s natural heritage, one plant at a time.

Plains Milkvetch

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Astragalus L. - milkvetch

Species

Astragalus gilviflorus Sheldon - plains milkvetch

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA