North America Native Plant

White Clouds Milkvetch

Botanical name: Astragalus vexilliflexus var. nubilus

USDA symbol: ASVEN

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

White Clouds Milkvetch: A Rare Idaho Native Worth Knowing If you’re passionate about growing truly local native plants, White Clouds milkvetch (Astragalus vexilliflexus var. nubilus) might just capture your gardening heart. This low-growing perennial shrub represents the kind of specialized native that makes Idaho’s flora so unique—though it comes with ...

Rare plant alert!

Region: Conservation status by state

Status: S4T2: 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) ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

White Clouds Milkvetch: A Rare Idaho Native Worth Knowing

If you’re passionate about growing truly local native plants, White Clouds milkvetch (Astragalus vexilliflexus var. nubilus) might just capture your gardening heart. This low-growing perennial shrub represents the kind of specialized native that makes Idaho’s flora so unique—though it comes with some important considerations for the conscientious gardener.

What Makes White Clouds Milkvetch Special?

White Clouds milkvetch is a compact, perennial shrub that stays refreshingly manageable in size. You can expect this little beauty to remain under 1.5 feet tall in most situations, never exceeding 3 feet even at full maturity. This makes it perfect for gardeners who love native plants but don’t want something that’ll take over their landscape.

As a member of the legume family (those clever plants that can fix nitrogen in the soil), milkvetches often play important ecological roles in their native habitats. While we don’t have specific details about this variety’s wildlife benefits, many Astragalus species support native bees and other pollinators.

Where Does It Call Home?

This milkvetch is native to the lower 48 states, with its known distribution centered in Idaho. It’s truly a regional specialty—the kind of plant that connects your garden directly to the local ecosystem in ways that more widespread natives simply can’t match.

Important Conservation Considerations

Here’s where things get interesting (and important): White Clouds milkvetch has a Global Conservation Status of S4T2. While the specific meaning of this ranking isn’t entirely clear from available data, any plant with a conservation status deserves our careful attention and respect.

If you’re interested in growing this plant, please ensure you source it responsibly:

  • Purchase only from reputable native plant nurseries
  • Never collect plants or seeds from wild populations
  • Consider participating in or supporting conservation efforts for rare native plants
  • Choose nursery-propagated plants over wild-collected specimens

Is White Clouds Milkvetch Right for Your Garden?

This milkvetch could be an excellent choice if you’re:

  • Creating a native Idaho plant garden
  • Looking for low-maintenance, compact shrubs
  • Interested in supporting local ecosystems with truly regional plants
  • Committed to responsible sourcing of rare native plants

However, you might want to consider other options if you’re looking for plants with well-documented garden performance, readily available sources, or immediate visual impact.

Growing White Clouds Milkvetch

Unfortunately, specific growing conditions and care requirements for this particular variety aren’t well-documented in readily available sources. However, as with most Astragalus species, you can generally expect it to prefer:

  • Well-drained soils (many milkvetches dislike wet feet)
  • Full sun to partial sun exposure
  • Low to moderate water once established
  • Minimal fertilization (remember, legumes fix their own nitrogen!)

If you’re serious about growing this plant, we’d recommend connecting with native plant societies in Idaho or contacting botanical experts familiar with regional Astragalus species for more specific guidance.

The Bottom Line

White Clouds milkvetch represents the fascinating world of highly localized native plants—species that connect us intimately with specific places and ecosystems. While it may not be the easiest native plant to source or grow, it offers something special for the dedicated native plant gardener: a direct connection to Idaho’s unique botanical heritage.

Just remember to approach this plant with the respect its conservation status deserves, and always prioritize responsible sourcing over convenience. Sometimes the rarest treasures require a little extra effort—and that’s exactly what makes them so rewarding to grow.

White Clouds 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 vexilliflexus Sheldon - bentflower milkvetch

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