North America Native Plant

Isely’s Milkvetch

Botanical name: Astragalus iselyi

USDA symbol: ASIS

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Isely’s Milkvetch: A Critically Rare Utah Native Worth Protecting Meet Isely’s milkvetch (Astragalus iselyi), one of Utah’s most precious and endangered native plants. This unassuming perennial might not grab headlines like a flashy wildflower, but it represents something far more important: a living piece of Utah’s natural heritage hanging by ...

Rare plant alert!

Region: Conservation status by state

Status: S1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘

Isely’s Milkvetch: A Critically Rare Utah Native Worth Protecting

Meet Isely’s milkvetch (Astragalus iselyi), one of Utah’s most precious and endangered native plants. This unassuming perennial might not grab headlines like a flashy wildflower, but it represents something far more important: a living piece of Utah’s natural heritage hanging by a thread.

A Plant on the Brink

Before we dive into the details of this remarkable plant, there’s something crucial you need to know: Isely’s milkvetch is critically imperiled. With a Global Conservation Status of S1, this species typically has five or fewer known locations and fewer than 1,000 individual plants remaining in the wild. That makes it rarer than many animals we consider endangered!

If you’re thinking about adding this plant to your garden, please reconsider. This is a species that desperately needs every individual plant to remain in its natural habitat to survive as a species.

Where to Find This Rare Beauty

Isely’s milkvetch is what botanists call an endemic species – it’s found naturally in only one place on Earth. In this case, that place is Utah, where it clings to existence in very specific locations within the state.

What Makes It Special

Like other members of the milkvetch family, Isely’s milkvetch is a hardy perennial that has adapted to some pretty tough growing conditions. These plants are survivors, which makes their current endangered status all the more concerning – if even these tough cookies are struggling, it tells us something important about habitat loss and environmental pressures.

The plant produces the characteristic flowers you’d expect from a milkvetch – typically small, white to cream-colored blooms that attract native bees and other pollinators. Every flower that gets pollinated and produces seeds is literally helping to save the species from extinction.

Growing Conditions (For Educational Purposes Only)

While we strongly discourage attempting to grow Isely’s milkvetch, understanding its needs helps us appreciate why it’s so rare:

  • Requires very specific, well-drained, alkaline soils
  • Needs full sun exposure
  • Adapted to Utah’s extreme temperature variations (likely hardy in USDA zones 4-7)
  • Drought tolerant once established, but may need specific moisture patterns
  • Extremely difficult to cultivate outside its native habitat

How You Can Help Instead

Rather than trying to grow this endangered beauty, here are meaningful ways you can support Isely’s milkvetch and other rare native plants:

  • Support organizations working on native plant conservation in Utah
  • Choose other native Utah plants for your garden that aren’t endangered
  • Learn to identify rare plants and report sightings to local botanists
  • Advocate for habitat protection in areas where rare plants grow
  • Practice responsible hiking and outdoor recreation to avoid trampling rare plants

Garden Alternatives

If you’re drawn to milkvetch plants, consider these more common native alternatives that won’t put additional pressure on endangered species:

  • Other non-rare Astragalus species native to your area
  • Native legumes like lupines or clovers
  • Consult with local native plant societies for the best regional alternatives

The Bigger Picture

Isely’s milkvetch represents something larger than itself – it’s a reminder that even in our modern world, we can still lose species forever. Every rare plant that disappears takes with it millions of years of evolution and adaptation, along with potentially important ecological relationships we might not even understand yet.

By learning about and respecting plants like Isely’s milkvetch, we become better stewards of the incredible biodiversity that makes our natural world so fascinating. Sometimes the best way to love a plant is to admire it from a distance and work to protect the places where it naturally belongs.

So next time you’re exploring Utah’s diverse landscapes, keep your eyes open for this little survivor. And if you’re lucky enough to spot it, take a moment to appreciate that you’re looking at one of nature’s rarest treasures – then leave it exactly where you found it for future generations to discover.

Isely’s 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 iselyi S.L. Welsh - Isely's milkvetch

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