North America Native Plant

Bastard Draba Milkvetch

Botanical name: Astragalus drabelliformis

USDA symbol: ASDR2

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Bastard Draba Milkvetch: A Rare Wyoming Native Worth Knowing Meet the bastard draba milkvetch (Astragalus drabelliformis), one of Wyoming’s most exclusive native plants. This little-known perennial shrub might not win any beauty contests, but it’s got something far more valuable: it’s a true Wyoming original that plays an important role ...

Rare plant alert!

Region: Conservation status by state

Status: S2S3: Status is uncertain but is somewhere between the following rankings: 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) ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

Bastard Draba Milkvetch: A Rare Wyoming Native Worth Knowing

Meet the bastard draba milkvetch (Astragalus drabelliformis), one of Wyoming’s most exclusive native plants. This little-known perennial shrub might not win any beauty contests, but it’s got something far more valuable: it’s a true Wyoming original that plays an important role in the state’s unique ecosystem.

What Makes This Plant Special

The bastard draba milkvetch is a compact, low-growing shrub that stays humble in stature, typically reaching only 1.5 feet tall and never exceeding 3 feet at maturity. As a member of the legume family, it produces small flowers that may not grab attention from across the garden, but up close, they’re perfectly formed miniature blooms that serve an important purpose for local pollinators.

What truly sets this plant apart is its rarity. With a Global Conservation Status of S2S3, this species is considered imperiled to vulnerable, making it one of Wyoming’s botanical treasures that deserves our respect and protection.

Where You’ll Find It

This Wyoming endemic calls only the Cowboy State home, with a distribution limited to specific areas within the state. It’s adapted to the challenging conditions of Wyoming’s arid landscapes, making it a true specialist of the region.

A Word of Caution: Rarity Matters

Before we dive into growing tips, let’s address the elephant in the room: this plant is rare. Its S2S3 conservation status means populations are limited and potentially declining. If you’re interested in growing bastard draba milkvetch, it’s absolutely crucial to source plants or seeds only from reputable native plant nurseries that use responsibly collected material. Never collect from wild populations.

Why Grow This Rare Beauty?

You might wonder why you’d want to grow such an uncommon plant. Here’s why conservation-minded gardeners are taking notice:

  • **Conservation value**: Growing rare natives helps preserve genetic diversity
  • **Unique Wyoming heritage**: It’s a plant that exists nowhere else in the world
  • **Pollinator support**: Native bees and other pollinators rely on native legumes
  • **Low maintenance**: Once established, it thrives with minimal care
  • **Conversation starter**: Your garden becomes a living museum of Wyoming’s natural heritage

Growing Conditions

This Wyoming native has adapted to tough conditions, and your garden should reflect that. Here’s what bastard draba milkvetch needs to thrive:

  • **Sunlight**: Full sun exposure
  • **Soil**: Well-draining soils; avoid heavy clay or constantly moist conditions
  • **Water**: Minimal irrigation once established; overwatering is more harmful than drought
  • **Climate**: Hardy in USDA zones 4-6, perfect for Wyoming’s temperature extremes

Perfect Garden Settings

This isn’t a plant for traditional flower borders or cottage gardens. Instead, consider these specialized settings:

  • **Rock gardens**: Its low stature and drought tolerance make it perfect among stones
  • **Native plant gardens**: Essential for authentic Wyoming landscape recreations
  • **Xeriscaping projects**: Ideal for water-wise landscaping
  • **Conservation gardens**: Perfect for gardeners focused on preserving rare species

Planting and Care Tips

Growing rare natives requires a gentle touch and patience:

  • **Plant in spring** after the last frost when soil has warmed
  • **Improve drainage** if your soil tends to hold water
  • **Water sparingly** during establishment, then rely on natural precipitation
  • **Avoid fertilizers** – native plants typically don’t need them and may be harmed by excess nutrients
  • **Be patient** – rare plants often grow slowly but reward you with longevity

Supporting Pollinators

As a legume, bastard draba milkvetch produces flowers that attract native bees and other pollinators. While the blooms may be small, they’re perfectly designed for the local pollinator community that has co-evolved with this species over thousands of years.

The Bottom Line

Bastard draba milkvetch isn’t for every gardener, but for those passionate about conservation and Wyoming’s natural heritage, it offers something truly special. This rare native represents a chance to participate in conservation right in your own backyard.

Remember, with great rarity comes great responsibility. Only source this plant through legitimate channels, never from wild populations, and consider yourself a steward of one of Wyoming’s most precious botanical resources. It may be small and humble, but in the world of native plants, the bastard draba milkvetch is pure gold.

Bastard Draba 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 drabelliformis Barneby - bastard draba milkvetch

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