North America Native Plant

Waterfall’s Milkvetch

Botanical name: Astragalus waterfallii

USDA symbol: ASWA3

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Waterfall’s Milkvetch: A Rare Southwestern Native Worth Protecting Meet Waterfall’s milkvetch (Astragalus waterfallii), a perennial wildflower that’s as elusive as it is intriguing. This little-known native plant calls the American Southwest home, but finding reliable information about it is like searching for a needle in a haystack – and that’s ...

Rare plant alert!

Region: Conservation status by state

Status: S3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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 ⚘

Waterfall’s Milkvetch: A Rare Southwestern Native Worth Protecting

Meet Waterfall’s milkvetch (Astragalus waterfallii), a perennial wildflower that’s as elusive as it is intriguing. This little-known native plant calls the American Southwest home, but finding reliable information about it is like searching for a needle in a haystack – and that’s exactly what makes it so special.

Where You’ll Find This Southwestern Gem

Waterfall’s milkvetch is native to the lower 48 states, specifically thriving in the desert landscapes of New Mexico and Texas. This regional native has adapted to life in some pretty challenging conditions, making it a true testament to the resilience of our native flora.

The Rarity Factor: Handle with Care

Here’s where things get serious – Waterfall’s milkvetch carries a Global Conservation Status of S3?, which puts it in the rare category. This means that if you’re lucky enough to encounter this plant or find seeds, you’re looking at something truly special. We strongly recommend only planting responsibly sourced material, and better yet, consider supporting conservation efforts for this species instead of trying to grow it in your garden.

What Makes It Garden-Worthy?

As a member of the milkvetch family, this perennial likely shares some family traits that make Astragalus species interesting garden additions:

  • Drought tolerance once established
  • Potential nitrogen-fixing abilities that benefit soil health
  • Adaptation to challenging growing conditions
  • Support for native pollinators and wildlife

Growing Conditions and Care

While specific growing information for Waterfall’s milkvetch is limited due to its rarity, we can make some educated guesses based on its native habitat in New Mexico and Texas:

  • Likely prefers well-draining, sandy or rocky soils
  • Probably thrives in full sun conditions
  • Should be drought tolerant once established
  • May require minimal supplemental watering

The Bottom Line for Gardeners

While Waterfall’s milkvetch would undoubtedly be a conversation starter in any native plant garden, its rarity means it’s not readily available for home cultivation. Instead of seeking out this rare gem, consider these alternatives that offer similar benefits:

  • Other Astragalus species native to your region
  • Regional milkvetch varieties that are more common
  • Native legumes that provide nitrogen fixation

If you’re passionate about rare native plants, consider supporting botanical gardens, seed banks, or conservation organizations working to protect species like Waterfall’s milkvetch. Sometimes the best way to grow a plant is to help preserve it in its natural habitat.

A Plant Worth Protecting

Waterfall’s milkvetch reminds us that not every native plant is meant for our backyard borders – some are meant to be cherished and protected in their wild spaces. By understanding and respecting the rarity of species like this one, we become better stewards of our native plant heritage.

Waterfall’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 waterfallii Barneby - Waterfall'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