North America Native Plant

Torrey’s Milkvetch

Botanical name: Astragalus calycosus var. scaposus

USDA symbol: ASCAS

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Torrey’s Milkvetch: A Southwestern Native Worth Knowing If you’re passionate about native plants and live in the American Southwest, you might want to get acquainted with Torrey’s milkvetch (Astragalus calycosus var. scaposus). This perennial native is one of those understated beauties that exemplifies the resilient spirit of southwestern flora. Where ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Subspecies or variety is 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. ⚘ 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. ⚘

Torrey’s Milkvetch: A Southwestern Native Worth Knowing

If you’re passionate about native plants and live in the American Southwest, you might want to get acquainted with Torrey’s milkvetch (Astragalus calycosus var. scaposus). This perennial native is one of those understated beauties that exemplifies the resilient spirit of southwestern flora.

Where You’ll Find This Native Gem

Torrey’s milkvetch calls the southwestern United States home, naturally occurring across Arizona, Colorado, Nevada, New Mexico, and Utah. As a true native to these regions, it’s perfectly adapted to the challenging conditions that define much of the American Southwest.

Why Consider Torrey’s Milkvetch for Your Garden?

As a native plant, Torrey’s milkvetch offers several compelling reasons to include it in your landscape:

  • True regional native: Supporting local ecosystems by growing plants that naturally belong in your area
  • Perennial resilience: Once established, this hardy perennial returns year after year
  • Low-maintenance nature: Like most native milkvetches, it’s adapted to local conditions and requires minimal intervention
  • Ecological value: Native plants typically support local wildlife and pollinators better than non-natives

Growing Conditions and Care

While specific growing information for this particular variety is limited, we can draw from the broader milkvetch family’s preferences. Most Astragalus species thrive in:

  • Well-draining soil: Essential for preventing root rot in these desert-adapted plants
  • Full sun exposure: These plants love bright, direct sunlight
  • Minimal water: Once established, they’re typically drought-tolerant
  • Alkaline to neutral soil pH: Common preference among southwestern natives

A Word of Caution: Limited Availability

Here’s where things get a bit tricky. Torrey’s milkvetch isn’t commonly found in nurseries, and detailed cultivation information is scarce. This could indicate that it’s either quite specialized in its habitat requirements or perhaps not widely cultivated.

If you’re determined to grow this native beauty, your best bet is to:

  • Contact native plant societies in your region
  • Reach out to specialized native plant nurseries
  • Ensure any plants or seeds are responsibly and legally sourced
  • Consider starting with more readily available milkvetch species to gain experience

The Bottom Line

Torrey’s milkvetch represents the kind of specialized native plant that makes regional flora so fascinating. While it may not be the easiest plant to source or grow, it offers the reward of cultivating a true local native. If you can’t find this specific variety, don’t despair—there are many other beautiful milkvetch species that might be more readily available and equally valuable to your native landscape.

Remember, the best native garden is one that actually gets planted and thrives. Sometimes that means starting with more common natives and working your way up to the rare gems like Torrey’s milkvetch.

Torrey’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 calycosus Torr. ex S. Watson - Torrey'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