North America Native Plant

Geyer’s Milkvetch

Botanical name: Astragalus geyeri var. triquetrus

USDA symbol: ASGET

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Astragalus triquetrus A. Gray (ASTR19)   

Geyer’s Milkvetch: A Rare Native Wildflower Worth Knowing About Meet Geyer’s milkvetch (Astragalus geyeri var. triquetrus), a fascinating little annual wildflower that’s part of America’s native plant heritage. While you might not find this particular variety at your local garden center, it’s worth getting to know – especially if you’re ...

Rare plant alert!

Region: Conservation status by state

Status: S4T2T3: 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) ⚘ 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. ⚘ 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 ⚘

Geyer’s Milkvetch: A Rare Native Wildflower Worth Knowing About

Meet Geyer’s milkvetch (Astragalus geyeri var. triquetrus), a fascinating little annual wildflower that’s part of America’s native plant heritage. While you might not find this particular variety at your local garden center, it’s worth getting to know – especially if you’re passionate about rare native plants and conservation.

What Makes This Plant Special

Geyer’s milkvetch belongs to the legume family, which means it’s related to beans, peas, and other nitrogen-fixing plants. As an annual, this plant completes its entire life cycle in one growing season – sprouting, blooming, setting seed, and dying all within a single year. It’s also known by the scientific synonym Astragalus triquetrus A. Gray, if you happen to encounter it in older botanical references.

Where You’ll Find It Growing Wild

This rare native has a pretty limited range, naturally occurring in just two southwestern states: Arizona and Nevada. It’s adapted to the unique conditions of these desert and semi-desert regions, making it a true specialist of the American Southwest.

A Word About Rarity

Here’s something important to know: Geyer’s milkvetch variety triquetrus has a conservation status that suggests it’s quite rare. This means we need to be extra thoughtful about how we interact with this plant. If you’re lucky enough to encounter it in the wild, please observe and photograph rather than collect. And if you’re interested in growing it, make sure any seeds or plants come from reputable, conservation-minded sources that practice responsible collection.

Should You Grow It?

Given its rarity status, this particular variety of Geyer’s milkvetch isn’t really a plant for casual gardening. However, if you’re:

  • A serious native plant enthusiast
  • Involved in conservation efforts
  • Working on habitat restoration in Arizona or Nevada
  • Committed to growing only responsibly-sourced rare plants

Then you might consider adding it to a specialized native plant collection. Just remember – with rare plants comes great responsibility!

Growing Conditions and Care

While specific growing requirements for this variety aren’t well-documented, we can make some educated guesses based on its native habitat. As a plant from Arizona and Nevada, it likely prefers:

  • Full sun exposure
  • Well-draining, sandy or rocky soils
  • Low water conditions once established
  • Protection from excessive moisture

Being an annual, you’d need to collect seeds each year or allow the plant to self-seed for continuous generations.

Alternative Native Options

If you’re drawn to the idea of growing native milkvetches but want something more readily available, consider looking into other Astragalus species native to your area. Many milkvetches offer similar ecological benefits and are more suitable for home gardens. Your local native plant society or extension office can point you toward appropriate alternatives that won’t put rare plants at risk.

The Bottom Line

Geyer’s milkvetch variety triquetrus represents the incredible diversity of America’s native flora, even if it’s not destined for most home gardens. By learning about and respecting rare plants like this one, we become better stewards of our natural heritage. Sometimes the best way to grow a plant is to protect the wild spaces where it naturally thrives!

Geyer’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 geyeri A. Gray - Geyer'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