North America Native Plant

Ferris’ Milkvetch

Botanical name: Astragalus tener var. ferrisiae

USDA symbol: ASTEF

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Ferris’ Milkvetch: A Rare California Gem Worth Protecting Meet Ferris’ milkvetch (Astragalus tener var. ferrisiae), one of California’s most endangered wildflowers that deserves our attention and protection. This delicate annual herb might be small in stature, but it plays an outsized role in California’s native plant heritage. A True California ...

Rare plant alert!

Region: Conservation status by state

Status: S2T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is 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) ⚘ 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) ⚘

Ferris’ Milkvetch: A Rare California Gem Worth Protecting

Meet Ferris’ milkvetch (Astragalus tener var. ferrisiae), one of California’s most endangered wildflowers that deserves our attention and protection. This delicate annual herb might be small in stature, but it plays an outsized role in California’s native plant heritage.

A True California Native

Ferris’ milkvetch is exclusively native to California, making it a genuine Golden State original. This rare variety grows naturally in the Central Valley and surrounding foothills, where it has adapted to the region’s unique Mediterranean climate patterns over thousands of years.

Why This Plant Matters (And Why You Should Care)

Here’s the thing about Ferris’ milkvetch – it’s critically rare. With a conservation status of S2T1, this little wildflower is hanging on by a thread in the wild. Habitat loss and development have pushed this species to the brink, making every garden that hosts it a potential conservation sanctuary.

But before you rush to plant it, there’s an important caveat: only use responsibly sourced material. This means purchasing from reputable native plant nurseries that propagate from legally collected seeds, never wild-harvesting plants or seeds yourself.

What It Looks Like

Don’t expect a showstopper – Ferris’ milkvetch is all about subtle beauty. This annual herb produces compound leaves and small, pea-like flowers in shades of purple or pink. Like other members of the legume family, it has that classic butterfly-shaped flower structure that pollinators find irresistible.

Growing Conditions and Care

If you’re lucky enough to find responsibly sourced seeds, here’s how to give Ferris’ milkvetch the best chance:

  • Sunlight: Full sun is essential
  • Soil: Well-draining soils are a must – this plant hates wet feet
  • Water: Drought-tolerant once established, but appreciates winter moisture
  • Climate: Thrives in USDA zones 8-10, perfect for California gardens

Planting Tips

Since this is an annual, you’ll need to sow seeds each year. The best approach is direct seeding in fall, which allows the seeds to experience the winter chill they need to germinate properly in spring. Think of it as nature’s way of ensuring the timing is just right.

Garden Design Ideas

Ferris’ milkvetch works beautifully in:

  • Native wildflower meadows
  • California native plant gardens
  • Restoration projects
  • Rock gardens with other small natives

Pair it with other California natives like poppies, lupines, and native grasses for an authentic Golden State wildflower display.

Supporting Pollinators

Those small flowers might look modest, but they’re pollinator magnets. Native bees and other small pollinators rely on plants like Ferris’ milkvetch for nectar and pollen. By growing this rare species, you’re supporting both plant conservation and pollinator health.

The Bottom Line

Should you grow Ferris’ milkvetch? If you’re passionate about California native plants and can source it responsibly, absolutely. Every garden that successfully grows this rare species becomes part of a conservation effort. Just remember – only purchase from reputable sources, never collect from the wild, and consider it a privilege to help preserve this botanical treasure for future generations.

Sometimes the most important plants aren’t the flashiest ones – they’re the rare gems that need our help to survive.

Ferris’ 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 tener A. Gray - alkali milkvetch

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