North America Native Plant

Crescent Milkvetch

Botanical name: Astragalus amphioxys var. amphioxys

USDA symbol: ASAMA

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Astragalus amphioxys A. Gray var. melanocalyx (Rydb.) Tidestr. (ASAMM3)   

Crescent Milkvetch: A Charming Native Annual for Desert Gardens Meet Crescent milkvetch (Astragalus amphioxys var. amphioxys), a delightful little native annual that’s perfectly suited for gardeners looking to embrace water-wise landscaping. This member of the pea family brings subtle beauty and ecological value to southwestern gardens without demanding much in ...

Crescent Milkvetch: A Charming Native Annual for Desert Gardens

Meet Crescent milkvetch (Astragalus amphioxys var. amphioxys), a delightful little native annual that’s perfectly suited for gardeners looking to embrace water-wise landscaping. This member of the pea family brings subtle beauty and ecological value to southwestern gardens without demanding much in return.

Where You’ll Find This Desert Gem

Crescent milkvetch is native to the lower 48 states, specifically thriving across the southwestern United States. You’ll find this hardy annual growing naturally in Arizona, Nevada, New Mexico, Texas, and Utah, where it has adapted beautifully to desert and semi-arid conditions.

What Makes Crescent Milkvetch Special

This charming annual produces small purple to pink pea-like flowers that add a gentle splash of color to the landscape. The silvery-green compound leaves create an attractive backdrop and help the plant conserve moisture in harsh desert conditions. As an annual, Crescent milkvetch completes its entire life cycle in one growing season, making it a perfect choice for gardeners who enjoy seasonal variety.

Perfect for Desert and Drought-Tolerant Gardens

Crescent milkvetch shines in several garden settings:

  • Desert gardens and xeriscapes
  • Rock gardens and gravelly slopes
  • Native plant gardens
  • Erosion control areas
  • Water-wise landscapes

This low-maintenance plant works wonderfully as a ground cover and pairs beautifully with other southwestern natives like desert marigold, brittlebush, and various cacti.

Growing Crescent Milkvetch Successfully

One of the best things about Crescent milkvetch is how easy it is to grow once you understand its needs. This plant thrives in USDA hardiness zones 4-9, making it suitable for a wide range of climates.

Ideal Growing Conditions

  • Sunlight: Full sun exposure
  • Soil: Well-draining sandy or rocky soils
  • Water: Drought tolerant once established; avoid overwatering
  • Climate: Prefers dry, desert-like conditions

Planting and Care Tips

The key to success with Crescent milkvetch is mimicking its natural desert habitat:

  • Timing: Direct seed in fall for best results
  • Soil preparation: Ensure excellent drainage; amend heavy soils with sand or gravel
  • Watering: Provide minimal water after establishment; this plant actually suffers from too much moisture
  • Maintenance: Very low maintenance once established

Benefits Beyond Beauty

Crescent milkvetch isn’t just pretty – it’s also ecologically valuable. The flowers attract native bees and small butterflies, supporting local pollinator populations. As a member of the legume family, it also helps improve soil nitrogen levels, benefiting neighboring plants.

Is Crescent Milkvetch Right for Your Garden?

Consider adding Crescent milkvetch to your garden if you:

  • Live in an arid or semi-arid climate
  • Want to support native wildlife and pollinators
  • Prefer low-maintenance, drought-tolerant plants
  • Enjoy the subtle beauty of wildflowers
  • Are creating a native plant or desert garden

However, this plant might not be the best choice if you have heavy clay soil, prefer lush tropical gardens, or live in very humid climates where fungal issues might arise.

Crescent milkvetch proves that native plants can be both beautiful and practical. By choosing this southwestern native, you’ll be supporting local ecosystems while enjoying a charming, low-maintenance addition to your drought-tolerant landscape.

Crescent 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 amphioxys A. Gray - Crescent milkvetch

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