North America Native Plant

Robbins’ Milkvetch

Botanical name: Astragalus robbinsii var. alpiniformis

USDA symbol: ASROA

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Astragalus alpinus L. var. alpiniformis (Rydb.) Rydb. ex M. Peck (ASALA6)  âš˜  Atelophragma alpiniforme Rydb. (ATAL3)   

Robbins’ Milkvetch: A Rare Alpine Gem for High-Elevation Gardens If you’re dreaming of creating an authentic alpine garden or live in a high-elevation area, Robbins’ milkvetch (Astragalus robbinsii var. alpiniformis) might just be the native treasure you’ve been searching for. This petite perennial legume brings a touch of mountain wilderness ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3: Status is uncertain but is somewhere between the following rankings: 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. ⚘

Robbins’ Milkvetch: A Rare Alpine Gem for High-Elevation Gardens

If you’re dreaming of creating an authentic alpine garden or live in a high-elevation area, Robbins’ milkvetch (Astragalus robbinsii var. alpiniformis) might just be the native treasure you’ve been searching for. This petite perennial legume brings a touch of mountain wilderness to specialized garden settings, though it’s definitely not a plant for every gardener or every garden.

What Makes Robbins’ Milkvetch Special

This charming native plant is a true Oregon original, naturally occurring in the state’s high-elevation alpine and subalpine regions, particularly in the Cascade Range. As a member of the milkvetch family, it produces the characteristic compound leaves and pea-like flowers that make legumes so distinctive. The delicate purple to pink blooms appear in small clusters, creating a subtle but beautiful display against rocky mountain landscapes.

Robbins’ milkvetch is found exclusively in Oregon within the lower 48 states, making it a genuinely regional native species.

Is This Plant Right for Your Garden?

Here’s where we need to have an honest conversation. Robbins’ milkvetch isn’t your typical garden center find, and there are several important considerations before deciding to grow it:

  • Rarity concerns: This plant has a conservation status that suggests limited populations, so responsible sourcing is absolutely essential
  • Specialized needs: It requires very specific alpine conditions that are difficult to replicate in typical garden settings
  • Geographic limitations: Only suitable for gardeners in or near its native Oregon range

Perfect Garden Settings

If you’re still intrigued (and live in the right area), Robbins’ milkvetch can be a stunning addition to:

  • Alpine rock gardens
  • High-elevation native plant gardens
  • Specialized collections focusing on Oregon natives
  • Rocky slope plantings in mountainous areas

Growing Conditions and Care

Think mountain top when planning for this plant:

  • Drainage: Absolutely critical – soggy soil will quickly kill this alpine specialist
  • Sun exposure: Full sun, just like its natural mountain habitat
  • Soil: Rocky, well-draining soil that mimics alpine conditions
  • Climate: Cool summers and cold winters (USDA zones 4-7)
  • Elevation: Best suited for high-elevation gardens

Benefits for Wildlife and Pollinators

Like other legumes, Robbins’ milkvetch provides valuable nectar for native bees and other small pollinators. Its flowers are particularly attractive to specialized alpine pollinators that have co-evolved with high-elevation plant communities. The plant also contributes to soil health by fixing nitrogen, a valuable service in nutrient-poor alpine soils.

A Word of Caution and Responsibility

Given the limited distribution and potential conservation concerns surrounding this plant, it’s crucial to source any plants or seeds responsibly. Never collect from wild populations, and only purchase from reputable native plant nurseries that can verify their propagation methods. Consider this plant only if you can provide the specialized conditions it requires and are committed to supporting conservation efforts for rare native species.

The Bottom Line

Robbins’ milkvetch is a plant for the dedicated native plant enthusiast with the right conditions and a strong conservation ethic. While it’s not suitable for most gardens, those who can provide appropriate alpine conditions and source plants responsibly will be rewarded with a truly unique piece of Oregon’s high-country heritage. For most gardeners, exploring other native Oregon plants that are more readily available and easier to grow might be a better starting point for supporting local ecosystems.

Robbins’ 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 robbinsii (Oakes) A. Gray - Robbins' milkvetch

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