North America Native Plant

Maricopa Milkvetch

Botanical name: Astragalus lentiginosus var. maricopae

USDA symbol: ASLEM2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Maricopa Milkvetch: A Rare Southwestern Native Worth Knowing Meet the Maricopa milkvetch (Astragalus lentiginosus var. maricopae), a fascinating perennial that represents one of Arizona’s unique botanical treasures. This native plant embodies the resilient spirit of the Sonoran Desert region, though it remains one of the lesser-known members of the diverse ...

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. ⚘

Maricopa Milkvetch: A Rare Southwestern Native Worth Knowing

Meet the Maricopa milkvetch (Astragalus lentiginosus var. maricopae), a fascinating perennial that represents one of Arizona’s unique botanical treasures. This native plant embodies the resilient spirit of the Sonoran Desert region, though it remains one of the lesser-known members of the diverse milkvetch family.

Where Does Maricopa Milkvetch Call Home?

This distinctive variety is native to Arizona, where it has adapted to the challenging desert conditions over thousands of years. As a true Arizona native, it’s perfectly suited to the state’s unique climate and soil conditions, making it an excellent choice for authentic southwestern native gardens.

A Rare Find in the Garden World

Here’s something important to know: Maricopa milkvetch appears to be quite rare, with a conservation status that suggests limited populations. If you’re considering adding this plant to your garden, it’s crucial to source it responsibly from reputable native plant nurseries that propagate rather than wild-collect their specimens. Never collect plants from the wild – it’s both illegal and harmful to already vulnerable populations.

Why Consider Maricopa Milkvetch for Your Garden?

As a perennial, this milkvetch offers several compelling reasons to include it in your landscape:

  • Authentic Arizona native: Perfect for creating genuine desert landscapes
  • Water-wise: Naturally adapted to low-water conditions
  • Perennial longevity: Returns year after year once established
  • Conservation value: Supporting rare native species in cultivation

Garden Design and Landscape Role

While specific information about this variety’s exact appearance and size is limited, milkvetches generally work well in:

  • Native desert gardens
  • Water-wise xeriscapes
  • Natural area restorations
  • Wildlife-friendly landscapes

These plants typically serve as mid-story elements in desert plant communities, bridging the gap between ground covers and larger shrubs.

Growing Conditions and Care

Like most Arizona natives, Maricopa milkvetch likely thrives in:

  • Full sun exposure: Desert plants need plenty of sunshine
  • Well-draining soil: Poor drainage can be fatal to desert natives
  • Minimal water: Once established, these plants prefer infrequent deep watering
  • Hot, dry conditions: They’re built for Arizona’s challenging climate

Planting and Establishment Tips

When growing any rare native like Maricopa milkvetch:

  • Plant in fall for best establishment before summer heat
  • Provide some protection from extreme conditions during the first year
  • Water regularly during establishment, then gradually reduce frequency
  • Avoid fertilizers – native plants prefer lean soils
  • Mulch lightly with gravel or decomposed granite rather than organic mulch

The Bottom Line

Maricopa milkvetch represents an opportunity to grow something truly special – a rare Arizona native that connects your garden to the state’s natural heritage. However, its apparent rarity means you’ll need to be a responsible gardener, sourcing plants ethically and perhaps considering it more of a conservation effort than a typical landscaping choice.

If you can’t locate responsibly sourced Maricopa milkvetch, consider other Arizona native milkvetches or legumes that offer similar ecological benefits while being more readily available. The key is supporting your local ecosystem with plants that truly belong in your desert landscape.

Maricopa 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 lentiginosus Douglas ex Hook. - freckled milkvetch

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