North America Native Plant

Alkali Sandmat

Botanical name: Chamaesyce astyla

USDA symbol: CHAS2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Euphorbia astyla Engelm. ex Boiss. (EUAS2)   

Alkali Sandmat: A Rare Texas Native Worth Protecting Meet alkali sandmat (Chamaesyce astyla), one of Texas’s most imperiled native plants. This tiny perennial forb might not win any beauty contests, but it plays a crucial role in the Lone Star State’s botanical heritage. If you’re passionate about native plant conservation ...

Rare plant alert!

Region: Conservation status by state

Status: S2: Status is uncertain but is somewhere between the following rankings: 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) ⚘

Alkali Sandmat: A Rare Texas Native Worth Protecting

Meet alkali sandmat (Chamaesyce astyla), one of Texas’s most imperiled native plants. This tiny perennial forb might not win any beauty contests, but it plays a crucial role in the Lone Star State’s botanical heritage. If you’re passionate about native plant conservation and have the right growing conditions, this rare gem deserves a spot in your specialized garden.

Why Alkali Sandmat Deserves Your Attention

Alkali sandmat is what botanists call a conservation priority species. With a Global Conservation Status of S2 (Imperiled), this little plant is hanging on by a thread, with typically only 6 to 20 known occurrences remaining in the wild. That makes every garden specimen potentially valuable for the species’ survival.

Also known by its scientific name Chamaesyce astyla (formerly Euphorbia astyla), this native Texan is a true specialist. It’s adapted to thrive in alkaline soils that would make most other plants throw in the towel.

Where You’ll Find This Texas Treasure

Alkali sandmat is exclusively native to Texas, making it a true state endemic. It’s naturally found in the southwestern portions of the state, where alkaline soils and arid conditions create the perfect storm of challenging growing conditions that this tough little plant calls home.

What Does Alkali Sandmat Look Like?

Don’t expect showy flowers or dramatic foliage from this understated native. As a forb (a non-woody perennial plant), alkali sandmat keeps a low profile with:

  • Small, inconspicuous flowers that won’t stop traffic but serve their purpose
  • Modest growth habit that hugs the ground
  • Tough, drought-adapted foliage designed for survival, not spectacle

Think of it as the botanical equivalent of a reliable friend – not flashy, but dependable and uniquely valuable.

Growing Alkali Sandmat: Special Considerations

Important: Due to its imperiled status, only grow alkali sandmat from responsibly sourced material. Never collect from wild populations, and purchase only from reputable native plant nurseries that propagate their own stock.

Ideal Growing Conditions

Alkali sandmat is particular about its living arrangements:

  • Soil: Alkaline soils are a must – this plant won’t tolerate acidic conditions
  • Drainage: Well-draining soil is essential to prevent root rot
  • Sunlight: Full sun exposure mimics its natural habitat
  • Water: Drought-tolerant once established; avoid overwatering
  • Climate: Best suited for USDA hardiness zones 8-10

Perfect Garden Settings

Alkali sandmat shines in specialized garden environments:

  • Native plant conservation gardens
  • Rock gardens with alkaline soil
  • Xerophytic (drought-adapted) landscapes
  • Educational botanical collections
  • Wildlife habitat restoration projects

Wildlife and Ecological Benefits

While alkali sandmat may not be a pollinator magnet, its small flowers can attract tiny native bees and flies. More importantly, growing this rare native helps preserve genetic diversity and supports Texas’s unique botanical heritage.

Care and Maintenance

Once established, alkali sandmat is refreshingly low-maintenance:

  • Water sparingly – this plant prefers to stay on the dry side
  • Avoid fertilizing, which can harm adapted native plants
  • Let it spread naturally to form small colonies
  • Protect from foot traffic due to its ground-hugging nature

The Conservation Gardener’s Choice

Growing alkali sandmat isn’t about instant gratification or curb appeal – it’s about playing a role in conservation. By cultivating this imperiled Texas native in your garden, you’re helping ensure that future generations will know this unique piece of the state’s natural heritage.

If you’re ready to embrace the challenge of growing one of Texas’s rarest plants, alkali sandmat offers the satisfaction of nurturing a true botanical treasure. Just remember: source responsibly, provide the right conditions, and take pride in growing a plant that few gardeners will ever encounter.

Alkali Sandmat

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

Euphorbiales

Family

Euphorbiaceae Juss. - Spurge family

Genus

Chamaesyce Gray - sandmat

Species

Chamaesyce astyla (Engelm. ex Boiss.) Millsp. - alkali sandmat

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