Native Plants

Southwestern Ringstem

Anulocaulis leiosolenus var. leiosolenus

USDA symbol: ANLEL2

perennial forb

Lower 48 states: native

If you’re looking to create an authentic southwestern landscape that thrives in harsh desert conditions, meet your new best friend: the southwestern ringstem (Anulocaulis leiosolenus var. leiosolenus). This unassuming but resilient native perennial might not win any flashy flower contests, but it’s got something better—serious desert survival skills and a ...

Southwestern Ringstem may be listed as rare in your area.
Global Conservation Status

Status: S4T3 | Apparently Secure: Uncommon but not rare, and usually widespread. Possible cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals.

Southwestern Ringstem: A Hardy Desert Native for Water-Wise Gardens

If you’re looking to create an authentic southwestern landscape that thrives in harsh desert conditions, meet your new best friend: the southwestern ringstem (Anulocaulis leiosolenus var. leiosolenus). This unassuming but resilient native perennial might not win any flashy flower contests, but it’s got something better—serious desert survival skills and a knack for making water-wise gardening look effortless.

What Is Southwestern Ringstem?

Southwestern ringstem is a native perennial forb that belongs to the four-o’clock family. As a forb, it’s an herbaceous plant without woody stems—think of it as the desert’s version of a hardy wildflower. You might also see it listed under its scientific synonym, Boerhavia leiosolena, but don’t let the fancy names intimidate you. This is a down-to-earth desert dweller through and through.

Where Does It Call Home?

This southwestern native has claimed its territory across four states: Arizona, Nevada, New Mexico, and Texas. It’s perfectly adapted to life in the Sonoran and Chihuahuan desert regions, where it has spent millennia learning how to thrive in conditions that would make other plants wilt just thinking about them.

  • Species observed
  • No observations

Why Consider Adding It to Your Garden?

Here’s where southwestern ringstem really shines as a garden choice:

  • Drought Champion: Once established, this plant laughs in the face of water restrictions
  • Native Credentials: Supporting local ecosystems while reducing maintenance needs
  • Pollinator Friendly: Its small flowers attract native desert bees and other beneficial insects
  • Low Maintenance: Perfect for gardeners who prefer plants that don’t need constant attention
  • Authentic Desert Look: Creates genuine southwestern landscape character

A Word About Rarity

Before you rush out to find this plant, there’s something important to know: southwestern ringstem has a conservation status that suggests it’s not super common in the wild. If you decide to add it to your garden, make sure you source it from reputable native plant nurseries that propagate their own stock rather than collecting from wild populations. This way, you can enjoy this desert gem while helping preserve it for future generations.

Perfect Garden Situations

Southwestern ringstem is tailor-made for specific garden styles:

  • Desert Gardens: Natural choice for authentic southwestern landscapes
  • Xeriscaping: Excellent for water-conservation focused designs
  • Rock Gardens: Thrives among rocks and gravel
  • Native Plant Gardens: Perfect for supporting local ecosystem restoration

Growing Conditions and Care

The beauty of southwestern ringstem lies in its simplicity. Here’s what it needs to thrive:

  • Sunlight: Full sun—the more, the better
  • Soil: Well-draining sandy or rocky soil (heavy clay is its kryptonite)
  • Water: Minimal once established; drought tolerance is its superpower
  • Climate: USDA hardiness zones 8-10
  • Space: Works well as ground cover or scattered throughout desert plantings

Planting and Care Tips

Getting southwestern ringstem established is refreshingly straightforward:

  • Planting Time: Fall or early spring for best establishment
  • Soil Prep: Improve drainage by adding coarse sand or gravel if needed
  • Initial Watering: Water regularly the first growing season, then back off significantly
  • Ongoing Care: Less is more—overwatering is more dangerous than drought
  • Maintenance: Minimal pruning needed; let it follow natural growth patterns

The Bottom Line

Southwestern ringstem might not be the showiest plant in the desert, but it’s definitely one of the most reliable. If you’re gardening in the southwestern United States and want to create an authentic, low-water landscape that supports native wildlife, this hardy perennial deserves serious consideration. Just remember to source it responsibly, and you’ll have a piece of genuine desert heritage growing in your own backyard.

Your water bill will thank you, local pollinators will appreciate the native nectar source, and you’ll have the satisfaction of growing a plant that’s perfectly adapted to your local climate. Sometimes the best garden choices are the ones that have been quietly thriving in your region for thousands of years.

Anulocaulis leiosolenus var. leiosolenus is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Anulocaulis leiosolenus var. leiosolenus is also known as:

Boerhavia leiosolena | USDA symbol: BOLE3

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Caryophyllidae
Order: Caryophyllales
Family: Nyctaginaceae Juss. - Four o'clock family
Genus: Anulocaulis Standl. - ringstem

Species: Anulocaulis leiosolenus (Torr.) Standl. - southwestern ringstem

Variety: Anulocaulis leiosolenus (Torr.) Standl. var. leiosolenus - southwestern ringstem

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