North America Native Plant

Barneby’s Serpentweed

Botanical name: Tonestus kingii var. barnebyana

USDA symbol: TOKIB

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Aster kingii D.C. Eaton var. barnebyana (S.L. Welsh & Goodrich) S.L. Welsh (ASKIB)  âš˜  Machaeranthera kingii (D.C. Eaton) Cronquist & D.D. Keck var. barnebyana S.L. Welsh & Goodrich (MAKIB)   

Barneby’s Serpentweed: A Rare Utah Native Worth Protecting in Your Garden Meet Barneby’s serpentweed (Tonestus kingii var. barnebyana), a charming yet elusive native wildflower that calls Utah’s unique landscapes home. This petite perennial might not be the showiest plant in the garden center, but for native plant enthusiasts and conservation-minded ...

Rare plant alert!

Region: Conservation status by state

Status: S3T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ 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 ⚘

Barneby’s Serpentweed: A Rare Utah Native Worth Protecting in Your Garden

Meet Barneby’s serpentweed (Tonestus kingii var. barnebyana), a charming yet elusive native wildflower that calls Utah’s unique landscapes home. This petite perennial might not be the showiest plant in the garden center, but for native plant enthusiasts and conservation-minded gardeners, it represents something special: a rare piece of Utah’s natural heritage that deserves our attention and protection.

What Makes Barneby’s Serpentweed Special?

This delicate perennial forb belongs to the sunflower family (Asteraceae) and produces small, daisy-like blooms that add subtle beauty to any native landscape. As a herbaceous plant without woody stems, it dies back to the ground each winter and returns faithfully each spring – assuming it’s given the right conditions to thrive.

What truly sets Barneby’s serpentweed apart isn’t just its beauty, but its rarity. With a conservation status of S3T1, this plant is considered of conservation concern, making every garden specimen a small but meaningful contribution to the species’ survival.

Where Does It Come From?

Barneby’s serpentweed is a true Utah endemic, found nowhere else in the world. This makes it extra special for Beehive State gardeners who want to showcase plants that are truly unique to their region. The plant has adapted to Utah’s specific climate and soil conditions over thousands of years.

Should You Grow Barneby’s Serpentweed?

The Conservation Consideration: Before we dive into growing tips, there’s an important caveat. Due to its rarity status, you should only plant Barneby’s serpentweed if you can source it responsibly. This means:

  • Purchase only from reputable native plant nurseries
  • Ensure plants are nursery-propagated, not wild-collected
  • Never collect seeds or plants from wild populations
  • Consider this plant an investment in conservation

Why It’s Worth Growing: If you can source it ethically, Barneby’s serpentweed offers several benefits:

  • Supports local pollinators with its daisy-like flowers
  • Requires minimal water once established
  • Adds authentic Utah character to native landscapes
  • Helps preserve a rare species through cultivation

Perfect Garden Settings

Barneby’s serpentweed isn’t a plant for every garden, but it shines in the right setting:

  • Rock gardens: Its compact size and drought tolerance make it ideal for rocky, well-draining spots
  • Native plant gardens: Perfect for Utah-focused native landscapes
  • Xeriscaping: Excellent choice for water-wise gardening
  • Conservation gardens: Ideal for gardeners focused on preserving rare species

Growing Conditions and Care

Like many Utah natives, Barneby’s serpentweed has adapted to challenging conditions, which actually makes it relatively low-maintenance once you understand its needs:

Soil Requirements: The key to success is exceptional drainage. This plant likely evolved in rocky or serpentine soils, so heavy clay or moisture-retentive soils will spell disaster. Consider raised beds or rocky slopes.

Water Needs: Once established, this drought-tolerant native needs very little supplemental water. Overwatering is more likely to kill it than drought.

Sun Exposure: Full sun is likely preferred, matching its natural habitat conditions.

Climate Tolerance: Being a Utah native, it’s well-adapted to cold winters and hot, dry summers (likely hardy in USDA zones 4-7).

Planting and Care Tips

  • Plant in spring after the last frost date
  • Amend heavy soils with coarse sand and gravel for drainage
  • Water regularly the first year to establish roots, then reduce watering
  • Avoid fertilizers – native plants typically don’t need them
  • Allow the plant to go dormant naturally in winter
  • Be patient – rare plants often grow slowly

Wildlife and Pollinator Benefits

As a member of the sunflower family, Barneby’s serpentweed likely provides nectar and pollen for native bees, butterflies, and other pollinators. While specific wildlife benefits aren’t well-documented, most Asteraceae family plants are valuable pollinator resources.

The Bottom Line

Barneby’s serpentweed isn’t a plant for everyone, but for the right gardener – one who values rarity, supports conservation, and can provide proper growing conditions – it’s a meaningful addition to the landscape. Just remember: only grow this special plant if you can source it responsibly. Every garden specimen helps ensure this Utah treasure continues to grace our landscapes for future generations.

Consider Barneby’s serpentweed not just as a garden plant, but as a living piece of Utah’s natural heritage that you’re helping to preserve, one garden at a time.

Barneby’s Serpentweed

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Tonestus A. Nelson - serpentweed

Species

Tonestus kingii (D.C. Eaton) G.L. Nesom - King's serpentweed

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