North America Native Plant

Desert Thistle

Botanical name: Cirsium aridum

USDA symbol: CIAR9

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Desert Thistle: A Rare Wyoming Native Worth Knowing About Meet the desert thistle (Cirsium aridum), one of Wyoming’s most elusive native plants. If you’ve never heard of this particular thistle, you’re not alone – it’s one of those botanical treasures that keeps a pretty low profile, even among wildflower enthusiasts. ...

Rare plant alert!

Region: Conservation status by state

Status: S2Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ 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) ⚘

Desert Thistle: A Rare Wyoming Native Worth Knowing About

Meet the desert thistle (Cirsium aridum), one of Wyoming’s most elusive native plants. If you’ve never heard of this particular thistle, you’re not alone – it’s one of those botanical treasures that keeps a pretty low profile, even among wildflower enthusiasts.

What Makes Desert Thistle Special?

Desert thistle is a perennial forb, which is just a fancy way of saying it’s a non-woody herbaceous plant that comes back year after year. Unlike its woody cousins, this thistle puts all its energy into soft stems and leaves rather than developing bark or thick branches. It belongs to the diverse thistle family, though it’s carved out its own niche in the American West.

Where You’ll Find Desert Thistle (Spoiler: It’s Not Easy!)

Here’s where things get interesting – desert thistle is native to the lower 48 states, but its distribution is remarkably narrow. Currently, it’s only documented in Wyoming, making it one of the state’s botanical specialties. This limited range is part of what makes it so special, but also so challenging to study and understand.

The Rarity Factor: Why This Matters

Desert thistle carries a Global Conservation Status of S2Q, which essentially means rare and we’re still figuring things out. The Q indicates some taxonomic uncertainty – scientists are still working to fully understand this species and its relationships to other thistles. This rarity status is something every gardener should take seriously.

Should You Grow Desert Thistle?

This is where we need to have an honest conversation. While supporting native plants is always admirable, desert thistle presents some unique challenges:

  • Its rarity means seeds or plants are extremely difficult to source responsibly
  • Limited research means we don’t fully understand its specific growing requirements
  • Removing plants from wild populations could harm already vulnerable communities
  • Its narrow geographic range suggests very specific habitat needs

If you’re absolutely committed to growing this species, the golden rule is responsible sourcing. Never collect from wild populations, and only purchase from reputable native plant sources that can verify their plants were propagated, not wild-collected.

What We Know (And Don’t Know) About Growing Desert Thistle

Here’s the honest truth – information about successfully cultivating desert thistle is scarce. What we do know is limited:

  • It’s a perennial, so it should return each year once established
  • As a forb, it likely prefers well-draining soils
  • Being native to Wyoming suggests it can handle cold winters and potentially dry conditions
  • Like most thistles, it probably attracts pollinators when in bloom

Alternative Native Thistles to Consider

If you’re drawn to the idea of growing native thistles but want something more readily available and better understood, consider these alternatives based on your location:

  • Look for other Cirsium species native to your specific region
  • Research locally adapted thistle varieties through your state’s native plant society
  • Consult with local botanical gardens or native plant nurseries

The Bigger Picture

Desert thistle reminds us that not every native plant is suited for cultivation, and that’s perfectly okay. Sometimes the best way to support rare species is to protect their wild habitats rather than trying to bring them into our gardens. By learning about plants like desert thistle, we develop a deeper appreciation for the incredible diversity hiding in plain sight across our landscapes.

If you’re passionate about Wyoming’s native flora, consider supporting habitat conservation efforts or citizen science projects that help researchers better understand rare species like desert thistle. Sometimes the most meaningful contribution we can make is simply paying attention and spreading awareness about these botanical gems.

Desert Thistle

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

Cirsium Mill. - thistle

Species

Cirsium aridum Dorn - desert thistle

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