North America Native Plant

Spalding’s Orange Lichen

Botanical name: Caloplaca spaldingii

USDA symbol: CASP21

Habit: lichen

Native status: Native to North America  

Spalding’s Orange Lichen: A Tiny Natural Wonder You Can’t Grow (But Should Appreciate!) Have you ever spotted tiny patches of bright orange growing on rocks and wondered what they were? You might have encountered Spalding’s orange lichen (Caloplaca spaldingii), a fascinating little organism that’s more complex than it appears. While ...

Spalding’s Orange Lichen: A Tiny Natural Wonder You Can’t Grow (But Should Appreciate!)

Have you ever spotted tiny patches of bright orange growing on rocks and wondered what they were? You might have encountered Spalding’s orange lichen (Caloplaca spaldingii), a fascinating little organism that’s more complex than it appears. While you can’t add this beauty to your garden wishlist, it’s definitely worth knowing about!

What Exactly Is Spalding’s Orange Lichen?

Let’s clear up a common misconception right away: lichens aren’t plants! Spalding’s orange lichen is actually a symbiotic organism made up of a fungus and algae living together in perfect harmony. The fungus provides structure and protection, while the algae produce food through photosynthesis. It’s like nature’s ultimate roommate situation – and it works beautifully.

This particular lichen is native to North America and creates small, bright orange crusty patches that can really catch your eye when you’re hiking or exploring rocky areas.

Where Does It Call Home?

Spalding’s orange lichen is primarily found in the western regions of North America, particularly thriving in arid environments where it colonizes calcareous (limestone-rich) rocks. You’re most likely to spot it in desert regions and dry rocky outcrops.

How to Identify Spalding’s Orange Lichen

Spotting this little orange wonder is pretty straightforward once you know what to look for:

  • Color: Vibrant orange patches that really stand out against gray rock
  • Texture: Crusty and somewhat flaky appearance
  • Location: Growing directly on rock surfaces, especially limestone or other calcareous rocks
  • Size: Forms small patches, typically just a few inches across
  • Habitat: Prefers sunny, dry locations in arid climates

Is It Beneficial to Have Around?

While you can’t invite Spalding’s orange lichen into your garden, it does play some important ecological roles:

  • Rock breakdown: Slowly helps break down rock surfaces, contributing to soil formation over geological time
  • Habitat creation: Provides microhabitats for tiny invertebrates
  • Environmental indicator: Lichens are sensitive to air quality, so their presence indicates relatively clean air
  • Natural beauty: Adds splashes of color to otherwise stark rocky landscapes

Why You Can’t Grow It (And That’s Okay!)

Here’s the thing about lichens – they’re incredibly picky about their living conditions and grow extremely slowly. Spalding’s orange lichen has very specific requirements for the type of rock it grows on, the climate it needs, and the delicate balance of moisture and dryness it requires. These conditions are nearly impossible to replicate in a garden setting.

Plus, lichens grow so slowly that what looks like a small patch might actually be decades or even centuries old! They’re best appreciated in their natural habitats where they’ve found their perfect spot.

Appreciating Nature’s Patience

Instead of trying to grow Spalding’s orange lichen, consider it a special treat to discover during your outdoor adventures. When you spot those bright orange patches on rocks during hikes or nature walks, take a moment to appreciate this incredible example of natural cooperation and resilience.

If you’re interested in supporting lichen diversity, focus on maintaining clean air quality in your area and protecting natural habitats where these fascinating organisms can continue their slow but steady existence.

So while Spalding’s orange lichen won’t be making an appearance in your garden beds anytime soon, it serves as a beautiful reminder that nature’s most interesting relationships often happen in the most unexpected places – like tiny patches of orange bringing life and color to seemingly barren rocks!

Spalding’s Orange Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Teloschistales

Family

Teloschistaceae Zahlbr.

Genus

Caloplaca Th. Fr. - orange lichen

Species

Caloplaca spaldingii Zahlbr. - Spalding's orange lichen

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