North America Native Plant

Schaerer’s Orange Lichen

Botanical name: Caloplaca schaereri

USDA symbol: CASC24

Habit: lichen

Native status: Native to North America  

Schaerer’s Orange Lichen: A Tiny Natural Wonder for Your Rock Garden If you’ve ever noticed tiny patches of bright orange or yellow-orange color decorating rocks in natural settings, you might have encountered Schaerer’s orange lichen (Caloplaca schaereri). This fascinating organism isn’t actually a plant at all, but rather a unique ...

Schaerer’s Orange Lichen: A Tiny Natural Wonder for Your Rock Garden

If you’ve ever noticed tiny patches of bright orange or yellow-orange color decorating rocks in natural settings, you might have encountered Schaerer’s orange lichen (Caloplaca schaereri). This fascinating organism isn’t actually a plant at all, but rather a unique partnership between fungi and algae that creates some of nature’s most vibrant miniature displays.

What Exactly Is Schaerer’s Orange Lichen?

Schaerer’s orange lichen belongs to a remarkable group of organisms called lichens, which are composite life forms consisting of fungi living in partnership with algae or cyanobacteria. This particular species appears as small, crusty patches of brilliant orange to yellow-orange color that seem to paint themselves across rock surfaces. The lichen gets its name from Swiss botanist Ludwig Emanuel Schaerer, who made significant contributions to lichen taxonomy in the 19th century.

Where You’ll Find This Orange Beauty

This native North American lichen naturally occurs across temperate and boreal regions of the continent. You’re most likely to spot it on exposed rock surfaces, particularly on limestone, concrete, or other calcium-rich substrates. It thrives in areas with clean air and appropriate moisture levels, making it somewhat of a natural air quality indicator.

Is It Beneficial to Have in Your Garden?

While you can’t exactly plant Schaerer’s orange lichen like you would a flower or shrub, having it appear naturally in your garden is actually a wonderful sign. Here’s why it might be beneficial:

  • Acts as a natural air quality indicator – lichens are sensitive to pollution
  • Adds subtle, natural color to rock features and stone walls
  • Contributes to biodiversity in your outdoor space
  • Requires absolutely no maintenance once established
  • Helps with minor soil formation processes over very long periods

How to Identify Schaerer’s Orange Lichen

Spotting this little beauty is easier than you might think once you know what to look for:

  • Color: Bright orange to yellow-orange, sometimes appearing almost flame-colored
  • Texture: Crusty or powdery appearance, firmly attached to rock surfaces
  • Size: Forms small patches, typically just a few centimeters across
  • Location: Found on exposed rock surfaces, walls, or concrete
  • Shape: Irregular patches with somewhat rounded edges

Creating Conditions Where It Might Appear

You can’t plant lichens in the traditional sense, but you can create conditions that might encourage them to establish naturally:

  • Maintain clean air quality around your property
  • Include natural stone features like rock gardens or stone walls
  • Avoid using harsh chemicals or cleaners on stone surfaces
  • Allow some areas to remain undisturbed for extended periods
  • Ensure good air circulation around stone features

The Patience Game

Here’s the thing about lichens – they operate on geological time scales, not gardening time scales. Schaerer’s orange lichen grows incredibly slowly, sometimes just millimeters per year. If it does decide to grace your stone features with its presence, consider yourself lucky and resist the urge to disturb it. These slow-growing organisms can take decades to establish substantial colonies.

A Living Partnership Worth Appreciating

Schaerer’s orange lichen represents one of nature’s most successful partnerships. The fungal component provides structure and protection while gathering minerals from rock surfaces, while the algal partner performs photosynthesis to create food for both organisms. This collaboration has been so successful that lichens can survive in some of Earth’s most extreme environments.

While you might not be able to add Schaerer’s orange lichen to your shopping list at the local nursery, learning to appreciate and identify these remarkable organisms adds another layer of wonder to any garden or natural space. Keep your eyes open for those bright orange patches on rocks – you might just be witnessing one of nature’s most enduring success stories.

Schaerer’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 schaereri (Flörke) Zahlbr. - Schaerer'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