North America Native Plant

Catillaria Lichen

Botanical name: Catillaria glauconigrans

USDA symbol: CAGL26

Habit: lichen

Native status: Native to North America  

Understanding Catillaria Lichen: A Tiny Marvel in Your Garden Have you ever noticed small, grayish patches seemingly painted onto rocks or tree bark in your yard? You might be looking at catillaria lichen (Catillaria glauconigrans), one of North America’s fascinating native organisms that’s actually neither plant nor animal, but something ...

Understanding Catillaria Lichen: A Tiny Marvel in Your Garden

Have you ever noticed small, grayish patches seemingly painted onto rocks or tree bark in your yard? You might be looking at catillaria lichen (Catillaria glauconigrans), one of North America’s fascinating native organisms that’s actually neither plant nor animal, but something wonderfully unique.

What Exactly Is Catillaria Lichen?

Let’s clear up a common misconception first: lichens aren’t plants! Catillaria lichen is actually a remarkable partnership between a fungus and an algae (or sometimes cyanobacteria) living together in perfect harmony. Think of it as nature’s original roommate situation – the fungus provides structure and protection, while the algae produces food through photosynthesis. Pretty clever, right?

This particular lichen species is native to North America, making it a legitimate part of our natural heritage. Unlike the flashy flowers we typically associate with native gardening, catillaria lichen works quietly behind the scenes, contributing to the ecosystem in its own subtle way.

Where You’ll Find This Little Wonder

Catillaria glauconigrans naturally occurs across North America, with populations documented in various regions throughout the continent. You’re most likely to spot it in areas where it can find suitable surfaces to call home.

Identifying Catillaria Lichen

Spotting catillaria lichen takes a keen eye, as it’s not exactly shouting for attention. Here’s what to look for:

  • Thin, crusty patches that appear almost painted onto surfaces
  • Grayish coloration, sometimes with subtle variations
  • Small size – we’re talking about patches typically measured in centimeters, not feet
  • Found on rocks, tree bark, or other stable surfaces
  • Smooth, flat appearance without the leafy or branching structure of other lichen types

Is Catillaria Lichen Beneficial in Your Garden?

While you can’t exactly plant catillaria lichen in your flower beds, its presence is actually a good sign! Lichens are excellent indicators of air quality – they’re quite sensitive to pollution, so finding them suggests your local environment is relatively clean.

Here are some ways this tiny organism benefits your outdoor space:

  • Helps break down rock surfaces over time, contributing to soil formation
  • Provides food for various small creatures
  • Indicates good air quality in your area
  • Adds to the biodiversity of your landscape
  • Creates microhabitats for tiny invertebrates

Can You Grow Catillaria Lichen?

Here’s where we need to manage expectations: you can’t grow catillaria lichen like you would grow tomatoes or roses. These organisms have very specific requirements and establish themselves naturally over long periods. Attempting to cultivate lichens is notoriously difficult and generally unsuccessful for home gardeners.

Instead of trying to grow them, the best approach is to:

  • Appreciate them when they appear naturally
  • Avoid disturbing areas where they’re established
  • Minimize chemical use in your landscape (lichens are sensitive to pollutants)
  • Leave suitable surfaces like rocks or mature tree bark undisturbed

The Bottom Line

Catillaria lichen might not be the showstopper of your native garden, but it’s a fascinating example of nature’s ingenuity. If you’re lucky enough to discover these small, grayish patches in your landscape, take a moment to appreciate this remarkable partnership between fungus and algae that’s been perfecting its act for millions of years.

Rather than trying to cultivate catillaria lichen, focus on creating conditions that support the biodiversity of your local ecosystem. Sometimes the most valuable native species are the ones we barely notice – quietly doing their job while we’re busy admiring the flowers.

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Catillariaceae Hafellner

Genus

Catillaria A. Massal. - catillaria lichen

Species

Catillaria glauconigrans (Tuck.) Hasse - catillaria lichen

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