North America Native Plant

Coccotrema Lichen

Botanical name: Coccotrema

USDA symbol: COCCO5

Habit: lichen

Native status: Native to North America  

Coccotrema Lichen: The Air Quality Detective in Your Garden Have you ever noticed those crusty, whitish patches on the bark of your trees and wondered what they are? Meet coccotrema lichen – a fascinating organism that’s doing more for your garden than you might realize. While you can’t plant it ...

Coccotrema Lichen: The Air Quality Detective in Your Garden

Have you ever noticed those crusty, whitish patches on the bark of your trees and wondered what they are? Meet coccotrema lichen – a fascinating organism that’s doing more for your garden than you might realize. While you can’t plant it like a typical garden specimen, understanding this native North American lichen can tell you a lot about the health of your outdoor space.

What Exactly Is Coccotrema Lichen?

First things first – coccotrema lichen isn’t actually a plant at all! It’s a remarkable partnership between a fungus and algae (or sometimes cyanobacteria) living together in perfect harmony. This crusty, pale-colored lichen forms irregular patches on tree bark, creating what looks like natural artwork on your trees.

As a native species to North America, coccotrema lichen has been quietly doing its thing in our forests and gardens for centuries, particularly thriving in temperate and boreal forest regions.

Is Coccotrema Beneficial to Your Garden?

Absolutely! While coccotrema lichen might seem like just another growth on your trees, it’s actually providing several benefits:

  • Air quality indicator: Lichens are extremely sensitive to air pollution, so their presence indicates clean, healthy air in your garden
  • Ecosystem support: They provide food and shelter for tiny insects and other small creatures
  • Natural beauty: They add character and a sense of maturity to your landscape
  • Tree health indicator: Healthy lichen growth often indicates your trees are thriving

How to Identify Coccotrema Lichen

Spotting coccotrema lichen is easier than you might think once you know what to look for:

  • Appearance: Forms crusty, whitish to light gray patches on tree bark
  • Texture: Has a rough, cracked surface that might remind you of old paint
  • Location: Typically found on the bark of mature trees, especially in areas with good air circulation
  • Size: Can form patches ranging from a few inches to several feet across

Creating Lichen-Friendly Conditions

While you can’t plant coccotrema lichen like you would a flower or shrub, you can create conditions that encourage its natural growth:

  • Maintain mature trees in your landscape – lichens love established bark surfaces
  • Avoid using harsh chemicals or pesticides that might harm these sensitive organisms
  • Ensure good air circulation around your trees
  • Be patient – lichens grow very slowly, sometimes taking years to establish visible colonies

Common Misconceptions

Many gardeners worry that lichen might be harming their trees, but here’s the good news: coccotrema lichen is completely harmless to your trees! It’s simply using the bark as a surface to grow on – it’s not a parasite and doesn’t damage the tree in any way. In fact, its presence often indicates that your tree is healthy and your air quality is good.

When to Be Concerned

The only time you might want to investigate further is if you notice a sudden disappearance of lichen from your trees. This could indicate:

  • Changes in air quality
  • Stress on your trees from other factors
  • Environmental changes in your garden

Remember, coccotrema lichen is a sign of a healthy, balanced garden ecosystem. Rather than trying to remove it, celebrate its presence as evidence that you’re providing a clean, welcoming environment for native species. Your garden is literally wearing a badge of environmental honor!

Coccotrema Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Pertusariales

Family

Coccotremataceae Henssen

Genus

Coccotrema Müll. Arg. - coccotrema lichen

Species

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