North America Native Plant

Crabseye Lichen

Botanical name: Ochrolechia inaequatula

USDA symbol: OCIN60

Habit: lichen

Native status: Native to North America  

Crabseye Lichen: A Fascinating Natural Visitor to Your Landscape Have you ever noticed crusty, grayish-white patches on tree bark in your yard and wondered what they were? You might be looking at crabseye lichen (Ochrolechia inaequatula), a remarkable organism that’s neither plant nor animal, but something altogether different and wonderful. ...

Crabseye Lichen: A Fascinating Natural Visitor to Your Landscape

Have you ever noticed crusty, grayish-white patches on tree bark in your yard and wondered what they were? You might be looking at crabseye lichen (Ochrolechia inaequatula), a remarkable organism that’s neither plant nor animal, but something altogether different and wonderful.

What Exactly Is Crabseye Lichen?

Crabseye lichen is actually a fascinating partnership between a fungus and an alga, working together in perfect harmony. This collaboration creates the crusty, pale patches you see growing on tree bark and occasionally on rocks. The fungus provides structure and protection, while the alga photosynthesizes to create food for both partners – nature’s ultimate roommate situation!

As a native species to North America, crabseye lichen has been quietly doing its thing in our forests and landscapes for countless years, serving as a living indicator of environmental health.

Where You’ll Find Crabseye Lichen

This lichen calls North America home, particularly thriving in eastern and central regions where air quality is good. You’ll most commonly spot it growing on the bark of deciduous trees, though it occasionally makes itself comfortable on rocks and other hard surfaces.

How to Identify Crabseye Lichen

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

  • Crusty, whitish-gray appearance that looks almost painted onto tree bark
  • Distinctive circular structures called apothecia that resemble tiny crab eyes – hence the common name
  • Flat, spreading growth pattern that hugs tightly to its substrate
  • Rough, somewhat granular texture when viewed up close

Is Crabseye Lichen Beneficial in Your Garden?

Absolutely! While you can’t plant or cultivate crabseye lichen like traditional garden plants, its natural presence is actually a wonderful sign. Here’s why you should appreciate this quiet garden guest:

  • Acts as a natural air quality monitor – lichens are sensitive to pollution, so their presence indicates clean air
  • Provides habitat and food for various small insects and arthropods
  • Adds natural texture and visual interest to tree bark
  • Contributes to the overall biodiversity of your landscape
  • Requires absolutely no maintenance from you

The Reality of Growing Lichens

Here’s where crabseye lichen differs dramatically from your typical garden plants – you simply can’t plant or grow it in the traditional sense. Lichens establish themselves naturally when conditions are right, and attempting to transplant or cultivate them rarely succeeds. They’re incredibly slow-growing and have very specific environmental requirements that are nearly impossible to replicate artificially.

Instead of trying to grow crabseye lichen, the best approach is to create conditions that welcome it naturally by maintaining good air quality around your property and preserving mature trees where it might choose to settle.

Appreciating Nature’s Quiet Workers

If you discover crabseye lichen in your landscape, consider yourself fortunate! Its presence indicates that your local environment is healthy enough to support these sensitive organisms. Rather than removing it, take a moment to appreciate this ancient partnership between fungus and alga that’s been perfecting its survival strategy for millions of years.

While crabseye lichen may not provide the showy blooms or dramatic foliage of traditional garden plants, it offers something perhaps even more valuable – a sign that your little corner of the world is ecologically sound and supporting the intricate web of life that makes our landscapes truly complete.

Crabseye Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Pertusariaceae Körb.

Genus

Ochrolechia A. Massal. - crabseye lichen

Species

Ochrolechia inaequatula (Nyl.) Zahlbr. - crabseye lichen

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