North America Native Plant

Crabseye Lichen

Botanical name: Ochrolechia subathallina

USDA symbol: OCSU

Habit: lichen

Native status: Native to North America  

Crabseye Lichen: The Fascinating Ochrolechia subathallina in Your Landscape Have you ever noticed those curious, eye-like spots adorning the bark of trees in your yard or local forest? Meet the crabseye lichen (Ochrolechia subathallina), a remarkable organism that’s been quietly enhancing North American landscapes for centuries. While you can’t exactly ...

Crabseye Lichen: The Fascinating Ochrolechia subathallina in Your Landscape

Have you ever noticed those curious, eye-like spots adorning the bark of trees in your yard or local forest? Meet the crabseye lichen (Ochrolechia subathallina), a remarkable organism that’s been quietly enhancing North American landscapes for centuries. While you can’t exactly plant this fascinating species in your garden like a traditional flower, understanding and appreciating its presence can transform how you view your outdoor space.

What Exactly Is Crabseye Lichen?

Crabseye lichen isn’t actually a plant at all – it’s a remarkable partnership between a fungus and an algae living together in perfect harmony. This symbiotic relationship creates those distinctive pale, whitish-gray patches you see on tree bark, complete with eye-like structures called apothecia that give this species its memorable common name.

As a crustose lichen, Ochrolechia subathallina forms a crust-like growth that adheres tightly to its host surface, primarily the bark of hardwood trees. Think of it as nature’s living wallpaper, creating beautiful patterns and textures that add visual interest to any landscape.

Where You’ll Find This Native Beauty

This native North American species has made itself at home across eastern and central regions of the continent, thriving in temperate forests and woodland environments. You’re most likely to spot crabseye lichen in mature forest settings where hardwood trees provide the perfect substrate for its growth.

Identifying Crabseye Lichen

Spotting Ochrolechia subathallina is easier than you might think once you know what to look for:

  • Pale whitish-gray to light greenish-gray coloration
  • Crustose (crust-like) growth pattern that hugs tree bark closely
  • Distinctive round, eye-like apothecia (reproductive structures) that resemble tiny crabs’ eyes
  • Typically found on the bark of hardwood trees
  • Smooth to slightly rough texture

The Garden Benefits You Didn’t Know About

While you can’t cultivate crabseye lichen like traditional garden plants, its presence in your landscape offers some pretty amazing benefits:

  • Air quality indicators: Lichens are sensitive to air pollution, so their presence suggests good air quality in your area
  • Ecosystem health: They contribute to biodiversity and provide microhabitats for tiny organisms
  • Natural beauty: Their unique textures and patterns add visual interest to tree bark
  • Low maintenance: They require absolutely no care from you – nature handles everything

Creating a Lichen-Friendly Landscape

Want to encourage crabseye lichen and other native lichens in your outdoor space? Here’s how to create conditions they’ll love:

  • Preserve mature hardwood trees, especially oaks, maples, and hickories
  • Avoid using harsh chemicals or fungicides near trees
  • Maintain good air quality by choosing eco-friendly landscaping practices
  • Allow natural forest succession in parts of your property
  • Resist the urge to clean lichen off trees – they’re not harmful to the tree

A Word of Reassurance

If you discover crabseye lichen on your trees, don’t worry! Unlike some organisms that grow on bark, lichens don’t harm their host trees. They’re simply using the bark as a surface to call home, much like an apartment building. The tree continues to thrive while providing real estate for these fascinating organisms.

The Bottom Line

Crabseye lichen represents one of nature’s most successful partnerships, quietly contributing to the health and beauty of North American forests and landscapes. While you can’t plant it in your garden, you can certainly appreciate and protect it when it appears naturally on your trees. Consider yourself lucky if you spot these eye-catching organisms – they’re a sign that your landscape is supporting native biodiversity in wonderful, unexpected ways.

Next time you’re walking through your yard or a local forest, take a moment to look closely at tree bark. You might just spot the distinctive eyes of Ochrolechia subathallina watching back at you!

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 subathallina H. Magn. - 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