North America Native Plant

Disc Lichen

Botanical name: Buellia uberior

USDA symbol: BUUB

Habit: lichen

Native status: Native to North America  

Synonyms: Buellia contermina Arnold (BUCO8)   

Disc Lichen: The Tiny Garden Helper You Never Knew You Had Have you ever noticed small, dark, crusty patches growing on the bark of trees in your yard? Meet Buellia uberior, commonly known as disc lichen – a fascinating organism that’s probably been quietly living in your garden ecosystem without ...

Disc Lichen: The Tiny Garden Helper You Never Knew You Had

Have you ever noticed small, dark, crusty patches growing on the bark of trees in your yard? Meet Buellia uberior, commonly known as disc lichen – a fascinating organism that’s probably been quietly living in your garden ecosystem without you even realizing it!

What Exactly Is Disc Lichen?

Before we dive in, let’s clear up what disc lichen actually is. Despite its name suggesting it’s a plant, Buellia uberior is actually a lichen – a remarkable partnership between a fungus and an algae working together in perfect harmony. This crusty little organism belongs to a completely different kingdom than your typical garden plants, but it plays an equally important role in your outdoor space.

You might also see this species referred to by its scientific synonym, Buellia contermina Arnold, in older field guides or research materials.

Where You’ll Find Disc Lichen

Disc lichen is native to North America, making it a true local resident of our ecosystems. You’ll typically spot these small, dark patches growing naturally on tree bark and occasionally on rocks throughout temperate regions of the continent.

Spotting Disc Lichen in Your Garden

Identifying Buellia uberior is easier than you might think once you know what to look for:

  • Small, dark, crusty patches that appear almost black or dark gray
  • Grows flat against bark surfaces, forming disc-like structures
  • Typically found on the bark of various tree species
  • Has a somewhat rough, granular texture
  • Usually measures just a few millimeters to a couple centimeters across

Is Disc Lichen Beneficial for Your Garden?

Absolutely! While you can’t plant or cultivate disc lichen (it simply appears naturally when conditions are right), its presence in your garden is actually a wonderful sign. Here’s why you should be happy to see it:

  • Air quality indicator: Lichens are sensitive to air pollution, so their presence suggests your garden enjoys relatively clean air
  • Ecosystem health: They contribute to the complex web of microorganisms that keep your garden ecosystem balanced
  • Wildlife support: While lichens don’t provide nectar like flowers, they can offer nesting materials for small creatures
  • No harm to trees: Despite growing on bark, disc lichen doesn’t damage or parasitize your trees – it’s simply using the bark as a surface to call home

Can You Grow Disc Lichen?

Here’s where disc lichen differs dramatically from your typical garden plants – you simply can’t plant it! Lichens like Buellia uberior establish themselves naturally when environmental conditions are just right. They require specific moisture levels, air quality, and substrate conditions that occur naturally but are nearly impossible to replicate artificially.

Think of disc lichen as nature’s way of adding a little extra character to your garden trees. If you’re lucky enough to have it appear naturally, consider it a bonus feature rather than something you need to manage or maintain.

Living Alongside Disc Lichen

The best approach with disc lichen is simply to appreciate it for what it is – a fascinating example of nature’s ingenuity and a sign of a healthy garden ecosystem. There’s no need to remove it (it won’t harm your trees), and there’s no way to encourage more of it to grow.

Next time you’re walking through your garden, take a moment to look closely at your tree bark. You might just discover you’ve been hosting these remarkable little partnerships all along, quietly contributing to the biodiversity that makes your outdoor space truly special.

Disc Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Physciaceae Zahlbr.

Genus

Buellia De Not. - disc lichen

Species

Buellia uberior Anzi - disc lichen

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