North America Native Plant

Wreath Lichen

Botanical name: Phaeophyscia erythrocardia

USDA symbol: PHER6

Habit: lichen

Native status: Native to North America  

Wreath Lichen: A Natural Air Quality Indicator in Your Garden Have you ever noticed those flat, leaf-like growths spreading across tree bark in your yard? If they form neat, circular patches that look almost like tiny wreaths, you might be looking at wreath lichen (Phaeophyscia erythrocardia). This fascinating organism isn’t ...

Wreath Lichen: A Natural Air Quality Indicator in Your Garden

Have you ever noticed those flat, leaf-like growths spreading across tree bark in your yard? If they form neat, circular patches that look almost like tiny wreaths, you might be looking at wreath lichen (Phaeophyscia erythrocardia). This fascinating organism isn’t actually a plant at all, but rather a remarkable partnership between fungi and algae that can tell you a lot about the health of your local environment.

What Exactly Is Wreath Lichen?

Wreath lichen belongs to a group of organisms called lichens, which are composite creatures made up of fungi and photosynthetic partners (usually algae or cyanobacteria). Think of it as nature’s ultimate roommate situation – the fungus provides structure and protection, while the algae produces food through photosynthesis. This partnership has been so successful that lichens have colonized almost every habitat on Earth.

Phaeophyscia erythrocardia is what scientists call a foliose lichen, meaning it has a leafy, flattened appearance that loosely attaches to its substrate. The name wreath lichen comes from its tendency to form circular, wreath-like colonies on tree bark.

Where You’ll Find Wreath Lichen

This lichen is native to North America and can be found growing naturally on the bark of various trees, particularly hardwoods. It’s most commonly spotted in areas with relatively clean air, as lichens are notoriously sensitive to air pollution.

Is Wreath Lichen Good for Your Garden?

Absolutely! While you can’t plant or cultivate wreath lichen (it simply appears where conditions are right), its presence in your garden is actually a wonderful sign. Here’s why you should celebrate finding it:

  • Air quality indicator: Wreath lichen only thrives in areas with clean air, so its presence suggests your garden enjoys good environmental conditions
  • Harmless to trees: Unlike some organisms that grow on bark, lichens don’t damage their host trees – they’re just using the bark as a place to live
  • Adds natural character: These lichens contribute to the authentic, woodland feel that many native gardeners strive to achieve
  • Supports biodiversity: While not a major food source, lichens do provide some nutrition for various insects and small creatures

How to Identify Wreath Lichen

Spotting wreath lichen is easier once you know what to look for:

  • Color: Typically grayish-green to brownish, sometimes with a slightly bluish tint
  • Shape: Forms circular or semi-circular colonies that resemble wreaths
  • Texture: Flat and leafy with a somewhat wrinkled or folded appearance
  • Location: Found on tree bark, particularly on the trunks and larger branches of hardwood trees
  • Size: Individual patches can range from a few inches to several inches across

Creating Conditions Where Wreath Lichen Might Appear

While you can’t plant wreath lichen directly, you can create conditions that might encourage its natural appearance:

  • Maintain mature trees in your landscape, especially native hardwoods
  • Avoid using chemical treatments on tree bark
  • Support local air quality initiatives in your community
  • Create a naturalistic garden environment that mimics woodland conditions

The Bottom Line on Wreath Lichen

Wreath lichen is one of those garden inhabitants that appears on its own timeline and terms. Rather than something you actively cultivate, it’s more like a gift that arrives when conditions are just right. If you spot these circular, leafy patches on your trees, take a moment to appreciate them – they’re telling you that your garden is part of a healthy ecosystem with clean air and good growing conditions.

Remember, lichens grow incredibly slowly, sometimes taking years to establish visible colonies. So if wreath lichen graces your trees with its presence, consider yourself lucky to be stewarding a space where these remarkable organisms can thrive.

Wreath Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Physciaceae Zahlbr.

Genus

Phaeophyscia Moberg - wreath lichen

Species

Phaeophyscia erythrocardia (Tuck.) Essl. - wreath lichen

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