North America Native Plant

Imbricate Wreath Lichen

Botanical name: Phaeophyscia imbricata

USDA symbol: PHIM3

Habit: lichen

Native status: Native to North America  

Synonyms: Physcia imbricata Vain. (PHIM4)  ⚘  Physcia lacinulata Müll. Arg. (PHLA25)   

Understanding Imbricate Wreath Lichen: A Natural Garden Indicator Have you ever noticed those intricate, crusty patches decorating the bark of your trees? If they look like overlapping shingles in shades of gray-green to bluish-gray, you might be looking at imbricate wreath lichen (Phaeophyscia imbricata). This fascinating organism isn’t actually a ...

Understanding Imbricate Wreath Lichen: A Natural Garden Indicator

Have you ever noticed those intricate, crusty patches decorating the bark of your trees? If they look like overlapping shingles in shades of gray-green to bluish-gray, you might be looking at imbricate wreath lichen (Phaeophyscia imbricata). This fascinating organism isn’t actually a plant at all – it’s a lichen, which makes it a unique partnership between fungi and algae working together in perfect harmony.

What Exactly Is Imbricate Wreath Lichen?

Imbricate wreath lichen gets its name from its distinctive appearance – imbricate refers to the way its lobes overlap like roof shingles or fish scales. This native North American lichen creates beautiful, circular or irregular patches that can spread across tree bark and occasionally rocks, forming what looks like nature’s own decorative art.

You might also encounter this lichen under its scientific name, Phaeophyscia imbricata, or its older synonyms Physcia imbricata and Physcia lacinulata in older field guides.

Where You’ll Find This Lichen

Imbricate wreath lichen is widely distributed across North America, making appearances from Canada all the way down to Mexico. It’s particularly fond of deciduous trees and can often be spotted on oak, maple, and other hardwood species in both urban and rural environments.

Is It Beneficial for Your Garden?

While you can’t plant imbricate wreath lichen like a typical garden species, its presence is actually a wonderful sign for your landscape! Here’s why you should celebrate finding it:

  • It serves as a natural air quality indicator – lichens are sensitive to pollution, so their presence suggests clean air
  • It adds authentic ecological character to mature landscapes and woodland gardens
  • It contributes to biodiversity without causing any harm to trees (lichens don’t parasitize their hosts)
  • It creates visual interest with its unique textures and patterns

How to Identify Imbricate Wreath Lichen

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

  • Color: Gray-green to bluish-gray, sometimes with brownish tones
  • Texture: Crusty with overlapping, scale-like lobes
  • Growth pattern: Forms circular or irregular patches on tree bark
  • Size: Individual patches can range from a few inches to several feet across
  • Location: Primarily found on the bark of deciduous trees

Encouraging Natural Establishment

Since lichens can’t be planted or cultivated in the traditional sense, the best way to encourage imbricate wreath lichen in your landscape is to create conditions that support its natural establishment:

  • Maintain good air quality around your property
  • Preserve mature trees that provide suitable bark surfaces
  • Avoid using harsh chemicals or pressure washing tree trunks
  • Allow natural moisture patterns to develop in your woodland areas

A Living Sign of Environmental Health

Finding imbricate wreath lichen in your garden is like receiving a gold star from Mother Nature herself. These remarkable organisms serve as living barometers of environmental health, and their presence indicates that your landscape is supporting clean air and natural ecosystem processes.

Rather than trying to remove or control lichens, embrace them as part of your garden’s natural character. They’re harmless to trees, fascinating to observe, and add an element of wild authenticity that no planted species can replicate. Next time you’re walking through your woodland garden or examining your mature trees, take a moment to appreciate these incredible partnerships between fungi and algae – they’re truly one of nature’s most successful collaborations.

Imbricate 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 imbricata (Vain.) Essl. - imbricate 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