North America Native Plant

Dimple Lichen

Botanical name: Gyalecta truncigena

USDA symbol: GYTR

Habit: lichen

Native status: Native to North America  

Dimple Lichen: The Tiny Garden Guest You Never Planted Have you ever noticed tiny, crusty patches on tree bark in your garden and wondered what they are? If you’ve spotted small, dimpled structures that look like miniature craters, you might be looking at dimple lichen (Gyalecta truncigena) – a fascinating ...

Dimple Lichen: The Tiny Garden Guest You Never Planted

Have you ever noticed tiny, crusty patches on tree bark in your garden and wondered what they are? If you’ve spotted small, dimpled structures that look like miniature craters, you might be looking at dimple lichen (Gyalecta truncigena) – a fascinating organism that’s neither plant nor animal, but something wonderfully in between.

What Exactly Is Dimple Lichen?

Dimple lichen is a crustose lichen, which means it forms a crust-like layer that’s tightly attached to its host surface. Unlike the mossy or leafy lichens you might be more familiar with, this little fellow creates a flat, often grayish coating on tree bark. Its claim to fame? Those characteristic dimpled or pitted reproductive structures called apothecia that give it its common name.

As a lichen, Gyalecta truncigena is actually a partnership between a fungus and algae (or sometimes cyanobacteria), working together in perfect harmony. The fungus provides structure and protection, while the algae photosynthesizes to create food for both partners. It’s like nature’s original roommate arrangement!

Where You’ll Find This Native Wonder

Dimple lichen is native to North America, particularly thriving in eastern regions. You’ll typically spot it growing on the smooth bark of deciduous trees, especially younger branches and trunks. It has a particular fondness for trees like maples, oaks, and birches.

Is Dimple Lichen Good for Your Garden?

The short answer? Absolutely! While you can’t plant or cultivate dimple lichen (it does its own thing, thank you very much), having it show up naturally in your garden is actually a wonderful sign. Here’s why you should celebrate its presence:

  • Air quality indicator: Lichens are sensitive to air pollution, so their presence indicates clean air in your garden
  • Biodiversity boost: They contribute to the complex web of life in your outdoor space
  • Minimal impact: Unlike some organisms, lichens don’t harm their host trees – they’re just hitching a ride
  • Year-round interest: They provide subtle texture and visual interest throughout all seasons

How to Identify Dimple Lichen

Spotting dimple lichen is like playing nature’s version of Where’s Waldo? Here’s what to look for:

  • Location: Smooth bark of deciduous trees, often on younger branches
  • Appearance: Thin, crusty patches that appear almost painted onto the bark
  • Color: Typically grayish, sometimes with slight variations
  • The telltale dimples: Small, round, crater-like structures (apothecia) that look like tiny dents in the surface
  • Size: Individual patches are usually small, often just a few inches across

Can You Encourage Dimple Lichen in Your Garden?

While you can’t exactly plant dimple lichen, you can create conditions that might encourage its natural establishment:

  • Maintain clean air: Avoid using excessive chemicals and support air quality in your area
  • Plant diverse trees: Include native deciduous trees that lichens naturally favor
  • Practice patience: Lichens grow slowly and establish naturally over time
  • Avoid scrubbing: Don’t clean or scrub bark where lichens might establish

A Sign of a Healthy Garden Ecosystem

Think of dimple lichen as nature’s stamp of approval for your garden’s environmental health. Its presence suggests that your outdoor space is supporting clean air and biodiversity – something every gardener should feel proud of!

While dimple lichen might not be the showstopper in your garden like those prize-winning roses, it’s quietly playing an important role in the ecosystem. Next time you’re wandering through your garden, take a moment to appreciate these tiny, dimpled treasures. They’re proof that sometimes the smallest residents make the biggest difference in creating a truly healthy, thriving garden environment.

Dimple Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Gyalectales

Family

Gyalectaceae Stizenb.

Genus

Gyalecta Ach. - dimple lichen

Species

Gyalecta truncigena (Ach.) Hepp - dimple lichen

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