North America Native Plant

Anisomeridium Lichen

Botanical name: Anisomeridium distans

USDA symbol: ANDI9

Habit: lichen

Native status: Native to North America  

Synonyms: Arthopyrenia distans (Willey) Zahlbr. (ARDI24)  ⚘  Ditremis distans (Willey) R.C. Harris (DIDI17)   

Anisomeridium Lichen: The Tiny Ecosystem Helper You Never Knew You Had Have you ever noticed small, dark, crusty patches growing on tree bark in your yard and wondered what they were? You might be looking at anisomeridium lichen (Anisomeridium distans), a fascinating organism that’s doing more for your garden ecosystem ...

Anisomeridium Lichen: The Tiny Ecosystem Helper You Never Knew You Had

Have you ever noticed small, dark, crusty patches growing on tree bark in your yard and wondered what they were? You might be looking at anisomeridium lichen (Anisomeridium distans), a fascinating organism that’s doing more for your garden ecosystem than you might realize.

What Exactly Is Anisomeridium Lichen?

First things first – anisomeridium lichen isn’t actually a plant at all! It’s a lichen, which is essentially a partnership between a fungus and an algae living together in perfect harmony. This particular lichen species is native to North America and has been quietly going about its business on tree bark for centuries.

Scientifically, you might also see this species referred to by its former names, Arthopyrenia distans or Ditremis distans, but Anisomeridium distans is the current accepted name.

Where Can You Find It?

Anisomeridium distans is native to North America, with populations particularly common in the southeastern United States. You’re most likely to spot it in mature forests and wooded areas where air quality is good – which brings us to one of its most important qualities.

Is It Beneficial to Your Garden?

Absolutely! While you can’t exactly plant anisomeridium lichen (more on that in a moment), having it show up naturally in your garden is actually a great sign. Here’s why:

  • Air quality indicator: Lichens are incredibly sensitive to air pollution, so their presence indicates clean, healthy air
  • Ecosystem support: They contribute to the overall biodiversity of your garden
  • Habitat provider: Small insects and other tiny creatures use lichens for shelter
  • Natural beauty: They add subtle texture and visual interest to tree bark

How to Identify Anisomeridium Lichen

Spotting anisomeridium lichen takes a bit of practice, but here are the key features to look for:

  • Forms small, dark, crusty patches on tree bark
  • Appears as tiny black dots or bumps embedded in the bark surface
  • Typically found on smooth-barked trees
  • Very small – you might need a magnifying glass to see the details clearly
  • Grows flush with the bark surface rather than projecting outward

Can You Grow It in Your Garden?

Here’s where things get interesting – you can’t actually cultivate anisomeridium lichen the way you would a flower or shrub. Lichens have very specific requirements and form naturally when conditions are just right. They need:

  • Clean air free from pollutants
  • Appropriate host trees
  • The right balance of moisture and humidity
  • Time – lots of it, as lichens grow very slowly

Encouraging Lichens in Your Space

While you can’t plant anisomeridium lichen directly, you can create conditions that might encourage lichens to establish naturally:

  • Maintain mature trees with diverse bark types
  • Avoid using pesticides and chemicals that could harm these sensitive organisms
  • Keep your garden as pollution-free as possible
  • Be patient – lichen establishment can take years or even decades

The Bottom Line

Anisomeridium lichen might be small and easy to overlook, but it’s a sign of a healthy, thriving ecosystem. Rather than trying to grow it, focus on creating the kind of clean, diverse environment where it can flourish naturally. Think of finding this little lichen in your garden as nature’s way of giving you a gold star for good environmental stewardship!

Next time you’re wandering through your wooded areas or examining the trees in your yard, take a moment to look closely at the bark. You might just discover you’ve got these tiny ecosystem helpers already calling your garden home.

Anisomeridium Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Dothideales

Family

Monoblastiaceae Walt. Watson

Genus

Anisomeridium (Müll. Arg.) M. Choisy - anisomeridium lichen

Species

Anisomeridium distans (Willey) R.C. Harris - anisomeridium lichen

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