North America Native Plant

Lichenoconium Erodens

Botanical name: Lichenoconium erodens

USDA symbol: LIER2

Habit: lichen

Native status: Native to North America  

Lichenoconium erodens: The Tiny Fungal Parasite You’ll Never See Coming Meet Lichenoconium erodens, one of nature’s most specialized and sneaky little organisms. This microscopic fungal parasite is native to North America, but don’t expect to spot it during your next garden stroll – it’s far too small and specialized for ...

Lichenoconium erodens: The Tiny Fungal Parasite You’ll Never See Coming

Meet Lichenoconium erodens, one of nature’s most specialized and sneaky little organisms. This microscopic fungal parasite is native to North America, but don’t expect to spot it during your next garden stroll – it’s far too small and specialized for the average gardener to notice!

What Exactly Is Lichenoconium erodens?

Despite what its name might suggest, Lichenoconium erodens isn’t actually a lichen at all. It’s a parasitic fungus that makes its living by attacking and feeding on various lichen species. Think of it as nature’s microscopic vampire – it latches onto healthy lichens and slowly drains them of their resources.

This tiny organism belongs to a specialized group of fungi that have evolved specifically to target lichens. While most gardeners focus on the plants they can see and touch, countless microscopic dramas like this are playing out on tree bark, rocks, and other surfaces throughout North American ecosystems.

Where You’ll Find This Microscopic Drama Unfolding

As a North American native, Lichenoconium erodens can be found throughout various regions of the continent, wherever suitable lichen hosts are present. It’s particularly common in areas with diverse lichen communities, such as forests, woodlands, and even urban environments where lichens grow on trees and stone surfaces.

Is It Beneficial to Your Garden?

Here’s where things get interesting from an ecological perspective. While Lichenoconium erodens might seem like a troublemaker for attacking innocent lichens, it actually plays an important role in maintaining ecological balance. Like all natural parasites, it helps regulate lichen populations and contributes to the complex web of interactions that keep ecosystems healthy.

For gardeners, this organism is neither friend nor foe – it’s simply part of the natural background processes happening in your outdoor space. You won’t need to worry about controlling it, encouraging it, or even noticing it most of the time.

How to Identify Its Effects

Since Lichenoconium erodens itself is microscopic, you’ll need to look for its effects on lichen hosts instead. Here’s what to watch for:

  • Small, dark spots or discolored patches on lichen surfaces
  • Areas where lichen tissue appears to be breaking down or eroding
  • Lichens that look unhealthy or are declining in specific spots
  • Tiny black fruiting bodies (perithecia) visible under magnification

Keep in mind that these signs could also indicate other types of lichen stress or damage, so definitive identification requires microscopic examination by specialists.

The Bottom Line for Gardeners

Lichenoconium erodens represents one of countless microscopic interactions happening in your garden ecosystem every day. While you can’t cultivate it (and wouldn’t want to), understanding that these tiny parasites exist helps paint a fuller picture of the complex natural world surrounding us.

If you’re interested in supporting healthy lichen communities in your landscape – which in turn support the full range of organisms that depend on them – focus on maintaining good air quality, avoiding unnecessary chemical treatments on trees and surfaces, and preserving mature trees and stone features where lichens naturally establish themselves.

Sometimes the most fascinating aspects of our native ecosystems are the ones we can’t see with the naked eye!

Lichenoconium Erodens

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Uncertain Ascomycota Class

Subclass
Order

Uncertain Ascomycota Order

Family

Uncertain Ascomycota Family

Genus

Lichenoconium Petr. & H. Sydow - lichenoconium lichen

Species

Lichenoconium erodens M.S. Christ. & D. Hawksw.

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