North America Native Plant

Clypeococcum Lichen

Botanical name: Clypeococcum grossum

USDA symbol: CLGR10

Habit: lichen

Native status: Native to North America  

Clypeococcum Lichen: The Tiny Garden Detective You Never Knew You Had Have you ever taken a close look at the lichens growing in your garden and noticed tiny, dark spots scattered across their surfaces? You might be looking at clypeococcum lichen (Clypeococcum grossum), one of nature’s most specialized inhabitants that ...

Clypeococcum Lichen: The Tiny Garden Detective You Never Knew You Had

Have you ever taken a close look at the lichens growing in your garden and noticed tiny, dark spots scattered across their surfaces? You might be looking at clypeococcum lichen (Clypeococcum grossum), one of nature’s most specialized inhabitants that calls North America home.

What Exactly is Clypeococcum Lichen?

Unlike the plants we typically think about for our gardens, Clypeococcum grossum isn’t something you can plant, water, or tend to in the traditional sense. This fascinating organism is actually what scientists call a lichenicolous fungus – essentially, it’s a lichen that grows on other lichens! Think of it as nature’s ultimate specialist, having evolved to live exclusively on the surfaces of its lichen hosts.

This native North American species represents one of the more mysterious members of our local ecosystem. While we know it belongs to our continent’s natural heritage, the specific details of its range and distribution remain largely unstudied, making every sighting a small scientific discovery.

Spotting Clypeococcum Lichen in Your Garden

Identifying this tiny organism requires a bit of detective work and possibly a magnifying glass! Here’s what to look for:

  • Small, dark, round fruiting bodies (called apothecia) sitting on the surface of other lichens
  • Typically appears as black or very dark brown spots
  • Usually quite small – often just a millimeter or two across
  • Found exclusively on other lichen species, never on bare rock, bark, or soil

Is Clypeococcum Lichen Good for Your Garden?

While you can’t cultivate clypeococcum lichen like you would a flower or shrub, its presence can actually be a positive sign for your garden’s health. Here’s why:

  • Indicates a diverse, healthy lichen community in your landscape
  • Shows that your garden supports complex ecological relationships
  • Contributes to the overall biodiversity of your outdoor space
  • Serves as a natural indicator of good air quality (lichens are sensitive to pollution)

The relationship between clypeococcum lichen and its host lichens is generally considered harmless – it’s more like a quiet neighbor than a destructive parasite.

Supporting Lichen Diversity in Your Garden

Since you can’t plant clypeococcum lichen directly, the best way to encourage its presence (along with other beneficial lichens) is to create conditions that support lichen communities overall:

  • Avoid using pesticides and fungicides that can harm sensitive lichen species
  • Maintain trees and shrubs that provide bark surfaces for lichen growth
  • Keep some areas of your garden slightly wild and undisturbed
  • Consider leaving fallen branches and natural debris in designated areas
  • Reduce air pollution when possible (lichens love clean air!)

The Bigger Picture

Finding clypeococcum lichen in your garden is like discovering a hidden world of ecological interactions happening right under your nose. While it might not add vibrant colors or attract butterflies like traditional garden plants, it represents the intricate web of relationships that make healthy ecosystems function.

Next time you’re wandering through your garden, take a moment to examine any lichens you find growing on trees, rocks, or other surfaces. You might just spot these tiny dark specialists doing their quiet work, adding another layer of complexity and wonder to your outdoor space.

Clypeococcum Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Dothideales

Family

Dacampiaceae Körb.

Genus

Clypeococcum D. Hawksw. - clypeococcum lichen

Species

Clypeococcum grossum (Körb.) D. Hawksw. - clypeococcum lichen

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