North America Native Plant

Skin Lichen

Botanical name: Leptogium rivale

USDA symbol: LERI2

Habit: lichen

Native status: Native to North America  

Synonyms: Polychidium rivale (Tuck.) Fink (PORI6)   

Discovering Skin Lichen: Nature’s Air Quality Monitor in Your Garden Have you ever noticed those peculiar, leaf-like growths clinging to rocks or tree bark in the shadier corners of your garden? You might be looking at skin lichen (Leptogium rivale), a fascinating organism that’s neither plant nor animal, but something ...

Discovering Skin Lichen: Nature’s Air Quality Monitor in Your Garden

Have you ever noticed those peculiar, leaf-like growths clinging to rocks or tree bark in the shadier corners of your garden? You might be looking at skin lichen (Leptogium rivale), a fascinating organism that’s neither plant nor animal, but something wonderfully unique that can tell you a lot about your local environment.

What Exactly Is Skin Lichen?

Leptogium rivale, commonly known as skin lichen, is actually a remarkable partnership between fungi and algae living together in perfect harmony. This collaboration creates what looks like thin, wrinkled skin-like patches that can range from blue-gray to brownish in color. The name skin lichen comes from its distinctive texture that resembles, well, skin – complete with wrinkles and folds.

You might also encounter this species listed under its scientific synonym, Polychidium rivale, in older field guides or botanical references.

Where You’ll Find Skin Lichen

As a native North American species, skin lichen has been quietly going about its business in our ecosystems long before any of our gardens existed. It thrives in moist, shaded environments where the air is clean and humidity levels stay relatively high.

What Does Skin Lichen Look Like?

Identifying skin lichen is easier than you might think:

  • Thin, leaf-like growths that feel papery when dry
  • Wrinkled, skin-like texture (hence the name!)
  • Blue-gray to brownish coloration
  • Often found growing on rocks, soil, or decaying wood
  • Typically found in patches rather than single specimens

Is Skin Lichen Beneficial for Your Garden?

Absolutely! While skin lichen might not provide the showy blooms that attract pollinators like traditional flowering plants, it offers some unique benefits that make it a welcome sight in any garden:

  • Air quality indicator: The presence of skin lichen signals that your garden has good air quality, as lichens are sensitive to air pollution
  • Natural aesthetics: Adds authentic woodland character to shaded garden areas
  • Ecosystem support: Provides microhabitat for tiny invertebrates
  • Soil protection: Helps prevent erosion on slopes and bare soil areas

Creating the Right Conditions

Here’s the thing about skin lichen – you can’t exactly plant it like you would a typical garden plant. Instead, it appears naturally when conditions are just right:

  • Consistent moisture without waterlogging
  • Shade to partial shade conditions
  • Clean air (no heavy pollution)
  • Suitable surfaces like rocks, logs, or undisturbed soil

If you want to encourage skin lichen in your garden, focus on creating a naturalized woodland area with:

  • Native trees and shrubs for shade
  • Consistent moisture through mulching or proximity to water features
  • Undisturbed areas where natural processes can take place
  • Avoiding chemical treatments that could harm these sensitive organisms

A Living Testament to Garden Health

Think of skin lichen as nature’s stamp of approval on your gardening practices. When you spot these fascinating organisms establishing themselves in your shaded, moist garden areas, it’s a sign that you’re creating a healthy, balanced ecosystem. Rather than something to remove or control, skin lichen should be celebrated as an indicator that your garden is supporting diverse life forms and maintaining good environmental conditions.

So next time you’re exploring the quieter corners of your garden, take a moment to appreciate these remarkable organisms. They may not have flashy flowers or dramatic foliage, but skin lichens represent something equally valuable – a thriving, healthy garden ecosystem that supports life in all its wonderful forms.

Skin Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Collemataceae Zenker

Genus

Leptogium (Ach.) A. Gray - skin lichen

Species

Leptogium rivale Tuck. - skin lichen

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