North America Native Plant

Myriotrema Rugiferum

Botanical name: Myriotrema rugiferum

USDA symbol: MYRU2

Habit: lichen

Native status: Native to North America  

Myriotrema rugiferum: The Mysterious Lichen Living on Your Trees Have you ever noticed crusty, grayish patches on tree bark and wondered what they might be? You might be looking at Myriotrema rugiferum, a fascinating North American lichen that’s quietly doing important work in your local forest ecosystem. While you can’t ...

Myriotrema rugiferum: The Mysterious Lichen Living on Your Trees

Have you ever noticed crusty, grayish patches on tree bark and wondered what they might be? You might be looking at Myriotrema rugiferum, a fascinating North American lichen that’s quietly doing important work in your local forest ecosystem. While you can’t plant this unique organism in your garden like a typical flowering plant, understanding what it is and why it matters can help you appreciate the incredible biodiversity happening right in your backyard.

What Exactly Is Myriotrema rugiferum?

Before we dive in, let’s clear up a common misconception: Myriotrema rugiferum isn’t actually a plant at all! It’s a lichen – a remarkable partnership between a fungus and algae (or sometimes cyanobacteria) that work together as one organism. Think of it as nature’s ultimate roommate situation, where both partners benefit from the arrangement.

This particular lichen is native to North America and has been quietly colonizing tree bark for centuries. Unlike plants that have roots, stems, and leaves, lichens create their own unique structures and get their nutrients in completely different ways.

Where You’ll Find This Bark-Dwelling Partner

Myriotrema rugiferum calls North America home, with populations documented across various regions of the continent. You’re most likely to spot it in forested areas where it makes itself comfortable on the bark of hardwood trees.

Identifying Myriotrema rugiferum in the Wild

Ready to become a lichen detective? Here’s what to look for when you’re out exploring:

  • Appearance: Forms thin, crusty patches that can range from grayish to brownish in color
  • Texture: The surface appears rough and crusty, hence the rugiferum part of its name
  • Key feature: Look for small, visible pores called ostioles – these are like tiny windows into the lichen’s reproductive structures
  • Location: Almost exclusively found growing on tree bark, particularly hardwoods
  • Size: Individual patches can vary widely, sometimes forming larger colonies that merge together

Why This Lichen Matters in Your Garden Ecosystem

While you can’t add Myriotrema rugiferum to your shopping cart at the garden center, its presence in your landscape is actually a wonderful sign. Here’s why this little crusty character deserves your appreciation:

  • Air quality indicator: Lichens are sensitive to air pollution, so finding them suggests your local air quality is relatively good
  • Ecosystem health: Their presence indicates a balanced, functioning forest ecosystem
  • Biodiversity support: Lichens contribute to the complex web of life that supports other organisms
  • Soil building: Over time, lichens help break down rock and organic matter, contributing to soil formation

Can You Grow Lichens in Your Garden?

Here’s where things get interesting – you can’t really cultivate lichens like traditional plants. They’re not something you can buy, plant, and water. Instead, lichens establish themselves naturally when conditions are right. However, you can create an environment that welcomes them:

  • Maintain mature trees: Lichens love established bark surfaces
  • Avoid chemical treatments: Pesticides and fungicides can harm these sensitive organisms
  • Preserve natural areas: Leave some wild spaces in your landscape
  • Minimize air pollution: Support practices that keep your local air clean

The Bottom Line on Myriotrema rugiferum

While Myriotrema rugiferum won’t add colorful blooms to your garden or attract hummingbirds to your feeders, it’s doing something equally valuable – serving as a living indicator of ecosystem health. The next time you’re walking through wooded areas or even looking at mature trees in urban settings, take a moment to appreciate these crusty little partnerships quietly thriving on bark surfaces.

Finding lichens like Myriotrema rugiferum in your area is actually cause for celebration. It means your local environment is supporting the kind of biodiversity that makes ecosystems resilient and healthy. And isn’t that exactly what we want in our native gardening efforts – landscapes that support the full spectrum of life, from the tiniest lichen to the mightiest oak?

Myriotrema Rugiferum

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Graphidales

Family

Thelotremataceae Stizenb.

Genus

Myriotrema Fée - myriotrema lichen

Species

Myriotrema rugiferum (Harm.) Hale

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