North America Native Plant

Tube Lichen

Botanical name: Hypogymnia mollis

USDA symbol: HYMO5

Habit: lichen

Native status: Native to North America  

Tube Lichen: The Fascinating Hypogymnia mollis in Your Backyard Have you ever noticed those grayish-green, crusty growths on tree trunks and wondered what they are? Meet tube lichen, scientifically known as Hypogymnia mollis – one of nature’s most intriguing partnerships that’s probably growing somewhere near you right now! What Exactly ...

Tube Lichen: The Fascinating Hypogymnia mollis in Your Backyard

Have you ever noticed those grayish-green, crusty growths on tree trunks and wondered what they are? Meet tube lichen, scientifically known as Hypogymnia mollis – one of nature’s most intriguing partnerships that’s probably growing somewhere near you right now!

What Exactly Is Tube Lichen?

Tube lichen isn’t actually a plant at all – it’s something much more fascinating. This native North American species is a partnership between a fungus and algae (or sometimes cyanobacteria) living together in perfect harmony. Think of it as nature’s ultimate roommate situation, where both parties benefit from the arrangement.

The tube part of its name comes from its distinctive hollow, finger-like lobes that give it a unique three-dimensional appearance. These structures help distinguish it from other lichens that might be growing on the same tree.

Where You’ll Find This Natural Wonder

Tube lichen is widespread across North America, thriving in temperate and boreal regions from coast to coast. You’ll most commonly spot it growing on the bark of deciduous and coniferous trees, particularly favoring species like oak, maple, and pine.

Spotting Tube Lichen: Your Identification Guide

Here’s what to look for when lichen-hunting:

  • Gray-green to pale yellow-green coloration
  • Hollow, tube-like lobes that feel slightly inflated
  • Foliose (leaf-like) growth pattern that’s loosely attached to bark
  • Smooth upper surface with a slightly wrinkled texture
  • Typically grows 2-6 inches across

Is Tube Lichen Good for Your Garden?

While you can’t exactly plant tube lichen in your garden, its presence is actually a wonderful sign! Here’s why you should celebrate finding it:

  • Air quality indicator: Lichens are extremely sensitive to air pollution, so their presence indicates clean, healthy air in your area
  • Ecosystem health: They contribute to biodiversity and create microhabitats for tiny insects and other organisms
  • Natural beauty: They add subtle texture and color variation to tree bark, enhancing the natural aesthetic of your landscape
  • Low maintenance: They require absolutely no care from you – nature handles everything

Creating Lichen-Friendly Conditions

While you can’t cultivate tube lichen directly, you can encourage its natural growth by:

  • Maintaining good air quality around your property
  • Avoiding harsh chemicals and pesticides that might harm these sensitive organisms
  • Preserving mature trees where lichens naturally establish
  • Ensuring adequate humidity and air circulation in wooded areas

Common Misconceptions

Let’s clear up a few myths about tube lichen:

  • It doesn’t harm trees: Lichens are epiphytes, meaning they simply use trees as a growing surface without taking nutrients from them
  • It’s not a sign of disease: Healthy trees can host abundant lichen growth
  • It’s not parasitic: Unlike mistletoe or other plant parasites, lichens don’t steal resources from their host

The Bottom Line

Tube lichen is one of those quiet natural treasures that many people overlook. While you won’t find it at your local nursery, discovering it growing naturally on your trees is cause for celebration. It’s a sign that your local environment is healthy and functioning well.

Next time you’re walking through your yard or a nearby forest, take a moment to appreciate these remarkable organisms. They’ve been perfecting the art of cooperation for millions of years – something we humans are still learning!

Tube Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Parmeliaceae F. Berchtold & J. Presl

Genus

Hypogymnia (Nyl.) Nyl. - tube lichen

Species

Hypogymnia mollis L. Pike & Hale - tube lichen

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