North America Native Plant

Tube Lichen

Botanical name: Hypogymnia pulverata

USDA symbol: HYPU6

Habit: lichen

Native status: Native to North America  

Tube Lichen: Nature’s Air Quality Indicator in Your Garden Have you ever noticed those peculiar, grayish-green, tube-like growths decorating the bark of trees in your yard? Meet the tube lichen (Hypogymnia pulverata), a fascinating organism that’s part fungus, part algae, and all kinds of amazing. This native North American lichen ...

Tube Lichen: Nature’s Air Quality Indicator in Your Garden

Have you ever noticed those peculiar, grayish-green, tube-like growths decorating the bark of trees in your yard? Meet the tube lichen (Hypogymnia pulverata), a fascinating organism that’s part fungus, part algae, and all kinds of amazing. This native North American lichen isn’t something you can plant in your garden, but finding it growing naturally is actually fantastic news for both you and your landscape!

What Exactly Is Tube Lichen?

Tube lichen belongs to that unique group of organisms called lichens – they’re not plants, but rather a symbiotic partnership between fungi and algae. The tube lichen gets its name from its distinctive hollow, branched structures that look remarkably like tiny tubes or hollow fingers extending from tree bark. These structures are typically grayish-green in color and can create intricate, almost coral-like patterns on the surfaces where they grow.

Where You’ll Find Tube Lichen

This lichen is native to western North America, with a particular fondness for the Pacific Northwest region. You’ll typically spot it growing on the bark of various trees, especially conifers and hardwoods in forested areas. It thrives in regions with clean air and adequate moisture, making it more common in rural and suburban areas than in heavily polluted urban environments.

Why Tube Lichen Is a Garden Hero

Here’s where things get exciting for gardeners: tube lichen is essentially a living air quality monitor! These sensitive organisms are extremely intolerant of air pollution, particularly sulfur dioxide. If you find tube lichen thriving in your garden, congratulations – you’ve got clean air! This makes them valuable indicators of environmental health.

While tube lichen doesn’t directly benefit pollinators like flowering plants do, it plays an important role in the broader ecosystem:

  • Provides food for various insects and small creatures
  • Contributes to the overall biodiversity of your garden ecosystem
  • Indicates a healthy environment suitable for other sensitive species
  • Adds unique texture and natural character to tree bark

How to Identify Tube Lichen

Spotting tube lichen is easier than you might think once you know what to look for:

  • Look for hollow, tube-like or finger-like projections growing from tree bark
  • Color ranges from grayish-green to pale green
  • Structures are typically 1-3 inches long and branch irregularly
  • Often grows in patches or clusters on the same tree
  • Most commonly found on the bark of both coniferous and deciduous trees

The Growing Reality: You Can’t Cultivate Tube Lichen

Here’s the thing about lichens – they’re not something you can plant, propagate, or cultivate like traditional garden plants. Tube lichen will only appear in your garden naturally if conditions are just right. These conditions include:

  • Clean air with minimal pollution
  • Adequate moisture and humidity
  • Suitable host trees (they don’t harm the trees, just use them as a growing surface)
  • Time – lichens are notoriously slow growers

Encouraging Lichen-Friendly Conditions

While you can’t plant tube lichen directly, you can create conditions that make your garden more welcoming to these beneficial organisms:

  • Maintain diverse, mature trees in your landscape
  • Avoid using harsh chemicals or pesticides that might affect air quality
  • Preserve natural bark textures (avoid excessive pruning or bark damage)
  • Support overall environmental health in your area

Appreciating What You Have

If you discover tube lichen in your garden, consider yourself lucky! These slow-growing organisms take years to establish and indicate that your local environment is healthy enough to support sensitive species. Rather than trying to remove them (they don’t harm trees), embrace them as a sign of your garden’s ecological health.

Remember, the presence of tube lichen is nature’s way of giving your garden a gold star for air quality. In our increasingly polluted world, that’s something worth celebrating and protecting.

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 pulverata (Nyl. ex Crombie) Elix - 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