Lung Lichen: The Forest’s Natural Air Quality Monitor
If you’ve ever wandered through an old-growth forest in the Pacific Northwest and spotted what looks like large, leafy lettuce growing on tree trunks, you’ve likely encountered lung lichen (Lobaria pseudopulmonaria). Don’t let the name fool you though – this isn’t actually a plant at all!
What Exactly Is Lung Lichen?
Lung lichen is a fascinating organism that’s actually a partnership between a fungus and an algae (and sometimes cyanobacteria too). This botanical tag-team creates those distinctive, lobed structures that can grow quite large – sometimes reaching over a foot across. The name lung lichen comes from its resemblance to lung tissue, with its wrinkled, lobate appearance that looks remarkably similar to the branching patterns of our respiratory organs.
As a native species to North America, lung lichen has been quietly doing its job in our forests for thousands of years, long before we understood just how important these organisms really are.
Where You’ll Find This Forest Dweller
Lung lichen is primarily found in the old-growth forests of the Pacific Northwest, where it thrives in the cool, humid conditions that these ancient woodlands provide. You’ll typically spot it growing on the bark of mature trees, particularly conifers like Douglas fir, western hemlock, and Sitka spruce.
The Garden Reality Check
Here’s where we need to have a frank conversation: lung lichen isn’t something you can plant in your garden. Unlike traditional plants that you can buy, plant, and nurture, lichens have very specific requirements that are nearly impossible to replicate in a home landscape setting. They need:
- Extremely clean air (they’re super sensitive to air pollution)
- High humidity levels
- Specific tree hosts with the right bark chemistry
- The complex ecosystem balance found in old-growth forests
So while you can’t grow lung lichen in your backyard, you can certainly appreciate and protect it in its natural habitat.
Why Lung Lichen Matters
Even though you can’t cultivate it, lung lichen serves as nature’s own air quality monitor. These sensitive organisms are what scientists call indicator species – their presence tells us that the air is clean and the forest ecosystem is healthy. When air pollution increases, lung lichen is often one of the first species to disappear.
In forest ecosystems, lung lichen also provides important benefits:
- Adds nitrogen to the forest through its cyanobacteria partners
- Provides nesting material for birds and small mammals
- Serves as food for various wildlife species
- Contributes to the overall biodiversity of old-growth forests
How to Identify Lung Lichen
If you’re out forest hiking and want to spot lung lichen, here’s what to look for:
- Large, leafy lobes that can be several inches across
- Greenish-gray to brown coloration (green when wet, brownish when dry)
- Wrinkled, ridged surface that resembles lung tissue
- Growing on tree bark, usually on the trunk or large branches
- Often found alongside other lichen species in healthy forest environments
Supporting Lung Lichen Without Growing It
While you can’t add lung lichen to your garden, you can support its conservation:
- Advocate for clean air policies in your community
- Support old-growth forest conservation efforts
- Choose native plants for your garden that support overall ecosystem health
- Reduce your own air pollution footprint
Think of lung lichen as nature’s gentle reminder that clean air and healthy forests go hand in hand. While it may not be destined for your garden bed, spotting this remarkable organism in the wild is always a sign that you’re in a truly special, unpolluted place.
