Muehlenberg’s Navel Lichen: A Fascinating Natural Garden Visitor
Have you ever noticed peculiar, coin-shaped gray patches clinging to rocks in your garden or nearby natural areas? You might be looking at Muehlenberg’s navel lichen (Umbilicaria muehlenbergii), one of nature’s most intriguing organisms that’s neither plant nor animal, but something wonderfully unique.
What Exactly Is Muehlenberg’s Navel Lichen?
Muehlenberg’s navel lichen is a fascinating composite organism made up of a fungus and algae living together in perfect harmony. This partnership, called symbiosis, allows the lichen to thrive in places where most plants simply can’t survive. The fungus provides structure and protection, while the algae produces food through photosynthesis—it’s like nature’s own little cooperative!
This species is native to North America and has been quietly decorating our rocky landscapes for centuries. You might also see it referenced in older scientific literature under its synonyms Actinogyra muehlenbergii or Gyrophora muehlenbergii, but don’t let the name changes fool you—it’s the same remarkable organism.
Where You’ll Find It
Muehlenberg’s navel lichen calls eastern North America home, particularly favoring the rocky outcrops and mountainous regions where it can attach to acidic rock surfaces. It’s especially common in shaded, humid areas where the conditions are just right for this moisture-loving lichen.
How to Identify Muehlenberg’s Navel Lichen
Spotting this lichen is easier than you might think once you know what to look for:
- Circular, flat appearance resembling a grayish-brown coin or disk
- Distinctive single attachment point in the center (the navel that gives it its common name)
- Smooth or slightly wrinkled surface texture
- Typically ranges from gray to brownish in color
- Usually found growing on acidic rock surfaces, particularly in shaded areas
The navel attachment point is your biggest clue—this central umbilicus (hence the genus name Umbilicaria) makes it look like nature’s own belly button!
Is It Beneficial to Have in Your Garden?
While you can’t exactly plant or cultivate Muehlenberg’s navel lichen like you would a flower or shrub, having it appear naturally in your garden is actually a wonderful sign. Lichens are excellent indicators of air quality—their presence suggests your garden environment is relatively clean and healthy.
Here’s why you should appreciate these little natural decorations:
- They’re completely harmless and won’t damage rocks or structures
- They indicate good air quality in your area
- They add subtle natural beauty to rock gardens and stone features
- They’re part of the natural ecosystem, providing microhabitats for tiny organisms
- They help with soil formation over very long periods by slowly breaking down rock surfaces
A Word About Conservation
Since you can’t grow or transplant lichens, the best thing you can do is simply appreciate them where they naturally occur. If you’re lucky enough to have Muehlenberg’s navel lichen on rocks in your garden, consider yourself a steward of a small piece of natural heritage. Avoid disturbing or trying to remove them—they’re slow-growing and take years to establish.
The Bottom Line
Muehlenberg’s navel lichen might not be something you can add to your garden shopping list, but it’s definitely something to celebrate if it shows up naturally. These remarkable organisms remind us that gardens aren’t just about the plants we choose to grow—they’re also about the wild, wonderful life that chooses to make itself at home alongside our cultivated spaces. Next time you spot one of these living coins on a rock, take a moment to appreciate the incredible partnership between fungus and algae that makes it all possible.
