Rimmed Navel Lichen: A Fascinating Natural Occurrence in Your Garden
Have you ever noticed those peculiar circular, grayish-green patches growing on rocks in your garden or local hiking trails? You might be looking at the rimmed navel lichen (Rhizoplaca glaucophana), a remarkable organism that’s more complex and beneficial than you might think!
What Exactly Is Rimmed Navel Lichen?
Despite its name suggesting it’s a plant, rimmed navel lichen is actually a fascinating partnership between a fungus and algae working together as one organism. This collaboration, called symbiosis, allows the lichen to thrive in harsh conditions where most plants would struggle to survive. The rimmed navel lichen gets its common name from its distinctive appearance – it forms circular patches that often have raised, rim-like edges resembling tiny navels scattered across rock surfaces.
Scientifically known as Rhizoplaca glaucophana (formerly classified as Lecanora glaucophana), this lichen is native to North America and plays an important ecological role in its natural habitat.
Where You’ll Find This Unique Organism
Rimmed navel lichen is primarily found across western North America, thriving in the arid and semi-arid regions of the southwestern United States. It’s particularly common in desert environments where it colonizes exposed rock surfaces, from granite boulders to sandstone cliffs.
How to Identify Rimmed Navel Lichen
Spotting rimmed navel lichen is easier once you know what to look for:
- Circular to irregular patches ranging from gray-green to bluish-gray in color
- Distinctive raised edges or rims around the perimeter
- Smooth to slightly rough texture
- Grows directly on rock surfaces, appearing almost painted on
- Size typically ranges from a few millimeters to several centimeters across
- Often found in clusters with multiple navels grouped together
Is Rimmed Navel Lichen Beneficial for Your Garden?
While you can’t plant or cultivate rimmed navel lichen like traditional garden plants, its presence can actually be quite beneficial:
- Natural rock weathering: The lichen slowly breaks down rock surfaces, contributing to soil formation over time
- Ecosystem indicator: Its presence often indicates good air quality, as lichens are sensitive to pollution
- Low-maintenance beauty: Adds natural character to rock gardens and stone features without any care required
- Wildlife habitat: Provides microhabitats for tiny insects and contributes to the broader ecosystem
Living Alongside Rimmed Navel Lichen
If you discover rimmed navel lichen on rocks in your garden, consider yourself lucky! This slow-growing organism can take decades to establish and indicates a healthy, unpolluted environment. The best approach is simply to appreciate and protect it:
- Avoid using harsh chemicals or pressure washing on affected rocks
- Don’t attempt to remove it – lichens are harmless to rock surfaces
- Consider incorporating natural stone features in your landscape design to encourage lichen growth
- Use it as a conversation starter about the fascinating world of symbiotic organisms
The Bottom Line
Rimmed navel lichen represents one of nature’s most successful partnerships, thriving in conditions that would challenge most other organisms. While you can’t plant it like a traditional garden species, its natural occurrence in your landscape adds ecological value and serves as a testament to the health of your local environment. Rather than viewing it as something to remove, embrace these tiny marvels as part of your garden’s natural heritage – they’re working hard to support the ecosystem, one microscopic partnership at a time!
