North America Native Plant

Crater Lichen

Botanical name: Diploschistes bisporus

USDA symbol: DIBI5

Habit: lichen

Native status: Native to North America  

Crater Lichen: The Fascinating Crusty Partner Living in Your Garden Have you ever noticed small, circular, crusty patches dotting rocks, soil, or even old concrete around your garden? Meet crater lichen (Diploschistes bisporus), one of nature’s most resilient and overlooked organisms that might already be calling your outdoor space home! ...

Crater Lichen: The Fascinating Crusty Partner Living in Your Garden

Have you ever noticed small, circular, crusty patches dotting rocks, soil, or even old concrete around your garden? Meet crater lichen (Diploschistes bisporus), one of nature’s most resilient and overlooked organisms that might already be calling your outdoor space home!

What Exactly Is Crater Lichen?

Before we dive in, let’s clear up a common misconception: crater lichen isn’t actually a plant at all! It’s a fascinating partnership between a fungus and algae (or sometimes cyanobacteria) that work together as a single organism. This incredible team-up allows lichens to survive in some of the harshest conditions on Earth.

Crater lichen gets its common name from its distinctive appearance – it forms circular, raised structures that look remarkably like tiny volcanic craters. These craters typically measure anywhere from a few millimeters to several centimeters across, with raised edges surrounding a depressed center.

Where You’ll Find This Native Wonder

Crater lichen is native to North America and can be found across a wide range of the continent. This hardy organism thrives in arid and semi-arid regions, making itself at home on various surfaces including rocks, compacted soil, and even human-made structures like old concrete or stone walls.

Spotting Crater Lichen in Your Garden

Identifying crater lichen is easier once you know what to look for:

  • Circular, crater-like formations with raised edges
  • Grayish to brownish coloration that may appear almost white when dry
  • Crusty, hard texture that feels firm to the touch
  • Size ranging from tiny dots to patches several inches across
  • Found on exposed surfaces, particularly in areas with good drainage

Is Crater Lichen Beneficial for Your Garden?

While you can’t exactly plant crater lichen like you would a flower or shrub, its presence in your garden is actually a good sign! Here’s why crater lichen deserves your respect:

Soil Health Indicator: Lichens are sensitive to air quality, so their presence often indicates relatively clean air in your area. They’re like nature’s air quality monitors!

Ecosystem Pioneer: Crater lichen helps break down rock and hard surfaces over time, contributing to soil formation. It’s essentially doing the groundwork (literally!) for future plant communities.

Low-Impact Beauty: These organisms add subtle texture and interest to rock gardens, stone walls, and natural areas without requiring any water, fertilizer, or maintenance.

Wildlife Support: While not a major food source, some small insects and arthropods do utilize lichen habitats, contributing to your garden’s biodiversity.

Living Alongside Crater Lichen

The beauty of crater lichen is that it requires absolutely no care from you – in fact, it prefers to be left alone! Here’s how to coexist peacefully with this fascinating organism:

Avoid Disturbance: Lichens grow extremely slowly, sometimes taking decades to reach full size. Try not to scrape or remove them from surfaces where they’re not causing problems.

Appreciate Natural Processes: If you notice crater lichen appearing on garden stones or retaining walls, consider it a sign of a healthy, balanced ecosystem rather than something to remove.

Create Lichen-Friendly Spaces: If you’re designing a rock garden or natural area, leave some exposed stone surfaces and avoid over-watering nearby, as lichens prefer drier conditions.

The Bottom Line

Crater lichen might not be the showiest addition to your garden, but it’s certainly one of the most fascinating and low-maintenance. This native North American species represents millions of years of evolutionary partnership and adaptation. Rather than viewing it as something to remove, consider crater lichen a quiet testament to the resilience and creativity of nature – right in your own backyard!

Next time you’re wandering through your garden, take a moment to appreciate these tiny craters dotting your landscape. You’re looking at one of nature’s most successful partnerships, silently working to build soil and support the ecosystem around your home.

Crater Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Graphidales

Family

Thelotremataceae Stizenb.

Genus

Diploschistes Norman - crater lichen

Species

Diploschistes bisporus (Bagl.) J. Steiner - crater lichen

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