North America Native Plant

Orange Lichen

Botanical name: Caloplaca herbidella

USDA symbol: CAHE22

Habit: lichen

Native status: Native to North America  

Orange Lichen: The Tiny Colorful Crust You Might Be Overlooking Have you ever noticed small, bright orange patches growing on rocks, tree bark, or even concrete surfaces around your garden? You might be looking at orange lichen, scientifically known as Caloplaca herbidella. While most gardeners focus on flowering plants and ...

Orange Lichen: The Tiny Colorful Crust You Might Be Overlooking

Have you ever noticed small, bright orange patches growing on rocks, tree bark, or even concrete surfaces around your garden? You might be looking at orange lichen, scientifically known as Caloplaca herbidella. While most gardeners focus on flowering plants and shrubs, these fascinating organisms are quietly adding splashes of color to landscapes across North America.

What Exactly Is Orange Lichen?

Orange lichen isn’t actually a plant at all – it’s something much more interesting! Lichens are remarkable partnerships between fungi and algae (or sometimes cyanobacteria) that work together as a single organism. Think of it as nature’s ultimate roommate situation, where both parties benefit from the arrangement.

The fungal partner provides structure and protection, while the algae partner uses photosynthesis to create food for both. This teamwork allows lichens to survive in some pretty tough conditions where regular plants would struggle.

Where You’ll Find Orange Lichen

As a North American native, orange lichen has been part of our natural landscapes long before any of us started gardening. You’ll typically spot these small, crusty patches growing directly on surfaces rather than having roots like traditional plants.

Is Orange Lichen Good for Your Garden?

Here’s where orange lichen gets really interesting for gardeners. While you can’t exactly plant it like you would a flower, its presence in your garden is actually a great sign. Lichens are sensitive to air pollution, so finding them growing naturally indicates you have relatively clean air around your property.

Orange lichen won’t compete with your plants for soil nutrients or water since it gets everything it needs from the air and surfaces it grows on. It’s essentially a zero-maintenance addition to your landscape that:

  • Adds natural color and texture to rocks, walls, and tree bark
  • Indicates good air quality in your area
  • Provides food for some wildlife species
  • Requires absolutely no care from you

How to Identify Orange Lichen

Spotting orange lichen is pretty straightforward once you know what to look for:

  • Bright orange coloration (though it may fade to yellow or gray when dry)
  • Crusty, flat appearance that seems painted onto surfaces
  • Grows directly on rocks, concrete, brick, or tree bark
  • Forms small patches, usually just a few inches across
  • No visible roots, stems, or leaves

Should You Encourage Orange Lichen?

The short answer is: you don’t need to do anything! Orange lichen will appear naturally if conditions are right. Trying to remove it is unnecessary and potentially harmful to local ecosystems. Instead, consider it a natural accent that adds character to hardscaping elements like stone walls, stepping stones, or decorative rocks.

If you’re designing a natural landscape, leaving spaces where lichens can establish themselves – like unmortared stone walls or natural rock outcroppings – can add authentic wildness to your garden design.

The Bottom Line

Orange lichen might not be the showstopper that a blooming native wildflower is, but it’s a fascinating part of North America’s natural heritage. Rather than viewing it as something to manage or remove, appreciate it as a sign of a healthy environment and a unique addition to your garden’s ecosystem. After all, how many other gardeners can say they’re growing organisms that are part fungus, part algae, and 100% amazing?

Orange Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Teloschistales

Family

Teloschistaceae Zahlbr.

Genus

Caloplaca Th. Fr. - orange lichen

Species

Caloplaca herbidella (Hue) H. Magn. - orange lichen

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