North America Native Plant

Caloplaca Oblongula

Botanical name: Caloplaca oblongula

USDA symbol: CAOB13

Habit: lichen

Native status: Native to North America  

Synonyms: Apatoplaca oblongula (H. Magn.) Poelt & Hafellner (APOB)  ⚘  Lecidea oblongula H. Magn. (LEOB6)   

Discovering Caloplaca oblongula: The Bright Orange Lichen in Your Garden Have you ever noticed vibrant orange or yellow patches decorating the rocks in your garden and wondered what they were? You might be looking at Caloplaca oblongula, a fascinating lichen species that’s been quietly beautifying North American landscapes for centuries. ...

Discovering Caloplaca oblongula: The Bright Orange Lichen in Your Garden

Have you ever noticed vibrant orange or yellow patches decorating the rocks in your garden and wondered what they were? You might be looking at Caloplaca oblongula, a fascinating lichen species that’s been quietly beautifying North American landscapes for centuries. While this isn’t a plant you can buy at the nursery, it’s definitely worth getting to know!

What Exactly Is Caloplaca oblongula?

Let’s clear up some confusion right away – Caloplaca oblongula isn’t actually a plant in the traditional sense. It’s a lichen, which is essentially a partnership between a fungus and an algae living together in perfect harmony. Think of it as nature’s ultimate roommate situation, where both partners benefit from the arrangement.

This particular lichen goes by a few scientific names, including Apatoplaca oblongula and was once called Lecidea oblongula. But don’t worry about memorizing all those tongue-twisting names – what matters is recognizing this little orange beauty when you see it.

Where You’ll Find This Orange Wonder

Caloplaca oblongula is native to North America and has been making itself at home on rocks across the continent for quite some time. You’re most likely to spot it in drier regions, where it happily colonizes various stone surfaces.

What Does It Look Like?

This lichen is quite the showoff when it comes to color! Here’s what to look for:

  • Bright orange to yellow crusty patches on rock surfaces
  • Typically forms circular or irregular shaped colonies
  • Has a somewhat granular or powdery texture
  • Usually quite small, often just a few centimeters across

Is It Beneficial to Have in Your Garden?

Absolutely! While you can’t exactly plant Caloplaca oblongula, having it show up naturally in your garden is actually a good sign. Here’s why you should be happy to see it:

  • Air quality indicator: Lichens are sensitive to air pollution, so their presence suggests you have relatively clean air
  • Natural beauty: Those bright orange patches add unexpected pops of color to stone features
  • Low maintenance: It asks for absolutely nothing from you – no watering, no fertilizing, no pruning!
  • Wildlife support: While not a major food source, some small creatures may use lichen for shelter or nesting material

Creating Lichen-Friendly Conditions

You can’t plant lichens like you would a flower, but you can create conditions that encourage them to find your garden appealing:

  • Include natural stone features like rock walls, boulders, or stone paths
  • Avoid using chemical treatments on stone surfaces
  • Ensure good air circulation around rock features
  • Be patient – lichens grow very slowly and establish themselves over time

Living Alongside Your Lichen Neighbors

The best thing about Caloplaca oblongula is that it’s the perfect low-maintenance garden resident. It doesn’t compete with your other plants, doesn’t spread aggressively, and actually adds character to your stone features. Think of it as nature’s way of aging your rocks gracefully!

If you’re designing a rock garden or incorporating stone elements into your landscape, don’t be surprised if these orange patches start appearing over time. Consider it a compliment – your garden environment is healthy enough to support these fascinating organisms.

The Bottom Line

While Caloplaca oblongula isn’t something you’ll find at the garden center, discovering it naturally occurring in your garden is like finding a small treasure. These bright orange lichens are harmless, beneficial, and add a touch of wild beauty that you simply can’t buy. So next time you spot those cheerful orange patches on your rocks, take a moment to appreciate this amazing example of nature’s cooperation – and maybe give yourself a pat on the back for maintaining a garden healthy enough to support such interesting life forms!

Caloplaca Oblongula

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 oblongula (H. Magn.) Wetmore

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