Native Plants

Coral Orange Lichen

Caloplaca coralloides

USDA symbol: CACO63

North America: native

Have you ever spotted bright orange patches on rocks during a hike and wondered what they were? You might have been looking at coral orange lichen (Caloplaca coralloides), one of nature’s most vibrant little organisms. But here’s the thing – this isn’t actually a plant you can add to your ...

Coral Orange Lichen: A Colorful Natural Wonder You Can’t Plant (But Might Find!)

Have you ever spotted bright orange patches on rocks during a hike and wondered what they were? You might have been looking at coral orange lichen (Caloplaca coralloides), one of nature’s most vibrant little organisms. But here’s the thing – this isn’t actually a plant you can add to your garden shopping list!

What Exactly Is Coral Orange Lichen?

Let’s clear up some confusion right away. Despite its plant-like appearance, coral orange lichen isn’t a plant at all. It’s actually a fascinating partnership between a fungus and an algae (or sometimes a cyanobacterium) living together in perfect harmony. Think of it as nature’s ultimate roommate situation – the fungus provides structure and protection, while the algae whips up food through photosynthesis.

Scientifically known as Caloplaca coralloides, this lichen also goes by the synonym Polycauliona coralloides in some scientific circles. But honestly, coral orange lichen is much easier to remember and perfectly describes its stunning coral-to-orange coloration.

Where You’ll Spot This Orange Beauty

Coral orange lichen is native to North America, where it makes its home on rocky surfaces throughout various regions. You’re most likely to encounter it growing on calcareous rocks (that’s limestone and similar calcium-rich stones) in natural settings.

Is It Beneficial to Have Around Your Garden?

While you can’t exactly plant coral orange lichen in your flower beds, having it appear naturally on stone features in your landscape is actually pretty wonderful. Here’s why:

  • It adds natural color and texture to rock walls, stone pathways, or boulder features
  • Lichens are excellent indicators of good air quality – their presence suggests your garden environment is healthy
  • They contribute to the natural ecosystem, slowly breaking down rock surfaces and creating soil over very long periods
  • They provide habitat for tiny insects and other micro-organisms

How to Identify Coral Orange Lichen

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

  • Color: Bright orange to coral-colored patches that really stand out against gray or white rocks
  • Texture: Forms crusty, somewhat bumpy patches on rock surfaces
  • Location: Almost exclusively found growing on limestone, concrete, or other calcium-rich surfaces
  • Size: Individual colonies can range from tiny spots to patches several inches across
  • Growth pattern: Tends to form circular or irregular patches that may merge with neighboring colonies

Can You Encourage It in Your Landscape?

Here’s where things get interesting – you can’t plant or cultivate coral orange lichen like a traditional plant, but you might be able to create conditions where it could naturally establish itself:

  • Include limestone rocks, concrete features, or calcium-rich stone in your landscape design
  • Maintain good air quality around your property (avoid excessive pesticide use)
  • Be patient – lichens grow incredibly slowly, sometimes taking years to become noticeable
  • Avoid cleaning or scrubbing stone surfaces where you’d like lichens to grow

A Word of Caution

If you do spot coral orange lichen growing naturally on rocks in your landscape, resist the urge to scrub it away! These slow-growing organisms take years to establish and play important roles in their ecosystems. Plus, that pop of natural orange color is pretty spectacular against neutral stone backgrounds.

The Bottom Line

While coral orange lichen won’t be making it onto your plant shopping list anytime soon, it’s one of those delightful natural surprises that can add unexpected beauty to rocky areas of your landscape. Think of it as nature’s way of decorating – no planting required, just patience and the right conditions. And hey, if it does show up on your stone features, consider yourself lucky to have such a colorful little tenant!

Caloplaca coralloides is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Caloplaca coralloides is also known as:

Polycaulonia coralloides | USDA symbol: POCO40

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Lichen
Kingdom: Fungi - Fungi
Division: Ascomycota - Sac fungi
Class: Ascomycetes
Order: Teloschistales
Family: Teloschistaceae Zahlbr.
Genus: Caloplaca Th. Fr. - orange lichen

Species: Caloplaca coralloides (Tuck.) Hulting - coral 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