North America Native Plant

Catillaria Lichen

Botanical name: Catillaria endochroma

USDA symbol: CAEN5

Habit: lichen

Native status: Native to North America  

Catillaria Lichen: A Tiny Rock-Dwelling Wonder in Your Garden Have you ever noticed small, crusty patches growing on rocks or tree bark in your garden and wondered what they were? You might be looking at Catillaria endochroma, commonly known as catillaria lichen. While this isn’t a plant you can buy ...

Catillaria Lichen: A Tiny Rock-Dwelling Wonder in Your Garden

Have you ever noticed small, crusty patches growing on rocks or tree bark in your garden and wondered what they were? You might be looking at Catillaria endochroma, commonly known as catillaria lichen. While this isn’t a plant you can buy at the nursery or deliberately cultivate, understanding this fascinating organism can help you appreciate the tiny ecosystems already thriving in your outdoor space.

What Exactly Is Catillaria Lichen?

Catillaria lichen isn’t actually a plant at all – it’s a remarkable partnership between fungi and algae working together as one organism. This crusty little lichen forms small, patches that might look unremarkable at first glance, but they’re actually quite extraordinary. Think of lichens as nature’s ultimate roommate situation, where the fungus provides structure and protection while the algae handle the food production through photosynthesis.

Where You’ll Find This Native Wonder

Catillaria endochroma is native to North America, making it a true local resident in many gardens and natural areas. You’ll typically spot this lichen growing on rock surfaces, where it forms those characteristic crusty patches that blend seamlessly with their surroundings.

Is Catillaria Lichen Good for Your Garden?

While you can’t plant catillaria lichen like you would a flower or shrub, its presence in your garden is actually a positive sign. Here’s why having lichens around is beneficial:

  • They indicate good air quality – lichens are sensitive to pollution
  • They contribute to the biodiversity of your garden ecosystem
  • They help break down rock surfaces very slowly, contributing to soil formation over time
  • They provide habitat for tiny creatures like mites and other microorganisms

How to Identify Catillaria Lichen

Spotting catillaria lichen requires looking closely at the rock surfaces in your garden. Here’s what to look for:

  • Small, crusty patches that appear to be painted onto rock surfaces
  • Colors that typically blend with the rock substrate
  • A texture that’s neither soft nor mossy, but rather hard and crusty
  • Growth that follows the contours of the rock surface

Living Alongside Lichens

The best thing about catillaria lichen is that it requires absolutely no care from you. It thrives in its own specific conditions and will appear naturally if your garden provides the right environment. There’s no watering, fertilizing, or pruning involved – just appreciation for these tiny marvels of cooperation.

If you’re interested in encouraging lichen diversity in your garden, the best approach is to maintain good air quality, avoid using chemical treatments on rocks and trees, and simply let nature take its course. Remember, lichens grow incredibly slowly, so any patches you see may have been developing for years or even decades.

The Bottom Line

While Catillaria endochroma isn’t something you’ll add to your garden shopping list, discovering it growing naturally in your outdoor space is like finding a hidden treasure. These remarkable organisms remind us that gardens are complex ecosystems filled with life forms both big and small, all playing their part in the grand scheme of nature.

Catillaria Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Catillariaceae Hafellner

Genus

Catillaria A. Massal. - catillaria lichen

Species

Catillaria endochroma (Fée) Zahlbr. - catillaria lichen

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