North America Native Plant

Farnoldia Lichen

Botanical name: Farnoldia jurana

USDA symbol: FAJU

Habit: lichen

Native status: Native to North America  

Synonyms: Lecidea albosuffusa Th. Fr. (LEAL32)  ⚘  Lecidea jurana Schaerer (LEJU3)  ⚘  Melanolecia jurana (Schaerer) Hertel (MEJU)  ⚘  Tremolecia jurana (Schaerer) Hertel (TRJU2)   

Farnoldia Lichen: A Crusty Rock Dweller Worth Knowing Ever noticed those pale, crusty patches adorning rocky outcrops during your hiking adventures? You might have encountered Farnoldia jurana, commonly known as farnoldia lichen. This unassuming organism is more fascinating than it first appears, and understanding its role in our native ecosystems ...

Farnoldia Lichen: A Crusty Rock Dweller Worth Knowing

Ever noticed those pale, crusty patches adorning rocky outcrops during your hiking adventures? You might have encountered Farnoldia jurana, commonly known as farnoldia lichen. This unassuming organism is more fascinating than it first appears, and understanding its role in our native ecosystems can deepen your appreciation for the subtle beauty of North American landscapes.

What Exactly Is Farnoldia Lichen?

First things first – farnoldia lichen isn’t actually a plant at all! It’s a lichen, which means it’s a remarkable partnership between a fungus and algae (or cyanobacteria) living together in perfect harmony. This biological tag-team creates those distinctive whitish to pale gray crusty patches you’ll find decorating rock surfaces across western North America.

Scientifically known as Farnoldia jurana, this lichen has collected quite a few names over the years. Botanists have previously called it Lecidea albosuffusa, Lecidea jurana, Melanolecia jurana, and Tremolecia jurana – proof that even scientists sometimes can’t make up their minds!

Where You’ll Find This Rocky Resident

Farnoldia lichen is a true native of North America, with a particular fondness for the Rocky Mountain region and other western areas. It’s quite the picky eater when it comes to real estate – this lichen almost exclusively calls calcareous rocks (think limestone and similar calcium-rich stones) home.

Spotting Farnoldia Lichen in the Wild

Identifying farnoldia lichen is fairly straightforward once you know what to look for:

  • Crusty, thick appearance that seems almost painted onto the rock surface
  • Whitish to pale gray coloration
  • Preference for limestone and other calcareous rock substrates
  • Forms irregular patches that can spread across rock faces
  • Texture reminds you of dried paint or plaster

Is Farnoldia Lichen Beneficial for Your Garden?

Here’s where things get interesting for us gardeners. While you can’t exactly plant farnoldia lichen in your flower bed, its presence (or absence) can tell you quite a bit about your local environment. Lichens like Farnoldia jurana are excellent air quality indicators – they’re sensitive to pollution and tend to thrive in areas with clean air.

If you have natural limestone features, rock walls, or calcareous stone elements in your landscape, you might be lucky enough to have this lichen establish itself naturally over time. Consider it nature’s seal of approval for your garden’s air quality!

The Lichen Lifestyle

Unlike traditional plants, farnoldia lichen doesn’t need soil, regular watering, or fertilizer. It gets everything it needs from the air and occasional moisture from rain or dew. The fungal partner provides structure and gathers water and minerals, while the algal partner photosynthesizes to create food for both – it’s like the ultimate sustainable living arrangement!

Supporting Lichens in Your Landscape

While you can’t cultivate farnoldia lichen like a typical garden plant, you can create conditions that might encourage lichens in general:

  • Maintain clean air around your property by avoiding excessive use of chemicals
  • If you have natural stone features, resist the urge to power-wash them too frequently
  • Consider incorporating native limestone or calcareous rocks into your landscape design
  • Be patient – lichens are slow growers and may take years to establish

A Word of Appreciation

Next time you’re out exploring rocky terrain in western North America, take a moment to appreciate these humble organisms. Farnoldia lichen might not have the flashy appeal of wildflowers or the majesty of towering trees, but it represents millions of years of evolutionary cooperation and serves as a living indicator of environmental health.

While you won’t find farnoldia lichen at your local nursery, recognizing and appreciating it in its natural habitat connects us to the incredible diversity of life that makes up our native ecosystems. Sometimes the most remarkable garden inhabitants are the ones that choose us, rather than the ones we choose ourselves.

Farnoldia Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Porpidiaceae Hertel & Hafellner

Genus

Farnoldia Hertel - farnoldia lichen

Species

Farnoldia jurana (Schaerer) Hertel - farnoldia lichen

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