North America Native Plant

Mountain Lichen

Botanical name: Dimelaena radiata

USDA symbol: DIRA4

Habit: lichen

Native status: Native to North America  

Synonyms: Buellia radiata Tuck. (BURA3)  ⚘  Rinodina radiata Tuck. (RIRA2)   

Mountain Lichen: The Fascinating Dimelaena radiata in Your Garden Have you ever noticed those crusty, grayish patches growing on rocks or tree bark in mountainous areas? You might be looking at mountain lichen (Dimelaena radiata), a remarkable organism that’s neither plant nor animal, but something wonderfully unique. While you can’t ...

Mountain Lichen: The Fascinating Dimelaena radiata in Your Garden

Have you ever noticed those crusty, grayish patches growing on rocks or tree bark in mountainous areas? You might be looking at mountain lichen (Dimelaena radiata), a remarkable organism that’s neither plant nor animal, but something wonderfully unique. While you can’t exactly plant this fascinating species in your garden like you would a rose bush, understanding what it is and recognizing its presence can add a whole new dimension to your appreciation of the natural world around your home.

What Exactly Is Mountain Lichen?

Mountain lichen is actually a fascinating partnership between fungi and algae (or sometimes cyanobacteria) living together in perfect harmony. This symbiotic relationship allows them to thrive in places where neither could survive alone. The fungus provides structure and protection, while the algae produce food through photosynthesis – it’s like nature’s own little cooperative!

Scientifically known as Dimelaena radiata, this species was previously classified under different names including Buellia radiata and Rinodina radiata, which you might encounter in older field guides.

Where You’ll Find Mountain Lichen

This hardy little organism is native to North America, particularly thriving in the western mountainous regions. Mountain lichen has a preference for rocky surfaces and tree bark, where it forms distinctive crusty patches that seem to radiate outward – hence the name radiata.

Identifying Mountain Lichen in Your Landscape

Spotting mountain lichen is easier once you know what to look for:

  • Small, crusty patches with a grayish to brownish coloration
  • Radiating pattern that spreads outward from the center
  • Typically found on rocks, boulders, or tree bark
  • More common in mountainous or elevated areas
  • Appears dry and brittle when not moist

Is Mountain Lichen Beneficial to Your Garden?

While mountain lichen won’t directly attract butterflies or produce showy blooms, its presence in your landscape is actually a positive sign! Lichens are excellent indicators of air quality – they’re quite sensitive to air pollution, so finding them around your property suggests you have relatively clean air.

Mountain lichen also plays several beneficial ecological roles:

  • Helps break down rock surfaces, contributing to soil formation over time
  • Provides microscopic habitat for tiny invertebrates
  • Serves as a natural air quality monitor
  • Adds subtle texture and interest to natural rock gardens or woodland settings

Can You Cultivate Mountain Lichen?

Here’s where mountain lichen differs dramatically from your typical garden plants – you simply can’t plant it like you would a perennial or shrub. Lichens grow incredibly slowly and have very specific requirements that are nearly impossible to replicate artificially. Attempting to transplant or cultivate lichens typically results in their death.

Instead of trying to grow mountain lichen, the best approach is to:

  • Appreciate and protect any lichens that naturally occur on your property
  • Avoid disturbing rocks or tree bark where lichens are growing
  • Minimize the use of chemicals that might affect air quality
  • Create conditions that might naturally attract lichens, such as maintaining natural stone features

Living in Harmony with Mountain Lichen

If you’re fortunate enough to have mountain lichen growing naturally in your landscape, consider yourself lucky! These slow-growing organisms can take years or even decades to establish themselves. Rather than viewing them as something to manage or control, think of them as natural artwork that adds character and ecological value to your outdoor space.

The presence of mountain lichen suggests you have a healthy, unpolluted environment – something increasingly rare in our modern world. By simply leaving them undisturbed and appreciating their quiet beauty, you’re supporting biodiversity in your own backyard.

So the next time you’re exploring the rocky outcrops or examining the bark of mature trees around your property, take a moment to look for these fascinating organisms. Mountain lichen may not be the showiest resident of your landscape, but it’s certainly one of the most intriguing!

Mountain Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Physciaceae Zahlbr.

Genus

Dimelaena Norman - mountain lichen

Species

Dimelaena radiata (Tuck.) Müll. Arg. - mountain lichen

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