North America Native Plant

Miriquidica Plumbeoatra

Botanical name: Miriquidica plumbeoatra

USDA symbol: MIPL4

Habit: lichen

Native status: Native to North America  

Synonyms: Lecidea plumbeoatra Vain. (LEPL5)   

Miriquidica plumbeoatra: The Rock-Dwelling Lichen You Might Already Have If you’ve ever noticed dark, crusty patches on rocks in your garden or while hiking, you might have encountered Miriquidica plumbeoatra without even knowing it! This interesting organism isn’t actually a plant at all—it’s a lichen, which makes it quite special ...

Miriquidica plumbeoatra: The Rock-Dwelling Lichen You Might Already Have

If you’ve ever noticed dark, crusty patches on rocks in your garden or while hiking, you might have encountered Miriquidica plumbeoatra without even knowing it! This interesting organism isn’t actually a plant at all—it’s a lichen, which makes it quite special in the world of garden ecology.

What Exactly Is Miriquidica plumbeoatra?

Miriquidica plumbeoatra is a crustose lichen native to North America. Unlike the flowering plants we typically think about for our gardens, lichens are fascinating partnerships between fungi and algae (or sometimes cyanobacteria) that work together to create something entirely unique. Think of it as nature’s ultimate roommate situation—the fungus provides structure and protection, while the algae handles the food production through photosynthesis.

This particular lichen was previously known by the scientific name Lecidea plumbeoatra, so don’t be confused if you see that name in older field guides or botanical references.

Where You’ll Find It

As a North American native, Miriquidica plumbeoatra has been quietly doing its thing on rock surfaces across the continent for centuries. It particularly favors acidic, siliceous rocks in mountainous and hilly regions, where it forms thin, dark grayish to blackish crusts that might look unremarkable at first glance.

What Does It Look Like?

Identifying Miriquidica plumbeoatra takes a bit of detective work, but here’s what to look for:

  • Dark gray to blackish, crusty patches on rock surfaces
  • Thin, closely adhered to the rock substrate
  • Smooth to slightly rough texture
  • Often found on acidic rocks like granite or quartzite
  • May have small, dark fruiting bodies (apothecia) that look like tiny black dots

Is It Beneficial to Your Garden?

While you can’t exactly plant Miriquidica plumbeoatra in your flower beds, having it occur naturally in your garden is actually a wonderful sign! Here’s why this little lichen deserves your appreciation:

  • Air quality indicator: Lichens are sensitive to air pollution, so their presence suggests you have relatively clean air
  • Ecosystem support: They provide food and habitat for tiny insects and other microorganisms
  • Rock protection: Lichens help prevent rock erosion while simultaneously breaking down minerals
  • Natural beauty: They add subtle texture and color variation to stone features in your landscape

Can You Cultivate It?

Here’s where things get interesting—you can’t really grow Miriquidica plumbeoatra in the traditional sense. Lichens can’t be planted from seeds or propagated like regular garden plants. They establish themselves naturally when conditions are right, which means:

  • You need appropriate rock substrates (acidic rocks work best)
  • Clean air quality
  • Natural spore dispersal from existing populations
  • Time—lots and lots of time, as lichens grow extremely slowly

How to Encourage Lichens in Your Garden

While you can’t plant lichens directly, you can create conditions that make them more likely to appear naturally:

  • Incorporate natural stone features like rock gardens or stone walls
  • Avoid using chemical treatments near stone surfaces
  • Be patient—lichen establishment can take years or even decades
  • Maintain good air quality by reducing pollution sources
  • Resist the urge to scrub rocks clean—let nature do its thing

The Bottom Line

Miriquidica plumbeoatra might not be the showstopper that draws visitors to your garden, but it’s one of those quiet, essential players in the ecosystem that deserves recognition. If you’re lucky enough to have this lichen naturally occurring on rocks in your landscape, consider yourself blessed with a little piece of ancient natural history. These remarkable organisms have been around for millions of years, quietly doing their part to keep ecosystems healthy and balanced.

So the next time you’re walking through your garden, take a moment to appreciate those humble crusty patches on your rocks—you might just be looking at Miriquidica plumbeoatra, a true North American native that’s been perfecting the art of rock living long before we humans started thinking about landscaping!

Miriquidica Plumbeoatra

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Lecanoraceae Körb.

Genus

Miriquidica Hertel & Rambold - miriquidica lichen

Species

Miriquidica plumbeoatra (Vain.) A.J. Schwab & Rambold

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