North America Native Plant

Lecidea Lichen

Botanical name: Lecidea plana

USDA symbol: LEPL2

Habit: lichen

Native status: Native to North America  

Synonyms: Lecidea latypea Ach. (LELA26)   

Meet the Lecidea Lichen: A Fascinating Rock-Dwelling Partner in Your Garden Have you ever noticed those thin, crusty patches decorating the rocks in your garden or on that old stone wall? Chances are, you’ve encountered Lecidea plana, commonly known as the lecidea lichen. This remarkable organism isn’t actually a plant ...

Meet the Lecidea Lichen: A Fascinating Rock-Dwelling Partner in Your Garden

Have you ever noticed those thin, crusty patches decorating the rocks in your garden or on that old stone wall? Chances are, you’ve encountered Lecidea plana, commonly known as the lecidea lichen. This remarkable organism isn’t actually a plant at all—it’s a lichen, which makes it one of nature’s most interesting partnerships!

What Exactly Is a Lichen?

Before we dive into the specifics of lecidea lichen, let’s clear up what a lichen actually is. A lichen is a fascinating partnership between a fungus and an algae (or sometimes cyanobacteria). Think of it as nature’s ultimate roommate situation—the fungus provides structure and protection, while the algae produces food through photosynthesis. It’s a win-win arrangement that has been working successfully for millions of years!

Lecidea plana is native to North America and can be found naturally establishing itself on various rock surfaces throughout the continent. You might also encounter it listed under its scientific synonym, Lecidea latypea.

Spotting Lecidea Lichen in Your Garden

Identifying lecidea lichen is relatively straightforward once you know what to look for:

  • Forms thin, flat, crusty patches (called a crustose growth form)
  • Colors range from grayish to brownish, sometimes with a slightly greenish tint
  • Grows directly on rock surfaces, appearing almost painted on
  • Patches can be small and scattered or form larger, continuous crusts
  • Surface may appear smooth or slightly rough and granular

Is Lecidea Lichen Beneficial for Your Garden?

While you won’t find lecidea lichen at your local nursery (since it can’t be traditionally cultivated), its presence in your garden is actually quite beneficial:

  • Natural colonizer: It helps break down rock surfaces over time, contributing to soil formation
  • Low maintenance: Requires absolutely no care from you—it thrives on neglect!
  • Weather indicator: Lichens are sensitive to air quality, so their presence suggests relatively clean air
  • Natural beauty: Adds subtle texture and color to stone features
  • Habitat creation: Provides microhabitats for tiny invertebrates

Where You’ll Find It Thriving

Lecidea lichen is incredibly adaptable when it comes to climate, thriving across a wide range of USDA hardiness zones from 2 through 9. However, it’s quite particular about its growing surface—it needs hard substrates like:

  • Natural rock outcrops
  • Stone walls and foundations
  • Concrete surfaces (occasionally)
  • Rocky garden features

Encouraging Lecidea Lichen (Without Actually Planting It)

Since lichens establish naturally, you can’t plant lecidea lichen in the traditional sense. However, you can create conditions that might encourage its natural colonization:

  • Include natural stone features in your landscape design
  • Avoid using chemical treatments on rock surfaces
  • Be patient—lichen establishment can take several years
  • Maintain good air quality around your property
  • Leave existing lichen patches undisturbed

A Word of Caution: Don’t Scrub It Away!

Many gardeners mistakenly think lichens are harmful to their stone features and try to scrub them off. Please don’t! Lecidea lichen and other rock-dwelling lichens are completely harmless to your stonework. In fact, they can help protect surfaces from weathering. Their presence indicates a healthy environment, so consider them a badge of honor for your garden’s ecological health.

The Bottom Line

Lecidea lichen might not be the showiest addition to your garden, but it’s certainly one of the most fascinating. This native North American species represents millions of years of evolutionary partnership and adds subtle beauty to any stone feature. Rather than something to plant, think of it as something to appreciate and protect when it appears naturally in your landscape. After all, any organism that can thrive on nothing but rock, air, and water deserves our respect!

Lecidea Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Lecideaceae Chevall.

Genus

Lecidea Ach. - lecidea lichen

Species

Lecidea plana (J. Lahm) Nyl. - lecidea lichen

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