North America Native Plant

Eggyolk Lichen

Botanical name: Candelariella subdeflexa

USDA symbol: CASU40

Habit: lichen

Native status: Native to North America  

Eggyolk Lichen: A Tiny Golden Treasure in Your Garden Have you ever noticed small, bright yellow-orange patches decorating the rocks, tree bark, or even concrete surfaces around your garden? You might be looking at eggyolk lichen (Candelariella subdeflexa), one of nature’s most charming and beneficial tiny organisms that’s actually helping ...

Eggyolk Lichen: A Tiny Golden Treasure in Your Garden

Have you ever noticed small, bright yellow-orange patches decorating the rocks, tree bark, or even concrete surfaces around your garden? You might be looking at eggyolk lichen (Candelariella subdeflexa), one of nature’s most charming and beneficial tiny organisms that’s actually helping your garden ecosystem in ways you probably never imagined!

What Exactly Is Eggyolk Lichen?

Despite its name suggesting it’s a plant, eggyolk lichen isn’t a plant at all – it’s actually a fascinating partnership between fungi and algae living together in perfect harmony. This crustose lichen forms thin, crusty patches that really do resemble bits of scrambled egg yolk scattered across surfaces, hence the delightfully descriptive common name.

As a native species to North America, Candelariella subdeflexa has been quietly doing its job in our ecosystems for countless years, often going completely unnoticed by gardeners who mistake it for just another bit of natural debris.

Where You’ll Find This Golden Helper

Eggyolk lichen is widely distributed across North America, thriving in various climates and conditions. You’re most likely to spot these cheerful yellow-orange patches in temperate regions, where they’ve made themselves perfectly at home.

How to Spot Eggyolk Lichen in Your Space

Identifying eggyolk lichen is pretty straightforward once you know what to look for:

  • Bright yellow to orange coloration that really does look like egg yolk
  • Crusty, flat appearance that seems painted onto surfaces
  • Small patches, typically a few centimeters across
  • Found on rocks, tree bark, concrete, or even old wooden structures
  • Feels rough or granular to the touch

Why Eggyolk Lichen Is Actually Great for Your Garden

Before you think about removing these little golden spots, consider the wonderful benefits they’re providing:

  • Air quality indicators: Lichens are incredibly sensitive to air pollution, so their presence indicates your garden enjoys relatively clean air
  • Soil building: Over time, lichens help break down rock and other surfaces, contributing to soil formation
  • Ecosystem support: They provide food and shelter for tiny insects and other small creatures
  • Natural beauty: These colorful patches add subtle, natural decoration to otherwise plain surfaces

Living Alongside Your Lichen Friends

The wonderful thing about eggyolk lichen is that it requires absolutely no care from you – in fact, it’s better if you just leave it alone! These hardy little organisms:

  • Thrive without any watering, fertilizing, or maintenance
  • Actually prefer being left undisturbed
  • Can survive extreme weather conditions that would kill most plants
  • Grow very slowly, so changes happen gradually over years

A Gentle Reminder About Respect

While eggyolk lichen isn’t rare or endangered, it’s worth remembering that these organisms grow incredibly slowly – sometimes taking years to establish a small patch. If you’re doing garden maintenance or cleaning surfaces, try to work around these golden treasures when possible. They’re not hurting anything, and they’re actually contributing positively to your garden’s ecosystem.

Next time you’re wandering through your garden, take a moment to appreciate these tiny golden partnerships. Eggyolk lichen might be small and easily overlooked, but it’s a perfect example of how nature finds ways to thrive in the most unexpected places – including right in your own backyard!

Eggyolk Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Candelariaceae Hakul.

Genus

Candelariella Müll. Arg. - eggyolk lichen

Species

Candelariella subdeflexa (Nyl.) Lettau - eggyolk lichen

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