Lichens
Lichenized fungi with algal or cyanobacterial partners
Pale green, silver, and gray patches spread across bark and stone. Lichens are easy to overlook until rain deepens their colors or bare winter branches bring their varied shapes into view.
WHEN TO NOTICE IT
Year-round; winter and damp weather make their colors and forms especially noticeable.
WHERE TO LOOK
Look on tree trunks, branches, boulders, and exposed rock across the Blue Ridge. Some lichens form a thin crust; others have leafy lobes or branching growth. Compare shaded and sunlit surfaces from the trail, without peeling lichens from the bark or stone where they grow.
Common greenshield lichen spreads in leafy lobes across tree bark.
British soldiers lichen bears bright red fruiting structures
above its tiny stalks.
HOW TO RECOGNIZE IT
CRUSTS AND LOBES
Growth may lie tightly against a surface or form small, leaf-like folds.
BRANCHING FORMS
Some lichens grow as little shrubs, tufts, or hanging strands.
SUBTLE COLORS
Look for gray, green, yellow, orange, or brown, often more vivid when wet.
NO TRUE LEAVES
Even leafy lichens lack the stems, veins, and roots of a leafy plant.
Ecological context
A Shared Way of Living
A lichen combines a fungus with a partner that uses sunlight to make food, usually an alga or cyanobacterium. The fungus forms much of the visible body, while the photosynthetic partner supplies sugars. Together they can occupy bark and stone where a rooted plant could not grow. The pale patch on a trunk is a living association rather than a stain.
Ruby-throated hummingbirds place pieces of lichen on the outside of their nests, helping the small cups resemble the branches that hold them. On the tree itself, lichens use bark as a growing surface without feeding on the tree’s living tissues. A single trunk can support the tree, its lichens, and birds gathering material from its outer surface.
Useful Beyond the Bark
Its place in the Blue Ridge
The Blue Ridge’s varied forests, rock faces, and moisture conditions support many kinds of lichens. Different species favor different surfaces and amounts of light. A patch on an old hardwood trunk may look unlike one on a sunny boulder, even along the same short stretch of trail.
A small wonder
Many lichens become less active as they dry, then resume activity when moisture returns. Rain can change their appearance as well as their activity. A familiar gray patch may look greener or more translucent after the next wet morning.
Notice for yourself
Choose one patch you can revisit without touching it. Compare its color and texture on a dry day and after rain. Look for crusts, folded edges, or small branches, and notice whether neighboring patches share the same shape or only the same growing surface.
Explore further
Follow more stories from this forest.
Mosses
Liverworts
Ruby-Throated Hummingbird