Fungus
Old Man's Beard Lichen
Usnea barbataAlso known as Beard Lichen, Tree Beard, Fishbone Beard Lichen
Old man's beard hangs in pale grey-green tufts and strands from tree trunks and branches in cool, humid forests across the northern hemisphere. Pulling a main branch gently reveals a stretchy white central core surrounded by a green fungal-algal cortex. Because it absorbs moisture and nutrients directly from rain and atmosphere, this lichen serves as a vital bioindicator of pristine air quality.
EpiphyticBioindicatorForest Dweller
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & preyPhotosynthetic (symbiosis between fungus and green algae)
Predators
- Snails
- Slugs
- Caribou
ThreatsAir pollution, industrial sulfur emissions, forest clear-cutting
HabitatsHumid temperate forests, boreal woodlands, coastal fog belts
Life spanDecades to over a century
Classification
- FamilyParmeliaceae
- SpeciesUsnea barbata
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Elasticity Test: Gently stretch a main branch to reveal the elastic white central axis, confirming identity.
- Air Quality Indicator: Treat dense hangings as a reliable sign of unpolluted, clean woodland air.
- Leave Intact: Admire hanging strands on tree bark without peeling or damaging the host lichens.
Look-alike (c) wweellll, some rights reserved (CC BY), uploaded by wweellll · cc-by
Host Tree (c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · cc-by-sa
Co-occurring Lichen (c) Paul Cook, some rights reserved (CC BY), uploaded by Paul Cook · cc-by
Image unavailableClose Relative
Help improve the field guideSomething wrong?
Checking your Fauna account…Report a name, category, or profile issue for review.