Fauna
Fungus

Jack-o'-Lantern Mushroom

Omphalotus olearius

Also known as European Jack-o'-Lantern

Jack-o'-lantern mushrooms grow in striking, dense clusters on hardwood stumps, buried roots, and decaying logs throughout European woodlands. Their bright orange caps and decurrent gills produce a faint green bioluminescent glow visible in pitch darkness, generated by luciferase enzymes. Easily mistaken for chanterelles by the untrained eye, these fungi play a vital role as saprotrophic decomposers breaking down dead wood.

BioluminescentPoisonousWood-decaying
Jack-o'-Lantern Mushroom reference1 / 7
Antonio Abbatiello / Public domain · cc0
—observations
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—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyDead hardwood, Lignin, Cellulose
Predators
  • Fungus gnats
  • Slugs
  • Rove beetles
ThreatsDeforestation and clear-cutting of ancient hardwood stands
HabitatsDeciduous forests, woodland margins, decaying hardwood stumps
Life spanUnderground mycelium lives decades; fruiting bodies last 1–2 weeks
Classification
  1. FamilyOmphalotaceae
  2. SpeciesOmphalotus olearius
Range & activity
Range data is not available yet.
Safe observation
Interaction riskHigh
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is high
Contains severe gastrointestinal toxins and has toxic look-alikes; never eat wild fungi based on app identification alone.
Why it is dangerous
Contains illudin toxins that trigger severe gastrointestinal distress, violent vomiting, sharp abdominal cramps, and diarrhea.
How to recognize a risky encounter
Recognized by bright orange decurrent gills running seamlessly down the stem and dense growth on decaying wood.
What to do
Do not harvest or consume; wash hands thoroughly after touch to prevent accidental ingestion.
Responsible observation
  • Night Observation: Allow eyes to adjust in total darkness for 15 minutes to spot the pale green gill glow.
  • Cluster Check: Examine the base of the stems to confirm whether mushrooms emerge from wood or soil.
Related species
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