In short: Bioluminescent mushrooms glow green using a chemical called luciferin and an enzyme called luciferase — the same reaction that lights up fireflies. Over 70 species worldwide create this eerie green glow, and people have historically used the light to see in the dark.
What are bioluminescent mushrooms?
Some mushrooms glow in the dark with an eerie green light. This glow is called bioluminescence, which simply means "light made by living things." Over 70 known species of fungi around the world can make their own light, mostly in temperate and tropical forests.
How does the glow work?
The glowing mushrooms use the same chemistry as fireflies. Here's what happens:
Inside the glowing fungus is a chemical called luciferin. When oxygen meets luciferin, an enzyme called luciferase speeds up a reaction. This reaction releases energy as light — a greenish glow that shines at night.
Think of it like a tiny, natural light bulb inside the mushroom. The best part? The reaction is cool, not hot, so there's no heat burning away energy. Scientists have been studying this reaction for hundreds of years.
Which mushrooms glow?
The most famous glowing fungi include:
Armillaria mellea (honey fungus) — a bioluminescent fungus found in temperate forests. Its mycelium (the thread-like growth underground) glows more brightly than its mushroom fruiting bodies.
Omphalotus olearius (jack-o'-lantern mushroom) — an orange mushroom that glows a ghostly green. It grows in the Mediterranean region of Europe and North Africa.
Panellus stipticus — a small, shelf-like fungus that grows on dead wood in the forest.
Other species glow from Japan to China to Australia. Each one creates that same pale green glow when conditions are right.
Safety first: Many bioluminescent mushrooms, especially jack-o'-lantern mushrooms, are poisonous. They contain toxins that cause stomach upset, vomiting, and diarrhea. Never pick or eat wild mushrooms — especially glowing ones. These are for looking at with your eyes only, from a distance, and always with a grown-up.
What was "foxfire"?
Foxfire is an old name for the glow from bioluminescent fungi on rotting wood. Centuries ago, when people stumbled upon glowing logs in the dark forest, they called it fairy fire or foxfire — a mysterious, ghostly light.
Miraculous as it seemed, people found practical uses. In 1823, scientists realized this light came from fungi. By the Revolutionary War era, sailors and explorers had figured out they could use foxfire to light dark spaces. The submarine Turtle, one of the first submarines ever built, used foxfire to illuminate its compass and depth gauge — a fungal lamp guiding the vessel underwater!
Miners also discovered luminescent wood deep in mines and used the soft glow to work in the dark before electric lights existed.
Why do mushrooms glow?
Scientists still debate why so many fungi evolved this trick. The leading ideas:
Attracting insects — The glow might lure insects to the mushroom, which then spread its spores as they crawl around. Just like flowers use colors to attract bees, some fungi use light to attract bugs.
Warning signal — Some researchers think the glow warns hungry animals: "Don't eat me! I'm toxic." Bright colors and lights are nature's stop signs.
Just a byproduct — Some scientists think the glow might simply be leftover energy from the fungus's metabolism, not serving any purpose at all.
The truth? We're still learning. Fungi are full of surprises.
Can you see them glow?
In a completely dark forest, after your eyes adjust to the darkness, you might see a faint green glow on dead wood where bioluminescent fungi live. They glow according to a circadian rhythm—an internal clock that follows roughly a 24-hour cycle, just like our sleep-wake cycle.
If you want to safely see glowing fungi, go on a forest walk with a grown-up at night — but never pick them or take them home. Look, wonder, and leave them where they belong, lighting up the forest for the insects and the rest of us who pass through.
The short version
Bioluminescent mushrooms are rare, glowing fungi that use a chemical reaction (luciferin + luciferase) to create a soft green light in the dark. Over 70 species worldwide do this, with Armillaria and Omphalotus being among the most famous. Foxfire was the historic name for this glow, and people once used it to light dark spaces — even submarines! Today, these fungi remain one of nature's coolest mysteries, still growing on forest logs and reminding us that the forest floor is a magical place.
Curious questions
How many species of bioluminescent mushrooms are there?
Approximately 74 known species of fungi glow in the dark worldwide, with new species still being discovered in tropical and temperate forests. The most common are Armillaria mellea and species in the Omphalotus genus.
Are glowing mushrooms the same as the luciferin that makes fireflies glow?
Yes! Bioluminescent fungi use the same luciferin-luciferase reaction as fireflies and some other glowing animals. It's one of nature's most elegant chemical tricks, evolved separately by many creatures over millions of years.
Can I eat bioluminescent mushrooms?
No. Many glowing mushrooms are poisonous, especially the jack-o'-lantern mushroom, which contains toxins that cause stomach upset and vomiting. Never pick or eat wild mushrooms — these are strictly look-don't-touch wonders.
What was 'foxfire' used for?
Foxfire was the historical name for bioluminescent fungi glow. Before electric lights, people used foxfire to illuminate dark spaces, including mines and even the submarine Turtle during the Revolutionary War, where it lit the compass and depth gauge.
Why do some mushrooms glow?
Scientists believe fungi glow to attract insects (which spread spores), to warn predators they're toxic, or possibly as a byproduct of their metabolism. The exact reason is still being researched.
Sources & further reading
- Ask A Biologist (Arizona State University) — Mushroom Bioluminescence
- Wikipedia — Foxfire
- NCBI/PMC — Diversity, Distribution, and Evolution of Bioluminescent Fungi
A note for growers: only grow and eat mushrooms from our kits or from species you know are safe, and always check with an adult. Never eat a wild mushroom unless an expert adult says it’s safe.
