10 Bioluminescent Mushrooms That Glow in the Dark

Of all the wild and wonderful things to find in a forest, mushrooms are some of the most bizarre. They sprout up in the dankest, most unforgiving places. They "bleed" poison and take just about any shape and color. One of their quirkiest qualities, though, is bioluminescence. Amazingly, more than 70 fungal species can glow in the dark, transforming these usually plain and drab plants into a wondrous sight.

Certain mushrooms release a glow of cold light thanks to a chemical reaction between oxyluciferin molecules, an enzyme called luciferase, and oxygen. It's the same bewildering trick fireflies use to illuminate their backsides on summer nights—and it's used for basically the same purpose in both cases. Whereas fireflies light up to attract mates, mushrooms light up to attract insects that will help them spread their spores. In the mushroom world, the phenomenon is called foxfire, and it occurs mostly amid fungi growing on decaying wood.

Furthermore, mushrooms tend to glow on a cycle, much like human bodies are regulated by the circadian rhythm. Mushrooms maintain themselves on a 22-hour cycle that corrects to 24 hours based on temperature. Glowing also costs energy, which is why most mushrooms intensify their glow only at night, when it's dark and most effective. "An added bonus is that spores prefer to become active and grow at night when it is more humid."

Here are 10 incredible bioluminescent mushrooms you might catch glowing in dark forests.

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Bitter Oyster (Panellus stipticus)

Panellus stipticus mushroom on tree trunk glowing green at night — Ylem / Wikimedia Commons / Public Domain

Panellus stipticus is one of the brightest-glowing bioluminescent mushrooms on Earth. These flat fungi, which look like a collection of tiny fans growing on sticks, are a dull shade of yellow-beige during the day, but they transform into dazzling decorations after dark. Bitter mushrooms, as they're commonly called, hail from the family Mycenaceae and genus Panellus, which it shares with other glowing fungi.

Although Panellus stipticus has a global distribution, only some strains of it—specifically, those growing in certain parts of North America—are bioluminescent. They glow from the gills and mycelia (internal threadlike hyphae), and most prominently during spore maturation.

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Little Ping-Pong Bats (Panellus pusillus)

Close-up of tiny Panellus pusillus covering a tree limb — Alison Harrington / Flickr / CC BY-SA 2.0

At night, Panellus pusillus—a fellow bioluminescent member of the Panellus genus—looks like viridescent string lights wrapped around tree branches in the forest. In the daytime, these mushrooms are a little less interesting. They appear like tiny white palm fans or ping-pong paddles (hence its common name), usually in large clusters.

Panellus pusillus has a wide distribution like its cousin, the bitter oyster. It occurs on every continent except Africa and Antarctica but is seldom photographed while glowing.

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Honey Mushroom (Armillaria mellea)

Cluster of Armillaria mellea growing on mossy forest floor — Stefano Merli / Flickr / CC BY-SA 2.0

These orange-hued mushrooms are some of the most widely distributed bioluminescent fungi, found from North America all the way to Asia. Whereas Panellus pusillus and Panellus stipticus glow in both their fruit bodies and mycelia, Armillaria mellea glows only in the mycelia, a part of the mushroom that isn't usually visible.

So, what's the point of emitting light if that part of the fungus is invisible? Scientists hypothesize it may be quite the opposite effect of glowing mushroom caps: to discourage animals from eating it.

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Bulbous Honey Fungus (Armillaria gallica)

Low-angle shot of armillaria gallica cluster on tree stump — empire331 / Getty Images

One of four other bioluminescent species in the Armarilla ("honey mushroom") genus, Armillaria gallica has a smaller distribution but can still be found throughout Asia, North America, and Europe. Aesthetically, it differs in that it has wide, flat caps that are yellow-brown in color and often scaly. It, too, displays bioluminescence only in the mycelia.

The bulbous honey fungus is one of the better-known glowing mushrooms thanks in part to the famous "humongous fungus" tourist attraction in Michigan. A colony of the species covering 37 acres and weighing 880,000 pounds was discovered in the forest in the 1990s. It's thought to be 2,500 years old.

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Green Pepe (Mycena chlorophos)

Mycena chlorophos glowing green at night on log — ICHIRO / Getty Images

Most of the world's glowing mushrooms belong to the genus Mycena. Mycena chlorophos' pale-green glow is visible because it occurs in its fruiting body, not just in its mycelia. It's brightest when it's just one day old and the temperature is around 80 degrees Fahrenheit. This is consistent with the subtropical climate of its native Indonesia, Japan, Sri Lanka, Australia, and Brazil.

The glow of the green pepe, a common name given to the species by the Micronesian Bonin Islands, is also fleeting. Once its cap opens, the bioluminescence quickly fades.

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Lilac Bonnet (Mycena pura)

Purplish Mycena pura growing in mossy spruce forest — Igor Kramar / Getty Images

Mycena pura is pretty even when it isn't glowing. Its quintessential bell-shaped caps are usually soft purple in color. That's where it gets its common name, lilac bonnet.

In fact, you probably wouldn't know it if it were glowing because its bioluminescence is limited to the mycelium. The mushroom is most common throughout Great Britain and Ireland. It's more elusive in North America and rarely distinguished from its close relative, the similar-looking and also-bioluminescent Mycena rosea.

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Eternal Light Mushroom (Mycena luxaeterna)

Mycena luxaeterna growing in leaf litter with stipes glowing green — Cassius V. Stevani / Wikimedia Commons / CC BY 3.0

Though their thin, hollow, gel-covered stems glow constantly, the Mycena luxaeterna—aptly dubbed the eternal light mushroom—is rather nondescript in the daylight. You can typically see its hairlike stipe lit up in its signature eerie green only after dark. And no, the cap doesn't glow.

The eternal light mushroom's distribution is extraordinarily limited to the rainforest of Sāo Paulo, Brazil.

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Bleeding Fairy Helmet (Mycena haematopus)

Cluster of Mycena haematopus mushrooms growing on mossy log — weinkoetz / Getty Images

Also known as the bleeding fairy helmet, Mycena haematopus is arguably one of the prettiest bioluminescent mushrooms. It gets its name from the red latex it oozes when damaged. While the bleeding fairy helmet does glow even from its fruit body from youth through maturity, its bioluminescence is relatively weak and can be extremely difficult for humans to see.

What the bleeding fairy helmet lacks in the brightness, though, it makes up for in the beautiful burgundy hue of its delicate caps. The species can be found throughout Europe and North America.

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Jack-O'-Lantern Mushroom (Omphalotus olearius)

Omphalotus olearius cluster growing on mossy forest floor — photoguy15237 / Getty Images

One of the more widely known bioluminescent mushrooms, the so-called jack-o'-lantern glows in both its mycelia and the gills on the underside of its cap. A dark-adapted eye can usually see it glowing, but only if it's a fresh specimen. These mushrooms lose their brightness over time. Jack-o'-lanterns have a very similar appearance to edible chanterelles, but are poisonous, so do not eat them. If in doubt, check out Treehugger's guide to identifying wild mushrooms.

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Eastern Jack-O'-Lantern Mushroom (Omphalotus illudens)

Bright golden mushroom cluster growing from tree — Karen (oldmanofthewoods) / Wikimedia Commons / CC BY-SA 3.0

Omphalotus illudens is, in fact, the Eastern counterpart to Omphalotus olearius. While the common jack-o'-lantern grows throughout Europe and parts of South Africa, this one is found only in eastern North America. Both resemble chanterelles in their fiery orange color, glow in the dark, and contain the illudin S toxin, making it poisonous.