Jack-o-lantern Mushroom: A Toxic Fungus That Glows In The Dark

This boldly colored mushroom is sure to grab your attention on an autumnal walk through a forest. Its bright orange cap provides a beacon of color amongst the subdued colors of forest and woodland floors.

There are several species known as jack-o-lantern mushrooms, with a European species (Omphalotus olearius) and two American jack-o-lantern mushrooms. Each is known as the western jack-o-lantern (Omphalotus olivascens), and the eastern jack-o-lantern mushroom (Omphalotus illudens).

While its appearance is bold, it definitely isn’t unique… The jack-o-lantern mushroom is a lookalike of chanterelle mushrooms. And unlike the chanterelle mushroom, it isn’t edible. Careful identification is needed to differentiate between the two mushrooms as jack-o-lantern mushrooms are actually incredibly toxic.

A large group of jack-o-lantern mushrooms at the base of a tree.
Western Jack-o-lantern mushroom| Photo by Ron Pastorino (Ronpast) at Mushroom Observer

Because of this similarity, they are the cause of a number of accidental poisonings, as inexperienced foragers accidentally forage, cook and consume them. There are a number of notable characteristics that allow foragers to tell the difference, but accidents still occur.

What Are The Active Compounds in Jack-o-lantern Mushrooms?

The active compounds in jack-o-lantern mushrooms are known as illudins. They are highly toxic, and can actually damage DNA within the body, in some areas this damage is not always repaired.

Jack-o-lantern Mushroom Poisoning Symptoms

Eating a jack-o-lantern mushroom will result in severe gastrointestinal distress, with cramps, vomiting, diarrhea, and nausea. Symptom intensity will depend on how much is consumed, but medical assistance is usually recommended.

Fatalities generally do not occur, but the severe symptoms are warning enough for mushroom foragers to sharpen their identification skills.

Cultural Symbolism of Jack-o-lantern Mushrooms

Because of their similar appearance to chanterelles, jack-o-lantern mushrooms are well documented in old and new field guides and foraging identification books as a toxic lookalike.

Their bright orange coloring is thought to be the reasoning behind their common name ‘jack-o-lantern’, like the carved pumpkins of Halloween. The fruiting bodies of the mushroom will also emerge from forest floors around October 31st, making their naming even more appropriate.

A close up of the orange gills on the underside of a small jack-o-lantern mushroom.
Gills on the Eastern jack-o-lantern mushroom | Photo by  Adam Arendell (julius) at Mushroom Observer on Wikimedia Commons

Their bioluminescence is a great area of interest as scientists are eager to study the reasoning behind luminescence in different plants, animals, and fungi. With highly sensitive cameras, the gills of the jack-o-lantern mushroom will glow a bright blue/green color.

What is the Medicinal Potential of the Jack-o-lantern Mushroom?

The active compound illudin that makes these mushrooms so poisonous may actually contain an interesting medicinal secret. Studies are currently observing the ‘antibiotic’ effect that illudin has on some forms of cancer cells.

Illudin is, however, highly toxic to humans, so scientists are experimenting with ways they can harness this natural ability.

A photo filled with bright orange caps of jack-o-lantern mushrooms packed tightly together.
European jack-o-lantern mushroom (Omphalotus olearius) | Photo by Noah Siegel on Wikimedia Commons

What Does A Jack-o-lantern Mushroom Look Like?

The cap, gills, and stem of the Jack’o’lantern mushroom are bright orange. Even when sliced open, the orange color persists right through the stem. This is in contrast to chanterelle mushrooms which are usually more yellow in color, with a paler inside.

At night, these mushrooms will emit a faint green glow, as the gills are bioluminescent. To the human eye, this glow in the dark coloring appears very faint, but to wildlife, this light is thought to attract insects which will then help to spread the spores.

A dark photo showing only 4 mushrooms with a faint, eerie green glow.
The glowing gills of the European Jack-o-lantern mushroom (Omphalotus olearius) | Photo by Noah Siegel on Wikimedia Commons

Where Do Jack-o-lantern Mushrooms Grow?

Jack-o-lantern mushrooms will usually be found growing on tree stumps, old logs, and fallen trees. They tend to favor oak trees and deciduous forests and will form fairly large clusters.


With its glow-in-the-dark gills and bright orange body, the jack-o-lantern mushroom is definitely a fascinating fungus to find around Halloween. It’s a mushroom that also holds amazing potential as a future cancer treatment — however, for now, it’s a mushroom best admired on a chilly autumnal walk.

Featured Image: Eastern jack-o-lantern mushroom (Omphalotus illudens) | Photo by  Karen (oldmanofthewoods) at Mushroom Observer on Wikimedia Commons

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