Night light: These mushrooms glow in the dark

When you hear someone talking about something that glows in the dark, you might think of a candle, a glow stick or even a lightning bug if it is summertime. But there are other living things that glow in the dark.

Jack-o'-lantern mushrooms. (Photo by Marissa Jones)

Jack-o’-lantern mushrooms are a type of fungus that glows in the dark. Yes, you read that right. Just like the Halloween decorations, this fungus can glow in the dark. The ability of something natural to glow in the dark is called bioluminescence, which is the same thing that makes lightning bugs light up at night.

What’s in a name

This type of mushroom is one of more than 70 mushroom species that can glow in the dark. Only a small number of these species can be found in North America, and Jack-o’-lantern mushrooms are one of them. They can be found right here in Illinois, including in the Will County forest preserves. One preserve where you might see them is Goodenow Grove Nature Preserve in Beecher.

These mushrooms don’t only look cool at night. During the day they are easy to spot because they are yellow-orange or orange, just like the pumpkin you might carve for Halloween. At night they glow green, but it can be very faint if your eyes are not adjusted to the darkness.

Check out the glowing mushrooms in this news report:

Decomposers 

Jack-o’-lantern mushrooms are found on or near dead trees and stumps, especially oak trees. The wood from the dead trees is where the mushrooms get their nourishment. These mushrooms are beneficial to the ecosystem because they clean up the forest floor to make room for more plant growth and put nutrients back into the soil.

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Words to know

Bioluminescence: The ability of natural organisms to glow in the dark. 

Gill: The underside of the mushroom cap where the spores are produced and spread from.  

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The green glow of bioluminescent mushrooms is called fox fire, a term that is thought to come from the Finnish name for the northern lights. It refers to a Finnish myth about a magical Arctic fox that would run through the snow at night. The fox’s tail would sweep snow crystals into the sky that reflected the light from the moon and stars.  

Lookalikes 

There are other mushrooms that look like these glow-in-the-dark fungi. Jack-o’-lantern mushrooms grow in clusters, but many of their lookalikes grow as just a single mushroom or as two together. 

The gills are also a good way to tell them apart. Jack-o’-lantern mushrooms have true gills, which means the gills can be separated from the cap of the mushroom, like you are pulling apart pieces of paper. The lookalikes have false gills that can’t be separated.

The night life

One of the best ways to experience the forest preserves at night is to attend a night hike or to book a campsite at one of the Forest Preserve’s campgrounds. If you aren’t attending a night program or camping, you won’t have access to the preserves at night because they close at sunset.

If you get the chance to be out in the preserves at night, keep an eye out of the green glow of the jack-o’-lantern mushrooms. Just remember that you cannot remove anything from a forest preserve, so please do not pick the mushrooms.