Jack o’lantern mushrooms are named partly for their round, orange caps and partly for their ability to glow in the dark. But what gives this mushroom such a unique ability? Why does the jack o’lantern mushroom glow? Are there any other bioluminescent mushrooms out there? Keep reading to find out more!
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What Causes Jack O’Lantern Mushrooms to Glow in the Dark?
The idea of glowing mushrooms may sound bizarre, but if you think about it, there are a number of things in nature that glow–fireflies, for example, and many deep sea-dwelling creatures.
All of these, including jack o’lanterns, have one thing in common: a luminescent enzyme known as luciferase or luciferin.
This enzyme is abundant in fireflies and glow worms, giving them the ability to blink brightly and be seen from a great distance. It is not usually as abundant in jack o’lantern mushrooms, so their glow is typically more muted and less noticeable.
Of course, fireflies light up for the purpose of attracting mates; but mushrooms don’t need to attract mates. What, then, is the reason behind their nocturnal glowing?
Believe it or not, the answer is also related to reproduction.
Mushrooms reproduce by releasing spores, which blow on the wind and start new mushroom colonies in different locations. But mushrooms that grow from dead wood, such as the jack o’lantern, are often so close to the ground that the breeze may not reach them.
So, at night, the mushrooms glow to attract insects, which in turn act as “pollinators” to help spread the mushroom spores. This phenomenon is known as foxfire.
The jack o’lantern’s glow can is sometimes strong enough to be seen by humans, especially on a dark night. The glow is most prominent when the mushrooms are young and fresh. The glow fades as the mushrooms age and stop producing spores.
What Does a Jack O’Lantern’s Glow Look Like?
A jack o’lantern’s glow begins in the mycelium, the mushroom’s “root system” which typically can’t be seen. Most of the luciferase enzyme exists in the mushroom’s gills on the underside of the caps; this is the part of the jack o’lantern that you are most likely to find glowing.
Jack o’lanterns typically grow in tightly packed clusters, so a patch of young mushrooms on a particularly dark night may look a bit like a clump of green landscape lights.
The light produced is a pale greenish yellow, similar to a firefly’s glow, but the glow is easy to miss except on a very dark night with little other light interference. Even then, they only glow from the undersides of their caps, and the glow is usually very dim, so it takes a keen eye to be able to spot glowing jack o’lanterns.
Check out this brief video to see what glowing jack o’lanterns look like.
Do Other Mushrooms Glow in the Dark?
The glow of the jack o’lanterns is intriguing, but it’s hardly an isolated occurrence in the mushroom world. According to research found in the journal Current Biology, as many as 70 mushroom species are bioluminescent, or glow in the dark.
Some of these mushrooms only glow from the mycelium, while others are so rare or produce such a faint glow that humans rarely see them. But a few are more widespread and produce a slightly more noticeable glow.
Some of these more noteworthy glowing mushrooms include:
- Bitter oyster: This mushroom is found throughout the world. Only certain subspecies found in North America produce a glow, but those that do are some of the most brightly glowing mushrooms on earth.
- Little ping-pong bats: These tiny ping-pong-paddle-shaped mushrooms grow in clusters up tree trunks and branches. When they glow at night, they look a bit like strings of Christmas lights wound through the trees.
- Green pepe: This mushroom, found scattered throughout the southern hemisphere, glows brightly on its first day and fades dramatically as it matures. Its pale green glow lights up the entire stem and cap of the mushroom.
- Eternal light: Eternal light mushrooms have long, worm-like stems that glow constantly, but the glow is easiest to spot at night. Only the stems glow, making these mushrooms look like neon spaghetti in the dark.
- Bleeding fairy helmet: These mushrooms produce an extremely weak glow that is difficult to spot even in the dark. However, they produce this glow steadily throughout their lifetime, and it doesn’t weaken with age.
Jack o’lantern mushrooms contain a bioluminescent enzyme known as luciferase. This enzyme gives them the ability to glow in the dark, which helps them to attract insects that spread and disperse their spores.