A Light In The Dark

Cheshire Wildlife Trust’s latest newsletter shares some fascinating facts about fungi.

Imagine taking an evening autumn stroll through your local woodland, crunching over the crispy fallen leaves and watching the light slowly fade. Something catches your eye in the now dark surroundings, a dim light, almost like a comforting bedside night light. The closer you get the more obvious it becomes that the small glowing hummocks are in fact fungi.

Bioluminescent fungi are fungi that, incredibly, glow in the dark. There are around 80 species worldwide that produce the fairy-like luminosity which has caught many a dreamer’s imagination. Mark Twain even noted the phenomenon in his book,The Adventures of Huckleberry Finn, writing, "Rotten chunks that’s called ‘Foxfire’ that just makes a soft kind of glow when you lay them in a dark place."

Foxfire, is just one of the many words through the ages that has been used to describe the glowing fungi. The bioluminescence emitted has also been mistaken for strange fixations such as a ghostly presence or fairy light.

So what is it about certain species of fungi that makes them glow? Well, it’s caused by a chemical reaction between oxygen and the compound luciferin in the presence of an enzyme. This results in the formation of oxidized luciferin (oxyluciferin), which when it decomposes, gives off light. The bioluminescence of fungi is produced without heat and still glows in the daylight - it’s just not easy to see. The luciferin found in fungi of this kind is actually the same compound that is found within glow worms and those deep sea curiosities we watch on David Attenborough’s Blue Planet.

Why would fungi glow?

There have been many debates as to the reason. Some argue it is to attract more insects to carry off their spores; some say it’s just an unusual by-product of fungal metabolism. Whatever the reason it’s been supplying us with endless entertainment for years and even sometimes been put to use. It’s been said that the soldiers in the WWI trenches fixed bits of rotten wood to their helmets to guide their way in the dark.

The luminescent species we have in the UK include the likes of Sulphur tuft (above) and Mycena chlorophus (top). They don’t however give off as much light as some species overseas. In the United states, Omphalotus illudens' ability to glow in the dark has given it its common name of Jack O’Lantern.

So, you now know it’s not all doom and gloom in the decaying world of fungi - there is always a light in the dark to be found.

Be a fungi detective

Autumn is the perfect time of year to get out there and look for fungi. Use our above guide to help you ID some of the most common species.

Don't know where to begin? Our nature reserves are a great place to start the search:

Cleaver Heath Nature Reserve, Heswall

Eastwood Nature Reserve, Stalybridge
Black Lake Nature Reserve, Delamere

Let us know what you find and where by sharing your pictures with us on Facebook, Twitter or Instagram.