A forgotten fungus found in 1840 has been reclassified and its glowing properties studied to understand how and why it shines brightly enough to read a book by.
In 1840, renowned English botanist George Gardner discovered the fungus over 170 years ago when he saw children playing with the glowing object, which they called “flor-de-coco.” Gardner sent a sample to England’s Kew Herbarium and it was classified as Agaricus gardneri.
The mushroom is bioluminescent, ie it produces a glowing light, like fireflies and some jellyfish. This phenomenon is also known as “foxfire” and is seen in some other fungi like jack o’lantern mushrooms.
However, what makes these fungi glow, and why, are questions that present-day researchers want to answer.
To find new specimens of the fungus, Dennis Desjardin at San Francisco State University and Cassius Stevani at the University of Sao Paulo went hunting in Brazilian forests. They had to “go out on new moon nights and stumble around in the forest, running into trees,” said Desjardin in a press release.
Using digital cameras, the scientists took photos of potentially biolumiscent fungi to check the images for any glow invisible to the naked eye, and located new specimens of the forgotten mushroom.
After examining samples to determine the mushroom’s anatomy, physiology and genetics, they reclassified it as Neonothopanus gardneri.
“They glow 24 hours a day, as long as water and oxygen are available,” said Desjardin. “But animals only produce this light in spurts. This tells us that the chemical that is acted upon by the enzyme in mushrooms has to be readily available and abundant.”
Yet the reason why mushrooms glow has not come to light. One hypothesis is this attracts insects and aids spore dispersal. However, in jack o’lanterns, the foxfire comes from the mycelium or root-like network that gathers food for the fungus.
“We have no idea yet why this happens,” said Desjardin. “Maybe the mycelium is glowing to attract the enemy of these insects, and will eat them before they can eat the mycelium. But we don’t have any data to support this.”
Desjardin has studied bioluminescent fungi from all over the world to determine why and how this happens, and whether it is the same chemical phenomenon occurring in each species.
