They're called 'ghost mushrooms' and look like something from a mythic forest - elegant caps attached to trees or scattered about the forest floor with softly glowing gills in the dark.
Photographer Colin Douglas captured these photos of the mysterious fungus on the Central Coast recently. The wet and cooler temperatures have led to a bloom.
Mushrooms create their own light through a chemical reaction similar to fireflies. A compound called luciferin inside the plant interacts with an enzyme to produce a glowing bioluminescence.
"If you give it a bit of energy and oxygen, there's a chemical process that then emits light. The luciferin gets 'excited' and emits light to get less excited," Professor Celeste Linde from ANU Research School of Biology said in an article for the institution in 2023.
"You just don't see it in the day because there is too much other light drowning it out."
Mr Douglas, a hobby photographer for the past six or seven years, said he knew the area around the Central Coast had glowing mushrooms, but he was waiting for the perfect time to capture them. He said he used a long-exposure and "focus stacking" technique to capture a series of photos of the mushrooms recently before combining them to produce the colourful final product.
A 2015 research project that looked at similar mushroom species in the US and Brazil set out to discover why the fungi glowed and found that rather than glowing constantly, they instead circulated through light and dark in a kind of circadian rhythm. Filming the mushrooms at night showed that they were swarmed by rove beetles, leading researchers to believe that the glow attracted insects, which could, in turn, spread the plant's spores.
However, Professor Linde, in the later ANU report, wasn't convinced by that reasoning, as a similar experiment in Australia didn't show any insect attraction to bioluminescent fungi.
"We still really don't know what this does," she told the Univeristy's College of Science website. "It is a function or a characteristic that seems to have been present in old evolutionary times and has been retained in some lineages but lost in most."
"The amazing thing about bioluminescence in fungi is that it keeps glowing even after it is picked. One we picked kept on glowing for a day or two until it dried up," she added.
NSW South Coast photographer David Finlay told the ABC in 2021, after coming across a considerable patch of the mushrooms in a nature reserve, that the prevailing La Nina weather conditions could have played a part in the sudden abundance.
The broadcaster noted that the fungus called Omphalotus nidiformis emerges in late autumn following good rain and continues into winter.
The mushies appear pale white during the day but take on an eerie green glow at night. However, experts warn that they are poisonous and shouldn't be eaten.
The state's health department warns that we should avoid eating any wild mushrooms, just to be on the safe side, and stick to the grocery store varieties.
"Many types of fungi grow wild in Australia and produce a variety of mushrooms, some of which look very similar even though they come from different fungi," the state says. While some mushrooms that grow in the wild can be eaten, some are poisonous and can make you very sick, and some are even deadly."
They do look pretty cool, though
