Ghosts of the Southern Forests

Creamy coloured fungi on a tree

Venture out at night into the forests of Southern Australia and you might be lucky enough to witness the eerie glow of the ghost fungus Omphalotus nidiformis lighting up the understory.

For thousands of years people have been wondering about the glow sometimes seen on decaying wood. Aristotle called it foxfire, and for centuries legends abounded about the fairly lights in olive groves, forests and even deep in coal mines. It wasn’t until the early 19th century that scientists realised that the source of the luminescence was fungi.

In southern Australia, Traditional Owners have witnessed this phenomenon for millennia. It was first described to European science from specimens found on Noongar country by the colonial botanist James Drummond in 1841:

‘The first species in which I observed this property, was about two inches across, and was growing in clusters on the stump of a Banksia tree, near the jetty at Perth, Western Australia. The stump was at the time surrounded with water when I happened to be passing on a dark night, and was much surprised to see what appeared to be a light in such a spot.’

Drummond suspected that the glowing fungi was an undescribed species. He found another specimen, this time in Toodyay, and took it home to study:

‘The specimen in question was hung up inside the chimney of our sitting room to dry, and on passing through the apartment in the dark I observed the Fungus giving out a most remarkable light ….. No light is so white as this, at least none that I have ever seen. The luminous property continued, though gradually diminishing, for four or five nights, when it ceased on the plant becoming dry. We called some of the natives, and showed them this fungus when emitting light, the room was dark, for the fire was very low and the candles extinguished, and [they] cried out ‘Chinga!’ their name for a spirit, and seemed much afraid of it; and I certainly must own it as a very extraordinary Will-o’the-Wisp.’

Later that year, Drummond went on an expedition further south and had an even more uncanny experience:

‘During my late expedition to the south of the Vasse, my opportunities of discovering luminous phosphorescent Fungi were rather better then I could have wished. For several days and nights I was incessantly wet to the skin, my lucifer matches incapable of ignition from the damp, and my hands blistered with making fire after the native fashion; when, one night, after all my efforts to procure a fire had been unavailing, I descried afar off, in the forest, a tree which I imagined must have been set ablaze by lightning. On making my way to it, I found that the light was produced by a remarkable Agaric, which grew, tier above tier, up the trunk of a dead Eucalyptus occidentalis.’

Drummond sent his descriptions back to the UK, where the mycologist Rev MJ Berkeley used them to name two new species of Agaricus, and yet another species from Tasmania. It wasn’t until much later that scientists realised all three were in fact the same species, now named Omphalotus nidiformis.

Despite being described, named, and classified, aspects of the bioluminescent fungi remained mysterious, and it wasn’t until the 20th century that the mechanics of bioluminescence was identified.

The glow of the Omphalotus genus is produced by oxygenation from an enzyme called luciferin, or ‘light-bearer’ in Latin. The active elements are carbon, hydrogen, and oxygen, and the reaction produces water and a photon. 21st century scientists have isolated the DNA that produces this enzyme reaction and are attempting to bio-engineer plant-based lighting.

Why do fungi glow? Research done in Brazil found that some species have evolved bioluminescence to attract insect pollinators. But unlike the Brazilian fungus, Omphalotus nidiformis glows both day and night, and similar research failed to reproduce the same results. Perhaps there is a yet to be discovered evolutionary advantage for the fungus, or the glow may simply be a by-product of a chemical reaction.

The fruits of Omphalotus do often have their attendant insects however, and in one of the images beow you’ll see a Heleomyzidae (sun, or fungi fly) guarding it’s territory.

To read more of James Drummond’s account, see the article on the Australian National Herbarium website: Drummond’s luminous fungus.