Luminous Life - Into the Woods

© Luxgene 2000

Softly glowing mushrooms rising from the forest floor - no wonder people in bygone times concluded that they had suddenly been transported to the realm of the faeries.

The strange bioluminescence of mushrooms and other fungi defies understanding. The usual reasons given for bioluminescence - mating, predation, defense, communication - don't seem to apply to luminous mushrooms, and no one seems to understand why they developed this ability.

© D. Hibbett

Mushrooms aren't the only light-generating organisms in the woods. Slime molds, which are no longer considered fungi but classified as protista, are capable of bioluminescence, but that's mostly the tropical varieties. It can get confusing. One of my favorite stories about a cold-light encounter comes from the magazine The Smithsonian, which ran a photo essay some years ago featuring slime molds (images similar to these). In the next issue, there was a letter from a couple who told a story about how they went to their local parks department to get free wood chip mulch, which they spread in their yard. One night not long after, they noticed that a region of the wood chips was glowing. Not sure what to do and apparently alarmed, they turned the hose on it.

They wondered whether they had sprayed away a slime mold. But those intrepid suburbanites were most likely dealing with foxfire, another type of fungi that emits light.

Bruce McAdam/Creative Commons License

Foxfire can be found on rotting wood in damp forests. The fungi will glow at temperatures as low as 34 degrees F, but the optimal temperature is 77. If you want to hunt foxfire, there are some great tips in this extension bulletin from the University of Georgia's School of Forest Resources. The tips include going out on overcast or moonless nights to spot the low-intensity green glow, and staying away from artificial lights to give your eyes time to adjust to the dark.

In the depths of the nighttime forest, mysterious lights beckon, inviting us to explore their domain. No need to grab the hose - just marvel at how the mundane by day becomes the wondrous by night.