If you’ve ever walked through the woods at night, you know how dark it can get. But imagine that you’re deep in the Pine Barrens of south Jersey one night, surrounded by pines and oaks, when you suddenly spot a faint green glow shining from a rotting log. Early travelers in New Jersey described these ghostly apparitions as the work of spirits, fairies, or even omens of the Jersey Devil. The truth is just as enchanting: the glow comes from mushrooms.

Glowing in New Jersey’s forests for centuries, these eerie organisms are known as foxfire fungi. Foxfire is a type of bioluminescence, which is a mechanism some living things have to produce light. In foxfire mushrooms, an enzyme called luciferase reacts with oxygen and emits a soft, greenish-blue glow.

In New Jersey, foxfire is most often spotted in damp, decaying wood in forests, especially in the Pine Barrens and oak-hickory woods of South Jersey.

Folklore

Before science could explain the foxfire phenomenon, people told stories about the mysterious glow. In Europe, glowing wood was linked to will-o’-the-wisps, ghostly lights that were said to lure travelers off their paths. Early settlers in New Jersey gave the glow nicknames like “fairy fire” and “spirit lights.”

Foxfire is also an important part of New Jersey’s ecosystems. These fungi break down dead wood and recycle nutrients back into the soil. Their glow has also inspired scientists to study bioluminescence more deeply. Researchers hope the same chemical reactions that make fungi glow could help in fields like medical imaging and biotechnology.