Nature’s Jack-o’-lanterns

With Halloween’s recent passing, pumpkins carved by humans to create glowing Jack-o’-lanterns dotted the region. Leading up to the festive holiday in the Town of Highland, NY, several brilliant orange clumps of Omphalotus olearius—Jack-o’-lantern mushrooms—lit the landscape on Clark Road, where they fruited at the base of a large rotting tree stump.

Depicted here in an early immature stage, the mushrooms are noted for an interesting quality. “The gills tend to glow in the dark, hence the name,” explained herbalist and local mushroom expert Nathaniel Whitmore. “If taken into a dark room at the right stage of growth they look just like glow-in-the-dark plastic. This bioluminescent quality is actually quite common to mushrooms and mycelium.”

The bioluminescence is not easily observed, requiring low-light conditions and time for the eye to adapt to darkness. Only the gills glow, due to the actions of the enzyme luciferase upon a compound called luciferin, which produces a bluish-green color. The glow is an indication that the mushroom is eliminating its waste products.

Jack-o’-lantern mushrooms are saprobes, which survive by decomposing dead or decaying organic material. Despite their appealing appearance and odor, the bright mushrooms are not edible. While not typically deadly, consuming them leads to severe cramps, vomiting and diarrhea.