This week thousands of Americans will scoop out the flesh of a gourd, crudely carve a haunting face into its rind, and stick a candle inside. Then the jack-o’-lanterns will proudly be displayed on porches and stoops. Who or what is this wacky tradition named after? The British can claim ownership of the original use of the phrase “jack-o’-lantern.” In the 17th century, it referred to a night watchman, a man who literally carried a lantern. (Jack has been a general term for a boy since the 16th century.) But it was also a nickname for strange, flickering lights seen at night over wetlands or peat bogs and mistaken to be fairies or ghosts. This natural phenomenon is also called ignis fatuus, which means “foolish fire,” and will-o’-the-wisp. By the mid-1800s what was called a “turnip lantern” became known as a jack-o’-lantern. Young boys used these hollowed-out and lit-up gourds to spook people. Irish legend has it that this use of jack-o’-lantern was named after a fellow named Stingy Jack, who thought he had tricked the devil, but the devil had the last laugh, condemning Jack to an eternity of wandering the planet with only an ember of hellfire for light. Immigrants brought the jack-o’-lantern custom to North America, which is where pumpkins were first used to make the Halloween decorations. Impress fellow partiers this weekend with this fact: a jack-o’-lantern is also the name for an orange fungus. The mushroom Omphalotus olearius is found at the base of hardwood tree stumps, and it is extremely poisonous.