As per tradition, lovers who stand beneath the mistletoe are expected to kiss. It's a Christmas custom: the mistletoe is an icon of the season, often used as decoration, whether in the home or on wrapping paper, Christmas cards, and other Yuletide paraphernalia.
The mistletoe is a parasitic plant. It grows on the branches of a tree or a large shrub. Its roots penetrate the boughs, from which it draws water and nutrients. In ancient Celtic culture, druids made use of the mistletoe, believing it had medicinal and mystical properties that brought luck, protection, and fertility, due to its evergreen nature. It was during this period that the mistletoe was first hung within the home.
But as to why we kiss under the mistletoe, no one is quite sure of the reason, nor its historical accuracy. One variation of the its origin leads us back to a tale by the Vikings.
In Norse mythology, the mistletoe is famously the downfall of the god of goodness and purity, Baldur. Baldur woke up one day having dreamt of a prophesy of his own death. To protect him, Baldur’s mother, Frigga, asked all things in the world -- animals, plants, inanimate objects -- to make an oath not to harm her son.
But Frigga overlooked the tiny, innocuous mistletoe, and the Norse god of deceit, Loki, shot Baldur through the heart with an arrow made of this plant. Devastated, Frigga cried tears that turned into the mistletoe’s berries, and ever since, the gods proclaimed that mistletoe can no longer be used to harm. It was said that Frigga herself would place a kiss upon any who passed beneath it.
By the 18th century, mistletoe had become a fixture in Christmas celebrations, especially in the Western world. Washington Irving, American author, wrote of the custom of kissing under the mistletoe in one short story, called “Christmas Eve.” As Irving’s footnote explains: "The mistletoe is still hung up in farm-houses and kitchens at Christmas, and the young men have the privilege of kissing the girls under it, plucking each time a berry from the bush. When the berries are all plucked the privilege ceases."