Which plant, common around Christmas time, contains poisonous berries which can cause acute stomach irritation if eaten?

This festive but hazardous plant has a long and storied history as a symbol of love and vitality, yet it harbors a toxic secret. All parts of the plant, including its leaves and the familiar white berries, contain poisonous proteins called phoratoxin and viscotoxin. If ingested by humans or pets, these toxins can lead to a range of unpleasant symptoms, most notably acute gastrointestinal issues like stomach pain, vomiting, and diarrhea. While a single berry is unlikely to cause a severe reaction, it's the reason this decoration should be hung with care, well out of reach of curious children and animals.

Long before it became a prompt for a holiday smooch, this parasitic plant was revered by ancient cultures. Celtic druids, for instance, considered it a symbol of vitality for its ability to stay green through winter and believed it could ward off evil spirits. Its association with romance may stem from Norse mythology, where it was declared a symbol of love. The specific tradition of kissing beneath a sprig of it, however, appears to have gained popularity in 18th-century England.

The custom originally involved plucking one berry from the branch for every kiss given. Once all the berries were gone, the opportunity for kisses was over. This playful ritual, popularized during the Victorian era, helped solidify the plant's place as an enduring, if slightly risky, symbol of Christmas cheer and affection.