Strip Christmas of its baubles, batteries and Amazon deliveries, and what you’re left with is, at heart, a festival of plants. Trees dragged indoors. Mistletoe hung from the ceiling. Berries admired but (wisely) not eaten.

Researchers from the University of Essex have grown the festive plant in controlled laboratory conditions and are studying its genetic make-up

Servant classes in Victorian Britain are said to have popularised the link with kissing. A man was allowed to kiss any woman who stood under the mistletoe, and if she refused, this would bring her bad luck.

Mistletoe – the plant that encourages kissing at Christmas – is actually a parasite and has an unusual feeding strategy, new research suggests. Like other plants, mistletoe can use sunlight to create its own food, a process called photosynthesis.