The future supply of traditional English mistletoe is under threat, conservationists have warned.
Mistletoe thrives in established apple orchards but such habitats have seen a big decline over the past 60 years.
The National Trust is urging people to buy home-grown mistletoe in the run-up to Christmas in a bid to ensure revellers can go on kissing under it.
Trust ecologist Peter Brash said it would be a "sad loss" if mistletoe disappeared from its traditional areas.
At least 60% of old orchards in the "cider country" of Somerset, Gloucestershire, Herefordshire and Worcestershire have disappeared since the 1950s.
The decline has been even more dramatic in Devon and Kent, where the figure is as much as 90%.
Mr Brash said: "Mistletoe is part of our Christmas heritage and has a special place in a wonderful winter landscape.
"It would be a sad loss if mistletoe disappeared altogether from its heartland. We could end up relying on imports of mistletoe from mainland Europe for those festive kisses."
The trust also wants people to ask where the mistletoe they are buying is sourced from.
Mistletoe is a parasitic plant that favours the domestic apple tree, but can also be found on lime, poplar and hawthorn trees across the UK.
The market town of Tenbury Wells in Worcestershire holds an annual mistletoe festival with a procession led by druids.
One of the druids, Suzanne Thomas, said of the plant: "It's magic. It's just amazing stuff. It's got this lovely energy about it."
Mistletoe expert Jonathan Briggs said the plant benefited from a managed environment.
"Unchecked, it will swamp its host tree and ultimately cause it to die," he said.
"Regular, managed cropping will ensure that the host tree remains productive while ensuring that a healthy population of mistletoe will persist."
Agriculture minister Jim Paice said there was more to mistletoe than its "traditional amorous role".
"Buying mistletoe helps traditional British cider apple orchards thrive by removing mistletoe from apple trees," he said.
"By buying mistletoe at Christmas, you're continuing a tradition that helps apple trees to flourish."