The mistletoe in Ireland has long been regarded as a pest and would probably be classified as a foreign invasive species were it to arrive today.
Paul Maher, curator of the National Botanic Gardens, said mistletoe is a real pest and “a disastrous presence” in the Botanic Gardens, and to date has killed two lime trees.
“The infestation is usually high in the crowns, so difficult to get at. When male and female plants are present and pollination is good, berries are produced and our birds distribute it successfully. We also have infestations on Poplar.”
It has taken root in the gardens and Mr Maher, who is a native of Tralee, says they advise people to take care when planting it.
“We now tell people to exercise great caution when trying to establish mistletoe.”
The environmentalist and broadcaster Eanna Ní Lamhna said kissing under the mistletoe was a common custom in Britain.
“If a girl was not kissed under the mistletoe she wouldn’t be married that year, it was believed.”
In other places not being kissed under the plant meant she would be barren.
Only in Co Armagh was there such a custom, where the sprig would be hung over the door.
“In other parts of Ireland, holly was the magic tree, but nobody kissed under it.
“Young women would put holly leaves or indeed ivy leaves in some places under their pillows on New Year’s eve and then they would dream of their future husbands. But no kissing traditions,” Ms Ní Lamhna said.
The explanation may lie in the fact that most romance in Ireland came here as recently as the 12th and 13th centuries.
The late Professor Seán O’Tuama, in his book An Grá in Amhráin na nDaoine, explained how dancing, carolling, and love songs all came in with the Normans.