Mistletoe
The name mistletoe was originally applied to Viscum album (European mistletoe, Santalaceae), the only species native in Great Britain and much of Europe. It is rarely found on oaks in Britain and northern France because it prefers trees with tender bark such as apple trees. Mistletoe was introduced in Ireland in the 18th century. Later the name was extended to other related species, including Phoradendron serotinum (the mistletoe of North America, also Santalaceae).
Mistletoe is commonly used as a medicinal herb in Europe and has been approved for use in tumor therapy. Another name for mistletoe in Europe is “All-Heal”. The American variety has not been studied as much as the European variety and should not be ingested. When the stomach contents of Lindow Man were examined, it was determined that he had been given a concoction of mistletoe before death. Probably not as a poison, but as a ritual antidote to poison, as the Druids believed it was. Seventeenth century French herbalists prescribed mistletoe for nervous disorders, epilepsy, and the spasms known as the St. Vitus dance (Huntington’s Disease).
The word "mistletoe" is derived from the Anglo-Saxon words, "mistel" (dung) and "tan" (twig) -- misteltan is the Old English version of mistletoe. It's thought that the plant is named after bird droppings on a branch. Besides droppings, mistletoe seeds are left on branches by birds, who after eating the fruits, leave the seeds stuck to tree branches when they rub their beaks on them.
Mistletoe figures prominently in Druidic lore and of course Norse myth, in the story of Balder. Pliny the Elder (77 AD) wrote the following about the Mistletoe cult among the Gauls:
‘The Druids – that is what they call their magicians – hold nothing more sacred than mistletoe and a tree on which it is growing, provided it is a Valonia Oak. Groves of Valonias are chosen even for their own sake, and the magicians perform no rites without using foliage of those trees, so that it may be supposed that it is from this custom that they get their name Druids, from the Greek word meaning ‘oak’; but, further, anything growing on oak trees they think to have been sent down from heaven, and to be a sign that the particular tree has been chosen by God himself. Mistletoe is, however, rather seldom found on Valonia Oak, and when it is discovered it is gathered with great ceremony, and particularly on the sixth day of the moon (which for these tribes constitutes the beginning of the months and the years).”
Pliny doesn’t note any particular time of year that this happened, or if the mistletoe had berries, which would indicate that the ritual was in winter.
Other folklore of the mistletoe includes:
The custom of kissing beneath hanging Mistletoe is said to have originated in Britain, but in France wishes are exchanged under a bunch of Mistletoe at midnight.
In Italy women carried a twig of Mistletoe to induce conception.
German farmers hung Oak-mistletoe from the ceilings of their rooms to prevent disaster and especially fire.
In Switzerland there was the belief that trees on which mistletoe grew were not struck by lightning. Since the plant itself was seen as the product of lightning (the consequence of arguments between witches or evil spirits), it were also able to keep lightning away.
In England the Mistletoe with its white berries was allowed to hang in the house until it was replaced by a similar sprig the following Christmas. This was still done until 1968 at the brewery of W.H. Brakspear and Sons Ltd. in Henley-on-Thames.
Sources:
http://www.howstuffworks.com/mistletoe.htm
http://en.wikipedia.org/wiki/Mistletoe
http://www.botanical.com/botanical/mgmh/m/mistle40.html
http://www.answers.com/topic/mistletoe