There are more than 1,300 species of mistletoe, including the two varieties popularly hung as a lure to sweethearts. All species can grow as parasites on trees and shrubs, stealing their food and water.
Well, who knew? That's from When Mistletoe Attacks: Investigating a Forest Parasite. The article includes the usual sort of stuff about mistletoe traditions :
Posted on December 24, 2002 10:32 AM. Filed under: Christmas.The exchange of a kiss under the mistletoe is linked back to the ancient times of the Druids. When enemies met under mistletoe in the forest, they had to lay down their arms and observe a truce until the next day.
From this tradition, Christmas historians believe, comes the custom of hanging mistletoe from the doorway or ceiling and sharing a kiss under it as a sign of friendship or goodwill.