In his short story “Christmas Eve,” Washington Irving wrote, “The mistletoe is still hung up in farmhouses and kitchens at Christmas, and the young men have the privilege of kissing the girls under it, plucking each time a berry from the bush.”
While the custom of removing the berries may be forgotten, the tradition of stealing a kiss remains widely accepted. But what are mistletoes?
Mistletoes are flowering plants that grow on the branches of host trees and shrubs, sending out roots that tap into their hosts’ vascular systems, which they then rely on for water, minerals and carbohydrates. The word mistletoe translates from its Anglo-Saxon origin as dung on a twig, derived from the ancient belief that the plants grew from bird droppings. Actually, they grow from seeds found in bird droppings.
In the wild, the two varieties most often hung at Christmas both parasitize deciduous trees. The plant originally named mistletoe, Viscum album, is a green shrub native to much of Europe and parts of Asia that produces small, yellow flowers and white, sticky berries, considered poisonous.
Phoradendron flavescens, or P. leucarpum, referred to as leafy mistletoe, is a North American native, very similar in appearance to its European cousin. It ranges across much of the Eastern U.S. but can be found in some midwestern and southwestern states. It does not grow as far north as New York.
There is a mistletoe that does grow in our region, however, Arceuthobium pusillum. Known as eastern dwarf mistletoe because of its lack of leaves and reduced visible growth habit, it is a parasite of spruce and larch trees.
Considered a potentially serious pest, especially in stands of black spruce, dwarf mistletoe is capable of forcibly ejecting seeds coated with an extremely sticky substance called viscin, which acts like glue, allowing seeds projected onto nearby trees to stick to the limbs where they germinate, producing rootlets that easily penetrate the bark and wood tissue of younger branches.