Mistletoe, a small, parasitic shrub that grows on trees. The plant is widely known through its use for Christmas decorations. There are more than 1,000 species of mistletoe. Most of the 200 American species are tropical.

MistletoeMistletoe is a plant parasite with thick leaves, small flowers, and waxy, glutinous berries.

The common European mistletoe is a yellowish-green shrub one to four feet (30 to 120 cm) high. It has branching stems; thick, leathery leaves; and small, yellowish flowers. The waxy white berries, about one-fourth inch (6 mm) in diameter, grow in clusters. Birds eat the berries and leave the seeds on the limbs of trees. Each seed grows haustoria (long, rootlike projections), which extract fluids from the tree limb, often killing the host. European mistletoe is parasitic on apple trees and oak trees. It was considered sacred by the Druids. The custom of kissing under the mistletoe owes its origin to an old Norse legend telling of the dedication of the shrub to the goddess of love.

American mistletoe, the state flower of Oklahoma, resembles European mistletoe. It is parasitic on such deciduous trees as oak, red maple, and black gum. It grows wild from New Jersey west to Illinois and Texas. American mistletoe cannot be cultivated and is gathered in the wild and stored in cool warehouses until the Christmas season.

Dwarf mistletoe has tiny needlelike leaves and clusters of brown berries. It is found in the western United States on such conifers as Douglas fir, white pine, and spruce. The seeds are dispersed by the wind.

European mistletoe is Viscum album; American, Phoradendron serotinum; dwarf, Arceuthobium pusillum. All belong to the mistletoe family, Loranthaceae.