Mistletoe is often found hanging in American homes as a traditional decoration during the holiday season. Once believed to have magical powers, as well as medicinal properties, the custom in which kissing under the mistletoe would inevitably lead to marriage developed in England. Thankfully, our modern American interpretation of this tradition between partners, families, and friends is much more innocent. Most mistletoes are evergreen, making them easy to locate and harvest after leaves of their deciduous hosts drop in late fall and winter. Their visibility during this time is likely why the plants often are used as festive decorations at Christmas time.
European mistletoe (Viscum album) is likely the mistletoe species of northern European literature and the origin of this unique Christmas tradition. European mistletoe’s North American counterpart, eastern or oak mistletoe (Phoradendron leucarpum), is the native plant found in the canopies of trees throughout South Carolina. As the name suggests, oak mistletoe parasitizes oak trees; however, it can grow on up to 105 tree species. A pest of many ornamental, timber, and crop trees, it forms a drooping yellowish-green, evergreen bush, 2 to 3-feet long, on the branches of a host tree. Mistletoe has crowded, forking branches with 2-inch long oval to lance-shaped, leathery leaves arranged in pairs opposite of each other on the branch. The inconspicuous flowers are yellower than the leaves, appear in late winter, and are arranged in compact spikes. The flowers give rise to one-seeded white berries that are toxic to humans and many animals. However, birds eat the berries and distribute the sticky seeds in their droppings or by wiping their seed-covered beaks against a tree’s bark.
As a hemiparasite, mistletoe contains chlorophyll to make their food, but rely on their hosts for water and nutrients. Once a mistletoe seed germinates, a modified root (haustorium) penetrates the bark of the host tree to form a connection through which water and nutrients pass from host to parasite. Mistletoes are slow-growing but persistent; their natural end is determined by the death of their host plant. The only effective control measure is the complete removal of the parasite from the host.