Species Profile: Phoradandram leucarpum; Mistletoe
Scientific Name: Phoradandram leucarpum
Common Name(s): Oak mistletoe, American mistletoe, Eastern mistletoe, and hairy mistletoe
By: Karla Sayre
Oak mistletoe is a common parasite that prefers the high branches of hardwood trees where it forms into a shrub-like clumping ball of vegetation that can grow up to 3.5 feet in length. It lives on the branches of living trees and is an evergreen, which makes it most visible in the winter when trees are bare of leaves. They form smooth, green, jointed stems with thick leathery leaves which are oriented opposite from one another. Oak mistletoe is a vascular plant which produces flowers and berries. The flowers bloom between September and October and are small and yellow. Their berries form in November and can remain until late winter. The berries are white and around 3 to 6 mm in diameter with a thick wax coating and sticky pulp. The pulp is toxic to humans, but the berries are enjoyed by birds such as waxwings, grouse, mourning doves, evening grosbeaks, robins, and bluebirds.
Oak mistletoe is found in the southern, southeastern, and east coasts of the United States as well as Mexico.
Oak mistletoe is a type of obligate hemiparasitic plant. Obligate means it needs its host to complete its life cycle. Hemiparasitic, meaning it is a parasite but produces its own chlorophyll. It does rely on the host plant for water, carbon, and some minerals, which means it remains photosynthetic but also relies on its host plant for water and some carbon or minerals. Mistletoe berries are eaten by birds. Some seeds survive digestion and can form new plants when they are excreted onto living branches. Similarly, birds can wipe seeds on branches when they are cleaning their beaks. Mistletoe can live on up to 60 species of tree but prefer high branches of hardwood trees such as oaks, maples, willows, poplars, elms, walnut, and plane trees. Oak mistletoe can form thick clumps sometimes referred to as “witches’ brooms.” These are used as nesting spaces for many types of owls (spotted, great gray, large-eared) and hawks (goshawk and sharp-shinned). They are also used as homes for many common migratory birds, including gray jays, house wrens, mourning dove, chickadee, cassin’s finch, and pine siskin.
In Bella Vista, mistletoe is visible on tall oaks and other common hardwood trees. Being an evergreen shrub, it is especially noticeable during the winter months when trees are bare of leaves. Our local species is a surrogate for the European species and the tradition of “kissing under the mistletoe” around the winter holidays. Mistletoe is still harvested and sold for that purpose.