American Mistletoe
‘Tis the season for native plants. American Mistletoe (Phoradendrum leucarpum) is a broadleaf everygreen widely known for its romantic ties during Christmastime. If you find yourself under a sprig during the holidays, you may seek out a special kiss. Even after the holidays, this plant continues to shine as a symbol of love and peace in the human world; however, mistletoe serves a much more complicated role in ecology.
American Mistletoe (Phoradendrum leucarpum) is a common species of mistletoe native to our Southern Appalachian region. The broadleaf evergreen is a small, shrubby plant relative to the size of basketball that reaches high into the canopy of mature trees. Although small and unobtrusive, all mistletoes share one defining characteristic: parasitism. This means the plant survives by deriving nutrients from another, often weakening the host. Specifically, American Mistletoe is an obligate hemiparasite, meaning the plant requires water and minerals from its host but can still produce sugars independently through photosynthesis. This plant can grow on a variety of tree species but has a strong preference for oaks and maples. Once a sticky seed finds itself in the crook of a branch, the little plant grows and attaches to its host with a specialized organ called a haustorium. This root-like structure reaches deep into the tree’s vascular tissue and tricks the tree into providing nutrients as if it were a branch itself.
Although American Mistletoe may have thieving livelihood, the plant gives to our local ecosystem in unique ways. The presence of mistletoes often indicate a healthy, balanced ecosystem. Pollinators of all kinds—bees, wasps, ants, and butterflies—visit the yellow flowers for sweet nectar. American Mistletoe is the sole host for the great purple hairstreak butterfly (Atildes halesus) in its caterpillar stage. During late fall and winter, fruit-loving birds like Cedar Waxwings and Eastern Bluebirds feed on mistletoe’s waxy white berries. White-tailed deer even feast on its branches when food is scarce. The shrubby foliage provides shelter for birds and arboreal mammals, and they make great nesting sites. The evergreen leaves also provide a constant stream of fertilizer to the surrounding trees when dying specimens fall to the forest floor. In this way, mistletoe is an important part of our local ecosystem.
Next time you spot American Mistletoe in the wild, you can appreciate those you love and the complexity of our natural world. Just avoid eating the plant—it’s toxic to humans!
