BELOVED CHRISMAS PARASITE
Author, Ellen Holtman, active Master Gardener
Many species of mistletoe are native to the U.S., and about 1500 species worldwide, but only American Mistletoe (Phoradendron serotinum) is native to Virginia. It is unique among our flora as a woody shrub that grows on broadleaved trees. It is an obligate hemiparasitic flowering plant. It does take nutrients from its host tree through a root-like structure called the haustorium, but it also has chlorophyll and makes some of its own food.
Mistletoe species grow on a wide range of host trees, a few of which experience side effects including reduced growth, stunting, and loss of outer branches. A heavy infestation may also kill the host plant. However, mistletoe is important to a broad array of animals that eat its foliage and young shoots. Studies have shown that some other plants, notably juniper, flourish when mistletoe is present because it draws birds that eat and plant many kinds of seeds. Three species of butterfly and a few other insects in the U.S. depend entirely on mistletoe, and it is an important source of nectar and pollen for native bees and honeybees. Many of our birds including cedar waxwings and bluebirds, eat the berries.
Mistletoe serves as a nesting site for many birds around the world, including 43% of endangered spotted owls in the western U.S. (The mistletoe species in the west is dwarf mistletoe, species Arceuthobium.) Australia has 97 native species of mistletoe, and 78% of resident birds in Australia are known to nest in it.
Melbourne plants mistletoe in city trees for wildlife. Many mammals, including squirrels, chipmunks and porcupines, eat mistletoe, and it provides high-protein fodder for elk, deer, and cattle in winter. Cattle farmers in Texas even remove it from trees for winter food. (Don’t try it at home! Mistletoe is TOXIC to humans!)
Mistletoe is mostly spread by birds that eat its fruit. The sticky seed, containing at least four embryos, is regurgitated or excreted in droppings, or might be stuck to the bill and wiped off. It clings tightly to the stem, germinating there. The tiny bit of root tissue pushes into the bark, sometimes supporting itself by photosynthesis for a year until the roots reach the tree’s vascular system. As mistletoe plants mature, they grow into masses of branching stems which result in the common name witch’s broom.
Most of us recognize mistletoe because it is central to a cherished Christmas tradition. Pagan cultures including the Celts and the ancient Greeks regarded the white berries as symbols of male fertility. In Norse mythology poison arrows were made of mistletoe. The Romans associated mistletoe with peace, love and understanding and hung it over doorways to protect the household. They also met with their enemies under the mistletoe to work out peace agreements.
Mistletoe traditions came to Europe with the Vikings, and by the 18th century it had been incorporated into Christmas celebrations around the world as a decoration under which lovers are expected to kiss. The tradition dictated that a man was allowed to kiss any woman standing underneath mistletoe, and that bad luck would befall any woman who refused the kiss. A variation of the tradition said that with each kiss a berry was to be plucked from the mistletoe, and the kissing must stop after all the berries had been removed.
In colonial Virginia Christmas was celebrated with lots of food and drink and hunting parties spent a day shooting down mistletoe for the women. William Byrd, an early Virginian, left instructions for drying the berries in a warm kitchen, but nobody knows why! The first mention of mistletoe in the press in Virginia. was this poem in the Virginian-Pilot in 1933:
Tis done beneath the mistletoe,
Tis done beneath the rose,
But the proper place to kiss, you know,
Is just beneath the nose.
Mistletoes vary in toxicity to humans. The effects include blurred vision, diarrhea, nausea and vomiting, and less often cardiac problems, but rarely death. Toxins are more concentrated in leaves and berries, so teas made with the plant are very dangerous. Symptoms are more pronounced in children and in animals. Many sources recommend against having the plant in homes with children or pets.
According to local nurserymen, some years in Virginia produce bountiful harvests of mistletoe while other years are lean and most plants don’t have the berries that customers want. Some folks can drop a cluster from a tree with a rifle, but it’s important to catch it before it hits the ground and loses berries. Also, legend has it that the cluster loses its magic if it hits the ground. In our area, it grows on more than 100 different types of trees, but is most often found on pecan, hickory, oaks, red maple and black gum. and it’s up high because it needs sun.
If you haven’t found your sprig this year, you might want to kiss outdoors under the trees and take the opportunity to teach some natural history. Or you can buy the imitation online, or make your own with instructions found on Pinterest or eBay. The felt models are quite nice! And if you are lucky enough to find berries, rub them into the bark of a hardwood tree near you for future years, but always leave some for the birds!