Mistletoe – An Old Tradition and a Fascinating Plant

By Jim White, Associate Director, Land and Biodiversity
The Christmas season is upon us and colored lights, inflatable Santas, and other traditional and not so traditional holiday decorations are popping up everywhere. There is one very old traditional decoration that, much to my dismay, has lost favor in recent years. Not only do I miss the activity that is associated with hanging this decoration, I miss the plant itself. Of course the decoration is mistletoe – one of the most unusual and interesting of our native plants.

American Mistletoe on a Red Maple branch.  Photo by Jim White.
American Mistletoe on a Red Maple branch. Photo by Jim White.

There are approximately 365 species of Mistletoe worldwide with approximately 10 species or subspecies found in the US. There is only one species found in Delaware, the American Mistletoe, Phoradendron serotinum serotinum. Here it typically is found along the edges of wet woodlands or freshwater swamps. In Delaware it seems to be most common along the Delaware Bay coast but can also be found inland along freshwater streams and swamps as far north in the state as the town of Smyrna.
Mistletoe species are in the unusual plant family Viscaceae. Plants in this family are hemi-parasitic on other plants obtaining their all of their water and essential elements such as nitrogen from the host plant. However mistletoe, like other typical plants, manufactures its food in its leaves by photosynthesis. In our area the American Mistletoe’s favorite host appears to be the Red Maple but it can also be found growing on other species of maples and several other tree species.

American Mistletoe berries at Bombay Hook National Wildlife Refuge, Smyrna, Delaware.  Photo by Jim White.
American Mistletoe berries at Bombay Hook National Wildlife Refuge, Smyrna, Delaware. Photo by Jim White.

The life cycle of the American Mistletoe starts when the white berries are eaten by Cedar Waxwings, American Robins, and other berry-eating birds. The berry then passes through the bird’s digestive tract, removing the outer fruit covering, leaving a very sticky seed. If the bird defecates while perched in a tree, the seed will stick fast to the branch. In fact the name “mistletoe” roughly is an Anglo Saxon word meaning a twig with bird droppings. The seed then sends out embryonic roots that spread laterally, and down into the branch, anchoring the seed. If the branch belongs to an appropriate host tree the seed sends down a root-like structure called the haustorium into the branch. The haustorium is used to extract all the water and minerals from the tree that the mistletoe needs to survive. Soon the seed sends up a stem that sprouts the green, fleshy leaves. The shrubby plant can grow as large as three feet in diameter. The number of mistletoe plants growing in an individual tree varies greatly from a single plant to so many plants that a majority of the branches are infected.

American Mistletoe at Finis Pool, Bombay Hook National Wildlife Refuge, Smyrna, Delaware.  Photo by Jim White.
American Mistletoe at Finis Pool, Bombay Hook National Wildlife Refuge, Smyrna, Delaware. Photo by Jim White.

Mistletoe apparently has played a part in the folklore of many cultures over the years. The Christmas tradition of hanging mistletoe overhead may have its roots in the pre-Christian druid culture in Eastern Europe. The evergreen plant was collected and used in rituals associated with the winter solstice. The origin of the more recent tradition of kissing under the mistletoe is difficult to pinpoint but may be connected to folklore that suggests that the plant has power over love. Whatever its origin, it always seemed like a great Christmas tradition to me. So the next time you are along the Delaware coast look for green patches in otherwise leafless trees. And if you happen to be with your favorite guy or gal in the wilds of Delaware this winter you might want to take advantage of this yule-time tradition.

3 thoughts on “Mistletoe – An Old Tradition and a Fascinating Plant”

  1. Thank you for the article – It brings back some holiday memories! Back in the earlier part of the 20th century, and really through much of the 1970s, collecting and selling mistletoe was quite an industry here in Delaware. I remember you could buy a sprig at the local grocery stores and it was quite popular. Now you rarely find it in the stores, except I noted it recently at Trader Joe’s, and it is imported from the Pacific Northwest. I wonder if it was overharvesting that caused this, or perhaps just changes in Christmas traditions?

  2. Doesn’t mistletoe seriously harm the host tree. It is much more common than people think if you know what you are looking for. I have watched it spread throughout Caroline County, Maryland and into Kent and Sussex County. I have watched it kill trees after a certain point granted it takes years-but. No it isn’t over-harvested, I believe it loss in popularity is concern over toxicity.

  3. Gerry…
    You make some very good points. Mistletoe can kill branches of the trees it grows on and sometimes can contribute to the death of a tree. This seems to occur more often on trees that are otherwise stressed by flooding, soil compaction or disease. It is my opinion that in most cases the loss of a host tree is a natural part of the cycle of life in a woodlands. However, if a specimen tree is being harmed by an unusually large infestation I see nothing wrong with controlling the mistletoe. I agree with you that mistletoe is not overharvested today probably because of the lack of demand for the plant. In addition to the fact that the berries of mistletoe are poisonous to ingest the lack of demand for the plant at Christmas may also be a result of our society’s changing attitude towards the appropriateness of certain casual behaviors between men and women.
    Thanks you for your comments – Jim

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