I really can not explain the mystique that Mistletoe has upon me. Other than the plastic variety, I was not really exposed to it in my childhood and God knows that I did not spend a lot of time hanging out underneath it, hoping to benefit from its amorous historic tradition.
For me, I think that it is because I associate it with heading south in the colder months, on trips to recharge my soul and escape the winter chill. With the leaf fall of autumn, we can see it in the upper reaches of deciduous trees throughout the south, flaunting its persistent photosynthesis, and giving us hope of spring to come.
Our Mistletoe, Phorandendron serotinum, is one of 1,300 mistletoe species worldwide and 36 in North America. While its range extends up into the midwest and the plains, it is much more abundant and noticeable in the south. Though many species of Mistletoe are parasitic, Phorandendron serotinum is labeled hemiparasitic; getting water and some nutrients from its host tree, but also able to meet some of its nutritional needs through photosynthesis. The genus name “Phorandendron” literally translates into “tree thief”. The other species of Mistletoe that occur in North America do not appear to be as common as Phorandendron in the American south.
The life cycle is such that birds or other animals will ingest the pearly berry which contains a single sticky seed and may deposit it on a branch with its feces. Alternatively, the seed may get attached to a body part and be transferred without passing through the digestive tract. The seed germinates, sending a root like structure, the haustorium, into the vascular system of the branch. Then, over a period of 3 to 5 years, it grows slowly till it reaches the “witch’s broom” stage and can make fruit itself. Mistletoe flowers late in the season and the berries ripen just in time for fall bird migration and Christmas. Evolutionarily speaking, what better way to guarantee widespread seed dispersal than to offer it to a bird that is just passing through on its way further south.
Mistletoe is typically found in the upper branches of larger trees but that may be because its greenery is a preferred fodder for many animals including deer, elk, squirrels, chipmunks and porcupines, who may feast on specimens growing on lower branches.
The pearly white berries, as seen in the photo above, are eaten by many species of birds as well as some small mammals. In addition, there are 3 species of Hairstreak butterflies that depend on Mistletoe greenery for the survival of their larval stage. All parts of the plant are toxic to humans.
The clustered witch’s broom is a frequent nesting site for many birds including hawks and owls.
Minor infestations will not greatly affect a tree, but heavier colonization can lead to an early demise. Researchers report that forests with greater mistletoe growth have an increased number of dead tree snags and up to three times as many cavity nesting birds.
Over 100 species of trees have been identified hosting Mistletoe, but Oaks, Elms, Hackberries, and Walnuts seem most often involved.
There really are no good management options once a tree is affected by Mistletoe. You can prune the damaged branch out but that may leave a non-healing wound that leads to the tree’s demise itself. Not to mention, the location of the Mistletoe witch’s broom could make any pruning attempt perilous.
Harvesting live Mistletoe for holiday decorations presents the same challenges as pruning it out, and is generally done with a shotgun, a good eye, and steady hand.
So I think that we just need to embrace this neighbor and appreciate the role it plays in the ecosystem, providing nutrition and nesting sites, directly and indirectly, to many animals, and for the foreshadowing of spring it provides to a soul like mine.
Please check the links below for more thorough discussions on the folklore and natural history of Mistletoe. If you are an audio learner listen to The Nature Guys recent podcast on Mistletoe.
Photo credits to Peggy Juengling Burns
Photos taken at Bernheim Arboretum and Research Forest and Sally Brown and Crutcher Nature Preserves.