It’s the time of year when we hang mistletoe in doorways, but did you know that there is more to this unique plant than just its legend of beckoning a kiss from your beau beneath its perch? Here are four fascinating facts about mistletoe.
Mistletoe is a parasitic plant, meaning that it needs a host tree or shrub in order to thrive. The plant is actually considerer hemi-parasitic because it uses photosynthesis for a short period of time while young. As it grows, it sends roots through the bark of the host plant and into that plant’s circulatory system. Once established this way, mistletoe stops using photosynthesis and collects water and nutrients directly from its host plant.
This practice sounds harmful to the trees and shrubs mistletoe parasitizes, but it rarely causes enough cumulative damage to kill a tree unless there are multiple plants in every branch. Mistletoe does, however, weaken the tree’s immune system, making it more susceptible to disease and insect attack.
So it sounds like this harmful plant should be weeded from the forest canopy, right?
Not so fast. Mistletoe is ecologically important because it is a keystone species.
Studies have found that forests with a moderate amount of mistletoe are much more biodiverse and ecologically healthily. For some species of birds, mistletoe berries are their main food source, while for others the plants are their nests. Mistletoe doesn’t just impact the canopy, it also provides nutrient dense leaf litter, which increases the numbers of spiders and insects found on the forest floor. These arthropods then provide a secondary food source for insectivores like swallows, geckos, and bats.
These parasitic plants might take a small amount of nutrients away from their host, but they greatly enrich the ecosystems in which they grow.
Because mistletoe thrives higher up in the canopy, the seeds found inside the berries are covered with a sticky material called viscin. This material is so indestructible that it remains incredibly sticky even after passing through the digestive tracts of birds.
Mistletoe produces white berries that are irresistible to birds; the birds consume them and deposit the seeds where they roost. The seeds effortlessly stick to bark and branches, and the life cycle of mistletoe starts all over again.
Caution: Birds find mistletoe berries to be delectable, but they are VERY POISINOUS to humans and pets, so keep mistletoe out of reach if you make your holiday “kissing ball” out of real plants.
Mistletoe as Medicine
While the berries are poisonous to ingest in large doses, mistletoe has been used homeopathically for years to treat a number of ailments including headaches, seizures, and arthritis. According the National Cancer Institute, mistletoe is even being used in clinical trials in Europe as a complementary therapy alongside chemotherapy and radiation. Research is limited, but studies show promising results including improved quality of life and improved tumor response. In Europe, doctors have started using mistletoe extract to treat colon cancer. However, in the United States, the FDA does not approve the use of mistletoe for cancer treatment.
Now that you know more a little more about mistletoe, see if you can find it when you are walking through the woods. The rounded masses are easier to see in winter or early spring before the leaves come back.
If you find a place where mistletoe grows in abundance, see if you can spot more birds and insects nearby. Or just acknowledge the important role that this fascinating plant plays in our ecosystem.