Everybody is familiar with mistletoe and the Christmas tradition of kissing under it. What many people don't know is that mistletoe is actually a parasite. They have no roots of their own in order to survive the mistletoe has to attach itself to a host tree.
Mistletoe is spread from tree to tree by birds that eat the berries, there is a pulp in the berries that drips out of the birds beak and allows the mistletoe to attach itself to a new tree. Most people who have trees in their yards think of mistletoe as a nuisance that can damage the trees. It often causes the branches to become deformed and it steals water away from the tree. The damage can be limited by cutting off the mistletoe but it will grow back, if the infestation is serious the tree will likely have to be cut down. Mistletoe is also poisonous and can cause a rash if you come into contact with it.
However mistletoe isn't all bad it has been used as a herbal remedy in Asia for centuries, according to the flowers guide. Although it's berries are poisonous there does seem to be some medicinal value to an extract made from the leaves. Herbalists claim it can treat everything from circulation problems to epilepsy to cancer. Whether this is true or not is open to debate but there is some research that seems to indicate that mistletoe can help to improve the immune system. At least it has in animal studies, there haven't been any studies on humans as of yet.