Mistletoe, a parasitic plant that grows on a wide range of host trees, shows up on every continent but Antarctica - and on each continent, it's been used in folk medicine. From ancient Greece into twentieth-century America, it was prescribed for epilepsy. Over the centuries, healers have used mistletoe to treat arthritis, menstrual problems, miscarriage (through controlling bleeding), hypertension, and pain - and that's just the short list. It's prescribed frequently in Europe. But don't try any of these uses without a trained health practitioner, because mistletoe can be toxic.