Here’s the odd, sad truth about mistletoe. Plus, is the kissing custom a mystery?

If you celebrate Christmas, it’s likely that at some point this season you’ll find yourself puckering up under a mistletoe branch. What is the tradition of kissing under a plant all about? And does the name have anything to do with human toes?

Mistletoe is a European plant that grows parasitically on trees. The etymology of the word is uncertain. Because mistletoe can be spread through birds’ feces, it is possible that it comes from the German mist, which means “dung,” and tang, which means “branch.” (Hence, there is no connection between the toes on your feet and the plant hanging above your head.)

The parasite is used to decorate homes during Christmas. When two people meet under a hanging of mistletoe, it is customary to smooch. The origin of this tradition is also shrouded in uncertainty, but one of the first descriptions comes from a book by Washington Irving published in 1820. And historically, mistletoe represents romance, fertility, and vitality.

Now, let’s move on to the darker side of mistletoe. In Norse mythology, the plant plays a key part in a story with a violent conclusion; the god Balder is killed by his blind brother Hoor with, of all things, a mistletoe projectile.

Also, in South Africa “bird lime,” or a juice made from mistletoe berries, is used as an adhesive to trap small birds. Coils of the sticky substance are placed on tree branches. When birds land on them, they get stuck. The birds can then be caught by hand.

Here’s one more redemptive aspect of the plant. According to the National Cancer Institute, mistletoe is one of the most widely used alternative medicine therapies for people with cancer.