Students of Ethnobotany: Underneath the mistletoe

Edit: This post won Best post by a high school or undergraduate blogger from the Science Seeker blog awards. Well done, Joycelyn!

This holiday themed edition of Students of Ethnobotany comes from the festive Joycelyn Cheung.

I saw mommy kissing Santa Claus, underneath the mistletoe last night.

It’s that time of year again, when Christmas trees are being put up and decorated, chocolate advent calendars are ready to be opened (mmm!), and mistletoe is used as an excuse to kiss your boyfriend, girlfriend, secret crush, or stranger. Mistletoe hanging from the ceiling at a Christmas party is quite powerful, so pucker up!

But did you know mistletoe was first observed to appear where birds had left their feces? The name mistletoe comes from Anglo-Saxon; “mistel” means “dung” and “tan” means “twig”, in other words, “dung on a twig.” Kissing under a plant found in bird poop doesn’t sound very romantic to me… Is this kissing-promoting plant really associated with bird poop?

It turns out certain birds eat the white berries of mistletoe as a source of food. The ingested seeds from the berries are then excreted in the birds’ feces, sticking onto twigs and branches, ensuring future mistletoe germination on host trees. The birds act as vehicles to spread mistletoe seeds from tree to tree for future growth. I guess the fertility and reproduction aspect makes smooching underneath a mistletoe a little less gross.

Viscum album

You may have seen American mistletoe (Phoradendron spp.), which is native to the Southern and Eastern US (from New Jersey to Florida), used for Christmas decorations. There is also dwarf mistletoe (Arceuthobium spp.) and European mistletoe (Viscum album), all belonging to the Santalaceae family. Dwarf mistletoe is native to regions in Western America and Mexico, while European mistletoe is native to Great Britain and other parts of Europe.

Mistletoe plants have been around for millions of years. Yet not everyone likes mistletoe. Why might you ask? Well, mistletoe is hemi-parasitic – once on a host tree, the plant penetrates the tree for its nutrients and minerals. Yet the plant also contains green leaves useful for conducting its own photosynthesis – that’s why it’s considered a ‘hemi’ parasite. Because of this characteristic, the plant was commonly considered a disease that kills trees like conifers. But it has been found that the death of an individual tree from mistletoe plants may take several decades. Instead, according to a United States Geological Survey scientist, mistletoe should be regarded as a keystone of healthy forest ecosystems because it has an important influence on animals. Animals like birds, bees, and butterflies consume the berries and/or leaves for survival. They give back by eventually spreading the expelled sticky seeds from tree to tree for further germination. This is known as mutualism! Both mistletoe and the animal gain a benefit from interaction with each other. Mistletoe can essentially have a positive effect on biodiversity, providing nourishment for a broad range of animals in forests worldwide.

Besides lip-locking, there exist other uses of mistletoe from various cultures: as a symbol of romance, fertility, and vitality in pre-Christian European cultures; as an antidote against poison by the Celts in Medieval Europe; to treat problems in circulatory and respiratory systems by herbalists in Germany; as protection against effects of witchcraft or evil spirits; as a plant of peace to declare a truce between enemies by Scandinavians.

For the upcoming holiday celebrations, try changing things up this year. Consider using mistletoe as a means of repairing broken friendships or protecting yourself against holiday drama that arises. Warning: If you’re at a Christmas party, don’t eat the leaves or berries of mistletoe, unless you’re a squirrel, chipmunk, or porcupine. Otherwise, you may die. It’s toxic to humans.

Happy holidays! J

References:

http://www.sdnhm.org/archive/research/botany/hp-mistletoe.html

http://www.usgs.gov/newsroom/special/mistletoe/