Growing up as a young Jewish boy in New York, my family and I did not celebrate Christmas, but many of our friends did. When we would visit, they always had mistletoe hanging in the center of a doorway.

Initially, I thought the idea of kissing under the mistletoe was silly. As a teenager, this became a good way to kiss a girl even if she was a friend of the family.

So how did mistletoe become entwined with Christmas?

This holiday has been modified over the years, incorporating multiple customs and traditions from many different cultures – and kissing under the mistletoe is one of them. But what is mistletoe? What is the basis of this tradition?

The plant is an obligate hemiparasite – which doesn’t sound too appealing. The etymology of mistletoe is also less than endearing. It comes from two Anglo-Saxon words: “Mistel,” which is dung, and “tan,” for twig. “Misteltan” is the Old English version of mistletoe. It is thought the plant derives its name from bird droppings on a branch.

Indeed, it was believed that mistletoe grew from birds. People first believed that rather than just passing through birds in the form of seeds, which we now know is how many seeds are dispersed – the seed itself is non-digestible, but the bird eats the seed to obtain the surrounding nutrients like we do when we eat a peach or a plum (although we do not swallow the pit or seed) – then when the seed passes through the gut of the bird, it is deposited at some remote location.

Mistletoe in a sycamore tree at Placerita Canyon near the Nature Center. Photo: Paul A. Levine

The mistletoe seed has a sticky outer layer, and when the bird droppings hit a branch high up in the tree, the seed sticks to the branch rather than falling to the ground.

The scientific name for the mistletoe growing in Europe is Viscum album, the genus “viscum” meaning thick and sticky, helping the seed to stick to the branch of a tree rather than falling to the ground.

The sycamore tree is deciduous, which means it drops its leaves in winter, making visualization of the mistletoe easy. However, before the days of binoculars, and with the bird landing high in the tree, it seemed like the mistletoe came directly from the birds.

Many species of mistletoe are found all over the world. Depending on the locale and the specific species of bird as well as mistletoe, the seeds are either passed through the gut during the digestive process, regurgitated from the crop, or stuck on the bird’s bill, in which case the bird wipes it off on an appropriate branch. The sticky secretion, viscin, causes it to adhere to its future host rather than falling to the ground where it germinates, sending roots to penetrate the bark of the tree.

As an obligate hemiparasitic plant, it cannot survive on its own, and it gets many of its nutrients from the tree on which it is growing. But it also has green leaves and utilizes photosynthesis to make sugars, as do other plants. The leaves are green all year, allowing it to be identified easily when the leaves of a deciduous tree fall during the winter. Although it can make some of its own food, it is absolutely dependent on the tree on which it is growing.

The seeds would not grow if one were to plant them in the soil as with most other plants. However, if the seed were rubbed against a branch until it stuck, it would send out roots, which would undermine the bark to gain access to the nutrients from the tree and then begin to grow. While it might deform the local branches to which it was attached, it rarely kills the tree on which it grows; for otherwise it too would die.

While mistletoe seeds are poisonous to humans – or at least they will make us ill and hence should not be eaten – they are not poisonous to many animals, such as birds.

Phainopepla

A bird located in the southwestern United States (Southern California, Arizona and New Mexico) is the phainopepla, a medium-sized black (male) or brown (female) bird with a feathery crown and red eyes that is a member of the flycatcher family. Thus, in addition to catching insects on the wing while flying, it also feasts on mistletoe seeds. Phainopepla have been seen on bird outings in Placerita Canyon and elsewhere in Santa Clarita.

Many insects, such as bees, like mistletoe for its nectar. For the great purple hairstreak, a small but impressive butterfly, mistletoe is the host plant. The butterfly usually is high in the tree in and around the mistletoe except when it comes down to take nectar from various flowers nearer to the ground.

Great purple hairstreak nectaring on sugarbush. Photo: Paul A. Levine

A host plant is the plant where the adult butterfly will lay its eggs and the caterpillars will feed on the leaves as it grows. Many butterflies and other insects have specific host plants, allowing multiple different species and families to survive in the same physical environment.

There are many myths surrounding mistletoe. The Vikings, dating back to the 8th Century, believed mistletoe had the power to restore life from death relating to Balder, the god of the summer sun. Balder had a dream that he was going to die. His mother, Frigga, the Norse goddess of love and beauty, was frantically worried that her son might die – just like any mother. She proclaimed that if he died, everything on Earth would die, including all animals and plants.

As with many requests from parents to children to not pick on one particular child, it had the reverse effect. Balder’s only enemy, Loki, found a loophole in Frigga’s request in that mistletoe which grew high in the trees did not have roots in the ground and would not be affected by her request.

Loki took the crushed mistletoe berry, coated an arrow and convinced Balder’s brother, Hoder, who was blind to shoot the arrow, and it hit Balder. No one could seem to bring Balder back, but Frigga changed the red (blood) berries to white after three days and raised her son from the dead. Then she kissed everyone who walked underneath the mistletoe out of gratitude for getting her son back.

Another myth dates to the 1st Century and involves the druids in England who believed mistletoe could perform miracles – from providing fertility in man and animals to curing diseases and protecting everyone from witchcraft. The druids would cut sprigs of mistletoe off of oak trees in a special ceremony five days after the new moon following the winter solstice, about the time Christmas is celebrated today. They also believed it would become contaminated if it touched the ground, so it would be hung up, and after a special ceremony, the priests would give out sprigs of mistletoe to people who believed it would protect them from evil spirits and storms.

Mistletoe was also thought to be a sexual symbol, since it promoted fertility; and possibly an aphrodisiac, as it was the “soul” of the oak tree from which it grew in Europe. The tradition of kissing under the mistletoe stems either from Frigga, who kissed everyone who passed beneath it, or the belief that it was associated with fertility.

There is a specific etiquette associated with mistletoe. The sprig must have berries on it. Either before or after the man kisses the girl on her cheek, he is to remove one berry. Once all the berries are gone, no more kissing is permitted under that mistletoe sprig.

There is a legend that a couple who kiss under the mistletoe sprig will have good luck, but a couple neglecting to kiss will have bad luck. More specifically, the couple who kiss will have a good marriage with a long and happy life, while the unmarried woman who is not kissed when under the mistletoe will remain single for another year.

What if it is two men who meet under the mistletoe? Like, on a battlefield under a large tree with mistletoe growing in it? Mistletoe also represents peace, and if two enemies encounter each other under the mistletoe, they will lay down their weapons and agree to a truce, at least until the next day.

This act of goodwill is yet another possibility for why we kiss under the mistletoe – abstaining from violence and exchanging greetings under a plant that may have contributed to the custom of kissing.

Paul A. Levine is a docent-naturalist at Placerita Canyon Nature Center and an avid butterflier.