Mistletoe Mystique

Credit: Carol Sharp

Even more than the aroma of fir trees, sage stuffing and brandy-soaked cake, mistletoe epitomizes the spirit of the Christmas season, for what demonstrates the beauty of giving and receiving better than a parasite? And mistletoe, with hundreds of different forms among its 2,000 species worldwide, is one of the best parasites around. That’s what intrigued Dr. Job Kuijt decades ago when, as an undergraduate student at UBC, he chose to write his graduating thesis on the plants.

“Biologically, parasites are very successful, very sophisticated. They’ve learned to take a ride on other organisms,” says the University of Victoria professor. “As a biologist, you can’t fail to be interested in that kind of sophistication.”

With the approach of the holiday season, most of us aim for efficiency in our tasks and at least a touch of sophistication in our decor. And that’s just what mistletoe offers, although not exactly the way fashion and entertaining gurus have in mind.

Such exotic mistletoes as New Zealand’s Peraxilla tetrapetala can be exuberant masses of brilliant hot-pink buds. Temperate species are more staid, although the European plant, Viscum album, with its green leaves and white berries, is beautiful enough to be our Yuletide standard.
British Columbia is home to the most highly evolved mistletoes of all. Dwarf species Arceuthobium campylopodum and A. douglasii are smaller than the pine, hemlock or Douglas fir needles of their hosts, so they are all but invisible. They are even “emancipated from the birds,” says Kuijt, because they shoot their seeds from the tiny green or blue berries, independent of a mobile creature’s digestive system.

Although it doesn’t kill the host tree – sophisticated parasites don’t commit suicide – mistletoe can stunt its growth or make the host more vulnerable to other infections like fungi. Hikers and gardeners can spot the characteristic “witch’s broom” appearance of the trees, the result of disorganized growth or swellings at the site of infection.

On southern Vancouver Island, the plants live only on lodgepole pines at the tops of hills like the Gowlland Range or Mount Finlayson on the Saanich Peninsula. In other parts of the province, though, they’re more widespread – and they can be devastating. In two Okanagan valleys, Douglas firs are infected but there isn’t much economic impact; in the Interior, damage to lodgepole pines is overshadowed by bark beetle infestations. In the United States, however, several economically important timber stands are severely infected. There are no known control methods. “They’re too smart,” Kuijt comments. After all, they’ve been around for millions of years.

For thousands of those years, people have been draping legends around mistletoe like robes around a Druid. Pliny the Elder (AD 23-79) wrote that Druids believed a drink of mistletoe would impart fertility to any barren animal, and that it was an antidote for all poisons. That, according to the Oxford Dictionary of Plant Lore, has resulted in more nonsense being written about mistletoe than any other British plant. The Welsh apparently believed that mistletoe would keep evil spirits away. Others thought that keeping the Christmas mistletoe in the house until the following year’s festivities would prevent the house being struck by lightning, hold love in the house or keep the witches out (choose one).

And, of course, the most famous of all: permission to steal a kiss. According to a 1993 exhibit in London’s Victoria and Albert Museum, “…mistletoe symbolizes freedom: this might explain the custom of kissing under the mistletoe, an act of liberation from the usual restraint….” As far as we know, the Druids had nothing to do with this tradition, which is Anglo-Saxon and only a couple of hundred years old. The same people who brought us Christmas trees as an excuse to light up and sing had already brought us the excuse to get cosy in the shadow of the doorway.

That’s not to detract from the mystique of ages, which surrounds the parasite.

“Mistletoe plants are green balls of life in a leafless tree in midwinter,” explains Kuijt. “But most significantly, mistletoe has no contact with the vile earth. That’s probably why the Druids considered it divine.”

Rachel Goldsworthy is a freelance journalist and budding native-plant gardener in Victoria.