British Wildlife of the Week

Mistletoe

When we think of parasites, we tend to think of tapeworms within our bodies, or fleas on our pets, or perhaps even wasps that lay eggs inside caterpillars. We almost certainly wouldn’t think of plants engaging in such sinister behaviour – yet the truth is that many plants have highly parasitic lifestyles.

One well-known plant that few would suspect as being a parasite is that popular Christmas decoration, mistletoe. The European mistletoe Viscum album – the only species native to Britain – does not have roots. Instead, it attaches itself to the branches of a tree to anchor itself. Although it can grow leaves and photosynthesise to produce its own food, its lack of roots means that this plant is wholly reliant on absorbing water from the tree it is attached to, thereby reducing its host’s liquid.

The European mistletoe has always been surrounded by a number of myths and legends. Most notably, it has long been closely linked to the festive season. This may be because this evergreen plant is much more noticeable in winter, as its almost spherical form is clearly visible in the bare branches of the tree it is parasitising, as seen in the image at the top of the page.

The fact that mistletoe produced green leaves from trees whose own foliage had fallen, and could blossom even during frozen winters, meant that this plant came to symbolise vitality in many cultures across pre-Christian Europe, including among the ancient druids. Its paired leaves and pale berries filled with sticky white juices were seen as representatives of male essence, and thus romance and fertility. Women would sometimes wear a sprig of mistletoe around their necks or wrists as they believed this would help them conceive.

Partly because of a fascination for Druidry in the 18th and 19th centuries, many of their ancient beliefs were taken up by Christians and still survive as superstitions to this day. Thus, bringing mistletoe indoors is a tradition that we’ve grafted onto our Yuletide celebrations, although the plant’s links to human fertility have been changed, somewhat chastely, into kissing.

But if kissing under a parasitic plant sounds a tad unromantic, wait until you hear about the origins of its name. The word ‘mistletoe’ comes from the Old English misteltan, with tan meaning ‘twig’ and mistel likely coming from an old Germanic-derived noun meaning ‘dung, filth’, because mistletoe seeds can be spread through birds’ faeces. So although mistletoe has become a symbol of love and affection (and possibly regret) during the holiday season, just remember that if you ever kiss someone under the mistletoe at a Christmas party, you are actually doing so under the parasitic ‘dung-twig’.

In the next British Wildlife of the Week, we’ll be looking at a feisty little bird that, like mistletoe, has long been associated with the festive season – the robin.