by Ian Brand

Wharfedale Naturalists Society

EVERYONE has a few places they regard as special. One of mine is a small café in the Yorkshire Dales. It is where I often stop for a well-deserved pot of tea and slice of cake while out cycling in the summer. As I sit in the small orchard garden where tea is served on the lawn, it is not just the beautiful rural tranquillity that makes it so perfect, but also the rare chance in Wharfedale to see Mistletoe (Viscum album).

Greeks, Romans, Norsemen and Druids all regarded the plant as entirely magical: “A plant without roots or obvious sources of food, that grew way above the ground and stayed green-leaved when other plants were bare.”

More recently, the Victorians popularised the most British of traditions of kissing under the Mistletoe at Christmas, the origins of which remain obscure.

Engrained in myth and folklore, it has an equally fascinating biology.

Mistletoe is a partial-parasite, choosing apple, lime, poplar and hawthorn as its main hosts. It produces much of its own food by photosynthesis, relying on its host primarily for water and nutrients.

Like 15 per cent of our native flora, it is dioecious, having separate male and female plants. These flower in early spring, but come the winter months it is only the female plants that will bear the berries (just like another Christmas favourite, the Holly).

Mistletoe relies entirely on winter birds for berry and therefore seed distribution. Birds are essential, but the white sticky berries are not attractive to many species. The main contender is the eponymously named Mistle Thrush. They usually swallow the whole berry, seed and all, excreting a mass of semi-digested berry pulp just 30 minutes later, due to its laxative effect. Some seeds, still sticky, may stick to a branch where they can germinate, but many will hang uselessly below.

In recent decades, Mistletoe has spread east, away from its stronghold of the apple orchards of Herefordshire. This is due to the Blackcap now overwintering in the UK in increasing numbers. These smart little birds only swallow the berry skin and pulp, wiping each seed off their beaks onto the bark before swallowing, leaving them perfectly placed to germinate glued by the Mistletoe’s own super-glue - Viscin.

There is so much more I could tell you, but time has come to wish you “A Very Happy Christmas, and be sure to make time to visit some of your special places in 2020”

www.wharfedale-nats.org.uk