Yew Trees Talk by Dr Jane McLauchlin, 8 February 2006

Dr Jane McLauchlin, President of the Croydon Natural History and Scientific Society, gave a fascinating talk on the natural history of, as well as history and folklore attached to, the yew tree.  Yews are found in many different situations - natural, semi-natural and formal - and there are a number of different varieties.  As well as the familiar dark bushy form of the native yew (Taxus baccata), there are golden forms, and the fastigiate Irish yews, which are all the offspring of one tree discovered by chance in Ireland in 1780.   (This tree is still alive!)  There are also introduced species planted in the UK, including Japanese yew (T. cuspidata) and Chinese yew (T. sinensis).

Yews are evergreens but are not conifers, and although technically classified as 'softwoods' their wood is in fact much harder than many 'hardwoods'.  Their foliage and seeds contain toxic alkaloids, making them very poisonous, and have killed cattle (which casts doubt on the wisdom of grazing cattle in churchyards!), although not to birds such as thrushes and starlings which feed on the seeds and berries.  The trees are dioecious (i.e. each tree is either male or female).  Male trees are easily identified in spring by their small orange flowers and the clouds of golden pollen they waft around.  Female trees bear seeds surrounded by red flesh, and the berries are sticky, earning them the wonderful name 'snotty gogs' in some areas! In nature, yews prefer well drained calcareous soils, but they are not too fussy, and occur throughout Britain, except the north of Scotland, on all kinds of soils.  Wherever they occur they always create a bare area beneath them, where nothing but ivy can tolerate the shade.

In gardens, yews have been clipped into many weird and wonderful shapes, and into dense, long-lived hedges.  In churchyards, some have grown to a very great age.  However, dating yews is a tricky business; the oldest ones tend to be hollow, which rules out dendrochronology, even if you had a chance to use it.  Girth measurement is not simple either: yews have a complex growth pattern, and pollards are difficult to distinguish from multi-trunked trees.  The great Tandridge yew is a case in point: are we looking at one tree or three?  Jane has been doing work with Gwyneth Fookes on the dating of churchyard yews in the Croydon area., based on previous measurements done in 1880.  They have produced a graph which charts the average growth of these trees in the early part of their lives (those that have survived; quite a few have gone).  Jane believes that, on the whole, yews were planted when churches were built and that few, if any, pre-date the church.

As for the idea that churchyard yews were planted to provide wood for bows, she can see little sense in it.  Churches are hardly ideal places for the production of weapons!  Besides, English yew is gnarled and twisted, and doesn't provide the straight lengths of inner (orange) and outer (paler) wood required for making bows.  This wood was imported from Europe.  Bows did, though, have a good run as a battle weapon (and a terrifying one!), as seen in the Bayeux Tapestry, and in their final phase in the arsenal recovered from the Mary Rose.  The latter demonstrate the toughness of the wood, having survived immersion in brine since 1535.  Place names related to yew usually occur where they are infrequent.  In Surrey this tends to be in the Weald, for example Ewhurst.

In modern times, yew has demonstrated its huge value as the source of Taxol, a very effective treatment for cancer, especially ovarian cancer.  This was originally isolated from the Pacific yew (T. brevifolia), but now a semi-synthetic version has been developed based on clippings from UK native yews.

Thanks to Jane for introducing us to this fascinating tree.  It should inspire us to go out and visit some of the wonderful specimens we have in Surrey, such as those in Tandridge and Crowhurst in East Surrey, and Hambledon, near Godalming.

DICK ALDER