Taxus baccata is a spreading, evergreen tree, growing to about 15 m (50 ft.), with a rounded crown and reddish-brown scaly bark. The leaves are dark-green, flattened needles, arranged alternately. It is a dioeciously tree, and the male flowers are small! globular cones, which release clouds of pollen in very early spring; the female flower is a small green bud, followed by the fruit, a highly poisonous seed, partially enclosed in a fleshy, red, non-poisonous aril.
History and traditions
Yews were sacred to the Druids and used in their ceremonies. They have also been grown in churchyards from the beginning of the Christian era. As evergreens and exceptionally long-lived trees (1,000-2,000 years), they were a life symbol and often used to decorate the church or to scatter in graves. Taxus is from the Greek word taxon, a bow, and the flexible, close-grained wood was the traditional material for longbows. Yew is from the Anglo-Saxon name for the tree. There are rare references to its former medicinal uses, in treating snakebite and rabies for example, but its poisonous nature was always recognized and it was known to kill cattle at a stroke. It has sometimes been used in homeopathy. In recent times yews have come to prominence as a source of taxol, used in the treatment of ovarian cancer.
Related species
Taxus brevifolia, the Pacific yew, has the highest taxol content, mostly in the bark, and is the main source of the drug. But six trees are needed to make one dose and wild stocks have been grossly over-exploited. Taxus baccata, the common yew, contains less significant levels of taxol-yielding compounds, found in the leaves, but is now used in taxol synthesis.
Habitat/distribution
Taxus baccata is native to Europe, Asia and northern Africa and taxus brevifolia is found in north-western North America to the south-west of Canada.
Growth Yews will grow in any soil, including chalk. Propagated by seed, sown in early spring, or by cuttings in September. Taxus baccata responds well to close clipping and is frequently used as a hedge, or in topiary work.
Parts used
Leaves, bark for extraction of taxol.
Uses
Medicinal
Extracts of yew are used in drugs for treatment of cancers, mainly ovarian, breast and lung.
