The yew, Taxus baccata, is a dark, dense evergreen of extraordinary longevity, some British churchyard yews are credibly well over a thousand years old, and a few may be far older, older than the churches beside them. That longevity, together with its evergreen foliage and its habit of regenerating from within a hollowed trunk, made it a natural emblem of death and of life persisting through death, and yews were planted in burial grounds long before and long after the arrival of Christianity in Britain. The tree is also deeply toxic: nearly all of it, foliage and seed, contains taxine alkaloids that are lethal to livestock and people, the fleshy red aril around the seed being the only non-poisonous part.
A single specimen often cited as the oldest living thing in Europe is the Fortingall Yew, growing in a Perthshire churchyard in Scotland, whose age has been estimated anywhere from several hundred to as much as five thousand years by different methods, since ancient yews hollow out from the centre and lose the growth rings that would otherwise date them precisely; whatever its exact age, it was already renowned as remarkably old when first recorded by antiquarians in the eighteenth century.