Yew big girly!
How ancient tree def ied experts ...by changing sex after 5,000 years
IT is Scotland’s oldest and most famous tree.
But despite being around 5,000 years old, the Fortingall Yew has lost none of its capacity to surprise.
For botanists say the ancient tree has suddenly and unexpectedly changed sex.
The yew, in the churchyard of the village of Fortingall in Perthshire, is thought to be the oldest living organism in Europe. But after thousands of years as a male, the tree, or part of it, is now turning female.
Dr Max Coleman, science communicator at the Royal Botanic Garden Edinburgh, made the discovery after finding a group of ripe red berries on the tree. He said: ‘Yews are normally either male or female and in autumn and winter sexing yews is generally easy.
‘Males have small spherical structures that release clouds of pollen when they mature. Females hold bright red berries from autumn into winter. So it was quite a surprise to find a group of three ripe red berries on the Fortingall yew when the rest of the tree was clearly male.’
Dr Coleman said yews and many other conifers that have separate sexes have previously been observed to switch sex.
He added: ‘It’s not fully understood – normally the switch occurs on part of the crown rather than the entire tree changing sex.
‘In the Fortingall Yew it seems that one small branch in the outer part of the crown has switched and now behaves as female.’
The berries have been collected and the seeds will be included in an ambitious project begun last year to conserve the genetic diversity of yew trees around the world.
The existing perimeter hedges at the Botanic Garden will be replaced by a conservation yew hedge grown from cuttings and seed collections from wild populations and signifi-
‘They are normally either male or female’
cant ancient trees, including the Fortingall Yew.
The hedge, which will eventually encircle the entire garden, could be the largest of its kind. Dr Coleman said: ‘The Fortingall Yew will be represented in the hedge and so, too, will its offspring via the ability of yew trees to change sex.’ The suggestion that the tree could be 5,000 years old is based on a girth measurement of 56ft taken in 1769.
Dr Coleman added: ‘It is a remarkable thought that this individual yew tree could have been growing before the Great Pyramid of Giza or Stonehenge were even begun.’
Legend has it that the Roman pre- fect Pontius Pilate, best known from the Biblical account of the trial and crucifixion of Jesus, was born in its shade and played there as a child.
These days the ancient tree is surrounded by a small stone enclosure, built in 1785 to deter souvenir hunters who would help themselves to parts of the tree.