Ancient British tree is ‘undergoing sex change’

A British tree thought to be up to 5,000 years old has started to change sex, a “rare and unusual” phenomenon not fully understood by scientists, a botanist said on Monday.

The Fortingall Yew, in Perthshire, central Scotland, has for hundreds of years been recorded as male, but has recently begun sprouting berries, suggesting that at least part of the tree is changing gender. “Yews are normally either male or female and in autumn and winter sexing yews is generally easy,” said Max Coleman, of the Royal Botanic Garden Edinburgh, who spotted the berries. “Males have small spherical structures that release clouds of pollen when they mature. Females hold bright red berries from autumn into winter,” Coleman told the Telegraph. “It was, therefore, quite a surprise to me to find a group of three ripe red berries on the Fortingall Yew this October when the rest of the tree was clearly male,” Coleman said.

Coleman said while it may seem “odd”, it was not unheard of for yews, and other conifers that have different sexes, to switch sex. “Normally this switch occurs on part of the crown rather than the entire tree changing sex,” he said. “In the Fortingall Yew it seems that one small branch in the outer part of the crown has switched and now behaves as female,” he said. The gnarled tree is situated in an old church yard, and is difficult to age because its heartwood — the wood in the centre of the tree — has long rotted away. Scientists have been able to estimate by comparing its current size with measurements taken in the 1700s.