Europe’s oldest tree isn’t transgender… it’s actually intersex
One of the UK’s oldest trees has been labelled transgender… but it might actually be intersex.
The 3,000 year old Fortingall Yew Tree in Perthshire, Scotland has widely been reported as having undergone a “sex change” in many national media outlets.
The questions came after the male tree sprouted berries. Berries are usually found on female Yew trees, whereas male Yew trees produce pollen instead.
Dr Max Coleman of the Royal Botanical Gardens in Edinburgh first reported the occurrence in his blog last week.
He noted: “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.
“It was, therefore, quite a surprise to me to find a group of three ripe red berries on the Fortingall Yew when the rest of the tree was clearly male.”
However, speaking to PinkNews, Dr Max Coleman explained that the female gender variance of the tree is limited to one branch – whilst the rest of the tree maintains male sexual characteristics.
He said: “In plants gender can often be more diverse than in animals.
“Although some plants have male and female individuals, like the yew tree, other species of plant are often both male and female at the same time. The male and female parts might be on different parts of the tree or may mature at different times to avoid the plant pollinating itself.
“In the case of the Fortingall Yew it is only a small part that has become female in an otherwise male tree. Whether more of the this female part will switch back again is hard to say. This situation in yew trees is pretty rare, but a range of conifer trees have been observed to undergo partial or total sex change.”
He added: “Reporting in the media has generally been accurate, but the use of the words ‘sex change’ could be regarded as a bit misleading.
“At a simple level this is correct and I’m not surprised the press have picked up on this, but given that yew trees are able to switch sex through changes in plant hormones that we don’t fully understand, and that this switch seems to only change part of the tree it is not really a sex change as most people would think of it.
“Having said that what has been really remarkable about this story is how much press interest it has generated. It has really helped to put our conservation hedge on the map.”
“What is going on with this particular yew tree is not entirely understood.
“What we do know is that the plant hormone system can be altered by environmental factors or age and that these changes can manifest themselves in changes of sex that may affect all or part of the tree.
“This situation in yew trees is pretty rare, but a range of conifer trees have been observed to undergo partial or total sex change.”
Explaining the work, he said: “The conservation work is to do with creating a conservation hedge that will preserve the genetic diversity of yew trees from across their natural range.
“Around 2,000 trees grown from cuttings or seed will compose the hedge and each will have its own story to tell.
“Each tree will be identified by a unique number that will link back to the information about it. Britain is fortunate in having many ancient yews that are several thousand years old.”
Max Coleman and his son discovered the ‘sex change’ tree
He added: “The Fortingall Yew in Perthshire is one of these and it along with many other ancient yews is being included in the conservation hedge.
“The hedge will be a living expression of this diversity as different individual trees will show different patterns of growth and colour of foliage. In this way it will be very different in appearance from a traditional yew hedge where uniformity is the key.
“Uniformity is normally made possible by growing a single clone, which means that all the trees in the hedge are genetically identical to each other.
“Our trees will hail from across Europe, North Africa, the Caucasus and south west Asia.”
