The oldest tree in Europe recently changed its sex after 5,000 years of existence. Although most of the tree is still male, one of its branches is starting to show characteristics that are present only in female yew trees.
CS Monitor reported that generally, yew trees are dioecious, which indicates that the plants are either male or female. The effect of being dioecious is that the trees can yield bigger fruits that have more seeds.
The Fortingall Yew in Scotland is estimated to be about 3,000 to 9,000 years old, although its exact age remains unknown, due to some of the parts of the initial tree have already decayed. Scientists are able to provide an estimate of its age by comparing its present dimensions to its trunk size in 1769. Through its whole history, the tree was categorized as male. Male yews feature small conical structures that produce clouds of pollen when they reach maturity. Female yews bear red berries during fall and winter.
“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,” stated botanist Max Coleman in a Royal Botanic Garden Edinburgh blog post. Coleman noted that it is not completely uncommon or trees to change from one sex to another, but it is a rare happening, not fully understood by experts. Coleman also stated that the tree seemed to be in healthy condition, although there might be some hormonal imbalance and environmental stress factors affecting its sex change.
According to Coleman and his colleagues, the gender change might have been caused by environmental factors. The tree may also be trying to change its sex to lengthen its lifespan. Brian Muelaner, chair of the Ancient Tree Forum, told the Guardian that it is a strategy for longevity. The Fortingall Yew is reportedly fragmented and very compartmentalized that part of it has already become sexually ambiguous. The recent discovery is still considered as new science.
Huffington Post reported that one lady named Janis Fry observed a female branch on the Fortingall Yew in 1996. She informed that garden about her previous finding after Coleman’s discovery was announced. The lady said that it seemed to be the same branch, which would give some evidence that the branch had actually been female for at least two decades.
Three seeds from the female part of the Fortingall Yew have been gathered and planted at the botanic garden.