Ancient trees can also create separate entities within their structure to protect themselves from disease. “It’s a strategy for longevity,” says Brian Muelaner, chair of the Ancient Tree Forum. “The Fortingall yew is fragmented and it may be so compartmentalised that part of it has become sexually ambiguous. We are all continuously learning about ancient trees – the ageing process of trees is a new science.”
http://www.theguardian.com/environment/shortcuts/2015/nov/02/britain-oldest-tree-fortingall-yew-change-sex?CMP=share_btn_tw