Gleann Iubhair is Gaelic (valley of yews) and the Irish Gaelic cultural influence in this area of western Scotland certainly stems back to the early medieval period when Gaelic settlement began to prevail over the Pictish culture. The Gaelic naming of the valley (inheriting an unknown previous Pictish placename) means over 1,500 years ago at the very least, for a glen to be named for yew trees, there must have been a remarkable yew population. The region became a centre for Gaelic longbow manufacture from the early medieval period until the 18th century (over 1,000 years) by when firearms were the weapon of choice for warfare, and the bow was obsolete. By then the supply of yew in Glen Ure and surrounding areas such as Esragan were pretty much exhausted. The only survivors today grow on cliffs above the steep ravine at the head of Glen Ure, in habitats beyond interference by humans or animals and such environments are proven in the UK to produce yews so slow growing, they can be amongst the slowest growing woody plants in the world. Sites in Glen Ure are inaccessible without specialist climbers being involved, and the potential of the glen to host exceptionally ancient yews, survivors from the longbow trade, is self-evident, and more research is clearly needed.