One of the world’s rarest trees grows in north Wales. There are only 30 of the Menai whitebeam left in the world, all growing along a tiny strip of steep coast in a nature reserve by the Menai Strait. “I was amazed to realise that such a highly threatened tree could be found in the nature reserve not far from our university,” said Julia Jones, a professor of conservation science at Bangor University. Urgent work has begun to map each tree, monitor its wellbeing and collect seeds so it can be cultivated and planted in the wild in the future. The Menai whitebeam illustrates the plight of many other tree species at serious risk of extinction, some reduced to fewer than 50. Of the 60,000 tree species worldwide, 17,500 are endangered – nearly one in three of all tree species, according to a report by Botanic Gardens Conservation International. That is more than twice the number of threatened mammals, birds, amphibians and reptiles combined but the threat to trees receives far less attention.