The common alder tree was a sacred tree to the druids and in ancient times was regarded as the faerie tree as it was thought to be able to grant access to the faerie realms the common alder is a hardy tree that thrives in wet conditions and is a common inhabitant of riverbanks and areas with high rainfall its resistance of rot made its wood perfect for making bridges boats and even clogs it was also thought that putting an alder leaf in shoes before starting a long journey would cool ones