The Wisdom of Trees

As I've mentioned in a previous post, trees were central to life, both physical and spiritual, to many cultures, the Celts, Greeks and Saxons being three. Trees are often centuries old, and how much wisdom have they learned in that time?
The Norse often built their houses next to or sometimes around a tree, which symbolised the growing family over several generations, with links to past and future family members. This links to the shamanic concept of the souls still to be born being found among the branches of the World Tree.
Trees were used to witness sacred vows such as marriages, and many important rites took place beneath their branches. The Anglo-Saxon word 'treow' meant both tree and truth. This concept was later crushed in Britain by the incoming Christians, who proscribed that no vows should be taken except within a church.
Trees also formed the basis of a Celtic alphabet, with each letter represented by a particular tree, and also the Scandinavian runes.
 Many trees had important functions, both practically, spiritually and mythically , and this is something I shall return to in the coming weeks.