When I was rearranging my bookshelves the othe day I found I had book called "The Tree of Life" by Roger Cook which had some marvellous images of the tree of life from many cultures both ancient and more recent. It is interesting to speculate about how the use of tree symbolism spread around the world or whether it arose more or less spontaneously because trees are all around us and are so useful. It is also nteresting to see how the trees depicted relate to the particular culture involved.
The above is a bronze representation of the "Tree of Life and Knowledge" from India made in the 14th or 15th century.
On the lower portion of the shaman's coat from Siberia the tree represents the shaman's descent to the underworld. On the back is another tree representing the ascent to the sky world.
The beautiful interlaced curves in this picture show the Scandinavian "World Tree" or Yggdrasil associated with the god Odin,
The Navaho sand painting shows the giant corn plant which embodies much of the same symbolism as the Tree of life.
I'll put a few more of the images up later.