Tree bark is made of which tissues?

What is the Wood Of A tree Made Of?The Bark of a tree is made from old xylem tubes that have hardened. The Old Tubes of Xylem ( which make up a trees rings along with phloem) no longer transport the water and minerals, so as the stuff in it begins to fill up that space in the tube it becomes hard. Then the old tube is considered the wood of the tree which is bark.