My first thought was tree with blue flowers - Chaste tree ( Vitex agnus-castus) but the leaf structure isn't exactly palmate. Chaste trees normally have a 5 or 7 palmate leaf structure. So I thought about the "tree" I see every day on my way to work which isn't really a tree. The people have a wisteria that has formed into a "tree". Wisteria has what is called alternate pinnate leaves which look like the leaves in the picture. I almost certain that you have a Wisteria. I'll try to take a picture of the tree tomorrow on my way to work.