Lacebark Elm

This tree is a native of China, Korea and Japan. It was introduced into the United States to be used primarily as an ornamental tree.  However, now it is popularly used as a street tree. Some of its notable characteristics are its resistance to Dutch elm disease, rapid growth and drought resistance. It can grow to heights of 50 ft.and widths of 25-40 ft.   As its name implies, mature trees shed their bark revealing a multicolored inner bark in various tones of red, orange, brown and green.  The leaves are dark green in the summer and can be a colorful yellow or purple-red in the fall. This tree is a popular choice for bonsai gardens.  The wood is very hard and actually contains silica.  It is popular in the making of tool handles.
Wikipedia, Missouri Botanical Garden