Silk tree is a deciduous arbor. Its crown is like an umbrella. The leaves are thin and the shade of the tree is umbrella-shaped. With clusters of red flowers, silk trees are pretty and special. Silk trees are good for the neighborhood factories and mines with the green color. Silk trees can grow in the barren and arid land, even in cold regions. With an ability to solidify the earth, silk trees can function as protective belt along an embankment. In May 1993, the Standing Committee of Weihai People's Congress determined the silk tree as the city tree.