There are many mulberry varieties. Some grow on trees and others on bushes. However, there are three main species of mulberries: White Mulberry (native to Eastern and Central China). Black Mulberry (native to Western Asia and Europe). Red Mulberry (native to the Eastern United States). There are also hybrid varieties and related species like the Korean Mulberry and Himalayan Mulberry. In China, the white mulberry tree (Morus alba) is mainly grown for its leaves. You see, the leaves are what silkworms feed on. In fact, the worms make silk in their cocoons that is then harvested to be used commercially. You can learn more about this fascinating topic at the following link: Mulberry Trees and Silkworms.