The simple, alternate, toothed leaves of Morus alba are extremely variable in shape, ranging from unlobed to heavily lobed, even on the same branch, as shown above. The younger trees and especially sprouts and trees in full sun tend to have a high proportion of deeply lobed leaves. Fully mature trees, especially under canopy where growth is slow, tend to have more (rarely all) unlobed leaves. Regardless of the degree of lobing, the leaves always have three strong veins from the base (one on either side of the midvein) and the sap is milky colored rather than clear. The color of fruits may vary from white to dark purple.

Morus alba is a native of China, but it has been widely planted elsewhere, including most of the eastern U.S. In Wisconsin it is occasionally planted and sometimes escapes in about the southern third of the state. In the Brown County area escaping plants have only been noted on disturbed sites in urban areas, but it is probably found on farms and in rural yards too.