- Kuwa(Mulberry) is a deciduous tree of the genus Mulberry in the Moraceae family. It is dioecious or monoecious. It will bear flowers from around April and red fruits from around May. In fact, in the summer, it becomes black and ripe and can be eaten. Mulberries was known as a feed on silk moths. Sericulture has been popular since ancient times, and the leaves of Yamaguwa(Wild mulberry) with large leaves were used for feeding. Mulberry seems to had been considered a spiritual tree in ancient times.