Morus, a genus of flowering plants in the family Moraceae, comprises 10–16 species of deciduous trees commonly known as mulberries, growing wild and under cultivation in many temperate world regions.
The closely related genus Broussonetia is also commonly known as mulberry, notably the paper mulberry, Broussonetia papyrifera. Mulberries are fast-growing when young, but soon become slow-growing and rarely exceed 10–15 m (33–49 ft) tall. The leaves are alternately arranged, simple and often lobed; lobes are more common on juvenile shoots than on mature trees. The leaves are serrated on the margin.
The trees can be monoecious or dioecious. The mulberry fruit is a multiple fruit, 2–3 cm (0.79–1.18 in) long. Immature fruits are white, green, or pale yellow. In most species the fruits turn pink and then red while ripening, then dark purple or black, and have a sweet flavor when fully ripe. The fruits of the white-fruited cultivar are white when ripe; the fruit of this cultivar is also sweet, but has a very bland flavor compared with darker varieties.
The taxonomy of Morus is complex and disputed. Over 150 species names have been published, and although differing sources may cite different selections of accepted names, only 10–16 are generally cited as being accepted by the vast majority of botanical authorities. Morus classification is even further complicated by widespread hybridisation, wherein the hybrids are fertile.