White, red and black mulberries are named for their buds, not their fruit
The three best-known mulberries take their colour names from dormant buds, so a white mulberry can bear dark fruit. Fruit colour and leaf shape are useless for telling species apart; the texture of the leaf's upper surface works far better. And despite the look of the berries, mulberries are not close kin to blackberries.
Morus is a genus of deciduous trees in the fig family, Moraceae, with 17 species recognised in one count and more than 150 names published over the years, fewer than 20 of which most botanists accept. Fertile hybrids between species make the classification even messier. Fossils turn up in Pliocene deposits in the Netherlands, and chromosome-level genomes have recently been assembled for several species. Raspberries and blackberries share the order Rosales with mulberries but are brambles in the rose family.
Young trees grow fast and can reach 24 metres. The alternate leaves are often lobed and toothed, with lobes more common on juvenile shoots. The fruit, a multiple fruit about two to three centimetres long, starts white, green or pale yellow, passes through pink and red, and ends dark purple or black and sweet. To separate the two species most grown in Europe, feel the leaves: black mulberry's are matt and rough, white mulberry's smooth and glossy. North America's native red mulberry is rough too but downy underneath.
Silk shaped the tree's travels. Morus alba, native to China, is the silkworm's favourite food and has naturalised across Europe, the Americas and southern Africa. It is now considered invasive in Brazil, the United States and parts of Australia; in North America it has overrun native plants, including the red mulberry. Black mulberry reached Britain in the seventeenth century in hopes of starting silk production and was used in folk medicine, notably against tapeworms.
Mulberries are widely grown from southern Europe and the Middle East to Central Asia and India. The Peloponnese was known in the Middle Ages as Morea, a name drawn from the Greek word for the tree. Some plants called mulberries belong elsewhere entirely, such as the paper mulberry in the genus Broussonetia and two Australian natives from other families.
Source: Morus (plant)
