Mulberries (morus) are among the oldest crops known to humanity. Like most fruits the black mulberry was propagated by the Romans in Europe and the Alps, within wine cultivation areas (warm, protected from wind, loose fresh soil). Three species are known in Europe: The white mulberry (Morus alba), the black mulberry (Morus nigra) and the red mulberry (Morus rubra). The white mulberry has been cultivated since 4,500 years for silkworm rearing. Since the 16th century black mulberries are planted in Europe. Aside from raw use sap and mash. The North American red mulberry is more frost tolerant, but is planted more rarely.