The date palm ('phoenix dactylifera') was cultivated in Egypt from early times, mainly for its fruit. The wood of the tree was also used, however. Although it was not suitable for making furniture, it was used to make the roofs of houses - the trunk was sawn into planks, or else the entire trunk was used as a beam. This system was also used in a number of early tombs at Saqqara; in a few later tombs from the Old Kingdom this method was copied in stone. Columns, too, were sometimes made of date palm wood. The tree is regularly depicted on tomb walls.