Asian walnut is a type of lumber often used for flooring. Its name is somewhat misleading, and confusing, however. The wood commonly marketed and sold under this name is not walnut at all but acacia. Walnut trees belong to the family Juglandaceae, of which there are several species. Acacia trees are members of the family Fabaceae. Many species of acacia, from almost every continent, are also known, but they are primarily from the drier areas of Asia, Africa, and Australia. Acacia wood is marketed as Asian walnut because suppliers and retailers feel that the name is more appealing to buyers.
More than 1,300 species of acacia are known to exist. They were previously grouped into the genus, Acacia. In 2005, however, they were split into five separate genera. The acacia trees of Australia, which make up a majority of the species, are grouped into the new version of the Acacia genus which also includes a few other species from tropical Asia and scattered Pacific islands. All other species were classified into the other four genera. This created a fair amount of controversy and some confusion, however, as many of the species newly classified into genera other than Acacia had "acacia" as part of their common names.
To further the confusion over the identity of Asian walnut, several walnut species can be found in Asia, particularly the Persian walnut, which is known in much of Europe as the common or English walnut. For this and other reasons, this type of tree is difficult to decisively identify as any one species. Many trees of the former Acacia genus are harvested for lumber and sold as Asian walnut. Many of these come from Asia, primarily from the hot, dry areas of the continent, but acacia sold as Asian walnut can come from Africa, Australia, or even the tropical areas of southeast Asia. Australian blackwood is one of the most common acacia species sold under this name.
The properties of this lumber make it an attractive choice for flooring and other uses. It is regarded as having an attractive grain and a rich dark color that holds stain well. Nearly all acacia species are known for having dense, very hard wood which is resistant to wear, making it very suitable for flooring. Acacia lumber marketed as Asian walnut is also sometimes used for furniture, wooden utensils, toys and cabinets.