The English name “walnut” derives from Old English “wealhhnutu” and literally means “foreign nut”.
Juglans regia (tree) originally came from Persia, and spread in Europe thanks to the Greeks and Romans.
Currently, China and the United States are the world's largest producers of walnut, which vividly demonstrates its foreignness.
Juglans regia in some European countries is an invasive or alien species that is established but not classified as invasive.
The inconspicuous little shells hiding walnut kernels are a great example of the redefinition of the word “foreign”.
