Norway spruce: The plant is an evergreen conifer that spreads throughout most parts of the United States and Canada and is probably the most common spruce. Also, it is native to central and northern Europe, including Norway, so it is called Norway spruce.
Christmas tree: Its shape is conical, so it is also widely used as a Christmas tree. Every Christmas, the Norwegian capital provides Picea abies for London, Edinburgh and Washington. Basically, the Christmas tree in the most central square of each city is Picea abies. Hence, it is also called the Christmas tree.