Picea abies outside of its native range, and one of the most economically important coniferous species in Europe. It is used as an ornamental tree in parks and gardens. It is also widely planted for use as a Christmas tree. Every Christmas, the Norwegian capital city, Oslo, provides the cities of London (the Trafalgar Square Christmas tree), Edinburgh and Washington D.C. with a Norway spruce, which is placed at the most central square of each city. This is mainly a sign of gratitude for the aid these countries gave during the Second World War. In North America, Norway spruce is widely planted,
Christmas tree of the oldest references to the Christmas tree: "Note on how to put the Christmas branch, "scilicet": On the Christmas eve, you will look for a large Branch of green laurel, and you shall reap many red oranges, and place them on the branches that come of the laurel, specifically as you have seen, and in every orange you shall put a candle, and hang the Branch by a rope in the pole, which shall be by the candle of the "altar-mor"." The relevance of ancient pre-Christian customs to the 16th-century German initiation of the Christmas tree custom is disputed.