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 Christmas trees are variously erected on days such as the first day of Advent or even as late as Christmas Eve depending on the country; customs of the same faith hold that the two traditional days when Christmas decorations, such as the Christmas tree, are removed are Twelfth Night and, if they are not taken down on that day, Candlemas, the latter of which ends the Christmas-Epiphany season in some denominations. The Christmas tree is sometimes compared with the "Yule-tree", especially in discussions of its folkloric origins. Modern Christmas trees originated during the Renaissance of early modern Germany. Its 16th-century