This is the legend of how the thistle came to be the national emblem of Scotland. No-one is truly sure of how the thistle came to be Scotland’s national flower. However, a well-known story attributes the thistle being chosen as the emblem of Scotland to the Battle of Largs (a coastal town in Ayrshire) in the 13th century. A Norse army journeyed to Scotland, intent on conquering the land. The legend has it that they left their ships under cover of night, and were planning to ambush the sleeping S

"Edward Tufte Principles" lecture