The prickly purple thistle is the national emblem of Scotland. Ever present in fields and pastures throughout Scotland, thistle has been Scotland's emblem for centuries. The first use as a royal symbol was on silver coins issued by James III in 1470. The plant, which grows to a height of five feet, has no enemies because of the vicious spines that cover it like armour plating.

There are many different stories of how the Thistle became Scotland's symbol, but most point to the events surrounding the Battle of Largs in 1263. It is generally forgotten that for more than 600 years most of Scotland was part of the Kingdom of Norway. By 1263 Norway seemed to have little interest. King Alexander III proposed to buy back the Western Isles and Kintyre, still Norwegian territory. However this re-awoke Norse interest in the territory and King Haakon IV attacked with a large Norse force. He was finally defeated at Largs. At some point during the campaign the Norsemen tried to surprise the Scots with a night attack. It was deemed unwarlike to attack an enemy in the darkness of the night, instead of a pitched battle by day but on one occasion the Norse invaders resolved to use this stratagem. In order not to be heard they removed their footwear for a silent approach but found the ground covered with thistles.

As they neared the Scottish force unobserved It is said their leader stepped with his naked feet on a superb prickly thistle and instinctively uttered a cry of pain. His painful shout warned the Scots who discovered the assault and ran to their arms and defeated their Norse foe with a terrible slaughter, thus saving Scotland. The role of the thistle in the Scottish success was understood and appreciated and was chosen as Scotland's national symbol, with the motto "Nemo me impune lacessit", "No one harms me without punishment" but more commonly translated in Scots dialect as "Wha daurs meddle wi me".