The emblem of Scotland is the thistle.  There are about twenty species of thistle in the UK with the creeping thistle, marsh thistle and spear thistle being the most common in Scotland and the spear thistle generally regarded as the emblem.
According to legend, in 1263 an invading Viking army was attempting to sneak up at night upon a Scottish army’s encampment on the Clyde coast.  As they did so they came across an area of ground covered in thistles and one of the Vikings unfortunately stood on one.  His shrieks of pain alerted the Scots of the invaders and so at the Battle of Largs the Norsemen were defeated.  The thistle subsequently became Scotland’s emblem.