Each part of the United Kingdom has its own national flower.
England, Rose
The rose was adopted as England’s emblem around the time of the War of the Roses - civil wars (1455-1485) between the royal house of Lancaster (whose emblem was a red rose) and the royal house of York (whose emblem was a white rose). King Richard III and the Yorkists were defeated at Bosworth on 22 August 1485 by the future Henry VII.
The two roses were combined to make the Tudor rose (a red rose with a white centre) by Henry VII when he married Elizabeth of York.
Northern Ireland, Shamrock
The shamrock isa three-leaved plant similar to a clover. It is said that St. Patrick used the shamrock to illustrate the doctrine of the Holy Trinity.
Scotland, Thistle
The thistle isa prickly-leaved purple flower which was first used in the fifteenth century as a symbol of defence.
Wales, Daffodil
The national flower of Wales is usually considered to be the daffodil. However, the leek has even older associations as a traditional symbol of Wales - possibly because the its colours, white over green, echo the ancient Welsh flag.