No individual flower serves as the national flower for Great Britain itself. Instead, each province within Great Britain has its own national flower. England has the rose, Scotland has the thistle, Wales has the daffodil and Northern Ireland has the shamrock.
According to Project Britain, the rose became England's national flower due to the War of the Roses, the name of the decade-long conflict between the House of Lancaster and the House of York in the 15th century. The bluebell is an alternative to the thistle in Scotland, and the leek is an alternative to the daffodil in Wales. In Northern Ireland, the shamrock is notable for its use in describing the Holy Trinity.