War of the Roses
The house of Lancaster uses Red Rose as their flower as you can see in the image on. As for The House of York they used the White Rose referred to as the Rose alba or rose argentwhich is also depicted in the same picture. The two houses fought in several battles between 1455 and 1485. Henry Tudor defeated the last Yorkist king Richard III and married Edward IV’s daughter Elizabeth of York to unite the two houses. The result was the Tudor rose (the Union rose) which you can see on your below.