Symbols associated with Saint David and Wales.

The flag of Saint David is a yellow cross on a black background...

On Saint David´s Day, the flag of Saint David and the Red Dragon Wales´s national flag, will be flown more than usual.
People often wear leeks in remembrance of Saint David´s guidance during the battle against Saxons when, supposedly, Saint David advised Welsh warriors to wear a leek during the battle with the saxons, so enemies and allies could be distinguised .They won the battle and the leek became a Welsh symbol.

Boy with leek