The Leek, as seen above, is the national emblem for Wales. How the leek was selected for this honor is in some dispute. Some argue it was because St. David ordered his soldiers to wear them on their helmets in a battle with the Saxons. It is still a tradition in the Welsh military.
Another argument is that the leek was linked to St. David and consequently adopted as a national symbol due to its importance in the national diet...especially during lent.
However, the daffodil has largely supplanted the Leek among the general populace as a symbol among the Welsh people...probably due to its pleasing appearance and the Leek's somewhat questionable aroma.