One traditional icon of the day is the Shamrock.
And this stems from a more bona fide Irish tale that tells how St. Patrick used the three-leafed shamrock to explain the Trinity. He used it in his sermons to represent how the Father, the Son, and the Holy Spirit could all exist as separate elements of the same entity. The Irish have considered shamrocks as good-luck symbols since earliest times, and today people of many other nationalities also believe they bring good luck. The name shamrock comes from an Irish word that means trefoil (three-leafed).