Four-Leaf Clover
In Ireland, four-leaf clovers are a symbol of good luck. As the old Irish verse says:
One leaf is for fame, And one leaf is for wealth, And one is to bring you glorious health, Are all in the four-leaf clover.
People look for them grass, and they won't resist picking a four-leaf clover and carrying it with them for luck and all the good things that it might bring.