YES! Shamrocks are edible, and they make a lovely garnish. So are false shamrocks, better known as sorrel. Shamrocks have three leaves (not four) and were used by St Patrick to teach the concept of the Holy Trinity to the Irish people. Like the Irish people themselves, shamrocks are one of those plants that survive under very difficult circumstances, which is why there is a pot of them (shamrocks, not Irish people) thriving on my kitchen windowsill year-round.