The 'real' special relationship
Ronald Reagan used his to hold jelly beans. Bill Clinton liked them so much he gave them a prominent spot on his White House shelves.
"Upstairs in our residence, there is so much Irish crystal now," he laughed after his eighth and final shamrock ceremony took place and yet another Waterford Crystal bowl was handed to him.
The annual giving of the bowl of shamrock by the Taoiseach of the day at the White House is now a tradition, though not a particularly old one.
We all know that since the mid-20th century, US presidents have sent warm words to Ireland on St Patrick's Day.
But the Taoiseach's White House visit on St Patrick's Day only became a permanent fixture during the tenure of Bill Clinton, for whom the Northern Ireland peace talks were a priority.
He used the glitzy events as a chance to bring both sides together. During Clinton's presidency, the term "shamrock ceremony" came into use in the United States.
As far back as 1952, Irish diplomacy was at work: that was when the Irish ambassador to the US John Joseph Hearne stopped by the White House and left a box of shamrock in honour of St Patrick's Day for then president, Harry Truman.
Over the years, the degree of prominence for the event ebbed and flowed. In the 1970s, Jimmy Carter delegated the task to his vice president while Ronald Reagan began to transform St. Patrick's Day in Washington into an all-day affair.
But it was Bill Clinton who took the ceremony to a new level. Clinton set a precedent by meeting only with the Taoiseach - not lowly diplomats.
He began hosting lavish St. Patrick's Day receptions and inviting Northern Ireland politicians to the party.
When George W Bush took over, one of his speechwriters, Matthew Scully, moaned that the event had become "boring." "How many different ways can you accept a bowl of shamrocks, or celebrate the sterling qualities of the noble Irish people?" he told The New York Times.
But President Obama has maintained the ritual, calling it "an affirmation of one of the strongest bonds between peoples that exist in the world."
A government report in 2009 underlined the importance of the shamrock ceremony: "Over the years these occasions have given Ireland generous access to the president ... access that few other countries of our size enjoy."
So the bowls survive but alas the shamrock does not: White House security regulations dictate that any food, drink or plant presented to the president be destroyed immediately after an event.