What is a shamrock and what does it have to do with St. Patrick's Day?

Updated March 07, 2018
  • By Fiza Pirani, The Atlanta Journal-Constitution

The shamrock is the most iconic symbol of St. Patrick’s Day, but what do you really know about the three-leafed plant you’ll probably see adorned on all things green on March 17?

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What is the shamrock?

Photo: Getty Images/Paul McErlane/Getty Images

Merriam-Webster defines a shamrock as “a small plant with three leaves on each stem that is the national symbol of Ireland”—not to be confused with the lucky four-leaf clover.

The yellow-flowered Old World clover, according to the dictionary, is often regarded as the “true” shamrock.

History of the shamrock

An acolyte burns incense during the procession prior to Mass on Sunday, March 11, 2017 during the Celtic Cross Ceremony at the Cathedral of Saint John the Baptist in Savannah, Ga. Many things have changed in the nearly two centuries since Georgia's oldest city held its inaugural St. Patrick's Day parade in 1824. Now thousands of tourists from across the U.S. flock to Savannah every March 17 for a sprawling street party that may be the South's largest celebration between Mardi Gras and Spring Break. Still, many of Savannah's Irish descendants maintain St. Patrick's Day traditions that have nothing to do with beer-swilling revelry. Photo: Robert S Cooper/Savannah Morning News via AP

Its history dates back to ancient Ireland when the shamrock, also called the “seamroy” by the Celts, represented the rebirth of spring.

During the 1798 Irish Rebellion when the English began to conquer Irish land and make laws against their language and practice of Catholicism, wearing the shamrock became a symbol of Irish nationalism, according to History.com.

But contrary to popular belief, Ireland’s national symbol isn’t the shamrock. It’s actually the harp, which you’ll find on Irish coins, state seals and the presidential flag.

And while green is the color most associated with Ireland today—arguably due to both the shamrock and Ireland’s lush nature—the national color of origin was actually a shade of blue used by the Order of St. Patrick, the patron saint of Ireland.

Why is the shamrock linked to St. Patrick’s Day?

A woman wearing tinted shamrock glasses watches the 243rd Anuual St. Patrick's Day Parade March 17, 2004 in New York City. Photo: Photo by Stephen Chernin/Getty Images

According to St. Patrick's Day lore, St. Patrick used the leaves of a shamrock as a metaphor for the holy trinity. Each leaf represented either the Father, the Son or the Holy Spirit.

Many representations of St. Patrick depict the patron saint with shamrocks tied to his robes, the Sun reported.

Others show him in pictures alongside shamrocks.

According to academic folklorist Jack Santino, some pictures of St. Patrick even present him driving the snakes out of Ireland—a popular, debunked legend associated with the Christian figure—with a cross in one hand and a spring of shamrocks in the other.

Learn more about the holiday, its symbols, history and legends.