At the end of 2019, Dr. Edward E. Moore donated a collection of family documents to Historic Kenmore. Dr. Moore’s is the great-great grandnephew of Esther Maria Lewis Moore, who was the great granddaughter of Lawrence Lewis. Lawrence was the son of Betty and Fielding Lewis. Among the papers donated was a small pocket diary covered in blue silk. This diary, dating from 1826, belonged to Esther Moore’s grandmother, Esther Maria Coxe, and then to Esther Moore’s father, Henry Llewellyn Dangerfield Lewis, who received it on his sixteenth birthday in April 1859.
Upon cataloguing this diary, I was surprised to find eleven four-leaf clovers pressed between the various pages. I had never seen a four-leaf clover personally and was surprised to find the dried remains of so many in this 200-year-old book. Besides knowing the three-leafed varieties are called shamrocks and the four-leafed varieties are considered lucky, I knew really nothing else about clover. With St. Patrick’s Day approaching and on my mind, I decided to investigate what clover is, when it became “lucky”, and what exactly is the difference between four-leaf clovers and shamrocks. In the process, I learned how this symbol of Ireland first evolved out of the tumultuous political atmosphere of the 18th century and an Irish political group that looked to the American Revolution for inspiration?
There are over 300 different types of clover but the one most associated with the “four-leaf clover” is white clover. White clover is an allotetrapoloid, meaning it has 4 chromosomes instead of 2 like humans and most other organisms. Additionally, each pair of white clover’s four chromosomes comes from different species. Basically, these little plants have incredibly complicated genetic structures.
Why some white clover sprout four leaves and some only three is not entirely clear but it is likely some combination of genetic mutation and weather.
Similarly, the association of four-leaf clovers with “good-luck” is not entirely clear either and seems to mostly come from the fact that they are rare. Your chances of finding one are around 1 in 5,000 three-leaf clovers.
While there is no genetic different between a shamrock and a four-leaf clover, the shamrock is traditionally considered to have just three leaves. It also has much more of a historical mythology or folklore, which is wrapped up tightly with St. Patrick and Ireland. The word shamrock comes from the Irish word “seamrog,” meaning “little clover.” It is an ambiguous term that includes white clover, hop clover, red clover, and many other different types.
The first documented mention of shamrock in the English language was in the works of Elizabethan scholar Edmund Campion in 1571. In his work Boke of the Histories of Irelande [sic], he stated the Irish ate “shamrotes, watercresses, rootes, and other herbes” and, soon enough, the shamrock became a plant associated with the Irish people.
The shamrock didn’t become associated with 5th century missionary St. Patrick, Ireland’s patron saint, until about a hundred years later. The first thing connecting him with the shamrock was an image from around 1675 showing him holding one. Then, about fifty years later, around 1725, the legend of St. Patrick and the shamrock was first recorded. It says that St. Patrick used the three leaves of the clover to represent the Holy Trinity when trying to convert Ireland’s native Celts to Christianity.
Around the same time as the emergence of the St. Patrick legend, Ireland, much like the America, was in political upheaval. At the time, the shamrock became a symbol of Irish politics. The Irish Volunteers, a militia raised to defend Ireland from French and Spanish invasion after the British withdrew troops to fight in the war in the colonies, began using the shamrock as its symbol. Additionally, inspired by the American Revolution and its anti-monarchical goals, the Society of United Irishmen sought to get rid of the rule of the King in Ireland. They used the iconic clover as a symbol of freedom.
Even today, the shamrock continues to be used in the emblems of many state organizations, both in the Republic of Ireland and Northern Ireland. In fact, the traditional green shamrock is a registered trademark of the Government of Ireland and they advocate its use only to sell products that have a connection with Ireland or are Irish products.
So at your St. Patrick’s Day party you can entertain your friends with the interesting genetics of clover, the history of the shamrock, and how Ireland’s iconic emblem evolved in turbulent political times to represent a group inspired by the American Revolution. All thanks to the lucky find of some lucky four-leaf clovers in a centuries old diary donated to Kenmore by a descendant of Betty and Fielding Lewis.
 Allan Blackstock, Double Traitors?: The Belfast Volunteers and Yeomen, 1778-1828, Ulster Historical Foundation, 2000: pg 2
 The Shamroc, [sic]. Printed by Joseph Mehain 22, Castle-street. 11 March 1799.