First published in The Irish Times March 15, 2012
Are you one of the millions of people around the world who will wear a sprig of ‘shamrock’ this St Patrick’s day? Did you know, there is no such thing as ‘shamrock’?!
The tradition of wearing shamrock dates back centuries, and the small, three-leafed (or trefoil) plant is famously a symbol of Irishness. Yet, it’s all a bit of a sham because – whisper it! – scientifically speaking, there is no such thing as ‘shamrock’.
Wearing of the green
The conundrum led to a detective hunt in the 1890s, and one Dublin naturalist chased after shamrock specimens around Ireland trying to uncover the plant’s identity. His hunt would reveal a surprising answer.
But our story begins in 1681, when an English traveller, Thomas Dinely, published an account of his travels in Ireland, with the earliest reference to the ‘wearing of shamrock’. Dinely wrote that, on March 17th:
“… the vulgar superstitiously wear shamroges… [a] three-leaved grass which they likewise eat to cause a sweet breath”.
All the older references describe shamrock as a salad! A green leaf that, like watercress, the ‘wild Irish’ liked to eat.
For an explanation as to why people should wear shamrock on St Patrick’s day, we have to wait another 50 years, and an account by another English man, with the wonderful name of Caleb Threlkeld.
Threlkeld was a Dissenting minister and medical doctor from Cumberland, who had come to Dublin in 1713 to a parish in theLiberties. Today, he is best remembered for compiling the first account of Irish native plants. His Synopsis Stirpium Hibernicarum, or “A Short Treatise of Native Plants”, was published in 1726, and helpfully includes each plant’s English, Latin and Irish name, as well as any medicinal uses and interesting anecdotes.
Excess in liquor & debauchery
For white clover, Threlkeld writes:
“This plant is worn by the people in their hats on the 17th day of March yearly which is called St Patrick’s day. It being the current tradition that by this 3-leafed grass [Patrick] emblematically set forth the mystery to them of the Holy Trinity.”
“However that be, when they wet their Seamar-oge, they often commit Excess in Liquor, which is not a right keeping of a Day to the Lord… generally leading to debauchery”.
According to the director of the National Botanic Gardens, Dr Matthew Jebb, this revealing note is the earliest written reference that explains St Patrick’s connection with shamrock and the Holy Trinity.
If shamrock was popular on hats in 1726, that was nothing to how popular it would become over the next century, sprouting up everywhere in art and sculpture, decorations and architecture, even on coins. The harp may be Ireland’s official emblem, but the shamrock soon became the one most popularly associated with the country. By the early 1800s, however, scientists and linguists had begun to debate the very nature of shamrock.
Yes, but which clover is it?
There were, for example, fanciful linguistic suggestions that the name was originally Persian, but the word ‘shamrock’ simply means ‘young clover’ (seamair óg). However, three very different types of clover grow in Ireland, so which one is it? The small yellow-flowered Trifolium dubium? The larger, white-flowered T. repens? Or the even bigger red-flowered T. pratense?
Or perhaps, something else entirely? Seamsóg is the similar-sounding Irish name for wood sorrel (Oxalis acetosella), sometimes known as sourgrass and – here’s a clue – ’false shamrock’.
So, in the 1890s a Dublin naturalist set out to answer the question once and for all. Nathaniel Colgan began his detective work by writing to clergymen around the country, and asking for people to send him rooted samples of ‘shamrock’ around the time of St Patrick’s day.
According to Dr Jebb, Colgan received dozens of samples, all trefoil plants that looked much the same. The rooted specimens were planted out and Colgan waited patiently till they flowered in early summer, at which point they could be formally identified.
Colgan found that he had five very different species of plant, which were being used around the country as shamrock:
- the yellow, white and red clovers (in that order of popularity); also
- wood sorrel; and,
- a small herb called black medic (Medicago lupulina), that resembles a cross between a clover and a small creeping buttercup.
Intriguingly, there were regional differences: yellow clover was most common in the southeast, and white clover in the north-west.
No national flower?
According to Dr Jebb, the timing of St Patrick’s day in early spring is a crucial factor in this botanical mix-up, as none of the five species will be in flower this early. “With just their leaves they all look more or less the same. Actually, when people see the small yellow clover later in the year, they think it’s such an insignificant flower!” He believes that this explains why Ireland has no national flower, though we do have an (unofficial) national plant.
In 1988, nearly a century after Colgan’s detective work, another naturalist repeated the shamrock experiment. Dr Charles Nelson, then curator at the National Botanic Gardens, again asked people around the country to send in shamrock specimens. Intriguingly, the same five species turned up – even though few people get their shamrock in the wild now, as they would have done in Colgan’s day – and the most popular was still yellow clover.
Official & legal ‘shamrock’
While there is no single ‘scientific’ shamrock species, the Department of Agriculture had at some point to nominate an ‘official’ one
for commercial licences to companies that export shamrock. It chose the most popular species, the yellow clover (T. dubium) – something you can easily check, if you plant out one of the commercial living shamrock specimens, and check the flower colour in summer.
This botanical puzzle also has implications for the timing of St Patrick’s day. Back in the 1960s, the then government considered moving the national holiday to summer, in hope of better weather. Just as well they didn’t: there’s lots of clover in July, but you won’t find any ‘shamrock’ then!
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