The word, shamrock, comes from the old Irish word, seamróg, meaning clover. The Irish derived this from the Gaelic word, seamrag, meaning trefoil, or three-leafed. It is not clear which clover, but the most commonly regarded clover thought to be a shamrock is the ordinary white clover (Trifolium repens). The “repens” in its Latin name refers to the creeping nature of the plant.
Records indicate that this was a sour-tasting plant eaten by the Irish in times of famine. This seems the most plausible theory because this clover contains calcium, vitamin C, protein, phosphorous and magnesium, so is very rich in nutrition. They would make a kind of porridge out of the plant.
According to Nathaniel Colgan, in his work, “The Shamrock in Literature: A Critical Chronology,” poor Irish people, in a scarcity of corn, made a kind of bread of the dried flowers of Trifolium repens by reducing them to a powder. They called the plant shamrock and the bread was very wholesome and nutritious. By 1681, the superstitious Irish would wear this shamrock on St. Patrick’s Day every March 17th, as a good luck charm.
The widespread distribution of the plant in North America is due to its use as nutritional forage for livestock. It spreads readily by rhizomes (runners), and invades gardens, lawns and open grasslands.
The plant we now think of as a shamrock, only remotely related to clovers, is a creeping wood-sorrel called Oxalis triangularis, or False Shamrock. This is the plant with purple leaves and pinkish flowers that is commonly seen in nurseries and markets around St. Patrick’s Day. The plants with green leaves and white or yellow flowers are also Oxalis. These plants grow from bulbs and many varieties of Oxalis are quite invasive. They are best controlled by keeping them indoors and in a pot. Outdoors, they can spread and take over the garden. Their seeds are spread by the wind and by birds.
So this St. Patrick’s Day, as we dine on corned beef and cabbage (not a tradition in Ireland) and enjoy the decorations of shamrocks and the wearing of the green, be careful where you plant Oxalis.
There’s a dear little plant that grows in our isle,
‘Twas St. Patrick himself, sure, that set it;
And the sun on his labour with pleasure did smile,
And with dew from his eye often wet it.
It thrives through the bog, through the brake, and the mireland;
And he called it the dear little shamrock of Ireland.
– Andrew Cherry, 18th century Irish dramatist
Sources: “White Clover Establishment and Management Guide,” by John Andrae, College of Agricultural and Environmental Sciences, University of Georgia
“Clovers,” University of California Davis Integrated Pest Management, http://ipm.ucanr.edu/PMG/PESTNOTES/pn7490.html
Francie McGowan is a former University of California Cooperative Extension Master Gardener of Tuolumne County who has managed to keep her garden clover and Oxalis free.
