The shamrock, known as the symbol of the Irish people, was once a Celtic emblem for luck based on their sun wheel. Today, the shamrock appears as part of the emblem of sporting teams and official organizations such as: the Irish Rugby Football Union, Tourism Ireland, IDA Ireland, the Police Service of Northern Ireland, and the Irish Guards.
Not only is the shamrock associated with Ireland, it's used also on emblems of various United Kingdom organizations and businesses. In the United States the Boston Celtics (basketball team) incorporated the shamrock in their logo, and General Mills uses the emblem on their Lucky Charms cereal as a mascot and as the shape of the cereal as well.
The word shamrock derives from the Irish word seamrog (pron. sham-roh-g), which is the suffix for clover (seamair). The plant's scientific name, Trifolium, comes from two Latin words: treis, "three" and folium, "leaf". About 150 distinct kinds of Trifoliums are known. The variety that's most associated with St. Patrick's Day is the Trifolium repens, the white clover (Irish: seamair bhan). The species name, repens, is Latin for "creeping".
Trifoliums are a large group of hardy annuals and herbaceous perennials. They are native to the temperate and subtropical regions of the Northern Hemisphere, and of the mountain regions of tropical America, Africa, and non-tropical South America. The Trifolium repens, however, is native to Europe, North Africa, and West Asia. It has become introduced worldwide as a pasture crop, and also common in grasslands of North America and New Zealand. The repens is low growing, and produces whitish flowers that often has a tinge of pink or cream which usually happens with aging plants. The plant is fragile and does not keep long after it has been disturbed from its habitat. The trifoliolate (three leaves) form the symbol known as the shamrock.
Trifolium repens, often used within the mixture that lawn grass seeds, is the species most generally thought of as the "true" shamrock. Although there are differences of opinion as to which particular plant St. Patrick selected to illustrate the doctrine of the Trinity.
Legend claims that St. Patrick used the shamrock to illustrate the Christian doctrine of the Trinity (the Father, the Son, and the Holy Spirit) when Christianizing Ireland. While trying to convert the Druidic people, he was challenged by a chief to explain the Christian idea of the Trinity, three gods in one person. Patrick plucked a shamrock leaf from the plant and pointed to its three leaves growing from one stem. By understanding the new doctrine in the old lucky symbol, the chief became a Christian. Another tale passed through the ages states that the shamrock was also connected with the banishment of the serpent tribe from Ireland by a tradition that snakes are never seen on trefoil.
Traditionally, the shamrock was used for its medical properties for snake bits, and scorpion stings. The Cherokee and other Native America tribes used the plant to treat fevers as well as kidney ailments. The Delaware and Algonquian Indians used the same infusion, but as a treatment for coughs and the common cold.
Besides an excellent forage crop of livestock, the shamrock/clovers are valuable survival food. They are high in protein, and very abundant. Fresh plants have been used for centuries as an additive to salads and other dishes with leafy vegetables; however raw clovers are not easily digested by humans. It's best if they are boiled for several minutes. Dried flower-heads and seedpods can also be ground into a nutritious flour and mixed with other foods.
Whether you call the plant a shamrock, a clover or a trifolium, its three leaves have played an important part in Ireland; therefore three is Ireland's magic number. It was sacred to the Celtic goddess Brigid, and represented the understanding of the Trinity to Christians. It is believed that everything good in Ireland comes in threes. Even the tradition of Irish story telling is based on a threefold rhythm.