Badge of Ireland
The Shamrock is also used as a badge for sports teams, state organisations and troops abroad from Ireland. It is registered with the World Intellectual Property Organisation as a symbol of Ireland. According to what the Oxford English Dictionary calls "a late tradition" (first recorded in 1726), the plant was used by Saint Patrick to illustrate the doctrine of the Trinity. It has subsequently become an emblem of Ireland, but it is not the official one, which is the harp. The English word comes from seamróg, an Irish word meaning young clover.
Detailed History
A detailed history, including discussion of the identity of shamrock, by E. C. Nelson (1991) Shamrock, botany and history of an Irish myth ISBN0863141994, is still in print and available direct from the author.
Disambiguation
For other meanings of the term shamrock see shamrock (disambiguation)