A shamrock is a type of clover, used as a symbol of Ireland. Saint Patrick, one of Ireland's patron saints, is said to have used it as a metaphor for the Christian Holy Trinity.[1] The name shamrock comes from Irish seamróg ([ˈʃamˠɾˠoːɡ]), which is the diminutive of the Irish word seamair and simply means "young clover".[2]
At most times, Shamrock refers to either the species Trifolium dubium (lesser/yellow clover, Irish: seamair bhuí)[3] or Trifolium repens (white clover, Irish: seamair bhán). However, other three-leaved plants—such as Medicago lupulina, Trifolium pratense, and Oxalis acetosella—are sometimes called shamrocks. The shamrock was traditionally used for its medicinal properties,[4] and was a popular motif in Victorian times.
St. Patrick is said to have used the shamrock in explaining to the pagan Irish the idea of the Holy Trinity.