A shamrock is a young sprig, used as a symbol of Ireland. Saint Patrick, Ireland's patron saint, is said to have used it as a metaphor for the Christian Holy Trinity. The name shamrock comes from Irish seamróg ([ˈʃamˠɾˠoːɡ]), which is the diminutive of the Irish word seamair and simply means "young clover".
At most times, Shamrock refers to either the species Trifolium dubium (lesser clover, Irish: seamair bhuí) 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 and was a popular motif in Victorian times.