What plant is a symbol of St. Patrick?

The plant that is a symbol of Saint Patrick is the shamrock.

A shamrock is a young clover traditionally associated with Ireland and Saint Patrick. The Irish word seamróg means “young clover,” and the name can refer to several three-leaved plants rather than one universally agreed botanical species. Lesser clover and white clover are among the plants commonly identified as shamrock.

Legend says that Saint Patrick used the shamrock’s three leaflets to illustrate the Christian doctrine of the Holy Trinity: three persons in one God. The story is famous, but it is not supported by contemporary records of Patrick. The earliest surviving written version appeared in the work of botanist Caleb Threlkeld in 1726.

The shamrock became strongly associated with Irish identity and Saint Patrick’s Day. It is worn on March 17, displayed in decorations, and used as a national emblem. A four-leaf clover is a related but different popular symbol of good luck, while Scotland’s traditional plant symbol is the thistle.