What four-leafed plant is said to protect against fairies?

The four-leaf clover is the four-leafed plant traditionally said to protect against fairies.

A four-leaf clover is an unusual form of the common three-leaf clover, with four leaflets instead of the typical three. Folklore assigns magical powers to the extra leaflet: in some traditions it brings good luck, while in others it lets a person see fairies or protects them from fairy influence.

The belief is older than modern St. Patrick’s Day symbolism. One early written reference appears in John Melton’s 1620 work Astrologaster, which connects finding four-leaved grass with discovering something good. By the nineteenth century, four-leaf clovers were widely treated as lucky charms.

A four-leaf clover is not the same as a shamrock. “Shamrock” generally refers to a three-leafed plant associated with Ireland, often identified as white clover or another similar species. Botanically, “four-leaf” is also a loose term: each clover leaf is made up of several leaflets, rather than being a single simple leaf.