What’s the difference between a four-leaf clover and a shamrock?
I guess I get where this can be confusing, because both are clovers, but it’s pretty clear: A shamrock has three leaves, and a four-leaf clover has, well, four.
Though there are around 300 species of clover, a shamrock isn't one of them—in fact, it could be any of them. Any type of clover that typically has three leaves can be considered a shamrock. The shamrock is the main symbol of St. Patrick’s Day and all things Irish because it’s supposedly what St. Patrick used to illustrate the concept of the Holy Trinity. Four-leaf clovers, on the other hand, are just freaks of nature in those same species of clover.
The three leaves of a shamrock are also said to stand for faith, hope and love. A fourth leaf is where we get the luck from. The four-leafed clover, or “lucky clover”, is an uncommon variation of the three-leafed clover, and widely considered to be a symbol of good luck.