Why Do Four-Leaf Clovers Have Four Leaves?

Finding a four-leaf clover is lucky, but how lucky?  Scientists have estimated that there is one four-leaf clover for every 10,000 three-leaf clovers making them very rare.  Four-leaf clovers occur in nature because of their genes.

All living things have genes.  In a simple definition, a gene is the basic unit of heredity.  For example, my daughter has blue eyes because of her genes which she received from her Dad and I.  Over the past 15 years, scientists have been able to identify many genes not only in people, but also in plants and animals.  In 2010, researchers led by Professor Wayne Parrott at the University of Georgia found the gene for the four-leaf trait in clover.  This is a recessive gene meaning that it happens less frequently.  Additionally, this gene is influenced by the environment.  For example, clover growing at different temperatures or subject to different amounts of light with the same genes can grow differently with three or more leafs.

Clovers are associated with St. Patrick’s Day because legend has it that St. Patrick used the three-leaf clover to teach Christianity in Ireland.  Each of the leaves represented the Father, Son, and the Holy Spirit.    In modern times, people believe that the leaves on a four leaf clover represent hope, faith, love, and luck. 

Happy St. Patrick’s Day!

Here is the link to the paper by Professor Parrott and his research team on leaf traits in clover.