Like a standard three-leaf clover, a four-leaf clover is entirely green in color, has a stem approximately 2.8 inches long and leaves between 0.6 and 0.8 inches wide. Four-leaf clover leaves spread evenly around the stem, with the leaf tips forming the arcs of a circle.
Some plants, such as the four-leaf sorrel, look similar to four-leaf clovers but contain purple pigmentation near the base of the leaves. The exact cause of four-leaf clovers is debatable, and different theories consider recessive genes and environmental factors as possible explanations for the mutation. About one in every 10,000 clovers contains four leaves. They are considered lucky in many cultures.