The Mysterious Genetics of the Four-Leaf Clover
J Thoendell stashed this in Science
They grew 178 plants and recorded—among other leaf traits like pattern and color—any plants with at least one four-leafed stem (A single clover plant sends out many runners). In the study, four-leafed stems favored warm conditions—there were double the amount of outdoor four-leaf clovers in the summer than winter. And in the winter, more lucky shamrocks grew in the greenhouse than outside. This could mean that three leaves is an adaption for colder or wetter climates. Clovers are a member of the bean family, which Parrott says have been steadily losing leaves over the millennia.