To any person who has spent enough time sitting on a patch of lawn to get a little bored, the leaf in the picture below will be instantly familiar.
|One clover leaf.|
|A patch of clover. See any lucky ones?|
|A small clover plant with leaves, stems and roots.|
|Root nodules on a clover - where nitrogen is fixed.|
Clover is related to bean-type plants (pinto beans, Limas, black beans, lentils, peas), and all types of bean plants have the same pet bacteria for making nitrogen (actually called fixing nitrogen). This type of interaction between two organisms that live in close contact and help each other is called mutualism. Can you think of other examples of mutualisms?
Have you ever found a four-leaf clover? Sometimes the plant makes an error when growing its leaves, resulting in our four-leaf symbol of good luck. If you look at a patch of clover for long enough, you will probably find a four-leaf clover. If you do, press it flat between pages of a book for a week or so, then you can glue it to paper or press it between clear tape to preserve it.