This rhyme introduces children to the parts of the plants. When going to the original site you are able to find other cool activities that you can incorporate into your lesson such as taking white carnations and putting them into water with food colouring and watching the flower change colours. Very engaging and hands on for the children.
I would use this as an anchor chart in my classroom and keep it up throughout our plant unit. It would be primarily used to explain the plant life cycle and all living things have a cycle of development.