Flowering plants (angiosperms) began to appear about 130 million years ago. The diversity of flowering plants is tremendous and can be readily observed, even on a casual walk in the woods or flower garden at the right time of year. Of course, the flower is the reproductive structure and is essential for completion of the plants life cycle. The molecular mechanisms that control flower formation have been the subject of a much research but much remains to be understood.
The time-lapse movies available here focus on the last stages of flower development, flower opening and flower senescence. Once a flower bud is fully formed and conditions are right, flower opening can occur. The process of flower opening involves differential expansion of cells and tissues in the different flower parts. The most extreme changes in cell and tissue expansion usually occurs in the petals of flowers. The movies that you will find here allow you to watch the unfolding of several different types of flowers. Although the flowers on different types of plants open differently, cells on opposite sides of the petals expand at slightly different rates to cause opening, and in some cases closing as well.