While flowers may add color to our tables or gardens, in nature their purpose is much more about function than form. Flowers enable plants to reproduce, and their colors and shapes facilitate pollination, seed growth and seed dispersal. Understanding the purpose of flowers can help you plan and choose the best plants and flowers for your garden or table.
Flowers have several key parts, all related to plant reproduction. The sexual reproductive organs of the flower are the pistil, or female parts, and the stamen, or male parts. The pistil is typically bowling pin-shaped and consists of three parts — the stigma, style and ovary. The stamen consists of the anther or pollen sac and a supporting filament. The petals, sepals and nectar glands make up the remainder of the flower.
Flowers may be complete, containing both male and female sex organs, or incomplete with just male or female organs. Incomplete flowers cannot fertilize themselves, and female flowers will not produce seeds without pollen from a male flower. Plants that produce both male and female flowers on a single plant are monoecious, while those that produce only male or female flowers are dioecious. A complete flower does not require birds or insects for pollination.
Color and Fragrance
The bright colors and sweet fragrances of flowers also serve an essential purpose. Incomplete flowers require reproductive assistance, unless they are wind-pollinated. Insects and birds transport pollen from male flowers to female flowers, allowing fertilization to occur. Colors and scents attract pollinators, like butterflies, bees and hummingbirds. Nectar glands provide food for many of these creatures, then they carry the pollen with them on their feet as they leave the flower and travel to the next.
When a flower is pollinated, the stigma, one of the female reproductive parts, stimulates the pollen to grow down into the flower’s style to reach the ovules in the ovary. Sperm is released by the pollen, and the ovules are fertilized. Eventually, these fertilized ovules will form the seeds for the next generation of flowers. Seeds may form on their own or as part of a fruit.