Introduction of Flowers

What is a flower?

The purpose of a flower is to produce fruits or seeds for reproduction. Each part of the flower has a specific job. Most flowers have both male and female parts.


Flame Azalea

Parts of flowers

Sepals - Many sepals are bud covers which protect the flower before it blooms; some help support the petals when the flower blooms. These are often, but not always, green in color. Some flowers, such as lilies, have sepals that are the same color as the petals, also called "tepals". Other flowers have only colored sepals and no petals.

Petals - Many flowers have large, colorful petals. Petals serve as "cafe signs" to attract pollinators. Bees, butterflies, hummingbirds and other pollinators come to the flowers to drink the sweet nectar. In the process of getting a meal, they also spread pollen from one flower to another. Some petals have special markings called nectar guides. These markings serve as "road maps" to show the pollinators where to find the nectar. Some nectar guides are spots or stripes or they may be a different colored single petal, as seen on the flame azaleas above. Wind-pollinated flowers, such as grasses, ragweed, and many trees, do not have petals.

   
Wild Petunia (notice the nectar guides on the petals)

Stamens - The male parts of the flower, the stamens, produce pollen on the anthers. Pollen fertilizes the ova inside the ovary to produce seeds. The staminate flowers of wind-pollinated plants dump loads of pollen into the air to be spread to the tiny pistils by the wind. These flowers are an allergy sufferer's nightmare!

Pistil - The female part of the flower is made up of the ovary, style, and stigma. To avoid self-fertilization, many flowers have pistils that are either shorter or longer than the stamens. Some flowers prevent self-fertilization by having the pollen on the anthers mature at a different time than the stigma. The stigma is sticky to help trap the pollen grains. Pollen grains grow a long tube down through the style (which is several inches long in the case of corn silks), the genetic material from the pollen travels down the tube to the eggs. The ovaries sometimes become edible fruits such as apples, cucumbers, corn, oranges, tomatoes, beans, etc. Not all fruits are edible, for instance, cotton bolls are the fruits of the cotton flower.