The Structure of Flowers
All flowers are variations on a simple, basic plan. Some flowers are tiny and hard to see: others are showy and flamboyant, like orchids and roses. Some flowers grow in clusters, some bloom alone. All flowers, however, have a protected ovary to contain the seeds, and stamens to produce the pollen.
Flowers were developed by land plants. Showy petals and sweet nectar are often produced to lure insects to the blossoms. Insects carry the pollen from flower to flower, ensuring exchange of the information encoded in the chromosomes.
Flowers have a well-defined structure.
When the bud appears on the stem, we see the green sepals. Sepals are the green parts that protect a flower bud before it opens. There is usually one sepal for each petal. All together the sepals are called the calyx (pronounced kay-licks).
After the flower opens the sepals can often still be seen behind the petals. The sepals protect and sometimes support the corolla (all the petals together).
Let's look more closely at the parts of the flower that make the seeds.
The inside of the flower holds the reproductive parts. The stamens, which are orange in our diagram, produce the pollen, which is represented by yellow dots. The pistil, which is the green part in the centre of the flower, is considered to be the female part: you can see the unfertilized seeds waiting in the ovary at the bottom of the pistil.
The pistil is the part of the flower that produces the seeds.
| It consists of three parts:|
Stamens are slender structures that hold the pollen.
They consist of two parts:
The pollen grains form in the anthers, which open when the pollen is mature. The pollen is a fine, powdery, golden dust that is easily picked up by an insect or a finger. A flower may receive pollen from many different kinds of plants. However, only pollen grains from the same kind of plant will begin to grow.