THE FLOWER AND ITS FLORAL PARTS
A complete flower has flower parts arranged in four concentric circles around a floral axis. Each circle (known as a whorl) has a set number of parts for a species. The outer two, non-reproductive whorls are called the perianth. The two inner whorls are the reproductive parts. The photo shows a section through the flower of a Wild Cherry. From the outside towards the centre the flower parts are:-

1. The sepals, collectively known as the calyx (Greek for husk or pod) protect the flower parts as the flower bud develops. Most sepals are green but in some flowers the sepals and petals are identical and both are called tepals (as in most Monocots)
2. The petals, collectively known as the corolla, attract pollinators and provide landing sites for them.
3. The stamens (male Androecium) – each one consists of a filament supporting an anther which produces and releases pollen grains.
4. The carpels (female Gynoecium) – each one consists of an ovary with ovules, a style and a stigma on which pollen grains are received. The ovary becomes a fruit and the ovules become seeds. A flower may have one or more carpels.
To understand how these parts are combined in the process of pollination click on the first button below. Note that incomplete flowers have one or more of the flower parts missing. To learn more about these flowers click on the second button and to learn how flowers have adapted to insect pollinators click on the third button below. To understand how pollination results in different fruits click on the fourth button

This simplified floral diagram shows a flower with only 5 stamens and formula K5 C5 A5 G1.
