Just as with most living things, there needs to be a male and a female for reproduction to occur within flowers. These male and female parts are often contained together within a single flower. This is not always the case, however, and some flowers are distinctly male or female. Female flowers are called carpellate and male flowers are referred to as staminate flowers. All the female parts of a flower are referred to, as a group, as the gynoecium. The collective male anatomy of a flower is referred to as the androecium.
Female Egg and Ovary
As with female mammals, the eggs of the female flower are contained within the ovary. The ovary is hollow and contains one or more ovules. The eggs are contained within these ovules, along with the flower's embryo sac. After fertilization the ovule transforms into the flower's seed.
Female Style and Stigma
The style is a tube-like structure that extends out from the top of the ovary. The stigma is the swollen, bulbous portion that sits on top of the style. The stigma is usually visible in the middle of the flower, and is often divided into three or more separate parts. Flowers that are pollinated by insects will have a smaller stigma than flowers that are air-pollinated; the latter require more surface area in order to catch the pollen that floats by.
Male Flower Parts
Male flower parts are comprised of the pollen, anther and filament. The job of the male parts is to create the pollen the flower needs in order to reproduce. The pollen is produced within the anther, which sits on top of the filament. These are the long, slender growths that grow around the stigma and style. The pollen must come into contact with the stigma for pollination to occur. When it does, the pollen forms a pollen tube by germinating on the stigma. This tube then delivers the pollen to the egg, inside the ovum. Pollen comes into contact with the stigma either when insects or birds feed off the flower's nectar, and inadvertently transfer the pollen to the stigma, or by the wind, which carries pollen to the stigma.