What Are the Gynoecium Parts of a Flower?

The set of female organs of the flower is collectively known as the gynoecium. Located in the center of the flower, the gynoecium is made up of one or several pistils, themselves made of one or more carpels. Carpels are the floral whorls specialized in the production of ovules or female gametes. In fact, the gynoecium varies depending on the type of classification within the plant kingdom.

In the case of angiosperm plants, the carpels are fused to create a structure that protects the ovary to promote the production and development of ovules. In the case of types of gymnosperm plants, the carpels of the plants are free and open. For this reason, the ovules are without any protection. Taking these differences into account, we can begin to talk in depth about the parts of the gynoecium so that you can learn to differentiate them.

Learn more about the differences between angiosperm and gymnosperm plants with our related article.

Below, we explain in a clear and simple way what parts make up the gynoecium. We explain how they are formed and of what each part of these structures that make up the organs of the female reproductive system of flowers are made:

Stigma

It is located in the upper part of a carpel or, in the case of angiosperms, in the upper area of the set of carpels.

Style

It is a slim and elongated structure, formed by a folding of the carpel itself or by the union of several carpels. Some plant species have a gynoecium with no styles.

Ovary

The ovary is formed by a widened portion at the base of a single carpel or as a result of several fused carpels. Depending on their location, the ovaries are classified in the following ways:

• Supero: if located in the floral receptacle.
• Semiinfero: if located in an intermediate position.
• Infero: if located inside the floral receptacle.

In the same way, they are also classified depending on the number of carpels that form it. We can describe it as unicarpellary ovary when it is made up of a single carpel capable of folding to protect the ovules, bicarpellary when it is formed by two carpels and multicarpellary (or pluricarpellary) if it is formed by a fusion of several carpels.

The ovaries can also be classified depending on the number of eggs found inside. As is the case with the caprels, they will be uniovular (with a single ovule), biovular (with two ovules inside) and multiovular (with several ovules).

The function of the gynoecium is the production and protection of ovules, the female sexual gametes that allow for plant reproduction. This occurs in order to ensure the pollination process that will result in the creation of seeds. In addition, it also facilitates the reproduction and dispersal of seeds in order to ensure the survival of the species.

Each part that makes up the gynoecium is responsible for fulfilling a vital function to achieve pollination of the plant. We will explain the function that each of these parts perform separately:

Stigma

The main function of the stigma is to receive pollen grains or male gametes. It is impregnated with a sticky substance to ensure that pollen does not spread.

Style

This tubular-shaped structure, whose length varies depending on the species, is responsible for uniting the stigma with the ovule. In this way, when the pollen grain remains attached to the stigma, the style germinates to create a pollen tube so that it reaches the ovary.

Ovary

The ovary is the cavity formed by a single or several carpels where fertilization occurs. Once pollinated, the ovary grows until it becomes a fruit, inside which the seed is protected. However, the main function of the fruit will be to ensure the dispersion of the plant. Many of the fruits we know are fleshy to attract animals that will be in charge of transporting the seeds and passively dispersing them through feces.

Different fruits may also have structures capable of easily adhering to animals or simply facilitating their dispersion by other climatic agents. This is especially thanks to the wind, as happens with samaras.

Now you know about the structure and function of gynoecium, you can learn about another important flower part with our article on what is the perianth of a flower?

This is how the gynoecium functions in sexual reproduction in plants. However, in some plants, it can also be very useful for asexual reproduction. There are two main ways this occurs:

• Apomixis: this is a asexual reproduction in plants where the seeds can develop from ovules which are not fertilized. The plants which are reproduced in this way do not have any genetic variance since they do not obtain genetic information from the male gamete.
  
  
• Vegetative propagation: while the gynoecium can create fruit to attract pollinators, it can also acts as a vegetative vehicle for asexual reproduction. This is the case with tubers such as potatoes and beans such as runner beans which do not require seeds to make new plants.

Now that you have learned all this about the gynoecium parts of a flower, you may want to learn more about plants with our articles on types of spermophyte plants and plants that flower annually.

If you want to read similar articles to What Are the Gynoecium Parts of a Flower?, we recommend you visit our Biology category.