Parts of a Flower: Vegetative and Reproductive Part

Since ancient times, flowers have had a deep connection with human beings. They express happiness, grief, and celebration of human beings. A flower is the reproductive part of a plant. These flowers are not only involved in reproduction but are also a source of food for other living organisms. Flowers are also a rich source of nectar. A flower’s biological function is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Check out the article to learn more about the flower, its function, pollination and more.

Flower

Generally, the structure of the flower includes four whorls calyx, corolla, androecium and gynoecium. Based on the presence or absence of one or more floral whorls, flowers can be classified into two types:

• Complete Flower: A flower with all four whorls is called a complete flower. Mustard and hibiscus are some examples of complete flowers.
• Incomplete Flower: If one or more whorls are missing in a flower, it is called an incomplete flower. Papaya and watermelon are some examples of incomplete flowers.

Based on the presence or absence of the male and female reproductive parts, flowers can be classified as:

• Bisexual: A flower with stamen and pistil is a bisexual (perfect flower).
• Unisexual: A flower that lacks one of the male or female reproductive structures is called a unisexual flower.

Parts of a Flower

Flowers have four main components: sepals, petals, carpels, and stamens. A complete flower consists of two different parts: the vegetative and reproductive parts.

Vegetative Parts of a Flower

A flower’s vegetative parts include the following:

• Petals: The petal is a bright-coloured part that attracts bees, insects, and birds. The petals’ colour varies from plant to plant. Some are bright, while some are pale coloured. These petals are collectively known as the corolla. 
• Sepals: It is the green-coloured part beneath the petals to protect rising buds. And is the outermost whorl of the flower. Some flowers have fused petals-sepals, whereas others have separated petals-sepals.

Reproductive Parts of a Flower

The number of petals, sepals, stamens and pistils varies in different plants. The presence of these components distinguishes the flower as complete or incomplete. A flower also has reproductive parts, which are the stamen and pistil. A flower may be composed entirely of female parts, entirely of male parts, or entirely of both.

A flower’s reproductive parts include the following:

• Stamen: Stamen, also known as androecium, is the male reproductive organ. It is made up of two parts: an anther and filaments. The anther is a sac-like structure that is involved in producing and storing the pollens. Whereas filament is a slender, threadlike object that serves as a support for the anther.
• Pistil: The pistil is the innermost part and the female reproductive organ, which comprises three parts – stigma, style and ovary. And is collectively known as the pistil. Stigma is the receptive tip of carpels in the gynoecium of a flower. Whereas style is the long tube-like slender stalk that connects the stigma and the ovary. An ovary is the ductless reproductive gland that holds a lot of ovules. 

Functions of a Flower

Following are the important functions of a flower:

• Since flowers are the reproductive parts of the plant, the primary purpose of a flower is the process of reproduction. 
• Flowers can also produce diaspores without fertilisation.
• The ovary of the flower develops into a fruit containing a seed after fertilisation.
• Flowers help in the union of male and female gametes.
• They provide nectar to some birds and insects, which in turn help in pollen transfer from one flower to the next.
• Flowers may promote selfing, in other words, the union of sperms and eggs from the same flower, cross-fertilisation, or the union of sperms and eggs from different flowers.

Pollination

Pollination is the process by which pollen grains are extracted from an anther, the male part of a flower, and transferred to the stigma, the female part of the flower. Pollen grains must be transferred from the same species of flower for pollination to be successful. All plants having flowers depends on the pollination method for reproduction. The two types of pollination are self-pollination and cross-pollination.

The pollination begins when the pollen grains from the respective flowers land on the stigma and form a pollen tube with a style length that connects both the stigma and ovary. After the completion of the pollen tube, the pollen grain begins to transmit sperm cells from the grain to the ovary. Later, when the sperm cells reach the ovary and egg cells, the process of fertilisation in plants will begin. The seed is then released from the parent plant, allowing it to grow into a plant and continue the reproductive cycle via pollination.

We hope this article on Parts of a Flower has helped you. Stay tuned to Embibe for more informative articles.