Profile
Settings
Refer your friends
Sign out
Flowers are the most beautiful part of a plant. Angiosperms are the only group of plants on the planet that can produce. Angiosperms are often known as flowering plants. It is the most extensive and varied group of flowering plants in the kingdom Plantae. It consists of 300,000 species. Among all green plants, 80% belong to the Angiosperm family.Flower is short or long on flower stalks which is called pedicel. The upper part of the pedicel is swollen, spherical shaped or conical which is called thalamus/Receptacle. Floral leaves are present on it.In a flower there are 4 types of floral leaves.
(1) Sepal
(2) Petal
(3) Stamen
(4) Carpel
The flower is the reproductive part of a plant. Flowers offer an almost infinite variety of combinations in terms of colour, size, form, and anatomical arrangement. The individual flowers may appear very small in other plants, such as aster snapdragon, and are borne in a distinctive cluster known as an inflorescence. Irrespective of their complexity, all flowers have the same purpose: to reproduce.
Stamen is the male reproductive organ in plants. It consists of a long slender stalk, the filament, with a two-lobed anther at the tip. The anther consists of four saclike structures (microsporangia) that produce pollen. Pollens are the male germ cells of a plant grown in the stamen, the male reproductive part of a plant. It appears like a speck of dust, but, when observed, each pollen consists of microspores that vary in size, shape, and colour in different species of plants. Pollens are transferred to female parts of a plant to undergo fertilisation. Pollination is defined as moving male germ cells (pollen) to the female parts of a plant (pistil). It occurs through various modes; through the wind, it is called anemophily; through the water is called hydrophily; through the insects -it is called entomophily. In addition to that, there are small secretory structures, called nectaries, which are often found at the base of the stamens. These provide food rewards for insect and bird pollinators. All the stamens of a flower are collectively called the androecium.
Female parts of a flower
The gynoecium or pistil is the central whorl of the flower. It shows one to many carpels, which are morphologically equal to megasporophylls. The carpel is naked in gymnosperms and closed in angiosperms. Gynoecium is the female reproductive organ.If only one carpel is present in gynoecium this condition is called monocarpellary.If more than one carpel is present in gynoecium this condition is called polycarpellary. If all the carpels in polycarpellary/multicarpellary condition are free, then the condition is called apocarpous. If all the carpels are fused together, then the condition is called syncarpous.
Few flowers have independent male and female components; such plants are called unisexual or diecious plants. While in the majority, some flowers contain both sexes in the same flower are called bisexual flowers or monoecious plants. The pistil is the plant’s female reproductive organ. The stigma, style, ovary, and ovules are the four components of the pistil. The female reproductive part of the plant is also called gynoecium.
Stigma
The stigma is a distant part of the style. It is the pollen receiving part of the flower. It is composed of specialised cells called stigmatic papillae that receive pollen. These are restricted to the apex of the style or assumed to cover a wide surface, especially in wind-pollinated species. It has a sticky surface, which holds the pollen that lands on them. Once the landing is done, pollen germinates and reaches the pollen style.
Style
Style is a narrow tube-like extension from the ovary. It connects the stigma to the ovules located inside the ovary. The length and size of the style may vary from flower to flower. For example, flowers that pollinate through wind have a longer style, which helps catch the pollen. While animal and insect-pollinated styles are shorter styles, they are designed to attract close enough animals to transfer pollen.
Ovary
The ovary is found at the base of the pistil. It is a fleshy spot that holds the ovules firm in place. When the embryos in the seeds develop, the ovary increases in size to produce a structure called fruit. The fruit protects the developing roots. The fruit has evolved from plants that require animals to disseminate their seeds, and it is a delicious food source for birds and mammals. When the seeds are prepared to be dispersed, the fruit turns juicy and sweet, and the colour changes from green to red, orange, or purple to attract hungry animals.
There is a single ovary with a single ovule, for example, peaches or avocados in most plants. At the same time, some plants also contain multiple ovules, as found in tomatoes.
Ovules
The ovules are the sites for the production of female reproductive gametes. The pollen tube developing within the style of the flower reaches the ovary and then ovule. Once it reaches the ovule, fertilisation of pollen cells with the egg cells occurs. The fertilised ovules develop to form seeds. Inside the sources are the embryos that grow to create a new plant. The ovule comprises the nucellus, the integuments that form the outermost layer, and the female gametophyte (an embryo sac in flowering plants), which are found at the centre. The nucellus is the most significant part of the ovule that provides nutrition to the developing embryo.
Significance of ovules
In sexual reproduction, the ovule is vital. When pollen grains belong to the same species, a pollen tube develops. It reaches down the style and ensures fertilisation occurs.
Conclusion-
Flowers are the most beautiful part of a plant. Angiosperms are the only group of plants on the planet that can produce. Angiosperms are often known as flowering plants. It is the most extensive and varied group of flowering plants in the kingdom Plantae.Flower is short or long on flower stalks which is called pedicel. The upper part of the pedicel is swollen, spherical shaped or conical which is called thalamus/Receptacle. Floral leaves are present on it.
