A flower is a modified shoot of a plant intended for propagation by seeds. Unlike ordinary twigs (shoots), it develops from a flower bud. The stem part of the flower is the pedicel and the receptacle. Corolla, calyx, stamen and pistil are formed by modified leaves. To understand why a plant needs all these organs, one should study in more detail the structure of any flower. So, in its center there is a pistil, which, despite its name, is a “female” reproductive organ. As a rule, numerous stamens are located around it, which are the "male" reproductive organ. In any flower, the stamen and pistil are its main parts. From them, the fruit of the plant will subsequently be formed, the seeds of which are a reliable means of reproduction.
The stamen and pistil play an essential role in the life of flowering plants. The male genital organ of any flower, which is the totality of all stamens, is commonly called the "androecium". Each of them has a "filament" and 4"pollen sacs" enclosed in "anther". It consists of two halves, each of which, in turn, has two more cavities (chambers or nests). They produce the well-known pollen. The filaments carry water and nutrients. The female genital organ of the flower is the "gynoecium", which, in fact, is called the "pistil". It consists of a "column", "ovary" and "stigma". It is on this “stigma” that the pollen ripened on the stamens falls. The “column” performs supporting functions, and from the “ovary” containing ovules (one or more), seeds grow during fertilization. The ovules contain embryo sacs that develop rapidly and form the fruit of the plant. The pistil and stamen, whose scheme would not be complete without "nectaries" that secrete sweet nectar, most often receive pollen with the help of insects flying from flower to flower. The perianth consists of a corolla and a calyx. Pistil and stamen surrounded by perianth.
There are many different types of flowers, which are due to the presence of certain organs. So, plants on which flowers have a pistil and stamens are referred to as "bisexual". If there are only stamens or only pistils, the plant is classified as "separate". "Monoecious" are those representatives of the flora on which there are flowers with both stamens and pistils. "Dioecious" are plants that have only pistillate or only staminate flowers.
The structure of the pistil and stamen was formed over millions of years. The flower is the reproductive organ of allangiosperms. The stamen and pistil provide the plant with the formation of fruits (seeds). The fruit appears in the process of fusion of the carpel. It can be simple (peas, plums, cherries) or complex (consists of several fused pistils - carnation, water lily, cornflower). Many representatives of the flora have underdeveloped (rudimentary) pistils. Species diversity in the forms and structure of flowers is associated with differences in their pollination methods that have arisen in the process of long evolution.
