The flowering department is a large class of plants that form, in the course of their life, special shortened modified shoots - flowers. Unlike vegetative organs (roots, leaves and shoots), they, together with seeds and fruits, perform the most important generative functions. In this article, we will consider several serious topics, including the structure of the flower and the functions of its main parts. We will discuss what flowers are, how they are classified and how they differ from each other.
Biology: flowers. The structure and functions of their stem part
In nature, there is a wide variety of colors, differing from each other in structure, color and size. Each of them is beautiful in its own way. Biologists consider the flower as a complex organ necessary for seed reproduction. In general terms, it consists of three parts:
- stem (receptacle, peduncle);
- leaf (petals, sepals);
- generative (pistil (s), stamens).
The flower is attached to the top of the shoot with the peduncle - a special elongated organoid, the continuation of the stem.
In the flowers of some plants, for example, sunflower, corn, verbena, plantain, clover, pedicels are practically invisible due to their strong shortening. At the nodes of the receptacle - the upper, wider part of the pedicel - are a calyx, stamens, corolla and pistils (one or more). The receptacle can be of different sizes and has a diverse shape - convex (raspberry), flat (chamomile), concave (rose hips, bird cherry) or elongated (gravilate).
Leaf part of the flower
The calyx is an organ consisting of mutated leaves (sepals). Its main function is to protect the inside of the flower until the bud opens. The calyx can be either dicotyledonous (in case the sepals are separated from each other), or congenital (if they are fused). The corolla is the brightest, most noticeable part of the flower. It consists of petals, which in the flowers of different plants can vary greatly in shape (tubular, bell-shaped, wheel-shaped, funnel-shaped, etc.) and color. The main functions of the corolla are to protect the pestle and stamens from adverse environmental conditions and to attract pollinating insects. The corolla and calyx form the integument of the flower, which is called the perianth. It can be simple, consisting of similar loose or fused leaflets, or complex, clearly differentiated into a corolla and a cup, which differ significantly from each other in size and color.
A simple perianth is found in lily of the valley and a tulip, and a complex one is found in a bell, clove, petunia and cherry. There are flowers and completely devoid of the mentioned element, they are called naked (willow, ash). Now you know what flowers are in terms of the structure of the corolla and calyx. Next, we will talk about the flower organs that perform reproductive functions.
The generative part of the flower
Stamens and pistils are the most important parts of a flower. They are in its center. Stamens are arranged in one or several circles near the inner edge of the perianth and consist of a stamen filament and anther in which pollen is formed. Pestle consists of 3 parts: column, stigma and ovary. The latter contains ovules, of which the seed appears after fertilization. Most plants have one pistil and several stamens - from three to hundreds. They are called bisexual. Some flowers, for example, Cannes, have only one stamen. There are plants that have either stamens or pistils. They are called same-sex - staminate or pistillate. Some flowers, such as cornflower and sunflower, do not have one or the other organ. Therefore, they are called asexual. What are the flowers in this case? Species of plants that simultaneously have stamens and pistillate flowers are called monoecious. Representatives of this group are pumpkin, oak, cucumber, corn. If male and female flowers are on different individuals (specimens), the plants are called dioecious. An example of such are willow, poplar, sea buckthorn.
Variety of colors
Despite the fact that different types of plants have modified shoots that perform generative functions, have a similar structure, outwardly they can vary greatly. Their sizes can vary from millimeter (for small cassocks) and up to one meter in diameter. One of the most interesting representatives of the flora is tropical rafflesia. It has the largest flowers in the world that emit a repulsive smell of rotting meat. Other plants, such as garden jasmine, wild rose, lily of the valley, exude a pleasant aroma. This delicate, delicious smell is determined by special essential oils that are formed in the cells of the epidermal layer of the petals and perianth. The flowers of many plants are endowed with special beauty and give people aesthetic pleasure. One of the most beautiful flowers are roses and orchids.
Petals coloring
Let's look at what flowers are by color. The shade of their petals is determined not only by chromoplasts, but also by special coloring substances - pigments of cell juice. For example, anthocyanin determines pink, red, blue or violet color of the corolla, anthofein - brown, carotenoids - yellow, red and orange, etc. It is interesting that the color of the petals can change throughout the day - depending on the acidity of the cell sap. For example, the flowers of the Victoria amazonica plant change color from snow-white to pink, and then to red.
The white color of the petals (for example, in cherries, water lilies, apple trees) is determined by the absence of pigments and the reflection of light rays. Are there black flowers? No, there is no such pigment in petals. Dark color represents saturated dark violet or condensed maroon shades.
Wildflowers
About half a million different types of forest and field plants are known. But only 290 of them were described and received their name. From ancient times, wildflowers (the photo shows their diversity) were used for the manufacture of medicines. And no wonder, because so many of them have healing properties. The most prominent representatives are: cornflower, chamomile, poppy, bells, dandelion, violet, forget-me-nots. Cornflowers are extremely beautiful flowers in bright blue. Often they grow in wheat crops. Field poppies stand out for their richly red, "fiery" petals. They are found along roadsides, in wastelands, but are especially common in the steppes. Field chamomile has beautiful flowers with a yellow head and white petals. Pharmacy chamomile is widely used in the treatment of many diseases, including for the treatment of the digestive tract, liver, throat and oral cavity.
Forest flowers. What color are snowdrops?
The most famous flowers growing in the forest are anemone, St. John's wort perforated, lilies of the valley, snowdrops, common sour acid, etc. Their beauty leaves no one indifferent. But the most tender of all the variety of the forest flower kingdom is snowdrop. He first appears on the thaw, directly from under the melting snow, and symbolizes the onset of spring. Do you know what color snowdrops are?
Most often, these delicate primroses have white bell-shaped petals. But there are pale blue, and even blue. The genus of snowdrops includes about two dozen species, the most famous of which are snow white snowdrops, Elvis snowdrops, Caucasian snowdrops and others. They like to grow in partial shade, under the canopy of shrubs and trees.
One of the most valuable forest plants is considered to be Hypericum perforatum. You can recognize it by the branching stem and oblong-ovate leaves having a smooth surface. The flowers of this herbaceous perennial have a bright yellow color. St. John's wort is used in medicine as an anti-inflammatory, antimicrobial and hemostatic agent.
Beautiful garden flowers
Garden flowers are a large group of ornamental plants that are designed to decorate our lives and ennoble summer and home gardens. They can be classified according to some parameters. For example, garden flowers are often divided into three subgroups - annuals, biennials and perennials.
The most unpretentious and at the same time bright and beautiful annuals are considered pansies,
marigolds (calendula), alissum, nasturtium. Perennials are decorative flowers that retain their excellent properties for several years. They are ideal for any garden, and do not require annual transplantation and serious maintenance. What are the
flowers? The names of the most famous perennials are as follows: astilbe, rose, peony, frankincense, daylily, Lychnis, crocus, daffodil, tulip, etc. The most famous biennial crops are daisies, viols, Turkish cloves, digitalis, mallow, etc.