Department ferns are vascular plants, which include both modern and ancient higher. Now there are about ten thousand species of various ferns, widely distributed throughout the world, which can be found anywhere in the world.
General characteristics of ferns, species, names
Moist tropical forests have the best conditions for their growth. Here there are the largest number of fern species that grow not only on the soil, but even on the trunks and shoots of trees.
Fern-like plants can be found in the crevices of rocks, swamps, lakes, walls of houses, roadsides. The dark areas of the rainforest are ideal for the breeding of liana and tree ferns, and perennial floating ones live near water bodies. They do not attract attention, but they are ubiquitous due to their unpretentious growth.
Ferns of our forests
In our latitudes, where the climate is temperate, tree ferns cannot be found, but there are a lot of perennial herbaceous species of ferns. If you look at how many typesferns grows in Russia, then there will be about a hundred of them. The most common ferns are common ostrich, female and Japanese nodule, male shield fern, multi-row, centipede leaf, common bracken.
Plants belonging to the fern division differ from the simplest lower ones, such as algae, by the presence of a stem, roots and leaves, which have their own characteristics.
Stems, rhizomes and their structure
The stalk of ferns is not very developed. It is fragile and small. The exceptions, perhaps, are tropical tree ferns, which look like erect trunks, at the top of which there is a small crown consisting of fairly large leaves.
In most cases, herbaceous fern plants have a short stem called a rhizome. Rhizomes are divided into two types, depending on the shape and location of the leaves and root.
The first type includes rhizomes, in which the adventitious root is located on the underside, and the leaves are at the top. In the second type, the surface of the rhizome is evenly covered with leaves and roots. The rhizomes of some fern species can be poisonous.
Features of leaves
The leaves, compared to the stem, are large and much more massive. In some species of ferns, leaves can grow up to thirty meters in length. Most fern leaves have a petiole and a dissected pinnate plate, which has a stem, which is a kind of continuationpetiole.
Young leaves growing from the rhizome have a twisted appearance. The apical growth of fern leaves persists for a long time. This fact is quite interesting, since such growth is absolutely not typical for the leaves of higher plants.
In addition to providing the plant with important organic matter, the leaves of some fern species are sporulation organs.
Reproduction
There are types of ferns, the leaves of which can be completely different. On the same plant there are sterile leaves that do not have sporangia and leaves that these sporangia have. Such leaves are called fertile, translated from Latin - fertilizing.
Spores in most species are located at the bottom of the reverse surface of the leaf. As with most higher plants, the process of reproduction in ferns occurs when the spores mature. Special formations where spores develop are called sporangia. A large cluster of spores located close to each other form sori. They look like "bags" where spores are stored.
After the spores are ripe, they fall out, are blown by the wind and fall into comfortable conditions for growing. Soon, a small green plate, having a diameter of only a few millimeters, is formed from the germinated spore, which is a fern growth.
Gametes
This growth begins an independent life, clinging to the soilwith their filamentous formations. On its underside, female and male gametes (eggs and spermatozoa) develop. By drops of water or dew, which lingers under the growth, the spermatozoa are delivered to the eggs, thereby making fertilization.
Fern gymnosperms are fundamentally different from other species. The main difference is the reproduction of plants by pollen, and the gametes are inside it. The wind carries the pollen over long distances. Seeds are formed in cones, they do not have a shell, therefore they are called gymnosperms.
Dinosaur peers
The fern-like department is very ancient; together with other plants, it constituted the vegetative surface layer of the soil. In the Carboniferous period, in addition to huge horsetails and club mosses, ancient ferns grew in swampy areas of the forest, the height of which reached thirty meters.
The imprints of large leaves of large tree ferns still remain on pieces of coal. Now the distribution of ferns is observed throughout the Earth, regardless of climate. They are found both in the hot tropics and in the northernmost points of the world.
The seasons also have their effect on the fern plant. In spring, it begins its growth and development, and closer to autumn, these processes stop. In most species, leaves die off, but there are also species in which they overwinter and remain green, recalling that in a tropical climate, against the background of other constantly greenplants, ferns also remain green all the time.
The name "fern" comes from the beautiful feather-like shape of the leaves. Unlike other higher spore plants, ferns are of great ecological importance in nature, for example, they are an important component of the forest ecosystem.
Economic use
Department of ferns, is widely used in the economy. So the inhabitants of some countries use young shoots and the core of ferns that look like a tree for food. These parts are marinated and s alted. For example, Common Bracken is edible, which has a high content of proteins and starch in its leaves.
Many species of ferns are used as ingredients to create drugs against intestinal parasites. The root of the plant has a cleansing effect and is used to remove toxins and toxins, as well as ulcers, eczema, headaches, and wounds. Roots can contribute to the full restoration of the optimal functioning of the cardiovascular system.
Decorative leaves
Due to its large beautiful and dissected leaves, the fern is often used as a decoration for gardens or parks. For example, the Marsilia four-leaf fern is used to decorate ponds and is planted directly into the water. The fern, which has the name "nephrolepis", has long been used as an ornamental houseplant, attracting people with its large openwork leaves.
Water ferns widelyused as decorations for aquariums. In addition to decor, such ferns play a vital role in providing the inhabitants with oxygen. No matter how many types of ferns there are, they all play an important role in the life of the forest.
Poisonous representatives
But you should be careful, because some types of ferns are poisonous. Plants of the shield family are the most dangerous, since their rhizomes contain toxic derivatives of phloroglucinum. However, the shield has medicinal properties and is used to treat helminthiasis.
As we can see, they have a lot of useful properties, so ferns need to be protected. When visiting forests and parks, you do not need to cut off a growing fern to decorate bouquets, because the leaves of these ancient plants quickly collapse and lose their appearance when damaged.
The plant becomes unattractive, wilted, drooping and just thrown away. Due to such actions, the number of these ancient plants, which have a mass of useful properties, is reduced. The unique features of ferns require special sensitivity.
