What plants are called spore? Spore plants and their classification

Everyone who touched botanical questions at least a bit had to hear about such a differentiation of plants, like flowering and non-flowering plants. In this case, the latter have another name, reflecting the essence of their mode of reproduction - spore. What plants are called spore? Those who for the reproduction and distribution of their seeds have chosen the most ancient in the evolutionary plan - the formation of tiny, diverse in form structures - a dispute.

What plants are called spore?

To answer this question as completely as possible, we begin with the definition of the spore itself (in the translation from the Greek spora - "seed", "seed", "sowing"). It is a shallow structure not larger than 1 micron (10 ^-3 millimeters), diverse in shape and color, which plays the role of seed in all spore plants, giving rise to the development of the embryo of a future plant.

Forming disputes is not the prerogative of all kinds of plants that exist now. It is believed that this ability generally came to the representatives of the flora from the distant past, when the first land plants were just starting to appear, and life in addition to water was born on land.

It is known that the most ancient plants are algae, horsetails, mosses and ferns. It is their historical roots that go into periods such as Cretaceous, Carboniferous and Silurian. And they are to this day the inhabitants of forests, plains, marshes, steppes and the polar region of different continents.

Such a long existence has become possible for them, in part, because they are just about spore. Therefore, we can give a definite answer to the question of which plants are called spore plants. These are ferns, mosses, mosses, horsetails (from the category of higher plants), as well as algae and lichens from the lower category.

Distinctive features

The main features that distinguish all spore plants include the following:

1. Thanks to the formation of structures such as spores, these plants never form flowers (biologically they are not adapted). Therefore, all the myths about the flowering fern in the night of Ivan Kupala - just a fairy tale.
2. The life cycle of these plants has its own characteristics. Spore plants are characterized by alternation of generations in the life cycle. So, gametophyte - the sexual generation, formed by the fusion of the spermatozoon (antheridium) and the ovum (archegonium) - eventually forms an adult plant that produces spores. Sporophyte sprouts from the spore - the sexless generation, which forms small spores in special structures and gives rise to a new plant. Such a change in the sex and asexual generation accompanies spore plants throughout their entire period of existence.
3. For reproduction, they need water. It is through the fluid that the spermatozoon gets to the archegonies, in which the egg is hidden. Without water, the process of fertilization in spore is impossible. This is further proof that these are the most ancient representatives of the flora, whose life has always been closely connected with the water environment. It is from there that all the plants originate.

These are the main features that distinguish spore plants from seed. Now let us examine in more detail the main representatives of this department.

Ferns

Ferns - the most widely known for ornamental purposes, and in the historically formed ideas about the ancient flora are spore plants. Examples of plants are known to all amateur gardeners and connoisseurs of nature and forest seclusion. Orlyak, a nomad, an ostrich are plentiful plants in volume, attracting the lush and juicy foliage of foliage. They are ubiquitous in forest areas in temperate and humid areas.

Anyone who loves domestic potted flowers, for sure, also has or has seen in others nephrolepis - the most common indoor fern. In addition to external beauty, such plants are rather unpretentious and require only abundant and constant watering. Like all spore, they can not breed without water.

On the leaves of the ferns, sporangia with spores are very clearly visible. They are located on the reverse side of the vai (leaf) and have the appearance of small round pouches of brown or dark orange color. In them a fine yellow powder is densely poured with spores. After maturation, sporangia is revealed, and spores are poured out into the external environment.

Ferns total more than 10 thousand species, united in 300 genera.

Moss

Very interesting and beautiful plants that form a real forest litter, similar to a carpet, are mosses. Spore plants that have very small structures - a stem, leaves, a stalk with sporangia in the form of a capsule - is all about them. Therefore, very few people distinguish them in appearance, except that real moss experts.

The color of these plants is rich, juicy-green, the leaves are hard, small, wedge-shaped. Although there is another form, it depends on the type of moss. The main groups are as follows:

• Polytrichovye;
• Brieves;
• Hypnotic;
• Sphagnum.

The total number of mosses is about one hundred species, so the list includes only the most common and practical ones.

An interesting feature of these plants is that their sporangia are similar to mugs with caps of various forms. When the spores mature, the lid opens, and the stem, at the top of which is located sporangium, bends, and spores are poured out.

Seaweed

Algae - spore plants, numbering today about one hundred species, united in 11 main divisions. The main distinguishing feature of these representatives of the flora is life in the aquatic environment at very different depths. Their body is represented by a thallus, it has no leaves and roots. Function of the latter in these plants are semi-transparent, tenacious hooks, called rhizoids.

Algae belong to the lower plants precisely because of the lack of division of the body into organs. They also multiply by spores. The main four sections of algae, which are most widely distributed and applicable in human practice, are the following:

1. Green.
2. Brown.
3. The Reds.
4. Diatoms.

Horsetail

Together with the ferns, this group of spore plants once inhabited the entire land, but gradually withdrew to the formation of peat and coal deposits. Today, horsetails are represented by a small number of species - about thirty of them.

The most common in Russia is the horsetail field. It has the appearance of a low plant with a rigid erect stalk, divided into small segments by internodes, from which bunches of leaves look like needles. Therefore, in general, the horsetail looks like a small fur-tree.

Separation of the body into small segments is a distinctive feature of all the indicated representatives of the flora. The horsetail breeds like other spore plants, with the help of a generational change, that is, asexually (spores) and sex (spermatozoa and eggs).

The Plains

An interesting group of marsh plants, which differ from all other spores by their appearance. They have beautiful stems, stained with small leaves. Each of them seems to be spreading on the ground.

Altogether, there are about forty-five species of plains. The biology of the plant is no different from that of the spores already considered by us earlier. They also have a change in the sporophyte and gametophyte in the life cycle , they depend on water, so they grow only in swampy and very moist soils. Their sporangia are small, dense, elongated structures. After the maturation of the dispute, they burst, and the spores go out.

Lichens

Approximately 26 thousand species of these plants, united in 400 genera, are modern biology. These plants have different features of the structure and lifestyle. The fact is that they represent a product of close mutually beneficial cooperation, a partnership between two species of living things - unicellular algae and fungi.

Such symbiosis has several advantages:

• Tolerance to temperature fluctuations (lichens are able to survive in extreme polar conditions);
• Constant exchange of nutrients (algae gives organic fungus, and fungus - mineral substances);
• Adaptability to different soils.

Therefore, lichens are even the lowest spore plants, but they have undoubted advantages over the higher in terms of lifestyle.

Phylogenesis

It is from spore plants that the modern flora of our planet began its existence. According to a number of theories, life originated in the ocean. In the same place, the first plants appeared, which were the lower spore plants, algae. Gradually, they moved to the land, they formed the leaves and roots for retention in the soil. However, for reproduction, water was still needed.

Then the algae gave rise to ancient ferns, horsetails, mosses and plauns, which in the process of withering for several million years formed whole deposits of minerals. If the ancestral forms of spore plants had a tree structure, then modern trees do not have anything to do with trees.

The entire process of phylogenesis of the representatives of the flora described has taken about four hundred million years. However, now the general characteristics of spore plants make it possible to separate them into a department that has not lost its final connection with its ancestors (water is still needed for reproduction), but has already formed and has new signs.

Domestic applications

The characteristics of spore plants make it possible to understand that they are not of such global practical importance as flowering plants. However, the areas of their use are numerous:

1. The wood forms of spore plants in the middle of the Selura and Carboniferous period formed huge deposits of coal, which the person still uses.
2. Young shoots of ferns can be eaten.
3. Different parts of horsetail and fern plants are used in medicine as anodyne, diuretic, astringent, anti-inflammatory and other means.
4. Plants have very small and soft texture in the texture, which can be used as a baby powder.

Thus, we have received a full and detailed answer to the question of which plants are called spore plants.