The structure of mosses, mosses, horsetails, ferns. Modern higher spore plants

What is fabric called?
Which plant tissue You know?
What structure do conductive tissues have and what function do they perform?
What structure do mechanical tissues have and what function do they perform?

Moss mosses, horsetails and ferns grow mainly in moist, shady places. These are perennial, most often herbaceous plants. Tree ferns are common in tropical latitudes. They all have roots, stem and leaves. These plants have well-developed conductive and mechanical tissues, which allows them to reach large sizes. They reproduce by spores and belong to higher spore plants.

Modern mosses, horsetails and ferns are descendants of very large tree-like plants that lived about 300 million years ago during the Carboniferous period Paleozoic era on all continents, including Antarctica. Dying away, they formed coal deposits.

They grow mainly in pine forests. These plants have a long creeping stem with many branches covered with small leaves (Fig. 71). In summer, mosses develop spore-bearing spikelets with spores on erect shoots.

Rice. 71. Moss

The creeping branched shoots of the club moss are very decorative. They are used to make wreaths and garlands to decorate buildings.

Currently, in many areas, the club moss has become a rare plant in need of protection.

Perennial herbaceous plants with long branching rhizomes that overwinter in the soil (Fig. 72).

Rice. 72. Horsetails

In spring, brown shoots appear, at the tops of which there are spore-bearing spikelets. Spores ripen in them.

Green summer shoots contain chlorophyll.

Horsetails grow in fields, forests or near bodies of water, usually in areas with moist, acidic soil. If there are a lot of horsetails in the field, then the soil needs liming.

The structure of spore-bearing horsetail

Using a magnifying glass, examine the summer and spring shoots of horsetail from the herbarium.
Find the spore-bearing spikelet. What is the significance of spores in the life of horsetail?
Sketch the horsetail shoots.

Widely distributed throughout to the globe. They grow both on land and in water.

There are more than 10 thousand species of ferns. These are mainly herbaceous plants, but in tropical areas there are also tree-like forms.

The sizes of ferns are varied: from a few millimeters to 20 m in height. The strongly dissected leaves of ferns are called fronds. Some ferns have entire fronds. Most ferns growing in temperate climate, rhizomes (underground shoots) are located underground parallel to the soil surface. Fronds grow directly from rhizomes.

If you look at the underside of a fern frond in summer, you can see small brown tubercles. These are groups of sporangia (from the Greek words “spore” and “angeion” - vessel), in which spores mature. The structure of sporangia can only be seen under a microscope (Fig. 73).

Rice. 73. Fern

The structure of a spore-bearing fern

Explore external structure fern. Consider the shape and color of the rhizome; shape, size and color of the fronds.
Examine the brown tubercles on the underside of the frond with a magnifying glass. What are they called? What develops in them? What is the importance of spores in the life of a fern?
Compare ferns with mosses. Look for similarities and differences.
Justify that fern belongs to higher spore plants.

The meaning of mosses, horsetails, ferns. From the ancient tree-like forms of these plants, millions of years ago, deposits of coal were formed, which serves not only as fuel, but also as a valuable chemical raw material. It produces lubricating oils, resins, coke, plastics, perfumes and many other products.

Moss moss spores were previously widely used in the pharmaceutical industry in the manufacture of baby powder. In metallurgy, casting molds are sprinkled with spore powder, and metal parts easily come off the walls.

Horsetail is a hard-to-eradicate field weed with increased acidity soil

Horsetail shoots are tough, contain a lot of silica and were previously used in polishing metal products. In some areas of our country, spring shoots of horsetail are eaten (raw, steamed, and as a filling in pies), as well as young leaves of bracken fern.

New concepts

Vaii. Rhizome. Sporangia. Plaun. Horsetail Fern

Questions

Why are mosses, horsetails and ferns classified as higher spore plants?
Where do they grow?
What is their structure?
Which plants - ferns or mosses - have more complex structure? Prove it.
What is the significance of club mosses, horsetails and ferns?

Think

Why can many types of ferns, also being spore plants, unlike mosses, reach significant sizes?

Quests for the curious

Find and examine pieces of coal with imprints of ancient plants.

Did you know that...

About 300 million years ago, the climate on our planet was constantly humid and warm. Under these conditions, ancient mosses, horsetails and ferns developed well (Fig. 74).

Rice. 74. Landscape of the Carboniferous period

At that time, tree-like giant plants grew along the banks of reservoirs, forming forests. Under their canopy there were also small plants that resembled modern mosses, ferns, horsetails and mosses.

There were no birds yet on the branches of plants that reproduced by spores. Huge dragonflies were flying in a gloomy, silent forest. Insects, spiders and scorpions crawled along the ground.

During floods, high-water rivers carried fallen trees to shallow waters, covering them there with silt and sand. Under the pressure of sediment and water, the trees were compressed and over many millions of years without access to oxygen they turned into coal. Along with plants that reproduced by spores, peculiar ferns existed in the Carboniferous period. On their leaves there were formations that can be considered primitive ovules. This was established through the study of imprints and fossils of ancient plants found in layers of sedimentary rocks. These ferns were called seed ferns. Scientists believe that gymnosperms originated from them.

Higher spore plants are living fossils that have survived to this day, so they must be protected. The Red Book of our country includes 60 species of mosses, 23 species of ferns and 4 species of mosses (information for 2000).

Quests

Based on studying the material in the paragraph and additional text, compose a message “The diversity of higher spore plants and their significance in nature and human life.”

>>Ferns, horsetails, mosses

§ 84. Ferns, horsetails and mosses

Many of you have probably seen beautiful feathery leaves fern, but no one has ever seen its flowers. Only an ancient belief stated that the fern blooms in the dead of June night, on the eve of the religious holiday of Ivan Kupala.

In the old days, people went looking for a wonderful flower, believing that it was endowed with magical power- helps to find treasures hidden in the ground. But it has long been known that ferns do not have flowers. They, like mosses, reproduce not by seeds, but by spores.

The ferns of our forests are perennial herbaceous plants.

They grow in damp, shady places, often under the forest canopy and along damp ravines. 173 .

The diversity of ferns is especially great in tropical forests. There they grow not only on the ground, but also settle on branches and tree trunks. In tropical Asia, Australia, Central and South America There are tree ferns that look like palm trees. In our country, tree ferns can be seen in the greenhouses of botanical gardens.

Ferns not only have stems and leaves, like mosses, but also roots. The ferns of our forests have rhizomes. The rhizome produces adventitious roots and leaves with long petioles.

The cells of fern leaves contain chlorophyll; that's why they are green, like everyone else plants, themselves form organic matter from inorganic.

These substances are used to nourish the plant and are stored in the rhizome. The rhizomes of some ferns are poisonous.

If you lift a fern leaf in summer, you can see small brown tubercles 174 on its underside. The tubercles contain groups of small sacs in which spores ripen. Spore sacs can only be seen under microscope.

Ripe spores fall out carried by the wind, find themselves in favorable conditions and germinate like moss spores. But from the sprouted fern spore a small green plate with a diameter of several millimeters develops. 174 . This is a fern outgrowth. It lives independently, attaching itself to the soil by rhizoids.

On the underside of the germ, male gametes - sperm and female gametes - eggs develop. Droplets of dew or rainwater are retained under the growth. Sperm swim through the water to the eggs. Fertilization occurs. An embryo develops from a zygote.

The embryo first receives nutrients from a green shoot. It grows and gradually a root and a very short stem with the first leaf develop. Over time, a plant develops from the shoot, which we usually call a fern. Reproduction also occurs in horsetails and mosses. Like ferns, they have stems, leaves, roots and reproduce by spores 175 . Often all these plants - ferns, horsetails and mosses - are combined under common name ferns.

Horsetails are perennial herbaceous plants with long branching rhizomes that overwinter in the soil. Brown ones appear in spring shoots, on the tops of which there are spore-bearing spikelets. Spores ripen in them. Green summer shoots contain chlorophyll. Horsetails grow in fields, forests or near bodies of water, usually in areas with moist, acidic soil. In fields where horsetails live, the soil needs liming.

Moss mosses are found mainly in pine forests. These plants have a long creeping stem with many branches covered with small leaves. In summer, club mosses develop small yellow spores on erect shoots. 175 .

Many species of ferns and mosses have become rare. These plants are protected. Some species are listed in the Red Book.

1. What is the structure of a fern?
2. Where do ferns grow?
3. Where do ferns produce spores?
4. How do ferns reproduce?
5. What fern-like plants do you know? What is their structure?

Korchagina V. A., Biology: Plants, bacteria, fungi, lichens: Textbook. for 6th grade. avg. school - 24th ed. - M.: Education, 2003. - 256 p.: ill.

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Question 1. What is called fabric?

Tissue - a collection of cells and intercellular substance that have common origin, building and performing certain functions.

Question 2. What plant tissues do you know?

There are several types of plant tissues: integumentary, basic, mechanical, conductive and educational.

Question 3. What structure do conductive tissues have and what function do they perform?

Conducting tissues are formed by living or dead cells that look like tubes. There are two groups of conducting tissues: vessels and sieve tubes. Vessels are dead hollow cells connected in series, the transverse partitions between them disappear. Sieve tubes are elongated, nuclear-free living cells connected in series to each other. There are quite large holes in their transverse walls.

Question 4. What structure do mechanical tissues have and what function do they perform?

Mechanical tissues are formed by groups of cells with thickened membranes. In some cells, the membranes become lignified. Often the cells of mechanical tissue are elongated and have the appearance of fibers. These give strength to plants.

Laboratory work No. 11. The structure of spore-bearing horsetail.

1. Using a magnifying glass, examine the summer and spring shoots of horsetail from the herbarium.

2. Find a spore-bearing spikelet. What is the significance of spores in the life of horsetail?

With the help of spores, horsetails reproduce in the spring.

3. Sketch the horsetail shoots (see picture).

Conclusion: horsetails, unlike mosses, have a rhizome. Spores, like those of mosses, serve for reproduction.

Laboratory work No. 12. The structure of a spore-bearing fern.

1. Study the external structure of the fern. Consider the shape and color of the rhizome; shape, size and color of the fronds.

The rhizome (underground shoots) grows in the soil parallel to the soil surface. It brown. The heavily dissected green or light green leaves of ferns are called fronds. Fronds grow directly from rhizomes. The length of adult fronds ranges from 20 to 70 cm.

2. Examine the brown tubercles on the underside of the frond with a magnifying glass. What are they called? What develops in them? What is the importance of spores in the life of a fern?

If you look at the underside of a fern frond in summer, you can see small brown tubercles. These are groups of sporangia in which spores develop and mature. Ferns reproduce with the help of spores (this generation is called sporophyte).

3. Compare ferns with mosses. Look for similarities and differences.

Differences: Mosses do not have roots, but ferns have many adventitious roots growing from a rhizome (a modified shoot). The leaves of mosses are small, the leaves of ferns - fronds - have a complex structure. In mosses, spores are located in a capsule on a stalk, in ferns - with reverse side fronds (on sporophyte). Ferns have vascular bundles in their stems (which gives them a greater advantage over mosses) - this is the result of ferns’ adaptation to a terrestrial lifestyle.

Similarities: there are shoots (stem, leaves). They reproduce by spores. They gravitate toward moist habitats.

4. Justify that fern belongs to higher spore plants.

Ferns are classified as higher spore plants because they reproduce by spores. The body is also divided into stem, root and leaf. Characteristic feature- the presence of a conducting system (tracheids and blood vessels) that ensures the exchange of substances between the polar parts of the body.

Conclusion: ferns belong to higher spore plants. Ferns also have many adventitious roots that grow from the rhizome (modified shoot). Ferns have spores on the back side of the frond (on the sporophyte). Ferns have vascular bundles in their stems. All this gives ferns an advantage over mosses in nature.

Question 1. Why are mosses, horsetails and ferns classified as higher spore plants?

Higher spore plants are called mosses, mosses, horsetails, and ferns primarily because their body is divided into organs, each of which performs specific functions. Secondly, they all reproduce by spores.

Question 2. Where do they grow?

Moss mosses, horsetails and ferns grow mainly in moist, shady places. Moss mosses grow mainly in pine forests. Horsetails grow in fields, forests or near bodies of water, usually in areas with moist, acidic soil. Ferns are widespread throughout the globe. They grow both on land and in water. Tree ferns are common in tropical latitudes.

Question 3. What is their structure?

Moss mosses have a long creeping stem with many branches covered with small leaves. In summer, spore-bearing spikelets with spores develop on their erect shoots.

Horsetails are perennial herbaceous plants with long branching rhizomes that overwinter in the soil. In spring, brown shoots appear, at the tops of which there are spore-bearing spikelets. Spores ripen in them. Green summer shoots contain chlorophyll.

The strongly dissected leaves of ferns are called fronds. Some ferns have entire fronds. Most ferns growing in temperate climates have rhizomes (underground shoots) located underground parallel to the soil surface. Fronds grow directly from rhizomes.

If you look at the underside of a fern frond in summer, you can see small brown tubercles. These are groups of sporangia in which spores mature.

Question 4. Which plants - ferns or mosses - have a more complex structure? Prove it.

Ferns have a more complex structure than mosses. Because: Ferns have roots that grow from the rhizome. Mosses have no roots, only rhizoids. Mosses have very small leaves, while ferns have complex and large leaves. Ferns have better developed tissues and a conducting system.

Question 5. What is the significance of club mosses, horsetails and ferns?

From the ancient tree-like forms of these plants, millions of years ago, deposits of coal were formed, which serves not only as fuel, but also as a valuable chemical raw material. It produces lubricating oils, resins, coke, plastics, perfumes and many other products.

Moss moss spores were previously widely used in the pharmaceutical industry in the manufacture of baby powder. The creeping branched shoots of the club moss are very decorative. In metallurgy, casting molds are sprinkled with spore powder, and metal parts easily come off the walls.

Horsetail is a difficult-to-eradicate weed in fields with high soil acidity.

Think

Why can many types of ferns, also being spore plants, unlike mosses, reach significant sizes?

Because, unlike mosses, ferns have roots growing from the rhizome and well-developed conductive and support system, which allows nutrients to be transported to high altitudes.

Quests for the curious

This suggests that fern-like plants grew on land or in water in Carboniferous period Paleozoic era. Because it was the mosses, horsetails and ferns that formed the coal deposits.

Horsetail cabbage soup(Equisetum) are perennial herbaceous plants that grow in wet fields and meadows, swamps and damp forests. Although appearance they differ from ferns and mosses, but are similar to them in many ways. Horsetails, like ferns, are spore plants. Currently, horsetails do not play a major role in the formation of vegetation cover. Although horsetails often form thickets in places where other plants cannot exist.

The species diversity of horsetails is small - about 30 species. In forests on moist soil, horsetail with highly branched drooping lateral branches is often found. On sandy soils and wintering horsetail grows in ravines; marsh horsetail and riverine horsetail grow in wetlands, along the banks of rivers and lakes (Fig. 88).

Horsetail

A typical representative is horsetail (Fig. 87). This is a perennial weed that grows in fields and arable lands. In the soil there is a branched rhizome with adventitious roots and buds, from which above-ground shoots develop every year. When cultivating the soil, pieces of horsetail rhizome do not die, and an independent plant grows from each. Therefore, this weed is very difficult to control.

Structure

Horsetails have unique articulated stems. Leaves are located at the joints. The stem is impregnated with silica, which gives it greater strength.

IN favorable conditions Horsetail spores, like ferns, grow into small plants, unlike leafy plants. Organs of sexual reproduction are formed on them, in which germ cells mature. In the presence of dripping water, fertilization occurs. A young horsetail plant with a rhizome is formed from the egg.

After the formation of spores, the spring shoots die, and green summer shoots grow from the rhizome, similar to small pine trees (see Fig. 87).

The stems of wintering horsetail contain a significant amount of silica - a hard, well-polishing substance. Therefore, its stems are especially tough and durable. They have long been used for cleaning metal utensils and instead of sandpaper.

Shoots of some horsetails (for example, horsetail) are used in folk medicine as a diuretic and astringent.

Ferns, horsetails and mosses have common features structure and reproduction, most of them grow in shady, moist places. Collectively they are called pteridophytes. Woody forms are rare among these plants; those that exist grow in tropical forests.

Ferns, horsetails and club mosses are ancient plants. 350 million years ago there were many large trees among them; they formed the forests on the planet. At that time the Earth was warm humid climate, including where Antarctica is today. When trees fell into the water, they became saturated with mineral salts and petrified. Subsequently, coal was formed from them. Today it serves as a source of energy for us. Thus, we can say that the energy of the sun was converted by plants and stored on Earth.

Ferns

Large horsetail

Those few species of ferns, horsetails and mosses that have survived to this day can be considered living fossils.

Externally different types ferns, horsetails and mosses differ from each other. However, they are similar in internal structure, development and reproduction.

Ferns, horsetails and club mosses are classified as higher plants. They are more complex than mosses, but simpler than seed plants. All of them form spores, so they are classified as spore plants.

Ferns, horsetails and mosses have not only the main tissue, but also integumentary, conductive and mechanical tissue. The conductive tissue forms a cylinder in the center of the root and shoot - a stele consisting of wood and bast. There is an upward flow of water with minerals through the wood, and a downward flow of organic matter through the bast.

The development of specialized tissues allowed these plants to have large sizes and spread more widely across the Earth’s land than mosses could.

Sexual and asexual reproduction alternate. The spores develop into a small shoot that does not live long. Gametes (sex cells) are formed on the outgrowth. With the help of water, sperm reach the eggs. From the resulting zygote a large green plant develops, which lives for many years and produces spores.

Among ferns, horsetails and mosses, the latter are the most ancient. Today, living club mosses are perennial herbaceous plants with small, narrow leaves. Their sporangia are collected in spikelets. A representative of the club mosses is the club moss, which can be found in coniferous forests.

Horsetails grow in the Northern Hemisphere. More than 300 million years ago, horsetails were predominantly huge trees; now horsetails are represented exclusively by herbs. The leaves of horsetails are small and scale-like. The stems are impregnated with silica, so they are quite rigid. Horsetails can be found in swamps, meadows, and forests. A representative of the horsetail species is horsetail. It usually grows in acidic soils and is medicinal plant and weed. In ancient times, this plant was even eaten.

Ferns are enough large group plants (about 12 thousand species). Among them there are both herbs and trees. They grow almost everywhere. Representatives of ferns are ostrich and bracken. Their young shoots are even eaten.