Our planet is covered with water more than half, and therefore there are aquatic plants. These include hydrophytes, which are attached by their roots to the bottom of a reservoir or pond, and plestophytes, which have no roots at all. A striking representative of the first type is elodea, and the second is pemphigus. Life in water provided plants with huge thin leaves, and sometimes division of the leaf blade into sections that resemble threads. You can see these amazing plants in South America, Europe and the territory of the former USSR.
Adaptation of plants to an aquatic environment
In any pond, river or other body of water there are always many different plants that grow and reproduce well in their natural environment. They are characterized by leaves with a large surface, sometimes dissected. The root system is usually weak and is designed to be fixed to the bottom soil; some species do without roots. The stems have cavities and a system of intercellular spaces that help consume oxygen when immersed in water, which also keeps them afloat.
Hydrophytes are divided into several species, each of which has its own habitat and performs a specific function in a given biozone. They are also characterized by a method of reproduction in which seeds spread under water: when they fall to the bottom, they begin to germinate.
Types of aquatic plants differ from the area where they are located:
- coastal, which are located along the coast, exposing some of the stems and leaves above the surface: horsetail, arrowhead, cattail, reeds, reeds;
- semi-aquatic: irises, pondeteria, susak, marigolds, etc.;
- aquatic, whose entire life is spent at the depth of the reservoir: water moss, hornwort, chara, nitella;
- floating on the surface or in the water column: pistia, fontinalis moss, water buttercup, duckweed, watercolor, marsh flower, water chestnut;
- deep-sea or submerged, which take root in the ground, and above the surface there are flowers: egg capsule, water lily, orontium, lotus;
- Oxygenators are plants immersed in water and actively releasing oxygen, which is necessary to ensure the vital activity of all inhabitants of the reservoir: water star, hornwort, marsh turcha, spicate urut.
Where do they grow
Few people think about it, but algae live almost everywhere where there is water - from small streams and swamps to huge oceans. Some species thrive in fresh water, while others prefer salty sea water.
But still, shallow waters and areas off the coast are most densely populated. The algae growing here receives the most benefits. On the one hand, there is enough sunlight needed for photosynthesis. On the other hand, the water warms up well and all living organisms, from tiny single-celled organisms to fish, act as actively as possible, releasing the carbon dioxide needed by the algae. With all this, it is possible to gain a foothold in the soil, receiving from it substances important for successful development. However, it is worth considering that not all aquatic plants take advantage of this opportunity. Many people prefer to either live on the surface of the water, or simply drift in the depths, never in their lives contacting the bottom and certainly not trying to gain a foothold in it.
The size of algae also varies greatly. Some cannot be seen without a microscope, while others can be tens of meters long. And all these underwater plants have names and detailed descriptions compiled by experienced biologists. Of course, it is simply impossible to talk about everyone - even the simplest algae deserves to have a book written about it. By the way, such an event actually took place in history. For example, connoisseurs are familiar with Konstantin Balmont’s book “Underwater Plants.” Of course, here he was looking at algae from the point of view of a poet, not a biologist. But such attention already says a lot.
Plants of natural reservoirs
All natural bodies of water are surrounded by thickets of coastal vegetation, which grows in stripes along the banks of rivers, lakes and ponds. The only exception may be the leeward side, which is devoid of large plantings.
Various types and forms of aquatic plants are grouped or arranged in stripes depending on the direction of flow or depth. Along the shore, as a rule, there are dense thickets of reeds or reeds with hard leaves. Fish prefer to live among plants with softer stems and leaves.
The species composition of underwater plants in natural reservoirs can change quite significantly over time, since some of them deplete the soil, release harmful substances into the bottom, and then die. They are also influenced by climate or weather changes, anthropogenic impact, and environmental pollution.
Moss balls
It is difficult to unambiguously provide a photo of the most unusual underwater plant in the world. Still, there are quite a lot of them and each is amazing in its own way. But, of course, one of them is moss balls.
They grow in only a few places on the globe: the Black Sea, the Tasman Sea, lakes in Iceland and Japan. As you can see, the list is very limited.
As the name implies, these are completely round plants - of course, not ideal from a geometric point of view, but close to that. Soft to the touch but dense, they resemble a ball of woolen thread - an extremely unusual phenomenon in the plant world.
As studies have shown, a small plant grows starting from the center and further - in all directions. The color is deep green and the size can vary considerably - usually from 10 to 30 centimeters in diameter! Some experts argue that this indicator depends on age, while others believe that it depends on environmental conditions.
This amazing plant has no root system, stem or leaves. Just an elegant, smooth ball of rich green color.
Coastal
Plants growing along the perimeter of the reservoir define the border with the shore. These include:
- The aquatic plant arrowhead (sagittaria or common bogwort) is widely used for landscaping ponds, its root is represented by cord-like shoots with rounded tubers, immersed in water, the stem has a porous tissue filled with air bubbles, its length is 0.2-1.1 m. Above-water part has a petiole, the leaves are triangular in shape, similar to an arrowhead up to 30 cm long. In mid-June, sagittaria blooms and blooms until the end of summer with white flowers with a spherical middle; inside the petal there may be red or cherry spots. In total, there are about 40 species of mireweed, including decorative varieties. Many of them are used to decorate man-made ponds and go well with other aquatic plants.
- Reed or ocheret is a herbaceous plant from the Poaceae family, which is found in the middle zone in all reservoirs with a depth of up to 1.5 m, has hard stems that repel fish, has long rhizomes, from which long hollow stems grow up to 5 m in height. The reed inflorescence is a violet-silver panicle. Used in oriental medicine.
- Skirpus or reed is a perennial pond plant, growing up to 3.5 m tall, has a cylindrical strong stem and paniculate/capitate inflorescence, prefers swampy places. Many people confuse it with reed.
- Cattail, which is often confused with reeds, has a rigid stem with long leaves, at the end of which there is a beautiful brown velvet ear with seeds. Grows in reservoirs up to 1.5 m deep.
Agricultural crops.
One of the leading food crops in the world is rice ( Oryza
) – is an aquatic grass. The North American Indians also consumed grain from Canadian rice, a different type of cereal that is now sold as a delicacy, usually served with game. Watercress, which grows in cold streams and along their banks, is also used as a spicy herb. Chinese cooking knows especially a lot of aquatic plants; among them are starch-rich tubers of arrowhead and marshwort (sitnyaga), horned water chestnut fruits (chilima), lotus rhizomes, etc. Some tribes eat pollen and starchy rhizomes of cattails.
Pondweed species are excellent food for waterfowl: ducks, for example, feed on the tubers and seeds of these plants. Other valuable foods for birds include reeds and Canadian rice. Moose eat the leaves of water lilies and other aquatic plants, and beavers eat their fleshy rhizomes. Starch-rich cattail rhizomes and arrowhead tubers serve as food for muskrats. Shoots of rushes, sedges, etc. provide good roughage for cattle.
Near-aquatic
Submerged or semi-aquatic plants are common in the wild and are available for cultivation in artificial ponds.
Examples of aquatic plants growing in shallow or near water:
- Swamp iris - distinguished by bright yellow flowers with a brown pattern, prefers sunlit areas and fertile soil, stem height up to 1.5 m, suitable for ponds, planted to a depth of 40 cm.
- Smooth iris - blooms from June to October with blue or purple flowers, up to 1 m high, and goes well with other aquatic plants.
- Marigold (Caltha) (marsh, thin-cupped, fistula, etc.) is a winter-hardy, unpretentious plant (poisonous!), prefers sunny places, tolerates flooding up to 20 cm, has golden, white-yellow flowers, planting depth depends on the variety (20-120 cm).
- Pondetheria - decorated with blue or purple flowers, loves the sun and nutritious soil, a capricious and non-winter-hardy plant (transported indoors for the winter), planting depth is about 8 cm.
- Susak (Butomus) is an unpretentious plant, blooms with small pink-crimson flowers, grows very quickly, planting depth is 10 cm.
- Amphibian knotweed (Persicaria) - blooms all summer with bright pink small flowers arranged in a cone; when planting, they are buried down to 0.5 m, it is better to plant in containers, winter-hardy and unpretentious.
Oxygenators
One of the most important types of underwater plants that supply the entire body of water with additional oxygen. Many of them are also used as food for fish. Their advantage is also the improvement of sanitary conditions and biological purification of water.
Names of aquatic plants-oxygenators:
- Common marsh grass (Callitriche), also called water star.
- Urut (Myriophyllum) belongs to the perennials of the Slanoyagodnikov family; it has shoots rising above the water and a creeping rhizome. Long stems (up to 1.5 m) are covered with thin leaves and form an elegant lace of thickets under water, for which it is called “pinnate”. It is grown as a coastal plant, propagated vegetatively, its parts can be planted directly into the ground to a depth of 1.2 m in the spring and summer. Looks great in small ponds, where it forms beautiful patterns under water.
- Turcha (Hottoni) - is a relative of primroses, has about 100 species in the Primrose family. The second name - “water feather” is given for the rosette consisting of dissected feathery leaves floating in the water. In the summer months, flower stalks appear, which rise 15-30 cm above the water and are decorated with flowers; in the fall it dies and overwinters at the bottom in the buds.
- Hornwort (Ceratophyllum) is dark green and has a long stem that branches at the top. The leaves are dissected into segments, grows at a depth of up to 9 m, has unique aquatic pollination, thanks to which it is widely distributed in water bodies of Russia and other European countries. Instead of roots, it has stems that hold the plant on the ground in the silt. In autumn, the upper part dies off, and the shoots with buds overwinter at the bottom of the reservoir.
- Elodea - belongs to the perennials of the Vodokrasaceae family, lives entirely under water, shoots branch up to 1 m long, and has small leaves located throughout the stem. It blooms very rarely with small white flowers with red sepals.
Hornwort
If we talk about underwater plants of lakes and rivers of our country, we cannot fail to mention hornwort. Quite delicate, thin, beautiful, but at the same time tenacious algae.
The appearance is very sophisticated. It has a thin but rather rigid stem. It is covered evenly on all sides with leaves that resemble thin needles like pine needles. Three or four leaves grow from one point. There are no roots, but there are special rhizoid branches that can easily penetrate the soil. However, roots are not particularly necessary. An interesting feature of hornwort is the ability to absorb useful substances from water over its entire surface - leaves, trunk, rhizoid branches.
The flowers are very small, almost invisible - they do not differ in color from the leaves and have a size of no more than two to three millimeters. It is not surprising that a not very attentive person may decide that the hornwort does not bloom.
It is found almost all over the world - from the tropics to the Arctic Circle. However, different types may vary. For example, experts distinguish light green hornwort and dark green. The first one grows all year round, as it lives mainly in warm climates. The second has adapted to the harsh winter, when a thick layer of ice almost does not allow light to pass through. By this time, the upper part of the plant becomes thicker and tougher, and the lower part simply dies. But with the arrival of spring, this “bump” comes to life and continues to grow.
It can grow well at different depths - from 1 meter to 10. Most often it depends on the light intensity. Hornwort does not like excessive amounts of light, preferring slightly shaded areas.
floating plants
Such plants can be successfully used to decorate an artificial pond. They do not require any maintenance, you just need to carefully monitor the growth rate so that the pond is not completely overgrown with them. The difference between these aquatic plants is that the roots are not fixed and therefore float freely, while the leaves and flowers are located on the surface.
The most popular floating ones:
- Duckweed covers the entire surface of the reservoir with a green carpet and is a small plant consisting of stems held together in several pieces (leaves). It blooms only in artificial reservoirs, reproduces vegetatively when young leaves are separated from the mother leaves, and overwinters at the bottom.
- Watercolor (Hydrocharis) is a perennial plant with small round leaves, a heart-shaped base, from which fleshy roots hang down. The flowers are small, white, located 3-5 cm above the surface of the water above the leaves.
- Azolla (Carolina or fern) came to Europe from the tropical reservoirs of America, resembles openwork moss, grows very quickly, which is why it has to be removed from the pond with a net, and by autumn the leaves acquire a reddish color.
- Eichhornia, which has the name “Water hyacinth,” is a floating, heat-loving plant with dark green leaves that blooms in late summer with lilac-blue or yellow orchid-like flowers. In the fall, it must be moved indoors to an aquarium, placing it in a ring float, where the plant successfully overwinters. According to scientists, it has fantastic abilities to process organic pollutants (that is, it loves dirty water bodies).
- Water chestnut (Chilim) is an annual plant with original fruits decorated with horns (for which it received the names “devil’s” and “horned”), with which it clings to the bottom. Floats thanks to leaves that have swellings with an air layer. It reproduces by self-pollination, but only in regions with a warm climate: in the second half of summer, white flowers appear, protruding above the water, and by autumn, hard drupes of 1-15 pieces ripen. on each plant, which gradually sink to the bottom.
Pemphigus
Probably every reader has heard about insectivorous plants that do not feed like their normal counterparts, but lead a predatory lifestyle. Because of this, a completely expected question may arise - are there underwater predatory plants? Surprisingly, the answer to this question will be positive. Bladderwort is capable of catching and eating not only insects, but also small animals and fish.
It can be found in most regions of the world. The only exceptions are some of the islands in Oceania - due to their isolation - and Antarctica - for obvious reasons. You can even see some types of bladderwort on the southeastern coast of Greenland, an acute region known for its extremely harsh climate.
The plant is quite tall, but has no leaves at all. It also contains no chlorophyll and is completely rootless. This means that it cannot feed in the usual way for most plants - it has to make do only by hunting.
There are a number of bubbles with small holes on the trunk. They have special valves on the inside. As soon as an insect flies into this bubble out of curiosity, it touches sensitive cells and the valve closes the exit. After some time, the victim dies, decomposes and serves as a nutrient medium for the plant.
deep sea
These aquatic plants have rhizomes buried in the bottom of the reservoir, and stems, leaves and flowers are located above its surface. Their main diet consists of organic matter in the bottom soil. The leaf blades are usually large in size. This creates shade and prevents the water from heating, which helps prevent the active proliferation of small algae. The main advantage of deep-sea species is their beautiful flowering.
Some types of deep-sea plants:
- Orontium or “Golden Club” (Orontium) is a perennial with green-blue leaves, silvery below, in April-May it blooms with inflorescences-cobs sticking out of the water (12-15 cm long), consisting of small yellow flowers, similar to white-yellow pencils.
- Nuphar (Nuphar) is a perennial that is widely used for landscaping large bodies of water that have shade. Its roots are fixed in the bottom soil, and leaves and yellow flowers floating on the surface, located on thick peduncles.
Nutrient requirements.
Free-floating plants, such as duckweed and aquatic ferns, obtain the salts they need for nutrition directly from the water, but most aquatic plants extract them, at least in part, from the bottom soil and develop best on a fertile, organic-rich substrate. In poor soils, such as sand, the growth of many species is inhibited, and some aquatic plants, particularly arrowhead ( Sagittaria
) and
Echinodorus
, under these conditions remain in the juvenile stage, which is often used by aquarists. For normal development, aquatic plants also need adequate lighting.
Water lily and lotus
These 2 types of deep-sea plants are among the most spectacular and spectacular, having bright beautiful flowers and large leaves. When planted in a home pond, they will become a wonderful decoration.
The water lily flower (Nymphaea) takes its name from water nymphs in various European mythologies. There are 35 species and are divided into 2 groups: tropical and winter-hardy. The latter are suitable for growing in open reservoirs in the central and northern parts of Russia, preferring sunny places with standing water. The required area for each plant is 0.5-4 square meters. m.
The most common winter-hardy varieties of water lilies:
- The white water lily, which is often found in natural reservoirs, has powerful roots up to 5 cm thick; petioles and peduncles are located on the surface, which begin flowering in May and continue until frost. The leaves are round and wide up to 25 cm, the flowers are snow-white, each lasts 4 days, after which the fruit sets under water. After ripening, the seeds spill out of the boxes and gradually sink to the bottom, where they then germinate.
- The flower of the fragrant water lily is white, emitting a pleasant aroma; the leaves are bright green in color, turning red at the bottom over time. Some varieties bloom yellow (spotted Sulphurea), pink or cream flowers.
- Hybrid water lily (nymphea) - becomes a decoration of any pond, thanks to its beautiful flowers and heart-shaped bright leaves (some with spots or red tints).
Lotus (Nelumbo) is a perennial aquatic plant, the leaves of which are located both under water and on the surface, funnel-shaped and large, up to 70 cm in diameter. The lotus is decorated with large fragrant flowers (up to 30 cm) with pink-white petals, brightly placed in the center -yellow stamens. The fruits are dark brown in color with 30 seeds, the germination of which lasts for tens and hundreds of years. In the East, this plant is worshiped and ancient legends and traditions are told. In Europe, it has been grown in greenhouses and artificial ponds since the 18th century.
Chemical composition of water.
According to the requirements for the chemical composition of water, four groups of aquatic plants can be distinguished: 1) species growing in soft, neutral or slightly acidic waters, common in areas where there is little limestone; 2) types of fresh waters rich in calcium carbonate; 3) types of desalinated sea and alkaline (rich in sulfates) waters of arid regions; 4) marine species. Some widespread aquatic plants grow well in different water chemical compositions, others - only in strictly defined ones. For example, Phyllospadix
found only in seawater,
Ruppia
only in brackish or alkaline water, many pondweeds (
Potamogeton
) prefer lime-rich water, and most pondweeds (
Isoetes
) grow only in soft swamp water.
Creating a reservoir: rules
Using aquatic plants to decorate an artificial pond in a garden plot or on the territory of a country house will create a unique natural landscape and provide the opportunity to admire beautiful leaves and flowers throughout the warm season.
Regardless of the size of such a reservoir, it is necessary to select several types of plants with different flowering periods, sizes and shapes of leaves, also taking into account their height and planting depth. The main rule is to maintain biobalance in an artificial pond, in which, for the safe coexistence of all plants, fish and microorganisms, it is necessary to ensure that the vegetation covers the water surface by half or more.
The center of the pond is given over to beautifully flowering plants - water lilies, the variety of which is selected based on the area of the pond. Coastal species (arrowhead, calamus, susak) are planted along the edge; forget-me-nots or marigold are planted in shallow water; moisture-loving plants (sedges, irises, daylilies) with a strong root system can be placed on the soil along the edge, which will help preserve the shore from erosion.
Free-swimming species (duckweed, teloris, vodokras) under favorable conditions multiply very quickly and can occupy the entire surface, so they must be periodically removed with a net.
Aquarium species.
Many aquatic plants, especially small ones, are grown in aquariums to decorate and enrich the water with oxygen. Elodea , thrive in heated water.
(
Anacharis
), some
Echinodorus
from South America,
Cryptocorne
from tropical Asia,
Aponogeton
from Madagascar, Africa and tropical Asia, and
Vallisneria
from Southern Europe.
Among the North American aquatic plants that are often bred in aquariums are eggplant ( Nuphar
), arrowhead, hornwort, Elodea, cabomba, pitwort, urut, duckweed and bladderwort. For successful growth of all these plants, sufficient light is required - solar or artificial. However, too much lighting is fraught with the rapid development of algae, which clouds the water.
