What are cereals? Cereals: types, cultivation characteristics, beneficial properties. Introduction to cereal crops The structure of the flower and fruit of plants of the cereal family

Botanical features of the family members

Classification

The cereal family includes about 600 genera and 9-10 thousand species. The modern APG II classification identifies the following subfamilies:

• Reed ( Arundinoideae)
• Bamboo ( Bambusoideae)
• Bluegrass ( Pooideae)
• Millet ( Panicoideae)
• Centothecoideae
• Chloridideae
• Feather grass ( Stipoideae)

Note: The last three subfamilies are not universally recognized. Thus, according to Takhtadzhyan’s classification, rice plants are considered instead ( Oryzoideae) and Polevichaceae ( Eragrostideae) .

Information about cereals in Russia at the end of the 19th - beginning of the 20th centuries (according to the Encyclopedic Dictionary of Brockhaus and Efron)

Cereals (Gramineae Juss.) is one of the most extensive and useful plant families for humans. This includes about 3,500 species, but there are probably more in nature. These are mainly herbs and, moreover, perennials; There are few trees or bushes, and those that exist grow in hot and warm countries.
The stems of all consist of knees (internodes), connected to each other by bridles, extremely pronounced and swollen. The knees of the vast majority are hollow, and inside the nodes there are very dense partitions, so that the stem resembles a tube, partitioned from place to place and knotted at the places where the partitions are placed; This achieves greater strength with as little material as possible. Such a stem is a typical culm (culmus). In rare cereals, the stem knees are not hollow, but filled with loose tissue with thin tufts; this is noticed, for example, in corn, sugar cane, sorghum and some others. In tree-like plants, such as bamboos, the knees are also hollow, and the partitions are unusually strong and thick. The roots of cereals are always secondary, because the main root either barely develops or dies early after germination, being replaced by lateral ones, forming a more or less large bundle of relatively thin roots protruding from under the outer layers of tissue of the stem base, from the lower nodes. Branching of cereals occurs in herbaceous plants either from the underground rhizome or from the lower nodes; the aerial part of the stem for the most part does not branch. Trees have rich branching, but the branches fall off as they age, so that the trunks appear, for example. in bamboos, exposed to half or more.
The leaves of cereals are always equipped with tubular sheaths, starting from the bottom of the nodes and clasping the knee to a considerable height. These vaginas are rarely completely intact; in most cases they have holes on the side opposite to the leaf, but, however, their edges overlap each other so that they fit tightly to the stem. The leaf blade directly extends from such a vagina. In most it is ribbon-shaped and no wider than the circumference of the stem, in some it is even narrower, in rare cases it is wider, such as. in millet. Mostly flat, but in dry-loving species, for example. of steppe cereals, it is rolled up in a tube towards itself, in the form of a twig, which prevents excessive evaporation (feather grass, white grass). At the border between the plate and the sheath, a thin and short process is noticed, which is therefore placed between the leaf and the stem and is called the lingula; it is either thin and translucent, or contains not only underdeveloped vascular-fibrous bundles, but even chlorophyll. Under the tongue, a transverse stripe is noticeable, paler and thinner than the rest of the leaf, representing a depression, concavely facing the side of the stem. This strip allows the sheet to bend to the side. Few, like bamboos, have a true petiole. The edges of the leaves are often lined with hard teeth that are invisible to the eye, giving them a rough feel to the touch and even sometimes a cutting ability. The veins in the leaves of cereals are approximately parallel in a large part of it, or slightly curved, but always converge towards the apex. The middle nerve, which can be distinguished in all cereals, is very pronounced in some (corn, bamboo, etc.). The lower leaves of cereals, that is, under which the shoots begin, often lack true sheaths and are incomparably shorter, appearing in the form of more or less developed scales. The leaf arrangement of cereals is two-row, as a result of which the sterile shoots, leafy to the top, appear as flat green feathers.
In the majority, the last stem knee before the inflorescence is extremely long and, turning into the inflorescence, often branches greatly. In a few, special types of involucres are formed during inflorescences, such as. in corn with female inflorescences, in Coix(Job's tears) Lygeum, but these are rare exceptions.
The internal structure of the stems and leaves of cereals is characteristic. The vascular-fibrous bundles in the stem are twofold: some run parallel to each other close to the surface, others, upon exiting the leaves, are directed indirectly to the middle of the stem, and then approach its surface and merge with the bundles below, so in the cross section the vascular-fibrous bundles fibrous bundles of cereals, like other monocots, are distributed over the entire cut surface. In the majority, however, the internal tissue, as said, is destroyed, but where such destruction does not occur (see above), this tissue, consisting of large faceted cells, takes up a lot of space. In sugar cane it is filled with a thick sugar solution; also in sweet sorghum, etc. At the nodes, nodal buds and shoots, where they are present, send out transverse branches of vascular bundles, forming a dense network, helping to strengthen the partitions dividing the stem. In the leaves, the vascular-fibrous bundles run parallel, converging, however, towards the apex, and each bundle is surrounded by green parenchyma, so that the entire leaf consists of narrow ridges, between which thin transparent tissue is placed; therefore, the leaf in cross section presents a series of papillae and grooves. Each vascular-fibrous bundle has, for the most part, a parallelogram or oval shape in cross section. The entire bundle is equipped with a more or less developed sheath of thick-walled (sclerenichymatic) cells, and inside there are usually 2 very large spotted vessels, between which in front, that is, on the side facing outward, lattice elements are collected, and behind - large spiral vessels and woody parenchyma. Since there is no cambium, that is, an active educational layer, the bunch and the entire stem do not thicken. Bundles of leaves are similar to stems. A lot of silica is deposited in the external tissues, namely in the cell walls; the denticles along the edges of the leaves are nothing more than prominent silicified cells.
The inflorescences of cereals are very diverse, but the basis of each is the so-called spikelet (spicola). It is easy to learn, e.g. in oats, where it is relatively large. The spikelet is a short branch on which several scale-like leaves sit. Oats have 4 such scales, placed in 2 rows and alternating with each other. The lower ones are empty and close together (they are called coverts), the upper two have a flower in their corners and are called external floral scales, each flower is also equipped with its own scale, located opposite the outer one and called the internal floral scale. The covering scales are so much larger than the rest that they completely enclose the entire spikelet when it is not open. There is also a third flower in the oat spikelet, sitting higher than the others, but it is underdeveloped. Other cereal flowers have fewer or more spikelets. For some, for example. for Belous, only one, for others up to 10 or more. The size and development of the scales that make up the spikelet are very different: in some only one covering scale develops, in others their number increases. The spikelets, in turn, are connected in the form of complex inflorescences, such as: a simple spike, a complex spike (wheat, rye), a plume or hair-like panicle, a spreading panicle. The outer flower scales often bear more or less long awns at the tip or back, giving the inflorescences a peculiar, fluffy appearance; the fluffy-hairy awns of the common feather grass are especially long.
The flowers of cereals themselves are small and for the most part bisexual, although in rare cases they are unisexual, like those of corn. A cereal flower consists of 3 stamens, the anthers of which hang on thin and delicate threads, and a single-locular ovary bearing 2 stigmas or a style forked at the top. The stigmas have different pubescence, characteristic of different genera. With such a flower there are usually 2, rarely 3, delicate films, considered to be the perianth. One ovule. Rare cereals have 6 or only 2 stamens (fragrant spikelet). The fruit of cereals is accepted in the community as their seed - it is a grain or caryopsis, the only seed tightly grown and fused with the fruit, the main mass of which is mealy protein; Some bamboo fruits are berry-shaped. So in Melocanna bambusoides Trin. The fruit is about the size of a large apple and is eaten. A small embryo is located in the lower part of the seed on the side, directly under the integument (pericarp), and forms a slight swelling on the surface of the fruit. Its spine is facing downwards, and therefore easily breaks off during careless machine threshing. The cells contain the most protein - coarse starch, and protein, nitrogen-containing substances are collected mainly in the outer layers of the grain. Therefore, when peeling, the most nutritious, although less digestible, part is removed with the bran. During germination, the roots break through the base of the embryo. The first of them, the main one, soon freezes. There are not many deviations from the described structure of the flower and inflorescence; they are indicated in the description of the corresponding genera.

Cereals are clearly related only to the sedge family. They form such a natural group that their separation is difficult and has not yet been done entirely satisfactorily.

• I. Half-family. Millet ( Panicoideae R.Br.). Flowers in spikelets develop from. tops to base. Each spikelet contains, for the most part, 2 flowers, of which the lower one under-grows, being a barren flower or a male one. Distributed mainly in hot countries.
  • Knee 1. Rice (Oryzeae R. Br.). The spikelets contain 1 full flower and 1 or 2 underdeveloped lateral flowers. There are often 6 stamens.
    • Genera: Rice ( Oryza L.), water rice ( Hydropyrom Link), Zizania L., Ehrharta Thunb. etc.
  • Knee 2. Canaries (Phalarideae). The spikelets mostly have 2 underdeveloped and one full flower. There are 3 stamens, sometimes 2. The inflorescence is often a dense panicle.
    • Genera: Canary, canary seed - Phalaris L., Chapolocha - Hierochloa Gmel., Scented spikelet - Anthoxanthum L., etc.
  • Knee 3. Maydeae. Flowers are unisexual: male and female on the same plant, but often in different inflorescences. They differ from other Z. in many respects. This includes Corn - Zea L., Euchlaena Schrad., Job's or Mother of God's Tears - Coix L. and so on.
  • Leg 4. Saccharineae N. ab E. or Andropogoneae auct. pl. The spikelets contain one full spikelet and one male or empty spikelet; they sit in pairs - less often 3: one or 2 on a stalk, the other without it. Large, sometimes branchy herbs.
    • Genera: Sugar - Saccharum L., Alang-Alang - Imperata Cyr., Sorghum or gomi, beyond the Caucasus, where Panicum italicum, Andropogon L., etc. are apparently also called by this name.
  • Knee 5. Millet (Paniceae Kunth). Spikelets 2 flowered, the lower one incomplete. Covering scales are more delicate than floral scales, sometimes even disappear. Plants mainly from hot countries.
    • Genera: Millet - Panicum L., Crabgrass - Digitaria Scop., Bristlegrass - Setaria P. V., Paspolum L., Olyra L., Pennisetum P. B.
• II. Half-family Poeideae R.Br.. The spikelets contain from 1 to a large number of flowers, which develop from the base to the center, so that the undergrown flowers are the apical ones. More common in temperate countries.
  • Knee 6. Chlorideae Kunth. The spikelets are located in rows, on the inner sides of the branches of the inflorescence, which are collected in bunches or alternating.
    • Genera: Cynodon Rich., Chloris Rich., Eleusine G., Beckmannia Host. and so on.
  • Knee 7. Feather grasses (Stipaceae Kunth.). The spikelets are single-colored, the covering scales fit tightly to the grain, and in many the awns are sometimes extremely long.
    • Genera: Bor - Milium L. Feather grass - Stipa L. - with the subgenus Lasiagrostis Link., Aristida L., etc.
  • Knee 8. Polentinaceae (Agrostideae A. Br.). The spikelets are mostly single-flowered, with no awns or very insignificant ones. The panicle is compressed or spreading.
    • Genera: Arzhenets or Timofeyka - Phleum L. Butlachiki or Foxtail - Alopecurus L., Polevitsa - Agrostis L., Veinik - Salamagrostis Ad. and so on.
  • Knee 9. Oats (Avenaceae Kunth.). The panicles are spreading, the spikelets contain 3 flowers, of which the upper one is underdeveloped, the outer covering scales wrap around and close the entire spikelet.
    • Genera: Oats - Avena L. Meadow - Aira L., Triodia R. Br. and so on.
  • Knee 10. Pappoforeae Kunth. There are 2 or more flowers in a spikelet. The lower floral scales are fragmented into parts, often turning into awns.
    • Genera: Sesleria - Sesleria Scop., Echinaria Desf. etc.
  • Knee 11. Reed (Arundinaceae Kunth). The spikelets are multi-flowered, with long hairs on all or the top flower.
    • Genera: Reed - Arundo L., Reed - Phragmites Trin., Molina Echrh., Gynerium N. et V., etc.
  • Knee 12. Festuaceae (Festucaceae). Spikelets multi-flowered, less often 2-flowered, often with awns, inflorescence panicle, herbs.
    • Genera: Pearl barley - Melica L., Keleria - Koeleria Pers., Shaker - Briza L., Bluegrass - Poa L., Manna - Glyceria R. Br., Fescue - Festuca L., Brome - Bromus L., etc.
  • Knee 13. Bamboo (Bambuseae). The same as for fescue, but the trees and shrubs are branched, the leaves are often petiolate, and the fruit is sometimes fleshy.
    • Genera: Bamboo - Bambusa Schreb., Arundinaria Rich. etc.
  • Knee 14. Barley (Hordeaceae Kunth.). Inflorescence spikelets, spikelets on projections of the main stem.
    • Genera: Wheat - Triticum L., Rye - Secale E., Aegilops - Aegilops L., Barley - Hordeum Monch., Tares - Lolium L., Belous - Nardus L.

There are 300 genera and 3,200 to 3,500 species known so far, distributed throughout the globe and under all climates. They reach the limits of all vegetation, on the islands of the Arctic Ocean, and on high mountains - to the line of eternal snow. In terms of the number of species, there are most of them between the tropics, but in terms of the number of individuals - in temperate, and, moreover, in moderately cold countries, since it is Z. that serves as the basis for real meadows; they mainly form turf. In hot countries, where meadows correspond to shrouds, bamboo grows taller than human height, and bamboo forms indestructible forests. The benefits brought by Z. to humans are such that in this respect they are far superior to all other families. Not a single cultivated plant extends as far to the pole as Z., namely barley, not to mention fodder. This is indicated in more detail in the descriptions of individual Z.

Among all families of flowering plants, grasses occupy a special position. It is determined not only by their high economic value, but also by the large role they play in the composition of herbaceous vegetation groups - meadows, steppes, prairies and pampas, as well as savannas. Cereals include the main food plants of mankind - soft wheat (Triticum aestivum), rice (Oryza sativa) and corn (Zea mays), as well as many other grain crops that supply us with such necessary products as flour and cereals. Perhaps no less important is the use of cereals as feed plants for domestic animals. The economic importance of cereals is also diverse in many other respects.

There are 650 genera and: from 9,000 to 10,000 species of cereals. The range of this family covers the entire landmass of the globe, excluding areas covered with ice. Poa (Roa), fescue (Festuca), pike (Deschampsia), foxtail (Alopecurus) and some other genera of grasses reach the northern (in the Arctic) and southern (in the Antarctic) limits of the existence of flowering plants. Among the flowering plants that rise highest in the mountains, cereals also occupy one of the first places.

Cereals are characterized by a relative uniformity of their distribution on Earth. In tropical countries this family is about as rich in species as in temperate countries, and in the Arctic the cereals rank first among other families in the number of species. Among the cereals there are relatively few narrow endemics, but they are cited for Australia - 632, for India - 143, for Madagascar - 106, for the Cape Region - 102. In the USSR, Central Asia (about 80) and the Caucasus (about 60) are rich in endemic cereals species). Cereals are usually easy to recognize by their appearance. They usually have articulated stems with well-developed nodes and two-rowed alternate leaves, divided into a sheath covering the stem, a linear or lanceolate blade with parallel venation, and a membranous outgrowth located at the base of the blade, called a ligule or ligula. The vast majority of cereals are herbaceous plants, however, many representatives of the bamboo subfamily (Bambusoideae) have tall, highly branched in the upper part, with numerous nodes, stems that become heavily lignified, however, retaining the structure typical of cereals. In South American species of bamboo (Bambusa), they are up to 30 m high and 20 cm in diameter. In the South Asian giant dendrocalamus (Dendrocalamus giganteus), the 40 m tall stem is as tall as many trees. Among bamboo, climbing or climbing, sometimes thorny liana-like forms are also known (for example, Asian Dinochloa - Dinochloa). The life forms of herbaceous cereals are also quite diverse, although outwardly they appear to be the same. Among the cereals there are many annuals, but perennial species, which can be turfy or have long creeping rhizomes, predominate significantly.

Like most other monocots, grasses are characterized by a fibrous root system, which is formed as a result of underdevelopment of the main root and its very early replacement by adventitious roots. Already during seed germination, 1 to 7 such adventitious roots develop, forming the primary root system, but after a few days, secondary adventitious roots begin to develop from the lower adjacent nodes of the seedling, from which the root system of an adult plant is usually composed. In cereals with tall, erect stems (for example, corn), adventitious roots can also develop from nodes above the soil surface, acting as supporting roots.

In most cereals, branching of shoots occurs only at their base, where the so-called tillering zone is located, consisting of closely spaced nodes. In the axils of the leaves extending from these nodes, buds are formed, giving rise to lateral shoots. According to the direction of growth, the latter are divided into intravaginal (intravaginal) and extravaginal (extravaginal). When an intravaginal shoot is formed (Fig. 192, 1), the axillary bud grows vertically upward inside the sheath of its covering leaf. With this method of shoot formation, very dense turfs are formed, as in many species of feather grass (Stipa) or fescue (Festuca valesiaca). The bud of the extravaginal shoot begins to grow horizontally and pierces the sheath of the covering leaf with its apex (Fig. 192, 2). This method of shoot formation is especially characteristic of species with long creeping underground shoots-rhizomes, for example, creeping wheatgrass (Elytrigia repens). However, there are frequent cases when extravaginal shoots quickly change the direction of their growth to vertical, as a result of which turfs are formed that are no less dense than with the intravaginal method of shoot formation. In many cereals, mixed shoot formation is also known, when each plant produces shoots of both types (Fig. 192).

Branching of stems in their middle and upper parts is rare in grasses from extratropical countries and usually only in species with stems creeping along the ground (for example, in the coastal plant - Aeluropus). Much more often it can be seen in cereals of the tropics, and their lateral shoots usually end in inflorescences. Turfs of such cereals often resemble bouquets or brooms in appearance. Stems that are especially strongly branched in the upper part are characteristic of large bamboo trees, and they even have a whorled arrangement of lateral branches, for example, in some Central American species of bamboo - Chusquea (Fig. 193, 5). Many grasses with creeping and rooting above-ground shoots at nodes, for example, bison grass (Buchloé dactyloides) of the North American prairie (Fig. 194, 6), can form large clones that cover the soil with a thick carpet. Also in the North American Muhlenbergia torreyi and some other species, such clones grow along the periphery and die off in the middle, forming something like “witch’s rings” in some types of mushrooms.

For perennial grasses of extratropical countries, the formation of often very numerous shortened vegetative shoots with nodes closely spaced at their base is very characteristic. Such shoots can exist for one or several years and then begin to flower. Elongated reproductive shoots are formed from them after the emergence of the primordium of the general inflorescence due to the rapid intercalary growth of internodes. In this case, each segment of the cereal shoot grows independently under the protection of the leaf sheath, having its own zone of intercalary meristem. The pith in growing internodes usually dies quickly and they become hollow, but in many cereals of tropical origin (for example, corn), the pith is not only preserved throughout the stem, but also has scattered vascular bundles. Many bamboo-like vines also have internodes filled with pith. Sometimes, during the transition to an elongated reproductive shoot, only the uppermost internode, located under the inflorescence, lengthens, for example, in the blue molinia (Molinia coerulea).

As a rule, the stems of cereals have a cylindrical shape, but there are also species with strongly flattened stems, for example, the common bluegrass (Poa compressa), which is widespread in the European part of the USSR. Some of the lower shortened internodes of the stem may thicken in a tuberous manner, serving as a storage facility for nutrients or water. This feature is present in some ephemeral cereals (for example, bulbous barley - Hordeum bulbosum), but it also occurs in mesophilic meadow species. In the bluegrass (Poa sylvicola), the shortened internodes of creeping underground shoots become tuberously thickened.

Signs of the anatomical structure of the stem are used in the taxonomy of cereals. Thus, most extratropical grasses, usually called festucoid (from Festuca - fescue), are characterized by internodes of stems with a wide cavity and an arrangement of bundles of conductive tissue in 2 circles (the outer one of smaller bundles), and for predominantly tropical ones - panicoid (from Panicum - millet) - internodes with or without a narrow cavity and with the arrangement of vascular bundles in many circles.

The leaves of cereals are always arranged alternately and almost always in two rows. Only the Australian genus Micraira has a spiral leaf arrangement. Leaves in the form of more or less leathery scales, homologous to leaf sheaths, are usually present on the rhizomes, and often also at the base of above-ground shoots. In many bamboo trees, falling scale-like leaves without blades or with very small blades are often located along almost the entire length of the main shoot. The scales have a predominantly protective significance and usually follow the very first leaf-shaped organ of the shoot - always a scale-like and usually two-keeled preleaf.

In ordinary, assimilating leaves, the sheath is formed by the base of the leaf that has grown in the form of a sheath enveloping the stem and serves as protection for the growing internode. The sheaths of cereals can be either split to the base (for example, in the predominantly tropical tribes of millet - Paniceae and sorghum - Andropogoneae), or fused at the edges into a tube (in the tribes of brome - Bromeae and pearl barley - Meliceae). In some species of steppes and semi-deserts (for example, in the bulbous bluegrass - Poa bulbosa, Fig. 195, 4), the leaf sheaths of vegetative shoots become a storage organ, and the shoot as a whole resembles a bulb. In many cereals, dead sheaths of the lower leaves protect the base of the shoots from excessive evaporation or overheating. When the vascular bundles of the sheaths are connected to each other by strong anastomoses, a mesh-fibrous sheath is formed at the base of the shoots, characteristic, for example, of the coastal brome (Bromopsis riparia), common in the steppes of the European part of the USSR.

Located at the base of the leaf blade and directed vertically upward, a membranous or thin-skinned outgrowth - a tongue, or ligula, apparently prevents the penetration of water, and with it bacteria and fungal spores, into the vagina. It is no coincidence that it is well developed in mesophilic and hydrophilic grasses, and in many xerophilic groups, especially in the bent subfamily (Eragrostoideae), it is modified into a series of densely located hairs. In most species of the widespread genus Echinochloa and in the North American genus Neostapfia, the uvula is completely absent and the vagina merges into a plate without a clearly defined boundary between them. On the contrary, the Mexican Muhlenbergia macroura has very long (2-4 cm) tongues. At the top of the vagina on the sides: from the uvula, some grasses (especially bamboo) have 2 lanceolate, often crescent-shaped outgrowths called ears.

In the vast majority of cereals, the leaf blades have parallel veins, a linear or linear-lanceolate shape, and are connected to the sheath by a wide or only slightly narrowed base. However, in the genus Arthraxon and in a number of other, mainly tropical, genera they are lanceolate-ovate, and in two African genera - Phyllorachis and Umbertochloa - they are even arrow-shaped at the base (Fig. 196, 10) . In the bamboo subfamily, the leaf blades are usually lanceolate and narrowed at the base into a more or less developed petiole. In the Brazilian herbaceous bamboo Anomochloa, the leaf blades are heart-shaped and connected to the sheaths by a petiole up to 25 cm long (Fig. 197, 7). The leaves of another American genus, Pharus, also have very long petioles, which have another feature not characteristic of other cereals - pinnate venation of the blades. In most bamboo, as well as in some broad-leaved grasses from other subfamilies, the leaf blades have well-developed transverse anastomoses between parallel main veins. The overall dimensions of the leaf blades also vary greatly. In the North American littoral species Monanthochloe littoralis, the plates of densely arranged leaves rarely exceed 1 cm in length, and in the South American bamboo neurolepis elata they are up to 5 m long and 0.6 m wide. Very narrow, bristly folded along or Many types of feather grass, fescue, and other, usually xerophilic grasses have folded leaf blades. In the African miscanthidium teretifolium, very narrow plates are represented almost by the midrib alone.

The anatomical structure of leaf blades as a systematic character is of even greater value in cereals than the anatomical structure of stems, and is usually characteristic of subfamilies and tribes. Currently, there are 6 main types of anatomical structure of leaf blades: festucoid, bamboozoid (from Bambusa - bamboo), arundinoid (from Arundo - arundo), panicoid, aristidoid (from Aristida - triostida) and chloridoid or eragrostoid (from Chloris - - chloris and Eragrostis - bent grass). The festucoid type (mainly extratropical tribes of cereals) is characterized by a disordered arrangement of chlorenchyma, a well-developed internal (sclerenchyma) and relatively weakly demarcated external (parenchyma) lining of vascular bundles (Fig. 198, 1). The bamboozoid type, characteristic of the bamboo subfamily, is in many ways similar to the festucoid type, but differs in chlorenchyma, consisting of peculiar lobed cells located in rows parallel to the epidermis, as well as an outer covering of vascular bundles that is more separate from chlorenchyma (Fig. 198, 2). With the arundinoid type, characteristic of the reed subfamily (Arundinoideae), the inner lining of the bundles is poorly developed, and the outer one is well developed and consists of large cells without chloroplasts; chlorenchyma cells are located densely and partly radially around the bundles. The remaining types (mainly the tropical subfamilies bentgrass and millet) are characterized by a radial (or crown) arrangement of chlorenchyma around the vascular bundles, and in the chloridoid type the internal (sclerenchyma) lining of the bundles is well developed, and in the panicoid and aristidoid types it is absent or poorly developed (Fig. 198, 5).

It turned out that the radial (crown) arrangement of chlorenchyma and the well-separated outer (parenchyma) lining of the vascular bundles are associated with many other physiological and biochemical features (the so-called kranz syndrome, from German kranz - wreath), primarily a special method of photosynthesis -- C4 pathway of carbon dioxide fixation, or cooperative photosynthesis, based on the cooperation of chlorenchyma cells and parenchyma sheaths that perform different functions. Compared to the usual C3 by fixing carbon dioxide, this path is very economical in terms of moisture consumption and is therefore beneficial when living in arid conditions. The advantages of kranz syndrome can be seen in the example of the species of bentgrass (Eragrostis), bristleweed (Setaria) and lyricist (Crypsis) in the southern regions of the USSR: the maximum development of these species occurs in the driest time of the year here - July - August, when the majority cereals ends the growing season.

According to the structure of the epidermis of the leaves, especially the silicified cells and hairs, the above types of anatomical structure of the leaves are also clearly distinguished. The stomata of cereals are very peculiar. They are paracytic, with guard cells of a special, so-called graminoid type. In the middle part, these cells are narrow with very thick walls, and at the ends, on the contrary, they are expanded with thin walls. This structure allows you to regulate the width of the stomatal fissure by expanding or narrowing the thin-walled parts of the guard cells.

Cereal flowers are adapted to wind pollination and have a reduced perianth, stamens with long flexible filaments and anthers hanging on them, long feathery stigmas and completely dry pollen grains with a smooth surface. They are collected into elementary inflorescences very characteristic of cereals - spikelets, which, in turn, form general inflorescences of various types - panicles, brushes, ears or heads. A typical multi-flowered spikelet (Fig. 199, 1) consists of an axis and two rows of scales alternately located on it. The two lowest scales, which do not bear flowers in their axils, are called spikelets - lower and upper (usually larger), and the higher located scales with flowers and their axils are called lower floral scales. Both are homologous to leaf sheaths, with the lower lemmas often bearing awn-like appendages that are generally considered homologous to leaf blades. Some bamboo have more than two glumes, and in the leaf glume (Phyllostachys) such glumes often bear small leaf blades (Fig. 200, 7). On the contrary, in some herbaceous cereals one (in the chaff - Lolium) or both (in the sheath - Coleanthus, Fig. 201, 6) glumes can be completely reduced. True glumes are in origin the upper leaves, and not bracts (bractea), like the lower glumes. However, in many cases (especially in the millet tribe) the reduction of flowers in the axils of the lowermost lemmas makes the latter very similar to additional glumes. The spikelets and lower floral scales of the most primitive bamboo have, like the leaf sheaths, a large and variable number of veins, which during the evolution of the family decreased to 5, 3 or even 1 vein.

The number of flowers in spikelets can vary from very large and indefinite (for example, in two-spikelet - Trachynia - up to 30 flowers, Fig. 201, 14, 15) to constantly one (in reed grass or foxtail) or two (in calamus - Aira ). Chinese bamboo (Pleioblastus dolichanthus) has very primitive multi-flowered spikelets with a highly elongated and often branched axis. Such spikelets are more similar not to spikelets, but to branches of a paniculate general inflorescence (Fig. 200, 1). Even less distinguishable are the spikelets in the general inflorescences of the tropical bamboo Melocanna. In the axils of the arranged lower flower scales, not 1, but 2 or 3 flowers are placed on lateral axes equipped with bracts. It is likely that the evolution of common inflorescences in cereals went from such common inflorescences, not yet differentiated into spikelets, to inflorescences with well-separated, first multi-flowered, and then single-flowered spikelets.

The axis of a multifloral spikelet usually has articulations under each lower floral scale and, when fruiting, splits into segments. The base of the lower flower scale, fused with such a segment, forms a thickened callus, which can be long and sharp, like that of a feather grass. The part of the spikelet that includes one flower, the lemma and the adjacent segment of the spikelet axis is often called the anthecia. In single-flowered spikelets, there may be no articulation under the lower flower scale, and then the spikelets fall off completely when fruiting.

Common inflorescences of cereals usually have the form of a panicle, often very dense and spike-shaped, a brush or spike. Only small specimens of two-spikelet (Fig. 201, 14), species of brome (Bromus) and some other cereals bear only one large spikelet at the top of the stem. There are also very dense, head-shaped common inflorescences, for example, in the African bamboo oxytenanthera abyssinica (Oxytenanthera abyssinica, Fig. 193, 1) or in the Mediterranean ephemerals of the hedgehog (Echinaria, Fig. 201, 11), and the sandbox (Ammochloa, Fig. 201, 7 ). In the thorny bristlecone (Cenchrus), the common inflorescence consists of several spiny heads (Fig. 202, 8, 9). The result of a higher specialization of common inflorescences is the ordered arrangement of spikelets one at a time or in groups of 2-3 on one side of the flattened axes of spike-shaped branches, which, in turn, can be arranged alternately or palmately (as in the pigweed - Cynodon, Fig. 194 , 4). With this arrangement of spikelets, especially characteristic of the millet, sorghum and pigwort tribes, some of the spikelets on spike-shaped branches (usually located on stalks next to sessile bisexual spikelets) may be male or even have only a rudiment of a flower. In Artraxon from the sorghum tribe, only a stalk with a barely noticeable rudiment of a spikelet remains from the spikelet on the stalk. Unisexual spikelets are generally not so rare in cereals. In this case, spikelets with male and spikelets with female flowers can be located within the same inflorescence (in Zizania, Fig. 196, 7, 9), on different inflorescences of the same plant (in corn) or on different plants (in Pampas grass, or Cortaderia Sello - Cortaderia selloana, table 45, 3, 4).

In the axils of the lower floral scales on the side of the spikelet axis there is another scale, usually having 2 keels and a more or less noticeable notch at the apex. Since it does not belong to the axis of the spikelet, but to the axis of the flower and, therefore, is located above the base of the lower lemma, it is called the upper lemma. Previously, L. Chelakovsky (1889, 1894) and other authors took it for 2 fused segments of the outer circle of the perianth, but now most authors consider it the preleaf of a strongly shortened shoot located in the axil of the lower floral scale, bearing a flower. In some genera of grasses (for example, in foxtail), the upper floral scale can be completely reduced, and in the very original American herbaceous bamboo streptochaeta (Streptochaeta), it is split almost to the base.

Above the upper floral scale, on the flower axis of the vast majority of cereals, there are 2 small colorless scales, called floral membranes or lodicules. There is still no consensus regarding their nature. Some authors take them for the rudiments of one of the two three-membered perianth circles, others for the rudiments of bracts. The presence of a third, dorsal lodicule in many bamboo, as well as in the genera of the feather grass tribe, seems to confirm the first of these points of view, although the dorsal lodicule usually differs in structure from the two ventral ones, usually closely approximated and often connected to each other at the base.

The structure of the lodicules is considered an important systematic character characteristic of entire tribes of cereals (Fig. 203). Many bamboo plants have large scale-like lodicules with vascular bundles, where they have a predominantly protective function. In most other cereals, the lodicules have the appearance of small solid or bilobed scales, devoid or almost devoid of vascular bundles and strongly thickened in the lower half. It is assumed that such lodicules accumulate nutrients for the development of the ovary, regulate the water regime of the flower and contribute to the spreading of the flower scales during flowering. Usually there are 4 main types of lodicule structure: bambusoid, festucoid, panicoid and chloridoid, corresponding to the main types of leaf anatomy. Often there is also a melicoid type (from Melica - pearl barley), characteristic of the pearl barley tribe (Meliceae): very short (as if chopped off at the top) lodicules stick together with their anterior edges. The streptochaete mentioned above has 3 large, spirally arranged lodicules, but not all authors mistake them for lodicules. Finally, in many genera (including foxtail and sheathweed) the lodicules are completely reduced.

The most primitive number of stamens - 6 - is found among cereals only in many bamboo and rice plants (Oryzoideae). The vast majority of cereals have 3 stamens, and in some genera their number is reduced to 2 (in the fragrant spikelet - Anthoxanthum) or to 1 (in the cinnamon - Cinna). The number and structure of stamens varies greatly in the bamboo subfamily. Thus, in the South Asian genus Ochlandra, the filaments of stamens branch multiple times, as a result of which one flower can have up to 50-120 stamens. In the genera Gigantochloa and Oxytenanthera, the filaments of 6 stamens grow together into a rather long tube surrounding the ovary (Fig. 193, 3). Brazilian Anomochloa has 4 stamens. The filaments of cereal stamens can quickly elongate during flowering. So, in rice they lengthen by 2.5 mm per minute. Pollen grains of cereals are always single-pore with a smooth and dry shell, which is an adaptation to wind pollination.

There is still no consensus on the structure of the gynoecium in a cereal flower. According to a more widely accepted point of view, the gynoecium of cereals is formed by 3 carpels fused at their edges, and the fruit of cereals - the caryopsis - is a type of paracarpous fruit. According to another point of view, the gynoecium of cereals is formed by one carpel, which is a consequence of the reduction of the other two carpels of the primarily 3-membered apocarpous gynoecium. The ovary is always unilocular with a single ovule, which can be orthotropic to hemitropic (rarely campylotropic) with a downward directed micropyle. The integument is usually double, but in the otherwise anomalous genus Melocanna it is simple. Usually the ovary transforms at the apex into 2 pinnately hairy stigmatic branches, but many bamboo can have 3 of them. The bare bases of the stigmatic branches vary greatly in length in different tribes. They are especially long in the predominantly tropical millet tribe, which is apparently due to more closely closed floral scales. In some cereals, the stigmatic branches may be fused with each other along their entire or almost entire length. Thus, in corn, only the upper parts of very long stigmatic branches are free, and in white beetle (Nardus), the ovary passes at the apex into a completely solid thread-like stigma, covered not with hairs, as in other cereals, but with short papillae. In bamboo - streptogyna (Streptogyna), the stigma branches covered with spines after flowering become very rigid and serve for the spread of grains (Fig. 204, 4).

The indehiscent dry single-seeded fruit of cereals, called the caryopsis, has a thin pericarp, usually so tightly adjacent to the seed coat that it appears fused with it. Often, when a caryopsis ripens, its pericarp sticks together with the flower scales tightly adjacent to it. In the sporobolus (Sporobolus), the pericarp remains separated from the seed and the caryopsis in this case is called sac-shaped. The shape of the grains varies from almost spherical (in millet) to narrow-cylindrical (in many feather grasses). On the convex, flat or concave in the form of a longitudinal groove, the ventral (ventral) side of the caryopsis has a scar, or hylum, usually painted in a darker color compared to the rest of the caryopsis and having a shape from almost round (in bluegrass) to linear and almost equal in size. the length of the entire grain (in wheat). The hilum is the site of attachment of the ovule to the peduncle (funiculus), and its shape is determined by the orientation of the ovule.

The most original in their structure are the caryopsis of some bamboo, which can be berry-shaped with a thick fleshy pericarp or nut-shaped with a rather thick and very hard consistency pericarp, separated from the seed coat. In Melocanna, which is widespread in Southeast Asia, the berry-shaped caryopses are obverse pear-shaped and reach 3-6 cm in diameter (Fig. 193, 9, 10). They have one more feature that is absent in all other cereals: during the development of the embryo, the endosperm of the seed is completely absorbed by the embryo and in the mature grain only a dry film remains between the pericarp and the greatly expanded scutellum.

In all other cereals, the majority of the mature grain is endosperm, and the ratio in the sizes of the endosperm and the embryo is of significant systematic importance. Thus, festucoid cereals are characterized by relatively small embryo sizes, while panicoid cereals are characterized by larger embryos compared to the endosperm. Typically, the endosperm of mature grains is hard in consistency, but it can be looser - mealy, when there is little protein in it, or denser - glassy when there is a relatively high protein content. It can be noted that the endosperm of cereal grains contains prolamin proteins, which are very characteristic of them and not found in other plants. In the grains of some cereals (especially from the oat tribe), the endosperm is especially rich in oils and retains a semi-liquid (jelly-like) consistency during their full maturity. This endosperm is characterized by extraordinary resistance to drying, maintaining a semi-liquid consistency even in grains stored in herbariums for over 50 years.

Endosperm starch grains have different structures in different groups of cereals. Thus, in wheat and other representatives of the wheat tribe they are simple, very variable in size and without noticeable edges on their surface (triticoid type, from the Latin Triticum - wheat); in millet and other festucoid cereals they are also simple, but less variable in size and have a granular surface, while in fescue and many other festucoid cereals the starch grains are complex, consisting of smaller granules (Fig. 205).

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The embryo of cereals (Fig. 206) is quite different in structure from the embryos of other monocots. On the side adjacent to the endosperm, it has a thyroid body - the scutellum. Outside of it and closer to its upper part there is an embryonic bud, covered with a two-keeled vagina-shaped leaf - coleoptile. In many cereals, against the scutellum on the outer side of the bud there is a small folded outgrowth - the epiblast. In the lower part of the embryo there is an embryonic root, covered with a root sheath, or coleorhiza. The nature of all these parts of the embryo is a matter of debate. The scutellum is usually taken to be a single, modified cotyledon, and the coleoptile is taken to be its outgrowth or the first leaf of a bud. The epiblast, when present, is taken either as a folded outgrowth of the coleorhiza, or as a rudiment of the second cotyledon. Coleorhiza, according to some authors, is the lower part of the subcotyl - the hypocotyl, in which the embryonic root is formed; according to others, it is a modified main root of the embryo.

The structural features of the cereal embryo are of great systematic importance. Based on the presence or absence of an epiblast or a gap between the lower part of the scutellum and the coleorhiza, as well as differences in the course of the vascular bundles of the embryo and in the shape of the first leaf of the embryo on a cross section, 3 main types of embryo structure were established: festucoid, panicoid and intermediate between them, eragrostoid (Fig. 206, 3). Thus, here too, significant anatomical and morphological differences were revealed between predominantly extratropical, festucoid cereals and predominantly tropical, panicoid and chloridoid cereals.

The anatomical and morphological characteristics of cereals determine the very high plasticity and adaptability of representatives of this family to a wide variety of environmental conditions, which allowed them to spread throughout the entire landmass of the globe, right up to the most extreme limits of the existence of flowering plants. Grasses are found in almost all plant groups, although they are most typical for meadows, steppes and savannas of various types. There are species that live on shifting sands (selina - Stipagrostis, sand-loving sand - Ammophila, etc.) and salt marshes (especially the coastal sand - Aeluropus and the sand grass - Puccinellia), both coastal and inland. Some species of anthrax grow in the strip flooded by tides, and one Arctic species confined to such habitats, the creeping anorak (P. phryganodes), often does not bloom, reproducing with the help of vegetative shoots that creep and take root in the nodes. The lowland and mountainous meadows of Eurasia are especially characterized by numerous species of the genera bluegrass, fescue, bentgrass (Agrostis), reed grass (Calamagrostis), foxtail, brome (Bromopsis), timothy grass (Phleum), shaker (Briza), etc. In the steppe zone and in the mountainous In the steppes of Eurasia, feather grass, fescue, thin-legged grass (Koeleria), wheatgrass (Agropyron), sheep grass (Helictotrichon), and in more southern regions - bearded vulture (Bothriochloa) become of leading importance. In the prairies of North America, chloridoid grasses take first place: Bouteloua, Chloris, buffalo grass (Buchloe dactyloides), etc. In the arid regions of Asia, unique plant groups - commonweed - form the large turf grass (Achnatherum splendens) ). In the pampas of South America, pampas grass species play an important role. -- Cortaderia, forming giant tufts (Table 45, 3, 4).

In forests, the role of grasses in the vegetation cover is naturally less significant, however, even here, some species of this family can dominate the herbaceous layer. Thus, in the spruce forests of Eurasia, reed grass (Calamagrostis arundinacea) often grows in abundance, and in oak forests - bluegrass (Poa nemoralis), Elymus caninus, giant fescue (Festuca gigantea) and other species. Unlike steppe grasses, which are usually densely turfed and have very narrow, lengthwise folded leaf blades, forest grasses have less dense tufts and wider and less rigid leaf blades. Of the two species of pearl barley common in the deciduous and mixed forests of Eurasia, the more northern one, the drooping pearl barley (Melica nutans), belongs to the loose-turf grasses, and the more southern and therefore more xerophilic colored pearl barley (M. picta) belongs to the dense-turf grasses. Among tropical and subtropical forest grasses, many have recumbent or climbing densely leafy shoots and very wide, lanceolate or lanceolate-ovate leaf blades, reminiscent in appearance of the Tradescantia species widespread in greenhouse and indoor culture. Such a life form is found, for example, in representatives of the genus Oplismenus, one of whose species, O. undulatifolius, is found in the humid forests of the Mediterranean, as well as in the Colchis lowland (Fig. 202, 1). and the other, O. compositus, is very common in the forests of South Asia.

As for the grasses of the bamboo subfamily, their role in the vegetation of the humid tropics and subtropics is quite large. Tree-like bamboo usually form large thickets along the banks of reservoirs, along watercourses descending from mountains, on the edges and clearings of tropical forests. Many herbaceous bamboo grow under the canopy of tropical rain forests and tolerate considerable shade. Aboveground shoots of tree-like bamboo are often considered homologous to the rhizomes of other cereals. They are characterized by extremely rapid growth and along their entire length they bear scale-like leaves - cataphylls, characteristic of the rhizomes of other cereals. All tree-like bamboos are evergreen plants, although their leaves gradually fall off as a result of the formation of separating tissue either at the base of the petioles, or at the base of the sheaths, which in this case fall off along with the blades.

Among bamboo with more or less lignified stems, two main life forms are distinguished, confined to different climatic conditions (Fig. 207). Most tropical bamboos, whose development in natural conditions is controlled by humidity levels (usually the onset of the rainy season), have stems relatively close together, forming a kind of loose bush. Such bamboo have so-called pachymorphic (from the Greek “pachys” - thick) rhizomes: short and thick, sympodial, with core-filled asymmetrical internodes, the width of which is greater than the length. Another group of bamboo is common in areas with relatively cool or even cold winters, where the onset of active growth of their shoots is controlled by temperature conditions. The genera belonging to it have leptomorphic (from the Greek “leptos” - thin) rhizomes: long and thin, monopodial, with hollow internodes, the length of which is much greater than their width. Such bamboo usually have relatively small overall dimensions, although some types of bamboo can reach a height of up to 10 and even 15 m. The only bamboo genus growing wild in the USSR, Sasa, also has leptomorphic rhizomes, forming very dense and impenetrable thickets on the mountain slopes in the south Sakhalin and the Kuril Islands.

Herbaceous bamboo, like grasses of other subfamilies, bloom annually, but bamboo with woody stems, as a rule, bloom once every 30-120 years and after that they usually die, being obligate or facultative monocarpics. In 1969, massive and simultaneous flowering of the bamboo plant (Phyllostachys bambusoides), which is very widely cultivated there for technical purposes, was observed throughout almost all of Japan. This was a real disaster for those who grew it, since a significant part of the plantations died after flowering. Almost all Japanese psyllium came from the same clone, brought to Japan from China, and therefore it is not surprising that it bloomed everywhere at the same time.

Among the perennial herbaceous grasses, especially tropical ones, there are gigantic forms, not inferior in height to many bamboo. These are, for example, common reed (Phragmites australis) and reed arundo (Arundo donax), which have multinodal but unbranched stems up to 3, sometimes up to 5 m high and long, highly branched rhizomes (Fig. 208, 3).

Reeds are among the moisture-loving plants that form large and almost pure thickets along the banks of reservoirs, and often in the water. Common reed is almost cosmopolitan and is widespread on all continents, both in the tropics and in warm temperate countries. This species has a fairly wide ecological range. It can also grow in swamps of various types, in swampy forests, on mountain slopes with groundwater inflows and in salt marshes, forming in extreme conditions of existence a unique form with shoots creeping along the ground and only vegetative ones. However, even in normally developed flowering reed clones, caryopses are not always formed and in small quantities, which is apparently due to the great antiquity of this species. Another giant grass, up to 3 m high, is pampas grass, or cortaderia, one of the species of which was introduced into the Mediterranean countries, forms very dense turf with intravaginal shoots (Table 45, 3, 4). Its narrow and very rigid leaf blades bear large spines along the edges and midrib, reminiscent in this respect of the leaves of the aquatic plant Stratiotes.

The formation of dense turf is especially beneficial in arid climates, since in this case the base of the plant is well protected from the overheating top layer of soil. That is why among the steppe and desert grasses there are so many dense turf grasses (for example, brilliant grass, many types of feather grass, etc.). On the contrary, many meadow grasses belong to the long-rhizoma group, especially those living on loose, weakly turfed soils, for example, creeping wheatgrass and awnless brome (Bromopsis inermis), often growing in abundance in the meadows of riverine floodplains, as well as some coastal species, like reeds, forming dense thickets, for example, species of manna (Glyceria), reed grass (Scolochloa), broadleaf zizania (Zizania latifolia), etc. Among the species of the generally hydrophilic rice tribe (Oryzeae) there are also true aquatic plants. Such, for example, is the South Asian hygroryza aristata with short and wide leaves collected in rosettes floating on the surface of the water thanks to highly swollen sheaths.

A large and very interesting group of life forms in many respects is formed by annual grasses, which can be either spring, when seed germination begins in the spring, or winter, when seeds begin to germinate in autumn and young plants overwinter, continuing their development in the spring. Such a widely cultivated bread plant as wheat has not only many spring and winter varieties, but also “two-handed” varieties, which can be spring or winter depending on the sowing time. Annual cereals can be divided into 2 groups also according to their origin. One of these groups consists of spring ephemerals. Quickly completing their life cycle during spring and early summer, they play a very significant role in the composition of ephemeral vegetation in arid and subarid regions of Eurasia, Africa and North America. It is very important that such valuable food and feed crops as wheat, rye, oats and barley come from ancient Mediterranean ephemerals.

Another large group of annual grasses belongs to the predominantly tropical tribes of millet, sorghum, pigweed, triocytaceae, etc., although some species of this group (for example, species of bristle grass, bentgrass, crabgrass - Digitaria and barnacle grass) penetrate far beyond the tropics. All these cereals are relatively heat-loving and late-developing. They usually bloom in the second half of summer - early autumn, being well adapted to withstand the dry season. Among the late annuals there are also many economically valuable species (sorghum, millet, chumiza, etc.), but there are also many harmful weeds of fields and plantations of various crops.

Among annual cereals, species that are very original in appearance are known. Thus, in the double spikelet (Trachynia distachya) the general inflorescence consists of only 1-2 large multi-flowered spikelets (Fig. 201, 14); in the capitate barnyard grass (Echinaria capitata), the spikelets are collected into an almost spherical apical head, spiny at the fruit (Fig. 201, 11); in the eastern rhizome (Rhizocephalus orientalis) and the Palestinian sandpiper (Ammochloa palaestina), the spikelets collected in a thick head are located in the center of the leaf rosettes (Fig. 201, 1-7). In the latter species, known in the USSR only from the sands of the Absheron Peninsula, often almost the entire plant is covered with sand, from which only the tops of the leaves of the rosette are visible. Very interesting from a biological point of view is the late ephemeral small clamweed (Coleanthus subtilis), which lives on the coastal shallows of more or less large rivers. It develops very quickly after emerging from the shallows, reaching full development in September - early October. This is a small plant, 3-5 cm high, with recumbent or ascending shoots and very small single-flowered spikelets without glumes, collected in umbrella-shaped bunches (Fig. 201, 5). In years when the shallows remain flooded with water, this species does not develop at all and may even disappear for many years. It is widespread in extratropical countries of the northern hemisphere, but extremely sporadically. So, in the USSR it was found only along the upper reaches of the Volkhov, the middle reaches of the Ob and the Amur.

The high specialization of cereal flowers for pollination by wind has already been noted above. However, accidental transfer of cereal pollen by insects, even in extratropical cereals, cannot be considered completely excluded. Recently, it has been established that herbaceous bamboo from the genera Olyra and Pariana, growing under the canopy of trees in tropical rain forests, where air movement is extremely small, are usually pollinated by insects, mainly flies and beetles, although such a secondary transition to entomophily is not yet associated with any special adaptations.

The vast majority of perennial grasses are cross-pollinated, and self-pollination is usually prevented by complete or partial self-sterility. However, among annuals there are a lot of facultatively self-pollinating species. These are, for example, all types of wheat and aegilops (Aegilops), as well as most types of brome (Bromus). Some cereals, in addition to the usual spikelets with chasmogamous flowers, also develop spikelets with cleistogamous flowers, pollinated with closed glumes. The formation of these spikelets guarantees the possibility of seed propagation under unfavorable weather conditions or when the plant is excessively nibbled by herbivores. Thus, in the widespread coastal grass Leersia oryzoides and the North American sporobolus cryptandrus, in unfavorable years only spikelets with cleistogamous flowers are formed and panicles do not protrude from the expanded sheath of the upper leaf. In the panicles of many feather grasses of the USSR flora in dry years only cleistogamous flowers are formed, and in cooler and more humid weather all or almost all flowers of the panicle bloom openly. Many Arctic grasses also flower primarily cleistogamously in particularly cold weather conditions.

In all species of the Eurasian genus Cleistogenes and some representatives of other genera, cleistogamous spikelets are constantly formed on short lateral branches hidden in the sheaths of the upper and middle stem leaves (Fig. 194, 2). The Central Asian northern nine-axle (Enneapogon borealis) forms single spikelets with cleistogamous flowers inside special kidney-shaped shoots located at the base of the turf. Thanks to this feature, this species is able to reproduce even in conditions of intensive pasture grazing, when every year all the turf is nibbled almost to the ground by cattle. At the same time, the grazing cattle breaks the turf with their feet and carries away the weevils of the nine-axe grass along with the lumps of earth stuck to them. Even higher specialization in this regard is observed in the North American amphicarpum. Its single spikelets with cleistogamous flowers are formed on the tips of creeping underground shoots under the soil surface (Fig. 202, 3).

Unisexual flowers are often found in cereals, but mainly in tropical species. These flowers can be located in the same spikelet along with bisexual flowers, for example, in the bison (Hierochloe) of 3 spikelet flowers, the upper one is bisexual, and the 2 lower ones are male, but more often they are located in different spikelets. Such unisexual spikelets can, in turn, be located in the same inflorescence or in different inflorescences. As noted above, for many genera of the sorghum tribe, the arrangement of spikelets on the spike-shaped branches of the general inflorescence in groups of 2 is very characteristic: one sessile with a bisexual flower, the other on a stalk - with a male flower. Bisexual, but with unisexual spikelets, the inflorescences of the South American herbaceous bamboo plant Piresia are located on creeping rhizome-like shoots, covered with scale-like leaves, and are often hidden under a litter of fallen leaves. Unfortunately, the method of flower pollination in species of this genus remains unknown. In the upper part of the panicle-shaped inflorescences of zizania there are larger spikelets with female flowers, in the lower part there are smaller ones with male flowers. In the genus Tripsacum, related to corn, spikelets with female flowers are located in the lower part of the spike-shaped branches of the panicle, and with male ones - in their upper part (Fig. 209, 6). In corn, spikelets with male flowers form an apical panicle-shaped inflorescence, and spikelets with female flowers are collected in longitudinal rows on a strongly thickened axis of the cobs, located in the axils of the middle stem leaves and wrapped in sheath-shaped leaves (Fig. 209, 1-3). The arrangement of unisexual spikelets is even more original in the South Asian relative of corn - beadweed (Coix). The lower, female part of the spike-shaped branches, located in the axils of the upper stem leaves, consists here of one spikelet with a female flower and the rudiments of two other spikelets, enclosed together in a kind of false fruit with a very dense, horn-like or stony shell. By origin, this fruit is a modified sheath of the apical leaf. From its upper part emerge the long stigmatic branches of the female flower and the stem of the male part of the branch, which is a rather thick false spike (Fig. 210, 7).

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Examples of dioecious grasses include pampas grass (Cortaderia selloana, table 45, 3, 4) cultivated in gardens and parks in the south of the USSR and bison grass (Buchloe dactyloides) from the American prairies, male and female specimens of which were first described as species of different genera (Fig. 194, 6-9). Various methods of asexual reproduction are quite widely represented among cereals. In particular, vegetative propagation with the help of creeping rhizomes, as well as creeping and above-ground shoots rooted in nodes, is found in many perennial grasses. For example, common reed reproduces mainly by rhizomes; in extratropical countries it only rarely forms normally spaced grains. Some ephemeral grasses of the arid regions of Eurasia, including bulbous bluegrass (Poa bulbosa) and low catabrosella (Calabrosella humilis), have bulbous thickened bases of turf shoots. Later, in the dry season, their tufts are broken up by herbivores, and the bulbs are carried by the wind or on the feet of animals across the pasture.

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Asexual reproduction is no less common in cereals with the help of those parts or organs of the plant that are related to sexual reproduction. This includes vivipary, when a young plant develops not from a seed, but from spikelets modified into bulb-shaped buds. Complete or almost complete transformation of all spikelets of the panicle into such buds is found in a number of Arctic grasses from the genera Poa, fescue, pike, as well as in the bulbous bluegrass, widespread in the arid regions of Eurasia. In all cases, vivipary can be considered as an adaptation to more severe living conditions, although vivipary species and varieties can also arise as a result of hybridization between species.

Cases of apomixis in the narrow sense of this term or agamospermia, when a young plant develops from a seed, but without the fusion of gametes preceding its formation, are even more frequent, especially in the predominantly tropical millet and sorghum tribes. Of the extratropical grasses, there are many apomictic and semi-apomictic species in the genera Poa and Reed grass.

For cereals, highly specialized anemophilous plants, the daily rhythm of flowering and pollination is of particular importance. The precise timing of the flowering of all individuals of a given species during any limited time of day greatly increases the chances of cross-pollination and is an important adaptation to increasingly advanced anemophily. Among extratropical grasses, several groups of species are distinguished, differing in flowering time: with one-time morning flowering (the most numerous group), with one-time midday or afternoon flowering, with two-time, morning and evening flowering (evening is weaker), with round-the-clock flowering, with night flowering . The latter is found only in a few extratropical cereals. However, in hot and dry areas of the tropics, night flowering is known in many species, as it avoids overheating and rapid death of pollen during a hot day. Interestingly, in tropical night-blooming grasses, flowering shifts to early morning when moving outside the tropics, as the danger of pollen overheating decreases. Grasses that bloom at noon and afternoon flower during the hottest part of the day. At this time, pollen grains shrink and die relatively quickly, but such cereals are especially often characterized by the so-called explosive flowering, in which massive and simultaneous opening of flowers occurs in a very short time - no more than 3-5 minutes. With batch flowering, which is also characteristic of many cereals, not one, but several such explosions of flowering occur during the day. It has been shown that even very close species, for example, steppe fescue: Wallis (Festuca valosiaca) and false sheep (F. pseudovina), when living together, can be genetically completely isolated from each other, because they bloom at different times of the day. Thus, a certain daily rhythm of flowering in cereals turned out to be a good species-specific systematic feature.

The unit of fruit distribution - the diaspora - in cereals is usually the anthecium: a caryopsis enclosed in floral scales with an adjacent segment of the spikelet axis. Much less often, bare (devoid of any scales) grains, whole spikelets, parts of a common inflorescence, the entire common inflorescence, or even the entire plant serve as diaspores. In the above-mentioned small sheathweed, the caryopses that strongly protrude from the flower scales fall out of them and are carried by water during fluctuations in river levels associated with floods, rains, changes in wind direction, etc. The psammophilous ephemeral sandpit of Palestine can serve as a rare example when caryopses falling from the spikelets carried by the wind. In the sporobolus (Sporobolus), which is widespread in the tropics, the sac-shaped grains, when wetted by rain or dew, quickly swell, burst, and the seeds squeezed out of them, surrounded by sticky mucus, hang from the spikelets, sticking to the fur of animals and the feathers of birds. Large grains of many bamboo plants falling from the spikelets are distributed mainly by water flows during tropical rainfalls, as well as with the help of birds. The berry-shaped grains of Melocanna begin to germinate on the mother plant, without a dormant period, then fall onto the moist soil with their sharp end down and continue their development on their own. They can also spread with the help of birds and animals that eat them.

Spreading by means of whole common inflorescences or their parts is also not very rare in cereals. The spike-shaped panicles of the whorled bristleweed (Setaria verticillata), very tenacious due to the presence of backward-pointing spines on the bristles surrounding the spikelets, often cling to animal fur or human clothing along with the stems. The ears of many species of Aegilops with large awns protruding to the side easily become entangled in animal fur, but can be transported over long distances and by the wind. Clusters of spikelets of barley (Hordeum jubatum), bearing very long and thin awns, can also be carried either by animals or by wind. In the latter case, numerous groups of spikelets can cling together, forming a spherical tumbleweed, carried by the wind over long distances, especially along highways. Many other cereals are spread by the wind like tumbleweeds, the latter being based on very large, widely and widely branched panicles. Examples of this kind are the Siberian bluegrass (Poa subfastigiata) or the Lower Volga zingeria Biebersteinii. In the littoral Asian and Australian genus Spinifex (Spinifex, Fig. 211, 3), the female common inflorescences, which have an almost spherical shape, fall off entirely, then roll along the sandy coast with the wind or float in the water and, having already lingered somewhere, gradually disintegrate. The method of distribution of the splayed snake (Cleistogenes squarrosa) - one of the characteristic plants of the steppes and deserts of Eurasia (Fig. 194, 2) is also very interesting. The stems of this species bend serpentinely when fruiting and break off at their base. Clutching with each other, they form tumbleweeds that are easily carried by the wind, and the grains gradually fall out not only from the apical panicle, but also from the axils of the stem leaves, where shortened branches with cleistogamous spikelets are located.

In cereals, the distribution of diaspores by wind and animals is almost equally represented, and in many cases, diaspores can spread in both ways (for example, in the feather grass Stipa capillata, which is common in the Eurasian steppes). Apparently, in many groups of cereals during evolution there was a transition from a predominantly zoochorous mode of distribution to a predominantly anemochoric one. Thus, in the genus reed grass, diaspores of more ancient, forest species (reed reed grass, etc.) have long, geniculately bent awns and a tuft of short, stiff hairs on the callus - an adaptation to zoochory, and diaspores of a relatively younger species of ground reed grass (Calamagrostis epigeios) are equipped with very a short awn and a tuft of very long (longer than the lemma) hairs on the callus, spreading exclusively anemochorously. Species of the feather grass, but more primitive genus Achnatherum, which is often combined with feather grass, also have small zoochorous diaspores, while highly specialized anemochoric species with very long (40 cm or more), doubly geniculate and pinnately hairy in the upper part of the awns are known among feather grasses. . A long and sharp callus with stiff hairs directed upwards allows feather grass diaspores to seem to be screwed into the soil. In this case, the upper, horizontally located part of the awn is fixed among other plants, and its lower, twisted part is hygroscopic and, with changes in humidity, either curls or unwinds, moving the flower scales with the grain deeper and deeper into the soil. In some feather grasses that can spread on animal fur, such as the feather grass, the diaspores can become embedded in their skin, causing serious damage to the animals.

An increase in the windage of diaspores in anemochoric cereals is especially often achieved due to long hairs, which can be located on the sides of the lower flower glume (in transylvanian pearl barley - Melica transsilvanica), on the highly elongated callus of the lower flower glume (in reed), on the segment of the spikelet axis above the base flower scales (in many species of reed grass), on highly elongated awns (in many feather grasses). In the cirrus (Stipagrostis pennata), common in the sandy deserts of Eurasia, the spine is divided into 3 pinnate branches, resembling a parachute in appearance. In many species of Chloris, the parachute device looks like a transverse row of long hairs in the upper part of the lower flower scales, and in the Persian nine-awned tree (Enneapogon persicus) - like a transverse row of 9 pinnately hairy awns. Thick but very light segments of ears of psammophilous genera - double scale (Parapholis) and single scale (Monerma) - are easily carried by the wind. The windage of diaspores consisting of a whole spikelet can increase due to winged glumes (in the canary plant - Phalaris) or due to their sac-like swelling (in Beckmannia - Beckmannia). In the shaker (Briza), the windage of the anthecia diaspores increases due to the greatly expanded and almost entirely membranous lower floral scales.

The adaptations of cereals to zoochory are no less diverse. Especially often, their diaspores-anthecia have geniculate, rough awns and stiff hairs on the callus, but in representatives of the genus Tragus and some other genera, hooked spines are located in rows on the back of the lower floral scales. In the herbaceous bamboo Leptaspis cochleata, the closed and swollen lower flower scales, which fall together with the grain, are covered with small spines hooked at the apex and are easily attached to the fur of animals (Fig. 197, 4). In the spiny bristlecone (Cenchrus), rather large spiny heads, consisting of several spikelets, enclosed in a wrapper of expanded and fused in the lower part of the setae - modified branches of the general inflorescence - spread exozoochorously (Fig. 202, 8-9). The fruiting spikelets of the tropical genus Lasiacis are spread by birds, which are attracted to the oil-rich, thickened spikelet scales. Diaspores of many species of pearl barley (Melica) have succulent appendages made of underdeveloped flower scales at the top of the spikelet axis and spread with the help of ants eating these appendages.

The diaspores of many aquatic and coastal grasses (for example, zisania, manna, etc.) have good buoyancy and are easily carried by water flows, and some other species (for example, wild oats, Fig. 212) are capable of independent movement (autochory) due to hygroscopic twisting or unwinding of the awns. Currently, both the conscious and unconscious role of man in the spread of cereals has increased enormously. The ranges of cultivated species are expanding significantly, often together with their specific weeds. Many cereals from other continents are introduced into cultivation as forage plants and then go wild (for example, wheatgrass or New England wheatgrass, introduced from North America, became widespread in the USSR). Many types of cereals introduced into cultivation long ago have lost the method of distribution characteristic of their ancestors. Thus, in cultivated species of wheat, rye, and barley, the ears do not disintegrate into segments; Cultivated oats do not have articulations on the spikelet axis; Chumiza and mogar (Setaria italica) do not have articulations at the base of the spikelets, characteristic of wild representatives of this genus. Only in culture are cereals such as corn and bead grass known to be unable to reproduce without human help.

When a grain germinates, first of all, the embryonic root begins to grow, and then the embryonic bud, covered by the coleoptile. After the coleoptile emerges from the soil surface, the first leaf of the seedling emerges from it, which continues to rapidly lengthen and takes on a shape characteristic of this species. In cereals, there are 2 main types of seedlings: festucoid, when the first leaf of the seedling is narrow and directed almost vertically upward (it is found in festucoid tribes of cereals), and panicoid, when the first leaf of the seedling is wide (lanceolate or lanceolate-ovate) and almost horizontally deviated from the axis escape (it is known among panicoid tribes). In addition, there is an intermediate eragrostoid type, and recently two more types have been identified - bambusoid and orizoid, in which on the axis of the seedling the coleoptile is followed not by ordinary leaves, but by one or more cataphylls - scale-like leaves, and with bambusoid In the type characteristic of the bamboo subfamily, the first fully developed leaf of the seedling is built according to the panicoid type, and in the orizoid type, characteristic of the rice subfamily, it is closer to the festucoid type.

The initial versions of the cereal system were based mainly on easily noticeable features in the structure of common inflorescences and spikelets. For a long time, the system of the famous grain specialist E. Gakkel (1887) was generally accepted. This system was built on the principle of gradual complication in the structure of spikelets, from the sorghum and millet tribes, which usually have spikelets with one developed flower, to bamboo, many of which have multi-flowered spikelets of a very primitive structure. However, already at the beginning of the 20th century. Much new data has accumulated on the anatomy of leaves and stems, the structure of the embryo and seedlings, small details in the structure of flowers, and the structure of starch grains, which made it possible to radically revise the Gakkel system. It became clear that the main direction in the evolution of the generative organs of cereals was not their complication, but, on the contrary, simplification: a decrease in the number of flowers in a spikelet, floral films, stamens and stigma branches.

Important data for building a new system were also provided by the study of cereal chromosomes, associated with the rapid development of genetics. In the classic work of N.P. Avdulov, published in 1931, it was established that the size of chromosomes and their basic number (x) in the family of cereals are characteristics not only constant within the majority of genera, but also characteristic of larger divisions of this family. Relatively small chromosomes with a basic number of 6, 9 and 10 turned out to be characteristic primarily of tropical tribes of cereals (sorghum, millet, pigwort, etc.), and larger chromosomes with a basic number of 7 were found to be predominantly characteristic of extratropical tribes of bluegrass, oats, wheat and others. etc. In the system proposed by Avdulov, cereals were divided into 2 subfamilies - sugarcane (Sacchariflorae) and bluegrass (Poatae). The last subfamily, in turn, was divided into 2 series: the reed (Phragmitiformis) with more ancient tribes having small chromosomes, and the fescue (Festuciformis) with the majority of extratropical grass tribes having large chromosomes, usually in a multiple of 7.

Avdulov's system became the basis for subsequent cereal systems, in which the bamboo subfamily (Bainbusoideae) took first place. Based on the characteristics mentioned above, 5 more subfamilies were identified, one of which - rice (Oryzoideae) - occupies an intermediate position between bamboo and other cereals, and the remaining 4 - bluegrass (Pooideae), reed (Arundinoideae), bent ( Eragrostoideae) and millets (Panicoideae) - form a gradual transition from a full set of festucoid characters characteristic of extratropical cereals to a full set of panicoid characters characteristic of tropical cereals. It should be noted that the differences between the last 4 subfamilies turned out to be not as consistent as it seemed at first, as a result of which they are not recognized by all authors. Thus, among the millets there were a number of species (including those in the genus millet) with festucoid leaf anatomy (and, therefore, without kranz syndrome). Among the bluegrass, which are characterized by relatively large chromosomes with a basic number of 7, there are genera with small chromosomes (for example, Brachypodium) and genera with a basic chromosome number of 6 (canarygrass - Phalaris), 9 (barley) and 10 (manna). . Recently, in two festucoid cereals - Zingeria biebersteinii and Colpodium versicolor - the lowest total number of chromosomes in higher plants was found (2n = 4) with a basic chromosome number of 2. Previously, such a number was known only in one American species from the family Asteraceae. Even within the same festucoid species, the Mediterranean spring boron ephemeral (Milium vernale), races with basic chromosome numbers of 5, 7 and 9 have been identified.

Forest herbaceous plants Wikipedia - ? Zingeria Bieberstein Scientific classification Kingdom: Plants Division: Flowering plants ... Wikipedia

Angiosperms (Magnoliophyta, or Angiospermae), a division of higher plants that have flowers. There are over 400 families, more than 12,000 genera and probably at least 235,000 species. According to the number of species of C. r. significantly superior to all others... Great Soviet Encyclopedia

Cereals (lat. Gramineae), or Bluegrass- the largest family of plants, which includes crops popular in agriculture such as rye, barley, wheat, corn, rice, millet, oats, sugar cane, bamboo, amaranth and other well-known plants. Cereals are common on all continents, they grow even in Antarctica - in any case, annual bluegrass was discovered there not so long ago. In savannas and steppes, cereals make up the overwhelming majority of the phytomass. In total, there are about 6,000 plant species in the family.

Cereal family - description

Cereal plants belong to the class of monocots. Among them there are herbaceous annuals and perennials, shrubs and trees. Cereals can be long-rhizome, stolon-forming or turfy.

The shoots of cereals are generative and vegetative, the stems are hollow, like straws, and the leaf blades are alternate, double-rowed, long and narrow, with parallel veins. Inflorescences are spike-shaped, paniculate, racemose or in the form of a spadix and consist of many elementary spikelet inflorescences. The flowers are small and pale, consisting of three stamens, one fruit, a short style and two feathery stigmas. The fruit is a grain - a seed fused with a shell.

Cereal cereal plants

Wheat

Wheat (lat. Triticum)– a genus of herbaceous, mainly annual plants of the Poaceae family. Wheat is the leading grain crop in most countries. Flour, which is produced from wheat, is used to bake bread, make pasta and confectionery. It is included in the recipes of some types of beer and vodka. The main producer of wheat in the modern world is China, followed respectively by the USA, France, Australia, Canada, Russia, Argentina, Germany, Ukraine, Kazakhstan and Brazil.

Wheat has been in cultivation for about 10,000 years. Its origin can be traced to Asia Minor, North Africa and Southern Europe - it was there that three cereals grew, which, in all likelihood, are the ancestors of modern wheat. Since then, plants introduced into cultivation have changed their appearance under the influence of new conditions. For example, einkorn and spelled increased their grain size and lost their brittleness after ripening, and those ears that were discovered in the tombs of the pharaohs are not much different from modern species. The most ancient type of wheat is spelled - the grain of this species is difficult to grind into flour, since flowering and spikelet scales grow to it. In total, there are 20 species of wheat and 10 hybrids - 3 intergeneric and 7 intraspecific.

Wheat is a herbaceous plant with a height of 30 to 150 cm with erect, hollow and leveled stems, flat linear or broadly linear leaves 15-20 cm wide, rough to the touch, glabrous or hairy. The general inflorescence is a straight, ovoid or oblong spike up to 15 cm long. Single sessile spikelets up to 17 cm long with closely spaced flowers are located on the axis of the spikes in longitudinal regular rows.

Three types of wheat are important for the economy:

• common, or summer, or soft wheat - Triticum aestivum. It is a wheat grown throughout the world and used to make baked goods. The most famous awnless varieties are Sandomirka, Girka, Kuyavskaya, Kostromka, and among the awned varieties the most popular are Saxonka, Samarka, Krasnokoloska, Belokoloska and others;
• Durum wheat – Triticum durum, a gluten-rich spring wheat grown for pasta. All varieties of durum wheat are awned and spring - Kubanka, Beloturka, Krasnoturka, Chernokoloska, Garnovka;
• dwarf or dense wheat – Triticum compactum, used for crumbly baked goods.

Types of wheat such as spelt (embellic wheat), spelled, emmer, Polish, English (or fat) are also grown in cultivation.

Wheat is cultivated in almost all climatic zones, with the exception of the tropics. All cultivated varieties are divided into winter varieties, which are sown in the fall and harvested in the summer, and spring varieties, which are sown in the spring - from March to May. Spring wheat requires at least 100 frost-free days to mature. Winter wheat is grown not only for grain, but also as feed for livestock, which is released to graze on the field when the seedlings reach a height of 13-20 cm.

Rye

Rye, or cultural rye (lat. Secale cereal) is a biennial or annual herbaceous plant. The species includes more than forty varieties. Rye is cultivated mainly in the Northern Hemisphere. About 40 varieties of crops are grown in the middle zone. Rye, like wheat, can be spring or winter. Modern rye varieties are thought to be descended from the perennial species Secale montanum, which still grows wild in southern Europe and central and southwestern Asia. In cultivation, rye became an annual plant. There is an assumption that eastern peoples began to cultivate rye, much later than wheat. The earliest remains of rye date back to the end of the Bronze Age and were found in Moravia. The most accurate indications about culture in Europe appeared in the first century AD - Pliny writes that at the foot of the Alps the Taurians cultivate rye and other cultivated plants, and the first mention of the cultivation of rye in Rus' can be read in the chronicles of Nestor, dating back to the 11th century.

Rye has a fibrous root system that goes 1-2 meters deep, so it can be sown even on sand. The stem of rye is hollow, straight, with 5-6 internodes, height from 70 to 200 cm, bare, pubescent only under the ears. The leaves are flat, broad-linear, bluish in color, like the stem. The length of the leaf plate is from 15 to 30 cm, width up to 2.5 cm. At the top of the stem an inflorescence is formed in the form of an elongated drooping complex spike with an axis that does not break into segments from 5 to 15 cm in length and up to 12 mm in width. The spike consists of a tetrahedral shaft and flat two-flowered spikelets. Rye flowers have three stamens with elongated anthers, the ovary is superior, and they are pollinated by the wind. The rye grain has an oblong, somewhat laterally compressed shape with a deep groove in the middle on the inside. The greenish, white, yellow, gray or dark brown grain reaches a length of 5 to 10 mm and a width of 1.5 to 3.5 mm.

Today, winter rye is predominantly sown, and this crop is more winter-hardy than any other cultivated cereals. Rye is not particularly sensitive to soil acidity, but it grows best in soil with a pH of 5.3-6.5. And it is not as demanding on other growing conditions as wheat - rye grows well not only in sand, but also on podzolic soils unsuitable for wheat. The best soil for rye is chernozems and gray forest soils of medium and light loam. Clayey, waterlogged or saline soils are unsuitable for growing rye. Winter rye is sown after flax, corn and leguminous crops, and in areas with a harsh or arid climate - in clean fallows. The most popular winter rye varieties include mid-season Voskhod 2, Vyatka 2, Chulpan, Saratovskaya 5, as well as short-stemmed, disease-resistant varieties Purga, Korotkostelbnaya 69, Bezenchukskaya 87, Dymka and others.

Rye is a grain crop from which flour is produced, kvass is made, and starch is produced. Rye is used to produce alcohol. Grown as green manure, rye successfully suppresses weeds, structures loamy soil, making it more moisture- and breathable and lighter. Fresh rye stalks can be used as fodder.

In the world, rye is cultivated most of all in Germany, Poland, Ukraine, Scandinavian countries, Russia, China, Belarus, Canada and the USA.

Corn

Sweet corn, or maize (lat. Zea mays) is an annual herbaceous plant, the only cultivated representative of the corn genus. In addition to sweet corn, the genus includes four more wild species and three subspecies. There is an assumption that corn is the most ancient representative of cereals, introduced into culture 7-12 thousand years ago in Mexico, and at that time corn cobs reached only 3-4 cm in length. There is indisputable evidence that corn as a cultivated plant cultivated 8,700 years ago in the center of the Balsas Valley.

The role of corn cannot be overestimated: the emergence and flourishing of all Mesoamerican civilizations (Olmecs, Mayans, Aztecs) became possible thanks to cultivated corn, since it formed the basis of highly productive agriculture. Proof of the importance of this cereal for the American Indians is the fact that one of the central gods of the Aztecs was the corn god Centeotl (Shilonen). Before the Conquest, corn had spread to both the south and north of America, and Spanish sailors brought it to Europe, where it quickly gained popularity in the Mediterranean countries. Corn came to Russia through Ukraine and the Caucasus, but it did not gain recognition immediately, but only when in the middle of the 19th century a decree was issued on the free distribution of corn seeds to the peasantry.

Corn has a developed fibrous root system, penetrating to a depth of 1-1.5 m, an erect stem reaching a height of 4 m, and a diameter of 7 cm, not hollow inside, like most cereals. The leaves are linear-lanceolate, up to 10 cm wide and up to 1 m long. On one plant there can be from 8 to 42. Flowers are unisexual: male - apical, in large panicles, female - in axillary cobs from 4 to 50 cm long and in diameter from 2 to 10 cm. Usually no more than 2 ears are formed on one plant. The crop is pollinated by the wind. Corn fruits are cubic or rounded kernels that form and ripen on the cob. They are pressed tightly against each other and, depending on the variety and variety, are yellow, reddish, purple, blue and even black in color. The growing season of corn is from 90 to 150 days. Corn is heat-loving and needs good lighting.

The cultivated type of corn is divided into nine botanical groups, which differ in the structure of the grain: dentate, semi-dentate, popping, sugar, mealy or starchy, starchy-sugar, waxy and filmy.

Corn is the second most sold grain crop in the world after wheat. The top seller is the United States, followed by countries such as China, Brazil, Mexico, Indonesia, India, France, Argentina, South Africa, Russia, Ukraine and Canada. Corn is grown as a valuable food and feed product, and it is also used as a raw material for medicines. Since 1997, genetically modified corn has been grown commercially and is becoming increasingly popular around the world.

Rice

Rice (lat. Oryza) is a cereal crop, an annual herbaceous plant of the Cereals family. It is very demanding on growing conditions, but despite this it is the main agricultural crop in many Asian countries, even ahead of wheat. Rice is sometimes called Saracen grain or Saracen wheat. Rice was introduced into culture about 9,000 years ago in East Asia, then it spread to South Asia, where it was fully domesticated. The ancestor of rice is, in all likelihood, the wild species Oryza nivara. In Africa, naked rice (Oryza glaberrima) is cultivated, which was domesticated on the banks of the Nile two or three thousand years ago, but recently it has been replaced as an agricultural crop by Asian species and is used mainly in rituals. Africans also grow such types of rice as dotted rice (Oryza punctata) and short-tongued rice (Oryza barthii).

The stems of rice reach a height of one and a half meters, its leaves are wide, rough around the edges, and dark green. At the top of the stem, a paniculate inflorescence is formed from spikelets, each of which contains four awned or awnless scales that cover the flower. A rice flower has 6 stamens and a pistil with two stigmas. The grains are covered with scales.

Rice (Oryza sativa) grown in the tropics and subtropics of America, Asia, Africa and Australia, as well as in warm temperate regions. To protect from direct sunlight, rice fields are flooded with water before the grains ripen, which also protects the crop from weeds. The fields are drained only before harvesting.

Rice grains are high in carbohydrates and contain very little protein. In China and Southeast Asian countries, this crop is the main national product. Starch and cereals are produced from rice, and oil is obtained from the germ. Rice flour is not suitable for making bread, but porridge is cooked from it and pies are baked. And with cereals they cook soups, prepare main courses and use them as a side dish. Rice dishes such as pilaf, risotto and paella have become widely popular, and in Japan rice cakes and sweets are baked from rice for the tea ceremony. In Asia, Africa and America, rice is also used to obtain alcohol and make alcoholic beverages. Rice straw is used to produce paper, cardboard and wickerwork. Rice bran and chaff are fed to livestock and poultry.

The main varieties of rice are:

• Long-grain rice, the length of the grains is 6 mm. This rice remains fluffy after cooking;
• medium rice - the length of the grains is about 5 mm, and depending on the color and manufacturer, they may stick together after cooking;
• Round grain rice - the length of the grains that stick together during cooking is 4-5 mm.

According to the type of mechanical processing after harvesting, rice is divided into:

• unhulled or unhusked rice;
• brown, or cargo - rice of a characteristic beige hue, with a nutty aroma;
• white, or unpolished - the same brown rice, but without the top layer;
• polished - white rice, peeled and polished, and in some countries also enriched with microelements and vitamins;
• glazed – polished rice coated with a layer of talcum powder with glucose;
• parboiled - unhusked rice, washed and soaked in hot water, then treated with low pressure steam, polished and bleached;
• Camolino - polished rice coated with a thin layer of oil;
• puffed - rice fried on hot sand or processed with heat, first at high and then at low pressure;
• wild is a very expensive product, which is not rice, but grain of marsh grass. It is mixed with brown rice for sale.

Elite rice varieties include Indian Basmati, Thai Jasmine and Italian Arborio.

Oats

Oats (lat. Avena sativa), or fodder oats, or common oats is an annual herbaceous plant widely used in agriculture. This is a crop that is unpretentious to growing conditions and can be successfully cultivated even in the northern regions. Oats are native to Mongolia and the northeastern provinces of China; they were introduced into culture in the second millennium BC. It is interesting that at first they fought with it because it contaminated spelled crops, but over time, when its excellent feeding properties became known, cold-resistant oats replaced spelled. In Europe, the first traces of oats were discovered in Bronze Age settlements in Denmark, Switzerland and France. Pliny the Elder wrote that the Germanic tribes grew oats and ate them, for which the ancient Greeks and Romans despised the barbarians, believing that oats were only suitable for livestock feed. Dioscorides used oats in medical practice. Since the 8th century AD. and for many centuries in Great Britain and Scotland oatcakes were a staple food, as this was the only crop capable of producing good crops in cold climates. And in the 17th century, German brewers learned to brew white beer from oats. For centuries, oats and oatmeal (oatmeal) fed the people of Rus'. And oats, along with other grain crops, were brought to America by the Scots, who sowed them on the islands near Massachusetts, from where they soon spread throughout all states, first as a fodder crop, but then they began to use it for making porridges, puddings and baked goods.

The height of oat stems with a diameter of 3-6 cm with several bare nodes reaches from 50 to 170 cm. The roots of the plant are fibrous, the leaves are alternate, linear, green or bluish, vaginal, with a rough surface, from 20 to 45 long and up to 3 cm wide Small flowers, collected several times in spikelets and forming a one-sided or spreading panicle up to 25 cm long, bloom in June-August. The fruit of oats is a grain. The composition of oat grains includes starch, proteins, fats, fiber, B vitamins, alkaloids, choline, organic acids, manganese, zinc, cobalt and iron.

The main suppliers of oats in the world are Russia, Canada, Australia, Poland, the USA and Spain. Oats can be hulled or filmy. Hulless oats require moisture and are not very common, while film oats occupy large sown areas. Oats are not as picky about soil as other cereal plants. The best predecessors for oats are row crops - corn and potatoes, as well as flax, legumes and melons. The most popular is white oat grain, black grain is slightly less valuable, and red and gray grain are grown for fodder. The most cultivated oat varieties are Krechet, Talisman, Gunter, Dance, Lgovsky 1026, Astor and Narymsky 943.

Barley

Sowing barley, or ordinary (lat. Hordeum vulgare) is an important crop domesticated in the Middle East about 17 thousand years ago. The ancient Palestinians, the ancient Jews, and all their neighbors sowed it in significant quantities. Barley flour was the subject of sacrifice, and bread made from barley, although coarser and heavier than wheat, was considered a healthier food. Barley came to Europe from Asia Minor 3-4 millennia BC, and in the Middle Ages it was grown in all countries of this part of the world. But for America, this crop is relatively new, since barley was brought to the New World in the 16th-18th centuries.

Barley is an annual herbaceous plant up to 90 cm high, with straight bare stems, flat, smooth leaves up to 30 cm long and up to 3 cm wide with ears at the base of the leaf blade. Barley forms a spike up to 10 cm long with an awn, and each four-hexagonal spikelet is single-flowered. Barley is a self-pollinating plant, but cross-pollination is also possible. The fruit of barley is a grain. The composition of grains includes proteins, carbohydrates, fats, fiber, ash, fatty oil, vitamins D, E, A, K, C, B, sodium, iodine, phosphorus, magnesium, zinc, selenium, iron, copper, calcium, bromine and enzymes.

Today, barley is grown not only as a fodder and industrial crop, but also as a food crop, for the production of pearl barley and barley groats and flour, as well as beer, which is the oldest drink of the Neolithic era. Barley is cultivated on an industrial scale in some countries of Western Europe, Ukraine, Belarus, Russia, the USA, Canada, China, India and the countries of Asia Minor, and in Tibet this cereal is the main food. Winter barley is not as ancient a crop as spring barley, but currently countries such as Romania and Bulgaria have completely switched to growing winter barley; a lot of winter barley is sown in Germany, France, Poland and Hungary. The most popular barley varieties are Sebastian, Duncan, Talbot, Vodograi, Helios, Stalker, Vakula, and among the new varieties, the Ukrainian selection products Avgiy, Yucatan, Psel and Soncedar have proven themselves to be excellent.

Millet

Millet (lat. Panicum) is a genus of annual and perennial herbaceous plants of the Poaceae family. Representatives of the genus are distinguished by their unpretentiousness to growing conditions and tolerate heat and dry soil well. About 450 species of millet grow in the nature of Africa, America, Europe and Asia, but the most valuable species is the common millet (Panicum milliaceum), an annual plant native to Southeast Asia. The Mongols, residents of Manchuria and southeastern Kazakhstan cultivated this cereal from time immemorial, and millet came to Europe along with the army of Genghis Khan. Millet was also cultivated in India, back in the first millennium BC, and from there the culture was brought to Iran and the Caucasus. In the Bronze Age, thanks to Greek traders, millet appeared in Europe - in Hungary, Switzerland, southern Italy and Sicily. Millet was grown by the Celts, Scythians, Sarmatians and Gauls. In the 19th century, Ukrainian settlers brought millet to Western Canada and North America.

Hollow, slightly pubescent, cylindrical stems of millet, consisting of 8-10 internodes and forming a bush, reach a height of 50 to 150 cm. The root of the plant is fibrous, penetrating into the soil up to one and a half meters or more; the root system can grow up to a meter in width and more. The leaves of millet are alternate, glabrous or pubescent, linear-lanceolate, green or slightly reddish, reaching a length of 18 to 65 cm and a width of 1.5 to 4 cm. Two-flowered spikelets 3 to 6 cm long are collected in a paniculate inflorescence from 10 to 60 cm. The fruit of the plant is a round, oval or elongated grain with a diameter of 1-2 mm. The color of the fruit, depending on the variety, can be yellow, white, brown or red.

The composition of millet grains includes proteins, fat, starch, carotene, copper, manganese, nickel, zinc, vitamins B1, B2, PP. Millet contains practically no gluten, so it is included in the diet for people suffering from celiac disease. The grain is used to produce millet, which is used to make soups and porridges, and also as feed for poultry.

Millet is grown on any soil, even saline soil. The plant does not tolerate only high acidity. The crop is grown in large volumes in countries such as Ukraine, Russia, India, and the countries of the Middle East. In the USA, millet is cultivated as a dietary product or for poultry feed. The most common millet varieties include Saratovskoe 853, Veselopodolyanskoe 367, Kazanskoe 506, Dolinskoe 86, Skorospeloe 66, Omskoe 9, Orenburgskoe 42, Kharkovskoe 25.

There are also ornamental species and varieties of crops that are widely grown in horticulture:

• a type of millet, the panicles of which are used to make dry bouquets;
• species of switchgrass, varieties Blue Tower, Cloud Nine, Heavy Metal, Prairie Sky, Red Cloud, Strictum and others.

Ornamental cereal plants

Bamboo

Common bamboo (lat. Bambusa vulgaris)– a herbaceous plant, a species of the genus Bamboo. In total, the genus includes about 130 species of evergreen plants growing in humid areas of the tropics and subtropics of Asia, the Americas, Africa and Australia. Common bamboo is the most recognizable of all species of this genus. The homeland of common bamboo is unknown, but it is grown in Madagascar, in the tropics of Africa and throughout East, South and Southeast Asia. This species is also common in Pakistan, Tanzania, Brazil, Puerto Rico and the USA. Since the beginning of the 18th century, bamboo has become a popular greenhouse plant in Europe.

Bamboo is a deciduous plant. It has bright yellow, stiff stems with thick walls and green stripes and dark green, pubescent, spear-shaped leaves growing at the top of the stem. The height of the plant reaches 10-20 m, and the thickness of the stem can be from 4 to 10 cm. The nodes on the stems are swollen, the length of the knees is from 20 to 45 cm. Bamboo rarely blooms, but once every few decades the entire bamboo population blooms simultaneously. The plant also does not produce seeds, and fruits are formed very rarely. Bamboo is propagated by vegetative methods - cuttings, layering, shoots, division of rhizomes. The composition of bamboo stems includes cellulose, fats, proteins, calcium, phosphorus, iron, vitamin C, lignin, ash and silica.

Bamboo stems are used as fuel, building material and raw materials for making furniture, fishing rods, tool handles, smoking pipes and flutes, and bamboo leaves are used to feed livestock. Bamboo is also grown as an ornamental plant, planted as a hedge. Young bamboo shoots are eaten boiled and preserved.

There are three varieties of common bamboo - green-trunked, golden-trunked or yellow-trunked and Bambusa vulgaris var. Wamin. The most interesting varieties of decorative bamboo are:

• aureovariegata - bamboo with golden stems with thin green stripes;
• striata - a compact variety with bright yellow constrictions between the knees and light green and dark green stripes;
• vittata - a variety with stems with small stripes resembling a barcode;
• maculata is a plant with green stems speckled with black, the stems of which turn completely black with age.

Cane

Reed (lat. Phragmites)- a genus of perennial herbaceous plants, the most famous species of which is the common reed (Phragmites australis), growing in Europe, Asia, North Africa and the Americas around lakes, swamps, ponds and along river banks. This moisture-loving plant can be found on isolated islands and in desert places, and this is a sure sign that the groundwater is shallow in this place.

Reed is a perennial coastal plant that develops powerful, thick and branched underground rhizomes up to 2 m long. Bamboo stems are straight, flexible, hollow, smooth, bluish-green, up to 1 cm thick. In addition to stems, reed forms creeping shoots. The leaves of the reed are dense, hard, long and narrow, linear or lanceolate-linear, tapering towards the ends and rough at the edges. The leaf width is from 5 to 25 cm, the color is gray or dark green. The peculiarity of reed leaves is that they always turn their edges towards the wind. The reed stem is crowned with a spreading, thick drooping panicle of purple, yellowish or dark brown spikelets, each of which has 3-7 flowers - the lower one is male, and the upper ones are bisexual. Reed blooms from July to September. The fruit is an oblong grain.

Before flowering, young cane contains extractives, protein, fat, carotene, cellulose and vitamin C. The leaves of the plant contain vitamins, phytoncides and carotene. The rhizomes contain a lot of starch and fiber. Reed shoots are used to make paper, baskets, mats, and reeds are obtained from pressed reeds - an excellent building material. Musical instruments are made from the stems of the plant - clarinets, pipes and pipes for flutes. Reed is also used for silage.

Sugarcane (Saccharum officinarum), or noble cane also a cereal plant, but belongs to the Millet subfamily. This plant, along with sugar beets, is used to produce sugar. Plants of this genus originate from the southwestern part of the Pacific region. In wild form, they are found in tropical areas of the Middle East, North Africa, China, India, Taiwan, New Guinea and Malaysia. Sugarcane is a very ancient crop and its name is found in Sanskrit documents. The Chinese refined sugar from cane already in the 8th century AD. e., in the 9th century the crop was grown along the shores of the Persian Gulf, in the 12th century the Arabs brought reed to Egypt, Malta and Sicily, in the 15th century it grew in the Canary Islands and Madeira, in 1492 it was transported to the Antilles, and in Saint-Domingue they began to grow it in large quantities, since by that time sugar had already become a necessary product. A little later, sugar cane reached the borders of Brazil, and then Mexico, Guiana and the islands of Martinique and Mauritius. It was difficult to grow sugar in Europe due to climatic conditions; it was cheaper to bring it from tropical countries, and since sugar began to be produced from beets, the volume of cane sugar imports has decreased significantly. Today, the main sugarcane plantations are in India, Indonesia, the Philippines and Cuba, Argentina and Brazil.

Sugar cane is a fast-growing perennial up to 6 m high. Its rhizome is short-jointed. Numerous dense, bare, knotty cylindrical stems with a diameter of up to 5 cm are colored yellow, green or purple. Reed leaves, 60 to 150 long and 4-5 cm wide, resemble corn leaves. The stem ends in a pyramidal paniculate inflorescence from 30 to 60 cm long, consisting of small, pubescent single-colored ears, collected in pairs.

To obtain sugar from cane, its stems are cut before flowering begins and, placed under metal shafts, the juice is squeezed out of them, to which freshly slaked lime is added, heated to 70 ºC, then filtered and evaporated until crystals appear. The share of sugar cane in world sugar production is 65%. The countries that produce the most cane sugar are Brazil, India, China, Thailand, Pakistan, Mexico, the Philippines, the USA, Australia, Argentina and Indonesia.

Miscanthus

Miscanthus (lat. Miscanthus), or fan- a genus of herbaceous plants of the Poataceae family, the name of which is formed from two Greek words meaning “petiole, stem” and “flower”. Miscanthus is widespread in the subtropics and tropics of Africa, Asia and Australia. These are undemanding plants that will do well in any soil except heavy clay. Miscanthuses are not bothered by waterlogged soils; they survive in dry places, although they do not grow as much.

Miscanthus is a plant with a height of 80 to 200 cm, forming large loose turfs with creeping rhizomes. The stems of miscanthus are erect, the leaves are scale-like, leathery, with hard linear or lanceolate-linear leaf blades up to 2 cm wide. Picturesque fan-shaped panicles with long lateral branches and a very short awn reach a length of 10-30 cm.

Miscanthus is very popular in gardening. They decorate the banks of reservoirs and are planted in rockeries and mixborders. All types of miscanthus are distinguished by a long period of decorativeness; they are attractive even in autumn, when their leaves turn different shades of yellow, burgundy and brown. Paniculate inflorescences of miscanthus are included in dry bouquets and compositions. The plant is also used as bioenergy fuel.

The genus includes about forty species, but most often grown in culture:

• gigantic miscanthus - a powerful plant used as a screen or accent in the background;
• Chinese miscanthus, or Chinese reed, is a winter-hardy plant, the best varieties of which are Blondeau, Flamingo, Morning Light, Nirron, Strictus, Variegatus and Zebrinus;
• Miscanthus sugarflower is a plant with white or pinkish-silver panicles. Also popular is the Robustus variety of miscanthus, a larger plant than the main species.

Amaranth

Amaranth (lat. Amaranthus), or amaranth, velvet, fox (cat's) tail, cockscombs, axamitnik - a genus of herbaceous annuals widespread in cultivation. The name of the genus is translated from Greek as “unfading.” The plant originates from South America, where most of the species of the genus still grow in nature. For eight thousand years, amaranth was one of the main food crops of the natives of South and Central America, along with corn and beans. From there, amaranth was transported to North America, as well as to India, Pakistan, Nepal and China. From the amaranth seeds brought to Europe by the Spaniards, they first began to grow ornamental plants, but since the 18th century, interest in amaranth arose as a cereal and fodder crop.

The stems of amaranth are simple, the leaves are entire, diamond-shaped, ovoid or lanceolate in shape, alternate, with a sharp apex, and at the base smoothly turning into a petiole. The flowers are arranged in bunches in the axils or formed on the tops of the stems in the form of spike-shaped panicles. The fruit of amaranth is a capsule with grains. All parts of the plant are colored either green or purple-red.

Young or dried amaranth leaves are used for preparing hot dishes or for salads. The grain of the plant is a valuable feed for poultry, and the greens are for cattle. Shchiritsa silage has a pleasant apple smell.

Four types of amaranth are grown as ornamental plants:

• paniculate amaranth, or crimson amaranth, is a brownish-red plant, the best varieties of which are Roter Dam, Roter Paris, Zwergfakhel, Hot Biscuits, Grune Torch;
• sad or dark amaranth. The best varieties are Green Tam, Pidzhmi Torch;
• caudate amaranth, which has several decorative varieties. The most famous varieties are Grunschwanz and Rotschwanz;
• Tricolor amaranth is an ornamental deciduous plant. The best varieties are Aurora, Early Splendor, Illumination.

Dried amaranth inflorescences can retain their shape and color for several months.

Amaranths prefer light, nutritious, calcareous soils. Waterlogged, acidic soil is not suitable for them.

Feather grass

Feather grass (lat. Stipa)- a genus of monocotyledonous herbaceous perennials, the name of which is translated from Greek as “tow.” In nature, there are more than 300 species of feather grass, which are predominantly semi-steppe or steppe plants. Feather grass is not a valuable forage crop; on the contrary, it is considered a weed and a harmful plant: in the second half of summer, on grassy pastures, the plant's awns dig into the skin of animals and cause inflammatory processes in it.

The rhizome of the feather grass is short, and a large bunch of hard, wire-like leaves grows from it. Sometimes the leaves are collected in a tube. The spikelets forming the inflorescences contain one flower each. The fruit of feather grass is a grain.

The most famous types of feather grass are feathery, hairy (or hairy, or Tyrsa), beautiful, giant, Zalessky, pebble, Caucasian, hairy, Clemenza, Lessing, magnificent, Siberian and narrow-leaved.

Some varieties of beautiful feather grass, feathery and narrow-leaved, have been introduced into cultivation for growing in rock gardens and making dry bouquets. Such Central Asian species of feather grass as mastlifica, longiplutnosa, lipskyi and lingua attract the attention of gardeners and landscape designers. And the esparto feather grass, or Stipa tenacissima, serves as raw material for artificial silk and paper.

Canary

Canary plant (lat. Phalaris)- a genus of herbaceous cereal plants, which includes about 20 species, distributed in all parts of the world except Antarctica. These herbs grow in both dry areas and swamps.

The seemingly harmless but dangerous herb received its scientific name in honor of the mythological hero Phalaris, whom the inhabitants elected king and entrusted to him with the temple of Zeus in Agrigentum. Phalaris, taking advantage of the trust of the townspeople, turned into a bloodthirsty despot who promoted cannibalism, devoured babies and roasted enemies in a bronze bull, as if in a brazier. The inhabitants rebelled against Phalaris, and he suffered the same fate as his enemies - he was roasted in a bull.

Only one species of the genus is grown in culture - perennial reed grass (Phalaris arundinacea), or silk grass. This plant reaches a height of one meter, it has narrow long striped leaves and inconspicuous small spike-shaped apical inflorescences. The rhizome of the dvukistochnik is creeping, located horizontally in the soil. At a distance of 1.5-2 m, fibrous roots develop on the rhizome, from which turf of silk grass grows. This species has several variegated varieties, differing in the intensity of the contrast of stripes of white-pink, light yellow or white on a green background.

Other types of canary grass have green and unattractive leaves. In addition, species that live in wet grasslands are invasive, and some of them contain the alkaloid gramine, which can attack the nervous system of grazing sheep.

Properties of cereal plants

The fruits of cereal crops are pseudomonocarps, that is, grains, the membranous pericarp of which adheres tightly to the seed, and sometimes sticks to the spermoderm. Cereal grains contain a lot of starch and protein, and the grains of some plants contain coumarins and essential oils.

Cereals are the oldest cultivated plants, from which essential products are produced - flour, cereals, sugar, livestock feed, as well as building materials and fibers, and wild cereals are used as livestock feed.

When growing cereals, it is necessary to observe crop rotation and correct sowing dates. Winter subspecies of cereals are sown at the end of summer or early autumn, trying to do so before the onset of persistent frosts. In order to begin to grow and develop, winter grains need low temperatures - from 0 to 10 ºC. Spring grains go through the first stages of development at temperatures from 10-12 to 20 ºC, which is why they are sown in the spring. Winter varieties of cereals are considered more productive because they make better use of nutrients, as well as winter and spring moisture reserves. Winter varieties are sown after early-harvested crops, for example, after legumes, as well as in clean fallows. It is better to sow spring crops after row crops, winter crops, leguminous crops and perennial grasses.

The main application of fertilizer is carried out in the fall, before autumn tillage: granular nitrogen and phosphorus fertilizers are applied to the rows during sowing. In spring, cereals also need nitrogen or nitrogen-phosphorus fertilizing.

Ornamental grasses, of which there are about 200 species, are grown on alpine hills, in rockeries, they frame flower beds, ponds, and plant large spaces. They are sown mainly in open sunny areas, although they also grow in partial shade. The main advantage of ornamental grasses is that they are able to decorate the site both in summer and winter. Perennials are propagated vegetatively - by dividing bushes, although the seed method is also quite applicable. Cereals are almost not affected by pests; only aphids and mites - sucking insects - can cause them trouble, which can be eliminated with the help of acaricidal preparations. Spring care of ornamental perennial grasses consists primarily of trimming dried stems, and you need to work with gloves, since the leaves of the grasses are hard and sharp. To prevent plants from scattering their seeds throughout the area, it is advisable to remove the shoots in advance.

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The Latin name is gramineae (poaceae).
Monocot class.

Description. Among flowering plants, grasses have continued to occupy a special position for many centuries, which is determined both by their high economic value and by the enormous role they play in the formation of herbaceous vegetation groups. All representatives of this family belong to herbs, even though the stem of some bamboos becomes woody, reaching 40 meters in height and about 20 cm in diameter.

Cereal plants are divided into two types: cultivated and meadow. The first includes the main food plants of mankind - wheat, rice and corn, as well as many other grain crops that supply the inhabitants of all continents with such vital products as cereals and flour. Among them, two forms are distinguished: spring and winter. Spring crops are sown in the spring; until autumn they go through a full development cycle and produce a harvest. Winter crops are sown in the fall, they germinate before the beginning of winter, and continue to grow in the spring, ripening a little earlier than spring crops. The second type includes wild plants - timothy, wheatgrass, wheatgrass, bluegrass, fescue, etc., which are used as food for domestic animals.

The main feature characterizing the cereal family is the structure of the stem, which has clear distinctive features from the stems of other plants. It is completely empty inside and is a thin tube with knots - a straw (except for reed and corn). Its growth is carried out due to the educational tissue, which is located at the base of the internodes, and is called intercalary. In some representatives, the stem is prone to lignification during life (bamboo).

Cereal flowers almost identical, very unremarkable, small and pale. They are found in spikelets, which are collected in various inflorescences:

• complex ear (wheat, barley, wheatgrass, rye);
• panicle (oats, rice, millet, bluegrass, feather grass);
• sultan or false ear (foxtail, timothy);
• cob (corn).

Spikelets consist of one, two or several flowers and have a length of 2 mm to 3 cm. Each flower is equipped with outer and inner scales and is supported by a tiny rod, which attaches the spikelet to the inflorescence. Its internal parts are hidden between these scales and consist of an ovary with two stigmas, three (sometimes two) stamens and two lodicules. Cereal flower formula: TsCh 2+ Pl 2+ T 3+ P 1 (TsCh - flower scales, Pl - films, T - stamens and P - pistil).

Leaves in all representatives of cereals, they are simple, sessile and narrow. Their structure is a long leaf blade with parallel veins and a sheath that encloses the stem at the nodes. The arrangement of the leaves is regular. Root system fibrous type. Rarely, underground shoots can turn into rhizomes. Bluegrass branches by tillering, forming new shoots in the lowest part of the stem directly at the soil surface.

After the flowering period is completed, a rich in starch, vitamins, gluten and protein is formed. fetus, called caryopsis. Its grains consist of an embryo, endosperm and shells. The fruit is the same in both cultivated and meadow plants of the family, but has a different structure and chemical composition.

Spreading. Due to their unpretentiousness to germination and existence, cereals occupy a very wide habitat. They are found almost all over land, with the exception of ice-covered areas. The range of bluegrass, fescue, foxtail and pike grass reaches the northern and southern limits of the existence of angiosperms. Among those that rise highest in the mountains, cereals also occupy a leading position.

Representatives of the bluegrass are also characterized by a relative uniformity of distribution on Earth. In the tropics this family is almost as rich in species as in temperate regions, and in the Arctic it is the most numerous in number of species.

Reproduction. Pollination in cereals occurs primarily by wind, although some, such as wheat, are capable of self-pollination. These plants reproduce not only with the help of seeds, they also have vegetative propagation, that is, shoots and rhizomes.

The grass family belongs to the class of monocotyledonous angiosperms. Cereals include more than 10 thousand species. Many of them include plants of agricultural importance for humans (wheat, rice, rye, corn, sugar cane, etc.). Most cereals are perennial herbs.

Cereals are characterized by a predominantly fibrous root system. A distinctive feature of cereals is that their stems grow in length not only at the top, but also at the base of the internodes, i.e., by intercalary growth. Many types of cereals have hollow stems at the internodes (wheat). This is a straw stalk. In other species, the internodes are not hollow (corn).

Cereals are also distinguished by their leaves, which are long and narrow. The venation is mostly parallel. The leaves have so-called sheaths, which are the bases of the leaves in the form of a tube that covers the stem. The sheaths protect the educational tissue at the bases of the internodes.

The flowers of cereals are small and inconspicuous. Self-pollination or wind pollination are most common. The flowers are collected in inflorescences, usually a spike, a complex spike, or a panicle of spikelets. The number of flowers in spikelets depends on the species, ranging from one to many.

The structure of the flowers themselves in cereals is special. In many species, the flower consists of two scales and two films. There are 3 stamens in the flower, 1 pistil with two stigmas.

The fruit of cereals is the caryopsis. In caryopses, the pericarp fuses with the seed coat. In a cereal seed, the endosperm is located on one side of the embryo, adjacent to its cotyledon-scutellum. Cereal grains are collectively called grain.

Representatives of cereals

Wheat cultivated by humans since ancient times (more than 10 thousand years ago). Wheat grains are used for food and processing, from which flour is obtained. Bread is baked from flour, pasta and cereals are made. Wheat is not just one species. There are more than 20 types of wheat, each of which can include many varieties.

One wheat plant can have from several to more than a dozen stems. The inflorescence is a complex spike consisting of spikelets. Each spikelet contains several flowers. In wheat flowers, self-pollination occurs even before they bloom.

There are durum wheat and soft wheat. Their endosperm is different. In durum wheat it is denser and contains gluten (vegetable protein). Durum wheat is more demanding of heat, light and soil fertility. It is sown in early spring in more southern regions than soft wheat. Soft wheat is winter (sown in autumn).

U rye the inflorescence is also a complex spike. However, each spikelet consists of two flowers and one underdeveloped one. Rye is wind pollinated. The grains of wheat and rye also differ. In rye they are more elongated. Rye flour is darker in color than wheat flour.

U oats inflorescence panicle consisting of spikelets. Each spikelet has 2-3 flowers. Oats are characterized by self-pollination. Oatmeal, oatmeal, rolled oats, etc. are made from oats.

Millet has a panicle inflorescence, its stems branch. Millet is made from millet.

Demanding on heat and moisture.

It has a high stem of about 2 m, its roots go more than 1 m deep. It was brought from South America. Demanding on warmth. Used as a fodder and food crop.

Corn is characterized by dioecious flowers. Pistillate flowers form a complex spadix located in the axils of the leaves and wrapped in modified leaves. The pistil columns are long and carry stigmas out of the cobs. Staminate flowers form a panicle at the top of the stem. Each spikelet of the panicle has two flowers. In corn, cross-pollination occurs with the help of wind.

Among wild cereals it should be noted feather grass, wheatgrass, timothy grass .