Plants are monoecious and dioecious. Monoecious and dioecious plants Monoecious and dioecious plants

Plants protect plants Man has long been using environmentally friendly and harmless methods to control pests and diseases on strawberries, using a number of plants because of their insecticidal properties. But many of them are poisonous to people. So, decoctions and infusions of henbane and dope

Monoecious plants

Compare Dioecious plants, Polyecious plants.

Modern encyclopedia. 2000 .

See what "MONOECY PLANTS" are in other dictionaries:

Monogamous, plants that have unisexual flowers, male (staminate) and female (pistillate), or other male. and wives the reproductive organs (in non-flowering plants) are located on the same plant. Birch, hazel, oak, pine, spruce, corn, pumpkin, many... ... Biological encyclopedic dictionary

Alder monoecious plant Monoecious are plants that have unisexual flowers, with male and female flowers located on the same plant. Monoecious are, in particular, birch, alder, corn, and many plants from the family ... Wikipedia

Plants that have unisexual female (pistillate) and male (staminate) flowers on the same individual, e.g. hazel, corn. Wed. Dioecious plants, Polyecious plants... Big Encyclopedic Dictionary

Monoecious plants- MONOOCYCY PLANTS, plants in which unisexual female (pistillate) and male (staminate) flowers are on the same individual, for example hazel, corn. Compare Dioecious plants, Polyecious plants. ... Illustrated Encyclopedic Dictionary

Plants in which unisexual female (pistillate) and male (staminate) flowers are on the same individual, for example, hazel, corn. Wed. Dioecious plants, Polyecious plants. * * * MONOOCY PLANTS MONOOCY PLANTS, plants,… … Encyclopedic Dictionary

Plants that have unisexual male (staminate) and female (pistillate) flowers on the same plant. Examples of organic trees: birch, hazel, oak, pine, spruce, corn, pumpkin. O.r. plants that do not have flowers are also called... Great Soviet Encyclopedia

Plants that have unisexual females, (pistillate) and males. (staminate) flowers are on the same individual, e.g. hazel, corn. Wed. Dioecious plants, Polyecious plants... Natural science. Encyclopedic Dictionary

MONOOCYCY PLANTS- plants in which staminate (male) and pistillate (female) flowers or male and female reproductive organs (in non-flowering plants) develop on one individual. K O. r. This includes most seed plants with heterosexual cones and flowers... Agricultural Encyclopedic Dictionary

monoecious plants- plants in which staminate and pistillate flowers (in flowering plants) or antheridia and archegonia (in archegonial plants) are formed on the same plant... Anatomy and morphology of plants

MONOOCYCY PLANTS- plants in which male and female generative organs (staminate and pistillate flowers in flowering plants, antheridia and archegonia in archegonial plants) are located on the same specimen (for example, in Zea mays L., species of the genus Fagus, many mosses) ... Dictionary of botanical terms

All plants from the Angiosperms (flowering) department are divided into groups and can be classified as dioecious or monoecious. This article will discuss the differences between dioecious and monoecious plants, what dioeciousness is and which plants belong to the dioecious group.

What is dioecy

The dioecious group includes specimens that are endowed with female or male flowers, that is, pistils and stamens cannot be located together on one flower or even on one representative of the flora. Due to this feature, the possibility of self-pollination is completely excluded. Plants can be pollinated through xenogamy - cross-pollination, due to which pollen from one plant is transferred to the stigma of another plant.

Thus, pollination of flowers is possible only if bees and other insects that consume plant pollen carry out the pollination process. The disadvantage of cross-pollination is the fact that half of the flowers never produce seeds.

Important! Some scientists are inclined to think that not only angiosperms, but also non-flowering plants, which are endowed with male and female generative organs, can separate the sexes of plants and classify them as dioecious or monoecious. Therefore, these groups often include plants that are not prone to flowering.

How do monoecious plants differ from dioecious plants?

Monoecious plants are characterized by the presence of flowers of different sexes on one specimen, while dioecious ones have flowers of only one sex on one plant. Monoecious plants are often pollinated by wind, that is, under the influence of air, pollen from one flower is transferred to another; dioecious plants are pollinated only if pollen is transferred from a male flower to a female flower by insects.

Dioecious plants are represented pistachio, poplar, aspen, actinidia, sorrel, figs, hemp, velvet.

Dioecious representatives

In order to have an idea of ​​dioecious plants, it is necessary to consider a brief description of some representatives of this group.

Actinidia is a genus of woody vines that has 75 species. Actinidia are widespread in the southeastern part of Asia and the Himalayas. They belong to shrubs and vines, the peculiarity of which is a tendency to fall leaves. The buds of these plants are all or partially hidden in leaf scars; the leaves are arranged alternately and have a jagged edge. Flowers can be small, about 1 cm in diameter, or medium-sized up to 3 cm.

Most species have odorless, white flowers; sometimes there are buds with a golden yellow or orange tint. The fruit of the plant is an oblong berry, yellow-green or light orange in color. The most famous representative of actinidia is actinidia deliciosa, which is known to everyone as kiwi.

Actinidia is planted as an ornamental plant, often used as a medicine, and the fruits of edible varieties are eaten.

In nature, actinidia grow in sparse forests, where natural partial shade is created, therefore, for planting at home, it is advisable to create the same conditions. Despite the fact that actinidia grows well in shaded areas, it is better to plant it on the sunny side, since fruiting occurs only with sufficient light. Actinidia thrives in soils with low amounts of nitrogen and phosphorus, but does not tolerate alkaline soils. The best option is slightly acidic soils. It is not advisable to plant plants on heavy clay soil.

Important! If actinidia is planted as a fruit-bearing crop, then it is imperative to combine female and male plants in one planting - for every 3 specimens with female flowers there must be at least 1 male representative.

Velvet is a deciduous tree, reaches from 20 to 30 m in height, with a large trunk diameter - about 120 cm. The crown of the tree in forests is highly raised, in single plantings it is characterized by a spherical shape. The plant has ash-gray bark, with an excellent decorative appearance; young trees have bark with a silvery tint. The upper layer of the bark is characterized by a velvety structure, represented by a cork more than 5 cm thick, the inner layer of the bark has a yellow color and a specific smell. The foliage is rich green in color, the leaves are arranged alternately, the shape is similar to the leaves of ash, but with narrower blades and a characteristic unpleasant odor.

The flowers are quite small, inconspicuous, diameter - up to 1 cm, have a greenish tint, the flowers are collected in paniculate inflorescences, length - up to 12 cm. Fruit ripening occurs in the fall, the fruits are spherical, black, shiny drupes, unsuitable for consumption, characterized by a sharp unpleasant odor. Velvet can be found in Manchuria, Khabarovsk Territory, Amur and Primorye, China, Korea, Taiwan, Sakhalin, Kuril Islands, Japan. Velvet is a relict plant, since this tree existed long before glaciation.

Did you know? Relict plants include representatives of the flora that were common in past geological eras.

Velvet as an ornamental plant is very common in European countries and North America, and is popular for planting in the regions of Central Asia and the Caucasus. Velvet is used for medicinal purposes and is a good honey plant. The bark is also often used to make yellow dye for dyeing various types of fabrics. A large layer of cork is used to make stoppers for capping bottles, used as a building material, for floats, lifebuoys, bibs, and souvenirs. Cork is removed from wood quite easily, without harming the tree itself. Velvet wood is characterized by a beautiful color and expressive pattern, therefore it is used for the production of furniture and decorative elements.

When choosing a place to plant velvet, you must take into account that the tree is a long-liver, therefore, so that its roots do not harm buildings, place the tree away from buildings. Also, if in the future you plan to build something near a tree, try to move away from the velvet as much as possible so as not to harm the roots or destroy the plant. The tree must be provided with shade, so it is better to plant it in the garden; cultivated loam soils are suitable for planting; sandy soils are not suitable for planting.

Sandman is an annual, biennial, or in some cases perennial plant, reaches a height of 80 cm. Depending on the age of the dormancy, the plant is characterized by some differences in appearance. Small specimens have oval leaves reaching a length of 10 cm; over time, forked stems with paired lanceolate leaves appear on the plant. Buds up to 3 cm in diameter are presented in the form of inflorescences and are located at the top of the stem, each bud has 5 petals, blooms from late spring to early autumn, blooms white. Napping is common in European countries, western Asia and North America.

Sandman is sometimes used for the production of hygiene products, as it has a large amount of saponins, which in the form of solutions, when shaken, can form a thick, persistent foam. Sandman is a fairly frost-resistant plant, so it can withstand cold, harsh winters. At the moment, doze is not cultural and is not used in industry.

Important! The maximum decorative effect of dormancy is achieved when planted on drained neutral, slightly acidic soils; a normal plant develops on sandy, dry soils.

Sandman grows in well-lit areas, but can tolerate light partial shade, so it is better to plant it in sunny areas. The plant does not need particularly fertile soil; it grows well on ordinary garden soils; the only necessary condition is loose soil.

Willow is a genus of woody plants, which includes about 550 species. Trees grow up to 15 meters in height, sometimes species up to 40 meters are found. Specimens growing in the north are low-growing, and in mountainous regions willows are found as low-growing creeping shrubs, with a minimum height of several centimeters. Depending on the type of willow, the leaves can be thick, curly, bright green, or sparse, see-through grayish-green or grayish-white. The leaves are planted alternately, the leaf blade can be wide elliptical or quite narrow and long, with solid or jagged edges, the blades are shiny.

A characteristic feature of some species is the presence of fairly large stipules, which develop most often in young shoots. The stems are branched, the branches of the plant are quite thin, flexible, prone to brittleness, the buds can be dark brown, red-yellow. Willow flowers are very small, collected in dense inflorescences, so they are easy to notice. After flowering, fruits appear - boxes with small fluffy seeds. Willow is a common plant and grows in central Russia, North America, and some species grow in the tropics.

Willow is used as a decorative specimen, also, some species are often planted in order to strengthen loose soils and sands, since the root system of the tree is abundant, very developed, with numerous branches. The wood is used to produce tableware and decorative elements. Willow is a valuable honey plant; the bark of certain species is suitable for tanning leather. Wood is often used as a material for making wickerwork. Willow leaves are popular in folk medicine as a medicinal raw material.

Willow develops well on loam and sandy soils; plant the tree in an area with maximum moisture-absorbing soil, in a well-lit area.

Figs are a subtropical deciduous plant belonging to the genus Ficus. The tree has light gray smooth bark. The plant is characterized by the presence of large, alternately planted multi-lobed or divided rigid leaves. The leaf axils have generative shoots and contain two types of inflorescences - caprifigs and figs. Caprifigs are male flowers, they have small inflorescences, figs are female flowers with large inflorescences.

Pollination of figs occurs thanks to blastophagous wasps; they transfer pollen from male trees to female ones. Fruits appear on the tree - figs, with a lot of seeds inside, sweet and juicy. Depending on the variety, the color of the fruit can be yellow, blue or dark blue; yellow-green fruits are often found.

Figs are widespread in the Mediterranean, Transcaucasia, the southern coast of Crimea, and Central Asia. Often, a fig tree is planted in order to obtain a harvest of figs, which are eaten fresh, dried and canned; they are a separate delicacy, and can also be used to make jam and as an additive to other desserts. In folk medicine, fig leaves are used as medicinal raw materials.

Plant the tree in a well-lit area, in the south of the site so that the figs are protected from strong winds. The tree prefers light loams with good breathability.

Important!Figs are also planted as a houseplant in an apartment; they do not grow very large, but are capable of bearing fruit.

Hemp is an annual bast-fibre plant. It is characterized by the presence of an erect stem, rounded at the base, with opposite leaves on the upper part of the plant and with alternate leaves on the lower part. The leaves are compound, numbering 5-7 leaves with a serrated edge; there are more leaves towards the base of the stem than towards the apex. The flowers of the plant are represented by inflorescences in the form of a complex spike, in place of which appear bivalve nuts that have an ovoid or elongated shape, a smooth or ribbed structure, and a gray-green or brown color. The plant is widespread throughout the world and can grow in both tropical and temperate zones.

Previously, the plant was grown in order to obtain seeds and oil from it, as well as fibers that were used in everyday life. Hemp was also used for medicinal purposes, and recreational drugs were made from it. Hemp can be useful for producing ropes, ropes, cables, clothing, paper and threads, since the plant consists of very strong fibers.

Hemp is quite demanding on the soil and place of growth. Therefore, before planting, it is necessary to create all the necessary conditions. The plant prefers well-lit areas in the open sun; the soil must contain many nutrients and be moisture-absorbing, since hemp does not tolerate drought.

Nettle is classified as a perennial herb. it is characterized by the presence of strong roots and with multiple small branches. The height of nettle varies from 30 cm to 2 m. There are many stinging hairs on the stem and leaves. The stem is herbaceous, on which leaves are arranged crosswise and opposite each other. The leaf blade is ovate-heart-shaped or lanceolate, up to 17 cm long, up to 8 cm wide.

The edges are covered with large teeth. Quite long inflorescences develop on nettles, on which many small greenish flowers are planted; in place of the flowers, over time, seeds appear, represented by dry, compressed yellow or brownish nuts. One specimen can produce up to 22,000 seeds. It is found in Europe, Asia, China, and North America.

Nettle is a plant that is often eaten; soups, borscht, and salads are prepared on its basis. Used as livestock feed. In folk medicine, nettle leaves are used to prepare infusions and decoctions.

Stinging nettle is a weed, therefore, it can grow on any soil; plants are especially common on nitrogen-rich soils. The plant is light-loving, but can also grow well in partial shade and shade.

The genus Laurel belongs to subtropical trees or shrubs. Laurel is an evergreen plant that reaches a height of about 15 m, with smooth brown bark and bare shoots. The crown of the tree is dense, pyramidal in shape. The leaves on the shoots are planted alternately, have a solid edge, are bare, simple, can reach 20 cm in length and 4 cm in width. The leaves have a pleasant aroma, they are characterized by an oblong lanceolate or elliptical plate, narrowed towards the base. The foliage color is dark green on the upper part of the leaves, lighter on the lower part.

Laurel flowers are collected in inflorescences, umbrellas, located at the ends of the branches in several pieces, in the leaf axils. The flowers are residually small, yellowish, and over time turn into dark blue fruits. Laurel grows in the Mediterranean, Transcaucasia and the Canary Islands.

Laurel is used as a spice; essential oil is prepared from the leaves and used in cooking. Also, bay leaf is a medicinal raw material for the preparation of various medicinal products.

Laurel will do best in a well-lit area, but can tolerate light partial shade. The plant is not picky about soil and tolerates drought well. It is advisable to add organic and mineral fertilizers to the soil before planting so that the plant develops better.

The sea buckthorn genus includes two species. Plants are represented by shrubs or trees from 10 cm to 6 m in height, sometimes up to 15 m. The leaves are planted alternately, quite long and narrow, the foliage color is green, the surface of the plate is covered with small gray dots. Sea buckthorn blooms before the leaves bloom; the flowers are small and inconspicuous. In place of the flower, a drupe appears, which consists of a nut and a receptacle. The color of the fruits has a red or orange tint, and they are located very densely on the branch. Sea buckthorn grows in Europe, Asia, Mongolia, and China.

Sea buckthorn fruits are often used as a food product, they are eaten raw, drinks are prepared, and sea buckthorn oil is used in cosmetology and medicine. Certain types of sea buckthorn are ornamental plants; they are planted to strengthen road slopes or to create hedges. Leaves from the tree are used as tanning raw material.

The place for planting sea buckthorn should be well lit, the tree is not afraid of direct sunlight, prefers light neutral soils, tolerates regular fertilizers well and responds to them with a bountiful harvest.

It blooms with very small buds, up to 3 mm in diameter, greenish-yellow in color; in place of the flower, a yellowish or reddish fruit appears, represented by a false berry, with sticky pulp. In nature, there are up to 70 species of mistletoe, which grow mainly in the subtropics and tropics of the African continent, in the tropics of Asia and in the north of Australia, and almost throughout Europe.

Did you know?Mistletoe was used as a traditional Christmas decoration in England until the second half of the 19th century, at which time the British began decorating the Christmas tree, which became a symbol of Christmas.

Mistletoe fruits are food for birds. Also suitable for making glue. Traditional medicine contains recipes for an extract from the young leaves of the plant, used for various health problems.

Aspen is classified as a type of deciduous tree of the Poplar genus. The plant is characterized by the presence of a columnar trunk, height - up to 35 m, diameter - 1 m. The tree grows very quickly, but is prone to wood diseases, so its lifespan is no more than 90 years. The roots go deep underground, growing abundantly over several meters. The tree has smooth greenish or gray bark, which cracks with age and changes color to a darker one.

Aspen has a regular leaf arrangement, they are represented by round or rhombic plates, up to 7 cm in length, with a sharp or blunt apex, the leaf has crenate edges. The flowers are characterized by their small size, they are collected in catkin inflorescences, can be reddish or greenish, up to 15 cm long, flowering occurs before the buds open. After flowering, the fruit capsule is formed, the seeds are covered with down (powder puff), thanks to which they spread over tens of kilometers. Aspen can be found near forests and tundra; it grows in forests and forest-steppe. The tree is found in Europe, Kazakhstan, China, Mongolia, and Korea.

Aspen is often popular as an ornamental tree, planted along alleys and in city parks. The bark is used for tanning leather and is a source of yellow and green dye. The tree is considered a good honey plant. Wood is used in the construction of houses, in the form of roofing material. Aspen is also used as a raw material in folk medicine; the bark and leaves are considered medicinal.

It is better to plant aspen in well-lit areas, but it can also tolerate light partial shade, is not picky about soil, and grows well in both poor and nutritious, acidic and alkaline soils. The only requirement for the soil is that it should not be dry, sandy, swampy or frozen. Also, aspen does not tolerate high groundwater levels, so these features must be taken into account when planting the plant.

Asparagus is a genus of plants that has about 210 species. Can grow as grass and shrubs. The plant has well-developed rhizomes and highly branched stems. There are many needle-shaped branches on the stems. Asparagus has underdeveloped, small leaves, represented by scaly or spiny specimens. The plant blooms with small buds, which are collected in single, thyroid or racemose inflorescences.

The flower has 6 petals, which are arranged in two circles. In place of the flower, a fruit is formed in the form of a berry, which contains one or more seeds. The berries are red or bright orange when ripe. Asparagus can be found in temperate climates of North America, Europe, Central Asia, Australia and New Zealand.

Did you know?Asparagus is a natural aphrodisiac. In Ancient Greece, newlyweds wore wreaths made from this plant on their heads for the early appearance of offspring, and at French wedding feasts, at least three dishes with asparagus were always present on the newlyweds’ table.

Often, asparagus is used as a vegetable that is grown commercially for sale. Particularly valuable are the shoots of asparagus officinalis, which grow no more than 20 cm, have an unopened head, and in this state they are most useful for eating. Such shoots are boiled, canned, and prepared into salads and soups. Asparagus shoots are also used in folk medicine, and the essence obtained from the plant is used in the manufacture of homeopathic remedies.

Asparagus is a rather demanding crop, so it is necessary to very carefully select the place for planting; the area should be well lit, windless, and it is better to plant it on the south side of the site. The plant prefers to grow on light sandy loam soils rich in humus.

Poplar belongs to the genus of deciduous, actively growing trees, which has 95 species. A tree up to 50 m high, sometimes 60 m, with a trunk diameter of more than 1 m, the crown has a spherical shape. The brown-gray or dark gray bark has many cracks. Poplar is characterized by a strong root system, which lies on the surface and extends many meters from the trunk. Poplar leaves are planted alternately, the plates are lanceolate or wide oval, with reticulate venation.

Flowering begins before the buds open; small flowers are located on inflorescences of catkins that hang from the branches. In place of the flower, a capsule is formed - a fruit with small seeds with numerous hairs. The seeds are oblong or oblong-ovate, black or black-brown in color. Poplar is widespread in the northern hemisphere, in the subtropics of China, the boreal zone, in America, Mexico, and East Africa.

Poplar is characterized by the presence of light white wood, which is easy to process and is used as a raw material in paper production. In sparsely forested areas, poplar is used as a building material. The buds of the plant can be a source for obtaining purple dye, and the leafy part can be a source for yellow dye. Poplar is planted as an ornamental tree for landscaping alleys in cities; in addition, the tree is an excellent honey plant.

Poplar is not picky about soil and can grow on any type of soil; it prefers sunny areas. It normally tolerates wetlands and high groundwater levels, but is demanding on air permeability and soil nutrition, so when choosing a site for planting, pay attention to these features.

Pistachio is a genus of evergreen or deciduous trees and shrubs, which has 20 species. The plant has a two-tiered root system, the roots go 30 m beyond the crown and 15 m deep. The tree is characterized by the presence of a thick layer of dark gray bark; young shoots have a waxy coating. Pistachio leaves are pinnate, have an entire edge, and are shiny. The flowers are small, collected in yellow, red, dark pink inflorescences, in place of which drupes appear, suitable for consumption.

The tree grows in Africa, the Mediterranean, Asia and Central America.

Did you know?Pistachio seedlings were first brought to Europe from Syria in 1 tbsp. n. e. Roman Emperor Vitellius, the Italians liked the nut so much that they began to actively add pistachio to various dishes.

Due to the fact that pistachio has dense and strong wood, it is used in carpentry, and resins are also obtained from it to produce varnishes. The leaves contain many tannins used in leather processing. The most popular product of the pistachio tree is pistachio nuts. which are considered a valuable and useful product. Nuts are eaten on their own or used to prepare various dishes.

Pistachio can be planted on gray soils and brown soils. The plant is light-loving, drought-resistant, loves soils that contain a lot of calcium. It is better to plant in sandy soil and maintain acidity at pH 7.

Spinach is a genus of herbaceous plants that has three species. It is annual or biennial, grows up to 50 cm in height, and can be naked, simple or branched. The leaves are arranged in pairs, have an oval, oblong shape with a solid edge. The leaves have a smooth or rough structure, small flowers are collected in spike-shaped paniculate inflorescences of yellow color, in place of which spherical fruits appear. Spinach grows in Iran, the Caucasus, Central Asia, and Afghanistan as a wild crop, but is also planted everywhere for industrial cultivation.

Spinach is a valuable plant that is eaten and used raw, added to salads, boiled, fried, and stewed. It is used in folk medicine because it has medicinal properties and helps treat certain diseases.

Spinach is picky about the planting site; it prefers fertile soils, so it is better to plant it in an area enriched with organic matter. It grows well on loamy soils; it can be grown on sandy soils, but with regular watering.

Sour sorrel is a species of herbaceous plant in the genus Sorrel.. The plant has a taproot, very short and branched root, characterized by the presence of an erect stem, which can reach 1 m in height. The stem is silver in color, with a purple tint at the base.

The leaves grow from the root, they are long, petiolate, have an arrow-shaped base, a solid edge and a pronounced central vein, the blade reaches a length of 20 cm, the leaves are arranged alternately. The flowers are planted on paniculate inflorescences and are pink or reddish in color. In place of the flowers, triangular seeds appear, black-brown, smooth, shiny. The plant is distributed in North America, Asia, Europe, Western Australia.

Sour sorrel is used as a food product and is therefore cultivated as a vegetable crop. Green cabbage soup and borscht are prepared using sorrel; the leaves are used for canning. Sorrel is used in folk medicine; its leaves and juice can be used to treat various diseases.

It is better to plant sorrel in a well-lit area, preferably in partial shade. Sorrel is not picky about soil, but still prefers light sandy or loamy soil and grows well on peat soils. Sorrel prefers to grow on breathable soils with low groundwater levels.

Thus, dioecious plants are distributed throughout the world and can be represented by grass, shrubs, trees, and vines of various sizes. They are completely different, but they have one thing in common - male and female flowers cannot be located together on one specimen. This feature should be taken into account when planting some plants to ensure the possibility of pollination and ovary formation.

Was this article helpful?

Thanks for your opinion!

Write in the comments what questions you have not received an answer to, we will definitely respond!

24 times already
helped

Dioecy- the main way of plants to prevent self-pollination; female and male flowers are on different individuals (“in two houses”). This method is effective, but half of the population (male) in this case does not produce seeds. Dioecious plants include: willow, laurel, lemongrass, sea buckthorn, mistletoe, aspen, asparagus, poplar, hemp, pistachio, ginkgo.

Monoeciousness- female and male flowers are on the same individual (“in the same house”). More often found in wind-pollinated plants. Monoecy eliminates autogamy (pollination of the stigma with pollen of the same flower), but does not protect against geitonogamy (pollination of the stigma with pollen of other flowers of the same individual). Monoecious plants include: watermelon, birch, beech, walnut, oak, corn, hazel, cucumber, alder, pumpkin, breadfruit.

Other types of gender distribution:

• andromonoecy- male and bisexual flowers are on the same individual
• gynomonoecy- female and bisexual flowers are on the same individual
• androdiecy- male and bisexual flowers are on different individuals
• gynodiecy- female and bisexual flowers are on different individuals
• trietius, or three-household- bisexual, female and male flowers are on different individuals.

About 75% of flowering plant species have bisexual (hermaphroditic) flowers, and only about 25% of flowering plant species have dioecious flowers.

Individuals of some dioecious plants, such as hemp, under certain stressful conditions can produce flowers of both sexes, that is, become monoecious.

Flower formula and diagram

The formula of a flower represents a symbol of its structure using letters of the Latin alphabet, symbols and numbers .

When drawing up the formula, use the following notation:

P – perianthium;

Ca (or K) – calyx (calyx);

Co (or C) – corolla (corolla),

A – androecium (androeceum),

G – gynoecium (gynoeceum).

The * sign placed before the formula indicates the actinomorphy of the flower; sign – for zygomorphy. A staminate flower is indicated by the sign; pistillate – bisexual with a combined sign. The “+” sign indicates the arrangement of parts of the flower in two or more circles, or that the parts separated by this sign are opposed to each other. The brackets mean the parts of the flower are fused together.

The number next to the symbol indicates the number of parts (members) of this type in the flower. A line under the number indicating the number of carpels in the gynoecium, for example 3 , indicates that the ovary is superior; the line above the number is the inferior ovary; the line from the number is the semi-inferior ovary. A large and indefinite number of members is indicated by a sign.

For example, the formula for a tulip flower *P 3+3 A 3+3 G (3) shows that it is actinomorphic, has a simple six-membered perianth, the free lobes of which are arranged in threes in two circles; the androecium is also six-membered, consisting of two circles of stamens, and the gynoecium is coenocarpous, consisting of three fused carpels (compound pistil), forming the superior ovary.

Dandelion flower formula ↓ C a 0 Co (5) A (5) G (2) indicates that its flowers are zygomorphic, bisexual, have a double perianth, in which the calyx is reduced, the corolla consists of five fused petals, the androecium - of five stamens stuck together by anthers, and the gynoecium - of two fused carpels, forming the lower ovary. For the dandelion flower formula, a more rational notation G (1) is also acceptable.

Rice. 30. Flower diagram. 1 – shoot axis, 2 – bract, 3 – sepal, 4 – petal, 5 – stamen, 6 – carpella, 7 – leaf

A flower diagram represents a conventional schematic projection of the parts of a flower onto a horizontal plane (Fig. 30).

Inflorescences. Classifications

Inflorescence - part of a shoot or a system of modified shoots bearing flowers. The biological meaning of inflorescences is the increasing likelihood of flower pollination. An insect will visit many more flowers per unit of time if they are collected in inflorescences. In addition, flowers collected in inflorescences are more noticeable among the green leaves than single flowers. Many inflorescences sway easily under the influence of air movement, thereby facilitating the dispersal of pollen.

Any inflorescence has a main axis and lateral axes, which can be branched to varying degrees or not branched (Fig. 31). The axes of the inflorescence are divided into nodes and internodes. At the nodes of the inflorescence axes there are leaves and bracts - modified leaves.

Rice. 31. Inflorescence structure: 1 – main axis, 2 – lateral axis, 3 – nodes, 4 – internodes, 5 – bracts, 6 – pedicels, 7 – flowers

Inflorescences in which the lateral axes branch are called complex . In simple inflorescences, the lateral axes are not branched and are pedicels. Simple inflorescences arose in the process of evolution from complex ones, which is associated with the reduction of their lateral axes. In bisexual plants, the inflorescences bear bisexual flowers, but in monoecious and dioecious plants the inflorescences can also be staminate, pistillate and polygamous. In the latter case, staminate, pistillate and bisexual flowers are found simultaneously.

Classification of inflorescences

- botryoid (bothrical, or racemose) - monopodial branching;

- cymoid (cymose) – sympodial branching.

1) Botrioid inflorescences (Fig. 32)

- brush(flowers sit on pedicels evenly distributed along the axis) (representatives of the cruciferous family).

- ear- a derivative of the raceme, which has sessile flowers (orchis ( Orchis);

- earring(poplar Populus, willow Salix);

- cob with a thickened inflorescence axis;

There are a number of inflorescences with a shortened axis - umbrella, head and basket.

- umbrella- an inflorescence derived from a raceme, in which all the pedicels and bracts are located at the top of the shortened axis of the inflorescence (primrose ( Primula), ginseng ( Panax). - head is a modified umbrella, in which the pedicels are reduced, and the shortened axis of the inflorescence grows;

- basket- this is a head surrounded by an involucre, that is, close apical leaves (family Asteraceae).

- panicle- branched inflorescence with a gradual decrease in the degree of branching of the lateral axes from the base to the apex;

- complex shield(modified panicle with shortened internodes of the main axis and highly developed internodes of the lateral axes).

- antela- an inflorescence in which the internodes of the lateral axes are greatly elongated and the flower ends up at the bottom of the funnel formed by the lateral branches.

- complex brush- an inflorescence in which the botryoid inflorescences are simple racemes.

- double And triple compound brushes(derived from a complex raceme - a complex spike, in which sessile flowers are located on the lateral axes and the inflorescences are simple spikes);

- double and triple compound spike(most grasses and many sedges);

- complex umbrella(representatives of the umbrella family), which has lateral axes of two orders - first and second.

In addition to the listed inflorescences, there are a number of types in which the branching features of the main axis differ from the branching features of partial inflorescences - they are called aggregate(panicle of umbrellas - Aralia Manchurian Aralia mandshurica, panicle of baskets, raceme of baskets (row drooping Bidens cernua), ear of baskets (forest dried grass Gnaphalium sylvaticum) (rice. 32).

Rice. 32. Types of botryoid inflorescences. A - simple botryoid: 1 - brush, 2 - ear, 3 - ear, 4 - simple umbrella, 5 - head, 6 - basket, 7 - scutellum (4. 5, 6 - with a shortened main axis, others - with an elongated one) ; B – complex botryoid.

Panicle and its derivatives: 1 – panicle, 2 – complex scutellum, 3 – antelela; B – complex botryoid. Complex brush and its derivatives: 1 – triple brush, 2 – double brush, 3 – double spike, 4 – double umbrella

Rice. 33. Aggregate inflorescences: 1 – panicle of umbrellas, 2 – panicle of baskets, 3 – shield of baskets, 4 – raceme of baskets, 5 – spike of baskets

1) Cymoid (cymose) inflorescences: cymoids and thyrsi .

Rice. 34. Cymoid inflorescences. A – cymoids: 1-3 – monochasia: 1 – elementary monochasia, 2 – gyrus, 3 – whorl, 4 – double whorl, 5-6 – dichasia: 5 – dichasia, 6 – triple dichasia, 7-8 – pleiochasia: 7 – pleiochasium, 8 – double pleiochasium; B – thyrsus

1) Cymoids- These are simplified thyrsi with sympodial branching. There are three types of cymoids: monochasia, dichasia and pleiochasia.

- monochasia- under the flower that completes the main axis, only one inflorescence or a single flower (gyrus, curl and ball) develops (ranunculaceae, borage).

- dikhazia- from the main axis, under its final flower, two partial inflorescences extend, and in the simplest cases, two flowers.

Simple, double, triple dichasias are possible. Dichasia is found in a number of carnation plants, for example species of the genus Chickweed ( Stellaria).

- pleiochasy- under the flower that completes the main axis, three or more partial inflorescences (or flowers) develop. Double, triple and more complex pleiochasias are fundamentally possible.

2) Thyrsae are more complex than cymoids. These are branched inflorescences, in which the degree of branching decreases from the base to the apex.

The main axis of the thyrsus grows monopodially, but the partial inflorescences of one order or another are cymoids. For example, thyrsus is the inflorescence of horse chestnut ( Aesculus hippocastanum), another example of thyrsus is the mullein inflorescence ( Verbascum) from the Norichnikov family. Thyrses of various types represent inflorescences of all Lamiaceae. The inflorescence of birch is an earring-shaped thyrsus.