Flower monoecious and dioecious plants. Monoecious plants. Flowers bisexual and dioecious

All plants, without exception, known to science are classified into three groups - single, double and multiple. In the former, heterosexual inflorescences are located on the same plant, in the latter, on different ones. At the same time, the flowers themselves can be either bisexual - with pistils and stamens, or dioecious, which have either a pistil or a stamen. Polyecious plants provide for the presence of two varieties of inflorescences on one plant. The so-called polygamy is observed in horse chestnut, grapes, forget-me-nots, ash.

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Characteristics of monoecious plants

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Many scientists believe that unisexual flowers arose from bisexual ones, but this happened as a result of evolutionary processes. Monoecious plants are characterized by the presence of pistillate or staminate inflorescences on one individual. Flowers of both sexes are "in the same house" - hence their name. The flowers of some plants do not have a formed perianth. Plants of this type are predominantly wind-pollinated, but there are cases when they are pollinated by insects - this process is called entomophily. Plants can self-pollinate, this is when pollination takes place in the bowl of one flower. Most often, pollen enters the bosom from other inflorescences located on the same plant. And it has a bad effect on the properties of seeds. Monoecious plants are very common. For example, corn, alder, watermelon, beech, pumpkin, walnut, hazel, birch and oak. In addition, there are species that reorganize from dioecious to monoecious under stressful conditions - for example, such a plant as hemp.

Walnut is one of the brightest representatives of monoecious wind-pollinated plants. Bees visit only male flowers, and ignore female flowers, for this reason their importance in pollination is negligible. The difference in the blooming of male and female flowers on the same plant reaches $15$ per day. As a result, cross-pollination occurs.

Hazel is a monoecious plant. Male flowers in sagging catkins, female flowers are hidden inside the buds, only raspberry stigmas protrude. Pollinated by the wind. The fruit of the hazel is a brown-yellow one-seeded nut, surrounded by a bell-shaped cupule of modified bracts. Hazel shrubs is a versatile monoecious plant.

Characteristics of dioecious plants

In dioecious plants, female and male flowers grow on different plants of the same species, so they may differ in appearance. It's like a rooster and a hen. For the process of fertilization, cross-pollination is necessary, that is, the transfer of pollen from the anthers of male flowers to the stigmas of female ones. In this they are helped by insects to attract, which plants of this species have large and colorful flowers. Such pollination is considered more perfect, as it helps to strengthen the species. Most fruit trees require both sexes. One male flower serves to pollinate several female flowers. And only after that, fruits can form on female flowers. But it is not necessary to have one plant of the opposite sex for each female plant, one male can pollinate a number of females. The number of which depends on the type of green spaces. For example, a whole grove of date palms is fertilized by several male trees. One is enough to pollinate about $40-$50 palm trees. Sometimes, for better and more successful pollination, a branch of a male tree is grafted onto female trees.

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For practical purposes, it is important not only to know which plants are dioecious, but it is also necessary to be able to distinguish between the sexes of individuals of the same species. In representatives of one species, sex is initially difficult to determine. If we consider the structure of the male and female flower, we note that the male flower has an underdeveloped or completely absent stigma, but its stamens are dotted with pollen. In turn, the female flower is devoid of stamens, or if there is a stamen, then there is very little pollen on it. This knowledge is important for gardeners. For example, if there is a tree in the garden that does not bear fruit, then it is probably dioecious, and it is necessary to determine its sex, and plant a tree with the opposite sex on the site. Or graft a branch to it from another individual of this species. Well, if it is necessary to decorate an ornamental garden or a personal plot, we choose a dioecious tree of the same sex, so that overripe fruits do not spoil the aesthetics, and it would not be necessary to constantly clean the site.

Dioecious male plants produce large amounts of pollen because the female tree may not be around. Therefore, there should be a lot of pollen, that some percentage flew to the stamens of a far-growing female. The pollen is very light and shaped to float in the air.

Consider a dioecious plant using the example of a fig. Fig flowers are small and inconspicuous. Only female plants bear fruit. Figs are pollinated only by blastophage wasps. In order for the female of such a wasp to be fertilized, she is looking for male fig flowers, since her wingless prince sits there. Fertilizing, inside the flower on her belly, she collects the pollen of the male flower. Having fertilized, it gets out in search of a new flower, and thus transfers pollen to the stamens of female flowers.

Among dioecious plants, forms are known in which it is impossible to determine the difference between the sex chromosomes. For example, hemp. It is capable of turning from a dioecious plant into a monoecious one in extreme situations, it is also bred by breeders as a monoecious plant. In some dioecious flowering plants, forms with intermediate male and female individuals have been observed. Thus, the mechanism of sex determination is currently unclear.

Cannabis that bears male flowers is called a cannabis plant. Women's cannabis is called mother. Materka is more thick-stemmed, leafy and tall. Materka ripens later. Poskoni dry quickly, almost immediately after flowering. For sowing hemp, female and male individuals are taken in a ratio of $ 1: 1 $. But despite this, the yield is different. Materka reproduces a third of the total fiber yield.

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Dioecious plants have specific sex chromosomes similar to animals. For the first time in $1917$, Allen identified sex chromosomes in a liver moss plant. It is known that moss plants are always haploid, while the sporangium and its stem are diploid. Allen discovered that the male moss plant has $7$ regular chromosomes and one small Y chromosome. The female plant has 7 Y chromosomes and one very long X chromosome.

During fertilization, these two sets of chromosomes unite, forming a sporophyte with a set of $14A+X-b Y.$ At the stage of meiosis, seven pairs of autosomes and one pair of $X Y$ are formed. It follows that half of the disputes will receive $7A+X$ and the other half $7A+ Y$. From these disputes directly develop female and male of this species.

To date, breeders have the power to shift the sex of plants. It is quite possible to change the number of female flowers in cucumber, spinach, by treating plants on the eve of flowering with carbon monoxide, ethylene or other reducing agents. Under the influence of the conditions of mineral nutrition, photoperiodicity and temperature conditions, the ratio between the number of male and female generative organs (flower) is significantly shifted.

All plants in nature have their own differences. According to the division of sexes, all types of flora are divided into the following groups:

monoecious;
dioecious;
multi-house.

Dioecious plants are those that have female flowers on some individuals and male flowers on others. They cross pollinate. So the fruits of dioecious trees are tied if the pollen of individuals from male flowers is transferred to trees with female flowers. This process would not be possible without bees, on which further pollination depends. The disadvantage of such a device as dioeciousness is that seeds do not appear in 50% of plants of a certain species. In nature, such species occur no more than 6%. These include the following plants:

Sorrel

mistletoe

laurel

Nettle

Poplar

Hemp

Aspen

Differences between males and females

Distinguishing male and female dioecious species is always difficult, those who grow flowers, trees and other crops must learn to determine the sex. The flowers of males have stamens dotted with pollen, and their stigma is underdeveloped. Female flowers almost always lack a stamen.

If a tree in the garden does not bear fruit, then most likely it belongs to the dioecious species. To remedy the situation, you need to plant a plant of the same species nearby, and then, thanks to the bees that help the flowers to pollinate, the tree will begin to bear fruit.

Male flowers of dioecious plants usually produce a lot of pollen. This is due to the fact that females do not always grow nearby, which means that there should be enough pollen to pollinate far-growing female plants. It is light and can be spread by gusts of wind to distant territories.

How do dioecious pollinators work?

The fig is a dioecious plant, and using its example, we will consider how its pollination occurs. It has small and not too remarkable flowers. Pollination occurs due to blastophage wasps. The female of this species searches for male flowers on which male wasps sit. Thus, the wasp collects pollen from male flowers and further pollinates female flowers of figs. So fertilization occurs in wasps, and thanks to them, fig flowers are pollinated.

Dioeciousness is a special adaptation of plants, which is manifested in the fact that one species has female and male individuals, but it is often difficult to determine their sex. In such cases, breeders are trying to develop new monoecious species so that gardeners do not have problems with the fruitfulness of crops in the future.

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Characteristics of monoecious plants

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Characteristics of dioecious plants

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All plants known to science are divided into three groups - monoecious, dioecious and polyecious. In the former, heterosexual inflorescences are on the same individual, in the latter, on different ones. At the same time, the flowers themselves can be either bisexual - with pistils and stamens, or dioecious, which have either a pistil or a stamen. Polyecious plants provide for the presence of two varieties of inflorescences on one individual. The so-called polygamy is observed in ash, grapes, forget-me-nots. But it's not about them now. This article describes which plants are monoecious and provides a brief description of their brightest representatives.

Monoecious plants: characteristics

Many scientists believe that unisexual flowers were formed from bisexual ones, and this happened due to evolutionary processes. Speaking about monoecious plants, it is necessary to emphasize that they are characterized by the presence of pistillate or staminate inflorescences on one specimen. Representatives of both sexes are "in the same house" - hence the name of these green spaces.

Plants of this type are most often wind-pollinated. There are cases when pollen is carried by insects - this process is called entomophily. Plants are not inherent in autogamy, when pollination occurs in the bowl of one flower. Most often, pollen enters the bosom here from other inflorescences located on the same plant. And this directly affects the properties of seeds.

At every step there are monoecious plants. Examples of such green spaces are: watermelon, corn, pumpkin, walnut, hazel, alder, beech, birch and oak. There are also species that, under extreme conditions, can transform from dioecious to monoecious - these include, for example, hemp.

Walnut

One of the brightest representatives of monoecious plants. It is rich in vitamins, alkaloids, carotene, essential oils, iron salts and other beneficial substances. Walnut improves memory, helps to get rid of constipation, is indispensable for heart disease and diabetes, prevents the appearance of breast and prostate cancer.

It starts blooming in May. Useful fruits of the tree can be enjoyed already in September. Inflorescences are collected in small groups - from two to five pieces. Due to the fact that male and female flowers do not ripen at the same time, cross-pollination occurs between them. Walnut fruits can also be tied without pollination, but then their properties will be of very poor quality.

Oak

Monoecious plants are also trees of the beech family. Oak is a typical representative of them. It has long been considered the personification of wisdom, durability, beauty and strength. The bark, leaves, acorns of the plant have similar qualities. They are very strong, enduring winter frosts and summer heat, poor climatic conditions and sudden changes in weather. The height of the oak is no more than 30 meters, although real giants are often found in nature. Few people know that oak begins to bear fruit only after thirty years from the date of planting.

Both female and male flowers are located on the oak, so these trees are monoecious plants. Staminate individuals are usually collected in small inflorescences, have a greenish color. Their top is decorated with a crimson edging. There are fewer male flowers - they are located "in one bunch" of three and have a pleasant pale pink color. Much is known about the medicinal properties of oak. For the production of healing drugs, everything is used - bark, acorns, leaves, which have wound healing, astringent, anti-inflammatory properties. Oaks grow well in any climatic conditions: both in wet swamps (virgin species) and in dry areas.

Birch

Monoecious plants include not only walnut and oak, but also birch. The components of the tree are often used in traditional medicine. For example, tincture from the kidneys is actively used by healers to eliminate various diseases. And the birch mushroom restores strength well. It effectively neutralizes headaches, increases appetite. And everyone's favorite perfectly cleanses the body, fights against the formation and growth of internal tumors.

Birch can reach a height of up to twenty-five meters. It is slightly inferior to the beech family in terms of the number of genera and species. And it's significant. There are only 150 varieties of the birch "clan", in beech this figure is much higher - 800 species. Almost all representatives are resistant to frost, only Japanese, Chinese and Himalayan individuals do not belong to them.

Hazel

Walnut, oak, birch - these are not all green spaces that are included in a group called "monoecious plants". Examples are endless. Hazel also belongs to this category - a long-lived shrub, which, on average, can please mankind with tasty and healthy nuts for about eighty years.

(staminate) are located in the catkins of the plant, but the female (pistil) are in the flower buds. Hazel shrubs are universal monoecious plants. Fruits, bark, leaves and even roots - all this is actively used in medicine. Varicose veins, constipation, lack of milk in lactating women, rickets, anemia, hypertension - decoctions, tinctures, ointments and other remedies made from hazel components can easily cope with all these problems.

Sedge

Listing monoecious plants, I would like to dwell on this herbaceous specimen. Today, more than two thousand of its species are known. Sedge loves moisture very much, so it can most often be found in swamps. It can also grow right in the water. A prerequisite for its normal existence is the presence of light. However, the plant can easily adapt to a semi-dark area.

Inflorescences are unisexual: male and female specimens have from 2 to 5 stamens and pistils. Sedge leaves reach one meter in height. They are tightly grouped, so they look more like bumps that can easily support the weight of a person. They are very dense with hard edges, so it is not recommended for a person to tear them with bare hands: you can cut yourself badly. Recently, the plant has been increasingly used for decorative purposes - especially in areas where there are artificial reservoirs. Small lakes and ponds are decorated with sedge. Also, the plant is often used as feed, less often used in pharmacology.

Monoecious plants are plants in which male (staminate) and female (pistillate) flowers of the same sex are on the same plant. Dioecious plants must be represented by male and female specimens. Dioecious plants - plants that have male (with stamens) and female (with pistils) flowers on different individuals.

Monoecious plants include birch, hazel, oak, beech, many sedges, gourds. This feature of plants is an adaptation that prevents self-pollination and promotes cross-pollination. Individuals of some dioecious plants, such as hemp, under certain stressful conditions, can produce flowers of both sexes, that is, become monoecious.

Monoeciousness is more common in wind-pollinated plants. Monoecious plants include: watermelon, birch, beech, walnut, oak, corn, hazel, cucumber, alder, pumpkin and other pumpkin, breadfruit. When monoecious is understood in a broad sense, spruce, pine, and many mosses and algae also belong to monoecious plants.

Dioeciousness is the main way modern plants prevent self-pollination. This method is effective, but half of the population in this case does not produce seeds. Dioecious plants include: actinidia, willow, hemp, laurel, lemongrass, sea buckthorn, mistletoe, aspen, asparagus, poplar, pistachio. Of the non-flowering plants, the gymnosperm plant Ginkgo is dioecious - sporangia appear on its male trees, in which pollen develops, and ovules develop on female plants.

Ponomarev A.N., Demyanova E.I. Separation of the sexes as an adaptation to cross-pollination // Life of Plants. M .: Education, 1980. - V. 5. Part 1. Flowering plants. If the female flowers are on one plant and the male flowers on another, the plants are called dioecious (willow, hemp, hops). Dioecious PLANTS - plant species, in which the husband. (staminate) and wives. (pistillate) flowers or other male. and wives. the genital organs (in non-flowering plants) are not on one individual, but on different ones.

Dioecious plants are:

Dioecious Plants - The division of the sexes in plants is one of the devices by which the representatives of the vegetable kingdom try to prevent self-pollination. In the center of the flower (Fig. 68), most plants have one or more pistils. Flowers with a double perianth may also have fused sepals and petals.

Cherry ranunculus flowers have a single-leaved calyx and a single-petaled corolla. She moves away from the stem and connects it to the flower. In some plants (wheat, clover, plantain), pedicels are not expressed. Such flowers are called sessile. Some plants (willow, poplar, corn) have only pistil or stamens in the flower.

In poplar, willow, sea buckthorn, stinging nettle, some plants have only staminate flowers, while others have pistillate ones. 1. What parts of the flower are in its center and what is their structure? In dioecious plants, as well as in animals, specific sex chromosomes have been found in a number of cases. In humans, as well as in Drosophila, female cells contain two X chromosomes, and male cells contain one X and one Y chromosome.

Although most plants are hermaphrodites, there are many mechanisms that prevent a given plant's egg from being pollinated by its own pollen. They are formed on the same (monoecious) or different (dioecious) plants.

Plants for herbarium are collected in dry weather, plants moistened with dew or rain quickly turn black during herbarization. Plants that bear male flowers are called pokonie, or zamushka, and plants that form female flowers and seeds are called mother. The ratio between male and female plants in the sowing is usually 1 1, but their share in the yield is different. Materka plants are thicker and taller, strongly leafy, ripen later.

In the vast majority of angiosperms, the development of flowers proceeds according to the type of proterandria; first, the anthers ripen and crack, and then the pistil ripens. Although actinidia are usually strictly dioecious, the female flowers also contain stamens, which, however, do not produce viable pollen. This also favors cross-pollination, but they can also self-pollinate. In angiosperms, there are two types of pollination self-pollination autogamy) and more progressive in evolutionary terms and more often occurring in nature cross-pollination xenogamy).

See what "DIOCOMMINE PLANTS" is in other dictionaries:

A special form of self-pollination is geitenogamy, which is observed in dioecious but monoecious plants, in which female flowers are pollinated by pollen from male flowers of the same plant. Recent studies have confirmed the possibility of using monoecious gynoecium plants for the production of hybrid seeds without the use of manual pollination. In the offspring from crossing two E ballium elaterium plants, exclusively hermaphroditic plants arise.

Thus, the roots affect the sexualization of plants as organs synthesizing cytokinins. Gibberellin treatment of monoecious cucumber plants, in contrast to auxin treatment, increases the number of male flowers produced. Treatment of gynoecium cucumbers (that is, those specimens of dioecious varieties that usually form only female flowers) with gibberellin leads to the formation of mulsian flowers as well. In Zea mays, staminate and pistillate spikelets are in different inflorescences, spikes and panicles, respectively.

At the same time, a new moss plant was obtained, which retained the diploid set of sporangium chromosomes. In dioecious moss species, such a diploid will have both an X and a Y chromosome. What gender will this plant be? As a rule, it will be monoecious and both Nsensky and male organs develop on it. Dioecious make up the 21st class in the Linnaean classification, but in modern systems they did not stay within the same group.

Often the female flowers are far removed from the male ones. This leads to the fact that plants during pollination cannot do without intermediaries, which contributes to cross-pollination.

In dioecious monoecious and dioecious plants, male inflorescences also ripen first, and then female ones. Bisexual flowers are those that have stamens and pistils. Flowers bisexual and unisexual. Bisexual flowers are such flowers, each of which contains both male and female organs (for example, in a lily).