Plants that have representatives of different sexes - male and female - are dioecious plants. Examples of such plants are nettle, poplar, mulberry tree (mulberry), asparagus, spinach, willow, hemp, pistachio, podocarpus and others. But this is not a complete list.
And all dioecious plants have flowers, but some will have "male" flowers and others will have "female" flowers. Such representatives of the flora are characterized by cross-pollination. Monoecious and dioecious plants differ in that the former have "male" and "female" flowers on the same plant.
Pollination of dioecious plants
Dioecious plants in terms of evolutionary development are considered more perfect. They are not capable of self-pollination, and this circumstance contributes to the strengthening of the species.
For some fruit trees, both sexes are important. In the process of fertilization and production of seeds and fruits, the pollen of stamen male flowers is taken by the stigmas of female ones. Only in this case, you can get the fruits. But this does not mean that for every "female" plant you need to have one tree.opposite sex.
One male will serve to pollinate a range of female plants. The approximate amount varies depending on the type of plant. For example, to fertilize a whole grove of date palms, only a few "male" trees are planted. One male date palm tree is enough to pollinate 40-50 palms of the opposite sex. Often, a branch of a male tree is grafted onto the female trees to ensure successful pollination.
Differences between representatives of different sexes of the same species
Very often it is initially difficult to determine which house a plant belongs to. But it ceases to be a mystery when the time comes for the first harvest - the fruits will be on the female. At the same time, the difference in the structure of the male and female flower is noticeable. The male flower has little or no stigma, while the female flower may lack stamens. The stamens in the female flowers produce almost no pollen, while the stamens of the male flowers are abundantly dotted with pollen.
Practical application of knowledge about dioecious plants
For practical purposes, it is important not only to know which plants are dioecious, but also to be able to distinguish between the sexes of individuals of the same species. For example, if there is a mulberry tree on the site that does not bear fruit, then most likely it is a male tree. And in order to enjoy tasty and he althy berries, you need to plant a couple for him - a female tree. Or at least graft a branch of a female tree. And vice versa: graft a male branch into a female tree.
At the same time, if you need to purchase a mulberry tree for a personal plot solely for decorative purposes, so that you do not have to constantly remove overripe berries that have crashed on the ground, it is better to choose a male tree - it has a beautiful lush crown, but it will never bear fruit.
Dioecious plants, in particular their male parts, produce huge amounts of pollen. This circumstance has a very simple and logical explanation: the female tree may not be nearby, so there must be a lot of pollen in order for it to reach its goal. Male trees produce more pollen, particles are very light and shaped to "travel" on air currents with ease.
Figs are a special dioecious plant
Figs, also called figs or figs, are one of the most curious representatives of the dioecious. It is considered the oldest cultivated plant. There is even a mention of the fig tree in the Bible.
The fig tree does not have a beautiful flowering - fig flowers are small and inconspicuous. But this disadvantage is more than compensated by juicy and honey-tasting fruits. True, only female plants bear fruit. Therefore, a fig tree grown from seeds may turn out to be, as the people say, an empty flower, that is, a male tree. But without it, there will be no fruit on female trees either.
Pollination of figs is a very interesting topic for a separate study. The fact is that fig flowerspollinated only by blastophage wasps. A wingless male wasp waits for a female inside a male flower. A fertilized blastophage female collects pollen from a male flower on her body, getting out of it, and transfers pollen to female flowers in search of new male inflorescences.
Scientists have found that for the he alth of a person prone to allergies, dioecious plants are very dangerous. Among them, allergenic plants are more common. And those of them that have earned the reputation of the most powerful allergens are also dioecious. But when choosing plants for landscaping, you can not refuse dioecious plants, you just need to give preference to female plants - they do not produce as much pollen as male plants, which means they have less effect on humans.
Under certain unfavorable conditions, dioecious plants, such as hemp, can become monoecious. In this case, male and female flowers will be presented on the same plant.
In ancient times, the knowledge of what dioecious plants are was widely used. Examples of this can be found even in the history of military confrontations. For example, during raids on foreign territories, troops destroyed males in date groves - this is much easier than completely cutting down all plantings, but it guarantees no harvest and will cause significant economic damage to the state.