Why did gymnosperms get such a name: the peculiarities of the structure

Each taxon of plants has its own characteristic features that distinguish it from the rest. For what reason it is impossible to see flowers and try the fruits of pine? Why did Gymnosperms get this name? Briefly and as clearly as possible on these questions we will answer in our article.

Why the Gymnosperms received this name: the answer

Gymnosperms named these plants the famous botanist Andrei Nikolaevich Beketov. Being the founder of the geography of vegetation in Russia, he wrote the first textbook on taxonomy. The feature that is the basis of this name is the peculiarity of the location of the seeds. They are located on the generative organs openly, "hollow". In contrast to flowering plants, in which the seeds are securely protected by the walls of the ovary.

Features of the structure

The life forms of these plants are represented by shrubs or trees, since in their stems a lateral educational tissue is formed - cambium. Gymnosperms originated from higher spore. However, the process of fertilization in them no longer depends on water, which is a progressive feature of the structure. Leaves of gymnosperms are called needles. They have a needle-like shape, which reduces the surface with which water evaporates.

Why the Gymnosperms received such a name, still explains the structure of the ovary itself. It is a scaly, which is not at all capable of covering the germ from the cold and drought.

Are there any fruits in Gymnosperms?

Many believe that cones are the fruits of gymnosperms. But this opinion is erroneous. The fact is that the fruits are formed only after the development of flowers. In plants that are representatives of this department, such generative organs are absent. They are represented by female and male cones, in which gametes are the sex cells.

The process of pollination in Gymnosperms occurs with the help of wind. So from the male cones of the sperm get into the female, where the fertilization and seed formation takes place. When the latter ripen, the scales of the cone open. This happens only after 18 months. During this period, you can look at the seeds with the naked eye, which lie directly on the scales. That's why gymnosperms got such a name. Thus, cones are modified shoots, performing the function of sexual reproduction.

Winter and summer ...

The children's mystery about the Christmas tree is known to everyone from childhood. Most gymnosms really do not shed their leaves for the winter. Why? Gymnosperms have received such a name by the type of structure of generative organs. But their ability to remain evergreen is associated with vegetative: leaves and stems. The first, due to its shape and small surface, protect plants from excessive transpiration.

For the winter the stomata is sealed with resin, which in this period evaporation practically ceases. Protection is complemented by the fact that the needles are covered with a cuticle. But this does not mean that Gymnosperms do not change foliage at all. Khvoinki can live up to 7 years, after which they die and are replaced with new ones. The only exception is larch. This plant changes its outfit every season.

Classification

Despite a number of common signs, in this department distinguish several classes. The most numerous of these are Coniferous. Spruce, pine, fir, cypress, yew, cedar, larch are typical representatives of the class. They got their name by the type of leaves - needles.

To the class of Gnetovye belongs velvichiya amazing. This plant with the largest leaves, reaching several meters in length. They never fall off. At the same time, the trunk itself, which is almost entirely in the ground, is not visible. Velvichiya grows in the desert, where a strong wind constantly blows. It tears the leaves along, so they resemble a tangle of snakes.

But representatives of the class Sagovnikov can be confused with a palm tree. Their stem does not branch. It is characterized by the presence of a developed core and weak wood. When the leaves of the Sagonnikov fall off, the petioles remain on the stem.

The next class is represented by a single species - bilobed ginkgo. This plant is endemic to China and Japan. Ginkgo reaches a height of 30 meters, and the diameter of the trunk is three and has a spreading crown. Its leaves resemble a fan with a notch in the middle. Translated from the Japanese language, the name of this plant means "duck paws", which also corresponds to their shape. In autumn, the leaves become bright red, then fall off. In countries where ginkgo grows, they are considered sacred plants and protected by law.

So, we examined why the Gymnosperms got such a name. The reason for this is the location of seeds on the scales of generative organs. They are not protected by the walls of the ovary and lie there naked, openly. The characteristic features of these plants are the absence of flowers and fruits, vessels in the wood. Pollination occurs in the Gymnosperms with the help of wind, and the leaves are called needles.