The group of angiosperms representatives of the flora is usually divided into monocotyledonous and dicotyledonous plants, differing mainly in the structure of the embryo. Nevertheless, these classes of plants have other differences in the structure of vegetative and generative organs.
Class Dicotyledons, or Magnoliopsids: the structure of plants and their brief description
Today, this class is considered quite large, as it includes about 200 thousand species. Its representatives have a number of very characteristic distinguishing features.
Dicotyledonous plants are presented in different forms - these are trees, and bushes, and herbs. The woody species inside the stem have a rather powerful layer of cambium - a special fabric that ensures its growth in width. The leaves of plants can be either simple or complex, but in almost all species they are cuttings - sessile leaf blades are not typical for this class. Venation of the plate in most cases mesh. The root system is predominantly pivotal - it has a main, main root, from which lateral, small sizes grow.
Another feature is the structure of the generative organs. Most species have large flowers with bright colors. They have a double perianth (sepals and petals), flowers are mainly five- or four-membered. Dicotyledonous plants are most often pollinated by insects.
And, of course, the structure of the embryo, which has two lateral cotyledons, is very characteristic. By the way, it is with this feature that the name of the class is connected.
Dicotyledonous plants: the most common species
This class includes a huge number of species that are included in several thousand genera and three hundred families. The most famous of them are the following.
Cruciferous family - its representatives are distributed mainly in the northern hemisphere of the planet. Most of its species are grassy forms or small shrubs. Everyone knows such representatives of cruciferous as cabbage, radish, horseradish, turnip, mustard and radish.
The Pink family combines trees, shrubs, and herbaceous plants that are mainly distributed in temperate or subtropical climates. For example, the well-known rose hips and decorative roses belong to this group. This also includes most of the fruit trees and bushes, including apple, pear, cherry, mountain ash, raspberries, bird cherry, blackberries.
The Bean family - its woody forms and shrubs are distributed mainly in tropical and subtropical countries, and grassy ones prefer a more temperate and even cold climate. All representatives of the group are characterized by a specific whisk of the "moth" type. The following known plants belong to this group: peas, beans, alfalfa, beans, soy. By the way, some species are actively involved in the nitrogen cycle.
Class Monocotyledonous plants: a brief description
This group is represented mainly by herbaceous plants - trees and shrubs in it are extremely rare. Their stems, as a rule, do not contain cambium and, therefore, are not capable of growing in thickness. Leaflets are simple, with solid edges. They have no petiole and are attached to the stem by the edge of the leaf blade, which is why they are called sessile leaves. Venation in most cases parallel or arc.
Another feature is the fibrous root system, in which there is no main root. There is only one cotyledon in the bud, as evidenced by the name of the class.
Most monocotyledonous plants are pollinated with the help of wind. Therefore, their flowers are small, soft, with a single perianth, mainly trinomial.
Typical representatives of this group are cereals: wheat, oats, corn, rice and others.