Quite a lot of interest is what is the basis of the life of simple leaves falling from trees. What is a vein? What provides them with a good water supply? We will answer this and other questions a little later!
What is a leaf?
Leaf - in botany, this is the external apparatus of a plant, the main functions of which are considered to be synthesis, gas exchange and evaporation. In order to provide the cells with an azo-pigment element, the leaf has a plate-like texture. The leaf, in addition, is considered the organ of respiration, volatilization and guttation (separation of water grains) of plants. Leaves have every chance to retain water and caloric elements, and other functions are carried out in individual plants.
What is a leaf made of?
Usually, the structure of the leaf consists of the following matters:
- The epidermis is a layer of cells that protects against the harmful effects of the external environment and excessive water volatilization. Often, on top of the epidermis, the leaf is wrapped in a protective layer of waxy material (cuticle).
- Mesophyll is an internal chlorophyll-bearing matter that performs the main function - photosynthesis.
- Network of leaf veins intelligently bunched together(conductive matter) are formed in blood vessels and sieve tubes. They are designed to achieve the purpose of moving water, dissolving s alts, sugars and automatic components.
- Stomata - specialized complex complexes of cells located in the main plane of the leaflets; with their help, self-evaporation of excess water (evaporation) and gas exchange takes place.
What is a vein?
Veins - we can say that this is the "circulatory system" of the leaf, according to which the sheets can receive moisture and rottisite elements. They also accompany the intake of basic elements during photosynthesis. Distinguish synchronous, arcuate (practically only in monocotyledonous plants), digital nerve and peritoneural (in dicotyledonous plants) nerves. Leaves with a well-formed network of small veins are called retinal. The veins are also present in the sepals, petals, embryos and stems of plants. The type of venation is often a significant regular criterion.
Almost the same character has veins in many species of insects. Insect veins are hollow cylindrical thickened sclerotized plates in the wing, into which the branches of the tracheal trunks and nerves are directed. They guarantee the reliability of the wing and are the only type of this feature.
