Definition Leave

In morphological and anatomical, leaves the most varied plant organ. The leaves can be divided into several parts, the base of the leaf, petiole and leaf blade. Shape, structure, and size of leaves on different plants. It is used for the classification of plants. The leaves are composed of three types of network systems, namely the epidermis, mesophyll, and vascular tissue.


a. The epidermis


The leaves have epidermis on the surface, both the top surface, called the surface adaksial, and on the lower surface, called the surface abaksial. Epidermal cells are generally compact form a compact layer, without intercellular space. In some plants, the epidermal cells elongated cells called long. On top of the short cell leaves the bone are composed of two types of cells, namely silica cells and cell cork. In the epidermis there is a relationship which is dotted by a very small hole. These sections are intercellular space bounded by two specialized cells called guard cells. Guard cells together form the stroma. Thus, closing the stomata consist of cells that have chloroplasts, cells that do not have chloroplasts, and the gap stomata. Stomata function in gas exchange and water evaporation. On land plants, the stomata are generally located on the lower leaf surface. Meanwhile, the water plants, stomata located on the upper surface of leaves.


b. Mesophyll


Mesophyll is a parenchyma tissue nature, next to the epidermis. Mesophyll consisting of palisade tissue and spongy tissue (spongy tissue). Both networks contain many chloroplasts thus becomes the site of photosynthesis. Palisade tissue located directly below the epidermis, but occasionally there are hypodermic tissue between the epidermis and the palisade. Parenchyma cells sponges varied shapes, can resemble palisade cells, because its diameter is almost the same or can be parallel to the longitudinal direction of the leaf surface. In the spongy tissue there is space between cells (the cells are not tightly). In the spongy tissue, there are fewer chloroplasts than palisade tissue. Characteristic of parenchyma cells the sponge is the lobes that connect adjacent cells.


c. Vascular tissue


Veins on the leaf tissue found in bone leaves. In addition, the leaves are delicate veins that act as arteries that carry food through the body. Serves to strengthen the bone leaves leaves. In addition, the veins of the leaves on the plant leaf acts as a framework.

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