Internal structure of the sheet.

The epidermis (upper skin) is the integumentary tissue of the leaf, which is often covered with hairs, wax, or cuticles. It protects the sheet from adverse conditions for example: from drying out, mechanical damage, etc. This skin contains various living cells. These are the chloroplasts that give the leaf its green color. There are stomata on the lower part of the leaf, they perform the functions:
1) absorb carbon dioxide;
2) provide the plant with respiration;
3) evaporate the water and thus help the solutes move along the stem.
Under the skin is the pulp of the leaf. It is one of the most important parts of the sheet. Its main function is photosynthesis, that is, plant nutrition.