What are the main parts of a plant leaf?

The main parts of the sheet:
1. Base of the sheet
This is the extended bottom of the sheet. In some plants, it grows and transforms into an open or closed tube, which is called a leaf sheath.
2. Leaf blade
Performs the main functions of the leaf – gas exchange and photosynthesis; at the base, the plate narrows and turns into a stem-shaped petiole.
3. Petiole
This is a thin stem-like part of the leaf, extending from the leaf blade to the shoot node. Changing its shape, the petiole displaces the leaf blade. Thus, the main function of the petiole is to provide the greatest possible illumination of the leaf blade, to bring the leaves to light. This is how the leaf mosaic is created – the arrangement of the leaves on the plant, in which they do not shade each other. Leaves with petioles are called petiolate, without petiole – sessile.
4. Stipules
Leafy outgrowths located at the base of the leaf. They can grow together with the stem or be free-standing. In many plants, stipules are absent in principle, or they are formed, but die off early.