A leaf is a flat, thin and broad outgrowth of a stem. It is generally green in colour. A leaf develops from node. Node is the point on the stem from where leaf arise.
The shape and size of different from one plant to another, but all leaves have the following main parts:
- Lamina or leaf blade: It is the thin, flat and expanded part of a leaf. It is mostly green in colour.
- Leaf stalk or petiole: It is the sort cylindrical part of a leaf. It attaches lamina to the stem. The leaves of some plants do not have petiole. They directly arise from the leaf base.
- Midrib: The lamina has a thickened vein along its centre. It is called Midrib. It extends from the petiole up to the tip of the leaf.
- Veins and Veinlets: Veins are the lateral branches which are arise from the Midrib. Veins further branch out to form Veinlets.
- Leaf Base: This is a small, slightly awollen part at the end of the Pettiole.
