Parts, functions and types of leaves
The leaf is one of the most important parts of vegetables since it is the part of the plant that is in charge of carrying out photosynthesis, as well as plant respiration and transpiration.
Schematic drawing of leaf parts
There are many types of leaves that allow us to distinguish one plant from another, but, essentially, every leaf is made up of the following parts:
4.- UPPER SIDE
The limbo is the wide part of the leaf. It is its most attractive part and what most people understand and identify as a leaf when such a name is mentioned. Within the limbus of the leaves, we have to talk about the following parts:
The upper-side of the leafs: It is usually bright green in color.
The underside of the leaves: It is the part opposite to the upper side. Its color is usually darker and often has hairs.
The nerves of the leaves: they are a kind of wrinkles or channels that run along the limb of the leaf. Actually, they are the conducting vessels that run along its surface.
The edge of the leaves: It constitutes the margin or end of the limbus. It can be of different forms that are used to distinguish some leaves from others.
The petiole of the leaves: it is the part of the leaf that joins the limbus to the branch. It is shaped like a stalk and the conducting vessels run through it. There are some leaves that do not have petioles. These leaves without petiole are called sessile leaves.
Examples of types of leaves and their parts
Detail of a holly leaf held up to light, seen from the underside. Note the central main vein and lateral veins. Between them, other smaller nerves branch out to form a wide network that covers the entire leaf. In the background you can see a kind of green grains. They are the chloroplasts that are in charge of carrying out photosynthesis.
Photo of poplar leaf (Populus nigra). Click on the image to see enlarged details and test to see if you can distinguish the parts of the leaf.
Different leaves depending on the type of leaf limbus
One leaf with petiole and one sessile leaf
More information on leaves and other parts of plants
11 August, 2023