Leaves are very important for plants: through the pores they absorb energy from the sun and carbon dioxide, and after a series of chemical reactions they manage to transform all of this into food in a process called photosynthesis. They also turn out to be essential for the rest of life on Earth, since as a consequence, they release oxygen, a gas that allows cells to exist and, consequently, the body to function.
But also, knowing the different parts of the leaves will be very useful when it comes to caring for them, since when a plant is bad, on many occasions the first symptoms appear on its foliage. So that, Let’s see what name each of the parts have, and what is their function.
What are the leaves?
Leaves are organs that plants use to carry out both photosynthesis and transpiration. The first helps them to obtain food and, therefore, to grow; On the other hand, the second is very useful for them, for example when temperatures are very high, since although they lose water, it is released in the form of steam, and when a little air blows their body temperature drops a little.
You could say that it is like when we ourselves sweat: it is true that we can lose a lot of water and more in summer, but why do we feel cooler when we stand near the fan or the wind blows a little? But, unlike us, thanks to that water vapor and the shade that the plants give, they can create a fantastic microclimate that is slightly cooler, thus becoming shelters for some animals.
What are the different parts of the leaves?
In order to better study them, botanists have named each of the parts of the leaves. And they all have a function:
Blade or lamina
The limbus, also called lamina, it is the normally flat and wide, or long and / or narrow part, which is responsible for photosynthesis. For this reason, in most cases it is of some shade of green since it has chlorophyll, which is the pigment that gives it that color.
Two parts are distinguished: the upper side, which is the upper side, and the lower side, which is the lower side. The top is usually of a brighter color than the underside; however, in the latter it is almost always easy to see the nerves so the sap circulates.
In the leaves of many species, especially those of trees, the pores are also clearly visible, without the need for a magnifying glass or microscope (although if you have one, we recommend observing them through it. You will surely enjoy).
The petiole, which may be longer, shorter, or even absent, is the part that joins the sheet with the stem. It is a kind of stem almost always very thin, less than 0 centimeters, which has three important functions:
- One is to provide a certain stability to the sheet, avoiding as much as possible that it is damaged when the wind blows very hard or it rains, for example;
- the other is to supply raw sap (which comes from the roots, and contains water and mineral salts);
- and finally it is to transport the processed sap (proteins, carbohydrates, and other foods processed during photosynthesis) through the trunk and, again, to its root system.
Some plants, at the base of the petiole they have like two “leaves” that grow opposite to said petiole called stipules. They are responsible for protecting the young leaves, so when they finish maturing they often fall off.
The sheath is the base of the petiole, that is, is the part that joins the stem of the plant. It is widened a little so that the sheet is well supported. The color varies depending on the species, but it is usually darker than that of the lamina.
What types of leaves are there?
There are many types of leaves, so much so that they can be classified in up to five different ways: according to whether or not they have petioles, depending on how the blade is divided, how its shape is, what the characteristics of the edge are, and even how its rib is . So we have:
- According to the petiole: there are leaves that have it, and others that do not. The former are called petiolate leaves, and the other sessile.
- According to the division of the limbo: They can be simple leaves (that is, they have a blade that does not divide) or compound.
- According to its shape: the leaves can be heart-shaped, oval, elliptical, lanceolate, acicular, linear, palmate, reniform, oblong, …
- According to the edge: the edge or margin of the leaves can be whole, wavy, lobed, serrated, split or toothed.
- According to its rib: they can be palminervias, that is, the nerves are distributed in such a way that they look like those of the palm of a hand; penninervias, when a clear main nerve is distinguished from which the others arise; and parallelinervias, when the veins are distributed almost parallel throughout the leaf.
And we could still classify them in another way: depending on whether they are perennial or expired. The first ones are those that remain in the plants for several months or years and that at a given moment they are falling little by little, as new ones appear; the latter, on the other hand, are those that fall every year, when conditions are not favorable (for example, it may be because temperatures begin to drop a lot, or because the rains stop).
Did you know the different types of leaves and their parts?