Leaf Function – Of course, Sinaumed’s already knows that every plant must have leaves. This is because the leaves become one of the parts or organs of plants that have various important functions for plant life.
One example is that leaves have the ability to absorb solar energy which is then used as a material for plants to photosynthesize. In other words, leaves have the function of absorbing energy which can be used as a food source for plants.
Leaves can be grouped based on the bones. Does Sinaumed’s already know what types of leaf bones there are?
In this article, we will discuss the function, structure, and various types of leaf veins. So, let’s look at the discussion below!
Definition of Leaf
Leaves are one part of a plant that is on a branch or stem and can grow in strands and even become dense. The leaves themselves usually have a green color. Many leaves have a green color because the leaves contain chlorophyll.
Even so, the leaves on some plants have a less green color or not even green at all. Some leaves have a less or less green color or even no green at all because there is not enough chlorophyll in these leaves to affect the color of the leaves.
Not only that, the leaves also have a function as a breathing area for plants. Inside the leaves are organs called stomata. Stomata are the respiratory organs in plants. So, it can be said that if a plant does not have leaves, then the respiratory system in the plant will be disrupted.
Leaf Function
The main function of leaves in plants is as a place for photosynthesis, but did Sinaumed’s know that leaves also have various other functions besides photosynthesis?
Here are some of the functions of leaves that Sinaumed’s needs to understand.
1. The function of the leaves as a place to store water and food reserves
The function of the leaves apart from the first photosynthesis is to store water and food reserves. In general, plants store their food reserves in the roots, but in some plant species, food and water reserves can be stored in the leaves.
One plant that uses its leaves as a place to store food is aloe vera. If you pay close attention, when opening or peeling the leaves from aloe vera, you will be able to see the flesh which is shaped like jelly.
2. The function of the leaves as a tool for reproduction
As Sinaumed’s already knows, reproduction in plants usually occurs in the flowers and rarely occurs in the leaves. However, in some plant species, the leaves function as a means of reproduction, for example in the Cocor Bebek plant.
In cocoa duck plants, if the quality of the leaves is not maintained properly, it can affect the results of the reproduction of the cocoa duck plant which is also not good.
3. The function of the leaves as a respiratory tool
Plants can breathe using leaves because inside the leaves there are organs called stomata. Stomata on leaves can help plants to run the respiratory system. If the growth of leaves on plants is disrupted, for example when attacked by pests or excessively uprooted by humans, the plant will find it difficult to breathe, gradually wither and die.
4. The function of the leaves as an evaporation device
Besides having a function as a breathing apparatus, leaves also have a function as an evaporation tool. However, in the process of evaporation, the leaves will be assisted by the cuticle. In fact, in this evaporation process, the cuticle has a bigger role when compared to the stomata. Even so, the leaves still contribute to the evaporation process in plants.
5. The function of the leaves as a guttation site
In general, the guttation process that occurs in plants is carried out in the leaves. Guttation itself has a meaning, namely the process of releasing water in liquid form from leaf tissue. The guttation process can occur when soil conditions are in accordance with what is needed by plants so that water absorption is high, but the rate of evaporation or transpiration is low or when water evaporation is difficult due to high levels of air humidity.
Leaf Structure
The leaf structure can be divided into two groups, namely the outer leaf structure and the inner leaf structure. In each group of leaf structures there are also other parts. In the following, an explanation of the structure of a leaf complete with its parts.
1. Outer Leaf Structure
Sinaumed’s can observe this leaf structure easily because it is located on the outside of the leaf. The outer leaf structure has three parts, namely the leaf sheath, petiole, and also the leaf blade. For further explanation, come on Sinaumed’s, see the following explanation!
1. Leaf midrib
The leaf sheath is the part at the base of the leaf that has a widened shape. Leaf sheaths are often known by another name, namely upih daun. Leaf sheaths generally have a function to wrap the stem or as a place to place the leaves on the stem.
This leaf structure is often found in plants that have one seed (monocots), especially plants that are part of the families Musaceae, Graminae, Cyperaceae, and so on.
2. Leaf stalks
The petiole is the part of the leaf that is used to support or hold the leaf blade so it does not fall. In each type of leaf, the petiole has a different location and function.
- Complete leaves, the stalks on these leaves can unite the leaf blade with the leaf sheath
- Stemmed leaves, the petioles on this type of leaf will be attached to the nodes of the stem.
- Single leaf, petiole supports only one leaf.
- Compound leaves, leaf stalks can grow and branch to form new leaf stalks or what can be called child stalks. This child stalk has the function of supporting the leaf children.
3. Leaves
Even though they have very diverse forms, all leaf blades become leaf structures on the outside which are very important because it is on the leaf blade that photosynthesis can occur. The shape of the leaf blade itself is thick and thin and also has a very diverse color and size.
The diversity in the leaf blade can be identified by Sinaumed’s from the various plant species around Sinaumed’s .
There is a special type of leaf blade, namely the leaf blade in ferns. The leaf blade can be said to be special because it has a function as a spore carrier.
2. Inner Leaf Structure
After discussing the structure of the leaves on the outside, the next discussion is the structure of the leaves on the inside. This inner structure consists of two parts, namely the epidermis and mesophyll tissue. Come on, Sinaumed’s, look at the information about the following two sections!
1. Epidermis
The epidermis is a layer of tissue that is on the underside of the leaf. The epidermis in higher plants has a different thickness. The epidermis of higher plants is only one layer thick. Meanwhile, in plants at lower levels, the epidermis tends to be thin and generally does not contain chlorophyll in it.
There are many cells that are located in the epidermis of leaves that are interested in studying them. This is because these epidermal cells have their own characteristics from a physiological point of view. One of the epidermal cells that is often studied is the stomata.
2. Mesophyll Network
Mesophyll tissue is a network formed from photosynthetic parenchyma cells and is located on the inside of the leaf. This mesophyll tissue has two parts, namely palisade tissue and also spongy tissue or spongy tissue.
- Pole tissue is a network that has many chloroplasts. The function of this network is as a means of making food.
- Sponge tissue is a network whose cavity has a function as a place to store food reserves.
Types of Leaf Bones Based on the Size
There are 3 types of leaf bones which are grouped based on their size, namely:
1. Mother of bones or Costa
The mother bone is the leaf bone which is a continuation of the petiole and is located in the middle which is longitudinal and divides the leaf. This mother bone can be said to be the leaf bone which is the largest in size when compared to the other leaf bones.
The leaves on the mother of the bones can be divided into two types, namely there are parts that are symmetrical and symmetrical and some are asymmetrical or asymmetrical.
The symmetrical part is the mother of the bone which is located in the middle of the leaf blade so that the left side of the leaf and also the right side of the leaf become symmetrical or symmetrical. Meanwhile, the parts that are not symmetrical are the mother bones that are not in the middle of the leaf so that the left side of the leaf and the right side of the leaf become asymmetrical or asymmetrical.
2. Branches or lateral nerves
The branch bones or lateral nerves are the bones in the leaves and are smaller in size when compared to the main leaf bones. These branch bones are located at the base of the mother bone or are between the branches of other bones.
The naming of these branch bones is based on the distance or how far the branch bones are from the mother bone.
Thus, it can be said that each branch bone will be very dependent on the mother bone. If the mother bones are asymmetrical or asymmetrical, then there is a possibility that the bones of this branch will also become asymmetrical.
3. Leaf veins or veins
Basically, leaf veins or veins are part of the branch bones, only with a smaller size. Besides that, the leaf veins have a finer texture when compared to the branch bones. This finer texture makes it difficult to see with the Sinaumed’s eye .
One leaf vein and the other leaf veins will form an arrangement that is shaped like a road or pathway. In the process of this formation, leaf veins are assisted by branch bones that have a larger size.
Thus, mother bones, branch bones, and leaf veins are interconnected with one another. In fact, it can be said that the growth or formation of these parts is mutually determining one another.
Kinds of Leaves Based on the Arrangement
After discussing the bones of the leaves based on their size, the next discussion is about the bones of the leaves based on their arrangement. Tulan – leaf bones which are classified based on their arrangement are divided into four, viz
1. Bone Leaf Pinnate or Penninervis
Pinnate leaf bones are leaf bones whose arrangement is shaped like the fins of a fish. The arrangement in the veins of the pinnate leaves can be said to be neat and orderly, even this neat arrangement can be seen from the petiole to the tip of the leaf blade.
Leaf bones with a pinnate shape can usually be seen by Sinaumed’s in plants that have dicot seed types (dicotyledoneae). As for plants that have dicot seed types, for example rambutan, guava, jackfruit, mango, durian, melinjo, and so on.
2. Bone Leaves Menjari or Palminervis
Finger leaf bones are leaf bones that have a fairly large size. Just as the name suggests, this leaf bone has a shape like a stretched finger.
The number of finger leaf bones is generally odd in number and also the bones in the middle have the longest shape as well as the biggest.
It is very likely that Sinaumed’s has seen leaf spines on plants because plants with finger bones are often used as a cooking ingredient. Plants that have finger bones, for example, are papaya leaves, cassava leaves, and the like.
3. Curved Leaf Bones or Cervinervis
Curved leaf bones are leaf bones which can be said to have several large bones located in the middle of the leaf. The big bone will open and make a path on the edge of the leaf. When viewed at a glance, these leaf bones form like curved lines or the ends of the leaves look like they are fused together.
If Sinaumed’s wants to see these curved leaf bones, then Sinaumed’s can see them in hibiscus, betel, gadung, genjer and the like.
4. Parallel Leaf Bones or Rectinervis
Parallel leaf veins are leaf bones that have a straight shape like parallel. This parallel shape makes the leaf shapes look as if they are blending together. Parallel leaf bones can be said to have a small shape, but long.
Plants that have parallel leaf veins, for example, corn, sugar cane, coconut, rice, and the like.
5. Spiny Leaves
The last leaf bone is the spiny bone. In general, this spiny leaf bone belongs to the type of conifer plant. As for plants that have this type of thorny leaf bone, Sinaumed’s can see on pine, fir, and other similar trees.