The term xylem comes from the Greek word "xylon" which means "wood." The official term was coined in 1837 by a German botanist as "xylem" and, finally, it began to be known in Spanish as xylem. But What is xylem and what is its function?
At Ecologista Verde we want to bring you some knowledge of botany in the simplest way possible so that you understand a little about those small and large plants that accompany us every day. Read on if you want to find out everything about xylem, as well as its difference from phloem.
What is the xylem of plants and where is it located?
It is known as xylem when woody tissue of metaphytic plants. This is formed by the vessels, the parenchyma and the fibers, which is, in short, where the raw sap.
Xylem is a type of plant tissue is located throughout the plant, especially in stem and leaves. This tissue is always found together with the other conductive plant tissue: the phloem. Phloem is in charge of transporting the elaborated SAP throughout the plant, thus completing the process carried out by the xylem. This plant tissue that we call xylem is made up of different types of elongated cells. Among them, as we have commented previously, are tracheids, vascular and fibers.
- Tracheid cells are characterized by being very thin and elongated, but thick-walled. Its function is to help transport water and other nutrients.
- In the case of vascular cells, we are talking about the cells present in angiosperm plants, those that have flowers.
- The xylem fibers or fibers are responsible for providing support to the plant, these are very resistant.
Likewise, the xylem is divided into two: primary xylem and secondary xylem.
The primary xylem
It is the one that is composed of a protoxylem and a metaxylem. The protoxylem, or first conductive tissue, has thick, ring- or spiral-shaped vessels that are very resistant. We call metaxylem the tissue that is present in all the stages of the plant and that is formed by vessels in the form of prismatic tubes and they are slightly more elongated than the protoxylem.
The secondary xylem
It is where the division of the cells of the Cambium takes place. This is composed of conductive and non-conductive elements. This is where the tracheae that have basal walls are found.
You can learn much more about this and other types of plant tissues with this other Green Ecologist article.
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Xylem: function
The xylem is the plant tissue responsible for transporting water, mineral salts and other nutrients necessary for the plant from the root to the leaves. The raw materials absorbed and synthesized by the plant from the root are transported by the xylem to each organ. This set of nutrients is known as raw sap and it is produced thanks to the osmosis and suction processes. Next, we briefly explain what these two are vital processes for plant nutrition:
- It is known as osmosis to the displacement of the water that has been accumulated or retained in the root and that is sent to the upper part of the plant thanks to the difference between the soluble potential of the root tissue of the plant and the moisture found in the soil. It is also interesting to know that the osmosis process does not always reach the top of the plant. This will depend on each plant species.
- The suction It is the process that completes the transport of liquids carried out by the xylem. The leaves are in charge of doing it to replace the liquid lost in perspiration or in other natural processes.
Therefore, thanks to the energy generated by this process, the xylem can easily transport the collected water and take it not only to each part of the plant, but also to the atmosphere. In the same way, the xylem also performs other secondary functions, such as maintaining mineral reserves if necessary and being part of the support to offer greater stability to the plant.
Here we explain much more about the process of nutrition of plants.
Xylem and phloem: differences
Next, we have created a list with the main differences between xylem and phloem, taking into account that the two conductive fabrics:
- The xylem is the tissue in charge of transporting the raw sap while the phloem transports the processed sap, that is, the product obtained after photosynthesis.
- The xylem's main function is to transport water, while the phloem is specialized in the transport of nutrients necessary for the plant.
- The transport system of xylem is unidirectional while in the case of phloem it can carry out the transport of nutrients in a bidirectional way.
- The xylem only transports the beneficial substances for the plant from the roots to the leaves. However, the phloem does it in the opposite direction, from the leaves to the root and including the rest of the plant.
- It is also interesting to know that xylem has lignified cell walls, while phloem has a structure made up of soft cell walls.
If you want to read more articles similar to What is xylem and its function, we recommend that you enter our Biology category.
