TRACHEOPHYTES: CLASSIFICATION AND CHARACTERISTICS - BIOLOGY - 2025

The tracheophytes, the first plants of our planet Earth are also known as vascular plants, and descended from the first embriofitas. They are characterized by having a corm made up of a stem, and because it is clearly differentiated into stem, leaves and root.

Also because they have a sap transport system in the form of tubes known as xylem (woody vessels that transport the raw sap from the root) and phloem (or Liberian vessels that transport the sap made from the leaves).

They reproduce by spores, and are also called embryophytes because once fertilization has occurred, they develop a multicellular embryo. It is such a diverse group of plants that it encompasses most of the land plants that we know of.

They have been called vascular plants since Jeffrey used the term for the first time in 1917. In fact, it was later that the term tracheophytes emerged, because their xylem (or plant tissue) is firm and durable.

Tracheophytes show: cuticle that helps limit water loss, stomata that allow gas exchange, special tissues that provide support, and special tissues for the transport of water and nutrients.

They are nourished by the process of photosynthesis. According to fossil research, tracheophytes appeared 415 million years ago in Australia. Their fossils could have survived so long, thanks to the presence in them of a substance called lignin that is very resistant to biological and geological degradation.

Classification

Tracheophytes can be classified into:

Psylopsid

They are primitive vascular plants, which today are represented by only 3 species.

Lycopsid

This group of plants includes approximately 1000 species, ancient and basal vascular plants that survive from the Lycophyta division.

Sphenopsid

In this division are the equisettes, a type of plant that grows in humid soils and exhibits an underground rhizome or stem, from which shoots or aerial stems grow, which can measure between 1 and 2 meters in length.

It groups approximately 25 species without flowers or seeds that can have medicinal uses because they have diuretic and antiseptic effects.

Pteropsid

It is the largest group in the plant kingdom and is divided into three classes filicineae, gymnosperms and angiosperms:

Filicineas

These plants are also called filicinas. Its leaves are generally more developed than its stem, they do not have nodes or internodes.

Within this group fall the almost 10,000 species of ferns distributed in the world, especially in hot and humid regions whose conditions allow the largest and most leafy species to develop.

The normal thing is that the filicíneas are herbaceous and rhizomatous plants, but there are cases, especially in tropical climates, in which they occur arborescent.

Even when it comes to terrestrial plants, they include a number of aquatic species such as the salvinia (they float in water) and the marsilia (they are born in the water but their leaves emerge from it). In turn, it is divided into four subclasses: leptosporangiatas, ceonopteridinas, eusporangiatas and hidropteridinas.

Gymnosperms

They are also known as coniferous plants. These plants are distinguished because they have conductive vessels and flowers but do not have fruits, except for some false fruits (pineapples, for example), whose main function is to protect the seed.

They are large, with small leaves and flowers, with many branches and can live for many years. Between pollination and fertilization of these types of plants, more than a year may pass.

This category includes trees and shrubs such as: juniper, pine, cedar, araucaria, cypress and fir.

Angiosperms (flowering plants)

Angiosperms are characterized by clearly differentiated tissues and organs. They are known as flowering plants because, indeed, all angiosperms have flowers.

They can be herbaceous, shrubby or arboreal.

Its flower can contain the female structures, this is the carpel or the pistil, at the same time as the male ones (the stamen).

The pollen is transported to the pistil (pollination) where the fertilization of the ovule occurs, which then becomes a seed.

Angiosperm plants are classified into:

• Dicotyledons: Its seed has two cotyledons located on both sides of the embryo. Its main root is usually resistant and accompanies the entire life of the plant, while its stem has vessels arranged in circles. Plants such as: potatoes, seibo, carob and tobacco are located here.
• Monocots: In this case, they are plants with a single embryonic leaf or cotyledon in their seeds; short-lived, fasciculate root; and a stem that is neither branched nor very thick. Its flower generally has three floral elements. In this category of plants enter: corn, tulip, onion, cereals and jonquil, for example.

Importance of tracheophytes

Vascular plants or tracheophytes represent a plant group of great importance for human life because they are used for the food, paper and textile industries, as well as for medicine and even for ornament.

In other words, it is a species so varied and numerous that it ends up participating in many of the scenarios of human civilization.

References

1. Atreyo, Spain (2013). Classification of tracheophytes. Recovered from: tracheofitas.blogspot.com
2. Science and Biology (2016). Vascular plants: characteristics and classification. Recovered from: Cienciaybiologia.com
3. Faculty of Agricultural Sciences of the National University of the Northeast, Argentina (2013). Vascular Plant Morphology. Recovered from: biologia.edu.ar
4. Garrido, Rocío and others (2010). Angiosperm and gymnosperm plants. Recovered from: botanipedia.org
5. Gray, Jane and others. Primitive life on dry land. Original text in English, taken from: Gray, J. & Shear, W., 1992. American Scientist, vol 80, pp. 444-456. Recovered from: Librosoa.unam.mx
6. Sánchez, Mónica (2017). What are vascular plants ?. Recovered from: jardineriaon.com
7. Central University of Venezuela. Organization of tracheophytes. Recovered from: ciens.ucv.ve.