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What is Plant Anatomy?

Meaning and Definition of Plant Anatomy

As in humans and animals, plants also have cells, tissues and organized structures, and Plant Anatomy studies the entire functioning and organization of these structures.

It will study the internal and external structures, and its origin is confused with the discovery of cells by Hook in 1663. The basic organization of a plant consists of plant organs (root, stem and leaf) and reproductive organs (flowers, fruits and seeds ).

Root

Part of the plant that in the vast majority of species is underground but in others, can appear on the surface. It has two basic functions: fixation to the substrate and absorption of water and mineral salts, but they can also have storage and conduction functions.

In some special cases, the roots can adapt and end up performing other functions in addition to those already mentioned, such as photosynthesis (in the case of some orchids), penetration into the host tissue (parasitic plants), constriction – strangulation – of the trunk of the tree (some species of fig trees) or aerial support for trunk and/or branches.

We also find some types of associations with other species that are important to plants, such as mycorrhizae, an association between root and fungi.

In this case, the fungus converts organic matter into inorganic matter, and in return, the root provides amino acids and other elements produced by the plant.

Stem

Structure of support and conduction of vegetables. Together with the leaves, it forms the Caulinar System that guarantees a good location so that they can carry out photosynthesis efficiently.

All the material produced in the leaves is transported to the plant through the vascular system to the roots, flowers and fruits. Like all the material that is obtained by the roots.

In addition, we will find structures called gems that are responsible for the growth of the plant. They are located just above the nodes (where the leaves come from).

Some stems can also perform other functions, they can be photosynthetic (an example is asparagus), they can store water and carbohydrates (cacti), they can wrap around other plants and places (climbing plants), or they can protect that plant (spine formation). ) )

Sheet

Structure responsible for photosynthesis and gas exchange. It is basically made up of a petiole (base of the leaf), a limb or lamina (the leaf itself) and a sheath (which surrounds the trunk and fixes the leaf).

Their shapes and sizes depend a lot on the conditions of the place where that plant lives. The availability of water and exposure to the sun are fundamental factors and directly influence this aspect.

In addition to photosynthesis (food production), leaves are also responsible for respiration and transpiration. For this, it has structures called stomata, which act like little doors that let air and water in and out.

During the day they mainly capture carbon dioxide (a key element for photosynthesis) but also capture oxygen (used in respiration). And at night, they capture only oxygen.

Transpiration is the release of excess water from the plant during the day which eventually evaporates but at night accumulates in droplets through the leaves, the famous dew.

In addition to the roots and stems, the leaves can also be adapted to perform other functions in the plant, such as defense (with the formation of spines and the production of toxic substances), the storage of water (succulent plants), for the capture of insects (carnivorous plants), they provide shelter for animals such as ants and small insects, or they do not exist to prevent water loss by the plant.

reproductive organs

Flower

Main reproductive organ of vegetables. They are born from the axils of the leaves and are formed by the receptacle and the pedicel (flower stem).

In the receptacle we find perianth, androecium and gynoecium. The perianth will present the structures that we know most about flowers, the petals (colored part) and the sepals (small “green leaves” at the base of the petals, in addition to the stamens and carpels important in reproduction.

The androecium is the male organ of the flower, where we find the stamens that produce pollen, which are stored in structures called anthers. And Gynoecium is the female organ, where eggs are produced and we find carpels.

The carpels are formed by the ovary, the stigma and the stylet. The stylet is responsible for receiving and selecting pollen, the stigma attaches the stylet to the ovary, which in turn produces and houses the ovules.

The petals that provide the color of the flowers are responsible for attracting pollinators. In some cases, the stamens may not produce pollen and start producing substances (nectars) to also attract pollinators.

We can find isolated flowers (like roses) or in groups called inflorescences (like the flowers of the Flamboyant).

Fruit

It is the development of the ovary after the fertilization of the ovule and it has the seed inside. The basic functions of the fruit are to protect, preserve and guarantee the development of the seeds.

Its shape is closely linked to its form of pollination, in this case we can have fruits that can keep their interior more humid for the development of seeds, others can form wings that will open and release the seeds so that they spread with the wind or Water. .

Seed

It is the fertilized egg. Basically formed by the embryo and the nutritive tissues (endosperm and perisperm).

The embryo already has young structures that will give rise to the new plant, they are radicle (which will give rise to the root), epicotyl (will give rise to the stem) and cotyledons (which will give rise to the leaves).

This last structure is important because it is a fundamental part of the classification of plants as monocots or eudicots.

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