The 12 most important types of fruits, and their characteristics.

A summary classification of the main types of fruits according to various criteria.

Fruits are an essential part of our diet, since according to the Spanish Federation of Fruit and Vegetable Exporting Producers Associations (FEPEX), each Spanish citizen consumes about 90 kilos of fruit per year, investing in this type of food, approximately, 139 euros per year (about 165 dollars).

In addition, fruit consumption per household increased by 1.5% in 2019, with citrus fruits (oranges and lemons, with 28% of total consumption) topping the consumption list, followed closely by bananas, kiwis and other exotic fruits. Overall, the cultivation and purchase of fruits moves more than 6.3 billion euros in many places.

Beyond these market data, there is a world of fruit to be discovered further away from the fridge. From both a Biological and physiological point of view, fruits are the structures that allow plants to live, thus perpetuating ecosystems as we know them. Dive with us in this space, where we will tell you about the types of fruits and their characteristics. We assure you that, after reading these lines, you will no longer see them as mere food.

The types of fruits of plants, classified

The fruit, defined as the organ coming from the flower that contains the seeds, is a biological structure believed to be a biological structure that is believed to have appeared on the planet more than 174 million years ago.. Several theories speculate that these fleshy compounds arose based on evolutionary pressure, since plants had to prevent living beings from feeding on their vegetative part, and at the same time, spread their seeds effectively through the environment.

For these reasons, it is not random that fruits are delicious. They are made for it, because they have sugars such as glucose or fructose, which sweeten our palate and make us want to eat more. After all, we vertebrates are nothing more than vehicles for transporting the progeny of plants, because in a natural world, we expel the seeds of fruits in different environments with our feces.

Beyond all this evolutionary and biological conglomerate, the physiology of fruits defines to which type they belong. Up to 5 types can be distinguished according to their characteristics and certain parameters. We show them all below.

1. According to the nature of the pericarp

The pericarp is the outer part of the fruit that surrounds the seed, or to put it more clearly, the fleshy portion. If we imagine in our mind the transversal cut of a peach, from the inside to the outside we will see the "stone" or "pit", from the inside out we will see the "stone" or seed, the endocarp (the area closest to the stone), the mesocarp (the flesh of the fruit) and the epicarp, the final covering that gives the fruit its color and texture. that gives the fruit its color and texture.

Depending on the nature of the pericarp, a fruit can be either dry or fleshy. A dry fruit, as its name suggests, differs from a fleshy fruit in that it contains less than 50% water in its natural composition. In this group we find almonds, hazelnuts, cashews and many other examples.

Fleshy fruits, on the other hand, have a juicy or fibrous pericarp, with abundant pulp or flesh that stores water in its interior.. Even if a dried fruit (such as a raisin) has almost no water in its structure, it is still a fleshy fruit, since its content of this liquid was naturally higher than 50%.

2. According to the number of seeds it contains

The seed is defined as each of the bodies that are part of the fruit that gives rise to a new plant. In addition to being a biological structure of great interest, the number of seeds enclosed within each one of them is also an important differentiating factor when it comes to the when it comes to considering the types of fruits in nature.

Monosperm fruits are those that contain only one seed inside, such as the peach mentioned above, a mango or an olive. On the other hand, polysperms have more than one seed inside, and here many more examples come to mind: bananas, oranges, watermelons, papayas, strawberries...etc. Any fruit that has "pips", from a botanical point of view, is a polysperm.

Depending on whether or not they set the seed free.

We enter a slightly more complex terrain, because this group cannot be elucidated in such a simple way just by observing the external appearance of the fruit. From a purely botanical point of view, dehiscence is defined as the spontaneous opening of a plant structure, once it has reached maturity, to release its contents. Thus, if the fruit "breaks" on its own to release the plant progeny, we are dealing with a dehiscent structure..

Although this is not so common in the general collective thinking, an example of a dehiscent structure could be the pod of a legume, as it spontaneously opens to let the seeds fall to the ground. Depending on the way the fruit breaks, the types of dehiscence reach a dizzying number of terms: poricidal, septicidal, transverse, elastic... the variety is endless.

On the other hand, indehiscent fruits are those that cannot be opened "by magic" to let the seeds free, and therefore have to count on breaking when falling, rotting or being eaten by animals so that the plant progeny can germinate underground. This is where commonly consumed fruits come to mind: watermelons, citrus fruits, bananas, and basically all fruits consumed in the general market.

4. According to the parts of the flower involved in its formation

After the fertilization of an ovule (located in the flower of the plant), some structures of the flower disappear, dry and fall off.They dry up and fall off, to give rise to the fruit from the ovary. According to the parts of the flower involved in this formation, we can distinguish the following groups:

• Simple: a single ovary gives rise to the fruit. This is the case of the strawberry tree (Arbustus unedo).
• Polycarpic: grouping of simple fruits. The fruit of the magnolia (Magnolia grandiflora) is an example.
• Complex: parts of the flower beyond the ovary are involved in the formation of the fruit. As an example, we have strawberries.
• Synanthocarpic: set of fruits that come from an inflorescence.

5. According to the number of carpels involved in their formation.

The carpels are modified leaves that form the female reproductive part of the flower of angiosperm plants.. A set of carpels is known as a gynoecium, and this, in turn, may be composed of one or more pistils (which are the structural unit formed by the ovary, style and stigma). Beyond these complex terms, depending on the number of carpels that form the fruit, we can find different types of them:

• Monocarpic: the fruit comes from a single carpel.
• Polycarpic: the fruit comes from more than one carpel.

Of course, the classification of polycarpic fruits is much more complicated, as they can be apocarpic or apocarpic. can be apocarpic or syncarpic, and within the latter group, open or closed.. Nor do we want to explain each of these groupings, because we would be incurring in a botanical lesson too complex. The general idea of this classificatory criterion should be the following: a peach is a monocarpic fruit, since it comes from a single carpel. On the other hand, a custard apple is polycarpic, since the sutures of the numerous carpels that compose it can be seen on the surface of the fruit.

Summary

Incredible, isn't it? It was very difficult to imagine, before reading these lines, that the world of fruit types contained such an intricate physiological complexity. Human beings have a fascinating tendency to compartmentalize everything around them, whether or not it is of specific use. Even so, and from a purely utilitarian level, what matters to people who are not botanists is whether a fruit is dry or fleshy or whether it has a single seed or many, as this affects us when it comes to consuming it directly.

Beyond the shopping basket, these classificatory criteria are of essential importance for the study of botany and living beings in general.The use of such specific traits allows us to create dichotomous keys, i.e., tools that facilitate the classification of organisms through a series of simple steps.

Bibliographical references:

• Consumption of fruits and vegetables, Spanish Federation of Associations of Exporting Producers of Fruits, Vegetables, Flowers and Live Plants (FEPEX). Collected on October 24 at https://www.fepex.es/datos-del-sector/consumo-frutas-hortalizas.
• Fruits, Polytechnic University of Valencia, UPV. Collected on October 24 at http://www.euita.upv.es/varios/biologia/web_frutos/Frutos%20verdaderos.htm#:~:text=Fruits%20monoc%20monoc%3%C3%A1rpicos%3A%20when%20proceed%20from%20a%20gineceo%20monocarpelar.&text=El%20fruto%20procede%20de%20de%20una,gineceo%20formado%20formado%20por%20varios%20varios%20carpelos.
• Types of fruits, University of Granada. UGR.es. Retrieved October 24 from http://www.ugr.es/~mcasares/Organografia/Fruto/Tipos%20de%20frutos%20marcos.htm.