Fruits
A fruit is a matured fertilized ovary of a flower containing one or more seeds. But, in fruits like banana and pineapple, fertilization is not needed in making fruits but at the end, such fruits do not have seeds. Fruits that grow without fertilization are called Partenocarpic fruits.
Structure of a fruit.
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)[Image source]
https://pixabay.com/en/diagram-fruit-labelled-labeled-41532/
The structure of a fruit is made up of the outer part which is also called the Epicarp, the middle layer which is known as the Mesocarp, and the inner layer which is called the Endocarp, within the endocarp is the seed. The combination of the epicarp, mesocarp, and the endocarp is called the Pericarp.
A fruit consists of the following parts:
The fruit wall or epicarp
The seed or seeds inside the fruit.
The remains of style or scar showing point of attachment of the style.
The fruit stalk or scar showing point of attachment of the fruit to the plant.
Differences between a fruit and a seed.
| Fruits | Seeds |
|---|---|
| Fruits develops from an ovary and contains seeds. | Seed develops from an ovule and so contains an embryo. |
| It has fruit stalk or scar (due to the receptacle). | It has a scar (hilum) formed by attachment of funicle. |
|---|---|
| It bears remains of style or scar left by it. | It does not bear remains of style. |
| It has no micropyle. | It has micropyle. |
| Fruit has a pericarp and one or more seeds. | Seed has a seed coat and a single embryo. |
Classification of fruits.
Fruits are classified into various groups according to their origin and structure.
True and false fruits.
Simple aggregate and multiple fruits.
Fleshy and dry fruits.
Dehiscent and indehiscent fruits.
True and false fruits:
True fruits- This is the type that develops only from a fertilized ovary. Example: mango and orange.![]
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)[Image source]
https://pixabay.com/en/fruit-mangoes-round-orange-fresh-316001/
False fruits- This is the type that is formed from the ovary and other parts of the flower. Example: apple, pineapple, and cashew.
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)[Image source]
https://pixabay.com/en/apple-fruit-red-apple-fruits-3117507/
Simple, aggregate and multiple fruits:
Simple fruits- They develop from a flower with one ovary. The ovary may be able to flower only once as in cowpea, or may have the carpels united as in tomatoes and pawpaw.![]
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)[Image source]https://pixabay.com/en/tomato-tomato-carving-carving-3032040/
Aggregate fruit- They develop from a single flower with several ovaries. Such flower has the female reproductive part where the carpels are separated and so have many ovaries. Each ovary developing into a small fruit. Example: apple and strawberry.![]
[Image source]
https://pixabay.com/en/berry-breakfast-calories-closeup-1239306/
Multiple fruit- They develop from many flowers making them very close to one another. Here, all the small fruits and
floral parts are joined together to form one large false fruit. Example: pineapple.
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)[Image source]
https://pixabay.com/en/isolated-pineapple-fruit-beach-1443385/
Fleshy and dry fruits: Fruits may distributed into fleshy or dry according to the type of their pericarp.
Fleshy fruits- They are fruits in which the whole fruits or at least one layer is soft (succulent) when it is ripe.
Types of fleshy fruits:
Drupes- The drupe has three layers which are the epicarp, mesocarp and endocarp. The epicarp is thin, the mesocarp may be fibrous or fleshy, example coconut and mango. in mango, the soft mesocarp is the edible part while the endocarp covers the seed.
Berry- They are similar to drupe with thin epicarp, soft mesocarp and endocarp. But the endocarp in berries are not as hard as in drupe, they are soft. Example: tomatoes, orange, pepper and pawpaw.
Pome- They are simple fresh fruits in which the skin and the edible part are gotten from the container for the fruit and only the tough part containing the seeds are from the ovary. Example: apples.
Sorosis- They are multiple false fruits, formed from a thick part of flowering. Every part of each flower forms part of the fruit while the stalk of flowers on a plant swells to form the tough central part of the fruit which contains the seed.
Dry fruits- They are the type that the pericarp becomes hard and strong when the fruits get ripe.
Dehiscent and indehiscent: Fruits may be grouped into dehiscent and indehiscent depending if their pericarps split when ripe or unripe. But for you to know, all fresh fruits are indehiscent while dry fruits may be dehiscent or indehiscent.
Dry dehiscent- This are fruits that open when ripe to release their seeds, thus, leaving the remains of the fruits on the plant. We have different types of dry dehiscent fruits, they are legumes, follicle capsule and schizocarp.
Legumes or pod- A legume is a simple fruit formed from a good monocarpous female part of flower. It is mostly long and fat on the sides. When the fruit is ripe, the fruit opens straight form top to bottom on both sides to release its seeds.
Capsules- The fruit of a capsule is formed from one ovary that is divided into many independent compactment called Carpels. The fruit wall will become hard when it's dry, which makes it open on many sides. Examples are: castor oil fruit, para-rubber fruit, okra fruit and cotton.
Follicle: This is a simple fruit which is made from a strong monocarpic part of a female flower. It opens along one side when it is ripe. Examples are silk cotton and kola.
Schizocarp: This is made from an ovary with only one carpel, it has several seeds. It splits into units when dry, with each releasing its seeds. Examples are desmodium and cassia.
Dry dehiscent fruits:
This type of fruits does not split when ripe instead they fall to the ground and decay then release their seeds. They are mostly small and are released in large numbers.
Types: Nuts, Caryopsis, Achene, Cypsela, and Samara.
Nuts: This is a simple fruit with a very hard pericarp, they contain one seed enclosure with only one seed. A very simple example is chashew nut.
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Caryopsis: This is a small simple fruit consisting of one female part of a flower which contains just one ovary. The pericarp and the seed coat are joined together to make a cover for the seed. Examples are maize grain, rice, millet and guinea corn.
Cypsela: It is a small simple true fruit developed from a strong monocarpous ovary, it contains only one seed. It's pericarp does not have seed coat, Each fruit is a triangle in shape and is developed from one ovary. When it gets ripe, the petals and the hairy sepals become well known and forms a parachute.
They open wide on top of the fruit and makes it easy to released in the air and taken from one place to another, the seed coat is hard and it does not split when dried. Examples are tridax fruit and emilia.
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Achene: Achene is a small simple fruit that contains only one seed. Achenes develop from a single plant pistil. Examples are strawberry and sunflower.
Samara: Samara is a simple true fruit that the pericarp is extended to create one or more wing-like structures.
it develops from a higher ovary that consists of more than a carpel and often has one or more seeds. Examples are the combretum and pterocarpus
References
https://en.wikipedia.org/wiki/Fruit
https://www.britannica.com/science/seed-plant-reproductive-part
http://science.jburroughs.org/resources/flower/fruit2.html
http://science.jburroughs.org/resources/flower/fruit3.html
http://theseedsite.co.uk/fruits.html