Table of Contents
Fruit Definition
Flowering plants are known for their fruits. The ovary of a plant becomes a fruit and the ovules become seeds as soon as pollen and fertilisation occur. Fruits are mostly used to preserve seeds throughout their growth.
What is Fruit?
The fruit is made up of two main parts:
- Pericarp: The fruit’s wall is called the pericarp.
- Seed: Fruit seed is the innermost component of the fruit.
The pericarp is made up of three layers:
- The epicarp is the pericarp’s outermost layer, which creates the skin.
- The thick, meaty, juicy, or fibrous central layer of the pericarp is known as the mesocarp.
- The endocarp is the pericarp’s deepest layer.
Fruit Types
The fruit is classified into three groups based on the quantity of eggs and blooms involved.
i. Simple Fruits: In this instance, a monocarpellary or syncarpous ovary of a flower with or without accessory components produces only one fruit. Mango, Walnut, and Plum, for example.
ii. Aggregate Fruits: An aggregate fruit is a group of simple fruitlets produced by a flower’s apocarpous pistil. A typical stem carries the fruits. Custard apple, grapes, etc.
iii. Multiple Fruits / Composite Fruits: These fruits are made up of several blooms from a single inflorescence. Fig, pineapple, etc.
i. Simple Fruits
A single ovary of a monocarpellary or syncarpous gynoecium of a single flower, with or without accessory components, produces these fruits. The simple fruit is divided into two types based on the characteristics of the pericarp: dry fruits and fleshy fruits.
Dry Fruit: When these fruits reach maturity, the pericarp becomes dry, thin, thick, leathery, hard, or papery. It is impossible to separate it into layers. These are further split into,
- When these fruits reach maturity, they dehisce or split open.
- Fruits that are indehiscent do not split open when they reach maturity.
a) Dehiscent Dry Fruits
Legume:
- This is a basic dry, dehiscent fruit with one chamber and numerous seeds.
- It arises from a monocarpellary, top, unilocular uterus with two placement lines that alternate. Through the spinal and ventral muscles, the legumes are pulled. Peas, for example.
Follicle:
- This is a basic dry, dehiscent fruit with one chamber and numerous seeds.
- It is present in the superior, monocarpellary, unilocular ovary.
- It does, however, dehisce by only one suture; particularly ventral. Delphinium, for example.
Capsule:
- This is a simple dry, dehiscent, unilocular or multilocular fruit with numerous seeds.
- It is derived from the superior ovary, which is multicarpellary.
- All dehiscent fruits produced from the syncarpous ovary are referred to as capsules. Cotton, Lady’s finger, Datura, Papaver, and Eucalyptus are just a few examples.
b) Indehiscent Dry Fruits
Achene:
- This is a single-seeded, dry, indehiscent fruit with no seeds.
- It is derived from a superior monocarpellary ovary.
- This fruit’s pericarp is devoid of a seed coat.
- Pericarp can be leathery or firm. Mirabilis, for example.
Cypsela:
- This is a one-seeded fruit that is plain, dry, indehiscent, and unilocular.
- It’s made up of the carpellary, syncarpous, and inferior ovaries.
- The fruit’s pericarp is firm and free of the seed covering.
- A persistent calyx cap with scales or hairs clings to the fruit. Sunflower and Tridax, for example.
Caryopsis:
- This is a single-seeded, dry, indehiscent fruit with no seeds.
- It is derived from a superior monocarpellary ovary.
- This fruit’s pericarp collided with the seed coat. e.g. Maize, Wheat
Fleshy Fruits
The fruit wall, or pericarp, is big and meaty in these fruits. They don’t decompose. After the pericarp decomposes or animals consume it, the seeds are released.
Drupe:
- This is a basic fruit that is fleshy and indehiscent.
- It originates from the superior ovary and monocarpellary or syncarpous ovary.
- The epicarp (outside skin), mesocarp (fleshy/fibrous flesh), and hard and rocky endocarp make up the pericarp. As a result, drupe is also known as stone fruit.
- Drupes are usually single-seeded. Mango, for example, or coconut.
Berry:
- A simple, delicious, indehiscent fruit with a large number of seeds.
- It develops properly with the axil or parietal Placentation from the upper syncarpous uterus. The outer layer epicarp creates the fruit’s skin, while the mesocarp and endocarp fuse together to form the fruit’s pulp. Tomatoes with brinjal, for example.
Hesperidium:
- This is a simple, fleshy, indehiscent fruit with numerous seeds.
- A syncarpous, superior ovary with axil placentation is the most common source.
- The endocarp extends inwards, producing separate chambers, and the endocarp’s unicellular, juicy, glandular hairs extend into the chambers. The loose or tight skin (rind) of the fruit is formed by the epicarp and mesocarp fused together.
- The epicarp has a large number of oil glands, such as those seen in oranges and lemons.
ii. Aggregate Fruits
The apocarpous pistil (free carpet) of flowers produces a cluster of basic fruits known as combined fruit. The term ‘etaerio’ refers to a collection of simple fruits produced by a single bloom. Berries etaerio include Annona squamosa, A. reticulata, and Artabotrys. Clematis, strawberries, and lotus are examples of achenes’ etaerio. Calotropis, Vinca, and Michelia are examples of follicular etaerio.
Etaerio of Berries:
- Annonaceae is a plant family that includes these fruits.
- The individual berries in Artabotrys (Hirva Chapa) and Polyalthia (Ashok) are free from one another, but in Anona squamosal (custard apple) and Anona reticulate (Ramphal), the berries grow fleshy and are crowed on thick thalamus, forming a complicated one fruit.
- The fruit’s common rind is created by the fusing of separate berry apices.
Etaerio of Achenes:
- Each fruit in this aggregation fruit is an achene.
- In Clematis, each achene has a persistent feathery style attached to it.
- The thalamus in strawberries is fleshy, with tiny achenes on its surface.
- The thalamus becomes spongy in the lotus, and some achenes become lodged in it.
Etaerio of Follicles:
- Each fruitlet in this fruit is a follicle.
- They are carried by the thalamus, which has grown in size.
- Calotropis and Vinca have two follicles each, whereas Michelia has several (Sonchapha).
iii. Multiple Fruits / Composite Fruits
A multiple or composite fruit is one that grows from all of an inflorescence’s blooms. In general, fruit development involves all components of the inflorescence. Catkin inflorescence causes sorosis in Morus alba (Mulberry).
Sorosis:
- Flowers are placed on thick club-shaped rachis in Artocarpus integrifolia (Jackfruit) spike inflorescence.
- Tepals grow juicy, bracts become more or less juicy chaffs, and the rachis becomes succulent and huge, in addition to the fertile fruit.
- The fruit’s thick skin is created by the fusion of floral apices, while the rind’s spines symbolise the stigmas of the carpels.
- The edible portions of fruits are the seeds and the juicy perianth.
- In Ananas comosus (Pineapple), hypertrophy causes the axis of the spike inflorescence to become fleshy, enveloping the flowers almost entirely except for the ends of the floral bracts.
- A flower is represented by each polygonal region on the fruit’s surface.
- Seeds are not produced in most cases.
- The inflorescence axis rises above the flowers to produce the leaf crown.
- The rachis, perianth, and bracts are all edible parts of this fruit.
Syconus:
- The complete hypanthium inflorescence is used to make this fruit.
- The hollow pyriform hypanthium receptacle holding female flowers at the base of Ficus (Fig) becomes mushy.
- Achenes were generated by the female flowers.
- At the tip of the receptacle is an ostiole, which is encircled by scales.
- The fleshy receptacle is a portion of the fruit that may be eaten.