Fruit

The seeds are protected inside fruit. But in some fruits, seeds are not found like in grapes, banana and such type of fruits are called parthenocarpic or seedless fruit.

Pericarp: After ripening, the ovarian wall changes into pericarp. This pericarp may be thick and fleshy or thick and hard or thin and soft.

Pericarp is made up of 3 layers:

(a) Outermost layer: Epicarp

(b) Middle layer: Mesocarp

(c) Inner most layer: Endocarp

(a) Epicarp: It is the outermost layer it is thin and hard or soft part. It forms outermost layer of fruit which is also called rind

(b) Mesocarp: It is the middle layer which is thick and fleshy in mango, peach, date palm. In coconut, this layer is made up of fibres which is also called coir.

(c) Endocarp: It forms the innermost layer it may be thin membrane (eg. Orange, datepalm) or thick and hard (eg. Mango, Coconut)
 

True Fruit

When the fruit is developed only from the ovary, the fruit is called as true fruit. Eg. Mango, Coconut,

Zizyphus

False Fruit OR Pseudocarp

In some fruits, in place of ovary, some other parts of flower like thalamus, inflorescence, calyx are modified to form a part of fruit. These types of fruit are called false fruits.

Eg. Apple, Strawberry.
 

Classification of Fruits

(1)    Carpels present in gynoecium are whether free or in fused state.

(2)    One or more flower takes part in formation of fruit.

On the above two basis, fruits are divided into:

(1) Simple

(2) Aggregate

(3) Composite

1. Simple fruit: These fruit develop from monocarpellary ovary or multicarpellary syncarpous ovary and only one fruit is formed by the gynoecium: Simple fruits are of two types:

(a) Fleshy fruit

(b) Dry fruit  

(a) Fleshy Fruit: In fleshy fruit, fruit wall is differentiated into epicarp, mesocarp and endocarp. These fruit develop from superior or inferior syncarpous gynoecium. These may be unilocular or multilocular, these fruits are indehiscent. Dispersal of fruit occurs after pericarp is destroyed. In this fruits pericarp is distinguished into epicarp, mesocarp and endocarp.

Fleshy Fruits are of Following Types

(A) Drupe fruit: These fruit develops from mono or multicarpellary, syncarpous, superior ovary. In these fruits endocarp is hard and stony so these fruits are also called stony fruits. Eg. Mango, coconut, almond; peach walnut, plum. In mango the outermost cover or rind is called epicarp. Edible fleshy part is mesocarp and the part where seed is protected is called as endocarp. In ber, epicarp and mesocarp both are edible part while endocarp is drupe.

The rind of Almond and walnut are endocarp and their edible part is seed. In coconut epicarp is hard and thin while mesocarp is thick and consists of hard fibres. The endocarp is hard and -seed is protected in it. The sweet water of coconut are liquid and solid endosperm.

(B) Berry: These fruits develop from mono or multicarpellary syncarpous ovary. Ovary may be superior or inferior. Placentation is axile or parietal. In these, epicarp is thin like membrane and seeds are embedded in fleshy part initially seeds are attached with placenta of fruit but after maturation these seeds are detached with placenta and are spread randomly in fleshy part.

(i) Plants with superior ovary = Tomato, Grapes, Brinjal.

(ii Plants with inferior ovary = Guava, Banana Date palm is one seeded berry. In it pericarp is divided into epicarp, mesocarp and endocarp. Epicarp is thin and soft while mesocarp is thick and fleshy and endocarp is thin like a membrane, which is attached with seed.

Arecanut is one seeded fibrous fruit. When its' thick fibrous layer is removed then seed comes out which is hard.

(C) Pepo: These fruit develops from tricarpellary, syncarpous and inferior ovary- This fruit is unilocular and have parietal placentation. These fruits 'are fleshy and spongy. Eg. fruits of cucurbitaceae family like cucumber, melon, Cucurbita maxima, bitter gourd, muskmelon.

(D) Pome: This fruit develops from bi or multicarpellary syncarpous inferior ovary. The rind and sponge are made up of thalamus. The main part of ovary is like to cartilage. It means it is hard and dry, remain inside the fruit seeds are present in it. Eg. Apple, Pear. These are false fruits. Fleshy swollen thalamus of these fruits is edible part. 

(E) Hesperidium: This fruit develops from multicarpellary, syncarpous, superior ovary. This fruit is specialy found in plants of Rutaceae family. Eg. Orange, Lemon.

Epicarp of these is made up of thick rind which is leathery and many oil glands are found in it. Mesocarp is the white fibrous structure which is attached with epicarp. Membranous endocarp projects inward and formed many chambers. Many glandular hairs are present on the inner side of endocarp. These glandular hairs are only edible parts.

(F) Balausta: It is a multilocular multiseeds fruit, which develops from inferior ovary. It's pericarp is hard. Calyx is persistent which is arranged in the form of crown. If persistant carpels are arranged systemetically. Seeds are irregularly arranged on placenta. Endocarp is hard. Testa is fleshy and Juicy. This is the edible part of fruit. Eg. Pomegrana+ (Punica granatum).

(G) Amphisarca: This fruit is multicarpeUary a~d . multichambered which develops from superior ovary. Pericarp is hard and fleshy placenta is found in them. The inner part of pericarp and placenta is' edible part of fruit. Eg. Wood apple (Aegle marmelos), elephant apple. 

Pericarp of simple dry fruits is hard and dry and not diffrentiated into epicarp, Mesocarp and endocarp. Such fruits are called dry fruit. In some dry fruits, this pericarp is ruptured and seeds are dispersed. These fruits are called dehiscent fruits. In some fruits, pericarp is divided into one or more seeded segments. Such fruits are called schizocarpic fruits. In some fruits, pericarp does not dehisce even after maturing/ripening. Such fruits are called Indehiscent Fruits.

Simple dry fruits can be divided into following three groups:

(A)    Indehiscent

(B)    Dehiscent

(C)    Schizocarpic
 

Simple Dry-Fruit

(A) Indehiscent fruits: These simple dry fruits are generally of small size and single seeded.

(a) Cypsela: It is a small, one seeded dry fruit which develops from bicarpellary, syncarpous inferior ovary.In it, pericarp and seed coat are free from each other. In these fruits a bunch of hair is attached with the fruit which is known as Pappus. Pappus helps in fruit dispersal. Pappus is modification of calyx. Eg. mainly compositae family plants. Eg. Sunflower, Marigold.

(b) Caryopsis: These are small, one seeded dry fruits, which develop from monocarpellary, superior ovary. Pericarp of these fruits is fused with the seed coat and form a joint surface. These fruits are present in family gramineae. Eg. Wheat, rice, maize etc.

(c) Achene: These are single seeded fruit which develops from monocarpellary superior ovary. In it, pericarp is free from the seed coat Eg. Clematis, Mirabilis, Boerhaavia are egs. of single seeded fruit.

(d) Nut: This is a single seeded fruit which develops from bi or multicarpellary, syncarpous superior ovary.

In it pericarp is hard and unilocular. Eg. Quercus (oak), Anacardium occidentale (Cashewnut) Trapa, (Water chest-nut), Litchi.

In Litchi epicarp and mesocarpis fused and give leathery appearence. Endocarp is membrane like thin.

Outer seed coat grows forward and forms an additional coat arround the seed which is called as aril. In mature fruit, this aril is fleshy and is only edible part.

(e) Samara: These are dry indehiscent one seeded feathery fruit. It develops from bi or tri carpellary, syncarpous and superior ovary. The main character of these-fruits is that wing like structure develops from its pericarp which helps in dispersal. Eg. Holoptelia. 

In Shorea robusta wing develops from calyx instead of pericarp and, these fruits are called samaroid.

(B) Dehiscent Fruits: After ripening when the pericarp of the fruit become dry and hard than these fruits are called dry fruit'). When pericarp of such fruits are ruptured and seeds are dispersed outside, then such fruits are called dehiscent fruits.

These fruits are mainly of 5 types:

(a)   Legume or pods: These fruits develop from monocarpellary unilocular, superior ovary. It is generally long and multiseeded fruit. Dehiscense of fruit occurs at both sutures i.e. Dorsal and ventral side. Dehiscence start from apex and reaches to basal part. Eg. Pea, Beans.

When only one or two seeds are present in fruit,

When only one or two seeds are present in fruit, then it is also called as pod.

(b) Follicle: It is also multi seeded fruit which develops from superior unilocular, monocarpellary ovary but the dehiscence of it occur only at ventral suture. Eg. Asclepias, Rauwolfia Periomble or Vinca, Michelia(Champa), Delphinium.

(c)  Siliqua: This fruit develops from bicarpellary, syncarpous superior ovary and ovary has parietal placentation. Dehiscence occurs at both dorsal and ventral suture and starts from lower part and proceeds upward. Due to false septum ovary become bilocular. On false septum, seeds are attached This type of fruit is found in Cruciferae family.

Eg. Brassica, Mustard.

(d) Silicula: It is reduced form of siliqua. It's dehiscense is similar to siliqua. It is also found in Cruciferae family.

Eg. Candy tuft (Iberis amara)

(e) Capsule: This is dry multichambered and multi seeded fruit and develop from multicarpellary syncarpous, superior ovary. In it, axile placentation is found and dehiscence Occurs by various methods. Poricidal (Porous), loculicidal, septifragal, septicidal.

Eg. Papaver (Poppy), Gossypium (Cotton) Datura, Hibiscus (Lady finger) 

1. Schizocarpic fruit: It is a multi seeded fruit. After ripening, it is divided into mericarp and seeds come out sometimss after desfruction of pericarp seed comes out. The fruits develop from mono or bi or multicarpllarv superior or inferior ovary. The mericarp, contains one or two seeds.

Schizocarpic Fruits are of Four Types

(a) Lomentum: It develops like the legume. These are bisutural fruits which are constricted or divided in one seeded mericarp, after maturity these are separated from each other. Eg. Tamarind, Cassia fistula, Mimosa pudica, Arachis hypogea, Desmodium.

(b) Cremocarp: It is a double seeded fruit and develops from bicarpellary, syncarpous, inferior ovary. It is generally found in urnbellifetae family. On maturation, it dehiscence from apex to base in such a way that two mericarp forms and each contain one seed. These mericarp are attached with carpophore. Carpbphore is -the extended part 'of receptacle.

Eg. Coriander, Daucus, Cuminum, Foeniculum.

(c)  Regma: This fruit develops from tri to pentacarpellary, syncarpous superior ovary. In it 3 to 5 locules are present and its fruit is breaks into 3 to 5 one seeded part. Each part is known as coccus. At the outer end of pericarp, spines are found. Eg. Euphorbiaceae family (Castor) has three cocii and Geranium has 5 coccus.

(d) Carcerulus: It is a dry fruit which develops from multi carpellary or bicarpellary, syncarpous, superior ovary. It divided into four ns seeded locules. Eg. Ocimum (Basil), Salvia.

In hollyhock and abutilon (family malvaceae), the no. of locules is more than four because it develops from multicarpellary ovary.

(e) Utricle: It is a single seeded fruit which has thin membrane. It dehiscence generally from cap. It develops from bicarpellary, unilocular, syncarpous, superior ovary.
 

Aggregate Fruits

These fruits develop from multicarpellary apocarpous ovary. Because in apocarpous ovary, each carpel is separated from one another, therefore it forms a fruitlet. These fruits make a bunch of fruitlets which is known as etaerio.

(i) Etaerio of follicles: Each fruit of etaerio are follicle.

.Eg. Calotropis, Catharanthus, Magnolia -e.

In calotropis only stigma are fused or jointed in bicarpellary ovary and ovaries of ovoule are separated. It means only two follicles are present in etaerio. In Caiharanthus and Magnolia etaerio develops from many follicles.

(ii) Etaerio of achenes: In this aggregate fruit, each fruit is an achene. Eg. Rananculus, Strawberry, Rose, Lotus.

In lotus, thalamus become spongy and some achenes are embedded in it. In strawberry, thalamus is fleshy and small achenes are found on its surface. In rose, many achenes are present on a­saucer (Cup) like inner surface of thalamus.

(iii)  Etaerio of berries: It is an aggregate of small berries.

Eg. Polyalthia, Annona squamosa (Custard-apple). In etaerio of Anona all the berries are arranged densly on thallamus.

(iv)  Etaerio of drupes: In this type of fruit, many small drupes develop from different carpels.

Eg. Raspberry

In this type carpel of apocarpus ovary form drupe fruit. 

Composite Fruits

All composite fruits are false fruits.

This type of fruit differ from aggregate fruit that in place of single ovary many ovaries and other floral parts combine together to form fruit. In composite fruits, generally whole inflorescence is modified into fruit. These are of two types:

(i) Sorosis: This fruit develops from spike, spadix or catkin inflorescence. Peduncle become thick spongy and woody or spongy sepals of female flower fused with each other resulting into a mass formed by the flowers of a whole inflorescence. eg: Jack fruit, Kevda (screwpine),

In jack fruit (Kathal) pistillate flowers are developed arround the penducle. In fruit formation pericarp become spongy and fused. Spiny and rough rind is formed by the upper part of ovaries. In Pine apple peduncle bracts and perianth become fleshy. Due to the fusion of perianths of flower a composite fruit is formed. Outer growth indicates the flower.

In mulberry perianth becomes fleshy and calyx of every flower becomes thick, sweet and fleshy and are edible.

(ii) Syconas: This fruit develops from hypanthodium inflorescence. Receptacle become hollow having a pore surrounded by small scales. Staminate pistillate flowers are present near the, pore and normal pistillate as well as gall pistillate flowers are present on the lower side. Many achenes develop from the pistillate flower.

Eg. Ficus species Peepal 

Geocarpic fruit: Underground fruits are called geocarpic fruit.

Example: Arachis
 

Dispersal of Fruits, and Seeds 

We know that most of the plants do not move from one place to another. They grow, produce flower and fruits while remaining fixed at one and the same place. The seeds falling directly under the mother plant have to germinate and develop under limited food supply and space. To overcome this problem, the fruits and seeds have developed several special devices for wide dispersal. The natural agents like wind, water and animals and even mechanism of dehiscence in some fruits, help the seeds and fruits to disperse from one place to another, and to long distances from the parent plant.

Wind: In the species where the seeds are light in weight or have some accessory part to help dissemination, are dispersed by the air current. The seeds of Drum-stick and Cinchona, and (fruits of yam, maple) aridsiil tree, are provided with one or more appendages. In the form of thin, flat and membranous wings, which help them to float in the air and be carried away to long distances. In the members of Asteraceae, the calyx is modified into hair like structures called pappus. They persist in fruit and open out like umbrella, helping the seeds to float in the air. In poppy and prickly poppy (Argemone), the fruit dehisces and seeds are thrown out to a distances away from the parent plant. The seeds of Calotropis, Alstonia arid cotton are provided with hair and cover sufficient distances along with the wind. The seeds of orchids and some grasses are very small and light in weight and may be. Easily carried away by wind to far off places.

Water: The fruits and seeds with specialised devices which may be in the form of spongy and fibrous outer walls as in coconut and spongy thalamus as in lotus, and small seeds with airy aril as in water lily, float very easily in water, and are carried away to long distances with the water current.

Animals: The fruits and seeds with hooks, spines, bristles, stiff hair, etc., get attached to the body of hairy and woolly animals and are carried away by them to distant places. For instance fruits of Xanthium and Urena bear curved hooks, spear grass has a bunch of stiff hair, Tribulus has sharp and rigid spines. Boerhaavia has sticky hair which help their dispersal by animals. The edible fruits like guava, grape, fig and plum are dispersed by birds and even human beings, either by feeding on them and passing out undigested seeds with faeces or by carrying them to other places for later feeding. 

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