marjanblan-GOP07ZOjBEU-unsplash.jpg

Morphology of Flowering Plants 3

continued...

 

Simple Dry Fruit -

  1. Pericarp of simple dry fruit is hard and dry and not differentiated into epicarp, mesocarp and endocarp. Such fruits are called dry fruit.

Simple dry fruits can be divided into following three groups :

✧ Indehiscent ✧ Dehiscent ✧ Schizocarpic

  1. Indehiscent fruits : These simple dry fruits are generally of small size and single seeded pericarp does not rupture even after maturity.

    1. Cypsela : It is a small, single seeded dry fruit which develops from bicarpellary, syncarpous inferior ovary. 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. eg. Compositae family Plants. 

    2. Caryopsis : These are small, single seeded dry fruits. It 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. Wheat grain or rice grain is a fruit. 

    3. 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 

    4. Nut : This is a single seeded fruit which develop from monocarpellary syncarpous superior ovary. In it pericarp is hard eg. Quercus (oak), Anacardium occidentale (Cashewnut) Trapa, (Water chest-nut), Litchi. 

    5. In Litchi epicarp and mesocarp is fused and give leathery apperence. Endocarp is membrane like thin. Outer seed coat grows forward and forms an additional coat around the seed which is called as aril. In mature fruit, this aril is fleshy and is only edible part.

    6. 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 wing like structure develops from its pericarp which helps in dispersal. eg. Holoptelia. ​In Shorea robusta wing develops from calyx instead pericarp and these fruit are called samaroid.

  2. Dehiscent Fruits :

After ripening pericarp are ruptured and seeds are dispersed outside.

  1. 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, then it is also called as pod. 

  2. Follicle : It is also multiseeded fruit which develops from superior unilocular, monocarpellary ovary but the dehiscence of it occur only at ventral suture. eg. Asclepias, Rauwolfia, Vinca, Michelia (Champa), Delphinium. 

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

  4. Silicula : A short broad siliqua is known as Silicula. It is also found in Cruciferae family. eg. Candytuft (lberis amara), Capsella, 

  5. Capsule : This is dry multichambered and multiseeded fruit and develop from multicarpellary syncarpus, superior ovary. In it, Axile placentation is found and dehiscence occurs by various methods. Poricidal (Poppy), loculicidal (cotton), septifragal (Datura), septicidal (Lineseed). 

  1. ​Schizocarpic fruit : It is a multiseeded fruit. After ripening, it is devided into mericarp and seeds come out after destruction of pericarp. The fruits develop from mono or bi or multicarpellary superior or inferior ovary. The mericarp contains one or two seeds.

    1. Lomentum : It develops like legume. Fruits are constricted or divided in one seeded mericarp, after maturity these are separated with each other. Eg Tamarind, Cassia fistula, Mimosa pudica, Archis hypogea, Desmodium. 

    2. Cremocarp : It is a double seeded fruit and develops from bicarpellary, syncarpous, inferior ovary. On maturation, it dehisces from apex to base in such a way that two mericarp forms and each contain one seed. These mericarp are attached with carpophore. Carpophore is the extended part of receptacle. eg. Coriander, Cuminum, Foeniculum. 

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

    4. Carcerulus : It is a dry fruit which develops from multi carpellary or bicarpellary, syncarpous, superior ovary. Number of mericarp is more than locules because of formation of false septum. It divides into four one seeded locules. eg. Ocimum (Basil), Salvia. In hollyhock and abutilon (family malvaceae), the no. of locules is more than four 

    5. Utricle : It is a single seeded fruit which has thin membrane. It dehiscence generally from cap. It develops from bicarpellary, unilocular, syncarpous, superior ovary. eg. Achyranthes, Amaranthus. 

    6. Double Samara : It develop from bicarpellary syncarpous superior ovary. Pericarp develops into two wings. On maturation it divides in two single seeded mericarp eg . samara , acer. 

​AGGREGATE FRUIT

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 are made up of bunch of fruitlets which is known as etaerio.

  1. Etaerio of follicles : Each fruitlet is a follicle. eg. Calotropis, Catharanthus, Magnolia.

  2. Etaerio of achenes : In this aggregate fruit, each fruitlet is an achene. eg. Rananculus, Strawberry, Rose, Lotus

  3. 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 thalamus.

  4. Etaerio of drupes : In this type of fruit, many small drupes develop from different carpels. eg. Raspberry

COMPOSITE FRUIT :-

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.

  1. Sorosis : This fruit develops from spike, spadix or cartkin inflorescence. Peduncle become thick spongy and woody. eg. Jack fruit, Pandanus (screwpine), Pineapple

    1. In jack fruit (Kathal) pistillate flowers are developed around the peduncle. In fruit formation pericarp become spongy and fused.

    2. In Pine apple peduncle bracts and perianth become fleshy. Due to the fusion of perianths of flower a composite fruit is formed.

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

  2. Syconus : This fruit develops from hypanthodium inflorescence. eg. Ficus species like fig, Peepal

  1. ​Geocarpic fruit : When fruit development occurs inside soil e.g. ground nut

DISPERSAL OF FRUITS AND SEED

  1. 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.

  2. The natural agents like wind, water, 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 (Anemochory) :

  1. In the species where the seeds are light in weight or have some accessory part to help dissemination, are dispersed by the air current.

  2. The seeds of Drum-stick and Cinchona, and fruits of yam, maple and sal tree, are having 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.

  3. 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.

  4. In poppy and prickly poppy (Argemone), the fruit dehisces and seeds are thorwn out to a distances away from the parent plant. (Censor mechanism)

  5. The seeds of Calotropis, Alstonia and cotton are provided with hair and cover sufficient distances alongwith the wind.

  6. 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.

  7. In fruits of physalis swollen persistant calyx is present and fruit can easily be carried out by air.

  8. Some plant like chenopodium, amaranthus etc. are uprooted after drying and carried away by wind and seeds are dispersed distantly. These plants are known as tumbler weed.

WATER (Hydrochory) :

  1. The fruit 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.

ANIMAL (Zoochory) :

  1. The fruit and seeds with hooks, spines, bristles, stiff hair, etc., get attached to the body of animals and are carried away by them to distant places.

  2. Fruits of Xanthium and Urena bear curved hooks.

  3. Spear grass has a bunch of stiff hair.

  4. Tribulus has sharp and rigid spines.

  5. Boerhaavia has sticky hair, which help their dispersal by animals. In Martynia two curved hooks are present.

  6. The edible fruits like guava, grape, fig and plum are dispersed by birds and even human beings by feeding on them and passing out undigested seeds with faeces or by carrying them to other places for later feeding.

DEFENSE MECHANISM IN PLANTS :

These specialized structures, organs, substances and adaptations which protect the plants from destroying by animals, insects and disease carriers are called as defence mechanism in plants. Some of these are as follows:

  1. Epidermis, periderm, cork and bark. 

  2. Trichomes, hairs and spines.  Laticiferous glands or ducts. 

  3. Secretory glands. 

  4. Taste of different plant parts. 

  5. Underground plant parts. 

  6. Myrmecophily 

  7. Colour, shape and structure of plants. 

Epidermis, Periderm, Cork and Bark :

  1. Epidermis acts as a protective layer which saves internal tissues from being damages by high temperature, microbes, acidic rain and high wind velocity etc.

  2. In Vanda (orchid), Nerium, Peperomia etc. it is multilayed. In Peperomia, it consists of 14 to 15 layers of cells

  3. All parts of a plant except root, have a layer of wax-like substance or cutin on the outer surface of the epidermis. This layer is known as cuticle.

  4. In Cycas and Pinus the cuticle is lignified

  5. On aerial parts of Equisetum and members of grass family silica or silicon oxide is found which protect them from grazing animal.

  6. On epidermis of some plants wax, oil, resin crystallized salts, silica, lignified substances etc. are deposited.

  7. In woody plants periderm is present which is a secondary epidermal tissue and is formed by activity of the phellogen. Here the cork is a protective layer.

  8. Bark is the tertiary epidermal tissue found in woody plants. Its main function is to protect the internal tissues from mechanical injury.

Trichomes, Hairs and spines :

  1. Leafy epidermal hairs regulate atmospheric humidity,

  2. Covering hairs protect plants from disease causing insects

  3. Glandular epidermal hairs secrete some chemical substances to protect them from animals.

  4. Stinging hairs pierce the skin of animals and secrete poisonous substances which cause irritation and protect the plants from animals. eg. Urtica diocea.

  5. Spiny stipules and spines found in xerophytes protect these plants from grazing animals. eg. Zizypus, Acacia.

  6. Spines of Euphrbia act as defensive devices against grazing animals.

  7. Prickles of Capparis, Bombax and rose and needle like hairs of cacti save these plants from animals.

Laticiferous glands or Ducts :

  1. Woody plants of arid and semi arid areas secrete a white milky fluid which is called latex.

  2. It is a viscous fluid which contains various substances like water, hydrocarbons, resins, oils, proteins, acids, salts, sugars and rubber in suspended form. It is found in members of family Moraceae, Euphorbiaceae, Apocyanaceae etc. Latex help in protection of these plants from animals. The latex secreted by plants of Calotropis is poisonous.

Secretory glands or cells :

  1. They are filled with different types of excretory or secretory substances such as oils, tannins, gums, mucilage and different type crystals

  2. Smell of oily substances secreted by oil glands present in the leaves and bark of Eucalyptus and pericarp of lemon fruit protect these plants from animals.

  3. Taste of different plant parts :

  4. Aerial parts like fruits, seeds leaves, branches and bark of some plants contain different type of alkaloids or excretory substances which are repulsive or bitter in taste and are disliked by animals e.g.

  5. Azadirachta indica, Momordica charantia, Trigonella, Ocimum sanctum, Datura stramonium, Papaver somniferum, Mentha arvensis, Nicotiana tabacum, Carica papaya, Cinchona officinalie etc.

  1. UNDER GROUND plants :

  1. In some plants, plant parts remain under the soil i.e. out of reach of grazing animals e.g. underground modified roots of radish (Raphanus sativus), carrot (Daucus carota), turnip (Brassica rapa), chukandar (Beta vulgaris), heeng (Ferula asafoetida) etc. underground modified stems of potato(Solanum tuberosum), arbi (Colocasia antiquorum), onion (Allium cepa), garlic (Allium sativum). ginger (Zingiber officinale), turmeric (Cucrcuma domestica) etc. and underground fruits of ground nut(Arachis hypogea).

 

Myrmecophily :

  1. Gauva (Psidium guajava), mango (Mangifera indica), litchi (Litchi chinensis), mulberry (Morus alba) etc. secrete some substances which attracts some ants. These ants take their abode on these plants and act as bodyguards against any animal attack. This relationship is called myrmecophily.

  2. Colour, shape and structure of plants :

  3. Certain plants strickingly resemble some dreaded animals so that they are carefully avoided by other animals. This is known as mimicry e.g. plants of Caladium and Sensviria resemble spotted serpents.

​MORPHOLOGY OF ANGIOSPERM (Point to be remembered always) 

  1. Arrangement of flowers on peduncle and study of flowers is called Anthology. National flower of India is Lotus (Nelumbo nucifera)

  2. Longest styles are found in maize. Longest inflorescence is in Agave (12m),

  3. In Mussanda, One (odd) sepal is enlarged to form a leafy structure called Advertisement Flag. National fruit of India is Mango (Mangifera Indica)

  4. Largest fruit and largest seed is of Lodoicea maldivica (double coconut, weight is 18 Kgs.)

  5. False nuts are Coconut (drupe), Areca nut (Berry), Pea nut or Ground nut (Lomentum), Walnut

  6. (drupe) and Chilgoza (seed)

  7. Dispersal of fruits and seeds by ants is called myrmechory eg. Ulex and Trillium (seeds).

  8. Monophyllea is a plant with single leaf.

  9. Welwitschia (a gymnosperm) is a plant with two leaves throughout the life.

  10. Victoria regia has broadest leaves each with a diameter of 1.5–1.8m. Leaves are longest in Raphia vinifera (10–15m)

  11. Small protein rich glands called Belt's corpuscles are present at the tip of leaflets in Acacia sphaerocephola.

  12. In Musca the suckers are called sword suckers.

  13. In knol-khol (Ganth Gobhi) the entire stem becomes tuberous.

  14. Largest bud is cabbage.

  15. Pseudostem is a trunk formed by leaf bases in Banana.

  16. A plant with reduced stem is called as Acaulescent.

  17. Ulex possesses both stem thorns as well as leaf spines.

  18. Shruby climbers which climb with the help of hooks are called Stragglers eg. Bougainvillea,

  19. Artobotrys.

  20. Marine angiosperm is Zostera.

  21. Pseudobulb is swollen part of stem in orchids for storing water and food reserve.

  22. Annuals and biennials are monocarpic. The perennials are polycarpic as they bear fruits every year. Some perennial plants such as Agave, Bamboo are monocarpic as they flower and fruit only once in their life after a long period of vegetative growth.

  23. Smallest angiosperm is Wolffia (less than 0.1 mm) and largest or tallest angiosperm is Eucalyptus regnans (height more that 114 m or 375 ft)

  24. Plants with roots only are podostemon, Arceuthobium, Rafflesia and Sapria.

  25. Hypocotyl develops into a large tuber in Myrmecodia enchinata family Rubiaceae. In the cavities of tuber many ant live. So it is an example of myrmecophily.

  26. Gynostagium : It is formed due to the fusion of crowned stamens with the carpels. It forms a protective covering around the carpels, thus protects the gynoecium. Presence of Gynostagium is the characteristic feature of family Asclepediaceae.

  27. Maize (Zea mays) has largest stigma and style.

  28. The sterile pistil is called pistalloide.

  29. State tree of Rajasthan → Prosopis cineraria.

  30. State flower of Rajasthan → Rohira (Tecomela undulate)

Back

REVISION NOTES

 

CLASS 11 BIOLOGY

UNIT I – DIVERSITY IN THE LIVING WORLD

Chapter 1 – The Living World 

Chapter 2 – Biological Classification 

Chapter 3 – Plant Kingdom 

Chapter 4 – Animal Kingdom 

UNIT II – STRUCTURAL ORGANISATION IN PLANTS AND ANIMALS

Chapter 5 – Morphology of Flowering Plants 

Chapter 6 – Anatomy of Flowering Plants 

Chapter 7 – Structural Organisation in Animals 

UNIT III – CELL : STRUCTURE AND FUNCTIONS

 

Chapter 8 – Cell: The Unit of Life 

Chapter 9 – Bio-Molecules 

Chapter 10 – Cell Cycle and Cell Division 

UNIT IV – PLANT PHYSIOLOGY 

Chapter 11 – Transport in Plants 

Chapter 12 – Mineral Nutrition 

Chapter 13 – Photosynthesis in higher plants 

Chapter 14 – Respiration in Plants 

Chapter 15 – Plant Growth and Development 

UNIT V – HUMAN PHYSIOLOGY 

Chapter 16 – Digestion And Absorption 

Chapter 17 – Breathing and Exchange of Gases 

Chapter 18 – Body fluids and circulation 

Chapter 19 – Excretory Products and their Elimination 

Chapter 20 – Locomotion and Movement 

Chapter 21 – Neural Control and Coordination 

Chapter 22 – Chemical Coordination and Integration 

CLASS 12 BIOLOGY

Unit-VI Reproduction
  

Chapter 1 : Reproduction in Organisms 

Chapter 2 : Sexual Reproduction in Flowering Plants 

Chapter 3 : Human Reproduction 

Chapter 4 : Reproductive Health 

Unit-VII Genetics and Evolution

Chapter 5 : Principles of Inheritance and Variation 

Chapter 6 : Molecular Basis of Inheritance 

Chapter 7 : Evolution 

Unit-VIII Biology and Human Welfare

Chapter 8 : Human Health and Disease 

Chapter 9 : Strategies for Enhancement in Food Production 

Chapter 10 : Microbes in Human Welfare 

Unit-IX Biotechnology  

Chapter 11 : Biotechnology Principles and Processes 

Chapter 12 : Biotechnology and its Applications 

Unit-X Ecology and Environment 

Chapter 13 : Organisms and Populations 

Chapter 14 : Ecosystem 

Chapter 15 : Biodiversity and Conservation 

Chapter 16 : Environmental Issues 

  • LinkedIn
  • YouTube
  • Facebook
  • Twitter

RAVSUN

NEET/Board/Foundation

Contact Us