Morphology of flowering Plants
INTRODUCTION
+ Morphology – (Morphe = form + logos = study). It deals with the study of forms and features of different plant organs like roots, stems, leaves, flowers, seeds, fruits etc.
+ The body of a typical angiospermic plant is differentiated into :
an underground root system
an aerial shoot system.
The shoot system consists of stem (including branches), leaves, flowers and fruits.
+ The roots, stems and leaves are vegetative parts, while flowers constitute the reproductive part.
Classification of Plants
Depending upon their life span, plants are classified as –
+ Annuals – Complete their life cycle in one year or singlerowing season or few weeks to a few months. They pass the unfavourable period in the form of seeds eg. Mustard, Pea.
Radicle comes out/arise from the seed coat in the form of soft structure and move toward the soil. It develops and forms primary root.
+ eneral Characters :
+ Roots are non green, underground, (+) geotropic, (–) phototropic and (+) hydrotropic.
+ Roots do not bear nodes and internodes.
+ Roots have unicellular root hairs.
4 Types of Roots
Roots are of two types :
G Tap root G Adventitious root
+ Tap root : It develops from radicle and made up of one main branch and other sub branches.
+ Adventitious roots : When root is originated from any other part of plant than radical. It is known as Adventitious root.
Root System :
+ Root systems are of two type : (i) Tap Root System, (ii) Fibrous Root System
(i) Tap root system - Primary root and its branches constitute tap root system. e.g., Dicot
(ii) Fibrous root system – In some plant mainly in monocots, after sometime growth of tap root stop and than roots develop from other part of plant which are highly branched and fibrous and form fibrous root system.
REGIONS OF ROOTS
Morphologically four distinct regions are present in roots.
+ Root cap : It is terminal structure. It protects tender apex of root.
+ Elongation region : The cells proximal to meristematic zone undergo rapid elongation and enlargement and are responsible for rapid growth of roots.
MODIFICATION OF ROOTS
1. Modified tap root for storage :
+ Fusiform roots : These root are thicker in the middle and tappered on both ends. In this type of roots both hypocotyl and root help in storage of food. eg. Radish.
+ Conical roots : These roots are thicker at their upper side and tapering at basal end. eg. Carrot.
2. Nodulated root : Nodules are formed on branches of roots by nitrogen fixing bacteria, (Rhizobium). eg. Plants of leguminosae family (Papilionatae) – Pea.
3. Respiratory roots : Halophyte or mangrove grow in oxygen deficient marshy area. Some branches of tap root in these plant grow vertically & comes out from soil. These roots are called pneumatophores through which air entered inside the plant. eg. Rhizophora, Heritiera, Sonaratia and other mangrove plant.
Modification of adventitious roots :
1. Storage adventitious roots
Tuberculated root : When food is stored in these roots, they become swollen and form a bunch. eg. Sweet potato (Ipomea batata)
G Fasciculated – Roots arise in bunch (cluster) from lower node of the stem and become fleshy eg. Dahlia, Asparagus.
G Nodulose : In this type, tips of roots swell up. eg. Melilotus, Curcuma amoda.
G Beaded or moniliform : When root swells up like a bead at different places after a regular interval. eg. Vitis, Momordica (Bitter gourd), Portulaca.
Annulated : Roots having series of ring like swellings eg. Psychrotia
Tuberous Fasciculated roots Moniliform Nodulose Annulated roots
2. Stilt roots or brace roots : When root arises from lower nodes and enter in soil obliquely, known as stilt roots eg. Maize, Sugarcane, Pandanus (screwpine)
3. Prop root or pillar roots : when root arises from branches of plant and grows downward towards soil. It function as supporting stem for the plant. eg. Banyan.
4. Butteress root – Such roots appear from the basal part of stem and spread in different directions in the soil. eg. Ficus, Bombax , Terminalia. It is a characteristic feature of tropical rain forest.
5. Climbing roots – These roots arise from nodes and helps the plant in climbing. eg. Money plant (Pothos), Betel, Black pepper, Techoma.
6. Foliar roots or Epiphyllous roots – When roots arise from leaf they are called as foliar roots.
eg. Bryophyllum, Bignonia.
7. Sucking or haustorial roots or Parasitic roots : In parasitic plant roots enter in the stem of host plant to absorbed nutrition from host. eg. Dendrophthoe, Cuscuta, Viscum.
12. Reproductive roots : These are fleshy, adventitious roots used for vegetative reproduction e.g., sweet potato (Ipomea batata), Dahlia.
13. Leaf roots : In Salvinia, one leaf of each node modifies into root like structure for balancing the plant in water.
FUNCTIONS OF ROOTS
STEM
Stem is a part of plant which lies above from surface of soil i.e. it shows negative geotropic growth. It has nodes and internodes. Branches, leaf, flower bud and bracts are developed from nodes. Stem arises from plumule.
FORMS OF STEM
TYPES AND MODIFICATION OF STEM
+ Aerial stems (Epiterranean stem) :
It may be reduced, erect and weak.
+ Reduced – Stem reduced to a disc. eg., Radish, Carrot, Turnip.
Creepers – The stem creeps on earth and the roots arise at the nodes, e.g., Grasses, Strawberry, Oxalis.
Lianas (Stem climber). Woody perennial climbers found in tropical rain forests are lianas. They twin themselves around tall trees to secure sunlight, e.g., Hiptage, Bauhinia vahlii (Phanera).
Climbers – Plants are with long weak stem and have organs of attachment to climb the object. They may be of following type .
w Rootlet climbers – Roots produced at nodes help in climbing e.g., Tecoma, Pothos, Piper betal (pan).
w Hook climbers – In Bougainvillea, Duranta and Carrisa, the thron is modification of axillary vegetative bud which helps in climbing. In Bignonia, terminal leaflet is converted into
hook.
Twiners – The stem body twines around the support without any special organ of attachment. e.g., Cuscuta, Dolichos.
+ Sub-aerial modification :
+ Underground modification :
This type of modification occurs generally for food storage and vegetative propagation.
+ Special stem modification :
FUNCTION OF STEM
The main function of the stem is spreading out branches bearing leaves, flowers and fruits. It conducts water, minerals and photosynthates. Some stems perform the function of storage of food, support, Protection and of vegetative propagation.
LEAF
The leaf is a lateral generally flattened structure borne on the stem. The leaves develop from the nodes. Their main function is photosynthesis and food making. Axillary buds are found in its axil. Axillary bud later develops into a branch. All the leaves of a plant is known as phyllome. Leaves originated from shoot apical meristem and are arranged in acropetal order.
+ Leaf is divided into 3 main parts :
G Leaves are attached to stem by leaf base.
G In some plants, leaf base becomes swollen and is called pulvinus which is responsible for sleep movement e.g., Cassia, mimosa, bean.
G In some plants, leaf base expands into sheath (Sheathing leaf base), e.g., grasses and banana (monocots).
When the leaf base partially encloses the stem, it is called semi amplexicaul e.g., Prickly poppy, Calotropis procera (Madar).
It completely encloses the stem, it is called amplexicaul e.g., Sonchus, Polygonum.
The part of leaf connecting the lamina with the branch of stem. Petiole help to hold the blade to light.
In Eichhornia petiole swell and in citrus it is winged.
Petiole is modified in tendrils in Nepenthes.
In Australian acacia petiole is modified in phyllode.
Long thin flexible petiole allow leaf blade to flutter in air, thereby cooling the leaf and bringing fresh air to leaf.
+ Lamina (Epipodium) :
G It is a broad and flatted part of leaf. Its main function is photosynthesis and transpiration.
+ Stipules :
Leaves of some plants have lateral appendages on either side of leaf base, known as stipules. If stipules are present in leaf it is called stipulated leaf, if it is absent then leaf is called exstipulated.
Stipules are of various types –
+ Duration of leaf :
VENATION OF LAMINA
The arrangement of veins and veinlets in leaves (Lamina) is known as venation. It is of 2 types
+ Reticulate venation :
+ Parallel venation :
In this type of venation, all veins run parallel to each other and they do not from network. They are of 2 types.
+ Simple and Compound Leaf :
It is of two types –
It is of following types -
Unipinnate – In this type of leaf, division occurs only once and leaflets are directly attached on both sides of rachis.
If the number of leaflet is even, then leaf is known as paripinnate. eg. Cassia fistula, Sesbania
If the number of leaflet is odd, it is known as imparipinnate. eg. Rose, Neem.
Bipinnate – A twice pinnate compound leaf eg. Acacia, Gulmohar, Mimosa.
Tripinnate – A thrice pinnate compound leaf eg. Moringa.
Decompound – A compound leaf, which is more than thrice pinnate. eg. Carrot, Coriander.
It is of following types -
Unifoliate – When single leaflet is found. eg. Lemon
Bifoliate – When two leaflets are present. eg. Bauhinia, Regnelidium, Bignonia.
Trifoliate – When three leaflets are attached. eg. Oxalis, Aegle, Trifolium
Tetrafoliate – When four leaflets are attached to the petiole. eg. Marsilea.
Multifoliate – when more than four leaflet are found, then leaf is called multifoliate palmate compound leaf. eg. Silkcotton.
+ Phyllotaxy :
It is the pattern of arrangement of leaves on stem or stem branch. It is of following type –
G Decussate : Leaves that stands at right angle to next upper or lower pair eg. Calotropis, Mussaenda.
G Superposed : Successive pairs of leaves stand directly over a pair in the same plane eg. Psidium (guava), Ixora.
Spiral Alternate Opposite decussate Opposite superposed Whorled
+ Heterophylly – It is the occurrence of more than one type of leaves on the same plant. It is of three types –
+ Developmental Heterophylly : Leaves of different forms and shape occur at different period or places on the same plant eg. Mustard, Sonchus, Eucalyptus.
MODIFICATION OF LEAVES
Arrangement of flower on floral axis is called inflorescence.
Racemose – In this type of inflorescence-
This is of following different types :
+ Raceme – When peduncle (main axis) is elongated and flowers are pedicellate.
eg. Radish, characteristic feature of cruciferae family
Compound raceme or panicle. eg. Gulmohar, Neem.
+ Spike – In it peduncle is elongated but flowers are bisexual and sessile.
eg. Achyranthes
When peduncle is branched and each branch bear spike, like inflorescence then the small branch having flower is called spikelet and this arrangement is called as spike of spikelet. Characteristic inflorescence of family gramineae.
+ Catkin – In it peduncle is thin, long and weak, and flowers are sessile and unisexual. Peduncle is pendulus. eg. mulberry, betula, oak.
+ Spadix – In it peduncle is thick, long and fleshy and have small sessile and unisexual male and female flowers covered with one or more green or colourfull bracts known as spathe.
eg. Colocasia, Maize, Aroids, Palms.
* In mustard corymbose raceme type of inflorescence is present
+ Umbel – An inflorescence in which the flower stalks of different flowers are of more or less equal length, arise from the same point. At the base of flowers stalks, there is whorl of bracts forming the involucre.
eg. Centella
+ Compound Umbel – eg., Coriander, Foeniculum, Cuminum.
Characteristic feature of umbeliferae.
+ Capitulum / Racemose head – In it the growth of peduncle is retarded and it become broad, flattened concave or convex. On it small flowers are found. These flowers are called floret. If all the flower of capitulum are same , then it is called homogamous. If two different type of floret, ray floret and disc floret are present in same inflorescence than it is known as heterogamous. In this type of inflorescence florets may be unisexual, bisexual and sterile. This inflorescence is surrounded by one or more involucre. It is most advanced type of inflorescence. eg. Sunflower, Zinnia, Marigold, Cosmos.
Characteristic feature of asteraceae family.
CYMOSE
In this type of inflorescence,
It is of following types.
+ Uniparous cyme / Monochasial cyme - The peduncle ending in a flower producing lateral branch at a time of ending in flower. It is of two types -
+ Dichasial or biparous cyme – In it peduncle ends in a flower, from the basal part of peduncle two lateral branches arise, which also end in a flower, now this same arrangement occur on these lateral branches.
eg. Bougainvillea, Jasmine, Nyctanthes.
+ Multiparous cyme / polychasial – In it peduncle ends in a flower and from the base of it many lateral branches arise which also terminates in flower, this arrangement now also occur on these lateral branches. eg. Calotropis (Madar), Nerium, Asclepias.
SPECIAL TYPE OF INFLORESCENCE
Mixed spadix – Banana Cymose raceme or thyrsus – Grapes.
FLOWER
Flower is defined as highly condensed and modified reproductive shoot.
Floral leaves are present on it.
In a flower there are 4 type of floral leaves are found.
Sepal Petal Stamen Carpel
SOME WORDS RELATED TO FLOWER
+ Complete Flower – When calyx, corolla, androecium and gynoecium are present.
+ Incomplete Flower – Flower with one of the four whorl missing.
+ Bisexual Flower – Both gynoecium and androecium present in the same flower.
+ Unisexual Flower – Androecium (staminate flower) or gynoecium (Pistillate flower) any one of them are present in the flower.
+ Monoecious Plant – When both male and female flowers are present on the same plant. eg. Cocos, Ricinus, Colocasia, Zea, Acalypha.
+ Dioecious Plant – When male and female flowers are present on separate plant eg. Mulberry, Papaya.
+ Polygamous Plant – When unisexual (male or female), bisexual and neuter flowers are present on the same plant eg. Mango, Polygonum.
+ Monocarpic Plant – The plant which produces flowers and fruits only once in life eg. Pea, Mustard, Bamboo, Agave.
+ Polycarpic Plant – The plants which produces flowers and fruits many times in life, eg. Pear, Mango,
+ Cauliflory : Production of flowers on old stem from dormant buds eg. Artrocarpus, Ficus.
+ Symmetry of flower : Floral symmetry is of three type-
Internodal elongation in flower :
Note : - Part of flower which lies near to mother axis is posterior part while the part which is far from mother axis is anterior part of flower.
INSERTION OF FLOWER LEAVES
Notes :
+ Bracts : Bracts are specialized leaves present in axis of flower.
The outermost whorl of flower is called calyx. Each member of this whorl is called sepal. When all the sepals are free from each other, then it is called poly-sepalous condition eg. Mustard, Radish. When the sepals are fused each other, then it is called gamosepalous condition eg. Cotton, Datura, Brinjal.
* Sometime below calyx, a whorl similar to sepals is found which is called epicalyx. eg. Malvaceae family
The second whorl of flower is called corolla and each member of it is called Petals. When all the petals are free, then it is called polypetalous while when petals are fused, then it is called gamopetalous.
+ Forms of Corolla -
POLYPETALOUS
+ GAMOPETALOUS
+ ZYGOMORPHIC POLYPETALOUS COROLLA -
Papilionaceous – Five petals are present. It's posterior petal is largest and is known as standard or vexillum. Vexillum covers two lateral petals which are called as wings and the innermost basal petals are united to form a keel or carina. Both lateral parts covers the keel. eg. Pea, Gram, Arher
+ ZYGOMORPHIC GAMOPETALOUS COROLLA -
+ AESTIVATION -
The mode of arrangement of sepals or petals in floral bud with respect to the other members of the seme whorl is known as aestivation. It is of following types -
It is of two types -
G Ascending imbricate – The posterior petal is innermost i.e., its both margins are overlapped. eg. Cassia, Bauhinia, Gulmohur etc.
G Vexillary or Papilionaceous – There are five petals the standard overlaps the two lateral petals which in turn overlap the smallest anterior petals. eg. Pea, Bean.
Valvate Twisted Imbricate Vexillary Quincuncial
+ Perianth
It is made up of one or more stamens. Each stamen consist of filament, anther and connective. Each anther is usually bilobed and each lobe has two chambers the pollensac. The pollen grains are produced in pollensac.
+ Attachment of filament to anther lobe :
The attachment of filament to another lobe is of 4 type -
+ Cohesion of stamens :
When the floral parts of similar whorl are fused, then it is called cohesion. When the stamens of an androecium are free from one another, it is called polyandrous condition.
Monoadelphous – When all the filaments are united into a single bundle but anthers are free from each other. In this type of cohesion a tube is formed around the gynoecium which is called staminal tube eg. Cotton, Hollyhock, Ladyfinger, Chinarose.
Diadelphous – When the filaments are united in two bundles but the anther remains free eg. Gram, Pea, Bean
Polyadelphous – When filaments are united into more then two bundles. eg. Citrus, Castor.
+ Adhesion of stamens :
When the stamens are attached to other parts of flower, then it is called adhesion of stamens.
+ Note :
Didynamous
Tetradynamous
In syncarpous gynoecium four types of cohesion are found
The ovules are attached on ovary walls on one or more cushion called placenta. The arrangement of ovule within ovary wall is known as placentation. It is of following types –
Fertilized and ripened ovary is fruit. A Fruit consist of (i) Pericarp (fruit wall), (ii) seed.
The seeds are protected inside fruit. But in some fruits. seeds are not found like in grapes, banana and such type of fruits are seedless fruit.
If a fruit is formed without fertilization of the ovary it is known as parthenocarpic fruit.
Pericarp : After ripening, the ovary wall change into pericarp. This pericarp may by thick and fleshy or thick and hard or thin and soft.
Pericarp is differentiated in 3 layers
+ Epicarp :- It is the outermost layer, which is also called rind
+ Mesocarp :- It is the middle layer.
+ Endocarp : It forms the innermost layer.
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, Pear.
Fruits are divided in three groups
Simple Aggregate Composite
+ SIMPLE FRUIT :-
These fruit develop from monocarpellary ovary or multicarpellary syncarpous ovary. Only one fruit is formed by the gynoecium. Simple fruits are of two types –
Fleshy fruit Dry fruit
+ Fleshy Fruit:- These fruit develop from superior or inferior syncarpous gynoecium. These may be unilocular or multilocular. These fruits are indehiscent. Dispersal of seeds occur after pericarp is destroyed.
Fleshy fruits are of following types :
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. Brachysclereids are present in endocarp.
In mango 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.
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 consist of hard fibers The endocarp is hard and seed is protected in it. Endosperm is edible in coconut.
G 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 and seeds are embedded in fleshy part. Initially seeds are attached with placenta of fruit but after maturation these seeds are deteched with placenta and are spread randomly in fleshy part.
? Plants with superior ovary = Tomato, Grapes, Brinjal.
? 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 berry. When its thick fibrous layer is removed then seed comes out which is hard.
G Pepo - These fruit develops from tricarpellary, syncarpous and inferior ovary. This fruit is unilocular and have parietal placentation. These fruits are fleshy and spongy. sometime fruits are bitter in taste due to presence of tetracyclic triterpine in flashy pulp. eg. fruits of cucurbitaceae family.
Pome - This fruit develops from bi or multicarpellary syncarpous inferior ovary. The rind and fleshy pulp are made up of thalamus. The main part of ovary is hard and dry and remain inside the fruit. Seeds are present in it. eg. Apple, Pear.
Hesperidium : This fruit develops from multicarpellary, syncarpous, superior ovary. This fruit is specialy found in plants of Rutaceae family. eg. Orange, Lemon, Citrus fruit.
Epicarp of these is made up of thick rind which is leathery and many oil glands are found in it. Mesocarp is white fibrous structure which is attached with epicarp. Membranous endocarp projects inward and form many chambers. Many glandular hairs are present on the inner side of endocarp. These glandular hairs are only edible parts.
Balausta : It is a multilocular multiseeded fruit, which develops from inferior ovary. Its pericarp
is hard. Persistent calyx is arranged in the form of crown. Seeds are irregularly arranged
on placenta. Endocarp is hard. Testa is fleshy. This is the edible part of fruit. eg. Pomegranate (Punica granatum).
Amphisarca : This fruit is multicarpellary and 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. Testa of seed is mucilegenous eg. wood apple (Aegle marmelos), elephant apple.
+ Simple Dry Fruit - 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
+ Indehiscent fruits : These simple dry fruits are generally of small size and single seeded pericarp does not rupture even after maturity.
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.
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.
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
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.
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.
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.
+ Dehiscent Fruits : After ripening pericarp are ruptured and seeds are dispersed outside.
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.
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.
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.
G Silicula : A short broad siliqua is known as Silicula. It is also found in Cruciferae family. eg. Candytuft (lberis amara), Capsella,
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).
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.
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.
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.
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
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.
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.
+ Etaerio of follicles : Each fruitlet is a follicle. eg. Calotropis, Catharanthus, Magnolia.
+ Etaerio of achenes : In this aggregate fruit, each fruitlet is an achene. eg. Rananculus, Strawberry, Rose, Lotus
+ 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.
Etaerio of Follicles Etaerio of Achenes Etaerio of Berries Etaerio of Drupes
+ 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.
+ Sorosis : This fruit develops from spike, spadix or cartkin inflorescence. Peduncle become thick spongy and woody. eg. Jack fruit, Pandanus (screwpine), Pineapple
In jack fruit (Kathal) pistillate flowers are developed around the peduncle. In fruit formation pericarp become spongy and fused.
In Pine apple peduncle bracts and perianth become fleshy. Due to the fusion of perianths of flower a composite fruit is formed.
In mulberry perianth become fleshy and axis of every flower becomes thick, sweet and fleshy and are edible.
Geocarpic fruit : When fruit development occurs inside soil e.g. ground nut
+ WIND (Anemochory) :
+ WATER (Hydrochory) :
+ 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) :
Propagation of new plant by any plant part other than seed is known as vegetative propagation. The structural unit that is employed in place of seed for the propagation of new plants is called propagule. In Angiosperms any part of the plants – roots, stems and leaves used for vegetative propagation.
+ Natural Vegetative propagation :
+ By roots :- Modified tuberous root of Sweet potato (Ipomoea batatas), Asparagus, Tapioca, Yam, Dahlia and Tinospora can be propagated vegetatively when planted in soil.
In some plants adventitious buds develop on the ordinary roots like-Dalbergia sisso, Populus, Guava, Murraya, Albizzia lebbek etc. which grow to form new plants.
The buds present on the roots grow into leafy shoot above the ground is called Slips.
Rhizomes – Typha, Canna, Ginger, Turmeric, Lotus, Musa etc.
Corm – Gladiolus, Colocasia, Crocus, Amorphophallus, Alocasia etc.
Bulbs – Onion, Garlic and Lilies
Tubers – Potato, Helianthus tuberosus etc. which grow to form a new plants.
+ Sub aerial stem :
Runners – Cynodon, Oxalis and Centella
Stolon = Fragaria (Strawberry) & Vallisneria
Sucker – Mint and Chrysanthemum.
Offset – Pistia, Eichhornia (water hyacinth) etc.
+ Aerial stem - Opuntia
+ Leaves :- Some plants produce adventitious buds on their leaves e.g., Bryophyllum, Begonia, Streptocarpus, Saintpaulia. These buds remains dormant, when the leaves attached with plants but after separation, when it comes in contact with moist soil develop new plantlets [buds] which form new plants.
+ In Kalanchoe, plant whole portion of leaf blade regenerate a new plant.
+ In some of the plants, fleshy axillary buds develop from axis of leaves are called Bulbils
Example – Dioscorea, Oxalis, Dentaria, Globba, Agave, Lilium.
+ There are special type of fleshy buds develop in Aquatic plant are called Turions.
Example – Potamogeton, Utricularia.
+ Artificial Propagation :
+ Cutting :- A cutting is separated portion of root, stem or leaf which is used for propagation. Some time the stem cutting are treated with rooting hormone [IBA, IAA or NAA] for proper development of adventitious roots e.g., Sugarcane, Rose, Croton, Tapioca, China rose (Stem cutting) Lemon, Tamarind (Root Cutting) etc.
[Favourable time for cutting - Rainy season]
+ Grafting :- In this method, parts of two plants are joined in such a way that they grow as one plant. Grafting is done between two closely related dicotyledonous plants having vascular cambium. The rooted supported portion of one plant called Stock is joined with a twig of another plant called Scion. Generally, the root stock belong to wild variety which is resistant to disease & pest. The scion is derived from the plant possessing better characters. In grafting, the stock and scion cuts are marked in such a oblique manner so that they fix with each other. This joint is covered with clay or a layer of wax. Within a few days, tissues of stock and scion combined together and to form a new plant e.g., Grafted Mango, Roses, orange, Seedless Grapes and Guava, Apple, Pear.
Types of Grafting –
Tongue/Whip grafting Wedge grafting
Crown grafting Side grafting
Approach grafting
+ Bud grafting :- This method is similar to grafting except that scion in this case consist of a bud along with some portion of bark having intact cambium.
Generally bud grafting is done during the rainy season e.g., Roses, Peach.
+ Layering :- This method is used in those plants which are having flexible long branches. In this method, first roots are artificially induced on the stem branches then are detached from the parent plants for propagation. There are two common types of layerings.
Mound/Ground Layering – This method is only utilized in herbaceous plants. In this method, the lower branch of stem is bent down and partially defoliated and injury is made on defoliated part. It is covered by thin layer of moist soil in such a way that the growing tip of the branch remains above the soil surface. After a few days the pegged portion developos adventitious roots. Then rooted branch cut and separed from parent and grown into new plant e.g., Jasmine, strawberry, Raspberry etc.
Air Layering or Gootee –
This method is commonly employed in case of shrubs and trees
which do not possess branches near the ground. In this method a ring of bark is removed [girdled] from the aerial branch. This girdled portion is covered with moist grafting clay [2 parts clay + 1 part cow dung + some pieces of hay + cotton + water] and wrapped with a polythene sheet.
This wrapped portion of the branch is called gootee. Inside the gootee roots developed within a period of one or two month(s) e.g., Litchi, Pomegranate, orange, Lemon and Bougainvillea, Guava etc.
+ Merits of Vegetative propagation :
+ It is good for the multiplication of seedless plants e.g. Banana, Sugarcane, Pineapple and seedless Orange and Grape.
+ It is the fastest method of reproduction.
+ By grafting, desirable quality of fruit/flower/seed can be obtained.
+ Plants with long seed dormancy or poor seed viability or poor seed can be propagated vegetatively e.g., Cynodon dactylon (Lawn, Doob or Bermuda grass).
+ The greatest advantage of this method is that a Biotype of plant (original plant) can be retained & multiplied indefinetly without any change or variation.
+ Good quality and better yield varieties can be preserved for a long duration in off site collection, herbarium, botanical gardens etc.
+ It produce 100% genetically similar to their parents i.e., clone.
+ Demerits of Vegetative propagation :
+ Diseased parents always give diseased clone.
+ Clone undergoes degeneration due to the absence of sexual reproduction.
+ Vegetative organs can not be preserved for long duration like culms of Sugarcane.
+ Vegetative propagatory organs or structures cannot be safely and easily stored as comparison to seeds. They are easily decomposed and attached by various pathogens like Bacteria, Virus, Fungi.
+ Do not cause any variation in plantlets, thus decrease in the adaptation power.
+ There is absence of dispersal mechanism. Vegetative propagation in a particular area causes overcrowding. It results in intraspecific competition.
MORPHOLOGY OF ANGIOSPERM
+ Arrangement of flowers on peduncle and study of flowers is called Anthology.
+ National flower of India is Lotus (Nelumbo nucifera)
+ Longest styles are found in maize.
+ Longest inflorescence is in Agave (12m),
+ In Mussanda, One (odd) sepal is enlarged to form a leafy structure called Advertisement Flag.
+ National fruit of India is Mango (Mangifera Indica)
+ Largest fruit and largest seed is of Lodoicea maldivica (double coconut, weight is 18 Kgs.)
+ False nuts are Coconut (drupe), Areca nut (Berry), Pea nut or Ground nut (Lomentum), Walnut (drupe) and Chilgoza (seed)
+ Dispersal of fruits and seeds by ants is called myrmechory eg. Ulex and Trillium (seeds).
+ Monophyllea is a plant with single leaf.
+ Welwitschia (a gymnosperm) is a plant with two leaves throughout the life.
+ Victoria regia has broadest leaves each with a diameter of 1.5–1.8m.
+ Leaves are longest in Raphia vinifera (10–15m)
+ Largest bud is cabbage.
+ Shruby climbers which climb with the help of hooks are called Stragglers eg. Bougainvillea, Artobotrys.
+ Marine angiosperm is Zostera.
+ 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)
1. What is morphology in plants? |
2. What is the significance of studying the morphology of flowering plants? |
3. What are the different parts of a flower? |
4. How do the roots and stems differ in morphology? |
5. What is the role of fruits in the morphology of flowering plants? |
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