Diversity of flowers - e

5
Diversity of flowers
By the end of this chapter, you will be competent to...
w identify the morphological diversity of flowers.
w describe a flower by using scientific conventions.
w investigate the patterns of inflorescences.
w analyse the structure of fruits.
w use the diversity of life time of plants to fulfil the day - today pursuits.
73
For free distribution
5.1 Morphological diversity of flowers
The plants which bear flowers are known as flowering plants. Plants which do
not bear flowers are categorised as non-flowering plants. e.g. mosses, ferns, algae
and conifers.
Majority of the plants in the plant kingdom produce flowers. Though flowers are
generally considered as structures which are colourful, beautiful and consist of petals,
small flowers which are not noticeable at first glance are also found in herbs and
grass varieties.
Flowering plants can be divided into two categories as dicotyledons and
monocotyledons.
Flowers are specially structured for reproduction. A Flower can be considered
as a special structure designed to determine the survival and existence of its species.
5.1.1 Parts of a flower and their arrangement
A flower is a modified shoot. That is instead of a bud grows and produces a
shoot, it gets modified to produce a flower. The flower is fixed on to the stem by a
stalk. The top of the stalk is expanded to form a torus or thalamus. All the parts of
the flower is arranged in four whorls on the torus. In a flower four types of flower parts
can be identified. They are calyx, corolla, androecium and gynaecium (from outer
ring to inner).
anther
filament
}
stamen
Petals
(corolla)
Sepals
(calyx)
Stigma
Style
Ovary
thalamus
(torus)
pedicel (stalk)
Fig 5.1.1 Main parts of a flower
74
For free distribution
}
gynaecium
Calyx
Calyx is a cup shaped structure. It is found at the bottom of all the other parts. It
is the outer most whorl of a flower. It consists of sepals. Sepals are similar to small
green leaves. Colurful sepals can be seen in some flowers.
Function of the calyx is the protection of the tender flower bud. Photosynthesis
takes place in green coloured sepals. Colourful sepals are important to attract insects
for pollination. (Fig 5.1.2 and 5.1.3)
Rose
Sesbenia
Tribulus
Fig 5.1.2 - Flowers with green sepals
Muntingia
Species of Musandas
Fig 5.1.3 - Flowers with colourful sepals
Do you know
In some flowers a whorl of floral
leaves can be seen outside the calyx. It
is known as epicalyx
Example:- Shoe flower
Cotton flower
Shoe flower
Cotton flower
calyx and epicalyx
75
For free distribution
Do you know?
In some flowers the
sepals do not fall off even
after the fruits are produced.
Example :- Mangoosteen
Guava
Rose apple
Guava
Mangoosteen
Fruits with persistent sepals
Corolla
Within the calyx are the whorl of floral leaves called petals, together forming the
corolla. It is the most beautiful and attractive part of most flowers.
The corolla protects the internal parts of the flower and also helps to attract
insects for pollination. The corolla is colourful in majority of flowers which are pollinated
by insects. Corolla shows diversity in colour and shape. Examples:- Fig 5.1.4
Clitoria
Wrightia
Catharanthus
Shoe flower
Orchid
Fig 5.1.4 - Diversity of Corolla in shape and colour
76
For free distribution
Alstonia
In most of the flowers which bloom during the night, the corolla is white in colour,
and the flowers are scented. This is also important to attract insects for pollination.
Examples:-Fig 5.1.5
Coral jasmine (Sepalika)
Kadupul
Fig 5.1.5 - Flowers bloom during the night
Getapichcha
Androecium
Androecium is the male part of a flower. It is the whorl of floral leaves found
inside the corolla.
Andreoecium consists of stamens. A stamen consists of the anther and the filament.
The function of the androecium is to produce pollen grains for reproduction.
Structure of Androecium in different Flowers
Stamens of flowers can be independent or connected to the petals. e.g: Fig 5.1.6
Passion fruit
Torenia
Shoe flower
Gloriosa
Brassica
Calotropis
Fig 5.1.6 - Situation of anthers in different flowers
77
For free distribution
Gynoecium or Pistil
stigma
Gynoecium or pistil is the female part of a flower,
It is the innermost part of a flower. It consists of three
parts namely stigma, style and ovary. The stigma
is situated at the top and the ovary is situated at the
base. The style is a tube like structure which connects
the stigma and the ovary. Ovules can be seen in the
ovary.
After pollination and fertilization the ovary becomes the fruit and the ovules become seeds.
style
ovary
Fig 5.1.7 - gynoecium of a
flower
Unisexual and Bisexual Flowers
If both the gynoecium (pistil) and the androecium are present in a flower it is
called a bisexual flower.
Examples:- Hibiscus (Shoe flower) , Sesbenia, Lotus, Blue Lily
Shoe flower
Cannon ball tree
Fig 5.1.8 - Bisexual Flowers
Caesalpinia
In some flowers only one of these parts is present. Such flowers are called
unisexual flowers.
Example:- Coconut, Maize
staminate
flower
pistilate
flower
a - staminate flowers b - pistilate flowers
Fig 5.1.10 - coconut
(In coconut, both staminate and pistilate
Fig 5.1.9 zia - maize
flowers present in the same in florescense)
78
For free distribution
Flowers which consist of only the gynoecium (pistil) are called pistilate flowers
while flowers consist of only the androecium are called staminate flowers.
Activity - 5.1.1
Divide your class into four groups. Select 10 kinds of flowers which can be
easily found from your surrounding. Observe and identify the diversity in the calyx,
corolla, androecium and gynoecium
Symmetry of flowers
Actinomorphic Flowers
If a flower can be divided into two similar halves by cutting vertically through any
one of its axis which passes through the centre, such flowers are known as radially
symmetrical flowers or an actinomorphic flowers.
Examples:- Shoe flowers, Jam, Temple flowers, Hendirikka (Mirabilis)
Wrightia, Kaduru, Pupmpkin
Catharanthus
Pumpkin
Shoe flower
Kaduru
Mirabilis
Fig. 5.1.11 – Actinomarphic flowers
Temple flower
Wrighita
Zygomorphic flowers
Some flowers can be divided into two similar halves by cutting along only one
symmetrical axis. These flowers are known as bilaterally symmetrical flowers or
zygomorphic flowers.
79
For free distribution
Sesbenia
Thunbergia
Orchid
Leucus zeylaniea
Caesalpinia
Salvia
Crotolaria
Fig 5.1.12 - zygomarphic flowers
Asymmetrical flowers
Some flowers cannot be divided into two similar halves by cutting along any axix.
These flowers are known as irregular or asymmetrical flowers.
Examples:- Cannas, Cactus
Species of Cactus
Species of Cactus
Fig 5.1.13 Irregular flowers
Species of Canna
Activity - 5.1.2
Bring 20 kinds of flowers which can be easily found from your surrounding to
the school. Observe its symmetry and group them as actinomophic, zygomorphic
and asymmetrical flowers.
80
For free distribution
5.2 Structure of flowers
There are some standard methods to describe the structure of flowers. They are
1.
Whole flower and half flower
2.
floral diagram
3.
floral formula
Whole Flower
By observing a flower
externally we can study the
structure of the flower. To observe
the colour, the nature, its parts and
their position in the flower by the
naked eye one has to observe a
whole flower.
Half Flower
To observe the parts of a
flower more clearly we can
separate a flower into two similar
halves through a symmetrical axis
of the flower.
Fig - 5.2.1 – whole flower
Because some parts which
cannot be seen by observing the
flower externally, can be clearly
seen in a half flower. (fig 5.2.2)
Therefore a half flower is
used to describe the structure of a
flower. Half flower can be depicted
by a line diagram.
Fig 5.2.2 – a half flower
81
For free distribution
Floral Diagram
A transverse section drawn so that all the
parts of the flower are in the same level is called
a floral diagram. This is similar to a diagram of
a flower drawn as seen from the top. To draw a
ksm;%h
bract
floral diagram the main axis of the tree should
main axis
placed to the anterior side and the bract should
of
the tree
placed to the posterior side.
a
b
a) Position of a flower in the tree
Fig 5.2.3 - Position of a Flower and
b) Floral diagram of a flower
Floral diagram
Floral Formula
A formula written using standard symbols to describe the morphological features
of a flower is known as floral formula.
Example :- floral formula of a shoe flower
K(5)
C 5 Aα G
(5)
The symmetry of the flower is depicted by the first symbol.
Symbol
Symmetry
-
Actinomorphic
-
Zygomorphic
According to this, the symmetry of a shoe flower is actinomorphic.
The second symbol depicts the sex of the flower
-
staminate
pistilate
bisexual
According to this, the shoe flower is bisexual
The third symbol ‘K’ depicts the calyx. The numeral at the bottom shows the
number of sepals. If the numeral is written within brackets it depicts that the sepals are
connected.
82
For free distribution
According to this, the shoe flower has 5 connected sepals.
The fourth symbol ‘C’ depicts the corolla The numeral at the bottom shows the
number of petals in the . If the numeral is written within brackets it indicates that the
petals are fused.
According to this, the corolla of the shoe flower has five independent
petals.
The fifth symbol ‘A’ depicts the androecium. The numeral at the bottom shows
the number of stamens. If the numeral is written within brackets the stamens are fused.
According to this, the number of stamens in the androecium cannot be
counted easily.
C A
All the filaments of the stamens of a shoe flower are connected
to make the staminal tube.
The sixth symbol ‘G’ depicts the gynaecium. The numeral at the bottom shows
the number of parts in the pistil. If the numeral is written within brackets, it depicts that
these parts are connected to each other.
The situation of gynaecium is depicted by drawing a line over or below its symbol.
If it is situated above all the other parts of the flower, the short line should be drawn
below the letter ‘G’. If the ovary is situated below the other parts of the flower, the
short line should be drawn above the letter ‘G’.
According to this, the gynaecium of the shoe flower consists of five parts
and they are connected. The gynaecium is situated above all the other parts.
Now let us consider the floral formula of two other kinds of flowers.
Sesbenia
K(5) C(2)+2+1 A(9) +1 G(1)
Ipomea
K5 C(5) A5 G(2)
Assignment 1
Try to describe the features of the Sesbenia and Ipomea flowers by studying
their floral formula.
83
For free distribution
5.3 Inflorescence
Leaves and flowers are situated on the tree
trunks according to a certain way. Some flowers are
situated alone while some are situated as groups on a
central axis. When flowers are situated as groups on a
central axis it is called an inflorescence.
The main axis of an inflorescence is the peduncle
while the stalk of each flower is called a pedicel.
Inflorescence can be divided into two categories
according to the way in which flowers are arranged on
the main axis.
1. Racemose Inflorescence
2. Cymose Inflorescence
Fig - 5.3.1- an inflorescene
5.3.1 Racemose inflorescences
Terminal buds of racemose inflorescences continuously grow for some time and
flowers gradually start growing from the bottom of the axillary bud towards the top of
it. Matured flowers can be seen at the bottom of the inflorescence while tender flowers
can be seen on the top. Flowers start blooming from the bottom of the inflorescence
and continue upwards towards the top.
Raceme
These flowers consist of pedicels.
Examples:- Crotolaria, Orchid, Ehela (Cassia fistula)
Ehela (Cassia fistula)
Orchid
Fig - 5.3.2- Racemose inflorescence
84
For free distribution
Spike
This is similar in all aspects to a raceme, but the flowers are sessile.
Examples Amaranthus, Stachetophyta
Spadix
Cat's tail
(Acalypha)
Stachetophyta
(Balunakuta)
Fig - 5.3.3- Spike
Amaranthus
(Tampala)
The flowers are sessile. These flowers are attached to a fleshy, thick central axis.
A leaf like structure called spathe can be seen at the bottom of the central axis.
This is an adaptation of the bract. Before the inflorescene bloom it is
completely covered by the spathe. Examples:- Anthurium, Alocasia
inflorescence
sheath
Anthurium,
Alocasia
(Gahala)
Corymb
Anthurium species
Fig - 5.3.4 Spadix
As the stalks of the basal flowers are longer than the stalks of the terminal
flowers, they seem to be in one level.
Examples – Caesalpinia pulcherima, Some Cassia species
Thora (Cassia)
Caesalpinia pulcherima
(Monera mal)
Fig - 5.3.5- Corymb
85
For free distribution
Umbel
All the flowers appear in the same level. Matured flowers are situated outside the
inflorescence while tender flowers are seen at the centre of the inflorescence.
Examples – Red onion, Crinum, Lantana, Isora
Capitulum
Lantana
Fig - 5.3.6 - Umbel
Crinum
The flowers are sessile. A disc like structure is created as a result of the flat
central axis. The flowers are seen on this disc like structure. Here too the tender
flowers are situated at the centre of the inflorescence while matured flowers are seen
in the outer part of it. Examples – Tridax, Zenia, Monarakudumbiya, Sun flower
Sun flower
Zenia
Fig 5.3.7 - Capitulum
Tridax
5.3.2 Cymose Inflorescenses
There are more than one axis in cymose inflorescences. The main axis ends
with a flower. In a cymose inflorescene tender flowers can be seen at the bottom while
the matured flowers are at the top. Flowers bloom from the top towards the bottom
according to the centrifugal method. Cymose
inflorescences can be further classified into several
types.
Simple cyme
There are only three flowers in a Simple cymose
inflorescene.
Example:- Some Jasminum species.
86
For free distribution
A species of 'Pichcha'
Fig - 5.3.8 - Simple cyme
Dichasial cyme
A dichasial cyme can be formed due to the continuous branching of lateral
branches. Examples:- Begonia, Girithilla
Begonia
Fig - 5.3.9 - Dichasial cyme
Girithilla
Helicoid cyme
Lateral branches always grow on one side of the central axis. As a result a curved
inflorescence is formed. Examples :- Brinjal, ' Ethhonda'
Brinjal
Scorpoid cyme
'Ethhonda'
Fig - 5.3.10 - Helicoid cyme
Lateral branches grow on the either
sides of the central axis. Here monochasiums
formed by inhibiting the lateral branches side
by side.
Examples:- Leucus zelaynica,
'Uruhonda '
Though the inflorescences are
classified as racemose and cymose, you
may find other types of inflorescences which
do not belong to any of these catagories .
Leucus zelaynica
Fig - 5.3.10 - Helicoid cyme
Assignment - 1
Make a small booklet about inflorescences including examples for each type
of inflorscene you studied in this chapter.
87
For free distribution
5.4 Diversity of fruits
Fruits
A fruit is an ovary developed and grown larger after stimulated by pollination.
After pollination the ovary becomes the fruit while the ovules become the seeds.
Fruits are mainly of three types. They are
1. Simple fruits
2. Aggregate fruits
3. Composite fruits / Multiple fruits
5.4.1. Simple fruits
Simple fruits can be divided into two, according to the nature of pericarp. They are
1. Fleshy (Succulent ) fruits
2. Dry fruits
Simple Fleshy fruits
Pericarp of this fruits are fleshy or fibrous. Fleshy fruits are of many types.
Mango
Coconut
Tomato
Guava
Apple
Orange
Fig 5.4.1 - Simple Fleshy fruits
Pumpkin
88
For free distribution
Simple dry fruits
The fruits which are having a dry nature at the time of seed dispersal are simple
dry fruits.
Example - Beans, Olinda, Calotropis, Ladies fingers.
Sun flower, Paddy, maize, Wheat, Vernonia, Dipterocarpus, cashew nuts, Anona
Mimosa and castor.
Calotropis
beans
Paddy
Cashew
Ladies finger
Maize
Fig 5.4.1 - Simple dry fruits
Wheat
Popy
5.4.2 Aggregate fruits
An aggregate fruit is produced by a single flower with an apocarpous ovary.
Fruitlets develop one by one gradually. A fruit of this type is a collection of fruitlets.
Anona
Strawberry
Fig 5.4.3 - Aggregate fruits
Anona specias
89
For free distribution
5.4.3 Composite fruits
If a simple fruit originates from an inflorescene it is known as a composite fruit
(multiple fruit).
Example :- Pineapple, jak, mulberry, Ficus (Bo, Nuga, Attikka), Bread-fruit.
Pineapple
jak
Fig 5.4.4 Composite fruits
bread-fruit
5.5 Dispersal of fruits and seeds
A fruit is produced in a tree for the purpose of reproduction to produce a new
plant. A new plant is produced by the germination of seeds in a fruit. A single tree
produces a large number of fruits at a time. Therefore a tree produces a large number
of fruits in a number of seasons throughout its life time. The aim of producing fruits is
to ensure the existence of the species.
All these seeds may not get a chance to produce new plants.Only a few of them
are able to produce new plants.
If all the seeds get germinated near the mother plant they will rarely grow into
healthy, matured plants. The probability of these seeds growing into healthy, matured
plants is less. This is due to the competition for space, water, air, nutrients etc.
Sometimes when a certain species of plant is limited to one area they can get
destroyed by natural disasters. So dispersal of fruits and seeds is essential for the
survival of the species.
There are 4 ways in which fruits and seeds are dispersed. They are :
1. By wind
2. By water
3. By animals and
4. By explosive mechanisms
90
For free distribution
Fruits that use explosive mechanisms for dispersal, dispersal agents are the seeds.
The fruits that depend on other factors such as wind, water and animals for dispersal,
dispersal agent can be a whole fruit or a part of a fruit.
Fruits and seeds show various adaptations for dispersal.
5.5.1 Dispersal by wind
A large number of fruits and seeds are produced in trees where the dispersal of
fruits and seeds is caused by wind. Sometimes these fruits and seeds may land in
places which are not suitable for the germination, causing a wastage. That is the reason
for producing a large number of fruits and seeds.
Some of the adaptations seen in fruits and seeds for dispersal by wind is stated below.
1. Light weighted and small seeds
examples - Orchid
2. Having Structures such as wings
Examples – Dipterocarpus, Shorea, Pterocarpus, Tecoma
3. Having hair like structures
Examples – Vernonia, Nerium, Calatropis, Cotton
Pterocarpus
' Thotila '
Dipterocarpus
Calotropis
Fig 5.5.1 - Fruits and seeds dispearsed by wind
Tecoma
Cotton
91
For free distribution
5.5.2 Dispersal by water
In plants growing in or around water, dispersal of fruits and seeds is occured by
water.
There are various adaptations in these seeds and fruits to float on water. Some of
them are, presence of air spaces, holes, having a fibrous covering and being
impermeable to water.
Examples :- Calophyllum, Terminalia, ' Kaduru ', Lotus, Coconut, Arecanut
Rhizophora(Kadol), Water lily, Blue lily
Arecanut
Calophyllum
5.5.3
Coconut
Terminalia
Kaduru
Fig 5.5.2 - Fruits and Seeds dispersed by water
Lotus
Dispersal by animals
Seeds that are dispersed by animals show various adaptations.
1. Having a fleshy part which can be consumed by animals
Fruits or seeds which can be consumed by animals and dispersed in various
places. Most of the time the seed is thrown away after eating the fleshy part.
Examples:- papaw, mango, dates, orange, avacardo
In some instances the seed too is consumed with the fruit. Afterwards the seed
will come out of the body with the waste matters. When the seed is passing through
the digestive system no harm will be caused to the seed. After coming out of the body,
it will get germinated when it finds a suitable place.
Examples:- guava, tomato, chillie
92
For free distribution
2. Having appendages to cling on to animals
Examples:- Love grass, 'Karal heba', 'Nerenchi', Tiger claws (Nagadarana)
Seeds of some fruits are visible as small insects to trick the animals. So the
birds carry them off and drop them in another place. Through this method too the
seeds get dispersed.
Examples:- Castor, 'Madatiya' , 'Crabs eyes' (olinda)
Tomato
Tiger claws
5.5.4
Papaw
Guava
Chillie
Castor
' Nerenchi '
Fig 5.5.3 - Fruits and seeds dispearsed by animals
Dispersal by explosive mechanisms
Due to a change caused in pericarp the fruits burst and the seeds are thrown
away to a distance.
Examples –
Balsom, ' Madatiya ' , ' Crabs eyes ' Bauhenia" Rubber
Rubber
Balsam
Bauhenia
Fig 5.5.4 - Fruits and seeds dispearsed by explosion
Madatiya
The method of dispersal by explosion is not very successful as the seeds are not
thrown far away.
93
For free distribution
5.6 Diversity in plant habit
Grouping plants according to its life span
Plants show a diversity in the life span too. They can be divided into 3 groups.
1. Annuals
2. Biennials
3. Perennials
5.6.1 Annuals
The plants which completes its life span and die within one season or one year are
known as annuals.
Example :- Grains like paddy and wheat, vegetables like cucumber and tomato.
Paddy
Maize
Fig 5.6.1. Some annual plants
Tomato
The growth of these plants occur during the early stage. Reproduction occurs
during the last stage after the growth stops. They produce flowers, fruits and seeds and
die at the end of a season or a year. These plants spend the unfavourable season as
seeds.
5.6.2
Biennials
Plants which completes its life cycle and die within two years or two seasons are
known as biennials. Growth continues upto two years and at the end of the second
year they die after producing flowers, fruits and seeds.
Example:- Vegetables like cabbage, carrot and beet- root.
The food produced during the growing stage of the first year is stored in storage
organs like underground roots. Flowers are not produced at the end of the first
growing stage. At the beginning of the unfavourable season the aerial parts of the plant
die and the undergroond roots and the terminal bud remains inactive (dormant). Again
when the favourable season begins the underground roots and the terminal buds begin
their work, start growing and produce a new shoot. These plants produce flowers,
fruits, seeds at the end of the second season of growth and die.
94
For free distribution
These plants spend one unfavourable season as underground stems and
terminal buds, and spend the other unfavourable season as seeds.
Carrot
Beet root
Fig 5.6.2 Some biennial plants
Cabbage
5.6.3 Perennials
Plants which live for more than two years are known as perennials. These plants
are adapted to survive even during the unfavourable seasons. Surviving these
unfavourable seasons using various methods is known as perennation. Perennation is
a characteristic of perennials. There are different adaptations in plants for perennation.
Some of them are given below.
1. Live underground and being inactive.
2. Have inactive (dormant) buds
3. Covered with a bark containing non living tissues.
4. Leaves fall off to avoid transpiration during dry seasons.
Perennials are mainly of two types.
1. Herbaceous perennials
2. Woody perennials
Herbaceous perennials
These plants live as herbs. They have underground stems. Perennation is done as
underground stems.
Examples:- grass, ginger, colocasia, onion
95
For free distribution
Colocasia
Ginger
Fig 5.6.3 Some herbaceous perennials
Crysanthimum
Woody perennials
Shrubs and trees are included. The aerial parts continue growing for some years.
Reproduction occurs after growth. After that flowers and fruits are produced untill the
end of their life span. Having a bark with phellem, having inactive or dormant buds and
leaves falling off are some adaptations for perennation.
Mango
Jak
Fig 5.6.4 Some woody perennials
Coconut
5.6.4 Uses of plants to humans
Annuals
Most of the plants taken as food by humans and animals fall under this category.
Paddy, wheat, maize which are considered as main food items of humans are annuals.
Leafy vegetables and medicinal plants too belong to this category. These plants
complete their life span at the end of a year or a season and the fruits, seeds and other
parts are taken into use by humans and animals.
Biennials
These plants too are taken as food by humans.
96
For free distribution
Perennials
These plants are used as food and for many other needs.
Examples 1. As food items (jak, bread fruit)
2. As fruits (Mango, jambu, avacardo, rambutan).
3. To make drinks (tea, coffee, cocoa)
5. As medicines (Aralu, Bulu, Nelli)
6. To obtain oils (coconut, Citronella, castor)
7. To obtain fibres (cotton, jute&
8. To produce useful objects (rubber)
9. As timber (Satinwood, halmilla, teak, nedun)
10. For shade (Mara)
11. For beauty (Plumeria, roses)
Assignment - 1
Prepare a list of plants found in your home - garden or school garden. Classify
and tabulate them as annuals, biennials and perennials.
Exercises
1. Select the correct answer for the statements given below from the words within
brackets.
(calyx, receptacle, umbel, androecium, floral formula, spadix, corolla, gynaecium)
i. The most outstanding colourful part of a flower ii. The whorl that protects the tender flower iii. The male part of a flower iv. The female part of a flower v. Use to describe the structure of a flower vi. A racemose inflorescene covered by a structure (sheath) called spathe vii. All the parts of a flower situated in whorls on this structure 2.
i
Fruits and seeds get a chance to germinate far away
from the mother plant by various dispersal methods.
Give two reasons for the necessity of such a process.
ii What is the dispersal method of the seed given in the
picture according to its adaptations.
iii Write two characteristic features of the above
mentioned seed to be dispersed by the method you mentioned.
97
For free distribution
3. Plants are classified into three categories according to the plant habbit. They can
be classified into three categories according to the life span also.
i
What are the three categories of plants according to their life span ?
ii
Classify the plants which are giving the following products according to the
above classification,.
tomato, bread fruit, mango, onion, carrot, cucumber, papaw, beet-root, zea
maize, jak, anona, cabbage.
iii
Classify and tabulate the fruits mentioned below as simple, aggregate, and
multiple composite.
tomato, cucumber, bread fruit, mango, jak, anona.
4. Floral formula are used to describe the morphological features of a flower.
Mentioned below is a floral formula of an imaginary flower. Study it carefully and
fill in the blanks.
(Please copy this paragraph into your note book before you do the exercise)
K5 C(5) A5 G 2
The flower depicted by this floral formula is ........................... (actinomorphic/
zygomorphic). That is a ..........(unisexual / bisexual) flower.This flower has five ...........
(free/ combined) petals. The number of stamens are ................... (five / two). Gynacium
has two chambers. The gynaecium is situated ................... (below/ above) the other
parts of the flower.
98
For free distribution