1. The document discusses the structure and parts of flowering plants. It describes that flowering plants can be divided into underground and above-ground parts. 2. The underground part is the root system, which can be either a taproot or fibrous root system. The above-ground part is the shoot system consisting of stems, leaves, flowers and fruits. 3. The structure of a flower is also described, which usually has four whorls: sepals, petals, stamens and a pistil. Stamens are the male part containing pollen, while the pistil is the female part containing the ovary.

1. Getting to Know Plants
Life is impossible without flowers and flowering plants. Nine-tenths of that part of the
world that is covered with vegetation is covered with flowering plants. In this chapter, we
are going to study about the structure of a flowering plant and the modifications which
the various plant organs have undergone to ensure their survival.
1. CELLS TO ORGANISMS
We know, basic structural unit of living organisms, the cell, was described. Let us see how
the cells are organized to form the multicellular body of living organisms.
Cells in multicellular organisms are not similar. Rather they are specialized to perform
different functions. For example, nerve cells are specialized to conduct messages while
muscle cells are specialized to conduct and help in locomotion.
The specialized cells, which group together to perform a particular function are known as
tissues. A tissue represents a group of cells similar in structure and function.
Different tissues are often grouped together into larger units called organs. An organ,
thus, consists of several different tissues. For example, stomach is an organ to digest
food, and is made up of different tissues like epithelial and muscular tissues. Similarly,
heart is an organ consisting of muscular and nervous tissues. Likewise in plants, the root,
stem, leaves and flowers are the different organs which perform different functions and
consist of various tissues.
Organs, in turn, are organized into organ-systems. An organ-system consists of
different organs that function together. For example, the digestive system consists of
various organs like the mouth, stomach, intestine, liver, pancreas and rectum which
perform the role of digestion of the ingested food.
Different organ-systems comprise the multicellular organism. This organization of cells
into tissues, organs, organ-systems and the organism is found in all multicellular
organisms – plants as well as animals.
2. PARTS OF A FLOWERING PLANT
We have studied earlier that a flowering plant may be a herb, shrub or a tree. Now
collect a herb along with its underground parts.
Having collected a herb, see into what parts can you divide this plant.
A flowering plant can be divided into two parts
(Figure) :
(i) An underground part called the root system, and
(ii) An above ground part called the shoot system.
The root system consists of the roots, while the shoot system consists of the stem,
branches, leaves, flowers and fruits.
The root, stem and leaves constitute the vegetative parts of a plant body. The shoot
system also bears the flowers and fruits which comprise the reproductive parts.
Parts of flowering plant

2. 3. THE ROOT SYSTEM
The part of the plant body which fixes it to the soil is called the root system. In
certain plants like mustard, gram, pea, balsam, tulsi, marigold, rose, oleander, mango and
neem, the root system consists of a main root called the tap root (Figure) and its
branches.The tap root grows vertically down into the soil and then gives out branches.
In some plants like wheat, maize, millets, other grasses, sugarcane and banana, there is
no main root. A number of roots arise in a cluster below the stem and spread out in the
soil. Such roots are called Fibrous root fibrous roots (Figure).
Tap root
Fibrous root

3. Functions
1. Roots fix the plant to the soil.
2. Roots absorb water and mineral salts from the soil which are then conducted upwards
to the stem and leaves.
3. Roots help in holding the soil together, thus, preventing erosion or blowing away of
the soil particles.
4. In some plants, roots are modified to perform additional functions of storage, support
or respiration.
Modifications of Root for Storage
In plants like sweet potato, radish, carrot, turnip and beet root, the roots instead of
spreading in the soil, become swollen [Figure.(a), (b), (c)]. These swollen roots store food,
which we eat. Such roots are called tuberous roots.
Figure(a) Modified root of Turnip
(b) Modified root of Sweet potato
(c) Modified root of Carrot

4. Modifications of Root For Additional Support
In the Botanical Garden at Kolkata, a 200 year old banyan (bargad) tree which has a
crown circumference of more than 400 metres is present. In banyan, a number of roots
arise from the tree branches and these roots grow downwards. These roots are
called supporting roots or prop roots. These act as pillars and support the big heavy
horizontal branches (figure). Maize and sugarcane also have supporting roots.
Supporting roots of Banyan tree
Breathing roots in mangrove plant
Modification of Root For Respiration
In certain plants growing in saline marshy habitats, the root system produces vertically
upward growing branches above the soil. These roots help in respiration and are known
as breathing roots or pneumatophores, as found in mangrove plants
like Rhizophora (Figure).
4. THE STEM

5. Buds
Stem forms the main axis of the plant body. It is divided into nodes and internodes. The
place from where the branches and leaves arise on the stem is called the node. The
portion of the stem between two nodes is called the internode.
The tip of the stem or a branch bears an apical or terminal bud(Figure).Apical bud
helps in lengthwise growth of the plant, that is, it leads to an increase in the height of
the plant body. Buds are present in the axils of leaves too. These buds are
called axillary buds. They grow into branches.
When young, a stem is green and soft. In an herb, the stem remains soft and tender. But
in a tree, it becomes hard and woody and is called the trunk.
It is no longer green. It becomes brownish in colour, and is in fact covered with bark. The
bark protects the inner parts of the tree.
In some plants, the stem is very weak and needs a support to stand erect and grow. Such
plants are called climbers. Grapevine, sweet pea and cucurbita are some examples of
climbing plants.
Functions
1. A stem bears the leaves, flowers and fruits. It serves as a link between the roots, the
leaves and flowers.
2. The stem and its branches hold the leaves in such a manner that the leaves get
maximum possible sunlight.
3. When young, it is green and manufactures food through the process
of photosynthesis.
4. It carries water and mineral salts from the roots to the leaves and flowers.
5. It carries food manufactured in the leaves to roots and other parts of the plant body.
6. In some cases, the stems may be modified to perform the functions of storage, food-
manufacture (photosynthesis), and support.
Modifications of Stem For Storage
(a) In some plants, the stems are underground. The underground stems are modified to
store food materials, and help the plant to survive unfavourable conditions. The
underground modifications are stems, as they possess nodes and internodes.

6. The main modifications are as follows:
(i) Tuber : Look at a potato. It is a small, thick and fleshystructure. It has buds which are
called ‘eyes’. It also hassome scaly leaf-like structure (Figure. a).
This swollen-structure which stores food (in the form of starch) is calleda tuber. New
plants develop from the ‘eyes’ of the tuber.
(ii) Bulb : Observe an onion (Figure. b). It is a thick, bulb-like structure. The stem is short
and bears small fibrousroots at the base and leaves above.
(a): Tuber of potato
The outer leaves are dry and scaly (scale leaves). The outer dry scales enclose
thick fleshy leaves which store food.
(iii) Rhizome : In plants like ginger and turmeric, food is stored in underground stems
called rhizomes (Figure. c). In a piece of ginger (adrak), we will find nodes and
internodes, brown scale leaves arising from nodes, small buds and adventitious roots.
(b): Bulb of onion
(c): Rhizome of ginger

7. (b) In cactus plant (Figure.), the stem becomes fleshy and green. The stem prepares food
and also stores water for long periods. The leaf is reduced to spines. Prickly
poppy (Opuntia) is another such type of plant.
A cactus plant; the stem prepares food
Modification of Stem For Photosynthesis
Look at the cactus plant again. In addition to the stem being fleshy, it is green, too. The
green stem performs the functions of the leaf. It manufactures food for the plant. Leaves
are reduced to spines.
Modification of Stem For Support
In climbers like grape vine, cucurbita, gourd or passion flower, the stem is very weak and
needs support (Fig).
The thread-like structures are called the stem tendrils as these are modifications of
stem. The tendrils coil around any object in the neighbourhood and thereby help the
plant to climb up.
Tendrils
DIFFERENCES BETWEEN ROOT AND STEM
Root Stem
1. Develops from radicle.
2. Nodes and internodes absent.
3. Never green.
4. Leaves and buds absent.
1. Develops from plumule.
2. Nodes and internodes present.
3. Often green.
4. Bears leaves and buds.

8. 5. Generally develops below ground. 5. Generally develops above ground.
5. THE LEAF
A leaf is a flattened green structure. It arises from the node of a stem or its branches.
Leaves differ in shape and size.
The flat green part of a leaf is known as the leaf blade or lamina. It is attached to the
stem by means of a short stalk called the petiole
(Figure.). The region of attachment of the leaf with the stem is called the leaf base.
Structure showing parts of a leaf
The leaf blade has many fine veins forming a network throughout its body. The
arrangement of veins in the leaf blades is called venation.
Leaves contain a pigment called chlorophyll. This pigment imparts green colour to the
leaves.
Functions
(1) Leaves manufacture food for the plant body. The process of manufacturing food by
the leaves is called photosynthesis. Leaves require water, carbon dioxide, sunlight and
chlorophyll for making food.
(2) The leaves on their surfaces carry tiny pores called stomata. Through these pores,
plants take in gases for respiration and photosynthesis. The gases produced during these
processes are also given out through stomata.
(3) The plants give out extra amount of water in the plant through stomata, in the
form of vapours. This process is known as transpiration.
(4) In addition, leaves may be variably modified into spines or tendrils or modified to
trap insects.
· The largest leaf is present in Giant, Water lilly, Victoria regia, more than 1metre in
diameter.
· Flowering plant with no leaf-Dodder (Cuscuta).
· All leaves are not green. Some leaves have patches of white or yellow or red colour. Such
leaves are called
variegated leaves.
· Plants with variegated leaves – Money plant (Coleus).
Types of Leaves
(i) Simple and Compound leaves:
Try to examine the leaves of mango and neem trees. In a mango leaf, the lamina is entire

9. whereas in a neem plant, the leaf lamina is cut into small parts, called leaflets, on a
common stalk.
The leaf with a single lamina, as in mango, castor, cotton, china-rose, is called a simple
leaf
(Figure). A simple leaf has an axillary bud. The leaf in which the lamina is cut into a
number of small leaflets on a common stalk is called a compound leaf(Figure). Rose,
neem, tamarind show compound leaves. Leaflets do not bear axillary buds. The stalk of a
compound leaf is called rachis which has an axillary bud.
A simple leaf
A compound leaf
Venation
Venation found in the leaves is of two types.
(i) Reticulate and (ii) Parallel.
Reticulate venation: When the veins in the leaf lamina divide repeatedly forming a
network, it is called reticulate venation (Figure).
Examples: Dicotyledonous plants like mango, peepal show this type of venation.
Parallel venation: When the veins run parallel to each other from the base to the tip of
the lamina, it is called parallel venation (Figure).
Examples: Monocotyledonous plants like banana, wheat, palms.

10. Reticulate venation
Parallel venation
Arrangement of Leaves
The leaves are arranged in various ways on the stem. The arrangement of leaves on the
stem is called phyllotaxy. The main aim of phyllotaxy is to expose all the leaves of the
plant to maximum sunlight and air.
Three types of leaf arrangement (Figure) are commonly noticed in plants. These are:
(i) Alternate : A single leaf arises at each node and on opposite side of the previous
leaf.
Examples : Mango, sunflower.
(ii) Opposite : Two leaves arise at each node apposite to each other.
Examples :Calotropis, guava.
(iii) Whorled : More than two leaves arise at each node, and are arranged in a whorl or

11. circle.
Examples : Oleander, asparagus.
Arrangement of leaves
Modifications of Leaf
(a) In xerophytic plants like cacti, opuntia, the leaves are modified into spines (Figure.).
These spines check the loss of water from the plant body and, thus, help the plant to
conserve water.
(b) In sweet pea and pea, some leaves are modified into thin, coiled thread-like tendrils.
These help the plant in climbing.
(c) In onion, the fleshy leaves store food material.
(d) In some plants, the leaves are modified to trap insects. Such plants are called
insectivorous plants. Examples—Pitcher plant (Figure), sundew plant and bladderwort.
Leaf tendril in garden pea
Pitcher plant – the leaf modified into a pitcher

12. 6. THE FLOWER
The flower is the main reproductive organ of a plant.
Structure of A Flower
Observation:
Let us examine a flower of gulmohr to know about the structure of a flower. The flower
has a fairly long stalk. This stalk is called pedicel. Other floral parts arise at the end of
the stalk.
There are five triangular, green structures. They are slightly coloured on the inner side.
They are the sepals and form a whorl.
Flower of Gulmohr
Observe a floral bud (figure. A). In the next whorl, we find outer leafy structures of the
bud are the sepals of the flower (figure C).
Next to the sepals are five brightly coloured petals (figure D). They are the most
conspicuous part of the flower and make it attractive.
In next whorl, we find long filaments. Each filament is a part of a stamen (figure E). It has
a distinct tip with two anthers.

13. Split open an anther. We find fine yellow particles in the anther. These are the pollen
grains.
In the next whorl, we find a single elongated structure in the centre of the flower. It is
broader below and tapers at the top. This is the pistil or carpel (figure F). The lower
broader part is the ovary. Its slender elongated part is the style. The end of the style
which is sticky is the stigma.
In longitudinal section of ovary, we find whitish structures (figure G). These are
the ovules. The ovules are attached to the margin of the ovary (figure H).
Gulmohr has both male (stamens) and female (pistil) parts of the flower. It is, therefore,
a bisexual flower.
Note:
All plants do not have flowers with both stamens and carpels. Some have only stamens
and are the male flowers. Some have only pistil, and are the female flowers. Such
flowers are called unisexual flowers.
Examples: Cucumber and gourd.
Conclusions:
A flower represents the reproductive part of a plant body. It is, the most important part
meant for multiplication of the species.
Often, each flower has a stalk called the pedicel. But some flowers do lack the pedicel,
and such flowers are called sessile. Besides the stalk, a flower, in general, shows four sets
of whorls or parts arranged in rings or whorls (Figure).
Parts of a Flower
1. Calyx is the outermost whorl or set composed of green, leaf-like protective structures
called sepals.
2. Corolla is the next inner whorl composed of brightly coloured petals. Being brightly
coloured, petals attract insects for pollination.
3. Stamens are next to corolla and consist of anthers and filaments. Anthers are swollen
structures present on the tip of filaments. The anthers produce a powdery substance
consisting of tiny structures called the pollen grains. The stamens represent the male
part of a flower. Male sex cells are produced inside the pollen grains.
4. The central part of the flower is the female part, consisting of a flask-shaped organ,
called the carpel. Each carpel consists of a basal swollen part called the ovary. The ovary
continues into a long style and ends in a knob-like part, called the stigma. The ovary
contains many ovules. Female sex cell is present inside the ovule. Ovules and ovary
finally develop into seeds and fruits respectively.

14. Largest flower – Rafflesia grows in Indonesia ; nearly 1 metre in dameter.
Smallest flower – Duckweed (Wolffia); only about 0.5 millimetre in diameter.
Types of Flowers
Based on the presence of whorls, flowers can also be classified as follows:
Complete flower: A flower consisting of all the four whorls-calyx, corolla, stamens and
carpels is called a complete flower.
Examples: mustard, china-rose and pea.
Incomplete flower: In some flowers, one or more whorls may be missing. Such flowers
are called Incomplete flowers.
Examples: date palm and mulberry.
Functions of A Flower
1. Role in reproduction and multiplication:
The flower is the most important part of a plant i.e., it takes part in reproduction and
leads to the formation of seeds and fruits. Seeds on germination produce new plants.
2. Ornamental value: Flowering plants are grown in gardens and in homes because
of their bright colors and fragrance.
3. Source of food: Nectar from flowers serves as food for insects.
7. SEXUAL REPRODUCTION
In nature, sexual reproduction occurs in plants as well as in animals. It is the most
common method of reproduction. A flower is the seat of sexual reproduction in plants.
Two parents, one male, and the other female are required for sexual reproduction. Two
types of sex or reproductive cells, called gametes are produced from the reproductive
organs of two parents. The male parent produces the male gametes and the female
parent produces the female gametes.
The stamens produce pollen grains which contain the male gametes. The female
gamete is a large egg-cell produced inside the ovule.
A male gamete is usually small with a nucleus and little cytoplasm. The female gamete is
larger, with a nucleus and more cytoplasm than the male.
The fusion of the two gametes is called fertilization. The product of the fusion of the
two gametes is called the zygote.
After fertilization, the zygote undergoes cell division and growth. Ultimately, it forms the
new individual.
8. POLLINATION
Pollination is the transfer of pollen grains from the ripe anther to the stigma. The
transfer of pollen grains to the stigma can take place in two ways:
(i) Within the same flower or between flowers of the same plant.
(OR)
(ii) Between flowers from different plants of the same species.
Pollination in the first case is called self-pollination, while it is called cross-
pollination in the second case(Figure.).
Cross-pollination often involves various external agencies to carry pollen grains from one
flower to another one. These agencies may be air, water, or insects. Most flowers are
pollinated by insects.
Pollen grains of all flowers are not carried by insects. In some cases, they are carried by

15. wind (wind pollination). In the case of water plants, pollen grains are carried by water
(water pollination).
Self and Cross-pollination
DIFFERENCE BETWEEN INSECT-POLLINATED AND WIND-POLLINATED
FLOWERS
Insect-pollinated flowers Wind-pollinated flowers
1. Large and brightly-coloured
2. Nectar and scent is produced.
3. Pollen grains are sticky.
4. Pollen grains are produced in less
quantity.
1. Small and inconspicuous.
2. No nectar or scent is produced.
3. Pollen grains are dry.
4. Pollen grains are produced in large
quantity.
9. FERTILIZATION
Fertilization is a step between pollination and seed formation. The fusion of the male
gamete with the female gamete is called fertilization.
During fertilization, the following events take place:
1. The pollen grains germinate on the stigma, and pollen tubes develop.
2. The pollen tubes move downwards into the style (Figure).
3. The pollen tubes are the carriers of male gametes.
Pollen grain develops into a pollen tube carrying male gametes

16. Female gamete (egg cell) inside the ovule
Process of fertilization
2. One pollen tube finally enters the ovule, where the female gamete (egg) is located
(figure)
Female gamete or egg cell is present inside the ovule.
3. Finally the male gamete fuses with the female gamete. This completes the process of
fertilization.
10. FORMATION OF FRUIT AND SEED
Formation of Fruit and Seed
1. The flower loses its bright color.

17. 2. The sepals, petals, and stamens fall off.
3. The ovary increases in size and becomes the fruit.
4. The ovary wall becomes the fruit wall.
5. Inside the ovary, the ovules develop to form the seeds.
Types of Fruits
(i) Dry fruit: Fruits of the type of pea are called dry fruits. The fruit wall in such fruit is
thin and dry.
Examples: Cotton, lady’s finger, maize, sunflower, bean.
(ii) Fleshy fruit: On the other hand, mango fruit is a fleshy fruit, as the fruit wall is thick
and fleshy.
Examples: Tomato, brinjal, orange, coconut, plum.
Functions Of Fruits
(i) The fruit wall gives protection to the seeds and therefore to the embryo.
(ii) The fruit is a storehouse of food material.
(iii) The fruit helps in the dispersal of seeds.
Seed
A seed contains an embryo, one or two cotyledons, and a protective seed coat (Figure).
The embryo, after germination of the seed, develops into a new plant. The cotyledons
often contain reserve food material for the developing plant.
Structure of gram seed
11. STRUCTURE OF A FRUIT
The fruit is a ripened ovary formed after fertilization. The fruit consists of two parts
(i) The fruit wall (or pericarp), and(ii)Seeds.
Fruit Wall
The fruit wall develops from the wall of the ovary. It may be thick or thin. It may be dry as
in pea or gram (Figure) or fleshy as in tomato (Figure) and papaya. In fruits like mango,
the pericarp may be differentiated into three layers (Figure):
The fruit wall has three layers:
1. The outer layer called the epicarp,
2. The middle layer called the mesocarp, and
3. The inner layer called the endocarp.
Parts of a Fruit (Tomato)

18. Parts of fruit (mango)
Seeds
Seeds that develop from the ovules are present inside the fruit wall. Fruit may contain
only one seed (as in mango, plum) or many seeds, as in the case in tomato, orange,
apple.
Fruits of the type of pea are called dry fruits. The fruit wall in such fruit is thin and dry.
On the other hand, mango fruit is a fleshy fruit, as the fruit wall is thick and fleshy
Functions of a Fruit
1. It protects the seeds from animals and unfavorable climatic conditions.
2. It helps in the dispersal of seeds to distant places by means of various devices which
the fruits often develop.
12. THE SEED
A seed contains a baby plant inside. It also contains food for the new plant to develop.
More precisely, the seed consists of an embryo, one or two cotyledons, and a
protective seed coat. The embryo is represented by plumule and radicle (Figure). The
cotyledons often contain the reserve food material for the developing plant. On
germination, plumule gives rise to the shoot system while radicle gives rise to the root
system (Figure) and thus, develops a new plant.
Parts of a seed – The two cotyledons slightly separated showing the embryo plant between
them

19. Seed Germination
13. DISPERSAL OF SEEDS AND FRUITS
The plant does not move. The seeds and fruits produced by them have developed
devices that help them to be carried to faraway places. This prevents overcrowding at
one place and also leads to the spread of plants to newer places. There are three main
types of dispersal mechanism:
(i) By Wind (ii) By Water (iii) By Animals
Dispersal by Wind
Examine the seeds of a dandelion, Calotropis (Madar), Acer (maple), cotton, and pine.
Seeds of dandelion (Figure.) and cotton possess a tuft of fine hair, while in Acer and pine
(Figure), the fruits/seeds develop flat, wing-like structures.
Dandelion

20. Winged fruit of Acer
The hair or the wings help in the dispersal of seeds and fruits too long distances by wind.
Dispersal By Water
Coconut plants are grown on the seashore. The fibrous fruit falls in the water and is
carried away from the parent plant by water currents.
In the lotus, the fruit floats on the surface of the water and the seeds are liberated in
water. Water currents carry the seeds too long distances.
Dispersal By Animals
Seeds and fruits dispersed by animals are either edible or develop hooks and thorns.
Seeds of fruits like mango, orange and plum get dispersed after the fleshy part of these
fruits is eaten by humans and birds.

21. Fruit of Xanthium with spines
Fruits of gokhru (Tribulus) and okra (Xanthium) possess hooks and spines (Figure). These
fruits stick to our clothes and to the body of passing animals and then get carried away
from one place to another.
This, plants have developed various means to get their seeds and fruits carried away too
long distances.