Plants are very useful to us. We get oxygen, food and almost all the basic needs of plants. so our topic is parts of a flower. As you know there are many kinds of plants around us.
Some of them bear flowers and some do not.
The plants like mustard, sunflower, pea, lily, marigold, mango, rose, etc bear flowers.
The body of flowering plants consists of two distinct parts.
They are root system and shoot system.
The part of plants that remains underground except those vegetables, fruits, and nuts that grow inside the soil is called root.
The root anchors the plant to the soil.
There are two types of a root system. They are taproot and fibrous root.
The main part of the taproot that grows deep into the soil is a primary root. The primary root gives many branches called secondary roots and in turn tertiary roots.
The fine branches of the tertiary roots are rootlets.
The tip of the rootlet is soft and delicate which is covered by a root cap.
Behind the tip, there are a large number of hair-like outgrowths root hairs.
Example: a mustard plant.
Fibrous Root System
In this system, all the roots are generated directly from the stem.
They do not have primary, secondary and tertiary roots.
This type of root does not occur very deep in the ground. The roots are present in the form of a cluster. Such roots do not have a root cap.
Examples: wheat, maize, rice, etc.
The stem along with its branches, leaves, flowers, and fruits is called the shoot system.
Usually, it grows vertically above the soil.
Based on the functions, the shoot system consists of two types of organs. They are vegetative organs and reproductive organs.
The stem, branches, and leaves are the vegetative organs of the shoot system of a plant.
The stem is said to be the main axis of the shoot system. It is the aerial part that develops from the plumule of the embryo of a seed. It bears lateral branches.
The lower part of the stem is thick and gradually thinner towards the apex.
The stem has swollen points called nodes.
Branches and leaves arise from the nodes.
The part of the stem between two nodes is known as the internode.
Buds are condensed stems and are found at different parts of a stem.
On the basis of their position on the plant, buds are classified into two types.
axillary buds and terminal buds.
Axillary buds are borne in the axil of leaves.
They uplift either branches or flowers.
Terminal buds are present at the apex that
of the stem and branches. They help to increase the height of the plant.
Functions of Stem
The functions of stem are:
1. The stem helps the plants to stand upright.
It supports the leaves and the branches.
2. It conducts water and minerals through the xylem from the root to the leaves for photosynthesis.
3. It also supplies food through the phloem from the leaves to different parts of the plant after photosynthesis.
4. It helps in asexual reproduction in some plants like a rose.
5. The stem stores water in desert plants.
6. They have lenticels for respiration and transportation.
The Leave – as parts of a flower
A leaf is a thin, flattened, lateral outgrowth of a plant. Leaves are borne on the nodes of the stem.
They are green in color just because of the presence of chlorophyll
A typical leaf consists of three parts:
leaf base, petiole and leaf blade.
Leaf Base – as parts of a flower
A leaf base is the lowermost part of a leaf. It connects the leaf to the node of the stem.
In some dicotyledonous plants like pea, the leaf base bears lateral outgrowth called stipules.
Petiole – as parts of a flower
A petiole is a stalk between the Base and the blade of the leaf.
A leaf with a petiole is a petiolate leaf.
If the petiole is absent in a leaf, it is known to be sessile.
Usually, leaves are sessile in monocotyledonous plants like maize.
Leaf Blade – as parts of a flower
The leaf blade is also called lamina. It is flattened, expanded green part of the leaf.
There is a midrib in the middle of the leaf blade running from its base to the apex. It gives rise to
a number of lateral veins.
These veins further form a network of the veinlets on the leaf blade.
The arrangement of veins and veinlets in the leaf blade is called venation.
The venation of leaf is classified into two types.
They are reticulate venation and parallel venation.
The arrangement of veins in a net-like form in the leaf blade is called a reticulate venation.
This type of venation is present in the dicotyledonous plants like peepal, mustard,
china rose, etc.
The arrangement of veins is more or less parallel to one another in the leaf blade that is parallel venation.
It is found in the leaves of the monocotyledonous plants like maize, banana, bamboo, etc.
Those parts of a plant that either help in sexual reproduction or are the products of sexual reproduction are called reproductive organs.
They are flowers, fruits, and seeds.
The flower is the reproductive organ of flowering plants. All the flowers develop from floral buds. The flower has a stalk pedicel, by which it is attached to the stem. The flower with a pedicel is a pedicellate flower e.g. hibiscus, rose, etc.
The flower without a pedicel is sessile flower e.g. sunflower, marigold, etc.
Parts of flower
As we have already seen many flowers, so we know that there are some parts of the flower.
They are the calyx, corolla, androecium, gynoecium.
The outermost whorl of a flower is called calyx.
Calyx is usually green in colour.
It protects the inner floral organs during the bud stage.
The calyx is made up of many sepals which may be free or united.
The flowers with free sepals are polysepalous flowers e.g. mustard.
The flowers having united sepals are gamosepalous flowers e.g. pea.
The second whorl of the flower is corolla.
It is made up of many petals.
The unit structure of corolla is a petal.
Usually, corolla is prominent showy and brighty coloured part of a flower.
The number of petals and sepals are same in a flower.
In some flowers, petals are joined while in other flowers, they are free from each other.
Like calyx, the corolla consists of free or united sepals .
The flowers with free petals are polypetalous flowers.
The flowers with the united petals are gamopetalous flowers.
The bright color and strong scent of the petals of the corolla attracts the insects for pollination.
The androecium is the third whorl of a flower present just inside the petals.
The androecium is the male reproductive part of the flower.
stamen is the unit structure of androecium.
It consists of free or united stamens.
A stamen consists of two parts: a thin stalk-like structure called filament and a bilobed anther at the tip of the filament.
A number of pollen grains are produced within the anther.
The pollen grains from male reproductive cells
or male gametes.
These gametes take part in sexual reproduction.
A gynoecium or pistil is present centrally in a flower.
The gynoecium is the female reproductive part of a flower.
The gynoecium consists of one or more carpels.
If the carpels are more then one, they may be free or united.
The pistil (gynoecium) is a flask-shaped structure.
It consists of three parts.
They are ovary, style, and stigma.
The basal swollen or cylindrical part of the pistil is an ovary.
. The ovary contains one or many outgrowths called ovules.
The ovules form the female reproductive cell or female gamete in it.
The female gamete takes part in sexual reproduction.
The style is a long, thread-like structure attaches to the ovary.
The stigma is the terminal part of the gynoecium (pistil).
Its shape is either bilob or feathery.
The stigma helps to receive the pollen grains during pollination.
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