Morphology Of Flowering Plants

Morphology of flowering plants is the study of their external structures, including roots, stems, leaves, and reproductive organs, to understand their form and function. Roots anchor the plant and absorb water and nutrients. There are three types of root systems: tap root, fibrous root System, and adventitious root System. Stems provide support and facilitate the transport of water and nutrients. Stem exhibits different modifications like runners, suckers, climbers, and cladode. Leaves are the primary sites for photosynthesis and gas exchange. Flowers form the reproductive structures of the plant. In the flower the process of fertilisation takes place, involving the fusion of male and female gametes, ultimately leading to the formation of seeds within the fruit.

Flowering Plants

Flowering plants, or angiosperms, constitute a diverse group of plants characterized by the presence of flowers and enclosed seeds. They are believed to have evolved in the Triassic period and over 300,000 species are known. Flowers are the reproductive structure in plants that facilitate pollination. In the process of pollination, pollen grain transfer from the anther of male flowers to the stigma of the female flower. Here the process of fertilization takes place that results in the formation of fruit and within it, the seed is formed. Angiosperms exhibit various life cycles, including annuals, biennials, and perennials.

In studying the Morphology of flowering plants, a plant has two systems root system and shoot system. Root forms the underground part and the shoot is present above the ground.

Morphology of Flowering Plant

Root System

The root is the part of the plant that grows under the ground. The primary root, also known as the taproot, emerges from the seed during germination. It serves as the main axis of the root system and provides structural support while absorbing water and nutrients from the soil. The root is the brown, non-green, and inner part of a plant. The root with its branches is collectively called the root system. There are three types of root systems. 

• Taproot System 
• Fibrous root System
• Adventitious root System

Taproot System

The taproot system is mainly present in dicotyledonous plants. It develops from the root of the germinated seed with its first roots and branches giving rise to the root system. Mustard seeds, mango, gram, and banyan are some examples of cotyledon plants that have root systems.

Modification of Taproot 

• The Conical Root: This root is narrow from above and thin from below. Such as- Carrot
• The Fusiform Root: This root is swollen from the middle and thin on both sides below. Such as Raphanus sativus
• The Napiform Root: The outer part of this type of root is inflated like a pitcher and the lower part of this root is thin. 

Fibrous Root System

The fibrous root is present mainly in ferns and all monocotyledonous plants. This type of root developed from thin, medium-branching roots or primary roots growing from the stem. The fibrous root system usually does not penetrate deep into the soil, therefore, at full maturity, these roots look like a mat or carpet on the floor. One or more examples of monocot plants having fibrous root systems are wheat, paddy, grass, carrot, onion, and grass.

Adventitious Root System

Roots arising from any part of the plant body other than the radicle are called adventitious root systems. This root system is mainly present in all monocot plants. In plants, adventitious root systems are used for various purposes, such as mechanical support, vegetative propagation, etc. Banyan trees, maize, oak trees, and horsetails are some examples of monocotyledonous plants with adventitious root systems.

Modification of Adventitious Root

Tuberous Or Fasciculated: When food is reserved in the roots, they are inflated and form clusters like in sweet potato
Glandular: When the ends of the roots swell, they are called glandular roots like in melilots

Function of Roots

The functions of the roots are as follows:

1. Roots anchor the plant in the soil, providing stability.
2. They absorb water and minerals from the soil, supporting plant hydration and nutrition.
3. Knots in leguminous plant roots house nitrogen-fixing bacteria, aiding in nutrient cycling.
4. Roots of floating plants help maintain buoyancy and balance in aquatic environments.
5. Certain roots function as suckers, enabling vegetative reproduction and spread.
6. Roots synthesize the growth regulator cytokinin, influencing plant growth and development.

Regions of Root

The three important parts of root are:

1. Root Cap
2. Region of Maturation
3. Region of Elongation

Shoot System

The stem is the ascending part of a plant axis and consists of branches, leaves, and fruits, leaves and helps in the process of conduction of water and minerals. It is known to be the aerial part of a plant, which is developed from the plumule of an embryo or from the germinating seeds. The color of young stems is green in color and subsequently turns woody as well as brown. According to the functions which is performed by the stems, they are modified accordingly.

Stem

Stems are central supporting structures in plants, providing a framework for leaves, flowers, and fruits. They transport water, nutrients, and sugars between roots and leaves through vascular tissues. Stems can be herbaceous or woody, with herbaceous stems being soft and flexible, while woody stems are rigid and contain secondary growth. Buds on stems give rise to new shoots, leaves, or flowers, contributing to the plant’s growth and development. Stems also play a role in photosynthesis, with green stems capable of producing energy through this process.

Features of Stem

Features of the stem are as follows:

1. The stem originates from the plumule and epicotyl of the embryo during germination.
2. It grows erect, away from the soil, responds to light for photosynthesis.
3. The stem typically possesses a terminal bud at its apex, contributing to vertical growth.
4. Angiosperm shoots are organized into nodes, where leaves or branches attach.
5. Young stems are green and photosynthetic, contributing to the plant’s energy production.
6. Multicellular hairs can be present on the stem, aiding in various functions such as protection and water retention.
7. Mature stems and branches bear fruits and flowers, essential for reproduction and the plant’s life cycle.

Modification of Stems

The stem is modified into the following different forms:

1. Runners
2. Suckers
3. Climbers
4. Cladode
5. Tendrils
6. Rhizome
7. Thorns

Leaves

Leaves are the main photosynthetic organs of plants, containing chlorophyll for capturing sunlight. They typically arise from nodes on stems and branches, optimizing exposure to light. It absorbs light and helps in the exchange of gases through stomata. The important parts of the leaf include the leaf base, petiole, and lamina. They grow at the node and bear a bud on the axilla. The maintenance of veins and veinlets in a leaf is also known as venation. Leaves are green due to the presence of a photosynthetic pigment called chlorophyll and have a small pore called stomata, where gaseous exchange takes place. The leaves can be further classified into simple and compound leaves, which are based on the pattern of the leaf blades. There are other types of leaves and they are classified on the basis of their size, arrangement of leaves, and location.

Characteristics of Leaves

The characteristics of leaves are as follows:

• The leaf arises from the node.
• Leaves are exogenous in origin.
• It has a bud at its axis.
• The growth of the leaf is limited.
• The leaves don’t bear an apical bud.

Modifications of Leaves

The leaves are modified according to the function performed. The different structural forms of leaves include:

1. Spines
2. Leaf Tendrils
3. Storage Leaves
4. Insect-catching leaves

Functions of Leaves

The important functions performed by leaves are as follows-

1. Transpiration
2. Photosynthesis
3. Storage
4. Defence
5. Guttation

Flowers

Flowers serve as the reproductive structures of plants, that facilitates pollination and seed production. The arrangement of flowers on the floral axis is termed inflorescence. There are two main types: racemose, where the main axis continues to grow, and cymose, where the main axis terminates in a flower. A typical flower consists of four whorls

• Calyx: It is the outermost whorl, that consists of sepals which protect the developing flower bud.
• Corolla: It is the second whorl which consists of petals and attract pollinators.
• Androecium: It is the third whorl which contains the stamens with pollen-producing anthers.
• Gynoecium: It is the innermost whorl which comprises the female reproductive structures. It includes the ovary, style, and stigma.

Reproduction in plants occurs through the process of pollination.This is the transfer of pollen, containing male gametes, from the anther of one flower to the stigma of the same or a different flower.

Functions of Flowers

The flower performs some important functions:

1. Flowers support the process of plant reproduction.
2. Some plants create diaspores without fertilization, a form of asexual reproduction that contributes to genetic diversity.
3. Gametophytes, the reproductive structures of plants, grow inside the flower, where male and female gametes are produced.
4. Flowers attract insects and birds, serving as intermediaries for pollen transfer from one flower’s anther to another flower’s stigma, an important step in sexual reproduction.
5. The ovary of the flower develops into a fruit, enclosing the seeds. This process is vital for dispersal and germination, ensuring the survival and spread of plant offspring.

Fruits

The fruit is the special feature of flowering plants, which is a ripe or mature ovary and the seed is the one that develops into the ovule after fertilization. A fruit that develops without fertilization is called parthenocarpy.

Types of Fruits

There are three different types of fruits and are primarily grouped on the basis of the way they develop.

• Simple: They grow from the monocarpellary ovary or multicarpellary syncarpous ovary. 
• Aggregate: Grow from the multi-carpellary apocarpous ovary.
• Composite: These are false fruits, developed from the entire inflorescence rather than from a single flower.

Seed

The seed is the root part of a plant, which is found enclosed within the fruit. It is composed of a seed coat and an embryo. The wall of the ovary becomes the pericarp during the development of the fruit. In some plants, the ovary wall dries up completely, while in some it remains fleshy.

Types of Seeds

On the basis of the number of cotyledons, the seeds are further classified into two types – dicot and monocotyledonous seeds.

• Monocotyledonous— The embryo has an embryonic axis and contains only one cotyledon. Cereals, including rice, millet, wheat, and other plants such as onions, maize, ginger, bananas, and palm trees, are examples of monocot seeds.
• Dicotyledonous—  The embryo has an embryonic axis and contains two cotyledons. Legumes including beans, lentils, peas, peanuts, and tomatoes are examples of dicot seeds.

FAQs – Morphology Of Flowering Plants

What is the Morphology of Flowering Plants?

The morphology of flowering plants is the branch of science that studies their different structures such as leaves, roots, stems, and reproductive organs i.e flower. It help in uderstanding the form and function of the flower.

Why is Flower Morphology Important?

Flower morphology is important for understanding plant reproduction, and how it influences pollination process and seed formation. It helps in plant identification and classification and provides insights into its evolutionary patterns and ecological relationships.

What are the Basics of Flower Morphology?

Flower morphology consists of the study of a flower’s different parts: androecium, gynoecium, calyx, and corolla. The variation and arrangement of these parts contribute to the classification and diversity of flowering plants.

Write the Difference Between Monocots and Dicot Seeds.

Monocot seeds have a single cotyledon floral parts in multiples of three and parallel venation, and Dicot seeds have two cotyledons, floral parts in multiples of four or five and reticulate venation.

Name Different Types of the Root System with Examples.

Fibrous root systems consist of thin, branching roots of similar size such as in grasses. Taproot systems have a main, central root with smaller lateral roots such as in carrots.