Morphology of Flowering Plants

The morphology of flowering plants refers to their physical structure, including roots, stems, leaves, flowers, and reproductive organs. Morphology is the study of the form and structure of organisms and their parts. Understanding the morphology of flowering plants is essential as it provides insights into plant identification, classification, and function

By examining the external and internal features of plants, scientists can figure out the complex adaptations that enable plants to thrive in diverse environments. In this article, we will cover the morphology of flowering plants and their different parts in detail.

What are Flowering Plants?

Flowering plants, also known as angiosperms, are a diverse group of plants. There are approximately over 300,000 species of flowering plants on Earth. Flowering plants are characterized by the presence of flowers and seeds enclosed within a fruit. They represent the most abundant and widespread group of plants on Earth. Flowering plants include a variety of species ranging from small herbs to tall trees. Unlike non-flowering plants like ferns and mosses, flowering plants have specialized reproductive structures called flowers, which attract pollinators and facilitate sexual reproduction.

Morphology of Flowering Plants

The morphology of flowering plants shows that it is made up of two system – a root system and a shoot system. The detailed morphology of flowering plants is discussed below:

Root System of Flowering Plants

A root is the underground part of a plant that typically grows downward into the soil. The root arises from radicle. Its main functions are to anchor the plant, absorb water and nutrients from the soil, and store food reserves. The different branches of root form root system which varies in monocots and dicots. The different types of root system are:

Taproot System

This type of root system is commonly seen in dicots. The taproot system is characterized by a main root, known as the taproot, which grows vertically downward. It gives rise to smaller lateral roots. These roots provide structural support and help in the absorption of water and nutrients from deep within the soil. Example of plants with taproot system are carrot, mustard, and mango.

Also Read: Tap Root Diagram

Fibrous Root System

The fibrous root system is characterized by a network of thin, branching roots that spread out close to the soil surface. This type of root system is typical in monocotyledonous plants. Fibrous roots provide excellent anchorage and efficient absorption of water and nutrients from the soil. Example of plants with fibrous root system are grasses and cereals.

Adventitious Root System

An adventitious root system consists of roots that arise from any part of the plant other than the radicle. These roots may develop from stems, leaves, or even other roots, and they serve functions such as support, anchorage, and nutrient uptake. Adventitious roots are common in plants like ivy, mangroves, and maize.

Regions of Root 

The root has various regions:

• The root is covered with a root apex, also known as a root cap, which protects the tender apex of the root as it grows through the soil.
• The region of meristematic activity, although very small, repeatedly divides and forms the root enlargement, causing the root to grow in different directions.
• Another region is the root elongation zone, responsible for increasing the root’s length.
• The region of maturation, located at the base of the root in the ground, contains hair-like structures called root hairs, which aid in the absorption of water from the soil.

Also Read: Difference Between Radicle and Plumule

Modification of Root

In some plants, roots change their structure and shape to perform functions other than water and mineral absorption. Roots can develop from various regions of the plant, including branches, and may grow upwards into the soil. Additionally, some roots, such as carrot, turnip, and sweet potato, serve as storage organs. Also, roots play a role in respiration through various mechanisms.

Function of Root

The root functions are:

• Anchors the plant in the soil
• Absorbs water and minerals from the soil
• Stores food reserves
• Facilitates the uptake of nutrients through root hairs

Shoot System

The shoot system of a plant refers to the above-ground part of plant that is responsible for photosynthesis, reproduction, and support. It includes stems, leaves, flowers, and fruits. The shoot system plays a crucial role in the plant’s growth, development, and interaction with the environment. The shoot arises from the plumule of seed.

Stem

The stem is the ascending part of the axis bearing branches, leaves, flowers, and fruits. They have the nodes and internodes. The region where the leaves are born is called nodes and the internodes are present between the two nodes. The stem bears buds which may be terminal or axillary. The stem is generally green later it becomes the wood it turns dark brown.

Modification of Stem

Modification of stems refers to the changes in structure and function that occur in certain plants to adapt to specific environmental conditions or to perform some tasks. The modified stems help to provide protection, vegetative propagation, and other functions which helps plant survive.

Various modifications of stems include:

• Climbers
• Runners
• Suckers
• Tubers
• Rhizome
• Tendrils
• Thorns
• Cladode

Also Read: Difference Between Rhizome and Tuber

Functions of Stem

The functions of stem are:

• Supports the plant and holds up leaves, flowers, and fruits
• Transports water, nutrients, and sugars between roots and leaves
• Stores food reserves for future use
• Produces new shoots and branches through vegetative propagation
• Provides structural support for climbing plants

Leaves of Flowering Plants

The leaf is a flattened structure borne on the stem. Leaves develope at the node and bear a bud in its axil. Later, the axillary bud develops into a branch. Leaves originate from the shoot apical meristem and are arranged in an acropetal order, making them the most important vegetative organs for photosynthesis. A typical leaf consists of three main parts: the leaf base, petiole, and lamina. The leaf attaches to the stem through the leaf base and may bear two lateral small leaf-like structures called stipules.

In monocots, the leaf base expands into the sheath partially covering the stem, while in some plants, it may become swollen, known as a pulvinus. The petiole helps hold the blade to the light, while the lamina blade, green and expansive, contains veins and veinlets. Veins provide rigidity to the leaf blade and act as channels for water transport. The shape, margin, apex, surface, and extent of incisions of the lamina vary among different leaves.

Venation of leaves

The arrangement of the leaves to the veins and veinlets in the lamina of the leaf is called venation. When there is a network-like structure is called reticulate venation, and when the leaves are arranged in equal or one on each side of veins and veinlets is called parallel venation. Some trees have reticulate venation and some have parallel venation and reticulate venation mostly shows on the dicot plants and parallel venation shows on the monocot plants. 

Types of Leaves

There are two main types of leaves – simple leaf and compound leaf. The difference between them is given below:

Feature	Simple Leaves	Compound Leaves
Structure	Consist of a single leaf blade	Consist of multiple leaflets attached to a common petiole
Leaflet Presence	Not present	Present
Leaf Arrangement	Alternate, opposite, or whorled	Usually arranged in a pinnate or palmate pattern
Complexity	Less complex	More complex
Examples	Mango, guava, rose	Rosewood, mimosa, honeylocust

Inflorescence

The arrangement of flowers on the floral axis is termed an inflorescence. As the shoot apical meristem changes into the floral meristem, the flower undergoes modification. Internodes cease to elongate, and the axis becomes condensed. Floral appendages develop laterally at successive nodes instead of leaves.

When a shoot tip transforms into a flower, it remains solitary. There are two main types of inflorescence: cymose and racemose. In racemose inflorescence, the main axis continues to grow, with flowers blooming laterally in acropetal succession. Conversely, in cymose inflorescence, the main axis terminates in the flower, limiting its growth, and flowers blossom in a basipetal order.

The Flower

The flower is the reproductive unit in angiosperms, comprising of four distinct whorls arranged successively on the end of the pedicle known as the thalamus. These whorls are the calyx, corolla, androecium, and gynoecium. While the calyx and corolla serve as accessory organs, the androecium and gynoecium function as reproductive organs. In certain flowers like the lily, the calyx and corolla are distinct and collectively referred to as the perianth. When a flower possesses both androecium and gynoecium, it is termed bisexual; however, if it contains only stamens, it is considered unisexual.

Also Read: Morphology of Flower

Flowers may exhibit actinomorphy or zygomorphy.

• Actinomorphic flowers can be divided into two equal radial halves in any plane passing through the center, such as the chili flower.
• Zygomorphic flowers can only be divided into two similar halves in one particular vertical plane, exemplified by the bean flower. Floral appendages may occur in multiples of 3, 4, or 5, resulting in trimerous, tetramerous, or pentamerous configurations, respectively.

Also Read: Difference between Actinomorphic and Zygomorphic Flowers

Based on the position of the calyx, corolla, and androecium in relation to the ovary on the thalamus, flowers are categorized as hypogynous, perigynous, or epigynous.

• Calyx: The outermost whorl of the flower, consisting of sepals, may be gamosepalous or polysepalous.
• Corolla: Comprising petals, usually brightly colored to attract insects for pollination, the corolla may be gamopetalous or polypetalous.
• Androecium: Consisting of stamens, the male reproductive organs, each stamen typically comprises a filament and an anther, the latter usually bilobed with two chambers, or pollen sacs, producing pollen grains. A sterile stamen is termed a staminode.
• Gynoecium: The female reproductive part of the flower, composed of one or more carpels, each consisting of stigma, style, and ovary.

The fruit is a characteristic feature of flowering plants which develops after fertilization. If formed without fertilization, it is termed parthenocarpic. The fruit consists of a pericarp enclosing seeds, which may be dry or fleshy.

Seeds of Flowering Plants

Seeds are essential for the reproduction of plants. They contain all the necessary components for the development of a new plant.

Parts of a Seed

The various parts of the seed are:

• Seed Coat: The outer protective layer of the seed, providing mechanical protection and regulating water absorption.
• Embryo: The young plant inside the seed, consisting of the radicle, cotyledons (in dicots), or endosperm (in monocots), and plumule.
• Radicle: The embryonic root, which develops into the primary root of the new plant.
• Cotyledons: Leaf-like structures that store food reserves for the developing plant in dicot seeds.
• Endosperm: Tissue containing nutrients for the developing plant in monocot seeds.
• Plumule: The embryonic shoot, which develops into the stem and leaves of the new plant.

Structure of a Seed

The structure of seed has following:

• Seed Coat: Made up of one or more layers, the seed coat protects the embryo and regulates water and gas exchange.
• Embryo: The central part of the seed, consisting of the radicle, cotyledons or endosperm, and plumule.
• Endosperm: Present in monocot seeds, the endosperm provides nutrition to the developing embryo.
• Cotyledons: Found in dicot seeds, cotyledons store food reserves and provide nourishment to the developing embryo.

Layers of a Seed

The various layers of seed are:

• Testa: The outer layer of the seed coat, providing mechanical protection.
• Tegmen: The inner layer of the seed coat, assisting in seed dormancy and protection.
• Endosperm: Present in some seeds, providing nutrients for the developing embryo.
• Embryo: The central part of the seed, containing the radicle, cotyledons or endosperm, and plumule.

Conclusion – Morphology of Flowering Plants

In conclusion, flowering plants, or angiosperms, constitute a vast and diverse group of plants, numbering over 300,000 species worldwide. Distinguished by the presence of flowers and seeds enclosed within fruits, they are the most abundant and widespread plants on Earth, ranging from small herbs to towering trees. Unlike non-flowering plants like ferns and mosses, angiosperms possess specialized reproductive structures called flowers, essential for sexual reproduction and attracting pollinators. The morphology of flowering plants reveals a sophisticated system comprising root and shoot systems, each with distinctive adaptations and functions.

Also Read:

• Parts Of Plants, Diagram And Functions
• Sexual Reproduction in Flowering Plants Notes Class 12
• Parts of a Flower and their Functions
• Diagram of Flower
• Anatomy of Flowering Plants
• NCERT Solutions for Class 11 Biology Chapter 5: Morphology of Flowering Plants

FAQs on Morphology of Flowering Plants

Who is the Father of Morphology of Flowering Plants?

The German Botanist  Wilhelm Hofmeister is known as the Father of Plant Morphology.

What is the Morphology of Flowering Petals?

Flowering petals are typically brightly colored to attract pollinators. They may be arranged in a gamopetalous (fused) or polypetalous (separate) manner, and their shape, size, and arrangement vary among different plant species.

Define Morphology?

Morphology is the branch of science concerned with the study of organisms, structure, characteristics, and forms the flowering plants have a wide range of structural diversity that shares several common characteristics. 

What are the Regions of Root?

A root is the underground part of a plant responsible for anchoring, absorbing water and nutrients, and storing food reserves. The regions of a root include the root cap, region of meristematic activity, root elongation zone, and region of maturation.

What are the Modifications of the Stem?

Stem modifications include climbers, runners, suckers, tubers, rhizomes, tendrils, thorns, and cladodes.

Name the Floral Parts of the Flowers?

The different floral parts of the flower are Calyx,  Corolla, androecium, gynoecium.