What is the Morphology of Flowering Plants?
In biology, the morphology of flowering plants focuses on the external form and structure of angiosperms—the most diverse group of land plants. Comprising around 300,000 species, they produce seeds enclosed within fruits. Their evolution dates back millions of years, diverging from gymnosperms.
Morphological studies help us understand how different parts of a plant—root system, shoot system, leaves, flowers, fruits, and seeds—are organised, function, and adapt to various ecological niches. In simpler terms, morphology reveals the “build” of a plant and how each part contributes to its survival and reproduction.
Root System
A plant’s root system is the underground structure primarily responsible for anchoring the plant, absorbing water and nutrients, and sometimes storing food. Roots can be brownish, non-photosynthetic, and typically develop from the radicle of a seed. Broadly, there are three types of root systems:
Taproot System
Found mostly in dicotyledons (e.g. mustard, mango, gram, banyan).
Originates directly from the radicle, developing one main primary root with secondary lateral branches.
Often penetrates deeply into the soil.
Fibrous Root System
Common in monocotyledons (e.g. wheat, paddy, grass) and ferns.
Comprises numerous thin, thread-like roots that form a dense, shallow network.
Offers a “mat-like” appearance on the top layer of soil, helping prevent soil erosion.
Adventitious Root System
These roots arise from parts of the plant other than the radicle (e.g. stems, leaves).
Seen in many monocotyledons such as maize and some other plants like banyan (for aerial prop roots).
Often serve specialised functions—extra support, vegetative propagation, storage, etc.
Main Functions of Roots
Anchorage of the plant in the soil.
Absorption of water and minerals.
Storage of reserve food (in some species).
Regions of a Typical Root
Root Cap: A protective covering at the root tip.
Region of Elongation: Area behind the root cap where cells rapidly increase in length.
Region of Maturation: Cells differentiate into specialised tissues here.
(For further reading, explore our Root Modifications article.)
Shoot System
The shoot system includes the stem and its branches, leaves, flowers, and fruits. It develops from the plumule of the germinating seed and typically grows upward, exposed to light. Young stems are often green and photosynthetic, later becoming woody in many species.
Characteristics of the Stem
Arises from the plumule and epicotyl of the embryo.
Shows distinct nodes (where leaves and branches arise) and internodes (the segments between nodes).
Usually grows vertically and bears buds, leaves, flowers, and fruits.
In many flowering plants, it becomes woody, lending structural support.
Different Forms of the Stem
Stems can undergo various modifications to assist in climbing, storage, reproduction, and protection. Commonly modified stems include tubers (potato), rhizomes (ginger), suckers, runners (stolon), tendrils, thorns, and cladodes.
(For more details, check out our Modifications of Stem resource.)
Leaf
Leaves are laterally borne, flattened structures primarily responsible for photosynthesis. They usually emerge from nodes on the stem and contain chlorophyll, enabling plants to convert sunlight into chemical energy. Leaves also facilitate gaseous exchange (through stomata) and transpiration.
Main Parts of a Leaf
Leaf Base: The part by which the leaf attaches to the stem.
Petiole: The stalk that supports the leaf blade.
Lamina (Leaf Blade): The flattened portion, containing veins and veinlets.
Leaves can be:
Simple: With a single undivided lamina.
Compound: Where the leaf blade is divided into distinct leaflets.
Important Leaf Characteristics
Emerges from nodes.
Limited growth (unlike the stem).
No apical bud at the tip.
Presence of stomata for gaseous exchange.
Leaf Modifications
Leaves may transform into tendrils (for climbing), spines (for protection), fleshy storage leaves (e.g. onion), and even insect-catching traps (e.g. pitcher plant).
(You can also explore the Morphology of Leaves to understand venation, phyllotaxy, and more.)
Flowers
Flowers are the reproductive organs of angiosperms. They consist of four main whorls:
Calyx (Sepals)
Corolla (Petals)
Androecium (Stamens)
Gynoecium (Carpels/Pistil)
The placement of flowers on the floral axis is called the inflorescence. Two main types are:
Racemose: The main axis continues to grow and produces lateral flowers.
Cymose: The main axis ends in a flower.
Pollination involves transferring pollen grains from the male stamen (anther) to the female stigma, leading to fertilisation and seed formation.
Functions of Flowers
Facilitate sexual reproduction in plants.
Often assists with pollinator attraction (insects, birds, etc.).
House the gametophytes that fuse to form seeds.
The fertilised ovary eventually develops into a fruit.
Fruits
A fruit generally develops from a fertilised ovary and encloses the seeds. However, certain fruits (called parthenocarpic fruits) can form without fertilisation.
Types of Fruits
Simple Fruits: Develop from a single ovary (monocarpellary) or a fused multicarpellary syncarpous ovary (e.g. mango, tomato).
Aggregate Fruits: Form from a multi-carpellary apocarpous ovary—multiple carpels in a single flower, each developing into a fruitlet (e.g. strawberries).
Composite Fruits: Develop from an entire inflorescence rather than a single flower (e.g.
Seeds
A seed encloses the plant embryo and stores nutrients. It is surrounded by a seed coat for protection. As the ovule develops into a seed, the ovary wall (pericarp) matures into the fruit wall.
Types of Seeds
Monocotyledonous Seeds (Monocots)
One cotyledon.
Examples: wheat, rice, corn, onion, millet.
Dicotyledonous Seeds (Dicots)
Two cotyledons.
Examples: peas, beans, peanuts, tomatoes.
Unique Additions for Better Learning
Handy Mnemonic for Floral Whorls
Remember the four floral whorls with the mnemonic “SCPA”:
Sepals (Calyx)
Corolla (Petals)
Pollen-bearing structures (Androecium)
Any female part (Gynoecium)
Quick Quiz on Morphology of Flowering Plants
Which type of root system is typical of monocots?
A. Taproot
B. Fibrous root
C. Adventitious root
D. Both A and C
Identify the part of the stem responsible for producing branches and leaves.
A. Node
B. Internode
C. Apical meristem
D. Root cap
In which part of the plant does photosynthesis primarily occur?
A. Stem
B. Root
C. Leaf
D. Flower
Quiz Answers
B
A
C
Practical Tip: Observe Plants at Home
Pull out a small weed (with permission!) to see if it has a taproot or fibrous root system.
Look for any stem modifications like thorns on rose stems or tendrils on peas.
Examine leaves under a magnifying glass to observe veins and stomata.
For more insights, visit our
FAQs on Morphology of Flowering Plants: A Complete In-Depth Guide
1. What are the main parts of a flowering plant that we study in its morphology?
In the morphology of flowering plants, we study the external structures, which are divided into two main systems. The part below the ground is the root system, and the part above the ground is the shoot system. The shoot system consists of the stem, leaves, flowers, and fruits.
2. Why do some plants have taproots while others have fibrous roots?
This difference is mainly seen between dicots and monocots. Taproots are common in dicot plants (like mustard) and feature a single main root that grows deep to anchor the plant and store food. Fibrous roots, found in monocot plants (like wheat), are a bushy network of thin roots that spread out near the surface, helping in rapid water absorption and preventing soil erosion.
3. What is the difference between a root and a stem?
The simplest way to tell them apart is that a stem has nodes (points where leaves grow) and internodes (the space between two nodes), which roots lack. Stems also possess buds. In contrast, a root is primarily for anchorage and absorption and typically has a protective root cap at its tip but no nodes or leaves.
4. How can you tell if a leaf is simple or compound?
You can identify it by looking for the axillary bud. A simple leaf has a single, undivided blade with an axillary bud at its base where it joins the stem. A compound leaf has a blade that is divided into several smaller leaflets. However, only the entire leaf structure has an axillary bud at its base; the individual leaflets do not.
5. What is the main purpose of aestivation in a flower?
Aestivation refers to the way sepals or petals are arranged in a floral bud. Its primary function is to protect the inner reproductive parts of the flower before it blooms. The specific type of aestivation, such as valvate or twisted, is also a key feature used by botanists to identify and classify plant species.
6. Why are some floral parts called 'accessory' while others are 'essential'?
This is based on their direct role in plant reproduction.
- The essential organs are the androecium (male part) and gynoecium (female part) because they are directly required for fertilisation and seed formation.
- The accessory organs, like the calyx (sepals) and corolla (petals), are not directly involved in reproduction. Instead, they help by protecting the bud and attracting pollinators.
7. How does a true fruit differ from a false fruit?
The key difference is the floral part from which they develop. A true fruit develops only from the ovary of the flower after fertilisation, like a mango. A false fruit, such as an apple or strawberry, develops from the ovary along with other floral parts like the thalamus.
8. What is the basic difference between a monocot and a dicot seed?
The most fundamental difference is the number of embryonic leaves, called cotyledons. A monocot seed (e.g., maize) contains only one cotyledon. A dicot seed (e.g., bean) contains two cotyledons, which often store food for the developing embryo.
