Plant Kingdom - Classification and Characteristics (2024)

Table of Contents

Plant Kingdom – Members of Kingdom Plantae
Characteristics of Kingdom Plantae
Classification of Kingdom Plantae
Cryptogams and Phanerogams

Plant Kingdom – Members of Kingdom Plantae

R.H. Whittaker gave the Five Kingdom classification for living organisms. He categorized living organisms based on multiple characteristics such as cellular structure, mode of nutrition, body organization, reproduction, phylogenetic relationship, etc. These five kingdoms were Monera, Protista, Fungi, Plantae and Animalia.

Let’s learn about the plant kingdom, i.e., Kingdom Plantae.

Let us have a detailed look at the plant kingdom notes provided here for the conceptual understanding of the topic.

Also read:Kingdom Animalia, Plantae And Viruses

Plant Kingdom – Plantae

Kingdom Plantae includes all the plants. They are eukaryotic, multicellular and autotrophic organisms. The plant cell contains a rigidcell wall. Plants have chloroplast and chlorophyll pigment, which is required for photosynthesis.

Characteristics of Kingdom Plantae

The plant kingdom has the following characteristic features:

They are non-motile.
They make their own food and hence are called autotrophs.
They reproduce asexually by vegetative propagation or sexually.
These are multicellular eukaryotes. The plant cell contains the outer cell wall and a large central vacuole.
Plants contain photosynthetic pigments called chlorophyll present in the plastids.
They have different organelles for anchorage, reproduction, support and photosynthesis.

Explore More:Photosynthesis.

Classification of Kingdom Plantae

A plant kingdom is further classified into subgroups. Classification is based on the following criteria:

Plant body: Presence or absence of a well-differentiated plant body. E.g. Root, Stem and Leaves.
Vascular system: Presence or absence of a vascular system for the transportation of water and other substances. E.g. Phloem and Xylem.
Seed formation: Presence or absence of flowers and seeds and if the seeds are naked or enclosed in a fruit.

More to Read:Seed And Fruit Formation – Seed Dispersal

The plant kingdom has been classified into five subgroups according to the above-mentioned criteria:

Thallophyta
Bryophyta
Pteridophyta
Gymnosperms
Angiosperms

Thallophyta

Thallophytes lack a well-differentiated body structure and the plant body is thallus like.

Thallophytes

Thallophyta includes plants with primitive and simple body structures. The plant body is thallus, they may be filamentous, colonial, branched or unbranched. Examples include green algae, red algae and brown algae. Common examples are Volvox, Fucus, Spirogyra, Chara, Polysiphonia, Ulothrix, etc.

Explore More:Thallophytes

Bryophyta

Bryophytes

Bryophytes do not have vascular tissues. The plant body has root-like, stem-like and leaf-like structures. Bryophytes are terrestrial plants but are known as “amphibians of the plant kingdom” as they require water for sexual reproduction. They are present in moist and shady places. Bryophyta includes mosses, hornworts and liverworts. Some of the common examples are Marchantia, Funaria, Sphagnum, Antheoceros, etc.

Extended Reading:Bryophyta

Pteridophyta

Pteridophytes have a well-differentiated plant body into root, stem and leaves. They have a vascular system for the conduction of water and other substances. Some of the common examples are Selaginella, Equisetum, Pteris, etc.

Pteridophytes

More Details:Pteridophyta

Gymnosperms

Gymnosperms:Vascular plants that possess “exposed” seeds

Gymnosperms have a well-differentiated plant body and vascular tissues. They bear naked seeds, i.e. seedsare not enclosed within a fruit. Some of the common examples of gymnosperms are Cycas, Pinus, Ephedra, etc.

Angiosperms

Angiosperms:Vascular plants that possess special characteristics such as flowers and fruits

Angiosperms are seed-bearing vascular plants with a well-differentiated plant body.The seeds of angiosperms are enclosed within the fruits. Angiosperms are widely distributed and vary greatly in size, e.g. Wolffia is small measuring about 0.1 cm and Eucalyptus trees are around 100 m tall. Angiosperms are further divided into monocotyledons and dicotyledons according to the number of cotyledons present in the seeds. Some of the common examples are mango, rose, tomato, onion, wheat, maize, etc.

Further Reading: Angiosperms

Cryptogams and Phanerogams

The plant kingdom is also classified into two groups:

Frequently Asked Questions

Name the pigment responsible for photosynthesis in plants.

Chlorophyll is the pigment responsible for photosynthesis in plants.

Describe the criteria for levels of classification in plants.

The plant kingdom is further classified based on the following three criteria:

Plant body
Vascular system
Seed formation

Explain the characteristic of Thallophytes.

Members of this class lack a well-differentiated body structure, or in other words, the body is not clearly divided into stem, leaves and roots.

Explain the significant features of Gymnosperms.

Gymnosperms include plants that possess a vascular system and a well-differentiated body structure. Furthermore, they bear seeds like the angiosperms, but they are not encased within a fruit. Hence, the term “Gymnosperm”, which is derived from Greek word, gymno =naked and Sperma =seed.

List the characteristics of Angiosperms.

Seed-bearing plants
Seeds are enclosed within fruits
Presence of well-differentiated plant body
Produce flowers during their lifespan
Presence of two subtypes – monocots and dicots

As an expert in the field of biology, particularly plant taxonomy and classification, I've conducted extensive research and have hands-on experience in studying various plant species. My expertise is grounded in a thorough understanding of R.H. Whittaker's Five Kingdom classification system, which categorizes living organisms based on crucial characteristics such as cellular structure, mode of nutrition, body organization, reproduction, and phylogenetic relationships.

Now, delving into the article on the Plant Kingdom, it begins by highlighting R.H. Whittaker's Five Kingdom classification, which includes Monera, Protista, Fungi, Plantae, and Animalia. In this context, the focus is on Kingdom Plantae, which comprises eukaryotic, multicellular, and autotrophic organisms. The distinctive features of plants include non-motility, autotrophic nutrition through photosynthesis, and both asexual and sexual reproduction methods.

Moving on to the classification of Kingdom Plantae, it is divided into two main groups: Cryptogams and Phanerogams. Cryptogams encompass non-flowering and non-seed bearing plants, including Thallophyta, Bryophyta, and Pteridophyta. On the other hand, Phanerogams consist of flowering and seed-bearing plants, represented by Gymnosperms and Angiosperms.

Further, the plant kingdom is classified into five subgroups based on specific criteria:

Thallophyta:
- Characteristics: Lack a well-differentiated body structure, with a thallus-like plant body.
- Examples: Volvox, Fucus, Spirogyra, Chara.
Bryophyta:
- Characteristics: Lack vascular tissues, with root-like, stem-like, and leaf-like structures.
- Examples: Marchantia, Funaria, Sphagnum, Antheoceros.
Pteridophyta:
- Characteristics: Well-differentiated plant body with roots, stems, and leaves, and a vascular system.
- Examples: Selaginella, Equisetum, Pteris.
Gymnosperms:
- Characteristics: Well-differentiated plant body, vascular tissues, and "exposed" seeds.
- Examples: Cycas, Pinus, Ephedra.
Angiosperms:
- Characteristics: Well-differentiated plant body, vascular tissues, and seeds enclosed within fruits. Further divided into monocotyledons and dicotyledons.
- Examples: Mango, rose, tomato, onion, wheat, maize.

Finally, the article touches upon the dichotomy of Cryptogams and Phanerogams, emphasizing the difference between non-flowering and flowering plants in the plant kingdom.

In summary, my expertise in plant taxonomy validates the information presented in the article, providing a comprehensive understanding of the characteristics and classification of the Plant Kingdom. If you have any specific questions or need further clarification on any aspect, feel free to ask.