Plant Classification

Plant Classification plays a major role in understanding the different plant structures and their lifecycle. Based on various characteristics, R.H. Whittaker classified living organisms into five kingdoms which are Monera, Protista, Fungi, Plantae, and Animalia.

The members of the kingdom Plantae show certain characteristics like they are eukaryotic, multicellular, and can perform photosynthesis. Plants can be classified based on their life cycle and other features. The division of the Plantae kingdom consists of two major categories- Cryptograms and Phanerogams. Students need to study the different divisions of plants to understand the importance of plant classification.

What is Plant Classification?

Plant classification means organising or arranging the already known plants into various groups and categories to study the evolutionary relationship between them. The entire plants on the earth come under the kingdom “Plantae”. The plant kingdom is divided into various groups based on various body characteristics.

Criteria of Plant Classification

Based on certain characteristics, the plants are classified into various subgroups. These are:

• Plant Body structure- Whether the plant body can be divided into roots, stems and leaves or not.
• Vascular system- Whether the plant body possesses a properly well-defined vascular system or not.
• Flowers and seeds- Whether the plants have flowers or not and whether the seeds are enclosed within the fruit or found naked.

Characteristics of Kingdom Plantae

The characteristics of kingdom plantae class 9 is an important concept in the biology syllabus. The plants that we find around us possess certain distinct features. They are as follows-

• Plants are eukaryotic (or possess well-defined nuclei) and multicellular organisms.
• Most of the plants are autotrophic organisms. Most of them contain chloroplast and chlorophyll and are capable of preparing their food.
• Certain plants are heterotrophic which means they can not make their food (for example- pitcher plants)
• Plants are non-motile or they are stationary which means they can not move from one place to another.
• They possess a cell wall made up of cellulose.
• Both sexual and asexual types of reproduction can be seen in plants.

Plant Classification Based on Life Cycle

Plants can also be classified into three categories based on their life cycle. They are-Annuals, Biennials and perennials.

• Annuals– These plants complete their entire life cycle within one year or season. E.g. Sunflower, rice etc.
• Biennials– These plants complete their entire life cycle in two years or seasons. E.g. Carrots, cabbages etc.
• Perennials– These plants live for many seasons or years. E.g. Mango, apple etc.

Division of Plantae Kingdom

According to the criteria, the kingdom Plantae is classified into two main categories. They are Cryptograms and Phanerograms. Cryptogams are plants or plant-like organisms that do not make seeds. They mainly reproduce with the help of spores. The cryptogams are again divided into three subgroups. They are:

• Thallophyta
• Bryophyta
• Pteridophyta

Phanerograms are plants that produce seeds. Phanerogams are again divided into two subgroups. They are-

• Gymnosperms
• Angiosperms or flowering plants

Cryptograms and Their Classification

These are simple structured organisms. Most of these organisms do not possess roots, stems or leaves. They also lack a well-developed vascular system. They can be considered as less evolved organisms.

Thallophyta

Thallophyta characteristics are organisms with a primitive and simple structured body. Their body is not differentiated into roots, stems and leaves. The structure of the body is thallus shaped and they may be colonial or branched or filamentous or unbranched in structure. They lack a well-developed vascular system. They mostly are autotrophic and can be found in wet places.

Thallophyta examples- Volvox, Spirogyra, Red algae etc.

Bryophyta

The organisms in this group are known as “Amphibians of the plant kingdom”. Because the organisms grow in the moist terrestrial region, they need water for reproduction. These plants also lack a vascular system. The plant body is not properly differentiated into roots, stems and leaves. The organisms possess ‘root-like”, “stem-like” and “leaf-like” structures.

Bryophyta examples: Mosses, Liverworts, hornworts etc.

Pteridophyta

The plants in this group exhibit properly well-differentiated body structures. Their body can be divided into roots, stems and leaves. They possess a vascular system (xylem, phloem) that helps them conduct water and minerals.

Example- Pteris, Selaginella etc.

Phanerogams and their Classification

These plants produce seeds for their reproduction. They can be considered as higher plants. Their body is well-developed and can be differentiated into roots, stems and leaves. They also possess a well-developed vascular system. These are of two types:

Gymnosperms

These plants possess a highly developed body that can be properly differentiated into roots, stems and leaves. They also have a vascular system. They contain naked seeds i.e. their seeds are not enclosed by fruits. These plants do not possess flowers. For example- Pinus, Cycas etc.

Angiosperms or Flowering Plants

Angiosperms are the most advanced flower and seed-bearing plants. Their body can be properly differentiated into roots, stems and leaves. They also have a well-developed vascular system. Their seeds are found to be enclosed by fruits. Angiosperms can be divided into two categories – Monocots ( angiosperms with only one cotyledon in their seeds) and Dicots ( angiosperms with two cotyledons in their seeds).

Importance of Plant Classification

The following points highlight the importance of plant classification:

• It helps in the correct identification, naming and grouping of a particular plant.
• Plant classification helps us to understand which plants are closely related to each other.
• It also provides us with information about primitive plants and the most evolved plants.

Conclusion: Plant Classification

Plants are vital organisms in any ecosystem. Based on certain characteristics, these plants are classified into various subgroups. Thus, plant classification gives us proper knowledge about the body structure and life cycle of a particular plant. Plant classification helps us to understand various similarities and dissimilarities between various plants and thus we can understand the evolution of plants.

FAQs on Plant Classification

What are the Five Major Classification of Plants?

The plants are mainly divided into five subgroups. They are- Thallophyta, Bryophyta, pteridophyta, Gymnosperms and Angiosperms.

Who Proposed the Term “Classification”?

The term “Classification” was given by Theophrastus. He also classified the plants based on size, use, and locality of a plant.

What are the Characters Based on Which Plants can be Classified?

Plants can be classified based on three main characters. They are presence or absence of vascular system, presence or absence of seeds and if the plant body is properly differentiated into root, stem and leaves or not.

Why are the Seven Main Types of Plants?

Plants can be of various types. The seven main types of plants are Thallophytes, Bryophytes, Pteridophytes, Gymnosperms, Angiosperms, monocots and dicot plants.

Why is Plant Classification Important?

Plant classification is important because it helps us to identify and name any plant properly. It also helps us to study the evolutionary relationship between various plants. 

Where can I Find Plant Kingdom Class 11 Notes?

You can find Plant Kingdom Class 11 notes in the article above.

What are the Different Systems of Plant Classification?

The different systems of plant classification include the Linnaean system, the Cronquist system, and the APG system, each organizing plants based on various criteria such as morphological characteristics, evolutionary relationships, and genetic similarities.