Classification of Kingdom Plantae

Here is the classification of the plant kingdom basis on the given criteria:-

Thallophytes

Algae is the sole member of the division Thallophyta. These are simple, autotrophic and are mostly found in aquatic habitats. Following are some of its characteristics:

1. They are found in colonial or filamentous form. One of them called kelp is capable of forming massive plant bodies.
2. Asexual reproduction occurs via zoospores, which are motile in nature.
3. Vegetative reproduction occurs via Fragmentation.
4. Sexual reproduction occurs via fusion of two gametes. It can be Isogamous or Anisogamous.
5. Their major role includes carbon dioxide fixation and also act as primary prouducers of energy rich compounds.
6. Based on the pigment present in them they are further classified as Chlorophyceae, Rhodophyceae and Phaeophyceae.
7. Some examples are Volvox, Ectocarpus, Red algae, Chalmydomonas, etc.

Bryophytes

Bryophytes are called amphibians of the plant kingdom because they require water for fertilization. These include mosses and Liverworts. Some of its characteristics are:

1. They lack true roots, stem or leaves.
2. The main plant body is haploid and is called gametophyte.
3. The male and female sex organs are different.
4. The male sex organ is called antheridium and the female sex organ is called archegonium.
5. The zygote produced is called the sporophyte which remains attached to the main plant body.
6. Some of the cells of sporophyte undergo meiosis to produce spores.
7. Some examples are Sphagnum, Marchantia,Funaria, etc.

Pteridophytes

Pteridophytes are known as the snake in the Botanical world. They are the first land plants with a vascular system. They are used for both medicinal and ornamental purposes. Some of its characteristics are:

1. They are found in shady areas.
2. Horsetails and Ferns are the dominant species in this division.
3. They possess true, root, stems and leaves
4. Sporophytic stage is the dominant phase.
5. The spores germinate to give rise to gametohytic body known as prothallus.
6. Some examples are Salvinia, Selaginella, Equisetum, etc.
7. These are further classified into our classes- Psilopsida, Lycopsida,Sphenopsida and Pteropsida.

Gymnosperms

Gymnosperms are naked-seeded plants. The plants are woody, perennial, and range from tall trees to dwarf shrubs. Some of its characteristics are:

1. They have a well differentiated plant body and vascular system.
2. In these plants, the ovules are not enclosed within an ovary wall and remain exposed.
3. Medium size trees and shrubs fall in this category.
4. Roots with associations like Mycorrhiza and collaroid roots are present.
5. The leaves are needle like in conifers, which help reduce surface area.
6. Gymnosperms are heterosporous.
7. Some examples are Pinus, Ginkgo,Cycas, etc.

Angiosperms

Angiosperms are highly developed and the most advanced plants in the plant kingdom. They are plants with sporophytes organized into flowers. Some of its characteristics are:

1. The seeds are enclosed within fruits.
2. A great variation in size is found in these ranging from small flowers like Wolfia to large trees like Eucalyptus.
3. These are further classified into monocotyledons and dicotyledons.
4. The female sex organ is the Pistil and the male sex organ is called the Stamen.
5. Reproduction occurs via double fertilisation.
6. Some examples are Wheat, Apple, Mango, Lotus, etc.

Kingdom Plantae was one of the kingdoms in the five-kingdom classification given by R.H Whittaker. All the organisms of the plant kingdom are multicellular and eukaryotes. Examples of the Plant kingdom include algae, mosses, ferns, gymnosperms, and angiosperms. Organisms belonging to the Plant Kingdom are all capable of synthesizing their food i.e. they are autotrophic. The further classification of Plant Kingdom is carried out according to both structural and reproductive characteristics.

The majority of plants are sessile, which means they have a single root system and do not move from one area to another. Most plants belong to the angiosperm plant family, including the flowering plants. Rose, Lily, and Jasmine are all examples of Angiosperms. On the other hand, Conifers are examples of Gymnosperms.