Plant Kingdom and Classification

All plants on this planet belong to Kingdom Plantae. Kingdom Plantae is a ramification group containing multicellular photosynthetic eukaryotes. They are primarily immovable and  in their early stages, and because photosynthesis can convert solar energy into chemical energy, they primarily serve as ecological producers. They have a hard cell wall  made primarily of cellulose. 

Characteristics of Kingdom Plantae:

Here are some of the features of Kingdom Plantae:

1. Plants are essentially immovable organisms that contain autotrophic chlorophyll. 
2. They are multicellular eukaryotes. 
3. There is a cell wall inside the cell consisting of cellulose, hemicellulose, and pectin. 
4. They occupy the foundation of the ecological pyramid and are called producers. 
5. Do not move from one place to another. 
6. They are fixed in one place. 
7. Propagate by vegetative propagation, sexual and asexual reproduction. 

Classification of Kingdom Plantae:

The first subkingdom consists of plants, which are avascular, seedless plants known as cryptogamae. The second subkingdom consists of vascular plants and seed plants known as phanerogamae. 

Cryptogamae:

1. Cryptogams are composed of seedless plants and plant-like organisms. 
2. Cryptogams also do not form flowers or fruits. 
3. Most cryptogams do not have a vascular system. 
4. The plant  is not differentiated into roots, stems and leaves. 
5. They are underdeveloped plants. 
6. Can be propagated by spores. 
7. Cryptogams can be divided into Thallophyta, Bryophyta and Pteridophyta. 

Examples of cryptogam are mosses, ferns, liches, algae.

Division Thallophyta:

These plants have the following characteristics:  

1. Thallophytes is a non-vascular plant containing eukaryotes, autotrophs (holophytic), and chlorophyll. 
2. The plant  is a thalloid i.e. the plant has no stem, leaf or root differentiation. 
3. These are the most primitive and simple forms. 
4. These are primarily found in both marine and freshwater habitats. 
5. The main reserve food is starch. 

Example- Ulothrix, Cladophora, Chara

Division Bryophyta:

They are known as  amphibians in the plant kingdom. They have the following properties: 

1. Bryophytes are autotrophic, unsown, cryptogams. 
2. Plants are gametophytes and can be divided into stems, leaves and rhizomes. 
3. These are the connections between algae and fern plants. 
4. These are primarily found in moist, shaded areas of hills and waters. 
5. They do not have the proper vascular tissue, but some  have hydroids (like xylem) and leptoids (like phloem) that help guide water and food, respectively. 
6. The reproductive organs of Bryophytes are multicellular. The male genitals are called antheridium and the female genitals are called archegonium. 

Example- The three bryophyte clades are the Marchantiophyta (liverworts), Bryophyta (mosses) and Anthocerotophyta (hornworts).

Division Pteridophyta:

They are considered to be the first true land plants. They have the following properties: 

1. Pteridophytes are non-nucleated vascular cryptogams. 
2. The plant  is a sporophyte, which is divided into stems, leaves and roots. 
3. These are the first plants to develop vascular tissue. 
4. These are mainly found in cool, damp and shaded areas. 
5. They have leaflets and biplanes known as the pinna.

Phanerogamae:

1. Phanerogams include plants with seeds. 
2. Phanerogams also form flowers and fruits. 
3. Phanerogams have a well-developed vascular system. 
4. The plant body is differentiated into roots, stems and leaves.  
5. They are highly evolved plants.  
6. The reproductive organs are well-developed. 
7. Phanerogams can be divided into gymnosperms and angiosperms. 

Examples of Pteridophyta include ferns, horsetails and club-mosses.

Gymnosperms:

Gymnosperms are also known as Phanerogamic Spermatophyta (seed plants). It has the following properties: 

1. Gymnosperms are naked seed plants that develop faster than  flowering plants. 
2. The plant  is a sporophyte, which differentiates into roots, stems, and leaves. 
3. Includes medium-sized or tall trees and shrubs. 
4. Pollen is always carried by the wind . 
5. All gymnosperms are heteroporeous and produce microspores (male spores) and megaspores (female spores). 
6. Gymnosperms show  alternation of generations with a diplomatic life cycle. 

Examples of these woody shrubs and trees include pines, spruces, firs, and ginkgoes

Angiosperms:

Also known as flowering plants. It has the following properties:

1. Angiosperms are seed plants. 
2. Plants are divided into  root system, sprout system, and leaves. 
3. Found in different types of habitats. 
4. Seeds are surrounded by ovaries, which grow into fruits. 
5. Double fertilization is shown. 
6. Depending on the number of cotyledons present in the seed, it is further divided into monocots plants and dicots plants. 

Examples of Angiosperms  are Fruits, grains, vegetables, trees, shrubs, grasses and flowers.

Conclusion:

The main purpose of the classification was to identify, name and understand the relationships between these plants. The botanical kingdom is not the largest, but an important kingdom. Plants produce almost all  oxygen on earth. Plants are also ecologically and economically important. It provides stability to ecosystems and plays an important role in providing food to animals and humans. They also deliver clothes, wood, medicine and more.