The Plant Kingdom: Diversity and Characteristics
by Yuvi K - December 16, 2023
Introduction to Plant Kingdom
The plant kingdom is an incredibly diverse kingdom of organisms, with hundreds of thousands of species and further subspecies within them. Plant species include trees, shrubs, herbs, mosses, ferns and grasses. These organisms are mainly terrestrial and need sufficient soil and water to thrive in an environment. They vary in size from microscopic algae to massive trees. Plants also play an important role in the ecosystems of the world, performing vital tasks such as carbon dioxide absorption, food production, water tunnelling, air purification, and many more.
Characteristics of the Plant Kingdom
The plant kingdom consists of organisms which are characterised by certain distinct characteristics, including many that are shared amongst all species. First and foremost, plants contain some form of chlorophyll, a key molecule in photosynthesis. Plants also have a modified cell wall which gives them their familiar shape and structure. In addition, plants are multicellular and eukaryotic, allowing for complexity and more efficient processes. Plants also produce their own food through photosynthesis using a variety of different parts which vary significantly between species, such as leaves, stems and vascular systems (xylem and phloem).
Divisions of the Plant Kingdom
The Plant Kingdom is divided into 4 main divisions – Phyta, Pteradophyta, Bryophyta, and Marchantiophyta. Each division is fairly distinct from one another due to the differing characteristics of the plants belonging in those divisions.
Phyta
The Phyta division is the largest of the 4, encompassing approximately 300, 000 species of plants. This division includes flowering plants (angiosperms) and non-flowering plants (gymnosperms). Angiosperms are characterised by a unique reproductive system – they have both male and female reproductive parts contained in the same flower. Gymnosperms are mostly comprised of conifers and cycads, and are characterised by a more primitive reproductive system where chromosomes fuse in a non-flower environment.
Pteridophyta
The Pteridophyta division is complex and diverse, containing about 12, 000 species of plants. These species include ferns, horsetails and club-mosses. This division is considered to be an intermediate between non-vascular and vascular plants. In contrast to non-vascular plants, which have no organs of support and transport, pteridophytes have well-developed organs of support such as stems, and some also have vascular systems for water transport.
Bryophyta
The Bryophyta division is significantly smaller than the others, with only about 13,000 known species in the world. This group includes mosses, liverworts, and hornworts. Bryophytes are particularly unique because they are the only plants that can reproduce by spores and not flowers. They also lack the vascular systems of other plants, and instead utilise diffusion to move substances throughout their bodies.
Marchantiophyta
The Marchantiophyta division consists of approximately 10,000 species, and includes both the thalloid and leafy liverworts. These species are characterised by having simple plant body structure that are singlecells thick and also lack vascular systems.
Significance of Plant Kingdom
Plants play an incredibly important role in the environments of our world. They are fundamental in ecosystem services, such as carbon dioxide absorption, air purification, the production of food, water tunnelling, and much more. Furthermore, plants are the basis for a variety of industries, from timber production to medicinal. Thus, the plant kingdom has an incredibly significant role in the world and is a fundamental component of the biodiversity of our planet.
Conclusion
The plant kingdom is a unique and incredibly diverse kingdom of organisms. While plants vary significantly in size, shape, and type, they are all characterised by certain characteristics such as chlorophyll, multicellular and eukaryotic organisms, and modified cell walls. The plant kingdom is divided into 4 main divisions, Phyta, Pteridophyta, Bryophyta, and Marchantiophyta, each of which is distinct from the others due to different characteristics specific to that division. From producing oxygen to medication, plants have proven to be essential for our planetary life-support systems, and play a significant role in biodiversity.
