Overview of Plant Kingdom

In this article we will discuss about “Plant Kingdom”. It is a part of General awareness section of many competitive exams. This article may help the candidates to qualify for many competitive exams such as SSC, NEET, Banking, and Railway. To Know more about the Plant Kingdom which is mentioned Below.

Plant Kingdom :

The Plant Kingdom is also referred to as Plantae. The scientist, R.H. Whittaker divided living organisms based on multiple features like cellular structure, mode of nutrition, body organization, reproduction, phylogenetic relationship, etc. The five kingdoms classification is also given by R.H. Whittaker. These five kingdoms’ names were Monera, Protista, Fungi, Plantae, and Animalia.

The Eukaryotic cells of plants have a cellulosic cell wall, chloroplast, multicellular, and chlorophyll-containing green-colored pigment. They include flowering plants, conifers, and other gymnosperms, ferns, Club mosses, hornworts, liverworts, mosses, and green algae, and they exclude red and brown algae.

They are autotrophic because they prepare their food spontaneously, but some members are heterotrophic such as insectivorous plants which capture and digest insects to get nutrition, for example, the Venus flytrap. Some heterotrophic plants are parasites i.e. they live on other plants and take water and nutrients from the host body, Such as Cuscuta.

Classification of Kingdom Plantae :

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

Plant body: it is the Presence or absence of a well-recognizable plant body. Such as. roots, Stem, and Leaves.

Vascular system: it is defined as the Presence or absence of a vascular system for the transportation of water and other substances. E.g. Phloem and Xylem.

Seed formation: It is defined as the Presence or absence of flowers and seeds and if the seeds are naked or enclosed in a fruit.

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

Thallophyta
Bryophyta
Pteridophyta
Gymnosperms
Angiosperms

Thallophyta :

Thallophyta is the first category of the plant kingdom which involved the primitive forms of plant life showing a simple plant body structure. Including unicellular to large algae, fungi, and lichens. The first ten phyla are known as thallophytes.

Algae :

Algae are mostly aquatic, simple, autotrophic, thalloid creatures that consist of chlorophyll. They can be present in wood, damp stones, soils, and other habitats.
Some algae also coexist alongside fungi (lichen), mammals, and other organisms. They typically reproduce sexually by the generation of gametes that may exhibit isogamy, anisogamy, or oogamy, and vegetatively through fragmentation.

• Algae are divided into 3 classes-
  Chlorophyceae
  Phaeophyceae
  Rhodophyceae

Fungi :

Fungus is a member of the group of eukaryotic organisms that involves microorganisms such as molds and yeasts, as well as mushrooms. Fungi regenerated sexually and asexually in both types and they also have symbiotic associations with plants and bacteria. Furthermore, they are responsible for some diseases in plants and animals. The study of fungi is known as mycology.

Bryophyta :

Bryophytes are terrestrial plants but are called  “amphibians of the plant kingdom” because they are dependent mostly on the water for sexual reproduction. Bryophytes are small, non-vascular plants that prefer moist environments. Bryophytes’ plant bodies are the absence of true roots and stems and have root-like stems and leaf-like structures. The primary plant body of the bryophyte is a haploid. They are found mostly in moist and shady places. It generates gametes, hence is known as a gametophyte. Bryophyta includes mosses, hornworts, and liverworts. Some of the common examples i.e. Marchantia, Funaria, Sphagnum, Anthoceros, etc.

Pteridophyta :

Pteridophytes are the first terrestrial plants that have a well-organized plant body into root, stem, and leaves. A vascular system is present for the conduction of water and other substances. Pteridophytes are extensively grown as ornamentals. The primary plant body of the Pteridophytes is a Sporophyte. Sporophytes produce sporangia that are covered by leaf-like appendages known as sporophylls. In a few plants, a compact structure referred to as strobila or cone is formed. Some of the main examples are Selaginella, Equisetum, Pteris, etc.

Gymnosperm :

Gymnosperms have a well-organized plant body structure that has vascular tissues. They produce naked seeds meaning that seeds are not enclosed within a fruit. Gymnosperms are plants in which the ovules are not enclosed by the ovary wall and remain open, both before and after fertilization condition.

Angiosperm :

Angiosperms are seed-producing plants with a well-recognizable plant body. In angiosperms, the pollen grains and ovules are generated in specialized structures that are referred to as flowers. In angiosperms, the seeds are surrounded by fruits. Stamen is a male flower sex organ and pistil or carpel is a female flower sex organ. The size differs from almost microscopic Wolfie (0.1cm) to tall tree Eucalyptus (more than 100m). The pistil contains an ovary enclosing one  more ovules.