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TAXONOMY OF ANGIOSPERMS, TYPES OF CLASSIFICATION

TAXONOMY OF ANGIOSPERMS

TAXONOMY OF ANGIOSPERMS

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INTRODUCTION to TAXONOMY OF ANGIOSPERMS

Taxonomy is concerned with the laws governing the classification of plants.

The term taxonomy includes two Greek words taxis – arrangement and nomos – laws. Plant taxonomy is other name for systematic botany.

Classification, identification, description and naming the plants are the bases of plant taxonomy.

The taxonomic knowledge about the plants is based on their form and structure.

The knowledge gained through taxonomy is useful in the fields of medicine, agriculture, forestry, etc.

The ultimate aim of classification is to arrange plants in an orderly sequence based upon their similarities.

The closely related plants are kept within a group and unrelated plants are kept far apart in separate groups.

The other aim of classification is to establish phylogenetic relationships among the different groups of plants.

The plants that are closely related show more similarities than differences.

The earliest systems of classification were simple and based on one or few characters.  They gave importance to vegetative characters.

The later systems of classification gave more importance to floral characters because floral characters are more stable and permanent.

Questions from TAXONOMY OF ANGIOSPERMS:

  1. What is taxonomy of Angiosperms?
  2. What is the other name for plant taxonomy?
  3. List the any three fields in which taxonomy is used?

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12th standard botany explanation TAXONOMY OF ANGIOSPERMS

notes for 12th std state board bio botany

bio botany +2 notes and study materials

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TYPES OF CLASSIFICATION IN TAXONOMY

TYPES OF CLASSIFICATION

Types of classification for taxonomists:

The different types of classification proposed by earlier taxonomists can be broadly categorized into three systems– artificial, natural and phylogenetic.

Artificial system

It was based on one or at most only a few superficial characters.  In 1753, Carolus  Linnaeus  of Sweden published his book “ Species Plantarum”  wherein he described 7,300 species.

He divided the plants into 24 classes based on number, union, length and certain other characters of stamens.   Hence, this system is also known as sexual system of classification.

In those days, it was an important over other systems of classification.  The importance of floral characters was felt by Linnaeus and his classification was more important than others.

The main defect of this system is that totally unrelated plants are brought together in a single group and those that are closely related plants are placed in widely separated groups.

For example, plants belonging to Zingiberaceae of Monocotyledons and that of Anacardiaceae of Dicotyledons had been placed in one group called Monandria, as these possess only one stamen.

Another defect  of  this  system  was  that  no importance was given to either natural or phylogenetic relationships among different groups of plants.

TYPES OF CLASSIFICATION  – NATURAL SYSTEM

The explanation about natural system in classification of taxonomy is provided below

Natural system

In this system of classification, plants are classified based on their natural affinities. More number of characters are taken into consideration in this system.

It is mainly based on all the informations that were available during the time of direct observation of plants.

The most important natural system of classification of seed plants was proposed by two British botanists George Bentham  and Sir Joseph Dalton Hooker.

It helps to determine the relationships between various groups of plants.  However, it does not attempt to bring out evolutionary relationships among different groups of plants.

PHYLOGENETIC SYSTEM – TYPES OF CLASSIFICATION

 

Phylogenetic system

This system is based on evolutionary sequence as well as genetic relationships among different groups of plants.

In addition to this, it employs as many taxonomic characters as possible. Charles  Darwin’s concept of Origin of Species had given enough stimulus for the creation of phylogenetic system of classification.

Adolf Engler (1844-1930) and Karl Prantl (1849-1893) of Germany published a phylogenetic system in their monograph on “Die Naturlichen Pflanzen Familien”.

In this system, floral characters such as single whorl of perianth or no perianth and unisexual flowers pollinated by wind were considered as primitive characters when compared to perianth with two whorls, bisexual flowers pollinated by insects.

According to them, members of Asteraceae of dicotyledons and Orchidaceae of monocotyledons were highly advanced.

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QUESTIONS :

  1. What is natural system?
  2. Explain in detail about types of classification?
  3. explain briefly the classification of taxonomy?
  4. What is artificial system?
  5. What is Phylogenetic system?
  6. Natural classification in taxonomy
  7. Artificial classification in taxonomy
  8. Phylogenetic system of classification

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Other links 

 

BIOSYSTEMATICS NOMENCLATURE


BINOMIAL NOMENCLATURE, ICBN


HERBARIA AND ITS USES IMPORTANCE OF HERBARIUM


Bentham and Hooker’s classification of plants


Dicot Families – MALVACEAE


Botanical description of Hibiscus and Economical importance of Malvaceae


Solanaceae – Datura metal and Economic importance


Euphorbiaceae and Ricinus communis and its Economic importance


Musaceae – Musa paradisiaca and its Economic Importance

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