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Biosystematics nomenclature

Biosystematics nomenclature

Biosystematics nomenclature

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Taxonomy is mainly concerned with the observation of similarities and differences that exist in the morphology of a vast number of plants.

But it has now been accepted that in general, morphological characters alone are not the criteria for distinguishing and classifying plants from one another.

One has to take into consideration, the characteristics and differences from other disciplines of science such as cytology, genetics, physiology, ecology, phytogeography, phytochemistry, numerical taxonomy, molecular biology, breeding systems and any other available sources for classification.

Biosystematics nomenclature may be defined as ‘taxonomy of living populations’.

In the present day classification of plants, species is taken as basic unit and it is the local breeding population.

Numerous disciplines of science thus provide innumerable number of datas of all the characters of the individual or a species.

This helps to clear problems concerning those plants that differ in their interrelationship, classification and evolution.

It provides sufficient genetic variations that warrants separation so as to recognise them as a separate taxon based on their evolutionary progress.

Variations in a species may be due to several factors such as genetic, ecological, physiological, population dynamic study and many other factors.

All the evidences provided by the biosystematist are taken for analysis and considered by the classical taxonomist in order to arrive at any controversial problems that may arise during their phylogenetic classification based on their evolution of species under study.

Aims of Biosystematics nomenclature

Camp and Gily 1943, coined the term ‘biosystematics’. The aims of biosystematics nomenclature are as follows.

  1. To delimit the naturally occurring  biotic community of plant.
  2. To recognise  the various  groups  as separate  biosystematic categories  such as  ecotypes,  ecospecies, cenospecies and comparium.

Methods in the study of Biosystematics nomenclature

Three important methods are as follows.

  1. It involves thorough sampling analysis of the taxonomic species under. Its population, cultivation, geographical range, cytology, anatomy, palynology, phytochemistry. Chromosomal number and behaviour are keenly observed and studied for finding any genetic differences that may arise among different populations.
  2. It includes determination of ability of different populations to interbreed. Among one another to form a variant species with its vigor and fertility.  This will reveal the presence or absence of breeding barriers between taxa at various levels.
  3. It involves the study of similarity of chromosomes in the hybrids during meiosis.

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What is Biosystematics nomenclature ?

What are the aims of  Biosystematics nomenclature ?

List the methods in the study of Biosystematics nomenclature ?

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Ecotype Ecospecies Cenospecies Comparium

Ecotype, Ecospecies, Cenospecies, Comparium

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Ecotype is the basic unit in biosystematics, adapted to a particular environment but capable of producing fertile hybrids with other ecotypes.

This ecotype is regarded as equivalent to subspecies of classical taxonomy.


The ecospecies is a group of plants comprising one or more ecotypes within the cenospecies, whose members are able to interchange their genes.

Ecospecies is regarded as equivalent to species of classical taxonomy.


Cenospecies is a group of plants representing one or more ecospecies of common evolutionary origin.

It is regarded as equivalent to subgenus of classical taxonomy.

Cenospecies of the same comparium are separated by genetic barriers and all hybrids between them are sterile.


Comparium is composed of one or more cenospecies that are not able to intercross.

Complete genetic barriers exist between different comparia.

The informations obtained from the above mentioned studies were compared with the data obtained through comparative morphology.

And geographical distributions resulted in the recognition and identification of a total variety or species.

To conclude, biosystematic study in the contemporary and modern taxonomy plays a vital role in separating and solving some of the problems that may develop in the identification of plants at the level of species.

Biosystematist provides all the necessary data in solving the real position of species that was in controversy.

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  1. What is Ecotype ?
  2. Explain about Ecospecies ?
  3. What is Cenospecies ?
  4. Explain Comparium ?

More Detail about Ecotype Click here

Other links 





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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