Botany Notes “Taxonomical Aids, What is Living” Chapter 1, for Class 12-CBSE


The laboratory and field studies are required for identification of various species and their placement in taxonomical hierarchy. The information thus gathered about the species, needs to be stored for future use. The taxonomical aids developed by biologists have established certain procedures and techniques to store and preserve the information as well the specimens.

  1. Botanical Gardens

From the time of Theophrastus, gardens have contributed to the science of botany. But, there was an impetus to the botanical explorations only in the Post-Linnean period.

In ancient Indian culture, cultivation of good and medicinal plants is known since 4000 to 2000 B.C. the ‘Hanging Gardens of Babylon’ are amongst the wonders of the ancient world.

During the middle Ages, from A.D. 600-1600, there was a lapse in learning and introduction of plants. In the seventeenth century, there was a revival in the interest and by eighteenth century , most of the famous Botanical Gardens known today and already been established.     

The functions of a botanical garden are :

  1. Provide records of local flora for monographic work.
  2. Provide facilities for collections and identification of living plant material for biosystematics studies/ references.
  3. Supply seeds and material for botanical investigations.
  4. Botanical gardens have an aesthetic appeal and attract a large number of visitors for observing general plant diversity.
  5. Provides means of ex-situ conservation strategies.

There are about 525 botanical gardens in various countries, but only about 125 have documented   collections of authenticated taxa.

The international Association of Botanical Gardens was established in 1962. This association has published the international directory of botanical gardens (1983).

          Botanical Gardens of India

          The Indian Botanical Garden, Kolkata, India : it was founded in 1787, by Lt. Col. Robert Kyd. It covers an area of 273 acres and contains collections of world’s tropical plants. It is one of the greatest botanical gardens of the world and one of the first to be established in tropics.

William Roxburgh, ‘Father of Indian Botany’ was its director from 1793 to 1813. It has the largest herbarium of east and is famous for the Great Banyan tree, Ficus benghalensis, which is two centuries old, the palm houses, nurseries and the Amazon lily, Victoria amazonica (Nymphaeaceae), the plant with the largest leaves. It is now under control of BSI( Botanical Survey of India).

Other botanical gardens of India are

          Lloyd Botanical Garden – Darjeeling

          National Botanical Garden- Lucknow

          Lalbag Gardens              –        Bangalore

          Saharanpur Botanical Gardens – Saharanpur

          Indian Botanical Gardens – Howrah

  1. Herbarium

It is defined as ‘ a store house of collected plant specimens  that are dried, pressed and preserved on sheets.” These sheets are arranged in the sequence of an accepted classification system. These specimens , along with their description on herbarium sheets, become a store house or repository for future use. The herbarium sheet contains a label on the right- hand side at lower corner. Label provides information about date and place of collection, English, local and botanical names, family, collector’s name etc. Herbaria also serve as quick referral systems in taxonomical studies. 

  1. Keys [Given by John Ray]

The scheme for identification of plants and animals based upon similarities and dissimilarities is known as a key. It is based on the set of contrasting characters known as couplet. Each character of couplet is called as lead. Separate taxonomic keys are required for each taxonomic category . keys are generally analytical in nature and are of two types (1) indented key (2) Bracketed key

  1. Indented Key : It has a sequence of choice between two or more statements of characters of species. These require great taxonomic skills to prepare, so are generally less followed.
  2. Bracketed Key : in the Bracketed key the pairs of contrasting statements are used for identification. The bracketed number on the right side indicates the next choice of paired contrasting statements. These are most popular keys.
  3. Zoological Parks
    1. Zoos or zoological gardens (parks) are protected areas on enclosed space where live wild animals are kept, under human care. This enables us to learn their food habits and behavior.
    2. Objectives are public exhibition to understand wild life, recreation, education, ex situ conservation and breeding of rare fauna.
    3. Largest zoo of the world is situated in Kruger (S. Africa)
    4. National Zoological Park (Delhi) is one of the finest zoo of Asia.
  4. Museums

These have collections of preserved plants and animals for study and reference. Specimens are preserved in jars or containers in preservative solution. Plant and animal specimens may also be preserved as dry specimens.  Insects are preserved in insect boxes after collecting, killing and pinning. Larger animals are usually stuffed and preserved. These often have collections of skeletons of animals too.

These are prepared to preserve algae, fungi, mosses, ferns and organs of gymnosperms since they cannot be kept in herbaria. These differs from parks because no living object is displayed in museums.

Some important  Museums :

  1. Natural History Museum, London(England)
  2. United States National Museum, Washington
  3. National Museum of Natural History (NMNH), Delhi
  4. Prince of Wales Museum, Mumbai etc.
  5. Flora, Manuals, Monographs and Catalogues

Flora : contains the actual account of habitat and distribution of plants of a given area. These provide the index of the plant species found in a  particular area.

Some important flora are given below :

  1. Flora of British India by J.D. Hooker.
  2. Flora of Delhi by J.K. Maheshwari
  3. Flora Indica by William Roxburgh.
  4. Flora Simlensis by H. Collet

Manuals : The complete listing and description of the plants growing in a particular area.  E.g., Manual of Cultivated Plants by L.H. Bailey

Monographs : Contain information on any one taxon.

e.g., The Genus Pinus by N.T. Mirov

Catalogues : This includes the alphabetical arrangement of species describing their features.

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