Herbarium

Introduction

• Taxonomic aid is defined as the techniques, stored information and the procedure which are required in the identification and classification of organisms.
• The first herbarium was developed by a professor of botany Luca Ghini at Pisa in Italy.
• This information helps in the studies of various species of plants, animals and other organisms which will be further helpful in agriculture, forestry, industry etc.
• Some different types of taxonomical aids offered by various biologists are herbarium, botanical gardens, zoological parks, museums, keys (analytical device), flora, manuals, monographs and catalogues.
   

Definition:

• Herbarium is a kind of repository or storehouse of collected specimens of plants that are usually dried, pressed and preserved on sheets.
   

Detailed explanation :

Herbarium technique

This technique includes the following steps -

(a). Collection of the specimen (plants).

• The collection of the flora (plants) should be done very carefully using a scientific mind.
• The plant parts should be collected in such a way that it should provide the full information and diseased plant parts must be avoided.
• Tools required for the collection and preservation of plant parts that are scissors, knives, vasculum (box of 45-60 cm length. 20 cm width and 25 cm depth) etc.
• Vasculum is necessary for the preservation of specimens to avoid moisture and distortion.

(b). Pressing and drying of the specimen.

• After the collection of specimens, the plants are pressed between the newspaper folder or blotting sheets.
• Drying of specimens takes place by absorbing water through the blotting sheets.

(c). Poisoning of specimens or protection of plants from insects or pests.

• The plants get protected from insects or pests by poisoning.
• The specimens are poisoned by dipping it into the chemicals like corrosive sublimate or mercuric chloride (HgCl2).

(d). Mounting and labelling of specimen

• After drying, the specimens are mounted on the herbarium sheets of size 41×29cm.
• Labelling should be done on the right hand side lower corner of the herbarium sheet. Generally the size of the label is 7×12 cm.
• The sheets are properly labelled and arranged accordingly with the accepted system of classification (Betham and Hooker's system).
• Labelling includes information like
  Date of collection
  Vernacular names (local names)
  Scientific name
  Family
  Habitat
  Collector’s name.

(e). Storing of herbarium sheets.

• The sheets are now stored in the almirahs (steel) to protect them from fire.
• For the protection from insects and pests they are treated with DDT (Dichloro diphenyl trichloroethane), naphthalene balls, carbon disulphide etc.

Importance of herbarium :

• It provides detailed scientific information about the plants for research and exhibition and thus acts as a quick referral system in taxonomic studies.
• It can be used for the identification and classification of unknown flora (plants).
• It provides safety to the important specimens.
• Compilation of Flora, Manuals and Monographs

Some important Herbaria:

• Royal Botanical Gardens, Kew (London) is the largest herbarium in the World with a total number of about 6.5 million plants specimens
• British Museum of Natural History (Paris) has total number of abouts 6 million species
• New York Botanical Garden (New York) has total number of about 4.0 million species
• Central National Herbarium (Indian Botanical Gardens) Sibpur, Kolkata, India (largest herbarium in India) has total number of about 2 million species
• Madras Herbarium, Coimbatore (MH), India has a total number of about 1,50,000 million species.
• Herbarium of National Botanical Research Institute, Lucknow, India has a total number of about 80,000.

Frequently asked questions (FAQ’s)

1.
Question
Which is the largest botanical garden in the world?

Solution :
Royal garden, Kew (London), England is the most famous and largest botanical garden, founded by William Alton in1759.

2.
Question
What are the major steps involved in herbarium technique.

Solution :
The steps involved in herbarium technique are -
1. Collection
2. Drying
3. Poisoning
4. Mounting
5. Labelling
6. Stitching
7. Deposition

3.
Question
How are succulent parts, fruits, tubers, rhizomes preserved in herbarium?

Solution :
They are preserved in bottles having FAA (formalin + acetic acid + alcohol). Some of them can also be dried and kept in packets or airtight boxes.

4.
Question
Which information is provided by the label given on the herbarium sheet?

Solution :
Labels given on the herbarium sheet provides the information like -
- Date of collection
- Vernacular names (local names)
- Scientific name
- Family
- Habitat
- Collector’s name

5.
Question
How does herbaria serve as a quick referral system in taxonomic studies ?

Solution :
Herbaria serves as a quick referral system in taxonomic studies because it provides detailed scientific information about the plants for research and exhibition.