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.

taxonomical-aids

Definition:

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

herbarium

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.