Herbarium – A taxonomic aid
E M Shimitha
Herbarium is a collection of preserved specimens of plants. It is a source of biodiversity, evolutionary and ecological studies. It is actually dried and labelled plant specimens that can be used for future research studies and all. The herbarium is actually a library, but here the information is stored in a biological form. What we actually do to make herbarium is, first we will collect the plants, dry them, and then label the plant specimen in an appropriate manner. The specimens are used to understand different Taxa. Well, what are taxa? Taxa is a group or category in taxonomical studies. And the different taxonomic categories are Species, Genus, Family, Order, Class, Phylum and kingdom. The Botanical Survey of India has more than 30,00,000 herbarium specimens persevered in different herbaria located in different parts of the country.
- The Central National Herbarium, Howrah. It is the first herbarium in India. It comprises 2 million specimens.
- Forest Research Institute (FRI), Dehradun. It has 350000 specimens.
- The National Botanic Garden, Lucknow. It has 260000 specimens.
- Blatter Herbarium, St. Xavier’s college, Bombay. It contains 200000 specimens.
- BSI (Botanical Survey of India) has its own regional centres and units of herbaria in different parts of India.
Botany and Herbarium
Botany is the study of plants. Herbarium is a collection of dried plant specimens. The plant specimens are collected, dried, placed and labelled in herbarium sheets. Then these sheets are arranged and stored in a universally accepted system of classification. Taxonomic studies are a part of Botany and this herbarium is an important source of taxonomical studies. In Taxonomy, first we identify the collected organism/specimens and then classify them. In herbarium, we will collect the specimen, identify and preserved in a herbarium sheet for further studies and future.
What we have to include in labelling Herbarium sheet
We have to label some information of the preserved plant species on the right side at lower corner of the Herbarium sheet. That are:
- The date in which specimen collected.
- Name of specimen in English.
- The name of the family of specimen.
- The name of the person who collected the specimen.
- Name of place from which the specimen was collected.
- Local name of the specimen.
What are the techniques to make a Herbarium
To make herbarium, we have to follow some techniques. The techniques are collection, drying, poisoning, mounting and labelling, finally preservation.
1. Collection of specimens
It is nothing but the plant specimens are collected here. An important thing to remember is the identification of the specimen has to be done in a appropriate way. Also, the material should be perfect and one can easily identify it. The plant must have fully grown leaves and complete inflorescence. Herbs are collected with root. While making herbarium, we should avoid the collection of diseased plants. We can use diseased plants of course, but it should be plant disease herbarium. We can also collect grains as specimens to study them. The specimens should be kept in metallic vasculum or polyethene bag without moisture.
2. Drying
The collected plant specimens should be pressed in a newspaper and try to avoid overlapping. To avoid decaying, moisture should be prevented and change the paper accordingly.
3. Poisoning
Poisoning is done to prevent the growth of microorganisms. Usually we use Mercuric Chloride for poisoning. After poisoning we have to dry the specimen again.
4. Mounting and Labelling
The specimens after poisoning are dried and glued on herbarium sheets. Then we have to label some information regarding the collected specimen on the right side of the sheet at lower corner. If there is any seeds or flowers, then we can attach fragment packets along with the sheets.
5. Preservation
Prepared sheets are arranged based on Bentham and Hooker’s classification. DDT and Copper Sulphate are used in interval to kill insects and keep the sheets long.
Check your knowledge
Herbarium is a collection of preserved specimens of plants. It is a source of biodiversity, evolutionary and ecological studies. It is actually dried and labelled plant specimens that can be used for future research studies and all.
Collection, drying, poisoning, mounting and labelling and finally preservation.
Mercuric Chloride
Fragment pockets are the bags in which seeds or flowers are attached with the herbarium sheets.
The Central National Herbarium, Howrah.
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