Botany is the study of plants. The herbarium is defined as a storehouse of collected plant specimens. These plant specimens are dried, pressed and are then preserved in sheets. These sheets are then stored and arranged in a sequence that is universally accepted by the system of classification. The herbarium botany comes under taxonomical studies. Taxonomic studies are the collection and preservation of the actual specimens of plants and animals. This becomes a prime source for taxonomic studies. The taxonomic study of a newly discovered organism is done by collecting its actual specimen and then identifying and classifying them. Under this topic of herbarium botany we will learn about how the herbarium sheets are made, some of the names of herbariums in the world, the technique of making herbarium botany and the functions of herbarium and botanical gardens.
It is very useful for us to make a study on diverse organisms and learn about them. We can exploit this knowledge of various species of plants, animals and other organisms. It is thus necessary to make accurate studies about them. This accurate classification demands rigorous hard work. The first step is the collecting of specimens, storing them and then making studies on them. The taxonomic studies help in
Studying different living organisms.
Storing of specimens for future studies.
All this provides aid in systematic studies.
So, biologists have established certain procedures and techniques that make our work easier. Herbarium and botanical gardens are also one of them.
As we studied above, the herbarium is a storehouse of collected specimens that are dried, pressed and then they are preserved on sheets. These sheets that have different specimens along with their accurate information forms a herbarium. These sheets are preserved carefully for future use. They carry a label on the right-hand side at the lower corner and the label provides the following information:
The date on which the specimen was collected.
The English name of the specimen.
The family of the specimen.
The name of the collector who collected the specimen.
The place from which the specimen was collected.
The local name of the specimen.
These herbarios serve as a quick source of reference in taxonomic studies. They are also very useful as they provide information about the local flora and the fauna. With the help of this information, we can locate the wild varieties and their relatives of the economic weaker plants.
The list of some herbaria of the world are:
The Royal Botanical Gardens, Kew, England
Central National Herbarium, Calcutta
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Figure: Sample of herbarium sheet
To make herbarium there is a certain technique that is followed. This technique involves Collection, Drying, Poisoning, Stitching, Labelling, Deposition.
Collection: In this step, the plant materials are collected. This can be done with a scientific mind and aesthetic sense. The material for determination should be perfect and complete for determination. This means that they must have fully grown leaves and complete inflorescence. The twigs represent the woody elements. They are 30-40cm in lengths. The herbaceous plants are collected with underground parts. When making herbarium and botanical garden, one thing should be kept in mind that the collection of diseased plants should be avoided. The collections that are made should be kept in metallic vasculum or polythene bags. This should be done to preserve moisture.
Drying: The plant specimens that are collected should be pressed in ordinary newspaper folders and overlapping should be avoided. These folders should then be preserved in a field press. To avoid the blackening and decay of plant material, the moistened folders should be changed.
Poisoning: Poisoning is necessary to avoid the growth of microbes. Mercuric chloride is the reagent that is used in the process of poisoning. After this treatment, the specimens are dried again.
Mounting, Stitching and Labelling: The specimens after the treatment from poison are dried and then are glued and stitched on the herbarium sheets. On the right hand lower side the field data is entered. Fragments packets are small paper envelopes that are attached to the herbarium sheets to hold the seeds and flowers.
Deposition: The sheets are arranged according to the genus and the classification. These sheets are arranged according to the Bentham and Hooker system of classification. DDT and copper sulphate is also sprayed upon them in intervals of 6 months to kill the insects such as silverfish.
Functions of Herbarium
The herbarium has primary and secondary functions. The primary function is accurate identification and taxonomic research. The secondary function is that it is easy for the students to learn about classification.
Some other important functions are: