Herbarium is "a collection of plant specimens which have been dried and pressed and arranged in the sequence of an accepted classifications". It forms a store house for future use. 

The preparation of Herbarium involves following steps: 

(i) Collection of Specimens: It is a field work. For collection one has to get information about the area, habitat, season and the time of collection. There is a requirement of digger for digging roots, scissors for cutting twigs, knife for woody twigs and a pole with a hook for collection. 

(ii) Drying and Pressing: After collection, the plants are dried up by keeping them between the folds of old newspapers. The plants, after drying, are pressed up by a set of two broad straps. 

(iii) Mounting: The dried specimens are pasted on the herbarium sheets of standard size (29 x 41 cm). The specimens are fixed on the sheets by applying glue or adhesive. The specimens are sprayed with fungicides like 0.1% solution of mercuric chloride and pesticides like DDT, naphthalene to check fungal growth and infestations.

(iv) Labelling: Labelling should be done with mounting. It should bear the botanical name, family, locality, data of collection with the habit of the plant specimen and the collector's name. 

(v) Storage: The sheets are arranged according to classification. They are stored in disinfected metallic cupboards. The information about the collected specimens is compiled and published in the form of a book.