Botanical gardens (in Latin, hortus botanicus) grow a wide variety of plants primarily categorized and documented for scientific purposes, but also for the enjoyment and education of visitors, a consideration that has become essential to secure public funding. Two less well-known but equally important elements in every botanical garden are its library and its herbarium of dried and documented plant material; and a further expectation is that these as well as the garden itself are staffed by professionals.
A herbarium with scientific merit usually relies on the plants which grow naturally in a specific geographic area, so it is important to distinguish between the wild species which actually are the objects of interest from those which have grown after a human intervention, as happens for some garden flowers or most cultivated plants. Anyway it is also true that often a plant species previously introduced by man can continue to spontaneously grow outside its original artificial environment; in that case the plant can actually become a new element of the spontaneous flora and can consequently become part of a herbarium method.
Make your own herbarium in three simple steps: Collecting, Drying and Mounting.
- You will need scissors to cut plant parts, a spade to dig out herbaceous plants, a strong bag to store collections, newspapers, and a good clean board to mount specimens.
- Small branches of trees, shrubs, and herbs that are free from disease and insects are cut and stored in the plastic bag. If the herbarium is to have some scientific value then you should tag every plant with its name. Make notes in an observation book about the date, location, the color of flowers and fruits, and other interesting information.
- If a plant has two different kinds of leaves or flowers, make sure to include them. Small herbs are usually uprooted and dried after shaking out the soil. Some flowers are delicate and don't last for more than a few hours. Pick such flowers early in the day and place them on paper for drying.
- Create a folder using newspaper bundle. Gently spread the plant specimens to remove any overlaps. Every plant specimen should have paper on both the sides.
- Put some heavy weight on the folder and leave it overnight.
- Change the sheets everyday, taking care to transfer the specimens gently on to a neat sheet. Put the weight back. This step is the longest and can take many days or weeks depending upon the specimen and the season.
- When the specimens are light, dry, and brittle they are ready for mounting.
- To mount a specimen, you will need several thin pieces of sticky tape. Tape only the stem and leave the delicate parts like flowers, fruits and seeds free.
- Every mounted specimen needs a label. Prepare one with your name, date and location of collection, the color of flowers and fruits.
- Identify the Latin name, family name for the specimen and write that down on the label.
Importance of Herbaria
- Herbarium is a source of knowledge about the flora of a region or a locality or a country.
- It is a data store in which the information on plants is available.
- The type specimens help in the correct identification of plants.
- Herbarium provides materials for taxonomic and anatomical studies.
- Typical pollen characters have been well emphasized in taxonomy. Morphological characters of the pollen remain unaltered even after storage up to nearly 200 years.
- Herbarium is very much useful in the study of cytology, structure of DNA, numerical taxonomy, chemotaxonomy, etc. It acts as a reservoir of gene pool studies.
- Due to its importance, several herbaria have been established at the national and international centres.