A herbarium (plural: herbaria) is a collection or 'library' of preserved plant specimens and is an information repository for plant study. Herbarium specimens can be used to identify and catalogue the local flora. A herbarium can also be a historical record of change in flora over the years, especially if some species become extinct.
Many universities, museums, botanical gardens and forestry departments maintain herbaria. Like airports, each herbarium has its own code--the University of Malaya's herbarium code is KLU!
Usually, plant specimens are pressed and dried, and mounted on a sheet of paper. Some forms of plants, such as fruits, cones and seeds that cannot be flattened may be oven-dried or preserved in formaldehyde. This tutorial will give instructions on how to make your own herbarium.
You will need:
Sheets of newspaper (at least 10 for one specimen)
Paper for envelop and label
Paintbrush (for applying glue)
Thread and needle
1. Collect plant specimens around your area. Try to collect specimens that show the branch structure, with more than one leaf, and flowers, seeds and/or fruits if present. If collecting grass or herbaceous plants, also include a root structure. Don't worry if the specimen is too big to mount; it can be trimmed or arranged later.
2. Record the date you collected your specimen, the location where you collected it, your name, and any special notes (e.g. the colour of leaves and flowers, which can change once dried; animals or insects found eating it; the microclimate of the area). If you are unsure of the common or scientific names, you can ask a botanist or do your own research later.
3. Press the specimen between two sheets of absorbent paper (newspaper is great!). This is to aid in drying the specimen and preventing mould growth. Try to arrange the specimen to fit between the sheets of newspaper: twist and turn the branches and fold the leaves if they are too big. Also arrange the leaves so that the morphology, or shape, is clear; it is important that future students or researchers can see both sides of the leaves, so make sure that at least one of the leaves is pressed bottom side facing upwards.
4. Place the newspaper containing the specimen between two sheets of corrugated cardboard (like cardboard from carton boxes). To prevent the specimen from sliding around, tie the cardboard sheets together with some raffia string. Weigh down your specimen with several heavy books and store it in a dry place.
5. Change the sheet of newspaper every day. This is important to prevent growth of mould.
6. After one week, your plant specimen should be sufficiently pressed and dried. Remove the specimen from the cardboard and the newspaper and arrange carefully on a piece of art block; this will be your herbarium sheet. Use polyvinyl acetate (PVA) glue to fix the specimen into position. When the glue is dried, sew the main stem and the branches of the specimen to the herbarium sheet with thread to keep the specimen in place.
7. Glue the label containing the information of your herbarium specimen you recorded in Step 2 on the herbarium sheet. If you have any loose seeds or fruits, you can put them in a small paper pocket and attach it to the herbarium sheet. Make sure all these are also fully dried or else mould will grow!
Congratulations! You've started your very own herbarium. Continue collecting more plant specimens to add to your herbarium, because it is a very valuable record of your area's plants, which may change over time as foreign plants are introduced or industrial or commercial development takes over the natural landscape. It may be the only resource showing what plants once grew in the area.