Herbarium: Kinds and Functions

Last Updated on January 19, 2020 by Sagar Aryal

Herbarium: Kinds and Functions

It is a collection of plant specimens that are pressed, preserved, dead and dried, also arranged in a sequence of classification for future purpose and study. The specimens\sample may be a complete plant or a part of the plant, specimens should be in dried form on a sheet paper.

Almost 3000 herbarians available in the world, mostly used by mycologists, plant pathologists, taxonomists, and health scientists.

Index herbarium

it is a project of the international association for plant taxonomy and New York botanical garden.

Image Source: VectorStock and Amazon

Functions

1. Act as a source of information about plants.
2. Help in research and teaching activities.
3. Help in the accurate identification of plants.
4. Also provide information about the plants that are collected worldwide, in one place.
5. The specimens in the herbaria are used as a source of material for chemo-taxonomical and anatomical studies.

Important herbarium

The first herbarium was founded in the University of Padua, in 1545, in worldwide 1500 herbaria (smaller herbaria not includes) are recognized.

Some important herbarium of the world:

Kinds of Herbaria

The kind of herbaria depend on the purpose, region, contents, plant groups present in these:

1. Herbaria of medicinal plants

This type of herbaria includes the specimen of plants having medicinal importance/medicinal properties.

ACECR; Central herbarium of medicinal plants, halejerd region, Karaj, Alborz province.

2. Herbaria of weeds

These herbaria contain weeds of cultivated fields & waste places.

3. Regional herbaria

As the name indicates, herbaria of a particular region or place.

Example: Herbaria of the central circle, Allahabad.

Plant collection

The importance of the botanical collection is that,

• Build new herbarium
• Carry out research on particular genus/species
• Write a flora
• Enrich the herbaria

What to collect?

• To collect specific groups, those in which taxonomists have interest or herbaria show better representation.
• Rootstock should be collected in herbaceous plants.
• For detail study and exchange purposes, at least 6 specimens of each plant should be collected.
• We should try to not collect rare or endangered species.
• For common species, we only collect a few parts of the plant.
• During collection should keep in mind that the final specimen, after pressing and drying has to fit on herbarium sheet of 42x28cm

Procedure to collect the plant specimens

Before collecting the sample, we should try to get available maps, collect information, help from the best guider and person who have knowledge about forest work.

Equipment’s

• A collecting pick for digging up roots.
• A strong knife (Required for cutting branches and other plant parts)
• Vasculum is used for accommodating the collected samples/specimens.
• Blotting papers
• Collecting bags
• Hand lens
• A field book (required to note the detail about specimen collection.

Field book

The purpose of the field book is to record data of taxonomic value that not be apparent from the specimen.

• Date
• Number of plants
• Habitat
• Locality
• Province
• Name of plant
• Altitude
• Description

Handling of fresh material

When specimens are collected, press each plant and keep all specimens in a vasculum and bring them to camp/organization/institute.

Pressing and drying

• Remove soil from the collected specimen.
• Use a press with a pair that is made from a hardboard and cut to the same size as the drying paper.
• Place the plant specimen on the blotting paper.
• Then remove leaves and flowers of congested specimens to reduce the bulk without losing the characteristic of the plant.
• When all samples included, cover with hardboard and place bricks or heavy objects.
• Apply pressure to keep the press tight.
• Place the material in a warm place such as a drying cabinet.
• Check the material after 24 hours, replace the blotting paper with a dry card.
• Check the material regularly, at least one week.
• Depending on the plants being pressed and the drying condition.
• Leaves, flowers, and fruits should be spread out so that they do not overlap.
• Best result obtains by using electric drier that holds the presses and provides heat between 95◦F to 113◦
• Sometimes, alternative methods such as freeze-drying and drying in a desiccant powder such as desiccant silica gel.
• The purpose behind the process of pressing and drying is to extract the moisture so that we store specimen for a long time in herbarium paper

Poisoning

• Used for avoiding fungus and pests attack
• Dip the whole plant in a saturated solution of mercuric chloride in ethyl alcohol for 15-20 minutes. mercuric chloride is corrosive for metals so use enamel coating trays.
• Formalin-10% used during collection tours.
• Fumigation-killing pest from mounted and unmounted specimens.
• Fumigators are harmful to human beings.

Mounting

• It is a process of attachment of dried pressed plant and their label to a sheet of heavy paper
• Plant are positioned in an arrangement in which roots and lower stem toward the bottom of the sheet and flowers toward the top.
• Glue is used to attach the plant on the sheet.

Labeling of specimen

These things should be there while labeling:

1. Name of family
2. Name of collector
3. Date of collection
4. Genus and Species
5. Locality of collection
6. Description

Storage of specimen

Put the specimen in a sealed plastic bag and freeze for 72 hours at -32◦c, regular freezing (every six months) is recommended.

References

• 4% – https://www.slideshare.net/bonnmengullo/herbarium-ppt
• 3% – http://www.biologydiscussion.com/plant-taxonomy/plant-herbarium/herbarium-meaning-functions-and-kinds/30287
• 13% – https://www.slideshare.net/DurgeshSirohi/herbarium-and-staining-techniques
• 1% – https://www.meritnation.com/ask-answer/question/plz-tell-how-to-make-herbarium/plant-kingdom/11506761
• 1% – https://www.landcareresearch.co.nz/resources/identification/plants
• 1% – https://www.ibiblio.org/pic/answers.htm
• 1% – https://www.floridamuseum.ufl.edu/herbarium/voucher.htm
• 1% – https://www.afcd.gov.hk/english/conservation/con_flo/con_flo_hkh/con_flo_hkh.html
• 1% – https://en.wikipedia.org/wiki/Blatter_Herbarium
• 1% – http://www.biologydiscussion.com/plant-taxonomy/plant-specimens/collecting-the-plant-specimens-7-steps/47638
• 1% – http://www.biologydiscussion.com/plant-taxonomy/herbarium-meaning-functions-and-significance/47626
• <1% – https://www.anbg.gov.au/cpbr/herbarium/collecting/field-note-book.html
• <1% – https://en.wikipedia.org/wiki/Herbarium

Herbarium: Kinds and Functions