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Herbarium
Meaning of Herbarium: A herbarium is a store house of plant specimens. In it
dried, pressed, preserved and mounted plant specimens are arranged in a sequence
of an accepted system of classification for future reference and study. The
collected plant specimens from far and wide are mounted on appropriate sheets and
kept in pigeon holes of steel or wooden cupboards for study at the same place and
time.
Types of herbarium
Davis and Heywood have classified herbarium into 3 categories;
A). National (or Regional) Herbaria: These herbaria geographically cover
respective country, or phyto-geographically similar neighbouring countries.
B). Local Herbaria: These represent a region within a country such as a state,
county, district or even a smaller area such as a nature reserve. e.g. Sabah Forest
Research Centre Herbarium, Sandakan, Sabah, Malaysia (SAN Herbarium)
C). Special Herbaria: These herbaria are usual small and serve specific purposes
or limited scope depending on its function.
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• Historical herbaria. They may be kept in separate herbaria within a general
herbarium (e.g. Wallich Herbarium at Kew). They may also belong to separate
institutions such as Linnean
• Herbaria of limited scope. These herbaria may be taxonomically (e.g.
cryptogamic herbaria) or ecologically (forest herbaria) limiting
• Job-related herbaria. These herbaria include collections of weed species by
agriculturists or honey-bee plants for bee keepers.
Techniques of Herbarium Preparation
Herbarium preparation involves the following steps and guideline which helps in
creating conventional useful and long lasting herbarium specimen;
 Collection
 Pressing
 Drying
 Poisoning
 Mounting and stitching
 Labeling
 Storage
 Fumigation
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1. Collection: The Plant specimen should bear flowers and fruits, if present.
Herbaceous small plant specimen should be collected with roots or other
underground parts. A twig of about 25 cm with leaves & flowers, will form an
ideal material. Note sheet’s no. & data are recorded in the field notebook. Soon
after the specimens are collected, they should be pressed in the field itself.
Collection material includes cutter, digger, scissors, herbarium sheet, vasculum
or plastic bag, notebook etc
2. Pressing: Specimens should be carefully placed in the center on the pressing
sheets. If specimens are large enough, they should be bent giving them shape
of V, N or W. The bundles should be uniform in thickness in the middle and on
the sides. Specimens should be kept one above the other.
3. Drying: Usually after two or three changes the specimens are finally kept in
fresh blotting sheets and dried either by natural or artificial heating.
4. Poisoning: This can be done by using mercuric chloride or Lauryl
pentachorophenate (LPCP) as substitute of mercuric chloride.
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5. Mounting and Stitching: The standard size of a herbarium sheet is 29 x 42 cm,
which is made of durable card sheets. It is advisable to mount one specimen on
each herbarium sheet. Dissected and loose parts such as flowers, fruits &seeds are
kept in paper packets & pasted to the mounted sheet.
6. Labelling : The labels are put on the right hand side, at the bottom of the
herbarium sheets they are of 3” x 5” size and should have the following
information : a) Name of organization with which specimen plant originated b)
Name of the family c) Botanical name of the plant d) Local name e) Locality of
collection f) Date of collection g) Habitat of the plant h) Field notes & collection
no. i) Name of collector.
7. Storage: Plant specimens, which have been properly mounted & identified, are
filled systematically in special wooden/ steel cabinets.
The herbarium sheets
loaded with specimens are filed inside folders which are of various color schemes
indicating species, genus, family , geographical area, etc .Plants are arranged &
stored following bentham & Hooker’s/ Engler & prantl’ system of classification.
8. Fumigation: This is done for killing insects which often damage plant. The
most common method is to keep Naphthalene balls within muslin bags in each
pigeon hole. Sometimes paradichlorobenzene is used. Small cloth bags with PDB
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are placed in the pigeon holes. The chemical also be sprinkled on sheets or
bundles.
Role of Herbarium
 To act as a repository of dried plant specimens, safeguard them against loss &
destruction by fungi, insects, etc. & make them available for study.

Several herbaria of repute, keep Type Specimens – the principal proof of the
existence of a species, in safe custody, often in rooms with restricted access.
 As original documents upon which knowledge of taxonomic characters rests,
herbarium specimens greatly help in developing floras, manuals and
monograph.
 Those engaged in taxonomic studies, can personally identify their engaged
collection by comparison with already identified herbarium specimens.

Voucher specimens preserved in various herbaria provide an index of
specimens on which studies on chromosomes, phytochemistry, ultrastructure
micro morphology, etc. have been undertaken.

Most herbaria have specimens collected from different parts of the world &
thus their scrutiny can provide information on the geographical distribution of
taxa.
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Official monograph
Pharmacopoeia is a reference book for the preparation of quality medicines
published by the authority of a government or a concerned society (e.g., British
pharmacopoeia, Indian pharmacopoeia, Japanese pharmacopoeia), while herbal
pharmacopoeia
and
therapeutic
compendium
represent
qualitative
and
therapeutic monographs on botanicals (description of preparation on single
topic). A pharmacopoeial monograph is a compiled data about Active
Pharmaceutical Ingredients (API) or Products (APP) with its identification tests,
assay method, impurity profile, test for impurity, solubility, storage conditions,
moisture content etc. An herbal monograph is a document that defines a botanical
drug and provides information that allows for its proper identification. It contains
the basic description including;
 Nomenclature,
 Part used,
 Constituents,
 Range of application,
 Contraindications and side effects,
 Incompatibilities with other medications,
 Dosage, use, and action of the herb.
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Pharmacopoeia is an essential reference for all individuals and organizations
working within pharmaceutical research and development, manufacture and testing
around the globe. Herbal pharmacopoeia intends to promote the responsible use of
herbal medicines with the highest possible degree of efficacy and safety through
the development of standards of identity, purity, and analysis for botanicals
including the review of traditional and scientific data regarding their efficacy and
safety. The American Herbal Pharmacopoeia (AHP) and those of other nations
(e.g., the British pharmacopoeia, the European pharmacopoeia, the pharmacopoeia
of the People’s Republic of China, the Indian Ayurvedic pharmacopoeia) intend to
promote the responsible use of herbal medicines with the highest possible degree
of efficacy and safety and disseminate such information through monographs and
other publications. BP is now used in over 100 countries as an essential reference;
the American Herbal Pharmacopoeia (AHP) intends to produce 300 monographs
on botanicals including many of the Ayurvedic, Chinese, and Western herbs most
frequently used in the USA; pharmacopoeia of the People’s Republic of China
(PPRC, Eng. ed. 2000) contains monographs for hundreds of medicinal plants used
in Traditional Chinese Medicine; the Indian Herbal Pharmacopoeia (IHP) in its
new edition covers 52 monographs on Indian medicinal plants; and the African
Herbal Pharmacopoeia (AfrHP) provides comprehensive and up to date botanical,
commercial, and phytochemical information on over fifty of the most important
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African medicinal plants. Many member states of WHO do not possess their own
pharmacopoeia, but they follow one or more pharmacopoeia of other nations (e.g.,
in Australia, herbal raw materials are required to be authenticated to the relevant
possible monograph in the British pharmacopoeia). Since 1999, the World Health
Organization (WHO) has published 117 herbal monographs in four volumes and
also an additional volume (30 monographs, 13 new and 17 adopted from the
existing monographs) for the Newly Independent States (NIS) and Countries of
Central and Eastern Europe (CCEE) to promote international harmony in the
quality control and use of herbal medicines and to serve as models for the
development of national formularies. Each of the WHO monographs contains a
systematically narrated body of information of about a particular medicinal plant or
crude drug on 19 points from (i) Definition, (ii) Synonym to …, (xvii) Dosage
forms, (xviii) Posology, and (xix) References. This guideline for herbal monograph
contains comprehensive scientific references on quality, safety, and efficacy of
medicinal plants, and herbal pharmacopoeia represents qualitative and therapeutic
monographs on botanicals. The monographs of WHO, however, should not be
regarded as official pharmacopoeial monograph to replace official compendia.
Monographs of organized drugs include crude materials of plant and animal origin
such as leaves, flowers, fruit, seeds, stems, wood, bark, roots, rhizomes, ergot,
ephedra or other parts, and Spanish fly, which may be entire, fragmented, or
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powdered, while monographs of unorganized drugs include such material as juices,
gums, fixed oils, essential oils, latex, resins, fish liver oils, musk, bees’ wax,
certain hormones, enzymes, and antitoxins in fresh or dry states.
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