herbarium types and techniques,its application

1. HERBARIUM
TYPES AND TECHNIQUES

2.  Herbarium is a collection of plants, which have
dried, pressed, mounted on herbarium sheets,
identified & classified according to some approved
system of classification
Luca Ghini initiated
the art of herbarium
making by pressing
and sewing
specimens on
sheets of paper

3.  Herbarium contains mostly vascular plants, but the
fungal and bryophyte collections are becoming more
active.

4. TOOLS FOR HERBARIUM PREPARATION
1) Digger/Trowel & Pruning Knife/Shear

5. 2) Vasculum
 Container-useful for handling & keeping the
specimens fresh before pressing them.

6. 3) Field Notebook
 To make field notes about the specimen

7. 4) Plant Press & Folders

8. Specimens have two parts …
1. The plant material

9. 2) Label
o Lbel is the important part of herbarium

10. HERBARIUM TECHNIQUES
 It involves a series of operations, such
as collection, pressing, drying and
poisoning, mounting and stitching,
labelling, filling and deposition.

11. 1. COLLECTION OF SPECIMEN
 Collection of botanical specimen
include 2 activities
 Gathering the specimen
 Recording th information

12. a) Gathering the specimen
 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 25cm with leaves & flowers, will
form an ideal material.
 Note sheet’s no. & data recorded in the field
notebook
 Soon after the specimens are collected, they
should be pressed in the field itself.

13. b) Recording of the data
 Should keep careful record of collection
data and field observation using field
notebook
 These record can use later for preparing
collection report
 Type of data recorded will depend on the
collecion, it iclude
- Collection number
- Name of collector
- Location
- Habitat information

14. 2) PRESSING
 Specimens should be carefully placed in
the centre 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 & on the sides
 Specimens should be kept one above the
other

15. 3) DRYING AND POISONING
 For effective drying, drying papers are replaced
by fresh ones
 Changing of papers is repeated everyday for
about fortnight, or until the plant specimens
appear perfectly dried
 In the humid climate, the changing of papers is
done twice a day to have good results
 Artificial heat may be given if the weather is too
humid

16. 4) MOUNTING AND STITCHING
 The standard size of a herbarium sheet is 29 x42 cm
 The dried specimens are glued on herbarium sheets
and the stem/branches can be stitched/glued with
cellophane tapes
 It is advisable to mount one specimen on each
herbarium sheet
 Dissected & loose parts, such as flowers, fruits &
seeds, are kept in paper packets & pasted to the
mounted sheet.

17. 5) LABELLING
 Name of organization with which specimen plant
originated.
 Name of the family
 Botanical name of the plant
 Local name
 Locality of collection
 Date of collection
 Habitat of the plant
 Field notes & collection no.
 Name of collector

18. 6) FILLING AND STORING
 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 colour schemes
indicating species, gen

19.  Plants are arranged & stored following
Bentham & Hooker’s / Engler & Prantl’s
system of classification us, family,
geographical area
 A periodical fumigation with chemicals
& re poisoning them by brushing with
solution of HgCl2 & using insect
repellents would save the herbarium
from damage & check the loss of
valuable plants.

21. PEST CONTROL
1. Treating of incoming specimen
 Specimen have to be pest free before
they get incorporated (Achieved in 3
days)
 Heating
 Up to 60°c for 4-8 hrs
 Effective but specimen will brittle
 Deep freezer
 Temperature of -20 to -60°c
 Microwave ovens

22. 2. Use of repellants
 Chemicals with offensive odour and tate
eg. Paradi-chlorobenzene (PDB)
PDB is more toxic, prolonged use may cause
harm to workers
3. Fumigation
 Involves exposing of specimen to the vapour
of crtain volatile toxic substances
eg. Ethylene bromide, Ethylene oxide,
Malathion
mixture of ethylene dichloride and carbon
tetra chloride (1:3)

23. 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 & monographs

24.  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

25.  Based on the contents and notes on
the sheets ,3 types
1) Regional herbaria- collection from
a particular region
2) Local herbaria- collection from a
local area
3) National herbaria- Specimen from
different parts of the country

26. Madras Herbarium (MH)
 One of the oldest and renowned herbaria of the
world
 Started in 1873 by Lawson, Situated at
coimbatore
 Housing many valuable classical collections of
Rottler, Hooker & Thomson, Wight, Bourdillon,
Beddome, Lawson, Barber, Gamble and
Fischer.
 Besides the collections from Southern India, this
herbarium also has specimens from the Indian
subcontinent and of Europe, Africa, Australia,

27. Central National Herbarium (CNH)
 National repository with about 2 million
plant species
 It is one of the largest herbaria in the world
 William Roxburgh established this
herbarium in 1795 at his office-cum-
residence
 In 1883 the herbarium was shifted to a
specially built building
 Maintains exchange relations with various
reputed international herbaria

28.  More than 15,000 type specimens, the
Wallichian collections, with more than
12,000 specimens, and one of the few
lithographed copies of Wallich’s catalogue
are housed in this herbarium
 Further, there is a large collection of
coloured illustrations, with the 2583 coloured
illustrations
 Graphic material is continually added in the
form of photo negatives and Cibachrome
prints of types and authentic materials
obtained from Kew Herbarium, England.

29. Thank you