BERAU HERBARIUM

Field books, pencils, paper, number tags (tie-on watchmakers tags), newspaper,
plastic string
Climbing equipment including harness (figure 8), climbing ropes of different length,
shoes with spikes, leather gloves
PRESERVATION OF SPECIMENS
Figure 9: Preparation of fresh material packing
Damaged material is worthless to a herbarium.
Fresh plant specimens will quickly rot or be
damaged by mildew unless preservative treatment is
given. Preservation techniques include drying and
chemical treatments.
Chemical treatment (Wet or Schweinfurth method)
Drying specimens in the field is time consuming and
the result often unpredictable. It is better to preserve
plant specimens in the field using methylated alcohol
(spiritus) at an 80% concentration. Whereas the
disadvantage of wet preservation is that the liquids
are bulky and heavy to carry, the material can be
kept in sealed plastic bags for as long as nine
months. To achieve this the spiritus should not drop below a concentration of 70%.
Each specimen, with its number tag, is
placed between newspaper sheets (figure 9).
Any plant parts sticking out from the
newspaper are clipped to stop them later
puncturing plastic bags (figure 10).
Figure 10: Trimming of plant samples to newspaper size
When enough sheets have been accumulated
make a convenient-sized bundle, the bundle
is compressed and tied (figure 11).
Bulky and spiny material is best placed in
the centre of the bundle.
The bundle is then put into a heavy polythene bag. About half a litre of 80% spirituous is
added per 10 cm of bundle height (figure 12). When full, the open end of the bag is folded
and sealed. The alcohol fills the bags as vapour, and preserves the contents. These bags
should be packed into a suitable strong sack for extra protection. Rice sacks are fine for this.
The final package is very robust and is strong enough to be carried and posted.
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