BERAU HERBARIUM

This newspaper folder is put on corrugated
cardboard (figure 14). In the case of thick and
fleshy fruits or flowers, a piece of foam the
same size as cardboard, with relatively big
holes, should be put on top of the folder. This
keeps the leaves flat and the cardboard level.
The specimen can than be put directly in the
drying stove. This procedure should be repeated
until the drying stove is full. A wooden board
should then be put on top of the pile with a
heavy weight like a stone on top. This will keep
the specimens flat during the drying and
shrinking processes, as the pressure always
remains the same. Temperature should be kept
70°C to avoid overheating and burning of the
paper as well as the material.
All specimens should be dry within 36 – 48
hours, however, after 24 hours material should
be checked for specimens that are already dry
(figure 15). These should be removed. If the
drying process takes too long the material can
become brittle.
PROCESSING UNMOUNTED SPECIMENS
As a rule usually 7 – 9 duplicates of each tree
will be collected. At least one set remains in
Berau, the other duplicates should be sent to the
Wanariset herbarium to be distributed later to
other herbaria (L, BO, BZF, K, A, SAN, etc.).
When sorting duplicates, the following points
should always be considered:
� If the flowers are unisexual, both male
and female flowers should be
represented in each duplicate.
� As far as possible make sure that each
duplicate has a complete range of stages
– flower buds, flowers, young fruits,
mature fruits
� Each duplicate should have a label
attached together with an “Ex HERB”
slip or a cancellation stamp
Figure 14:Layers of foam and cardboard keep leaves flat
during drying
Figure 15: Unpacked, dry fertile specimen with number tag
12