People Plant Collecting
Student Activity Sheet #3a
HOW TO MAKE A SCIENTIFIC PLANT COLLECTION
MAKING A PLANT PRESS
When scientists preserve a specimen of a plant (or
part of a plant) they usually flatten it, dry it and mount it on special
paper. Preserved in this way the plant specimen can be stored for many
years without falling apart.
To get a good preserved specimen, the plant material that is collected
in the field must be of good quality. A half-dead, wilted or dry plant
does not press well and will not make a good preserved specimen. Select
plant material that is growing well, is healthy and is representative
of that type of plant growing in the area. When collecting the specimen,
cut it to a size that will fit conveniently in the plant press. If the
specimen is small enough, it can be pulled from the ground so that the
whole plant, roots and all can go into the press. Sometimes a specimen
will need to be folded over or trimmed a little to make it fit in the
Plants that have been collected need to be pressed as soon as possible.
Plants can be kept in a paper or plastic bag for an hour of so, but once
they start to wilt they make poor specimens. Press cut specimens as
soon as possible.
The preservation process begins by flattening the plant specimen in a
plant press. A plant press is made of newspapers, cardboard, blotter paper
and wood and is held together with nylon straps. See the drawing below:
Plant Press Construction
Work in groups of two and make one plant press for your group. The press
should be put together as shown in the diagram above. Materials for your
plant press have been cut for you. The wooden pieces are the top and bottom.
The cardboard and blotter paper are alternated and strapped into the press.
Do not put any newspapers in the press yet. They will be used for
individual plant specimens and will be placed in the press when the specimens
are collected. Place two straps around your press to hold it together.
Write the names of the people using the press on the name label.