A. Collection of Specimens
Whenever possible, material should be pressed immediately after collection, and for some species,
particularly herbs, this is the only manner in which high quality specimens can be obtained. However, it
is not always convenient to carry your field press, and in such circumstances, satisfactory results can be
obtained for most species by storing the material in a sealed plastic bag until ready for pressing
providing they are stored under cool conditions and pressed within a few hours of collection.
B. Choice of Specimens
1. Ensure that the specimen has identifiable parts present (Vegetative material alone may be
exceedingly difficult to identify, and its value for comparative purposes is limited). For example, try to
include either fruits or flowers. For wildflowers, include both basal and upper leaves when possible.
2. If the species is herbaceous, try to include the underground parts to show their character.
3. Select healthy specimens free from insect damage, fungal infestation, etc.
4. Choose most specimens from typical plants, not from the occasional rare oddity.
C. Arrangement of Specimens for Pressing
1. Wherever possible, arrange one or more leaves with the lower side up.
2. Ordinarily, a specimen should be restricted to the size of the pressing paper.
3. Herbaceous specimens longer than the pressing paper may be accommodated intact by folding.
4. All roots or underground parts should be washed free of soil before pressing.
D. Equipment required for Pressing Specimens
1. Plant Press Notebook - The efficiency of a plant press is determined largely by its ability to hold
material under a constant and firm pressure while allowing the specimens to dry. Bricks, books, or other
weighty objects which can be used to maintain a firm even pressure, compressing the notebook when
not in use.
2. Absorbent Paper - Absorbent paper between specimens is used to remove water as the plant dries.
Newspaper or paper hand towels are satisfactory. Tissues are not recommended because with succulent
stems, leaves with glandular secretions or flowers with high quantities of nectar, they become stuck to
the specimen and cannot be removed easily.
3. Tape or Adhesive - Taping specimens using clear adhesive tape is OK. If gluing, a match or small stick is
suitable for applying the glue to the specimen. Care must be taken that all parts of the specimen in
contact with the paper receive a supply of glue.
E. Pressing Specimens
Care must be taken that excessive pressure is not applied resulting in squashed specimens having a
misleading appearance e.g. flat stems which should be round. The amount of pressure is variable
depending on the hardness of the specimens involved.
F. Drying Specimens
Specimens should be arranged appropriately and allowed to press for 24 hours. The press should then
be opened and the absorbent papers changed as needed. Specimens are usually allowed to dry from 1014 days. For some species, particularly succulents or nectar producing plants, it may be necessary to
change the absorbent paper several times.