Herrick Brown, Chanda Cooper
Collecting and preserving plant specimens is an important aspect of botany. A specimen—typically a
dried, pressed plant—serves as a permanent record of the appearance of an individual plant;
documents when, where, and the conditions under which a plant occurs in nature; provides plant
material for researchers to study at any time of the year; and can be cited as a reference in
publications. If properly curated (protected from moisture and insect damage), these specimens can
last hundreds of years. A collection of pressed, preserved specimens is called a herbarium.
Plant press configuration
- Plant press(es), 12" x 18"
- Field presses may be made from cardboard and tape
- Adjustable straps
- Ventilators (cardboard sheets, 12" x 18")
- Felt blotters (newspaper can be substituted)
- Permanent marker
- Field notebook
- Writing instrument (preferably something that won't smudge if/when wet)
- Hand shears
- Acid-free mounting paper (standard herbarium size is 12" x 18")
- Acid-free glue
In the field, you will need a field press, straps, newspaper, cardboard (optional), hand shears, a
field book, and a pen or pencil. Typically, only plants which are flowering or fruiting are added to
an herbarium, although sterile material may be collected if necessary or desired. Collect as much of
the plant as possible, including roots, stems, leaves, and especially flowers or fruits. If
the plant is small, pull it up by its roots. Next, arrange the plant in a folded piece of newspaper
(you may need to bend a long plant into an "N" shape or trim a large specimen down to size).
Remember that the plant will eventually have to fit onto a 12" x 18" paper. Number the newspaper
sheets as you go, and write the corresponding number in your field book along with notes about the
plant's location, habitat, and appearance. Most botanists maintain the same numbering system through
out their life, so your very first plant will be your only specimen #1, and after a few years, you
may have thousands of specimens.
As soon as possible after returning from the field (and certainly no more than two days later, as
your plants will begin to mold), prepare your specimens for drying. Transfer your plant specimens
into fresh, dry pieces of newspaper and carefully arrange the leaves, flowers, and stems as you want
them to appear when they are dry. Be sure that some leaves are right-side-up and others are
wrong-side-up so that both sides will be visible when the plant is glued down. Write the specimen
number on the newspaper. Stack the specimens in a plant press according to the following
arrangement: plant press base, cardboard, blotter or extra newspaper to absorb moisture, plant
specimen, (another blotter or more newspaper if the plant is fleshy or damp), cardboard, repeat.
Once all specimens are stacked in the press, slide the straps over the ends and pull them as tight as
possible. Kneeling on the press or having a friend stand on it while you pull the straps may be
helpful. Ideally, the press should then be placed in a low-heat drying oven (some ideas for making
your own drying oven are available on the
Botanical Garden website). However, botanists have successfully created herbarium specimens for
centuries without the aid of drying ovens. Keep the press in a warm, dry location (a car parked in the
sun, for example) and change the newspapers if they feel damp to avoid mold.
Creating Herbarium Specimens
Example specimen label
Once the plants are completely dry (a matter of days for small, thin plants and weeks for thick,
watery plants), they are ready to be labeled and mounted. A label should contain, at minimum, the
collector's name, the specimen number, the date the plant was collected, its scientific name (if
known), family name (if known), and information about the plant's location, habitat, and appearance.
The more information you include, the more useful the specimen will be to future researchers. Use
acid-free paper to print your labels; otherwise, they will eventually disintegrate and cause
consternation for the curators of your herbarium. The last step is mounting the specimens and their
labels on herbarium paper. Dots of acid-free liquid glue are usually sufficient to hold a plant in
place. Traditionally, labels are affixed to the lower right-hand corner. Separate specimens with
wax paper and cardboard so they will not stick to each other and will dry flat.
Congratulations! You now have your own herbarium. Store your specimens in a dry location and
protect them from insects. Many large herbaria, such as the
A.C. Moore Herbarium at the University of South Carolina, will be interested in adding some of
your specimens to their collections for research and reference.