Flora of North America - The Outreach Resources

Species and Specimens: Exploring Local Biodiversity

Collecting and Preparing Plant Specimens

Create your own collection of dried plants. Plants collected and prepared for study purposes are called specimens or scientific vouchers. Any collection of plant specimens is an herbarium (plural, herbaria).

Become a plant collector in a few simple steps

  1. Surround yourself with plants - a field or even your backyard will do.
  2. Find a choice plant, collect parts of the plant useful in identification, and record in your notebook the plant's collection number, information about its appearance, habitat, and location.
  3. Carefully position the plant sample on a newspaper, then fold the newspaper over the plant; write the plant's number from your notebook on the newspaper.
  4. Place samples in the plant press, tighten the straps after adding a new batch of samples.
  5. Place the plant press in a sunny place to dry.
  6. Identify the dried specimens using field guides and floras or the help of botanists.
  7. Mount and label the dried specimens.
  8. File the specimens in a safe storage system.
  9. Get back into the great outdoors.

Materials for Collecting Plant Specimens

       Field notebook        Old newspapers
       Permission to collect        Pencil or permanent ink pen
       Field press        (helpful in identifying your collections)
       Pruning shears or sturdy scissors  

Professional botanists usually carry a number of other useful tools: magnifying lens, compass, altimeter, maps, global positioning system unit, camera, pruning poles, and materials for collecting samples for later anatomical or DNA study.

What to collect? As a plant collector, your responsibility is to prepare samples useful for posterity (that's a long time - specimens collected in the 1700s can still be studied in herbaria).

If possible, select plants with flowers and fruits. They make attractive specimens. But more importantly, many plants are impossible to identify without these parts. Also choose plants that look typical for the species and avoid plants damaged by insects or disease.

Plants come in a wide variety of sizes and shapes, some easier to collect than others. Collecting small herbs is easy. Just pull the entire plant out of the ground by its roots. Fold over a portion of the herb if it doesn't fit on a piece of newspaper (but try not to hide important characters). When collecting shrubs or trees, snip off a branch about the size of a plant press. Spiny plants require special care when handling, and very fleshy plants and large fruit may difficult to fit in a press.

A note on responsible collecting: Respect nature and your fellow human when collecting. No matter where you collect plants, get permission and take only the amount needed to make good specimens. Some plants live only in America's extensive park system. To collect plants on city, state, and federal lands obtain a collecting permit from the authorities. Plants protected by the U.S. Endangered Species Act are very rare and can be collected only with a special permit. Ask for the owner's permission to collect on private property.

What to record in a field notebook? For each plant collection, record

  • Location - Give enough information that someone else could find the same location again. Botanists usually record the state, county, nearest town, longitude, latitude, and elevation.
  • Date of collection and names of all collectors.
  • Habitat type and other plants present; note if the plant grows on rocks or in rivers.
  • Description of features that can't be seen on a dried specimen, such as plant height, flower color and odor, pollinators visiting flowers, etc.

Number each plant collected: Begin the notebook with #1 and continue numbering consecutively. The notebook may record the collecting effort of an entire class, a collecting team, or an individual collector. This number is very important. If the plant cannot be identified with the help of a field guide, the plant is known by its number until a plant specialist can name it.

Collecting can become a passion and a career. Tom Croat has collected more than 85,000 specimens in his 3 decades with the Missouri Botanical Garden. (See Tom and others on the Frontiers of Discovery at http://www.mobot.org/MOBOT/research/unseengarden/

Once the plants are collected they must be dried, or they will mold and rot.

Materials for Preparing Plant Specimens

       Corrugated cardboard        Permanent ink pen
       Newspapers        Index cards or paper labels
       Place to dry plants        Glue
       Sturdy paper or thin, white cardboard        Small envelopes (optional)

A few days sitting in a sunny area with good air circulation will dry most plants. Prepare the plant samples for drying by placing corrugated cardboard or several newspapers between each plant specimen. The corrugated cardboard allows air to flow through the plant press, helping the plants dry. After a few days check the specimens. Remove the dried specimens; rebuild the plant press, replacing any damp corrugates with fresh ones.

In the field, botanists use a number of techniques to dry their plants quickly. Where warmth of the sun is in short supply, botanists often use heat lamps or gentle heat from a stove. Too much heat can be dangerous: The plants can catch fire. Traveling botanists sometimes strap the plant presses onto a car's roof rack, letting the wind dry the plants.

Dried plant specimens are ready for mounting. Glue the plant specimen onto your good-quality paper (or thin cardboard such as a shirt box). If flowers or fruit come loose from the specimen, place them in a small envelope and attach the envelope to the mounting paper. Glue the specimen label (index card or paper label) on the lower right-hand corner of the mounting paper. Fill in the specimen label with the plant's name, collection location and habitat, description, date of collection, collector's name and number.

Decide how to organize your plant collection. Put similar kinds of plants together or arrange the collection alphabetically by plant family, genus and species, or arrange by geographical location. Inspect your collection regularly for insect and mold damage.

For tips on working with a field guide or flora, see the fact sheet How do You Use a Flora?

For more collecting activities and links to online plant collections, see the lesson From Curiosity Cabinet to Museum Collection.