Botanical Treasures from Duke's Hidden Library

Delesseria decipiens

The Duke Herbarium contains over 800,000 specimens collected from all over the world since the mid-1800s—but scientists are not done! Duke faculty, staff and students still go out in the field to collect specimens for current research studies. As with any scientific pursuit, botanists need both new and old materials for their experimental analyses. Collections can document how the plant diversity of a particular region has shifted through time. They can also lead to the discovery of a new locality record, or even the description of a new species.

In recent years, Duke Herbarium botanists have traveled to Siberia, Sweden, Peru, Brazil, Malaysia, Taiwan, New Caledonia, Fiji, and Tierra del Fuego (as well as all over the U.S.) to collect plants for sponsored research projects.  

Generating herbarium specimens is a multistep process, which is outlined below:

Students collecting herbarium specimens.

A professor taking notes in the field about botanical specimen.

A press used to preserve specimens.

Hexastylis contracta

1. Find

Collecting plants “in the wild” is the first step toward generating herbarium specimens. To collect plants, a scientist has to plan ahead, which may involve obtaining collecting permits, buying plane tickets, and securing ground transportation. Depending on what is being collected, the botanist might have to scale steep rocky slopes, creep along riverbanks, or trek through marshy swamps. Plant collecting is full of adventures and sometimes even danger. Think Indiana Jones!

2. Identify

While doing fieldwork, the botanist looks for plants that exhibit as many “useful features” as possible. Flowers, fruits, spores, and seeds are critical for identifying the plant to species.
 

3. Collect

When the botanist finds a suitable specimen, the plant is carefully extracted from its habitat, with minimal damage to the roots and other delicate plant parts. Detailed notes about the plant’s specific location and other significant features of the plant and its habitat are made in a field notebook.

4. Preserve

While still in the field, the botanist arranges the plants between folded sheets of newspaper and inserts these collections between blotters and corrugated cardboard sheets that are stacked one on top of another to make up a multi-layered plant press—just like a Dagwood sandwich! The press is tightly secured with straps so that the plants inside are pressed flat, removing the moisture. Once a specimen is dry, it is preserved indefinitely and less likely to be destroyed by decomposition.

5. Label

A label is created that documents a tentative identification and exactly where, when, and by whom the specimen was collected.

A collection number, composed of the collector’s name and a number, is similar to a book’s ISBN number in that it is a unique identifier used to pinpoint a specimen.
 

6. Mount

After the collecting trip, the plants are brought to the herbarium.

To turn a pressed and dried plant into an herbarium specimen, the plant is glued onto a sheet of acid-free archival paper. String and linen tape are used to secure any loose, bulky, or delicate parts.

Lichen and moss specimens are often secured in folded packets instead of being glued directly to a sheet. Fungal specimens are not pressed and are stored in labeled boxes.

7. Catalog and Share with the World

Finally, a record of this new specimen is entered into a digital herbarium database and becomes available for researchers all over the world! Researchers can also “check out” specimens on loan, just like books from libraries, and request permission to remove small samples for DNA analysis. Every year, thousands of herbarium specimens are shipped to and from the Duke Herbarium for use by researchers.