In my fourth and final tour in this series of Smithsonian Institution visits, I will share with you the brief tour Carolyn Sheffield and I took of the U.S. National Herbarium. What’s in an herbarium? Many, many samples of botanical items collected during exploring expeditions all over the world.
Some of the benefits of having a National Herbarium include digitized resources that say what plant might be related to another plant, documentation of what plants grow where, and documentation of new plants that had yet to be discovered. According to the Smithsonian’s web site, the herbarium includes important historical collections such as “the United States Exploring Expedition (1838-1842), United States North Pacific Exploring Expedition (1853-1856), LaPlata Expedition (1853-1856), Mexican Boundary Survey (1854-1855), California Geological Survey (1860-1867), International Boundary Commission: U.S. and Mexico (1892-1894), and Colombia Cinchona missions (1940-1945).”
I was astonished to learn that researchers are able to borrow specimens, and in some cases, take samples from the specimens or dissect them. Our tour guide, Deborah Bell, Assistant Collections Manager, told us that some researchers use the samples to compare DNA with other samples in order to help identify plants. Additionally, researchers may add their annotations to a herbarium specimen if it adds to the knowledge of the plant.
The herbarium’s patrons include plant-science researchers from museums, universities, and botanical gardens around the world, who are engaged in studies of plant species, taxonomy, systematics, floristics, and evolution, says Rusty Russell, Collections Manager. Approximately 250 patrons per year are served by an army of professionals: 14 research curators, 18 research support staff, 8 collection support staff, and 4 informatics support staff. There also are 12 resident associates, pre- and post-doctoral students, and researchers on sabbatical at the herbarium. Notably, there are 20 volunteers per week who help out.
About the Collections
While the Department of Botany at the Smithsonian was established in 1892, the first samples were collected back in the 1840s for the herbarium’s predecessor, the National Institute, according to the Smithsonian’s web site. The herbarium holds 5 million specimens, with a large portion mounted on sheets such as the one shown below.
When I first saw this sheet, I wondered if it had grown some mold (from the gray spotted areas of the sheet). Deborah told us that it wasn’t mold, but in fact, the result of contamination by mercuric chloride. She said that mercuric chloride had been used as a fungicide by the scientists collecting the samples out in the field. When first applied, it appears clear, but then grays over time.
Here’s Deborah showing us some samples from the sample cabinets.
Some of the samples are quite old. For example, the materials below date from 1877.
Samples of flowering plants can comprise leaves, branches, flowers, fruits, and seeds. Other specimens include algae, lichens, mosses, and related organisms. Below is a sample of algae. I’m amazed by how it was able to keep its color.
The collections also include paper-based records, electronic records, images, maps, illustrations, and more. There are more than 280 families of botanical materials at the herbarium, organized from most primitive to most highly evolved. For example, below, Deborah shows us some bamboo skeletons.
She said that different bamboo species flower at different intervals and, when they do, every individual of that species flowers regardless of location. When that happens, like annual plants, they all set seed and die. An entirely new generation of that species arises from seed. It's pretty miraculous, if you ask me.
If you’re interested in doing some hunting in the cataloged collections (only one-fifth of the vast collections have been inventoried, but that’s almost 1 million items from which to choose, so it will keep you busy), you can do it online here: http://collections.mnh.si.edu/search/botany/?ti=3. In-person visits must to be arranged in advance, but if you’re a serious botanist, you should definitely visit our nation’s herbarium. It’s run by a great group of folks who tell fascinating stories and are very knowledgeable about the collections.
Collections and Informatics
United States National Herbarium
MRC166 - Botany
P.O. Box 37012
Washington, DC 20013-7012