From Plant Press, Vol. 22, No. 3, July 2019.
By Shannon Hicks and Erika Gardner
Tucked away in the US National Herbarium’s mounting preparation room is a specimen conservation cabinet that temporarily holds specimens in need of repairs. Many specimens are in need of simple repairs, but in some instances, the specimens require a major overhaul. One bundle awaiting repairs is a stack of 55 Poaceae specimens collected by Agnes Chase and Albert S. Hitchcock. The original herbarium paper and specimen label was acidifying and extremely brittle. With time, the plant material on the sheet would be compromised and eventually succumb to shattering with the slightest bump. It was pertinent to get these specimens remounted and filed back into the main collection as soon as possible for scientific use. Shannon Hicks, Botany summer volunteer, worked to get these specimens fully conserved.
Agnes Chase, born Mary Agnes Meara in 1869 in Illinois, was a pioneer for women in botany. In 1903, Chase began work as a botanical illustrator in the National Herbarium for the U.S. Department of Agriculture (USDA). Chase was a self-taught botanist; she would often stay late at the herbarium so that she could learn as much as possible about botany. Since her highest level of formal education was grammar school, her years as a botanical illustrator served as her primary form of education. She became very passionate about Poaceae, the grass family, later saying that, “Grass is what holds the earth.”
After a few years as a botanical illustrator, Chase’s enthusiasm and aptitude for botany was noticed by agrostologist Albert S. Hitchcock. Chase and Hitchcock worked together for many years, and she later succeeded him as Senior Botanist in charge of systematic agrostology at USDA in 1936. In 1937, Chase became in charge of the grass section of the National Herbarium, gaining the title of Custodian. Throughout her career, Chase traveled worldwide to study grasses; she often funded her own trips with the help of several women’s rights organizations she was a part of because the government would not pay for her to travel on other expeditions. In 1922, Agnes Chase’s First Book of Grasses was published, intended to demystify the study of grasses. By the end of her career, Chase had over 70 publications describing and classifying America’s grasses and had contributed 12,000 grass specimens to the herbarium.
This summer, Hicks conserved specimens from a 1908 field trip that Chase took with her mentor, Hitchcock, for the book they coauthored, The North American Species of Panicum. The specimens were mainly from Colorado, Wyoming, and Idaho. The grasses collected were primarily from the genus Poa, a very common group of grasses.
Specimen before and after restoration. Left: Signs of brittle paper crumbling is found near the bottom left corner of the sheet. Tears and rips would continue to occur if specimen is left in this condition on acidic paper. Right: All restored specimens are mounted on paper products that are pH neutral and museum archival quality. The original label is kept with the specimen.
The specimen conservation process is a very intricate one with many steps to ensure that the specimen is returned to a state where it will last for at least another 100 years. he first step in specimen conservation is to carefully dismantle or remove the plant from the herbarium sheet without incurring damage. Fortunately these specimens were not glued directly to the herbarium paper. The original adhesive strips that were used to tack down the specimens had begun to deteriorate or had broken. Using tweezers and a probe, Hicks carefully removed the strips and placed the plant in a newspaper folder, and loose seeds and flowers in an archival fragment packet. These fragments contain genetic material that could potentially be valuable to researchers. Each specimen label, sheet number, and annotation/note were cut from the sheet and kept with the plant to later be transcribed onto archival paper.
After the sheet was dismantled, the specimen was mounted onto archival paper. Remounting grasses requires an artistic eye because the goal is to make the specimen a usable identification and research tool. Hicks rearranged the specimens in a way that showed significant characters, such as the flower spikelets, auricles and ligules, which are used as a means for identification. The trick to mounting specimens is to not use too many strips and to arrange them in a way that is both functional and aesthetically pleasing. Some specimens, those that had bulky bases and roots, required sewing. After mounting, Hicks tested each specimen to make sure that all parts of the plant were properly tacked to the sheet.
Recreating labels is a very important part of the conservation process as it documents the scientific name of the plant, who collected it, and where it was collected. Chase often described the habitat where the plant was found and how it grew. Transcribing the labels was very challenging at first because Chase hand wrote all her labels. Often Hicks compared words and letters on different labels in order to decipher another. It became like detective work, and Hicks learned to recognize how Chase wrote specific letters and words. Once each label was printed on archival acid-free paper, it was glued onto the sheet. All original labels and notes were then stored in separate fragment packet, which were also attached to the sheets.
Hicks checked each scientific name for taxonomic changes. Paul Peterson and Rob Soreng’s recently published grass family phylogeny <https://dx.doi.org/10.1111/jse.12262> proved useful. For each grass specimen that had a name change, Hicks attached an annotation label to the specimen. After the specimens were conserved, they were handed over to the Poaceae team, which is currently working on rehousing and organizing the entire Poaceae collection. These valuable specimens will be refiled into the main collection and will be of great use to the scientific community for many years to come.
Thank you for this wonderful story! Please insert a link to the Peterson and Soreng phylogeny paper...also, how about a photo of Chase and Hitchcock in the field? Would love to see that!
Posted by: Denise E. Costich | 08/27/2019 at 09:58 AM
A link to the Peterson and Soreng phylogeny paper has now been added to this story. It is available at https://dx.doi.org/10.1111/jse.12262 . A photo of Chase and Hitchcock has also been added to this story. Thank you for your feedback.
Posted by: Gary Krupnick | 08/27/2019 at 03:09 PM