When I first joined the faculty at The College of New Jersey, in 2012, I knew we had a small collection of herbarium specimens available for use in our classes. The specimens were tucked away in the cabinets of the botany lab. At the time, my attention was turned to setting up my lab and continuing my existing plant systematics research agenda, but five years later, a planned renovation of the area where the specimens were kept gave me a reason to sort through these collections more carefully. Upon doing so, my students and I discovered a fascinating story about the origins of this small collection, a more than century-old link to botanical studies in the area, and a reminder of the value of preserving historical specimens that document how plant life is responding to a changing world. Within the collection were nearly 450 specimens collected during the late nineteenth century by three students enrolled in what was then the New Jersey State Normal School. One of the students, Nelson H. Pepper, had collected more than one hundred specimens in the spring and summer of 1892. Some of his specimens were exhibited the very next year at the 1893 Chicago World’s Fair, bringing examples of the plants of Trenton, New Jersey, to an international audience.
As I pulled out one of the first specimens, I noticed that the unmistakable pink anthers of the spring beauty (Claytonia virginica) were still visible under the white petals of the flower. The paper, thinning and stained with a shadow of the plant pressed upon it, could no longer support the weight of this 115-year-old specimen. This page was one of a hundred or more specimens that were kept together by a tattered leather binding. Nelson Pepper’s name was still legible in gold print on the spine, along with the word “HERBARIUM.” Several folders were loosely stacked in alphabetical order inside the leather cover, each marked with botanical family names. The violet family (Violaceae) was located toward the bottom of the pile, with ten specimens of flowering violets collected in late April and May of 1892. Each plant was pressed and arranged carefully, permitting this set of specimens to illustrate the major differences of Viola species he collected in New Jersey. Each heart-shaped leaf of Viola striata and each arrow-shaped leaf of V. sagittata were separated to show the entire outline of each leaf, and the highly dissected leaves of V. pedata were similarly spread across the page. Nectar spurs—short and rounded in V. cucullata and long and pointed in V. rostrata—extended out the back of the bilaterally symmetric flowers.
The two other books from the same era, compiled by Sarah Elizabeth Kandle and Margaret Todd, also included over one hundred specimens. Our understanding is that all three collectors were completing an assignment for their botany class, led by professor Austin Apgar. In Apgar’s more than forty-year career at the college, he was the botany and zoology instructor and, later in his tenure, the vice principal. All the while, he was a strong advocate for the establishment of the New Jersey State Museum. In his book Trees of the Northern United States: Their Study, Description and Determination for the Use of Schools and Private Students, published in 1892, Apgar presented a text for educating specialists and nonspecialists alike in botany. In the opening pages, he alludes to his own pedagogical approach of immersing students in studying botany and natural history. “Teach [the student] to employ his own senses in the investigation of natural objects, and to use his own powers of language in their description,” Apgar writes. Standing in his place a century later, with twenty-first-century students in my research group, I have continued the tradition of asking students to observe and document various aspects of plant diversity, such as floral morphology or geographical distribution, as they begin to explore possible directions for their own work.
After subjecting our collection to a typical freezing regimen applied to any specimen that has left an herbarium (to eliminate mold or insects), we relocated these books to archival boxes in the single herbarium cabinet in my lab. We then began the careful process of recording information from these specimens, wearing gloves to prevent further damage to the paper. The collection was rather typical of older herbarium specimens, having handwritten labels with little more information than a plant name, collection date, and vague locality. Herbarium labels now regularly include more information documented by the collector, such as detailed descriptions of the plant at the time of collection, robust accounts of the locality and habitat of the plant, and references to co-occurring species. Collectors increasingly include GPS coordinates, especially now that these data are collected with a tap on the screen of a smartphone. Most herbaria are likely to have more-recent, higher-quality collections of the nearly three hundred species documented in our herbarium books. Yet, these historic specimens represent an important snapshot in the history of the landscape surrounding Trenton, which has undergone significant changes over the past century. The specimens offer unique data points for the occurrence of these species and the developmental stage of the plant at the time of collection.
My undergraduate research team often uses herbarium specimens in their work. The College of New Jersey is a primarily undergraduate institution, and at any given time, my lab is comprised of six or seven undergraduates engaged in multi-semester research projects directly related to my ongoing studies in plant systematics. Students working with me begin by engaging with projects that match their interests and then take their investigations in new directions often inspired by their own observations from herbaria or living collections. We are fortunate that our college is located near major herbaria such as the New York Botanical Garden’s Steere Herbarium and the herbarium of the Academy of Natural Sciences of Drexel University, which have holdings of 7.8 and 1.4 million specimens, respectively. And now, as a result of major efforts to digitize museum collections, my students can access images of specimens from herbaria across the globe while sitting in the lab. Yet, as my students embarked on extracting data from the historic sheets, deciphering the handwritten labels and updating names to reflect the latest taxonomic changes, this time they had a direct connection to the collectors. In reflecting on their experience transcribing data from these specimens, student collaborators Linda Zhang and Aaron Lee wrote, “Between the faded illegible cursive and yellowed paper we got a glimpse of the lives of collectors and students that spent their time gathering, identifying, and preserving these records with little knowledge that they would be stumbled upon over a century later.”
A third student, Matthew Fertakos, came to see this collection as a way to think about how individuals of the same species, divided by time, may change their biology in response to the environment. Matthew had become fascinated with published studies that used herbarium specimens to document how important phases of a plant’s life cycle, such as flowering, may have changed over the past century in conjunction with changes in climate. As a DaRin Butz Intern at the Arnold Arboretum, he learned to generate maps that show the predicted distribution of a species based on locality data gathered from herbarium specimens and corresponding climate data for the year the plant was collected. Combining these two interests, Matthew asked what changes were happening in the rare but notable ecosystems of his home state, New Jersey, such as in the Pine Barrens. To date, his work has incorporated over eighteen hundred herbarium specimens, some dating back to the same era as our small collection. Many of the specimens were obtained from the Chrysler Herbarium at Rutgers University, the same institution that generously assisted with digitizing our own small collection. Focusing on a dozen herbaceous species native to the Pine Barrens, Matthew has used these herbarium specimens to generate distribution maps and estimate the first flowering date for many years over the past century. His work continues to test for correlations between changes in first flowering dates and shifts in climate to understand why some species native to the Pine Barrens now exhibit earlier flowering dates than the century prior.
Matthew’s work, inspired by this small collection, joins an ongoing movement that demonstrates the hidden potential of these historical artifacts to provide information about the effects of climate change on a plant’s biology. Over the past decade, herbaria worldwide have prioritized efforts to digitize their collections, increasing accessibility not only to botanists but to all scientists whose work could benefit from these data. The renewed life that digitization has brought to museum collections has also allowed us to establish our own herbarium at The College of New Jersey, registered with Index Herbariorum, the international registry for herbaria. Now, our collection, currently focused on historical plants of the Trenton area, will soon be accessible to all. Within this digital collective, our small collection is more powerful than it could have been alone.
The fact that our collection was preserved, waiting for students to use them, was not a coincidence. The families of collectors saw value in these specimens. Rather than ignoring or discarding the specimens among other attic keepsakes, the families donated these otherwise dusty old books of plant pressings back to our department. Now, more than a century after the specimens were mounted and nearly a quarter-century after the collections returned to our department, we are in a unique position to be able to breathe new life into these plants and use them in our quest to understand the effects of climate change on biodiversity, assessing changes that have happened over the past and predicting changes that will happen in the future. The story of how the collections returned to us is a testament to the value and power of amateur botanizing (what we would today call “citizen science”) and experiential fieldwork as part of an undergraduate education. As an instructor, I share Apgar’s emphasis on engaging students in hands-on observation and documentation of the natural world, and I stress to students the importance of preserving these botanical legacies. Now, the historical plant collections from our region of the country will join the millions of specimens available digitally as the botanical community continues to ask more questions about biodiversity in an ever-changing landscape.
Wendy Clement is an associate professor of biology at The College of New Jersey. She is a plant systematist and evolutionary biologist, and her current research focuses on the evolution of fusion in honeysuckles. She is a current James R. Jewett Prize awardee at the Arnold Arboretum.