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The Digitization Revolution: New Discoveries From Old Collections

Arkansas Natural Heritage Commission - Wednesday, January 29, 2020
by Theo Witsell

In 1999, when I was wrapping up an undergraduate degree in botany, most of the professional botanists in the state got together and formed a working group called the Arkansas Vascular Flora Committee. This committee came together around the common goal of compiling an updated checklist (and later an atlas) of all the wild plants known from the state, a project that I was fortunate to get to work on early in my career here at the ANHC.

For a species to appear on an official list of this sort, there must be some kind of verifiable documentation, or “hard evidence,” of its occurrence in a specific place, and not just a verbal report that someone saw it somewhere. The standard level of documentation is the citation of a “voucher specimen” deposited in an herbarium. This connection of a report to a physical herbarium specimen allows other researchers to examine that specimen, confirm its identification, and verify the information contained on the specimen’s label.

Back when we worked on the checklist and atlas, almost no specimens were digitized and very few herbaria had even written a list of their holdings. At that time, if you wanted to know what was in a particular herbarium you would have to travel there and go through the collection cabinet by cabinet, a process that could take weeks in a large collection. The costs and time required to do this made it untenable beyond the few collections housed in or near Arkansas, so the original checklist and atlas were based primarily on specimens here in the state.

Fast forward to 2020, and it’s a whole different world thanks to the efforts of the SouthEast Regional Network of Expertise and Collections (SERNEC) and other regional consortia of herbaria. SERNEC, a consortium of 233 herbaria (of which ANHC is a member) in 14 states, is the Southeast U.S. regional hub of an even larger effort to digitize all the world’s plant specimens and make them available online. We’re basically creating one big virtual herbarium where any researcher can log in on a computer and examine high resolution images of specimens of interest; it is difficult to overstate how much this resource is revolutionizing the study of botany.

As of January 2020, there are nearly 236,000 specimen records from Arkansas available through the SERNEC portal, with more being added regularly. However, only about 127,000 of those are located here in Arkansas herbaria. We had a pretty good idea of what specimens were housed in-state from the work on the checklist and atlas, but the 109,000 specimens from Arkansas housed in the out-of-state institutions that are now accessible contain a treasure trove of new data. We are learning so much that we didn’t know about the flora of Arkansas from our ongoing processing of this dataset. It has revealed species that we didn’t know occurred in Arkansas, improved our understanding of the range and habitat needs of many species, and alerted us to many occurrences of species of conservation concern that we didn’t know about. There are many examples I could highlight, but here is one of my favorites:

In early 2018, I conducted a search on the SERNEC portal for all grass specimens known from Bradley County. In the search results were records of two species, Kissimmee water grass (Paspalidium geminatum) and Eaton’s rosette grass (Dichanthelium spretum), neither of which we knew occurred in Arkansas. The specimens were collected on the same trip in 1988 from rare saline marsh habitat at Warren Prairie Natural Area (NA) and are stored in herbaria at the University of South Alabama, the University of South Carolina, and the Botanical Research Institute of Texas.

After carefully examining images of these specimens, and confirming their identification, I made a trip down to Warren Prairie NA to see if I could find them in the field. Sure enough, after a little looking, I found robust populations of both species, right where they had been documented 30 years before. Both species, and their habitat, were thriving. It turns out that the specimens were collected by a former ANHC staff member and sent to an expert for identification. Between the time that the specimens were sent off and the identified specimens were distributed, that ANHC employee had taken a job in another state and word never made it back about the grasses. Both are considered rare natives here and are restricted to a rare habitat, which makes them species of state conservation concern. In addition, their only known sites in the state are under our care on a state natural area.

Photos: Top - University of South Alabama specimen of Kissimmee water grass (Paspalidium geminatum) collected in 1988 at Warren Prairie NA. Botanists in Arkansas were not aware that this species occurred in the state until this specimen was digitized and made available on the SERNEC portal.
Bottom - Former ANHC Intern Ben Benton in a stand of Kissimmee water grass (Paspalidium geminatum) at Warren Prairie NA in 2018. Photo by Theo Witsell.
At left - Closeup of Kissimmee water grass (Paspalidium geminatum) at Warren Prairie NA in 2018. Photo by Theo Witsell.



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