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Our efforts to conserve rare plants and biodiversity in South Carolina depend on collections, like those archived at the Herbarium.
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— SCDNR BOTANIST KEITH BRADLEY
Herbarium grew from 40,000 to more than 100,000 specimens. Well-known as an expert in botanical studies, he has been a frequent guest on Making it Grow television show and featured in numerous periodicals. Nelson recently retired from his position as head curator of the A.C. Moore Herbarium and is honored as curator emeritus. PROTECTORS OF PLANTS In August 2019, Herrick Brown assumed the distinguished role as curator of the A.C. Moore Herbarium. Prior to his current appointment, he served as assistant botanist for the SCDNR Heritage Trust program and acted as an official liaison between the herbarium and the SCDNR. To prepare for this article, Brown led the staff of South Carolina Wildlife on a tour of the Herbarium. SCDNR Botanist Keith Bradley accompanied us on the tour, as he regularly works with Brown on a multitude of research projects. While touring the historic plant archives, we could clearly see how their collaborative work is an industrious continuation of pathways forged by the botanists, biologists and 44 South Carolina Wildlife
naturalists who preceded them. Brown began the tour with an overview. “Our estimated holdings consist of around 130,000 specimens, 120,000 with label metadata. In keeping with the digital age, we have 75,000 images of those specimens, 10,000 in the queue from Keith’s work in the field and others who are actively collecting specimens and contributing.” “Once we receive specimens in loose newspaper sheets, they are dried, pressed and labeled,” Brown said. “The dried specimens are attached to a elevenby-seventeen-inch paper, and each of these sheets has a number that uniquely identifies that specimen.” Placement of the plants on the sheets is especially important, he pointed out. “We make sure parts for [plant] identification are shown, some leaves facing up and some facing down. Sometimes there are tricks. We can remove a leaf or snip it in half. There is a lot of art to it.” THE PROCESS OF PRESERVING In the lab where he is regularly instructing biology students, Brown led us to the area where plants are prepared for the archive files. “When we receive previously dried specimens
from another institution, we put them in a minus-eighty-degree freezer overnight. Freshly collected specimens are carefully arranged between lattice boards or plywood to apply pressure and then placed in the drying oven. We use packing material and blotter paper to wick away moisture.” He pointed to the corrugated channels of the paper that allow air to run between the plant specimens. The oven is our next stop on the tour. According to Brown, the oven maintains about one hundred degrees Fahrenheit. “Different herbaria may do things differently,” he said. “For example, Nebraska has low humidity, so they just use box fans at room temperature. Here in South Carolina, we use this oven. It’s the best way to dry. Like a good barbecue, we use long and low heat to maintain the DNA. Depending on how much material is available on the specimen, we allow for some material to be sampled for DNA.” Bradley often brings specimens to add to the Herbarium collection. “If I’m collecting specimens in August, when it’s humid, plants may not preserve,” he said. “I dry plants out on the road on thick blotters and I use a portable dehydrator.