Specimen of Hydrangea arborescens subsp. radiata from the Walter Collection at the Natural History Museum, London Herbarium
In the last post, I described the work of Mark Catesby who traveled to the colonial South backed by patrons who were anxious for him to collect interesting plants, in part to adorn their English gardens. This trend continued and a later visitor, John Fraser, arrived in Charleston after the American Revolution, in September 1786. He was hunting for plants for British gardeners, most notably William Forsyth, Master of the King’s Garden in Kensington. After meeting with the French botanist, André Michaux, who had a nursery near Charleston, Fraser headed north to visit the plantation of Thomas Walter. An Englishman who settled in South Carolina around 1769, Walter eventually owned 4500 acres on the Santee River. He occupied himself with business interests in Charleston and running his plantation, which in the South meant owning slaves. In addition, he studied the botany of the region. By the time Fraser visited, Walter had completed a flora of the Carolinas that included over 600 species. Needless to say, he was a great help to Fraser in learning where to find interesting species.
Fraser traveled northwest to Augusta and spent the winter of 1786-87 collecting in northern South Carolina, some of the time accompanied by Michaux and his son. While Fraser did not note localities for his collections, some are suggested by notes in Michaux’s journals. In the fall of 1787 Fraser again visited Walter, who helped him identify his collections and write descriptions of new species, nearly 200 of them, that were added to Walter’s manuscript. Fraser then packed up his 30,000 specimens as well as seeds and cuttings, and headed back to England in January 1788. Walter entrusted his flora to Fraser, who arranged for its publication as Flora Caroliniana. Because so many of the plants Fraser had collected were described by Walter and the specimens annotated by him, this collection became known as the Thomas Walter Herbarium. But in a Taxon article entitled “The Thomas Walter Herbarium Is Not the Herbarium of Thomas Walter,” Daniel Ward (2007) makes it clear that this collection is of Fraser not Walter specimens. Fraser saw Walter’s collection and received portions of specimens from him, but essentially the herbarium he brought to England was his own and is now at the Natural History Museum, London (NHM).
This provenance has some significance because many of the plants are type specimens for species first described by Walter, particularly for the ones that were collected by Fraser. Ward’s article was written as he was preparing a book on Walter (2017) and involved in a project he called the “Walter Typification Project,” similar in its aims to the much larger Linnaeus Typification Project which spanned several decades and resulted in the publication of Order Out of Chaos (Jarvis, 2007). Ward was very careful in his work. Since the herbarium at NHM is not Walter’s, he assumes that these specimens weren’t used in writing species descriptions, so there are no holotypes in the collection. However, where there is clear evidence that Walter saw and used Fraser’s material, then these are considered lectotypes. For Walter names that do not have types, Ward chose recent collections as neotypes.
It is significant that Walter’s Flora Caroliniana was the first book on North American plants to use Linnaean nomenclature and to arrange species according to the Linnaean sexual system of classes. It is obvious from the species descriptions in the Flora that Walter was well versed in Linnaeus’s work. He owned copies not only of Species Plantarum, but also Systema Naturae and Genera Plantarum. Ward thinks that the only plant that Walter included without having seen it, is the Venus flytrap, Dionaea muscipula, described by the British botanist John Ellis in 1768 from specimens sent him by John Bartram.
Walter died soon after the Flora was published at a relatively young 49 after being in ill health for some time. One of his granddaughters became the mother of another prominent South Carolina botanist, Francis Peyre Porcher, who will be the subject of a future post. William Fraser began a nursery business in England and specialized in North American plants. He and his son traveled several times to the United States and also to Cuba and Russia. They started a nursery in Charleston in 1791 and continued to ship plants from there back to England for 20 years. It was Fraser’s son who gave his father’s herbarium to the Royal Horticultural Society, and when the Society got into financial trouble in the 1850s, the collection was sold to what was to become the NHM.
As with so much of the South’s past, there is little physical evidence of Walter’s life along the Santee. Near his home, he had created one of the first botanical gardens in North America, shortly after those of John Bartram and his cousin Humphry Marshall in Pennsylvania. This disappeared soon after his death, as eventually did his home and herbarium. However, 25 years after his death two of his daughters had a marble slab, still extant, laid near the house site in his memory. The dedication noted: “To a mind liberally endowed by nature and refined by a liberal education he added taste for the study of Natural History and in the department of Botany, Science is much indebted to his labours” (Rembert, 1980, p. 12).
References
Jarvis, C. E. (2007). Order Out of Chaos: Linnaean Plant Names and Their Types. Linnaean Society.
Rembert, Jr, D. H. (1985). William Pitcairn, MD (!712-1791)—A biographical sketch. Archives of Natural History, 12(2), 219–229.
Ward, D. B. (2007). The Thomas Walter Herbarium is not the herbarium of Thomas Walter. Taxon, 56(3), 917–926.
Ward, D. B. (2017). Thomas Walter and His Plants: The Life and Works of a Pioneer American Botanist. New York Botanical Garden.
Herbarium World 