The Case of the Florida Nutmeg: Empowering Research on Endangered Plants

April 2020 marks the 50th anniversary of Earth Day. Organizations around the world have commemorated the occasion by participating in the global Earth Optimism movement — an initiative spearheaded by the Smithsonian to “turn the conservation conversation from doom and gloom to optimism and opportunity”.

Throughout 2020, the Biodiversity Heritage Library (BHL) and our partners are joining the movement by sharing conservation success stories from and made possible by the BHL collection. Follow our blog for conservation stories — past and present — and visit our website for more information and to explore our Earth Optimism book collection.

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On 5 June 1834, avid amateur botanist Hardy Bryan Croom wrote a letter to botanist John Torrey describing a gymnosperm tree in northern Florida that he was struggling to identify. In this letter, he postulated—with some degree of confidence—that the tree was Taxus baccata, the common yew, and he hoped to acquire some specimens to send to Torrey for investigation.

Torrey was one of the most important 19th century botanists in America. He corresponded with hundreds of scientists in North America and Europe, many of whom sent him specimens from their various explorations for study and identification. As such a well-respected expert and advisor on botanical science, it comes as no surprise that Croom sought Torrey’s expertise regarding this mysterious Florida tree.

The next year, in a letter dated 18 November 1835, Croom wrote again to Torrey, stating:

“The letter which I wrote last summer has had the effect to procure me some perfect fruit of that remarkable Taxoid tree at Aspalaga. The result surprises me. It is an ovate one celled nut entirely enclosed in fleshy covering! as large as a pigeon’s egg! Calix imbricated; thus agreeing neither with Taxus nor with Podocarpus. Besides, the tree, I think, is dioecious, but of this I am not yet certain. What will you do with it? Will it make a new genus?”

The following year, Croom again wrote to Torrey in a letter dated 18 May 1836 that he had determined that the tree represented a new genus. He proposed the genus name Torreya and provided a description and habitat details for “this fine tree,” for which he remarked:

“It is so abundant about Aspalaga (especially on Flat Creek) as to have been sawed into plank and lumber. It is an elegant tree with dark green foliage.”

With this letter, Croom provided the first recorded description of the habitat and abundance of the Florida nutmeg, Torreya taxifolia.

Sadly, Croom and his family drowned in a shipwreck in the Atlantic Ocean near Cape Hatteras on 8 October 1837. As such, Torrey arranged that the new genus and species were formally named and described by botanist George Arnott Walker-Arnott in 1838.

While Croom characterized Torreya taxifolia as abundant in 1836, today the species is critically endangered. With a distribution restricted to the limestone ravines and bluffs along the Apalachicola River in northern Florida and southern Georgia, fewer than a thousand individual trees persist in their native habitat. The most significant threat to the species is continued reproductive failure resulting from fungal pathogens—a threat which is continuing but not well-understood [1].

Torreya taxifolia is one of the species highlighted in a recent study to be published in the Memoirs of the Torrey Botanical Society. Authors Dr. Brian M. Boom (Curator Emeritus and former Vice President for Conservation Strategy and Bassett Maguire Curator of Botany at The New York Botanical Garden) and Susan Fraser (Recently-retired Thomas J. Hubbard Vice President and Director of the LuEsther T. Mertz Library) review John Torrey’s botanical legacy, drawing heavily on Torrey’s extensive correspondence, most of which, along with drawings, books, and artifacts from Torrey’s collections, can be found in the holdings of the LuEsther T. Mertz Library of The New York Botanical Garden (NYBG) [2].

In 2016, NYBG embarked on a project to digitize and transcribe Torrey’s correspondence and make both freely available through the Biodiversity Heritage Library (BHL). To date, more than 9,500 pages of correspondence—including those from Croom regarding Torreya taxifolia—are available in BHL, and over 7,000 of those pages have been transcribed.

The Torrey correspondence available through BHL was an invaluable resource during Boom and Fraser’s research for their study, which highlights several rare, restricted-range, or threatened plant species for which Torrey was directly involved in the scientific discovery and description phases. This was especially true with regards to Torreya taxifolia.

“BHL was instrumental in researching the circumstances surrounding the discovery and naming of this species, particularly through access to the correspondence of Hardy Bryan Croom and John Torrey between 1834-1837,” asserts Boom.

Boom has been studying plant conservation, systematics, and ethnobotany for 40 years. His conservation work focuses on rare, restricted-range and threatened plant species in the American tropics and North Temperate areas, or, alternatively, on invasive species that pose threats to native flora in these regions. An important aspect of his research is aimed at understanding these species from the circumstances surrounding their discovery in the field and description and publication as a new species, through to subsequent documentation of their occurrence in the landscape, and with regards to the threats they are under, in the case of rare plants, or the threats they cause, in the case of invasives.

“Plant species with restricted geographic ranges, or that are rare or threatened, are of conservation concern because it could take relatively little perturbation to cause populations of such species to become further restricted, fragmented, or to become extinct,” states Boom.

Understanding the history of a species’ scientific discovery and subsequent changes in its population and distribution over time require access to historical data. As Boom articulates, BHL’s collections are rich in such data and thus play a vital role in research on threatened species.

“Conservation-related research benefits greatly from BHL in terms of providing access to some of the classic and most iconic images of plant species and to the early texts and archival materials, especially correspondence, pertaining to the focal species,” affirms Boom.

Beyond the published literature, correspondence and field notes are especially valuable as they may contain information that is not included in the published literature or on the herbarium labels of the specimens collected. For example, in the case of Torreya taxifolia, the type specimen is in the herbarium of the Royal Botanic Gardens, Kew. While there is no collector indicated on the actual specimen, John Torrey is listed as the collector in the Kew specimen database. However, Boom stresses that he knows of no record of Torrey visiting Florida before he made a five-week trip to the state in 1872, during which he did not observe Torreya taxifolia in its natural habitat, although in March of that year he did collect a cultivated specimen of this species in a garden near Tallahassee that he believed had been planted there by Croom (NY Barcode 9506).

“It seems very likely that the holotype was in fact collected by Hardy Bryan Croom, and that Torrey passed a specimen that Croom had sent to him on to Scottish botanist George Arnott Walker-Arnott, who described the new species in 1838,” explains Boom.

As further evidence for this hypothesis, the holotype specimen (K Barcode K000287662) contains a pencil notation, written in Croom’s handwriting, stating: “New genus of Coniferae allied to Taxus. To be described in the next number of the Lyceum of Natural History.”

Torreya taxifolia is a testament to the important role that BHL’s open access collections play in research on endangered species. The historical conservation and systematics research conducted for this species was made possible by reviewing the John Torrey correspondence that is available in BHL and enhanced with crowdsourced transcriptions generated via From the Page. BHL also provided access to the first known published illustrations of Torreya taxifolia, which appeared in Hooker’s Icones plantarum.

By providing open access to essential literature and archives, BHL is empowering the work of conservationists around the world. Easy and immediate online access to these materials allows scientists to conduct their research more quickly and efficiently—which is ever-more important as biodiversity faces unprecedented threats today, with at least one million species threatened with extinction [3].

“The BHL resources are the only or most readily available ones for accessing certain older titles and certainly for images of plants and correspondence of botanists involved with the discovery and description of new species and of their habitat,” asserts Boom. “Such literature is important for conservation work because the historical materials often contain first-hand commentary about the collection and discovery of threatened species, including information about their population size at the place of discovery and of the habitat in which the species occurred at the time.”

By providing conservationists with the information they need to help save biodiversity, the Biodiversity Heritage Library is improving our ability to respond to today’s biodiversity crisis. As such, free and open access to biodiversity knowledge is a reason to be an Earth Optimist.

References

[1] Spector, T., Determann, R. & Gardner, M. 2011. Torreya taxifolia. The IUCN Red List of Threatened Species 2011: e.T30968A9585489. Accessed on 4 February 2020. https://dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T30968A9585489.en.

[2] The New York Botanical Garden. 2019. John Torrey: American Botanist. NYBG.org. Accessed on 4 February 2020. https://www.nybg.org/john-torrey-american-botanist/?_ga=2.197485295.1948631947.1568819719-1112387120.1548794658.

[3] Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. (2019). Nature’s Dangerous Decline ‘Unprecedented’; Species Extinction Rates ‘Accelerating’. Available at https://www.ipbes.net/news/Media-Release-Global-Assessment.