This series of posts deals with the articles found in the systematic botany journal Taxon that deal with topics beyond conventional taxonomic treatments. Among my favorites are those with an historical slant, like a recent one dealing with the plant collections of Richard Thomas Lowe (1802-1874) on the island of Madeira (Mesquita et al., 2022). To put his work in context Joseph Banks and Daniel Solander visited there and made collections in 1768, early in James Cook’s first voyage around the world. Francis Masson also did so a decade later. Lowe was the next botanist to make significant collections on Madeira and the other islands of its archipelago, but his work was not confined to a brief visit. He lived on Madeira from 1826 until 1852, much of that time as a clergyman. He spent the rest of his life in England, but returned to Madeira for several months almost yearly. When he died in a shipwreck in 1874, he was still working on his flora of Madeira that was published in several volumes.
The Taxon paper covers the authors’ research on 2,280 of Lowe’s specimens that they were able to georeference, most now at the herbaria of the Natural History Museum, London and the Royal Botanic Gardens, Kew. Positional uncertainty was noted. Lowe’s locale descriptions varied in specificity but more than half rated as very high or high. During his years of collecting, he had managed to visit most parts of the island, though not surprisingly, areas with steep slopes, of which there are many, were not visited. His later work often involved returning to areas where he could find plant groups that posed taxonomic problems. He was someone who came to know his research area well as is revealed in his writings. His specimens were from 1350 locations and represented about 800 different taxa. Lowe visited many locations a number of times, including at different times of the year. He sent duplicates to several other botanists with exchanges of information on many taxa. His correspondents included William Jackson Hooker, John Henslow, Robert Brown, Augustin de Candolle, and Philip Webb. The researchers conclude: “As a result of Lowe’s sustained and systematic approach, he is the single most prolific contributor to the study of Madeira’s endemic flora (p. 876).”
Lowe’s work is an important contribution to biodiversity research because oceanic islands like Madeira have high proportions of endemic species and provide examples of rapid evolutionary radiations. Also, because of the island’s size, populations are relatively low for many species, so having a historical record of occurrence in the past is helpful for present-day conservation efforts. The fact that there were areas that Lowe found too remote or impossible to explore, including the many areas of cliffs, mean that these are good places in which to search for new species. Equipment for scaling rock faces has improved, and even drones can be employed in survey work.
There is much more to the article than I can recount in this post. The number and content of the figures indicate how much analysis went into this paper and thus how much it says about Lowe’s contributions. Maps are key, including the first figure, a topographic map with place names for Madeira and indicating just how much elevation variability exists there. Next are more detailed historical maps and then a series of maps showing where Lowe’s georeferenced specimens were collected noting first locations, then precision of locations, followed by vegetation zones, and slope. For slope, there is also a bar graph showing the relationship between slope and the amount of area at that slope.
Then comes my two favorite graphics, or at least the ones I found most telling. Figure 9 shows six maps of the island representing the itineraries for extended trips in six different years ranging from 1827 to 1860, including two Lowe made when he was no longer living there. These are color-coded to show the months when each location was visited. This is a good example of a well-designed graphic, as is figure 10, a graph that tracks with a line the number of specimens collected each year. Then for each year it also gives bars indicating the percent of specimens from the six most common families on the island. In most years, Lowe collected in all these families, but there are indications that, as mentioned in the text, he was focused on particular groups at certain points. For example, in 1872, near the end of his collecting, Poaceae and Lamiaceae specimens were particularly well-collected. Not coincidently they were the two families that had yet to be published in A Manual Flora of Madeira, which was left unfinished at the time of his death in a shipwreck that occurred when he was again bound for Madeira.
I had never heard of Richard Lowe before I read this article, but it pains me that his flora was left unfinished. The researchers who produced this work used the extensive data they generated from painstaking georeferencing and analysis to create not only a work of science but of history. They created a portrait of a botanist and of work that will inform biodiversity research in the future and also support further study of the history of botany in Madeira. They used specimen data and also delved deeply into Lowe’s correspondence and notes in a beautiful example of bioinformatics meeting the digital humanities.
Mesquita, S., Carine, M., Castel-Branco, C., & Menezes de Sequeira, M. (2022). Documenting the flora of a diversity hotspot: Richard Thomas Lowe (1802–1874) and his botanical exploration of Madeira island. TAXON, 71(4), 876–891. https://doi.org/10.1002/tax.12661