As discussed in the last post, older herbaria are being given increased attention because they shed light on what plants were in growing in Europe and in European gardens at the time, and how botanists approached their work. But as with any old documents, it is often difficult to unlock their secrets. A case in point is a beautiful herbarium at the natural history museum in Zierikzee in the Netherlands with no information on who the collector might have been. In 2021, two articles were published on its contents and provenance, each presenting different conclusions as to who created it and when. The article by a team from the Naturalis Biodiversity Center in Leiden came out first, and I read it first (Offerhaus et al., 2021). Like the herbaria discussed in the last post, also studied by a Naturalis team, efforts were made to identify all the species and provide up-to-date names. The organization of the sheets, the information on the labels, the type of paper used, and many other possible clues were presented.
In the case of the Zierikzee Herbarium, there was an analysis of the ornate printed labels and vases found on all but 21 of 348 plants. Their use seems to have been a primarily Dutch fad in the first half of the 18th century. They definitely perk up a specimen, giving it a bit of class or status, showing the taste of the collector. Carl Linnaeus’s patron in the Netherlands, the wealthy merchant and horticulturalist George Clifford used them; they befitted someone with a large garden, and a greenhouse each for Asian, American, European, and African plants. Historians of botany have studied them and in some cases identified the printers and the years when they were produced. In the case of the Zierikzee, the Naturalis group focused on labels with a putto on each side of a frame with the species information using pre-Linnaean nomenclature written, in the blank space between them.
Both articles also researched old auction catalogues to attempt to find the answer to who created this work. There is not direct evidence in the herbarium itself, which is the major mystery at the center of this controversy. In the second article, Gerard Thijsse (2021) found a resemblance between an herbarium auctioned in 1790, that of Martin Wilhelm Schwencke. It consisted of 10 volumes, and Thijsse thinks that six of them make up the herbarium in Zierikzee and that Schwencke collected the plants early in his long career. Thijsse gives a detailed explanation as to why this makes more sense than the Naturalis team’s hypothesis, which links the herbarium to Jacob Ligtvoet described in a 1752 auction catalogue shortly after his death. Reading these two reports reminded me of opposing lawyers carefully laying out their arguments, using a variety of different kinds of evidence, some of it scientific some of it textual.
Both articles also discussed evidence from computer analyses of similarities between the information given in published botanical sources and the label data, which included references to several authors. The two studies significantly diverge. The Naturalis group sees some resemblances between the label data and the information in Herman Boerhaave’s two catalogues of the plants in the Leiden botanical garden, one published in 1720 and the other in 1730. They suggest that the herbarium began to be put together between these two dates and consider the likely creator to be the gardener at Leiden, Jacob Ligtvoet who helped Boerhaave with the second catalogue. They note that along with the preponderance of the plants from the Netherlands but there are exotic species that Boerhaave obtained from those associated with the Dutch East India Company.
On the other hand, Thijsse found that the herbarium contains a “virtually” complete set of the plants mentioned by the unknown author of the 1738 Pharmacopoea Hagana. He also argues that one of the vases used is similar to one the Georg Ehret designed in 1734, so that the Naturalis date for the herbarium is too early. Since Thijsse’s article appeared later than the Naturalis one, he had the luxury of questioning some of its findings. I wouldn’t be surprised if Naturalis is now working on a rebuttal. Of course, there is much fertile ground for argument here. Many pharmacopoeia of the time included similar species, and the plants could have been mounted earlier and then the vases added later as a decorative afterthought. That’s the problem with history, it is impossible to know everything about the past, information is always limited and open to interpretation.
This is very reminiscent of scientific controversies, where researchers ask similar questions but use different protocols or methods of attack and come up with opposite conclusions. Is that because one of them is wrong or because they are really not looking at the same phenomenon? Only more research will provide the answer, which may very well be the case here, or there will be a stalemate. I’ve just finished rereading these articles, and my head hurts. For once I have reached my herbarium saturation point. I think there is more here than I want to know about this one collection. One the other hand, I am not sorry that I spent time on this because it helped me to see how historians work. Like scientists, they have to be creative in how they approach their problem, asking different kinds of questions so that eventually they may perhaps find a niche that opens up a new world of answers.
Offerhaus, A., de Haas, E., Porck, H., Kardinaal, A., Ek, R., Pokorni, O., & van Andel, T. (2020). The Zierikzee Herbarium: Contents and origins of an enigmatic 18th century herbarium. Blumea, 66, 1–52. https://doi.org/10.3767/blumea.2021.66.01.01
Thijsse, G. (2021). The four W’s of two 18th century Dutch herbaria: The “Zierikzee Herbarium” and the herbarium of Simon D’Oignies. Blumea, 66, 263–274. https://doi.org/10.3767/blumea.2021.66.03.09