Two hundred years of plant blindness in Baden (Germany) - from C.C. Gmelin´s 1817 "Nothülfe gegen Misswachs" to the post Covid-19 foraging hype, including a preliminary Checklist of the Flora of Karlsruhe

Abstract

Background: Plants have been used for centuries in almost all cultures worldwide as traditional medicines to cure many chronic infections, including viral diseases. In recent decades, scientists have been attempting to scientifically validate the health-improving potential of functional and nutraceutical foods. At the same time, lockdowns due to SARS-CoV-2 had a profound influence on urban foraging behavior. On the other hand, 21 century plant blindness has been well documented. Our hypothesis however was that this is not the case, and that plant blindness, especially in more urban environments, is not a new phenomenon at all. During the curatorial work it became evident that the first director of the collection, CC Gmelin also focused on ethnobotanical topics to improve livelihoods and increase government revenue, publishing a foraging volume in 1817 to remedy the effects of the Napoleonic Wars and the "Summer without harvest" caused by the 1815 Tambora eruption. The pure fact that such a volume was of interest in 1817 seems to proof our hypothesis that plant blindness is by no means a recent phenomenon. Thus, we decided to have a closer look at the volume and to compare the indications given with more recent uses of the respective species.

Methods: For this review we used a manual transcript made from using a digital facsimile edition from the British Library. For most recent uses of species we consulted the broader global literature, especially the recent series "Ethnobotany of Mountain Regions". To elucidate if Gmelin indeed referenced the species he promoted, correctly identified the material, and to review the current availability of the species, we reviewed the complete currently accessible spermatophyte, lycophyte and pteridophyte plant collection in KR (about 250000 specimens), and used this resource to elaborate a first preliminary checklist of the Flora of Karlsruhe including vouchered material from 1785 - 2025.

Results: Gmelin's 18 century foraging handbook contains 169 species (144 plants, 23 fungi, 2 lichens) belonging to 122 genera (104 plants, 16 fungi, 2 lichens), in 54 families (38 plants, 14 fungi, 2 lichen). Of these 143 are recommended for food, 88 for fodder, and 14 for utensils. All the species had contemporary uses, mostly in Eastern Europe, while only very few have contemporary uses in the original region. The Flora of Karlsruhe has been vouchered since 1785, but despite decades of discussion no preliminary checklist had been published. We take this opportunity of review of Gmelin's "Nothülfe" book to present a first preliminary, voucher based, Checklist of the Flora of Karlsruhe 1785-2025 including almost 2600 species.

Discussion: The publication of Gmelin is certainly interesting, because it underlines first, that plant blindness is by no means a problem of the 21. century. Apparently over 200 years ago citizens had similar issues. It is however not entirely clear why Gmelin wrote this volume. Certainly, Carl Christian Gmelin was not only Director of the Natural History Museum and the Botanical Gardens in Karlsruhe, but also Privy Councilor of the Grand Duchy of Baden and published his guide at a time when the still young Grand Duchy of Baden was struggling with particularly serious social, economic, ecological, and political conflicts. What is striking though is that all species that Gmelin mentioned in his 1817 volume are still used in the wider European and Mediterranean region.

Conclusion: Our review indicates that "plant blindness" is by no means a phenomenon of the 21. century. Already over 200 years ago, a guidebook was necessary to allow "ordinary" citizens, not only in urban, but also rural areas, the identification of wild plants as food and forage, to remedy years of bad harvests. Herbarium collections are essential to allow for a detailed revision of such publications, and have the potential to elucidate both genetic, as well as metabolic changes in species, e.g. important for food and medicine. The foraging and self-medication craze during and after SARS-CoV-2 underlines the dire need for better taxonomic assessment of plants used by the wider public. Our presented Checklist of the Flora of Karlsruhe 1785-2025 will serve as baseline for future analyses of this urban flora.

 Keywords: CC Gmelin, foraging, historic plant use, Baden, plant blindness