The Oldest Bryophyte Herbarium Specimens from Central Europe, Collected by M. E. Boretius in 1717: Taxonomy, Nomenclature, Datation and Ethnopharmacology

The WA Herbarium at the University of Warsaw houses a collection of plants created in 1717 by Matthew Ernest Boretius. They were gathered in former East Prussia, near Angerburg, now Węgorzewo (Poland). It is the oldest plant collection from this part of Europe. Boretius compiled the herbarium as a collection of all the surrounding plants, but their folk names (Polish and German) recorded in the herbarium confirm the ethnobiological or ethnopharmaceutical importance of some species. We identified bryophyte species and checked the accuracy of their original identifications recorded in the herbarium. We provided their Latin (scientific, pre-Linnaean) nomenclature together with German and Polish vernacular names. We contextualised this information within the history of the medicinal use of bryophytes around 1717, when the plant collection was created. We also investigated whether the specimens could have come from Northeastern Poland. Mosses and liverworts from the herbarium were identified nomenclaturally (by means of their original scientific polynomial names written on herbarium sheets) and taxonomically. The herbarium holds two species and one subspecies of liverwort and 27 species and one variety of moss. The accuracy of the original identifications was assessed, with a particular focus on the species considered medicinal at the time. We found that bryophytes were poorly known in the time of Boretius, which was the last period in bryology before the introduction of magnifying devices into this science (this crucial step was made by Dillenius in 1741). The vernacular names used in the herbarium were recorded for Marchantia polymorpha and Polytrichum commune—the only two species with confirmed medicinal use by the year 1717.


Introduction
Historical plant collections not only inform us about their former occurrence and diversity.They also reveal the old botanical nomenclature, which is not always published.In addition, the annotations on the herbarium sheets, the arrangement of the sheets in the herbarium, and the wider context of the origin of the collection and its creator can indirectly provide new ethno pharmacological and ethno botanical knowledge.
The collection.The WA Herbarium of the Faculty of Biology at Warsaw University houses a historical collection of plants that come from the former Prussian town of Königsberg (Polish: Królewiec, now Kaliningrad in the Russian exclave).The authorship of the collection in question has long been disputed.Until now, it has been attributed to either Helwing or Boretius, or both, and the date of creation is uncertain.We call it here the WA copy.
Matthias Ernst Boretius, a Prussian botanist and physician, was born in 1694 in Lötzen (now Gi życko, Poland) and died on 4 October 1738 in Königsberg (now Kaliningrad, Russia).He was a professor of medicine at the University of Königsberg, a city physician since 1728 [1], and a court physician to the Prussian king Friedrich Wilhelm I [2], but only since Plants 2024, 13, 349 2 of 20 1738 [1].In his study of botany, Boretius was a pupil of Georg Andreas Helwing (1666-1748), a prominent Prussian naturalist.Boretius was the author of four botanical-medical works, including his doctoral dissertation [1].He became Helwing's son-in-law [3].
Copies of Boretius' herbaria.In 1886, Caspary [5] communicated his discovery in an old Prussian newspaper Wochentliche Königsbergische Frag-und Anzeigungs-Nachrichten.The library resources of this newspaper from the 1730s are now lost, so we must rely on Caspary's account.We reproduce his report in full: "Georg Andreas Helwing became assistant to his father, who was a clergyman in Angerburg [today Polish: Węgorzewo], in 1691, became provost in Angerburg in 1725 and died in 1748.From spring 1717 onwards, the medical student Mathias Ernst Boretius, later professor ordinarius tertius at the medical faculty in Königsberg, who had to study botany, died in 1738, stayed with him for a longer period in order to acquire botanical knowledge from Helwing, the author of the [books] Flora quasimodogenita and Florae campana, and an excellent plant expert.In 1717, Boretius made herbaria under Helwing's supervision, they were distributed to various prominent people.In the Wochentliche Königsbergische Frag-und Anzeigungs-Nachrichten from the year 1737, volume 27, a journal that gave information about all things of practical life [. ..] but also [published] treatises of the most important scholars of Königsberg University (e.g., also by Immanuel Kant)-in this journal Boretius says in a treatise [entitled]: Von Nana Oder Ananas und deren Frucht ('Of Nana or Pineapple and its Fruit'): «After them (i.e., the Prussian botanists Wigand, Wolff, Mentzel, Loesel, Gottsched), the highly experienced and indefatigable M. Georg Andreas Helwing, the current provost in Angerburg, has searched out almost as much in the Prussian forests, shrubs and fields, as the Herbaria viva produced under his supervision 20 years ago, one of which has the honour of being preserved in the Royal Library in Dresden of His Majesty the King of Poland for more than some time.»This [Boretius'] account was published in 1737; the herbaria were therefore made by Boretius in 1717.Unfortunately, what the then King of Poland and Saxony received was burnt during the revolution in Dresden in 1848, or, as it is also called, came to Petersburg.One was given to the city secretary of Danzig: Jacob Theodor Klein.Three are in Königsberg, one in the Royal library, one in the Municipal [Library] and one in the Royal Botanical Garden.The last one was owned by Carl August Hagen, the author of [books]: Chloris Bor[ussica] und Preussens Pflanzen and was recently given to him by Hagen's grandson.It [i.e., Boretius' herbarium] consists of 5 thick volumes of writing paper bound in pigskin in folio, in which the plants are pasted, given the long names they had in Helwing's times, and mostly also by C. G. Hagen's hand with Linnean [names].The latter was owned by Carl August Hagen and was recently donated to the Royal Botanical Garden by Hagen's grandson, the present court pharmacist Hagen."[5] This discovery was soon summarised by Conwentz [6].The latter author described the copy of Boretius' herbarium, which was owned by the aforementioned Jacob Theodor Klein (1685-1759), as part of Klein's natural history cabinet.Klein's collection was bought by Friedrich, margrave of Brandenburg-Bayreuth, and moved to the old castle in Bayreuth.This copy was described by [6] as follows: "The herbarium consists of 5 thick leather-bound folio volumes, the covers of which are decorated with coloured plant illustrations.The dried specimens are glued to strong writing paper and are generally well preserved.The Latin designation is cumbersome, as it was in use before the introduction of Linnean nomenclature."[6] The author [6] mentioned five ornately bound volumes, and, in his article, he also reprinted the title page of the first volume, which might have been added whilst the volumes were being specially bound.The title page of Klein's copy reads, in Latin, Herbarium Plants 2024, 13, 349
Klein's copy, which was housed at the University of Erlangen until Conwentz's time and was transferred from Erlangen to Danzig (Polish: Gda ńsk) before 1888 on the initiative of Conwentz himself [6], is now lost [7].
The WA copy has no title page in any volume, and it has simple bindings, so we should consider its condition and form to be original.
Authorship.The two overlooked accounts [5,6] from the years 1888-89 resolve our earlier doubts about the authorship.We should also rely on the oldest bibliographical entry [8] from the catalogue of the Königsberg Municipal Library, which matches this collection with Boretius.There is also another herbarium in the National Library in Warsaw, which is undoubtedly the work of Helwing: the handwriting in this Helwing herbarium differs considerably from the handwriting in the WA copy [9]; for samples, see [10].
Notes on the contents of the copies of Boretius' herbaria.Caspary [5] dealt with the first appearance of Senecio vernalis L. in East Prussia.He found a specimen of this species in the copy of Boretius' herbarium kept at the Royal Botanical Garden in Königsberg.He wrote that the plant was included in vol. 4 on p. 66.The same species in the same volume number, and on a page with the same number, is included in the WA copy of Boretius' herbarium.The page with S. vernalis in the WA copy is signed in Latin in the same way (polynomial name), but the plant is structured differently (Caspary described the structure of the plant in detail).The author of [6] listed more peculiarities from Klein's copy (but without page numbers): • Pedicularis candida florubus candidis, which is probably a hybrid of Odontites vulgaris Moench.A specimen with the same polynomial exists in the WA copy (vol.The names of all these unusual plant forms listed by [6] are identical to those in the WA copy.Based on these coincidences, including the absolute rarities and their identical names, we can now claim that the contents of all copies of Boretius' herbarium were identical and probably created at the same time. The WA copy of Boretius' herbarium was originally kept in the former public municipal library (German: Öffentliche Stadtbibliothek in Königsberg).This historical object was catalogued in Latin as Matth.Ern.Boretii Herbarium vivum, Plantarum et Florum in Porussia nascentium Methodo Tournefortiana, in Classes divisum; adscriptis Nominibus Plantarum Latinis, Germanicis, Polonicis, cum Indice.Vol.V. Translation: "Matthew Ernest Boretius' living herbarium of plants and flowers growing in Prussia, divided into classes according to Tournefort's system, supplemented with Latin, German and Polish plant names, with an index, five volumes" [8] (p.66).After the turbulent events of the Second World War, four volumes survived in the WA herbarium, while volume no. 3 is missing.Each volume bears the stamp of the Königsberg Municipal Library [7].The original library reference numbers are given on the inside back cover of each volume.They range from "422.1" to "422.5".The reference number of this object in the WA inventory is WA-KH-13.1.This set of volumes will be referred to here as "the WA copy".
Datation.According to Boretius himself, he created his herbaria in 1717 [5].Some printed botanical works are cited in the volumes, notably the Flora quasimodogenita [11].The collection could also be expanded and annotated with plant nomenclature and bibliographical references after 1717.See the Discussion for more datation-related facts.
Arrangement of plants.Boretius' herbarium is arranged according to the system of Tournefort [12], established in 1700.He divided the plants into 22 classes according to the structure of the flowers.Class XVI included organisms that did not produce flowers: ferns and some lichens.Class XVII consisted of organisms that produced "neither flowers nor fruits": algae, fungi, bryophytes, Lycopodiopsida, and some other lichens [9], or at least plants that were mistakenly recognised as such.
Bryophytes.In the fifth volume of Boretius' herbarium, mosses (Bryophyta) are members of the class named in Latin Classis XVII exhibens herbas et suffrutices quorum flores et fructus vulgo desiderantur.Translation: "Class 17 showing herbs and prostrate shrubs whose flowers and fruits are generally desired".Liverworts Marchantiophyta are members of the class defined in Latin as Classis XVI exhibens herbas et suffrutices qui floribus carent et semine donatur-"Class 16 showing herbs and prostrate shrubs that are devoid of flowers and are endowed with seed"-and were placed in the fourth volume.

Aims of the Work
We identified bryophyte species included in the WA copy of Boretius' herbarium and ascertained whether their original identifications made by Helwing for Boretius or by Boretius himself were correct in view of modern taxonomy.We determined their Latin (scientific, pre-Linnaean) nomenclature as well as German and Polish names.We present these data against the history of the medicinal usage of bryophytes in past centuries.We also checked whether the specimens represent the local flora of Northeastern Poland.

Materials and Methods
Bryophyte specimens were identified by two authors in two independent ways: A.S. identified the species taxonomically.J.D. read the original polynomials handwritten in the herbarium and tracked their synonymy to the present day.These results were then compared to assess the accuracy of the identifications (i.e., Latin polynomial species names) written in the herbarium.

Taxonomy and Floristics
Bryophytes were identified using a magnifying glass (Nikon SMZ1500, Nikon, Tokyo, Japan).Due to the historic nature of the herbarium, no specimens were sampled for microscopic examination.However, most of the bryophytes in the herbarium are common, large, easily identifiable species.The names of the identified species correspond to the latest revision in the "WFO Plant List" [13] and the sources mentioned therein, as well as [14].
Based on historical information (including Boretius' biography), we assumed that the specimens had been collected near the town of Węgorzewo (formerly Angerburg) in Northeastern Poland.This allowed us to treat the bryophytes in the herbarium as representatives of the local flora at the beginning of the 18th century.Thus, we compared the occurrence of the identified species in the wild with the results of recent floristic research around Węgorzewo, published by [15][16][17].

Historical Naming of the Species
The interpretation of the names of bryophyte species recorded in the herbarium was the second independent method of our study.The names inscribed next to the specimens were searched for in the botanical literature published since the 16th century, and the successive synonyms found for these names, given by successive botanists, formed a chain that eventually led us to the modern accepted binomial.In almost all cases, the chain of synonyms led to the book by Dillenius (J.J. Dillen) [18], a key work for the pre-Linnaean nomenclature of bryophytes.Dillenius' names were then traced as synonyms of the binominal names given by Hedwig [19], which is the nominative source for mosses.Liverworts were traced back to Linnaeus' work, which is the nominative source for this group of bryophytes.The currently accepted binomials were found in [14].This allowed us to automatically detect polynomial basonyms that were established in Boretius' herbarium and subsequently published (or not published) by Helwing [11,20].

Historical Medicinal Usage
Johannes Boretius, as a physician, was familiar with plants, which, at the time, were the most important source of medicine.Bryophyte species known as medicinal plants in 1717 (based on our earlier research [21,22] and accounts cited therein) were indicated.We paid special attention to their German and Polish vernacular names included in the herbarium, recognising that names in national languages may provide evidence of the actual use of the species in question as medicinal herbs or more generally as economic plants.

Results
Below, we present the contents of each herbarium page where true bryophytes are found.We include transcriptions of the original handwritten names, their proper citations, the chain of synonymous polynomials, and its result as the accepted binomial (sometimes, more than one species was finally identified).Below each original name and its nomenclature, we give the independent taxonomical identification of each specimen, with the species name given in bold.
A total of two species and one subspecies of liverwort and 27 species and one variety of bryophyte were identified from the plant specimens collected in the herbarium.
Lat.: Polytrichum majus.This name, attributed to Tragus, is used in Bauhin [27] (p.356) and is another synonym of the taxon identified above.
Germ.: Groß gülden Wieder-Todt and Frauen oder Venus-Haar.These two German names exist also in the flora by Helwing [11] (p. 23).They can be rendered as "great gold death-again" and "Feminine or Venus-hair".
Identification: the specimens represent Dicranum scoparium Hedw., occurring mainly on the forest floor in coniferous forests, as well as on rotten wood, the bark of trees, and rocks.It still grows near Węgorzewo [15,16].
Identification: the specimens form a mixture of Ceratodon purpureus (Hedw.)Brid.(mainly from the left side) and Pohlia nutans (Hedw.)Lindb.(mainly from the right side).C. purpureus is one of the commonest Polish mosses; it grows in various habitats in forests and non-forest vegetation.P. nutans is a common moss, occurring mainly in forests on soil, rotting wood, and rocks, also in patches of psammophilous grassland.Currently, they are among the most common mosses in the bryoflora of the Węgorzewo region [15,16].
The bottom specimen has one Lat.name: Muscus squamosus ramosus tenuior capitulis Adianthi aurei Raij.This polynomial seems confused, and the closest correct names are the following:
Identification: the specimens represent Anomodon viticulosus (Hedw.)Hook.& Taylor.Its status in the vicinity of Węgorzewo is similar to that of Neckera pinnata discussed above.
Identification: the specimens are a mixture of Sphagnum cf.fallax (H.Klinggr.)H.Klinggr. and Straminergon stramineum (Dicks.ex Brid.)Hedenäs (only one shoot in the middle part).S. fallax is one of the most common sphagnum species in the flora of Poland, associated with oligotrophic peat bogs and marsh forests, currently rare in the vicinity of Węgorzewo [16].S. stramineum is a common species in Poland, growing in peat bogs and marshy forests, but recently not seen in the vicinity of Węgorzewo.
Identification: the specimens represent Sphagnum magellanicum Brid.(left side) and Sphagnum cf.rubellum Wilson [= S. capillifolium (Ehrh.)Hedw.subsp.rubellum (Wilson) M.O.Hill] (right side of the page).S. magellanicum is a species associated with oligotrophic peat bogs and marsh forests, currently rare in the vicinity of Węgorzewo [16].S. rubellum was found in the vicinity of Węgorzewo in the first half of the 20th century [40]; in recent years, it has not been observed.
The bottom specimen has one Lat.name: Muscus squamosus capillaceus minimus capitulo longo erecto.This polynomial is absent in [11,20], i.e., it is designated in the studied herbarium only.
Identification: the bottom specimen represents a mixture of Amblystegium serpens (Hedw.)Schimp.(mainly right side) and Pylaisia polyantha (Hedw.)Schimp.(mainly left side).A. serpens is one of the most common Polish mosses, growing in various habitats, such as soil, tree bark, and old walls, and, so far, it is common in the vicinity of Węgorzewo [15][16][17].P. polyantha grows mainly on tree bark and less often on old walls and rocks, and it is also a frequent species in Węgorzewo today [15].The Latin words capitulo longo erecto describe well the shape and position of the capsules of P. polyantha, so this polynomial must have been intended and designated for this species.
Identification: the specimens represent Climacium dendroides (Hedw.)F.Weber & D.Mohr var.fluitans Huebener.The occurrence of this species in the vicinity of Węgorzewo was described above.
Identification: the specimen is Fontinalis antipyretica Hedw., a common aquatic species in Poland, but recently it has been observed rarely near Węgorzewo.
Identification: the specimen represents Plagiomnium undulatum (Hedw.)T.J.Kop., a species common in Poland, still growing in wet forests and shrubs in the vicinity of Węgorzewo [15,16].
Identification: the specimens are Plagiochila cf.asplenioides (L.) Dumort.This liverwort grows most often in marshy forests and on the banks of streams.Currently, it is a rare species in the vicinity of Węgorzewo [16].

List of Identified Species
Table 1 lists the bryophyte species found in Boretius' herbarium that were identified correctly by him, as well as their medicinal importance in his time.Out of the nine species gathered in Table 1 as identified correctly (i.e., which Boretius knew well, and excluding his attempt to designate P. polyantha), six bryophytes are now common or frequent around the place in which he lived.Moreover, two of them were of medicinal importance already in his time: Marchantia polymorpha, which is seen on as many as three sheets in various forms of both sexes, and Polytrichum commune, which is on sheet 5.2 and also on 5.3 (Table 2).Table 2 shows the misidentified species.Boretius' polynomials can be resolved today as 21-23 binomials.However, our independent taxonomic check yielded 25 real (but different) taxa and revealed the essential difficulties that Boretius had encountered in his practice: some of these taxa are represented by more than one specimen, while four gatherings are clusters formed by more than a single species.

Boretius as a Bryologist
Taxonomy.Bryophyte species were generally misidentified.The names written on the herbarium sheets are correct for 10 of out of real 28 species.Of these, both species of liverwort are correctly identified.
Boretius' sources.Boretius made extensive use of the botanical literature of his time, or at least knew many authors of bryophyte polynomials, including the oldest local botanists: [34,45].Both these writers, Mentzel and Loesel, should be considered as the pioneers of the local Prussian flora.He also mentioned a Dutch author, Hermann Boerhaave, who was generally recognised as an influential and skilful physician rather than a materia medica writer.
Designation of polynomials.In the herbarium studied, we divulgated two polynomials of mosses used for the first time.(1) In vol. 5 p. 17 (top), Boretius attempted to designate Sphagnum capillifolium (Ehrh.)Hedw.In fact, there are two different peat mosses here (also S. magellanicum Brid.) and it is not clear which one Boretius had in mind.(2) At the bottom of the same page, he effectively designated Pylaisia polyantha (Hedw.)Schimp.as Muscus squamosus capillaceus minimus capitulo longo erecto.This name was repeated in [20] (p.49) without authorship.
Boretius' collection as voucher material for botanical publications of the time.All inscriptions present on the investigated herbarium sheets are written by one hand [6].The youngest polynomial used is Muscus squamosus palustris capitulis rufescentibus, for which the only published source is a list from 1726 [20], where it is established in print.Helwing intended this book [20] as a supplement to the flora of East Prussia [11] (issued in 1712).Thus, Boretius' herbarium may have been expanded or completed after 1717, also as a reference for this supplement.A similar study of the flowering plants in the herbarium should be undertaken to support this thesis.

Folk Medicine and Vernacular Names of Bryophytes
Some Polish and German vernacular phytonyms were written on herbarium sheets.We can consider their existence as proof of their ethnobotanical knowledge and possible use.There are 13 German names and 4 Polish names.The German Groß gülden Wieder-Todt = Frauen oder Venus-Haar and Polish Matki Bożey włoski are of medicinal origin.The name Venus' hair is generally applied to the medicinal fern Adiantum capillus-veneris L., native to the Mediterranean region.In Central Europe, this name was transposed to some representatives of the genus Polytrichum Hedw.These herbs, generally called, in pharmacy, "capillary herbs" (Lat.herbae capillares, e.g., in [47]), were believed to be a good remedy for hair and scalp disorders, thanks to the fact that the dried herb of A. capillus-veneris is conspicuous for its hair-thin petioles.According to the doctrine of signatures, this property was noticed in the herb of Central European mosses of the genus Polytrichum, which is even better represented here by the presence of thin, long, pale, and glittering trichomes on the calyptra, which together resemble a blonde female hairstyle.In Europe, Polytrichum was first reported as a moss of medicinal value as early as in 1549 [21]).
Vernacular names for liverworts associate them with the liver: Germ.Leber-Kraut, Grünnen-Leber-Kraut, Kleiner gestirnte Stern-flechten Leber-Kraut; Pol.W ątrobie ziele, and W ątrobiec.Other names, Germ.Stein-flechten Moß-flechten and Pol.liszajec, refer to the skin conditions called, in Latin, lichen planus (and impetigo contagiosa).It is generally accepted that, according to the doctrine of signatures, thalloid liverworts were used in ancient medicine in two ways: as liver remedies (thanks to the resemblance of their gametophytes to liver lobes) and in skin diseases called "lichen" (due to the shape and size of the "spots" on the patient's skin).
Boretius misidentified other mosses that were considered medicinal in his time and mentioned by other writers as articles of material medica.They were Funaria hygrometrica, Hylocomiadelphus triquetrus, and Brachythecium rutabulum.This omission or error may prove their insignificant role in the therapy of the time.
There are other observations about Boretius' expertise in bryology that are important for our view of bryophyte-based herbalism:

•
He identified three species mixed in a cluster as one (5.5).

•
He filled as many as three sheets of his herbarium with various forms of Marchantia polymorpha.Together with the rich folk nomenclature, this proves the good knowledge of this liverwort and suggests its popularity as a medicinal plant in 1717.
Most of the mosses present in the herbarium and listed in Table 2 had little chance of being promoted as medicinal plants, either because of their rarity in the environment or because of identification problems.Thus, even common species (such as Amblystegium serpens, Ceratodon purpureus, Hylocomium splendens, Pohlia nutans) could not objectively have been learned by doctors, pharmacists, botanists, herbalists, or patients harvesting herbal material for themselves.It must be remembered that the confirmation of taxonomic identity was the most desirable (and usually the only available) method of proving the identity, authenticity, and quality of medicinal plant materials in times when any assessment of chemical composition was far beyond the remit of quantitative and qualitative chemical analysis.
Boretius created his herbarium at a time when the microscope was not yet in use for the study of bryophytes.Dillenius [18], in the preface to his outstanding Historia Muscorum (on both the taxonomy and nomenclature of bryophytes), stated (on p. xv) that, at least in the case of the former genus Hypnum, there were structural details ". ..quae oculis nostris patent vel nudis, vel lente vitrea mediocri armatis"-"which are accessible to our eyes either naked or through a glass lens of medium power".We queried his book for the Latin words microscopium and lens (which both refer to "a microscope, a loupe, a magnifying glass") and for their declensed forms (genitive, accusative, and ablative case), and it was found that he mentioned microscopy at least 22 times in his text.Finally, Hedwig (1730-1799) was the first bryologist to use magnifications of up to 290× [19] as a standard in his research, which resulted in his fundamental illustrated work Species Muscorum. . .Thus, Boretius, who died in 1738, did not have sufficient tools to distinguish or harvest the herbal material from the world of bryophytes according to the method and requirements of scientific pharmacy at that time.

Conclusions
Among the specimens of bryophytes found in Boretius' herbarium, two species and one subspecies of liverwort and 27 species and one variety of moss were identified.Most of them are common species that still grow in the vicinity of Węgorzewo, so Boretius gathered his bryophytes locally.
Newly discovered historical sources show 1717 as the date of origin of Boretius' herbarium.This date justifies the poor taxonomic knowledge of bryophytes and proves their marginal role as a source of medicinal herbal material at the time that the collection was created.Thus, the motivation for creating this herbarium in 1717 was the plant taxonomy or floristics of bryophytes, rather than the economic/medicinal use of them.
If the 1717 herbarium proved to be unreliable support for the taxonomy of bryophytes, the botanical-medical texts of the time, which mention bryophytes as medicinal plants, must be even less reliable (as they are not even accompanied by voucher specimens).Even conspicuous mosses such as Polytrichum are subject to error in this herbarium.Even when Helwing identified the specimens for Boretius, the latter repeatedly made mistakes when mounting them on the herbarium sheets and combined them with incorrect names.We should therefore doubt the certainty of the recognition of bryophyte species as medicinal plants in the past and consider the taxonomic identity of the former moss-derived herbal materials as ambiguous.
Polish and German vernacular names appeared in Boretius' herbarium next to the species best known as medicinal from the 16-18th-century literature.He correctly recognised only two medicinal bryophyte species (Polytrichum commune and Marchantia polymorpha), and the folk names of both are related to old folk medicine or pharmacy.
An increase in the number of medicinal bryophyte species did not occur until the second half of the 18th century.This can be explained by the influence of the taxonomic-nomenclatural work of Dillenius [18], who used microscopic features to identify species.Taxonomic knowledge at the time of Helwing and Boretius (early 18th century) was limited to two to three species of bryophytes already known in antiquity or introduced for therapeutic purposes in the early Renaissance (as Marchantia).
Author Contributions: J.D.: identification by nomenclature.A.S.: taxonomical identification.M.G.: historical section and museum information on the herbarium; photographs.All authors have read and agreed to the published version of the manuscript.
Funding: Financial support for this research was provided by the Medical University of Silesia in Katowice (grant number: BNW-1-020/K/3/F).

Data Availability Statement:
The studied collection is housed at the WA Herbarium, Faculty of Biology, University of Warsaw, ul.Żwirki i Wigury 101, 02-089 Warszawa, Poland.

Table 1 .
Bryophytes included in Boretius' herbarium that are correctly identified therein, together with their historical medicinal use and contemporary occurrence in the local flora of Węgorzewo.

Table 2 .
Bryophytes included in Boretius' herbarium that are misidentified in it, together with the historical medicinal use of the species misidentified by Boretius, and with the contemporary occurrence in the local flora of Węgorzewo of the real taxon represented in the herbarium.