Józef Warszewicz (1812–1864) was one of the first Polish naturalists to explore the flora of the tropical New World. During two expeditions to Central and South America (1844–1850 and 1850–1853) he collected and delivered to Europe up to twenty thousand plant specimens. To honour his service and his achievements in plant collections, different taxonomists described more than 100 taxa using the surname Warszewicz, for example in the genus name (Warszewiczia) and the species epithets (warszewiczii, warscewiczii, warszewicziana). Unfortunately, a large part of Warszewicz’s collection of plant species deposited in the Berlin Herbarium (B), including many type specimens was destroyed during World War II. During digitisation of herbarium collections preserved in the Herbarium of the Jagiellonian University (KRA), we reviewed more than 650 herbarium sheets with plant specimens collected by Warszewicz and originating from his trips to Central and South America. In this paper, we present the typification of five names of species, described base on Warszewicz’s plant material. We select lectotypes for Berberis warszewiczii, Esenbeckia warscewiczii, Psammisia ramiflora, Remijia involucrata and Rondeletia orthoneura, and provide data on the presence of 17 specimens (isotypes) representing Esenbeckia cornuta, an extremely rare species, that to date is known only from the type locality in Peru. A list of all Warszewicz’s specimens preserved at KRA herbarium is also presented. Additionally, in the result of the revision of syntypes of Berberis multiflora and Rondeletia reflexa we designated here the lectotypes for these taxa.

Berberis, Esenbeckia, KRA herbarium, lectotypification, neotropics, plant hunter, Proclesia, Psammisia, Remijia, Rondeletia, Warscewicz

Józef Warszewicz (1812–1864) known also as ‘Josef Ritter von Rawicz Warszewicz or Josef Ritter von Warszewicz’ (sometimes misspelled e.g. as Warscewicz or Warczewicz), was one of the first Polish naturalists who had the opportunity to explore the flora of Central America. Having Aleksander von Humboldt’s recommendation letter, Warszewicz joined an expedition of the Belgian Horticultural Society to Guatemala in 1844. The expedition was organised to collect plant seeds, learn about natural resources of the area, and obtain knowledge on the possibilities of its colonisation. The expedition started tragically since all its participants got sick and except for Warszewicz and his colleague doctor Flemish, died of yellow fever. Nevertheless, after recovering, Warszewicz set off alone to explore the area (Zemanek 2013; Köhler 2014; Jungfer 2017; Zemanek et al. 2021). His first stay in Central America lasted from 1844 to 1850, but the exact route of these peregrinations is difficult to determine. He probably travelled from Guatemala, through Honduras and Nicaragua to Costa Rica and Panama (Savage 1970; Sauter 2010; Zemanek 2013; Jungfer 2017; Nobis et al. 2020a). Warszewicz collected mostly plant seeds, seedlings as well as living and dried plant specimens. Initially, his main recipient and sponsor was Luis van Houtte (1810–1876) associated with the Botanic Garden in Brussels, however, Warszewicz also sent plants to many public and private botanical gardens (mainly in Berlin, Hamburg, London and Zurich) which provided him the funds to continue the expedition. He collected also some animal specimens such as snails, amphibians, reptiles and birds for natural history museums. Warszewicz returned to Europe at the beginning of 1850 and stayed in Berlin for several months to work as a private assistant to Heinrich Gustav Reichenbach (1823–1889). Although Warszewicz was not a professional taxonomist, he described, in cooperation with Reichenbach, many new orchid species. Afterward, at the end of 1850, he set off on a second expedition to Central and South America (1851–1853). This time he explored vast areas of Panama, Ecuador, Peru, Bolivia and Brazil. The botanical collection made by Warszewicz was impressive. He delivered to Europe up to twenty thousand specimens of plants. The collection included several hundred new taxa, especially orchids (Orchidaceae, about 300 taxa), but also cycads (Cycadopsida), cannas (Cannaceae) and other groups of tropical plants (Jungfer 2017; Zemanek et al. 2021). Based on his collections, many new species were described by German taxonomists, such as Johann Friedrich Klotzsch (1805–1860), Heinrich Gustav Reichenbach and Eduard August von Regel (1815–1892). To honour his service and his achievements in plant collections, over 100 taxa were described by different researchers using Warszewicz’s surname (Warszewiczia, warszewiczii, warscewiczii, warszewicziana; IPNI 2021). Unfortunately, a large part of Warszewicz’s collection deposited at Berlin herbarium (B) including original specimens (holotypes and syntypes) was destroyed during World War II on the night of 1–2 March 1943. Fortunately, some of the types, or their duplicates, have survived and today are preserved in the herbaria of B, G, BR, K, BM, P, LD, F, NY and KRA (acronyms follow Thiers 2021).

During the digitisation process of the collections preserved in the Herbarium of the Jagiellonian University (KRA), we reviewed Warszewicz’s plant collections, originating from his trips to Central and South America. More than 650 herbarium sheets with specimens collected by him are preserved as a separate collection (all the sheets have been scanned and can be shared by request to the first author). In KRA, all the herbarium specimens collected by Warszewicz have the same label “Reliquiae Warszewiczianae, America merid: Columbia. lg. J. Warszewicz” (printed and attached to this collection at the beginning of 20^th century by Antoni Żmuda). However, to selected specimens/gatherings, the labels with original Warszewicz’s collection number and place of the collection are attached as well. It is worth noting that a number of Warszewicz’s specimens preserved in B, also did not have any information about the date and place of collection (see Berlin negatives at the F herbarium online: https://collections-botany.fieldmuseum.org/list). Specimens from Warszewicz’s collection deposited in KRA were studied and determined by Stanisław Kulczyński and Antoni Żmuda from the Institute of Botany, Jagiellonian University in Kraków in 1915. However, they were able to identify only a part of this collection, and numerous specimens still remained undetermined. Most of Warszewicz’s collection is represented by specimens of trees and shrubs (e.g.: Alnus Mill., Bejaria Mutis, Berberis L., Cinchona L., Esenbeckia Knuth, Lonicera L., Morus L., Nectandra Rolander ex Rottbøll, Petrea L., Pernettya Gaudichaud-Beaupré, Salix L., Warszewiczia Klotzsch, Weigeltia A. DC.). Although Warszewicz was focused mainly on ornamental plants that could be adopted in European botanical gardens, in his collection there are also several herbaceous plants without much ornamental value (e.g., species of Gentiana L., Lobelia L., Polygala L., Utricularia L., Vernonia Schreb.). Warszewicz’s collection preserved in KRA includes original specimens (duplicates) of the type material that was preserved at B herbarium but destroyed during the WWII. Fortunately, J. Francis Macbride documented on photographs most of the types preserved in B before WWII (Hiepko 1987; Nascimento et al. 2019; BGBM 2020), which nowadays can be used during comparative taxonomical studies. However, because we cannot be sure that Macbride photographed all duplicates of the type materials (Nascimento et al. 2019; BGBM 2020), the photographs cannot be considered as evidence that only one specimen of a particular gathering was originally present in B. Following the ICN (Turland et al. 2018) the photographs of original material have no nomenclatural standing, since they were not available to the author prior to being cited or published in the protologue, and therefore, cannot be designated as lectotypes. However, they can be designated as neotypes, standing in place of the destroyed Berlin specimens, if no other original material survives (Art. 9.8 in Turland et al. 2018). A detailed discussion on the nomenclatural value of photographs of type specimens, with a number of examples of how photographs were treated by different taxonomists has been presented by Staples and Prado (2018) and Nascimento et al. (2019), with some suggestions on future ICN improvements.

Thanks to the digitisation of herbarium collections, images of sheets with plant specimens are available on websites of many herbaria, making them available to a wide audience. Herbaria provide material samples for biological research in diverse fields (Funk 2003), including global change biology (Meineke et al. 2018; Lang et al. 2019), and are an important source of species discovery (Bebber et al. 2010). They play an integral role in a modern additive research process (Henning et al. 2018) that aims to describe and understand the evolution and diversity of organisms worldwide (Harris and Marsico 2017; Borsch et al. 2020). Easily accessible and searchable online data on herbarium specimens definitely increase research efficiency. Time previously spent travelling to collections or waiting for specimen loans could instead be spent on gathering data. Taxonomists are often able to use digitised collections to identify and annotate specimens (Harris and Marsico 2017), to indicate typical specimens and to typify names of species for which the type has not been designated or are regarded as lost or destroyed. In recent years, publications including typification made on the basis of available online herbarium databases are becoming more and more common (e.g. Sukhorukov et al. 2019; Alves-Araújo et al. 2020; Boltenkov and Güner 2020; Dalastra and Heiden 2020; Kottekkattu and Pradeep 2020; Liu et al. 2020; Naive and Sanders 2020; Nobis et al. 2020b; Wang et al. 2020; Wolski et al. 2020; Yang and Rushforth 2020). The present paper is also based on the revision of many online herbarium databases, and our main aim is the typification of five names of species described based on plant material collected by Warszewicz, which types were destroyed during World War II.

This work is based on the examination of herbarium specimens and the analysis of relevant literature (including protologues). The main source of original material of plants species collected by Warszewicz and described by Klotzsch (1851), Engler (1874), Hieronymus (1895), Schuman and Krause in Krause (1908) was herbarium of B. However, other original material of these species can be found in G, BR, K, BM, P, LD, F, NY and KRA. We reviewed plant material or used the online databases of above mentioned and some other herbaria (e.g. BGBM 2020, CRIA 2020, F 2020, MNHN 2020, NMNH 2020, NYBG 2020, S 2020, Virtual Herbaria JACQ 2020) to search for all the original material available. When there was more than one specimen or more than one gathering, we chose the most complete and best preserved one, following the description given in the protologue as well as by comparison with the photographs of the original material preserved at F as negatives. To evaluate the synonymy of typified names, we compared the plant specimens with the type specimens of the accepted species, revised the original description of these taxa and checked recent Neotropical Floras and any available taxonomic elaborations concerning particular species and genera. Names typified here are listed in alphabetic order. In some cases, we have proposed superseding some previously designated lectotypes, because they are based on photographs (Turland et al. 2018) and are therefore neotypes (Art. 9.10). The list of vouchers with specimens collected by Warszewicz, identified to the level of species or genus, and preserved in KRA, is presented in Suppl. material 1: Table S1.

Although Warszewicz’s specimens preserved in KRA have different labels in comparison with those on Macbride’s photographs, we are sure that they are duplicates of types preserved in B herbarium, because: i) some of these species and specimens still are known only from the protologue and type collection (e.g. Esenbeckia cornuta or E. warscewiczii); ii) all the specimens preserved in KRA and typified here are almost identical to those photographed by Macbride at B (they were collected in the same way and at the same phenological stage); iii) some of them have the same patterns of insect damage of leaves (e.g. Remijia involucrata). Thus, in accordance with the ICN (Turland et al. 2018) selected Warszewicz’s specimens preserved in KRA, we designate here as lectotypes.

We thank Dr Alessandra Marques de Paiva and Dr Carmen Ulloa Ulloa for their help in the determination of Remijia purdieana and Berberis multiflora specimens. We are also grateful to John McNeil and the two anonymous reviewers for all their valuable comments and improvements to the manuscript. The research was funded by the Institute of Botany, Jagiellonian University in Kraków (N18/DBS/000002).