The Bryophyte Flora of São Tomé and Príncipe (Gulf of Guinea): Past, Present and Future

Abstract

This chapter aims to present a review of the knowledge of the bryological flora for the São Tomé and Príncipe Islands (Gulf of Guinea). An updated catalogue is presented, as well as a brief overview of the first expeditions conducted by the University of Coimbra. The labels of the historical herbarium collections and correspondence were analyzed, which provides an important source of data contributing toward research in taxonomy and conservation of these oceanic islands. Since 2007, exploratory fieldwork was carried out in different habitats of this archipelago along an altitudinal gradient, aiming to improve the knowledge of the ecology and distribution patterns of its bryophyte flora. A total of 304 taxa of bryophytes (133 mosses, 164 liverworts and seven hornworts) are currently reported, of which 21 are endemic to São Tomé and Príncipe and 144 species are shared endemics with the African continent. Several vouchers, especially in the herbaria of the University of Lisbon and of the California Academy of Sciences, are still under study and will likely provide further insights and new discoveries.

Introduction

Bryophytes are a group of land plants that includes mosses, liverworts, and hornworts, and with over 20,000 described species, they are the second most speciose group of higher plants, after angiosperms (Patiño and Vanderpoorten 2018; Song et al. 2021). Bryophytes are a common component of tropical forests and provide important ecosystem functions. In tropical regions during rainstorms numerous bryophyte species can quickly absorb (and retain) many times their dry weight in water. The absorbed water is then slowly released over time back into the environment, thereby reducing the erosive effects of heavy rain and allowing other plants and animals to benefit from the rain and the humid environment for a longer period (Pócs 1982). Bryophytes are widely distributed in terrestrial ecosystems (St Martin and Mallik 2017), and islands provide an exceptional natural laboratory for ecological and evolutionary research in this group of terrestrial plants that is often poorly studied. Oceanic tropical islands usually host amazing bryophyte diversity, including endemic species, especially in the montane forests favoured by ideal climatic conditions, such as frequent rainfall and permanent fog (Ah-Peng et al. 2012).

The first known bryophyte collections of São Tomé and Príncipe were made by Friedrich Welwitsch (1806–1872) in 1853 and 1860, as part of the expeditions supported by the Portuguese government to Angola (Dolezal 1974), followed by Charles Barter (1821–1859) and Gustav Mann (1836–1916), botanists with special interest in vascular flora (Sérgio and Garcia 2011). One of the greatest Portuguese mentors of Botany in Africa was Júlio Augusto Henriques (1838–1928) and he outlined a plan for studying the flora of São Tomé and Príncipe (Coutinho 1929–30). Throughout his life, Henriques remained deeply invested in understanding the botanical diversity of the archipelago, which motivated his tireless research as professor and director of the Botanical Garden of the University of Coimbra for more than 50 years. His initial interest in the botanical study of São Tomé and Príncipe was likely related to cultivation of the Cinchona tree (Chinchona spp.) and other medicinal plants at the Coimbra Botanical Garden (Perpétuo et al. 2012). At the age of 65, Henriques led an expedition to the island of São Tomé to study the island’s flora, departing from Lisbon on June 23, 1903. The research based on this visit culminated in an important publication (Henriques 1917). During his stay in the archipelago, Henriques was received by the owners of many farms (roças), taking notes and obtaining important data on the natural history of the island. Fernandes (1980, 1986) noted that when Henriques planned the study of the flora of São Tomé and Príncipe in the 1880s, he implemented a set of measures that proved to be extremely important for the enrichment of the University of Coimbra herbarium (currently, Herbário do Instituto Botânico de Coimbra, Coimbra, Portugal - COI). First, he promoted and intensified the development of the Coimbra herbarium and trained qualified botany specialists. It was to this end that he appointed Adolpho Frederico Möller (1842–1920), a renowned collector of flora in Portugal and later in São Tomé and Príncipe (four months in 1885), and in turn Francisco Joaquim Dias Quintas (1864–1909) in botanical field studies in São Tomé and Príncipe. Second, Henriques sent material collected on these expeditions to the greatest bryologists at the time. Their results were published in the “Boletim da Sociedade Broteriana”, a scientific journal dedicated to Botany and co-published by the University of Coimbra and the Broterian Society (Sociedade Broteriana).

Herbarium Specimens and Associated Documentation

Numerous naturalists passing through or purposefully visiting São Tomé and Príncipe gathered biological collections, some of which were then published in different scientific outlets. The Austrian naturalist and explorer Friedrich Welwitsch visited São Tomé in 1853 and 1860, during stopovers at the beginning and end of his botanical survey of Angola (Sérgio and Garcia 2011). The major scientific expeditions during the nineteenth century were performed by Adolpho Möller in 1885 (Henriques 1917; Sérgio and Garcia 2011), Francisco Quintas from 1888 to 1889, and Francisco Newton (1864–1909) between 1885 and 1895 (Sérgio and Garcia 2011). Casual collections were made by different naturalists, for example, the French botanist Auguste Jean Baptiste Chevalier (1873–1956) in 1905 (Exell 1944).

In all these field studies, botanical collections were organized, and duplicates were distributed to different herbaria. These included COI, and the herbaria of the Museu Nacional de História Natural e da Ciência da Universidade de Lisboa, Lisbon, Portugal (LISU), of the Natural History Museum, London, United Kingdom (BM), of the Muséum National d’Histoire Naturelle de Paris, France (PC), of the Instituto de Investigação Científica Tropical - ULisboa (LISC), and of the Conservatoire et Jardin botaniques de la Ville de Genève, Geneve Switzerland (G), and the Brotherus Herbarium (H-BR) of the Finnish Museum of Natural History University of Helsinki, Finland (H) (Herbaria acronyms according to Thiers 2016). The original herbarium collections, details presented in field notes, draft descriptions of species, and the extensive correspondence between the collectors and the specialists that studied the biological material are a valuable source of data and a base for modern studies regarding São Tomé and Príncipe flora.

Presently, COI and LISU herbaria hold most of the bryophyte specimens cited in the bibliography for São Tomé and Príncipe, corresponding mostly to the collections of Friedrich Welwitsch, Möller, Quintas and Newton, in addition to the smaller collections of Júlio Henriques. However, duplicates of these collections are also found in other European herbaria (Sérgio and Garcia 2011). The bryological collections resulting from the expeditions organized by Júlio Henriques were studied by several experts. The liverworts were sent to Franz Stephani (1842–1927) between 1886 and 1913. The mosses were first sent to Carl Müller (1818–1889) in Halle (between 1885 and 1887) and later to Viktor Ferdinand Brotherus (1849–1929) in Helsinki (between 1889 and 1904). The letters that Henriques sent to Stephani and Brotherus (Biblioteca Digital de Botânica da Universidade de Coimbra 2021) list all the specimens exchanged. Thus, specimens originating from these collections were progressively divvied up and disseminated by several international herbaria at the discretion of the authors who studied them.

In this study, by cross-checking the LISU database referring to the aforementioned studied herbaria, we were able to confirm where the reference material and most of the respective nomenclatural types are currently located (Sérgio and Garcia 2011). Additionally, we also gathered and compared all available information on where the voucher specimens from São Tomé and Príncipe are currently housed (e.g., Figs. 9.1 and 9.2).

Fig. 9.1

Two specimens (1, 2) of Bryum coronatum Schwägr., corresponding to the same Welwitsch specimen (n° 126, Insula de S. Thomé loco called Monte Caffé) collected in December 1860, and (3, 4) Sendtnera mollis Steph. Typus, Slopes of Pico de São Tomé, 1500-2100 m, 1885, Adolpho Möller 23. (1) At BM herbarium with “Inter Angolense” labels, with original iconography; (2) At LISU herbarium without iconography but with a handwritten label by Welwitsch; (3) At COI herbarium with the Möller label; (4) At BM herbarium (BM000745048) of Stephani’s herbarium and handwritten data by the same author

Fig. 9.2

Brotherus specimen identifications. Two specimens of Ectropothecium drepanophyllum corresponding to the same specimen from Quintas, n° 23: (1) Holotypus in H herbarium (H-BR1415–022) with Brotherus handwriting; (2) Isotypus in COI herbarium with a handwritten label from Quintas

Most of the material of each specimen in the COI herbarium is abundant and generally corresponds to isotypes found also in BM, G, H or PC. The labels in COI are generally not the original and must have been written by Möller or Quintas (Fig. 9.2), who organized the collections, with many duplicates sent to other herbaria. Arthur Wallis Exell (1901–1993) first landed on São Tomé Island in October 1932 to initiate a botanical expedition of the islands of the Gulf of Guinea (e.g., Fig. 9.3.1–2). He visited the four principal islands (São Tomé, Príncipe, Bioko and Annobón), and the results of this expedition were published in 1944, in the Catalogue of the Vascular Plants of São Tomé (Exell 1944).

Fig. 9.3

Arthur Exell (1, 2) and Francisco Quintas specimens (3, 4). (1) Octoblepharum albidum, Esperança, circa 350 ft., 1932, Exell 675 in the herbarium of Coimbra (COI); (2) Hygrolejeunea pulcherrima, Santa Maria, circa 4200 ft., 1932, Exell 197 in the London (BM) collections; (3) Isotypus of Metzgeria thomeensis (BM); (4) The same material in COI, isotypes. Both labels (3, 4) correspond to Stephani’s manuscripts

There are also numerous other specimens with labels based on the printed text of the work published by Carl Müller (1886a), such as the mosses collected by Adolpho Frederico Möller in 1885 and published in the Boletim da Sociedade Broteriana. We also verified the presence of specimens with original handwritten labels by Stephani and Brotherus in COI herbarium collections (Fig. 9.3.3–4), although some labels have two handwritings with the numbering of localities corresponding to Adolpho Möller manuscripts and the identifications handwritten by Stephani (Figs. 9.3.3–4 and 9.4) or Carl Müller.

Fig. 9.4

(1) Original description of Lejeunea ramosissima Steph. included in the archives of the Botanical Institute of Coimbra Library as part of the letter dated 25 February 1886, and (2) Iconography of several species, including L. ramosissima Steph. (33 and 34) and Sendtneria mollis Steph. (22 and 23) by Stephani (1886)

The historical specimens from São Tomé and Príncipe archived in the Stephani collection in the herbarium of Genève (G) (Geissler 1982) have duplicates at COI. However, some taxa collected by Newton and Quintas were not returned to Coimbra, at least those studied after 1900. These correspond to the specimen references indicated in the most recent volumes of the Index Hepaticarum (Stephani 1901–1906, 1905–1909, 1909–1912, 1912–1917, 1917–1925). Likewise, there are a considerable number of specimens collected during Júlio Henriques career in the herbarium of Paris (PC), either included in the collections of Jules Cardot (1860–1934), Ferdinand Renauld (1837–1910) or Robert Potier de La Varde (1878–1961), that are often cited in revisionary studies of bryophyte genera.

At the Helsinki herbarium (H), a significant part of material from São Tomé was found in the Brotherus (H–BR) collections, particularly type specimens collected in this archipelago (Sérgio and Garcia 2011), corresponding almost exclusively to Quintas and Möller collections. However, some of the specimens originally studied by Brotherus are now at BM, PC or COI herbaria and were not found at H herbarium (e.g., Leucobryum homalophyllum Broth.). It should be noted that, contrary to Stephani, Brotherus returned all the material he studied to Coimbra, mostly with handwritten labels.

Historical Correspondence

The correspondence between naturalists who studied bryophyte specimens collected by Möller, Quintas and Newton, is largely housed in the archives of the University of Coimbra at present. The documentation referring to Welwitsch’s correspondence, currently in Lisbon at the Museu Nacional de História Natural e da Ciência (MUHNAC) of the University of Lisbon, does not provide any mention of bryophytes, despite the existence of bryophyte herbarium specimens of Welwitsch’s expeditions in LISU herbarium (MUHNAC). Among this documentation are lists of the identified species and, in some cases, the original descriptions of species are also included.

Although it was not possible to study all Júlio Henriques’ correspondence in some foreign institutions (except for the one in the library of the University of Helsinki and in the Botanical Garden of Geneva), we analyzed the correspondence exchanged between him and several specialists that is filed at the University of Coimbra (Biblioteca Digital de Botânica da Universidade de Coimbra). Some important parts of this correspondence are transcribed below.

Correspondence from Júlio Henriques to Franz Stephani

Henriques’ first letter referring sending material to Stephani, was on 8 January 1885. The first publication of Stephani concerning the liverworts of São Tomé (Stephani 1886) refers to the A. Moller 1885 collections, so the specimen identifications must have been rather hasty. It describes 19 new species, in addition to other taxa, such as those already described by Mitten from the Cameroon Mountains (Mitten 1863) (e.g., Radula bipinnata Mitt.). Among the first records for São Tomé and Príncipe there was, for example, Lejeunea ramosissima Steph. (Fig. 9.4), Plagiochila integerrima Steph., Sendtnera mollis Steph. and Anthoceros pinnatus Steph., all currently still considered as distinct species with valid names. In the letter of 25 February 1886, Stephani sent along a list referencing the figures with the iconographies that were included in the same publication of Stephani (1886).

Correspondence from Júlio Henriques to Carl Müller

The correspondence sent by C. Müller from Halle to Henriques is very sparse and consists only of four letters between 1885 and 1887. C. Müller’s second letter, dated 21 March 1886 (UC Digitalis 2021), is the most important as it includes a list of about 50 taxa, corresponding to the identification of the specimens cited in Müller (1886a, b). These specimens include more than 25 new species, some of them still recognized as species, as in the case of Funaria acicularis Müll.Hal and Leucobryum leucophanoides Müll.Hal.

Correspondence from Júlio Henriques to Viktor Ferdinand Brotherus

Sérgio and Garcia (2011) analyzed much of the correspondence between Henriques and Brotherus. Henriques’ first letter dated 31 January 1889, refers to sending (on 24 January 1889) a package including mosses from São Tomé to Copenhagen and then to Helsinki. The exchange of bryological material continued and Henriques must have sent a second package that also included material from Portugal. In Brotherus’s letter to Coimbra, sent on 19 August 1889, he states “J’ai reçu en bon état, il ya quelque jours, la quaisse avec des mousses du Portugal et j’irais à leurs déterminations et révision aussitôt qu’il me sera possible. Les mousses de l’île S. Thomé de votre second envoi j’ai déjà examinés et vous communique le nom des espèces. Sont-elles aussi recueillies par M. Quintas”? [“I received in good condition, a few days ago, the case with mosses from Portugal and I will make their identifications and revision as soon as possible. The mosses of the island S. Thomé of your second shipment I have already examined and communicated to you the names of the species. Were they also collected by Mr. Quintas”?] (UC Digitalis 2021).The reprints referenced in these letters correspond to the 1890 article, published in the “Boletim da Sociedade Broteriana” (Brotherus 1890), where 29 new species are described, some still considered valid species, including several endemics, such as Leucobryum homalophyllum Broth. and Ectropothecium drepanophyllum Broth (Fig. 9.2).

Correspondence from Júlio Henriques to Francisco Quintas

Although there are no extant records of correspondence from Möller to Henriques, a set of letters from Quintas sent from São Tomé to Henriques in Coimbra are still extant (Biblioteca Digital de Botânica da Universidade de Coimbra 2021). From most of this correspondence, it is evident that Quintas kept Henriques apprised of his research and situation on the island, attaching lists of the material he sent to Coimbra.

Although there is no specific numbering for the bryophyte specimens, there were indications of the boxes that contained cryptogams. For instance, the attachment to the letter issued on 21 July 1888 (UC Digitalis 2021). In that same letter, he also mentioned that mushroom specimens were listed separately. There are many bryophyte specimens collected by Quintas, which correspond to about 70 different bryophyte taxa, some of them corresponding to new species, such as Plagiochila flabellata Steph., P. amplifolia Steph. Among the liverworts and numerous species of mosses (ca. 31) described as new by Brotherus in 1890, we have the examples of Pilotrichella calomicra Broth., Porotrichum quintasii Broth., P. caudatum Broth., Trichosteleum dicranelloides Broth., among other new taxa.

Correspondence from Francisco Newton to Júlio Henriques

Some correspondence between Henriques and Newton is available in the historical archives of MUHNAC, but none of these letters has any reference to bryophytes. In Coimbra University, there is a letter sent by Newton to Henriques about his 1885 upcoming mission to Africa. Based on this letter, dated 23 August 1885, Newton makes Henriques aware of certain material from Angola (UC Digitalis 2021). He also confirms in that letter that he proposed to make a stop at Príncipe Island and then São Tomé. Ultimately, Newton arrived in São Tomé on 24 September 1885 (Guedes 2021).

Strangely, most of the bryophyte material collected by Newton and found in the different herbaria (BM, FH, G, JE and M herbaria) corresponds to specimens collected in 1887 on Príncipe and only a few are indicated to be from São Tomé. In fact, in the different publications concerning Newton, specimens correspond to Príncipe Island, excluding two references corresponding to São Tomé, in Angolares (Stephani 1888a, b). It is also interesting to note that the bryophyte specimens collected on Príncipe Island were only shipped in September of 1885 (Newton 1885), after this letter, but Newton should have sent more material later.

Apparently, Newton did not organize the numbering of his bryophyte specimens and the labels are very uninformative. The numbering of specimens was made when the plants arrived in Coimbra. However, it should be noted that based on Newton’s collections, some liverwort species were described by Stephani (1888a, b), as Microlejeunea africana Steph., Lejeunea newtonii Steph. (now included in Cheilolejeunea newtonii Steph. ex Schiffn.), Plagiochila thomeensis Steph. (currently a synonym for Plagiochila terebrans Nees et Mont. ex Lindenb); Cheilolejeunea principensis Steph. (synonymized to Cheilolejeunea serpentina (Mitt.) Mizut.), and Lophocolea newtonii Steph. (synonymized to Lophocolea martiana Nees).

Historical Collecting Localities

Based on the data associated with the aforementioned collections, the location (exact or approximate) of the historical collecting activities by the first naturalists dedicated to the study of bryophytes in São Tomé Island was georeferenced (Fig. 9.5), and used as a starting point for the most recent fieldwork performed by the authors.

Fig. 9.5

Historical collecting localities of naturalists who collected bryophytes specimens on São Tomé Island from the mid-nineteenth century to mid-twentieth century: (1) Auguste Jean Baptiste Chevalier (1873–1956), (2) Arthur Wallis Exell (1901–1993), (3) Gustav Mann (1836–1916), (4) Adolpho Frederico Möller (1842–1920), (5) Théodore Monod (1902–2000), (6) Francisco Newton (1864–1909), (7) Francisco Joaquim Dias Quintas (1864–1909), (8) Charles Aubrey Thorold (1906–1998), (9) Friedrich Welwitsch (1806–1872)

Exell’s 1944 plant catalogue (Exell 1944) includes all the species known at the time and new reports of some taxa for the islands (Figueiredo 1994, 2005; Figueiredo and Gascoigne 2001), including diverse bryophytes. He was based in Vanhulst (Macambrará), in the Roça Zampalma and collected most of the bryophyte material in this region. This bryophyte collection was the basis for two publications, in which about 40 taxa of liverworts and mosses are listed (Exell 1944). Most of Exell’s specimens are stored in BM, except for some specimens that are kept at COI.

After the Exell expedition, other collections were obtained in 1956 by the French naturalist Théodore Monod (1902–2000) and C. A. Thorold (1906–1998) in São Tomé and Príncipe, mainly in Pico de Príncipe, during the “6th Conférence lnternationale des Africanistes de I’Ouest” (Monod 1960). Most of this material is hosted in PC and was the basis of the publication of Potier de la Varde (1959). Arnaldo Roseira also collected in the islands between 1954 and 1958, corresponding to 79 specimens of three taxa in the PO herbarium (Universidade do Porto) (Costa 2020).

Recent Studies

Since the middle of the twentieth century and after the works of Exell, the study of bryophytes of São Tomé and Príncipe came to a halt. Only more recently has a new effort emerged through the project Bryotome (Sérgio and Garcia 2011). During this project, the first author carried out fieldwork in São Tomé and Príncipe in 2007 and 2008, collecting about 6000 specimens at various altitudes, including Pico de São Tomé. This project enabled the study of herbarium specimens, georeferencing historical specimens, planning new fieldwork more effectively, and studying different substrates (epiphytic, epiphyllous, rupicolous, terricolous and humicolous) to better determine specific microhabitats of species across the islands. In 2010, 2013 and 2016, expeditions sponsored by the California Academy of Sciences were carried out (Fig. 9.6). During these new expeditions, several species were discovered, including new records for the archipelago and the African continent, as well as species new to science (Figs. 9.7 and 9.8). One of the new species discovered was particularly interesting: Dendroceros paivae is distinct from most other species of the genus in its ecology, gametophyte, and sporophyte characters, resembling only the Bornean D. foliicola J. Haseg. In comparison to the type material of D. foliicola, D. paivae has a narrower sporophyte diameter. The thallus of D. paivae does not form rosettes, the cuticle is weakly papillose, and apices are plane to undulate, while D. foliicola forms rosette-like patches with strong crispate margins, even at branches apices, and the cuticle is slightly papillose (Garcia et al. 2012).

Fig. 9.6

Study localities in 2007, 2008, 2010, 2013 and 2016 for the enrichment of the University of Lisbon (LISU) and the California Academy of Science (CAS) herbaria

Fig. 9.7

Liverworts and hornworts from São Tomé and Príncipe: (1, 2) Dendroceros paivae C.A. Garcia, Sérgio & J. C. Villarreal. (hornworts) at the type locality (LISU 237201) (Garcia et al. 2012); (3, 4) Megaceros flagellaris (Mitt,) Steph. (hornworts) growing on a tree trunk in the first known locality in São Tomé and Príncipe and the second one reported for the African Continent (LISU 237200); (5) Anthoceros pinnatus Steph. (hornworts); (6) Phaeoceros carolinianus (Michx.) Prosk. (hornworts); (7) Colura sp. (liverworts); (8) Cyathodium cavernarum Kunze (liverworts)

Fig. 9.8

Liverworts and mosses from São Tomé and Príncipe. (1) Marchantia pappeana Lehm. subsp. pappeana (liverworts). (2), Plicanthus hirtellus (F. Weber) R.M. Schust. (liverworts). (3), Calymperes lonchophyllum Schwägr. (mosses). (4), Octoblepharum albidum Hedw. (mosses). (5), Orthostichella sp. (mosses). (6), Trematodon longicollis Michx. (mosses). (7), Macromitrium sulcatum var. sulcatum (Hook.) Brid. (mosses). (8), Calymperes palisotii Schwägr. (mosses)

Diversity, Composition and Endemism

In recent years, several papers resulting from these last expeditions have been published. These included the study of secondary metabolism compounds (Figueiredo et al. 2010) and the description of new species and new genera of bryophytes (Enroth and Shevock 2011; Müller et al. 2011; Garcia and Sérgio 2012a, b, c, d, e; Shevock et al. 2013; Pócs et al. 2015; Sollman et al. 2016; Enroth and Shevock 2017a, b; Müller and Shevock 2018; Müller et al. 2019).

These works allowed revising the number of species and endemics for each island individually and for the two islands combined (Table 9.1 and Appendix). One hundred and forty-four species of bryophytes occurring on the islands are currently considered endemic to Africa, 21 of which are endemic to the archipelago, including seven liverworts or hornworts and 14 mosses. One of these species is the hornwort Dendroceros paivae C.A. Garcia, Sérgio & J. C. Villarreal. (hornworts), endemic to São Tomé Island (Garcia et al. 2012) and found only in a single location, in a very restricted area.

Table 9.1 Bryophyte species diversity and endemism for each island individually and for the two islands combined

The known bryophyte species diversity of the islands has increased markedly as specimens of various families are critically examined. For example, prior to fieldwork by the authors, only three species of the moss genus Fissidens (Fissidentaceae) were reported (O’Shea 2006). Now, Fissidens Hedw. is the most species-rich bryophyte genus in the archipelago with 24 known species (Shevock et al. 2013). The liverwort genera, Lejeunea Lib. and Plagiochila (Dumort.) Dumort. are also quite diverse with 19 and 18 species respectively (Müller et al. 2011; Pócs et al. 2015). A similar story of species additions for the islands was provided in a recent study of the moss families Neckeraceae (Enroth and Shevock 2011, 2017a, b) and Pottiaceae (Sollman et al. 2016). Ongoing work on the moss family Calymperaceae also has discovered several new species for these islands. We anticipate species additions for these islands will continue for many years to come. Most studies were carried out on existing trails to reach higher areas, and several regions have not yet been surveyed (Figs. 9.5 and 9.6) due to the difficult terrain. Additional species will likely be documented and discovered as more remote cloud forest environments can be systematically surveyed. Our updated summary for the bryoflora of the islands reveals the documented diversity has increased significantly since the last reports of the mosses (O’Shea 2006) and of the liverworts and hornworts (Wigginton 2018). Thus, the 304 bryophytes documented for the archipelago at this time are likely a vast underestimate of the true diversity (Appendix).

The species catalogue of the bryophyte flora of the islands of São Tomé and Príncipe presented in this work (Appendix) is based on all known published literature. All the literature on bryophytes of São Tomé and Príncipe Islands was surveyed, including liverworts, hornworts, and mosses. The delimitation of families follows the latest version of the Checklist of sub-Saharan Africa of Wigginton (2018) for liverworts and hornworts and O’Shea (2006) for mosses. Taxa are presented in alphabetical order of all the accepted names (including subspecies and varieties). Taxa with synonymies (homotypic and heterotypic synonyms) whose type locality corresponds to São Tomé and Príncipe are designated in a second column with respective authors and the year of publication for São Tomé and Príncipe. The most accurate information about the original description, as well as the relevant synonyms, were considered with general taxonomic criteria. The present table includes only records published up until June 2020 (unpublished data of the authors, including new species and localities, are not included). The catalogue is not a taxonomic document, and no new taxonomic nor nomenclatural acts are published here. Synopses of families and genera are placed alphabetically within each order.

Final Remarks

The known bryoflora of São Tomé and Príncipe includes at least 304 species. Based on our ongoing studies and the number of specimens still awaiting critical study, this number will increase in the coming years as the diversity of this group becomes more comprehensively documented. The apparently low number of known species may be explained by the logistical and practical difficulties of carrying out fieldwork in dense forests and in areas of rough terrain, a reality that affects most of the scientists working in the region. Bryophytes are also generally very small plants, and many species occur in small populations. Therefore, during fieldwork some species can easily be overlooked or may occupy exceedingly specialized microhabitats that are difficult to find (e.g., fine twigs in the tree canopy). Further difficulty originates from the fact that the taxonomy of different bryophyte families is not well developed in the tropics, and world experts in bryophyte taxonomy are also starting to become scarce, especially those dedicated to the study of tropical species. Many bryophyte species reported from Africa are known only from type specimens or based on a handful of collections. Almost 45 bryophyte taxa reported for São Tomé and Príncipe have not been resampled since the nineteenth century. For a large number of bryophyte species, the ecology and habitat specificity are not well known or not known at all, and also the distribution patterns, elevational range, and abundance for most species remain to be determined.

The threats affecting forest habitats in São Tomé and Príncipe, such as habitat destruction or competition by invasive species, may affect the survival of bryophytes. One major threat to biodiversity conservation in the archipelago, particularly to the cryptogamic communities, forest structure, and habitat diversity along the altitudinal gradients is deforestation, especially that associated with the plantations of oil palm Elaeis guineesis Jacq. In the Emolve region (southern region of São Tomé), there is a monoculture of more than 600 ha of oil palm that is expected to continue growing, which would result in a significant loss in biodiversity (bryophytes and other taxonomic groups), especially to forests at lower elevations. By contrast, ancestral roças (old colonial farms), with Cofeea spp. and Theobroma cacao L. plantations, seem to preserve a high diversity of bryophyte species, mainly epiphytic taxa.

New bryological studies are urgently needed, especially in areas that have never been surveyed. Together with the recently collected material that is currently being studied by the coauthors and other colleagues, these new surveys will continue to increase our knowledge of distributions, species diversity and the particularities of bryophyte endemism in the country. A more comprehensive and updated species list will be essential to inform a future IUCN Red List assessment of bryophytes from São Tomé and Príncipe and to designate priority areas for conservation.

Appendix

Updated catalogue of bryophytes from São Tomé and Príncipe Islands. A: African endemics. E: Island endemism.

Taxon species/subspecies/variety	Synonyms (basionyms) based in São Tomé and Príncipe collections	P	ST	Year of first ref. P/ST
DIVISIONS Marchantiophyta and Anthocerotophyta Liverworts and Hornworts
Acrolejeunea emergens (Mitt.) Steph. var. emergens		X	X	2015/2011
Aneura pinguis (L.) Dumort. sens. lat.		X	X	1956/1886
Aneura latissima Spruce		X	X	1888/2011
Anthoceros pinnatus Steph.	Anthoceros pinnatus Steph. 1886		A	1886
Bazzania decrescens subsp. molleri (Steph.) E.W.Jones	Mastigobryum molleri Steph. 1886	X	X	2015/1886
Bazzania nitida (F.Weber) Grolle			X	2011
Brachiolejeunea laxifolia (Taylor) Schiffn.	Brachiolejeunea thomeensis Steph. 1912		X	1912
Calypogeia fissa (L.) Raddi			X	1970
Calypogeia peruviana Nees et Mont.			X	1976
Caudalejeunea africana (Steph.) Schiffn.		X	X	2011
Caudalejeunea dusenii Steph.			A	2015
Caudalejeunea hanningtonii (Mitt.) Schiffn.		A	A	2000/2000
Caudalejeunea lehmanniana (Gottsche) A.Evans		X		2015
Ceratolejeunea cornuta (Lindenb.) Steph.		X	X	1960/2015
Ceratolejeunea floribunda Steph.	Ceratolejeunea floribunda Steph. 2013 1913		E	1913
Cheilolejeunea intertexta (Lindenb.) Steph.	Cheilolejeunea newtonii Steph. ex Schiffn. 1893	X		2015/1893
Cheilolejeunea montagnei (Gottsche) R.M.Schust.	Euosmolejeunea thomeensis Steph. 1914		X	1863
Cheilolejeunea rigidula (Nees ex Mont.) R.M.Schust.	Cheilolejeunea principensis Steph. ex Paris 1888	X		1888
Cheilolejeunea surrepens (Mitt.) E.W.Jones			X	2015
Cheilolejeunea trifaria (Reinw. et al.) Mizut.	Lejeunea grandistipula Steph. 1886	X	X	2015/1886
Chiloscyphus difformis (Nees) J.J.Engel et R.M.Schust.	Lophocolea molleri Steph. 1886		X	1886
Cololejeunea africana (Steph.) R.M.Schust.	Physocolea africana Steph. 1915		A	1916
Cololejeunea cuneifolia Steph.		A		2015
Cololejeunea iradieri Infante et Heras			A	2015
Cololejeunea lanceolata E.W.Jones		A		2015
Cololejeunea leloutrei (E.W.Jones) R.M.Schust.			A	1960
Cololejeunea mocambiquensis S.W.Arnell		A		2015
Cololejeunea obliqua (Nees et Mont.) Schiffn.	Cololejeunea crenatiflora Steph. 1891	X	X	2011/1891
Cololejeunea obtusifolia (E.W.Jones) Tixier		A		2015
Cololejeunea papilliloba Steph.		X		2015
Cololejeunea platyneura (Spruce) A.Evans			X	2015
Cololejeunea pusilla Steph.		A		2015
Cololejeunea zenkeri (Steph.) E.W.Jones		A	A	2000/2015
Colura calderae Pócs			A	2011
Colura digitalis (Mitt.) Steph.		A	A	1958/1953
Colura hattoriana Pócs			A	2015
Colura obesa Jovet-Ast		A	A	2015
Colura tenuicornis (A.Evans) Steph.		X	X	2015/1958
Colura thomeensis Pócs		E	E	2015/2011
Conoscyphus trapezioides (Sande Lac.) Schiffn.	Lophocolea devexa Mitt. 1863	X	X	2015/1863
Cryptolophocolea martiana (Nees) L.Söderstr., Crand.-Stotl. et Stotler subsp. martiana	Lophocolea newtonii Steph. 1907	X	X	1953
Cyathodium cavernarum Kunze			X	1952
Dendroceros crispatus Nees			X	1863
Dendroceros herasii M.Infante			A	2010
Dendroceros paivae C.Garcia, Sérgio & J.C. Villarreal			E	2012
Dibrachiella africana (Steph.) X.Q.Shi, R.L.Zhu et Gradst.		A		2000
Dibrachiella autoica (Vanden Berghen) X.Q.Shi, R.L.Zhu et Gradst.		A		2015
Diplasiolejeunea cavifolia Steph.	Lejeunea cavifolia Steph. 1886		X	1886
Drepanolejeunea capulata (Taylor) Steph.			A	2011
Drepanolejeunea cultrella (Mitt.) Steph.	Drepanolejeunea molleri Steph. 1913	A	A	2015/1913
Drepanolejeunea physifolia (Gottsche) Pearson	Prionolejeunea fissistipula Steph. 1913	A	A	1960/1913
Dumortiera hirsuta (Sw.) Nees		X	X	1960/1886
Folioceros incurvus (Steph.) D.C.Bharadwaj		A	A	1888/1889
Fossombronia indica Steph.		X		2019
Fossombronia sp.		X		2011
Frullania angulata Mitt. var. angulata	Frullania angulata Mitt. 1863; F.subatrata Steph. 1911; F. cordifolia Steph. 1911		A	1863
Frullania apicalis Mitt.	Frullania laceriloba Steph. 1911	A	A	2015/1911
Frullania apiculata (Reinw. et al.) Nees			X	2011
Frullania caffraria Steph.	Frullania molleri Steph. 1894 (Probably synonym)		X	1894
Frullania diptera (Lehm.) Drège			A	1886
Frullania ericoides (Nees) Mont.		X	X	1886/1863
Frullania obscura (Sw.) Mont.	Frullania thomeensis Steph. 1910		X	1910
Frullania obscurifolia Mitt.		X	X	2015/2004
Frullania purpurea Steph.			X	1976
Frullania rio-janeirensis (Raddi) Ångstr.	Frullania africana Steph. 1891	X	X	1976/1891
Frullania serrata Gottsche var. serrata			X	1886
Frullania spongiosa Steph.		X	X	2011/2011
Fuscocephaloziopsis connivens subsp. fissa (Steph.) Váňa et L.Soderstr.		X	X	1988/1988
Herbertus dicranus (Taylor ex Gottsche, Lindenb. et Nees) Trevis.	Sendtnera mollis Steph. 1886	X	X	2011/1886
Heteroscyphus dubius (Gottsche) Schiffn.		X		1888
Heteroscyphus spectabilis (Steph.) Schiffn.	Isotachis perfoliata Steph. 1886 Chiloscyphus thomeensis Steph. 1893 nom. nud.?	A	A	2015/1886
Lejeunea abyssinica (Gola) Cufod.		A	A	2015/2015
Lejeunea acuta Mitt.		A	A	2019/1960
Lejeunea anisophylla Mont.		X	X	2011/2011
Lejeunea brenanii E.W.Jones			A	2015
Lejeunea cf. obtusata Gottsche			X	2011
Lejeunea conformis Nees et Mont.			A	2011
Lejeunea eckloniana Lindenb.		X		2015
Lejeunea flava (Sw.) Nees		X	X	1888/1960
Lejeunea grossecristata (Steph.) E.W.Jones	Hygrolejeunea grossecristata Steph. 1896; Taxilejeunea longirostris Steph. 1914		A	1896
Lejeunea helenae Pearson		X		2015
Lejeunea ibadana A.J.Harr. et E.W.Jones		A	A	2015/2015
Lejeunea jungneri (Steph.) Steph.		A		1901
Lejeunea lyratiflora Steph.			A	2015
Lejeunea papilionacea Prantl			X	2011
Lejeunea phyllobola Nees et Mont.		X		2011
Lejeunea pulchriflora (Pearson) G.E. Lee, Bechteler, Pócs, Schäf-Verw. & Heinrichs		X		2015
Lejeunea ramosissima Steph.	Lejeunea ramosissima Steph. 1886	X	X	1996/1886
Lejeunea setacea (Steph.) Steph.		A	A	1969/1969
Lejeunea tuberculosa Steph.		X		2011
Lepidozia succida Mitt.		A	A	2011/1891
Lepidozia ubangiensis Steph.		A	A	2015
Leptolejeunea astroidea (Mitt.) Steph.		A		2015
Leptolejeunea epiphylla (Mitt.) Steph.	Leptolejeunea quintasii Steph. 1891	X	X	2015/1891
Leptolejeunea maculata (Mitt.) Schiffn.	Lejeunea thomeensis Steph. 1886; Drepanolejeunea gomphiae Steph. 1913	X	X	2015/1886
Lopholejeunea nigricans (Lindenb.) Schiffn.		X	X	2011/2011
Lopholejeunea subfusca (Nees) Schiffn.		X	X	2015/2011
Marchantia debilis Goebel			A	2011
Marchantia pappeana Lehm. subsp. pappeana	Marchantia planiloba Steph. 1886		A	1886
Marchesinia excavata (Mitt.) Schiffn.	Homalolejeunea henriquesii Steph. 1888		A	1886
Marchesinia principensis Frank Müll. et Shevock		A		2018
Mastigophora diclados (Brid. ex F.Weber) Nees		X	X	2015/1886
Megaceros flagellaris (Mitt.) Steph.			X	2012
Metalejeunea cucullata (Reinw. et al.) Grolle		X		2015
Metzgeria furcata (L.) Dumort.	Metzgeria thomeensis Steph. 1891	X	X	2004/1891
Metzgeria leptoneura Spruce	Metzgeria recurva Steph. 1886	X	X	2004/1886
Metzgeria lindbergii Schuffn.		X		2015
Microlejeunea africana Steph.	Microlejeunea africana Steph. 1888	A	A	1888/1891
Microlejeunea ankasica E.W. Jones		A	A	2015
Microlejeunea kamerunensis Steph.	Microlejeunea cochlarifolia Steph 1888 (probably synonymy)	A	A	1990/1888
Neurolejeunea breutelii (Gottsche) A.Evans var. africana Pócs		E		2015
Notoscyphus lutescens (Lehm. et Lindenb.) Mitt.			X	2015
Odontolejeunea lunulata (F.Weber) Schiffn.	Odontolejeunea thomeensis Steph. 1912		X	2004/1912
Pallavicinia lyellii (Hook.) Carruth.	Pallavicinia pilifera Steph. 1891		X	1891
Phaeoceros carolinianus (Michx.) Prosk.			X	2011
Plagiochila barteri Mitt.	Plagiochila triangularis Steph. 1886; P. quintasii Steph. 1904	A	A	1962/1886
Plagiochila barteri var. valida (Steph.) Vanden Berghen		A	A	1981/1981
Plagiochila brunneola Steph.	Plagiochila brunneola Steph. 1904		A	1904
Plagiochila divergens var. capensis (Steph.) E.W. Jones			X	1962
Plagiochila flabellata Steph.	Plagiochila flabellata Steph. 1886; P. molleri Steph. 1886	A	A	2011/1886
Plagiochila fusifera Taylor	Plagiochila amplifolia Steph. 1901		X	1901
Plagiochila gibbiflora Steph.	Plagiochila gibbiflora Steph. 1904		E	1904
Plagiochila heterostipa Steph.		A		2015
Plagiochila integerrima Steph.	Plagiochila integerrima Steph. 1886	X	X	2011/1886
Plagiochila loloensis Steph.	Plagiochila rotundifolia Steph. 1904	A	A	2011/1904
Plagiochila moenkemeyeri Steph.		A	A	2011/1960
Plagiochila neckeroidea Mitt.		A	A	2011/1904
Plagiochila pectinata Willd. ex Lindenb.		A	A	2011/1960
Plagiochila pinniflora Steph.			A	2011
Plagiochila praemorsa Steph.	Plagiochila cacuminis Steph. 1918	X	X	1888/1918
Plagiochila sarmentosa (Lehm. et Lindenb.) Lindenb.	Requires confirmation
Plagiochila strictifolia Steph.		A	A	1962/1962
Plagiochila terebrans Nees et Mont. ex Lindenb.	Plagiochila thomeensis Steph. 1886	A	A	2011/1886
Pleurozia gigantea (F.Weber) Lindb.			X	1863
Plicanthus hirtellus (F.Weber) R.M.Schust.			X	1886
Porella abyssinica var. hoehnelii (Steph.) Pócs.			A	2011
Porella subdentata (Mitt.) E.W.Jones var. subdentata	Madotheca thomeensis Steph. 1910	A	A	1963/1910
Porella subdentata var. camerunensis E.W.Jones			A	2011
Prionolejeunea grata (Gottsche) Schiffn.		X	X	1960/1960
Prionolejeunea principensis Vanden Berghen		E		1960
Radula ankefinensis Gottsche ex Steph.		A	A	2011/2015
Radula appressa Mitt.	Radula angustata Steph. 1886; R. molleri Steph. 1910	A	A	1910/1886
Radula boryana (F.Weber) Mont.	Radula tamariscina Mitt. 1863; R. bipinnata Mitt. 1863	X	X	1996/1863
Radula flaccida Lindenb. et Gottsche		X	X	1939/1939
Radula fulvifolia (Hook.f. et Taylor) Gottsche et al.		X	X	2001/2011
Radula stenocalyx Mont.		X	X	2015/1910
Riccardia amazonica (Spruce) Schiffn. ex Gradst. et Hekking		X	X	2015/2011
Riccardia erosa (Steph.) E.W.Jones	Aneura erosa Steph. 1891	A	A	2011/1891
Riccardia limbata (Steph.) E.W.Jones	Aneura reticulata Steph. 1891	A	A	2011/1891
Riccardia longispica (Steph.) Pearson		A	A	2015/2011
Riccia congoana Steph.			X	2012
Riccia discolor Lehm. et Lindenb.		X		2015
Riccia lanceolata Steph.		A		2015
Riccia moenkemeyeri Steph.			A	2012
Riccia stricta (Lindenb.) Perold			X	2012
Schiffneriolejeunea occulta (Steph.) Gradst.		A	A	2015/2011
Schiffneriolejeunea pappeana (Nees) Gradst. var. pappeana	Ptychocoleus quintasii Steph. 1912		A	1912
Schiffneriolejeunea polycarpa (Nees) Gradst.	Phragmicoma amplectens Steph. 1886 = P. molleri Steph. 1886		X	1886
Solenostoma borgenii (Gottsche ex Pearson) Steph.			A	1974
Solenostoma dusenii (Steph.) Váňa, Hentschel et Heinrichs.		X	X	2019/1974
Spruceanthus abbreviatus (Mitt.) X.Q.Shi, R.L.Zhu et Gradst.		X		2015
Spruceanthus floreus (Mitt.) Sukkharak et Gradst.		A		1891
Stictolejeunea balfourii (Mitt.) E.W.Jones		X		2015
Symphyogyna podophylla (Thunb.) Mont. et Nees			X	2011
Syzygiella manca (Mont.) Steph.	Jungermannia geminiflolia Mitt. 1863		X	1863
Telaranea coactilis (Spruce) J.J.Engel et G.L.Merr.			X	2011
Telaranea nematodes (Gottsche ex Austin) M.Howe	Lepidozia quintasii Steph. 1922		X	1922
Thysananthus auriculatus (Wilson) Sukkharak et Gradst. var. auriculatus		X	X	2011/1949
Thysananthus humilis (Gottsche) Sukkharak et Gradst.		X	X	2014/1888
Thysananthus nigrus (Steph.) Sukkharak et Gradst.	Mastigolejeunea nigra Steph. 1891	A	X	2015/1891
Thysananthus turgidus (Steph.) Sukkharak et Gradst.	Mastigolejeunea turgida Steph.	A	X	1983/1917
DIVISION Bryophyta Mosses
Afrothamnium stipitatum (Mitt.) Enroth			X	1982
Anoectangium aestivum (Hedw.) Mitt.			X	2016
Anoectangium stracheyanum Mitt.			X	2016
Barbula cf. seramensis H.Akiyama			X	2016
Brachymenium leptophyllum (Bruch & Schimp. ex Müll.Hal.) Bruch & Schimp. ex A.Jaeger			X	1972
Brachymenium nepalense Hook.			X	1972
Brachymenium subuliferum (Mitt.) A.Jaeger	Bryum subuliferum Mitt. 1863; Bryum molleri Müll.Hal. 1886		A	1863
Brachymitrion moritzianum (Müll.Hal.) A.K.Kop.	Orthodon thomeanus Broth. 1890; Tayloria thomeana Broth. 1903		X	1890
Bryum apiculatum Schwägr.	Bryum areoblastum Müll.Hal. 1886		X	1886
Bryum argenteum Hedw. var. argenteum	Bryum squarripilum Müll.Hal. 1886		X	1886
Bryum coronatum Schwägr.	Bryum erythrostegum Müll.Hal. 1886		X	1886
Bryum huillense Welw. & Duby	Bryum quintasii Broth.1890		X	1890
Bryum thomeanum P. de la Varde	Bryum thomeanum P.de la Varde 1959		E	1959
Caduciella mariei (Besch.) Enroth		X		2017
Callicostella brevipes (Broth.) Broth.			A	1952
Callicostella chionophylla (Müll.Hal.) Broth.	Hookeria chionophylla Müll.Hal. 1886		E	1886
Callicostella fissidentella (Besch.) Kindb.	Hookeria thomeana Broth. 1890	A	A	1890/1890
Callicostella perpapillata Broth. & P.de la Varde		X		1944
Callicostella salaziae (Besch.) Broth.	Hookeria quintasi Broth. 1890		A	1890
Calymperes afzelii Sw.	Calymperes quintasi Broth. 1890		X	1863
Calymperes lonchophyllum subsp. saxatile (Müll. Hal. ex Besch.) S.R. Edwards		A		1944
Calymperes palisotii Schwägr.		X		1987
Calymperes pintasii Müll.Hal. ex Besch.			A	1896
Calymperes tenerum Müll.Hal.	Calymperes principis Broth. 1890	X	X	1890/1959
Calyptothecium acutifolium var. breviusculum (Müll.Hal. ex Dusén) Argent			A	2011
Campylopus flexuosus (Hedw.) Brid var. flexuosus.	Campylopus quintasii Broth. 1890		X	1890
Campylopus savannarum (Müll.Hal.) Mitt.	Dicranum divaricatum Mitt. 1863; Campylopus erythrocaulon Broth. 1890	X	X	1890/1863
Chionoloma bombayense (Müll.Hal.) P. Sollman			X	2016
Cyclodictyon filicuspis P.de la Varde		X		1944
Cyclodictyon laetevirens (Hook. & Taylor) Mitt.			X	1944
Deslooveria quintasii (Broth.) Enroth	Porotrichum quintasii Broth. 1890		A	1890
Deslooveria saotomensis (Enroth & Shevock) Enroth	Porotrichum saotomense Enroth and Shevock (2011)		E	2011
Dicranella falcularia Müll.Hal. ex Dusén		A		1944
Ectropothecium brevifalcatum (Müll.Hal.) Kindb.	Hypnum brevifalcatum Müll.Hal. 1886		A	1888
Ectropothecium diffusum (Mitt.) A.Jaeger	Stereodon diffusus Mitt. 1863	A		1863
Ectropothecium drepanophyllum Broth.	Ectropothecium drepanophyllum Broth. 1890		E	1890
Fissidens asplenioides Hedw.			X	2013
Fissidens borgenii Hampe		A	X	2013/2013
Fissidens crispulus Brid. var. crispulus		X	X	2013/2013
Fissidens crispulus var. robinsonii (Broth.) Z. Iwats.& Z.-H. Li		X	X	2013/2013
Fissidens crispus Mont.			X	2013
Fissidens darntyi Schimp.			A	2013
Fissidens enervis Sim		A	A	2013/2013
Fissidens flaccidus Mitt.		X	X	2013/2013
Fissidens glaucissimus Welw. & Duby	Fissidens subglaucissimus Broth. 1890	A	A	1890/1890
Fissidens intramarginatus (Hampe) A.Jaeger			X	2013
Fissidens metzgeria (Müll.Hal.) Broth.			A	2013
Fissidens microcarpus Mitt.		A		2013
Fissidens ovatus Brid.			A	2013
Fissidens pallidinervis Mitt.			X	2013
Fissidens palmatus Hedw		X		2013
Fissidens pellucidus Hornsch.		X	X	2013/2013
Fissidens porrectus Mitt.		A	A	2013/2013
Fissidens punctulatus Sande Lac.			X	1890
Fissidens ramulosus Mitt.		A	A	2013/2013
Fissidens sciophyllus Mitt.	Fissidens purpureocaulis Müll.Hal. 1900	A	A	2013/2013
Fissidens serratus Müll.Hal. var. serratus		X		2013
Fissidens submarginatus Bruch			X	2013
Fissidens usambaricus Broth.			A	2013
Fissidens zollingeri Mont.		X		2013
Floribundaria floribunda (Dozy & Molk.) M.Fleisch.			X	2011
Floribundaria vaginans (Welw. & Duby) Broth.	Papillaria patentissima Müll.Hal. 1886		A	1886
Funaria acicularis Müll.Hal.	Funaria acicularis Müll.Hal. 1886		E	1886
Funaria hygrometrica Hedw. var. hygrometrica			X	1901
Gymnostomiella erosula (Müll.Hal. ex Dusén) Arts			A	2016
Gymnostomiella vernicosa (Hook.) M.Fleisch.			X	2016
Hydrogonium consanguineum (Thwaites & Mitt.) Hilp.		X	X	2016/2016
Hydrogonium orientale (F. Weber) Kucera		X		2016/1987?
Hymenostylium recurvirostrum (Hedw.) Dixon var. recurvirostrum			X	2016
Hyophila involuta (Hook.) A.Jaeger		X	X	2016/2016
Hypopterygium tamarisci (Sw. ex Sw.) Brid. ex Müll.Hal.	Hypopterygium brevifolium Broth. 1890	X	X	1997/1863
Isopterygium nanoglobum (Müll.Hal.) Paris	Hypnum nanoglobum Müll.Hal. 1886		E	1886
Lepidopilum lastii Mitt.			A	1944
Lepidopilum niveum (Müll.Hal.) Kindb.	Hookeria niveum Müll.Hal. 1886		A	1886
Leptodontium viticulosoides (P.Beauv.) Wijk & Margad. var. viticulosoides			X	2016
Leucobryum fouta-djalloni Paris & Cardot			A	1959
Leucobryum homalophyllum Broth.	Leucobryum homolophyllum Broth. 1890		E	1890
Leucobryum leucophanoides Müll.Hal.	Leucobryum leucophanoides Müll.Hal. 1886		E	1886
Leucoloma gracilescens Broth.	Leucoloma gracilescens Broth. 1890		A	1890
Leucoloma secundifolium Mitt.	Leucoloma secundifolium Mitt.1863		A	1863
Leucomium strumosum (Hornsch.) Mitt.			X	1944
Leucophanes molleri Müll.Hal.	Leucophanes molleri Müll.Hal. 1886		X	1886
Leucophanes unguiculatum Mitt.	Leucophanes unguiculatum Mitt.1863	A		1863
Lopidium struthiopteris (Brid.) M.Fleisch.	Hypopterygium subtrichocladum Broth. 1890	X	X	1890/1997
Macromitrium sulcatum (Hook.) Brid. var. sulcatum	Macromitrium undatifolium Müll.Hal. 1886	X	X	1917/1886
Mesonodon flavescens (Hook.) W.R. Buck		X		2011
Mittenothamnium leptoreptans (Broth.) Cardot	Microthamnium leptoreptans Broth. 1890		E	1890
Neckeromnion lepineanum (Mont.) S.Olsson, Enroth, Huttunen & D.Quandt		X	X	2017/2017
Neckeropsis disticha (Hedw.) Kindb.		X	X	2011/1993
Octoblepharum albidum Hedw.		X	X	1944/1959
Orthostichella rigida (Müll. Hal.) B.H.Allen & Magill	Pilotrichella leptoclada Müll.Hal. 1886; P. calomicra Broth. 1890		X	1886
Orthostichella versicolor (Müll. Hal.) B.H. Allen & W.R. Buck	Pilotrichella inflatifolia Müll.Hal. 1886		X	1886
Orthostichidium involutifolium subsp. thomeanum (Broth.) Argent	Hildebrandtiella thomeana Broth.1890; Orthostichidium thomeanum (Broth.) Broth. 1906	A	A	1996/1890
Orthostichidium involutifolium (Mitt.) Broth. subsp. involutifolium.			A	1959
Philonotis nanothecia (Müll.Hal.) Kindb.	Bartramia nanothecia Müll.Hal. 1886		A	1886
Philonotis trichodonta (Müll.Hal.) Kindb.	Bartramia trichodonta Müll.Hal. 1886		E	1886
Pinnatella minuta (Mitt.) Broth.	Hypnum africanum Welw. & Duby 1872	X	X	1917/1872
Pinnatidendron piniforme (Brid.) Enroth		X	X	2011/2011
Plagiomnium rhynchophorum (Hook.) T.J.Kop. var. rhynchophorum.			X	1944
Pogonatum gracilifolium Besch.	Polytrichum rubentiviride Müll.Hal. 1886; P. molleri Müll.Hal. 1886	A	A	1944/1886
Pogonatum usambaricum (Broth.) Paris			A	1989
Pyrrhobryum spiniforme (Hedw.) Mitt.			X	1886
Racopilum orthocarpioides Broth.	Racopilum orthocarpioides Broth. 1890		A	1890
Racopilum thomeanum Broth.	Rhacopilum thomeanum Broth. 1890		A	1890
Radulina borbonica (Bél.) W.R.Buck	Trichosteleum subpycnocylindricum Broth. 1890		X	1890
Rhacopilopsis trinitensis (Müll.Hal.) E.Britton ex Dixon	Microthamnium subelegentulum Broth. 1890		X	1890
Rhizofabronia persoonii (Schwägr.) M.Fleisch var. persoonii.			A	1863
Rhynchostegium hopfferi (Welw. & Duby) A.Gepp	Hypnum hopfferi Welw. & Duby 1872		E	1872
Scabrellifolium elongatum (Welw. & Duby) Enroth	Hypnum molleri Müll.Hal. 1886		A	1886
Scabrellifolium substriatum (Hampe) Enroth	Porotrichum caudatum Broth. 1890		X	1890
Sematophyllum amblystegiocarpum (Müll.Hal.) Broth.	Hypnum amblystegiocarpum Müll.Hal. 1886		E	1886
Splachnobryum obtusum (Brid.) Müll.Hal.			X	2016
Symphyodon pygmaeus (Broth.) S.He & Snider			X	2011
Syrrhopodon gardneri (Hook.) Schwägr.	Syrrhopodon quintasii Broth. 1890		X	1890
Syrrhopodon lamprocarpus Mitt.			A	1886
Tayloria solitaria (Hedw.) T.J.Kop. & W.Weber			A	1972
Thamnobryum corticola (Kindb.) De Sloover			A	1902
Thuidium involvens subsp. thomeanum (Broth.) Touw	Thuidium thomeanum Broth. 1890		A	1890
Trachypodopsis serrulata (P.Beauv.) M.Fleisch. var. serrulata	Trachypodopsis quintasiana Broth. 1909		A	1909
Trachypus bicolor var. viridulus (Mitt.) Zanten	Papillaria molleri Müll.Hal. 1886		X	1886
Trematodon divaricatus Bruch	Trematodon flexifolius Müll.Hal. 1886??		A	1886
Trematodon longicollis Michx.	Trematodon flexifolius Müll.Hal. 1886		X	1886
Trichosteleum dicranelloides Broth.	Trichosteleum dicranelloides Broth. 1890		A	1890
Vesicularia glaucula (Broth.) Broth.	Ectropothecium glauculum Broth. 1890		A	1890
Vesicularia scaturigina (Brid.) Broth.			A	1863
Vesicularia strephomischos (Welw. & Duby) Broth.	Hypnum strephomischos Welw. & Duby 1872		A	1872
Wijkia monodii (P.de la Varde) H.Akiyama	Gollania monodii P.de la Varde 1959		E	1959
Wijkia trichocoleoides (Müll.Hal.) H.A.Crum	Hypnum trichocoleoides Müll.Hal. 1886		A	1886