Biodiversity of Sematophyllaceae s. str. in northeastern Brazil

In this study, we list 25 moss species belonging to Sematophyllaceae s. str. Six species are reported for the first time from some of the states in the Northeast Region of Brazil. Sematophyllum succedaneum (Hook.f. & Wilson) Mitt. stands out for being found for the first time in this region. The Atlantic Forest is the phytogeographic domain with the greatest number of Sematophyllaceae species, which are either exclusive to this domain or shared with the Caatinga and/or Cerrado. Our study expands on the previous knowledge of these species and provides a foundation for further studies.


Introduction
The Northeast Region of Brazil is the third largest region and, has of the largest number of bryophyte species, with an estimated 689 species (Costa and Peralta 2015). This region presents four phytogeographic domains: Caatinga, Cerrado, Amazon Forest (in Maranhão), and Atlantic Forest. According to Drumond et al. (2000), the Caatinga is the largest domain occupying the central, northeastern, and southern area of the Northeast Region of Brazil. The Cerrado occupies the western and southeastern portions, whereas the Atlantic Forest, with its area drastically reduced, lies in the easternmost portion of the Northeast region. Although the Caatinga covers the largest territory, this domain has the lowest species diversity of bryophytes (Costa and Peralta 2015). The predominant ombrophilous forest in the Atlantic region is characterized by a high diversity (Costa and Peralta 2015).
Sematophyllaceae is a large moss family with approximately 49 species in Brazil (Câmara and Carvalho-Silva 2020). Descriptions of Sematophyllaceae species from the Northeast Region are found in the publications by Yano et al. (2009), Varão et al. (2011, Oliveira et al. (2018), Evangelista-dos-Santos et al. (2021), Evangelista-dos-Santos and Almeida (2020), and Souza and Oliveira (2019). Although there are existing published studies on Sematophyllaceae, additional investigations of herbarium collections are required to provide invaluable information.
The five herbaria with the most specimens collected in the Northeast Region are ALCB, HABIT, HUEFS, UB, and UFB (SpeciesLink 2021). Approximately 126 Sematophyllaceae specimens were found on the Species-Link website without identifications to species. Here, we provide a list of all Sematophyllaceae s. str. species occurring in the Northeast Region of Brazil, with taxonomic comments, photographs, ecological information, and geographic and altitudinal distribution.

Study Area
The Northeast Region of Brazil is located in the Southern Hemisphere tropics (Fig. 1). In the north and east is borders the Atlantic Ocean. Rainfall is between 300 and 2220 mm per year, and the average temperature is between 20 and 40° C (Queiroz et al. 2018). The Northeast Region has a semi-arid climate (Araújo and Martins 1998
We undertook collection excursions in areas where fewer or dubious records existed (i.e., Serra da Jibóia, BA; Barra do Vento, BA; and Serra da Bela Vista, SE). Between 2019 and 2022, 212 samples were collected following the methodology proposed by Yano (1984). The collected material is deposited in HUEFS and ASE. Specimens were requested from the Alexandre Leal Costa (ALCB) and Anchieta (PACA) herbaria and analyzed in HUEFS. The specimens housed in the herbaria ASE, HABIT, HUESPI, HUNEB, UB, and UFP were observed during visits in 2019 and 2021. The taxonomic classification used here follows Carvalho-Silva et al. (2017) and Deshmukh et al. (2021).
The species are classified according to the substrate they were colonizing (Robins 1952;Bates 2009). The Brazilian phytogeographic domains follow the classification proposed by Fiaschi and Pirani (2009). Of the 25 species included in the list of species, we selected 13 to be described and illustrated, as these species are newly reported from Northeast Region or with is little information in the literature on them.

Results
Twenty-five species belonging to the family Sematophyllaceae s. str. (Table 1) are known form the Northeast Region of Brazil. Twenty-three species occur in the Atlantic Forest, of which 12 are exclusive to that domain, and 11 are shared with the Cerrado and Caatinga       Remor et al. 2021). The South and Southeast Regions are predominantly within the Atlantic Forest domain, which has the largest number of species of the family in Brazil, which justifies the similarity (Costa and Peralta 2015).
With our new data from previously unexplored locations and new records from the Caatinga or Cerrado domain, the number species know form the Northeast Region is considerably increased. The occurrence of the relatively larger number of Sematophyllaceae s. str. species found in this region can be explained by the variety of habitats, floristic heterogeneity, and environmental conditions (Giulietti et al. 2005;Moraes et al. 2020). Greater availability of water, which provides ideal microhabitats for bryophytes may also be of importance (Vanderpoorten and Goffinet 2009).
Although cited in the literature, some species have not since been recorded in certain places, such as Apty chopsis estrellae cited for the Serra de Itabaiana in Sergipe (Silva and Pôrto 2015), Jirivanaea caespitosa (Hedw.) U.B.Deshmukh & Rathor for the Serra do Cariri in Pernambuco (Yano 1981), and Trichosteleum sento sum for Pernambuco with no defined location (Costa et al. 2011;Yano 2011). These are likely misidentifications. The specimens originally identified as A. estrellae were found to be Sematophyllum beyrichii.
Sematophyllum adnatum (Michx.) E.Britton is frequently cited for the Northeast Region (Alvarenga et al. 2007;Yano et al. 2009;Costa et al. 2011;Yano 2011;), but it is excluded here, as specimens identified as this species instead belong to S. beyrichii. Donnellia commutata requires a detailed analysis of the sporophytic characteristics for its identification. In the absence of sporophytes, the gametophytes on leaves resemble some forms of Brittono doxa subpinnata (Evangelista-dos-Santos et al. 2021).
The species analyzed in this study occurr preferentially in the Atlantic Forest, and 10 occur exclusively in this domain (Fig. 1). In contrast, only Donnellia lageni formis (Müll.Hal.) W.R.Buck was found exclusively in the Caatinga, in campo rupestre, growing on decaying plant material. The presence of this species is known in the South and Southeast regions of the country, such as riparian forest formations or gallery and mixed ombrophilous forest of the Atlantic region (Câmara and Carvalho-Silva 2022). Its identification was possible thanks to the presence of the sporophyte that made it possible to distinguish between D. commutata (Buck 1994;Evangelistados-Santos et al. 2021).
According to Gradstein and Pócs (1989) and Frahm (1990), most bryophytes colonize the trunks of living trees, and pH and a rough cortex help in their establishment. Few species grow on only one type of substrate, such as Acroporium pungens (Hedw.) Broth. on the bases of living tree trunks, Colobodontium vulpinum on rocks, Trichosteleum papillosum on decaying plant material, and Trichosteleum glaziovii on rocks.
Our results show the importance of analyzing herbarium collections in better understanding species. Many of the new occurrences records come from materials originally identified at the family or genus level. Based on our results we highlight the important contribution of taxonomic study of herbarium collections.