Diversity of Scleria (Cyperaceae) in Amazonian restinga in Pará state, Brazil

This study aims to contribute to the knowledge on the taxonomy of Scleria in sandy coastal plains (restinga) in Pará state, Brazil. Material deposited in the herbaria of Museu Paraense Emílio Goeldi (MG), Embrapa Amazônia Oriental (IAN), and Instituto de Estudos Costeiros da Universidade Federal do Pará (HBRA) were analyzed and species were identified using relevant literature, protologues, and types available online. We recorded nine species of Scleria for restinga in the state: Scleria bracteata, S. gaertneri, S. hirtella, S. interrupta, S. macrophylla, S. microcarpa, S. reticularis, S. secans, and S. violacea. An identification key, descriptions, illustrations, and comments about diagnostic characters and geographic distribution are provided

Restinga areas are defined as sandy coastal communities from the Quaternary period that are closely associated with the ocean and nearby beaches, dunes, and depressions (Araújo & Henriques 1984;Brasil 1993). Along the Brazilian coast in Amazonia, restinga occurs discontinuously for 1,500 km in the states of Amapá, Pará, and Maranhão (Suguio & Tessler 1984;Amaral et al. 2008). Pará contains approximately 40% of the restinga in this region, which is represented by plains interspersed with islands, peninsulas, and bays (Amaral et al. 2008;Silva et al. 2010). This ecosystem is undergoing great anthropogenic impact from tourism, real estate speculation, and the removal of sand for building construction (Bastos et al. 2013).
In Pará state restinga studies were conducted in the area of vegetation formations (Santos & Rosário 1988;Bastos 1988Bastos , 1995Santos et al. 2003;Santos & Bastos 2014), phytosociology (Costa-Neto et al. 2001), and floristics , notably Cyperaceae, which is the richest and most abundant family in this ecosystem Costa Neto et al. 2001;Santos et al. 2003). Additionally, there are taxonomic studies about Cyperaceae in Pará, researched by Nunes et al. (2016), who studied the flora of the cangas of Serra dos Carajás, Schneider et al. (2017) and Maciel-Silva et al. (2018), who published a synopsis of Rhynchospora and a flora of Eleocharis for restinga, respectively.
Considering the diversity of Scleria in Brazil, the importance of restinga and the fragility of this coastal ecosystem in the face of anthropogenic pressures, this study aims to contribute to the knowledge of Scleria in the restinga of Pará state.

Material and Methods
The examined specimens were from the main herbaria located in Pará state: MG, IAN, and HBRA (acronyms according to Thiers, continuously updated). These specimens come from municipalities (counties) of Pará that containing restinga: São Caetano de Odivelas, Curuçá, Marapanim, Maracanã, Salinópolis, São João de Pirabas, Quatipuru, Tracuateua, Bragança, Augusto Corrêa, and Viseu (Fig. 1). We also collected material in the municipalities of Marapanim and Maracanã. Collecting and processing the herbarium specimens followed the standard techniques as described in Rotta et al. (2008).
Species identification was made by consulting some literatures (Core 1936;Kessler 1987;Camelbeke & Goetghebeur 1998, 2002 and the following websites with digitized protologues: Biodiversity Heritage Library (2018); Botanicus Digital Library (2018); and Open Library (2018). Similarly, for some species, digitized herbarium types at B, BM, M, PI, and PR were consulted (acronyms according to Thiers, continuously updated). The abbreviations of the protologues, periodicals, and authors are based on the websites Tropicos (2018) and World Checklist of Selected Plant Families (2018).
The morphological descriptions of the genus and species were made based on the material examined, and in the dimensions of the fruit are excluded the hypogynium and the stylobase. When the specimens from restinga of Pará did not have a structure of taxonomic relevance, the information was taken from the literature or additional herbarium specimens and included in a complementary description below the main description. The terminology used for the leaves, inflorescences, spikelets, and fruits follows Ahumada (2007), Ahumada &Vegetti (2009), andEspinoza et al. (2016).
Geographic distribution data are from information on labels of examined material, literature (Acevedo-Rodríguez & Strong 2012;Camelbeke & Goetghebeur 1998;Kessler 1987;Nunes & Prata 2013), and the websites World Checklist of Selected Plant Families (2018), Flora do Brasil 2020 (under construction), andSpeciesLink (2018). Habitats are based on the classification of vegetation formations by Santos & Bastos (2014) and information on labels of examined material.

Scleria bracteata
The species occurs in Mexico, Belize, Costa Rica, Guatemala, Honduras, Nicaragua, Trinidad and Tobago, French Guiana, Guyana, Suriname, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil, and Paraguay. In Brazil, this species occurs in all regions, except the southern region, and the states of Acre, and Rondônia. In restinga in Pará, it occurs in herbaceous marshes, fields between dunes, and open shrub formations.

Scleria hirtella
The species occurs in Mexico, Belize, Guatemala, Honduras, Panama, Cuba, Dominican Republic, Haiti, Jamaica, Porto Rico, Trinidad and Tobago, Guyana, French Guiana, Suriname, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil, tropical Africa, and Madagascar. Widely distributed in Brazil (all states). In restinga in Pará, this species is found in fields between dunes and open shrub formations.

S c l e r i a i n t e r r u p t a h a s s p i c i f o r m inflorescences, as observed in S. hirtella.
In addition, it is characterized by its leaf blades that are pilose on both surfaces, rarely glabrous, glumes with trichomes on the midrib and papillose-rugulose nutlets (Fig. 2d)  Scleria macrophylla is notable among the species in restinga in Pará for its robust size, wide leaves with a pseudopremorse apex, and puberulent glumes. The material examined of the restinga lacked nutlets, which are fundamental when determining species of Scleria. However, fertile collections made in the proximity of the Bragança restinga (A.F.S. Souza et al. 14 -HBRA) allowed the material to be identified, together with the type (Haenke PR25264) which has a sterile inflorescence and was useful to compare with the restinga material.
The species occurs in México, Belize, Costa Rica, Guatemala, Honduras, Nicaragua, Panama, Cuba, Jamaica, Trinidad and Tobago, French Guiana, Guyana, Suriname, Venezuela, Bolivia, Colombia, Ecuador, Peru, and Brazil. In Brazil, this species occurs in nearly all regions but has not been recorded in the states of Amapá, Pernambuco, Alagoas, Sergipe, Espírito Santo, and Rio de Janeiro, nor the southern region. In restinga in Pará, it occurs in fields between dunes.
Scleria reticularis differs from the other species in restinga in Pará by its reticulatedfoveate, pubescent nutlets and hypogynium with oblong lobes (Fig. 2g). Frequently, the pedicels of the subandrogynus spikelets are short and covered by bracteoles. Its rachises have winged margins, with a glabrescent and reddish surface, which extend from the base of the inflorescence branch to the base of the spikelet.

Scleria secans
Complementary description: 2-5 m tall, rhizomatous (Nunes & Prata 2013   Scleria violacea has short inflorescence internodes, which gives the appearance of a single terminal inflorescence subtended by three involucral bracts. For this species, the membranaceous appendix at the apex of contraligule is conspicuous, making it easy to identify in combination with the ligule of trichomes and ovoid nutlet (Fig. 2i). Its pistillate spikelets are frequently at the base of the rachilla, sessile or with a short pedicel covered with two bracteoles, and its staminate spikelets are usually pedicellate (characteristic inflorescence of the sect. Hymenolytrum), with pedicels 0.8-2 mm long. Scleria violacea is similar to S. macrogyne, which is cited by Amaral et al. (2008) for restinga in Pará. Scleria violacea differs by its inflorescences with lax spikelets, and inconspicuous wings sheaths (vs. inflorescences with densely grouped spikelets, and conspicuous wings sheaths).
The species occurs in French Guiana and Brazil. In Brazil, it is reported in the states of Pará, Tocantins, Maranhão, Piauí, Bahia, and Mato Grosso. In the restinga in Pará, this species occurs in fields between dunes and open shrub formations.