New occurrences of Salicaceae from the Atlantic Forest and Caatinga ( Brazil )

Based on new records, we expand the geographical distributions of 6 species of Salicaceae: Banara nitida Spruce ex Benth., Casearia marquetei Nepom. & M. Alves, C. souzae R. Marquete & Mansano, Macrothumia kuhlmannii (Sleumer) Alford, Xylosma glaberrima Sleumer, and X. pseudosalzmanii Sleumer, from the Atlantic Forest and Caatinga. Illustrations of the diagnostic characters of the species, maps of geographic distribution, and a key for identification of the genera of Salicaceae occurring in the Atlantic Forest and Caatinga are provided.

Banara has a Neotropical distribution with 30 species and a center of diversity in the Amazon and Caribbean (Sleumer 1980).In Brazil, is more diverse in the Amazon with 5 species and Atlantic Forest with 6 species (BFG 2015).Only 2 species are recorded from the Cerrado, 1 from the Pantanal, and none from the Caatinga (BFG 2015).Casearia is a pantropical genus with 181 species and a center of diversity in the tropics and subtropics of the American continent (Marquete and Mansano 2016, Nepomuceno and Alves 2017, Sleumer 1980).In Brazil, the center of diversity is in the Amazon, with 30 species, and in the Atlantic Forest, with 27 species (BFG 2015, Marquete and Mansano 2016, Sleumer 1980).It is also diverse on drier areas such as the Caatinga (9 spp.) and the Cerrado (22 spp.) (BFG 2015, Marquete andMansano 2016).
Macrothumia is a monospecific genus with a distribution restricted to the Brazilian Atlantic Forest (Alford 2006, BFG 2015).It was originally named as Neosprucea kuhlmannii Sleumer but transferred to the genus Macrothumia (Alford 2006).Xylosma is a pantropical genus of 95 species, with Central and South America being its center of diversity (Sleumer 1980).In Brazil, 6 species are recorded from the Atlantic Forest, 5 from the Cerrado, 4 from the Amazon, and only 2 from the Caatinga (BFG 2015).
The Atlantic Forest is the second-largest block of Neotropical vegetation and originally extended along the entire Atlantic coast of Brazil to parts of Paraguay and Argentina (Galindo-Leal and Câmara 2003).The Caatinga is endemic to Brazil, occurring from the states of Ceará and Piauí to northern Minas Gerais (Prado 2003).
Casearia marquetei Nepom.& M. Alves, C. souzae R. Marquete & Mansano, and Macrothumia kuhlmannii were described in recent years, all with narrow distributions, as was also the case for Banara nitida Spruce ex Benth., Xylosma glaberrima Sleumer, and X. pseudosalzmanii Sleumer, which were described some decades ago.Based on new records, we extend the geographic distribution of these species to areas belonging to the Atlantic Forest and Caatinga.

Methods
The new occurrences of the species were found during field trips carried out in the states of Ceará, Pernambuco, and Rio Grande do Norte, in addition to our study of vouchers deposited at ALCB, CEPEC, HUEFS, MAC, and UFRN herbaria.The herbaria acronyms are based on Thiers (2018).The geographic coordinates of the collected specimens were obtained using a Garmin eTrex Venture HC GPS receiver.If this information was absent at the specimen labels, the SpeciesLink database (http:// www.splink.org.br) was consulted.Maps were prepared using software QGIS v. 2.18.6.

Key to the genera of
Banara nitida was previously believed to be restricted to the Amazon phytogeographical domain, occurring in lowland forests in Brazil and montane forests in Colombia, Ecuador, Peru, and Venezuela (Sleumer 1980).We expand the geographic distribution to the Caatinga domain (Fig. 2A).It was collected in the semi-arid region of the state of Ceará in an area above 800 m with vegetation of semideciduous seasonal forest in crystalline soils.It is morphologically similar to Banara argura Briq., but can be distinguished by having glabrous leaves (vs pilose leaves) and glabrous inflorescence peduncles and flower pedicels (vs tomentose peduncles and pedicels).According to Gentry (1993), it is possible to identify plants that belong to the genus Banara using vegetative characters.This new record reinforces the connection between the Amazon and Atlantic Forest along the coast of the state of Ceará, through the Brejos de Altitude (Maciel et al. 2017).
Casearia marquetei is a recently described Brazilian endemic that was believed to be restricted to the states of Paraíba and Pernambuco in Coastal Lowland Forests and Sub-montane Forests locally known as Brejos de Altitude (Nepomuceno and Alves 2017).In Bahia, this species occurs in the Atlantic Forest and Caatinga, being a new record for this last domain (Fig. 2B).Our new record from the Caatinga (Bahia, municipality of Caetité) is an area in dry semi-arid region, where the altitude reaches up to 800 m.This species can be recognized by its oblong-elliptical to elliptical leaves, the glabrous inner surface of the sepals, the oblong and densely pilose nectariferous lobes and glabrous stigma (Nepomuceno and Alves 2017).
Casearia souzae is endemic to Brazil and has been described as restricted to the states of Espírito Santo and Rio de Janeiro where it lives in dense forests and on rocky outcrops (Marquete and Mansano 2013).The occurrence of this species in the states of Alagoas, Bahia, Minas Gerais, Paraíba, Pernambuco, and Rio Grande do Norte is here confirmed (Fig. 3A).Some of our new records are from the Caatinga and lowland forest north of the São Francisco River.As in other species, the new records reveal that it can grow in different habitats and physiognomies, including areas of secondary vegetation and ecotones.Previously cited specimens were found among exsiccates misidentified under C. arborea (Rich.)Urb. and C. sylvestris Sw.However, C. souzae can be differentiated from C. arborea by having glands dispersed over the leaf blade, sepals and ovary (vs glands absent on the leaf blade, sepals, and ovary) and sessile inflorescences (vs pedunculate inflorescences), and from C. sylvestris also by having glands on the leaf blade, sepals, and ovary (vs glands lacking on the leaf blade, sepals, and ovary), obovate sepals (vs ovate sepals), and capitate stigma (vs trilobed stigma) (Marquete and Mansano 2016, Nepomuceno and Alves 2017).
Xylosma glaberrima is endemic to Brazil and was initially known from the states of Paraná, Rio de Janeiro, and São Paulo, where it occurs in dense forests and restingas of the Atlantic Forest (Sleumer 1980).Here, it is recorded from the state of Rio Grande do Norte, where it was found in forested restinga vegetation at Mata da Pipa State Park (Fig. 4A).This record reinforces the connection between the more humid southern part of the Atlantic Forest to its much drier northern part (Barbosa 1996).In addition, we highlight the difference in altitude and rainfall between these 2 areas of Atlantic Forest (Pereira 2009).This species is morphologically similar to X. prockia (Turcz.)Turcz.due to the morphology of the leaf blade and apex.However, it can be distinguished by having 2 discoid glands at the base of the leaf blade (vs glands absent on the leaf blade) and flowers with glabrous pedicels (vs flowers with puberulous pedicels).Leaves alternate, blade 6.0-8.0 × 3.0-4.0cm, elliptic, chartaceous to subcoriaceous, glabrous on both surface, cuneate base, acuminate apex, margin gland-serrated, glands absent.Inflorescences 10-14, fascicule, axillary, multiflorous, sessile.Male flowers with pedicels 3.0-4.0mm long, cylindrical, articulated in the base, glabrous; 5-merous, sepals 2-2.5 × 1.5-2.0mm, ovate, glabrous, slightly pilose at the margin.Female flowers with pedicels 4.0-6.0mm long, cylindrical, articulated in the base, glabrous; 5-merous, sepals 2.0-3.0 × 1.5-2.5 mm, ovate, glabrous, slightly pilose at the margin.Berries 6.0-8.0 mm in diameter, globose, glabrous, smooth, vinaceous.Seeds not seen.
Xylosma pseudosalzmanii was earlier reported from Argentina and Paraguay, where it occurs in gallery for- ests, and in Brazil from the states of Paraná, Rio Grande do Sul, Santa Catarina, and São Paulo in dense forests and gallery forests (Sleumer 1980, BFG 2015).It is here recorded from the state of Bahia, in the municipality of Caetité (Fig. 4B).The new record is in Deciduous Forests, which shows that this species can live in drier habitats.Torres and Ramos (2007) considered X. pseudosalzmanii a synonym of X. tweediana (Clos) Eichler due to the overlap of vegetative characters and geographical distribution.However, both species are currently accepted (BFG 2015).Xylosma pseudosalzmanii has flowers with pedicels glabrous and articulated at the base, but in X. tweediana, they are puberulous and articulated in the middle portion.

Discussion
The new occurrences reported here confirm that several species of Salicaceae also grow in dry areas such as in the Caatinga.This was not previously known for these taxa, which were known only from humid areas.Our results corroborate the theories proposed by Cavalcanti and Tabarelli (2004) and Maciel et al. (2017), that there is a connection between the Amazon and the Atlantic Forest through the coastal areas of the state of Ceará.The new records also confirm the co-occurrence of these species along the Atlantic Forest of the Northeastern, Southern and Southeastern Brazil, as found in other species (Barborsa 1996, Pereira 2009).