Identification key for lycophytes and ferns from the Picinguaba and Santa Virgínia Nuclei, Parque Estadual da Serra do Mar, Ubatuba, SP, Brazil

This work contributes to the knowledge of the fern and lycophytes diversity in the Picinguaba and Santa Virginia Nuclei, Parque Estadual da Serra do Mar (PESM), Ubatuba, São Paulo, Brazil, as well as to provide subsidies to identification of the found taxa in these areas. In total, 30 collecting expeditions were conducted and the vouchers were deposited at UEC Herbarium. We have identified 135 species distributed in 53 genera and 19 families for both areas. The most representative families were Polypodiaceae (28 species) and Dryopteridaceae (19 species), whereas Asplenium (12 species), Blechnum and Elaphoglossum (8 species each) were the most important genera. Epiphytic species predominated (62 overall), probably due to the presence of favorable habitats. Among the taxa, 41 are considered endemic from Brazil, 35 of them endemic to the Brazilian Atlantic Forest. Five species are classified as vulnerable according to the “Official list of endangered species in the State of São Paulo”: Elaphoglossum macahense (Fée) Rosenst., Anetium citrifolium (L.) Splitg., Asplenium muellerianum Rosenst., Cyathea glaziovii (Fée) Domin, and Thelypteris angustifolia (Willd.) Proctor, which emphasizes the importance of preservation areas such as the Parque Estadual da Serra do Mar. An identification key has been elaborated to help with the recognition of these groups in Picinguaba and Santa Virgínia Nuclei.


Introduction
The Atlantic Forest is a complex set of ecosystems, with significant importance for harboring a considerable portion of Brazilian biological diversity (Joly et. al., 1999).According to Forzza et al. (2012) this vegetation presents 19,335 species of plants and fungi, which contributes substantially to the mega-diversity of the country.
However, studies reveal that only 7.9% of the Atlantic Forest remnants are larger than 100 hectares, a size that would be representative for biodiversity conservation (SOS Atlantic Forest and INPE, 2011).These data reinforce the need to better understand and protect this forest, which is considered one of the major biodiversity hotspots of the Neotropics (Myers et al., 2000).
The Serra do Mar (a mountain range within the Atlantic Forest Domain) is located mainly in the Southeastern region of Brazil.It is a primary center of diversity and endemism for lycophytes and ferns (Tryon, 1986), probably because of regional relief features.As amply documented in several previous studies, mountainous areas have favorable environmental conditions for the development of these two groups of plants (see Holttum, 1938;Page, 1979;Tryon 1986;Roos, 1996, andMoran, 2008).
Recently, Prado et al. (2015) reported 883 species of ferns and lycophytes in the Brazilian Atlantic Rain Forest.This number surpasses Amazon (with 503 species), Cerrado (269 species), Caatinga (26 species), Pantanal (30 species), and Pampa (eight species).In the Atlantic Rain Forest of São Paulo there are 603 species, distributed in 115 genera and 33 families of ferns and lycophytes.According to Prado (1998), the highest diversity of ferns and lycophytes within this area is found at Serra da Mantiqueira, Serra da Bocaína, Serra do Japi, and Vale do Ribeira.
For similar areas to the current study (i.e., Atlantic Forest mountain slopes in the state of São Paulo), there are the works by Custódio-Filho (1989) The Picinguaba and Santa Virgínia Nuclei are located in the Parque Estadual da Serra do Mar, municipalities of Ubatuba, São Luís do Paraitinga, and Cunha, protecting a very well preserved area of Atlantic Forest at northeastern São Paulo.These places harbor a rich flora of lycophytes and ferns and the main objective of this paper is to provide an identification key for determining the species of these groups in these areas.

Study area:
The "Parque Estadual da Serra do Mar" (State Park) represents the largest continuous area of well preserved Atlantic Forest in Brazil, with almost 315 000 ha (3.15 9 m 2 ) and covering areas from two states, São Paulo and Rio de Janeiro, in the southeast region of the country.This park is divided into 10 conservation units, among them Picinguaba and Santa Virginia.

Sampling design:
The lycophyte and fern of the Picinguaba and Santa Virginia Nuclei was investigated along trails, roads, and plots found in these areas.We conducted 23 collecting expeditions in the Picinguaba Nucleus, from 2008 to 2011.Eleven of these expeditions were made to the "Casa da Farinha" (Figure 1 -B, C, D, E), seven to the "Fazenda Capricórnio" (Figure 1 -F, G, H, I, J), and five to the "Praia da Fazenda" areas (Figure 1 -A).Seven expeditions with the same purpose were undertaken in Santa Virginia Nucleus (Figure 1 -K, L, M, N), totaling 30 collecting expeditions in both Nuclei.
The collected material was prepared according to the methodology indicated by Silva (1989).Herbarium vouchers were deposited at UEC.We adopted the classification system by Smith et al. (2006Smith et al. ( , 2008)), with changes by Christenhusz et al. (2011).
For the geographic distribution, we adopted four basic categories: Pantropical (species of the tropical zones), Tropical America (species of the tropical and subtropical America, including South of the USA), South America (only in South America), and Endemics from Brazil.The distribution of the endemic species was based on Prado et al. (2015).The habitat and growth are reported as guilds of the life forms, according to Paciencia (2008).
The identification key here presented was prepared through the observation of the morphological features of adult plants recorded from Picinguaba and Santa Virginia Nuclei.This key prioritizes the morphological features that are easily observed in the field as well as on herbarium specimens.Therefore, the intention was to develop a key containing the maximum set of possible macroscopic features and to avoid the practice of cutting herbarium specimens.
The key does not present families or genera.We avoided presenting our results in the traditional way, because we believe that the users of this key could be enthusiasts in the study of lycophytes and ferns and they are familiarized with the common morphological features of the different groups.Unlike keys that separate different groups, the present paper pays attention to the morphological structures that are similar between species, even if they are phylogenetically distant.

Results and Discussion
We found 135 species distributed in 53 genera and 19 families of ferns and lycophytes for the two areas (Table 1).The most representative families were Polypodiaceae, with 28 species, and Dryopteridaceae, with 19 species.The genera with more species were Asplenium (12 species), followed by Blechnum and Elaphoglossum (eight species each).Among the guilds of life forms, the epiphytes were predominant, with 62 species overall (Figure 2).According to Madison (1977), the high diversity of epiphytes in neotropical forests is favored by an abundance of favorable habitats, especially in montane regions.In these regions, these groups of plants represent about 50% of the total flora (Kelly et al., 1994), due, primordially, to the forest structure and water availability (Grubb & Withimore, 1966).
The high degree of endemism for south and southeastern Brazil (Tryon & Tryon, 1982;Prado & Silvestre, 2010) can be exemplified in this work, which presents about 30.37% (41 spp.) of the taxa considered endemic from Brazil.About 85% (35 spp.) of these are endemic to the Atlantic Rain Forest (Figure 3).Two invasive exotic species, Macrothelypteris torresiana (Gaudich.)Ching and Nephrolepis cordifolia (L.) C. Presl, were found in the study area.These species are common in various other sites of the Atlantic Forest (Zenni & Ziller, 2011).
In total, five species are considered endangered in the vulnerable category, according to "Lista oficial de espécies ameaçadas de extinção no Estado de São Paulo" (Resolução SMA nº 48/2004): Anetium citrifolium (L.) Splitg., Asplenium muellerianum Rosenst., Cyathea glaziovii (Fée) Domin, Elaphoglossum macahense (Fée) Rosenst., and Thelypteris angustifolia (Willd.)Proctor.This factor stresses the importance of the Picinguaba and Santa Virgínia Nuclei for the conservation of biodiversity in the State of São Paulo.This forest is lush and diverse, with humidity and relief suitable for the development of ferns and lycophytes.Thus, the present paper contributes to the knowledge of these groups and highlights the importance of the permanent preservation of these areas.
The key presented ahead is the first one for a broad area covered by the Atlantic Rain Forest in Brazil.It constitutes an important tool for the identification of ferns and lycophytes from the northeastern portion of the state of São Paulo.

Figure 1 .
Figure 1.Location of the study areas in the Parque Estadual da Serra do Mar.A= Restinga; B, C, D, E, F= Lowlands Rain Forest; G, H, I, J= Submontane Rain Forest; K, L, M, N= Montane Rain Forest.(Google Earth in 17 Nov 2015).

Figure 2 .
Figure 2. Species number per different life forms in the Picinguaba and Santa Virginia Nuclei.

Figure 3 .
Figure 3. Species number found in PESM area, separated by geographic distribution class.