New records of Aristolochia bahiensis F.Gonzalez for the State of Maranhão, Brazil

Novo registro de Aristolochia bahiensis F.Gonzalez para o Estado do Maranhão, Brasil R E S U M O Este trabalho teve como objetivo registrar a ocorrência da espécie Aristolochia bahiensis F. González em área do território do Estado do Maranhão, Brasil. A espécie foi coletada na cidade de Timon, em área de tensão que reúne características de Cerrado, em adjacência com Mata Ciliar. O estudo traz uma breve caracterização da família botânica e descrições sobre o gênero e a espécie, além de dados sobre sua distribuição. A espécie já tinha sido encontrada nos estados de Alagoas, Bahia e Espírito Santo. Além de retratar ocorrência geográfica da planta foi feita uma caracterização morfológica da espécie, com a montagem de uma prancha com imagens dos aspectos mais relevantes da sua morfologia além de mapas com sua localização. Palavras-chave: Aristolochiaceae, Aristolochia, Aristolochia bahiensis, Área de Tensão Ecológica, Cerrado, Mata Ciliar, Bacia do Rio Parnaíba, Nordeste Brasil.


Introdução
The state of Maranhão in northeastern Brazil covers an area of 331.983 km 2 (IBGE, 2020), which includes parts of five domains: i) the Amazon occupying the northwestern portion on the border with Pará; ii) the Cerrado occupying most of the State's area (about 60% of the territory) to the south, bordering the states of Tocantins and Piauí; iii) the coastal vegetation, to the north with formations of Mangroves and "Restingas", constituting the second largest coast in the Northeast region of Brazil; iv) Mixed subcaduciferous forest areas forming babassu forests, in the eastern region on the border with Piauí and; v) small enclaves of Caatinga vegetation, along the Parnaíba River basin (Santos-Filho et al. 2013).
The city of Timon is located to the east of Maranhão, whose territory is configured as ISSN:1984ISSN: -2295 Revista Brasileira de Geografia Física Homepage:https://periodicos.ufpe.br/revistas/rbgfe belonging to the Mesoregion of the East of Maranhão. The city is 69 m above sea level and is characterized as a place of flat relief where there are also residual reliefs on hills, ridges, pontoons and hills that can reach altitudes ranging from 120 to 155 meters (Correia Filho, 2011). The vegetation is influenced by the climatic transition, relief and soil conditions, which is represented by the Open Evergreen Seasonal Forest, interspersed with babassu, Cerrado with its various phyto physiognomies, interspersed with buritizais, and the discreet presence of carnaubal patches (Conceição et al., 2015). The main types of soils found in Timon (MA) are Yellow Latosols, Plintosols, Red-Yellow Argisols and Fluvic Neosols, according to EMBRAPA (2006) and Cardoso and Aquino (2014). It's classified as a tropical climate according to the Köppen classification (Aw), with nine dry months and three rainy months. The mean annual temperature is relatively high, reaching around 20,1 -36,2°C and with an annual mean temperature of 2,7°C with no significant oscillations. The total annual precipitation varies around to 1383 mm, with the wettest period in February and April (CLIMATEMPO, 2020). Aristolochiaceae is a family of Magnoliids posicioned in Piperales (APG IV, 2016). The family Aristolochiaceae Juss. is represented by four genera, Aristolochia L., Asarum L., Saruma Oliv. and Thotthea Rottb., which together have approximately 600 species with a cosmopolitan distribution (González, 1990(González, , 1998(González, , 2012, with Aristolochia being the most diverse, with 450 recognized species and with tropical and temperate distribution (Wanke et al., 2006a;Wanke et al., 2006b;González, 2011González, , 2012. In South America, Aristolochia is the only genus of Aristolochiaceae, and Brazil is configured as the main center of diversity of the genus with 93 described species, of these 38 endemic to the Brazilian territory and 40 to the Cerrado (Freitas, Alvez-Araújo, 2017;Aristolochiaceae, 2020). In addition, in the country, the species of this family occur in all regions, distributed in all the phytogeographic domains and their phyto physiognomies, as well as in the different vegetation formations, being the Cerrado (40 spp.), the Amazon (39) and the Atlantic Forest (39), the richest in number of species, followed by the Caatinga (8) and two in the Pampas (Aristolochiaceae, 2020).The family is formed by low, annual herbs, branched from the bae, with tuberous roots, decumbent or supportive herbs and robust vines, with 62 spp. in Brazil (Barroso et al., 2002). In Brazil, the states of Minas Gerais (32), Amazonas (27), Mato Grosso (24), Rio de Janeiro (23), Pará (23), São Paulo (22) and Bahia (21) are the most representative in terms of number of species in the family. The other states have one to 18 species (Aristolochiaceae, 2020). For the Northeast region, 29 species are cataloged, of these 18 are endemic, and the richest states are Bahia (21 spp.), followed by Maranhão with eight known species, which represents the second state in the region that is richest in number. In terms of the number of species of the Aristolochiaceae family, the eight registered for the state represent 1.45% of the world flora (550 spp.), 8.6% (93 spp.) in Brazil and 20% (40 spp.) for the Cerrado.
Aristolochia plants have alternate leaves, petiolate, with or without pseudostipules, considered undeveloped leaves. They have solitary flowers, axillary or rarely arranged in short flowering branches. Zygomorphic perigone of varying dimensions with three main parts: utricle, the perigone tube and the limbus or lip, as an expanded part of the perigone. The limbus or lip can have different shapes, from peltate to uni or bilabiate. The inner surface of the lip or lip may be smooth or warty and still have marginal fimbriae. In the utricle are the sexual organs that form a column (gynostemium). The gynostemium can be campanulated or cylindrical, presenting six erect stigmatiferous lobes with hairy edges. They have sessile, oblong or linear anthers inserted in the back of the spine. The ovary is located as inferior, formed by six carpels. The fruit is a hexagonal septicidal capsule (Barroso et al., 2002;Souza and Lorenzi, 2012). Among the registered species listed for the state of Maranhão, are: Aristolochia cordigera Willd. ex Klotzsch, A. holostylis F. González, A. odoratissima L., A. papillaris Mast., A. rugosa Lam., A. setosa Duch., A. stomachoides Hoehne and A. warmingii Mast (Aristolochiaceae, 2020). It should also be noted that in the literature consulted, none of the eight species cited in the online (Barros et al. 2015) for the state were sampled in studies with a floristic listing bias from samples from various locations carried out in the Amazon region of Maranhão, Cerrado, on the coast and sandbank (Cabral-Freire and Monteiro, 1993;Muniz et al., 1994;Medeiros et al., 2008;Silva et al., 2008;Conceição and Castro, 2009;Neres and Conceição, 2010;Amorim et al., 2016;Loch and Muniz, 2016;Serra et al., 2016;Almeida Jr. et al. 2017;Camelo Jr. et al., 2017;Lima and Almeida Jr., 2018;Rodrigues et al., 2019;Santos et al., 2019).
The present study records the first occurrence of the species Aristolochia bahiensis, collected in the county of Timon, Maranhão, Northeastern Brazil, in a preserved area adjacent to the riparian forest of the Parnaíba River, characterized as belonging to the Cerrado phyto physiognomy. The study provides a brief morphological description and illustrations of the species, as well as their location.

Methods
Our study was based on field collections, a literature review (Flora of Brazil 2020), and of digital collections in Reflora databases (http://reflora.jbrj.gov.br; accessed on: 2020-7-6) and SpeciesLink (http://www.splink.org.br/; accessed on: 2020-7-6) reviews For identification and confirmation of the species, specialized literature was used, being (Harris and Harris, 2001) for the descriptions of general morphological characters, and the unique characters in the flowers were described according to Freitas, Lírio and González (2013a)

Discussion and Conclusion
Aristolochia bahiensis is endemic to Brazil. According to Flora do Brasil (2020), the species occurs in the species occurs in the Atlantic Forest Domain in an Ombrophilous Forest environment, having already been registered in the States of Alagoas, Bahia and Espírito Santo.
The discovery and registration of A. bahiensis in the Parnaíba River basin, but precisely in a forest with characteristics of the Cerrado adjacent to its riparian forest, in the territory of Maranhão, reinforces the discussion raised by several authors that the region is home to a large ecotonal area, because it brings together species that occur in very diverse areas, from areas of more humid seasonal forests, passing through Cerrado areas, to drier areas, such as the Caatinga, reinforcing the dispersing role of water bodies in the dissemination of seeds and propagules.
It is believed, therefore, that there is still an exceptionally large gap in relation to the Aristolochia species that actually occur in Maranhão and that further studies on the state's flora are needed. This is the first record of the species Aristolochia bahiensis in a forest area strongly influenced by the presence of plants from the Cerrado, in addition to its first occurrence in the state of Maranhão, which expands its area of distribution in the Brazilian territory. and in another biome in the country (Cerrado).
The new occurrence of A. bahiensis calls attention to the need for floristic surveys in areas not yet sampled in Maranhão, as well as in neighboring states, especially in places of forest remnants with many species typical of the Cerrado, before these habitats. destroyed by anthropic action. It is believed that one of the possible reasons for the lack of registration in the state is due to the scarcity of collections of species of the Aristolochiaceae Juss. family, this may be due to the great difficulty of finding them during collects, or even their identification in the field, because in the area only one individual of the species was found, therefore, of rare occurrence.
Finally, it is important to know the regional flora, as it contributes to indicate the degree of richness and diversity of plants in the region, in the case of the occurrence of the species A. bahiensis in a Cerrado fragment, it can enable projects of conservation, management and recovery of areas belonging to this phyto physiognomy. In addition, it extends the area of geographic distribution of the taxon, in addition to providing knowledge related to ecology and taxonomic data of the species.