First record of Eurystyles actinosophila (Barb. Rodr.) Schltr. in the Central-West region of Brazil and notes on distribution of Eurystyles and Lankesterella (Orchidaceae, Spiranthinae) in Brazil

We report the first record of Eurystyles actinosophila (Barb.Rodr.) Schltr. and the genus Eurystyles Wawra (Orchida-ceae) in the Central-West region of Brazil. The species was found in the Brasília National Park, in Brasília, Distrito Federal, in the core region of the Cerrado. We also undertook a survey of collection sites in Brazil for species of Eurystyles and Lankesterella Ames, which together form the epiphytic clade of Spiranthinae, in order to create an updated distribution map. Previously identified only in the Atlantic Forest and Pampa, we note that some species of these two genera also occur in the Cerrado and Caatinga domains.


Introduction
The Orchidaceae Juss. comprise 27,801 species grouped into 736 genera (The Plant List 2013; Chase et al. 2015), and it is divided into five subfamilies: Apostasioideae (the most basal subfamily, restricted to tropical Asia), Cypripedioideae, Vanilloideae, Orchidoideae, and Epidendroideae (Cameron et al. 1999;Freudenstein et al. 2004;Kocyan et al. 2004;Chase et al. 2015). Representatives of this family are distributed in all terrestrial habitats, except in the driest deserts and on the Antarctic continent (Givnish et al. 2016). In Brazil, Orchidaceae are represented by 2,692 species, of which 642 occur in the Cerrado domain, and 241 in the Distrito Federal, seat of the capital of the country (Flora do Brasil 2020).
The Distrito Federal is completely inserted in the Cerrado domain, where grassland and savannah vegetation predominate, with few areas occupied by forest formations (Ribeiro and Walter 2008). Due to these characteristics, terrestrial species of Orchidaceae are more numerous than epiphyte species (Batista and Bianchetti 2003). Among the four subfamilies represented in the Distrito Federal, the most numerous is Orchidoideae, with 21 genera and 111 species, and the richest genus is Habenaria Willd., with 70 species (Flora do Brasil 2020). Among the Orchidoideae genera with exclusively epiphytic representatives are Eurystyles Wawra and Lankesterella Ames (Salazar and Dressler 2011). Of these, only the first genus, represented by E. ochyrana (Szlach. et al.) F. Barros and L. Guimarães, is found in the Cerrado, where it is is known from the Serra de Botucatu, Itatinga, São Paulo (Szlachetko et al. 2001), in the transition with the Atlantic Forest domain. The other species of these genera occur in the Brazilian Atlantic Forest and Pampa domains (Flora do Brasil 2020).
Molecular phylogenic studies have shown that Eurystyles and Lankesterella form a basal clade with strong support and high bootstrap percentages (Salazar et al. 2018). There are 20 species of Eurystyles, all restricted to the Neotropics, distributed from Mexico throughout the Caribbean and Central America to South America, except Chile and Uruguay. Eleven species of Eurystyles are found in Brazil (Pridgeon et al. 2003;Flora do Brasil 2020;Ackerman and Jordan 2021;Govaerts 2021). Lankesterella, with 11 species, occur in Cuba, Dominican Republic, Costa Rica, and South America, and have the same distribution as Eurystyles. Seven species of Lankesterrella occur in Brazil (Flora do Brasil 2020; Govaerts 2021).
Plants of these two genera resemble "small bromeliads" due to their rosulate leaves (Bogarín 2020). Vegetatively, these genera are difficult to separate and are characterized by having fasciculate, fleshy, and puberulous roots. Their leaves are ovate-lanceolate to oblanceolate, glossy, with ciliated margins, and last through many growing seasons (Górniak et al. 2006;Salazar and Dressler 2011). Although they are quite similar, representatives of these genera can be vegetatively differentiated by root trichomes, which are spiraled in Eurystyles and simple in Lankesterella (Bernal et al. 2015). Reproductive structures differ greatly, however, and in Eurystyles, the inflorescence consists of a condensed (capitate) raceme with non-resupinated flowers arranged in a spiral, whereas in Lankesterella the raceme is lax with resupinate and secund flowers, that is, arranged on only one side (Burns-Balogh et al. 1985;Górniak et al. 2006;Salazar and Dressler 2011).
So far, the only record of the genus Eurystyles from the Cerrado was collected less than 2 km from the Atlantic Forest. Here, we present the first record of this genus from the core region of the Cerrado, approximately 550 km from the edge of the Atlantic Forest. This record also consists of the first collection of Eurystyles for the Central-west region of Brazil. Furthermore, we discuss the expanded distribution in Brazil of Eurystyles and Lankesterella, which form the clade of epiphytic species of the subtribe Spiranthinae (Cranichidae, Orchidoideae).

Methods
We carried out a floristic survey in 2014 and 2015 in the gallery forest (sensu Ribeiro and Walter 2001) along the Acampamento stream located in Brasília National Park. There, we recorded the occurrence of Eurystyles actinosophila (Barb. Rodr.) Schltr. Some specimens were collected and kept in cultivation in the greenhouse of the Centro de Referência em Conservação da Natureza e Recuperação de Áreas Degradadas of the University of Brasilia (CRAD/UnB) until flowering. Afterwards, the flowering individuals were herborized according to IBGE (1991) methods and deposited in the herbarium (UB) in the Distrito Federal.
The national park is located at an altitude of 1,100 m, in the core region of the Cerrado known as Planalto Central (coordinates of the park's headquarters: 15°44′02″S, 047°55′30″W). In the Köppen climate classification, the region is AW, with annual precipitation of 1,300-1,600 mm and an annual average temperature of 20-22 °C, with minimum and maximum values of 10.1 °C and 36.4 °C, respectively, in 2020 (Alvares et al. 2014;INMET 2021).
Distribution. With our new record of E. actinosophila this species is confirmed from both the Distrito Federal and the Central-West region of Brazil (Fig. 1). The data obtained on the distribution of Eurystyles and Lankesterella reveal that these genera have a wider distribution than has been described in the literature ( Fig. 2
According to current distributional data, Eurystyles and Lankesterella are found only in the Atlantic Forest and Pampa domains, except for E. ochyrana, which occurs in the Cerrado (Flora do Brasil 2020). Eurystyles actinosophila had already been collected in the Cerrado in 1989 and 2005 (Table 1), but these data have not been published. Therefore, our record of this species from Distrito Federal extends the distribution to another region of Brazil. The closest collection to Distrito Federal There are unpublished occurrences of E. lorenzii from the Cerrado and Pampa biomes (Table 1). In the Cerrado of the state of Paraná, this species occurs less than 10 km from the border of the Atlantic Forest. In the Pampa, there is a record approximatley 170 km from the transition with the Atlantic Forest. Eurystyles cotyledon has been collected in the transition zone between Cerrado and Atlantic Forest in Minas Gerais and Paraná states. In the Caatinga, this species was found 40 km from the Atlantic Forest.
Lankesterella caespitosa and E. actinosophila have been collected in the Cerrado at the same location in São    Our new record of E. actinosophila from the Center-West region reveals that even in well-sampled areas such as Distrito Federal, it is still possible to find unreported species, for example, the two conspicuous bromeliads Vriesea friburgensis Mez. and Tillandsia polystachia (L.) L. (Lima and Soares-Silva 2016). Other records in well-sampled areas worth mentioning include that of E. lobata Chiron & V.P. Castro from Santa Catarina state (Guimarães et al. 2016); this species was known from a single record Espírito Santo state, and five new occurrences of Tillandsia L. from Bahia state (Leodegario et al. 2021). This highlights the importance of the periodic study of collections in herbaria and the systematic return to areas already sampled.
The range extensions of some species of Eurystyles and Lankesterella to the Cerrado reinforces the biogeographic relationships of this domain with the Amazon and Atlantic Forest (Batalha-Filho and Miyaki 2014). Furthermore, the presence of these species in the Cerrado corroborates the belief that in the past forests in northwestern and southeastern of Brazil were connected by the gallery forests of the Cerrado (Oliveira-Filho and Ratter 1995). These gallery forests would have been the bridge for the Spiranthinae from southeastern Brazil to colonize the American continent. According to Salazar et al. (2018), despite the epiphytic habit (Ackerman 1983), Eurystyles and Lankesterella form the most basal clade of the American Spiranthinae, whose origin would have been the Atlantic Forest. Thus, we expected that it is only a matter of time before species of these genera are found in the Brazilian Amazon, as there are several species to the north of the Amazon and in Central America.