Climbing plants from Seridó Ecological Station: diversity, interactive key and five new records from Rio Grande do Norte state, Brazil

Abstract In Brazil, Seasonally Dry Tropical Forests (SDTFs) are represented by Caatinga, which exhibits one of the greatest species richness and endemisms among the Neotropical SDTFs. However, studies of the flora of this biome remain deficient, especially in scientifically neglected areas, such as the Seridó region. Located between the states of Rio Grande do Norte (RN) and Paraíba, the Seridó region has an underestimated floristic diversity, especially for non-arboreal components such as climbers. Given this scenario, the study aimed to survey the climbers of the Seridó Ecological Station, a federal conservation unit located in the RN state, as well as to provide a multiple access online identification key. Collections were carried out from 2018 to 2019, as well as consultation of material deposited at the UFRN herbarium. In total, 56 species were listed, being 33 herbaceous and 23 woody climbers, respectively, adding 14 species of climbers to the previous checklist of the unit. Five new occurrences were found for the state of Rio Grande do Norte: Cuscuta globosa, Cuscuta partita (Convolvulaceae), Macroptilium bracteatum (Fabaceae), Heteropterys trichanthera and Tetrapterys longibracteata (Malpighiaceae), being the latest a new occurrence of the genus Tetrapterys for the state. Convolvulaceae is the most representative family (18 spp.), followed by Fabaceae (10 spp.), Apocynaceae (eight spp.) and Cucurbitaceae (five spp.). This is the first study that provides an interactive identification key for the Seridó region and for the RN state. The interactive identification key is published throughout the Xper³ platform, and can be accessed at . Resumo No Brasil, as Florestas Tropicais Sazonalmente Secas (FTSS) são representadas pela Caatinga, que exibe uma das maiores riquezas de espécies e endemismos dentre as FTSS Neotropicais. Contudo, o bioma segue deficiente quanto ao estudo da flora, principalmente em áreas negligenciadas cientificamente, como a região do Seridó. Localizada entre os estados do Rio Grande do Norte (RN) e Paraíba, o Seridó possui uma diversidade florística subestimada, principalmente em componentes não arbóreos, como as trepadeiras. Diante deste cenário, o trabalho teve como objetivo realizar um levantamento das trepadeiras da Estação Ecológica do Seridó, unidade de conservação federal localizada no estado do RN, bem como disponibilizar uma chave de identif