Synopsis of Orchidaceae Juss. in the northern lowland Atlantic Forest

Abstract

Lowland forests, also known as tabuleiro forests, are the predominant phytophysiognomy in the Atlantic Coastal Forest in northeastern Brazil. We inventoried the Orchidaceae present in the northern section of those forests, from the state of Rio Grande do Norte until the southern region of the state of Pernambuco. We examined specimens from seven regional herbaria and undertook field expeditions to four conservation units in the region. A total of 65 species belonging to 36 genera and to subfamilies Epidendroideae (44 species), Orchidoideae ( 16), and Vanilloideae (5) were identified. The most diverse genera are Epidendrum e Habenaria, with eight and seven species, respectively. Native species represented 96 % of the total observed, with 27 % being endemic to Brazil. Epiphytic (35) and terrestrial (27) species predominated; only three species are hemiepiphytic. We registered 14 new records of species for Rio Grande do Norte, two for Paraíba, and one for Pernambuco. Diagnoses of genera and species, as well as an identification key, data on geographic distribution, taxonomic and ecological comments, conservation status, and photos of the species are provided.