Taxonomic study of Epidendrum (Laeliinae-Orchidaceae) in the state of Maranhão, northeastern Brazil

Abstract

The Brazilian state of Maranhão is located in a transition zone between the Amazon and Cerrado domains; its geographic position enables the coexistence of species from both biomes. Taxonomic information of Orchidaceae and especially Epidendrum in the state are scarce; thus this study aimed to provide a taxonomic treatment for the genus based on field expeditions and analyses of herbarium specimens (IAN, MAR, MG, NY, SLUI, and UB). Epidendrum is represented in Maranhão by 10 species, of which three are new records: E. amapense, E. anceps, and E. carpophorum. Another three previously cited species, E. nocturnum, E. sculptum, and E. viviparum, were not collected and also not found in the herbaria visited; moreover, these records represent misidentifications. The majority of the species is distributed in the Amazon domain; however, E. macrocarpum is recorded for the first time for the Brazilian Cerrado. Here we provide an identification key, descriptions, photographs, and a distribution map of the species in the state.