Comparative anatomy of the vegetative systems of eight Cyrtopodium R. Br. species (Orchidaceae, Epidendroideae) occurring in Central Brazilian savannas

•Anatomical characters are useful to the taxonomy of Cyrtopodium.•Some characters reflect environmental conditions, life forms and adaptive strategies.•Some structures are first described here for Cyrtopodium.•Subsidizes micromorphological, phylogenetic and eco-physiological studies in monocots.•May shed light on the evolution of epiphytism in monocots.