Abstract
A new orchid species in Pleurothallis subsection Macrophyllae-Fasciculatae, is described and illustrated. It was discovered in semi-deciduous premontane forest from Southwestern Ecuador. The new species is named herein as Pleurothallis marioi; information about its distribution, habitat, phenology, and conservation status is provided. The new taxon is compared with P. acestrophylla, P. arctata, P. calamifolia, P. lemniscifolia, P. portillae, and P. subtilis, species to which it is morphologically similar.