Pleurothallis pembertonii (Orchidaceae, Pleurothallidinae), a new species from northwestern Ecuador in the Tropical Andes Biodiversity Hotspot

A new species of Pleurothallis (Orchidaceae, Pleurothallidinae) from the lower montane cloud forests of northwestern Ecuador is described and illustrated. Pleurothallis pembertonii M.F.Monteros & Mark Wilson, sp. nov ., belongs to Pleurothallis subgen. Pleurothallis sect. Pleurothallis , subsect. Acroniae , ser. Amphigyae , and is most similar in appearance to P. forceps-cancri , from which it can be readily distinguished by its vinaceous, oblong-subsigmoid petals that are long-attenuate and by a sagittate-trilobed lip bearing a well-developed reniform glenion and two small divergent basal keels. The new species is currently known only from a single locality within the Dracula Reserve, in the western Andean foothills of Carchi Province, a region characterized by high levels of microendemism and increasing pressure from mining activities.