Abstract
Field expeditions to the western Andean slopes of Colombia and ongoing herbarium research resulted in the discovery of a new species of Columnea (Gesneriaceae). Columnea rubromarginata J.L.Clark & Clavijo, sp. nov. is described from the Chocó Biogeographic Region in the premontane wet forests of Esmeraldas in northern Ecuador and the departments of Chocó and Valle del Cauca in Colombia. The new species is vegetatively remarkable for the presence of a rarely observed broad dark red submarginal band on the abaxial leaf surface. Based on International Union for Conservation of Nature (IUCN) guidelines, a preliminary conservation status of Vulnerable (VU) is recommended for C. rubromarginata.