The Huancabamba Depression in Neotropical South America, a natural barrier between the Northern and Central Andes, serves as a refuge for high levels of angiosperm diversity. However, this biodiversity remains understudied, especially in complex and species-rich genera, such as Carex L. (Cyperaceae). This genus is notably underrepresented in taxonomic and systematic research on the Neotropics. In this study, we employed an integrative systematic approach combining molecular and morphological data to elucidate the taxonomic status of several Carex populations from Ecuador and northern Peru, which exhibit morphological affinities with the sect. Porocystis Dumort. (Castanea Clade). We conducted a phylogenetic analysis using two nuclear (ITS and ETS) and one plastid (matK) DNA regions and carried out a detailed morphological comparison with Neotropical relatives within the section. Both phylogenetic and morphological results supported the systematic distinctiveness of the focal populations. As a result, we describe a new species, Carex huancabambica Gonz.Gallego & Jim.Mejías, sp. nov. and provide its taxonomic treatment. This study contributes to disentangling the biodiversity of the genus Carex in the Neotropics.