We describe a new genus with a new species belonging to Araceae, from southern Ecuador. Vivaria calvasensis gen. et sp. nov. inhabits semi-arid inter- Andean mountains at altitudes ranging between 1100-1300 m a.s.l. The species belongs to the tribe Spathicarpae, which in Ecuador is represented by two other genera, Incarum and Croatellia, both typical for humid environments such as montane forests. This new genus is clearly supported by molecular evidence based on the matK gene, and morphological traits that separate it from the closely-related genera included in this tribe. The analyzed material was collected during several field campaigns carried out during four years in two populations from Loja province (Calvas and Macará), southern Ecuador, near the border with Peru.