The fifth phase of the project (MYXOTROPIC V) began in 2015 and ended in December 2018. The focus was on the study of the myxomycetes of the Andean altiplano and inter-Andean dry valleys located at the headwaters of the rivers Apurimac, Mantaro and Marañón (Peru). All the areas sampled were between 3,000 and 5,000 m elevation. Given the extreme weather conditions in this area of the Tropical Andes, the vegetation is dominated by montane grasslands (known as «pajonales»), cushion plants and scrublands, while dry valleys are characterized by the presence of cactaceous species and other succulent plants such as bromeliads of the genus Puya, and deciduous bushes. The fact that almost 3,000 samples have been collected gives an idea of the great abundance of myxomycetes in these extreme environments. The first catalogue of myxomycetes from the Andean puna has been compiled, and a further part of the latitudinal and elevational transects of the neotropical arid zones has been completed during this phase of the project. New species have been discovered and the great richness and diversity of the area, one of the biodiversity hotspots of the planet, have been documented. (see publications)