A monograph of the genus (Rosaceae).

We present a monograph of the high Andean tree genus (Rosaceae), based on a species concept considering morphological, climatic and biogeographic distinctness as indicators of evolutionary independence. In total, we recognize 45 species of , grouped in five sections. Polylepissect.Sericeae is represented by 15 species in four subsections, P.sect.Reticulatae by seven species, P.sect.Subsericantes by three species, P.sect.Australes by two species and P.sect.Incanaee by three subsections with 18 species. We describe seven new species, one from Colombia (), one from Ecuador () and five from Peru (, , , and ). Three species from Peru (, and ) are re-instated as valid species. Two taxa from Bolivia ( and ) are elevated from subspecies to species rank. The morphology, habitat, distribution, ecology and conservation status of each species are documented. We also provide an identification key to the species of the genus and general introductions on taxonomic history, morphology, evolution, ecology and conservation.