Background and aims - The pantropical genus Peperomia consists of approximately 1,600 species with an extremely diverse vegetative morphology, especially in the Neotropics. One of the most startling yet overlooked growth forms is the geophytic one, as in subgenus Tildenia. This group occurs in seasonal Neotropical habitats with its highest diversity in Mexico-Guatemala and Peru-Bolivia with few species known from in between these hot spots. Methods - Recent fieldwork in Peru and Bolivia combined with herbarium study and a Bayesian analysis of an aligned sequence matrix of the chloroplast trnK-matK-psbA gene cluster of one accession of each species resulted in new findings within this subgenus. Key results - Fourteen new species are described, discussed in a phylogenetic framework and illustrated. Two species have a wide distribution and occur from central W. Peru to S. Bolivia: the common P. cerrateae and the rare P. parvisagittata. Three endemic species are described from the Amotape-Huancabamba Zone which is particularly rich in tuberous Peperomia species: P. gigantea, P. jalcaensis and P. klopfensteinii. Two species are only known from their type locality in central W. Peru: P. ocrosensis and P. pugnicaudex. Five other Peruvian species are P. ayacuchoana from Ayacucho, P. querocochana from Ancash, P. wernerrauhii from Huánuco, Peperomia umbrosa from three distant localities, and P. pseudoverruculosa which is relatively common in SE Peru. Two species are Bolivian endemics: the rare P. purpureonervosa from La Paz and the more common P. radiatinervosa from Cochabamba and Chuquisaca. Two former varieties, both endemics of the extreme northern Central Andes, are raised to species rank: P. lilliputiana and P. pseudoperuviana. Finally, basionym rejection and lectotypification are proposed for the widespread and commonly collected tuberous Peperomia in the southern Central Andes: P. peruviana. An emended description of Peperomia subgenus Tildenia is also provided. © 2011 National Botanic Garden of Belgium and Royal Botanical Society of Belgium.