Four new species of Marcgraviastrum are validated. The new species are Marcgraviastrum apaporensis (endemic to the Colombian Amazonia), M. glossostipum (endemic to Ecuador), M. grandiflorum (endemic to the Peruvian Amazonia), and M. vogelii (endemic to Colombia). On the basis of few collections of the genus Marcgraviastrum, we suppose that the species are very rare, caused principally, by deforestation of the forests in recent years
