We present one of the first lists of vascular plants for an area in the Brazilian State of Espírito Santo (ES). Field expeditions were carried out between 2011 and 2016 in four portions of vegetation in Serra do Valentim, ES, to collect samples of reproductive botanical material. After identification, we found a total of 590 species distributed in 327 genera and 112 botanical families. Orchidaceae (61 spp.), Melastomataceae (40), Asteraceae (37), Rubiaceae (29) and Polypodiaceae and Solanaceae (24) were some of the families with the highest species richness. We report 11 new records of species for Espírito Santo, three new species for science and 54 endangered species, demonstrating the floristic importance of Serra do Valentim. Our efforts were decisive in helping to fill knowledge gaps regarding the flora of Espirito Santo state, providing a basis for conducting species conservation and enhancing the value of small forest remnants, which should be considered in research and inventory proposals.

This study aims to report six new occurrences of angiosperm species from the state of Espírito Santo, widening their geographic distribution. These floristic novelties evidence the presence of knowledge gaps regarding the flora and little collecting effort in Espírito Santo, in addition to demonstrating the floristic importance of Serra do Valentim, with restricted distribution species.