We report a new diatom species for the Atlantic Forest of Brazil. The species, designated Eunotia trigona Fuhrmann, Metzeltin & Tremarin sp. nov., is also new to science. It was found on moss in the Itatiaia mountain range in the state of São Paulo. Among the Eunotia taxa, E. trigona is distinguished by its unusual (perhaps unique) triangular-shaped valve, similar to those found in a few species of the genera Staurosira and Staurosirella.
Eunotiaceae; Itatiaia National Park; neotropics; South America
