Ecology: Lowland to lower montane forest; often associated with stream habitats, on soil and soil covered rocks. Elevation: 35-2000 m (Venezuela: 35-1220 m, Colombia: 100-1530 m, Peru: 100-2000 m, Bolivia: 120-520(1736) m, Argentina: 540 m). Distribution: Widespread in the Neotropics; also various Pacific islands.
Fissidens angustifolius is characterized by the smooth margins, serrulate only at the apex, border on all laminae, vaginant laminae ca. 1/2 the leaf length, excurrent or rarely percurrent costa, vaginant laminae cells oblong and thin-walled, conspicuously enlarge from the upper firm-walled, smaller mammillose cells. Fissidens zollingeri is similar in exhibiting the differentiated enlarged vaginant cells, but the cells are smooth or weakly bulging.
Fissidens angustifolius se caracteriza por tener los márgenes lisos, serrulados sólo en el ápice, toda la lámina bordeada, lámina vaginante ca. 1/2 del largo de la hoja, costa excurrente o rara vez percurrente, células de la lámina vaginante oblongas y con paredes delgadas, conspicuamente alargadas desde las células superiores menores con paredes firmes y mamilosas. Fissidens zollingeri es similar porque presenta las células de la lámina vaginante agrandadas, pero tiene células lisas o débilmente abultadas.