Diversidad de helechos y licofitas del Parque Nacional Lago Puelo (Chubut-Argentina)

the ferns and licophytes from the national park lago puelo, chubut, argentina were studied. we registered 47 taxa with 12 of them new records for the province of chubut and 1new to patagonia. a high taxonom-ic diversity was observed, with about 50 % of the patagonian fern flora represented. some of the taxa are growing exclusively in this area and in chile at the same latitudes. the puelo pass, which is connect-ing argentina and chile, at the lowest altitude of the north- patagonian andes, constituted a penetrating route of valdivian species. the presence of pasture livestock, the invasion of exotic plants and the latent fires, are the principals dangers for the survival of the flora in this area. therefore these areas of the subantartic forest merit special attention for conservation. a taxonomic key is included and a distribu-tion map that shows the areas of highest diversity of ferns and lycophytes within the national park is given. for each taxon the geographical distribution and ecology data are also given.