A morphological comparison between Targionia hypophylla L. and T. stellaris Hässel is carried out based on fertile material from northern Argentina. The two species differed in a large number of gametophytic traits, including: epidermal pores, antheridia location and ventral scales shape. The spores of T. stellaris are also described in detail and compared to those of T. hypophylla; their potential taxonomic value is discussed in depth. The first photomicrographs of T. stellaris are provided.