Macro- and micromorphology of 124 specimens and 11 holotypes of South American taxa of subgenus Elfvingia (= G. applanatum complex) were examined, and were compared with isoenzymic data previously obtained. Two major dermis types were defined and illustrated. Spore ornamentation was inspected under SEM. Sixty-four per cent of the specimens had an anamixodermis, 80% had spores with longitudinal furrows under SEM and 83% had a context layer without streaks of melanoid deposits. Some of our South American collections could be ascribed to G. lipsiense, G. tornatum, G. testaceum and G. lobatum. Other taxa are critically discussed. The position adopted in this work was to join under synonymy closely related taxa on the grounds of morphology and geographical distribution. In general, correlation between morphological features and isoenzymic patterns could not be established. In this group, phenotypic plasticity appears to be great.