Spore morphology as a taxonomic tool in the delimitation of three Asplenium L. species complexes (Aspleniaceae: Pteridophyta) in Cuba

As a contribution to the taxonomic study of Asplenium L. for the new "Flora de la Republica de Cuba", the spore morphology was studied into three complexes of hardly delimited species. Twenty-two collections have been studied by SEM and eighty-nine by LM. Shape, number of spores per sporangium and perispore ornamentation, specially fine details revealed by scanning electron microscopy, were the most valuable characters in the recognition of taxa. Irregularities in spore shape and size, unusual development of perispore wall surface elements, and collapsed protoplast characterize aborted spores and suggest the occurrence of a possible hybrid species.