Cycad Literature Database

The Ceratozamia miqueliana species complex consists of six closely related species that exhibit similar gross morphology, but a wide range of leaflet shape from widely obovate in C. euryphyllidia and C. hondurensis to oblanceolate in C. zoquorum. However, despite the clear leaflet size variation, the taxon delimitation within the complex has been suggested to be uncertain when considering other traits, giving rise to doubts about the taxonomic validity of taxa, particularly of C. becerrae. Previous studies have shown that anatomical traits might be effective diagnostic characters to delimitate closely related cycad species. This study reviewed the anatomical variation of the Ceratozamia miqueliana species complex. We provide taxonomic treatment in the basis of anatomical trait variation. Although the six species occupy relatively mesic environments in tropical rainforest habitats, we found that some species exhibited leaflet anatomical traits associated to water stressed environments, suggesting historical adaptation to xeric conditions. The anatomical trait variation presented in this study agrees with a recent molecular phylogenetic study, clears up doubts on species relationships in the C. miqueliana complex, and validates the taxonomic recognition of C. becerrae.