The development of knowledge on the systematics, biogeography, and biology of American ferns, especially those from the Neotropics, owes much to the research career of Robbin Craig Moran. Three main aspects are outlined here to show the continuing influences of his labor on fern biology and hybridization, on the floristics and biogeography of the Andean region, and on the systematics of Neotropical Polypodiaceae. His pioneering work on hybrid complexes in genera such as Adiantum and Asplenium showed the intrinsic connection between morphology and cytotypes, the complicating role of disturbances, leading to a better understanding of the fern life cycle. Robbin’s contribution to the systematics of the Polypodiaceae are particularly noteworthy among the grammitoids, reflected in 81 species names connected to his collaborative efforts with Alan R. Smith in the genera Lellingeria and Melpomene, and for polypodioids with his work on Campyloneurum, and the recognition of species names in Pleopeltis and Serpocaulon. These efforts demonstrate his goals for attaining monophyletic entities in complex large genera. His careful combination of field and herbaria work is also reflected in his pursuit for understanding patterns of species distribution in tropical mountains, and through broad views of continental floristic affinities and their origins. Finally, this brief personal perspective of Robbin Moran’s long and prolific career also serves to thank him for his helpfulness and commitment to collaboration.