Several names in the ornamental aquatic plant genus Echinodorus (Alismataceae) have remained dubious due to insufficient taxonomic descriptions, sterility of the type material, and apparent hybridism. Non-destructive (or nearly so) DNA sequencing methods provide means to match inadequate type specimens with other specimens in order to clarify nomenclatural instability caused by conflicting interpretations of poor type material. In this study, my aim was to shed light on several names of uncertain applicability in Echinodorus.