Navicula is a genus of boat-shaped diatom (single-celled photosynthetic organisms), comprising over 1,200 species, though many Navicula species likely do not belong in the genus strictly speaking. Navicula is Latin for "small ship", and also a term in English for a boat-shaped incense-holder. Navicula is a cosmopolitan genus and species are present in both freshwater and marine environments, typically attached to surfaces (i.e. benthic).