Orthographical variant

In biology, within the science of scientific nomenclature, i.e. the naming of organisms, an orthographical variant (abbreviated orth. var.) in botany or an orthographic error in zoology, is a spelling mistake, typing mistake or writing mistake within a scientific publication that resulted in a somewhat different name being accidentally used for an already-named organism. The rules that govern what to do when this happens are laid out in the relevant codes of nomenclature.