The misidentification of ''nilad'' as the source of the toponym appears to have originated in an 1887 essay written by Trinidad Pardo de Tavera, in which he mistakenly used the word ''nila'' to refer both to ''Indigofera tinctoria'' (true indigo) and to ''Ixora manila'' (which is actually ''nilád'' in Tagalog). Early 20th century writings, such as those of Julio Nakpil and of Blair and Robertson, then simply repeated the claim. Today, this erroneous etymology continues to be perpetuated through casual repetition in both literature and in popular use. Examples of popular adoption of this mistaken etymology include the name of a local utility,  Maynilad Water Services, and the name of an underpass close to Manila City Hall, ''Lagusnilad'' (meaning "Nilad Pass").