What happens when scientists play telephone game? The cautionary tale of “Lippia grandis” and the importance of correct plant identification

Abstract

Species of Lippia Linnaeus (Verbenaceae) are rich in essential oils and have been subject of ethno- and pharmacological studies. Among several species, numerous publications mention “Lippia grandis” and its medicinal importance. However, this name is not validly published. Considering that accurate taxonomy and nomenclature are vital to reproducibility, lack of concern for both has undermined science. Therefore, we provide here a detailed discussion of the name “L. grandis” to avoid the impact of perpetuating an erroneous nomenclature. We performed a bibliographical search about “L. grandis” to carefully check how identifications were carried out, and whether or not vouchers were presented. We also analyzed herbarium collections and taxonomic literature of Lippia in order to recognize the correct identity of this plant. Unclear identification methods without citation of herbarium vouchers, and lack of taxonomic experts summarize problems related to this erroneous nomenclature. “Lippia grandis” is a nomen nudum with its authorship attributed to Schauer without any scientific rigor. This case clearly exemplifies a taxonomic error in cascade, and is particularly alarming considering the medicinal importance of this taxon. Plants previously treated as “L. grandis” are actually specimens of L. grata Schauer or L. origanoides Kunth, two morphologically similar species that are here further distinguished upon.