Great variability, especially in degree of indumentum and leaf shape, has led to recognition of many microspecies and infraspecific taxa that are not satisfactorily separated when the species is investigated over its geographic range. Apparent hybridization between Lythrum salicaria
and L. virgatum
and among the many races of L. salicaria
in E Europe and Asia have further confused the taxonomy. Lythrum salicaria
is recognized here as a single species with localized variants. Formal names are not recognized for variants within the species until a biosystematic study of the species complex can be made.