Herbertia lahue (Iridaceae) and its allies. Herbertia lahue is a taxon of difficult delimitationand the specific and infraspecific limits are reason of controversy among different authors. In thisstudy, different populations of the species were analyzed along its range of occurrence in SouthAmerica and also cultivated material from the state of Texas, United States. In order to complementthe data, botanical collections deposited in different Herbaria and mentioned in Material andMethods were examined. Herbertia lahue, H. amoena and H. caerulea are considered segregatedspecies. Lectotypes are designated for Herbertia amoena, H. caerulea and H. lineata. Herbertiafurcata and Ferraria plana are considered doubtful taxa.Key Words: bibi, lahue, lahui, prairie-nymph, Herbertia amoena, Herbertia caerulea, Tigridieae.Herbertia lahue (Iridaceae) and its allies. Herbertia lahue is a taxon of difficult delimitationand the specific and infraspecific limits are reason of controversy among different authors. In thisstudy, different populations of the species were analyzed along its range of occurrence in SouthAmerica and also cultivated material from the state of Texas, United States. In order to complementthe data, botanical collections deposited in different Herbaria and mentioned in Material andMethods were examined. Herbertia lahue, H. amoena and H. caerulea are considered segregatedspecies. Lectotypes are designated for Herbertia amoena, H. caerulea and H. lineata. Herbertiafurcata and Ferraria plana are considered doubtful taxa.Key Words: bibi, lahue, lahui, prairie-nymph, Herbertia amoena, Herbertia caerulea, Tigridieae.