First records of non-native species (Plantaginaceae), which was previously misidentified as in Japan.

Background: The cosmopolitan genus (Plantaginaceae) is a clade of small herbaceous plants that encompasses terrestrial and aquatic species. In Japan, six species have been identified: four native and two naturalised species. , a naturalised terrestrial species, was first reported in 1984 in Kanagawa Prefecture and it is thriving today.

New Information: We report the presence of a new naturalised terrestrial species, , which has been previously misidentified as because of its similar morphology. can be distinguished from through genetic differences and distinct morphological traits, such as longer pedicels. Re-examination of herbarium specimens in the Kanagawa Prefectural Museum of Natural History confirmed that most of the specimens labelled as , including voucher specimens from the original report, were indeed , but a few were . We also noted that the plants referred to as "" in our previous developmental studies should be corrected to .