Synonyms: Epilobium arcuatum (heterotypic); Epilobium axillare (homotypic); Epilobium chrysocoma; Epilobium hakkodense; Epilobium japonicum; Epilobium japonicum var. glanduloso-pubescens; Epilobium kiusianum; Epilobium makinoense; Epilobium myokoense; Epilobium nakaianum; Epilobium oligodontum; Epilobium prostratum (heterotypic); Epilobium pyrricholophum f. japonicum; Epilobium pyrricholophum f. kiusianum; Epilobium pyrricholophum f. macrocarpum; Epilobium pyrricholophum var. anoleucolophum; Epilobium pyrricholophum var. anuoleucholophum; Epilobium pyrricholophum var. curvatopilosum; Epilobium pyrricholophum var. japonicum; Epilobium quadrangulum; Epilobium rouyanum; Epilobium tetragonum var. japonica