Leucothoë is here defined as a genus of five species ( L. axillaris, L. fontanesiana, L. griffithiana, L. keiskei, and L. davisiae), occurring in eastern Asia and western and eastern North America. Generic autapomorphies include autumn-formed inflorescences with meiosis occurring in the autumn. Members of the Leucothoë clade, which are evergreen, are sister to the deciduous Eubotryoides grayana, sharing the apomorphies of winged seeds with a distinctly protuberant hilum, the former of which is homoplasious. Leucothoë axillaris and L. fontanesiana, both of eastern North America, form a closely related species pair, as do the eastern Asian L. griffithiana and L. keiskei. Leucothoë davisiae, occurring in western North America, is likely sister to the remaining species, and it differs in having erect branches and inflorescences, minutely bullate capsules, and in the lack of awns on the anthers. Species descriptions, nomenclatural information, specimen citations, and eco-geographical characterizations for these five species are presented, along with an identification key. [ABSTRACT FROM AUTHOR]