A genus of about 27 species, shrubs and trees, all but 2 (ours and 1 in sub-Saharan Africa) are in e. and se. Asia. The closest relative of our species is I. japonica Oliver, of Japan. Variously treated in a very broadly-conceived Saxifragaceae (RAB, F, G, GW, W), a less comprehensive Grossulariaceae (C, K), a narrow Escalloniaceae, or a very narrow (single genus) Iteaceae (S), the relationships of Itea remain problematic. Recent molecular data suggest that the relationship between Itea and other woody “saxifragaceous” genera (including Escallonia) is only distant (Morgan & Soltis 1993). Itea is here conservatively treated in a narrow Iteaceae.
ID notes: Sometimes confused needlessly with Clethra, whose much more coarsely serrate, obovate leaves contrast with the serrulate, elliptic leaves of Itea. Also often confused with Eubotrys racemosus in vegetative condition.