The geologic history of the Lythraceae

The known fossil record of the Lythraceae has been amplified by recent studies in northern Latin America. A total of 18 genera is recognized in geologic strata ranging in age from lower Eocene to Recent, and among the 22 or 23 modern genera, seven have a documented geologic history. The oldest remains are from an Indo-Malayan Old World warm-temperate to subtropical vegetation preserved in the lower Eocene London Clay flora. The most ancient of extant genera isLagerstroemia and the most recent (among those with an adequate fossil record) isCuphea (middle Miocene to Recent). These represent, respectively, primitive and advanced members of the family, and the paleobotanical record supports current concepts concerning phylogenetic relationships among genera of the Lythraceae. The family apparently had an Old World origin and became differentiated into a distinct modern taxon during Paleocene and early Eocene time.