The taxonomic composition of sectionTypha, genusTyphaL. (Typhaceae Juss.), is considered. An ecological reconstruction for the Cenozoic geological epochs is proposed. The representatives of sectionTyphareached acme in the Paleogene (Poltavian flora). Climate cooling, first manifested during the Pliocene, was followed by shrinkage and insularization of the Eurasian living range of the section in the Pleistocene. However, the rapid expansion of cattail populations to the numerous glacial lakes of European Russia started after the regression of the Valdai glacier. Asian populations of the sectionTyphawere formed under the harsh conditions to which the Arctotertiary flora of Eastern Siberia was exposed. The relief of Northeastern and Central Asia was transformed during the Oligocene, as the waters of the Thetys Sea regressed and vast land territories emerged: as a result, many Paleogene (Angarid) cattail populations became extinct. Some were preserved in refugia of the subarctic and Arctic zones. Cattail migrations during the Pleistocene were apparently halted and resumed according to the fluctuations of the water level of the Pacific Ocean and the joining or separation of land at the Beringian isthmus. The hybridization processes triggered by the separation of European and Asian populations attenuated the speciation processes. Cattail populations sensitive to moisture supply were incapable of a broad expansion. This had an especially strong influence on the formation of the northeastern populations. Most of the small autochthonous Angarid populations were eliminated, with some apparently preserved in refugia. The expansions of Pacific cattail populations into these regions were, on average, often disrupted during the Pleistocene due to ocean-level fluctuations, separation or joining of land, and cold periods, which were harsher than those in Europe. The emergence of hybrids and anomalies among the taxa in the living range of the sectionTyphaset a trend for convergence processes.
