Some fossil-plant taxa can eventually be used for paleogeographic purposes if several methodological requirements are respected. Their paleogeographic interest can be estimate only from a case-by-case analysis of their global distribution, from which some information related to their respective means of dispersal can be derived. The obligation of proceeding through case-by-case analyses implies the fundamental prerequisite of a sound systematic approach of the taxa under consideration, as for any of the other domains of paleontological research. The diverse information and conclusions published in the last decade concerning the distribution of Upper Paleozoic floras in East and Asia provide significant examples that illustrate the necessity of a clear methodological and systematical approach. The critical analysis of these results indicates the need for further field investigations in order to improve the understanding of the paleogeography of the entire area during Carboniferous times.