The genus Ceratozamia has an extensive distribution that starts in northeastern Mexico and continues southward and southeastward into Guatemala, Belize, and Honduras. Over this extensive distributional range Ceratozamia is found in numerous disjunct populations. These populations are never very widespread and are often restricted to a single mountain or canyon. Because of the restricted range of these populations, and the lack of genetic exchange between them, many of them have evolved into easily identifiable groups. At the present time there are 16 validly published species of Ceratozamia, with several more possible new species under investigation.