Relationships and phytogeography in Ceratozamia (Zamiaceae).

Abstract

Species relationships and phytogeography of Ceratozamia, an endangered neotropical cycad genus, based on morphology, leaflet histology, DNA sequencing and ecological data, are analysed and discussed. Seven species complexes are assigned within the genus. A centre of origin in south-eastern Mexico, with recent speciation and immigration patterns, is proposed.