Variation of chromosome count and genome size with traits such as the age of the group, species diversity, distributional range, hybridization, and clonal reproduction within the family Zingiberaceae. Pink (chromosome count variation) and purple arrows (genome size variation) represent the relationships tested in the present study, and grey arrows indicate traits that have not been tested in this study but are likely to affect the chromosome count and genome size variations in Zingiberaceae. ‘+’ sign indicates positive associations.