Do tropical plants have smaller genomes? Correlation between genome size and climatic variables in the Caesalpinia Group (Caesalpinioideae, Leguminosae)

•Here we explore the genome size evolution and its correlation with ecological traits in Caesalpinia Group (Leguminosae).•We found that the environment (latitude and temperature variables) has played a role in DNA content diversification.•It is suggested that the fragmentation of the Succulent Biome led to the formation of small populations subject to rapid changes in genome sizes.