Fig. 8From: The speciation and adaptation of the polyploids: a case study of the Chinese Isoetes L. diploid-polyploid complexKernel density plots of the six environmental variables for the Isoetes allopolyploid system in China. Differentiation among species and the results of the nonparametric Kruskal-test are indicated in each plot. The equal sign indicates the lack of significant differences (p ≥ 0.05), while the significant differences are indicated by either higher or lower sign (p < 0.05)Back to article page