Principal components (PCs, with the floral signals with highest loadings on them) and differences in selection gradients between regions and years.

This table shows statistics of a linear mixed model testing for differences in directional selection on PCs between altitudinal regions and years. For PC1 and PC2, significant interactions between PC and region, but not between PC and year were found, indicating consistent differences in selection between regions. For PC3 and PC5, selection differed between years rather than between regions (see also Fig 1).