Fig. 1

Silene littorea sampling and phenotypes with respect to anthocyanin accumulation. The map shows 21 populations covering the distribution range of S. littorea where frequencies of petal anthocyanin loss (PAL) and whole-plant anthocyanin loss (WAL) phenotypes were estimated (see Additional file 2: Table S2). Pink circles indicate populations in which only fully pigmented individuals (pink petals and anthocyanic photosynthetic tissues) are found, pink squares show populations in which WAL individuals are also found in at least one year of the studied period, and white squares represent populations where WAL and PAL individuals are found. The two polymorphic populations (Louro and Barra) and the two non-polymorphic populations (Trafalgar and Breña) in which flavonoids were biochemically analyzed are named. Photographs of the three phenotypes present in polymorphic (above) and non-polymorphic populations (below) are presented. Note the differences in anthocyanin accumulation in calyces and stems in fully pigmented and PAL plants vs. WAL individuals (indicated by red arrows) (more photographs available in Additional file 3: Figure S1)