Flower color polymorphism in the peacock anemone (Anemone pavonina) reflects spatiotemporal variation in pollinator...

Flower color polymorphisms are found across angiosperms and are shaped by multiple environmental factors. We investigated Anemone pavonina, which displays flower color variation from red to purple along an elevational gradient on Mount Olympus, Greece. This species serves as a model for studying how elevation-associated shifts in biotic and abiotic factors shape floral trait variation.

We examined the floral biology of A. pavonina in the field (Greece) and in greenhouse experiments (Germany). We studied plant breeding system and flowering phenology; quantified pollinator dependence, pollen limitation, and pollinator contribution to seed set; and investigated pollinator distribution and color preferences, linking these patterns to elevation.

Anemone pavonina is protogynous, partially self-compatible, but relies on pollinators for seed set. Both morphs experience pollen limitation, which increases with elevation in the red morph but not in the purple one. In polymorphic populations, the flowering of red morphs peaked 1-2 weeks after purple morphs. Field trapping of common flower-visitors showed that Pygopleurus beetles prefer red colors, whereas bees choose non-red colors. Beetle but not bee abundance decreased with elevation.

Anemone pavonina shows clear pollinator dependence. Flower color and phenology differ among morphs, reflecting adaptation to their local environment. The purple morph is better adapted to high elevations and associated with bee pollination, whereas the red morph is tuned to beetle vision and activity patterns. These findings demonstrate how spatiotemporal pollinator dynamics drive pollinator-mediated selection, contributing to the origin and maintenance of flower color variation.