European beech (Fagus sylvatica) colonized most European temperate regions in the last millenia. Species richness of beech-dominated forests is determined by environmental variation and also by the impact of postglacial history in species pools. This photo captures the flowering understory of early summer in Biogradska Gora National Park (Bosnia-Herzegovina), one of the regions with the highest number of plant specialists. Photo by Eleonora Giarrizzo.