The pollination of Epipactis Zinn, 1757 (Orchidaceae) species in Central Europe – the significance of chemical attractants, floral morphology and concomitant insects

A series of studies on pollination biology of the Epipactis atrorubens (Hoffm.) Besser, E. purpurata Sm., and E. palustris (L.) Crantz populations was conducted in Poland, Lithuania and Czech Republic between 2003 and 2010. The research focused on pollinators and visitors to aforementioned orchid species as well as on the chemical analysis of orchids’ nectar which was done using the GC/MS method. It was found that: 1) the type of pollinators depends on the orchid population size and the surrounding environment, where the temperature and amount of precipitation during the vegetative season are the most vital factors; 2) pollinators and visitors to the examined orchids might differ in successive growing seasons; 3) the studied Epipactis species differ in the chemical composition of their nectar and its scent, which can influence their pollination biology; 4) the tendency to autogamy observed in E. purpurata might be due to lack of pollinators in its habitats.