Biosystematics of Platanthera bifolia s.l. (Orchidaceae): Inferences from analysis of Scandinavian population samples

Over the years, various authors have (sub)divided the Eurasian moth pollinated Platanthera bifolia into several taxa. Advanced studies using multivariate morphometric analysis and/or genetic fingerprinting have all included regions where the situation appears particularly complex. With the aim to resolve variation patterns in a region where the situation seems less complex, we analysed morphometric and AFLP data from 13 Scandinavian populations using a range of uni- and multivariate statistical methods. Variation was largely continuous, though with (individuals from) short-spurred and long-spurred populations, respectively, forming loose groups. Provided that successful pollinator shifts usually occur between moth species with small difference in proboscis length, this pattern is congruent with the hypothesis that spur length in P. bifolia s.l. has mainly evolved through pollinator shifts followed by selection in response to proboscis length of the prevailing local pollinator species. A...