A Revision of the Taxonomy and Identification of Epipactis greuteri (Orchidaceae, Neottieae)

Epipactis greuteriis an obligate autogamous orchid species. Due to large differences in the interpretation of the diagnosis of this species, it is often mistakenly identified by botanists, which results in erroneous information provided in the literature about its distribution in Europe. In the present paper we review its description, including flower details, gynostemium features, and papillae morphology and compare it toE. helleborine, with which it is often confused. Based on thorough study of herbarium material (including holotype and isotype) and field research in Greece, Romania, and Poland, we confirm that gynostemium ofE. greuterihas strongly reduced clinandrium and does not produce viscidium. We also discuss taxonomic treatment ofE. preinensisandE. flaminia, two recently described taxa related toE. greuteri. The results of genetic analyses, as well as the range of phenotypic variability ofE. greuteriindividuals from various regions of Europe were presented and discussed. The analysis based on the ITS (internal transcribed spacer) nuclear marker showed no differences amongE. helleborine,E. purpurata,E. albensis,andE. greuteri, which probably indicates their close relationship. Based on the analysis of plastid regions, six haplotypes were detected in all investigated samples. An exhaustive description of morphological features ofE. greuteriis provided.