Biostatistical Studies of Western-european Allogamous Populations of the Epipactis-helleborine (l) Crantz Species Group (orchidaceae)

Multivariate methods using morphological characteristics were applied to the study of 23 western European allogamous Epipactis populations belonging to five taxa in the E. helleborine group and two taxa in the E. atrorubens group. The study concentrated on four recently described, not yet widely accepted, taxonomic entities of the former group and on the identification of discriminant characters. Several vegetative and floral differences allow proper discrimination of E. helleborine s. str., E. distans, E. neerlandica, and a subgroup composed of E. tremolsii and E. lusitanica. A more detailed analysis was needed for the latter two, for which the differences are chiefly vegetative. The five taxa also possess distinctive ecological characteristics and, considering the respective geographical ranges and sympatries, can be regarded as independent species