D. Tyteca et M. Dufrene, BIOSTATISTICAL STUDIES OF WESTERN-EUROPEAN ALLOGAMOUS POPULATIONS OF THE EPIPACTIS-HELLEBORINE (L) CRANTZ SPECIES GROUP (ORCHIDACEAE), Systematic botany, 19(3), 1994, pp. 424-442
Multivariate methods using morphological characteristics were applied
to the study of 23 western European allogamous Epipactis populations b
elonging 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 a
nd floral differences allow proper discrimination of E. helleborine s.
str., E. distans, E. neerlandica, and a subgroup composed of E. tremo
lsii and E. lusitanica. A more detailed analysis was needed for the la
tter two, for which the differences are chiefly vegetative. The five t
axa also possess distinctive ecological characteristics and, consideri
ng the respective geographical ranges and sympatries, can be regarded
as independent species.