Pedicel colour does not separate Epipactis dunensis (Dune Helleborine) from E. ‘sancta’ (Lindisfarne Helleborine) (Orchidaceae)

Abstract

The characters which supposedly differentiate the narrow endemic Epipactis sancta (Delforge) Delforge on Lindisfarne (north-east England) from ‘Tyne’ and west coast (type) populations of Epipactis dunensis (T. & T.A. Stephenson) Godfery are examined. Lindisfarne plants vary for purple staining of the pedicel, while ‘Tyne’ populations and at least some west coast plants lack this character. There is no significant difference between ‘Tyne’ and Lindisfarne populations for the relative length of the inflorescence (position of uppermost leaf). It is shown that other supposed differences are apparently trivial. It is considered that minor differences in sequence in chloroplast DNA between the populations do not in themselves suggest that E. sancta deserves specific rank. It is concluded that the Lindisfarne population is best regarded as E. dunensis.