Written Paper

Some thoughts about polymorphism in the genus Epipactis  [1999]

Claessens, J. Kleynen, J.

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The genus Epipactis is wellknown for its polymorphism. In this paper the authors give examples to illustrate the great plasticity of the genus. In their view polymorphism is inextricably bound up with most representants of the genus Epipactis, a fact that should be taken into consideration before describing new "species". Starting from this assumption, the authors come to several conclusions. After having studied many populations of small-leaved Epipactis helleborine, they conclude that those populations represent ecotypes of E. helleborine. In many cases the normal form of E. helleborine grew nearby. Therefore all ecotypes should be regarded as subspecies, thus following Klein's concept of E. helleborine subsp. orbicularis. After having studied Epipactis leutei for several years, the authors come to the conclusion that there are no significant differences between E. helleborine and E. leutei: therefore E. leutei is regarded as being a synonyme of E. helleborine. The morphology of the column and the mode of pollination are not absolute discriminative characters, since transitional forms can often be found. Deviant forms, like those showing the presence of a viscidium in Epipactis albensis, are discussed, but they are considered to fall within the variability of the species. As a consequence Epipactis mecsekensis is regarded as a synonyme of E. albensis, and Epipactis flaminia as a synonyme of Epipactis greuteri. Epipactis confusa has always provided much c
onfusion, the cause of which is discussed. Recent Danish research shows that Epipactis phyllanthes and E. confusa are conspecific, the name E. phyllanthes having priority. Due to an unlucky choice of the type specimen, there has long been much confusion about the true nature of Epipactis leptochila. Nowadays there exists a great number of publications illustrating the polymorphy of this species. The recently described Epipactis komoricensis represents probably one of the many variations of E. leptochila.

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Naturalistes Belges (Belgium)

ISSN : 0028-0801