Abstract. Devillers, P. & Devillers-Terschuren, J.- Characters and ecology of Epipactis pollinensis on Mount Pollino, its place in the constellation of E. viridiflora and E. pseudopurpurata [Natural. belges 81 (Orchid. 13) (2000): 353-361 + 8 figs]. Epipactis pollinensis has recently been described from Mount Pollino, southern Italy by Baumann & Baumann. Our observations, made in 1988, are presented as additional information. Sites are at altitudes between 1450 and 1530 m in beech forests of Mount Pollino. The characters noted confirm the diagnosis of Baumann & Baumann (2000). The link between hypochile and epichile, a character of the lip found useful in the definition of species within other groups of Epipactis  also differs between E. pollinensis and its closest relative, E. viridiflora. The presence of numerous dipterids in the hypochile cup suggests that the plant is nectar-producing. The species is at least partly or largely allogamous, with functional viscidium, although a rapid drying of the rostellar gland together with pollinias in place, was observed. The members of the E. viridiflora (E. purpurata) constellation are reviewed. Of species frequently attached to the group, it appears that E. bithynica rather belongs to the E. tremolsii constellation, while E. condensata, difficult to evaluate, may also be linked with the E. tremolsii, or, more probably, the E. atrorubens group. E. rechingeri, E. halacsyi, E. pseudopurpurata clearly belong to the same ensemble as E. viridiflora and E. pollinensis. E. pseudopurpurata, described from the Slovakian Carpathians, was found on 7 August 1991 in a beech forest within the Kiserleti Nature Reserve of the Bakony range, in western Hungary, apparently a first record for the country. The characters of the species are briefly discussed. The beech forests of Mount Pollino belong to the complex of southern Italian beech forests of the Geranio versicoloris-Fagion, a very fragmented and insularised ensemble of habitats whose components can be distinguished, in particular, by the orchid cort¸ge. In the present state of knowledge, E. pollinensis should be considered as endemic to a single islet of that archipelago, and as a rare species. We share Baumann & Baumann's opinion that the species is threatened. It appears to be, like its Hellenic vicariant, E. halacsyi, one of the rarest and most insular epipactids of the orchid flora of intact, biologically rich natural or seminatural forests of continental Europe, in particular, of the Mediterranean basin, its mountains and approaches.

Key-words: Orchidaceae, genus Epipactis, Epipactis pollinensis, Epipactis viridiflora, Epipactis purpurata, Epipactis pseudopurpurata, Italy, Monte Pollino, Lucanian Apennines, Basilicata, Calabria, Hungary, Bakony Hills, oromediterranean beech forests, biogeography.