Epipactis exilis (Baumann et Baumann) Delforge, une espèce d’orchidée nouvelle pour l’Auvergne et pour la France / Epipactis exilis (Baumann et Baumann) Delforge, a new species of orchid for the Auvergne region and for France

Epipactis exilis has been discovered on 30th June 2007 in the Auvergne region (commune Saint-Diéry, department Puy-de-Dôme). Hitherto, the species was known only in the Balkan peninsula, continental Italia and Sardinia. About at the same time as in the Auvergne (summer 2007), the species was also observed in the Cévennes (department Gard) by A. Gevaudan, a specialist of genus Epipactis. Epipactis exilis is the recent name for the ancient Epipactis gracilis Baumann & Baumann). It is included in subsectio Phyllanthes of sectio Euepipactis of genus Epipactis. Subsectio Phyllanthes is characterized by a thin, rigid, yellow-green, poorly haired stem, a small number of small leaves, and irregular denticulations of the side of the leaves. Within subsectio Phyllanthes, E. gracilis resembles E. fageticola (which is present in Southern France), but can been distinguished from the later species by the number of true leaves (generally three), the dark-red hypochilum, the rigid, pink-coloured callosities of the epichilum, and preference for acidic soils. The species has narrow ecological requirements : beech forests with dark shade, at altitudes 850-950 m, on acidic soils, at the bottom of watery, steeply sloping, facing north gullies. All the stations discovered in 2007 were observed again in 2008, a year with a rainy summer like 2007. It is possible that the species does not flower on dry years.