Abstract. Delforge, P.- Mr. von Hayek's admirable Ophrys [Natural. belges 81 (Orchid. 13) (2000): 93-110 + 2 figs]. In 1991, Ophrys mirabilis was described as a new species on the basis of three individuals discovered in Sicily, and placed in the O. omegaifera species group, mainly because of its flat trilobed labellum, apparently without V-shaped basal groove. Until now, only five populations of O. mirabilis are known, all in Central and South-East Sicily, of which three very weak. Otherwise, a taxon discovered by Hayek in Tunisia and described by So— as O. fusca subsp. hayekii (= O. hayekii nom. illeg., = O. atlantica subsp. hayekii ) seems to be extinct and undeterminable notably because of a curious labellum shape, described as longitudinaly folded and toothed in the middle, a presently unobserved structure among Pseudophrys. Tentatively proposed in 1994, the identification of the Tunisian O. hayekii with the Sicilian O. mirabilis on the basis of limited iconography and imprecise descriptions has been recently rejected and the identification of O. hayekii considered as a perfect and insoluble enigma. Personnal research in Sicily has shown that the original description of O. mirabilis is effectively inaccurate for the labellum which possesses a discrete but clear longitudinal groove from the throath to the apex, where exceptionally a small tooth can appear after desiccation. That very original structure fits well with the O. hayekii concise description. On the other hand, research in the litterature reveals old mentions for O. atlantica near Palermo (NW Sicily), perfectly illustrated by Nelson (1962). Comparison of Nelson's figure and floral analysis with Tunisian O. hayekii floral analysis and my own material for O. mirabilis from NE Sicily demonstrates the identity of the three taxa. The very remarkable labellum shape makes that conclusion robust. That taxon must be named O. mirabilis at the species rank. A discussion of its taxonomical status inside the Pseudophrys is made. The best provisional solution seems to consider it as the sole representative of a separate group close to O. migoutiana and to the traditionnal O. omegaifera species group.

Key-Words: Orchidaceae, genus Ophrys, sectio Pseudophrys, Ophrys mirabilis, Ophrys hayekii nom. illeg., Ophrys fusca subsp. hayekii, Ophrys atlantica subsp. hayekii. Flora of Sicily, flora of Tunisia.