Abstract. Delforge, P.- New data on the distribution of species of the Ophrys tenthredinifera species group in the eastern Aegean basin (Greece) [Natural. belges 87 (Orchid. 19) (2006): 23-35]. Just recently, the Ophrys tenthredinifera species group seemed to be represented in the eastern Mediterranean basin only by one polytypical species, O. villosa Desfontaines 1807, or by two subspecies of O. tenthredinifera Willdenow 1805, the subspecies tenthredinifera, regarded as a large- and late-flowering taxon, and O. tenthredinifera subsp. villosa, regarded as a small- and early-flowering one. A review of morphological and phenological variations of Ophrys villosa s.l. within its eastern mediterranean range, published in 2005, has shown that O. tenthredinifera s. str. is not present in the area and that at least four entities are identifiable in the Aegean and Ionian basins, well defined by flower size, phenology, as well as characteristics of the labellum and the stigmatic cavity. Among these, a small-flowered species, flowering in March, occurs at least in the eastern part of the Aegean basin and is identifiable to Ophrys villosa s. str. Another, O. leochroma, is a large-flowered species flowering later, normally from mid‑March till early in May; it possesses a larger distribution and occurs notably from the Ionian islands to the Cyclades and Crete. Personnal field research carried out in Rhodes (Dodecanese) during 7 weeks in 2006 has shown that O. leochroma and O. villosa are present and rather widespread in the island. Recent informations from the island of Chios have shown that O. leochroma is also present there. A distribution map for O. leochroma and a list of 19 localities attributable to O. leochroma and O. villosa, mainly based on prospections in Rhodes in 2006, are provided.

Key-Words: Orchidaceae, genus Ophrys, Ophrys tenthredinifera species group, Ophrys leochroma, O. villosa. Flora of Greece, islands of Rhodes (Dodecanese) and Chios.