Devillers, P. & Devillers-Terschuren, J. 2013.- EndŽmisme dans la flore orchidŽenne cyrno-sarde. Natural. belges 94 (Orchid. 26): 75-84.

Abstract. Devillers, P. & Devillers-Terschuren, J. 2013 - Endemism in the Cyrno-Sardinian orchid flora [Natural. belges 94 (Orchid. 26): 75-84]. The Cyrno-Sardinian subcontinent is the largest of the isolated insular ensembles in the Mediterranean. We have used two parameters to measure its isolation. One is the previously defined insularity index (Devillers  & Devillers-Terschuren 2012: Table 1), which shows that the Cyrno-Sardinian subcontinent is about 5 times more isolated than Rhodes and Krakatau, about as isolated as Cyprus. The second is its degree of isolation from north-western Africa, an important source of colonists, measured by taking into account the angular areas spanned by possible pathways of wind transport as well as the distances involved. Cyrno-Sardinia is 140 times more isolated from Africa than Rhodes is from Anatolia. By way of comparison the Iberian Peninsula is only 3 times, but Sicily about 125 times, Cyrenaica 220 times, the Balearics 240 times, Malta 250 times, Greece and Crete more than 7,000 times more isolated from north-western Africa than Rhodes is from Anatolia. It is thus highly unlikely that a significant gene-flow can be sustained between the Ophrys populations of Cyrno-Sardinia and those of any other land mass, or between Africa and any of the large Mediterranean islands, including Sardinia. The very high level of endemicity of the Cyrno-Sardinian Ophrys flora is thus to be expected. The Ophrys species groups present in the subcontinent are briefly reviewed and hypotheses evoked on their pattern of colonisation and evolutionary history. It is suggested that north-western Africa and Sicily are the main sources of colonists, and that 3 local radiations can be observed, in the groups of O. lutea, O. funerea and O. parvimaculata. In the last part of the communication, genera Serapias and Platanthera are briefly envisaged to illustrate the question of whether less endemism in other genera is better explained by different dispersal capabilities and responses to environmental pressures of the orchids, or by a lack of tools to evaluate their diagnosability.

Key words. Orchidaceae, Ophrys, Serapias, Platanthera; Mediterranean basin, Cyrno-Sardinian subcontinent, Corsica, Sardinia, biogeography, distribution, dispersal, endemism, phylogeny, speciation, evolution.