The article presents information on eco-phytosenological features of tuberous orchids spread in the territory of the Nakhchivan Autonomous Republic. Biometric properties of the Anacamptis coriophora, Dactylorhiza umbrosa, Orchis mascula species have been studied. Based on the literature data, materials included in the herbarium fund and the results of the investigations, 17 tuberous orchid species belonging to 5 genera have been identified in the territory of Nakhchivan.