A study of the structural and functional features of the rare orchid Epipactis atrorubens, which allows it to grow successfully in a transformed ecosystem (dump of overburden after asbestos mining), has been carried out. The main mesostructural parameters of the leaf (the thickness of the epidermis, mesophyll, the number of cells and chloroplasts, their size) and some physiological and biochemical characteristics (the content of photosynthetic pigments and the rate of CO2 uptake) have been studied. Significant compensatory structural and functional rearrangements of the photosynthetic apparatus in an orchid growing in a transformed habitat have been revealed, which make it possible to maintain the intensity of photosynthesis at a constant level under conditions of water deficit and increased insolation.