The chlorophyll-free Epipactis are looking completely white. The orchids seem to live only from the sub-terrannean fungus textures, with which they live in symbiosis. Some scientists talk of parasitism of the orchids, because an advantage for the fungus has not been recognized.
In the short article "Epipactis muelleri Godfery var. chlorotica" in Die Orchidee 44 (2): 104-105 (1993) Peter Kohns and Paul Schneider are describing, that of several available orchids not in every year one reaches flower, because usually long before flower they are burnt by the sun.