The world's richest concentration of orchid varieties is found in the tropics, mostly Asia, South America and Central America, but they are also found above the Arctic Circle, in southern Patagonia, and even two species of Nematoceras on Macquarie Island, close to Antarctica.The following are amongst the most notable genera of the orchid family:AaAbdomineaAcampeAcanthephippium AceratorchisAcianthu