This is a list of the genera in the family Orchidaceae. This list is adapted on a regular basis with the changes published in the Orchid Research Newsletter which is published twice a year by the Royal Botanic Gardens, Kew. At the moment, orchids are mostly defined by morphological similarity (structure of their flowers and other parts). Furthermore, each year about another 150 new species are being discovered. The list of genera alone currently stands just short of 1000 entries.